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Biomedical subjects

H Wachter

Publications and source records attributed to H Wachter.

At least 397 records · Page 22Linked to original sources
PubMed1985

The value of urinary neopterin as an immunological parameter in patients with malignant tumors of the genitourinary tract.

In 153 patients with verified neoplasias of the genitourinary tract, urinary neopterin excretion was monitored under different conditions. As control, urinary neopterin values were taken from 208 male and 209 female volunteers. Neopterin excretion was measured by high performance liquid chromatography. Patients with early tumor stages, both with bladder tumor and carcinoma of the prostate, presented almost normal urinary neopterin levels. The difference of urinary neopterin excretion between low and high stages in bladder tumor (T0-1 versus T2-4) as well in carcinoma of the prostate (stage A-B versus stage C-D) is highly significant (p less than 0.001). In the group of patients with renal cell carcinoma we could not find any correlation between tumor stage and neopterin excretion. The basal urinary neopterin values in patients with testicle tumors were as follows: 1 of 6 patients stage-I seminomatous tumors and 2 of 4 patients with stage-I non-seminomatous tumors demonstrated elevated neopterin levels. In the higher stages all patients, in both groups, exhibited pathologically increased neopterin excretion. During therapy and follow-up: all 24 stage-I (seminomatous and non-seminomatous tumors) patients showed normal neopterin levels: 1 of 3 stage-II (non-seminomatous tumors) patients and all 5 stage-IV (seminomatous and non-seminomatous tumors) patients had elevated urinary neopterin excretion. Our experience suggests that neopterin measurements may supplement laboratory examinations in patients with malignant tumor diseases of the genitourinary tract, providing meaningful information in regard to early detection of tumor progression, tumor recurrence and follow-up.

Adolescent↗
PubMed1985

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↗
PubMed1985

Neopterin, a biochemical indicator of cellular immune reactions, in the detection and control of patients with neoplastic diseases.

The incidence of elevated neopterin levels is presented for 748 patients with various malignancies. The mean urinary neopterin levels varied directly with stage and in patients with carcinoma of bladder according to histological grade of disease. In 178/208 patients with subsequent treatment for gynecological cancer, neopterin levels returned to normal within 3 weeks when tumor remission was achieved but remained high or even raised when persistent or recurrent cancer was later diagnosed. In 160 patients suffering from cervical carcinoma, significant differences in survival were demonstrated by Cox regression when patients were grouped according to their pretherapeutical neopterin level.

Adolescent↗
PubMed1984

Immune response-associated production of neopterin. Release from macrophages primarily under control of interferon-gamma.

Neopterin, a compound derived from GTP, represents a precursor molecule of biopterin that is an essential cofactor in neurotransmitter synthesis. We have recently reported that in vivo as well as in vitro immune responses are accompanied by an increased release of neopterin and that this phenomenon can be used for the biochemical monitoring of diseases accompanied by hyperimmune stimulation. This article deals with the cellular origin and the control of this immune response-associated neopterin release in vitro. Using highly purified or monoclonal cellular reagents we demonstrate that macrophages (M phi) stimulated with supernatants from activated T cells release large amounts of neopterin into culture supernatants. Further experiments involving induction of neopterin release from M phi with various human recombinant interferons (IFNs) or neutralization of the effect of T cell supernatants with various monoclonal anti-IFN antibodies revealed immune IFN as the active principle. It thus appears that a metabolic pathway so far exclusively known in context with the generation of an essential cofactor of neurotransmitter-synthesis during immune responses is also activated in M phi under stringent control by immune IFN-like lymphokines.

Biopterins↗
PubMed1984

[The first case of AIDS in the Tyrol].

This case report deals with a description of the first case of AIDS in Tirol. Our patient was an intravenous drug abuser and presented with both opportunistic infections (candidiasis, interstitial pneumonia due to Pneumocystis carinii) and with Kaposi's sarcoma. He died within 4 weeks as a result of staphylococcal septicaemia refractory to intensive chemotherapy.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Urinary pteridines on patients suffering from cancer. A comment on the method and results of Rao and associates and of Trehan and associates.

