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1.
The mechanism by which mechanical strain and estrogen stimulate bone cell proliferation was investigated using monolayer cultures of human osteoblastic TE85 cells and female human primary (first-passage) osteoblasts (fHOBs). Both cell types showed small but statistically significant dose-dependent increases in [3H]thymidine incorporation in response to 17beta-estradiol and to a single 10-minute period of uniaxial cyclic strain (1 Hz). In both cell types, the peak response to 17beta-estradiol occurred at 10(-8) - 10(-7) M and the peak response to strain occurred at 3500 microstrain ((mu)epsilon). Both strain-related and 17beta-estradiol-related increases in [3H]thymidine incorporation were abolished by the estrogen receptor (ER) modulator ICI 182,780 (10-8 M). Tamoxifen (10(-9) - 10(-8) M) increased [3H]thymidine incorporation in both cell types but had no effect on their response to strain. In TE85 cells, tamoxifen reduced the increase in [3H]thymidine incorporation associated with 17beta-estradiol to that of tamoxifen alone but had no such effect in fHOBs. In TE85 cells, strain increased medium concentrations of insulin-like growth factor (IGF) II but not IGF-I, whereas 17beta-estradiol increased medium concentrations of IGF-I but not IGF-II. Neutralizing monoclonal antibody (MNAb) to IGF-I (3 microg/ml) blocked the effects of 17beta-estradiol and exogenous truncated IGF-I (tIGF-I; 50 ng/ml) but not those of strain or tIGF-II (50 ng/ml). Neutralizing antibody to IGF-II (3 microg/ml) blocked the effects of strain and tIGF-II but not those of 17beta-estradiol or tIGF-I. MAb aIR-3 (100 ng/ml) to the IGF-I receptor blocked the effects on [3H]thymidine incorporation of strain, tIGF-II, 17beta-estradiol, and tIGF-I. HOBs and TE85 cells, act similarly to rat primary osteoblasts and ROS 17/2.8 cells in their dose-related proliferative responses to strain and 17beta-estradiol, both of which can be blocked by the ER modulator ICI 182,780. In TE85 cells (as in rat primaries and ROS 17/2.8 cells), the response to 17beta-estradiol is mediated by IGF-I, and the response to strain is mediated by IGF-II. Human cells differ from rat cells in that tamoxifen does not block their response to strain and reduces the response to 17beta-estradiol in TE85s but not primaries. In both human cell types (unlike rat cells) the effects of strain and IGF-II as well as estradiol and IGF-I can be blocked at the IGF-I receptor.  相似文献   
2.
Laparoscopic procedures continue to gain popularity over traditional open procedures for a number of abdominal and pelvic surgeries. With increasing experience, the application of this technique is rising because it provides an alternative, less invasive, approach to various surgical procedures. Herein, we report our experience with adult patients with polycystic kidney disease, requiring bilateral laparoscopic nephrectomy before renal transplantation.  相似文献   
3.
Summary It has been suggested that age changes in the morphology of the neuromuscular junction (NMJ) may reflect altered physical activity levels rather than the unique effects of ageing. Additionally, previous studies have indicated that the structure of the NMJ may be modulated with exercise. To investigate these questions, quantitative morphometry was determined on soleus and extensor digitorum longus (EDL) nerve terminals stained with zinc iodide-osmium from C57BL/6NNia mice under control and endurance exercised conditions at 12, 18 and 24 months of age.As previously observed, the area, perimeter, extent length and branch number of nerve terminals increased with age in both soleus and EDL. The changes were similar between the muscle types, although the changes were more pronounced in the phasic EDL. In 12-month-old animals, 2 months of endurance exercise resulted in significantly larger nerve terminals in both soleus and EDL, suggesting a functional adaptation. Exercised 18- and 24-month-old nerve terminals were smaller than corresponding controls, which indicated that exercise minimized or prevented further age-related nerve terminal elaboration. At all ages the exercised nerve terminals comprised a more homogeneous population than corresponding controls, which indicates that uniform physical activity can modulate NMJ morphometry. The magnitude of the changes suggests that subtle alterations in normal cage activity with advancing age do not have a significant effect on the morphology of nerve terminals. However, the morphology of the NMJ does change significantly in response to physical exercise training.  相似文献   
4.
