Search PubMed⌕ Search

Biomedical subjects

C Huber

Publications and source records attributed to C Huber.

At least 325 records · Page 18Linked to original sources

Surface glycoproteins (S-GP) on normal and malignant human leukocytes.

This study aimed to investigate high molecular weight surface glycoprotein (S-GP) patterns on various types of human leukocytes. S-GP were externally labelled by the Galactose-oxidase-NaB3H4 technique. Results based on the analysis of 120 samples derived from different types of normal and malignant leukocytes indicate that the relative expression of high molecular weight S-GPs changes during haemopoietic cell differentiation and to some extent these changes enable the classification of human leukocytes.

Antigens, Surface↗

Human interferon-gamma induces expression of HLA-DR on keratinocytes and melanocytes.

Primary human epidermal cell cultures composed of keratinocytes and melanocytes were exposed to supernatants of phytohaemagglutinin (PHA)-stimulated T cells, various lymphokines and interferon-beta, and checked for the emergence of HLA-DR antigen using immunofluorescence and immunoelectron microscopy. HLA-DR expression was induced by the supernatants and human recombinant interferon-gamma (rIFN-gamma), whereas recombinant interferon-alpha 2, interleukin-2 and non-recombinant human interferon-beta had no such effect. The threshold concentration of rIFN-gamma required to induce this phenomenon was 10 IU/ml; no further increase of reaction intensity was observed using doses of more than 100 IU/ml. Maximum reaction intensity was achieved after 72 h of incubation; a minimum of 3 h of incubation with rIFN-gamma followed by 72 h incubation in rIFN-gamma-free medium proved sufficient to induce HLA-DR expression. The inductive effect of the supernatants and rIFN-gamma could be completely abrogated by pretreatment with excess doses of the monoclonal antibody GZ4 specific for human IFN-gamma. Keratinocytes and melanocytes reacted in an identical fashion both qualitatively and quantitatively in all experiments. These data indicate that IFN-gamma possesses specific signal functions in the induction of HLA-DR expression on epidermal cells.

Cells, Cultured↗

Evaluation of spontaneous lymphocyte proliferation by single cell autoradiography in human allograft recipients.

Spontaneous lymphocyte proliferation was studied in 22 patients receiving cadaveric renal transplants before and at various times after grafting. Prophylactic immunosuppression consisted of CyA and prednisone. Spontaneous lymphocyte proliferation was evaluated in a total of 500 single cell autoradiographs after short term in vitro incubation with [3H]TdR. In 13 patients without clinical problems a transitory increase of lymphocyte labeling indices to approximately five times the pretransplant levels was observed. The failure to detect such increments in two patients receiving optimally matched grafts suggested that this early proliferative lymphocyte peak might be caused by in vivo recognition of major histocompatibility antigens. Much higher labeling indices were detected in close temporary association with acute cellular rejection (4 cases), severe infections and withdrawal of CyA (3 cases) and venous thrombosis (1 case). Only moderately elevated numbers of spontaneously proliferating lymphocytes were seen in one patient with a reversible vascular rejection episode. It appears that assessment of spontaneous lymphocyte proliferation is capable of discriminating on a quantitative level between patients with and without clinical problems such as acute cellular rejection and infection.

Adolescent↗

Neopterin release in human mixed lymphocyte culture: requirement of HLA-DR disparity.

Recent evidence suggests that immune responses in vivo as well as in vitro are accompanied by release of neopterin [C. H. Huber, et al. (1983) J. Immunol. 130, 1047]. This investigation aimed to elucidate the genetic control of in vitro neopterin release in family mixed lymphocyte culture (MLC) studies. Neopterin levels and responder cell proliferation were assessed in a total of 92 MLCs established from different intrafamilial combinations. Results indicated a strong association between the magnitude of responder cell proliferation and the neopterin levels induced by stimulation with allogeneic cells. This conclusion was based on three findings: first, almost no neopterin release and proliferation was seen in MLCs established between HLA genotypically identical siblings; secondly, very low proliferation and neopterin levels were observed in MLCs between HLA-DR phenotypically identical family members; and thirdly, high neopterin release and strong cellular proliferation were a feature of MLCs established between individuals differing for at least one HLA-DR antigen. We thus conclude that T cell activation subsequent to recognition of HLA-DR disparity represents an essential prerequisite for induction of neopterin release in human MLC.