A diagnostic test for detecting malignancies has been reported by Rao and associates. This test has been extended by Trehan and associates as an index of disease status in acute myeloblastic leukemic patients on antileukemic drugs. The authors were able to demonstrate that by using the described assay various pteridines are measured and not exclusively 6-hydroxymethylpterin as reported by the above-mentioned authors. Furthermore, the urinary component which correlates to the status of malignant disease has to be interpreted as being neopterin. This conclusion can be drawn from previous studies conducted by the authors' laboratory.

Biopterins↗
PubMed1984

[Neopterin, a new biochemical marker for clinical assessment of cell-mediated immune response].

Activated T-lymphocytes represent crucial effector cells. They are pathogenetically involved into various disease states such as allograft rejection or viral infection. So far their assessment is laborious and rarely possible in clinical routine. In this review article we present the compount neopterin as a new biochemical marker for the in vivo and in vitro detection of activated T-lymphocytes. Our main finding was that in vitro as well as in vivo stimulation of T-lymphocytes with foreign and chemically or virally modified autologous cells in invariably associated with increased neopterin production. It thus appeared that neopterin might represent a potential marker for biochemical monitoring of diseases caused by or associated with T-lymphocyte activation. Our clinical experience with neopterin determination in allograft rejection and in infectious or autoimmune states strongly support this view. We conclude that evaluation of neopterin represents a useful and simple tool for the biochemical monitoring of immunological and/or malignant states.

Adolescent↗
PubMed1984

Neopterin as a new biochemical marker in the clinical monitoring of bone marrow transplant recipients.

In previous reports we demonstrated that increased amounts of the pyrazinopyrimidine compound neopterin are released in the context of T lymphocyte activation. The aim of this investigation was twofold: (1) to define the contribution of hemopoetic cells to neopterin excretion, and (2) to search for the clinical utility of this biochemical marker in the monitoring of such patients. Thirteen patients were grafted with allogeneic, 1 with syngeneic, and 2 with autologous marrow. Urinary neopterin excretion was measured daily by means of high-performance liquid chromatography from the time before transplantation until the patients' discharge from the isolation unit. In all patients bone marrow aplasia was associated with depressed, and engraftment with increased, neopterin values. Rising neopterin levels invariably preceded the cytological definition of "take," on the average by seven days. After hematological reconstitution, neopterin excretion continuously declined in all 5 patients lacking infectious complications and/o-graft-versus-host disease (GVHD). A transitory increase of urinary neopterin followed by normalization was observed in 5 further patients. At the time of increased neopterin excretion, 4 experienced either herpetic infection or GVHD, both of which resolved promptly under the appropriate treatment. Neopterin values remained elevated after engraftment in 6 patients who suffered from persistent GVHD. Results of this pilot study suggest that (1) bone marrow derived cells are crucially involved in production of neopterin in vivo and (2) evaluation of neopterin excretion patterns after hemopoietic reconstitution enables one to discriminate between patients with and without an increased risk of developing GVHD or viral disease.

Biopterins↗
PubMed1984

Measurement of urinary 7,8-dihydro-6-hydroxylumazine in healthy and in Ehrlich ascites tumour-bearing mice.

An estimation of 7,8-dihydro-6-hydroxylumazine in urinary samples of mice by high performance liquid chromatography on reversed phase material is presented. Urinary samples are diluted with water and oxidized by iodine. Chromatographic elution is done isocratically using aqueous buffer containing methanol. Effluent 6-hydroxylumazine is monitored by its fluorescence (382 nm excitation, 449 nm emission). The described method can be performed rapidly with satisfactory accuracy and precision. The electrochemical detection of 7,8-dihydro-6-hydroxylumazine was studied additionally. Total values of daily excreted 7,8-dihydro-6-hydroxylumazine of healthy and of Ehrlich ascites tumour-bearing mice were measured.

Animals↗
PubMed1984

Urinary neopterin in the diagnosis and follow-up of neoplasia: a biochemical parameter to detect cell-mediated immune response.

