Biomedical subjects

W Schmidt

Publications and source records attributed to W Schmidt.

At least 199 records · Page 11Linked to original sources

PubMed1998

Validity of the minimal resistance index for discrimination between benign and malignant breast tumours.

We investigated the validity of the flow parameter minimal resistance index (min RI) for discrimination of breast tumours. Colour and spectral Doppler sonography was performed on 114 patients. An increase in number of tumour vessels was paralleled by a significant drop of the minimal (min) RI (p=0.004) and increase of the maximal (max) RI (p=0.03) while mean RI was not influenced. The present results question the validity of min RI as parameter for discrimination of breast tumours. Min RI does not represent the actual flow resistance.

Breast Diseases↗

PubMed1998

Immunohistochemical analysis of 1,25-dihydroxyvitamin D3 receptor in cervical carcinoma.

The immunohistochemical localization and expression of 1,25-dihydroxyvitamin D3 receptors (VDR) has been investigated in normal human cervical tissue (n = 15) and in cervical carcinomas (n = 23). VDR immunoreactivity (monoclonal antibody 9A7gamma) was compared with the staining patterns of transglutaminase K, cytokeratin 10 and Ki-67 in these tumours. Moderate to strong nuclear immunoreactivity for VDR was detected in almost all cervical carcinomas analysed. VDR staining was homogeneous, with no visual differences between individual tumour cells. Some 60% of normal cervical tissues revealed weak immunoreactivity for VDR. In normal cervical tissue, nuclear VDR staining was confined to the lower cervical layers, predominantly to the basal cell layer. Both the intensity of VDR immunostaining and the number of VDR-positive cells were up-regulated in cervical carcinomas compared with normal cervical tissue. No visual correlation was found for the coexpression of VDR with markers of proliferation and differentiation. Our findings indicate that: (1) cervical tissue may be a new target organ for therapeutically applied vitamin D analogues; (2) VDR is up-regulated at the protein level in cervical carcinomas compared with normal cervical tissue; (3) up-regulation of VDR in cervical carcinoma is induced not exclusively by alterations in epithelial differentiation or proliferation, but by different, unknown mechanisms; and (4) calcitriol and new vitamin D analogues exerting fewer calcaemic side-effects may be promising new drugs for the treatment or chemoprevention of metastasizing cervical carcinomas as well as of cervical precancerous lesions.

Adenocarcinoma↗

PubMed1998

Presence of the AZF region in a female with an idic(Y)(q11).

In a child with some features of Turner's syndrome, gonosomal mosaicism with an isodicentric nonfluorescent (idic)Y chromosome was detected (mos 45,X/47,X,idic(Y)(q11),idic(Y)(11)/46,X,idic(Y)(q11)). Histopathological examination showed streak gonads with some evidence of ovarian stroma and no sign of gonadoblastoma. Polymerase chain reaction (PCR) analysis in blood lymphocytes and gonadal tissues using primers of seven loci along the Y chromosome, including the sex determined region (SRY), azoospermia factor region (AZF) and the deleted in azoospermia (DAZ) gene was positive for all loci tested, confirming the isodicentric character of the Y chromosome and indicating the presence of the AZF region. It is remarkable that the existence of spermatogenesis controlling genes does not play an important role in gonadal development and differentiation in a phenotypic female with some Turner stigmata. The data presented here are briefly discussed with previously-described patients.

Child↗

PubMed1998

[Effects of extracorporeal ultrasound shockwaves on the relatively mature embryos of the teleost Oryzias latipes].

Exposure to low-energy ultrasound shock waves (1000 impulses at a frequency of 2/sec and an energy density of 0.08 mj/mm2; peak positive/negative pressure 16/-7 MPa; pulse duration about 10 musec) led to the following alterations in the cells and tissues of stage 35 embryos of Oryzias latipes ranked according to their extent: (1) In various tissues, especially in the trunk musculature, orthodox mitochondria were transformed into condensed (= low energy) mitochondria. (2) Nuclear envelopes and sarcoplasmatic reticulum of muscle fibres as well as endoplasmatic reticulum of epidermal ionocytes were often vesicularly dilated. (3) Muscle fibres in the trunk musculature began to separate from each other. Epidermal intercellular spaces were enlarged and increased in number. (4) Destruction of vessels and haematomas were observed in the circulatory system of the yolk sac. (5) Necroses up to total disintegration were found in various organs of the body cavity (intestine, liver, spleen). The less serious alterations (1 and 2) occurred in organs completely surrounded by other tissues. Major damages (4 and 5), however, affected only organs with free outer and inner surfaces, probably explained by cavitation and jet stream phenomena within the adjacent fluids.

