PubMed Health⌕ Search

Biomedical subjects

H S Bell

Publications and source records attributed to H S Bell.

15 recordsLinked to original sources
PubMed2000

Controlling blood glucose levels in patients with type 2 diabetes mellitus. An evidence-based policy statement by the American Academy of Family Physicians and American Diabetes Association.

OBJECTIVE: To review evidence about the benefit of intensive glycemic control for patients with type 2 diabetes and to develop practice recommendations. PARTICIPANTS: A 9-member panel composed of family physicians, general internists, endocrinologists, and a practice guidelines methodologist was assembled by the American Academy of Family Physicians, the American Diabetes Association, and the American College of Physicians. EVIDENCE: Admissible evidence included published randomized controlled trials and observational studies regarding the effects of glycemic control on microvascular and macrovascular complications and on adverse effects. We followed systematic search and data abstraction procedures. Greater weight was given to clinical trials and to evidence about health outcomes. CONSENSUS PROCESS: Interpretations of evidence and approval of documents were finalized by unanimous vote, with recommendations linked to evidence and not expert opinion. The full report was prepared by the chair and 2 panel members, representing each of the 3 organizations. The initial draft underwent external review by 14 diabetologists and family physicians and changes consistent with the evidence were incorporated. CONCLUSIONS: The evidence demonstrates that the risk of microvascular and neuropathic complications is reduced by lowering glucose concentrations. Whether glycemic control affects macrovascular outcomes is less clear. The potential benefits of glycemic control must be balanced against factors that either preempt benefits (eg, limited life expectancy, comorbid disease) or increase risk (eg, severe hypoglycemia). The magnitude of benefit is a function of individual clinical variables (eg, baseline glycated hemoglobin level, presence of preexisting microvascular disease). Appropriate targets for treatment should be determined by considering these factors, patients' risk profiles, and personal preferences.

Aged↗
PubMed1999

Effects of N-6 essential fatty acids on glioma invasion and growth: experimental studies with glioma spheroids in collagen gels.

OBJECT: Intracranial infusions of gamma-linolenic acid (GLA), an essential fatty acid, have been used as an adjuvant therapy following malignant glioma resection; however, little is known about the dose response of glioma cells to this therapy. In this in vitro study the authors address this important pharmacological question. METHODS: Glioma spheroids derived from U87, U373, MOG-G-CCM, and C6 cell lines were grown in collagen gel and exposed to a range of GLA concentrations (0-1 mM) for 5 days. The diameter of glioma spheroids was measured, the apoptotic index was assessed using both the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling technique and cell morphological testing, and the levels of proliferating cell nuclear antigen were also measured. CONCLUSIONS: The dose-response patterns were similar for all four glioma spheroids. Low concentrations of GLA (<100 microM) increased both apoptosis and proliferation with a net increase in tumor growth and invasion, whereas high-dose GLA (>100 microM) significantly impaired spheroid cell growth. The proliferative effects of low-dose GLA could be a hazard in the clinical treatment of malignant glioma; however, because of the low toxicity of GLA against normal cells, local delivery of millimolar doses of GLA could significantly reduce tumor size.

Animals↗
PubMed1998

Minor head injury in children: current management practices of pediatricians, emergency physicians, and family physicians.

OBJECTIVE: To describe variation in the clinical management of minor head trauma in children among primary care and emergency physicians. DESIGN: A survey of pediatricians, family physicians, and emergency physicians drawn from a random sample of members of the American Academy of Pediatrics, the American Academy of Family Physicians, and the appropriate American Medical Association specialty listings, respectively. Physicians were given clinical vignettes describing children presenting with normal physical examination results after minor head trauma. Different clinical scenarios (brief loss of consciousness or seizures) were also presented. Information was gathered on initial and subsequent management steps most commonly used by the physician. RESULTS: Surveys were returned by 765 (51%) of 1500 physicians. Of these, 303 (40%) were pediatricians, 269 (35%) family practitioners, and 193 (25%) emergency physicians. For minor head trauma without complications, observation at home was the most common initial physician management choice (n = 547, 72%). Observation in office or hospital was chosen by 81 physicians (11%). Head computed tomographic (CT) scan was chosen by 7 physicians (1%) and skull x-ray by 24 physicians (3%) as the first management option. Most physicians (n = 445, 80%) who initially chose observation at home would obtain a CT scan if the patient showed clinical deterioration. In the original scenario, if the patient had also sustained a loss of consciousness, 383 physicians (58%) altered management. Of these, 120 (18%) chose CT, 13 (2%) chose skull x-ray, 1 (1%) chose magnetic resonance imaging, 141 (21%) chose inpatient observation, and 125 (19%) chose a combination of CT scanning and observation. With seizures, 595 (90%) altered management, with 176 physicians (27%) choosing CT scan, 5 (1%) skull x-ray, 60 (9%) inpatient observation, and 299 (45%) a combination of radiological evaluation and observation. CONCLUSIONS: Most physicians surveyed chose clinic or home observation for initial management of minor pediatric head trauma. Clinical management was more varied when patients had sustained either loss of consciousness or seizures. Further study of the appropriate management of minor head trauma in children is needed to guide physicians in their care.

