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W Schmidt

Publications and source records attributed to W Schmidt.

At least 631 records · Page 35Linked to original sources
PubMed1982

[Mathematical methods in flow cytometry: the problem of evaluating DNA histograms of partially synchronous cell populations].

There is presented a procedure for determining the phase fractions in a cell population (i.e. the fractions of the G1-, S- and G2 + M-cells) from the corresponding DNA histogram obtained by flow cytometry. The evaluation procedure can regard arbitrary apriori information about the model parameters. It is based on a mathematical model of the DNA distribution for a growing cell population which contains the phase fractions and some further values as parameters. The parameter estimations rest on the Maximum-Likelihood-Principle by which the parameters of the theoretical model must be determined in such a way that the measured histogram corresponds to a maximum probability. As a consequence of the model flexibility especially the S-phase fraction which can be determined independently by labeling techniques, can be regarded as a fixed predetermined value. Such apriori information enhances the preciseness of the parameter estimation. The applications have shown that the determination of the S-phase fraction by means of flow cytometry can be very unprecise especially under partial synchronization. For the application of the evaluation programs (programming language ALGOL) the histograms must be free of cell detritus and clumping.

Animals↗
PubMed1982

[Pathophysiology and laboratory diagnosis of cholestasis].

Cholestasis--defined as a reduction or stasis of bile flow with corresponding rise of bile substances in blood--can be caused by obstructive and non-obstructive mechanisms. Common pathomechanisms, manifesting mainly in centrolobular liver areas, can be classified with regards to the subcellular location of the cholestatic components: Impairment of sinusoidal and lateral hepatocyte membrane; disturbance of bonds, storage, transport and secretion of bile substances (particularly reduction of bile-acid dependent and non-dependent bile flow); impaired bile acid and drug metabolism as a result of hypoactive, hypertrophied endoplasmatic reticulum; impairment of the mitochondrial energy metabolism; alteration of the canalicular membrane; impairment of filaments and "tight junctions"; the building of precipitates resulting from disturbed micellar function; impairment of ductulus permeability with reabsorption of bile.--These pathomechanisms explain the behaviour of biochemical and cholestatic-specific symptoms in blood-plasma, inclusive the appearance of abnorm substances whose diagnostic values are illustrated.

Carrier Proteins↗
PubMed1982

[Ultrasound determination of size and calcium content of gallstones].

In a prospective study, ultrasound examinations of the gallbladder as well as cholecystocholangiography were carried out in 77 patients with solitary stones and the ultrasound stone symptoms were compared with the x-ray findings. The ultrasound stone reflex as well as the wideness of the sonic-shadow correlated significantly with the size of the stones. The stone size can be approximately calculated from the wideness of the sonic shadow. On the other hand dependence of the ultrasound stone symptoms and the radiographic defined calcium was not evident. While the stone size can be sonographically defined, the indentification of calcium in gallstones continues to remain a domain of radiographic methods.

Calcium↗
PubMed1981

Cancer among the foreign-born in New York State.

Cancer deaths among white, foreign-born residents of New York State (exclusive of New York City) during the years 1969 through 1971 were analyzed according to country of birth. The largest numbers of immigrants came from Great Britain, Ireland, Germany, Austria, Poland, Italy, USSR, and Canada. Several distinctive features emerged from these data: Irish immigrants have an increased risk of dying from oropharyngeal, gastrointestinal, lung, and prostate cancers. Among all migrant groups studied, contrasting mortality patterns observed for carcinomas of the stomach, colon, and rectum provide further support for the concept that these neoplasms result from different etiologic processes. For the leukemias, lymphomas, and carcinomas of the breast and colon, each of the migrant groups acquired the higher risk common to others in the host country. This rise in risk suggests a major environmental component for cancers of these sites.

Canada↗
PubMed1981

[Progress in sterility therapy. Gonadotropin treatment, monitoring follicle maturation using real-time ultrasonics].

Results of prospective examination of follicle development under HMG-HCG-therapy by real time scanning are discussed. 1979-1980 37 patients were treated with HMG-HCG, 82 cycles of treatment were evaluated. In 93% of these cycles ovulation occurred, 17 patients became pregnant. Slight overstimulation was seen in 5% (4 of 82 cycles of treatment). Real time scan monitoring of follicular development allows a more efficient treatment with HMG-HCG, also multiple gravidity might theoretically be reduced.

Adult↗
PubMed1981

The role of drinking and smoking in mortality from cancer and other causes in male alcoholics.

