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Biomedical subjects

E Frost

Publications and source records attributed to E Frost.

At least 55 records · Page 3Linked to original sources
PubMed1986

Herpes-related polypeptides from a human cervical carcinoma cell line.

Using antiserum against herpes simplex virus type 2 (HSV-2) infected cells, eight polypeptides with similar molecular weights could be immunoprecipitated from the nearly diploid, human cervical carcinoma cell line C4II and from HSV-2 transformed hamster and mouse cells. Only two of these polypeptides corresponded to those from HSV-2 infected cells, including the putative HSV-2 transformation-related 35K protein. Partial proteolytic cleavage products of the immunoprecipitated 35K polypeptides from C4II and HSV transformed hamster and infected cells were indistinguishable; however, viral DNA and mRNA corresponding to the 35K polypeptide could not be detected in C4II or in transformed hamster or mouse cells by dot blot hybridization. A similar mechanism of transformation for the human cervical carcinoma cell line and HSV-2 transformed cells is proposed.

Animals↗
PubMed1986

[Structure elucidation of gestodene].

The structure of 17 alpha-ethinyl-17 beta-hydroxy-18-methyl-4,15-estradien-3-one (gestodene) was elucidated by the spectrometric methods UV, IR, NMR, MS.

Contraceptives, Oral↗
PubMed1985

Ethidium bromide-induced loss of mitochondrial DNA from primary chicken embryo fibroblasts.

Chicken embryo fibroblasts in uridine-containing medium are inherently resistant to the growth-inhibitory effect of ethidium bromide. The drug was found to inhibit the incorporation of [3H]thymidine into mitochondrial DNA circular molecules. Mitochondrial DNA was quantitated by DNA-DNA reassociation kinetics with a probe of chicken liver mitochondrial DNA. A mean number of 604 copies of mitochondrial DNA per cell was found. This number decreased progressively in cells exposed to ethidium bromide, and by day 13 ca. one copy of mitochondrial DNA was detected per cell. When the cells were then transferred to drug-free medium, the number of copies increased very slowly as a function of time. On the other hand, analyses of DNA extracted from cell populations exposed to ethidium bromide for 20 or more days, with or without subsequent transfer to drug-free medium, revealed very little or no mitochondrial DNA by reassociation kinetics or by Southern blot hybridization of AvaI- or HindIII-digested total cellular DNA. As a result of the elimination of mitochondrial DNA molecules, the establishment of cell populations with a respiration-deficient phenotype was confirmed by measuring cytochrome c oxidase activity as a function of the number of cell generations and the absorption spectrum of mitochondrial cytochromes.

Animals↗
PubMed1985

Prepartal infection of the placenta with Neisseria gonorrhoeae.

Placentas from 191 consecutive deliveries were cultured for Neisseria gonorrhoeae and other bacteria before being examined histologically. N gonorrhoeae was seen on direct microscopical examination and cultured from two placentas, one of which had chorioamnionitis and the other had a granulocytic invasion of the membranes. In both patients, rupture of the membranes had occurred two hours or less before delivery, and thus after infection. A third patient was also found to have light gonococcal infection of the placenta. Six infections with group B streptococci were identified, but only one correlated with chorioamnionitis. Chorioamnionitis was observed in 16 (8.4%) and granulocytic infiltration of the membranes in 18 (9.4%) of the deliveries.

Adolescent↗
PubMed1985

Auxotypes and serogroups of penicillinase producing and non-producing strains of Neisseria gonorrhoeae isolated in Franceville, Gabon.

The auxotypes and serogroups of 250 consecutive isolates of Neisseria gonorrhoeae from Franceville, Gabon, including 33 penicillinase producing (PPNG) strains, were identified and the results tabulated for four periods. The PPNG and certain non-PPNG strains were isolated in clusters against a relatively stable pattern of non-PPNG biotypes. Most of the non-PPNG strains were non-requiring or proline requiring strains of serogroup WII or non-requiring strains that could not be grouped with commercially available antisera. No strain requiring arginine, hypoxanthine, and uracil was observed. The PPNG strains were all serogroup WI or ungroupable and non-requiring or proline or arginine dependent auxotypes. Only one non-PPNG strain required proline or arginine and was not serogroup WII.

