Biomedical subjects

D Simon

Publications and source records attributed to D Simon.

At least 343 records · Page 19Linked to original sources

PubMed1989

cDNA sequence and chromosomal localization of the mouse parvalbumin gene, Pva.

In the homozygous condition, the mutation adr (arrested development of righting response) of the mouse causes a myotonia and a drastic reduction of the Ca2+-binding protein parvalbumin (PV) in fast muscles. Using a rat PV probe, a mouse cDNA clone was isolated from a lambda gt11 wild-type fast-muscle library and its nucleotide sequence was determined. The protein coding and the 3' nontranslated regions of the mouse gene show extensive homology with the rat PV gene. The result of Southern blot hybridization is consistent with a single copy gene for parvalbumin. Restriction fragment length polymorphisms (RFLPs) between Mus musculus domesticus (e.g. C57BL/6) and Mus spretus (SPE) were detected with the enzymes Eco RI, Pst I, and Sst I. The restriction fragment patterns of DNA samples from 65 individual offspring of (C57BL/6 x SPE)F1 x C57BL/6 backcrosses were tested with the PV probe and matched, for linkage detection, to pre-existing patterns established with various RFLP probes on the same samples. A co-distribution of PV-RFLPs with Pvt-1 and Mlvi-2, which had been localized on chromosome 15, was detected. Thus, the structural gene for PV, designated Pva, maps to chromosome 15 of the mouse whereas the adr mutation shows no linkage with markers on this chromosome. Gene locus homology between chromosome 15 of the mouse and chromosome 22 of man (which carries the human PV gene) is discussed.

Amino Acid Sequence↗

PubMed1989

Localization of murine X and autosomal sequences homologous to the human Y located testis-determining region.

Recently a candidate gene for the primary testis-determining factor (TDF) encoding a zinc finger protein (ZFY) has been cloned from the human Y chromosome. A highly homologous X-linked copy has also been identified. Using this human sequence it is possible to identify two Y loci, an X and an autosomal locus in the mouse (Zfy-1, Zfy-2, Zfx and Zfa, respectively). Suprisingly ZFY is more homologous to the mouse X and autosomal sequences than it is to either of the Y-linked loci. Both Zfy-1 and Zfy-2 are present in the Sxr region of the Y but Zfy-2 is absent in the Sxr deletion variant Sxrb (or Sxr") suggesting it is not necessary for male determination. Extensive backcross analyses map Zfa to mouse chromosome 10 and Zfx to a 5-cM interval between anonymous X probe MDXS120 and the tabby locus (Ta). We also show that the mouse androgen receptor locus (m-AR) believed to underlie the testicular feminization mutation (Tfm) shows complete linkage to Zfx. Comparative mapping indicates that in man these genes lie in separate conserved DNA segments.

Animals↗

PubMed1989

Prognostic value of serum creatinine and effect of treatment of hypertension on renal function. Results from the hypertension detection and follow-up program. The Hypertension Detection and Follow-up Program Cooperative Group.

The Hypertension Detection and Follow-up Program followed up 10,940 persons for 5 years in a community-based, randomized, controlled trial of treatment for hypertension. Participants were randomized to one of two treatment groups, stepped care and referred care. The primary end point of the study was all-cause mortality, with morbid events involving the heart, brain, and kidney as secondary end points. Loss of renal function, ascertained by a change in serum creatinine, was among these secondary events. Baseline serum creatinine concentration had a significant prognostic value for 8-year mortality. For persons with a serum creatinine concentration greater than or equal to 1.7 mg/dl, 8-year mortality was more than three times that of all other participants. The estimated 5-year incidence of substantial decline in renal function was 21.7/1,000 in the stepped-care group and 24.6/1,000 in the referred-care group. Among persons with a baseline serum creatinine level between 1.5 and 1.7 mg/dl, the 5-year incidence of decline was 113.3/1,000 (stepped care) and 226.6/1,000 (referred care) (p less than 0.01). The incidence of decline in renal function was greater in men, blacks, and older adults, as well as in those with higher entry diastolic blood pressure. Among persons with a baseline serum creatinine level greater than or equal to 1.7 mg/dl, serum creatinine concentration declined by 25% or more in 28.6% of stepped-care and 25.2% of referred-care participants. Although the incidence of clinically significant hypercreatininemia in a hypertensive population is low, an elevated serum creatinine concentration is a very potent independent risk factor for mortality. The slightly lower rate of development of hypercreatininemia and the higher rate of improvement in stepped-care compared with referred-care participants is consistent with the belief that aggressive treatment of hypertension may reduce renal damage and the associated increased risk of death.