Age Factors↗

PubMed1998

[Diagnostic and prognostic value of vascular resistance in breast tumors].

AIM AND METHOD: In a prospective study of 113 patients with breast tumours, we measured the vascular resistance index (mean RI) of physiologic tissue and the tumour by using pulsed colour coded Doppler sonography. RESULTS: The group of carcinomas showed a significantly higher mean RI (0.71 +/- 0.09 SD) compared to the group of benign tumours (0.66 +/- 0.09 SD) (p = 0.003). After dividing the groups according to menopausal status, this difference disappeared. In general the mean RI was higher in postmenopausal women. Only premenopausal women showed a significantly higher mean RI within the carcinoma (0.69 +/- 0.1 SD) compared to physiological tissue (0.65 +/- 0.07 SD, p = 0.02). The mean RI measured in the tumour area from carcinomas correlated with the S-phase fraction: r = -0.53 (p = 0.003). CONCLUSION: Mean RI reflects vascular resistance but does not allow discrimination between benign or malignant and is significantly influenced by menopausal status. The dynamics of proliferation and low vascular resistance seem to depend on each other. All these facts should be considered when doing Doppler sonographic examination of the breast.

Adult↗

PubMed1998

[Desflurane versus isoflurane in geriatric patients. A comparison of psychomotor and postoperative well-being following abdominal surgical procedures].

PURPOSE: The new volatile anaesthetic agent desflurane has a significantly lower blood-gas partition coefficient (0.42) than isoflurane (1.4), suggesting excellent intraoperative control of anaesthesia and rapid emergence and recovery from anaesthesia. However, only limited experience is available in geriatric patients undergoing major abdominal surgery. METHODS: After approval by the local ethics committee and with written informed consent, 52 patients (> or = 65 years old, ASA class II or III) scheduled for major abdominal surgery were randomised to receive either desflurane (DES) or isoflurane (ISO) for maintenance of anaesthesia. After oral premedication with midazolam 3.75-7.5 mg, anaesthesia was induced with etomidate 0.2-0.3 mg/kg and fentanyl 3 micrograms/kg. Vecuronium 0.1 mg/kg provided muscle relaxation for endotracheal intubation. All patients were mechanically ventilated to maintain normocapnia. For maintenance of anaesthesia, DES or ISO was administered in 60% N2O and additional boluses of fentanyl and vecuronium were given as required. At the end of surgery, the neuromuscular blockade was reversed with neostigmine 0.02 mg/kg and DES or ISO was discontinued at the end of skin closure. Episodes of bradycardia and tachycardia and hypo- and hypertension, the time from the end of anaesthesia to extubation, opening eyes, squeezing hand, stating name and birthdate and to discharge from the recovery room were recorded. Until 360 minutes after the end of anaesthesia, the recovery of psychomotor functions was measured by means of simple reaction time tests, critical flicker fusion test, labyrinth test, ball bearing test, short and long-term memory test and digit symbol substitution test. The patient's well-being was documented with scores for pain, sedation and postoperative nausea and vomiting. RESULTS: Demographic data in both groups was similar (Tab. 1). Anaesthesia was significantly prolonged in the ISO group. No significant differences between groups were found for MAC hours and the total dose of fentanyl and vecuronium administered (Tab. 3). Intraoperative haemodynamics were comparable between both groups (Tab. 4). No episodes of increases in heart rate or blood pressure associated with rapid increases in DES concentration were seen. Early emergence parameters were faster in the DES group (Tab. 5). When compared to ISO, the overall test performance and testing ability was superior following DES. Psychomotor tests showed significantly better results up to 240 minutes after the end of DES anaesthesia (Tab. 7, Fig. 4). Comparing the postoperative well-being, there were mild advantages for DES (Tab. 6, Fig. 1, 2, 3). However, time to discharge of geriatric patients from the recovery room was significantly shorter in the DES group (median 171 vs. 215 min., p < 0.05). CONCLUSION: Using a balanced anaesthesia technique, we found desflurane as suitable as isoflurane for geriatric patients. Additionally, due to the fast emergence from anaesthesia, an improved cooperativity was found. In the DES group overall better postoperative psychomotor performance resulted in a shortening of discharge times from the recovery room. Hence, desflurane anaesthesia may be advantageous in geriatric patients.

