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Biomedical subjects

A Fischer

Publications and source records attributed to A Fischer.

At least 649 records · Page 36Linked to original sources
PubMed1989

Successful HLA nonidentical bone marrow transplantation in three patients with the leukocyte adhesion deficiency.

Three consecutive patients with the severe phenotype of leukocyte adhesion deficiency characterized by a defective expression of LFA-1, Mac-1 (CR3), and p150.95 on leukocytes have received HLA partially incompatible bone marrow transplantation (BMT). The degree of HLA incompatibility between related donors and recipients was 2 HLA antigens in one and one full haplotype in the two others. Graft-v-host disease (GVHD) prophylaxis consisted in T-cell depletion of the bone marrow inoculum and a 60-day course of cyclosporin A. A first attempt led to autologous recovery in one patient. The second transplant in this patient and the first transplant in the two others led to stable partial engraftment of lymphocytes and phagocytic cells, as shown by expression of adhesion molecules (LFA-1, Mac-1) on leukocytes and by HLA typing and restriction fragment-length polymorphism studies using minisatellite probes. Although the level of mixed chimerism was lower in one patient (7% to 30% donor cells) and greater than 50% in the two others, recovery of lymphocyte and phagocytic cell functions was sufficient enough to allow the patient to lead a normal life, infection free in the three cases. These patients, now 57, 32, and 19 months post-transplant, are in good condition without any therapy. These results lead us to propose that the LFA-1 molecule plays a role in HLA-incompatible graft rejection, probably by mediating adhesion of cytotoxic T and non-T lymphocytes to their targets.

Antibody Formation↗
PubMed1989

[Neutropenias in children].

Whereas the clinical expression of childhood neutropenias is fairly uniform, consisting mainly in infections, a wide variety of etiologies may be involved. Pathophysiologic mechanisms have not all been completely elucidated. We review the different etiologies of neutropenia in children using the classification that we believe is the most helpful to clinicians. The clinical features and management of primary chronic neutropenias are described in detail. On the basis of our experience we suggest a practical diagnostic strategy for investigating children with neutropenia.

Agranulocytosis↗
PubMed1989

[Chediak-Higashi disease: a new case treated by bone marrow allograft].

We report a new case of Chediak-Higashi disease successfully treated by the transplantation of allogeneic bone marrow. Recurrent infections led to the diagnosis of the disease at the age of 15 months. At two and a half years of age, during a phase of accelerated disease activity, the patient received a bone marrow transplant donated by an HLA-identical brother. The patient was conditioned by chemotherapy alone; T-cells were removed from the graft and cyclosporin A was given to prevent graft-versus-host disease. Evidence of acceptance of the transplant was apparent 14 days after the procedure. Two months after the transplant, the blood count was normal, NK activity was satisfactory and no evidence of GVH disease was present. Incomplete hematopoietic chimerism was found (with two erythrocyte and lymphocyte populations). After four years follow-up, the patient is doing well and has no infections or evidence of active disease.

Bone Marrow Transplantation↗
PubMed1989

In vivo infusion of anti LFA-1 antibody in HLA non-identical bone marrow transplantation in children: serum concentrations and biological effects.

The mouse monoclonal antibody 25-3 specific for the alpha subunit of LFA-1 (CD11a) has been infused to children undergoing HLA non-identical bone marrow transplantation because of lethal inherited diseases or of leukemia in order to prevent graft failure. We have assessed the serum concentrations of the antibody infused according to two regimens: 0.1 mg/kg five times, every alternate day (eight patients) or 0.2 mg/kg daily for 10 days (30 patients). Serum trough levels of 25-3 antibody in the first group were constantly found to be low (less than 0.6 micrograms/ml) while 25-3 serum concentration in the second group rose progressively to a mean value of 2.2 micrograms/ml. Serum antibody concentrations were significantly lower in patients with greater antigenic mass, i.e. with splenomegaly, or non conditioned. The engraftment rate was slightly higher in patients treated by the daily infusion of 25-3 for 10 days. No immunization against 25-3 antibody occurred. One patient who subsequently received other mouse anti-B cell antibodies eventually produced anti-isotype antibodies. The consequences of 25-3 infusion on leukocyte counts has been evaluated in the group of patients (n = 6) with severe combined immunodeficiency who did not receive any chemotherapy and in one who was treated with 25-3 because of acute graft-versus-host disease. In none of the cases did 25-3 antibody infusion modify blood leukocyte counts. In addition, it was shown that saturation of LFA-1 on leukocytes was a transient phenomenon, since it could not be found 24 h following infusion of 25-3 antibody.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1989

[Study of blood cyclosporine after kidney or bone marrow transplantation. Comparison of immunofluorescence and radioimmunoassay].

The apparition of cyclosporine, immunodepressive drug, has largely improved the organ transplantations. However, the range of blood concentrations must be defined to allow the efficacity of cyclosporine therapy and to avoid toxic reactions, because there are very important variations for a same dosage according to the individuals and the diseases. Relative to the low concentrations to be determined (about one hundred ng/ml), the most useful methods for cyclosporine measurement are based on immunochemical assays. This work compare the two methods: radioimmunoassay (RIA) and fluorescence polarization immunoassay (FPIA) simultaneously performed on several hundred samples. A very significant correlation exists between the two techniques (r = 0,80). The advantages of immunofluorescent assay consists in rapidity, sensibility and facility to realize emergency analysis.

Bone Marrow Transplantation↗
PubMed1989

[The accelerated phase of Chediak-Higashi syndrome].

