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Biomedical subjects

S Smith

Publications and source records attributed to S Smith.

At least 487 records · Page 27Linked to original sources
PubMed1995

Differing patterns of electrodermal and finger pulse responsivity in schizophrenia and depression.

Non-response of the autonomic orienting response (OR), as indexed jointly by deficient skin conductance (SCR) and finger pulse amplitude responding (FPAR), has been shown to occur with excessive frequency in the schizophrenic population. The present study is an attempt to replicate earlier evidence that SCR-OR and FPAR-OR, when measured in concert, could distinguish schizophrenic from depressed patients (Bernstein et al. 1988). This issue is critical of the question of diagnostic specificity of OR non-responding, since reduced SCR has been found repeatedly in depression as well as in schizophrenia. We examined SCR and FPAR concurrently in 69 schizophrenic, 45 depressed, and 67 normal subjects. SCR non-responding was more frequent in both schizophrenics and depressives than in normal controls, while only the schizophrenics displayed excessive FPAR non-responding. Moreover, among SCR non-responders, concordant OR non-responding--defined as non-responding indexed simultaneously in both the SCR and FPAR components--was most common in the schizophrenic sample. These findings support our previous conclusion that OR non-responding in depression, may have distinct peripheral origins. Our results also suggest that measuring multiple biochemically distinct components of the OR may be more sound methodologically than obtaining a single channel recording.

Adolescent↗
PubMed1995

Androgen regulation of an elastase-like protease activity in the seminal vesicle.

The processing of secretory proteins in the guinea pig (GP) seminal vesicle epithelium (SVE) is altered by castration and restored by treatment of animals with androgens. To test the hypothesis that the changes in protein processing are due to changes in the activity of specific proteases, we examined the GPSVE for protease activities capable of cleaving a synthetic elastase substrate, succinyl-alanyl-alanyl-alanyl-p-nitroanilide (Suc(Ala)3pNA). We found that the GPSVE does contain a Suc(Ala)3pNA-cleaving activity that is sensitive to the serine protease inhibitor diisopropylfluorophosphate (DFP) and to the elastase inhibitor elastatinal. Furthermore, the amount of protease activity per milligram of SVE protein is reduced to about 50% of control levels by castration. The activity is completely restored within four days by treatment of castrated animals with androgens, but is not restored by treatment with estradiol, progesterone, or dexamethasone. Although the SVE enzyme did not yield a pattern of specific cleavage products when incubated with a secretory protein substrate in vitro, this enzyme activity was competitively inhibited by a peptide whose primary sequence included the cleavage site used by the processing machinery in vivo.

Amino Acid Sequence↗
PubMed1995

The prognostic significance of caffeine half-life in saliva in children with chronic liver disease.

To evaluate its clinical value, the half-life of caffeine (1,3,7-trimethylxanthine) in saliva (SCT) after 3 mg/kg-1 oral caffeine was measured in 53 children with chronic liver disease (mean age, 4.41 years) and 48 control children (mean age, 6.26 years) in five samples over 24 h and compared with parameters of liver function and outcome. Sensitivity was 60.3% and specificity 97% of SCT for diagnosis of chronic liver disease. The correlation of SCT with serum albumin (ALB) was -0.52 (p < 0.001), total bilirubin (SBR) was 0.585 (p < 0.001), prolonged prothrombin time (PT) was 0.387 (p = 0.004), and aspartate aminotransferase (AST) was 0.538 (p = 0.001). The correlation of SCT with a clinical score of liver dysfunction calculated from the presence of features of hepatic decompensation was 0.627 (p < 0.001) and with Malatack's paediatric prognostic score was 0.505 (p < 0.001). Serial SCT and liver function tests were performed on 53 patients on 127 occasions during a mean follow-up of 361 days (range, 4-709). Of this group, 18 were listed for liver transplantation. Predictive values of outcome by analysis of variance expressed as ratio of mean squares were SBR, 34.1 (p < 0.001); log10 SCT, 20.6 (p < 0.001); ALB, 5.2 (p < 0.05); PT, 1.2 (NS). SCT correlated with clinical and biochemical parameters of severity of liver disease, but SBR was a better predictor of listing for liver transplantation in this group of paediatric patients.

