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Biomedical subjects

H A Neumann

Publications and source records attributed to H A Neumann.

At least 91 records · Page 5Linked to original sources
PubMed1992

Light reflection rheography. A non-invasive diagnostic tool for screening for venous disease.

Light reflection rheography has been increasingly used in the last few years to screen for chronic venous insufficiency. It is non-invasive, easy to perform, and well-suited for repetition and standardization. Light reflection rheography is appropriate for the global assessment of calf-pump insufficiency regardless of whether it is caused by varicosis, the postphlebitic syndrome, or deep venous thrombosis. For this reason, it is a good method to use as a pretreatment selection test, especially for varicose veins. With the application of tourniquets, it can help to predict treatment results. When it is used in combination with ultrasound venous Doppler, a simple decision can be made for the treatment of nearly all venous patients.

Humans↗
PubMed1991

No inhibition of interferon gamma release in human lymphocytes by Ciamexone.

In previous experiments Ciamexone, derivative of 2-cyan-aziridine, was able to influence T-cell-mediated regulatory mechanisms but seemed to have no or only little effect on T cell effector mechanisms. On the basis of these observations Ciamexone seems to be a highly selective immunosuppressive agent. In order to evaluate further possible mechanisms of Ciamexone it was the aim of our investigation to study its influence on interferon gamma (IFN gamma) production in phytohaemogglutinin (PHA)-stimulated T lymphocytes of 15 tumour patients and 12 healthy reference subjects. The IFN gamma concentration of the cell supernatant was measured using an enzyme-linked immunosorbent assay. When the cells were stimulated with PHA at 7.5 micrograms/ml the IFN gamma concentration rose to significantly different values in the reference group (1.0 ng/ml) as compared to the tumour patients (0.4 ng/ml) (P less than 0.05). An addition of Ciamexone (at any of the concentrations administered) to PHA stimulation of peripheral blood mononuclear cells (PBMC) showed no influence on the IFN gamma release in either test group. The influence of hydrocortisone on the stimulation of PBMC with PHA resulted in a dose-dependent suppression of IFN gamma production in both test groups, again with significant differences between them. The IFN gamma concentration was 0.95 ng/ml in the reference group and 0.2 ng/ml in the tumour patients when 0.01 micrograms/ml hydrocortisone was added (P less than 0.05). At 10 micrograms/ml hydrocortisone suppressed IFN gamma production completely in both groups. Our results corroborate those investigations that showed no influence of the compound on T cell effector mechanisms. The attenuation of humoral immunophenomena, however, suggest a very specific point of action within the immune system by Ciamexone.

Adjuvants, Immunologic↗
PubMed1991

Improvement of impaired mitogen-induced interferon-gamma release of peripheral blood mononuclear cells derived from tumor patients by Factor AF2.

Factor AF2, a now standardized extract from liver and spleen of newborn lambs, showed myeloprotective capacity on platelet- and erythrocyte-count as well as on hemoglobinconcentration in patients undergoing aggressive chemotherapy. In addition, a possible influence on prolonged remission duration in patients with mammary carcinoma had been claimed. In this study, the effect of Factor AF2 on mitogen-induced interferon-gamma release by PBMC was tested in 23 healthy humans and in 23 tumor patients. All patients were prior to surgery and had not yet received radio- or chemotherapy at the time of examination. The interferon-gamma concentration of the supernatants was measured using an enzyme-linked immunosorbent assay (ELISA). The cells were stimulated with PHA at 7.5 micrograms/ml. In the reference group, interferon-gamma concentration rose to 26 units/ml and to 15.5 units/ml in the tumor patients. In the reference persons, an addition of Factor AF2 at concentrations from 10(1) micrograms/ml to 10(3) micrograms/ml resulted in a small non-significant decrease of interferon-gamma release. At 10(4) micrograms/ml, neither test group showed measurable interferon-gamma concentration. In the tumor patients, cocultivation with Factor AF2 until concentration of 10(2) micrograms/ml resulted in a dose-dependent increase of interferon-gamma release, where 20.5 units/ml interferon-gamma were reached. At 10(3) micrograms/ml, Factor AF2 showed no effect on interferon-gamma release compared with the stimulation with mitogen alone. Flow-cytometry analysis of CD3, CD4, CD8, CD16, CD19, CD56, and HLA-DR expression of the PBMC deriving either from reference persons or from patients revealed an almost identical distribution. A slight difference in CD16-positive and HLA-DR positive cells, respectively, was not significant.

