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Biomedical subjects

S Winkler

Publications and source records attributed to S Winkler.

At least 127 records · Page 7Linked to original sources
PubMed1995

Prediction of accelerated cure in Plasmodium falciparum malaria by the elevated capacity of tumor necrosis factor production.

Cytokine regulation was compared in three groups of Gabonese patients with Plasmodium falciparum malaria before and after therapy; adults with uncomplicated malaria, children with uncomplicated malaria, and children with severe malaria. Plasma levels of tumor necrosis factor (TNF), interleukin-6 (IL-6), IL-8, TNF receptors (TNF R), and the TNF/TNF R ratios were significantly higher in severe malaria compared with uncomplicated malaria. High plasma levels of all immunoregulatory molecules were associated with slow cure after therapy. In all patients, phytohemagglutinin-induced cytokine production was depressed on admission compared with convalescence. A significant difference was the higher TNF production capacity in patients with severe malaria on day 2 and day 5 compared with that in patients with uncomplicated malaria. In contrast to IL-6 and IL-8, a high TNF production capacity during the acute phase of malaria predicted a rapid clinical and parasitologic cure in the patients. These findings illustrate the dual role of TNF in the protection and pathology of malaria.

Adolescent↗
PubMed1995

[The "Patient Anxiety Seminar" as a graduate education program--effectiveness and use in general practice].

This article describes results of an evaluation study of a seminar for patients with anxiety, an education program for primary care physicians. Before and after the two seminars, 109 participants filled out a questionnaire about their opinion on the program as well as their attitudes, experience and knowledge in dealing with anxiety patients. They were compared with a control group which did not take part in the program. After 3 and 12 months, a part of the participants was interviewed again. It was found that anxiety patients call for a lot of attention from general practitioners and that diagnostic and therapeutic knowledge is not sufficient. The educational program was highly rated by the participants. The seminars were conducted in the practice by most of the participants in groups as well as on single patients. It became evident that in spite of high expenses there is a wide acceptance of such seminars and that the variables examined up to now indicate a surprisingly high efficiency of the educational programme.

Anxiety Disorders↗
PubMed1995

IL-10 augments CD23 expression on U937 cells and down-regulates IL-4-driven CD23 expression on cultured human blood monocytes: effects of IL-10 and other cytokines on cell phenotype and phagocytosis.

The effects of human recombinant interleukin-10 (IL-14) on the expression of several markers on U937 and human peripheral blood monocytes was studied by immunofluorescence and fluorescence-activated cell sorter (FACS) analysis. IL-10 augmented Fc IgE receptor (Fc epsilon RII/CD23) further enhanced by cotreatment with IL-4 or interferon-gamma (IFN-gamma). In contrast, the basal level of Fc epsilon RII expression on blood monocytes appeared to fall in response to IL-10, and this effect became more evident on IL-4-treated cells. Furthermore, the constitutive and IFN-gamma-triggered Fc gamma RI/CD64 expression was augmented on both monocytes and U937 cells. Thus the expression of Fc gamma RII/CD32, Fc gamma/RIII/CD16, Fc alpha R/CD89, the receptor for complement components (CR1/CD35, CD3/CD11b, CR4/CD11c) and the receptor for transferrin/CD71 was not significantly influenced on IL-10-treated cells. IL-10 modestly triggered CD14 antigen expression on monocytes but not U937. The expression of intercellular adhesion molecule-1 (ICAM-1)/CD54 on monocytes was significantly inhibited by IL-10. As expected, a marked reduction of the constitutive as well as of the IFN-gamma or IL-4-driven expression on HLA-DR, HLA-DP and HLA-DQ was observed on IL-10-cultured monocytes. On the other hand, the expression of major histocompatibility complex (MHC) class I molecules was slightly and dose-dependently induced on IL-10-treated monocytes. The ability of blood monocytes to phagocytose IgG-sensitized ox erythrocytes, and to bind and ingest opsonized Escherichia coli or latex particles, was amplified by IL-10. Our data demonstrate that IL-10 modulates the expression of a wide variety of structures on human mononuclear phagocytes, and augments their phagocytic capacity.

Cell Line↗
PubMed1995

Tumour necrosis factor-alpha and interleukin-6: early indicators of bacterial infection after human orthotopic liver transplantation.

