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Biomedical subjects

J Becker

Publications and source records attributed to J Becker.

At least 235 records · Page 13Linked to original sources
PubMed1988

Cognitive function and platelet membrane fluidity in Alzheimer's disease.

Increased platelet membrane fluidity, as reflected by a decrease in the fluorescence anisotropy of diphenylhexatriene in labeled membranes, identifies a clinically distinct subgroup of approximately 50% of patients at our center who meet NINCDS-ADRDA clinical criteria for Alzheimer's disease. In the current study, we compared the cognitive impairments of patients in this subgroup to those observed in the residual subgroup of patients with Alzheimer's disease who had normal platelet membrane fluidity. No significant differences in the number or distribution of deficits in six cognitive domains were observed between the two subgroups. However, in the subgroup with increased platelet membrane fluidity, there were significantly more patients who exhibited dissociation of deficits on tests related to left and right parietal lobe function than in the residual subgroup. Moreover, the cases with dissociation of deficits consisted almost entirely of patients with deficits on tests reflecting left parietal lobe function and no deficit on tests of right parietal lobe function.

Aged↗
PubMed1988

Suppression of yeast ingestion by dexamethasone in macrophage cultures: evidence for a steroid-induced phagocytosis inhibitory protein.

The mechanism by which glucocorticoid steroids suppress yeast phagocytosis in cultures of resident and thioglycollate-elicited murine peritoneal macrophages was examined. Time course and dose-response studies demonstrated that the phagocytic capacity of resident macrophages was suppressed by dexamethasone to the same extent in both newly established cultures and cultures that were incubated for several days. In contrast, relative to newly established cultures of elicited cells that were treated with the drug, elicited macrophages that were incubated for at least 1 day prior to exposure to dexamethasone, exhibited enhanced sensitivity to the action of the steroid. Steroid-induced phagocytic inhibitory responses were blocked by the metabolic inhibitors cycloheximide and actinomycin D. The suppression of phagocytosis by dexamethasone was mediated by a factor, present in the cellular homogenates of steroid-treated macrophages, that was partially purified by Sephadex G-25 chromatography. Since the phagocytic inhibitory activity in these homogenates was destroyed following exposure to heat and trypsin, the factor has been named phagocytosis inhibitory protein (PIP). The antiphagocytic activity of PIP was neutralized by treatment with RM23, a monoclonal antibody directed against lipocortin. The results support the hypothesis that the suppression of yeast ingestion is mediated by the action of PIP, which is induced in dexamethasone-treated macrophage cultures. Moreover, PIP appears to belong to the lipocortin family of phospholipase inhibitory proteins.

Animals↗
PubMed1988

Difficulties in assessing depressive-like reactions to chronic severe external stress as exemplified by spouse caregivers of Alzheimer patients.

Problems in making differential diagnoses and severity ratings of depressive-like reactions in chronically, heavily stressed persons are described. These assessment concerns are especially pertinent to older persons. The assessment concern discussed relates to difficulties in determining the extent to which stress reactions are inevitable consequences of stressor demands versus excessive pathological reactions versus natural manifestations of aging. The newly revised criteria of the Diagnostic and Statistical Manual of Mental Disorders, 3rd edition (DSM-III-R) and its associated structured interviews do not lessen the difficulties described. However, they reflect progress in specifying the amount of cross-sectional and longitudinal consistency required before maladaptive behaviours meet diagnostic and/or severity criteria as pathological indicators. Stressor level is important among the criteria for the less severe DSM-III-R depression-related disorders, but the specific response demands of the stressors are ignored. By contrast, biomedical factors are consistently given significant weight. To clarify these matters, the five DSM-III-R diagnostic axes, depressive diagnostic criteria, and associated structured interviews for eliciting relevant data are reviewed.

Adjustment Disorders↗
PubMed1988

EEG maturation on children with different economic and psychosocial characteristics.

