Muscle histology

Toop, J. and Emery, A. E. H. "Muscle Histology In Fetuses at Risk for Duchenne Muscular Dystrophy". Clin. Genet., (1974), 5, 230-233. 

Regensteiner JG, Wolfel EE, Brass EP, Carry MR, et al. Chronic changes in skeletal muscle histology and function in peripheral arterial disease. Circulation 1993 87 413 21. 

Some patients react favorably to vitamin Bg (40 to 200 mg/day). In cases which are not vitamin Bg responsive dietary protein restriction is indicated. Creatine supplementation does improve muscle histology. 

Muscle tissue is unique in its ability to shorten or contract. The human body has three basic types of muscle tissue histologically classified into smooth, striated, and cardiac muscle tissues. Only the striated muscle tissue is found in all skeletal muscles. The type of cells which compose the muscle tissue are known as contractile cells. They originate from mesenchymal cells which differentiate into myoblasts. Myoblasts are embryonic cells which later differentiate into contractile fiber cells. 

However, it is clear that the resting compliance is relatively more important to the springlike behavior of many active smooth muscles. Each smooth muscle must be analyzed individually since the extracellular compartment of each smooth muscle as a histological entity is different. 

In childhood and adult-onset forms of AM, more moderate glycogen storage and vacuolation of muscle are seen and not all fibers are affected. Although cardiomegaly is not apparent in childhood AMD, glycogen storage is detectable histologically in heart muscle. 

In atherosclerosis, ox-LDL is taken up ultimately by macrophages and smooth muscle cells in the arterial intima. Once loaded with lipid, these cells have a foamy appearance when examined histologically. The accumulation of these so-called foam cells in the artery wall leads to the formation of fatty streaks , which can lead to atheromatous plaque formation and consequent coronary heart disease. 

No gross or histological alterations in skeletal muscle were observed in rabbits exposed to 1,000 mg/kg/day of cyclotriphosphazene (Kinkead et al. 1989c, 1990) or in rabbits exposed to an unspecified amount of Cellulube 220 (Carpenter et al. 1959). Both of these studies were intermediate-duration dermal exposure studies. Studies examining musculoskeletal end points following acute- or chronic-duration exposure were not located. 

Histologic and skeletal abnormalities in all BaP-exposed groups depressed mitotic rates in retina and brain in groups exposed to 0.08 pg/L and higher muscle necrosis in all groups exposed to 0.2 pg/L and higher microphthalmia was observed in 17% of BaP-treated trout No DNA adducts detected in liver... 

Yearlings force-fed 370,000, 3.7 million, or 37 million Bq e5Zn/kg BW daily for 17 weeks, or 370 million Bq e5Zn/kg BW daily for 10 weeks Adverse effects on growth, survival, or gut histology at any dose leucopenia evident at week 10 at the highest dose. Residues, in Bq/kg FW, in the 37 million group at 17 weeks were 148 million in bone and 12.9 million in muscle 11, 15... 

The only information available for humans exposed to chlordecone pertains to a study of intermediate-to-chronic occupational exposures (exact durations not recorded) of one group of individuals employed at a facility in Hopewell, Virginia. Chlordecone was manufactured in this facility for 21--22 months because of poor hygiene at the facility, exposure by all routes was likely. In addition, concomitant exposure to a precursor was possible. Several studies have been published to describe the toxicity in this human population (Cannon et al. 1978 Taylor 1982, 1985), and results of these studies will be considered here. These results pertain to the chronic-duration exposure also. No deaths were reported (Cannon et al. 1978 Taylor et al. 1978). Skeletal muscle biopsy was conducted on six workers who experienced adverse neurological clinical signs (such as tremors) as well as muscle weakness and incoordination (Martinez et al. 1978). Abnormal histological and biochemical indices were revealed in this tissue. Joint pain was also reported (Taylor 1982, 1985). 

Musculoskeletal Effects. No gross or histological lesions were found in bones or skeletal muscle of rats exposed intermittently to <1.4 mg/m for 13 weeks (Shiotsuka 1989). 

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