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Biomedical subjects

A Fischer

Publications and source records attributed to A Fischer.

At least 793 records · Page 44Linked to original sources

Sclerotherapy of bleeding esophageal varices. Long-term results.

Sixty-one patients presenting with hemorrhage from esophageal varices were treated with sclerotherapy by means of a fiberoptic endoscope. Twenty-nine had acute bleeding, which was stopped in 90%. Thirty-two were treated after recent bleeding. The hospital mortality was 31%. Re-bleeding occurred in 55% of those discharged but was easily controlled. Fatal complications occurred in 5%. The calculated 4-year survival was 35%. Two thirds of this mortality could be attributed to liver failure. The intellectual function of the patients appeared to be unaffected.

Adult↗

Defective handling of mannan by monocytes in patients with chronic mucocutaneous candidiasis resulting in a specific cellular unresponsiveness.

Carbohydrate antigens from Candida albicans, essentially mannan, have previously been shown to persist in the serum of some patients with chronic mucocutaneous candidiasis, and to be able to inhibit specifically the candida antigen-induced proliferation of control lymphocytes. Lymphocytes from three out of six patients were shown to be hypersensitive to mannan inhibition. These data were explained by the demonstration of an apparently selective impairment of radiolabelled mannan handling by two patients' monocytes following a normal uptake. This defect was observed both in active and remission phases of the infection suggesting an intrinsic defect of patients' monocytes. In experiments performed with control lymphocytes, it was shown that mannan exerted its suppressive effect by interfering with candida antigen presentation by adherent cells to autologous T lymphocytes. Furthermore, mannan neither was cytotoxic nor induced suppressor T cells. Altogether, these data suggest that the in vivo persistance of mannan, in some patients, is secondary to a primary macrophage dysfunction leading to impairment of specific cellular immune responsiveness.

Antigens, Fungal↗

Lack of prostaglandin E2-mediated monocyte suppressive activity in newborn and mothers.

An excess of adult blood adherent cells (monocytes) inhibits mitogen, antigen and allogeneic cell-induced lymphocyte proliferations. This inhibition is dependent on the number of the adherent monocytes in the cultures and is substantially reduced (by 60%) by indomethacin or anti-PGE2 antiserum. Newborn monocytes exert only a weak inhibitory effect and produce about eight times less PGE2 than adult monocytes. The production of PGE2 and the suppression can be induced by incubating newborn monocytes with mixed leucocyte culture supernatants. Both monocytes from mothers at the time of delivery and from newborn infants, usually exert a poor suppressive activity related to a low production of PGE2. We strongly suggest that the expression of the PGE2-mediated suppression by monocytes is under the control of activated short-lived suppressor lymphocytes.

Adult↗

Inability of newborns' or pregnant women's monocytes to suppress pokeweed mitogen-induced responses.

Although an excess of human adult blood adherent cells inhibits the pokeweed mitogen- (PWM) induced normal adult lymphocyte proliferation and B cell maturation into immunoglobulin-containing cells (ICC), adherent cells collected from newborn infants or pregnant women at time of delivery were unable to exert a similar suppressor activity. After activation by Concanavalin A (Con A), newborns' and pregnant women's adherent cells acquired a suppressor activity comparable to that of control adult adherent cells. The adherent suppressor cell was shown to be radioresistant (3000 rad), indicating its probable monocytic origin. Both monocyte-suppressor activities (MSA) observed in adulthood (spontaneously) and in the neonatal period (after activation) were dependent on prostaglandin E2 (PGE2) secretion, because they were abolished by indomethacin or a specific anti-PGE2 antiserum. Expression of MSA appeared to be under a negative regulation exerted by naturally occurring T suppressor lymphocytes present in the blood of newborns or pregnant women, because incubation of adult monocytes or Con A-activated newborn monocytes with newborns' or pregnant women's T lymphocytes resulted in a dramatic decrease of their MSA. These results strongly suggest that the lack of MSA in the neonatal period and in late pregnancy is a consequence of activation of T suppressor lymphocytes.

B-Lymphocytes↗

Familial tiny 9p/20p translocation: 9p24. The critical segment for monosomy 9p syndrome.

The presence of a chromosomal translocation was suggested in a large kindred with several cases of mental retardation. Chromosome analysis by means of a high resolution technique revealed a translocation of a tiny terminal portion of 9p onto 20p in the presumptive balanced translocation carriers. Five of the affected family members demonstrated monosomy of the terminal portion of 9p. Their clinical features fitted well to the known 9p- syndrome. The breakpoint on 9p is in the distal part of band 9p23. This family confirmed the assumption that the critical segment for monosomy 9p syndrome is located within the terminal band 9p24.

Adult↗

[Immunologic study of familial lymphohistiocytosis. Eight new case reports (author's transl)].

