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Biomedical subjects

S Whitaker

Publications and source records attributed to S Whitaker.

16 recordsLinked to original sources
PubMed1990

Prognostic significance of tumor ploidy in patients with advanced ovarian carcinoma.

Fresh tumor specimens obtained from 53 consecutive patients with FIGO Stage III ovarian carcinoma were analyzed by flow cytometry. All patients were treated by a standard protocol: maximal tumor excision and cisplatin/cyclophosphamide/adriamycin chemotherapy, and followed-up for at least 24 months. Thirty-two percent of tumors were diploid (DNA index = 1.00) and 68% aneuploid (DNA index greater than 1.00), with more aneuploid tumors being associated with larger residual tumor and poor cellular differentiation. Patients with diploid tumors were found to survive significantly better than those with aneuploid tumors, in terms of survival rate (65% versus 31%), median survival time (33 months versus 13 months), and mean disease-free interval (17.8 months versus 8.2 months). The influence of the amount of residual tumor after primary surgery on survival was only significant in patients with diploid tumors. Our results support previous findings that tumor ploidy is an important prognostic indicator in ovarian cancer. We found aneuploidy to be associated with a poorer clinical outcome in Stage III disease, regardless of the amount of residual tumor after primary surgery and the degree of cellular differentiation.

Adenocarcinoma↗
PubMed1987

Determination of cell membrane permeability in concentrated cell ensembles.

The method of volume averaging is used to analyze the process of diffusion in concentrated cell ensembles in which significant resistance to mass transfer is caused by the cellular membrane. A general closure scheme is given that allows for direct theoretical prediction of effective diffusivities for any cellular geometry. Numerical results are presented for the classical parallelepiped arrangement used to model cellular systems, and these results are used in conjunction with experimental studies of concentrated cell ensembles to determine membrane permeabilities for solute diffusion in several cellular systems. Membrane permeabilities are compared with predictions from other models of diffusion in cellular systems.

Animals↗
PubMed1979

Predictive value of serial carcinoembryonic antigen levels in long-term follow-up of ovarian cancer.

The predictive value of serial levels of carcinoembryonic antigen (CEA) in tumor monitoring was examined in 213 patients with ovarian cancer; each patient had been followed-up at monthly intervals for at least 12 months. CEA was not detectable throughout the period of observation in 35% of the patients. In general. patterns showing a disappearance of CEA or persistently low levels were associated with a good prognosis, whereas those showing a reappearance or highly elevated and rising levels were associated with a poor prognosis. A transient reappearance of CEA was observed in 10 patients; this did not appear to be associated with tumor recurrence or progression. "False positive" results were obtained in 6 patients in whom no tumor has been clinically detectable to date. "False negative" results were obtained in 4 patients with obvious tumor progression. In terms of a good or poor prognosis, the use of CEA levels was highly accurate in patients with minimal or no residual disease (97% and 89%, respectively); the rate fell to 62% in patients with extensive disease. As the clinical significance and limitations become better known, serial CEA levels should contribute substantially to the monitoring of patients with ovarian cancer.

Carcinoembryonic Antigen↗
PubMed1979

Effect of blood dilution on recovery of organisms from clinical blood cultures in medium containing sodium polyanethol sulfonate.

This clinical study was designed to evaluate the standard laboratory protocol that requires blood specimens be diluted with greater than or equal to 10 volumes of media. Blood was collected from hospitalized patients, and 1 ml was inoculated into each of three vials containing 2.3, 7.3, and 24 ml of BACTEC 6B aerobic medium resulting in dilutions of 1:4, 1:10, and 1:30, respectively. The three test vials were treated identically, and the study was carried out at four hospitals. Of the 2,550 sets of vials inoculated, 174 were positive with clinically significant isolates from 105 patients. There was no difference in the number of positive cultures recovered by 24 h (67%) or 48 h (90%) from any dilution. These percentages agreed with other reports from BACTEC users. The number of positive vials (139, 144, 147, respectively) at each dilution was not significantly different, indicating that all three dilutions showed equal recovery of pathogenic microorganisms. Despite this overall equality, two patients, one on antibiotic therapy, were found to have correlated cultures which failed to grow at the 1:4 dilution. This finding implies that a 1:4 dilution of blood cannot be recommended unequivocably despite the higher overall recovery rate of positive cultures.

Bacteria↗
PubMedDate not supplied

The faculty advisor role: an imperative for student retention.

The decline in applicants to schools of nursing emphasizes the importance of retaining those students who do enroll. The authors review factors affecting student attrition and retention in academic settings. They then present an ideal model for enhancing student retention through effective, individualized, and consistent student advising.

Education, Nursing, Baccalaureate↗