Gene Therapy - Short Notes (10 Marks)

ls -la /tmp/workspace/ 2>/dev/null || mkdir -p /tmp/workspace && echo "created"

mkdir -p /tmp/workspace/gene-therapy && python3 << 'EOF' from reportlab.lib.pagesizes import A4 from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle from reportlab.lib.units import cm from reportlab.lib import colors from reportlab.platypus import (SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle, HRFlowable, KeepTogether) from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_JUSTIFY output_path = "/tmp/workspace/gene-therapy/Gene_Therapy_Short_Notes.pdf" doc = SimpleDocTemplate( output_path, pagesize=A4, rightMargin=2*cm, leftMargin=2*cm, topMargin=2*cm, bottomMargin=2*cm ) styles = getSampleStyleSheet() # Custom styles title_style = ParagraphStyle( 'CustomTitle', parent=styles['Title'], fontSize=20, textColor=colors.HexColor('#1a237e'), spaceAfter=4, spaceBefore=0, alignment=TA_CENTER, fontName='Helvetica-Bold' ) subtitle_style = ParagraphStyle( 'Subtitle', parent=styles['Normal'], fontSize=10, textColor=colors.HexColor('#5c6bc0'), spaceAfter=10, alignment=TA_CENTER, fontName='Helvetica' ) h1_style = ParagraphStyle( 'H1', parent=styles['Heading1'], fontSize=12, textColor=colors.white, spaceBefore=12, spaceAfter=4, fontName='Helvetica-Bold', leftIndent=-0.3*cm, backColor=colors.HexColor('#1a237e'), borderPad=4, ) h2_style = ParagraphStyle( 'H2', parent=styles['Heading2'], fontSize=10.5, textColor=colors.HexColor('#1a237e'), spaceBefore=8, spaceAfter=3, fontName='Helvetica-Bold', ) body_style = ParagraphStyle( 'Body', parent=styles['Normal'], fontSize=9.5, spaceAfter=4, leading=14, fontName='Helvetica', alignment=TA_JUSTIFY ) bullet_style = ParagraphStyle( 'Bullet', parent=styles['Normal'], fontSize=9.5, spaceAfter=3, leading=13, fontName='Helvetica', leftIndent=14, bulletIndent=4, ) note_style = ParagraphStyle( 'Note', parent=styles['Normal'], fontSize=8.5, textColor=colors.HexColor('#555555'), spaceAfter=4, leading=12, fontName='Helvetica-Oblique', alignment=TA_CENTER ) # Table style helper def make_table_style(header_color='#1a237e'): return TableStyle([ ('BACKGROUND', (0,0), (-1,0), colors.HexColor(header_color)), ('TEXTCOLOR', (0,0), (-1,0), colors.white), ('FONTNAME', (0,0), (-1,0), 'Helvetica-Bold'), ('FONTSIZE', (0,0), (-1,0), 9), ('ALIGN', (0,0), (-1,-1), 'LEFT'), ('VALIGN', (0,0), (-1,-1), 'TOP'), ('FONTNAME', (0,1), (-1,-1), 'Helvetica'), ('FONTSIZE', (0,1), (-1,-1), 8.5), ('ROWBACKGROUNDS', (0,1), (-1,-1), [colors.HexColor('#f5f5f5'), colors.white]), ('GRID', (0,0), (-1,-1), 0.4, colors.HexColor('#cccccc')), ('LEFTPADDING', (0,0), (-1,-1), 6), ('RIGHTPADDING', (0,0), (-1,-1), 6), ('TOPPADDING', (0,0), (-1,-1), 4), ('BOTTOMPADDING', (0,0), (-1,-1), 4), ]) story = [] # ── Title Block ────────────────────────────────────────────────────────────── story.append(Paragraph("GENE THERAPY", title_style)) story.append(Paragraph("Short Notes &nbsp;|&nbsp; Theory Exam — 10 Marks", subtitle_style)) story.append(HRFlowable(width="100%", thickness=2, color=colors.HexColor('#1a237e'), spaceAfter=8)) # ── 1. Definition ───────────────────────────────────────────────────────────── story.append(Paragraph("1. DEFINITION", h1_style)) story.append(Paragraph( "Gene therapy is the <b>deliberate introduction of genetic material into human somatic cells for therapeutic, " "prophylactic, or diagnostic purposes</b> (UK Gene Therapy Advisory Committee). " "More broadly, it is the therapeutic delivery of nucleic acid polymers into a patient's cells as a drug to treat disease. " "The goal is to correct genetic defects at their most fundamental level — the gene itself. " "In 2012, the first gene therapy product was licensed in the US and Europe (for lipoprotein lipase deficiency).", body_style )) # ── 2. Types ────────────────────────────────────────────────────────────────── story.append(Paragraph("2. TYPES OF GENE THERAPY", h1_style)) types_data = [ ['Type', 'Target Cells', 'Heritable?', 'Current Status'], ['Somatic gene therapy', 'Non-reproductive cells\n(liver, lung, bone marrow)', 'No', 'Permitted; in clinical use'], ['Germline gene therapy', 'Egg / sperm / early embryo', 'Yes — passes to offspring', 'Universally banned (ethically unacceptable)'], ] types_table = Table(types_data, colWidths=[3.8*cm, 5*cm, 3.5*cm, 4.5*cm]) types_table.setStyle(make_table_style()) story.append(types_table) story.append(Spacer(1, 6)) # ── 3. Approaches ──────────────────────────────────────────────────────────── story.append(Paragraph("3. GENE TRANSFER STRATEGIES", h1_style)) story.append(Paragraph("<b>A. Ex vivo (Indirect) Approach</b>", h2_style)) ex_vivo_bullets = [ "Cells removed from patient and cultured in vitro", "Therapeutic gene introduced into cells in culture", "Genetically corrected cells reintroduced into the patient", "<i>Example:</i> ADA-SCID — white blood cells corrected ex vivo and reinfused; bone marrow stem cells corrected ex vivo for beta-thalassemia", ] for b in ex_vivo_bullets: story.append(Paragraph(f"• {b}", bullet_style)) story.append(Paragraph("<b>B. In vivo (Direct) Approach</b>", h2_style)) in_vivo_bullets = [ "Therapeutic gene injected directly into target tissue/organ or bloodstream", "Most direct strategy; can theoretically treat many hereditary disorders", "<i>Example:</i> CFTR gene via nasal spray for cystic fibrosis; AAV vector IV injection for spinal muscular atrophy", ] for b in in_vivo_bullets: story.append(Paragraph(f"• {b}", bullet_style)) # ── 4. Vectors ──────────────────────────────────────────────────────────────── story.append(Paragraph("4. VECTORS USED IN GENE THERAPY", h1_style)) story.append(Paragraph("<b>A. Viral Vectors</b>", h2_style)) vec_data = [ ['Vector', 'Key Properties', 'Advantages', 'Limitations'], ['Retrovirus', 'RNA virus; integrates into host genome; incapable of replication (engineered)', 'Stable, long-term expression;\n~8 kb insert capacity;\nnon-toxic', 'Requires dividing cells;\nrisk of insertional mutagenesis'], ['Lentivirus\n(e.g., HIV-derived)', 'Retrovirus subtype; integrates into non-dividing cells', 'Infects neurons & non-dividing cells;\nno gene locus preference (lower oncogene risk)', 'Complex biosafety requirements'], ['Adeno-associated\nvirus (AAV)', 'Remains episomal; non-integrating; infects dividing and non-dividing cells', 'No strong immune response;\nlong-term