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61.
I Scheunert D Vockel J Schmitzer R Viswanathan W Klein F Korte 《Ecotoxicology and environmental safety》1983,7(4):390-399
Three laboratory short-term test systems were used to determine volatilization rates, mineralization rates, and conversion rates of 14 14C-labeled chemicals in soils or soil-plant systems. The chemicals covered a wide range of water solubility, vapor pressure, chemical stability, and biodegradability. In order to compare the data obtained with the environmental behavior of the respective chemicals, data from an outdoor experimental setup which had been shown to give residue data within the range limits of field conditions were used. Volatilization rates, mineralization rates, and conversion rates obtained in the laboratory were correlated to those found under outdoor conditions. Based on these correlations, predictions of field residues were made. The predicted values for total field residues were comparable to those found experimentally with the exception of two chemicals. The prediction of residues of unchanged parent compounds in the field was less satisfactory. The reasons for differences observed are discussed. 相似文献
62.
Kumar TS Scott JX Viswanathan S Agarwal I Raj PM Lalitha MK 《Acta paediatrica (Oslo, Norway : 1992)》2005,94(9):1342-1343
Nocardiosis occurs primarily as an opportunistic infection in an immunocompromised host. The infection may on rare occasion occur in a normal host confounding the diagnosis. It is also notably an uncommon infection in children. We report a 1-y-old girl with cervicofacial nocardial infection who presented with acute suppurative otitis media and lymphadenitis. This child did not have any predisposing risk factors for this infection and responded well to treatment with co-trimoxazole and chloramphenicol. She is doing well on follow-up. CONCLUSION: Nocardiosis in an immunocompetent small child is reported. 相似文献
63.
Small cell neuroendocrine carcinoma of the cervix: outcome and patterns of recurrence 总被引:18,自引:0,他引:18
Viswanathan AN Deavers MT Jhingran A Ramirez PT Levenback C Eifel PJ 《Gynecologic oncology》2004,93(1):27-33
OBJECTIVES: To analyze the sites of relapse and overall survival in women with neuroendocrine marker-positive small cell carcinoma of the cervix. METHODS: The records of all women who had their initial treatment for cervical cancer at The University of Texas M.D. Anderson Cancer Center between 1980 and 2000 were reviewed. Fifty-one patients had stages I-III cancers that were originally described as "small cell" or "neuroendocrine." Histological material was available for reexamination in 45 cases; of these, 21 were found to have small cell neuroendocrine carcinoma (SCNEC) as indicated by positive staining for chromogranin, synaptophysin, or CD56. Local treatment consisted of a radical hysterectomy in six patients and radiation therapy in 15. Thirteen patients received chemotherapy as part of their initial treatment. The median follow-up for surviving patients was 83 months (range, 25-209 months). RESULTS: Fourteen (66%) of the 21 patients had a relapse. The median time to first relapse from the initiation of treatment was 8.4 months (range, 3.6-28 months). Most patients developed hematogenous distant metastases before their death. Only 2 of 15 patients who were treated with radiation therapy had a recurrence within the radiation fields. However, five patients had a recurrence above the radiation fields in the paraaortic lymph nodes, and two patients had a recurrence distal to the pelvic fields in the vagina. No patient had brain metastases as the sole site of first recurrence. However, two patients developed brain metastases concurrently with lung metastases. The overall survival rate was 29% at 5 years; none of the patients who had disease more extensive than stage IB1 or clinical evidence of lymph node metastases survived their disease. CONCLUSIONS: Patients with small cell neuroendocrine cervical cancer have a poor prognosis. Their course is frequently characterized by the development of widespread hematogenous metastases; locoregional recurrence outside irradiated fields is also frequent. Brain metastases were seen only in patients who also had lung metastases, suggesting that prophylactic cranial irradiation would be of little benefit. 相似文献
64.
Alcohol remains second only to cigarette smoking as a risk factor for head and neck cancer worldwide. The increase in incidence in head and neck cancer in a number of countries appears linked at least in part to contemporaneous rises in alcohol consumption. The relative increase in risk in women may also relate to increasing alcohol consumption. Women may be particularly sensitive to alcohol-induced tumours in the oral/oropharyngeal sites. The risk is dose related, but with a non-linear increase for heavy drinkers (>100 g i.e. 12 units/day). The type of alcoholic beverage consumed seems less important. Potential mechanisms include local toxic cellular proliferation; carcinogenic action of metabolites e.g. acetaldehyde or impurities; induction of enzymes which activate procarcinogens; reduction of the protective retinoic acid; genetic polymorphism may play a part in certain geographic locations. Alcohol is also linked to stage at presentation, risk of second primary and the occurrence of comorbidity. Public awareness of the risks of alcohol remains disappointingly low. Those in identifiable high-risk groups should perhaps be targeted specifically for counselling. 相似文献
65.
