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M Simon

Publications and source records attributed to M Simon.

At least 469 records · Page 26Linked to original sources
PubMed1986

Involucrin acts as a transglutaminase substrate at multiple sites.

Involucrin is a keratinocyte protein with a specialized function in terminal differentiation. Synthesized initially as a soluble protein, it later becomes a preferred substrate for a membrane-bound transglutaminase and becomes cross-linked into an insoluble envelope. When a crude keratinocyte extract containing about 2% involucrin is heated to 95 degrees, most proteins precipitate, but all of the involucrin remains in solution, where it is over 90% pure. This step has been incorporated into a simplified procedure for purification of the protein. Like intact involucrin, polypeptide fragments formed by the tryptic hydrolysis of involucrin are good substrates for the keratinocyte transglutaminase. Evidently amino acid residues participating in the enzyme-catalyzed cross-linking are distributed at numerous sites along the involucrin molecule.

Binding Sites↗
PubMed1986

KIN28, a yeast split gene coding for a putative protein kinase homologous to CDC28.

We have isolated, in yeast, a nuclear gene named KIN28 which presents significant sequence homology with the cell-division-cycle CDC28 gene, with members of the protein-tyrosine kinase family (src, erb, abl, epidermal growth factor, etc.) and those of the family of protein kinases phosphorylating serine and threonine. This strongly suggests that KIN28 is endowed with a protein kinase activity. In contrast with CDC28, KIN28 is interrupted by an intervening sequence. The KIN28 gene failed to complement cdc28 mutations and was shown to be essential for cell proliferation.

Amino Acid Sequence↗
PubMed1986

Methods for in vitro percutaneous absorption studies. VII: Use of excised human skin.

Water permeability constants (Kp) were determined with skin from human cadavers. No difference was seen in Kp values from unfrozen skin or from skin frozen for a few days. Human skin could usually be stored at -20 degrees C for up to a year with no change in water permeability, but in some cases apparent deterioration of the barrier was observed. A rapid procedure was developed for checking barrier integrity of skin in diffusion cells before a penetration study. The percent of the water dose absorbed after 20-min contact with skin correlated with water Kp values. Changes in water permeation through human skin agreed with changes in the absorption of seven test compounds of varying solubility properties (acetylsalicylic acid, benzo(a)pyrene, cortisone, DDT, nicotinic acid, propylene glycol, and testosterone). Water permeation is therefore considered to be a good indicator of potential changes in the barrier integrity of human skin. No correlation was observed in Kp values and other characteristics of the donor skin samples such as age, sex, race, and length of time before skin harvest.

Body Water↗
PubMed1986

DNA polymorphism related to the idiopathic hemochromatosis gene: evidence in a recombinant family.

The metabolic error involved in idiopathic hemochromatosis, as well as the underlying genetic defect remain unknown. It has, however, been recently shown that this genetic lesion occurs at a locus linked to the major histocompatibility complex, probably close to the HLA-A locus, and that the disease is recessively transmitted. Therefore, in a family where one subject has idiopathic hemochromatosis his HLA-identical siblings should also be affected. We present here the restriction polymorphism with two MHC class I probes and one DR beta probe in an exceptional family with three HLA-identical siblings: one (the proband) has a major form of idiopathic hemochromatosis, while the other two are free of any clinical or biochemical signs of the disease. The restriction patterns observed after DNA digestion by enzymes EcoRI, EcoRV, BglII, BamHI, PvuII, TaqI, HincII, and HindIII led to the conclusion that one of the proband's chromosome 6 had undergone two alterations: one, a deletion in the DR region, was revealed by missing fragments all correlated with DR5; the other was an unbalanced cross-over or a genetic conversion in the MHC class I region. This latter alteration was revealed by modifications in the patterns of high molecular weight HindIII bands which hybridize with probe pHLA2 and also by the absence of a HindIII fragment of 7.4 kb hybridized by another class I probe. This latter alteration most likely involved the hemochromatosis gene and could be the first step toward a molecular approach to this gene.