expression;\nwidely used clinically', 'Small insert capacity (~5 kb only)'], ['Adenovirus', 'Non-integrating; high titer; wide cell tropism', 'Large inserts (30–35 kb);\ninfects many cell types', 'Strong immune response;\ncaused patient death (OTC trial, 1999);\nnow restricted to cancer therapy'], ] vec_table = Table(vec_data, colWidths=[3*cm, 4.8*cm, 4*cm, 4.5*cm]) vec_table.setStyle(make_table_style()) story.append(vec_table) story.append(Paragraph("<b>B. Non-viral Vectors</b>", h2_style)) nonviral = [ "<b>Liposomes</b> (cationic lipid particles): encapsulate DNA; fuse with cell membrane; lower efficiency than viral vectors", "<b>Nanoparticles</b>: targeted drug-like delivery of nucleic acids", "<b>Naked DNA</b>: direct injection into muscle (uniquely retains and expresses foreign DNA)", "<b>Modified mRNA (modRNA)</b>: uridine replaced by pseudouridine — evades Toll-like receptor recognition and RNase degradation; non-integrating; promising for cardiac therapy", ] for b in nonviral: story.append(Paragraph(f"• {b}", bullet_style)) # ── 5. Requirements ─────────────────────────────────────────────────────────── story.append(Paragraph("5. ESSENTIAL REQUIREMENTS FOR GENE THERAPY", h1_style)) req_data = [ ['Requirement', 'Detail'], ['1. Known molecular defect', 'Identity of the affected gene must be established'], ['2. Functional gene copy', 'A cDNA clone of the gene must be available'], ['3. Appropriate vector', 'Safe, efficient delivery into target tissue'], ['4. Appropriate target cell', 'Long-lived, accessible; able to be re-introduced if cultured ex vivo'], ['5. Regulatory components', 'Correct promoter/enhancer for regulated expression (critical in thalassemia — over-expression harmful)'], ['6. Efficacy & safety evidence', 'Demonstrated in cell culture and animal (ideally large animal) models'], ['7. Regulatory approval', 'Institutional review board + government agency (FDA in US; GTAC in UK)'], ['8. Favourable risk-benefit ratio', 'Substantial disease burden must justify the risks versus alternative therapies'], ] req_table = Table(req_data, colWidths=[5*cm, 11.3*cm]) req_table.setStyle(make_table_style()) story.append(req_table) # ── 6. Diseases ─────────────────────────────────────────────────────────────── story.append(Paragraph("6. DISEASES TREATED / CANDIDATES", h1_style)) story.append(Paragraph("<b>Approved / Successful Clinical Trials:</b>", h2_style)) dis_data = [ ['Disease', 'Defective Gene/Protein', 'Vector', 'Outcome'], ['X-linked SCID', 'IL2RG (γ-cytokine receptor)', 'Retroviral\n(SIN vectors)', '27/32 patients improved; 5 developed treatable leukemia-like disorder'], ['ADA-SCID', 'Adenosine deaminase (ADA)', 'Retroviral', '29/40 patients off enzyme replacement therapy'], ['X-linked adrenoleukodystrophy', 'ABCD1 (peroxisomal ABC transporter)', 'Lentiviral', 'Cerebral demyelination arrested in 17/19 boys'], ['Spinal muscular atrophy', 'SMN1', 'AAV (IV injection)', 'Marked improvement in >1800 patients; FDA approved (Zolgensma)'], ['Hemophilia B', 'Factor IX (F9)', 'AAV (IV injection)', 'Factor IX at 1–7% normal; >20 patients stopped prophylaxis'], ['Leber congenital amaurosis', 'RPE65', 'AAV (retinal injection)', 'FDA approved; ages 12 months–65 years'], ['Beta-thalassemia', 'β-globin mutations', 'Lentiviral', 'Some patients transfusion-independent'], ['LPL deficiency', 'LPL gene', 'AAV (intramuscular)', 'First ever approved gene therapy product (Europe 2012)'], ] dis_table = Table(dis_data, colWidths=[3.8*cm, 3.8*cm, 2.8*cm, 5.9*cm]) dis_table.setStyle(make_table_style()) story.append(dis_table) story.append(Spacer(1, 4)) story.append(Paragraph("<b>Other Candidates:</b> Cystic fibrosis, Parkinson disease, Familial hypercholesterolemia, " "Phenylketonuria, Muscular dystrophy, Sickle cell anemia, HIV/AIDS, Cancers " "(melanoma, brain tumours, lung, ovarian, renal), Cardiovascular disease, Rheumatoid arthritis.", body_style)) # ── 7. Risks ────────────────────────────────────────────────────────────────── story.append(Paragraph("7. RISKS AND LIMITATIONS", h1_style)) risks = [ ("<b>Adverse reaction to vector</b>", "Patient may mount a strong immune/inflammatory response to the vector. " "A patient in an OTC (ornithine transcarbamylase) deficiency trial died in 1999 from a massive immune reaction to the adenoviral vector."), ("<b>Insertional mutagenesis → Malignancy</b>", "Integrated gene may activate a proto-oncogene or disrupt a tumour suppressor gene. " "In X-linked SCID trials, retroviral vector inserted into the LMO-2 oncogene (chromosome 11), causing leukemia in 3–5 patients (one fatal)."), ("<b>Insertional inactivation of an essential gene</b>", "Random integration may disrupt a housekeeping gene (rare but possible). " "Current SIN (self-inactivating) vectors have been engineered to minimise this risk."), ("<b>Short-lived expression</b>", "Cell turnover and gene silencing may reduce efficacy over time; repeat dosing difficult due to immune memory."), ("<b>Delivery challenges</b>", "Targeting specific cell types in vivo; small insert size of AAV (~5 kb); CNS delivery requires invasive procedures."), ("<b>Extremely high cost</b>", "Zolgensma (SMA) costs ~$2–3 million per dose; Gaucher disease therapy >$150,000/year; limits global access."), ] for title, detail in risks: story.append(Paragraph(f"• {title}: {detail}", bullet_style)) # ── 8. Ethics & Regulation ──────────────────────────────────────────────────── story.append(Paragraph("8. ETHICAL AND REGULATORY ASPECTS", h1_style)) ethics = [ "<b>Somatic gene therapy</b>: Ethically acceptable; targets the individual only; does not affect offspring", "<b>Germline gene therapy</b>: Universally banned; heritable changes raise concerns about consent of future generations and eugenics; no country permits it", "<b>Enhancement vs. therapy debate</b>: Use for height, intelligence, or athletic ability is ethically prohibited", "<b>Equal access</b>: Ultra-expensive therapies raise justice concerns", "<b>Regulatory bodies</b>: FDA + Recombinant DNA Advisory Committee (USA); GTAC (UK); Institutional Review Boards worldwide", ] for b in ethics: story.append(Paragraph(f"• {b}", bullet_style)) # ── 9. Recent Advances ──────────────────────────────────────────────────────── story.append(Paragraph("9. RECENT ADVANCES", h1_style)) advances = [ "<b>CRISPR-Cas9 gene editing</b>: Corrects the mutation in its native