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Biomedical subjects

K Neuhaus

Publications and source records attributed to K Neuhaus.

At least 19 recordsLinked to original sources
PubMed1993

Immune restoration in children after partial splenectomy.

Splenectomy (SE) is recognized to be a therapeutical approach in treating children with severe autoimmune diseases (chronic idiopathic thrombocytopenia; hemolytic anemia) or hypersplenism because of portal hypertension. Nevertheless, removal of a main immune organ results in elevated infection risk for these patients. Partial splenectomy (PSE) was developed as a therapeutical compromise to retain immunologically active spleen tissue. Here, we document the analysis of immune parameters obtained from children after both partial and total splenectomy, which have been followed up for a period of more than 6 years: (i) Lymphocytes from both groups of patients failed to produce IgG in response to pokeweed mitogen in vitro. This was observed in 11/20 splenectomized patients even 10 years after operation, whereas in PSE patients a restoration of this parameter after 1-2 years was seen. (ii) In patients after PSE, but not in splenectomized persons, an elevated number of HLA-class II positive cells had been detected suggesting a different situation of immune regulation following this operation. However, in parallel with an improvement of B cell in vitro activity this parameter was found to achieve normal values. Our findings indicate that partial splenectomy may be a therapeutical alternative, if the therapeutic goal can be achieved by this procedure.

Adolescent↗
PubMed1991

Comparative analysis of the influences of IL-1, IL-3 and GM-CSF on the commitment of granulocyte-macrophage progenitors in vitro.

Our experiments were directed towards the detection of the influence of interleukin-1 (IL-1); interleukin-3 (IL-3), and granulocyte-macrophage colony-stimulating factor (GM-CSF) on the generation of granulocyte-macrophage progenitor cells. We also set out to examine whether this process is connected with changes within the early precursor cell compartment. Bone marrow suspension cultures (12 days) supplemented with these cytokines were tested for the presence of GM colony-forming cells (GM-CFC) in a colony-forming unit assay. The percentage of CD34+ and HLA-DR+ as well as the number of blasts and promyelocytes were estimated cytofluorometrically and morphologically. The proliferative effect of GM-CSF was associated with a net increase of GM-CFC and HLA-DR+ myeloid cells and a decrease in the percentage of CD34+ early precursor cells. IL-3 acted similarly and also caused an absolute decrease of CD34+ cells in the cultures. IL-1 did not stimulate the generation of blasts or GM-CFC but elevated the number of CD34- as well as HLA-DR-expressing cells in the cultures. These results imply that GM-CSF supported the maintenance of hematopoiesis in vitro. The transition from early precursor cells to committed myeloid progenitor cells (GM-CFC) and more mature precursor cells (G-CFC, M-CFC) may be supported by GM-CSF without affecting the self-renewing capacity of CD34+ early precursors. In contrast, the blast-generating and proliferation-inducing action of IL-3 is associated with a drop in the total number of CD34+ stem cells. An efficient renewal of this population obviously depends on the presence of IL-1.

Antigens, CD↗
PubMed1991

Characterization of human lymphocytes separated from fetal liver and spleen at different stages of ontogeny.

Membrane markers on human lymphocytes separated from fetal liver and spleen were studied. Depending on the period of intrauterine development, a growing percentage of T- and B-lymphocytes (up to 16% and 45%, respectively) among spleen cells was seen, but in liver the number was low independent of the gestational age (T cells less than 10% and B cells less than 15%). The majority of early CD3+ spleen cells (21st-28th week) expressed TCR alpha beta but not TCR gamma delta, although a significant proportion of these cells was still lacking CD4, CD8, and CD5 differentiation antigens, suggesting their immaturity. Later spleen T cells (29th-36th week) expressed the phenotype as mature adult-type T cells (CD3+TCR alpha beta +CD4/8+CD5+). During ontogeny in fetal spleen, a growing number of B cells could be estimated without any changes in the proportion of subsets, expressing the different light and heavy chains. However, the proportion of CD5+ B cells decreased with gestational age. The results suggest that the functional immaturity of antenatal splenocytes could not be caused by dramatic phenotypical differences in comparison with adult-type splenic lymphocytes.

Antigens, Surface↗
PubMed1991

[Bronchoalveolar lavage in patients with systemic scleroderma and systemic lupus erythematosus: characterization of cell activity by cytofluorometry, chemiluminescence and differential cell count].

