I want to learn this topic
python -m markitdown "/home/daytona/workspace/attachments/9832ab9b-5341-4ca9-9383-07ad59bbfde0/Muscle Plasticity (1).pptx"
cd "/home/daytona/workspace/attachments/9832ab9b-5341-4ca9-9383-07ad59bbfde0" && python3 -c " from pptx import Presentation prs = Presentation('Muscle Plasticity (1).pptx') for i, slide in enumerate(prs.slides): print(f'=== Slide {i+1} ===') for shape in slide.shapes: if hasattr(shape, 'text') and shape.text.strip(): print(shape.text) print() "
ls /home/daytona/skills/pptx/scripts/ && pip show python-pptx 2>/dev/null | head -5; pip3 show python-pptx 2>/dev/null | head -5; which node && node --version
cd "/home/daytona/workspace/attachments/9832ab9b-5341-4ca9-9383-07ad59bbfed0" 2>/dev/null; ls /home/daytona/skills/pptx/scripts/office/ && cat /home/daytona/skills/pptx/scripts/office/unpack.py | head -30
PPTX="/home/daytona/workspace/attachments/9832ab9b-5341-4ca9-9383-07ad59bbfde0/Muscle Plasticity (1).pptx" OUT="/home/daytona/workspace/muscle-plasticity-unpacked" mkdir -p "$OUT" python3 /home/daytona/skills/pptx/scripts/office/unpack.py "$PPTX" "$OUT" && echo "Done"
PPTX="/home/daytona/workspace/attachments/9832ab9b-5341-4ca9-9383-07ad59bbfde0/Muscle Plasticity (1).pptx" OUT="/home/daytona/workspace/muscle-plasticity-unpacked" mkdir -p "$OUT" unzip -o "$PPTX" "ppt/slides/*.xml" -d "$OUT" && echo "Done"
python3 << 'EOF' import os, re, glob slide_dir = "/home/daytona/workspace/muscle-plasticity-unpacked/ppt/slides" slides = sorted(glob.glob(f"{slide_dir}/slide*.xml"), key=lambda x: int(re.search(r'slide(\d+)', x).group(1))) for path in slides: num = int(re.search(r'slide(\d+)', path).group(1)) with open(path, 'r', encoding='utf-8') as f: xml = f.read() # Extract all text runs texts = re.findall(r'<a:t[^>]*>(.*?)</a:t>', xml) combined = ' '.join(t.strip() for t in texts if t.strip()) if combined: print(f"=== Slide {num} ===") print(combined) print() EOF
python3 << 'EOF' import os, re, glob slide_dir = "/home/daytona/workspace/muscle-plasticity-unpacked/ppt/slides" slides = sorted(glob.glob(f"{slide_dir}/slide*.xml"), key=lambda x: int(re.search(r'slide(\d+)', x).group(1))) for path in slides: num = int(re.search(r'slide(\d+)', path).group(1)) try: with open(path, 'r', encoding='utf-8') as f: xml = f.read() texts = re.findall(r'<a:t[^>]*>(.*?)</a:t>', xml) combined = ' '.join(t.strip() for t in texts if t.strip()) if combined: print(f"=== Slide {num} ===") print(combined) print() except Exception as e: print(f"=== Slide {num} === [ERROR: {e}]") EOF
python3 << 'EOF' import zipfile, re, io pptx_path = "/home/daytona/workspace/attachments/9832ab9b-5341-4ca9-9383-07ad59bbfde0/Muscle Plasticity (1).pptx" with zipfile.ZipFile(pptx_path, 'r') as z: names = sorted([n for n in z.namelist() if re.match(r'ppt/slides/slide\d+\.xml', n)], key=lambda x: int(re.search(r'slide(\d+)', x).group(1))) for name in names: num = int(re.search(r'slide(\d+)', name).group(1)) xml = z.read(name).decode('utf-8') texts = re.findall(r'<a:t[^>]*>(.*?)</a:t>', xml) combined = ' '.join(t.strip() for t in texts if t.strip()) if combined: print(f"=== Slide {num} ===") print(combined) print() EOF
python3 << 'EOF' import zipfile, re pptx_path = "/home/daytona/workspace/attachments/9832ab9b-5341-4ca9-9383-07ad59bbfde0/Muscle Plasticity (1).pptx" with zipfile.ZipFile(pptx_path, 'r') as z: print("All files in pptx:") for n in z.namelist()[:40]: print(n) EOF