We report 8 cases of familial lymphohistiocytosis collected in 6 families. Several data argue for an hyperactivation of the reticuloendothelial system (RES). An abnormal visualization of all organs was observed in a scintigraphic study after 99technetium labelled red blood cells injection. Blood monocytes contained very low peroxidase activity as detected by cytoenzymology and secreted large quantities of prostaglandin E2 (PGE2). Adherent cells isolated from blood exercised a strong suppressor effect on the proliferation of normal lymphocytes induced by phytohemaglutinin. This effect was reduced by indomethacin and therefore appears PGE2-dependent. One patient's serum exerced an inhibitory activity on antigen-induced proliferation of normal lymphocytes and on mixed leucocyte reaction. In contrast, cellular and humoral functions were not deeply impaired. The hyperactivation of the RES remains unexplained and not related to a graft versus host reaction, which could be excluded in 3 of our patients. Therapeutic attempts were not efficient, all patients dying despite steroid, vincaleucoblastin and indomethacin therapy.

Female↗

Possible association of angiosarcoma with oral contraceptive agents.

Angiosarcoma of the liver has been reported to be associated with the long-term use of androgenic-anabolic and oestrogenic steroids. It has been suggested that this tumour might develop in women after long-term exposure to oral contraceptive steroids, although this association has not yet been reported. We present here the clinical and pathological findings in a 42-year-old woman who died of hepatic angiosarcoma after taking oral contraceptive steroids for 10 years.

Adult↗

Duodenal ulcer, suicide, psychopathology and alcoholism.

The incidence of suicide in a consecutive series of 1,000 patients, who underwent Billroth II resection for duodenal ulcer, has been estimated. After an observation period of 21-29 years 13.7% of those who had died had committed suicide. The psychiatric morbidity in this ulcer group was found to be very high. Among the psychiatric diseases alcoholism was dominating, but also non-psychotic conditions such as neurosis and psychopathy were frequent. Fifty per cent of the persons who had committed suicide were alcoholics, and the alcohol abuse seemed to develop after surgery. Gastric resection for duodenal ulcer may have pathogenetic importance in the development of alcoholism, which is known as a predictor of suicide. The importance of considering psychiatric disturbances in the postoperative follow-up is stressed.

Adult↗

Haemoglobin synthesis in bone marrow of patients with beta O and beta +-thalassaemia.

Haemoglobin synthesis was studied in bone marrow erythroblasts and in reticulocytes of 4 children with beta O-thalassaemia major and of 7 children with beta +-thalassaemia major. In patients with beta O-thalassaemia the gamma/a ratio was found to be lower in bone marrow than in peripheral blood. On the contrary, in patients with beta + thalassaemia the beta + gamma/a ratio was more balanced in bone marrow, where the beta-chain synthesis was higher, than in reticulocytes. This last result could be explained by the presence of an abnormal m-RNA for beta-chains in beta +-thalassaemia.

Bone Marrow↗

Dysfunctions of pokeweed mitogen-stimulated T and B lymphocyte responses induced by gammaglobulin therapy.

Lymphocytes obtained from nonimmuno deficient children treated with commercially available preparations of gammaglobulin failed to proliferate and to mature into plasma cells in vitro after stimulation with pokeweed mitogen. The influence of the treatment on lymphocyte functions varied according to the cell population considered. A T helper cell activity was detected in these patients but only in the cell subset bearing receptors for IgG after irradiation. T lymphocytes exerted a suppressive effect that disappeared after irradiation or incubation at 37 degrees C. The suppressive cells were found among E rosette-forming cells depleted of leukocytes bearing receptors for IgG. Their suppressive effect was expressed only in the presence of normal radioresistant T lymphocytes that did not bear Fc receptors for IgG. Similar dysfunctions could be induced in vitro by incubation of normal T and B lymphocytes with gammaglobulin preparations. Because F(ab)'2 fragments or deaggregated preparations of gammaglobulin failed to activate T suppressor lymphocytes, this activation was likely triggered by attachment of Fc portion of denatured IgG to the corresponding membrane receptor. This activation step was prostaglandin E(2)-dependent, suggesting that activated monocytes were involved in the activation process. B lymphocyte responses appeared directly inhibited by attachment of denatured gammaglobulin on membrane Fc receptor. Our observations suggest that immunological effects of gammaglobulin therapy are not limited to antibody transfer, since it also induces subtle modifications of in vitro pokeweed mitogen-stimulated T and B cell responses. These modifications must be considered in interpreting results obtained in immunodeficient patients investigated under gamma-globulin therapy.

Antigens, Surface↗

Role of prostaglandin E2 in the induction of nonspecific T lymphocyte suppressor activity.

Activated human monocytes and concanavalin A (Con A)-activated T lymphocytes are known to suppress T and B lymphocyte proliferation and B cell maturation into immunoglobulin-producing cells. We have now shown that monocyte suppressive activity is predominantly mediated through release of prostaglandin E2 (PGE2), which is active only in the presence of a "short-lived," radiosensitive T lymphocyte subset. PGE2, at high concentration, can activate T suppressor lymphocytes (TS), which display the same characteristics as Con A-activated TS lymphocytes. Moreover, Con A activation of TS lymphocytes was obtained only in the presence of PGE2, as specific anti-PGE2 antiserum or indomethacin prevented TS activation; this suggested a double signal as a prerequisite for activation of the nonspecific TS cell subset. We propose that TS lymphocytes modified by Con A become sensitive to small amounts of PGE2 produced by monocytes that must be present during the Con A-stimulated activation phase of suppressive cells.

B-Lymphocytes↗