The purpose of the study was to determine the role of lymphocyte subsets (Ly) and reactive oxygen metabolites RSM, concerning the activity of BAL cells, in the pathogenesis of lung involvement in 12 patients with systemic sclerosis (SS) and 4 with systemic lupus erythematodes (SLE) in comparison with 10 control subjects. The cellular activity was measured by means of cytofluorometry (CFM) and chemiluminescence (CL). In SS/SLEY CD3+, CD4+, CD4/CD8-ratio, CD25 + T-Ly and luminol-dependent CL are increased (p less than 0.05). Correlations exist between CD3+, CD4+, CD8+ and CD25 + T-Ly and both luminol-dependent CL and neutrophils (p less than 0.01). The results suggest, that increased secretion of RSM by BAL-cells may be caused by local release of lymphokines by these activated T-Ly. Therefore CFM and CL seem to be useful in addition to BAL cell differentiation in characterizing the BAL cell activity in the diagnostic of lung involvement in SS and SLE.

Adult↗
PubMed1990

Polyclonal stimulation of human B lymphocytes derived from fetal liver and spleen cells at different stages of ontogeny.

The functional capacity of human lymphocytes derived from fetal liver and spleen at different stages of ontogeny (16-34 weeks of gestation) was studied using in vitro models (increase in cell volume, [3H]thymidine incorporation, Ig secretion) reflecting various stages of activation induced by mitogens (LPS, PWM) in vitro. Lymphocytes differed in their reactivity to LPS depending on the period of intrauterine development: cells from the early liver could respond with enhanced IgM production whereas lymphocytes derived from this organ after more than 25 weeks failed. The opposite was found to apply to spleen cells: only lymphocytes derived from the organ after more than 25 weeks showed significant LPS-induced in vitro differentiation. These data were in correlation with the proliferative response to LPS. It was clear that the number of CD20-positive mature B cells in the lymphocyte preparations was not responsible for these results, since comparable yields were found throughout the period of fetal development of the liver studied, whereas in the spleen increasing numbers of B cells were seen.

B-Lymphocytes↗
PubMed1984

A simple and rapid method for detecting and separating T lymphocytes by rosetting with autologous erythrocytes.

Counting and separation of auto-rosette-forming lymphocytes is a critical procedure since autologous rosettes are very unstable. It was demonstrated that human serum albumin efficiently stabilizes autologous rosettes, and makes it possible to distinguish at least three T-cell subsets by their different affinities for autologous erythrocytes. About 1% of T-cells have a high affinity for autologous erythrocytes and about 30% intermediate affinity. With a careful procedure, it is possible to detect a further subpopulation with very low affinity for erythrocytes. The sum of these three subsets was about 75% of the T-cells in the peripheral blood.

Cell Separation↗
PubMed1976

Acute intermittent porphyria with relapsing acute pancreatitis and unconjugated hyperbilirubinemia without overt hemolysis.

A 36-year-old woman was admitted to hospital with a first attack of acute intermittent porphyria. At the same time increased serum levels of amylase and lipase as well as an increased amylase clearance to creatinine clearance ratio were observed, permitting the diagnosis of acute pancreatitis. The etiology of the latter could not be determined. In addition, elevation of indirect bilirubin without evidence of hemolysis was observed Gilbert's syndrome was suspected. 40 weeks after the first episode, a second attack of identical abdominal pain was noted, with elevation of pancreatic enzymes in the serum. There is evidence that acute intermittent porphyria and acute relapsing pancreatitis may have some etiological connection in this patient.

Acute Disease↗
PubMed1975

[HL-A B27 associated rheumatic disease].

Report on a HL-A B27 positive female patient with the typical cardiac lesion occasionally found inankylosing spondylitis, peripheral arthritis, and acute anterior uveitis but without clinical or radiological evidence of spine or sacroiliac joint involvement. The concept of "HL-A B27 associated disease", including ankylosing spondylitis as well as Reiter's disease or other forms of seronegative rheumatic diseases, is suggested.

Aortic Valve↗
PubMed1975

Serum thyroxine and thyroxine-binding proteins in chronic renal failure without nephrosis.

Total serum thyroxine (T4), free thyroxine index (FTI), thyroxine binding globulin (TBG) binding capacity, serum albumin, alpha-globulins and urinary protein excretion were measured in 50 patients with chronic renal failure, but without nephrotic syndrome. 25 patients were undergoing chronic hemodialysis. T4 was within the normal range in most patients. There was a tendency to lower T4 values as compared to an age and sex-matched control group, but this did not reach statistical significance. TBG was normal in most patients. 4 patients showed elevated TBG concomitant with elevation of other alpha-globulins. Serum albumin was significantly decreased. No correlation existed between daily protein excretion and TBG or alpha-globulins, but the correlation between serum albumin and proteinuria was highly significant. T4 and proteinuria correlated with borderline significance. A highly significant correlation between T4 and TBG-albumin values was found. No correlation existed between FTI and TBG-albumin levels. The data suggest that T4 and TBG are normal in most patients with renal failure, even in the presence of significant proteinuria. Low T4 values, when found in renal insufficiency, may be secondary to low serum albumin and possibly prealbumin.

Adult↗