It has been shown that EEG maturation can be described in terms of regression equations on age of broad band EEG frequency parameters. In the present paper six groups of children with different economic and psychosocial characteristics of three countries were studied. Regression equations on age of the EEG relative power (expressed in percentages of the total EEG activity) in the delta, theta, alpha and beta bands in 8 bipolar derivations were computed in each group of children and the slopes compared with those previously published by John et al. (1980). Those children who grew up with adequate nutritional, sanitary and cultural environmental conditions showed the same slopes as U.S. and Swedish children selected with strict criteria of normality. Children nourished in poor socioeconomic and sanitary environments and who frequently had pathological personal antecedents with risk factors associated with brain damage showed either a slow maturation of the EEG characterized by smaller slopes of theta relative power or a great variance of EEG parameters and no relation of these parameters to age.

Child↗
PubMed1988

Effect of different factors on EEG spectral parameters.

We had previously observed that in groups of children with low socioeconomic and cultural level the EEG spectral parameters did not correlate with age due to the great variance in the distribution of such EEG parameters. In this paper we have made several statistical analyses in order to look for other factors that may explain the great variance observed. EEG during rest was recorded in 14 monopolar leads from 119 children. After FFT the following measures were calculated: absolute power, relative power, dominant frequency, coherence and left power/right power ratio for the delta, theta, alpha and beta bands in each derivation. For each measure, in each derivation, ANOVA analyses were performed taking age as covariable and sex, presence or absence of antecedents of risk factors and of learning disorders (LD) as independent variables. Age had its main effect on absolute power in the different bands and in the dominant frequency in the alpha band. Sex affected absolute and relative power in the alpha band. Risk factors per se had no effect. Presence of LD showed its main effect on absolute power. Many interactions between risk and LD and sex and LD were observed. Other analyses, such as MANCOVA, corroborated these results: significant differences between girls and boys, significant differences between children with and without LD and no differences between children with and without antecedents of risk factors.

Adolescent↗
PubMed1988

Circadian rhythms of cell cycle processes in the marine dinoflagellate Gonyaulax polyedra.

The circadian expression of several growth properties was examined in the dinoflagellate Gonyaulax polyedra under constant light and light-dark conditions. The cell concentration, mean cell volume and rate of DNA synthesis varied in a circadian rhythm, with the primary maximum of cytokinesis and DNA synthesis at about dawn. High rates of cell mortality also occurred during phases related to events of cytokinesis, and may be important in the expression of the other rhythms and in "red tide" generation. Flow-cytofluorimetric analysis indicated that cells of a population contain either a relatively high or a low amount of DNA, but the proportion of cells in each of these classes and the absolute amount of DNA in each cell varied rhythmically depending on the circadian time. This DNA-distribution pattern was unlike the usual G1-S-G2+M pattern typical of eukaryotic cell populations. Isotopically labelled thymidine, used as a marker of DNA synthesis, was continuously incorporated; but the incorporation rate fluctuated in a regular pattern that repeated each circadian period.

Animals↗
PubMed1988

Maternally induced graft-vs-host disease to minor antigens as a possible etiology of an acquired immunodeficiency syndrome in mice.

It has been postulated that an acquired immunodeficiency syndrome develops in neonates as the result of a maternally induced graft-vs-host disease (GVHD) that develops when sufficient numbers of maternal lymphocytes are transferred to the fetus across the placental barrier. The present study was done to determine whether major histocompatibility complex (MHC) antigens or non-MHC minor histocompatibility antigens (MiHA) were involved. Female C57BL/6 mice were bred to males of eight selected strains such that maternal-fetal disparity existed at MHC antigens and/or minor histocompatibility antigens. Offspring were tested for immune function at 6-7 weeks of age using a Jerne plaque assay to measure the humoral response to that T dependent antigen sheep red blood cells (SRBC). None of the offspring developed clinical signs of GVHD, but 3 of 124 mice tested made no immune response to SRBC. Immunodeficiency was associated with maternal-fetal disparity only at a small number of MiHA and not at the MHC. We postulate that immunodeficiency in this model is mediated by a subclinical maternally induced GVHD to paternally derived MiHA of the fetus.

Acquired Immunodeficiency Syndrome↗
PubMed1987

In situ hybridization to detect Epstein-Barr virus DNA in oral tissues of HIV-infected patients.