Adolescent↗
PubMed1995

Effects of carbohydrate supplementation during intense training on dietary patterns, psychological status, and performance.

The purpose of this study was to determine the effects of carbohydrate supplementation during intense training on dietary patterns, psychological status, and markers of anaerobic and aerobic performance. Seven members of the U.S. National Field Hockey Team were matched to 7 team counterparts (N = 14). One group was blindly administered a carbohydrate drink containing 1 g.kg-1 of carbohydrate four times daily, while the remaining group blindly ingested a flavored placebo during 7 days of intense training. Subjects underwent pre- and posttraining aerobic and anaerobic assessments, recorded daily diet intake, and were administered the Profile of Mood States (POMS) psychological inventory prior to and following each practice. Results revealed that the carbohydrate-supplemented group had a greater (p < .05) total energy intake, carbohydrate intake, and change (pre vs. post) in time to maximal exhaustion following training while reporting less postpractice psychological fatigue. However, no significant differences were observed in remaining psychological, physiological, or performance-related variables.

Adult↗
PubMed1995

Dealing with the difficult patient.

Dealing with difficult patients can represent a significant burden in the life of doctors. It is more productive, however, to view this burden as a product of the interaction between doctor and patient, for which both have a responsibility, rather than attributing any problems encountered to shortcomings of the patient alone. There is a significant risk in such situations of potentially harmful over-medicalisation. It behoves doctors, therefore, to try to prevent such problems becoming established, or make some attempt to rectify matters if they have already become so. Much is known about the factors that contribute to successful and unsuccessful clinical transactions. The awareness of what doctors bring both as professionals and as individual people to this interaction, will count as much as the practical clinical efforts made towards helping patients.

Attitude of Health Personnel↗
PubMed1995

Quantitation of progressive muscle fatigue during dynamic leg exercise in humans.

There is virtually no published information on muscle fatigue, defined as a gradual decline in force-generating capacity, during conventional dynamic (D) leg exercise. To quantitate progression of fatigue, we developed 1) a model featuring integration of maximal voluntary static contraction (MVC) of knee extension (KE) muscles with ongoing DKE and 2) a device that allows frequent rapid transfer between DKE isolated to the quadriceps femoris muscles and measurement of KE MVC. Eight healthy men performed graded and submaximal constant work rate one-leg DKE to exhaustion while seated. Work rate, a product of a contraction rate (1 Hz), force measured at the ankle, and distance of ankle movement from 90 degrees to 150 degrees of KE, was precisely controlled. Lack of rise in myoelectric activity in biceps femoris of the active leg during DKE and MVC was consistent with restriction of muscle action to quadriceps femoris. The slope of the linear relationship between O2 uptake and work rate was 13.7 ml O2/W (r = 0.93). This slope and the increase of heart rate relative to increasing work intensity agreed with published values for D leg exercise. Test-retest values for O2 uptake were similar (P > 0.05) for matched DKE work rates. To track fatigue, MVC (90 degrees knee angle) was performed every 2 min of DKE. After 4 min of DKE at work rates corresponding to (mean +/- SE) 66 +/- 2, 78 +/- 2, and 100% of peak DKE O2 uptake, MVC fell to 95 +/- 3, 90 +/- 5, and 65 +/- 7%* of MVC of rested muscle, respectively (*P < 0.01 from previous work rates). Virtually identical declines in MVC were observed by the end of graded work rate DKE and submaximal constant work rate DKE tests. Quantitation of progressive muscle fatigue during D leg exercise provides a framework to study the effects of a variety of interventions on the fatigue process and may permit unique insights into the involved mechanisms.

Adolescent↗
PubMed1995

A randomised controlled trial of stress reduction for hypertension in older African Americans.

