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Biomedical subjects

E May

Publications and source records attributed to E May.

At least 109 records · Page 6Linked to original sources
PubMed1984

Palliation of esophageal malignancy with photoradiation therapy.

Seven patients with severe or complete obstruction of the esophagus by malignancy were treated with photoradiation after presensitization of the tumor with intravenous hematoporphyrin derivative. The 625- to 635-nm therapeutic light was delivered from a tunable dye argon laser system coupled through quartz fibers, passed through the biopsy channel of a flexible esophagoscope, with local anesthesia. All tumors (adeno, squamous, and melanoma) responded, and swallowing was improved. Although tumor is still present, one patient is 11 months from initial treatment and is eating a regular diet. Another patient is 8 months from initial treatment and has no dysphagia. One patient died of aspiration of gastric tube feedings and 3 others died of their disease at 3 weeks, 3 months, and 6 months, respectively, from their initial treatment. Another patient died 11 months from his initial treatment due to a cardiac arrhythmia. During the 11 months after his initial treatment he continued to eat a regular diet.

Adenocarcinoma↗
PubMed1984

Simian virus 40 late promoter region able to initiate simian virus 40 early gene transcription in the absence of the simian virus 40 origin sequence.

To improve our knowledge of the simian virus 40 (SV40) late promoter control region, we took advantage of the fact that T antigen can be expressed with a heterologous promoter. We constructed three chimeric plasmids (pEMP-273, pEMP-LCAP-162, and pEMP-LCAP-113) each with a putative late promoter sequence positioned immediately upstream from the SV40 early gene coding region but in an orientation opposite to its natural orientation in the SV40 genome. After transfection of the recombinant DNA into HeLa or CV1 cells, T antigen accumulation, as scored by indirect immunofluorescence, was used as a functional test for promoter activity. We found that the sequence mapping from nucleotides 332 to 273 is not sufficient for promoting transcription of SV40 early gene but does potentiate the promoter activity of the 72-base-pair repeats in initiating the transcription at natural late cap sites. Considering that both plasmids pEMP-LCAP-162 and pEMP-LCAP-113 lack all of the sequence of the SV40 replication origin, we conclude that SV40 transcription can be mediated through a putative late promoter in the absence of the sequence for the SV40 replication origin.

Animals↗
PubMed1984

Conversion through homologous recombination of the gene encoding Simian virus 40 115,000-molecular-weight super T antigen to a gene encoding a normal-size large T antigen variant.

We have previously cloned the gene encoding a 115,000-Mr super T antigen (115K super T antigen), an elongated form of the Simian virus 40 large T antigen, originating from the rat cell line V 11 F1 clone 1, subclone 7 (May et al., J. Virol. 45:901-913, 1983). DNA sequence analysis has shown that the 115K super T antigen gene contains notably an in-phase duplication of a sequence located in the region of tsA mutations. We have also shown that the 115K super T antigen gene is able to induce the formation of transformed foci in transfected rat cells. After rat cell cultures were transfected with the cloned gene encoding 115K super T antigen, we obtained a large number of transformants as reported in this paper. In these transformants, we detected a very high frequency of new T antigen variants, as shown by immunoprecipitation of the cell extracts with anti-simian virus 40 tumor serum followed by electrophoresis in sodium dodecyl sulfate-polyacrylamide gels. Based on these results and all of the data presently available, it appears likely that the input plasmid or cosmid DNAs containing the cloned gene were first subjected to recombination events that yield new variant T antigen genes before these recombinant genes become integrated. The new variant T antigens observed in the transformants were predominantly those comigrating with normal-size large T antigen. In fact, these latter variants appeared to be indistinguishable from wild-type large T antigen as judged by restriction mapping by Southern blotting of the total genomic DNA of the transformants. Models of intermolecular or intramolecular homologous recombination occurring between or within the input plasmid or input cosmid DNA molecules are proposed to account for the formation of such revertants.

Animals↗
PubMed1984

[Tasks of family-oriented obstetrics in the maternity ward].

Psychological drawbacks of intensive obstetrics on the one hand and the results from psychology in the perinatal period on the other hand demand a new mental hygiene in the delivery room and on maternity wards. The "family-oriented obstetrics" met these problems best. Interviews were made with 650 mothers, just after delivery to find on the attitude for "family-oriented obstetrics". Presence of husband in the delivery room is wanted from 47,4% of the married couple. 98,15% from the mothers wanted nursing and 83,69% rooming-in.

Adolescent↗
PubMed1983

Hematoporphyrin-derivative and photoradiation therapy of malignant tumors.

Kodak projectors with #2418 red Corning filters were used as a light source to treat cutaneous and subcutaneous malignancies in five patients who previously had been given hematoporphyrin derivative (HpD). An argon dye laser system was used to treat malignancies in patients who also were given the HpD. These tumors included 11 melanomas of the eye, three carcinomas of the esophagus, one melanoma of the esophagus, four carcinomas of the lung, three basal cell skin cancers, and one retropharyngeal metastatic oral cancer. Clinical results and technical problems of this therapy are discussed.

