Impact of socioeconomic status on the prevalence of dementia in an inner city memory disorders clinic.

BACKGROUND: Socioeconomic status (SES) has been identified as a possible risk factor for the development of dementia, with low SES shown to be associated with a higher prevalence of dementia, increased psychiatric comorbidity and worse baseline cognitive functioning. Few studies have actually looked at the impact of SES within a clinical population using multiple measures of SES and cognition. METHODS: Data on 217 patients seen in an Inner City Memory Disorders Clinic were analyzed with respect to demographic status, clinical status and SES. Correlations were then examined looking at the relationship of SES to clinical variables and neurocognitive status. Regression analysis was undertaken to examine the relative contribution of individual sociodemographic factors to a diagnosis of dementia. RESULTS: In general, there was wide variation in the sample examined with respect to most measures of SES. Approximately one third (36%) of the sample had a diagnosis of dementia, the mean age was 66.1 years and the mean Mini-mental State Examination score was relatively high (25.4). There was a strong association between age, individual annual income range, education, medical comorbidity and a diagnosis of dementia, with increased age and medical comorbidity being the strongest predictors. CONCLUSION: Increased age, low education, high medical comorbidity and low annual income are all associated with a diagnosis of dementia in an inner city setting. Age and medical comorbidity appear to be more strongly associated with a diagnosis of dementia than SES in an inner city setting.

Knowledge of Alzheimer's disease and subjective memory impairment in Latin American seniors in the Greater Toronto Area.

BACKGROUND: This study examined knowledge levels of Alzheimer's disease (AD) in a sample of Latin American seniors attending AD educational sessions in a Canadian city; and investigated the relationship between knowledge of AD, demographic variables, education level, acculturation level (years living in Canada), subjective memory complaint and objective memory impairment. METHODS: One hundred and twenty-five Spanish-speaking adults living independently in the Greater Toronto Area completed subjective and objective memory measures and completed a questionnaire on their knowledge of AD. RESULTS: Knowledge of AD was very weakly correlated with level of education and years living in Canada. In addition, there were no correlations between knowledge level and gender or subjective memory complaints. CONCLUSIONS: The results suggest that Latin American seniors, in the Toronto community, are not knowledgeable about AD. In spite of showing subjective cognitive impairment the sample were not aware of the principal cause of their symptoms. Additional research is needed to develop better focused and specifically directed health promotion initiatives for the Latin American seniors living in the Toronto community.

Chronic monitoring of cardiovascular function in the conscious guinea pig using radio-telemetry.

An implantable radio-telemetry device for chronic monitoring of arterial pressure and heart rate in the conscious guinea pig was validated against measurements using an exteriorized, indwelling catheter. There were no significant differences between simultaneous measurements in animals instrumented with both the telemetry system and the conventional catheter (implanted 24 hrs prior to comparisons) in response to a variety of vasoactive agents. The device was shown to be accurate up to 3 weeks after implantation (longest time point tested). Resting pressures and heart rates in the telemetered guinea pig were stable in 100% of the animals tested. In contrast, animals instrumented with only exteriorized catheters showed a significant decline in pressure by 8 days after surgery and a 39% attrition rate due to loss of catheter patency. Performance of the telemetric device was examined in both normal and sodium-deficient animals, since the latter is a useful normotensive model in which blood pressure is rendered highly renin-dependent for evaluating the efficacy of potential antihypertensive agents that target the renin-angiotensin system. The telemetered guinea pig is an appropriate model for assessing responses to chronic exposure of cardiovascular agents.

Evaluation of an empirical dosing schedule for gentamicin in neonates.

The standard gentamicin dosing recommendations for neonates appear to be inappropriate because they fail to consider the influence of neonatal development on gentamicin pharmacokinetics. Recent reports have emphasized that the standard regimens of 2.5 mg/kg q8-12h produce steady-state trough serum concentrations greater than 2 micrograms/ml in up to 91 percent of preterm infants of less than 35 weeks' gestation. A new dosing schedule based on postconceptional age (PCA) was developed to provide a better guideline for initiating and maintaining gentamicin therapy in neonates: PCA greater than 34 weeks, 2.5 mg/kg iv q12h; PCA 28-34 weeks, 2.5 mg/kg iv q16h; PCA less than 28 weeks, 2.5 mg/kg iv q24h. The new dosing schedule reduced the number of neonates with elevated trough concentrations (greater than 2 micrograms/ml) from 68.4 percent to 33-40 percent. Pharmacokinetic parameters for gentamicin in the various PCA groups were determined. Volume of distribution was constant across age groups (0.5 +/- 0.09 L/kg). Elimination rate constants (kel), half-lives, and clearance rates (Cl) ranged from 0.069 +/- 0.02 to 0.14 +/- 0.04 h-1, 10.71 +/- 2.92 to 6.04 +/- 1.24 h, and 0.58 +/- 0.25 to 0.93 +/- 0.24 ml/kg/min, respectively. Significant relationships were found between kel and Cl and patient age and weight; significant correlations were found between actual and estimated (based on PCA and weight) kel and Cl. Variability in kel and Cl estimated was considerable in spite of the correlations. The observed variability stresses again the need for pharmacokinetic monitoring of gentamicin therapy in neonates.

The prenatal diagnosis of the cerebro-hepato-renal syndrome of Zellweger.

The prenatal diagnosis of the cerebro-hepato-renal syndrome of Zellweger (CHRS) was made by assaying the levels of very long chain fatty acids (VLCFAs) in amniotic fluid cell cultures, obtained by amniocentesis at 16 1/2 weeks of pregnancy. The family-at-risk, because they had previously borne a child with CHRS, accepted these results as indications of an affected fetus, and chose to terminate the pregnancy at 20 1/2 weeks of gestation. The diagnosis was confirmed by the phenotype of the aborted fetus and the presence of markedly elevated levels of VLCFAs in fetal liver homogenates. The prenatal diagnosis of CHRS, which can now readily be determined from amniotic fluid cell cultures, is an important step in genetic counselling of families-at-risk for this disease.

Reproduction and teratogenic studies of 5-thio-D-glucose in mice.

Under the conditions of the present study, 5-thio-D-glucose was found to be an effective and useful reversible male contraceptive. Treatment of male mice with 5-thio, administered intraperitoneally or orally at 40 or 60 mg/kg for 28 to 35 days produced germinal cell degeneration and complete inhibition of spermatogenesis in the seminiferous tubules. These treatment regimens also resulted in complete sterility in males lasting for several weeks. Resumption of sperm development and fertility occurred with 5 to 6 weeks after treatment was discontinued. The Leydig cell population, Sertoli cells, and spermatogonia apparently were not affected and male libido was not impaired. There was no evidence of embryotoxic or teratogenic effect in litters of pregnant females treated orally with 5-thio on days 6--12 of gestation.

Dominant lethal gene test of 5-thio-D-glucose in male mice.

Genetic effects of 5-thio-D-glucose (5-thio) were tested in male mice by the dominant lethal gene test. Males were treated with phosphate buffered saline (PBS) or 5-thio dissolved in PBS by oral intubation daily at 40 or 60 mg/kg for 7 or 35 successive days. Average implantations per pregnant female and the intrauterine postimplantation losses in females mated with 5-thio trated males did not show any significant differences when compared statistically with parallel controls. Furthermore, the compound had no effect on the appearance and mating behavior of the male mice. This is the first report on the genetic effects of 5-thio to show that the compound in the treatment regimens studied were not mutagenic in terms of the induction of dominant lethal mutation in male mice.