OBJECTIVE: To see if it was possible to predict the development of infection after liver transplantation from concentrations of endotoxin, tumour necrosis factor-alpha (TNF-alpha), or interleukin-6 (IL-6) in plasma. DESIGN: Prospective open study. SETTING: University hospital, Austria. SUBJECTS: 46 Consecutive patients who underwent liver transplantation for end stage liver disease, 1989-90. INTERVENTIONS: Samples of 4 ml blood were taken in endotoxin free tubes, and of 10 ml into heparinised tubes at the beginning of the operation, during hepatectomy, at the beginning and end of the anhepatic phase, 10 minutes after reperfusion, and at the end of the operation. MAIN OUTCOME MEASURES: Correlation between development of infections postoperatively and operative release of endotoxin, TNF-alpha, and IL-6. RESULTS: There was no correlation between development of postoperative infections and operative concentrations of endotoxin, and of TNF-alpha and IL-6 up to the end of the anhepatic phase. There was, however, a sixfold increase in TNF-alpha and IL-6 concentrations between the end of the anhepatic phase and the end of the operation in patients who subsequently developed infections (p = 0.01). CONCLUSION: The increase in the concentrations of these two cytokines in the blood after reperfusion of the transplanted liver seems to predict the development of subsequent bacterial infection.

Adult↗
PubMed1995

Malaria epidemiology in the province of Moyen Ogoov, Gabon.

In the course of epidemiological and immunological baseline studies parasitological surveys were conducted, in 1992, in three localities situated in our near rain forest in the area of Lambaréné, Gabon, western Central Africa. Anopheles gambiae s.s. and A. funestus are considered to be the main vectors of malaria. The three localities represent strata with obvious differences in the intensity of malaria transmission. The lowest parasite rates were recorded in the village around the Albert-Schweitzer-Hospital where environmental sanitation and easy access to diagnostic and therapeutic facilities afford a fair measure of malaria control. The villages of Bellevue and Tchad show a much higher prevalence of Plasmodium falciparum, followed by P. malariae and P. ovale. In all three villages parasite rates and geometric mean parasite densities of P. falciparum showed the age pattern typical for areas with stable, hyperendemic malaria. Analysis by season showed the period of the long rains to be the epidemiologically calmest while the dry season and even more the short rainy season produced an increase of parasite rates and densities. In Tchad, the most affected of the three villages, the parasite rates in female adults were significantly lower than in male adults. This was accompanied by lower parasite densities in female adults.

Adolescent↗
PubMed1995

The custom implant impression coping: technical note.

Unsupported soft tissue can collapse around a submerged implant or abutment head during the time interval between removal of the provisional prosthesis and placement of the impression material. A technique is described for accurately recording the implant or abutment position as well as the position of the soft tissue for a single tooth restoration using the provisional prosthesis as a custom implant impression coping.

Dental Abutments↗
PubMed1994

Transhepatic metabolism of TNF-alpha, IL-6, and endotoxin in the early hepatic reperfusion period after human liver transplantation.

Several studies have shown that the postoperative course of cytokines such as TNF-alpha or IL-6 is predictive of rejection and infection after human orthotopic liver transplantation (OLT). The aim of this prospective clinical trial was to evaluate the impact of transhepatic metabolism of endotoxin (ET), tumor necrosis-factor-alpha (TNF-alpha), and interleukin-6 (IL-6) after hepatic ischemia/reperfusion on the postoperative graft function. In 13 consecutive elective adult OLT patients with primary grafts, we determined concentrations of ET, TNF-alpha, and IL-6 in the radial artery, portal vein, and right hepatic vein at 1, 4, 7, 10, and 13 min after reperfusion. Of the 13 patients, four had ET levels below the detection limit (< 10 ng/L), and one patient had extremely high ET concentrations (151 ng/L in the hepatic vein). In the remaining patients the mean ET levels were 26 +/- 14, 26 +/- 15, and 24 +/- 14 ng/L in the portal vein, hepatic vein, and in the radial artery, respectively. These values indicate that in patients with a moderately elevated ET level, no transhepatic concentration differences of ET exist. However, in the patient with severe endotoxemia, the liver was apparently an ET-producing organ (HV-P: 29 +/- 13 ng/L). TNF-alpha levels were not measurable in four patients, and varied between 15 and 72 pg/ml (portal vein) in the remaining patients. The transhepatic concentration differences (HV-P and HV-A, respectively) of patients with PNF or dysfunction were higher than in those with "good" or "excellent" graft function (HV-P: 160 +/- 122 pg/ml vs. 7.3 +/- 9.7 pg/ml; P < 0.01 and HV-A: 137 +/- 101 pg/ml vs. 3.9 +/- 12 pg/ml; P < 0.01, respectively). Arterial IL-6 levels were below 88 pg/ml (mean value: 31 +/- 20 pg/ml) at the beginning of the operation, and increased considerably in three patients during the anhepatic phase and after reperfusion. No clinical correlation was found with the transhepatic concentration differences of IL-6. We conclude that in OLT patients without infection no transhepatic ET exchange was documented. However, a stimulated hepatic TNF-alpha release seems to be predictive of the beginning of liver dysfunction.