Culture Media↗
PubMed1984

Age of appearance of IgG, IgM, and IgE antibodies specific for Loa loa in Gabonese children.

IgG, IgM, and IgE antibodies against the filaria Loa loa were measured in umbilical cord blood and in blood from young Gabonese children by an ELISA technique using a homologous metabolic antigen. For children in eight consecutive age groups and adults the percentage of the population positive for each of the antibody classes was determined. The number of children with maternal IgG decreased until one year of age when new synthesis began to become apparent. IgM antibodies were detected only after six months, probably indicating an early infancy as opposed to a fetal infection. The percentage of individuals positive for IgM or IgE reached a peak between two and three years old, followed by a slight decline. Over half of the individuals over one year of age had IgM antibody against L. loa, indicating long-term synthesis of this class of immunoglobulin in many people. In the first two years of life, IgE antibodies were usually accompanied by L. loa-specific IgM. This specific IgE did not appear to trigger the synthesis of nonspecific IgE. By the age of two, 95% of the population had some antibodies against L. loa and by five the percentage of individuals positive for each antibody class had reached adult levels.

Adult↗
PubMed1984

Direction of synthesis of the message for a 35 000 polypeptide of herpes simplex virus type 2.

A restriction endonuclease map of the coding sequences for the transformation-related 35 000 polypeptide of herpes simplex virus type 2 is reported, using 11 enzymes that cut DNA infrequently. Hybrid-arrested translation with small DNA fragments was used to locate the 5' terminus of these coding sequences. A novel procedure involving translation of the 35 000 mRNA selected with cloned viral DNA that had been digested with exonuclease was employed to confirm that this message is transcribed from left to right. The 35 000 polypeptide can thus be assigned to a 1.2-kilobase mRNA recently reported with the same starting point and direction.

Cell Transformation, Viral↗
PubMed1984

[Gonococcal infections in Gabon (Haut-Ogooué)].

The isolation of N. gonorrhoeae in the region of Franceville was attempted on the one hand with 261 men and 261 women presenting urethral or cervical discharge, and on the other hand with 530 women attending a prenatal clinic of whom 42 had cervical discharge while 488 did not. Amongst the men, 69.7% of the urethritis cases were due to N. gonorrhoeae while this bacteria could be isolated from 15.3% of the women with cervical exudates. N. gonorrhoeae could be also identified in 5.5% of the pregnant women of whom 79% were without exudate. The frequency of N. gonorrhoeae isolates from STD consultations was 440 cases per year per 100,000 while the male: female ratio was 4.6. The isolation rate from pregnant women would indicate however a frequency in women in excess of 1 500 cases per 100,000. The isolation of N. gonorrhoeae was tabulated according to the age of the patients. The 15-20 year group was clearly the most frequently infected. Trichomonas was observed in 2% of the men and 23% of the women with discharges. Yeasts (chiefly Candida albicans) were found in 23.5% of the women but in none of the men.

Candida albicans↗
PubMed1983

Localization of the coding region for a 35000 Dalton polypeptide on the genome of herpes simplex virus type 2.

The cloned BglII N fragment of herpes simplex virus type 2 (HSV-2) DNA has been shown to code for a 35K polypeptide. Subfragments made by cleavage with XhoI, BamHI, SstII and XorII were then cloned and used with RNA extracted from HSV-2-infected cells for mRNA selection and in vitro protein synthesis. We found that the major translation product of such hybrid-selected mRNA has a molecular weight of 35 000. By further mapping, DNA coding sequences for this mRNA were located within the region of BglII N, at approximately 0.585 to 0.596 genome map units. DNA sequences complementary to mRNA encoding a 56K polypeptide were located between 0.607 and 0.612 map units.

Chromosome Mapping↗
PubMed1978

Structures of polyoma virus: on the histone component and virion core.

We have observed that purified polyoma virus is able to take up an amount of calf thymus histone equivalent to 10 to 50% of its normal histone content under conditions allowing the binding of considerably lesser amounts of several other proteins. Some of the bound histone could not be released by procedures procedures routinely used for virus purification. We have also found that some of the histone present in purified polyoma virus could be selectively released without major breakdown of virus particles. Possible models for virus structure are discussed in the light of the present and other recent data.

Centrifugation, Density Gradient↗