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Biomedical subjects

D Braun

Publications and source records attributed to D Braun.

At least 73 records · Page 4Linked to original sources
PubMed1992

[Asymptomatic giant thoracic dumbbell neurinoma. Apropos of a case].

Giant thoracic dumbbell neurinomas are usually revealed by neurological or mediastinal signs. The case we are reporting was discovered accidentally and allow us to add some accuracy to the current diagnostic criteria for these tumors. MRI provides the most interesting information. The surgical exeresis of these tumors must use a double approach: first laminectomy then thoracotomy.

Adult↗
PubMed1990

Effects of reappearance of fixated and attended stimuli upon saccadic reaction time.

The effects of visual attention and fixation upon the distribution of saccadic latencies: express (E-), fast regular (FR-), and slow regular (SR-) saccades were investigated. Extinguishing a fixation or an attention point 200-300 ms before target onset increases the incidence of E-saccades while concurrently decreasing the proportion of SR-saccades. Since this extinction forces a disengaging of attention, these changes in relative proportions of saccades reflect the elimination of one of the steps involved in programming saccades. It is shown that a previously attended stimulus has a favored status relative to other stimuli in the visual field. If, after being turned off, the previously attended fixation point or a peripheral attention stimulus is turned on near the time of the target's appearance, the occurrence of the E-saccades is greatly reduced. However, the appearance of any other stimulus in the visual field at or near the time of the target onset does not inhibit E-saccades. Contrary to the conclusions reached by Posner and Cohen (1984), a stimulus presented at the formerly attended location can attract attention more efficiently than a stimulus presented at another, new location.

Attention↗
PubMed1990

Automating a clinical management system.

Automating the clinical documentation of a home health care agency will prove crucial as the industry continues to grow and becomes increasingly complex. Kimberly Quality Care, a large, multi-office home care company, made a major commitment to the automation of its clinical management documents.

Boston↗
PubMed1989

Distribution of cells bearing "rheumatic" antigens in peripheral blood of patients with rheumatic fever/rheumatic heart disease.

Cell surfaces of some peripheral blood cells from individuals with a history of rheumatic fever/rheumatic heart disease (RHD) have been demonstrated by the use of monoclonal antibodies to be antigenically distinct from the majority of the population. Our study examines the distribution of cells bearing these "rheumatic" antigens in 23 subjects with rheumatic fever/RHD of Maori, Polynesian and Caucasian ancestry and 182 members of their families (rheumatic fever/RHD families) as well as in 46 members of families in which no member had been demonstrated to have had rheumatic fever/RHD (control families). Mononuclear cells from the blood of all cooperating family members were prepared and non-T cells isolated by sheep red blood cell rosette depletion. The binding of monoclonal antibodies 83S19.23 and D8103 to non-T cells was measured using an immunoperoxidase technique. Subjects with rheumatic fever/RHD had a significantly higher proportion of cells binding the antibodies than the unaffected members of all families. Unaffected members of rheumatic fever/RHD families had significantly higher levels of such rheumatic cells than control families. An increase in the proportion of rheumatic cells with age was noted in unaffected members of rheumatic fever/RHD families but not in rheumatic fever/RHD subjects of control families. A level of 13% 83S19.23 positive non-T cells optimally discriminated between rheumatic and nonrheumatic individuals. The relative risk for rheumatic fever/RHD with 13% or greater positive cells was 9.48. The negative predictive value of having less than 13% positive cells was 98.3%. In the population studied, 83S19.23 seems especially capable of identifying those with low risk for rheumatic fever/RHD.

Aging↗
PubMed1988

Receptor analogs and monoclonal antibodies that inhibit adherence of Bordetella pertussis to human ciliated respiratory epithelial cells.

