An electron microscopic study of local anesthetic-induced skeletal muscle fiber degeneration and regeneration in the monkey

An electron microscopic study was done on abductor pollicis brevis muscles of 18 Rhesus monkeys after intramuscular injections of 0.75% bupivacaine, 2% mepivacaine, or 2% lidocaine + epinephrine. The muscles were examined for from 2 h to 28 days. Severe muscle fiber damage, consisting of breakdown of sarcolemma and myofibrils, was seen as early as 2 h. Phagocyte mediated fragmentation of the degenerating muscle fibers was at its peak during the third and fourth days. Myoblasts were abundant during the fourth day. Early myotubes appeared on the fifth and sixth days, and they matured during the second week. Satellite cells appeared alongside mature myotubes. Overall, the local anesthetic-induced breakdown and regeneration of skeletal muscle fibers in the monkey followed a course quite similar to that seen in the rat.     

Reduction of Mortality in the Stockholm Ischaemic Heart Disease Secondary Prevention Study by Combined Treatment with Clofibrate and Nicotinic Acid

Consecutive survivors of a myocardial infarction from the Southern Hospital, below 70 years of age, were randomized into a Control group (n=276) and a Treatment group (n=279). The latter was openly prescribed the combination of clofibrate and nicotinic acid for serum lipid lowering. Each patient should remain in the study for 5 years and be seen regularly every 4 months at a special IHD outpatient clinic within the hospital. The concentration of serum cholesterol and triglyceride was lowered by 13% and 19%, respectively, in the Treatment group compared to the Control group. Total mortality was 82 cases in the Control group and 61 in the Treatment group, a 26% reduction (p<0.05). For patients above 60 years of age in the Treatment group the reduction in mortality was 28% (p<0.05). IHD mortality was reduced by 36% (p<0.01)in the Treatment group compared to the Control group. The beneficial effect of the serum lipid lowering treatment was related to the serum triglyceride concentration in two ways. First, it only occurred in patients with a triglyceride level >1.5 mmol/l (n=216). Secondly, it was most pronounced in the 44% of the treated patients who had a lowering of the serum triglyceride concentration by 30% or more, and in this subgroup the reduction of IHD mortality was 60% (p<0.01). For serum cholesterol there were no such relations. The difference between serum triglycerides and cholesterol concerning these relations to the treatment outcome may be due to the fact that hypertriglyceridaemia was the most common hyperlipidaemia among our patients, occurring in 50%, while hypercholesterolaemia only occurred in 13 %. Caution should be exercised in the interpretation of the results as the trial was not blind. However, the fact that the decrease in IHD deaths was directly related to the degree of serum triglyceride lowering indicates that it was the drug effect on serum lipids that was reponsible for the beneficial effect of the treatment.     

Total reconstruction of the hypopharynx and cervical esophagus: a 20-year experience.

We have reviewed 145 patients who underwent 148 total reconstructions of the hypopharynx and cervical esophagus between 1970 and 1989. The types and numbers of reconstruction included 45 deltopectoral (DP) flaps, 35 musculocutaneous (MC) flaps, 19 colon interpositions, 23 gastric transpositions, and 26 free jejunal transfers. Median hospitalization was 51 days for DP flaps, 24 days for MC flaps, 28 days for colon, 30 days for gastric, and 14 days for jejunum. Median resumption of oral intake was 92 days for DP flaps, 19 days for MC flaps, 12 days for colon, 13 days for gastric, and 9 days for jejunum. Functional failure, defined as the inability to maintain adequate nutrition without tube feedings, was 40% for MC flaps, 42% for colon interposition, 17% for gastric transposition, and 20% for free jejunal transfer. Microvascular free jejunal transfer has become our method of choice for reconstruction of the hypopharynx and cervical esophagus. Gastric transposition is an alternative when resection of the thoracic esophagus is necessary.     

Central serous chorioretinopathy in U.S. Air Force aviators: a review

Idiopathic central serous chorioretinopathy (ICSC) is an uncommon disease with the potential to cause loss of visual acuity, decreased color vision, and decreased depth perception. These visual changes may become permanent and require removal of aviators from flight status. This study reviews 55 eyes of 47 USAF aviators with ICSC examined at the United States Air Force School of Aerospace Medicine (USAFSAM), Brooks AFB, TX. Clinical and aeromedical findings, both on initial and on follow-up ophthalmic examination were studied. Ninety-seven percent of aviators otherwise medically qualified were ultimately returned to flight status. Overall, 51% had recurrent episodes, 17% had bilateral disease, and 13% underwent laser photocoagulation. Visual acuity correlated with active disease, and there was a trend toward poor stereopsis and diminished color vision with worsening visual acuity. Eighty-six percent attained a final visual acuity of 20/20 or better. On final examination, 90% had normal stereopsis, 87% had normal color vision, and 49% had a normal central visual field. Eyes with recurrent disease tended to have degraded final visual acuity, stereopsis, color vision, and central visual field. The visual and aeromedical prognosis from a single attack of ICSC is generally favorable, but repeated attacks can lead to a significant decrease in visual functions that may jeopardize flying status.     

Close correlation between high-density lipoprotein and triglycerides in normotriglyceridaemia.

The relationship between high-density-lipoprotein (HDL) particle size subclasses and the levels of the major lipoprotein lipids was studied in 74 men consecutively referred to the lipid clinic. HDL (density 1.070-1.21 kg l-1) was separated by polyacrylamide gradient gel electrophoresis (GGE) into five size-defined subclasses, in order of decreasing size as follows: HDL2b, HDL2a, HDL3a, HDL3b and HDL3c. Cholesterol and triglyceride concentrations in very-low-density (VLDL), low-density (LDL) and high-density (HDL) lipoproteins were determined. The level of VLDL triglycerides was negatively correlated with HDL2b (r = -0.66, P less than 0.0001), and positively correlated with HDL3b concentrations (r = 0.65, P less than 0.0001). Both correlations were restricted to subjects with VLDL triglyceride concentrations of less than 1.80 mmol l-1, i.e. those with normotriglyceridaemia. Patients with a history of myocardial infarction and/or angina pectoris (n = 18) had significantly lower HDL2b levels than subjects with asymptomatic hyperlipidaemia (n = 50), i.e. 0.16 vs. 0.22 mg protein ml-1 (P less than 0.05), despite essentially similar cholesterol and triglyceride levels in the VLDL, LDL and HDL fractions, including HDL2 and HDL3 cholesterol.     

Mechanism of UV-related carcinogenesis and its contribution to nevi/melanoma

Melanoma consists 4-5 % of all skin cancers, but it contributes to 71-80 % of skin cancers deaths. UV light affects cell and tissue homeostasis due to its damaging effects on DNA integrity and modification of expression of a plethora of genes. DNA repair systems protect cells from UV-induced lesions. Several animal models of melanoma have been developed (Xiphophorus, Opossum Monodelphis domestica, mouse models and human skin engrafts into other animals). This review discusses possible links between UV and genes significantly related to melanoma but does not discuss melanoma genetics. These include oncogenes, tumor suppressor genes, genes related to melanocyte-keratinocyte and melanocyte-matrix interaction, growth factors and their receptors, CRH, ACTH, α-MSH, glucocorticoids, ID1, NF-kappaB and vitamin D3.