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Biomedical subjects

B Hentschel

Publications and source records attributed to B Hentschel.

At least 19 recordsLinked to original sources
PubMed2006

Pattern of invasion is of prognostic value in surgically treated cervical cancer patients.

OBJECTIVES: Different patterns of invasion (representing different grades of tumor cell dissociation) are associated with prognostic outcome in cancer. We evaluated the prognostic value of different patterns of invasion (PI) in cervical carcinomas (CX). METHODS: Six hundred eleven surgically treated CX (FIGO IB to IIB) were re-evaluated histologically regarding the PI, using a three-level scoring system. Closed PI was defined as cohesive growth with well-delineated (pushing) borders. In finger-like PI the tumor grows in solid cords/trabecles. Highly dissociative growth in small groups or single cells was defined as spray-like PI. Types of PI were correlated to tumor stage, histo-morphologic factors and prognostic outcome. RESULTS: Sixty percent of the tumors showed a spray-like PI, 30% a finger-like PI and only 7.4% were of the closed type. Spray-like PI showed a significant correlation with advanced stage disease, lymphovascular space involvement, poorly differentiated tumors and pelvic lymph node metastases. Spray-like PI was accompanied by a reduced 5-year overall survival when compared to the finger-like and closed PI (68.7% vs. 80.9% vs. 88.5%; P=0.0004). The prognostic impact of the PI disappeared in node-positive patients (P=0.06) but persisted in patients without pelvic lymph node disease (P=0.03). In multivariate analysis, using COX regression model, the PI represented as independent prognostic factor. CONCLUSIONS: Spray-like PI (i.e., highest degree of tumor cell dissociation) is associated with advanced tumor stages, increased rate of recurrency and a reduced overall survival. In separate analysis of patients with and without lymph node metastases, the impact of PI persisted only in node-negative cases as a prognostic factor.

Adult↗
PubMed2006

[Vocal efficiency parameters in children and adolescents: effect of physical development and singing activity].

The influence of physical development and singing activity on vocal efficiency in children and adolescents is well known from clinical experience. There is, however, no comparative study between singing and non-singing children which also considers the influence of age and gender. Therefore, standard values for evaluation in clinical practice are missing. We examined the following parameters in 164 healthy children and adolescents (90 boys, 74 girls; 11-16 years), 86 without singing activity (group A) and 78 members of children's and youth choirs (group B): frequency and dynamic range of voice and its borders with a voice range profile, mean fundamental frequency (normal and loud phonation), maximum voice intensity, and maximum duration of intonation. The statistical analysis was performed using three-way ANOVA. We found significantly higher ranges of frequency and intensity in singing children and adolescents (p<0.0001). The borders of the dynamic range and the upper border of the frequency range were significantly higher in group B (p<0.0001). The boys in group B used a higher mean fundamental frequency during loud phonation. There were no significant differences between groups in maximum voice intensity (p=0.051) but a tendency towards higher values in singing children. As an unexpected result, we found significantly higher values in maximum duration of intonation in group A (p<0.0001) independent of age and gender, which seems to be related to the methods used. Regular training of the singing voice results in positive effects on several voice parameters in children as well as adolescents. Our results can be used for estimating standard values in professional clinical and educational care of young singing voices and non-singing children. For this purpose, voice range profile is particularly suitable.

Adolescent↗
PubMed2005

CD44-v6 concentrations in carcinoma of the uterine cervix: lack of prognostic significance.

Several kinds of cellular adhesion molecules, like different splicing variants of CD 44, have gained important as prognostic or markers for metastatic disease. Fresh frozen samples from 64 cervical carcinoma (CX) were stored in liquid nitrogen and examined using ELISA-technique, testing the prognostic impact. Normal cervical tissue served as control. CD 44-v6 concentration, was significant elevated in tumor tissue, when compared to the controls (P=0.04). There was no correlation to tumor stage (P=0.61), lymphovascular space involvement (P=0.075) or pelvic lymph node involvement (P=0.81). The CD 44-v6 concentration was not informative regarding recurrence-free and overall survival. Contrary to immunohistochemistry, the quantification of CD 44-v6 using ELISA-technique does not provide any further information.

Cell Adhesion↗
PubMed2004

Age-dependence of lipid parameters in the general population and vegetarians.