Biopterins↗

Follow-up studies on proliferative T cell responses in cadaveric kidney graft recipients under combined immunosuppressive treatment with cyclosporine and prednisone.

In 5 recipients of cadaveric renal allografts, we tested the influence of prophylactic immunosuppression with cyclosporine (Cy A) and low dose prednisone on in vitro proliferative T cell responses, T-helper/T-suppressor cell ratios and spontaneous- or lectin-induced unspecific suppressor cell activity and on serum mediated inhibition of proliferative T cell responses. Results revealed a reduction of the overall proliferative T cell responsiveness, which was particularly seen in cultures supplemented with autologous serum and was maximally expressed after approximately 30 days of treatment. This impaired proliferative capacity was neither accompanied by shifts of the T-helper/T-suppressor ratios nor by alterations of spontaneous- or lectin-induced suppressor activity. The capacity of patients' plasma to inhibit lymphocyte proliferation was also tested. Results indicated that almost every plasma of Cy A patients was capable of inhibiting mixed lymphocyte culture (MLC) responses. The inhibitory capacities of these plasma, however, were not directly correlated with their Cy A content.

Adult↗

Neopterin levels in long-term renal allograft recipients.

In this paper we present results dealing with neopterin levels in the urine of 21 kidney grafted patients during long-term allograft survival. Data dealing with results of urinary neopterin excretion to predict acute cellular allograft rejection during the immediate post-transplant period have been reported previously. The evaluation of patients included a physical investigation and numerous biochemical parameters as described below. We found that neopterin excretion is normal or elevated, but if elevated levels remain stable the prognosis for the allograft seems to be good.

Biopterins↗

Neopterin as a new biochemical marker in the clinical assessment of ulcerative colitis.

In previous publications we showed that neopterin, a pyrazino-pyrimidin compound, represents a biochemical marker for the assessment of cellular immune responses. We thought that the evaluation of this marker molecule might enable insight into the activity of cellular immune responses underlying ulcerative colitis (UC). Evaluation of urinary neopterin excretion in 25 consecutive untreated UC patients revealed striking correlations between neopterin levels and the severity of disease: elevated levels were observed in 9 out of 9 patients with moderately severe to severe, in 3 of 4 with mild and in none of 12 patients with quiescent disease. Further evidence for a correlation between disease activity and neopterin excretion was obtained on the basis of long-term follow-up studies performed in 4 cases. These studies indicated normalization of neopterin levels when clinical remission was achieved. Thereafter, the relative significance of neopterin excretion for determination of clinical stage was assessed by linear correlation analyses and was compared with conventional clinical parameters such as anemia, number of motions per day, raised temperature, ESR and extent of bowel involvement. The logarithm of neopterin excretion and the extent of bowel involvement were the two single parameters most closely related to the clinical stage of ulcerative colitis. We, therefore, conclude that evaluation of neopterin excretion in ulcerative colitis patients represents a new and useful tool for the clinical monitoring of disease activity.

Adolescent↗

[Vision test program for ophthalmologists on Apple II, IIe and IIc computers].

A microcomputer program for the Apple II family of computers on a monochrome and a color screen is described. The program draws most of the tests used by ophthalmologists, and is offered as an alternative to a projector system. One advantage of the electronic generation of drawings is that true random orientation of Pflueger's E is possible. Tests are included for visual acuity (Pflueger's E, Landolt rings, numbers and children's drawings). Colored tests include a duochrome test, simple color vision tests, a fixation help with a musical background, a cobalt blue test and a Worth figure. In the astigmatic dial a mobile pointer helps to determine the axis. New tests can be programmed by the user and exchanged on disks among collageues.

Color Perception Tests↗

[Immunosuppression with cyclosporin A in high-risk keratoplasties].

It is generally accepted that corneal grafts in hypervascular and sclerosed host corneas have little chance of success. At the end of a three-month postoperative immunosuppression period using the new immunosuppressant Cyclosporin A, full incorporation of transplants was achieved in 10 out of 11 high-risk patients. Patients were observed over a period of between 3 and 15 months, the median being 9 months.

Corneal Diseases↗

Treatment with low dose human recombinant interferon-alpha-2-ARG induces complete remission in patients with hairy cell leukemia.

