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Biomedical subjects

M Bell

Publications and source records attributed to M Bell.

At least 127 records · Page 7Linked to original sources
PubMed1994

Insight and psychosocial treatment compliance in schizophrenia.

Research has suggested that poor insight in patients with schizophrenia is associated with poorer medication compliance and heightened levels of psychopathology. This study examined the relationship of insight to compliance with a work rehabilitation program and with levels of psychopathology and psychosocial functioning. Poor insight was found to be positively associated with fewer weeks of participation and with poorer social skills and personal presentation in the fifth week of work. Poor insight was also associated with cognitive disorganization and a lower intelligence quotient, but not with heightened levels of psychopathology. Results suggest that poor insight may predict noncompliance with psychosocial treatment and may be related to a constellation of cognitive deficits.

Adult↗
PubMed1994

Substitution of class II alpha chain polymorphic residues defines location of A alpha k serologic epitopes and alters association between alpha beta and Ii polypeptides.

Structure-function studies of the MHC class II alpha chain have been performed by constructing a panel of A alpha k cDNA genes with one or more d allele substitutions at each polymorphic residue of the alpha 1 domain. The altered genes (A alpha k*) were transfected into a B lymphoma cell line (BKO), which is deficient in A alpha mRNA but retains constitutive wild-type A beta k mRNA expression. Cytofluorometric analysis of cell surface A alpha k* Ak beta molecules was used to map the polymorphic alpha chain residues comprising four serologic epitopes. A alpha k-reactive mAbs 1E9, 2A2, and 3F12 recognize an epitope that includes the polymorphic residue 44 of the A alpha k polypeptide, and the A alpha k-reactive antibody, K24-199, recognizes a conformationally determined epitope influenced by residues from all three polymorphic regions. In addition, we confirmed previous studies demonstrating that la.19 and la.2 mAbs bind to epitopes adjacent to residue 75 in A alpha k. A cell surface negative expression variant also was identified in the panel of mutant cell lines and biochemically characterized. Substitution of six d allele polymorphic residues at positions 11, 14, 28, 69, 70, and 75 in the A alpha k polypeptide (T.EG A alpha k* A beta k*) results in an A alpha k* polypeptide that associates with the A alpha k polypeptide but does not associate with the li polypeptide. This defect in li-A alpha k A beta k interaction is associated with a conformational change in the alpha 1 beta 1 domain that was identified by altered reactivity of the T.EG complex with conformationally dependent anti-alpha and anti-beta mAbs.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1994

Relationship of positive and negative symptoms to cocaine abuse in schizophrenia.

The prevalence of cocaine abuse by patients with schizophrenia has led researchers to investigate features of the disorder correlated with abuse. Although abuse has been found to be more common among patients with a diagnosis of paranoid subtype and a history of earlier and more frequent hospitalizations, it is unclear if it is related to any particular pattern of negative or positive symptoms. This study examines the severity of positive and negative symptoms for patients with and without histories of cocaine abuse. Subjects with a history of at least 2 months of cocaine abuse (N = 25), no lifetime substance abuse (N = 20), and 2 months of alcohol abuse with no other substance abuse (N = 23) are compared on five-factor analytically and three rationally derived scores from the Positive and Negative Syndrome Scale (PANSS). Following a multivariate analyses of variance (p < .01), univariate analyses indicated significant differences on the negative syndrome scales, with cocaine-abusing subjects exhibiting less severe negative symptoms than subjects with no substance-abuse history. Cocaine-abusing subjects were also found to have been younger at time of first psychiatric hospitalization and more likely to qualify for a diagnosis of the paranoid subtype.

Analysis of Variance↗
PubMed1994

Insight and cognitive impairment in schizophrenia. Performance on repeated administrations of the Wisconsin Card Sorting Test.

Research has suggested that poor insight in patients with schizophrenia is associated with poorer treatment compliance and outcome. Little is known about the etiology of poor insight. Poor insight has been attributed to a willful preference for illness, a psychological defense, and cognitive impairments. To test the hypothesis that poor insight is related to enduring cognitive deficits, the performance of 29 patients with schizophrenia and impaired insight and 63 patients with schizophrenia and unimpaired insight was compared on repeated administrations of the Wisconsin Card Sorting Test. Results indicate that subjects with impaired insight demonstrate consistently poorer performance over a period of 1 year than subjects with unimpaired insight. When the effects of IQ were partialled out, subjects with impaired insight made significantly more perseverative errors and achieved fewer categories correct, a pattern of performance deficits identified with neuropsychological dysfunction in schizophrenia. These results support the hypothesis that cognitive impairment may underlie poor insight in schizophrenia.

