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Biomedical subjects

R Cooper

Publications and source records attributed to R Cooper.

At least 73 records · Page 4Linked to original sources
PubMed1999

The distribution and mortality impact of chronic energy deficiency among adult Nigerian men and women.

OBJECTIVE: To determine the prevalence of chronic energy deficiency (CED) and associated mortality risk in a cohort of adult Nigerians followed from 1992 to 1997. RESEARCH METHODS AND PROCEDURES: The data for this investigation were derived from an international collaborative study on chronic diseases in populations of the African diaspora. Body mass index (BMI) was used to define three grades of CED in 4061 men and women aged 25 years and older: Grade I (mild CED) as BMI 17.5-18.4, Grade II (moderate CED) as BMI 16.0-17.4, and Grade III (severe CED) as BMI < 16.0 and BMI > or = 18.5 was considered normal. The odds of mortality associated with differing grades of CED was estimated with logistic regression analysis. RESULTS: The prevalence of CED (BMI < 18.5) increased from 14.3% in 1992 to 19.6% in 1997, both genders combined. The prevalence of CED was similar for both sexes in 1992 (14%) but increased to 22.4% in men and 17.4% in women by 1997. The prevalence of CED was 8.5%, 7.6 and 3.4 for Grades I, II and III, respectively. Two hundred and seven deaths occurred during the follow-up period. The mortality rate for the 5.5 y of follow-up was 5.1% (207/4061). The odds ratios (95% CIs) for all cause mortality were 1.4 (0.5, 3.8), 2.4 (1.2, 4.9) and 2.5 (1.0, 6.2), respectively, for CED grades I, II and III adjusting for age and sex. CONCLUSION: Under nutrition is an increasing problem in Nigerian men and women. The economic reforms (structural adjustment program (SAP)) introduced in 1986 in combination with the continued economic woes brought on by political instability, corruption and nepotism have been advanced by several investigators as the main factors in the growing problem of inadequate calorie intake. Intervention strategies both at the government and private sectors are urgently needed to increase food availability.

Adult↗
PubMed1999

Evidence of a major gene effect for angiotensinogen among Nigerians.

To dissect the genetic pathway of hypertension, we measured angiotensinogen in 685 members of 186 families recruited from a rural community in southwest Nigeria. Commingling and segregation analyses were carried out. A mixture of two and/or three distributions fits the data significantly better than a single distribution in commingling analysis, suggesting a major gene effect. Segregation analysis confirmed that a recessive major gene model for low values of angiotensinogen provides the best fit to the data and about 13% of the variance was due to the recessive gene segregation.

Adolescent↗
PubMed1999

The role of genetic and environmental factors in cardiovascular disease in African Americans.

Considerable interest has been focused over the years on estimating the relative importance of genetic and environmental factors on differences in rates of cardiovascular disease in blacks and whites. However, recent advances in molecular science have helped to illuminate the underlying complexity of this problem. Attempts to impute the genetic component from "what was left over" after control for a limited set of environmental exposures is increasingly recognized as naive. The requirements for a model that could account for interactions between genetic and environmental factors far exceeds the precision of our measurements. Although it is obvious that blacks experience not only unique environmental exposures, such as white racism, but more intense exposure to common factors, such as obesity, current methods make it very difficult to summarize these effects. Simpler models, using data from large samples, could provide greater precision and might illuminate the exposure-outcome relationships common to all groups. Meanwhile, efforts to identify genetic underpinnings of complex disorders will have to reach a much higher level of development before useful conclusions can be reached about the magnitude and variation of effects between racial and ethnic groups.

Black or African American↗
PubMed1999

Idiopathic giant-cell granulomatous hypophysitis mimicking acute meningitis.

A 32-year-old woman presented with severe headache, photophobia, fever, nausea, vomiting, and worsening vision. She had also noted several months of amenorrhea. She was febrile to 38.9 degrees C. Laboratory evaluation revealed a markedly elevated erythrocyte sedimentation rate. Lumbar puncture revealed a cerebrospinal fluid lymphocytic pleocytosis and an elevated protein level. Endocrine studies revealed evidence of panhypopituitarism without diabetes insipidus. A magnetic resonance imaging study showed a 2-cm pituitary mass with optic chiasmal compression. The patient had a trans-sphenoidal resection of the mass. Pathology revealed multinucleated giant cells in necrotic debris, but no evidence of pituitary tumor. Studies looking for evidence of systemic granulomatous disease were negative. The patient was considered to have idiopathic giant-cell granulomatous hypophysitis. After surgery, the patient's vision improved and hormone replacement therapy was initiated. This case illustrates that idiopathic giant-cell granulomatous hypophysitis should be considered in the differential diagnosis of a patient presenting with a pituitary mass, hypopituitarism, and meningitis-like symptoms.

