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Biomedical subjects

A Fischer

Publications and source records attributed to A Fischer.

At least 775 records · Page 43Linked to original sources
PubMed1983

[Development of hypertension and cataract in spontaneously hypertensive rats].

The investigations were performed on 3 groups of untreated, spontaneously hypertensive Wistar rats of the Okamoto line. All the rats in Group I developed arterial hypertension within 16 weeks of birth and 33 percent of them developed cataracts within 22 weeks. Reserpine application suppressed hypertension and cataract development in all the animals in Group II. After unilateral adrenalectomy and contralateral adrenal enucleation (Group III), hypertension and cataracts developed in both treated and untreated animals; in the former, however, blood pressure was about 10 percent higher and cataracts developed about 6 weeks earlier than in the untreated rats. These findings support the hypothesis that arterial hypertension may be involved in cataract development.

Adrenalectomy↗
PubMed1983

Unsuccessful experience with closure of Jaboulay gastroduodenostomies in the treatment of post-vagotomy dumping and diarrhea.

Eight patients after vagotomy and Jaboulay gastroduodenostomy had their gastroduodenostomy closed to treat dumping and diarrhea. Eight gastroduodenostomies were closed once and four were closed twice, a total of 12 procedures. Of these, ten were "simple" closures (direct suture of the opening into the duodenum via a gastrotomy) and two were "formal" (gastroduodenostomy formally dismantled). Among those gastroduodenostomies closed "simply," the closure remained intact for 2 to 9 months, relieving the patients' symptoms. Thereafter, the suture line broke down, leaving the patient with a patent gastroduodenostomy and recurrent symptoms. The two patients closed "formally" developed severe complications: one patient's stomach failed to empty permanently after the procedure and the second developed a duodenal leak. In addition to these major complications, another four of the 12 procedures were followed by transient gastric retention, and five of the 12 procedures were accompanied by minor pulmonary and wound complications. A satisfactory result was not achieved in any patient.

Adult↗
PubMed1983

Molecular-genetic and chemotaxonomic studies on Actinomadura and Nocardiopsis.

The relationships of 24 strains of 13 species of Actinomadura and 4 strains of Nocardiopsis dassonvillei were determined by nucleic acid hybridization studies. DNA-rRNA cistron similarity and DNA homology values reveal that Actinomadura is genetically heterogeneous. One cluster contained the type species Actinomadura madurae, Actinomadura pelletieri, Actinomadura verrucosospora, Actinomadura malachitica, Actinomadura citrea and 'Actinomadura kijaniata'. A second cluster embraced Actinomadura pusilla, Actinomadura roseoviolacea, Actinomadura libanotica, Actinomadura roseola and Actinomadura ferruginea. The internal homogeneity of the two Actinomadura clusters was demonstrated by a high similarity in the menaquinone and fatty acid composition of the strains enclosed. Actinomadura spadix, Actinomadura spiralis, and two strains of Actinomadura madurae were found to be unrelated to each other and could not be allocated to one of the two major Actinomadura clusters. Nocardiopsis dassonvillei was genetically and phenotypically clearly separated from all Actinomadura species investigated.

Actinomycetales↗
PubMed1983

Specific in vitro antimannan-rich antigen of Candida albicans antibody production by sensitized human blood lymphocytes.

We have developed a new antigenic system for the induction of specific in vitro antibody response in man. The antigen used was purified from the cell wall of Candida albicans strain A and contained greater than 96% polysaccharide mannan. Peripheral blood mononuclear cells from Candida-sensitized donors produced specific antimannan antibodies during a 7-d culture in the presence of mannan absorbed with methylated bovine serum albumin. Two methods were used to detect antimannan antibody responses. Antimannan antibody-producing cells were identified by radioautography with tritiated mannan. Antibody concentration in culture supernatants was measured by an enzyme-linked immunosorbent assay. In both methods, specific IgM and IgG (but not IgA) antibodies were detected. The antibody production to mannan was specific, since an antigenically unrelated polysaccharide (pneumococcal antigen S III) did not bind to methylated bovine serum albumin-mannan-induced blast cells and did not induce antimannan antibody-containing cells. Furthermore, a pulse with an excess of unlabeled mannan abolished [3H]mannan binding, whereas an excess of unlabeled S III did not. Similarly, no antimannan antibody was obtained in influenza virus-stimulated cultures and mannan-stimulated cultures were not inducing antiinfluenza antibodies. The antimannan antibody production was shown to be a T cell-dependent phenomenon. The T helper effect appeared to be radiosensitive. It was under a genetic restriction as it occurred only in autologous or semi-identical but not in allogeneic situations. This system is relatively simple, reproducible, and well suited for the study of specific secondary in vitro antibody responses to polysaccharide antigens in humans.

