Postnatal survival and growth of mouse irradiated in utero with low dose

In order to investigate radiation risks associated with low dose and low dose-rates, pregnant Swiss albino mice were exposed to gamma rays, 0.80 Gy from a cobalt-60 source at two different dose-rates (0.0795 and 0.0012 Gy/min) on 18 day post conception. In females exposed to lower dose-rate (0.0012 Gy/min), litter size was found to be decreased, while those exposed to higher dose-rate (0.0795 Gy/min), it remained unaltered. In both groups, appearance of fur and development of complete fur were delayed, whereas gait was delayed only in higher dose-rate group. Male offspring exhibited a biphasic mode of weight loss, while female offspring after an initial weight loss at 1 week, displayed a continuous recovery, but could not attain the normal weight till 12 weeks of age. It appears that higher dose-rate is more effective in delaying the appearance of physiological markers and weight loss, while in terms of litter size lower dose-rate (0.0012 Gy/min) is more effective.     

Facilitative responses to species-specific calls in cortical FM-FM neurons of the mustached bat

FM-FM neurons in the auditory cortex of the mustached bat are highly specialized for echolocation, responding facilitatively to the combination of frequency modulated (FM) components of biosonar pulse and its echo. Here we propose they are also specialized for processing bat communication calls. FM-FM neurons respond facilitatively to natural call syllable pairs, and exhibit inter-syllable interval tuning to the natural range of intervals. Our results support a role for 'combination-sensitive' neurons in communication, and suggest that cortical neurons can possess multiple distinct specialized modes of response.     

Martingales without tears

This pedagogical paper presents a casual introduction to martingales, or fair gambling processes. Our objective is to describe the concept of a martingale and its application to common statistical tests used in the analysis of survival data, but without the mathematical rigor required for formal proofs. We use heuristic arguments to demonstrate that the logrank statistic evaluated over followup time is a fair gambling process, and introduce some mathematical notation and terminology along the way. We then employ the counting process approach to show that the logrank statistic computed over followup time can be expressed as the difference of two martingale transforms, and thus is a martingale. These ideas are first time introduced in the context of a discrete time process, and are then generalized to a continuous time process. With slight modifications, the same idea extends from the logrank to other weighted Mantel-Haenszel statistics computed over time.     

Urologic complications after simultaneous pancreas-kidney transplantation: hand-sewn versus stapled duodenocystostomy

Pancreas transplantation with bladder drainage of exocrine secretions may be associated with significant urologic complications. Stapled and hand-sewn duodenocystostomies were compared in 61 recipients of simultaneous pancreas-kidney transplants. Both methods resulted in similar urologic complication and allograft survival rates. Duodenal segment leaks were associated with significant morbidity and decreased patient and allograft survival.     

Reconstitution of a functional interleukin (IL)-7 receptor demonstrates that the IL-2 receptor gamma chain is required for IL-7 signal transduction

The interleukin (IL)-2 receptor gamma chain has recently been shown to be a component of the IL-7 and IL-4 receptors. Using a transient transfection assay and the trans-activation of reporter gene constructs which are under the control of cytokine-responsive promoter elements, we have studied signal transduction through the IL-7 receptor (IL-7R). The reporter gene expression was not stimulated by receptors that contained the cytoplasmic domain of the IL-7R, either as intact IL-7R or as part of a chimeric receptor. However, co-expression of the IL-7R with the IL-2 receptor gamma chain was able to stimulate gene activation. For maximal stimulation the intact cytoplasmic domains of each chain was required.     

Chondrosarcoma of the jaw and facial bones

BACKGROUND: Osteosarcomas of the jaw frequently have chondroblastic differentiation, causing confusion with chondrosarcomas. METHOD: Clinicopathologic features and results of treatment were analyzed for a series of 56 patients (27 males and 29 females from 1.5 to 88 years of age) with chondrosarcoma of jaw and facial bones. Twelve patients (21.4%) were younger than 20 years. RESULTS: The major symptom was nasal obstruction or a painless mass; the median interval from the first symptom until initial treatment was 1 year. Of the 56 chondrosarcomas, 25(44.6%) involved the alveolar portion of the maxilla and maxillary sinus; 23 (41.1%) involved the nasal septum, ethmoid, and sphenoid; 6 (10.7%) involved the mandible; and 2 (3.6%) involved the nasal tip. Of the 19 patients with radiographic studies, 15 (78.9%) had an expanding soft tissue mass with varied matrix calcification and destruction of bone and 2 had a purely lytic lesion. The lesion was difficult to assess in the two others. Most tumors had a lobulated growth pattern of hyaline cartilage. Hypercellularity, nuclear pleomorphism, and binucleation were common features. Forty-three tumors were grade 1, 13 were grade 2, and none were grade 3. Modalities of treatment were known for 51 of the 56 patients. Forty-six patients (90.2%) had surgical treatment, 2 (3.9%) had combination radiation therapy and chemotherapy, 1 (2%) had radiation therapy alone, and 2 (3.9%) had biopsy only. Follow-up adequate for analysis was obtained for 42 patients. Of these, 14 (33.3%) had local recurrence; uncontrolled recurrence developed in 9 (21.4%) patients. No distant metastases were documented. Overall actuarial survival at 5, 10, and 15 years was 80.7%, 65.3%, and 56%, respectively. Survival was analyzed for location, size, and histologic grade of tumor. No statistically significant differences were found. CONCLUSIONS: Chondrosarcomas of the jaw and facial bones are extremely rare, locally aggressive tumors.     