The adherence of Bordetella pertussis to human respiratory cilia is critical to the pathogenesis of whooping cough. To explore the development of agents that could interrupt adherence, the structure of the receptor on the ciliary surface was investigated. Using an in vitro adherence assay to human ciliated epithelial cells, galactose, lactose, and complex carbohydrates containing lactose eliminated adherence when preincubated with the bacteria. 10(-2) M galactose eluted adherent bacteria from cilia. B. pertussis and its two purified adhesins bound specifically to natural lactose-containing glycolipids in a TLC assay. mAbs to eukaryotic glycoconjugates with specificity for substituted galactose-glucose moieties blocked adherence when preincubated with ciliated cells. The carbohydrates that serve as receptors for B. pertussis on human cilia are galactose-glucose-containing glycolipids. Receptor analogs and anti-receptor antibodies effectively block adherence of B. pertussis to cilia and thus should be considered candidates for therapeutic intervention against disease.

Antibodies, Monoclonal↗
PubMed1988

Cell surface markers and cellular immune response associated with rheumatic heart disease: complex segregation analysis.

A series of functional and cell surface markers associated with a significantly increased risk of rheumatic heart disease were analyzed for the contribution of genetic factors in their presence. Peripheral blood lymphocytes from nine large kindreds from the New Zealand Maori, Polynesian, and Caucasian populations were isolated, purified, and evaluated with lymphocyte surface markers (monoclonals 83S.19.23 and D8103), as well as studied for blastogenic response to a purified group A streptococcal extracellular product, blastogen A. Segregation analysis of blastogenic response and percent of cells positive for these cell surface markers was consistent with genetic control by single major genes; however, the contribution by polygenes varied by marker, indicating heterogeneity of genetic control of identification of cell surface glycoproteins and blastogenic response to streptococcal products.

Antibodies, Monoclonal↗
PubMed1988

Relationship between directed visual attention and saccadic reaction times.

Saslow (1967) and Fischer and Ramsperger (1984) found that saccadic reaction time (SRT) depends on the interval between the fixation point offset and the target onset. Using a continuously visible fixation point, we asked whether a similar function would be obtained if subjects attended to a peripherally viewed point extinguished at variable intervals before or after the target onset. The interval was varied between -500 ms (i.e., attention stimulus offset after saccade target onset = overlap trials) and 500 ms (i.e., attention stimulus offset before saccade target onset = gap trials). The results show a constant mean SRT of about 240 ms for overlap trials, and a U-shaped function with a minimum of 140 ms, at a gap duration of 200 ms, for gap trials. These findings suggest that saccadic latencies do not depend on the cessation of fixation per se, but rather on the disengagement of attention from any location in the visual field. The time required for subjects to disengage their attention is approximately 100 ms. This disengaged state of attention--during which short latency (express) saccades can be made--can be sustained only for a gap duration of 300 ms. At longer gap durations mean SRTs increase again.

Attention↗
PubMed1988

Effects of the antiallergic drug ketotifen on bronchial resistance and beta-adrenoceptor density of lymphocytes in children with exercise-induced asthma.

In a parallel, double-blind, placebo-controlled study we investigated the effect of the antiallergic drug Ketotifen on bronchial resistance (determined body plethysmographically) and beta 2-adrenoceptor density of lymphocytes (determined by 125-iodo-cyano-pindolol binding) in asthmatic children suffering from exercise-induced asthma (EIA). In order to provoke EIA a test which involved running for 7 min was performed with 22 asthmatic children. 13 age-matched children not suffering from asthma served as controls. Control children showed a 30% increase in the number but not in the affinity of beta-adrenoceptors in response to a 7-min run. Asthmatic children with EIA showed no difference in the number and affinity of beta-adrenoceptors under resting conditions when compared with the controls. In contrast to what has been observed with control children, however, no increase in the number of beta-adrenoceptors in response to exercise was observed. A 1-week treatment with placebo neither affected the bronchoconstriction nor the number of lymphocyte beta 2-adrenoceptors. Ketotifen (2 X 1 mg/day for 1 week) protected asthmatic children from EIA, at least in part, and restored the up-regulation of beta-adrenoceptors in response to exercise in 9 of 14 children with EIA. However, no correlation between the serum concentration of Ketotifen and the number of binding sites could be found. It is therefore concluded that the preventive effect of Ketotifen in EIA might also involve mechanisms other than a recovery of the beta-adrenergic system.

Adolescent↗
PubMed1988

Synthesis of eicosanoids by gamma-interferon-differentiated U937 cells.