Antibodies, Fungal↗
PubMed1983

Induction of a T-cell mediated suppressor activity by soluble products from antigen-specific helper/inducer human T-cell lines.

Influenza virus-specific (A/X31) long-term cultured human T-cell lines belonging to the helper/inducer T-cell set, produce high potency antigen specific helper factors which induce in vitro antibody production to A/X31 by autologous B cells, as well as small and variable amounts of non-specific helper factors. When added to unseparated peripheral blood mononuclear cells, both cultured T cells and their supernatants suppress in vitro antibody synthesis as measured by a solid phase enzyme-linked immunoassay, and T-cell proliferation to antigens and allogeneic cells, but not to mitogens. This phenomenon was further analysed and could be separated into several steps: (i) the production of suppressor inducer factor(s) by the T-cell lines which are distinct from the helper molecules; (ii) activation of T cells belonging to the suppressor/cytotoxic subset as defined by monoclonal antibodies, a process which is antigen-independent and non-genetically restricted, and is optimal with 18 hr incubation; (iii) the activated T cells non-specific suppress antibody production and antigen-induced or allogeneic cell-induced T-cell proliferation. Thus, antigen-specifically activated T-inducer cells exert multiple activities, including specific and non-specific help and non-specific induction of T suppressor cells.

Antibodies, Viral↗
PubMed1983

Antigen-specific and non-specific helper activities derived from supernatants of human influenza virus-specific T-cell lines.

A T-cell line (H3) was established by culturing human peripheral blood mononuclear cells with influenza virus A/X31 and maintained in long term culture with Interleukin-2 (TCGF). Supernatants were prepared by culturing these cells overnight in the absence of Interleukin-2 but with A/X31 and irradiated autologous E rosette negative cells as a source of antigen presenting cells, and harvesting by centrifugation. The supernatants were shown to replace T cells in helping E- (B) cells to produce antibody specific to A/X31 which was measured by enzyme immunoassay (EIA). Although maximal help was obtained with autologous or semi allogeneic B cells (in the latter case bearing HLA-DR 3 loci) there was still significant antibody production with allogeneic combinations. The supernatants were subsequently fractionated into specific and non-specific helper activities by gel filtration, giving an approximate mol. wt of 50-70,000 and 10-30,000 for each respectively. The specific HF was shown to be genetically restricted in its action upon B cells and also to generate antibody to A/X31 only. The lower molecular weight material acted on any responding B cell regardless of HLA-DR type and produced antibody non-specifically in culture with E- cells even in the absence of antigen. The apparent lack of restriction was therefore due to the masking effect of non-specific and non-restricted HF(s) on the genetically restricted specific HF produced by this line.

Antibodies, Viral↗
PubMed1982

[Evaluation of aortic dissection by transverse computerized tomography (CT scan)].

Twenty patients with dissection of the thoracic aorta were studied by CT-scanning. In 9 patients the diagnosis was previously documented by aortography, while in the other 11 patients the diagnosis of aortic dissection was first established by CT-scanning. The latter demonstrated the characteristic signs of aortic dissection and particularly the following features: a) the false channel (95%) and the intimal flap (90%), b) the displacement of aortic wall calcifications (60%), especially when the false channel is partially thrombosed (80%). In 19 patients, a bolus injection of contrast medium was performed. In the majority of cases opacification of the false channel occurred only partially, with some delay and with a non-homogeneous pattern. Six out of the 20 patients underwent one or more follow-up examinations performed between 15 days and 2 years later. CT-scanning clearly demonstrated the late persistence of a patent false channel and particularly the delayed thrombosis, even after surgical treatment of aortic dissection. CT-scanning appears to be a reliable non-invasive method for - establishing the diagnosis of aortic dissection, - delineating the extent of dissection, - follow-up of evolution after surgical or medical therapy.