Adolescent↗
PubMed1994

L-Arginine deficiency after liver transplantation as an effect of arginase efflux from the graft. Influence on nitric oxide metabolism.

L-Arginine plays an important role in protecting animals against ammonia intoxication, enhances immune function, stimulates wound healing, and is the precursor for the endothelium-derived relaxing factor, recently recognized as nitric oxide (NO). In this study, we investigated the influence of hepatic reperfusion on amino acid metabolism after human OLT. After 10 sec of reperfusion, the arterial plasma levels of L-arginine dropped from 105 +/- 12 mumol/L to 3.8 +/- 0.6 mumol/L (P < 0.001), whereas plasma ornithine increased from 40 +/- 5.5 mumol/L to 129 +/- 15 mumol/L (P < 0.001). The reduced L-arginine levels remained subnormal for several hours after OLT. This drop in plasma L-arginine was due to an arginase release from the implanted graft. Immediately after reperfusion, the plasma concentrations of arginase increased from pretransplantation values of 18 +/- 13 IU/L to 2384 +/- 1456 IU/L (P < 0.01). Measurement of plasma nitrite (NO2-) and nitrate (NO3-), which are the stable end products of NO, revealed that NO2- decreased about 50% after reperfusion (from 1.64 +/- 0.32 mumol/L to 0.80 +/- 0.17 mumol/L; P < 0.001), whereas NO3- levels remained unchanged (76 +/- 23 mumol/L vs. 63 +/- 8 mumol/L). We conclude that hepatic reperfusion causes L-arginine deficiency by liberating high amounts of arginase from the implanted graft. This L-arginine depletion may influence the NO synthesis in patients after OLT.

Adult↗
PubMed1994

Clindamycin in combination with chloroquine or quinine is an effective therapy for uncomplicated Plasmodium falciparum malaria in children from Gabon.

Multidrug resistance of Plasmodium falciparum is becoming common in Africa. In a randomized trial, four short-term regimens were compared for treating uncomplicated P. falciparum malaria in children 4-15 years old in Gabon. One hundred thirty patients received chloroquine (25 mg/kg over 48 h; group C), chloroquine (as above) plus clindamycin (5 mg/kg every 12 h for 6 doses; group CCl), quinine (12 mg/kg every 12 h for 6 doses; group Q), or quinine (as above) plus clindamycin (as above; group QCl). In group C, only 9% of patients were cured by day 28, 44% showed recrudescent malaria (RI), and 47% showed intermediate or high-grade resistance (RII/RIII). In group CCl, 70% of patients were cured and 30% showed recrudescences. In group Q, 32% were cured and 68% showed recrudescences. In group QCl, 88% were cured and 12% showed recrudescences after day 14. All treatment regimens were well tolerated. Thus, the combination of clindamycin with chloroquine or quinine enhances parasite clearance and improves response to therapy.

Adolescent↗
PubMed1994

Assessment of implant mobility at second-stage surgery with the Periotest: DICRG Interim Report No. 3. Dental Implant Clinical Research Group.

Many of the presently used methods of evaluating osseointegration at implant uncovering are highly subjective. The Periotest is claimed to offer a more objective means to assess osseointegration by means of microcomputer-controlled percussion. Investigators involved in a long-term clinical study of dental implants being conducted by the Dental Implant Clinical Research Group used the Periotest to evaluate the mobility associated with all study implants at second-stage surgery and correlate the Periotest values with various bone densities. The Periotest values for 1,838 root form implants ranged from -8 to +25. Implants that appeared to be osseointegrated at uncovering recorded a mean Periotest value of -3.37 +/- 3.25, while nonosseointegrated implants had a mean Periotest value of +13.87 +/- 14.27. Mean Periotest values were -3.82 +/- 3.04 for quality 1 bone, -3.70 +/- 3.06 for quality 2 bone, -3.31 +/- 3.18 for quality 3 bone, and -1.29 +/- 3.57 for quality 4 bone. The Periotest has the potential of being a valuable instrument for assessing the status of osseointegration at second-stage surgery.

Alveolar Process↗
PubMed1994

The influence of implant type, material, coating, diameter, and length on periotest values at second-stage surgery: DICRG interim report no. 4. Dental Implant Clinical Research Group.