Cerebral metabolism and neuronal function of prefrontal brain cortex were studied in 6 dog litters from birth to 3 months of age. Noninvasive phosphorus magnetic resonance spectroscopy (31P-MRS) was used to observe longitudinal biochemical changes in the phosphorus compounds associated with cerebral metabolism. Neurological tests, examining reflex, motor and sensory nerve function, were performed in conjunction with the 31P-MRS study. During the neonatal period, exponential increases in PCr, Pi, and phophodiesters preceded neurological changes. Phosphomonoesters showed an exponential, nearly linear, decrease and PCr/Pi was maintained during the 3-month period. Developmental increases in high energy phosphates and the maintenance of PCr/Pi indicate that the increased energy demands of the developing animal are met by increased mitochondrial function (ATP turnover).  相似文献   
5.
Cystic echinococcosis in Central Saudi Arabia: A 5-year experience.   总被引:1,自引:0,他引:1  
Background/aims: In this series of patients we aim to describe aspects of presentation, diagnosis and management of patients suffering from Echinococcosis in an endemic region. Methods: This is an observational study done at Riyadh Medical Complex, Saudi Arabia from 1999 to 2004. All adult patients admitted with the primary or incidental diagnosis of echinococcosis were included. These patients were followed up for 6 months. Data relating to patients' demographic characteristics, mode and duration of presentation, investigations, complications and treatment offered was collected. This data was then analyzed using SPSS 11.0. Result: 117 patients with a mean age of 40.9+/-20.7 years were admitted, male to female ratio being 1.7:1. 114 (97.4%) originated from Middle East which is an endemic area. Pain right upper quadrant (RUQ), followed by cough were the commonest symptoms. Nine patients presented with jaundice +/- choleangitis: 3 patients had intrabiliary rupture of the hydatid cyst, while 6 had extrinsic compression. Six patients had infected cyst. Fourteen patients had intrabronchial rupture diagnosed on bronchoscopy. Twenty five (21.4%) patients presented with recurrent disease. The Haemagglutination Inhibition test gave a sensitivity of 78.6. All cysts were visualized using USG, CXR and CT scan. Endocystectomy was the most frequent procedure. Post op 8 patients had biliary leakage and 3 had bronchopleural fistula a majority of whom settled conservatively while two required ERCP and one patient with bronchopleural fistula required surgery. Fifteen patients had infection related complications. During our follow up period no recurrences were recorded. All patients undergoing surgery also received medical treatment. Twenty five patients (21.4%) were unable to undergo operative treatment due to multiple reasons. They were medically treated. Conclusion: Cystic Echinococcosis is a disease of the middle aged. Ultrasonogram combined with a serological assay is the best diagnostic tool available for abdominal echinococcosis allowing diagnosis and staging, while chest X ray is the best screen for the pulmonary disease. The recommended treatment is endocystectomy with antihelmenthic therapy. But the problem of early detection of echinococcosis in endemic areas needs attention by workers as this approach can potentially prevent the devastating complications due to this disease.  相似文献   
6.
The aim of this study was to describe the effects of aluminum on the stromal cells of rat bone marrow using a combination of in vivo exposure and in vitro culture of bone marrow. The toxic effects of aluminum are manifested by a decrease in the erythrocyte count and hemoglobin level in the peripheral blood. Aluminum stimulated an increase in the number of fibroblasts while the macrophage count dropped. The number of adipocytes remained unaffected. An increase in mean corpuscular hemoglobin (MCH) was also found in the peripheral blood of experimental animals.  相似文献   
7.
8.
