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Biomedical subjects

C Gayle

Publications and source records attributed to C Gayle.

11 recordsLinked to original sources
PubMed2003

Circulating IGF-I levels in monitoring and predicting efficacy during long-term GH treatment of GH-deficient adults.

OBJECTIVE: To investigate the effects of long-term GH in GH-deficient adults, as predicted by IGF-I levels. METHODS: Patients received GH, 5 microg/kg per day for 1 Month and 10 microg/kg per day for another 12-30 Months. Changes in body composition, cardiac structure/function, serum lipids and quality of life were measured. RESULTS: There was a significant increase in lean body mass (LBM) (2.21 kg; P<0.0001) after 6 Months, which was sustained throughout treatment. A larger increase occurred in males than females (2.97 vs 1.19 kg; P<0.0001). Total fat mass was reduced (2.56 kg; P<0.0001 (3.26 kg males, 1.63 kg females)). Responsiveness to GH varied greatly, but LBM changes correlated with IGF-I changes (P<0.004). Furthermore, thinner patients experienced greater and progressive LBM increases. There was an increase in ejection fraction (3.85+/-9.95%; P=0.0002) after 6 Months, sustained to 18 Months. These cardiac effects were equal for males and females, and did not correlate with IGF-I levels. Serum low-density lipoprotein/high-density lipoprotein ratios decreased within 6 Months, and were sustained thereafter. Quality of life improved significantly after 6 Months, an effect that was sustained/enhanced as treatment continued. No major adverse events were identified. CONCLUSIONS: Improved body composition is both reflected by IGF-I changes and predicted inversely by baseline adiposity. Other effects of GH replacement on cardiac function, dyslipidaemia and quality of life, however, do not correlate with circulating IGF-I concentrations. Our findings validate the importance of sustained GH therapy, but caution on the interpretation of IGF-I levels in monitoring the long-term effects of GH treatment.

Adipose Tissue↗
PubMed2002

Gender-specific responses of lean body composition and non-gender-specific cardiac function improvement after GH replacement in GH-deficient adults.

GH deficiency (GHD) in adulthood is accompanied by physical and psychological impairments. One hundred fifteen patients (67 male, 48 female) with pronounced GHD were enrolled in a randomized, double-blind, placebo-controlled study with objectives that included effects on body composition, cardiac structure, and function and safety of replacement therapy with recombinant human GH (Saizen). Sixty patients (31 male, 29 female) received GH at a dose of 0.005-0.010 mg/kg.d, and 55 patients (36 male, 19 female) received placebo for 6 months. Assessment of body composition by dual-energy x-ray absorptiometry demonstrated a treatment difference in lean body mass increase of 2.1 kg (between-group comparison, P < 0.0001), which was significantly greater among males than females (P < 0.0001) [males: GH, +3.13 kg (2.42, 3.84); placebo, +0.11 kg (-0.60, 0.82); and females: GH, +0.64 kg (-0.15, 1.44); placebo: -0.90 kg (-2.20, 0.39)] [mean change 0-6 months (95% confidence limits)] and was associated with IGF-I changes. The decrease in fat mass of 2.8 kg (between-group comparison, P < 0.0001) noted by DEXA was also evident from bioelectric impedance and anthropometric measurements. Echocardiography showed comparable improvement in left ventricular systolic function after GH treatment in both genders. End-systolic volume decreased by 4.3 +/- 10.5 ml (from 35.8 +/- 17.6 ml; between-group comparison, P = 0.035) and ejection fraction increased by 5.1 +/- 10.0% (from 55.0 +/- 11.2%; between-group comparison, P = 0.048), approaching normalcy. Diastolic function did not change as assessed by isovolumic relaxation time, early diastolic flow, diastolic flow secondary to atrial contraction, or ratio of peak mitral early diastolic and atrial contraction velocity. GH treatment was well tolerated, with adverse events primarily related to effects on fluid balance. No apparent relationship between IGF-I levels and the occurrence or severity of adverse events was identified. In conclusion, GH replacement therapy in adults with GHD demonstrated beneficial effects on lean body mass composition that was more pronounced in males than females. In contrast, cardiac function improvement appears to benefit both genders equally.

Adult↗
PubMed1996

Back-projection and sensitivity analysis of the HIV-AIDS epidemic in the Caribbean.

In this study we estimated past human immunodeficiency virus (HIV) incidence in 19 nations in the primarily English-speaking Caribbean and projected the course of the epidemic to the year 1999. We compared the results obtained from several different models of HIV incidence and different assumed incubation distributions. Linear and nonlinear optimization methods were used to fit several models (power, logistic, spline, and step) to adult (age 15 years or older) AIDS incidence data derived from our existing surveillance system. All four models tested gave good fits to the data, with estimates of cumulative HIV incidence in 1993 ranging from 16,504 to 21,732. An increase in the assumed median of the AIDS incubation distribution by one year increased the estimates of current cumulative adult HIV incidence by approximately 12%; these estimates varied by as much as 6% between models. An adjustment of the data for possible reporting delay increased the estimates by approximately 7% and for underreporting by 25%. Despite their sensitivity to underlying assumptions, back-projection estimates provide useful insights into the patterns of HIV and AIDS incidence. The models indicate that HIV and AIDS incidences in the English-speaking Caribbean have been rising steadily, with adult HIV prevalence in the general population still less than 1%.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Community participation in dengue prevention and control: a survey of knowledge, attitudes, and practice in Trinidad and Tobago.

