Regional inequality, migration and development: the case of Zimbabwe.
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Africa↗
Biomedical subjects
D Simon
Publications and source records attributed to D Simon.
Cloning in Streptococcus lactis of plasmid-mediated UV resistance and effect on prophage stability.
Plasmid pIL7 (33 kilobases) from Streptococcus lactis enhances UV resistance and prophage stability. A 5.4-kilobase pIL7 fragment carrying genes coding for both characters was cloned into S. lactis, using plasmid pHV1301 as the cloning vector. The recombinant plasmid was subsequently transferred to three other S. lactis strains by transformation or protoplast fusion. Cloned genes were expressed in all tested strains.
Bacillus subtilis↗
High-efficiency transformation of Streptococcus lactis protoplasts by plasmid DNA.
Streptococcus lactis IL1403 protoplasts were transformed by plasmid pIL204 (5.5 kilobases), which conferred erythromycin resistance with an average efficiency of 5 X 10(6) transformants per microgram of supercoiled DNA. The procedure used and transformation efficiencies obtained were close to those described for Bacillus subtilis (G. Chang and S. N. Cohen, Mol. Gen. Genet. 168:111-115, 1979).
Drug Resistance, Microbial↗
Network and home healthcare.
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Demography↗
Hepatocellular carcinoma cell line and peripheral blood lymphocytes from the same patient contain common chromosomal alterations.
A cell line derived from the biopsy of a human hepatocellular carcinoma which retains the differentiated phenotype of the liver parenchymal cell is described. Comparison of the integration sites of hepatitis B virus within the cellular genome of the biopsy specimen and within the genome of the multiply-passaged cell line reveals five stable sites of viral integration in the host cell genome. Multiple chromosome abnormalities are found in this cell line, some in the same area of the genome in which abnormalities were found in other human hepatomas. Chromosomes obtained from the peripheral blood cultures of the same patient manifest multiple signs of chromosome instability including breaks, minutes, chromosome pulverization, and acentric fragments, some of which localize to the chromosomal sites involved in the abnormalities in the tumor cell line. Chromosomal instability and/or virus-induced chromosome damage as factors in the etiology of human hepatocellular carcinoma are discussed.
Adult↗
[Insulinoma: diagnostic elements. 13 cases].
The mean age of the 13 patients studied (9 women, 7 men) was 50.5 +/- 15.7 years. The disease was discovered on account of malaise (3 cases), behavioural disorders (4 cases), coma (3 cases), syncope (1 case) or right hemiparesis (1 case) or in the course of systematic examination (1 case). Eleven patients consulted for evaluation of hypoglycaemia and 2 for behavioural disorders. The history was characteristic, with malaise, loss of consciousness, severe neurological disorders (seizures, hemiparesis, hemiplegia or coma) and psychiatric disorders. These symptoms typically occurred in the morning before breakfast or between meals in 9 patients, and atypically at any point of time or after meals in 4 patients. Their hypoglycaemic nature was demonstrated by blood glucose determination in 11/13 cases and by response to ingestion of sugar in 12/13 cases. The mean period elapsed between the initial symptoms and the final diagnosis was 20.3 +/- 17.3 months. Inappropriate insulin secretion was elicited a.m. before breakfast, during Conn's diet or fasting test, or by calculating the blood insulin/glucose ratio or Turner's coefficient. Prior to surgery, the insulinoma was located by ultrasonography in 3/8 cases, by computerized tomography in 2/6 cases, by selective arteriography in 6/11 cases, and by phlebography with spleno-portal catheterization and staged sampling for insulin and C-peptide assays in 8/9 cases. Histological examination after surgery (11 cases) or necropsy (1 case) showed an adenoma without evidence of malignancy.
Adenoma, Islet Cell↗
Genes for skeletal muscle myosin heavy chains are clustered and are not located on the same mouse chromosome as a cardiac myosin heavy chain gene.
Myosin heavy chain (MHC) genes are expressed as several distinct isoforms in a tissue- and stage-specific manner; three skeletal muscle MHC isoforms appear sequentially during development. We have isolated cDNA clones, identified by RNA blot hybridization and by nucleotide sequence determination as coding for portions of the embryonic (pMHC2.2), perinatal (pMHC16.2A), and alpha(V1) cardiac (pMHC141 and pMHC101) MHC isoforms. These four probes and the adult skeletal MHC probe (pMHC32) have been used on Southern blots of genomic DNA to detect restriction fragment length polymorphisms defining the alleles for these genes in mouse species Mus musculus and Mus spretus. In this way, we followed the segregation of skeletal and cardiac MHC genes in 42 offspring resulting from an interspecies backcross. We found that the embryonic, perinatal, and adult skeletal MHC genes are clustered on chromosome 11 near the locus nude, the skeletal and cardiac MHC genes do not cosegregate, and the alpha(V1) cardiac MHC gene is located on chromosome 14 close to Np-1. This result is in contrast to that for other contractile protein genes such as the alkali myosin light chain and the actin multigene families, which are dispersed in the genome.