Age-dependent changes of lipid metabolism may arise both as a result of mechanisms of biological ageing and factors influencing age-dependent changes. To study possible influences of nutrition and life-style of vegetarians on age-dependence of lipid parameters, subjects of general population were compared with vegetarians. In the frame of population-based lipid screening projects in the city of Leipzig/Germany (Lipid Study Leipzig, LSL) 10 550 subjects (3,816 men and 6,734 women, age 18-99 years) of general population were compared with 417 vegetarians (vegans, lacto-vegetarians, lacto-ovo-vegetarians, 148 men and 269 women, age 18-93 years). Most of the vegetarians included in the study were members of the German Society of Vegetarians. The study program included capillary blood cholesterol measurements and the determination of high-density lipoprotein (HDL)-cholesterol, the measurement of other cardiovascular risk factors and the evaluation of dietary and life-style factors. Evaluation of cardiovascular risk profile within LSL was connected with individual consultation. The mean total cholesterol and non-HDL-cholesterol level and the total: HDL-cholesterol ratio showed the expected age-dependence, with maximum values within the decade 60-70 years. Vegetarians showed lower total and non-HDL-cholesterol levels in comparison with the general population. Furthermore, the age-dependent increase of these parameters is less pronounced under the conditions of vegetarian nutrition and life-style. Especially in young adulthood a significant difference is observed. Thus, the results of the present study reveal the role of nutritional and life-style factors that determine the lipid profile on a population basis and suggest that the known age-dependent rise of the level of atherogenic plasma lipoproteins is partly preventable.

Adolescent↗
PubMed2003

Prolactin receptor signaling during platelet activation.

Prolactin is a newly recognized platelet coactivator that functions through potentiation of ADP-induced platelet activation. However, the possible association between hyperprolactinemia and venous thromboembolism (VTE) has not been systematically investigated up to now; prolactin signaling mechanisms in platelets still need to be elucidated. In this study, plasma prolactin levels in healthy subjects and patients with VTE were determined, demonstrating that patients with VTE and no other congenital risk factors had significantly increased plasma prolactin levels. Moreover, prolactinoma patients demonstrated a higher incidence of VTE than the general population. To elucidate the molecular mechanisms for the development of venous thrombosis, prolactin receptor signaling during platelet activation was investigated with a focus on ADP-stimulated G-protein-regulated signaling pathways. The short isoform of prolactin receptors was detected on platelets. Signaling through this receptor, although not directly linked to Gq-proteins, substitutes for Gq-protein regulated signaling pathways involved in platelet activation. We identified protein kinase C, a well-established signaling molecule in platelet activation, as a target molecule for prolactin signaling pathways in human platelets. Our findings indicate that hyperprolactinemia may be an important novel risk factor for VTE, suggesting that its thrombogenic effect may be mediated through enhanced platelet reactivity. Revealing the molecular mechanisms of prolactin signaling will allow the design of new antithrombotic therapies.

Adult↗
PubMed2002

Mediastinitis and cardiac surgery--an updated risk factor analysis in 10,373 consecutive adult patients.

BACKGROUND: Deep sternal wound infection (DSWI) remains a serious complication after cardiac surgery. New evolving techniques including the utilization of internal mammary arteries (IMA), beating heart procedures, and minimal invasive surgery (MIC) require an updated risk factor analysis to identify high risk patients in order to improve perioperative treatment. METHODS: 10,373 consecutive patients receiving cardiac surgery between May 1996 and August 1999 were evaluated: 9,303 underwent full sternotomy whereas a minimally invasive (MIC) approach using partial sternotomy or lateral thoracotomy was used in 1,070 patients. DSWI was defined as the evidence of mediastinitis seen at reoperation along with one or more of the following: positive culture of mediastinal fluid, positive blood culture or temperature higher than 38 degrees C and/or leukocytosis. RESULTS: The overall incidence of DSWI in the "full sternotomy" group was 1.44 % (134 of 9,303). Univariate risk factor analysis showed a significant influence of IMA use, ICU / IC treatment > 5 days, postoperative ventilator time > or = 72 h, need for reexploration, diabetes, surgery time > or = 180 min, assist device implantation (including use of IABP), peripheral vascular disease and increased body mass index. Multivariate analysis identified double IMA, ICU treatment > 5 days, single IMA, diabetes, reexploration and increased body mass as significant risk factors. No mediastinitis was observed in the MIC group. CONCLUSION: As DSWI is related to sternotomy, a MIC approach should be considered for patients at high risk for DSWI. IMA takedown as a pedicled graft should be especially avoided in patients with diabetes since the risk for postoperative mediastinitis is unacceptably high in this patient group.