Acute Disease↗
PubMed1999

Radiosensitization with carboplatin for patients with unresectable stage III non-small-cell lung cancer: a phase III trial of the Cancer and Leukemia Group B and the Eastern Cooperative Oncology Group.

PURPOSE: To determine whether the administration of carboplatin concurrently with radiation treatment improves survival in patients with inoperable stage III non-small-cell lung cancer. PATIENTS AND METHODS: Two hundred eighty-three patients with inoperable stage III non-small-cell lung cancer were entered onto a randomized trial by the Cancer and Leukemia Group B and the Eastern Cooperative Oncology Group. Randomization was performed before initiation of any therapy. All patients received an induction chemotherapy program with vinblastine and cisplatin for 5 weeks, followed by 6,000 cGy of radiation therapy over 6 weeks. One hundred thirty-seven patients were randomized to this therapy regimen alone; 146 patients were randomized to receive carboplatin at 100 mg/m2/wk concurrent with the radiation therapy. RESULTS: The complete response was 18% with concurrent carboplatin versus 10% with radiotherapy alone (P = .101). There was no difference with respect to failure-free survival (10% with carboplatin and 9% with radiotherapy alone) or overall survival (13% with carboplatin and 10% with radiotherapy alone) at 4 years. In patients not receiving carboplatin, the relapse rate was 69% within the field of radiation and 53% in the boost volume. In patients receiving carboplatin, the relapse rate was 59% within the field of radiation and 43% in the boost volume. Patients with cancers more than 70 cm2 in size had significantly poorer survival (P = .01). CONCLUSION: Carboplatin at the dose and schedule used did not significantly impact on disease control or survival. The relapse rate within the chest remained more than 50%. More effective regimens will be required to impact on local disease control and survival.

Adult↗
PubMed1999

The use of honey as an antiseptic in managing Pseudomonas infection.

A laboratory study was undertaken to extend existing knowledge about the effectiveness of the antibacterial properties of honey against pseudomonads. To date, sensitivity testing has used non-standardised honeys, which may vary greatly in their antibacterial potency. Pure cultures of Pseudomonas spp, isolated from swabs from 20 infected wounds, were inoculated on the surface of nutrient agar plates containing various concentrations of honey in the medium. Two types of honey were used, a manuka honey and a pasture honey, each selected to have antibacterial activity close to the median for each type. The minimum inhibitory concentration of the manuka honey for the 20 isolates ranged from 5.5-8.7% (v/v) (mean 6.9% (v/v), standard deviation 1.3). The minimum inhibitory concentration of the pasture honey for the 20 isolates ranged from 5.8-9.0% (v/v) (mean 7.1% (v/v), standard deviation 1.0). Honeys with an average level of antibacterial activity could be expected to be effective in preventing the growth of pseudomonads on the surface of a wound even if the honey were diluted more than ten-fold by exudation from the wound.

Anti-Infective Agents, Local↗
PubMed1999

Reduction in human immunodeficiency virus patient hospitalizations and nontraumatic mortality after adoption of highly active antiretroviral therapy.

Highly active antiretroviral therapy (HAART) has been recommended for human immunodeficiency virus (HIV)-positive patients with a detectable viral load; it typically consists of two reverse transcriptase inhibitors combined with a protease inhibitor. In 1996, Madigan Army Medical Center began offering HAART to HIV-positive patients with a detectable viral load. We retrospectively reviewed the records of our HIV patients before and after the initiation of HAART to determine the impact of HAART on hospitalizations, mortality, and outpatient pharmacy expenditures. Comparing 1997 with 1994 and 1995, we found a greater than 700% increase in the average expenditure on antiretroviral agents after institution of HAART. At the same time, we found a dramatic reduction in hospitalizations and nontraumatic mortality. Therefore, the increase in expenditures on antiretroviral agents may be offset by a reduction in hospitalizations and mortality.

Adult↗
PubMed1998

Isolation of a nitrogen response regulator gene (nrr1) from Metarhizium anisopliae.