genomic context; more precise than gene addition; reduces insertional mutagenesis risk", "<b>iPSC-based therapy</b>: Patient somatic cells reprogrammed to iPSCs → gene corrected → differentiated → transplanted back; avoids immune rejection", "<b>modRNA therapy</b>: Modified mRNA (pseudouridine substitution) resists immune recognition and RNase; non-integrating; promising for cardiac regeneration", "<b>CAR-T cell therapy</b>: T cells genetically engineered ex vivo to express chimeric antigen receptors targeting cancer cells (e.g., haematological malignancies)", "<b>siRNA/RNAi</b>: Used to silence dominant mutant alleles (e.g., osteogenesis imperfecta); vectors carrying siRNAs selectively degrade mutant mRNA", ] for b in advances: story.append(Paragraph(f"• {b}", bullet_style)) # ── 10. Summary Table ───────────────────────────────────────────────────────── story.append(Paragraph("10. QUICK SUMMARY", h1_style)) summary_data = [ ['Feature', 'Key Point'], ['Definition', 'Introduction of genetic material into somatic cells for therapeutic purposes'], ['Types', 'Somatic (permitted) vs Germline (universally banned)'], ['Approaches', 'Ex vivo (cells removed, corrected, reinfused) vs In vivo (direct injection)'], ['Main viral vectors', 'Retrovirus, Lentivirus, AAV, Adenovirus'], ['Non-viral vectors', 'Liposomes, nanoparticles, naked DNA, modRNA'], ['First approval', 'Alipogene tiparvovec (LPL deficiency) — Europe, 2012'], ['Key FDA-approved therapies', 'Zolgensma (SMA), Luxturna (Leber amaurosis), Hemgenix (Hemophilia B)'], ['Main risks', 'Immune reaction, insertional mutagenesis, malignancy, short-lived expression'], ['Germline therapy', 'Ethically unacceptable; universally banned worldwide'], ['Future directions', 'CRISPR, iPSC therapy, modRNA, CAR-T cells'], ] summary_table = Table(summary_data, colWidths=[5*cm, 11.3*cm]) summary_table.setStyle(make_table_style()) story.append(summary_table) # ── Footer reference ────────────────────────────────────────────────────────── story.append(Spacer(1, 10)) story.append(HRFlowable(width="100%", thickness=0.5, color=colors.HexColor('#9e9e9e'), spaceAfter=4)) story.append(Paragraph( "<i>Sources: Thompson &amp; Thompson Genetics and Genomics in Medicine (9th ed.) • " "Emery's Elements of Medical Genetics and Genomics • " "Schwartz's Principles of Surgery (11th ed.)</i>", note_style )) doc.build(story) print("PDF created successfully:", output_path) EOF

python3 << 'EOF' from reportlab.lib.pagesizes import A4 from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle from reportlab.lib.units import cm from reportlab.lib import colors from reportlab.platypus import (SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle, HRFlowable, KeepTogether) from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_JUSTIFY output_path = "/tmp/workspace/gene-therapy/HIPEC_Short_Notes.pdf" doc = SimpleDocTemplate( output_path, pagesize=A4, rightMargin=2*cm, leftMargin=2*cm, topMargin=2*cm, bottomMargin=2*cm ) styles = getSampleStyleSheet() title_style = ParagraphStyle('T', parent=styles['Title'], fontSize=20, textColor=colors.HexColor('#b71c1c'), spaceAfter=4, alignment=TA_CENTER, fontName='Helvetica-Bold') subtitle_style = ParagraphStyle('ST', parent=styles['Normal'], fontSize=10, textColor=colors.HexColor('#c62828'), spaceAfter=10, alignment=TA_CENTER, fontName='Helvetica') h1_style = ParagraphStyle('H1', parent=styles['Normal'], fontSize=11.5, textColor=colors.white, spaceBefore=12, spaceAfter=5, fontName='Helvetica-Bold', backColor=colors.HexColor('#b71c1c'), borderPad=5, leftIndent=-0.3*cm) h2_style = ParagraphStyle('H2', parent=styles['Normal'], fontSize=10.5, textColor=colors.HexColor('#b71c1c'), spaceBefore=8, spaceAfter=3, fontName='Helvetica-Bold') body_style = ParagraphStyle('B', parent=styles['Normal'], fontSize=9.5, spaceAfter=4, leading=14, fontName='Helvetica', alignment=TA_JUSTIFY) bullet_style = ParagraphStyle('BL', parent=styles['Normal'], fontSize=9.5, spaceAfter=3, leading=13, fontName='Helvetica', leftIndent=14, bulletIndent=4) note_style = ParagraphStyle('N', parent=styles['Normal'], fontSize=8.5, textColor=colors.HexColor('#555555'), spaceAfter=4, leading=12, fontName='Helvetica-Oblique', alignment=TA_CENTER) def tbl(data, colWidths, hdr='#b71c1c'): t = Table(data, colWidths=colWidths) t.setStyle(TableStyle([ ('BACKGROUND',(0,0),(-1,0),colors.HexColor(hdr)), ('TEXTCOLOR',(0,0),(-1,0),colors.white), ('FONTNAME',(0,0),(-1,0),'Helvetica-Bold'), ('FONTSIZE',(0,0),(-1,0),9), ('ALIGN',(0,0),(-1,-1),'LEFT'), ('VALIGN',(0,0),(-1,-1),'TOP'), ('FONTNAME',(0,1),(-1,-1),'Helvetica'), ('FONTSIZE',(0,1),(-1,-1),8.5), ('ROWBACKGROUNDS',(0,1),(-1,-1),[colors.HexColor('#fce4e4'),colors.white]), ('GRID',(0,0),(-1,-1),0.4,colors.HexColor('#cccccc')), ('LEFTPADDING',(0,0),(-1,-1),6), ('RIGHTPADDING',(0,0),(-1,-1),6), ('TOPPADDING',(0,0),(-1,-1),4), ('BOTTOMPADDING',(0,0),(-1,-1),4), ])) return t story = [] # Title story.append(Paragraph("HIPEC", title_style)) story.append(Paragraph("Hyperthermic Intraperitoneal Chemotherapy &nbsp;|&nbsp; Short Notes — Theory Exam", subtitle_style)) story.append(HRFlowable(width="100%", thickness=2, color=colors.HexColor('#b71c1c'), spaceAfter=8)) # 1. Definition story.append(Paragraph("1. DEFINITION", h1_style)) story.append(Paragraph( "<b>HIPEC (Hyperthermic Intraperitoneal Chemotherapy)</b> is the intraoperative administration of heated " "chemotherapy directly into the peritoneal cavity, performed immediately after <b>Cytoreductive Surgery (CRS)</b>. " "It is a multimodal locoregional treatment strategy for peritoneal surface malignancies (PSM). " "The combined procedure is referred to as <b>CRS + HIPEC</b> and represents the gold standard for selected " "patients with peritoneal carcinomatosis.", body_style)) # 2. Rationale / Mechanism story.append(Paragraph("2. RATIONALE AND MECHANISM OF ACTION", h1_style)) story.append(Paragraph("<b>Why intraperitoneal (IP) chemotherapy?</b>", h2_style)) for b in [ "Achieves <b>higher local drug concentrations</b> directly at peritoneal tumor deposits than systemic IV chemotherapy", "<b>Reduced systemic toxicity</b> — peritoneal-plasma barrier limits systemic absorption", "Peritoneal carcinomatosis is predominantly a <b>locoregional disease</b>; systemic chemo alone poorly penetrates the peritoneum", ]: story.append(Paragraph(f"• {b}", bullet_style)) story.append(Paragraph("<b>Why hyperthermia (40–43°C)?