Neopterin is excreted at high levels during disease states challenging the T-lymphocyte-macrophage system. Stimulation of T-lymphocytes in mixed lymphocyte culture in the presence of macrophages is accompanied by raised neopterin levels in the supernatant. Neopterin may therefore be considered a specific indicator of cell-mediated immunity. Pretreatment analysis of patients with hemopoietic (191), urological (82) and gynecological (224) neoplasia revealed neopterin levels above the upper normal limits, with frequencies ranging from 57% (cervical carcinoma) to 96% (chronic lymphocytic leukemia). In patients with tumors of the genitourinary tract or with hemopoietic neoplasms, urinary neopterin levels were correlated with the tumor burden and became normal when remission was achieved. In gynecological cancer long term follow-up studies showed the value of neopterin excretion levels as a tumor marker. Tumor progression was indicated early by a rising neopterin level. Based on a comparison of different tumor types, the association of cell-mediated immunity and of neopterin excretion levels in less differentiated neoplasm is discussed.

Adolescent↗
PubMed1983

[Neopterin, a new biochemical marker for the detection of activated T lymphocytes].

In this review evidence is summarized indicating that the pteridine compound, neopterin represents a new and clinically useful biochemical tool to detect activated T-lymphocytes. T-cells stimulated in vivo or in vitro by allogeneic or virally or chemically modified autologous cells produce large amounts of this molecule. Other mononuclear blood cells, in contrast, lack this capacity. These findings suggested that evaluation of neopterin levels might represent a means for the biochemical monitoring of disease states mediated by or associated with activated T-cells. Our clinical data obtained on patients suffering from allograft rejection, viral disease, or autoimmune states strongly support this concept.

Arthritis, Rheumatoid↗
PubMed1983

Measurement of urinary neopterin in normal pregnant and non-pregnant women and in women with benign and malignant genital tract neoplasms.

Urinary neopterin was measured in healthy women (n = 209) and men (n = 208), in patients with benign gynecological tumors (n = 53), in women with precancerous lesions of the cervix and the endometrium (n = 24) and in women with cancer of the genital tract (n = 108). In addition urinary neopterin measurements were made in 109 pregnant women and 20 women in the puerperium. No significant difference was found between mean neopterin values in patients with benign gynecological tumors, in women with precancerous lesions and in healthy women. Patients with cancer had significantly higher mean urinary neopterin levels than the control group. Raised neopterin levels were found in 56% of patients with genital tract cancer, the figures varying between 93% for ovarian cancer and 47% for cancer of the cervix. Some of the cancer patients had serial urinary neopterin measurements and in about 80% there was some relation between urinary neopterin values and clinical progress as judged clinically and radiologically, the best agreement existing in patients with ovarian cancer. Significantly higher mean neopterin values were found during normal pregnancy and in the early puerperium than in non-pregnant healthy controls. Raised urinary neopterin excretion may be due to enhanced cell proliferation and alloantigenic activation of T-lymphocytes.

Adolescent↗
PubMed1983

Neopterin as a new biochemical marker for diagnosis of allograft rejection. Experience based upon evaluation of 100 consecutive cases.

The use of daily urinary neopterin evaluation to detect immunological complications has been tested in 96 consecutive cadaveric kidney recipients, three liver recipients, and one pancreas recipient. In 29 of these patients an immunologically uncomplicated posttransplant course was associated with stable or low neopterin levels, or both. In only 5% of daily determinations on these patients were increasing or high neopterin levels seen. On the other hand, major immunological complications, such as acute rejection episodes (38 cases), viral infections (17 cases), or both problems (8 cases), were preceded by increasing or high neopterin levels or both--on the average by one day. Withdrawal of cyclosporine was also found to be followed by increase of urinary neopterin levels. Neopterin evaluation enabled reliable and accurate prediction of immunological complications in 95% of patients with acute rejections and in 100% of patients with viral infections. It thus appears that daily assessment of urinary neopterin levels represents a useful tool for biochemical detection of immunological complications in allograft recipients.

Biopterins↗
PubMed1983

Elevated urinary neopterin levels in patients with the acquired immunodeficiency syndrome (AIDS). A preliminary report.

Neopterin excretion in urine of patients with AIDS was measured by high pressure liquid chromatography. Urinary neopterin levels in patients with generalized lymphadenopathy, which is considered to be part of the spectrum of AIDS, as well as in severe AIDS cases were significantly elevated, compared to normal controls. This finding may prove useful as a screening test for donors of blood products in order to prevent transmission of AIDS by this route.

Acquired Immunodeficiency Syndrome↗