首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
Healthy male and female human volunteers were exposed to 50 ppm or 100 ppm trichloroethylene (Tri) by inhalation for 4 h. Blood and urine samples were taken at various times before, during, and after the exposure period for analysis of glutathione (GSH), related thiols and disulfides, and GSH-derived metabolites of Tri. The GSH conjugate of Tri, S-(1,2-dichlorovinyl)glutathione (DCVG), was found in the blood of all subjects from 30 min after the start of the 4-h exposure to Tri to 1 to 8 h after the end of the exposure period, depending on the dose of Tri and the sex of the subject. Male subjects exposed to 100 ppm Tri exhibited a maximal content of DCVG in the blood at 2 h after the start of the exposure of 46.1 +/- 14.2 nmol/ml (n = 8), whereas female subjects exposed to 100 ppm Tri exhibited a maximal content of DCVG in the blood at 4 h after the start of the exposure of only 13.4 /- 6.6 nmol/ml (n = 8). Pharmacokinetic analysis of blood DCVG concentrations showed that the area under the curve value was 3.4-fold greater in males than in females, while the t1/2 values for systemic clearance of DCVG were similar in the two sexes. Analysis of the distribution of individual values indicated a possible sorting, irrespective of gender, into a high- and a low-activity population, which suggests the possibility of a polymorphism. The mercapturates N-acetyl-1,2-DCVC and N-acetyl-2,2-DCVC were only observed in the urine of 1 male subject exposed to 100 ppm Tri. Higher contents of glutamate were generally found in the blood of females, but no marked differences between sexes were observed in contents of cyst(e)ine or GSH or in GSH redox status in the blood. Urinary GSH output exhibited a diurnal variation with no apparent sex- or Tri exposure-dependent differences. These results provide direct, in vivo evidence of GSH conjugation of Tri in humans exposed to Tri and demonstrate markedly higher amounts of DCVG formation in males, suggesting that their potential risk to Tri-induced renal toxicity may be greater than that of females.  相似文献   

2.
Accumulated evidence shows that biology and the environment can mediate self-injurious behavior (SIB) in persons with mental retardation. Whether pharmacological treatment alters the environmental mediation of self-injury is unclear. Opioid antagonist effects on sequential dependencies for self-injury were studied in the context of experimental single-subject double-blind placebo-controlled designs. Direct observational data were collected for 4 adult subjects in real time on daily rate of SIB and staff interactions. Clinically significant reductions (i.e., ≥ 33%) in SIB rate were observed for 3 of the 4 subjects. For all subjects, the magnitude of the sequential dependency between staff behavior and self-injury was significantly greater during treatment with naltrexone than during treatment with a placebo. Results are discussed in relation to behavioral mechanisms of action regulating medication effects for self-injury. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

3.
OBJECTIVES: To evaluate midterm results of mechanical valves in pulmonary position in patients with pulmonary regurgitation and right ventricular dysfunction as an alternative to bioprostheses. PATIENTS: Mechanical valves (six tilting disc valves and two bileaflet valves) were implanted in eight patients previously operated on for tetralogy of Fallot (n = 7) and truncus arteriosus (n = 1), with severe right ventricular dysfunction caused by massive pulmonary regurgitation. RESULTS: All patients survived prosthesis implantation and are currently well. At follow-up (3 months to 9 years), they do not show signs of valve failure, and right ventricular function has dramatically improved in all but one, who still shows moderate ventricular hypokinesia. CONCLUSION: After operative correction of congenital heart defects in selected patients who show severe dysfunction of the right ventricle caused by pulmonary regurgitation/stenosis, mechanical valves may represent an alternative to bioprosthetic valves. The selection of the valve type is still a matter of debate. However, according to literature data, complications seem to have occurred only in patients with bileaflet mechanical valves in the pulmonary position, whereas no thromboembolic episodes or valve failure is reported in subjects with tilting disc valves in the right ventricular outflow. Tilting disc valves might perform better in the right ventricular outflow than bileaflet valves.  相似文献   

4.
S. Enteritidis HY-1 isolated during quarantine from chicks imported from England was used. Laying hens at the age of 34 weeks were inoculated orally with 10(10) organisms (10 birds), intramuscularly with 10(9) (5 birds), and intravenously with 10(9) (5 birds). Egg production did not change in hens infected orally, although it was reduced in hens infected intramuscularly for 2-3 weeks post inoculation. For one month, internally infected eggs of which the shells were not contaminated were found: one out of 65 eggs in hens infected orally and three out of 36 eggs in hens infected intramuscularly. This experiment demonstrated the ability of S. Enteritidis isolated from chicks imported from England to cause transovarian infection.  相似文献   