The priorities of public health planners are often at variance with the community's own environmental sanitation priorities and perspectives. Public opinion about individual, collective, and governmental responsibilities in addressing these issues and priorities is of particular importance when designing community-based programs. In a study conducted in Trinidad and Tobago on knowledge, attitudes, and practice regarding dengue, its prevention and control, a high level of awareness about dengue and its etiology was evident, but there was poor understanding of the symptoms and hence little concern about the health risks associated with it. The most important household pest problem identified by the respondents was related to mosquito nuisance, particularly from night-biting mosquitoes. Rodents were also a major concern perceived as being responsible for economic losses, ruined food, and a health hazard. Unreliable water supply, a factor associated with Aedes aegypti abundance, was an environmental sanitation issue of major importance to householders in rural areas. No correlation was found between knowledge of dengue and levels of Ae. aegypti abundance as measured by larval surveys of the respondents' premises. The study gave a clear indication of the need for broad-based environmental sanitation strategies when planning community-based vector control initiatives for the prevention and control of dengue in Trinidad and Tobago.

Aedes↗
PubMed1995

Severe sensory-autonomic neuropathy and endocrinopathy in insulin-dependent diabetes.

A patient developed insulin-dependent diabetes mellitus at the age of 9 years, complicated by a sensory/autonomic polyneuropathy which presented with a respiratory arrest at the age of 41 years. The neuropathy increased in severity over the subsequent two decades. At the age of 52 years she had hypopituitarism, hypothyroidism and low normal adrenal function. Autopsy at the age of 59 years revealed loss of pituitary tissue with evidence of hypophysitis, a lymphocytic thyroiditis and severe adrenal atrophy with lymphocytic infiltration of the medulla. The pancreas showed reduced numbers and size of the islets of Langerhans with total loss of immunoreactivity for insulin but intact glucagon-producing cells. These features are consistent with a type 2 autoimmune polyendocrine syndrome, in which lymphocytic hypophysitis has not previously been recorded. There was severe loss of myelinated nerve fibres in the sural nerve and rostrally accentuated fibre degeneration in the gracile fasciculi, but only mild cell loss in the dorsal root ganglia. This combination suggests the presence of a central-peripheral distal axonopathy. The cervical sympathetic ganglia were severely atrophic. Minor inflammatory infiltration was observed in the dorsal root and sympathetic ganglia. Significant vascular abnormalities were not present in the peripheral nerves. This, and the pattern of nerve fibre degeneration, suggest that in this case the neuropathy was likely to have been related to metabolic rather than vascular causes. The inflammatory infiltrates in sensory and sympathetic ganglia raise the possibility of an autoimmune inflammatory contribution to the neuropathy.

Autonomic Nervous System Diseases↗
PubMed1993

Evaluation of methods for the laboratory diagnosis of malaria in Guyana.

When 297 blood samples taken from patients attending a fever clinic in Georgetown Public Hospital were examined microscopically, after thick and thin blood films had been stained with Giemsa, one hundred and forty-two (47.8%) were microscopically positive for malaria. After processing the patient's serum, samples by the Indirect Fluorescent Antibody (IFA) technique, specific IgG and IgM antibodies were detected in 239 (81.3%) and 179 (60.1%), respectively, of the sera. Based on the microscopical findings, the IFAT gave positive predictive and negative values of 54.4% and 81.8% (IgG), and 57.5% and 67.8% (IgM), suggesting that the IgM would be more useful than the IgG in the diagnosis of current malaria. An odds ratio analysis showed that the presence of symptoms, IgG or IgM antibodies, as well as visits to endemic regions, could be good indicators of current malaria. Age and occupation were not. The microscopical method will continue to be the gold standard-the best available criterion for the validation of our tests-for diagnosis of acute malaria.

Animals↗
PubMed1992

Raclopride decreases sucrose intake of rat pups in independent ingestion tests.

To investigate the role of dopaminergic activity at D2 receptors in the mediation of the positive reinforcing effect of sucrose on ingestion in preweanling rats, we tested the effects of the D2 antagonist, raclopride, on the intake of 10% sucrose of rats on postnatal days (PN) 7, 14, and 21. Intake was measured during independent ingestion tests in which pups licked sucrose from the floor of a beaker and during oral catheter tests in which sucrose was continuously infused through an anterior, sublingual, oral catheter. Rats were tested once to eliminate the possibility that repeated test experience would affect the response to raclopride. Pretreatment with raclopride resulted in decreased intake in independent ingestion (II) tests, but not in oral catheter (OC) tests on PN 7, 14, and 21. The inhibition of intake was not due to a generalized motor deficit because raclopride did not affect latency to eat, time-sampled activity scores, or latency to withdraw the hindlimb from a raised position. These results demonstrate that dopaminergic activity at D2 receptors is necessary for the positive reinforcing effect of sucrose that maintains ingestion in the II test but not in the OC test.

Animals↗
PubMed1992

Intake of different concentrations of sucrose and corn oil in preweanling rats.

To investigate the orosensory control of ingestion in preweanling rats, we infused one of the following liquids continuously through anterior sublingual intraoral catheters for 20 min: sucrose solutions (5, 10, 20, and 40%) and corn oil emulsions (6.25, 12.5, 25, 50, and 100%). Pups were tested at 7, 14, 21, and 28 days of age. Each pup was tested only once. Intake of sucrose and of corn oil became increasingly correlated with concentration from 7 to 21 days. Sucrose elicited more intake than water by day 7, whereas corn oil did not until day 14. Low concentrations of sucrose had differential effects on intake by day 14, but low concentrations of corn oil emulsions did not have differential effects on intake until day 21. At all ages, the peak intake of sucrose was significantly larger than the peak intake of corn oil. These differences are probably not based on prior experience because each test of ingestion represented a first exposure to the stimulus. Thus we suggest that the differences are due to the maturation of the orosensory control of ingestion by sucrose and corn oil.

Aging↗