Abdomen↗

PubMed1998

Human ovarian cancer xenografts in nude mice: chemotherapy trials with paclitaxel, cisplatin, vinorelbine and titanocene dichloride.

The new cytostatics titanocene dichloride and vinorelbine were compared to cisplatin and paclitaxel using a human ovarian cancer xenografts model. Biopsy material from a native human ovarian carcinoma was expanded and transplanted into 96 nude mice. The animals were divided into six treatment groups: cisplatin 3 x 4 mg/kg, paclitaxel 5 x 26 mg/kg, vinorelbine 1 x 20 mg/kg, titanocene dichloride 3 x 30 mg/kg, titanocene dichloride 3 x 40 mg/kg and a control group treated with 0.9% saline. Each experiment was repeated with eight mice in each treatment group. Treatment groups were evaluated in terms of average daily increase in tumor volume and average daily body weight increase of nude mice based on slopes of least-square regressions performed on individual animals. The slope factors alpha and beta of the body weight (alpha) and tumor volume changes (beta) within each group during the course of an experiment were calculated. Both a statistically significant decrease (p<0.05) in the body weight of the experimental animals (cisplatin: alpha = -0.5163, vinorelbine: alpha = -0.6598, paclitaxel: alpha = -0.6746, titanocene dichloride 3 x 30 mg/kg: alpha = -0.6259, titanocene dichloride 3 x 40 mg/kg: alpha = -0.7758) and a significant reduction (p<0.05) of the increase in tumor volume (cisplatin: beta = 12.049, vinorelbine: beta = 0.504, paclitaxel: beta = -1.636, titanocene dichloride 3 x 30 mg/kg: beta = 6.212, titanocene dichloride 3 x 40 mg/kg: beta= -0.685) was shown in all treated groups compared to the control group (alpha = -0.1398; beta = 23.056). No significant weight changes were observed between the individually treated groups. A statistically significant reduction of the tumor growth occured under paclitaxel (beta = -1.636), vinorelbine (beta = 0.504) and titanocene dichloride medication 3 x 40 mg/kg (beta = -0.685), as compared to the group treated with cisplatin (beta = 12.049). We found titanocene dichloride to be as effective as paclitaxel and more effective than cisplatin. Vinorelbine seems to be a very effective antineoplastic agent exhibiting a significant higher cytostatic effect than cisplatin. Both titanocene dichloride and vinorelbine provide new therapeutic options in women with ovarian carcinoma not responding to standard chemotherapy.

Analysis of Variance↗

PubMed1998

Dopexamine attenuates endotoxin-induced microcirculatory changes in rat mesentery: role of beta2 adrenoceptors.

OBJECTIVE: To investigate the influence of dopexamine on endotoxin-induced leukocyte adherence and on vascular permeability in postcapillary venules of rat mesentery. DESIGN: Randomized, controlled trial. SETTING: Experimental laboratory. SUBJECTS: Twenty-seven male Wistar rats, weighing 250 to 350 g. INTERVENTIONS: Rats received one of three treatments: a) infusion of Escherichia coli endotoxin without dopexamine pretreatment; b) infusion of endotoxin with dopexamine pretreatment; or c) infusion of endotoxin after pretreatment with dopexamine and ICI 118,551, a selective beta2-receptor antagonist. MEASUREMENTS AND MAIN RESULTS: Leukocyte adherence, red blood cell velocity, and vessel diameters in postcapillary venules were evaluated using in vivo videomicroscopy. Vascular permeability was determined by measuring the extravasation of fluorescence-labeled albumin. Venular wall shear rate was calculated from red cell velocity and vessel diameter. Dopexamine attenuated both the increase in leukocyte adherence and vascular permeability during endotoxemia. The attenuating effect on leukocyte adherence could not be antagonized by the beta2-adrenoceptor antagonist. However, the attenuating effect on vascular permeability was antagonized by ICI 118,551. Dopexamine prevented a decrease in venular wall shear rate during endotoxemia. This effect was not influenced by ICI 118,551. CONCLUSIONS: Dopexamine attenuates endotoxin-induced microcirculatory disturbances in rat mesentery. The attenuating effect on vascular permeability is a beta2-adrenoceptor-mediated process, whereas the beta2-adrenoceptor actions of dopexamine play no significant role in attenuating leukocyte adherence.

