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Biomedical subjects

M Gunther

Publications and source records attributed to M Gunther.

At least 19 recordsLinked to original sources
PubMed2000

A set of proteins interacting with transcription factor Sp1 identified in a two-hybrid screening.

The two-hybrid system was used to isolate cDNA clones encoding polypeptides that interact with the N-terminal region (activation domains A, B and C) of the Sp1 transcription factor. Among the 65 collected clones, 43 contained cDNA fragments with open reading frames. They corresponded to 13 genes encoding proteins of known function and to 15 genes, the proteins of which have no known function. Six overlapping cDNA clones corresponded to the Hsc70 protein. Host cell factor (HCF-1) and the KIAA0461 gene (encoding a putative Zn-finger protein of unknown function) were both identified through the isolation of three overlapping cDNA clones. Two cDNA fragments encoding the same region of the SREBP-2 transcription factor were independently selected and two overlapping cDNA clones corresponded to the splicing factor SF3A120. Two different cDNA clones encoded the N- and C-terminal region of the Oct-1 transcription factor. Transcription factors Elf-1 and TIEG, as well as HSph2, the putative human homologue of a murine polyhomeotic gene, were each represented by a single clone. Noticeably, for the four identified transcription factors, the DNA-binding domain was excluded from the selected polypeptides. In vitro binding of the selected polypeptides to the Sp1 protein was demonstrated for the four transcription factors and for the SF3A120, Hsc70, HCF-1, HSph2 and pKIAA0461(245) proteins. Four other cDNA clones encoding polypeptides of unknown function were tested in the in vitro binding assay. All four polypeptides were found to interact with Sp1 in this assay.

Animals↗
PubMed1999

Transcriptional mechanisms responsible for the overexpression of the keratin 18 gene in cells of a human colon carcinoma cell line.

The keratin 18 (K18) gene is overexpressed in cells of tumorigenic clones isolated from the SW613-S human colon carcinoma cell line, compared to cells of nontumorigenic clones. The isolated minimal promoter (TATA box and initiation site) of the K18 gene has by itself a differential activity in tumorigenic and nontumorigenic cells. An Sp1 binding site located upstream of the TATA box contributes to the high level of expression of the gene in tumorigenic cells. We report here that the Sp1 gene is not differentially expressed between the two cell types and that this is also the case for genes coding for factors of the preinitiation complex known to directly interact with the Sp1 protein. Further, DNase I footprinting experiments and mutagenesis analysis indicated that the mechanism responsible for the differential activity of the minimal K18 promoter apparently does not involve the binding of a factor to a specific sequence. During the course of these experiments, it was found that the initiation site of the K18 promoter is actually located 11 bp upstream of the +1 position previously reported and that the TATA box is the only essential element of the minimal promoter. Treatment of the cells with histone deacetylase inhibitors was more efficient at stimulating the activity of the K18 promoter in nontumorigenic cells than in tumorigenic cells. We propose that overexpression of the K18 gene in tumorigenic cells could result from of a high level of acetylation of histones and/or of factors controlling the activity of the transcription complex.

Base Sequence↗
PubMed1999

[Breast-like carcinoma of the vulva].

Breast-like carcinomas of the vulva is a rare finding. Only 11 cases are reported in the literature. This article reports a painful tumor of the left vulvar labia in a 62 year-old woman. Excisional biopsy showed an infiltrating adenocarcinoma, histologically similar to a breast tumor with positive hormonal receptors. The origin of this tumor, ectopic mammary tissue or specific adnexal genito-anal gland, is discussed. From data of the literature, we offer guidelines for diagnosis, treatment and origin of this rare tumor.

Adenocarcinoma↗
PubMed1999

[The homeopathic patient: comparative results of homeopathic and conventional GP patient interviews].

