Biomedical subjects

W Schmidt

Publications and source records attributed to W Schmidt.

At least 1,009 records · Page 56Linked to original sources

PubMedDate not supplied

Aberrant MHC antigens in a sarcoma virus-induced mouse tumour.

From a series of mouse sarcomata, newly induced by Rous sarcoma virus (RSV), the DOH cell line was shown to lack expression of syngeneic H-2Kd and Dk antigens (Noll et al., 1986). It unexpectedly displayed determinants specific for H-2Kk molecules. Interferon treatment of DOH stimulated the expression of H-2Kk determinants and also the display of some, but not all, determinants of the syngeneic H-2Kd molecules. H-2Dk expression was not stimulated. Southern blot hybridization of genomic DNA digests from DOH cells confirmed the identity of the H-2K region with that from syngeneic C3H.OH liver cells, but also showed changes in the pattern of restriction fragments that contain class I genes from the D and Qa regions. These results suggest that aberrant MHC class I molecules that carry H-2Kd- and H-2Kk-like determinants are expressed by DOH sarcoma cells. These molecules may act as target antigens for tumour-specific cytotoxic T cells elicited by injection of DOH cells into syngeneic mice.

Animals↗

PubMedDate not supplied

Organization of the AKR Qa region: structure of a divergent class I sequence, Q5k.

We established the organization of the AKR Qa region and determined the sequence of the Q4 and Q5 genes. Restriction mapping and genomic Southern blot analysis revealed that the AKR strain codes for only three H-2K homologous genes in this region. The AKR Q5 gene is not homologous to the Q5 gene of the C57BL strain, but is presumably allelic to the Q5 gene isolated from Balb/c. The organization and structure of the AKR Qa family is virtually identical to the Qa genes of the C3H mouse. The AKR Q5 gene, in contrast to other H-2K homologous Qa region genes, codes for a typical transmembrane region, and upon transfection into BHK cells, a 1.6 kb Q5 transcript is detected.

Amino Acid Sequence↗

PubMedDate not supplied

Prenatal and perinatal aspects of a giant fetal cervicothoracal lymphangioma.

A massive cervicothoracal lymphangioma was diagnosed in a fetus at 25 weeks of gestation. On ultrasound study, the mass showed septated, cystic components and extended from the right submandibular region to the right anterolateral thoracic wall including the right axilla and right scapula. Close sonographic follow-up revealed an increase in the size of the lymphangioma without fetal hydrops. An interdisciplinary approach including a pediatric surgeon, neonatologist, perinatologist and anesthesiologist was chosen. Elective cesarean section under general anesthesia was planned at 37 + 0 weeks of gestation. Surgical correction of the lymphangioma was successfully performed on the 4th day of life. Possible differential diagnoses and the obstetrical management are presented.

Adult↗

PubMedDate not supplied

Increased nuchal translucency, hydrops fetalis or hygroma colli. A new test strategy for early fetal aneuploidy detection.

OBJECTIVES: Nuchal translucency measurement of 3 mm or more (> or = 95th centile for gestation age), hydrops fetalis or hygroma colli between the 11th and 14th weeks of gestation is associated with a higher risk of fetal Down syndrome and other aneuploidies. So far, chromosome preparation of chorionic villi samplings (CVS) after short-term (or direct) culture is the only valid, reliable and rapid method of choice for the early detection of chromosomal aberrations. However, because of the placental mosaicisms detected after short-term culture, CVS has to be confirmed by a second method. Moreover, short-term villi preparation does not always provide a sufficient quantity and quality of metaphases to enable cytogenetic analysis. Unfortunately, a predicative cytogenetic result will be available only after long-term cultivation (usually after 1-2 weeks). An alternative rapid method, inexpensive and suitable for diagnosing autosomal trisomies, is the quantitative fluorescence polymerase reaction (QF-PCR) using different polymorphic small tandem repeats (STRs) on CVS-DNA. Therefore, it was the aim of the study to evaluate whether a new CVS test strategy could be employed in early pregnancies at high risk after the rapid detection of fetal chromosomal abnormalities by QF-PCR for chromosomes 13, 18 or 21 and sexing in conjunction with short-term chromosome analysis. MATERIALS: Nineteen CVS were chosen for QF-PCR detection of trisomy 21, 18 or 13 after an increased nuchal translucency measurement (> or = 95th centile for gestation age), a hydrops fetalis or a hygroma colli. The amelogenin locus of chromosomes X and Y (AMXY) were used for sexing. The QF-PCR results were compared with routine karyotyping after short- and/or long-term cultivation of CVS cells. RESULTS: An informative result was demonstrated in all analysed specimens. Nine CVS were diagnosed as a QF-PCR trisomy either for chromosome 21, 18 and 13. The pathological samples also included 4 cases of mosaicism where the normal cell line was not identified by QF-PCR. In 1 additional case with a normal QF-PCR result, short-term CVS chromosome analysis showed a mosaic trisomy 13, whereas longterm CVS culture revealed a normal karyotype. The malformed aborted fetus showed no clinical signs of trisomy 13, confirming the normal results obtained by QF-PCR and long-term CVS chromosome analysis. One pregnancy with a Turner syndrome was not identified by molecular analysis. CONCLUSIONS: This study showed that all early pregnancies with a clinically relevant autosomal trisomy could be detected prenatally in routine practice by QF-PCR. The combined use of both rapid methods - QF-PCR and short-term chromosome analysis - optimise the results by minimising the possibility of false-positive or false-negative findings. We believe that after verification of a pathological result obtained by two independent methods (QF-PCR and short-term CVS chromosome analysis), long-term villi cultivation is no longer necessary. However, in all cases with discrepancies, especially in samples with mosaic findings at short-term CVS cultivation, further studies are still necessary.