Adjuvants, Immunologic↗
PubMed1991

Trends in the incidence of non-melanoma skin cancer in the SE Netherlands 1975-1988: a registry-based study.

The trends in the incidence and the sites of primary basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) of the skin were examined in a defined population of 650,000 persons in the SE Netherlands during the period 1975-88. The data was obtained from the Cancer Registry in Eindhoven and was from the dermatological and surgical clinics of 12 community hospitals. The incidence rates for BCC during this period rose from 42 to 53/100,000 person years for males and 24 to 38/100,000 person years for females. The rate of incidence for SCC varied with an increase mainly among males. In about 80% of the cases BCC and SCC occurred on the head and neck. Allowing for some detection bias a rise in the true incidence of BCC and SCC was observed, with an increase in SCC only since 1982. There was a marked decline in the incidence of SCC on the lips of males. These rates and trends fit into a pattern observed in other parts of Europe.

Adolescent↗
PubMed1991

[Quality control studies of 3 deep-frozen coagulation-active fresh frozen plasma preparations from various suppliers and a new virus-inactivated lyophilized pooled plasma preparation].

Fresh frozen plasma is the most important therapeutic agent in acquired coagulation disorders. We investigated the quality of three conventional fresh-frozen plasma preparations (groups I, II, IV) and one new virus-inactivated lyophilised pooled plasma preparation (group III). In the new plasma preparation we found a significant reduction in coagulation activity, a significantly higher pH value and a highly significant rise in plasma heparin levels. No significant difference in electrolytes, protein levels and concentration or complement activity was found in any of the groups. In conclusion, unlike conventional fresh-frozen plasma, this new virus-inactivated lyophilised pooled plasma preparation does not seem to be suitable for use in therapy of coagulation disorders.

Antiviral Agents↗
PubMed1991

[Cytotoxicity of lipid ether ilmofosine in combination with radiotherapy in vitro].

Alkyllysophospholipids (ALP) represent a new class of cytotoxic agents. The cytotoxic potential was demonstrated by in vivo and in vitro models. In this study the interaction of the ALP Ilmofosine in combination with radiotherapy was tested in vitro using the colony forming assay. The cell lines B-16, K-562 and Meth-A were used as targets. The cell lines showed similar sensitivity to radiation therapy. The B-16 cell line proved to be resistant to Ilmofosine; the K-562 cell line showed little sensitivity whereas the Meth-A cell line was very sensitive to Ilmofosine. In the K-562 and Meth-A cell lines that were sensitive to both agents a clear addition of both effects was observed. In the case of the B-16 cell line in combination no effect was seen exceeding the pure radiation effect. No synergistic and no antagonistic effect was observed.

Antineoplastic Agents↗
PubMed1991

Increased collagen IV layer in the basal membrane area of the capillaries in severe chronic venous insufficiency.

Lipodermatosclerosis is a sign of severe chronic venous insufficiency. In this stage of CVI one can find capillary leakage of water and plasmaproteins which results in a higher capillary filtration rate. In skin biopsies the result of this process can be seen as a pericapillary halo. The group of Burnand recently described fibrinogen deposits in this area. We studied the capillaries and their surrounding tissue to determine the thickness of the collagen IV deposits. In severe CVI with lipodermatosclerosis a significant increase of the collagen IV layer was observed. Collagen IV thickness was measured by an index method. The collagen IV thickness for this purpose refers to the capillary diameter. It can be suggested that the increase of the venous pressure in the capillaries leads to leakage of several proteins and namely fibrinogen. As a result of the increase of fibrinogen the collagen IV layer becomes thicker which leads to a decreasing function of the capillaries. In this way an auto-amplification mechanism maintains CVI. An other explanation can be induction of collagen IV due to the high capillary pressure in CVI.

Adult↗
PubMed1989

Treatment of human clonogenic tumor cells and bone marrow progenitor cells with bleomycin and peplomycin under 40.5 degrees C hyperthermia in vitro.