Adult↗
PubMed1994

Post-thaw sperm motility, cAMP concentration and membrane lipid peroxidation after stimulation with pentoxifylline and platelet-activating factor.

Earlier studies have demonstrated that pentoxifylline (PTX) and platelet-activating factor (PAF) can significantly improve the motion parameters of post-thaw human spermatozoa. This study has investigated the effects of PAF, PTX and their combination on cyclic adenosine monophosphate (cAMP) concentrations and membrane lipid peroxidation (LPO) in post-thaw human spermatozoa. Washed spermatozoa from normal volunteers (n = 10) were cryopreserved in Test-yolk buffer using a standard protocol. After 2 weeks the sperm samples were thawed, washed and incubated with either 1 microM PAF, 3 mM PTX or 0.5 microM PAF plus 1.5 mM PTX. Video sequences were recorded at 0, 30, 60, and 120 min for analysis of sperm motion parameters using the Cell Track Sperm Analysis System. Concentrations of cAMP were assessed by radioimmunoassay, and LPO levels were measured by malondialdehyde-thiobarbituric acid reactivity. Our studies indicate a time-course stimulatory effect with overall maximal stimulation observed in samples treated with the combination of PAF and PTX. The maximal stimulation of percentage motility compared to control was observed at 60 min in samples treated with PAF, PTX, or PAF plus PTX. PAF plus PTX stimulated straight-line velocity (VSL), curvilinear velocity (VCL) and lateral head displacement (ALH) after 30 min incubation. The primary effect of PAF was observed on VSL, while the main effect of PTX was on VCL. cAMP concentrations were 3-fold higher than controls in samples treated with PTX or PAF plus PTX. cAMP concentrations in PAF-treated samples did not differ significantly from controls. No significant differences were observed between any groups for LPO.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Influence of magnetic resonance imaging on a knee arthroscopy waiting list.

Magnetic resonance imaging (MRI) scans were performed on 155 patients who had been placed on a diagnostic knee arthroscopy waiting list 4 to 18 months previously. In all, 32 per cent were removed from the waiting list following this investigation. A total of 24 patients on the waiting list improved spontaneously, including 13 per cent of those with MRI-demonstrable meniscal tears. MRI had an accuracy of 93 per cent, a sensitivity of 100 per cent and a specificity of 67 per cent using arthroscopy as a standard; the false-positive rate was 7 per cent and the false-negative rate 1 per cent. It is concluded that the use of MRI can reduce the requirements for diagnostic arthroscopy, but that the ideal time for MRI is not clear.

Adult↗
PubMed1993

Platelet activating factor and pentoxifylline as human sperm cryoprotectants.

OBJECTIVE: To explore whether the addition of platelet-activating factor (PAF) or pentoxifylline before cryopreservation improves the recovery of motile viable sperm and what role cyclic adenosine monophosphate (cAMP) plays in this recovery. DESIGN: Washed sperm was cryopreserved in the absence of and in the presence of PAF and pentoxifylline. After 2 weeks these samples were quick-thawed and evaluated before and after washing for sperm motility and other motion characteristics. Sperm viability and cAMP concentration were determined to compare the effects of these cryoprotectants. RESULTS: When sperm samples were cryopreserved in the presence of PAF or pentoxifylline, an improvement in the recovery of motile sperm in unwashed and washed post-thaw samples was observed. There were 38% more motile sperm recovered with PAF and 15% more with pentoxifylline when compared with untreated samples. In comparison with the unwashed samples, sperm motility in post-thaw samples was lowered by the washing procedure. When PAF was used as a cryoprotectant, a significant improvement in the linearity and straight line velocity of the post-thaw sperm was observed. When pentoxifylline was used as a cryoprotectant, lateral head displacement was significantly improved in the post-thaw samples than in the control group. Both PAF-and pentoxifylline-treated samples contained a greater number of viable sperm than the control. The cAMP concentrations in post-thaw samples were 12-fold higher in pentoxifylline-treated samples and 4-fold higher in PAF-treated samples when compared with the untreated control. A 4-fold decrease in cAMP concentration was observed in post-thaw control samples compared with fresh-washed sperm. CONCLUSIONS: The results of this study suggest that both PAF and pentoxifylline are useful cryoprotectants for the increased recovery of motile, viable sperm. Although increased recovery of motile sperm in pentoxifylline-treated samples is related to higher cAMP levels, the cryoprotective effect of PAF does not appear to be due to increased cAMP.