Adrenergic beta-Agonists↗

PubMed1998

Relative accuracy of fine-needle aspiration and frozen section in the diagnosis of well-differentiated thyroid cancer.

The need for and extent of thyroid surgery for a thyroid nodule is usually primarily based on fine-needle aspiration (FNA) and frozen section diagnosis. The relative role of these modalities in 66 patients who had undergone FNA and subsequent thyroidectomy with frozen section was investigated. Cases that demonstrated discordance between FNA and frozen section (n = 22; 33%) were identified, and all slides were re-reviewed by a cytopathologist using current established cytologic criteria. A change in diagnosis was made in 13 cases with an increase in accuracy of FNA from 71% to 88%. The accuracy of frozen section (92%) did not change appreciably with re-review (94%). The accuracy of FNA and frozen section combined was found to be 98%. The rate of discordance decreased from 33% to 13% with re-review. When strict histologic and cytologic criteria are applied, FNA and frozen section are accurate and complementary methods that help in determining the operative management of thyroid masses. However, when FNA yields a diagnosis of "follicular neoplasm," frozen section is unlikely to change this diagnosis.

Adenocarcinoma↗

PubMed1998

Up-regulation of cytochrome P450 1A2, 2C9, and 2E1 in chronic pancreatitis.

The oxidative metabolism of xenobiotics is effected mainly by cytochrome P450 enzymes (CYP), which are expressed as a family of genetically related enzymes primarily in hepatocytes. The pancreas is among the extrahepatic tissues expressing CYP, and it has been suggested that intermediates generated by them might be of pathogenetic significance for diseases of the pancreas such as chronic pancreatitis. We studied 10 surgical resection specimens by immunohistochemistry with polyclonal antibodies against recombinant human CYP 1A1, 1A2, 2C9, 2E1, and 3A and used tissues from 11 normal pancreata as controls. In addition, we assayed microsomal preparations for their capacity to metabolize verapamil. In normal pancreata weak to moderate expression of all enzymes was demonstrated immunohistochemically in up to 50% of duct epithelia, acinar cells, and islet cells. In contrast, in chronic pancreatitis an up-regulation was observed, with immunohistochemical positivity in some cases in up to 100% of duct epithelia and acinar cells. The oxidative capacity of microsomal preparations from chronic pancreatitis was higher than that of preparations obtained from control tissues; compared to liver microsomes, however, it was low. The up-regulation of CYP may have pathogenetic significance for chronic pancreatitis. Yet considering the pancreas' capacity for conjugation reactions, conceivably low levels of reactive intermediates could effectively undergo inactivation.

Adult↗

PubMed1998

Increased immunoglobulin G production by short term cultured duodenal biopsy samples from HIV infected patients.

