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Biomedical subjects

R Pfeiffer

Publications and source records attributed to R Pfeiffer.

At least 19 recordsLinked to original sources
PubMed1992

[Secretion of hCG by mononuclear cells--a specific and essential reaction in pregnancy?].

Mononuclear cells in peripheral blood secrete immunoreactive hCG (ir-hCG) when they are stimulated in in-vitro culture with the proteinkinase C - activator phorbol-myristat-acetate (TPA). We examined the ir-hCG secretion in 61 fertile and 191 pregnant women and 38 men. Mononuclear cells of pregnant women secrete after TPA stimulation significantly more ir-hCG than mononuclear cells on non-pregnant but fertile women. This effect can be detected as early as 23rd days of a menstrual cycle which is accompanied by conception and persisted over the entire duration of a pregnancy. Maximal effects were observed in the 7th to 19th and 30th to 34th weeks of pregnancy. An artefact caused by adhesive serum-hCG could be excluded. The elevated potential of the mononuclear cells to be stimulated remained intact for about 14 days after termination of a normal pregnancy in the first trimester. An ir-hCG secretion similar to that seen in nonpregnant women was found in patients with early abortion. The possible physiological importance of the in-vivo secretion of beta-HCG during pregnancy is discussed.

Abortion, Incomplete↗
PubMed1992

Optimization of levodopa therapy.

While there is no single correct starting dose for levodopa therapy, many individuals can be started on either the 25/100 or controlled-release formula, following the general rule not to attempt to titrate carbidopa-levodopa to the point of "normality," which can lead to toxicity. The physician should also determine the proper use of any adjunctive medications; such combined therapy has become the standard approach to treatment. Following the initial period of therapy, emerging difficulties require a reassessment of therapeutic approaches, such as dosage adjustment or introduction of a dopamine agonist. Other possible adverse effects--such as gastrointestinal disorders, orthostatic hypotension, levodopa-induced psychosis, sleep disturbances or parasomnias, or drug interactions--also require carefully monitored individual treatment. Nonpharmacologic concerns can help the Parkinson's disease patient achieve and maintain optimal functioning, including daily exercise, physical therapy, and involvement with support groups.

Antiparkinson Agents↗
PubMed1990

Comparative study on lymphocyte subpopulations in cancer patients after immunostimulation with propionibacteria and in renal transplant patients after combined immunosuppression.

In two groups of patients the influence of unspecific immunostimulation (group 1) and combined immunosuppression (group 2) on lymphocyte subpopulations was studied. Patients constituting group 1 suffered from gastric and colorectal carcinoma, respectively, and were preoperatively treated with 10 mg whole cell preparation of immunostimulating Propionibacterium avidum KP-40 (Köln-Propioni, strain 40). Patients of group 2 were submitted to combined immunosuppressive therapy and treated with antilymphocyte globulin, prednisone, and azathioprine subsequent to renal transplantation. Immunostimulation with P. avidum KP-40 resulted in a significant increase (p less than or equal to 0.01) of the natural killer (NK) cell population, whereas total leukocyte and lymphocyte counts as well as helper and suppressor T lymphocyte subsets did not evidently differ from control values. On the contrary after immunosuppression all subsets of lymphocytes as well as NK cells significantly decreased.

Azathioprine↗
PubMed1989

Status of dopamine in bovine pineal glands and the stimulation of N-acetyltransferase activity by D2-dopaminergic receptor agonists in the rat pineal glands in culture.

In a previous study, we identified in the bovine pineal gland two [3H]spiroperidol-binding sites with KD values of 0.18 and 2.1 nM and Bmax values of 37 and 630 fmol/mg protein, respectively. In this study, the status of dopamine in the bovine pineal glands was delineated further by measuring the relative concentrations of dopamine and norepinephrine and the relative concentrations of serotonin and melatonin. Furthermore, the presence of 4.0 +/- 0.6 micrograms/dopamine/gm tissue encouraged us to delineate the effects of select dopaminergic receptor agonists and antagonists on the synthesis of melatonin in vivo and on the activity of N-acetyltransferase in the rat pineal gland in culture. The acute administration of haloperidol (3 mg/kg intraperitoneally [ip]) or sulpiride (200 mg/kg ip) increased the concentration of melatonin in the pineal gland from 160.6 +/- 8.18 to 327.6 +/- 45.43 and 306.5 +/- 40.53 pg/gland, respectively. Dopamine exhibited dual effects on the activity of N-acetyltransferase, inhibiting the basal activity at 0.1 microM and stimulating it at 10 microM, and the later effect was blocked by propranolol. D2-dopaminergic receptor agonists such as bromocriptine (4.0 microM) or LY-171555 (10.0 microM) partially attenuated the norepinephrine-induced stimulation of N-acetyltransferase, and these attenuating effects were reversed by D2-dopaminergic antagonists such as haloperidol (10 microM) or domperidone (10 microM). The results of these studies are interpreted to indicate that for the synthesis of melatonin, the pineal D2-dopaminergic receptors may function independently from those of the beta 1-adrenergic receptor sites. Furthermore, the said D2-dopaminergic receptor are amenable to down regulation since the activity of N-acetyltransferase remained unaltered (0.0717 vs. 0.0729 nmol/gland/h) following chronic treatment (4 mg/kg ip/day for 30 days) with bromocriptine.

