首页 | 官方网站   微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
trans, trans-Muconic acid (1,3-butadiene-1, 4-dicarboxylic acid, MA), a minor urinary metabolite of benzene exposure, was determined, after clean-up by solid-phase anion-exchange chromatography, by reversed-phase HPLC on a C18 column (5 x 0.46 cm I.D., 3 microns particle size), using formic acid-tetrahydrofuran-water (14:17:969) as mobile phase and UV detection at 263 nm. The recovery of MA from spiked urine was > 95% in the 50-500 microgram/l range; the quantification limit was 6 micrograms/l; day-to-day precision, at 300 micrograms/l, was C.V. = 9.2%; the run time was less than 10 min. Urinary MA excretion was measured in two spot urine samples of 131 benzene environmentally exposed subjects: midday values obtained in non-smokers (mean +/- S.D. = 77 +/- 54 micrograms/l, n = 82) were statistically different from those of smokers (169 +/- 85 micrograms/l, n = 30) (P < 0.0001); each group showed a statistically significant increase between MA excretion in midday over morning samples. Moreover, in subjects grouped according to tobacco-smoke exposure level, median values of MA were positively associated with and increased with daily smoking habits.  相似文献   

2.
In children and adolescents with type 1 diabetes, we have reported an association between duration of puberty and the prevalence of nephromegaly and microalbuminuria (MA), which are early markers of diabetic nephropathy. Growth hormone (GH), IGF-I, testosterone, and prorenin are potential mediators of this effect. This study examined the relationship of these hormonal factors to kidney volume (KV) and MA in 155 subjects (78 males, age 13.2 +/- 3.5 years [mean +/- SD]) with similar diabetes duration (6.83 +/- 1.6 years) but varying pubertal experience (0-10 years). KV (by ultrasound), plasma IGF-I, testosterone, prorenin, and NaLi countertransport, and urinary albumin, urinary GH, and urinary IGF-I from three 24-h collections were measured. Multiple regression analysis showed that BSA (P < 0.0001) and urinary IGF-I (P = 0.001) were significantly associated with KV. MA subjects (albumin excretion rate 15-200 microg/min) had higher urinary IGF-I (P = 0.005) and urinary GH (P = 0.05) compared with normoalbuminuric subjects. Only 9% of the variance in urinary IGF-I could be attributed to plasma IGF-I (r = 0.30, P < 0.0001). Testosterone and prorenin were not associated with MA, but they were associated with KV in univariate analyses. The strong association of urinary IGF-I with KV, a marker for glomerular hypertrophy, and of both urinary IGF-I and urinary GH with MA suggests a role for these growth factors in the development of human diabetic nephropathy. Together, these data support animal studies that have shown that renal GH and IGF-I may contribute significantly to the pathogenesis of early diabetic nephropathy.  相似文献   

3.
1. The contractile properties of the motor units of the masseter and temporal muscles of human subjects were studied during voluntary isometric contractions, using a method previously employed to examine units of a small hand muscle. 2. Over the range of forces studied (0-6 kg), the units of both muscles were recruited in an orderly fashion, with a nearly linear relationship between the voluntary force at which units were recruited and their measured twitch tensions. 3. The range of contraction times (25-90 msec) was similar to that observed for the hand muscle. In some subjects it seemed that small units, recruited at low forces, exhibited shorter contraction times.  相似文献   