Animals↗
Comparison of glycosylated hemoglobin and fasting plasma glucose with two-hour post-load plasma glucose in the detection of diabetes mellitus.
In the course of a screening for diabetes mellitus in the Hôtel-Dieu Hospital in Paris, from September 15, 1981 to April 1, 1984, an oral glucose tolerance test and a measurement of glycosylated hemoglobin were performed on 333 outpatients. With two-hour plasma glucose as a reference, the sensitivities of glycosylated hemoglobin, fasting plasma glucose, and a combination of glycosylated hemoglobin and fasting plasma glucose equal, respectively, 60.0%, 52.0%, and 40.0%; the specificities 90.9%, 98.7%, and 99.4%; the predictive value for a positive diagnosis 34.9%, 76.5%, and 83.3%. If one takes into account the implications of diabetes mellitus, especially its economic and psychosociologic consequences, it seems better for diagnosis--from a public health point of view--to use tests with a high degree of specificity and a high predictive value for a positive diagnosis, such as the combination of fasting plasma glucose and glycosylated hemoglobin, than tests with a good sensitivity but poor specificity. In the long term, validation of glycosylated hemoglobin as a diagnostic test for asymptomatic diabetes mellitus will be obtained only by reference to unquestionable criteria of the disease, determined by longitudinal survey.
Adolescent↗
A pluripotent human stem-cell clone isolated from the TERA-2 teratocarcinoma line lacks antigens SSEA-3 and SSEA-4 in vitro, but expresses these antigens when grown as a xenograft tumor.
Human embryonal carcinoma (EC) cells generally express the cell-surface, stage-specific embryonic antigens 3 and 4 (SSEA-3 and SSEA-4), the epitopes of which are defined by two monoclonal antibodies that recognize different portions of an extended globoseries oligosaccharide. To examine further the relationship between these epitopes and the human EC phenotype, we investigated the properties of two newly isolated clones from the human teratocarcinoma cell line, TERA-2. One clone expresses SSEA-3 and SSEA-4; the other does not. Nevertheless, these clones otherwise resemble one another, and based upon their morphology, their expression of other cell-surface antigens, and their ability to form xenograft tumors containing a variety of cell types, we conclude that both clones are composed of pluripotent human EC cells. When exposed to retinoic acid in vitro, neither clone differentiates as extensively as other clones that we have previously derived from TERA-2. These observations indicate heterogeneity among stem cells derived from a single human teratocarcinoma, and suggest that SSEA-3 and SSEA-4 are not necessarily integral features of the human EC phenotype. On the other hand, EC cells in xenograft tumors derived from the SSEA-3- and SSEA-4-negative clone re-express these epitopes. Further, this re-expression is stable, since EC cell lines that are SSEA-3- and SSEA-4-positive grow out when the tumors are explanted in vitro. We conclude that the expression of these globoseries epitopes can be modulated by environmental influences.
Animals↗
Brain transplants: can they restore single unit activity in the hippocampus?
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Animals↗
Methylation pattern of fish lymphocystis disease virus DNA.
The content and distribution of 5-methylcytosine in DNA from fish lymphocystis disease virus was analyzed by high-pressure liquid chromatography, nearest-neighbor analysis, and with restriction endonucleases. We found that 22% of all C residues were methylated, including methylation of the following dinucleotide sequences: CpG to 75%, CpC to ca. 1%, and CpA to 2 to 5%. Comparison of relative digestion of viral DNA with MspI and HpaII indicated that CCGG sequences were almost completely methylated at the inner C. The degree of methylation of GCGC was much lower. The methylation pattern of fish lymphocystis disease virus DNA differed from that of the host cell DNA.
Animals↗
Chromosomal site of hepatitis B virus (HBV) integration in a human hepatocellular carcinoma-derived cell line.
The single site of integration of hepatitis B virus in the human hepatocellular carcinoma cell line Hep 3B 2-1/7 was found to segregate with human chromosome 12 in somatic cell hybrids. Analysis of metaphase spreads of Hep 3B 2-1/7 following in situ hybridization with pHBV revealed integration at 12q13----q14, a location that coincides with a fragile site, fra (12q13). The possible significance of this location to the development of hepatocellular carcinomas is discussed.
Animals↗
Direct immunometric assay of active renin in human plasma.
None of the methods currently available can detect the small numbers of active renin (AR) molecules present in plasma. Among seven monoclonal antibodies (Ab), two Abs were selected which did not recognize the same epitope and could be used in a sandwich assay. The first monoclonal Ab, 3E8, binds soluble renin (B 50% = 1 x 10(-10) mol/l) and does not inhibit its enzymatic activity. It was coupled to magnetic beads (Magnogel) and was used to trap both active and inactive renin from 250 microliters plasma. The second Ab, 4G1, binds renin (B 50% = 3.5 x 10(-10) mol/l), inhibits its enzymatic activity, and recognizes inactive renin less than AR. It was iodinated and used to detect AR trapped on Magnogel by the first Ab during a 4-h incubation. The assay can detect 16 pg/ml in human plasma and is highly reproducible. The AR level of 15 normotensive subjects, aged 20-45 years, in an upright posture and on a normal sodium intake, was found to be 41 +/- 18 pg/ml (MRC renin standard). The plasmas were trypsin-activated and their total renin levels were measured with the same pair of monoclonal Abs. The mean value of 286 +/- 142 pg/ml is similar to the value obtained by other assay systems which measure total renin with Abs recognizing both active and inactive renin. The direct measurement of AR provides a convenient and standardized method, since the production of the two monoclonal Abs is unlimited.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Characterization of monoclonal antibodies to the estrogen-regulated Mr 52,000 glycoprotein and their use in MCF7 cells.