Adenocarcinoma↗
PubMed1983

Study of the functional activities concomitantly retained by the 115,000 Mr super T antigen, an evolutionary variant of simian virus 40 large T antigen expressed in transformed rat cells.

Simian virus 40 (SV40) transformed V 11 F 1 clone 1 subclone 7 rat cells (subclone 7) do not synthesize normal-size large T antigen (M(r), 90,000); instead, they produce a 115,000 M(r) super T antigen (115K super T antigen). This super T antigen is SV40 virus coded, and its synthesis results from rearrangement and amplification of integrated viral DNA sequences in subclone 7 (May et al., Nucleic Acids Res. 9:4111-4128, 1981). In this study the functional activities of 115K super T antigen were compared with the functional activities of SV40 large T antigen. Transfection experiments were performed with (i) cosmid SVE 5 Kb and plasmid pSVsT, both containing the super T antigen gene and (ii) plasmids pSV1 and pSV40, both containing the large T antigen gene. Transfection of pSVsT DNA or SVE 5 Kb DNA into secondary cultures of rat kidney cells induced the formation of transformed cell foci with an efficiency that was about 50% of the efficiency of pSV1 DNA or pSV40 DNA. Concomitant with the transforming activity, two other activities were also retained by super T antigen, namely, the ability to enhance the level of host cellular protein p53 and the capacity to bind to p53. In contrast, pSVsT and SVE 5 Kb DNAs were markedly deficient in the capacity to support tsA58 DNA replication in CV1-P cells at a nonpermissive temperature (41 degrees C), as shown by cotransfection experiments. The yield of virus produced in these experiments was 400-fold less than the yield obtained in parallel experiments with pSV40 or pSV1. However, SVE 5 Kb and pSVsT have a functional SV40 replication origin, as shown by their efficient replication in COS 1 cells which provided functional large T antigen. Super T antigen also possesses a specific affinity for sequences of SV40 viral origin. Our results suggest that under certain conditions, evolutionary changes in T antigen take place and that these changes could be restricted to the phenotypic requirement of maintaining a structure that is able to induce cell transformation, to form a complex with p53, and to enhance the cellular level of p53. Therefore, there appears to be a close relationship among the activities of T antigen involved in transforming cells, in binding to p53, and in enhancing the p53 cellular level. Moreover, this set of activities appears to be separable from the replicative ability of T antigen, based on the observation that 115K super T antigen is markedly defective for initiating viral DNA synthesis.

Animals↗
PubMed1983

Evidence of transcription from the late region of the integrated simian virus 40 genome in transformed cells: location of the 5' ends of late transcripts in cells abortively infected and in cells transformed by simian virus 40.

By means of S1 mapping, we observed that spliced 16S and 19S viral late mRNAs--in addition to early mRNAs--were present in cytoplasmic polyadenylated RNA preparations from simian virus 40-transformed cell lines of rat or mouse origin containing no detectable amount of free viral DNA. The amounts of early and late virus-specific mRNAs in these lines were quantified by hybridization of radioactive cytoplasmic polyadenylated RNA with cloned region-specific restriction fragments. The relative amount of late viral mRNA produced in these transformed cells was found to be of the same order as that produced in simian virus 40-infected, nonpermissive baby mouse kidney cells. Moreover, by using the S1 nuclease protection method, we compared the 5' ends of late mRNAs produced (i) in transformed cells, (ii) in abortively infected mouse cells, and (iii) in the late phase of the lytic cycle. The 5' ends of late mRNAs both in abortively infected and in transformed cells were less heterogeneous than the 5' ends of late mRNAs produced during the lytic cycle; however, they were a subset of the 5' ends of late transcripts produced in the lytic cycle.

Animals↗
PubMed1982

[Bone healing and dynamic interferential current (DIC) (author's transl)].

The aim of this investigation was to clarify the influence of dynamic interferential current (DIC). Two sinusoidal currents of medium frequency are superimposed within the body to determine the reactive changes of bone healing after osteotomy. An osteotomy was performed on the radius and ulna of the right foreleg of 34 'black-head breeding sheep'. The radius shaft was deperiostalized and unstably fixed with a four-hole AO-plate leaving a gap of at least 1 mm width. DIC of different mA-values were not treated 24 sheep 3 times per week for 10 mins. The other 10 animals were not treated with DIC but used as control animals. The different results of our clinical, radiological, histological and chemical analyses to date indicate that callus formation is accelerated by the application of DIC. The fracture callus of treated animals is strongly mineralized.

Animals↗
PubMed1982

[Bone healing and dynamic interferential current (DIC) (author's transl)].