5.
Metastatic tumor is one of several etiologies of space-occupying masses in the orbit that accounts for 1%-13% of all orbital masses (1). In the adult patient population, breast cancer is the most common tumor to metastasize to the orbit followed by metastases from the lung, prostate and gastrointestinal tract (2). It is rare for carcinoid tumors to metastasize to the eye or to the orbit. Carcinoid tumors arise from Kulchitsky cells that originate in the neural crest. Histologically, these tumors resemble, but are not as aggressive as, adenocarcinomas. Most carcinoids arise in the gastrointestinal tract or the lung. The most common site for carcinoid metastases is the liver. On anatomical imaging studies, such as CT and magnetic resonance imaging, metastatic orbital carcinoid tumors appear as nonspecific tumor masses. Carcinoid tumors have an affinity for uptake of the radiopharmaceutical 131I-metaiodobenzylguanidine (MIBG) (3). We report a case of a patient with a known carcinoid tumor who developed a left orbital mass that demonstrated abnormal uptake of 131I-MIBG indicative of metastatic carcinoid tumor to the orbit.  相似文献   

6.
This patient safety improvement study was conducted (1) to establish a database of intentional patient self-injuries and suicidal behavior among veterans in a large urban VA health care system, and (2) to investigate whether there were demographic and/or clinical characteristics of veterans who self-injure that might predict seriousness of suicidal intent and aid in future efforts at prevention. A total of 175 clinician-administered, post self-injury interviews were completed between 2006 and 2008 in a VA health care system in the Northeast. Findings suggest that self-injuries with high suicidal intent were characterized by male gender, older age, planning of self-injury, no wish to be saved, and a negative feeling about having survived. Additional results indicated that staff ratings of patient intent to die were significantly lower than patient self-rated intent to die, a finding that gives rise to questions of whether staff may tend to underestimate patient suicidal intent. Also, although more than 80% of the veterans in this sample considered their self-injurious actions impulsive, planning of self-injury was significantly associated with higher intent to die. Veterans who completed suicide during the study time period were significantly more likely than those who had nonfatal self-injuries to have experienced combat. The implications of these findings are discussed, including whether combat exposure may lead to an acquired capacity for lethal behaviors such as suicide (Joiner, 2005). (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   

7.
Describes the long-term treatment program and follow-up of a case of chronic, severe, multiple self-injurious behavior. The intensity, frequency, and multiplicity of self-injurious behavior in a boy 1st seen at age 61/2 yrs is unparalleled in the literature. Treatment spanned 10 mo and more than 1,000 therapy hrs. Contingent electric shock and differential reinforcement of other behavior were the primary techniques utilized. The specifics of the punishment and reinforcement contingencies were modified throughout the program as a function of the behavior, thereby allowing for evaluation of the various components of the treatment procedures. Although initial results were only partially successful, total suppression was eventually achieved in the laboratory setting. The procedures described for extending this control to the natural environment proved only moderately successful. The technical, ethical, and theoretical issues concerning the treatment of severe self-injurious behavior are discussed. It is suggested that the extrapolation of laboratory evidence to the natural setting is premature in the case of severe self-injurious behavior. Suggested criteria for the assessment of successful clinical treatment of self-injurious behavior are offered. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

8.
A comparison of shock intensity was conducted while treating a young woman with mental retardation and severe self-injurious behavior (SIB). Two levels of shock intensity were evaluated: 3.5 milliamps (mA) delivered via the Self-Injurious Behavior Inhibiting System (SIBIS) and 18.5 mA delivered via the Hot Shot Power Mite. A combined reversal and multiple baseline across behaviors design was used to evaluate treatment effects. SIBIS in conjunction with differential reinforcement and extinction of self-injurious escape behavior produced minimal reductions in SIB. The Hot Shot combined with extinction of self-injurious escape behavior and reinforcement for compliance resulted in immediate and large reductions in SIB. Residential staff were trained to implement contingencies by the fourth day of treatment with excellent generalization from 30-min sessions to the natural environment across all waking hours. Continuous protective restraints were eliminated within the first month of treatment. Progress occurred in personal care, vocational training, independence, and communication. Treatment effects were maintained for approximately 6 months until a relapse occurred after home visits.  相似文献   