Adult↗

PubMed1989

Functional pancreatic beta-cell line from SV40 T-antigen transgenic mouse.

Cell line IgSV195, derived from a pancreatic tumor that arose in an SV40 T-antigen transgenic mouse, retains certain morphological and physiological characteristics of pancreatic beta-cells throughout in vitro and in vivo passage. Insulin secretion is stimulated by exposure of these cells to fetal bovine serum and a combination of 3-isobutyl-1-methylxanthine and glutamine but not by concentrations of glucose in the physiological range. Insulin processing appears to be intact. Neither class I nor class II major histocompatibility complex (MHC) antigens are routinely expressed at the cell surface; however, MHC class I--but not class II--encoded gene products are detected after treatment with recombinant interferon-gamma (IFN-gamma) alone or in combination with tumor necrosis factor. Cytolysis of IgSV195 cells by SV40 T-antigen-specific H-2b-restricted lymphocytes is similarly dependent on IFN-gamma pretreatment. These results emphasize that SV40 T-antigen transgenic mice are likely sources of cell lines that retain their differentiated function in vitro. The IgSV195 cell line provides an accessible model in which to investigate the control of gene expression and function of pancreatic beta-cells.

Animals↗

PubMed1989

[Diagnosis of hereditary diseases with molecular biology methods].

The identification of phenotypically normal carriers of genetic defects is crucial for eliminating recessive defect genes from farm animal populations. Recombinant DNA techniques allow us to identify defect genes on the DNA-basis regardless of the animals age and time of gene expression. Genetic defects also are important as model systems to investigate the regulation of metabolic pathways and the mechanisms of embryonic development.

Animals↗

PubMed1989

[Management of large adrenal glands discovered incidentally].

Incidental adrenal tumors are more and more often discovered with development of the new radiological techniques (CT scan, sonography). In such an occurrence, the largest panel of adrenal hormones measurements is needed. In the absence of hormonal abnormality, no exam can help for the clinical decision-making. According to epidemiological findings, we propose to operate upon tumors larger than 6 cm and to repeat CT scans at 2, 6 and 18 months for tumors smaller than 6 cm which should be operated upon if an enlargement of the adrenal tumor is demonstrated by a control exam. This attitude relies upon the quite higher frequency of adrenal adenomas (more than 99% of non-functioning adrenal tumors) and the more important risk of malignant adrenal carcinoma in front of a huge tumor. It appears to be the right choice in a cost-effectiveness perspective.

Adrenal Gland Neoplasms↗

PubMed1989

First year after stroke: tracking cognitive and affective deficits.

A total of 58 cerebrovascular accident (CVA) rehabilitation inpatients with lateralized brain damage were assessed at two time points (T1 = admission to rehabilitation facility, about 7 weeks post-CVA, and T2 = 10 months post-CVA) in the following domains: hemispatial neglect, reaction time, depression, and affect comprehension. Performance was compared with 22 age-matched control subjects. Repeated measures ANOVAs were performed with patients subdivided into groups by laterality of lesion and visual field status (a strong predictor of psychometric performance, particularly in the hemispatial-neglect domain). During this initial year after stroke onset, significant improvements were observed in hemispatial neglect and affect comprehension in the two right-brain-damaged groups, but not the left-brain-damaged group. There was also a trend for improvement in observer rating of depression in all three groups. However, there was poor resolution of reaction time and self-reported depression in all three groups. These findings suggest that these latter domains should be targeted for more aggressive therapeutic intervention. An important component of such intervention, in addition to direct treatment of deficits, should be education of both patient and family as to the nature of deficits, expectations regarding resolution, and appropriate attributions of changed behavior after stroke.

Affect↗

PubMed1988

Comparative bioavailability of suprofen after coadministration with food or milk.