Cell Survival↗
PubMed1993

The New York High-Risk Project: anhedonia, attentional deviance, and psychopathology.

In the New York High-Risk Project (NYHRP) we followed subjects at risk for schizophrenic or affective disorders and low-risk controls from childhood to adulthood, with the goal of identifying early predictors of later schizophrenia-related psychopathology. In this article, we focus on two potential predictors: the Physical Anhedonia Scale administered in adolescence and the Attention Deviance Index obtained in childhood. Subjects of this report are 161 members of the NYHRP's first sample (sample A), who had scores on both attention and anhedonia and had followup clinical assessments in adulthood. We used a path analysis model and several separate regression analyses to examine the relationships of the parent diagnostic groups, attentional dysfunction, and anhedonia to each other and to each of three psychopathological outcomes: schizophrenia and schizophrenia-related psychoses, major affective disorder, and social isolation in nonpsychotic subjects. Subject groups did not differ in anhedonia scores but did differ in childhood attentional dysfunction, psychosis, and social isolation, all of which are more common in subjects at risk for schizophrenia. In these subjects at risk for schizophrenia, but not in the other two groups of subjects, childhood attentional dysfunction is related to anhedonia, social isolation, and possibly nonparanoid psychosis. Anhedonia is associated with social isolation and with psychosis in females. Several other gender effects are also noted.

Adolescent↗
PubMed1993

[Pseudo-ainhum in Vohwinkel disease. Keratoma hereditarium mutilans].

An 11-year-old Turkish boy who has suffered from palmoplantar keratosis since his first year of life is presented. He is the only one of a large family to be affected. The diffuse keratosis extends to the back of the hands and feet and still has a progressive course. At the age of 6 he developed a symmetric high-tone acoustic impairment and at 10, an ainhum-like constricting band around the fifth digit of the left hand. This constellation of symptoms is highly characteristic for mutilating keratoma (Vohwinkel's disease), which is a rare disorder of keratinization. The majority of cases in the literature have had an autosomal dominant pattern of inheritance, although sporadic cases like this have also been reported as well. If constricting band proceeds to the point where spontaneous amputation seems imminent, a therapy with orally administered retinoids should be considered.

Ainhum↗
PubMed1993

Abdominal fat deposition in 11-year-old children.

Although the metabolic complications accompanying visceral deposition of fat are well-established, the onset and extent of such fat patterning in children has not been fully documented. This has been due to the problem of computerized tomography exposing children to a prohibitive radiation risk. Nuclear magnetic resonance imaging (MRI) has provided a feasible alternative. Specifically, the purposes of this study were to use MRI (i) to assess the extent of intra-abdominal (IA) and subcutaneous abdominal (SA) fat deposition in 11-year-old boys and girls, and (ii) to identify the most useful anthropometric indicators of IA adiposity in children. Twenty-five boys and 25 girls were selected to represent, by quintiles, the body mass index range for their age. IA fat, SA fat, and total cross-sectional areas were measured from an MRI scan at the umbilicus. Body density was assessed by hydrostatic weighing, and skinfold thicknesses, circumferences and related ratios, and stage of sexual maturity were measured. Results showed that a wide variation in IA fat deposition was present with amounts ranging from 6 to 58 cm2 (mean = 17.8 +/- 10.0) for boys and 15 to 50 cm2 (mean = 24.8 +/- 8.8) for girls. Percentage of cross-sectional area taken up by visceral fat appears to be less than in normal weight adults. Fourteen children had intra-abdominal/subcutaneous abdominal fat ratios that have been associated with higher health risk in obese adults. Waist-hip circumference ratio (WHR), which is widely used as an indicator of IA deposition in adults, was not a useful predictor in these children.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdomen↗
PubMed1992

Object relations deficits in subtypes of schizophrenia.