9.
This study introduces a new method of determining sex based on four morphological features of the posterior, distal humerus. The technique was developed on a 20th century anatomy series, the University of Toronto Grant Skeletal Collection, and was tested on 35 known individuals from the University of New Mexico Documented Collection and 93 individuals from the William M. Bass Donated Skeletal Collection. Four statistically significant characteristics relating to the carrying angle of the arm are identified (p < 0.05). Together, they are capable of determining sex with 92% accuracy.  相似文献   

10.
A novel amino acid type poly(ethylene glycol) (aaPEG) was prepared and its application as a drug-carrier was examined. The peptides, Pro-Asp-Ser-Gly-Arg (PDSGR) and Tyr-Ile-Gly-Ser-Arg (YIGSR) which are active fragments of Laminin (a cell adhesion protein), were previously reported to be inhibitors of experimental metastasis. Both peptides were conjugated with aaPEG (average molecular weight, 3,000) to prepare a bifunctional peptide-PEG hybrid. The hybrid, PDSGR-aaPEG-YIGSR, was manually prepared by the solid-phase fluorenylmethyloxycarbonyl (Fmoc) strategy. The antimetastatic activity of the peptides in mice was not lost when conjugated to form a larger aaPEG molecule. YIGSR(375 nmol) and PDSGR (375 nmol and 750 nmol) did not demonstrate antimetastatic activity, but a mixture of PDSGR (187 nnmol) and YIGSR (187 nmol) exhibited an inhibitory effect. The inhibitory effect of the hybrid (187 nmol) was more potent than that of the mixture (PDSGR and YIGSR), indicating that the inhibitory effect of the peptides was potentiated by hybrid formation with aaPEG.  相似文献   

11.
The literature on self-injurious behavior suggests 5 major hypotheses concerning the motivation of such behavior: (a) Self-injurious behavior is a learned operant, maintained by positive social reinforcement (positive reinforcement hypothesis); (b) self-injurious behavior is a learned operant, maintained by the termination of an aversive stimulus (negative reinforcement hypothesis); (c) self-injurious behavior is a means of providing sensory stimulation (self-stimulation hypothesis); (d) self-injurious behavior is the product of aberrant physiological processes (organic hypothesis); and (e) self-injurious behavior is an attempt to establish ego boundaries or to reduce guilt (psychodynamic hypotheses). Data bearing on each hypothesis are reviewed and evaluated. It is suggested that effective treatment may depend on a recognition of the different motivational sources of self-injurious behavior and the developmental relationships existing among these sources. Animal analog experiments may provide clues to the motivation of self-injurious behavior in cases in which human experimentation is ethically indefensible. (88 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

12.
13.
14.
Acute ischemia in the complete territory of the carotid or the middle cerebral artery may lead to cerebral edema with raised intracranial pressure and progression to coma and death. Although clinical data suggest benefit for patients undergoing decompressive surgery for massive space occupying hemispheric stroke, little data about the effects of this procedure on morbidity and outcome is available. The experimental data support an early surgical approach. For early and probably most effective treatment of severe, space-occupying cerebral ischemia, the "malignant" character of the brain edema has to be recognized early after onset of vessel occlusion. Hereby magnetic resonance imaging (MRI) may allow to determine the clinical significance of brain edema early after onset, simultaneously allowing to monitor the evolution of ischemia. We performed serial SE-MRI in rats with acute hemispheric infarctions treated by decompressive craniectomy. Focal cerebral ischemia was induced in 36 rats using an endovascular occlusion technique. Decompressive craniectomy was performed 4 and 24 hours after vessel occlusion in groups of 12 animals each. Twelve animals were not treated by decompressive craniectomy (control group). Four, 24, 48, 72 and 168 hours after MCAO all animals were examined with conventional T1- and T2-weighted SE-MRI. Shift of the midline structures and compression of the ventricles were scored. Changes in weight and neurological performance were measured daily. The infarction volume was calculated by triphenyltetrazolium chloride staining 168 hours after MCAO. While mortality in the untreated group was 33.3%, none of the animals treated by a decompressive craniectomy died (mortality 0%). Neurological behaviour, weight loss and infarction volume were significantly better in the animals treated by early decompressive craniectomy (p < 0.05). Four hours after MCAO all untreated animals showed a massive shift of the midline structures and a massive compression of the ventricles; only 7 of 12 animals treated early by craniectomy showed mild mass effects. Correlation of the histological brain damage with T2-weighted MRI 4 hours after MCAO was poor (r = 0.41); later than 24 hours there was a good correlation (r > 0.7). Our results suggest that decompressive craniectomy in malignant cerebral ischemia reduces mortality and significantly improves outcome. If performed early after vessel occlusion, it also significantly reduces infarction size. In the acute phase of hemispheric infarction conventional SE-MRI is not sensitive in estimation of infarction size. Later than 24 hours, conventinal SE-MRI proved to be useful in monitoring brain edema and infarction size in this rat model of malignant hemispheric stroke.  相似文献   