4.
The interaction of the human immunodeficiency virus (HIV) Gag protein with the plasma membrane of a cell is a critical event in the assembly of HIV particles. The matrix protein region (MA) of HIV type 1 (HIV-1) Pr55Gag has previously been demonstrated to confer membrane-binding properties on the precursor polyprotein. Both the myristic acid moiety and additional determinants within MA are essential for plasma membrane binding and subsequent particle formation. In this study, we demonstrated the myristylation-dependent membrane interaction of MA in an in vivo membrane-binding assay. When expressed within mammalian cells, MA was found both in association with cellular membranes and in a membrane-free form. In contrast, the intact precursor Pr55Gag molecule analyzed in an identical manner was found almost exclusively bound to membranes. Both membrane-bound and membrane-free forms of MA were myristylated and phosphorylated. Differential membrane binding was not due to the formation of multimers, as dimeric and trimeric forms of MA were also found in both membrane-bound and membrane-free fractions. To define the requirements for membrane binding of MA, we analyzed the membrane binding of a series of MA deletion mutants. Surprisingly, deletions within alpha-helical regions forming the globular head of MA led to a dramatic increase in overall membrane binding. The stability of the MA-membrane interaction was not affected by these deletions, and no deletion eliminated membrane binding of the molecule. These results establish that myristic acid is a primary determinant of the stability of the Gag protein-membrane interaction and provide support for the hypothesis that a significant proportion of HIV-1 MA molecules may adopt a conformation in which myristic acid is hidden and unavailable for membrane interaction.  相似文献   

5.
OBJECTIVE: Hereditary spastic paraplegia (HSP) with dementia is a very rare condition. The aim of the paper is to present the first report of HSP in a Fijian Indian family. METHOD: A psychiatrist and a general physician examined the affected members of the family on five occasions over three years. RESULTS: There are three affected individuals in a sibship of seven. The parents are without symptoms and the marriage is non-consanguineous. The course of the disease has been remarkably similar. All subjects were healthy and performing well in the early years of school. In two, symptoms of cognitive loss preceded difficulty with ambulation and in the third, these symptoms appeared concurrently. All subjects had both symptoms by 13 years of age; they were unable to ambulate independently by the mid to late teens, at which time there was dysarthria spastic paraplegia and dementia. One subject suffered a three month episode of hypomanic behaviour. Over the three-year study period deterioration was slight but noticeable. CONCLUSIONS: It is possible that HSP is more commonly associated with pre-senile dementia than is currently recognised. HSP with dementia is a very rare cause of failing school performance. Physical examination of the patient and other family members is indicated if this diagnosis is being considered.  相似文献   

6.
Pattern reversal visual evoked potentials (PVEPs) were recorded in 20 patients with migraine with aura (MA), 19 patients with migraine without headache (migraine equivalent; ME) during interictal periods, and 34 normal subjects. All migraine patients had hemianopsia or fortification spectra during attacks. In both MA and ME patients of less than 49 years of age, there were significant (p<0.01) differences in amplitude of PVEPs at the mid-occipital and contralateral to visual aura electrode sites compared to normal subjects. Amplitude of PVEPs in MA and ME showed significant (p<0.001) increases when recorded soon after attacks, especially within 10 days. There was a significant (p<0.01) correlation between percentage asymmetries and the duration of illness in both MA and ME. We conclude from our PVEP findings that cortical spreading depression remains the most likely explanation for the migraine visual aura.  相似文献   

7.
OBJECTIVE: Forty-two persons were exposed to controlled low-speed rear-end automobile collisions to assess the relation between both gender and impact severity and the presence, severity, and duration of whiplash-associated disorders (WAD). Individual measures were also assessed for their potential to predict the onset of WAD. DESIGN: Experimental study subjecting individuals to a speed change of 4 km/h and 8 km/h and utilizing pretest and posttest physical examinations (immediately after and 24 hours after impact) to quantify subjects' clinical response. RESULTS: Approximately 29% and 38% of the subjects exposed to the 4 km/h and 8 km/h speed changes, respectively, experienced WAD symptoms, with cervical symptoms and headaches predominating. Objective clinical deficits consistent with WAD were measured in both men and women subjects at both 4 km/h and 8 km/h. At 4 km/h, the duration of symptoms experienced by women was significantly longer when compared with that in men (p < .05). There were no significant differences in the presence and severity of WAD between men and women at 4 km/h and 8 km/h or in the duration of WAD at 8 km/h. There was also no significant difference in the presence, severity, and duration of WAD between 4 km/h and 8 km/h. No preimpact measures were predictive of WAD. CONCLUSION: The empirical findings in this study contribute to establishing a causal relationship between rear-end collisions and clinical signs and symptoms.  相似文献   