Adult↗
PubMed1986

The effect of T cells from patients with infectious mononucleosis on CFU-CGM proliferation: a preliminary report.

The neutropenia occurring during infection is a poorly understood phenomenon. Immunologically-stimulated T lymphocytes, acting upon normal bone marrow stem cells, have been etiologically implicated in several disorders. Fifteen patients, ages 17 to 25 years, and diagnosed with infectious mononucleosis by positive heterophile titers, were studied. Peripheral blood T lymphocytes were separated using sheep red blood cell rosetting. They were then cocultured with normal bone marrow cells, in a concentration of 2 X 10(4) cells/ml, in methylcellulose containing 10% colony-stimulating activity. Normal BM was obtained from patients with nonmalignant hematologic disorders, or leukemia in remission. Bone marrow cells were cultured at a concentration of 1 X 10(5) or 5 X 10(5) cells/ml, alone (control) or with T lymphocytes. Plates were incubated at 37 degrees C with 5% CO2. Colonies were scored at 14 days. Inhibition of normal, bone marrow growth was observed at both concentrations, after addition of T lymphocytes to the culture system. Such suppression was significant (p less than 0.05) for the lower concentration of normal bone marrow cells only. Variable and partial abrogation of effect was seen after overnight incubation of T lymphocytes, possibly due to loss of suppressor activity. There were insufficient numbers of tests with supernatant to allow computation of statistical significance. Correlation between T-cell ratios and suppressive effect has not been determined, although it is suspected that the responsible cells are within the T-suppressor fraction.

Adolescent↗
PubMed1986

Serum lipid and lipoprotein levels in premature ageing syndromes: total lipodystrophy and Cockayne syndrome.

Serum lipids and lipoproteins were investigated in two girls who suffered from total lipodystrophy, in their family members, and in two brothers suffering from Cockayne syndrome. Hyperlipoproteinemia type IIb (Fredrickson) was detected in one case with total lipodystrophy. Very low levels of serum high density lipoprotein cholesterol (HDL-Ch) were observed in both of total lipodystrophic cases, in most of their first degree relatives, and in one of patients with Cockayne syndrome. Because total lipodystrophy and the Cockayne syndrome belong to ageing syndromes they can serve as a useful model of premature arteriosclerosis and the defect lipid metabolism.

Adult↗
PubMed1986

[Carpal tunnel syndrome: clinical and electrologic forms. Results after neurolysis (88 cases)].

Eighty-eight neurolyses of the median nerve in the carpal tunnel were performed. Clinical, anatomical and electrological characteristics allowed to classify the carpal tunnel syndromes in painful and dysesthesial type, in types with progressive (electromyographical, clinical, complete, incomplete) or acute hand muscle atrophy. After neurolysis, clinical and electrological results were analysed and correlated with initial severity of the chronic median nerve entrapment in the carpal tunnel.

Carpal Tunnel Syndrome↗
PubMed1986

Analysis of mutations in the transmembrane region of the aspartate chemoreceptor in Escherichia coli.

Site-specific mutagenesis was used to replace an alanine with a lysine residue and to create a deletion of seven amino acids into the first transmembrane region (TMI region) of the aspartate chemoreceptor in Escherichia coli. The mutations resulted in the loss of aspartate chemotaxis on tryptone motility plates. However, both mutant proteins were able to associate with the membrane and to bind aspartate. They were both refractory to methylation or to modification of the C-terminal region of the protein by the cheB gene product. These results suggested that the integrity of the TMI domain of the protein was required to maintain the function of the cytoplasmic portion of the receptor. The Lys-19 mutant retained the ability to generate a repellent response. Analysis of suppressor mutations of the Lys-19 mutation suggested that formation of an ion pair or specific changes in a 40 amino acid stretch in the cytoplasmic region of the protein (from amino acid 264 to amino acid 303) could suppress the effects of the Lys-19 mutation. The TMI region of the protein may be involved in transmembrane transmission of signals from the periplasmic portion of the cell to the cytoplasmic portion of the Tar protein.