We have retrospectively analysed the clinical and biological features as well as the outcome of 18 accelerated phases having occurred in 11 patients with the Chediak-Higashi syndrome. This complication is very frequent and is characterized by a multi-visceral lymphohistiocytic infiltration with hemophagocytosis leading to pancytopenia, a bleeding disorder secondary to low fibrinogen level, hypertriglyceridemia and hemodilution. The accelerated phase of the Chediak-Higashi syndrome is identical to the manifestations of familial erythrophagocytic lymphohistiocytosis and of the viral-associated hemophagocytic syndrome. The outcome was invariably fatal before the use of etoposide (VP 16) in association with steroids and intrathecal methotrexate. Complete remission with this management regimen was observed in 7/7 cases. However, remissions were only transient. HLA identical bone marrow transplantation appeared to be the only therapeutic strategy capable of curing the disease (3/3 patients). Non transplanted patients relapsed and died as well as one patient who received a HLA non identical bone marrow transplantation. Due to the frequency and the severity of the accelerated phase of the Chediak-Higashi syndrome, HLA identical bone marrow transplantation should be proposed as early as possible after the onset of the accelerated phase.

Adrenal Cortex Hormones↗
PubMed1989

[Severe Epstein-Barr virus infection in an infant].

A 11 month-old boy, without any informative familial pedigree, was admitted for peritonitis after intestinal perforation, associated with signs of pseudolymphoma and histiocytic activation. He developed later unexplained gastrointestinal bleeding and interstitial pneumonitis, which spontaneously improved. All infectious and immunologic studies were negative. Epstein-Barr Virus was found in throat, lungs and blood, whereas the specific antibodies production was delayed. No abnormality was detected 18 months later, except for a disappearance of vaccinal antibodies.

Humans↗
PubMed1989

[Hypoplasia of cartilage and hair with combined immune deficiency].

We report a case of cartilage-hair hypoplasia in a girl. The patient had short stature with short limbs and scalloped long bone metaphyses, sparse, poorly-pigmented hair, and increased susceptibility to infections. Several features of this case deserve attention: neutropenia, probably due to an autoimmune mechanism, was an initial manifestation; the immune deficiency (defective B and T cell immunity, autoimmune manifestations) was severe, and cytomegalovirus infection possibly aggravated the immune deficiency and hormone abnormalities. Whereas this patient's short stature is becoming more marked, prophylaxis of infections and administration of immune globulins have effectively prevented complications for the last two years.

Cartilage Diseases↗
PubMed1989

[The test of a centrifugal hematology system for use in clinical practice].

The QBC is a centrifugal haematology system. Modified haematocrit capillaries are measured optically. The parameters haematocrit, total leukocyte count, relative and absolute values of granulocyte and lympho-/monocyte fractions, and total thrombocyte count are stated. The microhaematocrit method, the counting chamber, and the differential blood count are reference methods. Blood samples of the dog, cat and horse were used for the study. As a screening method the QBC analysis meets all requirements for the veterinary practice.

Animals↗
PubMed1988

[Acute coronary occlusion following transluminal angioplasty: the role of an implanted parietal support via transluminal route].

Acute coronary artery occlusion complicates some 5% of balloon angioplasty procedures and often makes emergency surgical revascularization necessary. Initial experience is reported with emergency implantation of endoluminal stents for acute vessel closure following coronary balloon angioplasty. 10 patients received one stent and 2 patients two stents during the study period. In the study group, implantation was technically successful in all cases: there were no deaths, Q-wave infarctions or cases requiring emergency surgery.--2 patients showed a moderate rise in creatinine phosphokinase in the first 48 hours. During a mean follow-up period of 4 months (range 1-21 months) there have been no deaths and no cases requiring elective coronary bypass surgery. 10 patients underwent control angiography and none have developed significant restenosis within the stented segment. For selected patients, coronary artery stenting appears to be a promising technique as an alternative to emergency bypass surgery after acute vessel occlusion during balloon angioplasty.

Angioplasty, Balloon↗
PubMed1988

Immunosuppressive properties of synthetic peptides derived from CD4 and HLA-DR antigens.

Synthetic peptides derived from the beta 1 domain of HLA-DR antigens containing RFDS and a peptide derived from the immunoglobulin-like amino-terminal domain of CD4 and containing RADS were shown to exhibit specific dose-dependent inhibitory effects on antigen-induced HLA class II-restricted T-cell proliferation and in vitro antibody synthesis. These inhibitory activities are similar to those exhibited by anti-CD4 and HLA-DR antibodies, respectively. The peptides derived from HLA-DR or CD4 and anti-CD4 or anti-HLA-DR antibodies acted together in synergy to inhibit these responses when the relevant cell populations were incubated with infrainhibitory concentrations of the reagents. In contrast, these peptides were shown to exert no inhibitory activity on nonspecific T-cell activation mediated by ionomycin, phorbol myristate acetate, and interleukin-2.

Antibody Formation↗
PubMed1988

Role of the LFA3-CD2 interaction in human specific B cell differentiation.

We examined the role of the lymphocyte function-associated (LFA)3 molecule in human B cell response. A mAb to this molecule did not influence B cell proliferation induced by anti-mu antibody and IL. In contrast, the same mAb inhibited the specific T-dependent B cell response induced by a particulate Ag. In the same line, two anti-CD2 mAb (directed toward the T11-1 and T11-2 epitopes) inhibited this response, whether used alone or in association. These inhibitions took place at an early stage of the response, and anti-LFA3 and anti-CD2 mAb acted on B cells and T cells, respectively. In contrast, when T cell help was provided by exogenous IL-2, the B cell response was resistant to the inhibitory effect of anti-LFA3 mAb. Taken together, these results indicate that the LFA3-CD2 pair play a major role in the direct T-B interaction required for T cell help.

Animals↗