Acetyltransferases↗
PubMed1988

Is there any clinical relevance of serial determinations of serum carcinoembryonic antigen in small cell lung cancer patients?

Carcinoembryonic antigen (CEA) serum concentrations were serially determined by an enzyme immunoassay before, during, and after chemotherapy and radiotherapy in 129 male patients with small cell lung cancer (SCLC). Pretherapeutic CEA concentrations were as follows: 2.5 ng/ml or less for 37% of the patients; greater than 2.5 but less than or equal to 5 for 27%; and greater than 5 for 36%. Before therapy, CEA levels in patients with extensive disease (median value, 5.8 ng/ml) were higher than those in patients with limited disease (3.0 ng/ml; P less than 0.01). Median survival in patients with pretherapeutic CEA titers of 5 ng/ml or less (median survival, 14.3 months) was significantly longer than in patients with CEA levels greater than 5 but less than or equal to 10 and CEA levels greater than 10, respectively (8.3 and 9.7 months; P less than 0.01). Patients with pretherapeutic CEA levels greater than 10 ng/ml showed a significant decrease (P less than 0.01) of CEA while reaching partial remission (PR) or complete remission (CR). In five of 16 evaluable patients, a continuous increase of CEA titers was seen starting at least 3 months before relapse could be defined by clinical, radiologic, or endoscopic means. However, the number of patients for whom CEA serum determinations reliably indicate stage of disease and outcome of therapy is small (at best, 10% of all SCLC patients), and pretherapeutic CEA level cannot be used for individual prognosis. Moreover, it is still uncertain whether earlier detection of relapse in SCLC can improve the therapeutic results. So far, the clinical relevance of serial CEA serum determinations in SCLC patients is rather low.

Adult↗
PubMed1988

Subsequent development of acute non-lymphocytic leukemia in patients treated for Hodgkin's disease.

A nested case control study was carried out to investigate the association between treatment of patients with Hodgkin's disease (HD) and the risk of developing acute non-lymphocytic leukemia (ANLL). Seven Cancer Centers of the International Cancer Patient Data Exchange System of the UICC participated. A study cohort was selected consisting of 1,681 nonpretreated patients with HD, diagnosed from 1972 through 1978, and followed up through 1984. The median follow-up time was 66 months. Eighteen cases of leukemia were observed in the cohort. The risk of development of ANLL was significantly greater for male than for female patients. The treatment characteristics associated with an increased risk of developing ANLL were extensive radiotherapy, splenectomy and the chemotherapy combination of vincristine, procarbazine and mechlorethamine.

Acute Disease↗
PubMed1988

Cryptococcal meningoencephalitis with parkinsonian features.

The subacute onset of parkinsonism in a patient with cryptococcal meningoencephalitis is described. The prompt resolution of the extrapyramidal dysfunction with antifungal agents suggests direct involvement of basal ganglia structures by the cryptococcal infection. Rapid development of parkinsonism in immunocompromised individuals should prompt investigation for an infectious etiology.

Aged↗
PubMed1987

Subcutaneous heparin injection in the upper arm as a method of avoiding lymphoceles after lymphadenectomies in the lower part of the body.

The authors have measured the concentration of biologically active heparin in the drainage fluid after ilioinguinal, pelvic and retroperitoneal lymphadenectomy. After s.c. heparin administration in the thighs high levels of heparin were found in the drainage fluid of all patients (up to 0.89 IU/ml). After s.c. heparin application in the upper arms, no measurable concentrations of heparin were detected. Lymph loss in these patients was considerably lower. According to this experience, subcutaneous application of heparin into the upper arms is to be recommended in patients who undergo lymphatic surgery of the lower part of the body.

Heparin↗
PubMed1986

[Value of cardiotocographic studies in threatened premature labor and intrauterine retardation. A contribution to respiratory placental insufficiency].