Suprofen is a nonsteroidal analgesic with demonstrated efficacy in the treatment of mild to moderate pain associated with a variety of clinical conditions. Because nonsteroidal analgesic agents may cause gastrointestinal side effects, they are frequently prescribed with food or milk. The purpose of this study was to evaluate the effects of a standard meal and milk alone on the rate and extent of absorption of suprofen. In a randomized three-way cross-over study, 24 healthy volunteers each received a single 200-mg oral dose of suprofen in the fasted state half an hour after a standard meal or half an hour after an 8-ounce glass of milk. The influence of food and milk was greater on the rate than on the extent of absorption of suprofen as illustrated by a more pronounced effect on Cmax than on AUC. In addition, food had a greater influence on the bioavailability of suprofen than milk. Food decreased the mean Cmax to 44% and the mean AUC to 81% relative to the fasted state, whereas milk decreased the mean Cmax to 74% and the mean AUC to only 87% of the respective parameters in the fasted state. Symmetrical confidence intervals demonstrated that the mean AUCmilk was within only 19% and the mean AUCfood was within only 25% of the mean AUC in the fasted state, with 95% confidence.

Adult↗

PubMed1988

Proximity of the CTLA-1 serine esterase and Tcr alpha loci in mouse and man.

The serine esterase CTLA-1 gene was shown by in situ hybridization to map to the D segment of mouse chromosome 14, the same localization as a member of the immunoglobulin superfamily, Tcr alpha. To further demonstrate the proximity of CTLA-1 and Tcr alpha, genetic linkage was tested in mouse using restriction fragment length polymorphisms and a backcross progeny, and no recombination was observed in the 100 backcross products studied. Recombination events between Tcr alpha/CTLA-1 and the markers Gdh-X and NP-1 show that the most probable order of these loci in the mouse 14D region is NP-1-Tcr alpha/Ctla-1-Gdh-X. In man, the human homologue of CTLA-1 was shown by in situ hybridization to map on chromosome 14, at 14q11-q12, where Tcr alpha also maps. Using the human cell line SUP-T1, bearing the inversion inv(14) (q11;q32), we further demonstrated the loci order in man to be centromere-NP-1-Tcr alpha-CTLA-1. To complement the cytogenetic and genetic mapping data, we tried to determine the physical distance between the two genes by pulsed field gel electrophoresis (PFGE). DNA prepared from various cell types, both mouse and human, were digested with a panel of rare cutter enzymes and hybridized first with CTLA-1, then with Tcr alpha probes. None of the bands identified hybridized with both Tcr alpha and CTLA-1 probes for either mouse or human cells. Although the physical mapping by PFGE is inconclusive, the cytogenetic and genetic data support close linkage of the Tcr alpha and CTLA-1 genes in both mouse and man, suggesting homology between the D region of mouse chromosome 14 and the q11-q12 region of human chromosome 14, encompassing the Tcr alpha and CTLA-1 loci. These findings also provide another example of proximity of genes coding for a member of the Ig super-family and a serine esterase.

Animals↗

PubMed1988

Cytogenetics of an endometrial adenocarcinoma cell line and its implications.

Despite the fact that adenocarcinoma of the endometrium is currently the most common gynecologic malignancy in the United States, few chromosomal studies have been done to date characterizing this disease. HEC-1A, a cell line used by many laboratories as a reference cell line for endometrial carcinoma, has never been subjected to definitive karyotyping. For this reason, with the use of improved banding techniques, this has now been accomplished, and several consistent abnormalities have been identified. There was a marker chromosome formed from an insertion of 2q21, probably representing an insertion of the lacking chromosome 14. In addition, there was a translocation to the telomeric region of 1p; and trisomies of 3, 7, and 17. Many of these abnormalities are known to consistently be associated with other primary malignancies. In addition, the chromosomes in which trisomy is noted carry genes associated with epidermal growth factor and estrogen receptors, which also bear marked homology to known oncogenes. It would appear that further detailed studies of various grades and stages of endometrial carcinoma, as well as histologic types and "precursor lesions," may lead to an understanding of those chromosomal changes associated with disease initiation and progression.