Chorionic Villi Sampling↗

PubMedDate not supplied

Esophageal intramural pseudodiverticulosis.

A 66-year-old man presented with severe chronic dysphagia and weight loss. A barium esophagogram revealed a proximal esophageal stricture and multiple pseudodiverticula. After death from aspiration pneumonia, a postmortem examination revealed extensive esophageal pseudodiverticulosis. Clinical presentation, pathogenesis, diagnosis, and management of this unusual disorder are reviewed.

Aged↗

PubMedDate not supplied

[Effect of smoking and antioxidant vitamin concentrations of pregnant patients on birth weight of newborn infants].

An epidemiological study into the influence of cotinine validated maternal smoking and antioxidant vitamin concentrations on new born infants was carried out from 1992 to 1994 in the Department of Obstetrics and Gynaecology, University of Homburg/Saar. Of 222 participated pregnant women 26% were active smokers and 46% passive smokers. After adjustment a mean reduction in birth weight of 228 g was found in infants born to smokers, without dose correlation. Birth weight was not significantly reduced in infants born to passive smokers. There was no influence to the gestational age. A high correlation was established between maternal serum cotinine and umbilical cotinine (r = 0.91). In actively smoking mothers there was a positive correlation between vitamin E concentration and corrected infant birth weight (r = 0.33). Actively smoking mothers with children with a birthweight lower than the 25th percentile had significantly (p < 0.007) oftener lower vitamin E concentrations. Smoking increases the consumption of vitamin E, so that there is overproduction of peroxides and a reduction in prostacyclin. This lack of prostacyclin may lead to diminished perfusion of the placenta and may explain the birth weight reduction in smoker children.

Adult↗

PubMedDate not supplied

Immunohistochemical analysis of DNA mismatch-repair enzyme hMSH-2 and Ki-67 in breast carcinomas.

BACKGROUND: The human Mut-S-Homologon-2 (hMSH-2) gene product is a member of a highly conserved family of proteins involved in postrepiclation mismatch repair. MATERIALS AND METHODS: We have analyzed hMSH-2 expression in normal breast tissue (n = 10) and breast carcinomas (n = 30). hMSH-2 protein was investigated immunohistochemically on frozen sections using a specific mouse monoclonal antibody (clone FE11). hMSH-2 labelling pattern was compared with the staining pattern of the proliferation marker Ki-67. A hMSH-2-immunoreactivity score (hMSH-2-IRS) for the semiquantitative analysis of hMSH-2 expression is presented. RESULTS: In normal breast tissue, we only found weak nuclear immunoreactivity for hMSH-2 in 70%, while the remaining 30% were hMSH-2 negative (mean hMSH-2- IRS: 1.00; SD: +/- 0.82). All breast carcinomas analyzed revealed moderate to strong nuclear immunoreactivity (mean hMSH-2-IRS: 7.67; SD: +/- 3.55). hMSH-2 staining was heterogeneous, with visual differences between individual tumour cells. Expression of hMSH-2 protein was consistently and strongly upregulated in tumour cells of breast carcinomas as compared to normal breast tissue. No visual correlation in comparing the labelling patterns for hMSH-2 with the labeliing patterns for Ki-67 (mean percentage of Ki-67 positive tumour cells: 24.33%; SD: +/- 15.35) was observed in breast carcinomas. CONCLUSION: Our findings indicate that (a) hMSH-2 is expressed in normal human breast tissue; (b) expression of hMSH-2 may be of importance for the genetic stability of breast carcinomas in vivo.

