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Biomedical subjects

C Browne

Publications and source records attributed to C Browne.

32 records · Page 2Linked to original sources
PubMed1992

Estimates of the frequency of chromosome abnormalities detectable in unselected newborns using moderate levels of banding.

Data on structural chromosome abnormalities identified during prenatal diagnosis were used to estimate the number of such abnormalities that would be detectable in an unselected series of newborns using moderate levels of banding (400 to 500 bands). These estimates were compared with the rates detected in nonbanded surveys of newborns. Between 1976 and 1990 prenatal diagnosis using banding techniques was carried out in our laboratory on 14,677 women aged 35 and over. Among these, we detected 112 structural rearrangements, 32 unbalanced and 80 balanced. These figures were adjusted by two methods to give an estimate of the frequency of structural abnormalities in the newborn. Our data suggest that the use of moderate levels of banding increases the frequency of unbalanced structural abnormalities from 0.052 to 0.061% and of balanced structural abnormalities from 0.212 to 0.522%. Thus, the total number of chromosome abnormalities detectable in the newborn is increased from 0.60% in unbanded preparations to 0.92% in banded preparations.

Adult↗
PubMed1992

Substance use disorders in a sample of Canadian patients with chronic mental illness.

In a study designed to investigate the pattern of substance use disorders among a group of chronic mentally ill patients in Toronto, 102 patients completed the Structured Clinical Interview for DSM-III-R and a modified substance-use-disorder module of the Diagnostic Interview Schedule. Forty percent of the sample met criteria for substance use disorders, and 49 percent for personality disorder. Among patients with personality disorder, all those with a personality disorder in cluster B (that is, with antisocial, borderline, histrionic, or narcissistic personality disorder) had a substance use disorder, while the majority of patients in cluster A and cluster C were not substance abusers. In the overall sample, the group with substance use disorders was significantly younger than the group without. In contrast to findings of previous studies, women met criteria for substance use disorders as often as men did.

Adult↗
PubMed1989

Tumour necrosis factor-alpha enhances the cytolytic and cytostatic capacity of interleukin-2 activated killer cells.

The cytotoxic and cytostatic responses of peripheral blood lymphocytes from eight cancer patients and splenocytes from four patients activated with rIL2 and a combination of rIL2 and rTNF-alpha were tested against two tumour cell lines. The cytotoxic response of rIL2-activated lymphocytes did not exceed the natural killer cytotoxicity values in all patients tested. In fact the killing capacity of some PBL deteriorated after rIL2 activation. The combined use of rIL2 and rTNF-alpha reversed this detrimental effect and enhanced the cytotoxic capacity of all PBL tested. In instances where high levels of killing were already achieved by rIL2 alone additional rTNF-alpha did not induce a significant change. This indicates that the role of rTNF-alpha may be to promote the response to rIL2 of PBL which react suboptimally to this lymphokine. rTNF-alpha did not only enhance cytotoxic capacity but also conferred cytostatic capacity to rIL2-activated LAK cells which were cytotoxic but unable to inhibit the growth of the surviving target cells. Natural killer cell selected K562 target cells which were less susceptible to killing by untreated lymphocytes than the parent K562 tumour cell line were killed more aggressively by rIL2 + rTNF-alpha LAK cells than by rIL2-LAK cells. No phenotypic differences were detected in these two cultures of LAK cells which indicates that the increased cytotoxic and cytostatic capacity of rIL2 + rTNF-alpha-LAK cells may be due to a higher state of activation of these cells or due to their capacity to recognise a broader spectrum of targets than rIL2-LAK cells.

Cytotoxicity Tests, Immunologic↗
PubMed1981

The response of rabbit spleen explants to ionizing radiation.

Explants of rabbit spleen, responding to sheep erythrocytes in vitro, were exposed to ionizing radiation at different times in culture. Radiation was found to depress the development of specific haemolysin-producing cells (PFC) at subsequent times, while cells already engaged in haemolysin production were relatively resistant to radiation. The depressing effects of radiation on PFC was most marked at times when the rate of increase of PFC was highest. Recovery from low doses (less than 2 Gy) occurred while higher doses of radiation had persistent depressing effects on the level of PFC. Assessment of synthesis of other macromolecules in these irradiated cultures showed that protein synthesis was highly resistant and DNA synthesis was sensitive like the immune response. Irradiation in hypoxic conditions showed that this protected the tissues from damage by radiation and there were also indications of enhancement of repair of this damage. Finally it was found that the results obtained with these cultures correlated well with previous studies of intact mice.

Animals↗
PubMed1980

Cytotoxic effects of sodium selenite on tadpoles (Xenopus laevis).

The cytotoxic effects of sodium selenite on developing tadpoles (Xenopus laevis) were examined by scanning, light, and electron microscopy. Selenium exposure resulted in disorganization, vacuolization, and swelling of the outer layer of epithelial cells in the tadpole epidermis. Examination of muscle cells in the somites revealed myofibril disorganization and cell degeneration. Mitochondria in both epithelial and muscle cells were swollen and showed loss of cristae. It is likely that sublethal exposures to selenium compounds result in cellular damage which could affect motility, and thus survival, over longer periods of time.

Animals↗
PubMed1976

Quality, efficiency, and cost of a physician-assistant-protocol system for managment of diabetes and hypertension.

Briefly trained physicians assistants using protocols (clinical algorithms) for diabetes, hypertension, and related chronic arteriosclerotic and hypertensive heart disease abstrated information from the medical record and obtained history and physical examination data on every patient-visit to a city hospital chronic disease clinic over a 18-month period. The care rendered by the protocol system was compared with care rendered by a "traditional" system in the same clinic in which physicians delegated few clinical tasks. Increased thoroughness in collecting clinical data in the protocol system led to an increase in the recognition of new pathology. Outcome criteria reflected equivalent quality of care in both groups. Efficiency time-motion studies demonstrated a 20 per cent saving in physician time with the protocol system. Coct estimates, based on the time spent with patients by various providers and on the laboratory-test-ordering patterns, demonstrated equivalent costs of the two systems, given optimal staffing patterns. Laboratory tests were a major element of the cost of patient care,and the clinical yield per unit cost of different tests varied widely.

Costs and Cost Analysis↗
PubMedDate not supplied

Nurse practitioner management of common respiratory and genitourinary infections, using protocols.

Included in this study were all patients with symptoms of respiratory tract infection and female patients with symptoms of urinary tract and vaginal infections who sought care from a hospital-based outpatient department walk-in unit which was operated in two different modes: experimental (the "nurse-protocol mode")-in which a nurse practitioner guided by a protocol initially evaluated all such patients and independently managed many patients- and traditional-in which only physicians managed patients. Safety, effectiveness, efficiency, and cost of care rendered for these tracer conditions in the two modes were compared. No serious illnesses were overlooked by practitioners in either mode. Eighty-six percent of patients in the nurse-protocol mode and 73 percent of patients in the traditional mode reported good symptom relief. Patients reported equivalent satisfaction with care. The time physicians spent managing patients with these complaints was reduced by 91 percent from 15.5 minutes to 1.4 minutes per patient. Personnel costs were equivalent in the two modes. Costs of laboratory tests and medications ordered were 27 percent less in the nurse-protocol mode. The study indicated that care in the nurse-protocol mode was of equivalent quality, led to equivalent patient satisfaction, allowed a substantial reduction in physician time, and reduced overall costs of care.

Boston↗