In the course of supplementary physical and chemical investigations of the influence of Dynamic Interferential Current (DIC) on bone healing 24 black-head sheep were subjected to transversal osteotomy of the radius. After an instable osteosynthesis the site was exposed to repeated therapy with DIC of varying mA intensity. (Methodological details are described in part I). DIC therapy resulted in altering the temperatures in the treated tissue, dependent on the mA intensity. Further associations were verified between DIC intensity and the occurrence of hydroxyprolin, and amino acid specific collagen, which also reflected increased calcifying activity. Measurement of the calcium and phosphorus levels in the regenerated (newly forming) bone tissue documented full mineralization in the DIC-treated animals at a much earlier date than in the untreated controls that had undergone similar operations. Whether DIC specifically stimulates osteogenesis within "healing" bones is still unclear.

Alkaline Phosphatase↗
PubMed1981

Characterization of a gene encoding a 115 K super T antigen expressed by a SV40-transformed rat cell line.

It has been reported that SV40-transformed V 11 F 1 clone 1 subclone 7 rat cells (subclone 7) produce a super T antigen of 115,000 M. This super T antigen is entirely SV40 coded and is synthesized by translation of an elongated form of SV40 early mRNA (May, E., Kress, M. Daya-Grosjean, L., Monier, R. and May, P. (1981) J. Virol., 37, 24-35). The results reported here show that there is only one independent insertion of viral DNA in the cellular genome of subclone 7 cells. When DNA from subclone 7 cells was cleaved with Bam HI endonuclease two distinct SV40 sequence containing fragments were generated with sizes of 5 Kb and 10 Kb, respectively. Two recombinant cosmids were constructed by insertion of the 5 Kb and 10 Kb fragments, respectively, into cosmid pHC 79. Using restriction map analysis and nucleotide sequencing, we showed that the 5 Kb fragment actually contained the complete sequence of a gene encoding super T antigen. As compared to the normal SV40 early gene, the sequence of super T gene showed the following rearrangements: (i) The segment between nucleotides 4116 - 3544 was duplicated in a direct order and (ii) these two copies of 573 nucleotide sequence were separated by a 93 nucleotide tract which was a nearly perfect inverted repeat of the segment located between nucleotides 4868 and 4776 (nucleotide numbering used here = Weissmann number +17).

Animals↗
PubMed1981

Mapping of the viral mRNA encoding a super-T antigen of 115,000 daltons expressed in simian virus 40-transformed rat cell lines.

Simian virus 40-transformed V11 F1 clone 1 subclone 7 rat cells produced a considerable amount of an elongated form of large-T antigen with an Mr of 115,000 (115K super-T antigen), but these cells did not produce detectable traces of normal-sized large-T antigen (86,000 daltons) (P. May, M. Kress, M. Lange, and E. May, Cold Spring Harbor Symp. Quant. Biol. 44:189-200, 1980). First, a comparison of the tryptic peptide fingerprints of 115K super-T and large-T antigens suggested that 115K super-T antigen is simian virus 40 coded and contains a duplication of amino acid sequences of large-T antigen. Second, from S1 mapping analysis of 115K super-T mRNA, performed with various restriction fragments of simian virus 40 DNA, it was concluded that super-T mRNA is a form of large-T mRNA containing a tandem duplication of the sequence extending from approximately 0.46 to 0.35 map unit. The duplicated sequence corresponded to that region of the simian virus 40 genome in which 12 of 13 tsA mutation sites are clustered (C. J. Lai and D. Nathans, Virology 66:70-81, 1975).

Animals↗
PubMed1981

Ability of nonpermissive mouse cells to express a simian virus 40 late function(s).

Mouse cells are fully nonpermissive for simian virus 40 (SV40). Infection does not lead to detectable virus replication. In this report, it was shown, first, that spliced 16S and 19S SV40 late mRNA were present in cytoplasmic and polysomal polyadenylated acid+ RNA preparations from SV40-infected baby mouse kidney cells. The 16S and 19S SV40 late mRNA's produced in infected baby mouse kidney cells were identical to or similar to the 16S and 19S SV40 late mRNA's produced in permissive monkey cells as judged by their S1 mapping patterns performed with the late strand of HpaII-BamHI fragment B and by their sedimentation patterns in a sucrose gradient. It was also shown that the 16S late mRNA from infected baby mouse kidney cells could be translated into a polypeptide which was identical to or similar to virion protein VP1 in every aspect examined, including the patter of peptide mapping by limited proteolysis. Second, we reported that mouse kidney cells produced detectable, although low, levels of SV40 virion protein VP1, as shown by the sodium dodecyl sulfate-polyacrylamide gel autoradiogram of [35S]methionine-labeled proteins immunoprecipitated by a rabbit antiserum directed against SV40 virion proteins. Third, it was reported that infected baby mouse kidney cells produced late mRNA's either (i) when the infection was done at a restrictive temperature with the nonleaky tsA58 mutant or (ii) in cells treated with 100 microgram of cycloheximide per ml, in which large T antigen synthesis was inhibited by more than 99.9%. This suggested that large T antigen was not required for the synthesis of late mRNA in mouse cells.

