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Biomedical subjects

D Niethammer

Publications and source records attributed to D Niethammer.

At least 289 records · Page 16Linked to original sources
PubMed1976

The effect of trimethoprim on cellular transport of methotrexate and its cytotoxicity to human lymphoblastoid cells in vitro.

A study has been made of the effects of the antifolate drug trimethoprim (2,4-diamino-5-(3'4',5'-trimethoxybenzyl)pyrimidine) on the cellular transport of natural folates and of methotrexate in a human lymphoblastoid cell line grown in culture. The results indicated that cellular uptake of 5-methyltetrahydrofolate, folic acid and methotrexate could be inhibited by trimethoprim; the inhibition, for methotrexate at least, was competitive, but it was in every case rather weak. Calculations showed that under conditions used during therapy with methotrexate, trimethoprim could be employed as an antibacterial agent without the cellular uptake of methotrexate being impaired by more than 1%. The cytotoxic effect of trimethoprim against the cell line used was 2000 times less, on a molar basis, than that of methotrexate. However, the degree of growth inhibition caused by the two agents in combination was greater than the sum of the individual toxicities. Again, this effect was not large at clinically useful concentrations of trimethoprim.

Biological Transport↗
PubMed1976

A case of impaired chemotaxis and lymphocyte transformation.

The report describes the clinical syndroms of a 14-year-old boy which suffered from recurrent infections since early infancy. The clinical and general laboratory findings were similar to "the granulomatous disease of childhood" as described by Bridges et al. (8). The following serum factors were determined: Immunoglobulins, complement factors, isoagglutinins. The following assays with normal or patient's granulocytes were done: Chemotactic activity, nitroblue-tetrazolium test, bactericidal assay, fungicidal assay, myeloperoxidase, monocytes fungicidal assay. Immunological studies include kinetics of phytohaemagglutinin response, effect of serum of the patient on lymphocytic reactivity in vitro and skin tests. The following results were obtained: 1) Assays with normal or patient's granulocytes showed an impaired chemotatic activity, when serum of the patient was added. There was strong indication by treatment of the patient with plasma infusions, that the chemotactic defect is a serum dependent factor. 2) It could be demonstrated that the patient's serum also inhibited the response of lymphocytes to tuberculin and phytohaemagglutinin. Therefore the patient report focuses attention upon the possibility of serum related abnormalities that may influence granulocytic as well as lymphocytic functions leading to recurrent bacterial, fungal and viral infections.

Adolescent↗
PubMed1976

An inherited defect in granulocyte function: impaired chemotaxis, phagocytosis and intracellular killing of microorganisms.

The neutrophil granulocytes of a 1-year-old boy with severe recurrent infections were found to have almost no chemotactic responsiveness, impaired phagocytosis and reduced intracellular killing of Candida albicans "in vitro". During the course of a febrile illness of unknown etiology which was accompanied by a leukemoid reaction, phagocytic activity became normal; the chemotactic response was also increased but still remained slightly subnormal. Family studies suggested that the defect was an inherited autosomal recessive one.

Chemotaxis↗
PubMed1976

[Dysfunction of Granulocytes in Children with Frequent Infections].

Eight children with various diseases, who has frequent infections were examined for abnormalities of serum proteins and leucocyte function. Inborn or secondary defects could be recognized by the tests for chemotaxis, the intracellular killing of bacteria as well as yeast and the oxydative metabolism of the granulocytes. The defects were serum- or cell-dependent and they could be detected alone or in combination with other dysfunctions. Three children showed a reduced stimulation of the lymphocytes in addition to the impairment of chemotactic activity or fungicidal cavity.

Adolescent↗
PubMed1975

Impairment of granulocyte function in juvenile diabetes.

Granulocyte function of 10 diabetic children has been investigated. At the time of testing the diabetes was in poor control. Five children were retested one week later after adjustment of diet and insulin dose. In contrast to some reports we did not find a phagocytic defect in the ingestion of particles, but the capacity of intracellular killing of Staphylococcus aureus was impaired. Chemotaxis was also reduced whereas the NBT-index and intracellular killing of Candida albicans were normal. Better control of the diabetes led to an improvement of bactericidal killing capacity.

Adolescent↗
PubMed1975

[Granulocyte dysfunction. I. Inborn defects (author's transl)].

The insight in the function and dysfunction of granulocytes lately arouses more and more interest. This report summarises our present knowledge. In the first of two chapters the authors review the molecular basis of granulocyte function and the inborn defects of chemotaxis, opsonisation, phagocytosis and intracellular killing of bacteria and fungi.

Agranulocytosis↗
PubMed1975

Congenital stomatocytosis and chronic haemolytic anaemia.

A new case of congenital stomatocytosis associated with haemolytic anaemia, increased autohaemolysis, abnormalities in the erythrocyte metabolism, increased osmotic fragility and shortened erythrocyte survival is described. Intracellular cation concentrations are abnormal: Red cell sodium is high, and potassium is low. The pump rate for monovalent cations is increased.

Adenosine Triphosphatases↗
PubMed1975

[Diagnosis and therapy of primary defects of immunity (author's transl)].

Immunological responses are divided into those mediated by humoral antibody (B-Cells) and those by cells (T-Cells). Both depend upon the activity of small lymphocytes which become thymus or bursa analogue dependent during embryonic development. Primary immundeficiencies are therefor defects of lymphocytes attributed in most cases to gene defects. Early diagnosis is the necessary prerequisit for possible treatment. Tests for assessing the cellular immune status are: skin testes and in vitro tests. Clinical syndroms are: lymphocytopenia, hypoplasia, deficiency of lymphocytes in lymphatic tissues normal cortical germinal centres. Recurrent infections with viruses, candida or pneumocystis carinii are common. Tests for assesing the humoral immune status are: measurement of immunglobulin levels in serum, isohaemagglutinins, tests for antibody formation following active immunization, in vitro tests. Clinical syndroms are: no germinal centres in lymphnodes, no plasma cells. Recurrent bacterial infections. Treatment of B-cell deficiencies: immunglobulin replacement therapy. Treatment of T-cell deficiencies by grafting of thymus transplants. Combined immune deficiencies are treated with bone marrow transplants from matched donors. For bone marrow transplantation germfree state seems to be the ideal situation to protect the patient against infection before the therapeutic maneuver and for prevention of graft versus host reaction in the posttransplantation period.

B-Lymphocytes↗