Adenocarcinoma↗

PubMed1988

Construction of a vector plasmid family and its use for molecular cloning in Streptococcus lactis.

Cloning vector plasmids have been constructed on the basis of the broad host range plasmid pAM beta 1 and used for the cloning of a nisin resistance determinant in Streptococcus lactis. They incorporate several desirable features for gene cloning in S. lactis and other transformable Gram-positive bacteria. They carry an easily selectable erythromycin resistance marker, are present at low (6-9) or high (45-85) copy number in S. lactis and possess a convenient polyrestriction site sequence. A significant advantage of these plasmids is their capability to carry and stably maintain very large cloned DNA fragments (up to 30 kilobases).

Cloning, Molecular↗

PubMed1988

A randomized controlled study of peripheral parenteral nutrition in moderate and severe alcoholic hepatitis.

We performed a controlled trial of peripheral hyperalimentation in moderate and severe alcoholic hepatitis to determine whether improvement in survival and liver function could be obtained. Twelve patients with moderate and 22 with severe alcoholic hepatitis were randomized to 28 days of peripheral parenteral nutrition (PPN) or standard therapy (ST). In the moderate group, six were treated with each therapy. In the severe group, 10 were treated with PPN and 12 with ST. Routine liver tests, hepatocyte function (galactose elimination capacity), estimated hepatic blood flow (galactose clearance) and assessment of ascites and encephalopathy were performed at randomization and at 28 days. Groups were equally matched at randomization. In the moderate group PPN produced no improvement in morbidity (liver tests) and mortality (no deaths). In the severe group there were seven deaths (4 PPN, 3 ST). PPN produced greater improvement than ST in serum bilirubin and transferrin concentrations and a trend toward greater improvement in prothrombin time, serum albumin and galactose elimination capacity. PPN had no deleterious effect on encephalopathy or ascites as only ST patients developed ascites or encephalopathy after randomization. We conclude that PPN compared to ST (1) provides no benefit in moderate alcoholic hepatitis, but (2) did more rapidly improve morbidity (liver tests) and probably liver function in severe alcoholic hepatitis; (3) PPN did not improve early mortality, and (4) it had no deleterious effect on encephalopathy or ascites.

Amino Acids↗

PubMed1988

A simple technique to distinguish rat from mouse chromosomes in T cell hybridomas.

Antigen-specific rat mouse T-cell hybridomas, prepared by fusing the BW5147 AKR thynoma with helper T cells from rats immunized with chicken ovalbumin, express both the rat and mouse major histocompatibility complex gene products. Using these functionally defined T-cell hybridomas, we have devised a technique based on the differential staining of the heterochromatin region of the rat and mouse chromosomes to distinguish the species of origin of the chromosomes. This technique should prove useful for screening potential hybrid cell lines and should aid in differentiating mouse from rat chromosomes for gene mapping studies.

Animals↗

PubMed1988

hph-1: a mouse mutant with hereditary hyperphenylalaninemia induced by ethylnitrosourea mutagenesis.

Ethylnitrosourea mutagenesis of spermatogonial stem cells and a three-generation breeding scheme were used to screen for recessive mutations that cause defects in phenylalanine metabolism leading to elevated serum levels of this amino acid. This paper describes the isolation of such a mutation, hph-1, causing a heritable hyperphenylalaninemia in the neonate and weanling and an inability to effectively clear a phenylalanine challenge in the adult. Micro-pedigree analysis of the original mutant mouse and data obtained from crosses of affected and unaffected animals indicate that the mutation segregates in an autosomal recessive manner. An interspecies mouse backcross mapping experiment places the mutant gene locus on mouse chromosome 14 very near Np-1 and a backcross experiment with a conventional inbred mouse strain involving a nearby locus confirms the chromosome 14 assignment. The initial symptomatology of the mutant phenotype suggests this mutant may represent a useful animal model for the study of hyperphenylalaninemia in man.

Amino Acid Metabolism, Inborn Errors↗

PubMed1988

A mouse gene homologous to the Drosophila gene caudal is expressed in epithelial cells from the embryonic intestine.