</b>", h2_style)) for b in [ "<b>Direct cytotoxicity</b>: heat itself damages and kills tumor cells (tumour cells more sensitive to heat than normal cells)", "<b>Potentiates chemotherapy</b>: hyperthermia increases drug uptake, enhances DNA damage, impairs tumour DNA repair mechanisms", "<b>Increased tissue penetration</b>: heat increases vascular permeability allowing deeper drug penetration into tumour nodules", "Synergistic with platinum agents (cisplatin, oxaliplatin) and mitomycin-C", ]: story.append(Paragraph(f"• {b}", bullet_style)) # 3. Techniques story.append(Paragraph("3. TECHNIQUE OF HIPEC ADMINISTRATION", h1_style)) story.append(Paragraph( "HIPEC requires a <b>heating perfusion apparatus</b> that homogenously delivers heated chemotherapy solution " "through inflow/outflow cannulas with temperature probes.", body_style)) tech_data = [ ['Technique', 'Description', 'Advantages', 'Disadvantages'], ['Open\n(Coliseum technique)', 'Abdomen left open; surgeon manually agitates the heated chemotherapy to distribute it', 'Better distribution; direct visualization', 'Heat/chemical exposure risk to OR staff; heat loss'], ['Closed technique\n(more common)', 'Inflow/outflow cannulas placed; abdomen closed before chemotherapy infused; warmed to ~40°C then circulated for 30–90 min', 'Safer for OR staff; maintains hyperthermic temperature better', 'Less uniform distribution'], ['Laparoscopic HIPEC', 'Minimally invasive approach; complete laparoscopic peritonectomy described', 'Less morbidity; same oncologic outcomes in selected patients', 'Highly specialized; limited indications'], ] story.append(tbl(tech_data, [3.2*cm, 5*cm, 3.5*cm, 4.6*cm])) story.append(Spacer(1,4)) story.append(Paragraph( "<b>Temperature:</b> Abdomen warmed to 40°C; chemotherapy circulated at 40–43°C for <b>60–90 minutes</b> (varies by drug). " "At completion, chemotherapy solution is drained from the abdomen before closure.", body_style)) # 4. Drugs story.append(Paragraph("4. CHEMOTHERAPEUTIC AGENTS USED IN HIPEC", h1_style)) story.append(Paragraph( "Different drugs are used depending on the primary tumour histology. " "The most common agents are <b>Cisplatin, Mitomycin-C, Doxorubicin, and Oxaliplatin</b>.", body_style)) drug_data = [ ['Indication', 'First-line HIPEC Drug(s)', 'Notes'], ['Ovarian cancer', 'Cisplatin', 'CRS + HIPEC standard for interval cytoreduction'], ['Colorectal cancer', 'Mitomycin-C / Oxaliplatin', 'Mitomycin-C recommended by ASPSM; 60–90 min perfusion'], ['Pseudomyxoma peritonei', 'Mitomycin-C / Oxaliplatin', 'Gold standard regardless of PCI in resectable disease'], ['Peritoneal mesothelioma', 'Cisplatin / Mitomycin-C', 'Gold standard in resectable disease'], ['Gastric cancer', 'Mitomycin-C / Oxaliplatin / Cisplatin', 'PCI ≤7 may benefit'], ['Appendiceal cancer', 'Mitomycin-C / Oxaliplatin', 'CRS + HIPEC regardless of PCI if resectable'], ] story.append(tbl(drug_data, [4*cm, 4.5*cm, 7.8*cm])) story.append(Spacer(1,4)) story.append(Paragraph( "<i>Less commonly used: Paclitaxel, Gemcitabine, Melphalan.</i>", note_style)) # 5. CRS story.append(Paragraph("5. CYTOREDUCTIVE SURGERY (CRS)", h1_style)) story.append(Paragraph( "CRS is the surgical component performed <b>before</b> HIPEC. It aims to remove all visible tumour from the peritoneal cavity. " "<b>Completeness of cytoreduction (CC score)</b> is the most important prognostic factor.", body_style)) for b in [ "<b>Omentectomy</b>", "<b>Peritonectomy</b>: stripping of involved parietal and visceral peritoneum", "<b>Organ resection</b>: resection of any involved organs (spleen, bowel, gallbladder, uterus, ovaries, etc.)", "<b>Appendectomy</b> if appendix is still present", "No residual tumour nodules greater than <b>2 mm in diameter</b> should remain (macroscopic clearance)", ]: story.append(Paragraph(f"• {b}", bullet_style)) story.append(Paragraph("<b>CC (Completeness of Cytoreduction) Score:</b>", h2_style)) cc_data = [ ['CC Score', 'Residual Tumour', 'HIPEC?'], ['CC-0', 'No visible residual tumour', 'Ideal — HIPEC given'], ['CC-1', 'Nodules <2.5 mm (treated by HIPEC)', 'Acceptable; HIPEC given'], ['CC-2', 'Nodules 2.5 mm – 2.5 cm', 'Not ideal — HIPEC withheld'], ['CC-3', 'Nodules >2.5 cm', 'Incomplete — HIPEC not indicated'], ] story.append(tbl(cc_data, [2.5*cm, 7*cm, 6.8*cm])) # 6. PCI story.append(Paragraph("6. PERITONEAL CANCER INDEX (PCI)", h1_style)) story.append(Paragraph( "The PCI is the scoring system used to <b>quantify the extent of peritoneal disease</b> and guide patient selection for CRS+HIPEC. " "The abdomen and pelvis are divided into <b>13 regions</b>; each region is scored 0–3 based on the size of the largest tumour nodule. " "<b>Maximum PCI = 39.</b>", body_style)) pci_data = [ ['Lesion Size (LS) Score', 'Tumour Size', 'PCI Total', 'Recommendation'], ['LS-0', 'No tumour nodules', '≤10', 'Resection recommended (best outcomes)'], ['LS-1', 'Nodules <0.5 cm', '11–20', 'Resection may be considered'], ['LS-2', 'Nodules 0.5–5.0 cm', '>20', 'Resection generally not recommended'], ['LS-3', 'Nodules >5.0 cm', '—', '—'], ] story.append(tbl(pci_data, [3.5*cm, 3.5*cm, 3*cm, 6.3*cm])) story.append(Spacer(1,4)) story.append(Paragraph( "<b>Prognostic significance (colorectal cancer):</b> PCI ≤10 → ~50% 5-year survival; " "PCI 11–20 → ~20% 5-year survival; PCI >20 → near 0% 5-year survival.", body_style)) # 7. Indications story.append(Paragraph("7. INDICATIONS FOR CRS + HIPEC", h1_style)) ind_data = [ ['Tumour Type', 'Indication / Notes'], ['Pseudomyxoma peritonei (PMP)', 'Gold standard; CRS + HIPEC regardless of PCI in resectable disease'], ['Peritoneal mesothelioma', 'Gold standard; CRS + HIPEC in resectable disease'], ['Colorectal cancer with peritoneal metastasis', 'PCI ≤20; complete CRS achievable; combine with systemic chemo'], ['Ovarian cancer', 'Interval CRS + HIPEC (cisplatin) with perioperative systemic chemo; CRS ± HIPEC in upfront surgery'], ['Appendiceal cancer (LAMN, adenocarcinoma)', 'CRS + HIPEC if complete cytoreduction achievable'], ['Gastric cancer with peritoneal metastasis', 'PCI ≤7; limited, selected patients in combination with gastrectomy'], ['Rare primary tumours (pancreas, cholangiocarcinoma)', 'CRS + HIPEC with perioperative SC for limited chemosensitive disease'], ] story.append(tbl(ind_data, [5.5*cm, 10.8*cm])) # 8. Contraindications