Correlation of fecundability and serum estradiol after danazol treatment in patients with advanced endometriosis

OBJECTIVE: To examine the relationship between pregnancy incidence and the level of serum E2 during danazol therapy. DESIGN: Danazol was given by 200 mg four times daily for 3 months. Serum E2 level was checked after completing the therapy, but before stopping medication. Patients then were advised to conceive at the appropriate time over a 6-month period. SETTING: Reproductive and Endocrine Laboratory of the Department of Obstetrics and Gynecology, Keelung Chang Gung Memorial Hospital, Keelung, Taiwan. PATIENTS: Infertile women with invasive endometriosis receiving conservative surgery and danazol treatment. INTERVENTIONS: Serum E2 is checked before medication and at the end of danazol therapy, but before stopping medication. MAIN OUTCOME MEASURES: Whether pregnancy is related to the change of serum E2 caused by danazol therapy. RESULTS: There were 24 pregnancies in 38 patients with invasive endometriosis after treatment. Pregnant patients had significantly lower serum E2 levels as compared with the nonpregnant patients. CONCLUSIONS: After conservative surgery for invasive endometriosis associated with infertility, the therapeutic period of danazol treatment could be shortened to 3 months. Because there is significant correlation of fecundability and serum E2 after danazol medication, serum E2 could be a guideline for predicting pregnancy or for prolonging or changing of treatment after danazol therapy.     

Molecular characterization of erythrocyte glucose-6-phosphate dehydrogenase deficiency in Al-Ain District, United Arab Emirates

Operational skills involved in controlling a motor vehicle were measured in two groups of very healthy elderly drivers and a young control group to test the hypothesis that there are age-related declines in operational performance that may influence driver safety. An actual behind-the-wheel, standardized road test was employed using a motor vehicle equipped with sensors to record speed, braking activity, and lane position, as well as direction and magnitude of front-wheel and eye-movement excursions. The data from these sensors were used as dependent measures of operational performance. Older drivers made fewer steering and eye-movement excursions and drifted across the center line more frequently than the young control group. Younger drivers drove significantly faster and executed more braking applications than did their older counterparts. The motor-vehicle operational performance of older healthy drivers was related to visual-spatial attentional declines and the useful field of vision associated with the normal aging process.     

Effects of chronic U50,488H treatment on binding and mechanical responses of the rat hearts

The effects of chronic injection of U50,488H (trans-3,4-dichloro-N-[2-(1-pyrrolidinyl)cyclohexyl]benzeacetamidel++ +), a selective kappa opioid agonist, on the properties of the binding sites of tritiated U69593 [(5 alpha,7 alpha,8 beta)-(-)-N-methyl-N-(7-(1-pyrrolidinyl)-1-oxaspiro (4,5)dec-8-yl)benzeneacetamide], another selective kappa opioid agonist, and mechanical responses to U50,488H of the heart were studied. Rats received injection twice a day with U50,488H for 4 days. Binding studies on the crude membrane homogenates revealed that there was no change in maximum binding, but a significant increase in Kd after the treatment, indicating that the number of kappa binding sites remained unchanged whereas the affinity of the binding sites to kappa-agonist decreased. The study on the mechanical responses to U50,488H in the isolated perfused heart preparation showed that although the agonist at 10(-6) M caused MR2266 reversible reductions in heart rate and force of contraction as well as ventricular ectopic beat in the heart of rats in the control group, its effects were absent in the U50,488H-treated group, indicating the development of tolerance to the mechanical effects of U50,488H on the heart. The results indicate that the development of tolerance to the mechanical effects of a kappa-agonist after chronic treatment with the agonist was not accompanied by down-regulation, but only a slight and significant reduction in affinity of kappa binding sites in the rat heart.