The Mr 52,000 glycoprotein is regulated by estrogen and released by breast cancer cells in culture (B. Westley and H. Rochefort, Cell, 20: 352-362, 1980). This rare protein was partially purified from 25 liters of medium conditioned by MCF7 cells and injected into Biozzi's selected mice. The spleen lymphocytes of one immunized mouse was fused with the murine myeloma P3-X63-Ag8-653. Sixteen hybridomas producing monoclonal antibodies to the Mr 52,000 protein were isolated, and seven of them were cloned and purified. The seven monoclonal antibodies were all of the immunoglobulin G1 isotype, and their dissociation constants ranged from 0.35 to 2.3 nM. The antibodies specifically recognized the secreted Mr 52,000 protein as evidenced by double immunoprecipitation and by immunoblotting after electrophoretic separation and transfer. Double-determinant immunoradiometric assay indicated that the seven purified monoclonal antibodies recognized three distinct regions of the Mr 52,000 protein, and it was used to assay the Mr 52,000 protein in biological fluids. These antibodies did not react with the external plasma membrane of MCF7 cells, as shown by immunofluorescence analysis. By contrast, the cytoplasm of MCF7 cells (but not T47D and RBA cells) was stained by the peroxidase-immunoperoxidase complex after plasma membrane permeation, indicating that the protein is secreted by exocytosis rather than shed from the plasma membrane.
Animals↗
[Current aspect of Sheehan's syndrome. 20 cases].
The 20 women investigated were 22 to 59 years old (average 35.9 +/- 2.3 years) when the diagnosis of Sheehan's syndrome was confirmed. Fourteen had had previous pregnancies, 6 were primiparas; average parity was 4. The patients were delivered in hospital, in France, in 14 cases, and abroad (Algeria, Portugal) at home in 6 cases. A history of severe haemorrhage during delivery was recorded in all but 2 cases. This was serious enough to warrant hysterectomy in 2 cases. Agalactia and amenorrhea were observed in all but 1 case in the immediate post-partum period. Transient polyuria and polydipsia occurred in 3 patients. In the months following birth, most women lead restricted lives; they were apathetic, asthenic and indifferent. The diagnosis was established under three different circumstances: in the majority (15/20) on clinical grounds, in 3 cases after acute adrenal failure, in 2 cases, fortuitously. Clinical examination showed signs of global anterior hypophyseal insufficiency involving thyroid, adrenal and gonad stimulating hormones in 14 cases; in 6 cases, the pituitary failure was dissociated. Corticotrophin, somatotropin and prolactin deficiencies were observed in all patients; gonadotrophin (17/20) and thyrotrophin (16/20) deficiencies were common. The diagnosis was confirmed less than 1 month (2 cases) to over 12 years (7 cases) after obstetric haemorrhage (average 6.9 +/- 1.9 years). No correlation was observed between the severity of the syndrome and this time interval. The short term outcome was favourable with return of menstruation and even pregnancy in one patient.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
[Early infantile epileptic encephalopathy with electroencephalographic pattern of the "suppressive bursts" type. Apropos of a new case].
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Electroencephalography↗
Presence of poly (ADP-ribose) polymerase and poly (ADP-ribose) glycohydrolase in the dinoflagellate Crypthecodinium cohnii.
Poly(ADP-ribose) polymerase and poly(ADP-ribose) glycohydrolase have been detected in chromatin extracts from the dinoflagellate Crypthecodinium cohnii. Poly(ADP-ribose) glycohydrolase was detected by the liberation of ADP-ribose from poly(ADP-ribose). Poly(ADP-ribose) polymerase was proved by (a) demonstration of phosphoribosyl-AMP in the phosphodiesterase digest of the reaction product, (b) demonstration of ADP-ribose oligomers by fractionation of the reaction product on DEAE-Sephadex. The (ADP-ribose)-protein transfer is dependent on DNA; it is inhibited by nicotinamide, thymidine, theophylline and benzamide. The protein-(ADP-ribose bond is susceptible to 0.1 M NaOH (70%) and 0.4 M NH2OH (33%). Dinoflagellates, nucleated protists, are unique in that their chromatin lacks histones and shows a conformation like bacterial chromatin [Loeblich, A. R., III (1976) J. Protozool. 23, 13--28]; poly(ADP-ribose) polymerase, however, has been found only in eucaryotes. Thus our results suggest that histones were not relevant to the establishment of poly(ADP-ribose) during evolution.
Chemical Phenomena↗