story.append(Paragraph("8. CONTRAINDICATIONS", h1_style)) story.append(Paragraph("<b>Absolute Contraindications:</b>", h2_style)) for b in [ "Incomplete CRS (CC-2 or CC-3; CC-1 acceptable only for PMP)", "PCI above the disease-specific threshold", "Unresectable extraperitoneal (systemic) disease", "Severe malnutrition", "Serious renal disease", "Aggravation/progression on systemic chemotherapy", ]: story.append(Paragraph(f"• {b}", bullet_style)) story.append(Paragraph("<b>Relative Contraindications:</b>", h2_style)) for b in [ "WHO Performance Status >2", "Creatinine clearance <60 mL/min", "<i>Note: Age alone is NO longer a contraindication</i>", ]: story.append(Paragraph(f"• {b}", bullet_style)) # 9. Pre-operative workup story.append(Paragraph("9. PRE-OPERATIVE EVALUATION", h1_style)) eval_data = [ ['Goal', 'Investigation'], ['Confirm diagnosis', 'CT scan, biopsy'], ['Quantify tumour burden (PCI)', 'Diagnostic laparoscopy (most accurate), CT, MRI'], ['Detect extraperitoneal disease', 'PET-CT, CT chest/abdomen/pelvis'], ['Assess surgical resectability', 'Diagnostic laparoscopy, CT/MRI, exploratory laparotomy'], ['Tumour markers (for follow-up)', 'CEA, CA19-9, CA-125'], ] story.append(tbl(eval_data, [5.5*cm, 10.8*cm])) story.append(Spacer(1,4)) story.append(Paragraph( "<b>Imaging notes:</b> CT has low sensitivity but high specificity; detects only 11–28% of implants <0.5 cm. " "MRI has higher sensitivity and accuracy. PET-CT has low value for mucinous tumours. " "Diagnostic laparoscopy is the most accurate but may still miss small bowel/porta hepatis involvement.", body_style)) # 10. Outcomes story.append(Paragraph("10. OUTCOMES AND KEY CLINICAL TRIALS", h1_style)) trial_data = [ ['Trial', 'Population', 'Key Finding'], ['Verwaal et al. (Netherlands RCT, 2003)', '105 pts: colorectal peritoneal metastasis', 'CRS + HIPEC: 22.3 months median OS vs 12.6 months with 5-FU/leucovorin alone; significant improvement'], ['PRODIGE 7 (France RCT, 2021)\nLancet Oncol', '265 pts: CRS+HIPEC vs CRS alone (colorectal); HIPEC = oxaliplatin 30 min', 'No difference in OS (41.7 vs 41.2 months); CRS alone established as standard of care; PCI 11–15 subgroup benefited from HIPEC (HR 0.44)'], ['COLOPEC (Dutch RCT)', '204 pts: adjuvant HIPEC + chemo vs chemo alone (T4/perforated CRC)', 'No difference in metastasis-free survival at 18 months; slight increase in complications with HIPEC'], ['Spiliotis (RCT, 2015)', 'Recurrent ovarian cancer: CRS+HIPEC vs CRS alone', 'HIPEC + CRS: 13-month improvement in survival vs CRS alone'], ['General outcomes (colorectal)', 'After complete CRS + HIPEC', '5-year survival 30–40%; median OS ~36 months after complete cytoreduction'], ['Pseudomyxoma/mesothelioma', 'After CRS + HIPEC', 'Best outcomes: PMP 5-year survival 70–80%; mesothelioma median OS 5+ years in selected patients'], ] story.append(tbl(trial_data, [4*cm, 4.8*cm, 7.5*cm])) # 11. Morbidity/Mortality story.append(Paragraph("11. MORBIDITY, MORTALITY AND COMPLICATIONS", h1_style)) for b in [ "<b>Operative mortality:</b> Currently 1–3% at experienced centres (was 8% in early trials)", "<b>Major morbidity:</b> 20–40%; includes anastomotic leak, wound infection, bowel obstruction, haematological toxicity", "<b>Haematological toxicity:</b> Myelosuppression (cisplatin, mitomycin-C); neutropaenia", "<b>Renal toxicity:</b> Cisplatin-related nephrotoxicity", "<b>Neuropathy:</b> Oxaliplatin-related peripheral neuropathy", "<b>Prolonged hospital stay:</b> Mean 14–21 days", "<b>ERAS protocols</b> (Enhanced Recovery After Surgery) reduce complications and length of stay; now standard post-operative care for CRS ± HIPEC", ]: story.append(Paragraph(f"• {b}", bullet_style)) # 12. Summary story.append(Paragraph("12. QUICK SUMMARY", h1_style)) sum_data = [ ['Feature', 'Key Point'], ['Full name', 'Hyperthermic Intraperitoneal Chemotherapy'], ['Temperature', '40–43°C; circulated for 60–90 minutes'], ['Combined with', 'Cytoreductive Surgery (CRS) always'], ['Main drugs', 'Cisplatin (ovarian), Mitomycin-C (colorectal/PMP), Oxaliplatin'], ['Techniques', 'Open (Coliseum) or Closed (more common); laparoscopic in selected cases'], ['Disease staging', 'Peritoneal Cancer Index (PCI): 13 regions, 0–39 scale'], ['Best candidates', 'Complete cytoreduction achievable (CC-0/CC-1); PCI ≤20'], ['Gold standard for', 'Pseudomyxoma peritonei, peritoneal mesothelioma'], ['Proven benefit in', 'Ovarian (interval CRS), selected colorectal peritoneal metastasis'], ['Key trial', 'PRODIGE 7 (2021): CRS alone adequate; HIPEC benefit in PCI 11–15 subgroup'], ['Main risks', 'Haematological toxicity, renal toxicity, anastomotic leak, prolonged stay'], ['Contraindications', 'Incomplete CRS, PCI too high, extraperitoneal disease, severe malnutrition'], ['Post-op care', 'ERAS protocol recommended'], ['Newer alternative', 'PIPAC (Pressurized Intraperitoneal Aerosol Chemo) for unresectable/recurrent disease'], ] story.append(tbl(sum_data, [4.5*cm, 11.8*cm])) # Footer story.append(Spacer(1,10)) story.append(HRFlowable(width="100%", thickness=0.5, color=colors.HexColor('#9e9e9e'), spaceAfter=4)) story.append(Paragraph( "<i>Sources: Fischer's Mastery of Surgery 8th ed. • Sabiston Textbook of Surgery • " "Yamada's Textbook of Gastroenterology 7th ed. • Current Surgical Therapy 14th ed. • " "Mulholland and Greenfield's Surgery 7th ed.</i>", note_style)) doc.build(story) print("PDF created:", output_path) EOF