This paper compares the results of homeopathic and conventional patient interviews. It is based on data from 284 patient interviews, conducted by 14 General Practitioners in 1993-94. Homeopathic treatment was used with 174 of the patients, while 110 were treated using conventional methods. In this sample, homeopathic patients were younger and better educated than those treated conventionally. They tended to be involved in pedagogy, health-care and social services. Their knowledge of homeopathy is often minimal, yet their expectations concerning their illnesses and treatment often reflect homeopathic concepts. Apparently, their general life view corresponds to certain parts of homeopathic philosophy. Homeopathic patients are more critical of medicine in general, and often have negative experiences with conventional medicine. Conventionally treated patients and homeopathically treated patients are equally satisfied with their physicians and treatment. In some cases homeopathic treatment also had positive effects on the patient's mood, sleeping habits, etc. Homeopathic patients tend to have healthier lifestyles than the others. They tend to choose homeopathy for its perceived effectiveness, which is largely based on their own experience, and that of other persons in their social surroundings. Most of the homeopathic patients receive social support for homeopathy. They actively recommend homeopathy and regularly meet others who are also treated homeopathically. Dissatisfaction and negative experiences with conventional treatment may be one reason for turning to homeopathy initially. Long-lasting reasons to continue using homeopathy are: effectiveness, good care of the homeopathic doctors, congruence with the patient's world-view, and greater patient responsibility for his/her own health.

History, 20th Century↗
PubMed1995

An Sp1 binding site and the minimal promoter contribute to overexpression of the cytokeratin 18 gene in tumorigenic clones relative to that in nontumorigenic clones of a human carcinoma cell line.

Clones of cells tumorigenic or nontumorigenic in nude mice have been previously isolated from the SW613-S human colon carcinoma cell line. We have already reported that tumorigenic cells overexpress the cytokeratin 18 (K18) gene in comparison with nontumorigenic cells and that this difference is mainly due to a transcriptional regulation. We now report that a 2,532-bp cloned human K18 gene promoter drives the differential expression of a reporter gene in a transient assay. A 62-bp minimal K18 promoter (TATA box and initiation site) has a low but differential activity. Analysis of deletion and substitution mutants as well as hybrid SV40-K18 promoters and reconstructed K18 promoters indicated that an important element for the activity of the K18 promoter is a high-affinity binding site for transcription factor Sp1 located just upstream of the TATA box. This Sp1 binding element, as well as the intron 1 enhancer element, stimulates the basal activity of the minimal promoter through mechanisms that maintain the differential activity. Gel shift assays and the use of an anti-Sp1 antibody have shown that both tumorigenic and nontumorigenic SW613-S cells contain three factors able to bind to the Sp1 binding element site and that one of them is Sp1. A hybrid GAL4-Sp1 protein transactivated to comparable extents in tumorigenic and nontumorigenic cells a reconstructed K18 promoter containing GAL4 binding sites and therefore without altering its differential behavior. These results indicate that the Sp1 transcription factor is involved in the overexpression of the K18 gene in tumorigenic SW613-S cells through its interaction with a component of the basal transcription machinery.

Base Sequence↗
PubMed1989

Evidence for a ligation step in the DNA replication of the autonomous parvovirus minute virus of mice.

Newly replicated DNA of the autonomous parvovirus minute virus of mice was pulse-labeled with 32PO4 during the time of maximal viral DNA replication in highly synchronized A9 cells. The subsequent processing of viral DNA-protein complexes was monitored during a chase period with no label. Several distinct classes of duplex replicative-form and progeny single-stranded DNA molecules were characterized and found to accumulate at different times during infection. Analysis of the terminal structures associated with these various forms provided new insights into the mechanism by which viral DNA replicates and, in particular, suggested that interstrand ligation occurs during this process.

Animals↗
PubMed1988

The terminal protein of minute virus of mice is an 83 kilodalton polypeptide linked to specific forms of double-stranded and single-stranded viral DNA.

A new assay (label transfer from DNA to protein) enabled the identification of a terminal protein (TP) in nucleoprotein complexes extracted from cells infected with the parvovirus, minute virus of mice, MVM. In SDS-PAGE, TP migrates as a major band at 83 kDa, with a minor 65 kDa component, each of which exactly co-migrates with the cellular forms of the virally coded polypeptide NS-1. In parallel, the analysis of nucleoproteins by SDS-agarose gel electrophoresis allowed us to observe that the major species of viral DNA molecules (mRF, dRF and ssDNA) are all present in the form of DNA-protein complexes. Three forms of mRF DNA were identified, two of which are protein-associated and one which appears to be protein-free.

Animals↗
PubMed1988

Isolation and characterization of thermosensitive mutants from Kilham rat virus, a rodent parvovirus.

Thermosensitive mutants were isolated from nitrous acid-treated Kilham rat virus (KRV). At a restrictive temperature (39.5 degrees C), the mutants tested did not produce appreciable amounts of infectious particles, haemagglutinin or progeny single-stranded DNA. Virus antigen accumulation as detected by immunoperoxidase was reduced. Complementation tests revealed two distinct groups. The three members of complementation group 1 synthesized normal amounts of replicative forms but were restricted in single-stranded DNA production and capsid protein expression, exhibiting phenotypes compatible with cap mutations. The sole representative of group 2, KRV ts6, failed to accumulate replicative forms, displaying a rep- phenotype. These mutants provide new tools to test the role of viral products in the biology of autonomous parvoviruses.

