Search PubMed⌕ Search

Biomedical subjects

T Seki

Publications and source records attributed to T Seki.

At least 649 records · Page 36Linked to original sources
PubMed1983

Identification of three distinct papillomavirus genomes in a single patient with epidermodysplasia verruciformis.

Benign papillomas from a patient with a family history of epidermodysplasia verruciformis were examined for the presence of human papillomavirus (HPV) DNA. Employing stringent hybridization conditions that allow identification of a single type of HPV and radioactively labeled HPV-5 DNA as a probe, we have detected HPV DNA exhibiting sequence homology to HPV-5 in these tumors. Restriction endonuclease analysis of this HPV DNA confirmed its identity as HPV type 5. However, when hybridization was performed under less stringent conditions that allow all of the known types of HPV to react with the radioactively labeled HPV-5 DNA probe, two additional species of HPV DNA unrelated to HPV-5 were identified. As these two HPV types do not hybridize with HPV 1, 2, 3, or 4 under stringent conditions, they appear unique and have, as yet, not been reported to be associated with patients exhibiting epidermodysplasia verruciformis. Thus we have observed three distinct HPV species in benign papillomas from a single patient. These observations have important implications when attempting to correlate the type of HPV present in the various wart disease syndromes that have been described to date and further suggest that extreme care must be taken when analyzing carcinomas, occupying similar anatomic sites and suspected to have arisen from papillomas, for HPV species.

Animals↗
PubMed1983

Distribution of heterogeneous and homologous plasmids in Bacillus spp.

A total of 75 strains (including 5 reference strains) of Bacillus amyloliquefaciens, B. cereus, B. circulans, B. licheniformis, B. megaterium, B. pumilus, B. sphaericus, B. subtilis, and B. thuringiensis and 36 species-unidentified Bacillus strains were surveyed for plasmids by cesium chloride-ethidium bromide equilibrium centrifugation of cell lysates in a study of antibiotic resistance in host cells. Of the 111 strains, 13 (including 3 reference strains) were found to harbor plasmids, and 5 of the 13 showed antibiotic resistance. This antibiotic resistance appeared not to be due to the plasmids, however, because the trait was not cured by cultivation of cells in nutrient medium containing ethidium bromide (1 microgram/ml), sodium dodecyl sulfate (0.2 micrograms/ml), or novobiocin (1 microgram/ml), except in one strain, in which kanamycin and streptomycin resistances were cured by novobiocin. One strain of B. amyloliquefaciens, S294, was found to harbor a plasmid, pFTB14, which differed from the plasmid species of classes 1 to 6 in B. subtilis and B. amyloliquefaciens, as determined by restriction analysis and DNA contour length determination. However, in DNA-DNA hybridization on a filter after Southern blotting from an agarose gel, the pFTB14 DNA hybridized with plasmids of classes 1 to 5. Three strains of B. thuringiensis each carried at least 4 to 11 plasmid species, whereas no plasmids were detected in four strains of B. cereus, which, in relation to B. thuringiensis, is closely related taxonomically and has highly homologous DNA sequences. The plasmid DNAs prepared from species other than B. subtilis and B. amyloliquefaciens did not hybridize with that of pFTB14.

Anti-Bacterial Agents↗
PubMed1983

Corrected Version Distribution of Heterogeneous and Homologous Plasmids in Bacillus spp.