In a prospective study of a sample of male alcoholics, age standardized rates of death from cancer and other causes were compared with expectancies based on the mortality of the general male population of Ontario and that of U. S. veterans in the Dorn Study. A typical profile of mortality due to alcoholism was found with high excess mortality from cirrhosis, pneumonia, violent causes, lung cancer, and cancers of the upper digestive and respiratory tracts. There was no evidence of the associations recently reported in the literature between alcohol use and other cancers such as those of the stomach, colon, and pancreas. Comparison with veterans whose smoking resembled that of the alcoholics revealed similar rates of death from lung cancer, considerable excess mortality among the alcoholics from cancers of the upper digestive and respiratory tracts, and no difference in overall cancer mortality. Heavy alcohol use per se increases the risk of cancer at certain sites, but it may not increase the overall risk of neoplastic disease.

Adolescent↗
PubMed1981

Demonstration of astrocytes in cultured amniotic fluid cells of three cases with neural-tube defect.

We have investigated the origin of rapidly adhering (RA) cells in three cases of neural tube defects (two anencephali, one encephalocele). We were able to demonstrate the presence of glial fibrillary acidic (GFA) protein in variable percentages (4--80%) of RA cells cultured for 4--6 days by use of indirect immunofluorescence with GFA antiserum. Cells cultured from amniotic fluids of normal pregnancies and fetal fibroblasts were completely GFA protein negative. GFA protein is well established as a highly specific marker for astrocytes. Demonstration of astrocytes may prove to be a criterion of high diagnostic value for neural tube defects. The percentage of astrocytes decreased with increasing culture time, while the percentage of fibronectin positive cells increased both in amniotic fluid cell cultures from neural tube defects and normal pregnancies.

Amniocentesis↗
PubMed1981

Quantitative and qualitative assay of amniotic-fluid acetylcholinesterase in the prenatal diagnosis of neural tube defects.

In 110 amniotic fluids the specific acetylcholinesterase was determined quantitatively and qualitatively. In the quantitative assay there were a considerable number of false positives and false negatives, although the mean value of the normal controls differed significantly from that of neural tube defect pregnancies. By the electrophoretic separation of acetylcholinesterase, however, all fluid samples with borderline alpha-fetoprotein levels or fetal blood contamination could be correctly classified. With the exception of one skin-covered spina bifida all neural tube defects in the second trimester could be identified by this method. The second fast-moving band characteristic of the specific acetylcholinesterase was also present in abdominal wall defects and intrauterine death.

Acetylcholinesterase↗
PubMed1981

Variation of expression of histocompatibility antigens on tumor cells: absence of H-2Kk-gene products from a gross-virus-induced leukemia in BALB.K.

The antigenic profile of the K-GV tumor of BALB.K origin, induced by Gross virus and maintained in vitro and in vivo, was investigated by serological and immunochemical methods and techniques of cell-mediated immunity. The H-2Kk-gene products were absent by several criteria: (1) monoclonal antibody and conventional alloantisera directed against eh H-2Kk antigenic specificities were nonreactive by direct testing and by absorptions. (2) H-2Kk products could not be precipitated from glycoprotein or protein extracts of the radiolabeled K-GV tumor. (3) Cytotoxic effectors against H-2Kk produced by sensitization in vitro and in vivo failed to kill K-GV target cells. (4) The tumor could neither stimulate BALB.B congenic mice to produce cytotoxic effectors nor specific cytotoxic antibody against H-2Kk-gene products. In contrast, the H-2Dk antigen was readily detectable by all these criteria. These findings therefore describe a tumor which has selectively lost the H-2K-gene products. The K-GV tumor was able to generate Gross-virus specific CTL, but had greatly reduced susceptibility to lysis by Gross-virus specific CTL generated by H-2K expressing AKR (H-2k) tumors. These findings have important implications for the associative recognition of tumor antigens and the immune surveillance of virally induced tumors.

AKR murine leukemia virus↗
PubMed1981

Interspecies exchange of beta 2-microglobulin and associated MHC and differentiation antigens.

Radiolabeled human beta 2-microglobulin (beta 2m) can bind to mouse histocompatibility (H-2) antigens on the cell surface or to partially purified H-2 antigens in solution. The complexes containing human beta 2m and H-2 antigens from C3H (H-2k) mice could be immunoprecipitated specifically with alloantisera, rabbit anti-H-2 xenoantisera, and with monoclonal H-2-specific antibodies. Specific association with H-2 antigens was also observed with other haplotypes. The only exception was B10.D2 (H-2d) from which complexes containing human beta 2m could only be precipitated with anti-H-2-xenosera. Thus radiolabeled human beta 2m can be used as a specific label for mouse H-2 antigens in precipitation and radioimmunoassays. The application of this finding extends to major histocompatibility complex antigens of other species, and to differentiation antigens with primary association with beta 2m.