BACKGROUND: Secretory immunity is a major defence mechanism against infections at mucosal surfaces which are common in HIV infected patients. AIMS: To analyse intestinal immunoglobulin production in HIV infection in comparison with that in saliva and serum. PATIENTS AND METHODS: Immunoglobulin G (IgG), A (IgA), and M (IgM) concentrations were determined in supernatants of short term cultured duodenal biopsy samples, serum, and saliva from HIV infected patients (n = 28) and controls (n = 14) by radial immunodiffusion. RESULTS: IgG was increased in the supernatants of short term cultured biopsy samples and saliva from HIV infected patients compared with controls (p < 0.01), but IgA and IgM levels were normal. In contrast, both IgG and IgA concentrations in serum were higher in HIV infected patients than in controls (p < 0.002). No correlation was found between IgA produced by duodenal biopsy specimens and serum IgA. CONCLUSION: Abnormalities in mucosal immunoglobulin production in HIV infection were surprisingly small, indicating that specific secretory immunity rather than quantitative immunoglobulin production may be impaired. However, increased production of IgG could contribute to mucosal inflammation by complement activation. Our findings of normal mucosal IgA production and the lack of correlation between serum and mucosal IgA argues against an intestinal origin for the increased serum IgA levels in HIV infected patients.

Acquired Immunodeficiency Syndrome↗

PubMed1998

Is urodilatin the missing link in exercise-dependent renal sodium retention?

The purpose of the present study was to investigate the behavior of plasma atrial natriuretic peptide [ANP-(99-126)] concentration ([ANP]) and renal urodilatin [Uro; ANP-(95-126)] excretion during and after exercise and their possible effects on renal Na+ retention. Ten male subjects performed a cycle ergometer test for 60 min at 60% of maximum workload. Blood and urine samples were collected before, during, and up to 24 h after exercise. During exercise, plasma [ANP] and renal Uro excretion were oppositely affected: whereas [ANP] increased from 46.5 +/- 5.1 to 124.1 +/- 10.6 pg/ml, urinary Uro excretion decreased from 120.8 +/- 16.0 to 49.5 +/- 9.8 fmol/min and remained at a lower level until 1 h after exercise. Glomerular filtration rate showed lowest values during exercise (from 164.9 +/- 15.3 to 75.8 +/- 10.1 ml/min), and urine flow and the fractional excretion rate of Na+ (FENa+) and Cl- (FECl-) had their nadir during the first hour after exercise. Positive relationships were observed between Uro excretion and FENa+ (P < 0.05) and FECl-, whereas a tendency toward a negative correlation was obtained between [ANP] and FENa+. It seems possible that Uro may be, among other factors, involved in the exercise-related regulation of renal Na+ retention. The specific roles Uro and ANP play during exercise, however, remain to be investigated.

Adult↗

PubMed1998

Secretory immunity in HIV infection.

Secretory IgA plays a crucial role in the defense of pathogens at mucosal surfaces. As CD4+ T cells are lost early in the mucosa of human immunodeficiency virus (HIV)-infected patients and as CD4+ T cells play an essential role in the regulation of specific IgA responses to pathogenic agents at mucosal sides, it could be expected that this first line of defense is impaired in HIV-infected patients. Therefore, several studies were undertaken to characterize the humoral immune response at mucosal surfaces. However, the results obtained so far are in part contradictory. For intestinal IgA, reduced, increased and no changes compared to controls were described. The different results may be due to different methods applied. In most studies an abnormal predominance of HIV-specific IgG over IgA response was found in the intestine of HIV-infected patients. Studies on cytomegalovirus-specific intestinal antibodies indicate a complete lack of a specific intestinal IgA response. However, in cryptosporidiosis of HIV-infected patients, diarrhea persists despite a secretory IgA response indicating that other factors are also important for the clearance of this pathogen.

Cryptosporidiosis↗

PubMed1998

Mucosal HIV infection.

The gastrointestinal tract is not only a major site of clinical manifestations of the acquired immune deficiency syndrome but also an important compartment for HIV infection at all stages of the disease. In intestinal biopsies HIV has been detected so far mainly in mononuclear cells of the lamina propria but also in epithelial cells. Primary and permanent epithelial cell lines can be productively infected by HIV in vitro and epithelial cell monolayers can rapidly transport HIV by transcytosis. Both phenomena are most effective for cell-associated virus and do not require CD4 expression but seem to involve the interaction of gp120 with galactosyl ceramide. In vivo, productive HIV infection of epithelial cells appears to be rare if it occurs at all. Mucosal HIV infection is highly active at all stages of HIV infection and the gastrointestinal tract is probably a major source of HIV in the body. Highest mucosal HIV production is found rather early in HIV disease and is associated with histological abnormalities and gastrointestinal symptoms. The excessive production of HIV in the intestine appears to be due to transcriptional or translational upregulation and local variations in HIV production correlate with local cytokine levels.