Attempts to improve the effectiveness of entomopathogenic fungi as biological control agents require a clear understanding of the pathogenicity determinants at both the biochemical and molecular level. Proteases play a key role in entomopathogenicity, allowing the fungus to penetrate the insect cuticle and rapidly invade the host. The most extensively studied of these protease activities, PR1A and PR2, are both subject to nitrogen derepression. The Metarhizium anisopliae nrr1 (nitrogen response regulator 1) gene was identified using a PCR-based strategy; it encodes a putative DNA-binding protein with a single zinc finger motif defined by the C-X2-C-X17-C-X2-C sequence. M. anisopliae NRR1 shows a significant sequence similarity to Neurospora crassa NIT2. Sequence analysis identified the presence of two introns, suggesting a greater degree of similarity to N. crassa nit2 than to the areA-like genes that have been identified. However, functional equivalence of nrr1 to areA was demonstrated, by co-transformation and complementation of an A. nidulans areA loss-of-function mutant (areA18 argB2 pabaA1 inoB2) with the M. anisopliae nrr1 gene. The areA-/nrr1+ Aspergillus transformants were able to grow on media with nitrate and glutamate as the sole nitrogen source, whereas the areA- strain is unable to grow under these conditions. The possible relevance of nitrogen regulation to pathogenicity is discussed.

Amino Acid Sequence↗
PubMed1998

Antihyperglycemic activities of cryptolepine analogues: an ethnobotanical lead structure isolated from Cryptolepis sanguinolenta.

Cryptolepine (1) is a rare example of a natural product whose synthesis was reported prior to its isolation from nature. In the previous paper we reported the discovery of cryptolepine's antihyperglycemic properties. As part of a medicinal chemistry program designed to optimize natural product lead structures originating from our ethnobotanical and ethnomedical field research, a series of substituted and heterosubstituted cryptolepine analogues was synthesized. Antihyperglycemic activity was measured in vitro and in an NIDDM mouse model to generate the first structure-bioactivity study about the cryptolepine nucleus.

3T3 Cells↗
PubMed1998

The impact of obesity and body fat distribution on ambulatory blood pressure in children and adolescents.

To assess the relationship between obesity, body fat distribution, and blood pressure in children and adolescents, various measures of obesity and the waist-to-hip circumference ratio were related to casual and ambulatory blood pressure as measured using a SpaceLabs 90207 monitor during a regular school day. Seventy obese and 70 nonobese children aged 6 to 16 years were included in the study. Regardless of the time period analyzed (24 h, daytime, or nighttime), ambulatory blood pressure and casual blood pressure were significantly higher among the obese children. The differences in systolic blood pressure observed between the groups were attributable to the presence of obesity as estimated by the ponderal index and by skinfold thickness. Similarly, systolic and diastolic loads, as an assessment of high blood pressure values over 24 h, were significantly higher in the obese children when compared to the loads for the nonobese children. Waist-to-hip circumference ratio was independently associated, (in multiple regression analysis) with systolic blood pressure, whether during 24 h, daytime, or nighttime periods, after controlling for age, sex, current height, ponderal index, and tricipital skinfold thickness. This study demonstrates that obesity is a determinant of ambulatory and casual blood pressure. Since obese children with a predominantly abdominal fat mass show higher blood pressure values, evaluation of body fat distribution in children may help to identify subjects more susceptible to developing hypertension later in life.

Adipose Tissue↗
PubMed1998

New iridoids from the medicinal plant Barleria prionitis with potent activity against respiratory syncytial virus.

Two new iridoid glycosides (1 and 2), together with the known compounds barlerin (3) and verbascoside (4), were isolated from Barleria prionitis. The new iridoid glycosides were determined to be 6-O-trans-p-coumaroyl-8-O-acetylshanzhiside methyl ester (1) and its cis isomer (2) by using spectroscopic, especially 2D NMR, data. A 3:1 mixture of 1 and 2 was shown to have potent in vitro activity against respiratory syncytial virus (EC50 2.46 microgram/mL, IC50 42.2 microgram/mL).

Antiviral Agents↗
PubMed1998

Isolation and unambiguous synthesis of cryptolepinone: An oxidation artifact of cryptolepine

Cryptolepinone (3) was isolated as an artifact of extraction from Cryptolepis sanguinolenta. Previously, this compound had been identified as the natural products hydroxycryptolepine (2) and 3. Synthesis via an unambiguous pathway has confirmed the structure of cryptolepinone. Spectroscopic studies in various solvents have shown that the natural product artifact or its synthetic equivalent can exist in the keto (cryptolepinone) or enol (hydroxycryptolepine) form.

Journal Article↗