A total of 75 strains (including 5 reference strains) of Bacillus amyloliquefaciens, B. cereus, B. circulans, B. licheniformis, B. megaterium, B. pumilus, B. sphaericus, B. subtilis, and B. thuringiensis and 36 species-unidentified Bacillus strains were surveyed for plasmids by cesium chloride-ethidium bromide equilibrium centrifugation of cell lysates in a study of antibiotic resistance in host cells. Of the 111 strains, 13 (including 3 reference strains) were found to harbor plasmids, and 5 of the 13 showed antibiotic resistance. This antibiotic resistance appeared not to be due to the plasmids, however, because the trait was not cured by cultivation of cells in nutrient medium containing ethidium bromide (1 mug/ml), sodium dodecyl sulfate (0.2 mug/ml), or novobiocin (1 mug/ml), except in one strain, in which kanamycin and streptomycin resistances were cured by novobiocin. One strain of B. amyloliquefaciens, S294, was found to harbor a plasmid, pFTB14, which differed from the plasmid species of classes 1 to 6 in B. subtilis and B. amyloliquefaciens, as determined by restriction analysis and DNA contour length determination. However, in DNA-DNA hybridization on a filter after Southern blotting from an agarose gel, the pFTB14 DNA hybridized with plasmids of classes 1 to 5. Three strains of B. thuringiensis each carried at least 4 to 11 plasmid species, whereas no plasmids were detected in four strains of B. cereus, which, in relation to B. thuringiensis, is closely related taxonomically and has highly homologous DNA sequences. The plasmid DNAs prepared from species other than B. subtilis and B. amyloliquefaciens did not hybridize with that of pFTB14.

Journal Article↗
PubMed1982

Human papillomavirus DNA in cutaneous primary and metastasized squamous cell carcinomas from patients with epidermodysplasia verruciformis.

DNA extracted from squamous cell carcinomas from patients with the chronic wart disease syndrome, epidermodysplasia verruciformis, was analyzed for the presence of human papillomavirus (HPV)-specific DNA sequences by Southern blot hybridization analysis. Employing an HPV probe obtained by molecular cloning of viral DNA purified from benign warts from these patients, we have unequivocally identified HPV-specific nucleotide sequences in squamous cell carcinomas from these patients. Restriction endonuclease mapping indicated that the DNA present in the carcinomas was of the same type (type 5) as that found in the benign tumors from these patients and was present as unintegrated, free viral DNA. Moreover, we have demonstrated the presence of HPV-5 DNA in a subcutaneous metastatic tumor from one of these patients. This latter observation essentially eliminates the possibility that the HPV-5 DNA present in the malignant tumors in these patients resulted from cross-contamination from an adjacent benign warty lesion. In addition to wild-type HPV-5 DNA, both the primary and metastatic carcinomas analyzed also contained an HPV-5 DNA species lacking approximately 20% of the HPV-5 DNA genome. These subgenomic forms of HPV-5 DNA could not be detected in benign papillomas from these patients.

Carcinoma, Squamous Cell↗
PubMed1982

The effect of hypothermia and tissue perfusion on extended myocutaneous flap viability.

The salutary effect of hypothermia and tissue perfusion on extending the ischemic tolerance of the canine latissimus dorsi myocutaneous flap was demonstrated in this experimental study. A total of 175 flaps from 89 adult mongrel dogs were elevated with one-half the flaps perfused with iced Collins renal preservation solution. With the exception of control flaps kept at ambient temperature, the remaining flaps were stored at 4 degrees C for periods ranging from 24 to 192 hours followed by transplantation into the groins of recipient dogs, with anastomosis of the thoracodorsal artery and vein in an end-to-side manner to the femoral artery and vein, respectively. The study was divided into two distinct sections. The acute phase involved the transplantation of 77 flaps into random recipient dogs, and following a 3-hour period of systemic perfusion, the flaps were removed, weighed, and sectioned for later histologic study. Progressive increase in flap weight was observed up to 96 hours of hypothermia with a sharp decline in weight at 120 hours of hypothermia. The increase in flap weight in the nonperfused flaps was significantly greater than the previously perfused flaps. Histologically, at 120 hours of hypothermia, loss of vascular integrity was noted, suggestive of a no-reflow phenomenon. In the second, or extended-flap, study, 98 flaps were transplanted into the groins of the original donor animal and allowed to remain in situ for a 2-week period. The flaps were then carefully observed for viability, removed, and sectioned for histologic study. Hypothermic support of up to 96 hours extended viability in both perfused and nonperfused flaps, although beyond this hypothermic period viability was seen only in previously perfused flaps. The clinical implications of this study include hypothermic perfusion of a major-extremity amputation prior to replantation or the temporary storage of a free myocutaneous flap.

Animals↗