Muscle hypertrophy in men and women

It is widely believed that women experience less skeletal muscle hypertrophy consequent to heavy-resistance training than men. The purpose of this study was to test this hypothesis using both traditional indirect indicators as well as a direct measure of muscle size. Seven male experimental (ME), 8 female experimental (FE), and 7 control subjects were studied before and after a 16-wk weight training program, in which ME and FE trained 3 days.wk-1 at 70 to 90% of maximum voluntary contraction using exercise designed to produce hypertrophy of the upper arm and thigh. Strength increased significantly (P less than 0.05) in ME and FE, respectively, on elbow flexion (36.2 and 59.2%), elbow extension (32.6 and 41.7%), knee flexion (12.8 and 24.4%), and knee extension (28.8 and 33.9%) tests. Absolute changes were significantly greater in ME than FE in 2 of the 4 tests, whereas percentage changes were not significantly different. Substantial muscle hypertrophy occurred in the upper arms of both ME and FE as evidenced by significant increases in upper arm circumference (7.9 and 7.9%), bone-plus-muscle (B+M) cross-sectional area (CSA) estimated by anthropometry (17.5 and 20.4%), and muscle CSA determined from computed tomography scanning (15.9 and 22.8%). Changes by ME and FE were not significantly different, except for the absolute increase in estimated B+M CSA, which was significantly greater in ME (11.2 vs 7.4 cm2). No muscle hypertrophy occurred in the thigh of either ME and FE as evidenced by non-significant changes in thigh circumference (1.7 and 2.3%), B+M CSA (4.9 and 6.1%), and muscle CSA (2.9 and 2.9%). Changes by ME and FE in body weight, fat-free weight, and fat weight were not significant.(ABSTRACT TRUNCATED AT 250 WORDS)     

Covert inhalation of tablet causing fatal pneumonia

Inhalation of foreign bodies is usually associated with acute respiratory symptoms. We report a case of an elderly woman who died from pneumonia due to covert tablet inhalation. Clinicians caring for the elderly should consider this as a possible cause for pneumonia which fails to respond to usual therapy.     

Advanced primary breast cancer: assessment at mammography of response to induction chemotherapy

The response to induction chemotherapy is an important prognostic factor in patients with nonmetastatic, locally advanced breast carcinomas. Assessment at mammography of the response of 60 breast cancers in 59 women was performed between 1974 and 1986. Responses were excellent in 13 tumors, moderate in 34, and poor in 13 (excellent moderate = 78%). Assessment of response of discrete masses in a fatty breast was easiest; assessment of response of tumor areas that were poorly defined-such as a focal area of architectural distortion or mass in dense breast parenchyma-was more difficult. Of 17 patients with excellent pathologic responses-that is, minimal or no residual tumor-15 (88%) had complete responses (no residual tumor) as determined with mammography, physical examination, or both. Mammography provides information complementary to physical examination and is essential in the accurate assessment of the response to chemotherapy of locally advanced breast cancer.     

An experimental study of tumour size and radiosensitivity: analysis by regrowth delay

When designing experimental studies of tumours, it is considered important to control all variables that might alter the radiosensitivity and hence influence the variability of the data. One such variable is tumour size. We have studied the regrowth delay of a mammary carcinoma treated at 2-10 mm mean diameter (a 125-fold change of volume) with X-rays alone or X-rays plus misonidazole (MISO). The data were analysed to give dose-response curves, using four endpoints. Regrowth to a fixed size (4.5 mm larger than treatment size), or by a fixed increment (4 times the original volume) was expressed either as absolute delay, or as specific growth delay to allow for the changes in volume doubling time as the tumour grows. The method of analysis made no difference to the measured sensitizer enhancement ratio (SER) for MISO. The SER was dose-dependent, being higher at higher doses, but was not different in tumours of 2 or 10 mm diameter. However, when comparing response to X-rays alone, the method of analysis made a very big difference to the conclusions. Regrowth to R + 4.5 mm showed no change in radiosensitivity with tumour size, but regrowth to 4 times the original volume (the most logical endpoint) indicated that large tumours were more sensitive than small. We conclude that regrowth delay may be an inappropriate method for comparing absolute sensitivities of tumours of different sizes. However, for studying the effectiveness of a radiomodifier the constraints of tumour size at irradiation seem to be less severe than previously believed.     

Induction of islet cytodifferentiation by fetal mesenchyme in adult pancreatic ductal epithelium.

