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991.
Sarcomatoid carcinoma of the upper respiratory tract is a phenotypically complex neoplasm that has triggered much thoughtful discussion regarding histogenic origin and morphologic classification. In particular, its putative epithelial lineage and distinction from a pseudosarcomatous reaction are sometimes questioned. Little is known about the genetic alterations underlying sarcomatoid carcinoma. Although about 45% of conventional squamous cell carcinomas of the upper respiratory tract harbor p53 mutations, the p53 status of sarcomatoid carcinomas is not well established. p53 immunohistochemical analysis using the monoclonal antibody D07 was performed on 23 sarcomatoid carcinomas of the upper respiratory tract. Twenty tumors were biphasic, having dual epithelial and spindled components. In four of these biphasic tumors, the epithelial and spindled components were separately analyzed for p53 gene mutations by sequence analysis. p53 immunohistochemistry was also performed on 19 cases of postradiation stromal atypia. Strong and diffuse p53 staining was detected in 18 (78%) of the 23 sarcomatoid carcinomas. When the spindled component was compared with its corresponding epithelial component, identical patterns of p53 protein expression were noted in 19 (95%) of the 20 biphasic tumors. Weak p53 staining was observed in one (5%) of the 19 cases of postradiation stromal atypia. In the four biphasic tumors evaluated by DNA sequence analysis, p53 status was always the same in the paired epithelial and spindle cell components. These findings help further dispel the notion that sarcomatoid carcinoma represents a reactive spindle cell proliferation (pseudosarcoma) or a collision between a carcinoma and a sarcoma (collision tumor). Instead, the epithelial and spindled components share a common pathway of tumorigenesis despite their conspicuous divergence at the phenotypic level.  相似文献   
992.
Because bacterial colonization of medical devices may result in clinical infection, it is conceivable that antimicrobial impregnation of tissue expanders may reduce the rate of infection. The objective of this in vitro study was to examine the spectrum, durability, and shelf-life antimicrobial activity of minocycline/rifampin-impregnated silicone tissue expander shells. The impregnated devices exhibited zones of inhibition at baseline against Staphylococcus epidermidis, Staphylococcus aureus, and Escherichia coli. The impregnated devices exhibited strong residual activity against S. epidermidis and S. aureus after suspension in serum at 37 degrees C for 4 weeks. There was no significant decrease in the size of zones of inhibition after storing the impregnated devices at room temperature for 1 year. These results indicate that minocycline/rifampin-impregnated tissue expander shells provide broad-spectrum and durable antimicrobial activity and that the shelf-life antimicrobial activity exceeds 1 year. These findings prompt future exploration of the anti-infective efficacy of these antimicrobial-impregnated devices.  相似文献   
993.
OBJECTIVE: To assess the effect of chronic hypoxia on brain neuronal apoptosis, an animal model mimicking cyanotic heart disease was utilized. METHODS: Rats were placed in an hypoxic environment at birth and oxygen levels were maintained at 10% in an air-tight Plexiglass chamber. Controls remained in room air. Animals were sacrificed and the brains were harvested at 1 and 4 weeks, respectively. RESULTS: Significant polycythemia developed in the hypoxic rats at 1 and 4 weeks. Indexed brain mass to body weight was significantly increased in the hypoxic groups by 18% (p < 0.01) and 38% (p < 0.01) as compared to controls at 1 and 4 weeks, respectively. There was no difference in the number of apoptotic neurons between the chronically hypoxic rats and controls, as assayed by TUNEL labelling and Hoechst staining. The role of the sphingolipid ceramide was then examined because of its reported role in stress response, growth suppression and apoptosis. It was found that the brain ceramide accumulation was not significantly different in the hypoxic and control groups at 1 and 4 weeks. CONCLUSION: A protective adaptive response to chronic hypoxia in the neonatal brain may exist.  相似文献   
994.
995.
A nosocomial outbreak of Crimean-Congo hemorrhagic fever occurred in Rawalpindi, Pakistan in February 2002. The identified index case died shortly after admission to a hospital. Two of the health care workers became secondary cases; one of them died on day 13 after coming in contact with the index case. The other secondary case was successfully treated with oral ribavirin.  相似文献   
996.
