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Biomedical subjects

G Anderson

Publications and source records attributed to G Anderson.

At least 145 records · Page 8Linked to original sources
PubMed1996

Cervical cancer screening performed by a nurse. Evaluation in family practice.

OBJECTIVE: To determine whether a nurse practitioner could collect adequate Papanicolaou smear samples from the transformation zone of the cervix. DESIGN: A retrospective, descriptive study. SETTING: The Bella Coola Medical Clinic, a primary care facility located in the isolated, small village of Bella Coola, BC. PARTICIPANTS: All women who presented for Pap smears between July 1993 and June 1994. MAIN OUTCOME MEASURES: Endocervical or metaplastic cells in smear samples. RESULTS: All Pap smears performed in the Bella Coola Medical Clinic over 1 year by either the nurse or a member of the physician group (which includes family practice residents) were reviewed. Between July 1, 1993, and June 30, 1994, 149 Pap smears were done, 55 by the nurse and 94 by the physicians. All smears collected by the nurse practitioner showed endocervical or metaplastic cells. More than 90% of physician samples showed endocervical or metaplastic cells. CONCLUSIONS: A Canadian nurse practitioner can be trained to collect adequate Pap smears.

Adult↗
PubMed1995

Protecting children with chronic illness in a competitive marketplace.

Health care for children with chronic illnesses is significantly more expensive than for the average child. Children with chronic illnesses are especially vulnerable in a competitive health care environment because of the higher ongoing cost associated with treating their illnesses and the inherent pressures to reduce services to manage within the capitated rate. To minimize the adverse impact a competitive market could have on these children, a "carve-out" for specific medical conditions is discussed. A capitation pricing system that reflects their higher costs is proposed, as well as a delivery system that is focused on their needs.

Capitation Fee↗
PubMed1995

Positive selection of thymocytes involves sustained interactions with the thymic microenvironment.

CD4+8+ cortical thymocytes are critically dependent upon interaction with the thymic epithelium to undergo positive selection and maturation into single-positive CD4+ or CD8+ cells. Here we investigate further the nature of this interaction and provide evidence that positive selection requires sustained, rather than "single hit," interaction with thymic stromal cells. We also show that calcineurin-mediated signaling in thymocytes is required for the initial stages of positive selection, but is not essential throughout the period of thymocyte dependence on stromal cell contact during positive selection. In addition, we show that double-positive thymocytes that have initiated positive selection (CD69+4+8+) and newly generated single-positive (CD69+4+) cells differ markedly in response to the same stimulus through the TCR. The former undergo deletion, whereas the latter proliferate, indicating that a critical change in response to TCR ligation occurs within the narrow developmental window between these two stages.

Animals↗
PubMed1995

Stimulation of thymocytes before and after positive selection results in the induction of different NF-kappa B/Rel protein complexes.

Positive selection triggers the differentiation of immature CD4+8+TCRlow thymocytes into TCRhigh single-positive CD4+ or CD8+ cells and is associated with major changes in gene expression. However, little is known about the DNA binding factors controlling these fundamental changes. Here we have examined NF-kappa B/Rel subunit expression and DNA-binding activity in developing thymocytes before and after the induction of positive selection. We show that positive selection is accompanied by the strong up-regulation of c-rel mRNA expression and the constitutive activation of p50/p65 and p50/c-Rel NF-kappa B/Rel complexes, confirming the activation-like status of cells undergoing positive selection. Moreover, CD69+ cells that have initiated positive selection (but not their preselection CD4+8+TCR- precursors) respond to stimulation by the preferential activation of c-Rel-containing DNA-binding complexes. Because the different NF-kappa B/Rel dimers have distinct transcriptional activities and binding site preferences, this preferential activation of c-Rel-containing DNA-binding complexes may well have implications for the changes in gene expression and functional response associated with positive selection.