Recombinant tissue consisting of adult ductal epithelium isolated from pancreas and fetal mesenchyme was transplanted subcutaneously in the inguinal region of nude mice or epididymal fat pads of rats with a tissue chamber device for short-term (8-day) or long-term (6- to 12-wk) duration. We found that recombinant tissue underwent morphogenesis and cytodifferentiation, thereby forming islets that contained cells immunocytochemically positive for insulin and glucagon. Islet cytodifferentiation occurred in approximately 20% of the recombinants. In recombinants that developed into islets, the tissue was always in close association with an extracellular matrix, nerves, and blood vessels. Controls consisting of mesenchyme alone or duct epithelium alone showed no evidence of morphogenesis of cytodifferentiation. Pancreatic rudiments were also implanted to serve as positive controls. This is the first demonstration of islet cytodifferentiation from adult duct epithelium.     

Prospective study of bacterial and viral contamination of exercise equipment.

OBJECTIVE: Transmission of bacterial and viral pathogens is known to occur by hand contact with fomites. Exercise equipment in public facilities may serve as such fomites. It is not known whether equipment disinfection might reduce microorganism colonization. We performed studies to address these issues. DESIGN: Observational study of bacterial and viral culture results from hand-contact surfaces of exercise equipment, pre-exercise and postexercise; prospective study of viral culture results before and after intervention with disinfection solution. SETTING: Two fitness centers in a military community. INTERVENTION: One week trial of twice-a-day equipment disinfection. MAIN OUTCOME MEASURES: Type and number of bacteria and type of viruses present on equipment before and after exercise; prevalence of viral culture positivity on equipment before and after intervention. RESULTS: Bacterial cultures of body contact surfaces on equipment revealed benign bacterial species (coagulase-negative staphylococci, diphtheroids, and so forth) but no pathogenic bacteria whether obtained pre-exercise or postexercise, or whether from aerobic versus weight training equipment. Viral cultures revealed the presence of viruses (generally rhinoviruses) on 63 of 100 (63%) hand-contact surfaces of equipment. Weight equipment was significantly more often contaminated than aerobic equipment (73% vs. 51%; P = 0.026). Disinfection of equipment did not lower the prevalence of virus isolation (48% positive before cleaning; 86% positive after cleaning). CONCLUSIONS: There is little risk of exposure to pathogenic bacteria on exercise equipment. Such equipment may commonly serve as fomites for the transmission of viruses. These data do not suggest that disinfection of exercise equipment will offer significant protective effects against virus exposure.     

Safety and effect of transforming growth factor-β2 for treatment of venous stasis ulcers

Transforming growth factor-beta(2) promotes healing in a variety of animal models and exhibits clinical effects thought to be mediated by connective tissue formation. Two clinical trials were conducted to evaluate the safety and effect of transforming growth factor-beta(2) purified from bovine bone and delivered topically to venous stasis ulcers three times per week for up to 6 weeks by means of a lyophilized collagen vehicle. The first was an open-label trial comparing transforming growth factor-beta(2) purified from bovine bone (0.5 microg/cm(2)) with a placebo consisting of lyophilized collagen vehicle-without active drug. After no safety issues arose in that trial, a prospectively randomized, closed-label, observer-blinded, three-armed trial was conducted to compare bovine transforming growth factor-beta(2) (2.5 microg/cm(2)) with the collagen matrix placebo vehicle and with a standard dressing. Standardized elastic compression was applied to all test extremities. The rate of reduction of ulcer area as measured by planimetry was the primary measure of effect. No serious safety-related events occurred in either trial. Clinical evaluation suggested that improvement in the quality and quantity of granulation tissue appeared to precede epithelialization of ulcers treated with bovine transforming growth factor-beta(2). In both studies, treatment with bovine transforming growth factor-beta(2) appeared to have a positive effect on the rate of ulcer closure, whereas ulcers in the control groups continued to exhibit impaired healing. In the open-label study, the mean rate of closure of ulcers treated with bovine transforming growth factor-beta(2) was significantly greater than that of ulcers treated with placebo. There was likewise enhanced reduction in ulcer area in the ulcers treated with bovine transforming growth factor-beta(2) in the second trial. However, because of a higher variability in patient response and a greater placebo effect, the difference was not significant. The placebo was not worse than the standard care arm, thereby showing that the vehicle is not injurious to healing. The combined results of the two trials suggest that, at doses of 0.5 to 2.5 microg/cm(2), bovine transforming growth factor-beta(2) is safe as a topically applied agent in a collagen matrix vehicle and can have a positive effect on closure of venous stasis ulcers. Large multicenter trials appear to be indicated to evaluate fully the potential utility of transforming growth factor-beta(2) in accelerating closure of chronic dermal ulcers.