Forty-eight subjects with diagnoses of schizophrenia were assessed with the Bell Object Relations Inventory (BORI), the Positive and Negative Syndrome Scale (PANSS), the Brief Psychiatric Rating Scale (BPRS), and the Premorbid Adjustment Scale (PAS) to determine the distribution of object relations deficits in the whole sample and four subtypes: paranoid, schizoaffective, poor premorbid, and prominent negative symptoms. Results indicate that 92% of the sample had object relations deficits; 85% showed elevations on the BORI Alienation scale. Subjects with prominent negative symptoms produced lower values on Insecure Attachment and higher values on Egocentricity. This suggests that negative symptoms are associated with a reduction in perceived painfulness of attachment and increased egocentric investment. Other subtyping schemes showed no reliable pattern of object relations deficits.

Adult↗
PubMed1992

Forecast accuracy of Australian subnational population projections.

The authors assess demographic projections made over the last 20 years for Australia. "This paper first considers the role of accuracy amongst other objectives of projection activity. Accepting accuracy as a legitimate goal, we then assess the performance of 48 sets of population projections and forecasts for states and territories of Australia prepared since 1970. Projection accuracy is assessed by reference to length of forecast horizon, population size and rate of growth. We also examine the main sources of forecast error in selected projections for each state and compare the performance of past projections with alternatives based on simple extrapolation of contemporary population trends."

Australia↗
PubMed1992

The effectiveness of adherence intervention in a colon cancer prevention field trial.

BACKGROUND: Adherence interventions were implemented in a 1-year community-based colon cancer prevention clinical trial (n = 110) using wheat bran fiber and calcium dietary supplements. The adherence promotion strategy was guided by a theoretical model. METHODS: The adherence intervention contains both a generalized portion given to all participants and an individualized portion given to marginal (50-74% intake) and low (under 50% intake) adherers. A regression model was employed to assess the effectiveness of the interventions both at the first intervention and at subsequent times. RESULTS: The Health Behavior in Cancer Prevention Model-based adherence promotion intervention was associated with retention of participants, both during the run-in period and after randomization (P = 0.05); and maximization of the percentage of the 13.5-g recommended fiber supplement consumed during the trial (92.5%). The positive effects of the adherence intervention were greater with first-time nonadherers and the control group than with the experimental group. The high-fiber group had notably more biological GI effects from the increased fiber intake, more preexisting comorbidities, and lower perceived cognitive and physical health status. CONCLUSIONS: Randomized participants had excellent adherence overall. Retention rates in the trial were better than would be expected without the adherence intervention, especially among those participants who may have been at higher risk for dropping out of the study. This suggests that a systematic, theoretically based adherence strategy should be further tested in clinical trial settings in which lower adherence is a problem.

Aged↗
PubMed1992

Air-conditioned environments do not prevent deterioration of human semen quality during the summer.

OBJECTIVE: To determine if air conditioning might mitigate summer reductions in semen quality. DESIGN: Prospective study of semen quality in summer and winter. SETTING: Normal human volunteers were studied in the setting of a fertility laboratory. PATIENTS, PARTICIPANTS: Two groups of volunteers were selected from the vicinity of New Orleans: 64 men who worked indoors during the summer in air-conditioned environments and 76 others who worked outdoors. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Parameters of manual semen analysis were examined for seasonal and group differences. RESULTS: Remarkably similar reductions in semen quality during summer as compared with winter were observed in both indoor and outdoor workers, respectively, with regard to the following parameters of semen quality: 19% and 19% in sperm concentration, 25% and 27% in total sperm per ejaculate, 17% and 20% in motile sperm concentration, 13% and 15% in percent sperm with normal morphology, and 23% and 23% in concentration of morphologically normal motile sperm. CONCLUSIONS: These findings do not support the hypothesis that the heat of the summer is detrimental to male reproductive capacity. The available evidence suggests instead a possible role of photoperiod in causing the seasonal changes in semen quality.

Adolescent↗