8.
As part of an ongoing study of carpal tunnel syndrome (CTS) in industry, we measured plasma concentrations of pyridoxal 5'-phosphate (PLP, a measure of vitamin B6 status) and total ascorbate (ASC, a measure of vitamin C status) in 441 adult volunteers from six industries and a university exercise study. In the entire study group and in non-vitamin users (n = 218), there were no significant differences in mean plasma PLP or ASC concentrations between controls (neither symptoms nor slowing), subjects with symptoms only, subjects with median nerve slowing only, or subjects with CTS (symptoms + slowing). In male non-vitamin users (n = 137), there were significant inverse univariate associations between plasma PLP concentration and the prevalence of pain, the frequency of tingling and nocturnal awakening, and the Phalen test result. In this same subgroup, the ASC/PLP ratio was directly associated with the prevalence of pain and nocturnal awakening, and with the frequency of pain, tingling, and nocturnal awakening. In multivariate analyses, plasma ASC concentration predicted more median nerve slowing and confirmed CTS, and vitamin or vitamin interaction variables were independent predictors of 20 CTS-related outcomes. These multivariate relationships often occurred only after adjustment for age, gender, body mass index, serum alkaline phosphatase activity, or tobacco use. We conclude that there are significant relationships between plasma vitamin levels and both components of CTS (specific symptoms and median nerve slowing). The interaction between plasma PLP and ASC appears to be particularly important with respect to symptoms.  相似文献   

9.
A simple immunosensor based on a conductivity method was developed for determination of methamphetamine (MA, a stimulant drug) in urine. Anti-MA antibody was immobilized onto the surface of a pair of platinum electrodes. The reaction of MA with the antibody causes a decrease in the conductivity of the anti-MA immobilized layer between the electrodes. A linear relationship was obtained between the conductivity and MA concentration in the range of 1-10 micrograms/ml. The method requires the sample to be rinsed with water on the electrodes after the immunoreaction. This detection system was applied to the determination of MA in urine and proved to be a useful and a simple detection technique of MA in forensic science in comparison with a gas chromatography-mass spectrometry method.  相似文献   

10.
In this study, tactile sensitivity of gloved hand in the cold operation has been investigated. The relations among physical properties of protective gloves and hand tactile sensitivity and cold protection were also analysed both objectively and subjectively. Subjects with various gloves participated in the experimental study during cold exposure at different ambient temperatures of -12 degrees C and -25 degrees C. Tactual performance was measured using an identification task with various sizes of objects over the percentage of misjudgment. Forearm, hand and finger skin temperatures were also recorded throughout. The experimental data were analysed using analysis of variance (ANOVA) model and the Tukey's multiple range test. The results obtained indicated that the tactual performance was affected both by gloves and by hands/fingers cooling. Effect of object size on the tactile discrimination was significant and the misjudgment increased when similar sizes of objects were identified, especially at -25 degrees C.  相似文献   

11.
The Rorschach was given to 60 school children in two designs: CA and MA orthogonal (9 and 12 years) and CA =MA (for 6, 9 and 12 years). Responses were scored for Form Accuracy, Complexity, Movement, and Friedman's Developmental Level (DL) Scoring System. There were significant MA effects independent of CA on Form Accuracy, Complexity and DL, and significant CA effects on Complexity and Movement. Form Accuracy was highly correlated with the DL score and correlated with MA at a slightly higher level than DL with MA. The Complexity score provided some additional information about development. Movement decreased with age but was higher in intelligent subjects. The results suggested that the DL system does assess MA independently of CA, but this is accounted for primarily by Form Accuracy.  相似文献   