python3 << 'PYEOF' from reportlab.lib.pagesizes import A4 from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle from reportlab.lib.units import cm from reportlab.lib import colors from reportlab.platypus import (SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle, HRFlowable, KeepTogether) from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_JUSTIFY output_path = "/tmp/workspace/gene-therapy/Epigenetics_Short_Notes.pdf" doc = SimpleDocTemplate( output_path, pagesize=A4, rightMargin=2*cm, leftMargin=2*cm, topMargin=2*cm, bottomMargin=2*cm ) styles = getSampleStyleSheet() DARK = colors.HexColor('#1b5e20') # deep green MID = colors.HexColor('#2e7d32') LIGHT = colors.HexColor('#e8f5e9') ROW2 = colors.white title_style = ParagraphStyle('T', parent=styles['Title'], fontSize=22, textColor=DARK, spaceAfter=4, alignment=TA_CENTER, fontName='Helvetica-Bold') subtitle_style = ParagraphStyle('ST', parent=styles['Normal'], fontSize=10, textColor=MID, spaceAfter=10, alignment=TA_CENTER, fontName='Helvetica') h1_style = ParagraphStyle('H1', parent=styles['Normal'], fontSize=11.5, textColor=colors.white, spaceBefore=12, spaceAfter=5, fontName='Helvetica-Bold', backColor=DARK, borderPad=5, leftIndent=-0.3*cm) h2_style = ParagraphStyle('H2', parent=styles['Normal'], fontSize=10.5, textColor=DARK, spaceBefore=8, spaceAfter=3, fontName='Helvetica-Bold') body_style = ParagraphStyle('B', parent=styles['Normal'], fontSize=9.5, spaceAfter=4, leading=14, fontName='Helvetica', alignment=TA_JUSTIFY) bullet_style = ParagraphStyle('BL', parent=styles['Normal'], fontSize=9.5, spaceAfter=3, leading=13, fontName='Helvetica', leftIndent=16, bulletIndent=4) note_style = ParagraphStyle('N', parent=styles['Normal'], fontSize=8.5, textColor=colors.HexColor('#555555'), spaceAfter=4, leading=12, fontName='Helvetica-Oblique', alignment=TA_CENTER) box_style = ParagraphStyle('BOX', parent=styles['Normal'], fontSize=9.5, spaceAfter=3, leading=13, fontName='Helvetica', leftIndent=8, backColor=colors.HexColor('#f1f8e9'), borderPad=4) def tbl(data, colWidths, hdr=None): if hdr is None: hdr = DARK t = Table(data, colWidths=colWidths) t.setStyle(TableStyle([ ('BACKGROUND',(0,0),(-1,0), hdr), ('TEXTCOLOR',(0,0),(-1,0), colors.white), ('FONTNAME',(0,0),(-1,0),'Helvetica-Bold'), ('FONTSIZE',(0,0),(-1,0),9), ('ALIGN',(0,0),(-1,-1),'LEFT'), ('VALIGN',(0,0),(-1,-1),'TOP'), ('FONTNAME',(0,1),(-1,-1),'Helvetica'), ('FONTSIZE',(0,1),(-1,-1),8.5), ('ROWBACKGROUNDS',(0,1),(-1,-1),[LIGHT, ROW2]), ('GRID',(0,0),(-1,-1),0.4, colors.HexColor('#c8e6c9')), ('LEFTPADDING',(0,0),(-1,-1),6), ('RIGHTPADDING',(0,0),(-1,-1),6), ('TOPPADDING',(0,0),(-1,-1),4), ('BOTTOMPADDING',(0,0),(-1,-1),4), ])) return t story = [] # ── Title ──────────────────────────────────────────────────────────────────── story.append(Paragraph("EPIGENETICS", title_style)) story.append(Paragraph("Short Notes &nbsp;|&nbsp; Theory Exam — 10 Marks", subtitle_style)) story.append(HRFlowable(width="100%", thickness=2, color=DARK, spaceAfter=8)) # ── 1. Definition ───────────────────────────────────────────────────────────── story.append(Paragraph("1. DEFINITION", h1_style)) story.append(Paragraph( "<b>Epigenetics</b> is the study of <b>heritable changes in gene expression (phenotype) " "that cannot be explained by alterations in the underlying DNA sequence (genotype)</b>. " "The term was coined by <b>Conrad Waddington</b> (1942). " "Epigenetic changes regulate when, where, and how much a gene is expressed, without altering the nucleotide sequence. " "These changes are <b>mitotically heritable</b> (stable across cell divisions) and, in some cases, <b>transgenerationally heritable</b>.", body_style)) story.append(Paragraph( "The <b>epigenome</b> is the complete set of epigenetic marks in a cell. Each cell type carries a unique epigenome " "that contributes to cellular identity.", body_style)) # ── 2. Key Epigenetic Mechanisms ────────────────────────────────────────────── story.append(Paragraph("2. MECHANISMS OF EPIGENETIC REGULATION", h1_style)) story.append(Paragraph( "The four major mechanisms of epigenetic regulation are:", body_style)) mech_data = [ ['Mechanism', 'Basis', 'Effect on Transcription', 'Key Enzymes'], ['1. DNA Methylation', 'Addition of methyl group (-CH₃) to cytosine in CpG dinucleotides → 5-methylcytosine (5-mC)', 'Gene SILENCING (usually)', 'Writers: DNMT1, DNMT3A, DNMT3B\nErasers: TET1/2/3 (oxidative demethylation)\nReaders: MECP2'], ['2. Histone Acetylation', 'Acetyl group added to lysine residues on histone tails → relaxes chromatin (euchromatin)', 'Gene ACTIVATION', 'Writers: HATs (e.g., EP300, CBP)\nErasers: HDACs (HDAC1-18)\nReaders: Bromodomain proteins'], ['3. Histone Methylation', 'Methyl groups added to lysine (K) or arginine (R) on histone tails; can activate or repress', 'Depends on site:\nH3K4me3 = ACTIVE\nH3K27me3/H3K9me3 = REPRESSED', 'Writers: HMTs (e.g., EZH2 for K27)\nErasers: KDMs/JMJDs\nReaders: Chromodomain, Tudor domain'], ['4. Non-coding RNAs (ncRNAs)', 'miRNAs, siRNAs, lncRNAs — regulate gene expression post-transcriptionally or guide chromatin-modifying complexes', 'Silencing or activation', 'DICER, DROSHA (miRNA processing)\nRNA-Induced Silencing Complex (RISC)'], ] story.append(tbl(mech_data, [3*cm, 4.5*cm, 3.5*cm, 5.3*cm])) story.append(Spacer(1,4)) story.append(Paragraph( "<b>Other modifications:</b> Histone phosphorylation, ubiquitination, sumoylation, ADP-ribosylation — all modulate chromatin structure and gene expression.", body_style)) # ── 3. Chromatin structure ───────────────────────────────────────────────────── story.append(Paragraph("3. CHROMATIN STRUCTURE AND THE NUCLEOSOME", h1_style)) for b in [ "DNA is wrapped around <b>nucleosomes</b> — octamers of core histones (2× each of H2A, H2B, H3, H4); linker histone H1 stabilises internucleosomal DNA", "<b>Euchromatin</b>: open, loosely packed chromatin → transcriptionally ACTIVE (associated with histone acetylation, H3K4me3)", "<b>Heterochromatin</b>: condensed, tightly packed → transcriptionally SILENT (associated with DNA methylation, H3K9me3, H3K27me3)", "Histone marks abbreviated as: <b>H[histone number][amino acid][position][modification]</b> e.g., <b>H3K9ac</b> = acetylation of lysine-9 of histone H3", "<b>Chromatin remodellers</b> (e.g., SWI/SNF complex, SMARCA4/BRG1) use ATP to reposition or evict nucleosomes, altering chromatin accessibility", ]: story.append(Paragraph(f"• {b}", bullet_style)) # ── 4. Epigenetic Machinery: Writers, Readers, Erasers ──────────────────────── story.append(Paragraph("4. EPIGENETIC MACHINERY: WRITERS, READERS, AND ERASERS", h1_style)) wre_data = [ ['Role', 'Function', 'Examples'], ['Writers', 'Add chemical marks to DNA or histone tails', 'DNMT1/3A/3B (DNA methylation)\nHATs: EP300, CBP (acetylation)\nHMTs: EZH2, NSD1 (methylation)'], ['Erasers', 'Remove chemical marks', 'TET1/2/3 (DNA demethylation)\nHDACs (deacetylation)\nKDMs/JMJDs (histone demethylation)'], ['Readers', 'Bind specific marks; recruit effector complexes', 'MECP2 (reads 5-mC)\nBromodomain proteins (read acetyl-K)\nChromodomain proteins (read methyl-K)'], ['Remodellers', 'Alter nucleosome position, conformation, or histone composition using ATP', 'SWI/SNF (SMARCA4/BRG1)\nNuRD, ISWI, INO80 complexes'], ] story.append(tbl(wre_data, [3.2*cm, 5*cm, 8.1*cm])) # ── 