Many of the presently used methods of evaluating osseointegration at second-stage surgery are highly subjective. The Periotest is claimed to offer a more objective means to assess osseointegration by means of microcomputer-controlled percussion. In 1991 the Dental Implant Clinical Research Group initiated a long-term clinical study in cooperation with the Department of Veterans Affairs to investigate the influence of implant design, application, and site of placement on clinical performance and crestal bone height. As part of this investigation, the Periotest values for 1,565 root form implants were determined at second-stage surgery and correlated with type, material, coating, diameter, and length. Hydroxyapatite-coated implants and increased implant diameter and length produced Periotest values that indicated a greater extent of stability as compared with noncoated implants with shorter diameters and lengths. Hydroxyapatite-coated cylinder-type implants yielded the most favorable Periotest readings. Not only does the Periotest have the potential of being a valuable instrument for assessing implant mobility at second-stage surgery, but it also appears to have the capability of determining slight differences in the implant-bone complex.

Dental Alloys↗
PubMed1994

The effect of smoking on implant survival at second-stage surgery: DICRG Interim Report No. 5. Dental Implant CLinical Research Group.

Smoking has been reported to have a deleterious effect on the oral cavity. Research has associated smoking with oral cancer, periodontal disease, leukoplakia, stomatitis nicotina, and impaired gingival bleeding. In 1991 the Dental Implant Clinical Research Group initiated a prospective, randomized clinical study in cooperation with the Department of Veterans Affairs to investigate the influence of implant design, application, and site of placement on long-term clinical performance and crestal bone height. Over 70 dental and medical history variables and exclusion factors were analyzed to determine relationships, if any, with implant failure at the time of second-stage surgery. The variables were analyzed separately for individual implants, cases (prostheses), and patients. The cases ranged from one to five implants each, and more than one case from a single patient could be included in the investigation. At this interim analysis, 2,066 implants have been placed representing 433 cases in 310 patients. With regard to implant failure rates, possible exclusion variable (9) and medical history variables (39) were not found to be statistically significant. For the dental history variables (23), only the question related to smoking was statistically significant on an implant, case, and patient basis (P < 0.007). Results of this interim analysis suggest that smoking is detrimental to implant success.

Chi-Square Distribution↗
PubMed1994

Patient demographics and implant survival at uncovering: Dental Implant Clinical Research Group Interim Report No. 6.

Implant prognoses for healthy elderly patients have been found to be comparable with those reported for younger patients. In 1991, the Dental Implant Clinical Research Group initiated a prospective, randomized clinical study in cooperation with the Department of Veterans Affairs to investigate the influence of implant design, application, and site of placement on long-term clinical performance and crestal bone height. As a result of the large sample size and wide range of patient ages, the study provided an opportunity to determine if age correlates with implant survival. Interim analysis of 2,132 root form implants at uncovering on an implant, case, and patient basis suggests that implant survival does not appear to be influenced by age in the largely white, male sample.

Adult↗
PubMed1994

Second-stage failures related to bone quality in patients receiving endosseous dental implants: DICRG Interim Report No. 7. Dental Implant Clinical Research Group.

The quality of bone plays an important role in the long-term clinical success of dental implant treatment. An interim evaluation of the relationship between bone quality and the incidence of failure at second-stage surgery is presented. The data include 2,131 root form implants placed by the Dental Implant Clinical Research Group over the past three years. Trends to date suggest differences in the rates of osseointegration among the various bone qualities. Quality 1 bone experienced the greatest failure rate, whereas quality 2 and quality 3 bone had the lowest failure rates.

Alveolar Bone Loss↗
PubMed1994

Drug sensitivity of Plasmodium falciparum in Gabon. Activity correlations between various antimalarials.

The sensitivity of Plasmodium falciparum to chloroquine, mefloquine, quinine, halofantrine, and sulfadoxine/pyrimethamine has been investigated at Lambaréné, in the Gabonese rain forest, between April and September 1992. WHO standard micro in vitro tests were performed. Of 43 isolates tested for response to chloroquine all were resistant to the drug with mean EC 50 and EC 90 values of 1.86 and 4.18 mumol/l blood, respectively, indicating the highest degree of resistance ever reported from Central Africa. With sulfadoxine/pyrimethamine 19 out of 27 isolates showed 90% inhibition of schizont maturation at a pyrimethamine concentration of at least 75 nmol/l blood medium mixture, indicating 30% of resistance to sulfadoxine/pyrimethamine. In contrast all isolates tested were fully inhibited by mefloquine at 3.2 mumol/l blood (40 isolates), quinine at 5.12 mumol/l blood medium mixture (41 isolates) and halofantrine at 3 nmol/l blood medium mixture (40 isolates) indicating full sensitivity to these drugs. A significant positive correlation was found between responses to quinine and mefloquine. The response to halofantrine was positively correlated with the responses to quinine and mefloquine, in the case of chloroquine and halofantrine an inverse relationship was observed. Compared with previous data from Gabon, the findings suggest a substantial increase of chloroquine resistance, in contrast to reports from neighbouring countries, which show stabilising or even declining chloroquine resistance patterns.

Animals↗