Amino Acid Sequence↗
PubMed1986

Assignment of the human and mouse prion protein genes to homologous chromosomes.

Purified preparations of scrapie prions contain one major macromolecule, designated prion protein (PrP). Genes encoding PrP are found in normal animals and humans but not within the infectious particles. The PrP gene was assigned to human chromosome 20 and the corresponding mouse chromosome 2 using somatic cell hybrids. In situ hybridization studies mapped the human PrP gene to band 20p12----pter. Our results should lead to studies of genetic loci syntenic with the PrP gene, which may play a role in the pathogenesis of prion diseases or other degenerative neurologic disorders.

Animals↗
PubMed1986

Postoperative analgesia by nicomorphine intramuscularly versus high thoracic epidural administration. Effects on ventilatory and airway occlusion pressure responses to CO2.

In this study the effects of nicomorphine, administered either intramuscularly or by high thoracic epidural route, on the ventilatory and airway occlusion pressure response to CO2 were investigated and compared. Twenty-four patients scheduled for thoracic surgery were allocated randomly to postoperative pain relief by i.m. nicomorphine or by high thoracic epidural nicomorphine. The ventilatory response to 5% carbon dioxide was measured in all patients: first 1 day before operation, secondly on the first day after surgery immediately before nicomorphine administration and finally after the administration, at the moment when no further rise in end-tidal PCO2 (PETCO2) was measured. Respiratory response was assessed in two ways, by measuring minute ventilation (VE) and mouth occlusion pressure (P0.1). There was a significant depression in ventilatory response to CO2 in the intramuscular group (P = 0.03) due to nicomorphine as assessed by the slope of VE vs PETCO2. No significant depression was found in the epidural group, irrespective of measurement of VE or P0.1. No significant shift of apnoeic threshold-PETCO2 was observed in either group.

Analgesia↗
PubMed1986

Regulation of lateral flagella gene transcription in Vibrio parahaemolyticus.

Two distinctly different organelles of locomotion are produced by Vibrio parahaemolyticus. The polar flagellum is responsible for motility in a liquid environment (swimming), and the lateral flagella enable the bacteria to move over surfaces (swarming). Synthesis of lateral flagella occurs when V. parahaemolyticus is grown on agar media but not when it is grown in liquid media. We used lux (luminescence gene) fusions to conveniently and sensitively analyze the factors which influence transcription of lateral flagella genes (laf). Transposon mini-Mu lux was used to mutagenize V. parahaemolyticus and to generate laf::lux transcriptional fusions. Mutants with insertions of mini-Mu lux in laf genes were defective in the swarming phenotype and produced light when the bacteria were propagated on agar media, but not when cells were grown in liquid media. Thus, surface-dependent expression of lateral flagella synthesis is controlled by regulation of transcription. Such fusion strains were also used to further define the environmental conditions which induce laf gene expression. Cultivation on media solidified by gelling agents other than agar also induced light production in fusion strains, as did growth on a variety of hydrophilic membrane filters suspended over liquid media. Growth at an air-surface interface was not necessary for expression since embedding the fusion strains in agar was also effective. Furthermore, induction of laf gene transcription could also be accomplished by increasing the viscosity of the liquid medium by the addition of a high-molecular-weight polymer such as polyvinylpyrrolidone. Increase in luminescence of the fusion strains was detected within 30 min of initiation of the inducing circumstance, and reversal of induction, e.g., by dilution of the viscous medium, resulted in a rapid decline in the rate of increase in luminescence. Conditions that induced luminescence in the fusion strains also induced the synthesis of lateral flagella in wild-type V. parahaemolyticus. The growth environment of the genes, and it appears that the signal that triggers laf expression is physical rather than chemical in nature. Possibilities for a sensing mechanism are discussed.

Agar↗
PubMed1986

Decreased natural killer cell activity in lichen ruber planus.