Amino Acid Sequence↗
PubMed1995

A retrospective analysis of the long-term effect of splenectomy on late infections, graft-versus-host disease, relapse, and survival after allogeneic marrow transplantation for chronic myelogenous leukemia.

The present study was performed as a retrospective analysis of the role of pretransplant splenectomy to determine the incidence of late bacterial infections, acute and chronic graft-versus-host disease (GVHD), relapse, and survival among 358 patients receiving HLA-identical marrow grafts for chronic myelogenous leukemia. Sixty-eight (19%) of the 358 patients had undergone splenectomy before transplantation. There was a trend towards more grade II-IV acute GVHD among splenectomized patients, but this was not significant in the multivariate analysis. The incidence of chronic GVHD was similar for splenectomized and nonsplenectomized patients. Late infectious complications did not significantly differ between splenectomized and control patients (rates per patient year were 0.16 and 0.14, respectively). The overall risk of leukemic relapse was significantly increased for splenectomized patients (56% v 32% for controls, P = .001) and control patients with splenomegaly (P < .0001). Splenectomy and splenomegaly remained significant and independent hazards for relapse in the multivariate analysis (hazard ratio [HR], 1.82, P = .029; and HR, 1.49, P = .002; respectively). Relapse was also increased in patients with advanced disease (HR, 2.95; P = .0001), in patients with T-cell-depleted marrow (HR, 4.51; P = .0001), and in the female donor and male recipient combination (HR, 1.74; P = .044). Patients with splenectomy had an increased overall mortality (HR, 1.18), but this was not statistically significant in the multivariate analysis. In summary, our study showed no significant influence of splenectomy on late posttransplant infections, acute or chronic GVHD, or overall survival. There was no evidence that splenectomy decreased recurrence of chronic myelogenous leukemia.

Abscess↗
PubMed1995

Intracellular signaling events during positive and negative selection of CD4+CD8+ thymocytes in vitro.

We have used in vitro models of thymocyte positive and negative selection in conjunction with selective inhibitors of the TCR-mediated signaling cascade to investigate the intracellular signaling events that mediate these processes. We report that Ro 31.8425, a potent and selective inhibitor of protein kinase C, which blocks the activation of mature T cells in a dose-dependent fashion, has no effect on either positive or negative selection of CD4+8+ thymocytes. In contrast, cyclosporin A fails to prevent negative selection, but inhibits positive selection through a direct effect on developing thymocytes, rather than through the perturbation of stromal cell support. Thus, our data suggest that positive and negative selection may operate via distinct intracellular signaling pathways.

Animals↗
PubMed1995

Linkage between brain serotonin concentration and the sex-specific part of the Y-chromosome in mice.

The implication of the sex-specific part of the Y-chromosome (YS-SP) on brain serotonin (5-HT) level was investigated using congenic strains for this chromosomal region. The 5-HT level, which was higher in the NZB than in the CBA/H strain of mice, was depleted by the transfer of the YS-SP from NZB on CBA/H whereas the transfer of the YS-SP from CBA/H on NZB had no effect. The variations of 5-HT levels were not correlated with plasma testosterone concentration which is also dependent of the YS-SP.

Animals↗
PubMed1995

A peptide from the caudal neurosecretory system of the dogfish Scyliorhinus canicula that is structurally related to urotensin I.

Using reversed-phase HPLC in combination with a radioimmunoassay for ovine corticotropin-releasing hormone (CRH), a peptide with CRH-like immunoreactivity was isolated in pure form from an extract of the caudal spinal cord region of the spotted dogfish, Scyliorhinus canicula. The primary structure of the peptide was established as Pro-Ala-Glu-Thr-Pro-Asn-Ser-Leu10-Asp-Leu-Thr-Phe-His-Leu-Leu-Arg- Glu-Met-Ile- Glu20-Ile-Ala-Lys-His-Glu-Asn-Gln-Gln-Met-Gln30-Ala-Asp-Ser- Asn-Arg-Arg-Ile-Met - Asp-Thr40-Ile.NH2. This amino acid sequence shows moderate structural similarity to Catostomus urotensin I (51%) and to human CRH (56%). The data provide, therefore, chemical evidence to support the conclusions of earlier immunohistochemical studies that the diffuse caudal neurosecretory system of elasmobranchs produces a peptide that is immunochemically related to teleost urotensin I peptides. However, the primary structure of urotensin I has been poorly conserved during evolution.