Interferons induce morphological, biochemical and functional alterations in monocyte macrophage and myeloid cell lines. We studied the effect of 3 days incubation with gamma-interferon from human buffy coats on the global synthesis of arachidonic acid metabolites by U937 cells. Interferon-induced morphologic changes including cytoplasmic and nuclear changes and the appearance of multiple lysosomal-like granules consistent with cellular differentiation were observed by electron microscopy. The labeling of phosphatidylserine, phosphatidylcholine and phosphatidylethanolamine was increased and that of phosphatidylinositol, free fatty acids as 3H-arachidonic acid and neutral lipids reduced, when interferon-treated cells were incubated with 3H-arachidonic acid. Interferon caused qualitative and quantitative changes in the synthesis of cyclooxygenase and lipoxygenase products. A23187, a calcium ionophore, and the tumor promotor, phorbol myristate acetate, greatly increased the synthesis by interferon-differentiated cells of 2 cyclooxygenase products; synthesis of lipoxygenase products was reduced. In the presence of indomethacin, 'shunting' into putative lipoxygenase products occurred. The relationship between interferon-induced morphologic and functional changes, the development of altered phospholipid and eicosanoid metabolism and the identity of these metabolites are yet to be established.

Cell Differentiation↗
PubMed1987

Identification of an Epstein-Barr virus early gene encoding a second component of the restricted early antigen complex.

When the latent Epstein-Barr virus (EBV) genome in B95-8 cells is induced into a replicative phase, two abundant early RNAs are transcribed rightward from the EBV BamHI H DNA fragment into BamHI F. Analysis of cDNA clones prepared from the RNA of cells replicating EBV revealed that both RNAs contain the BHRF1 open reading frame. Part of BHRF1, cloned into a prokaryotic fusion protein expression vector, expressed a fusion protein in Escherichia coli and the purified fusion protein was used to generate a monoclonal antibody against BHRF1. This antibody was then employed to characterize the protein encoded by BHRF1 in cells replicating EBV. The monoclonal antibody reacted with a 17-kDa protein component of the restricted early antigen (EA) complex. The distribution of the protein in cells was similar to that noted when sera from patients with African Burkitt's lymphoma were used to stain these cells. The protein was synthesized before the major 47-56 kDa protein associated with the diffuse component of EA in superinfected Raji cells. All human sera containing antibodies to EA as determined by immunofluorescence (IF) reacted with the protein as did some sera determined to be anti-VCA positive and anti-EA negative by IF. The predicted amino acid sequence of the protein has characteristics which suggest that it is a membrane protein. It also has significant homology with both the anchor region of polyoma middle T antigen and with the predicted protein product of the bcl-2 mRNA activated by the 14/18 chromosome translocation characteristic of follicular lymphomas. This latter homology is extensive and colinear, suggesting common evolution and function. However, neither a mRNA which could efficiently translate the BHRF1 protein nor the BHRF1 protein could be detected in latently infected cells. Thus, the bcl-2 predicted protein is similar to an EBV protein synthesized in the early phase of virus infection.

Antibodies, Monoclonal↗
PubMed1987

Munchausen's syndrome: a reconceptualization of the disorder.

The American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, third edition (DSM-III) delineates three categories of factitious disorders: chronic with physical symptoms (Munchausen's syndrome); factitious disorder with psychological symptoms; and other factitious disorders with physical symptoms. Munchausen's syndrome served as the prototype for all factitious disorders at the time DSM-III was drafted, partly due to the disproportionate attention given to this variant of the disorder. Clinical experience suggests that existing categories do not adequately provide for commonly seen forms of factitious illness. It is now recognized that factitious disorder is the result of a complex interaction of personality factors and psychosocial stressors that often present with both medical and psychiatric symptomatology. Proposed changes in the revised edition of the diagnostic manual DSM-III-R include separate categories of factitious disorder with psychological, physical, and both psychological and physical symptoms. A case report of a patient for whom extensive records and thorough psychological assessment were available is exemplary of a more common course of the disorder (both psychological and physical symptoms) that by current classification would be considered "atypical." A reconceptualization of the disorder that gives emphasis to course and clinical features is suggested.

Adult↗