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Biomedical subjects

G Gibson

Publications and source records attributed to G Gibson.

At least 109 records · Page 6Linked to original sources

The determinants of hypertension awareness, treatment, and control in an insured population.

OBJECTIVES: The purpose of the study was to identify the determinants of awareness, treatment, and control of hypertension in a population with full access to medical care. METHODS: Unionized New York City health care workers (n = 1394) with comprehensive medical insurance were screened for hypertension. Union records documenting all physician visits and prescription medications for the year before screening provided the opportunity to relate patterns of treatment to blood pressure outcomes. RESULTS: Of the 409 employees found to have hypertension, 289 (71%) were aware of their condition and 201 (49%) had been treated, but only 51 (12%) had their blood pressure controlled at the recommended level (< 140/90 mm Hg). In a logistic regression model, the only variable of treatment associated with control was days of antihypertensive medication. The total number of physician visits was not associated with control. CONCLUSIONS: These findings demonstrate that in conventional community settings, even in the absence of financial barriers, treatment for hypertension continues to be characterized by poor outcomes. Improving access to primary care, without changes in the nature of that care, may not substantially improve blood pressure control.

Aged↗

HIV disease. Psychosocial issues for patients and doctors.

How a patient responds to a diagnosis of HIV disease depends on personality and coping skills learned throughout life. Health care professionals are seriously challenged to meet the psychosocial needs of HIV patients and their networks of partners, families, and friends. We find great satisfaction in being able to help these patients.

Acquired Immunodeficiency Syndrome↗

Gay patients. Context for care.

Gays and lesbians are a part of our society and our practices: real people with real lives, not stereotypes. Understanding their inner world and their social milieu is the first step to providing care that is holistic and appropriate. The "coming out" process and other unique health issues are described. Guidance is provided on how to identify and relate to gay and lesbian patients.

Adaptation, Psychological↗

Effect of lithium on incorporation of bromodeoxyuridine and tritiated thymidine into human parathyroid cells.

OBJECTIVE: To measure lithium chloride-stimulated incorporation of tritiated thymidine (3H-TdR) and bromodeoxyuridine (BrdU) by human parathyroid cells as an indicator of lithium's growth-promoting properties. DESIGN: Cell suspensions derived from abnormal human parathyroid tissue were incubated for 5 days with graded concentrations of lithium and pulsed with either 0.074 MBq of 3H-TdR or 0.6 microgram of BrdU. The 3H-TdR incorporation was measured by counting cell filtrates in a beta counter, and nuclear BrdU incorporation was determined by counting nuclei positively stained by an antibody to BrdU. Counts of BrdU-positive cells by two observers unaware of incubation conditions were correlated with 3H-TdR counts. RESULTS: Cell suspensions derived from adenomatous and hyperplastic parathyroid glands demonstrated a dose-related increase in 3H-TdR incorporation. There was close correlation between the two observers' counts of BrdU-positive cells (r = 0.70, P = .01) and between each observer's counts and 3H-TdR counts (r = 0.70, P = .02, and r = 0.90, P = .01, respectively). CONCLUSIONS: Lithium stimulates in vitro incorporation of 3H-TdR and BrdU by abnormal human parathyroid cells, consistent with a growth-promoting effect.

Adenoma↗

Access to plastics: assessing the need for plastic surgery services.

OBJECTIVE: To investigate the apparently poor access of one district's residents to plastic surgery services. DESIGN: Retrospective study of age-standardised operation rates for the year 1991-92. Operation rates were taken as a proxy measure for access. SETTING: Sunderland District Health Authority, and Durham District Health Authority. MAIN OUTCOME MEASURES: Operation rates for surgical specialties in the two districts. RESULT: There were considerable differences in the operation rates for plastic surgery between districts in the Region. Detailed analysis of two districts revealed a significant difference between the two (Sunderland 2.25/1,000; Durham 4.24/1,000, P < 0.001). Sixteen diagnoses were identified as contributing to this difference. However, when these diagnoses were examined across all surgical specialties, the difference in operation rates virtually disappeared (Sunderland 6/1,000; Durham 6.16/1,000). CONCLUSION: Sunderland residents were far more likely to have 'plastic' cases treated by other than plastic surgery specialists, which reflects the balance and expertise of specialties in the district. The need for plastic surgery services will be affected by the local interest and expertise. Operation rates should not be used on their own to indicate inequity in access.