Amino Acid Sequence↗
PubMed1995

Community organization to promote breast cancer screening among women ages 50-75.

BACKGROUND: To reduce breast cancer mortality, ways to promote the use of mammography screening among women age 50 and above are needed. Community organization may be a useful approach. METHODS: The Washington State Community Breast Cancer Screening Project involved implementation of promotional activities initiated by physician and lay community boards in two communities. Two comparable communities served as controls for evaluation purposes. Random-digit-dial telephone interviews were used to assess recent use of mammography at baseline and follow-up in independent samples of women ages 50 to 75 from the four communities. The extent of exposure to intervention activities and the relationship between exposure to intervention activities and mammography use were estimated from data collected at follow-up. RESULTS: Exposure to patient reminders from physicians, wallet reminder cards, and newspaper advertisements were consistently related to mammography use. Physician office staff encouragement and a display board were significantly related to mammography use only in Intervention Communities A and B, respectively. Neither exposure to promotional activities nor the change in prevalence of mammography use was significantly higher in the intervention communities than in the comparison communities at follow-up. CONCLUSIONS: Although several activities were useful in promoting mammography use, organization of the community did not enhance efforts undertaken spontaneously by comparable communities.

Aged↗
PubMed1995

A decrease from 8 to 6 weeks in obstetrics and gynecology clerkship: effect on medical students' cognitive knowledge.

We undertook this study to determine whether a decrease in the amount of time a third-year medical student spent in an obstetrics and gynecology clerkship would cause a decrease in the knowledge of the subject. We compared National Board of Medical Examiners (NBME) obstetrics and gynecology subject examination scores of 168 students at the University of Texas Medical Branch at Galveston completing an 8-week obstetrics and gynecology rotation or the 1989-1990 academic year to scores of 187 University of Texas Medical Branch students competing a 6-week rotation during 1990-1991. No significant change in the total mean NBME subject examination score in obstetrics and gynecology was noted after the decrease in rotation length. Passing scores were those greater than 445 points. The failure rate for those students who completed the 8-week rotation was consistent throughout the 1989-1990 academic year. In contrast, those students who rotated through obstetrics and gynecology during the 6-week clerkship in the first half of the academic year had a failure rate that was statistically higher than those taking the clerkship in the last half of the year. The length of the obstetrics and gynecology clerkship was shortened to 6 weeks without significantly affecting students' overall performance on the NBME obstetrics and gynecology subject examination. However, a greater percentage of students who completed the rotation during the first half of the year scored low on the NBME obstetrics and gynecology subject examination than did those taking the rotation and thus the NBME subject examination in the second half of the year.

Clinical Clerkship↗
PubMed1995

The role of the thymus during T-lymphocyte development in vitro.

To date, fetal thymic organ culture is the only in-vitro system capable of supporting a complete programme of T-lymphocyte development in a manner comparable to that seen in vivo. In this review, we will summarise recent studies in which thymic organ cultures have been used to investigate the regulatory mechanisms of particular stages of thymocyte development. In addition, the use of other culture systems of T-cell maturation will be discussed in an attempt to define the optimal conditions for T-cell development in vitro.

Animals↗
PubMed1995

Evaluation of a hospital-based utilization management program.