Tumor cells derived from 13 different individual human tumors were plated in a colony forming monolayer assay. The effect of bleomycin and peplomycin on colony formation was assessed in normothermic conditions and after a hyperthermic treatment at 40.5 degrees C for 2 h at the beginning of the culture. In three out of the 13 tumor samples (two colon carcinomas, one malignant melanoma), hyperthermic incubation resulted in a thermal enhancement of the effects of bleomycin and peplomycin. In addition, human bone marrow progenitor cells (CFU-C) were subjected to the same procedure. Peplomycin proved to be less toxic to CFU-C than bleomycin. In samples from eight different donors, homogeneous dose-response curves were observed. There was no difference between normo- and hyperthermic incubation.

Bleomycin↗
PubMed1988

A rapid in vitro assay for predicting thermochemosensitivity of human cancer: comparison with clonogenic assay.

We previously reported a rapid in vitro assay based on morphological changes in the nucleus in order to predict response to thermochemotherapy. It was strongly suggested that this simple method may be clinically useful. In the present study, a comparison with the clonogenic assay was carried out on eight different human tumors (three malignant melanomas, two lung carcinomas, two colon carcinomas and one leukemia). Melphalan, mitomycin C and vincristine were tested. Correlation between the two test systems was dependent upon the criteria for each test system. At the level of less than 50% survival of colony as compared with normothermic dishes in clonogenic assay, there was a high correlation between the two test systems for sensitive tumor to 43 degrees C. In respect of response to thermochemotherapy, when only karyorrhexis changes in the nucleus were selected as an activity criteria in our cytotoxic test, parallel data between the two test systems were obtained.

Antineoplastic Agents↗
PubMed1988

Predicting the sensitivity of human cancers to combined chemotherapy and hyperthermia.

In order to estimate its ability to predict the thermochemosensitivity of human cancers, a rapid in vitro assay based on morphological changes in the nucleus was performed on eight different human tumors (four malignant melanomas, two lung tumors, one renal carcinoma, and leukemia K-562). Nude mice, implanted with tumors, supplied the tumor material, with the exception of leukemia. Nimustine, melphalan, mitomycin C, vincristine and vinblastine were tested. Tumor cells developed karyorrhectic changes after incubation for 4 h with each of the aforementioned five drugs. An increase in the karyorrhectic changes was observed with hyperthermia at 43 degrees C. The individual tumors showed different sensitivities to 43 degrees C. Five of the eight tumors were significantly sensitive to 43 degrees C. However, in two thermosensitive tumors no drug enhancement was recognized at 43 degrees C. In four tumors several drugs were synergistically enhanced by hyperthermia at 43 degrees C. This study suggests that this simple method may be of clinical use in predicting response to thermochemotherapy.

Animals↗
PubMed1988

[Transmission of Dusseldorf Integrated Medical Documentation data by a personal computer. A new concept in the flexibility of the Dusseldorf Integrated Medical Documentation system].

The software package HOST PC was created as an important expansion of the oncological aftercare program INMEDD (Integrated Medical Documentation Düsseldorf). INMEDD itself provides only small evaluation capabilities. HOST PC is able to transmit data from INMEDD on a host computer to a personal computer. This transmission is fully automated. On the personal computer the data is stored in a database, which is completely compatible with the standards of dBase III. These created databases can be evaluated and analyzed by a lot of standard software packages. Therefore a wide range of individual statistical evaluation, analyzing with optional criteria and graphic presentation can be realized with small expenses of time and money. HOST PC increases the attractiveness of INMEDD and therefore improves the aftercare of cancer patients.

Aftercare↗
PubMed1987

[Recombinant leukocyte A interferon in metastasized malignant melanoma].

The efficacy and tolerance of recombinant leukocyte A interferon (interferon alpha-2a) in 30 patients with metastasized malignant melanoma in clinical stages III and IV were tested in a phase II study. During the first 10 weeks, the patients received 18 X 10(6) IU interferon alpha-2a i.m. daily and afterwards the same dose three times a week for a further four months. In 21 patients, the tumor growth was progressive. In six patients in clinical stage IV, there was a standstill for at least two months, and in three patients in clinical stage III, there was complete remission lasting between 12 and 16 months so far. The side effects of therapy differed in the individual patients. Fever, chills, limb pain, tiredness, nausea and lack of appetite were observed most often. All these symptoms as well as the frequently occurring leukopenia and elevation of the transaminases were especially pronounced at the beginning of therapy. They were dose-dependent, but reversible.

Adult↗