Base Pair Mismatch↗

PubMedDate not supplied

Predictive value of sperm chromatin condensation (aniline blue staining) in the assessment of male fertility.

A case control study was carried out to determine the value of sperm chromatin condensation in the assessment of male fertility. A total of 165 semen samples from 90 patients (cases) and 75 healthy donors (control) were examined for chromatin condensation (aniline blue staining), as well as conventional sperm parameters, notably sperm morphology, sperm count, and progressive motility. Whereas only 55 +/- 12.0% of the samples from the infertile patients were unstained by aniline blue (chromatin condensed), 78 +/- 19.0% of the samples in the control group did not take up the stain (chromatin condensed). A significant difference (p < .001) was observed between the two groups. Similarly, the difference between the mean percentage of morphologically normal spermatozoa for the infertile patients (12.1 +/- 1.2%) and the control (23.9 +/- 1.9%) was very significant (p < .001). In addition, only 50 out of the 90 patients (55.5%) had a normal sperm count, whereas all the 75 (100%) were normal in the control group. By comparing between the two groups a significant difference (p < .001) was also observed. Furthermore, a significant difference (p < .001) was also found between the cases and the control with regard to the percentage of spermatozoa illustrating linear progressive motility (40 +/- 9.7% vs. 70 +/- 12.3%). However, no correlation was found between sperm chromatin condensation and morphology, count, and motility. This study suggests that chromatin condensation constitutes a valuable parameter in the assessment of male fertility, completely independent of conventional sperm parameters. Consequently, the inclusion of chromatin condensation to routine laboratory investigations of semen prior to assisted reproduction is strongly recommended.

Adult↗

PubMedDate not supplied

Electron microscopic detection of copper in the liver of two patients with morbus Wilson by EELS and EDX.

A 20-year-old male patient with morbus Wilson was liver transplanted because of terminal failure of liver function. The explanted liver showed a strong macronodular cirrhosis as typically seen in Wilson disease. There were visible granular accumulations in the hepatocytes after the rubeanic acid or rhodanine method for histochemical detection of copper. The electron microscopic studies on ultrathin sections revealed numerous electron-dense lysosomes and residual bodies. The elemental analysis in transmission electron microscope (TEM) with electron energy loss spectroscopy (EELS) and in scanning electron microscope (SEM) with energy dispersive x-ray analysis (EDX) showed copper-specific signals of electron-dense accumulations inside these dark lysosomes and residual bodies. In a second case, Wilson disease was diagnosed after autopsy of a 31-year-old patient by liver electron microscopy and EELS; strong electron-dense lysosomes and residual bodies with positive copper signals were found inside hepatocytes. For negative control, hepatocytes with iron accumulation after idiopathic hemochromatosis and liver cirrhosis were also analyzed by EELS in TEM, which showed strong iron, but only a few or no copper signals. Atomic absorption spectroscopy (AAS) in 16 liver samples of healthy and cirrhotic liver revealed only in both cases of Wilson disease a strong increased copper concentration higher than 100 microg Cu/g. The electron microscopic detection of copper-containing hepatocytic lysosomes is helpful for the diagnosis of early stages of Wilson disease in addition to the quantification of hepatic copper by AAS.

Adult↗

PubMedDate not supplied

Changes in immunological characteristics of white blood cells after administration of standardized mistletoe extract.

After administering standardized mistletoe extract, Viscum album L, (Iscador injections of 0.1 mg twice and 1.0 mg in defined intervals) the functional characteristics of microcirculation and immunological behavior of the white blood cells in different target tissues (derma, intestine) were investigated in healthy volunteers by vital microscopic investigation over 13 days of observation. The investigations showed a temporarily improved function of the microcirculation and an increased adhesion and transmigration of white blood cells in the target tissue areas. This observation was evaluated as a biologically relevant immunomodulation. Further investigations under pathophysiological conditions with regard to complementary administration of the test substance (e.g. to cancer patients) appear promising.