12.
The present study tested the hypothesis that the short, low activity variant of a biallelic polymorphism in the 5' regulatory region of the human serotonin transporter (5-HTT) gene confers susceptibility to severe alcohol dependence marked by severe withdrawal symptoms. Applying a phenotype-genotype strategy, our population-based association analysis included 216 German controls and an extreme sample of 103 severely affected alcoholics who were selected from 315 German alcohol-dependent subjects by a history of alcohol withdrawal seizure or delirium. The frequency of the short allele (S) was significantly increased in the severely affected alcoholics, compared with that in the controls (X2 = 3.87, df = 1, nominal p = 0.049). The post-hoc exploration indicated that this allelic association resulted exclusively from a significant excess of the S/S genotype in the severely affected alcoholics (p = 0.035), suggesting a recessively acting effect. Consistently, we found a weak but significant correlation (p = 0.013) between the frequency of the S/S genotype and severity of withdrawal symptoms (WDS): no WDS [18.3%, odds ratio (OR) = 1.16], vegetative WDS only (21.8%, OR = 1.44), and severe WDS with either withdrawal seizure only or delirium only (25.0%, OR = 1.69), and both withdrawal seizure and delirium (30.8%, OR = 2.30). Further studies are required to test whether the tentative genotype-phenotype relationship occurred by chance or reflects a real genotypic association between a recessively modifying effect of the short variant of the functional 5-HTT promoter polymorphism and alcohol withdrawal vulnerability.  相似文献   

13.
BACKGROUND: The etiology of inflammatory bowel disease is unclear, and the role played by anxiety and depression is highly controversial. Anxiety and depression in patients with inflammatory bowel disease could be secondary to disabling symptoms, but the interaction between physical morbidity and psychologic illness in these subjects has not been sufficiently investigated. Patients with inflammatory bowel disease are nevertheless frequently undernourished, but there are no studies on the association between anxiety and depression and malnutrition. This study was designed to characterize anxiety and depression in subjects affected by inflammatory bowel disease and to establish the influence of physical morbidity and/or nutritional status on psychologic disorders. METHODS: Seventy-nine consecutive patients, 43 with Crohn's disease (CD) and 36 with ulcerative colitis (UC), were enrolled in the study. An index of the disease activity and physical morbidity was obtained by the simplified Crohn's Disease Activity Index and Truelove-Witts criteria and using the Clinical Rating Scale. Thirty-six healthy volunteers were studied as controls. All the subjects were given the State and Trait Anxiety Inventory (STAI) test and the Zung self-rating Depression Scale. RESULTS: The percentage of subjects with state anxiety was significantly higher in the CD (P < 0.001) and UC (P < 0.001) groups than in control subjects. There was no significant difference in trait anxiety among groups. The percentage of subjects with depression was significantly higher in the CD (P < 0.05) and UC (P < 0.05) groups than in control subjects. State anxiety and depression were significantly associated with physical morbidity and correlated with malnutrition in CD and UC patients. CONCLUSION: Anxiety and depression in patients with inflammatory bowel disease could be reactive to the disabling symptoms and to malnutrition. As measured with the STAI, personality trait of anxiety does not seem to play an important role in inflammatory bowel disease.  相似文献   