Animals↗
PubMed1984

Kilham rat virus DNA replication in subcellular fractions.

A subcellular system actively replicating Kilham rat virus DNA in vitro was developed. Cellular lysates and isolated nuclei from infected cells showed an amplification of replicative forms in vitro. Solubilized replicative complexes, either partly purified or in the form of a crude extract, were able to synthesize replicative forms and single-stranded DNA. DNA polymerase alpha played a major role in Kilham rat virus DNA synthesis in vivo and in vitro. Furthermore, a factor present in the cytosol of infected cells increased the polymerizing activity of viral replicative complexes.

Animals↗
PubMed1984

[Total vulvectomy with lasers. An interesting technic].

The authors describe a case of total vulvectomy without inguinal clearance using a CO2 laser for a micro-invasive epidermoid carcinoma. They agree with most that has been published in the literature and show that lasers can be used successfully for removal and coagulation in this type of operation. The authors show how well the patient did after the operation and they believe that this rapid recovery was due to the technique that was used.

Adult↗
PubMed1976

The new mother's view of herself.

A woman's attitude to breast-feeding is usually determined more by feeling than by rational thought; it is built on her adolescent views of the development of secondary sexual characteristics and subsequently on the breasts' part in sexual attraction. Early in pregnancy a mother is aware that fixed advice is more often offered than explanatory discussion. When birth is imminent, disinclination to breast-feed may be part of an unrecognized reluctance to submit to the changes which motherhood will bring. After the birth of her first child a mother finds herself enduring the discomforts of heightened moods and only too ready to interpret difficulties as signs of her inadequacy. Yet at the same time she is likely to discover her delight in her baby's repose and her own tranquillity at times of feeding.

Adolescent↗
PubMed1976

Isolation and structural characterization of monomeric and dimeric forms of replicative intermediates of Kilham rat virus DNA.

Two virus-specific species of newly synthesized DNA were isolated from rat fibroblast cell cultures infected with the Kilham rat virus (RV). These two DNA species were purified; their behavior on hydroxyapatite chromatography and their sedimentation coefficients in sucrose gradients were determined. One of the two species corresponds to the linear double-stranded form of the RV DNA, and the other corresponds to the dimeric duplex form. After denaturation, a fraction of both species showed an intramolecular renaturation; these molecules are composed of viral strand covalently linked to complementary strand. Models for the structure of both species are posposed. Both species may be considered as double-strand replicative intermediates of the single-stranded RV DNA.

Cell Line↗
PubMed1975

The neonate's immunity gap, breast feeding and cot death.

In many mammals infant behaviour imposes a period during which the young will only take the mother's milk. It is suggested that the immunological components of the milk serve in this period to augment the baby's immune system while he traverses from the antigenic isolation of a fetus to his independent defence. In humans almost all cot deaths occur during this phase. Diverse statistics relating to factors associated with greater risk of cot death are drawn on, suggesting that a number of seemingly unconnected factors can all (including lack of breast-feeding) be interpreted as potential immunity defaults. This interpretation lends support to the idea of an immune mechanism underlying cot death which in some way is an abnormal response resulting from the default and which, with at least one other precipitating mechanism, leads to death.

Anaphylaxis↗
PubMed1973

Mineral content of brands of milk for infant feeding.

The amounts of sodium, potassium, phosphorus, and nitrogen in several brands of milk used for infant feeding have been measured, and the concentrations of these substances in the reconstituted milks calculated. The known variation in the electrolyte content of cows' milk and the addition of minerals in the manufacture of many types of milk foods may account for the variation in the content of these substances, but the addition of neutralized whey in the manufacture of Trufood Formula 4 increased the concentration of sodium to a level twice that found in undiluted cows' milk. We think that details of all mineral additions to milks used for infant feeding should be made readily available and that the mineral content of the powders or liquids should be printed on the containers and expressed both in mg/100 g and mEq/kg. Milks reconstituted to a composition close to that of cows' milk present large osmotic loads to the kidneys, and may endanger water balance in some circumstances. This risk can be reduced by a greater dilution with water.

Animals↗