Antineoplastic Agents, Phytogenic↗

PubMedDate not supplied

Influence of complementary Viscum album (Iscador) administration on microcirculation and immune system of ear, nose and throat carcinoma patients treated with radiation and chemotherapy.

With the techniques of vital microscopic and reflection spectrometric imaging, representative characteristics of microcirculation and immunology of white blood cells were evaluated before, during and after radiotherapy and chemotherapy of patients suffering from ear, nose and throat carcinomas. Adverse effects of radiotherapy and chemotherapy on the microcirculation and the immune system were decreased and reconstitution processes were accelerated by complementary administration of a standardized mistletoe extract (Iscador).

Aged↗

PubMedDate not supplied

On the prenatal noxious effects of trypan blue and of a related azo dye.

Since 1948 trypan blue has been a well-known and extensively used experimental teratogen, belonging to the group of azo dyes. Chemically, trypan blue consists of a biphenyl molecule (0-tolidine or benzidine) combined by means of azo linkages with two molecules of a substituted naphthalene. Between 1987-89 the effect of the replacement of the biphenyl molecule by a molecule of p,p'-diaminobenzanilide upon the prenatal noxious action of trypan blue has been controlled. Investigations were carried out on three species: chick embryos, albino rats and albino mice. In the species used, the replacement annihilates the teratogenic properties of the dye, with the persistence of some embryotoxic effects. On the other hand, the control of o-tolidine and of p,p'-diaminobenzanilide revealed that no one had teratogenic properties (only some embryotoxic effect, more marked in the case of o-tolidine). It results that the teratogenic action of trypan blue cannot be attributed to the o-tolidine molecule proper but to an effect which results (in a for the moment unknown manner) from its combination with the other parts of the dye molecule.

Abnormalities, Drug-Induced↗

PubMedDate not supplied

[Doppler sonography--effect of fetal position, site of the placenta and measurement site of the fetal aorta].

The influence of fetal position, the site of placenta and the site of measurement in the fetal aorta on doppler-flow parameters was investigated in patients with uncomplicated pregnancies. In 20 cases the S/D-ratio was obtained in three different regions of the descending aorta. Measurements superior the renal vessels showed comparable values (4.1-4.3). No differences were found between signals obtained cranial or caudal of the diaphragma. Measurements at the aortal bifurcation showed significantly increased median values (6.6, p less than 0.05). No differences could be obtained concerning the influence of fetal position or site of placenta on S/D-ratio. All median values of a total of 197 patients were in the range of 4.8. Therefore it may be concluded that the above mentioned parameters do not have significant influence on doppler flow parameters in fetal vessels. However, a proximal site of measurement in the descending aorta fetalis should be reassured.

Aorta↗

PubMedDate not supplied

[Twin pregnancies with fetofetal transfusion syndrome].

During an observation period of 10 years 30 cases (11%) of twin transfusion syndrome were observed in a collective of 286 twin pregnancies at the University Women's Clinic Heidelberg. Typical symptoms of a twin transfusion syndrome as polyhydramnios, hydrops fetalis, polyserositis, disparity in fetal growth of the twins and pathological CTGs were examined for their diagnostic and prognostic values. A difference in birth weight of more than 25% was noted in only 28% of cases (range 2-58). A polyhydramnios was diagnosed in 63% of cases, an acute form in 30%. Eight of the nine pregnancies with an acute hydramnios ended in an abortion or intrauterine death up to 28 weeks of gestation. Amniocentesis for reduction of the excessive amount of amniotic fluid had no positive therapeutic effect. Eight of the pregnancies, in which a hydramnios had been detected, were further complicated by a hydrops fetalis (23%). Typical sinusoidal CTGs were registered in only 3 cases. Intrauterine fetal mortality respectively abortion up to 28 weeks of gestation was noted in 6 patients (12/60; 20%). Fetal mortality after 28 weeks of gestation occurred in 9/60 cases (15%). Four infants died more than 7 days post partum (7%). The fetal malformation rate was determined in our collective with 7% (4/60 fetuses). No chromosomal abnormalities were observed. The data collected show the prognostic relevance of the parameters analysed and reveal the cases in which a therapy might be effective. Ultrasonographic scanning of fetal activity or doppler flow measurements are further diagnostic procedures that can be employed in surveillance of risk pregnancies with twin transfusion syndrome. Also umbilical cord puncturing under direct ultrasonographic monitoring is of certain diagnostic and therapeutic value.