The aim of the present study is to use neuroscience theories about brain function (mirror-neurons MN) to draw inferences about the mechanisms supporting emotional resonance in two different groups of schizophrenia patients (with flat affect FA+ n = 13 and without flat affect FA- n = 11). We hypothesize that FA+ will not activate key brain areas involved in emotional processing. Conversely, FA- will have a functional mirror system for emotional resonance confirmed by activation of the prefrontal cortex and behavioral results. To test this hypothesis, we compared the two groups using blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) displaying a passive visual task (44 negative IAPS pictures and 44 neutral pictures). A random-effects analysis, for schizophrenia patients FA-, revealed significant loci of activation in the left mesial prefrontal (MPFC), right orbitofrontal (OFC) and left anterior cingulate cortices (ACC). Correlational analyses carried out between self-report ratings of negative feelings and BOLD signal changes revealed the existence of positive correlation in the LACC, LMPFC and ROFC. Conversely, FA+ did not show significant activation in the prefrontal cortex. We propose that negative emotional resonance induced by passively viewing negative pictures may be a form of "mirroring" that grounds negative feelings via an experiential mechanism. Hence, it could be argued that FA- were able to 'feel' emotions through this resonance behavior. Conversely, we suggest that the dysfunction seen in the FA+ group is a failure or distortion in the development of the MN system. This could be due to genetic or other endogenous causes, which affected prefrontal cortex MN involved in emotional resonance.  相似文献   
9.
A newborn infant was referred because of low-set ears, mild downward slant of the palpebral fissues, micrognathia with higharched palate, a flat midface, small mouth, and thin upper lip with cupid bow configuration. To some extent her cry resembled that associated with cri du chat syndrome. Cytogenetic findings with G- and Q-banding alone failed to characterize precisely the complex translocations. By the chromosome in situ suppression (CISS) hybridization technique using whole chromosome specific probes, a complex 4 breakpoint rearrangement involving both arms of a single chromosome 1 with the long arms of chromosome 5 and 11 was disclosed, i.e., 46,XX, der(1),t(1;5) t(1;11) (5qter→5q31::1p31.3→1q44::11q23→11qter;5pter→5q31::1p31.3→1pter;11pter→11q23::1q44→1qter). Gene deregulation and position effect may explain the multiple anomalies in individuals with apparently balanced translocations may shed some light towards unveiling the clinical consequences associated with aberrations which are presumably balanced. © 1993 Wiley-Liss, Inc.  相似文献   
10.
Lung cancer and exposure to tobacco smoke in the household   总被引:10,自引:0,他引:10  
BACKGROUND. The relation between passive smoking and lung cancer is of great public health importance. Some previous studies have suggested that exposure to environmental tobacco smoke in the household can cause lung cancer, but others have found no effect. Smoking by the spouse has been the most commonly used measure of this exposure. METHODS. In order to determine whether lung cancer is associated with exposure to tobacco smoke within the household, we conducted a population-based case--control study of 191 patients with histologically confirmed primary lung cancer who had never smoked and an equal number of persons without lung cancer who had never smoked. Lifetime residential histories including information on exposure to environmental tobacco smoke were compiled and analyzed. Exposure was measured in terms of "smoker-years," determined by multiplying the number of years in each residence by the number of smokers in the household. RESULTS. Household exposure to 25 or more smoker-years during childhood and adolescence doubled the risk of lung cancer (odds ratio, 2.07; 95 percent confidence interval, 1.16 to 3.68). Approximately 15 percent of the control subjects who had never smoked reported this level of exposure. Household exposure of less than 25 smoker-years during childhood and adolescence did not increase the risk of lung cancer. Exposure to a spouse's smoking, which constituted less than one third of total household exposure on average, was not associated with an increase in risk. CONCLUSIONS. The possibility of recall bias and other methodologic problems may influence the results of case-control studies of environmental tobacco smoke. Nonetheless, our findings regarding exposure during early life suggest that approximately 17 percent of lung cancers among nonsmokers can be attributed to high levels of exposure to cigarette smoke during childhood and adolescence.  相似文献   
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