Aged↗
PubMed2002

Prediction of remission or relapse for Graves' hyperthyroidism by the combined determination of stimulating, blocking and binding TSH-receptor antibodies after the withdrawal of antithyroid drug treatment.

The most likely reasons for the low predictive value of TSH-receptor antibodies (TRAbs) determinations in previous investigations are the biological heterogeneity of TRAbs and changes of the different stimulating (TSAb) or blocking (TSBAb) antibody bioactivities of TRAbs during the course of Graves' disease (GD), which have not been taken into account in most previous studies. Furthermore, in a recent study it has been demonstrated that the decline of TRAb values detected with highly sensitive hTBII or TSAB assays is not useful in evaluating remission or relapse of GD at the end of antithyroid drug treatment (ATDT). In order to make a thorough investigation of the predictive values of all different TRAb qualities for the recurrence for GD after the withdrawal, we investigated hTBII, TSAbs and TSBAbs in 54 consecutive patients with GD at the end of ATDT and 12 - 13.5 months after stopping ATDT. Using the TRAb values at the time of reinvestigation in a model, recurrence for GD was better predicted compared to the determination at the time of withdrawal of ATDT. Furthermore, using this model, the combined determination of hTBII, TSAbs, and TSBAbs revealed the highest level of significance for the prediction of remission or relapse of GD (OR = 15; p < 0.0001) compared to the detection of hTBII, TSAbs and TSBAbs alone. Therefore, significant changes of TSAbs after the end of ATDT and the biological heterogeneity of TRAb define the conditions for predicting remission or relapse of GD after ATDT by TRAb determinations. Consequently, our results suggest that the prediction of the individual course of GD can only be improved by combined determinations of all TRAb qualities (hTBII, TSAbs and TSBAbs) after the end of ATDT.

Adult↗
PubMed2002

Clinical relevance of urokinase-type plasminogen activator and its inhibitor type 1 (PAI-1) in squamous cell carcinoma of the uterine cervix.

OBJECTIVE: The expression of uPA and PAI-1 as parameters of tumour-associated proteolysis has been implicated in the process of tumour cell invasion and the metastatic process. However, there is limited information on the impact of these parameters in cervical carcinoma. METHODS: Quantitative levels for uPA (n = 114) and PAI-1 (n = 103) were researched in operatively treated, surgically staged squamous cell cancer of the uterine cervix, using an ELISA-technique. Results were assessed regarding their impact in predicting pelvic lymph nodes metastases, tumour recurrence rate and recurrence free survival (RFS) using uni- and multivariate analysis. RESULTS: Median levels of both parameters were significantly higher in tumour tissue than in normal cervical tissue (p < 0.001). Detection of uPA gave no useful prognostic information. PAI-1 concentration showed a positive correlation with advanced tumour stage (p = 0.008), but no significant correlation with nodal status (pN0: 2.6 vs. pN1: 4.0 ng/mg protein; p = 0.092). Using a cut-off level of 2.4 ng/mg protein, patients with elevated PAI-1 levels demonstrated reduced RFS (45.9 versus 52.9 months; p = 0.1). Multivariate analysis, including nodal status, tumour stage, lymphovascular space involvement and grading failed to demonstrate any prognostic impact of uPA and PAI-1. CONCLUSIONS: The results indicate, that PAI-1 expression is of some prognostic impact in cervical cancer, indicating an association of elevated PAI levels with local tumour progression and reduced recurrence-free survival.

Adult↗
PubMed2001

Influence of dietary intake and physical activity on annual rhythm of human blood cholesterol concentrations.

Seasonal variation in the plasma total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C) have been repeatedly reported, with contradictory results regarding the pattern of seasonal variation of these parameters. Furthermore, it is still not well established whether the variation is due to changes in the nutrition or changes in physical activity depending on the season. The aim of this study was therefore to determine plasma TC and HDL-C in different groups of healthy participants: 19 vegetarians with a constant diet independent of the season, 14 athletes with almost constant physical activity over the year, and 114 controls in the age groups 20-26 years (mean age 24 + 1.5 years) and 40-48 years (mean age 44.3 + 2.1 years). Over 2 years, blood samples were collected every 2-3 months and were analyzed for plasma TC and HDL-C. At all visits, body mass index (BMI) and waist-to-hip ratio (WHR) were calculated, and nutrition and physical activity profiles were obtained. The seasonal model was calculated using object-oriented software for the analysis of longitudinal data in S (OSWALD); multiple regression analysis was used to determine the influence of age, gender, diet, and physical activity on seasonal changes of the lipid parameters. In all groups, we found an annual rhythm of the plasma TC and HDL-C concentrations, which can be mathematically described by a sine curve with a maximum in winter and a minimum in summer. This rhythm was independent of the age, gender, BMI, diet, or physical activity. The observed seasonal differences between the maximum and the minimum were about 5%-10% for TC and about 5%-8% for HDL-C concentration. These differences were greater than the determined circadian (TC 3.5%, HDL-C 4%) and day-to-day changes for TC and HDL-C (coefficient of variation <5% for both). In conclusion, annual rhythm of TC and HDL-C is not primarily induced by seasonal differences in dietary intake or physical activity. Therefore, the annual rhythm in cholesterol levels is most likely determined by endogenous factors or factors directly related to seasonal changes in the environment.