Animals↗
PubMed1979

Relationship between single-stranded DNA isolated from mouse cells transformed by simian virus 40 and transcription of cellular and virus genes.

A minor fraction of single-stranded DNA (ssDNA) was isolated by an improved method of hydroxylapatite chromatography (HAC) from the native nuclear DNA (nDNA) of SV--3T3 cells, non-productively transformed by SV40. Molecular hybridization, monitored by the use of S1 nuclease, HAC, isopycnic centrifugation and thermal melting showed that ssDNA from SV-3T3 cells (which amounts to 1.5 to 2% of the total nDNA) has the same characteristics as ssDNA previously isolated from other cell species. Only 27 to 28% of ssDNA can be self-hybridized but the greatest part can be reassociated to the non-repetitive portion of nDNA and up to 38% hybridized to homologous RNAs, as compared with 7 to 8% for bulk nDNA. Highly radioactive virus probes (SV40-3H-cRNA synthesized in a cell-free system and the separated 'early' and 'late' strands of SV40 DNA labelled with 125I) were annealed to different excess amounts of cellular DNA. Both the quantities of each probe hybridized at saturation levels and the various reaction kinetics indicated that ssDNA is greatly enriched for virus sequences, mainly originating from the 'early' DNA strand which is predominantly expressed in SV-3T3 cells. The mode of formation of ssDNA is discussed in the light of other findings on the effects of DNA untwisting proteins and susceptibility of active animal genes to selective enzymic attacks.

Animals↗
PubMed1979

Regulation of simian virus 40 early and late gene transcription without viral DNA replication.

Primary cultures of African green monkey kidney cells were infected with the simian virus 40 temperature-sensitive mutant tsA58 at the nonpermissive temperature of 41 degrees C for 12 to 20 h. Under these conditions, a defective T antigen was produced and no viral DNA replication was detected. Viral transcription complexes were extracted from infected nuclei using Sarkosyl and the nascent chains of RNA elongated in vitro. Sixty to 70% of the viral RNA synthesized in vitro hybridized to late gene sequences. In contrast, 80 to 90% of the nuclear viral RNA labeled in vivo during a 15-min pulse with [3H]uridine hybridized to early gene sequences. This suggests that selective degradation of late gene transcripts occurs in vivo. The role of T antigen and viral DNA replication in regulation of simian virus 40 transcription is discussed.

DNA Replication↗
PubMed1979

Simian virus 40-transformed cells express new species of proteins precipitable by anti-simian virus 40 tumor serum.

In addition to the virus-coded large-T and small-t antigens, two new classes of proteins were immunoprecipitated by anti-simian virus 40 (SV40) tumor serum from extracts of various SV40-transformed cell lines. These were as follows: (i) proteins (termed "super-T proteins") with an Mr higher than that of large-T antigen (86,000), which were found in many SV40-transformed cell lines derived from mouse and rat cells (super-T proteins and large-T antigen appeared to have closely related structures as judged by the Chromobead elution patterns of their methionine-labeled tryptic peptides); (ii) proteins (termed "55K proteins") with an Mr ranging from 50,000 to 60,000, which were present in all SV40-transformed cell lines examined so far, including those obtained by chromosome-mediated gene transfer. The 55K proteins were not structurally related to large-T antigens, as judged by the Chromobead elution patterns of their methionine-labeled tryptic peptides. Our data are compatible with the assumption that the 55K proteins are largely or totally cell coded.

Animals↗
PubMed1978

Characterization of two SV40 early mRNAs and evidence for a nuclear "prespliced" RNA species.

Using in vitro translation of sucrose-gradient fractionated cytoplasmic mRNA from SV40-infected cells, we have shown that a deletion in the region mapping between 0.54--0.59 reduced the size of mRNA for small-t but not the size of mRNA for large-T. Mutants with a deletion in this region were shown to produce in vivo either shortened small-t or no small-t, and normal large-T. Similarly, in vitro translation of poly(A)+cytoplasmic RNA from cells infected with these mutants gave the same results. On the other hand in vitro translation of poly(A)+nuclear RNA from the mutants which made no small-t produced a small-t derivative possibly synthesized from a prespliced RNA species. We have also shown that poly(A)+nuclear RNA from mutant dl 2122 produced two small-t related proteins: one of these (MW: 11K) probably represents the product of a "prespliced" RNA, the other (MW: 17K) which is also found in the cytoplasm represents the product of the mutant specific small-t mRNA.

Antigens, Neoplasm↗