The objective of this study was to evaluate the impact of a utilization management (UM) program designed to decrease inappropriate use of acute care hospital beds while maintaining quality of care. The measure used to define appropriateness was the ISD-A, a diagnosis-independent measurement tool which relies on severity of illness and intensity of service criteria. The outcome measures for the study included appropriate admission to hospital and continued days of stay in hospital, 30-day readmission rates and physician perceptions of the impact of the intervention on quality of care, access to services and patient discharge patterns. The sample frame for the study included two control and two intervention community hospitals, involving 1,800 patient charts. Readmission rates were determined by analyzing all separations from medical services (N = 42,014) in the two experimental and two control hospitals. All physicians with admitting privileges (N = 312) at the intervention hospitals were surveyed; obstetricians, pediatricians, and psychiatrists were excluded from the survey. The results of the study demonstrated that the proportion of inappropriate admissions did not decrease significantly in any of the hospitals, but there were significant decreases in inappropriate continued stay in the intervention hospitals (p < 0.05). Both intervention and one of the control hospitals had lower 30-day readmission rates in the "after" period than in the "before" period (p < 0.05). Eighty-six percent believed that there had been no adverse impact on access to care and, although 25% thought the program may have led to premature discharge, this was not supported by the readmission data.

British Columbia↗
PubMed1995

Exfoliative cytology and electron microscopy in the diagnosis of hairy leukoplakia.

The diagnosis of lesions clinically suggestive of hairy leukoplakia was assessed by light and electron microscopic examination of cytologic smears. We found exfoliative cytology to be a simple and noninvasive technique that can confirm the clinical diagnosis of hairy leukoplakia. Our results suggest that electron microscopy may be more sensitive and reliable than light microscopy in confirming the clinical diagnosis of hairy leukoplakia.

AIDS-Related Opportunistic Infections↗
PubMed1995

Arteriole constriction following ischemia in denervated skeletal muscle.

Arteriolar diameters and flow patterns were determined in the isolated rat cremaster muscle following 4 hr of total ischemia. Two groups of six rats each were studied--an innervated group and a denervated group. The microcirculation was observed using intravital microscopy, and the images were recorded on videotape. The whole arterial tree was scanned, and the smallest vessel diameter for each arterial segment was measured. Preischemic mean arteriole diameters were significantly larger in the denervated group, compared to the innervated group. Following ischemia, during the 3 hr of reperfusion, the main (AI) cremaster arteriole from both the innervated and denervated groups constricted to 50 to 70 percent of pre-ischemic diameters. However, the actual diameters (as distinct from percentage change) were not significantly different between the innervated and denervated groups. There were significant differences in flow patterns. Some A2 and A3 vessels became temporarily nonflowing vessels (either open but without low, or closed by severe spasm). These poorly-functioning vessels were significantly more common in the denervated group. Furthermore, this phenomenon of temporary no-flow persisted longer in the denervated group over the 3-hr reperfusion period. These observations suggest that the ability to recover quickly from an ischemic insult is less in tissues that have been denervated.

Animals↗
PubMed1995

A randomized clinical trial of intraoral soft splints and palliative treatment for masticatory muscle pain.

Thirty subjects seeking treatment for masticatory muscle pain at a university-based TMJ clinic were randomly assigned to soft-splint, palliative-treatment, and no-treatment groups. After 4 to 11 weeks of treatment, subjects were evaluated for changes from their baseline levels of symptoms, maximum pain-free opening, pain thresholds measured by a pressure algometer, and occlusal contacts. With the use of the multivariate analysis of variance and analysis of covariance, the results suggest that the soft-splint group had statistically significant improvement (P < .01), the palliative-treatment group had improvement that was not statistically significant, and the no-treatment group had a slight aggravation of symptoms. The soft-splint group had fewer occlusal contact changes assessed with shimstock compared to the palliative-treatment and no-treatment groups. The findings of this study suggest that the soft splint is an effective short-term treatment for reducing the signs and symptoms of masticatory muscle pain in patients, and the soft splint does not cause occlusal changes.

Adolescent↗