Biomedical subjects

J P Malas

Publications and source records attributed to J P Malas.

9 recordsLinked to original sources

PubMed2001

Hazard analysis of Escherichia coli O157:H7 contamination during beef slaughtering in Calvados, France.

To identify hazard points and critical points during beef slaughtering, which is a necessary first step toward developing a hazard analysis and critical control point system to control meat contamination by Escherichia coli O157:H7, samples (n = 192) from surfaces, work tops, worker's hands, and beef carcasses were collected from a slaughterhouse in Calvados, France. Five strains of E. coli O157:H7 were isolated from a footbridge and a worker's apron at the preevisceration post and from a worker's hand at the defatting post. Three isolates carried stx2c, eae, and EHEC-hlyA genes and showed similar molecular types by random amplified polymorphic DNA, polymerase chain reaction IS3, and XbaI pulsed-field gel electrophoresis. Thus, this study has shown that preevisceration and defatting post and associated worker's materials are critical points for carcasses contamination by E. coli O157:H7 during beef slaughtering.

Abattoirs↗

PubMed1994

Biological markers and ovarian carcinomas: galactosyltransferase, CA 125, isoenzymes of amylase and alkaline phosphatase.

We present a comparative study of several biological markers (galactosyltransferase, CA 125, isoenzymes of amylase and alkaline phosphatase) with a view to ovarian carcinoma follow-up. Serum samples were obtained from a population of 75 patients under clinical observation. After a minimum 18-months period, we assessed the prognostic value of the markers. No marker permits the detection of discrete, evolving carcinomas. CA 125 is the marker that gives the best results, particularly in terms of sensitivity. Galactosyltransferase has a lower sensitivity except in the case of endometrioid carcinomas. Simultaneous analysis with CA 125 and galactosyltransferase results in no decisive improvement, other than greater precision in unfavourable prognoses. Isoenzymes of amylase and alkaline phosphatase are of no interest in the follow-up of such carcinomas.

Alkaline Phosphatase↗

PubMed1991

[Localization and modulation of galactosyltransferase during in vitro proliferation of a human ovarian adenocarcinoma cell line].

A cell line, IGROV1, originating from a human ovarian cancer, releases a galactosyltransferase activity in its culture medium during proliferation. The proliferating IGROV1 cells appear as two populations: some cells grow in floating clusters whereas the greater part of them adhere to the culture substrate. The study of galactose transfer by intact cells onto an exogenous glycoprotein acceptor (ovomucoid) shows the presence of surface-associated galactosyltransferase onto the two cellular sub-populations. Opposite to intracellular activity, surface-associated and released galactosyltransferase activities depend on cellular adhesion and proliferation.

Adenocarcinoma↗

PubMed1990

A simple serum galactosyltransferase assay method suitable for routine use.

UDP-Galactose: N-acetylglucosaminyl glycoprotein beta 1-4 galactosyltransferase (GT) catalyzes the transfer of galactose to N-acetylglucosamine from UDP-[3H]Gal. The uncharged reaction product (tritiated N-acetyllactosamine) is separated from the unreacted UDP-[3H]Gal by ion-exchange chromatography. The major advantage of this method is its rapidity compared to other isotopic techniques.

Chromatography, Ion Exchange↗

PubMed1990

Alteration in isoenzyme patterns of serum galactosyltransferase activity in ovarian cancer patients: preliminary results.

Isoelectric focusing on agarose gel was used to separate the isoenzymes of serum galactosyltransferase (uridine diphosphogalactose: N-acetylglucosaminyl galactosyltransferase, EC 2.4.1.22) from 8 healthy women, and 11 ovarian cancer patients of whom 4 were in clinical remission. In all cases, we found 7 major peaks with isoelectric points ranging from 4.0-5.4. The most acidic peaks were preferentially elevated in the tumor-bearing patients, particularly the peak with pI 4.44.

Aged↗

PubMed1988

Steroid receptors analysis in human mammary tumors by isoelectric focusing in agarose.

A high resolution and quantitative method for isoelectric focusing has been developed to separate the isoforms of estrogen and progesterone receptors in human mammary tumor cytosols stabilized by sodium molybdate. Agarose gels (0.5%) were used. Six samples can be analyzed on one gel in about 2 h, and 35-microliters samples are sufficient to determine the estrogen receptor isoform pattern. The constant yields and the reproducibility of data allow a quantitative analysis of these receptors. Four estrogen receptor isoforms have been observed (pI 4.7, 5.5, 6, and 6.5), isoforms with pI 4.7 and 6.5 being present in all tumors. After incubation at 28 degrees C in high ionic strength, the comparison of isoelectric focusing and high-performance size exclusion chromatography patterns of estrogen receptor confirms the oligomeric structure of the pI 4.7 isoform and suggests a monomeric structure for the pI 6.5 isoform. Under the same conditions of analysis, only one progesterone receptor isoform has been detected with pI 4.7.

Aged↗

PubMed1988

Charge heterogeneity of human mammary tumor estrogen receptors. Relationship with a hormonal sensitivity tumor marker.

A high resolution quantitative method for estrogen receptor analysis has been elaborated using isoelectric focusing in 0.5% agarose gel, without any prior trypsin digestion. The 23 cytosols analyzed were stabilized by molybdate and prepared from human mammary tumors with progesterone receptors (PR + cytosols) or without (PR - cytosols). Progesterone receptor was used as a tumoral hormonal sensitivity marker. The estrogen receptors usually resolved as 4 isoform peaks of close isoelectric points. In PR - cytosols, the mean pI values were 4.7, 5.5, 6 and 6.5. Significant differences between the two cytosol populations were observed concerning pI 4.7 and 6.5 isoforms. In PR - cytosols, the pI 4.7 isoform occurred in greater proportions than in PR + cytosols, whereas lower proportions of pI 6.5 isoform were seen. The comparison between high performance size exclusion chromatography profiles and isoelectric focusing patterns, before and after cytosol incubation at 28 degrees C with KCl (0.4 M), confirmed an oligomer structure for the pI 4.7 isoform and suggested a monomer structure (Stokes radius 2.9 mm) for the pI 6.5 estrogen receptor isoform. The results indicated that isoelectric focusing analysis of estrogen receptors could be useful in the prediction of breast cancer hormonal sensitivity.

Aged↗

PubMed1988

Serum galactosyltransferase activity with three acceptors in ovarian cancer patients.

Several laboratories have demonstrated the usefulness of serum galactosyltransferase as a biological marker for ovarian neoplasms. However, contradictory results have been published recently, which might be partially explained by differences in methodology. We thus decided to measure serum galactosyltransferase activity in patients with ovarian cancer and benign gynecological diseases using three different assay systems. A very good correlation was obtained between the results of these assays. Furthermore, we confirm that serum GT is frequently elevated in cancer patients, and is of potential value for their follow-up.

Acetylglucosamine↗

PubMed1988

[Comparative study of various technics for the determination of human serum galactosyltransferase].

We have compared three assays for serum galactosyltransferase activity, which use ovomucoïd, asialo agalactofetuin and free N-acetylglucosamine respectively as exogenous acceptors. A very good correlation between the three assays is obtained, for the whole range of GT activity. When the methods are compared to one another, the slopes of the regression lines are similar whether the sera are collected from healthy controls, pregnant women, or women suffering from benign gynecologic diseases or ovarian neoplasms. The methods which uses free N-acetylglucosamine as acceptor is rapid, cheaper and easier to perform.

Female↗