Gaucher disease: abdominal MR imaging findings in 46 patients.

Abdominal magnetic resonance imaging findings were reviewed in 46 patients with Gaucher disease. All patients had hepatosplenomegaly at the time of initial imaging. Splenic nodules were present in 14 patients (30%) and varied in signal intensity. These nodules were isointense on T1-weighted and hypointense on T2-weighted images. Splenic infarcts were seen in 15 patients (33%), and four of these patients (9%) also had subcapsular fluid collections. Both nodules and infarcts were present in the spleen in four patients (9%). Pathologic correlation was performed with specimens from two patients who underwent partial splenectomy. Focal areas of abnormal signal intensity were noted in the liver in nine patients (20%). They were either stellate or segmental, and may represent fibrotic septa with ischemic changes associated with aggregates of Gaucher cells. No changes were noted in the kidneys or abdominal lymph nodes.     

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.     

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.     

Two-tone suppression, excitation and the after effect in rate responses in auditory nerve fibres in the cat.

Responses were recorded from single, auditory nerve fibres in the anaesthetized cat. Acoustic stimuli consisted of two tones, one of which was at characteristic frequency (CF), the other (the suppressor) was at considerably lower frequency. Tones were presented in simultaneous and sequential configurations. For simultaneous presentations, well-known response properties were observed. The rising limb of the two-tone rate-intensity function closely matched that of the appropriately adapted response to the suppressor tone presented alone. Also, whether strongly suppressed relative to CF-driven rate, or equal to CF-driven rate, rate responses to the two-tone stimuli persisted unchanged when the CF tone was terminated and the suppressor tone continued alone. These results support the hypothesis that the suppressor tone has dual influences, suppressive and excitatory, that are distinct and additive. Peristimulus response histograms confirm in the cat that depression and slow recovery of sensitivity to CF may follow termination of the suppressor tone, as reported for the guinea pig [Hill, K.G. and Palmer, A.R. (1991) Hear. Res. 55, 167-176]. This delay in recovery of normal sensitivity to CF appeared to be directly related to the amount of excitation of the fibre that is attributable to the suppressor tone. A similar, delayed re-establishment of sensitivity also occurred in the response to a tone at CF, presented immediately following excitation by a suppressor tone. However, no delay occurred in the onset of response to the suppressor when preceded by the CF tone.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pathophysiology of experimental leishmaniasis: the role of parasite physiology in the development of metastatic disease

This paper addresses the issue of how physiological properties of Leishmania determine the pattern of development of disseminated leishmaniasis in the mammalian host. It presents direct experimental evidence from in vivo studies that species of Leishmania differ in their capacity to multiply in cutaneous and visceral sites which results in differences in the pattern and rate of development of leishmaniasis. It was found that Leishmania mexicana amazonensis begins to multiply in the cutaneous site of inoculation within 7 days. Parasites, detected in the liver and spleen at 4 weeks, increased 100-fold during the next 4 months. However, the slow multiplication of L. mexicana amazonensis in the liver and spleen was more apparent than real. Parasites implanted in those organs of athymic nude mice by an intravenous injection were rapidly eliminated with a half-time of 16 hr. Thus, the parasites found in small numbers in the liver during the development of disseminated cutaneous disease in mice are most likely those which have been recently removed from the blood. Those few parasites that are not removed from the blood can establish metastatic foci in distant cutaneous sites, and replicate progressively once there.