Animals↗
PubMed1981

Monitoring of HMG-stimulated follicular development by real-time ultrasound.

Monitoring of human follicular development by real-time ultrasound during HMG-HCG treatment is presented. With the aid of ultrasound monitoring, the ovulation rate is raised to 94.3% (formerly 80% without ultrasound). Serious side effects such as ascites and/or hydrothorax did not occur in this study (1.2% without ultrasound controls). The pregnancy rate was 21/47 (44%) of all hormonally treated patients. By means of real-time sector scan examination, the growing follicle could be detected in 103/106 (97.3%) of HMG-HCG treated cycles. Thus real-time ultrasound examinations provide results comparable to those achieved mostly by time-consuming compound scan in demonstration of the growing follicle.

Anovulation↗
PubMed1981

[Ultrasonographic findings in "Potter's syndrome" (author's transl)].

The foetal Potter's syndrome represents a relatively frequent malformation syndrome, the incidence being 0.3% of all live births. The phenotypical changes seen in these newborn occur in complete bilateral renal agenesia = the original Potter's syndrome, but they are also found in various congenital cystic diseases of the kidneys and/or the other urinary organs. In additional to the original Potter's syndrome, a patho-anatomical classification of cystic deformations of the kidneys or of the efferent urinary organs was introduced by Osathanondh and Potter (1976) (Potter Type I-Type IV). These severe foetal malformations can be diagnosed at least in part via timely ultrasonic examination during the first half of the pregnancy period. In such cases, an oligoamnion or sometimes an anhydramnion is regularly observed as principal sign. This diagnosis is probably confirmed if the foetal urinary bladder is not demonstrable following application of furosemide (Campbell). Occasionally the cystic changes of the urinary organs can be proven direct by means of sonography. Ten examples of cases are described presenting the typical ultrasonographic findings in the so-called extended "Potter's syndrome" (oligoamnion or anhydramnion, malformations of the kidneys and/or the efferent urinary organs and phenotypical changes). Due to their infaust prognosis these foetal diseases result in the indication for termination of pregnancy.

Abortion, Legal↗
PubMed1981

[The Meckel syndrome (author's transl)].

The Meckel syndrome is caused by an autosomal recessive gene. The three main features are encephalocele, polycystic kidneys and polydactyly. At least two of these should be present to establish the diagnosis. Several minor symptoms are observed in various combinations. The possibility of prenatal diagnosis is explained by a case report: A neural tube defect was diagnosed by ultrasonography and AFP-assessment in amniotic fluid whereas unfortunately the presence of polycystic kidneys was not recognized sonographically. The methods of today are able to detect the polydactyly but failed in this case. One can suggest that the complete prenatal diagnosis of the Meckel syndrome is not essential for clinical management since the presence of one major symptom will lead to legal abortion. The search for Meckel syndrome is important in cases of delivery of a child with multiple malformations, indicating a genetic counseling for each subsequent pregnancy.

Abnormalities, Multiple↗
PubMed1981

[Pyrexia during delivery (author's transl)].

Amnionitis with pyrexia during labor and delivery and the perinatal complications of this syndrome are described. In our series the incidence of pyrexia during delivery was 0.54%. In 70 of 83 cases (84%) an intra-uterine infection was assumed to be the cause of the pyrexia. In 13 of 83 cases (16%) an extra-genital infection was the presumed cause. Intra-uterine infections are a grave danger for the mother and the newborn and constitute a severe complication. The mortality in cases with pyrexia during labor and delivery was elevated to 7 of 83 newborns (9%). Rapid delivery and the timely administration of antibiotics in sufficiently high dosages can prevent the manifestations of severe infections. Recommendations for the obstetric management of cases with pyrexia during labor and delivery are given.

Amnion↗
PubMed1981

[Ultrasound diagnosis of omphalocele during the first trimester of pregnancy (author's transl)].

Ventral defects in the fetus occur in 1/3200 to 1/10,000 deliveries. Prognosis for the newborn is mostly fatal since these anomalies are frequently combined with other congenital anomalies. A through ultrasound study of the fetus in its longitudinal and transverse diameter permits the antenatal diagnosis of this severe fetal anomaly. The earliest diagnosis of the fetal omphalocele in the first trimester of pregnancy is described in detail in this paper.

Abortion, Induced↗