We tested the short-term efficacy and feasibility of two stress education approaches toe the treatment of mild hypertension in older African Americans. This was a randomized, controlled, single-blind trial with 3 months of follow-up in primary care, inner-city health center. Of 213 African American men and women screened, 127 individuals (aged 55 to 85 years with initial diastolic pressure of 90 to 109 mm Hg, systolic pressure of < or = 189 mm Hg, and final baseline blood pressure of < or = 179/104 mm Hg) were selected. Of these, 16 did not complete follow-up blood pressure measurements. Mental and physical stress reduction approaches (Transcendental Meditation and progressive muscle relaxation) were compared with a lifestyle modification education control program and with each other. The primary outcome measures were changes in clinic diastolic and systolic pressures from baseline to final follow-up, measured by blinded observers. The secondary measures were linear blood pressure trends, changes in home blood pressure, and intervention compliance. Adjusted for significant baseline differences and compared with control, Transcendental Meditation reduced systolic pressure by 10.7 mm Hg (P < .0003) and diastolic pressure by 6.4 mm Hg (P <.00005). Progressive muscle relaxation lowered systolic pressure by 4.7 mm Hg (P = 0054) and diastolic pressure by 3.3 mm Hg (P <.02). The reductions in the Transcendental Meditation group were significantly greater than in the progressive muscle relaxation group for both systolic blood pressure (P = .02) and diastolic blood pressure (P = .03). Linear trend analysis confirmed these patterns.(ABSTRACT TRUNCATED AT 250 WORDS)

Black or African American↗
PubMed1995

Optimistic bias in cancer risk perception: a cross-national study.

Results are presented from a pilot study in which risk perceptions for developing cancer in samples of American and British adults were compared. 61 American and 43 British people estimated the likelihood of cancer happening to themselves and the average person. As a group, participants tended to judge their personal likelihood of developing cancer as less than the average, supporting the presence of an optimistic bias. However, compared to the Americans, British respondents tended to perceive both themselves and the average person to be less likely to develop cancer. There were no gender differences or interactions between the variables. Discussion centered on possible variations between the two countries with respect to perceptions of control and responsibility for one's health status which may account for the findings.

Adult↗
PubMed1995

Cardiac troponin-I is not expressed in fetal and healthy or diseased adult human skeletal muscle tissue.

Cardiac troponin-I (cTnI) is not found in sera of patients with skeletal muscle disease in the absence of myocardial injury. It is not known, however, whether trace amounts of cTnI are expressed in regenerating human skeletal muscle, as has been observed with creatine kinase MB. Using immunohistochemical and biochemical techniques, we investigated cTnI expression in various human muscle tissues: human heart tissue (n = 5), normal adult skeletal muscle (n = 3), and fetal heart (n = 3) and skeletal muscle (n = 3) obtained, respectively, during heart transplant, from autopsy, or from a tissue bank. Specimens from diagnostic tissue biopsies were used as diseased skeletal muscle: polymyositis (PM), n = 13; Duchenne muscular dystrophy (DMD), n = 6. Frozen sections 8 microns thick were stained immunohistochemically for either cTnI or TnI (cardiac or skeletal) by using monoclonal antibodies (MAb) 2B1.9 (cTnI specific) or 3C5.10 (reactive with all TnI isoforms), respectively. cTnI was measured in tissue homogenates by an immunofluorometric assay. Cardiac muscle was stained by both MAbs. Normal fetal and adult skeletal muscle, and samples from all of the PM and DMD patients, stained only with the nonspecific MAb (3C5.10), confirming the sole presence of skeletal TnI. No cTnI was detectable by immunoassay in any skeletal muscle sample. We conclude that cTnI is not expressed in human skeletal muscle during development or during regenerative muscle disease processes such as PM or DMD.

Adult↗
PubMed1995

Serum oncoproteins in asbestosis patients.

Using ELISAs, we determined the concentrations of transforming growth factor alpha (TGF-alpha), the extracellular domain of the erbB-2 receptor (erbB-2 ECD), and mutant p53 protein in stored serum samples of asbestosis patients with and without cancer and control subjects (without asbestosis or cancer). The percentage of individuals in these three groups with increased serum concentrations of TGF-alpha, erbB-2 ECD, and mutant p53, respectively, were: asbestosis patients with cancer, 36%, 16%, 19%; asbestosis patients without cancer, 38%, 19%, 6%; control subjects, 0%, 5%, 10%. Although differences in serum positivity for these oncoproteins were apparent among these groups, the differences did not achieve statistical significance (P > 0.05). In several of the cancer cases, increased concentrations of TGF-alpha, erbB-2 ECD, and mutant p53 were also detected in the stored serum samples collected years before the clinical diagnosis of disease.