Aged↗
PubMed1982

An influenza virus matrix protein-specific human T cell line with helper activity for in vitro anti-hemagglutinin antibody production.

A human helper T cell line (F14m) activated by the matrix protein purified from A/X31 influenza virus has been developed. After activation by antigen for 7 days, and reculture with matrix protein and irradiated autologous feeder cells, the cells obtained from an in vivo influenza virus-immunized donor have been growing in the presence of interleukin 2 for more than 7 months. The cells all belong to the helper-inducer T cell subset and most of them express surface membrane HLA-DR antigens. A small number (approximately 10(3)) of F14m T cells provided optimal help for 1 X 10(5) autologous T-depleted lymphocytes for production of anti-A/X31 but not anti-B/HK antibodies. The F14m T cells produce soluble factors (S14m) able to help B cells to secrete anti-A/X31 antibodies. F14m and S14m were shown to help antibody production to hemagglutinin when cultured with B cells and the whole virus. The specificity of the T cell line for type-A matrix protein was confirmed by the ability of S14m to provide help for anti-A/JAP (A/H2/N2) but not for anti-B/HK antibody production. These data provide evidence for matrix protein-specific T helper cells and factors able to provide help for antibody production against hemagglutinin, a distinct protein of the same virus.

Antibodies, Monoclonal↗
PubMed1982

Tiny interstitial duplication of proximal 7q in association with a maternal paracentric inversion.

Paracentric inversion of chromosome 7 was found in a female infant with multiple malformations and in her phenotypically normal mother. Examination of prometaphase chromosomes revealed an additional small dark band on the inverted chromosome 7 of the girl. It was assumed that an unequal crossing over at the base of a meiotic loop of chromosome 7 had occurred in the mother and resulted in a tiny interstitial duplication in the girl.

Abnormalities, Multiple↗
PubMed1982

Biotin-responsive immunoregulatory dysfunction in multiple carboxylase deficiency.

The immunoregulatory system has recently been shown to require prostaglandins (PG) for its activation in man. We report here an impairment of immunoregulatory function, due to defective PGE monocytic production, in a 12-month-old boy with multiple carboxylase deficiency (MCD). The abnormal immune-response was corrected in vitro by adding PGE to the medium. Moreover, PGE deficiency and immunoregulatory dysfunction responded to biotin administration in vivo. It is suggested that the PGE deficiency in MCD could result from an impaired activity of a biotin enzyme, acetyl CoA carboxylase, since the product of this enzyme reaction, malonyl CoA, is required for prostaglandin synthesis.

Biotin↗
PubMed1982

Respective roles and interactions of T-lymphocyte and PGE2-mediated monocyte suppressive activities in human newborns and mothers at the time of delivery.

Recently the concept of a poorly functional humoral immune response in the newborn was proposed. Data have been presented indicating that the impaired newborn B cell maturation, as shown in vitro in a pokeweed mitogen-induced B cell maturation system, is due both to an immaturity of lymphocyte subsets and to an increased suppressive T activity. In the present work, we present evidence that there exists a predominance of a naturally occurring T lymphocyte suppressive activity in the cord blood in that the removal of the suppressive activity by irradiation allows a normal maturation of newborn B cells. Such normal maturation of newborn B cells can also be obtained using mixed cultures of adult T cells and newborn B cells. Newborn suppressor T cells belong to both EA gamma (+) and EA gamma (-) fractions, and it is not known whether these two groups do or do not belong to different subsets. The PGE2-dependent monocyte suppressive activity does not play any role in the suppression observed in newborns since newborn monocytes are poorly suppressive and since they produce a smaller amount of PGE2 than adult monocytes. Some observations suggest, on the contrary, that the suppressive T lymphocytes can regulate the level of the PGE2-dependent monocyte suppressive activity. It should be noticed that similar observations about T lymphocyte and PGE2-dependent monocyte suppressive activities have been made at the same time using mothers' cells. These observations suggest the possibility that such changes in B cell immune regulation may result from an interaction between maternal and fetal lymphoid cells.

B-Lymphocytes↗