14.
BACKGROUND: Occupational respiratory allergy to green coffee beans (GCB) and to castor beans (CB) was studied in 112 workers in a modern coffee manufacturing plant of Trieste (Italy), where the process is completely automatic, the environmental conditions are good and where exposure to CB can be considered absent because since 1970, only new sacks have been used for coffee transportation. METHODS: All subjects were interviewed by a trained doctor using a questionnaire to investigate allergic symptoms and predisposing factors. Sensitization to GCB and to common allergens (pollens, molds, house dust mites) were evaluated by the skin-prick test. The serum of subjects with a positive skin-prick test to CGB or who had symptoms at work was tested for specific IgE (RAST) for GCB and CB. Lung function was evaluated by a Ponigraph spirometer. RESULTS: Sensitization to GCB was found in 25.8% of green coffee workers (31 cases), in 2.7% of roasted coffee workers (37 cases) and in 4.5% of the clerks (44 cases), p < 0.01. The evaluation of IgE specific for CB gave positive results only in 3 of 10 subjects sensitized to GCB. A total of 20% of GCB workers (6 cases) complained of work-related respiratory symptoms (asthma and/or rhinitis) compared with only one subject in the roasted coffee group and one in the control group (p < 0.01). Asthma was reported by 2/31 of the green coffee workers and by 1/44 of roasted coffee workers. CONCLUSIONS: There was a significant correlation between sensitization to GCB and work related symptoms (p < 0.01), common allergic symptoms (p < 0.05) and atopy by prick test (< 0.01). These results point to the need to evaluate atopic status in workers and identify the most susceptible subjects, with the aim of informing them of their at-risk status and monitoring their progress. This makes it possible to diagnose sooner those symptoms possibly indicative of a work-related disease, because even in presence of good environmental conditions and even when symptoms are mild, it is almost always the atopic subjects who are affected.  相似文献   

15.
In this longitudinal study, we followed a large sample of first-time parents (both partners) across the first 2 years of the transition to parenthood. Guided by attachment theory (Bowlby, 1969), we tested several predictions about how attachment anxiety and avoidance are related to the incidence, maintenance, increase, and decline of depressive symptoms in both sexes across the first 2 years of the transition. We found that (a) the association between attachment anxiety and depressive symptoms was moderated by factors related to the marital and/or romantic relationship; (b) the association between avoidance and depressive symptoms was moderated by factors related to family responsibilities; (c) styles of caregiving provided by romantic partners affected depressive symptoms differently among anxious and avoidant persons; and (d) in certain predictable situations, depressive symptoms persisted at higher levels or increased to higher levels in anxious or avoidant persons across the 2-year transition period. Important implications of these results are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   

16.
OBJECTIVES: Much has been written about the use of static orthoses to maintain proper position and prevent deformity, but there are few empirical data to determine whether static orthoses improve function, maintain range of motion, or prevent deformity in the hand. METHOD: This study measured gains in hand function during a 3-month rehabilitation period in 13 persons with sixth cervical (C-6) level complete quadriplegia, 7 of whom wore a static orthosis at night (experimental group) and 6 who did not wear the orthosis (control group). Hand function, range of motion and strength were measured in all subjects 4 weeks and 8 weeks after the study commenced, and again after 12 weeks in only 69% of the subjects. RESULTS: No significant differences were found in hand function between control and experimental groups; hand function had improved significantly in all 13 subjects. CONCLUSION: As the effects of deformity have been clinically observed, future studies should examine the effects of static orthoses with increased daily wear or wear over a longer period of time.  相似文献   

17.
OBJECTIVE: To examine the association between different patterns of hand symptoms and the presence of delayed nerve conduction in the general population. METHODS: We performed a 2-stage screening survey involving a questionnaire on current hand symptoms, and nerve conduction testing in samples of subjects with and without symptoms. Of 648 respondents to the symptom questionnaire, 212 reported hand symptoms. In all, 155 were tested for nerve conduction of sensory and motor median nerve latencies, including 40 who had reported no symptoms. Patterns of hand symptoms were compared with nerve conduction results and associations weighted back to the general population. RESULTS: The presence of any hand symptoms had only a 40% sensitivity for delayed nerve conduction on latency testing. The presence of typical symptoms of carpal tunnel syndrome had a much lower sensitivity. CONCLUSION: In a community setting, the distribution of hand symptoms does not usefully correlate with the presence of delayed nerve conduction in the median nerve.  相似文献   