Galactosylceramides↗

PubMed1998

Expression of 1,25-dihydroxy vitamin D3 receptor in breast carcinoma.

We investigated immunohistochemically the expression of 1,25 dihydroxy vitamin D3 receptors (VDRs) in normal human breast tissue and in breast carcinomas. For the first time, a VDR immunoreactivity score (VDR-IRS) in breast tissue is presented. Mean VDR-IRS in breast carcinomas was 7.28 compared to 1.55 in normal breast tissue. Comparing staining patterns for VDR and Ki-67, no visual correlation was found, indicating that VDR upregulation in breast carcinomas is not exclusively controlled by the proliferative activity of these tumor cells. Our study adds to the body of evidence that breast tissue may be a sensitive target organ for therapeutically applied new vitamin D analogues that exert few calcemic side effects.

Breast↗

PubMed1998

Ultrasonography of the endometrium and endometrial pathology under tamoxifen treatment.

PURPOSE: The estrogenic effects of tamoxifen on the endometrium and the vaginal epithelium are evaluated. METHOD: 211 postmenopausal women were examined (tamoxifen group: 176 estrogen-receptor positive breast cancer patients; control group I: 35 estrogen-receptor negative breast cancer patients; control group II: 50 women without breast cancer taking no hormones). We determined the endometrial thickness and the maturation index (MI). Person's chi-square-test and the t-test for independent samples were used. RESULTS: In the tamoxifen group, the mean endometrial thickness and the MI were significantly higher (p<0.0001) than in the control groups. No evidence of correlation in duration of tamoxifen intake and endometrial thickness was found (Pearson's correlation coefficient: 0.4773; p=0.0001). The maturation index significantly (p<0.0001) increased under tamoxifen therapy. There was no correlation in the maturation index and endometrial thickness (Pearson's correlation coefficient: 0.1649; p=0.169). The histological clarification (N=47; endometrial thickness greater than 8 mm) revealed 3 neoplasms, 9 endometrial polyps, 2 glandular-cystic hyperplasias and in 32 cases atrophic endometrium. CONCLUSION: An apparent increase of endometrial thickness and the maturation of the vaginal epithelium caused by the estrogenic effect of tamoxifen was demonstrated.

Aged↗

PubMed1998

Primary tubal carcinoma: a retrospective analysis of four cases with a literature review.

With an incidence of 0.1% to 1.0% of all genital malignancies, primary tubal carcinoma is a rare malignant disease of the female genital tract. The prognosis is generally regarded as very poor. It is comparable with that of ovarian carcinoma. From 1980-1995, four patients were treated for primary tubal carcinoma at the Department of Gynecology and Obstetrics at the University of Homburg/Saar. FIGO stages IIa-IV were manifested as the primary stage. Surgery was performed as primary treatment in all patients. Both chemotherapy and percutaneous radiation were used as adjuvant postoperative therapy. The recurrence-free interval was 18-30 months. One patient died 21 months after primary diagnosis. The other free patients are in a period of follow-up observation of 16-96 months in an NC or CR status.

Adenocarcinoma↗

PubMed1998

[Uterine leiomyosarcoma with subsequent pregnancy].

Leiomyosarcoma are malignant tumors showing smooth muscle differentiation, they are rare, representing only about 25 percent of all uterine sarcomas and mixed malignant tumors and slightly more than 1 percent of all corporeal malignant tumors. Usually they arise in postmenopausal women and are not known to be related to the known risk factors for endometrial carcinoma (nulliparity, obesity, diabetes mellitus, hypertension, etc.) or carcinosarcoma (prior radiation therapy). They may occur in uteri that also bear typical benign leiomyomas, but leiomyosarcoma rarely can be proven to have arisen in or from benign leiomyomas. We report on two premenopausal women with leiomyosarcoma--out of totally 31 cases in our clinic from 1975-1995 who got pregnant after surgical treatment preserving the uterus. The patients are alive without evidence of disease 3 and 6 years after surgical resection.

Abortion, Incomplete↗