Adult↗
PubMed2001

PRL as a novel potent cofactor for platelet aggregation.

Pregnancy (including puerperium) is a period of hypercoagulability and seems to be an independent major risk factor for venous thromboembolism (VTE). However, the basis of the increased risk of VTE in pregnancy and around delivery is unknown. We hypothesized that changes in PRL, which is a prominently increased hormone during pregnancy and lactation, might be involved in the activation of platelets. To investigate platelet functional abnormalities in pregnancy, we assessed the ADP-stimulated and nonstimulated P-selectin expression of platelets in 42 consecutive pregnant women, 22 normo- and hyperprolactinemic patients with pituitary tumors, and controls. In addition, the aggregation of platelets by human PRL in vitro was studied. We found a significant correlation between PRL values and ADP stimulation of platelets in pregnant women (r = 0.56; P < 0.0001) and patients with pituitary tumors (r = 0.57; P = 0.006). Hyperprolactinemic pregnant women or hyperprolactinemic patients with pituitary tumors revealed significantly higher ADP stimulation of platelets (P < 0.0001) than healthy controls or normoprolactinemic patients with pituitary tumors. These results were reconciled by increased in vitro stimulation and aggregation of platelets using human PRL. Our novel findings demonstrate that hyperprolactinemia causes increased platelet aggregation via ADP stimulation both in vitro and in vivo. Moreover, our data indicate that PRL may be a physiological cofactor of the delicate coagulation balance during pregnancy and puerperium that might explain the increased risk of VTE in pregnant women around delivery. Further studies of the interaction between PRL and platelets will clarify the clinical relevance of hyperprolactinemia as a potential risk factor for VTE.

Adenoma↗
PubMed2000

[Similarity of monozygotic twins regarding vocal performance and acoustic markers and possible clinical significance].

Auditory similarities in voices of monozygotic twins have already been described in the literature. However, is there a clinical relevance? Thus, the present study was designed to identify parameters of vocal performance and acoustic features which are significantly more similar in monozygotic twins than in non-related persons. In our hypothesis, comparable prerequisites for an increased vocal load in a profession or in an artistic education of the voice could be due to these similarities. We compared intra-pair differences with data from a control group. Moreover, we examined the correlation of intra-pair differences with the age of the monozygotic twins. A greater difference in older twin pairs than in younger pairs could show the effect of an exogene influence. In addition to the few phoniatric studies in twins in the literature, we used current methods for acoustic analysis. We examined seven parameters of vocal performance and three acoustic features in 31 monozygotic twin pairs (median age 36 years, range 18-75 years) and compared them with 30 control group pairs, which consisted of non-related persons of the same age and sex, newly combined from the group of monozygotic twins ("statistical twins"). We found significant differences in seven of ten parameters (vocal range, highest and lowest vocal fundamental frequency, fundamental speaking frequency, maximum voice intensity, number of partials, vibrato of intensity; U-test by Mann-Whitney). No correlation of the differences of the identical twins with age was found in the examined parameters. The voices of identical twins are significantly more similar than those of non-related persons regarding the above mentioned features. Thus, the suitability of the voices of monozygotic twins for professions with a high demand on voice is comparable. Results of the group comparison correlate largely with the literature. The missing correlation with age could be due to the fact that the environmental effects were not measurable, and/or the development of the voice is more influenced by genetic effects.

Adolescent↗
PubMed2000

Treatment of anaemia in myelodysplastic syndromes with prolonged administration of recombinant human granulocyte colony-stimulating factor and erythropoietin.