18.
Brodimoprim is a long acting broad spectrum antibacterial agent. It is a new selective inhibitor of bacterial dihydrofolate reductase, structurally related to trimethoprim. The aim of the present study was to investigate the efficacy and tolerability of brodimoprim (10 mg/kg on the first day, 5 mg/kg/die onward) in the treatment of upper respiratory tract infections in children (age range: 2-14 years). This open group comparative study was performed either in 68 children affected by bacterial pharyngotonsillitis (37 treated with brodimoprim, 31 with erythromycin 560 mg/kg/8 hours) or in 50 patients affected by otitis media (25 treated with brodimoprim, 25 with amoxicillin/clavulanic acid 50 mg/kg/12 hours) or in 52 patients affected by acute sinusitis (25 treated with brodimoprim, 27 with amoxicillin/clavulanic acid 50 mg/kg/12 hours). All patients were clinically evaluated before admission, during the trial and 48 hours after the last dose of antibiotic. At the same time blood and secretion samples were collected for hematology/biochemistry and microbiological assays. A total of 170 subjects were treated and 141 patients demonstrated a clinical recovery/improvement following the treatment period, with approximately the same recovery rate (83%) among the groups. The bacteriological response was evaluated in 169 subjects. Eradication of pathogens was documented in 27 subjects treated with brodimoprim and 28 with erythromycin in the pharyngotonsillitis group, in 22 subjects treated with brodimoprim and 16 with amoxicillin/clavulanic acid in the otitis group and in 17 subjects treated with brodimoprim and 20 with amoxicillin/clavulanic acid in the sinusitis group. The overall eradication in brodimoprim treated patients was 77% in comparison with 76% of eradication obtained in the control groups.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

19.
The potential advantages of using digital techniques instead of film-based radiography have been discussed extensively for the past 10 years. A major future application of digital techniques is computer-assisted diagnosis: the use of computer techniques to assist the radiologist in the diagnostic process. One aspect of this assistance is computer-assisted detection. The detection of small lung nodule has been recognized as a clinically difficult task for many years. Most of the literature has indicated that the rate for finding lung nodules (size range from 3 mm to 15 mm) is only approximately 65%, in those cases in which the undetected nodules could be found retrospectively. In recent published research, image processing techniques, such as thresholding and morphological analysis, have been used to enhance true-positive detection. However, these methods still produce many false-positive detections. We have been investigating the use of neural networks to distinguish true-positives nodule detections among those areas of interest that are generated from a signal enhanced image. The initial results show that the trained neural networks program can increase true-positive detections and moderately reduce the number of false-positive detections. The program reported here can perform three modes of lung nodule detection: thresholding, profile matching analysis, and neural network. This program is fully automatic and has been implemented in a DEC 5000/200 (Digital Equipment Corp, Maynard, MA) workstation. The total processing time for all three methods is less than 35 seconds. In this report, key image processing techniques and neural network for the lung nodule detection are described and the results of this initial study are reported.  相似文献   

20.
The purpose of this study was to discover the influence of 2 determinants, ego disjunction (ED) and manifest anxiety (MA), on conflict resolution. ED, defined as antagonistic response tendencies within an individual, was measured by the Edwards Personal Preference Schedule, and MA by the Taylor MA scale. From a sample of 56 college Ss, it was found that Ss high in both ED and MA required significantly more time to resolve approach-approach and avoidance-avoidance conflicts than Ss high in only one determinant but low in the other and Ss low in both determinants. No significant differences in conflict scores were found when Ss low in both determinants were compared with Ss high in only one determinant but low in the other. The results were interpreted as indicating that ED and MA interact, producing interfering responses which hinder efficient resolution of conflicts when ED and MA are both high within an individual High MA and high ED scores, when taken alone, did not yield any conclusive results. It is only when both determinants are taken into consideration that greater confidence can be invested in those measures to predict conflict performance. (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-23

京公网安备 11010802026262号