5. DNA Methylation in detail ────────────────────────────────────────────── story.append(Paragraph("5. DNA METHYLATION — DETAIL", h1_style)) for b in [ "<b>CpG site:</b> cytosine preceding guanine (5'–CG–3'); the predominant site of methylation in mammals", "<b>CpG islands:</b> regions with high CpG density, often at gene promoters; normally unmethylated → gene ON", "<b>Methylation at promoter CpGs → gene silencing</b> (blocks transcription factor binding; recruits repressor complexes)", "<b>DNMT1</b> — maintenance methyltransferase: copies methylation patterns to newly synthesised DNA after replication (preserves epigenetic memory)", "<b>DNMT3A/3B</b> — de novo methyltransferases: establish new methylation patterns (e.g., during development, differentiation)", "<b>Demethylation:</b> TET proteins oxidise 5-mC → 5-hmC → 5-fC → 5-caC → cytosine (via base excision repair); active process", "<b>DMR (Differentially Methylated Region):</b> CpG regions with different methylation between tissues, phenotypes, or exposures; important regulatory regions", ]: story.append(Paragraph(f"• {b}", bullet_style)) # ── 6. Histone Modifications in detail ──────────────────────────────────────── story.append(Paragraph("6. HISTONE MODIFICATIONS — KEY MARKS", h1_style)) hm_data = [ ['Mark', 'Type', 'Effect', 'Written by', 'Erased by'], ['H3K4me3', 'Methylation', 'Active promoters', 'MLL/COMPASS', 'KDM5 family'], ['H3K27me3', 'Methylation', 'Gene repression\n(Polycomb)', 'EZH2 (PRC2)', 'KDM6A/6B'], ['H3K9me3', 'Methylation', 'Constitutive heterochromatin', 'SUV39H1/2', 'KDM3/4'], ['H3K27ac', 'Acetylation', 'Active enhancers', 'CBP/EP300', 'HDACs'], ['H3K4me1', 'Methylation', 'Active/poised enhancers', 'MLL3/4', 'KDM1'], ['H4K20me3', 'Methylation', 'Heterochromatin', 'SUV4-20H', 'KDM'], ['H2A.X (phospho)', 'Phosphorylation', 'DNA damage response (γH2AX)', 'ATM/ATR/DNA-PK', 'Phosphatases'], ] story.append(tbl(hm_data, [2.5*cm, 2.5*cm, 3*cm, 3.5*cm, 3.8*cm])) # ── 7. Genomic Imprinting ────────────────────────────────────────────────────── story.append(Paragraph("7. GENOMIC IMPRINTING", h1_style)) story.append(Paragraph( "<b>Genomic imprinting</b> is an epigenetic process in which certain genes are expressed in a " "<b>parent-of-origin-specific manner</b>. The allele inherited from one parent is silenced " "(imprinted) by methylation, allowing expression only from the other parent's allele. " "About 100 imprinted genes are known in humans.", body_style)) imp_data = [ ['Syndrome', 'Chromosome', 'Mechanism', 'Active allele affected'], ['Prader-Willi Syndrome (PWS)', '15q11–q13', 'Deletion of paternal region OR maternal UPD15', 'Paternal SNRPN/NECDIN silenced'], ['Angelman Syndrome (AS)', '15q11–q13', 'Deletion of maternal region OR paternal UPD15 OR UBE3A mutation', 'Maternal UBE3A silenced'], ['Beckwith-Wiedemann Syndrome (BWS)', '11p15', 'Gain of methylation at IC1 on maternal allele → biallelic IGF2 expression', 'IGF2 (growth promoter) overexpressed → overgrowth'], ['Russell-Silver Syndrome (RSS)', '11p15', 'Loss of methylation at IC1 on paternal allele → IGF2 silencing', 'IGF2 silenced → growth restriction'], ['Hydatidiform mole', 'Genome-wide', 'Complete: androgenetic (2 paternal genomes)\nPartial: 2 paternal + 1 maternal', 'Abnormal imprinting → abnormal placenta'], ] story.append(tbl(imp_data, [4*cm, 2.5*cm, 5.2*cm, 4.6*cm])) # ── 8. X Inactivation ───────────────────────────────────────────────────────── story.append(Paragraph("8. X-CHROMOSOME INACTIVATION (LYONISATION)", h1_style)) for b in [ "<b>Mary Lyon hypothesis (1961):</b> One X chromosome is randomly inactivated in each somatic cell of a female early in development", "Inactivation is <b>random</b> (paternal or maternal X) and <b>clonal</b> — all daughter cells maintain the same inactivated X", "Inactive X condenses into <b>Barr body</b> (sex chromatin); stained with Barr body test", "Mechanism: <b>XIST lncRNA</b> (X Inactive Specific Transcript) coats the inactive X → recruits Polycomb repressive complex → H3K27me3 deposition → heterochromatin", "<b>Pseudoautosomal regions (PAR)</b> and a subset of genes escape X inactivation (~15–25% of X-linked genes)", "Clinical relevance: explains variable expression in X-linked carrier females (e.g., haemophilia, Duchenne muscular dystrophy)", ]: story.append(Paragraph(f"• {b}", bullet_style)) # ── 9. Epigenetics in development ──────────────────────────────────────────── story.append(Paragraph("9. EPIGENETICS IN DEVELOPMENT", h1_style)) for b in [ "<b>Two waves of epigenetic reprogramming</b> occur in human development:", " 1. <b>Primordial germ cell specification (~5 weeks gestation):</b> Global erasure of DNA methylation → remethylation with sex-specific imprints in oocytes/sperm", " 2. <b>Post-fertilisation (pre-implantation):</b> Active demethylation of paternal genome + passive demethylation of maternal genome → lowest methylation at blastocyst stage; <i>imprinted loci are protected</i>", "After implantation: <b>de novo methylation</b> establishes cell-type-specific patterns; pluripotency gene promoters (OCT4, NANOG) hypermethylated during differentiation", "<b>Environmental influences (DOHaD):</b> Dutch Hunger Winter — in utero starvation → hypomethylation of IGF2 → increased obesity, cardiovascular disease in adulthood", "<b>Agouti mouse model:</b> Methyl-donor diet → methylation of retrotransposon in Agouti gene → brown fur, normal weight (vs yellow fur, obese in unmethylated mice)", ]: story.append(Paragraph(f"• {b}", bullet_style)) # ── 10. Epigenetics and Cancer ──────────────────────────────────────────────── story.append(Paragraph("10. EPIGENETICS AND CANCER", h1_style)) story.append(Paragraph( "Cancer involves both <b>genetic mutations</b> and <b>epigenetic alterations</b>. " "Key epigenetic hallmarks of cancer:", body_style)) for b in [ "<b>Global DNA hypomethylation:</b> activates proto-oncogenes, transposable elements → genomic instability", "<b>Promoter hypermethylation of tumour suppressor genes:</b> silences genes like BRCA1, MLH1, CDKN2A/p16, RB1 (equivalent to a 'second hit')", "<b>Histone modification changes:</b> loss of H4K16ac and H4K20me3 are common cancer hallmarks", "<b>EZH2 overexpression</b> → H3K27me3 → silencing of tumour suppressors in many cancers", "<b>SWI/SNF complex mutations</b> in ~20% of all human cancers (e.g., SMARCA4, ARID1A)", "<b>Example:</b> CpG