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Biomedical subjects

S Ogden

Publications and source records attributed to S Ogden.

26 records · Page 2Linked to original sources
PubMed1985

Cyclophosphamide, doxorubicin and cisplatin chemotherapy for patients with locally advanced urothelial tumors with or without nodal metastases.

Thirty-eight patients with primary urothelial tumors recurring in the pelvis or nodal presentation were treated with intravenous or intra-arterial cyclophosphamide, doxorubicin and cisplatin chemotherapy. The 38 patients were selected owing to unresectability by local criteria (12 patients) or by virtue of nodal metastases (26 patients). Histologically, the patients either had pure transitional cell carcinoma (29), transformation to a histological subtype of transitional cell carcinoma (7) or pure squamous cell carcinoma (2). An over-all 50 per cent complete remission rate was achieved with an 18 per cent objective pelvic response rate, and 32 per cent failed to respond to chemotherapy. Responses by histological subtype revealed that patients with pure transitional cell carcinoma had a 62 per cent complete remission rate, those with transitional forms had a 14 per cent complete remission rate and none with squamous cell carcinoma responded to chemotherapy. A significant difference in the incidence of responses among patients with transitional carcinoma and those with transition forms was seen (p less than 0.02). Complete remissions were independent of disease site. Nineteen patients achieved a complete remission with a mean duration of 86 weeks and median of 81 weeks (range 33 to 172 weeks). Toxicity of the chemotherapy was moderate with a high incidence of peripheral neuropathy and leukopenic infections. No deaths of chemotherapy were encountered. Patients with locally advanced or metastatic transitional cell carcinoma of the urothelium to lymph nodes can benefit from intravenous and intra-arterial cyclophosphamide, doxorubicin and cisplatin chemotherapy.

Adult↗
PubMed1984

An operator at -280 base pairs that is required for repression of araBAD operon promoter: addition of DNA helical turns between the operator and promoter cyclically hinders repression.

A site has been found that is required for repression of the Escherichia coli araBAD operon. This site was detected by the in vivo properties of deletion mutants. In vitro protection studies with DNase I and dimethylsulfate showed that araC protein can specifically bind in this area to nucleotides lying at position -265 to -294 with respect to the araBAD operon promoter (PBAD) transcription start point. The previously known sites of protein binding in the ara operon lie between +20 and -160. Since the properties of deletion strains show that all the sites required for araBAD induction lie between +20 and -110, the new site at -280 exerts its repressive action over an unusually large distance along the DNA. Insertions of -16, -8, 0, 5, 11, 15, 24, and 31 base pairs of DNA between the new site and PBAD were constructed. Repression was impaired in those cases in which half-integral turns of the DNA helix were introduced, but repression was nearly normal for the insertions of 0, +11, and +31 base pairs.

AraC Transcription Factor↗
PubMed1983

Doxorubicin, mitomycin-C, and 5-fluorouracil (DMF) in the treatment of metastatic hormonal refractory adenocarcinoma of the prostate, with a note on the staging of metastatic prostate cancer.

Sixty-two patients with metastatic hormonal refractory adenocarcinoma of the prostate received a combination of doxorubicin, mitomycin-C, and 5-fluorouracil (DMF). Thirty (48%) of the patients achieved an objective response. Response criteria excluded disease "stabilization" as a manifestation of response. Four clinical prognostic categories were identified: osseous I (OI) had metastatic axial skeletal involvement (23 patients); osseous II (OII) had axial and extremity skeletaL involvement (18 patients); visceral I (VI) had pulmonary metastasis (9 patients); and visceral II (VII) had pulmonary metastasis and involvement of other viscera (12 patients). The 20 responding patients survived a median of 47.5 weeks, whereas the 32 nonresponding patients survived a median of 23.8 weeks (n = 0.002). Response rates were highest among patients with OI (52%) and VI (88%) disease; response rates were lower amont patients with OII (33%) and VII (33%) disease. Responding patients in each clinical category survived longer than nonresponding patients except for those patients with VII disease. The median duration of response for patients with OI disease was 11 months, for OII 9.5 months, for VI patients it was 6.5 months, and VII patients it was 5 months. DMF is an effective treatment of metastatic hormonal refractory prostate cancer, resulting in consistent objective responses. The staging system employed identifies four clinical categories of metastatic prostate cancer and allows for accurate comparison of diet and stratification of study populations.

Adenocarcinoma↗
PubMed1980

The Escherichia coli L-arabinose operon: binding sites of the regulatory proteins and a mechanism of positive and negative regulation.

The locations of DNA binding by the proteins involved with positive and negative regulation of transcription initiation of the L-arabinose operon in Escherichia coli have been determined by the DNase I protection method. Two cyclic AMP receptor protein sites were found, at positions -78 to -107 and -121 to -146, an araC protein--arabinose binding site was found at position -40 to -78, and an araC protein-fucose binding site was found at position -106 to -144. These locations, combined with in vivo data on induction of the two divergently oriented arabinose promoters, suggest the following regulatory mechanism: induction of the araBAD operon occurs when cyclic AMP receptor protein, araC protein, and RNA polymerase are all present and able to bind to DNA. Negative regulation is accomplished by the repressing form of araC protein binding to a site in the regulatory region such that it stimultaneously blocks access of cyclic AMP receptor protein to two sites on the DNA, one site of which serves each of the two promoters. Thus, from a single operator site, the negative regulator represses the two outwardly oriented ara promoters. This regulatory mechanism explains the known positive and negative regulatory properties of the ara promoters.

AraC Transcription Factor↗
PubMed1980

Cervical ectopic pregnancy--case report.

A case is described of an early cervical pregnancy in a 30-year-old patient following curettage 6 months previously for an inevitable abortion. The condition was managed initially by suction aspiration, but further curettage with circumsuture of the cervix was required for delayed haemorrhage. The condition was suspected at laparoscopy and confirmed by ultrasonic scan. Laparoscopy indicated that the gestation sac was below the level of the uterine vessels, and was thus of prognostic as well as diagnostic value.

Adult↗
PubMedDate not supplied

Method for reducing the rate of light emission from chemiluminescent and bioluminescent reactions using frozen reagents.

Frozen assay reagents have been used to reduce the rate of light emission from the rapid chemiluminescent acridinium ester and the bioluminescent firefly luciferase reactions. Melting of the assay reagent delays the initiation of the light emission, thus eliminating the need to initiate these rapid reactions by injection of the assay reagents in front of the photodetector.

Acridines↗