Five cases with advanced hairy cell leukemia refractory to treatment with splenectomy and chemotherapy as well as one patient presenting with a stage-A response to splenectomy were treated with rhu-IFN-alpha 2-arg. 5 X 10(6) were administered intramuscularly every day. Both patients, with advanced disease resistant to conventional therapy and treated for six or more months with rhu-IFN-alpha 2-arg, achieved complete clinical remissions. Three further cases treated for less than half a year and also with advanced disease achieved partial remission states with marked reduction of circulating hairy cells and with recovery of normal hemopoiesis. Minimal residual disease in the remaining patient during a three-month period of treatment did not respond. Side effects of rhu-IFN-alpha 2 low dose therapy were minimal in 5 cases and comprised a severe leukopenia reversible after dose reduction in one patient.

Adult↗

Interferon-alpha-2C in the treatment of advanced hairy cell leukaemia. Results of a phase II trial.

The efficacy of recombinant interferon-alpha 2 in the treatment of advanced hairy cell leukaemia is investigated in 31 patients. Preliminary results show a complete and partial response rate of 69%. An optimal dose study utilizing maximal stimulation of an interferon-dependent pathway was carried out in 5 patients. The optimal dose of the order of 5 X 10(5) IU/day is effective and without side-effects. Interferon treatment did not enhance natural killer cell activity and therefore a direct mode of action upon tumour cells is proposed.

Dose-Response Relationship, Drug↗

Identification of 3-hydroxyanthranilic acid in mixed lymphocyte cultures.

3-Hydroxyanthranilic acid was identified in lymphocyte cultures during allogeneic stimulation. The metabolite and the synthetic product have identical HPLC retention times, fluorescence spectra, fluorescence intensities as a function of pH value and electrochemical behaviour.

3-Hydroxyanthranilic Acid↗

Studies on hydroxyethyl starch. Part I: Molecular characterization by size exclusion chromatography coupled with low-angle laser light scattering.

Two commercially available hydroxyethyl starch (HES) preparations (in clinical use as plasma expanders) specified with Mw = 450,000/MS = 0.7 and Mw = 200,000/MS = 0.5, respectively, and three experimental HES-samples (supposingly similar to the commercial product with the specification 450,000/0.7, except of one with MS = 0.5) were studied. The latter were prepared via acid or enzymatic hydrolysis of waxy-maize starch. Each of the samples was characterized by its intrinsic viscosity and molar substitution, and was studied with low-angle laser light scattering (LALLS) and with size exclusion chromatography (SEC) coupled with LALLS. The weight-average molecular weight Mw of the commercial samples was found to be 60-80% higher than the value given in the product declaration. This discrepancy can be explained by the argument that previous measurements were not carried out at sufficiently small scattering angles to enable reliable extrapolation to zero angle. The calibration functions Mw(v) of the individual HES-samples measured by SEC/LALLS-coupling are identical over a broad range of the elution volume v and are used for calibration of conventional SEC in a subsequent paper. The small, but detectable differences in the Mw(v)-functions indicate interesting differences between these HES-preparations with respect to the effective hydrodynamic density of the branched HES-molecules.

Chromatography, Gel↗

[Results of a phase II study on the treatment of hairy cell leukemias with various doses of alpha-2-recombinant interferon].

Hairy-cell leukemia has been shown to be extraordinary sensitive to treatment with alpha-interferon. In order to define clinically effective interferon doses associated with minimal toxicity two different dose regimens were applied in this clinical trial: firstly, a conventional dose schedule, and secondly, a biologically defined dose regimen. For dose finding in the latter group, neopterin, a GTP degradation product produced by macrophages under control of interferon, was chosen. Six patients (Group A) received conventional doses of recombinant interferon--alpha-2 (rIFN-alpha-2) 3 X 10(6) U/sqm/daily by the subcutaneous route. Five patients (Group B) were treated with the minimal dose of rIFN-alpha-2 which had previously been shown to induce maximum neopterin levels in urine. Already interferon doses in the range of 3 to 5 X 10(5) U/sqm2/daily administered subcutaneously proved to be sufficient for triggering maximum neopterin excretion in the urine. After six months of interferon treatment all patients were evaluable. At this time both doses regimens proved to be effective in terms of their anti-leukemic activity, but differed significantly in toxicity, which was only seen in Group A patients.

Adult↗