python3 << 'PYEOF' import zipfile, re, html pptx_path = "/home/daytona/workspace/attachments/9832ab9b-5341-4ca9-9383-07ad59bbfde0/Muscle Plasticity (1).pptx" with zipfile.ZipFile(pptx_path, 'r') as z: slide_files = sorted( [n for n in z.namelist() if re.match(r'ppt/slides/slide\d+\.xml$', n)], key=lambda x: int(re.search(r'slide(\d+)', x).group(1)) ) print(f"Found {len(slide_files)} slides") results = [] for name in slide_files: num = int(re.search(r'slide(\d+)', name).group(1)) raw = z.read(name) xml = raw.decode('utf-8', errors='replace') # Extract text runs grouped by paragraph paragraphs = re.findall(r'<a:p[^>]*>(.*?)</a:p>', xml, re.DOTALL) slide_text = [] for para in paragraphs: runs = re.findall(r'<a:t[^>]*>(.*?)</a:t>', para) line = ''.join(html.unescape(r) for r in runs).strip() if line: slide_text.append(line) if slide_text: results.append((num, slide_text)) for num, lines in results: print(f"\n=== Slide {num} ===") for l in lines: print(l) PYEOF
python3 << 'PYEOF' import zipfile, re, html pptx_path = "/home/daytona/workspace/attachments/9832ab9b-5341-4ca9-9383-07ad59bbfde0/Muscle Plasticity (1).pptx" with zipfile.ZipFile(pptx_path, 'r') as z: slide_files = sorted( [n for n in z.namelist() if re.match(r'ppt/slides/slide\d+\.xml$', n)], key=lambda x: int(re.search(r'slide(\d+)', x).group(1)) ) for name in slide_files: num = int(re.search(r'slide(\d+)', name).group(1)) raw = z.read(name) xml = raw.decode('utf-8', errors='replace') paragraphs = re.findall(r'<a:p[\s>](.*?)</a:p>', xml, re.DOTALL) slide_text = [] for para in paragraphs: runs = re.findall(r'<a:t>(.*?)</a:t>', para) line = ''.join(html.unescape(r) for r in runs).strip() if line: slide_text.append(line) if slide_text: print(f"\n=== Slide {num} ===") for l in slide_text: print(l) else: print(f"\n=== Slide {num} === [no text or image-only]") PYEOF
python3 << 'PYEOF' import zipfile, re pptx_path = "/home/daytona/workspace/attachments/9832ab9b-5341-4ca9-9383-07ad59bbfde0/Muscle Plasticity (1).pptx" with zipfile.ZipFile(pptx_path, 'r') as z: xml = z.read('ppt/slides/slide1.xml').decode('utf-8', errors='replace') # show first 3000 chars print(xml[:3000]) PYEOF
python3 << 'PYEOF' import zipfile, os pptx_path = "/home/daytona/workspace/attachments/9832ab9b-5341-4ca9-9383-07ad59bbfde0/Muscle Plasticity (1).pptx" out_dir = "/home/daytona/workspace/muscle-plasticity-images" os.makedirs(out_dir, exist_ok=True) with zipfile.ZipFile(pptx_path, 'r') as z: media = [n for n in z.namelist() if n.startswith('ppt/media/')] print(f"Found {len(media)} media files") for m in sorted(media): fname = os.path.basename(m) out_path = os.path.join(out_dir, fname) with open(out_path, 'wb') as f: f.write(z.read(m)) print(f"Saved: {fname}") PYEOF
Muscle Plasticity in Response to Electrical Stimulation
1. History & Background
2. Definition
- Modification of skeletal structures in response to environmental change
- The dynamic ability of a muscle to adapt when its level of use is increased
- In response to demands imposed on muscle, its structure, biochemical, and physiological characteristics change (1982)
3. Structure of Skeletal Muscle
4. Types of Muscle Fibers
| Property | Type I (Slow Oxidative) | Type IIa (Fast Oxidative Glycolytic) | Type IIb (Fast Glycolytic) |
|---|---|---|---|
| Fiber & motor unit size | Small | Intermediate | Large |
| Mitochondria & capillaries | Many | Many | Few |
| Myoglobin content | High (red) | High (red) | Low (white) |
| Glycogen content | Low | Intermediate | High |
| Main ATP source | Oxidative phosphorylation | Oxidative phosphorylation | Anaerobic glycolysis |
| Glycolytic enzyme activity | Low | Intermediate | High |
| Rate of fatigue | Slow | Intermediate | Fast |
| Myosin ATPase activity | Low | High | High |
| Contractile speed | Slow | Fast | Fast |
| Example locations | Postural muscles of back | Major muscles of legs | Extraocular eye muscles |
5. Electrical Stimulation
- Chronic Electrical Stimulation (CES) provides the clearest experimental model of muscle adaptation due to increased use
- Muscles performing different tasks respond to different electrical input depending on their architecture
- Slow twitch fibers respond to low-frequency currents
- Fast twitch fibers respond to high-frequency bursts
6. Chronic Low-Frequency Stimulation (CLFS)