Treatment with recombinant human erythropoietin (rhEPO) improves anaemia in approximately 20% of the patients with myelodysplastic syndromes (MDS). Recent reports suggest that a combination treatment with rhEPO plus recombinant human granulocyte colony-stimulating factor (rhG-CSF) given for up to 18 weeks may result in a higher erythroid response rate than with rhEPO alone. We investigated the potential advantage of an even more prolonged schedule of combined rhG-CSF and rhEPO treatment to obtain and maintain stable responses. In a phase II study, 33 patients with MDS [17 with refractory anaemia (RA), eight with RA with ringed sideroblasts (RARS), eight with RA with excess blasts (RAEB) with bone marrow blast counts less than 20%] were scheduled to receive at least 36 weeks of combined therapy with rhG-CSF and rhEPO. Seventeen of 28 evaluable patients demonstrated an erythroid response [61%; 95% confidence interval (CI) 41-78] after 12 weeks of treatment. The erythroid response rate was 80% (20 of 25 evaluable patients; 95% CI 59-93) after 36 weeks. Seven of these responses developed between week 12 and week 36, whereas two initially responding patients became refractory. The cytokine therapy was generally well tolerated. Nineteen of the 20 patients responding after 36 weeks continued to be treated with both cytokines. After 1 year and 2 years of continuous combined treatment, 50% of the initially included patients showed a continuing response. Our results suggest that a prolonged combination treatment with rhG-CSF and rhEPO is highly effective in achieving a stable and long-lasting erythroid response in many patients with MDS and low blast count.

Adult↗
PubMed2000

Differences between thyrotropin receptor antibody bioactivity and inhibition of 125I-bovine thyrotropin binding.

Thyrotropin (TSHR) receptor antibodies that bind to the TSHR without stimulating the TSHR have been identified with a direct binding assay. Moreover, TSHR antibodies that exhibit thyroid epithelial cell stimulation without inhibition of 125I-bovine thyrotropin (bTSH) binding and vice versa have been described. These data suggest that stimulation or blocking of the TSHR by stimulating (TSAB) or blocking (TSBAB) TSHR antibodies could be possible without detectable bTSH-displacement activity. However, to date, possible differences between TSAB or TSBAB activity and inhibition of 125I-bTSH binding have not been systematically investigated. Therefore we compared inhibition of 125I-bTSH binding and TSAB or TSBAB activity of sera from 113 patients with Graves' disease treated with antithyroid drugs. To exclude the different assay conditions of previous investigations as possible confounding factors, we determined TSAB or TSBAB and inhibition of 125I-bTSH binding (TBIIW) with the same Chinese hamster ovary (CHO) cells expressing the human TSHR. Furthermore inhibition of 125I-bTSH binding was also determined as thyrotropin-binding inhibitory immunoglobulin (TBII) with solubilized porcine thyroid membranes (TRAK, Brahms, Berlin Germany) and the highly sensitive recombinant human TSH receptor assay (hTRAK, Brahms, Berlin Germany). Only 78% (54/69) of TSAB-positive and 78% (21/27) of TSBAB-positive sera detected with JP26 cells exhibit inhibition of 125I-bTSH binding measured as TBII or TBIIW. Furthermore, 59% (10/17) of sera without TSAB and TSBAB activity revealed inhibition of 125I-bTSH binding measured as TBII or TBIIW. We found significant differences between TSHR bioactivities (TSAB or TSBAB) and inhibition of 125I-bTSH binding. Moreover, there was no agreement between the detectable TSHR bioactivities (TSAB or TSBAB) and their detectable inhibition of 125I-bTSH binding. Therefore, it is very likely that TSH displacement by TSHR antibodies and stimulation or blocking of the TSHR by TSHR antibodies are different functions that do not need to occur together.

Animals↗
PubMed1999

[Model trial: use and evaluation of a problem-oriented learning program in internal medicine].

BACKGROUND: Problem-based training is a new approach in medical education. It is in particular essential that students work actively with authentic medical cases. Modern software is appropriate for developing interactive case-based training systems and the use in teaching environments. This method is still rarely integrated within medical curricula. METHOD: In an educational trial with 287 students the conceptual background, feasibility and evaluation are discussed. The learning program CASUS was used to present the case of a macroprolactinoma for interactive training. A questionnaire with a return rate of 78% was used for evaluation. RESULTS: 96% of the students had no problems in learning how to handle and use the program. A major problem was to focus the contents of the program exactly to the students' needs. The students' judgement was independent of the individual computer skills. 82% of the students would like to use the program in the future. CONCLUSION: Case-based and computer-assisted learning increases motivation and probably improves the quality in medical education. Controlled trials have to be implemented in future to show the effectiveness and the long-term output of these learning systems.

Computer-Assisted Instruction↗