Island Methylator Phenotype (CIMP) — simultaneous hypermethylation of multiple CpG islands; common in colorectal, glioma, gastric cancers", ]: story.append(Paragraph(f"• {b}", bullet_style)) # ── 11. Epigenetic Disorders ────────────────────────────────────────────────── story.append(Paragraph("11. EPIGENETIC DISORDERS (CHROMATIN REMODELLING DISORDERS)", h1_style)) dis_data = [ ['Disorder', 'Gene/Mechanism', 'Clinical Features'], ['Rett Syndrome', 'MECP2 mutation (X-linked)\nMECP2 = reader of 5-methylcytosine', 'Girls: normal early development → regression, hand-wringing, autism, seizures, intellectual disability'], ['Rubinstein-Taybi Syndrome', 'CREBBP/EP300 mutation\nHAT activity reduced', 'Broad thumbs, intellectual disability, short stature, characteristic facies'], ['Kabuki Syndrome', 'KMT2D (MLL4) or KDM6A mutations\nHistone H3K4 methyltransferase', 'Intellectual disability, distinctive facial features, growth retardation, skeletal anomalies'], ['ATRX Syndrome', 'ATRX (chromatin remodeller)\nα-thalassaemia + intellectual disability', 'Alpha-thalassaemia, severe intellectual disability, genital abnormalities'], ['ICF Syndrome', 'DNMT3B mutation\nDNA methylation defect', 'Immunodeficiency, Centromeric instability, Facial anomalies'], ['Sotos Syndrome', 'NSD1 mutation\nH3K36 methyltransferase', 'Overgrowth, intellectual disability, macrocephaly, advanced bone age'], ['Weaver Syndrome', 'EZH2 mutation (gain-of-function)\nH3K27 methyltransferase', 'Overgrowth, intellectual disability, advanced bone age'], ] story.append(tbl(dis_data, [4*cm, 5*cm, 7.3*cm])) # ── 12. Epigenetic Therapies ────────────────────────────────────────────────── story.append(Paragraph("12. EPIGENETIC THERAPIES", h1_style)) story.append(Paragraph( "Since epigenetic changes are <b>reversible</b> (unlike genetic mutations), they are attractive therapeutic targets.", body_style)) rx_data = [ ['Drug Class', 'Drug Examples', 'Mechanism', 'Clinical Use'], ['DNMT inhibitors\n(Demethylating agents)', 'Azacitidine (5-azacytidine)\nDecitabine (5-aza-2\'-deoxycytidine)', 'Incorporates into DNA; traps and degrades DNMT → DNA demethylation → reactivates silenced tumour suppressor genes', 'Myelodysplastic syndrome (MDS), AML — durable responses'], ['HDAC inhibitors', 'Vorinostat (SAHA)\nRomidepsin\nPanobinostat\nBelinostat', 'Inhibit HDACs → histone hyperacetylation → chromatin opening → reactivates silenced genes; also pro-apoptotic', 'Cutaneous T-cell lymphoma\nMultiple myeloma (panobinostat)\nPeripheral T-cell lymphoma'], ['EZH2 inhibitors', 'Tazemetostat', 'Inhibits EZH2 (H3K27 methyltransferase) → reduces H3K27me3 → reactivates tumour suppressors', 'Follicular lymphoma, Epithelioid sarcoma (FDA approved 2020)'], ['BET bromodomain inhibitors', 'JQ1, I-BET762\n(investigational)', 'Block bromodomain proteins from reading H3K27ac at enhancers → suppress oncogene (e.g., MYC) transcription', 'Clinical trials in haematological malignancies, NMC'], ['IDH1/2 inhibitors', 'Enasidenib (IDH2)\nIvosidenib (IDH1)', 'Block mutant IDH → reduce 2-HG → restore TET activity → normalise DNA methylation', 'AML with IDH1/2 mutations'], ] story.append(tbl(rx_data, [3.5*cm, 3.5*cm, 4.5*cm, 4.8*cm])) # ── 13. Non-coding RNAs ──────────────────────────────────────────────────────── story.append(Paragraph("13. NON-CODING RNAs (ncRNAs) AS EPIGENETIC REGULATORS", h1_style)) ncrna_data = [ ['Type', 'Size', 'Mechanism', 'Examples & Roles'], ['miRNA\n(microRNA)', '~22 nt', 'Binds 3\'UTR of target mRNA → translational repression or mRNA degradation via RISC', 'miR-21 (oncomiR in many cancers)\nmiR-15/16 (target BCL-2; deleted in CLL)'], ['siRNA\n(small interfering RNA)', '~21–23 nt', 'Complementary to target mRNA → RISC-mediated cleavage (RNA interference/RNAi)', 'Endogenous: regulation of transposons\nTherapeutic: inclisiran (anti-PCSK9 siRNA for hypercholesterolaemia)'], ['lncRNA\n(long non-coding RNA)', '>200 nt', 'Scaffold/guide for chromatin-modifying complexes; cis or trans gene regulation', 'XIST (X inactivation)\nHOTAIR (PRC2 recruitment → cancer metastasis)\nH19 (imprinting at 11p15)'], ['piRNA\n(piwi-interacting RNA)', '~26–31 nt', 'Guides PIWI proteins to silence transposable elements in germline', 'Essential for germ cell development and genome integrity'], ] story.append(tbl(ncrna_data, [2.8*cm, 1.5*cm, 4.5*cm, 7.5*cm])) # ── 14. Summary ──────────────────────────────────────────────────────────────── story.append(Paragraph("14. QUICK SUMMARY", h1_style)) sum_data = [ ['Feature', 'Key Point'], ['Definition', 'Heritable changes in gene expression without DNA sequence change'], ['Coined by', 'Conrad Waddington (1942)'], ['4 main mechanisms', 'DNA methylation, Histone acetylation, Histone methylation, ncRNAs'], ['DNA methylation', 'CpG methylation → silencing; DNMT1 (maintenance), DNMT3A/B (de novo); TET = erasers'], ['Histone acetylation', 'HATs add acetyl → open chromatin (ACTIVE); HDACs remove → condensed (SILENT)'], ['Active marks', 'H3K4me3 (promoters), H3K27ac (enhancers)'], ['Repressive marks', 'H3K27me3 (Polycomb), H3K9me3 (constitutive heterochromatin)'], ['Writers/Readers/Erasers', 'Core machinery placing, reading, and removing epigenetic marks'], ['Genomic imprinting', 'Parent-of-origin gene expression; PWS, AS, BWS, RSS'], ['X inactivation', 'Random; driven by XIST lncRNA; one X → Barr body'], ['Cancer epigenetics', 'Global hypomethylation + local hypermethylation of tumour suppressors; CIMP'], ['Key epigenetic drugs', 'Azacitidine/Decitabine (DNMT inhibitors); Vorinostat/Romidepsin (HDAC inhibitors); Tazemetostat (EZH2 inhibitor)'], ['Epigenetic disorders', 'Rett (MECP2), Rubinstein-Taybi (CREBBP), Kabuki (KMT2D), ICF (DNMT3B)'], ['Reversibility', 'Epigenetic marks are reversible — basis of epigenetic therapy'], ] story.append(tbl(sum_data, [4.5*cm, 11.8*cm])) # Footer story.append(Spacer(1,10)) story.append(HRFlowable(width="100%", thickness=0.5, color=colors.HexColor('#9e9e9e'), spaceAfter=4)) story.append(Paragraph( "<i>Sources: Thompson &amp; Thompson Genetics and Genomics in Medicine (9th ed.) &bull; " "Harper's Illustrated Biochemistry (32nd ed.) &bull; " "The Developing Human: Clinically Oriented Embryology &bull; " "Goldman-Cecil Medicine &bull; Emery's Elements of Medical Genetics and Genomics</i>", note_style)) doc.build(story) print("PDF created:", output_path) PYEOF