Adolescent↗
PubMed1997

Glioma cells transduced with selection transgenes may not form gliomas in vivo and can also inhibit glioma formation by admixed wild glioma cell lines.

Following in vitro lipofection transfection of the rat glioma cell line A15A5 with the plasmid transgene CMV/HyTK, which confirms hygromycin resistance and ganciclovir sensitivity, a series of experiments was planned in which the "bystander" phenomenon would be evaluated using the rodent implantation glioma model. However examination of the brain of rodents in which the A15A5HyTK cells were implanted showed no evidence of glioma growth. Furthermore, rodents having intracerebral implantation of (i) wild A15A5 and A15A5HyTK cells in a 50/50 mix, (ii) wild A15A5 and A15A5HyTK cells in a 90/10 mixture and (iii) wild C6 and A15A5HyTK cells in a 50/50 mix all failed to grow macroscopic tumours by 15-17 days irrespective of whether the animals had been administered ganciclovir (GCV) in the week before sacrifice. Neuropathological and immunocytochemical analysis of the implantation sites showed no difference between the GCV and saline treated groups of animals for any implantation cell mix. These observations confirm previous results that suggest transduction of malignant rodent glioma cell lines with a variety of selection, oncogenic and marker genes significantly impairs their in vivo tumorigenic potential compared to the wild type cell lines. This study also demonstrates that even without GCV treatment the transduced cells inhibit, by an unknown mechanism(s), the tumorigenicity of other non transfected malignant cells. The implications of this study for gene therapy of human malignant glioma are discussed.

Animals↗
PubMed1977

Terminal ventriculostomy for syringomyelia.

The clinical course of 12 patients who underwent terminal ventriculostomy for syringomyelia is presented. Opening the central canal at the tip of the conus medullaris is a relatively benign procedure that improves the symptoms of syringomyelia and syringobulbia. This canal normally terminates at the tip of the conus, but in each of the 12 surgical specimens it continued into the filum terminale for distances up to 8 cm. In most cases the tip of the conus was located more caudally than normal, indicating some degree of tethering in fetal life. This belief is supported by the fact that the newborn, whose conus is tethered to a lipoma at the sacral level, may develop syringomyelia in adult life.

Adult↗
PubMedDate not supplied

Trial of labor or repeated cesarean section. The woman's choice.

OBJECTIVE: To develop recommendations for the preferred delivery method for a pregnant woman who underwent a previous low transverse cesarean section and who has no contraindications to labor. DATA SOURCES: MEDLINE searches and the references from retrieved articles yielded 759 citations. Search terms included trial of labor (TOL), trial of scar, vaginal birth after cesarean section (VBAC), and uterine rupture. STUDY SELECTION: Articles with primary outcomes data contrasting TOL and elective repeat cesarean section (ERCS) were analyzed. Studies from developing countries or before 1980 were excluded. DATA EXTRACTION: Data from 292 articles were extracted independently by at least 2 team members using a structured form. DATA SYNTHESIS: Outcome data were combined using commercially available software and are presented as absolute differences per 10,000, with 95% Bayesian confidence intervals. Maternal outcomes showed that TOL increased the risk for uterine rupture (23.9 [0.24%]); ERCS increased the risk for infection (522 [5.22%]) and bleeding (58.6 [0.59%]). Infant outcomes differed only for 5-minute Apgar scores of less than 7, which were more likely for infants whose mothers underwent TOL (85 [0.85%]). Other outcomes (eg, disability), patient preferences, and cost data did not lend themselves to meta-analysis and were examined separately. While two thirds of women desired TOL, one third preferred ERCS. Costs were 1.7 to 2.4 times greater for ERCS. CONCLUSIONS: A woman should be given information on both delivery methods and encouraged to undergo TOL, but her preference for ERCS should be respected.

Decision Making↗
PubMedDate not supplied

Competency-based education in family practice.

BACKGROUND AND OBJECTIVES: Since their inception, family practice residency programs have been designed on a rotation-based format. It has been assumed that by having residents rotate through a series of educational experiences, they would assimilate the skills necessary to effectively serve as a family physician. An alternative approach is based on the attainment of competency, rather than on the completion of a set of experiences. This method of education is known as competency-based education, mastery learning, or, more recently, outcomes-based assessment. Within family medicine, there is a strong interest in the application of competency-based education to family practice residency training. In response to the growing need to discuss these and other related issues, the Society of Teachers of Family Medicine (STFM) Board created the Task Force on Competency-based Education. Its mission is to disseminate this educational theory to STFM's membership. This article reviews the theory of competency-based education, describes development of a competency-based curriculum model, and discusses the academic issues surrounding adaptation of this form of education to family practice residency programs.

Clinical Competence↗