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Biomedical subjects

A Fischer

Publications and source records attributed to A Fischer.

At least 667 records · Page 37Linked to original sources
PubMed1988

Zidovudine therapy in children with acquired immunodeficiency syndrome.

Eight children with acquired immunodeficiency syndrome (AIDS), aged four months to 12 years, were treated with zidovudine (azidothymidine) 100 mg/m2 intravenously every six hours for 14 days, followed by oral zidovudine at the same dose for a total of six months. Of the eight, six were infected at birth and two were contaminated by blood transfusion at ages eight and nine years, respectively; seven of the eight showed specific neurologic impairment consisting of encephalopathy (six children) and myelopathy (one child). In two children, a dramatic improvement of clinical status occurred, including neurologic progress in one; in three, the improvement was dissociate or transient and in the other three, no modification was observed. A marked increase of total lymphocyte and CD4(+) cell counts occurred in four children but was transient without modification of in vitro antigen-induced lymphocyte proliferation; p24 human immunodeficiency virus serum antigens were detected in seven of eight children, then transiently disappeared in all children during intravenous therapy but reappeared progressively during the oral regimen in all but one. Progressive modification of human immunodeficiency virus serology was noted in five children, mainly characterized by the finding of anti-core antibodies. The hematologic toxicity of zidovudine was comparable with that observed in adults. These preliminary results support the need for further studies in order to delineate the optimal regimen of zidovudine in children with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1988

The role of lymphocyte function-associated antigen 1 (LFA-1) in the adherence of T lymphocytes to B lymphocytes.

The functional role of the LFA-1 molecule in the interaction between helper T lymphocytes and B lymphocytes was investigated using lymphocytes from patients with leukocyte adhesion deficiency, an inherited immunodeficiency characterized by a defective leukocyte expression of the LFA-1, Mac-1 (CR3) and p150,95 molecules. The ability of LFA-1- T lymphocytes to provide antigen-specific help for HLA-identical LFA-1+ B lymphocytes was reduced while their antigen-specific activation was normal. Antigen-independent conjugate formation between resting, nonactivated LFA-1- T lymphocytes and LFA-1+ B lymphocytes was impaired while LFA-1- B lymphocytes bound LFA-1+ T lymphocytes normally. Conjugate formation of activated LFA-1- T lymphocytes was mostly mediated by the CD2-LFA-3 adhesion pathway while the ICAM-1 molecule, a ligand of LFA-1, had no function. These results demonstrate that LFA-1 plays a major role in the cognate interaction between helper T lymphocytes and B lymphocytes that cannot be mediated instead by CD2 or other molecules on resting T lymphocytes.

Antibodies, Viral↗
PubMed1988

Heterogeneity in the molecular defect leading to the leukocyte adhesion deficiency.

Leukocyte adhesion deficiency (LAD) is a recessive autosomal disease characterized by life-threatening recurrent bacterial infections, by defective functions of leukocytes and by deficient membrane expression of leukocyte adhesion glycoproteins. These proteins, LFA-1, Mac-1 and p150,95, are alpha 1/beta 1 heterodimers composed of different alpha chains and of a common beta chain. Patients with the severe phenotype of the disease completely lack the three glycoproteins on cell surface. Previous studies showed a conserved synthesis of the LFA-1 alpha chain precursor in cytosol of patients' cells and an inconstant presence of the beta chain precursor. When present, precursors are in free form and not associated to alpha/beta complexes in the cells of patients with the severe phenotype. The availability of the beta chain cDNA probe allowed us to examine the beta chain gene expression in the lymphoblastoid cell lines of 4 patients. On the basis of the results obtained both at protein and RNA levels we can distinguish 3 types of mutations characterized by (a) barely detectable beta subunit messenger RNA and undetectable beta precursor, (b) decreased level of beta subunit mRNA and undetectable beta precursor and (c) normal beta subunit mRNA level and detectable beta precursor of normal size.

Antigens, Differentiation↗
PubMed1988

A phylogenetic survey of budding, and/or prosthecate, non-phototrophic eubacteria: membership of Hyphomicrobium, Hyphomonas, Pedomicrobium, Filomicrobium, Caulobacter and "dichotomicrobium" to the alpha-subdivision of purple non-sulfur bacteria.