A mouse gene, Cdx-1, was isolated from an embryonic cDNA library using a Drosophila caudal gene probe. The deduced amino acid sequence of Cdx-1 contains conserved sequence domains along the entire gene, as well as a highly conserved caudal-type homeo box. A structural comparison suggests a common ancestral origin of mouse Cdx-1 and Drosophila caudal. The expression of Cdx-1 during embryogenesis was analyzed by Northern blotting and in situ hybridization. Cdx-1-specific transcripts are localized in the epithelial lining of the intestines beginning at 14 days' gestation. The expression of Cdx-1 in the intestine continues into adulthood, but cannot be detected in any other tissues. The Cdx-1 gene is the first homeo-box-containing gene expressed in cells derived from the embryonic endoderm.

Amino Acid Sequence↗

PubMed1988

A computer-based program for the follow-up of prostatic cancer patients.

A computer-based record program for the follow-up of prostatic cancer patients is described and its practical applications discussed. The system enables the user to record personal data, medical history follow-up (including laboratory and imaging tests), treatment and the response to it. The program can generate reports as a summary letter to the referring physician, follow-up notes on a specific date, laboratory test results on a chronological base, etc. It has the capability to analyse statistically the medical database accumulated with the aid of SPSS (Statistical Package for Social Sciences). The program, which is designed for a micro-computer, is conducted on the IBM Personal Computer. By providing instant access to all comprehensive information, the system is a valuable tool for the correct staging of disease and for systematic follow-up; most of all, it is a "real-time instrument" for the analysis of medical results.

Follow-Up Studies↗

PubMed1988

Fim-1, Fim-2/c-fms, and Fim-3, three common integration sites of Friend murine leukemia virus in myeloblastic leukemias, map to mouse chromosomes 13, 18, and 3, respectively.

Three common proviral integration sites, Fim-1, Fim-2/c-fms, and Fim-3, have been described in mouse myeloid leukemias induced by the Friend murine leukemia virus. The nature and function of Fim-1 and Fim-3 are still unknown since no transcript from these loci has been detected so far. To identify these two loci, we undertook their chromosomal localization using restriction fragment length polymorphism detected between C57BL/6 mice and the wild-derived inbred strain of Mus spretus. Using interspecific backcross analysis, we mapped Fim-1 to mouse chromosome 13 and Fim-3 to mouse chromosome 3. Interestingly, Fim-3 is tightly linked to Evi-1, another common integration site of ecotropic virus involved in another model of mouse myeloid leukemogenesis. Fim-2 spans the 5' end of the c-fms gene, which encodes for the macrophage-colony-stimulating factor receptor. We located the c-fms gene on the D band of chromosome 18 by in situ hybridization.

Animals↗

PubMed1988

Expression and biosynthetic variation of the epidermal growth factor receptor in human hepatocellular carcinoma-derived cell lines.

Expression of the epidermal growth factor (EGF) was analyzed in six human hepatocellular carcinoma-derived and one human hepatoblastoma-derived cell line, each of which retained the differentiated phenotype and functions of the parenchymal hepatocyte. The level of receptor expression of each hepatoma cell line was similar to that of the normal human fibroblast, approximately 10(5) molecules per cell. However, NPLC/PRF/5, a subline of the PLC/PRF/5 cell line obtained following reestablishment of a xenograft tumor in vitro, was found to express 4 x 10(6) high-affinity EGF receptor molecules per cell. Proliferation of the NPLC/PRF/5 cell line was inhibited in the presence of nanomolar quantities of ligand. Receptor overexpression was found to result from EGF receptor gene amplification without apparent rearrangement of the EGF receptor coding sequences. Although cell-specific variability in posttranslational processing of EGF receptor N-linked oligosaccharides in the hepatoma cell lines was found, no difference between the receptors in PLC/PRF/5 and NPLC/PRF/5 was observed and no aberrant receptor-related species were detected. EGF receptor gene amplification in the NPLC/PRF/5 cell line is probably a reflection of genome instability and selection of variants with augmented growth potential in limiting concentrations of EGF in vivo. When viewed in this light, EGF receptor overexpression could represent a manifestation of tumor progression in the EGF-responsive hepatocyte.

Carcinoma, Hepatocellular↗