Thirty biopsies of oral mucosal lesions and normal oral mucosa were obtained from 26 HIV-seropositive individuals and studied for virus infections with Epstein-Barr virus-specific DNA probes (EBV). In situ DNA hybridization was carried out on frozen and formalin-fixed, paraffin-embedded tissues. Specifically bound biotinylated virus probes were detected with the streptavidin-gold-silver technique and visualized by standard and interference reflection microscopy. In 9/30 biopsies, EBV DNA was clearly demonstrated in the upper two thirds of oral epithelia. This finding corresponded to peculiar cytopathic effects including ground glass nuclei, basophilic nuclear inclusions, and ballooning of the cytoplasm, which were concentrated in the upper two or three layers of the stratum spinosum. Cytopathic effects together with the demonstration of EBV DNA were demonstrated in seven cases of tongue mucosa, and two cases derived from the gingiva. When comparing clinical and pathological findings with DNA detection rates, we saw 5/9 hairy leukoplakias associated with EBV infections. Four positive cases (two samples from the tongue, two gingival specimens) had not been regarded as hairy leukoplakia clinically. EBV infection of the oral epithelium occurred in male homosexuals (7 cases) and in male/female intravenous drug abusers (2 cases). Among the nine EBV-positive cases, 2 patients were asymptomatic, 4 patients were grouped into the ARC-, and 3 individuals into the AIDS-category. We conclude that HIV-seropositive patients are particularly prone to develop productive EBV infections in oral epithelia. This infection most frequently appears at the lateral border of the tongue, but may also occur at other sites of the oral cavity, and may already exist in a preclinical stage prior to the development of oral white lesions (hairy leukoplakia).

AIDS-Related Complex↗
PubMed1987

The extracellular matrix in oral Kaposi sarcoma (AIDS): the immunohistochemical distribution of collagens type IV, V, VI, of procollagens type I and III, of laminin and of undulin.

Twelve oral AIDS-associated Kaposi sarcomas (KS) were studied for the distribution of extracellular matrix components using indirect immunofluorescence. Staining for basement membrane (BM) components revealed two distinct patterns of distribution: a delicate and partly fragmented lining of BMs around sinusoid-like vascular spaces or an occasional diffuse interstitial fluorescence in the tumour stroma; or an irregular broad rim of fluorescence in walls of larger blood vessels. These findings support a vascular cell origin of the endothelial- and spindle cell component in KS. The tumour stroma was almost completely negative for collagen type V and undulin, whereas an intensive fluorescence was noted for procollagens type I, III and collagen type VI. In areas adjacent to KS a loss of procollagens type I and III, collagens type V, VI and undulin was noted. An intimal sheath of collagen type V was usually absent from blood vessels of the tumour or the peritumourous connective tissue. Immunohistochemical findings indicate that the preexisting interstitial connective tissue matrix is destroyed during tumour invasion and that subsequently procollagens type I, III and collagen type VI are synthesized de novo by cells of the tumour stroma.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Raw versus relative scores in the assessment of coping strategies.

Raw scores (frequency of efforts) versus relative scores (percentage of efforts) were compared on the five scales of the revised Ways of Coping Checklist. It was hypothesized that, conditional on the source of and appraisal of a stressor, problem-focused coping should be inversely related and Wishful Thinking should be positively related to depression when relative scores were used but that raw problem-focused scores would be less clearly related to depression in such a way. It was further hypothesized that these relationships would hold for very diverse samples: psychiatric outpatients (n = 145), spouses of patients with Alzheimer's disease (n = 66), and medical students (n = 185). Given the maladaptive status of the psychiatric outpatients, it was hypothesized that they would report more emotion-focused strategies and less problem-focused coping than the nonclinical samples and that these differences would be better observed using relative rather than raw scores. The hypotheses were generally supported.

Adaptation, Psychological↗
PubMed1987

Sex hormones in lesbian and heterosexual women.