The authors evaluated a total of 1,237 cardiotocograms obtained from 138 pregnancies where premature delivery was imminent, 49 pregnancies with intrauterine retardation and 10 pregnancies without pathological findings from a clinical and anamnestic point of view. The cardiotocograms resulted from antepartal screening, and the Fischer score was used for evaluation. Restricted fetal respiration was assumed in all cases where prepathological CTGs were significantly more frequent in the course of pregnancy (24%) and where there was a significant increase in such findings immediately before delivery (41%) in the event of imminent premature birth, compared with normal controls (10%) and pregnancies with intrauterine retardation in the absence of premature uterine contractions (13%). Similar findings were also obtained for individual parameters of the fetal heart frequency such as the oscillation frequency, oscillation amplitude, acceleration and deceleration. By way of comparison with normal controls of the same age it is insured in each case that the disturbance observed expresses a respiratory insufficiency in the feto-placento-maternal unit rather than an immature fetal heart and circulatory system. In this connection, particular hazards exist during early gestation where a premature delivery is imminent, whereas IUR carries only a limited risk. This assumption is reinforced by the greater number of prepathological findings encountered in pregnancies which have successfully been prolonged (beyond the 37th week), compared with normal controls of the same age. The connections shown between a prepathological CTG (particularly in the last week before delivery) and a greater frequency of intra- and postnatal disturbances (hypoxia, acidosis morbidity, impaired adaptation) confirm the value which must be attached to a prepathological cardiotocographic finding. In this connection it is important to include results gained in the course of monitoring and to see if the antepartal CTG is normal at all times, prepathological at all times or, in the case of variations, normal or prepathological in the end.

Acid-Base Equilibrium↗
PubMed1985

[Chemotherapy of advanced lymphogranulomatosis. Results of MOPP/COPP treatment at the West German Tumor Center, Essen].

Between 1968 and 1979, a total of 271 patients with advanced Hodgkin's disease received as first systemic chemotherapy MOPP (mechlorethamine [nitrogen mustard], oncovin [vincristine], procarbazine and prednisone) or COPP (as above, but cyclophosphamide instead of nitrogen mustard). In 162 of the 271 patients (60%) full remission was achieved. Demonstration of systemic signs, bioptically confirmed bone-marrow infiltration and suboptimal cytostatic dosage correlated significantly with a lower full-remission rate. A significant trend towards a lower remission rate was demonstrated for stage IV disease, in patients with lymphocyte-poor or unclassified Hodgkin's disease and in those older than 30 years. A five-year recurrence-free period was achieved in 75.5% of patients: stage of the disease and bone-marrow infiltration had a clear influence on recurrence-free survival rate. The results show that 50% of patients with advanced Hodgkin's disease can be cured by chemotherapy.

Adult↗
PubMed1985

[Effect of antineoplastic agents and ionizing radiation on a human testicular cancer heterograft].

Chemotherapy has afforded a high percentage of definitive cures in advanced testicular cancer. Nevertheless some patients with large tumor burden still succumb to chemorefractory disease. Therefore preclinical and clinical evaluation of new drugs and agents not primarily used against this type of disease are still mandatory. For preclinical drug screening purposes heterotransplantation of specific human tumors yields a model with high validity for tumor markers and drug response. Heterotransplantation of a human embryonal testicular cancer was used for simultaneous testing of established agents such as cisplatin, melphalan, bleomycin, vinblastine, etoposide and adriamycin and some newer derivatives such as PHM or mafosfamide. Furthermore agents such as procarbazine, dacarbazine and methyl-CCNU that cross the blood-brain-barrier displayed some interesting activity. The results hint at a unique chemosensitivity pattern of the xenograft line, with some accordance between clinical response to vinblastine and bleomycin and good response of the xenografts to bleomycin but not to vinblastine. Radiotherapy was also effective against this tumor line, but there was not much difference in response when the schedule of fractionation was changed. It is concluded that a combined modality approach might salvage patients with residual, chemorefractory disease.

Animals↗
PubMed1983

[Limitations of tumor marker surveillance after chemotherapy in advanced non-seminomatous testicular tumors].

Determination of the biochemical tumor markers, alpha-fetoprotein (AFP) and beta-human chorionic gonadotropin (beta-HCG) gained much importance in respect to staging and follow-up examination of patients presenting with testicular cancer. After cytostatic chemotherapy the reliability of tumor markers is diminished. Retroperitoneal lymphadenectomy (RLA) was done in 60 patients after chemotherapy. Tumor marker elevation was found only in 52% of the patients showing retroperitoneal carcinoma (n = 25).

Antineoplastic Agents↗