Natural killer cell (NK) activity of peripheral blood lymphocytes in 15 patients with moderate to exanthematic lichen ruber planus (LP) was studied. Markedly diminished NK response in patients with LP was revealed as compared with that of healthy controls. Decreased NK activity found in LP was supposed to be a secondary phenomenon.

Adolescent↗
PubMed1986

Expression of OKM5 antigen on human keratinocytes in vitro upon stimulation with gamma-interferon.

Using murine monoclonal antibodies against human OKM5, OKM1 and HLA-DR antigens antigenic characteristics of freshly separated human epidermal cells (EC) and those of EC cultured in the presence of Interferon-gamma (IFN-gamma) were studied. After 8-12 days of culture, primarily OKM1- OKM5- HLA-DR- keratinocytes displayed OKM5 and HLA-DR antigens when exposed to IFN-gamma. Our data support the concept, that human keratinocytes may possess accessory cell functions.

Antigens, Surface↗
PubMed1986

Limiting dilution analysis of proliferating and helper T cells in the in vivo immune response to KLH: derepression of helper T cells at moderately increased frequencies.

While it is clear that some T cells have the capacity for almost indefinite proliferation in vitro, it is a controversial issue how much of this proliferative capacity is utilized by T cells in a response to antigen in vivo. In the framework of a strict clonal selection model the functional activities of normal and immune lymphocyte populations are essentially determined by the frequencies of antigen-specific cells which are clonally expanded after recognition of antigen. In contrast, our group has proposed a network model in which the more prominent effect of immunization is a release of antigen-specific T cells from a state of suppression (= derepression) which exists in the non-immune situation and which is generated through interactions between T cells involving their antigen-specific receptors. In this model, derepression is achieved by competition of antigen with the interactions among T cells through which suppression is exerted. To test our model, we analyze in this paper how much of the immune response to keyhole limpet hemocyanin (KLH) in draining lymph nodes is accounted for by an increase in the numbers of KLH-reactive T cells or by their derepression. To this end, we immunize mice subcutaneously with KLH in CFA. For a period of 14 days after immunization draining lymph nodes are removed, and the frequencies of KLH-reactive proliferating T cells and of KLH-reactive helper T cells determined. We find that proliferating T cells increase 5 to 8 fold in frequency from day 1 to 4 after immunization (approximately 1/30,000 to approximately 1/5000) and no evidence for suppression of these T cells in the non-immune situation can be obtained. In contrast, T helper cells are strongly suppressed in non-immune lymph nodes and become derepressed suddenly between days 3 and 4 following immunization. From day 0 to day 3 T helper cell frequencies are in the order of 1/14,000-1/38,000, then increase suddenly approximately 3-6 fold within 1 day from 1/16,000-1/8,000 to 1/3,000-1/5,000 with no further change until day 14. Thus, helper T cell immunity in draining lymph nodes appears to be generated by a combination of increased frequencies of specific T cells with their release from suppression. In addition, we have reasons to suspect that we overestimate the increase in T cell frequencies. We therefore think that derepression is a major factor in the response of T helper cells to antigen.

Animals↗
PubMed1986

[Genetic markers in the blood and their relation to metabolic parameters in dairy cows].

A relationship between the genetic markers of blood (blood groups, serum polymorphic proteins) and the clinico-chemical parameters was studied in the dairy cows of the Slovak Pied breed. Antigens belonging to systems A, B, C, F, S, R, T, Z and the polymorphic traits genetically controlled from loci Tf, Cp, Am and Hb were identified in all the animals subjected to testing. The values of the parameters of acid-base balance and concentration of 13 metabolic components were repeatedly determined in the experimental period. The results of the F-test indicated that there were no significant differences in the values of any of the tested parameters between the phenotypes of the A, J, Am, Tf and Cp systems. Of the 21 parameters tested, statistically significant differences were found in 11 parameters between some alleles of the C, FV, T, Z and Hb systems.

Acid-Base Equilibrium↗