15.
Assessed client cooperation vs resistance in 16 university clients (mean age 28.6 yrs) on the basis of behavior during intake interviews in terms of a coordinating style construct (which assesses how well the client coordinates contributions to the interaction with the interviewer's contributions and the client's own contributions at other points in time). Ss then completed a brief course of counseling—9 in a paradoxical condition and 7 in a behavioral condition. Results indicate that there was a stronger negative relation between noncoordinating style and improvement in the behavioral condition as compared with the paradoxical condition. Findings provide preliminary empirical support for the widely held position that a paradoxical approach is especially well-suited for resistant clients, whereas behavioral approaches are appropriate for cooperative clients. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

16.
Responds to G. P. Koocher's (1976) interpretation of B. G. Tate and A. S. Baroff's (1966) study on the use of shock in controlling self-injurious behavior and expresses appreciation for Koocher's concern about the use of aversive techniques in controlling difficult behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

17.
以某商用汽车为研究对象,通过问卷调查的方式,测定了该商用汽车的偏好逆转阈限价格、偏好逆转阈限及偏好逆转韦伯分数的均值和标准差,分析该商用汽车价格上涨和下降过程中价格偏好逆转现象,并探讨价格偏好逆转的不对称性.研究表明,商品价格调整应控制在价格偏好逆转阈限范围内,且在价格调整过程中应针对价格上涨和下降进行区别对待,慎重考虑调价策略.  相似文献   

18.
AIM OF THE STUDY: Postoperative sensory component of the facial nerve after acoustic tumor surgery has received little attention in the literature. The object of the present investigation was to review this specific topic analyzing the postoperative frequency of taste and lacrimation (crocodile tears or dry eye) abnormalities. MATERIAL AND METHODS: 54 patients who underwent acoustic tumor removal were selected for this study. Each of these patients was recalled and pre and postoperative evolution of the sensory dysfunction were assessed. The latters were correlated with the facial function evaluated according to the House-Brackmann classification. RESULTS: Postoperative taste dysfunction (reduced or changed sensation) was complained by 38.5% of the patients. After surgery, 42.3% of the cases had crocodile tears, while in 59.6% altered tearing occurred. DISCUSSION: The present study, according to the Irving et al's experience confirmed a significant incidence of postoperative abnormal function of the sensory facial nerve. The influence of the motor component on these outcomes was variable. Lacrimation worsened when facial function was poor. On the other hand, grades V or VI did rarely manifest crocodile tears. Clinically, these findings implies the importance of a preoperative counseling of such particular aspect in the candidates to surgery of acoustic neuroma in order to adequately motivate them and, at the same time, to reduce their psychological discomfort.  相似文献   

19.
This article aimed to cover the range of techniques used in partner notification for sexually transmitted infections, including HIV. Many of the current methods were developed over the past 50 years, and very little operational research has since been undertaken to refine them. More work is needed to evaluate inexpensive strategies to improve patient referral, to determine the psychological and behavioral impact of partner notification and methods of incorporating social networks in partner notification programs.  相似文献   

20.
The present study investigated the role of endogenous opioids in the expression of defensive behaviors (DBs) and the suppression of cell proliferation (CP) in the dentate gyrus (DG) induced by exposure to predator odor, trimethyl thiazoline (TMT). Adult male rats were injected with either naltrexone (an opioid antagonist, 5 mg/kg) or saline 30 min before exposure to either TMT or a control odor. Behavior was scored for the first 15 min of odor exposure. Bromodeoxyuridine (BrdU, 200 mg/kg) was then injected, and the rats were perfused 1 hr later. Exposure to TMT increased the expression of DBs and suppressed the number of proliferating cells in the DG. Pretreatment with naltrexone attenuated the effects of TMT on DB expression but did not attenuate the effects of TMT on CP. In addition, naltrexone administration suppressed CP in the absence of TMT. These results demonstrate a dissociation between DBs and regulation of CP in the DG. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号