Female↗

Enhancement of peroxisomal enzymes, cytochrome P-452 and DNA synthesis in putative preneoplastic foci of rat liver treated with the peroxisome proliferator nafenopin.

The peroxisome proliferator (PP) nafenopin (NAF) enhanced tumor development in rat liver through promotion of a subtype of putative preneoplastic cell foci, characterized by weak cytoplasmic basophilia. In order to elucidate the selective growth advantage of these weakly basophilic foci (WBF) we investigated the effects of NAF on their metabolic phenotype and DNA synthesis. In WBF, as well as in other foci subpopulations and in hepatocellular carcinomas the occurrence of five NAF-inducible enzymes, i.e. of peroxisomal beta-oxidation (acyl-CoA oxidase, bifunctional protein and thiolase), catalase and cytochrome P-452 was studied by immunohistochemical methods. In untreated livers almost all foci were stained with the same intensity as the surrounding tissue. When NAF was applied, most of the liver foci showed considerably less staining than the non-focal parenchyma in which pronounced enzyme induction had occurred. However, the subpopulation of WBF showed a more heterogeneous pattern of enzyme expression varying from less to even more than in the adjacent tissue. A similarly broad range of expression of peroxisomal enzymes was found in hepatocellular carcinomas. On average, however, the tumors exhibited less staining and lower activity of peroxisomal beta-oxidation than the surrounding parenchyma. WBF always showed higher rates of DNA synthesis than other foci subtypes and unaltered liver. In approximately one-third of these foci DNA synthesis was found to be enhanced concomitantly with elevated expression of peroxisomal beta-oxidation enzymes. In conclusion, WBF may have a selective growth advantage as they 'overrespond' to the inducing effects of NAF on DNA synthesis and peroxisomal enzymes.

3-Hydroxyacyl CoA Dehydrogenases↗

A new odour-baited trap to collect host-seeking mosquitoes.

A new odour-baited entry trap which releases an air stream containing chemical cues collected from a bait, has been used successfully to collect West African mosquito species, most of them important vectors of malaria, such as Anopheles gambiae s.l. and An. funestus. 85% of the yield consisted of live, unfed and partially fed specimens. The trap has some practical and theoretical advantages over similar sampling techniques.

Animals↗

Aging and oral health: implications for women.

Of the 30 million Americans over age 65, 18.3 million are women and it is estimated that between 1989 and 2030, women will make up an increasingly large segment of this group. As one ages, the risk of chronic disease increases. These diseases and their treatment can have a significant impact on oral health. This article will discuss relevant issues in providing oral health care for older women. The demographics of aging in women, chronic diseases commonly seen in older women, and the impact of these diseases on oral health treatment planning will also be discussed. The article will highlight the importance of prevention of oral diseases throughout a woman's lifetime.

Aged↗

Cytosolic free calcium and gene expression during chemical hypoxia.

Understanding the cellular response to hypoxia may help elucidate the role of altered oxidation in neuronal death or abnormal cell function. In PC12 cells, 30 min of chemical hypoxia (i.e., KCN) reduced ATP concentrations by 92%, but diminished viability by only 10%. Ten minutes of hypoxia increased cytosolic free calcium ([Ca2+]i) 2.5-fold above control, but after 30 min of hypoxia, [Ca2+]i was slightly below that of nonhypoxic cells. Short periods of hypoxia also exaggerated the K(+)-induced elevation of [Ca2+]i, but by 30 min these ATP-depleted cells reestablished a calcium gradient that was equal to nonhypoxic, K(+)-depolarized cells. Thus, 30 min of severe ATP depletion left [Ca2+]i and viability relatively unaffected. Nerve growth factor caused slight, but significant, improvements in ATP and viability of hypoxic cells, but had no effect on [Ca2+]i. Although [Ca2+]i was equivalent in control and hypoxic cells after 30 or 60 min, hypoxia abolished the K(+)-stimulated elevation of [Ca2+]i. The nerve growth factor induction of c-fos, an indicator of the genomic response, was diminished by approximately 80%. Thus, hypoxic PC12 cells with greatly reduced ATP stores maintained normal [Ca2+]i, but their ability to respond to external stimulation was impaired. Further, the reduced oxidation that occurs in the brain in a variety of pathological conditions may interfere with the cellular response to stimulation and growth factors.