The phylogenetic position of various budding and/or or prosthecate Gram-negative eubacteria was determined by different methods. Members of the genera Hyphomicrobium, Filomicrobium, Pedomicrobium were investigated by 16S rRNA cataloguing, a 1373 nucleotide long portion of the 16S rRNA was sequenced from Hyphomicrobium vulgare and the 5S rRNAs were analyzed from two Hyphomicrobium strains, Hyphomonas polymorpha and Caulobacter crescentus. Comparison with published sequences indicated a membership of all of these organisms to the alpha subdivision of purple bacteria. While C. crescentus and Hyphomonas polymorpha constitute separate individual lines of descent, the position of a coherent cluster embracing Hyphomicrobium, Pedomicrobium and Filomicrobium is not yet settled. 16S rRNA cataloguing indicate the presence of a distinct line equivalent to other subgroups in its phylogenetic depth. 5S rRNA analysis, on the other hand, groups Hyphomicrobium vulgare and strain IFAM 1761 with members of subgroup alpha-2 (Rhodopseudomonas palustris, Nitrobacter winogradskyi and relatives). In contrast to the present classification, Pedomicrobium ferrugineum and Filimicrobium fusiforme are more closely related to certain Hyphomicrobium strains than these are related among each other. Budding mode of reproduction and prosthecate morphology are dominating morphological features of members of the alpha subdivision. These characteristics may gain diagnostic significance in a future formal description of this subdivision and its subgroups as a higher rank.

Base Sequence↗
PubMed1988

Xp21 DNA microdeletion in a patient with chronic granulomatous disease, retinitis pigmentosa, and McLeod phenotype.

The clinical, biochemical, and molecular analysis of a patient with chronic granulomatous disease (CGD), retinitis pigmentosa (RP), and McLeod phenotype and of his parents demonstrated the X-linked transmission of these three traits in this family and a deletion of the entire X-CGD gene of the patient DNA. All but one other DNA markers tested, including those in Xp21, were present. These findings strongly suggest that the McLeod locus and at least one XL RP gene are closely linked to the X-CGD locus in the Xp21 region of the human X chromosome.

Child, Preschool↗
PubMed1988

Prevention of coronary restenosis by stenting.

Balloon angioplasty fails to provide acceptable long-term results for a significant proportion of patients. An intravascular mechanical support, developed with the aim of preventing restenosis and acute closure of diseased arteries after transluminal angioplasty, was implanted in 44 patients (39 male and five female), aged from 35 to 70 years (mean 56 years) with documented restenosis of native coronary artery (41 stents) and bypass grafts (12 stents). In the group of bypass graft patients there was no local restenosis and no major complication. In patients in whom stents were placed in native coronary arteries, the complication rate was higher (two patients died after coronary bypass surgery). One patient died suddenly at home. Except for one patient, in whom a new lesion developed proximally with extension into the stent, no case of restenosis could be observed. Despite the still relatively high complication rate, we feel that stenting may present a rational approach to the unresolved problem of restenosis after coronary angioplasty.

Adult↗
PubMed1988

Emergency stenting for acute occlusion after coronary balloon angioplasty.

Acute coronary artery occlusion complicates 2-12% of the balloon angioplasty procedures, and despite repeat angioplasty, emergency surgical revascularization is often necessary. We report our initial experience with the emergency implantation of endoluminal stents for acute vessel closure after coronary balloon angioplasty. Nine patients received one stent, and two patients received two stents during the study period. Implantation was technically successful in all patients; there were no deaths, no myocardial infarctions as evidenced by Q wave on the electrocardiogram, and no need for emergency surgery. One additional patient, not satisfying the study inclusion criteria, died 16 hours after stent implantation from left ventricular failure and intractable arrythmias. Two patients in the study group had a moderate creatinine phosphokinase rise during the first 48 hours after implantation. During a median follow-up period of 3 months (range, 1-20 months), there have been no deaths and no need for elective coronary bypass surgery. One patient required emergency recanalization 3 months after implantation because of acute occlusion of the stented segment with limited myocardial infarction. Six patients have undergone control angiography, and none has developed chronic restenosis within the stented segment. For selected patients, coronary artery stenting appears to be a promising alternative to emergency bypass surgery after acute vessel occlusion during balloon angioplasty.

Adult↗
PubMed1988

Urothelial atypia and survival rate of 500 unselected patients with primary transitional-cell tumour of the urinary bladder.