Fast-twitch → Slow-twitch via indirect tonic, low-frequency electrical stimulation
7. Time Course of Muscle Fiber Transformation
- Change in contractile properties
- Metabolic changes
- Circulatory changes
- Structural changes
Components That Get Modified
8. Sequential Changes After Stimulation
Hours 2-3
- The earliest change is swelling of the sarcoplasmic reticulum (SR) membrane network
- Significance of this morphological change is not fully understood but is routinely observed
Days 2-12
- Increase in number of capillaries per mm² (angiogenesis)
- Increase in total blood flow
- Increase in total oxygen consumption
- Increased oxidative enzymes and muscle metabolic activity
- Decrease in muscle fatigability
Day 14
- Z-band increases in width
- Decrease in amount and activity of calcium ATPase
Day 28
- Myosin profile is altered - different myosin monomers incorporate into a single filament
- Light chain shift: LC1f, LC2f & LC3f → LC1s, LC2s (fast to slow isoforms)
- Heavy chain profile is altered
- Fast muscle fibers become more like slow muscle fibers
- Muscle mass and fiber area decreases
- Z-band reaches full width
End State (~8 weeks)
- The Z-band is the full width of a normal slow-contracting muscle
- Density of the T-system has decreased
- The transformed fast-contracting muscle is indistinguishable from a normal slow-contracting muscle (Lieber RL, ISI Atlas of Science, 1988)
9. Key Effects of CLFS (Summary)
- Reduction in muscle bulk and tetanic tension due to reduction in diameter of the largest fatigable fibers
- Slowing of time-courses of contraction and relaxation
- Increased fatigue resistance
- Profound alterations in gene expression leading to transformation of muscle fiber phenotype
10. Clinical Evidence
| Study | Key Finding |
|---|---|
| Trumble, Duan & Magovern (2001) - rabbit LD muscle, 6-12 weeks CLFS | Improved endurance capacity; increased % CSA occupied by slow-twitch oxidative fibers; remodeling of extracellular matrix (Type I collagen and fibrillin) |
| Lotri-Koffi et al (2019) - mouse NMES model | Muscle mass increased; insulin sensitivity improved; beneficial in chronic disease |
| Tsutaki & Ogasawara (2013) - rat gastrocnemius, LFS 10 Hz vs HFS 100 Hz | LFS recruits Type II fibers and produces muscle hypertrophy WITHOUT high force generation |
| Pette & Vrbová (2017) | Adaptive potential can be used to repair muscle damage, prevent muscle wasting in inactivity and aging |
| Schnyder, Kupr & Handschin (2017) | Coregulators are potent regulators of metabolic and myofibrillar plasticity; HDAC IIa inhibition enhances muscle endurance and systemic metabolic function |
| Nuhr MJ, Pette D et al (2004) - patients with advanced CHF | CLFS counteracts detrimental skeletal muscle changes in chronic heart failure and increases exercise capacity |
| Bruton (2002) | Muscle response to altered activity is extensively studied but individuality of responses means genotype likely determines phenotypic response |
11. Quick-Reference Summary
Fast fiber → CLFS (low freq, tonic) → Slow fiber
Timeline: 8 weeks, 8-24 h/day
2-3 hrs: SR swelling
2-12 days: ↑ mitochondria, ↑ capillaries (angiogenesis), ↑ oxidative enzymes, ↓ fatigue
14 days: ↑ Z-band width, ↓ Ca2+ ATPase
28 days: myosin light chain shift (fast → slow), ↓ muscle mass & fiber area
~8 weeks: fully transformed to slow-twitch phenotype
12. References (from slides)
- Chromiak & Antonio. Skeletal muscle plasticity. Essentials of Sports Nutrition and Supplements (2008)
- Nuhr MJ et al. European Heart Journal 2004;25(2):136-43
- Trumble DR et al. BAM-PADOVA 2001;11(2):91-8
- Tsutaki A et al. BioMed Research International 2013
- Robinson AJ. Clinical Electrotherapy, Chapter 8
- Pette D, Vrbová G. European Journal of Translational Myology 2017;27(1)
- Schnyder S et al. Biochimie 2017;136:49-54
- Bruton A. Physiotherapy 2002;88(7):398-408
- Lotri-Koffi A et al. Scientific Reports 2019;9(1):7252