The role of ionotropic glutamate receptors and voltage-dependent calcium channels (VDCCs) in potentiation phenomenon and epileptic activity induced by a transient pentylenetetrazol (PTZ) application in the CA1 region of rat hippocampal slices was investigated. Also we examined whether adenosine as an inhibitory neuromodulator would interact with expression of the long-lasting effect of transient PTZ. Population spikes (PS) were recorded in the CA1 cell body layer of the hippocampal slices following stratum radiatum stimulation. Changes in the PS amplitude potentiation and number of extra PS, which induced by transient PTZ were used as indices to quantify the effects of drugs. PS input-output curve was significantly increased 10 min after PTZ application and persisted at least for 60 min after PTZ washout. Polyspikes also appeared, but did not persist. Both ketamine and APV reduced the extent of potentiation of PS amplitude but had no effect on number of extra PS. The selective non-NMDA receptor antagonist CNQX prevented the amplitude potentiation and the generation of extra PS. The blocker of VDCCs, verapamil, prevented the amplitude potentiation and inhibited polyspike activity. Co-application of adenosine and PTZ produced a rapid and reversible decrease in the PS amplitude, but PTZ-induced potentiation phenomenon was observed after washout. It is concluded that ionotropic glutamate receptors as well as VDCCs involve in the PTZ-induced LTP of PS amplitude. PTZ-induced LTP is also insensitive to adenosine. The epileptiform activity induced by a transient PTZ application could be attributed to VDCCs. The polyspikes mediated by VDCCs are dependent on prior activation of AMPA receptors.  相似文献   
997.
Physical and hormonal profile of male sexual development in epilepsy   总被引:3,自引:2,他引:1  
PURPOSE: This study was designed to investigate the effect of epilepsy and antiepileptic drugs (AEDs) on both the physical and hormonal aspects of the sexual development of male patients with epilepsy. METHODS: One hundred thirty male subjects with epilepsy, their age ranging between 8 and 18 years (mean, 14 +/- 2.9 years), entered the study; all were taking AEDs. Anthropometric measurements [height, weight, and body mass index (BMI)], testicular volume, penile length, and pubarche were assessed in the studied groups, as well as measurement of the levels of testosterone (T), free testosterone (FT), estradiol (E2), lutenizing hormone (LH), follicle-stimulating hormone (FSH), and prolactin (PRL), and the results were compared with those of a control group. RESULTS: In this study, male patients older than 16 years were significantly shorter than their matched controls. The mean values of testicular volume and penile length were significantly lower in the patients in the different age subgroups, and the pubic hair staging (pubarche) was delayed in the patients older than 16 years. The mean values of total testosterone, estradiol, LH, and FSH serum levels were significantly higher, whereas the mean values of free testosterone, total-T/E2, total. T/LH, and FT/E2 ratios were lower in the patient subgroups compared with their age-matched controls. There were no significant changes in the mean basal PRL serum levels in the patients compared with the controls. The present study demonstrated a reduction in the testicular volume and penile length, significantly lower mean values of free testosterone and total-T/E2, and a higher mean value of E2 in the patients receiving polytherapy in the age subgroup older than 16 years compared with those on monotherapy; however, there was no demonstrable effect of seizure control or the duration of illness in any of the studied parameters. CONCLUSIONS: There is a delay in the sexual development of male patients with epilepsy in the different age subgroups, with endocrine changes in the form of increase in the total testosterone, but the free testosterone is lower, and an increase in estradiol, with lower T/LH levels. Patients receiving polytherapy, especially those older than 16 years, were more likely to have delayed gonadarch and disturbances in their hormonal profile.  相似文献   
998.