PURPOSE: To determine the prevalence of raised intraocular pressure (IOP) in patients with uveitis and to identify risk factors for raised IOP in patients with uveitis. PATIENTS AND METHODS: Consecutive case notes of 257 patients (402 eyes) attending a specialist uveitis clinic during a three-month period were reviewed. Patients with raised IOP were identified and further evaluated. Risk factors for raised IOP were determined. RESULTS: The prevalence of raised IOP in the study eyes was 41.8%. The prevalence of raised IOP requiring treatment was 29.8%. Raised IOP was found in 26.0% of eyes with acute uveitis and 46.1% of eyes with chronic uveitis. This difference was significant (P = 0.002). Similarly the prevalence of raised IOP requiring treatment in acute and chronic uveitis was 15.1% and 33.8%, respectively. This difference was also significant (P = 0.002). Active inflammation was significantly associated with raised IOP (P = 0.031). Steroid usage, increasing age, and number of years since diagnosis were significantly correlated with raised IOP (P = 0.008, P = 0.022, and P = 0.006, respectively); 9.6% of the study eyes developed glaucoma. The majority of these eyes (69.7%) were treated medically. The remainder (30.3%) required both medical and surgical management. CONCLUSION: Raised IOP is significantly more common in patients with chronic intraocular inflammation than those with acute uveitis. Risk factors for elevated IOP that should enable closer monitoring of 'at-risk' eyes have been identified. 相似文献
66.
Parkinson's disease (PD) results in various types of motor impairments including bradykinesia, tremor and rigidity. Recent research has implicated more fundamental processes at the source of the observed motor deficits. Among these, problems in the sequencing and/or timing of complex movements and in the execution of internally-guided tasks. Furthermore, PD patients exhibit procedural learning deficits which may complicate the interpretation of experimental results of studies involving novel sensorimotor tasks. The reach-to-grasp movement is a complex, overlearned sensorimotor task consisting of two semi-independent components, a relatively simple reach or transport phase and a more complex manipulation or prehension phase. In the present study, we used a novel technique in order to study the evolution of hand preshaping during the reach-to-grasp movement of PD patients and age-matched controls to objects of different shapes in three different spatial locations. Our results indicate that while PD patients are able to specify movement direction as well as controls, their hand preshaping exhibits substantial impairments. Other prehension measures, such as the time to peak aperture (TPA), indicate that PD patients delayed execution of the grasp until visual feedback of their hand was available. Overall, our results suggest that PD patients' internal guidance processes are severely disrupted, having to rely on visual feedback in order to modulate their hand shape to fit the contours of the target objects during a reach-to-grasp movement. 相似文献
67.
68.
A dynamic array of interactions occurs between pathogens and host mucosal surfaces. The signature molecules unique to microbial pathogens allow the mammalian immune system to recognize them as non-self. This recognition, mediated by the toll-like receptor proteins, results in innate immune responses targeted against the invading organism. Pathogens also elaborate a variety of proteins that actively engage host signaling pathways and subvert them to facilitate their growth and dispersal. These interactions, developed over a long evolutionary period, have been specialized to exquisite detail. These proteins and toxins are either secreted into the medium or directly delivered into host cells by specialized secretion systems. An array of host function alterations is mediated by microbial pathogens including inflammatory responses, secretory responses, alteration of host cytoskeleton, disruption of epithelial tight junctions and apoptosis. The signaling axes involved in these interactions are potential targets for therapeutic strategies against infectious microbes. 相似文献
69.
70.
Magnesium sulfate inhibits the oxytocin-induced production of inositol 1,4,5-trisphosphate in cultured human myometrial cells 总被引:1,自引:0,他引:1
Hurd WW Natarajan V Fischer JR Singh DM Gibbs SG Fomin VP 《American journal of obstetrics and gynecology》2002,187(2):419-424
OBJECTIVE: The purpose of this study was to determine the effects of magnesium sulfate on inositol trisphosphate production and the mechanism of these effects. STUDY DESIGN: Myometrium was obtained at the time of cesarean delivery from women before labor at term. Inositol trisphosphate was measured in the primary myometrial cell cultures after stimulation with oxytocin, sodium fluoride, or Bay K 8644 with or without preincubation with magnesium sulfate or nifedipine. Experiments were performed in either calcium-containing or calcium-free medium that contained egtazic acid and after preincubation with the intracellular calcium chelator BAPTA-acetoxymethylester. Inositol trisphosphate production was measured by radioreceptor assay. In separate experiments, changes in intracellular calcium concentrations ([Ca(2+)](i)) were measured with the use of Fura-2 and spectrophotofluorometry. RESULTS: Oxytocin, sodium fluoride, and Bay K 8644 increased inositol trisphosphate production 2- to 4-fold. Preincubation with magnesium sulfate (3 x 10(-3) mol/L) for > or = 5 minutes decreased oxytocin-, sodium fluoride-, and Bay K 8644-induced inositol trisphosphate production in either calcium-containing or calcium-free media. Preincubation with BAPTA-acetoxymethylester decreased oxytocin-stimulated inositol trisphosphate production by 78% in calcium-containing media and completely prevented the oxytocin response in calcium-free media. Magnesium sulfate decreased inositol trisphosphate production in calcium-containing media but had no additional effect in calcium-free media. Oxytocin and Bay K 8644 increased [Ca(2+)](i) in either calcium-containing or calcium-free media, and magnesium sulfate reduced this in both cases. CONCLUSION: Magnesium sulfate appears to inhibit phosphatidylinositol-4, 5-bisphosphate-specific phospholipase C activity and subsequent calcium release in cultured myometrial cells by a direct effect on phospholipase C. 相似文献