Adenosine Triphosphate↗

Mucopolysaccharidosis VI (Maroteaux-Lamy syndrome). An intermediate clinical phenotype caused by substitution of valine for glycine at position 137 of arylsulfatase B.

The Maroteaux-Lamy syndrome (mucopolysaccharidosis type VI) is a lysosomal storage disease with autosomal recessive inheritance caused by deficiency of the enzyme arylsulfatase B. Severe, intermediate, and mild forms of the disease have been described. The molecular correlate of the clinical heterogeneity is not known at present. To identify the molecular defect in a patient with the intermediate form of the disease, arylsulfatase B mRNA from his fibroblasts was reverse-transcribed, amplified by the polymerase chain reaction, and subcloned. Three point mutations were detected by DNA sequence analysis, two of which, a silent A to G transition at nucleotide 1191 and a G to A transition at nucleotide 1126 resulting in a methionine for valine 376 substitution, were polymorphisms. A G to T transversion at nucleotide 410 causing a valine for glycine 137 substitution (G137V) was identified as the mutation underlying the Maroteaux-Lamy phenotype of the patient, who was homozygous for the allele. The kinetic parameters of the mutant arylsulfatase B enzyme toward a radiolabeled trisaccharide substrate were normal excluding an alteration of the active site. The G137V mutation did not affect the synthesis but severely reduced the stability of the arylsulfatase B precursor. While the wild type precursor is converted by limited proteolysis in late endosomes or lysosomes to a mature form, the majority of the mutant precursor was degraded presumably in a compartment proximal to the trans Golgi network and only a small amount escaped to the lysosomes accounting for the low residual enzyme activity in fibroblasts of a patient with the juvenile form of the disease.

Alleles↗

Cytosolic free calcium concentrations in synaptosomes during histotoxic hypoxia.

Altered cytosolic free calcium concentrations ([Ca2+]i) accompany impaired brain metabolism and may mediate subsequent effects on brain function and cell death. The current experiments examined whether hypoxia-induced elevations in [Ca2+]i are from external or internal sources. In the absence of external calcium, neither KCl depolarization, histotoxic hypoxia (KCN), nor the combination changed [Ca2+]i. However, with external CaCl2 concentrations as small as 13 microM, KCl depolarization increased [Ca2+]i instantaneously while hypoxia gradually raised [Ca2+]i. The combination of KCN and KCl was additive. Increasing external calcium concentrations up to 2.6 mM exaggerated the effects of K+ and KCN on [Ca2+]i, but raising medium calcium to 5.2 mM did not further augment the rise. Diminishing the sodium in the media, which alters the activity and perhaps the direction of the Na/Ca exchanger, reduced the increase in [Ca2+]i due to hypoxia, but enhanced the KCl response. The changes in ATP following K+ depolarization, KCN or their combination in the presence of physiological calcium concentrations did not parallel alterations in [Ca2+]i, which suggests that diminished activity of the calcium dependent ATPase does not underlie the elevation in [Ca2+]i. Valinomycin, an ionophore which reduces the mitochondrial membrane potential, elevated [Ca2+]i and the effects were additive with K+ depolarization in a calcium dependent manner that paralleled the effects of hypoxia. Together these results suggest that hypoxia-induced elevations of synaptosomal [Ca2+]i are due to an inability of the synaptosome to buffer entering calcium.

Animals↗