The aim of this study was to evaluate the effects of school-based fluoride rinsing and tablet programs on plaque fluoride levels. A total of 42 children (8-9 years) were selected from two neighboring schools in Dhaka, Bangladesh. After caries recordings, vestibular plaque samples from the maxillary central incisors and mandibular first molars were collected and frozen on day 0 (baseline). The subjects of one school (rinsing group, n = 15) rinsed with 0.05% NaF, while those from the other school (tablet group, n = 16) used a 0.5 mg F tablet on the 5 school days during a 3-week period. The surfaces were sampled on the first and last school day every week. The fluoride and protein contents of each sample were analyzed using micro-techniques. The median plaque fluoride levels were 9.1 ppm at baseline in the rinsing group and 2.5 ppm in the tablet group (P < 0.05). This difference could in part be related to reported fluoride toothpaste usage. After 4 days on the fluoride programs, plaque fluoride levels in the rinsing group increased to 27.3, 24.5 and 14.2 ppm in the 3 consecutive weeks. The corresponding values after tablet usage were 8.0, 6.5 and 7.1 ppm, respectively. After 3 days without fluoride during the weekends, levels declined towards baseline values in both groups. Hence, the plaque fluoride levels in 8 to 9-year-old Bangladeshi children were increased by both rinsing and tablet programs, but the effect was not detectable 3 days later.  相似文献   
999.
Disparities in surgical resection of early-stage non-small cell lung cancer   总被引:1,自引:0,他引:1  
OBJECTIVES: The aim of our study was to identify the factors that determined whether a patient underwent surgery and its impact on patient outcome. METHODS: A retrospective evaluation of the records of all patients diagnosed with resectable stages I and II non-small cell lung cancer between 1990 and 1998 at the University of Arkansas and Veterans Administration Hospitals were included in the study. Demographic, clinical, pathologic, and outcome data were captured. Analysis was conducted to identify prognostic factors as well as factors leading to surgical treatment disparities. RESULTS: A total of 551 patients were included; 490 (89%) were men, 480 (87%) were white, and 315 (57%) were aged >65 years. Median follow-up of these patients was 24 months (1-109 months). Surgery was performed on 455 patients (82.6%); 26 patients received nonsurgical treatment including chemotherapy, radiation therapy, or both, and 70 patients did not receive any type of treatment. A univariate analysis revealed that age, race, sex, and forced expiratory volume in the first second were significantly different between the surgery and no surgery groups. However, a multivariate analysis showed that age, forced expiratory volume in 1 second, and hemoglobin were significantly different between both groups. The median overall survival was 45.5 months (1-109 months) for the surgically treated patients compared with 12.0 months (1-86 months) for those who did not undergo surgery (P <.0001). CONCLUSION: Elderly patients with early-stage non-small cell lung cancer are less likely to undergo a potentially curative surgical resection. Racial and sex disparities may be due to other comorbidities.  相似文献   
1000.
OBJECTIVE: To evaluate the recovery rate of sperm from the testis using percutaneous testicular aspiration with a 22-gauge hypodermic needle followed by evaluation of the fertilization rate and pregnancy rate after intracytoplasmic sperm injection. MATERIALS AND METHODS: This is a prospective observational study performed in a private in vitro fertilization setting in Kuwait. Fifteen patients with obstructive and non-obstructive azoospermia were included in the study. Thirteen of them had previous microepididymal sperm aspiration, percutaneous epididymal sperm aspiration or testicular sperm extraction. The sperm were retrieved using percutaneous testicular aspiration under local analgesia. This was followed by intracytoplasmic sperm injection. A total of 146 eggs were collected and 112 were injected. RESULTS: Normal fertilization occurred in 91 oocytes (87.5%) and the total number of embryos cleaved was 83 (91%). Embryo transfer was performed in 13 with pregnancy rate of 33.3 per treatment cycle and 38.5 per embryo transfer. Failure to retrieve sperm was encountered in 2 cases both in the hypospermatogenesis group. CONCLUSIONS: Percutaneous testicular sperm aspiration using hypodermic needles under local analgesic is an easy and cheap method with high patient acceptability, minimal complications and no need of special training. In this small group, it seems to have an acceptable success rate in terms of sperm retrieval and pregnancy in the obstructive type as well as hypospermatogenesis, but to lesser extent.  相似文献   
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