In a consecutive series of 500 unselected patients with primary urinary bladder tumours the influence of urothelial atypia on the 5 years survival-rate was examined. All tumours were transitional-cell tumours categorized according to the T-classification. Mucosal biopsies from 7 pre-selected sites were taken at the initial cystoscopy in 391 patients (78%) to identify urothelial atypia. The over-all cumulative 5 years survival-rate was 48%. Submucosal and muscle invasion had major influence on survival, whereas tumour grade was less important. Patients with urothelial atypia fared significantly worse than those with normal bladder mucosa (5 years survival 42% versus 62%). This difference in survival-rate became apparent first after two years of observation. Grade II atypia in the bladder mucosa and grade III (carcinoma in situ) had equal significance assessed by the survival-rates.

Adult↗
PubMed1988

Treatment of severe Epstein-Barr virus-induced polyclonal B-lymphocyte proliferation by anti-B-cell monoclonal antibodies. Two cases after HLA-mismatched bone marrow transplantation.

We treated two children who developed Epstein-Barr virus-induced polyclonal B-cell proliferation after HLA-mismatched bone marrow transplantation for congenital immunodeficiency with two monoclonal anti-B-cell antibodies. Lymphoproliferative syndrome occurred between 50 and 60 days after bone marrow infusion, and was diagnosed by the presence of spontaneously growing B cells containing Epstein-Barr-nuclear antigen in the blood and bone marrow. The mouse monoclonal anti-B-cell antibodies used were a CD21-specific antibody recognizing the CR2 receptor on B cells (BL13, IgG1) and a CD24-specific antibody binding B cells at all steps of differentiation (ALB9 IgG1). Both antibodies were given intravenously (0.2 mg/kg/body weight.d for 10 days). All clinical and biological manifestations resolved within 3 weeks of treatment. Recurrence was not seen at 18- and 15-month follow-ups. T-cell function developed normally; B-cell function remained partially deficient in one patient 21 months after bone marrow transplantation. These results suggest that monoclonal anti-B-cell antibodies could be useful in controlling severe polyclonal lymphoproliferative syndrome in profoundly immunodeficient patients after bone marrow transplantation.

Antibodies, Monoclonal↗
PubMed1988

Leukocyte adhesion deficiency: molecular basis and functional consequences.

Leukocyte adhesion deficiency disease is characterized by a mutation in the gene encoding the beta-subunit shared by three adhesive heterodimers, LFA-1, Mac-1 (CR3) and p150,95 expressed by leukocytes. An absent or abnormal beta-subunit leads to defective expression of the three heterodimers. Severe and moderate phenotypes of the disease are defined by absent and low surface expression of the adhesion molecules. The disease causes an inability of phagocytic cells to adhere to endothelial cells and thereafter to migrate to sites of infections. Severe widespread life-threatening bacterial and fungal infections are the consequences of this abnormality. Cure of the disease can be effected by allogeneic bone marrow transplantation. T-lymphocyte adhesion to various cells is also impaired; its consequences are, however, limited because of the existence of other T-cell-adhesive pathways. Nevertheless, haploidentical bone marrow graft rejection does not occur in the severe phenotype, an indication for possible immunotherapy with LFA-1 specific monoclonal antibodies.

Bone Marrow Transplantation↗
PubMed1988

[Training and conditioning in atopic patients following high altitude climate therapy].

The subjective and objective values have changed after a four weeks treatment in high mountain areas under cool climatic conditions. "Terrainkuren" (mountain walking under guidance of a therapist) under cool climatic- and body temperature conditions show besides training results (in sport medicine) also favourable thermoregulatory adaptations. Improvements of the endurance training can be objectivated by means of the reduced heart frequency and the decrease in lactit acid under standardized physical exercises. The simultaneous changes of thermoregulation can be looked upon as part of the reaction of the whole body (also called inurement). Both, the improvement of the training condition and the thermoregulatory change seem to support each other. Thus patients can train more effectively under the same standardized physical training, but cooler conditions. The decrease of comfort temperature of patients is due to the thermoregulatory adaptation. There is a considerable decrease in the sensibility to cold. The training in high mountain areas causes an improvement in the well being and behaviour of the atopic patients which can still be manifested three months after the therapy.

Acclimatization↗