The authors measured plasma testosterone (T), androstenedione (A), and cortisol (C) levels in seven lesbian and seven heterosexual women matched for age and socioeconomic status. In addition, psychiatric symptoms, physical activity levels, depression, subjective sense of stress, and sexual behavior variables were assessed. There were no significant differences in sex hormone levels between the two groups of women, who were also comparable in psychiatric symptom levels, depression, and self-perceived stress. Lesbian women reported significantly more current physical activity relative to peers. Other than the sexual orientation difference which was a prerequisite for entry into the study, there were virtually no significant differences in sexual behavior although lesbian women tended to have achieved psychosexual milestones at a younger age. We were not able to corroborate the finding of Gartrell, Loriaux, and Chase (1977) that lesbian women have higher T levels, possibly due to the fact that the two groups were closely matched on several behavioral variables potentially affecting testosterone levels.

Adult↗
PubMed1987

Depressive thinking and depression: relations with personality and social resources.

The mechanisms by which social supports and personality variables may buffer against psychopathology are not well understood. We studied depression, depressive cognitions, social supports, and self-esteem in a sample of 68 spouse-caregivers of patients with Alzheimer's Disease in an attempt to identify possible buffering mechanisms of the latter two variables. Specifically, we hypothesized that the well-known relation of depressive cognitions to depression would vary as a function of satisfaction with social supports and with level of self-esteem. Hierarchical multiple regression analyses conducted to predict depression revealed significant and independent main effects for depressive cognitions (p less than .01), social supports (p less than .025), and self-esteem (p less than .001), with depressive cognitions associated with higher depression and the other two variables associated with reduced depression (R2 = .53 for the three main effects). In addition, the relation of depressive cognitions with depression varied substantially depending on the level of social supports (p less than .01); caregivers with high levels of depressive cognitions had high levels of depression only if social supports were low (R2 = .61 including interaction). Self-esteem and depressive cognitions showed a similar interaction, but it failed to reach significance. Analyses to determine whether self-esteem and social supports were directly associated with lower depressive cognitive activity yielded a main effect for self-esteem only (p less than .03). Thus, whereas social supports and self-esteem were directly associated with lower depression, only the social supports variable was further associated with reduced depression because it apparently buffered the impact of depressive thinking. Self-esteem was also indirectly associated with lower depression via its relation with lower depressive thinking. Implications of our results for cognitive theories of depression and for the psychosocial mechanisms of stress buffering are discussed.

Adult↗
PubMed1987

Social networks: we get by with (and in spite of) a little help from our friends.

Studies of social support networks have almost exclusively measured only their positive aspects. In this research, we investigated both the helpful or positive and the upsetting or negative aspects of social networks in a longitudinal study of spouses caring for a husband or wife with Alzheimer's disease, a progressive senile dementia. Measures of helpful and upsetting aspects of the care givers' networks, derived from interviews and daily interaction ratings, were studied for their relations with overall network satisfaction and depression at an initial interview period (n = 68) and at a follow-up period about 10 months later (n = 38). Results from hierarchical multiple regression analyses, in which care givers' age and sex and a measure of the spouses' health status were controlled, showed that the care givers' degree of upset with their networks was strongly associated with lower network satisfaction and increased depression at both time periods. Helpful aspects bore little or no direct relation to either depression or network satisfaction. Helpful aspects of the network did, however, interact with network upset in predicting network satisfaction, and depression (combined probabilities test, p less than .05). Longitudinal predictions of follow-up depression, after age, sex, care givers' health status, and initial depression levels were controlled, showed that changes in upsetting aspects of one's network were predictive of changes in depression over time. We interpreted these results within an attributional framework that emphasizes the salience of upsetting events within a social network.

Adaptation, Psychological↗
PubMed1987

Side effects following metrizamide myelography and lumbar laminectomy.

A retrospective study of 50 patients was undertaken to observe the postoperative side effects experienced by patients undergoing metrizamide (Amipaque) myelography followed by laminectomy on the same day and to compare them with side effects experienced if the laminectomy was postponed at least one day. Results documented that the incidence of nausea was statistically greater in Group 1 (myelogram and surgery the same day) than in Group 2 (delayed surgery). While the occurrence of vomiting and headache in Group 1 was also greater, the numbers did not reach statistical significance. Group 1 did require significantly more doses of antiemetics for a longer period of time. The groups did not differ in the length of time an intravenous (IV) infusion was in place, but Group 1 patients required a significantly greater number of urinary catheterizations for retention and residual for longer than three days. The length of stay and the time from surgery to discharge was the same for both groups.

Adult↗