Cardiotocography↗

PubMedDate not supplied

Intracellular calcium in hypertension: effect of treatment with beta-adrenoreceptor blockers.

In 41 essential hypertensive patients, the intraerythrocytic free calcium (aiCa2+) was determined before and after oral treatment with beta-adrenoreceptor blockers (atenolol, metipranolol, and pindolol). The measurements were performed by means of an ion-selective electrode. During the 4 weeks of treatment, the aiCa2+ decreased from 7.4 +/- 2.3 (mean +/- SD) to 4.1 +/- 1.7 mumol/l (p less than 0.001) in the total group of 41 patients. In the patients treated with atenolol (n,15), the aiCa2+ decreased from 7.1 +/- 1.8 to 4.4 +/- 1.7 mumol/l (p less than 0.001); in those treated with metipranolol (n,13), aiCa2+ decreased from 7.4 +/- 2.7 to 4.3 +/- 2.0 mumol/l (p less than 0.001); and in those treated with pindolol (n,13), aiCa2+ decreased from 7.6 +/- 2.4 to 3.8 +/- 1.5 mumol/l (p less than 0.001). In the total group, the mean reduction of the mean blood pressure was 12 mm Hg. In the atenolol subgroup, the blood pressure was reduced by 11 mm Hg, in the metipranolol subgroup by 15 mm Hg, and in the pindolol subgroup by 18 mm Hg. Thus, the reduction of the blood pressure during beta-adrenoreceptor blockade is accompanied by a reduction of the free calcium of the red cells. The calcium lowering effect as the antihypertensive potency is roughly equal among the different beta-adrenoreceptor blockers.

Adolescent↗

PubMedDate not supplied

Exfoliative cytology of multiple endobronchial granular cell tumor.

A multicentric endobronchial granular cell tumor (GCT) in a 50-year-old man was diagnosed by the cytologic study of bronchial lavage specimens. The paraffin-embedded sections contained small clusters of medium-sized round tumor cells that had eccentric nuclei without nucleoli and eosinophilic finely granulated cytoplasm, which was positive with the periodic acid-Schiff stain. These cells were distinguishable from the macrophages and bronchial and squamous cells also found in the specimens. The excised tumors histologically mimicked a squamous cell carcinoma. Since 10% of all GCTs occur in the lung, where a multiple presentation can especially mimic a metastatic malignant process, it is important that the possibility of a granular cell tumor be considered in the screening of exfoliative cytologic specimens from the lung.

Bronchoalveolar Lavage Fluid↗

PubMedDate not supplied

[Prenatal sonographic diagnosis of a case of Desbuquois familial osseous dysplasia].

A rare form of osteodysplasia could be diagnosed by prenatal sonographic screening. Characteristic for this rare type of dysplasia, described only in 8 cases by Desbuqois and Piussan so far, is a severe dwarfism, generalized muscle hypotonia, mental retardation, asynchronized ossification, osteoporosis and considerable desaxiations of tubular bones and articulations. Radiologically, polydactylia and especially an increase in size of the trochanter minor can be observed. In the case described, this autosomal recessive hereditary disease had already been diagnosed for the first child of this consanguineous couple, which had died at 7 weeks after birth. During the second pregnancy of this patient the malformation could be diagnosed by ultrasound in the 24th week of gestation and the pregnancy was terminated. Autopsy and fetogram showed the malformations typical for this rare dysplasia.

Bone and Bones↗

PubMedDate not supplied

[Prune belly syndrome. Prenatal diagnosis and obstetric procedure].

With an incidence of between 1 in 30,000 and 1 in 50,000 births, prune-belly syndrome (PBS) is a rare malformation syndrome. The phenotypical and pathoanatomic changes range from discrete expression to very severe malformation complexes with extremely poor prognosis. Malformations of the kidneys and the efferent urinary tract are common. In such cases, oligohydramnios often develops early in such fetuses, followed by Potter's sequence. This syndrome can generally be diagnosed by timely ultrasound investigations, i.e., before the end of the first half of pregnancy. Striking features in the fetus are often oligohydramnios and a greatly dilated urinary bladder, more rarely multicystic-dysplastic kidneys and other malformations of the urogenital tract. Diagnostic possibilities and obstetric procedure are described on the basis of ten cases seen between January 1984 and July 1987 at Heidelberg University Gynecological Clinic.

Abdominal Muscles↗