Asbestosis↗
PubMed1995

Learning in the clinical area: the Portsmouth Partnership experience.

This paper outlines a new, innovative method of obtaining a degree pertinent to one's job description. The Partnership Programme implemented from the University of Portsmouth had its first intake of students in October 1992. The course is primarily aimed for students in full-time employment. Following submission of a portfolio, students can obtain a degree in two years. Students undertake part-time university modules and learning projects at the workplace, the latter forming up to 60% of their total credits. Presently there are only two similar course frameworks in the United Kingdom.

Education, Nursing, Continuing↗
PubMed1995

Endometrial biopsy dating. Interobserver variation and its impact on clinical practice.

To determine the degree of interobserver variation and the level of correlation in endometrial biopsy (EB) interpretation, five pathologists interpreted 30 EBs randomly selected from all EBs performed according to standard criteria. An EB was considered out of phase (OOP) if there was greater than a two-day lag in histologic development relative to the onset of the next menstrual period. Interobserver variation among the five pathologists was 0.85 and 0.82 days for one- and two-day dating ranges, respectively. Coefficients of correlation for histologic interpretation ranged from 0.839 to 0.934 (P < .0001). Seventy percent to 74% of the time all five pathologists agreed that a given EB was in phase or OOP. The low interobserver variation and high correlation between observers further validates the EB as a diagnostic test. However, up to 30% of the time a clinical management decision may be altered depending upon who interprets the EB. Thus, even with low interobserver variation, the clinical consequence of small changes in EB interpretation may be significant.

Biopsy↗
PubMed1995

Human sperm motility-enhancing agents have detrimental effects on mouse oocytes and embryos.

OBJECTIVES: To test the artificial activating properties of the human sperm motility-enhancing agents pentoxifylline, caffeine, 2-deoxyadenosine, and cyclic adenosine 3':5' monophosphate (cAMP) on mouse oocytes and determine if the agents exhibit an inhibitory effect on in vitro development of mouse embryos. DESIGN: CD-1 mouse oocytes were exposed to 1, 2.5, 5, or 10 mM pentoxifylline, caffeine, 2-deoxyadenosine, or cAMP for 10, 30, or 60 minutes and their activation and development was scored over 96 hours of culture. A 10% ethanol solution and aging unstimulated oocytes served as controls. Pronuclear embryos from CD-1, CF-1, and B6C3 F1 hybrid mice were cultured in 0.16, 0.33, 0.66, 1.25, 2.5, 5.0, or 10 mM of pentoxifylline, caffeine, 2-deoxyadenosine, or cAMP and development was scored over 96 hours of culture. RESULTS: Exposure to pentoxifylline, caffeine, and 2-deoxyadenosine, but not cAMP, artificially activated mouse oocytes in a concentration- and exposure time-dependent manner. The level of activation was significantly greater than that associated with oocyte aging but less than ethanol-induced activation. Agent-activated oocytes had limited developmental capacity compared with the ethanol-activated oocytes. Pentoxifylline and 2-deoxyadenosine were more toxic than caffeine, especially at the higher concentrations and after prolonged exposure. All of the agents affected embryo development in a dose-dependent manner with developmental inhibition and embryotoxicity that was often not evident until after one to three cell cycles. CONCLUSIONS: Pentoxifylline, caffeine, 2-deoxyadenosine, and cAMP have adverse effects on mouse oocytes or embryos at concentrations commonly used to activate sperm in human IVF. Therefore, care should be taken to minimize the exposure of human oocytes and embryos to these agents until their direct effects have been investigated more fully.

Animals↗
PubMed1995

Visual laser ablation of the prostate (VLAP).

Benign Prostatic Hyperplasia is a condition which occurs commonly in men as they age. The degree of impedence of the flow of urine from the bladder due to prostate gland enlargement varies from a slight slowing of the stream to complete urinary retention. Transurethral Resection of the Prostate (TURP) has historically been the most common treatment of this condition. While other alternative treatments are available, the use of lasers to perform Visual Laser Ablation of the Prostate (VLAP) is moving to the forefront as a treatment of choice for many Urologists.

Humans↗