Should echocardiography be performed to assess effects of antihypertensive therapy? Test-retest reliability of echocardiography for measurement of left ventricular mass and function.

OBJECTIVES: The purpose of this study was to determine the test-retest stability of echocardiography for the measurement of left ventricular mass and function in patients with hypertension. BACKGROUND: Determination of changes in left ventricular mass may be impaired by study variability. The amount by which variables of mass and left ventricular function must change in an individual patient to exceed temporal variability has not been determined in a multicenter trial. METHODS: Ninety-six patients with hypertension had two-dimensional targeted, M-mode Doppler echocardiography repeated at 6 +/- 8 days by the same technician utilizing the same machine. Left ventricular mass and variables of systolic and diastolic function were measured. Test-retest reliability and the width of the 95% confidence intervals of variable change, as well as the contributions of age, study quality and body size to measurement reliability, were determined. RESULTS: Despite excellent reliability (intraclass coefficient of correlation 0.86), the 95% confidence interval width of a single replicate measurement of left ventricular mass was 59g, exceeding usual decreases in mass during treatment. Study quality, which was dependent on age and weight, influenced test reliability. Although the confidence interval width for ejection fraction was narrow (5 U), those for peak early (E) and late (A) diastolic velocities were wide, resulting in a confidence interval width for the E/A ratio of 1.5. CONCLUSIONS: The temporal variability, particularly in obese or elderly patients, or both, of echocardiography for measurement of left ventricular mass precludes its use to measure changes in mass of the magnitude likely to occur with therapy. Measurement stability is affected by study quality, and age and body weight both influence study quality. Although ejection fraction shows little temporal variability, the large width of the confidence interval of the Doppler E/A ratio impairs its use to serially measure diastolic function.

Salivary analysis for determination of dextromethorphan metabolic phenotype.

Debrisoquin oxidative phenotype is a determinant of pharmacologic response for many drugs. Poor and extensive metabolizers can be identified by the dextromethorphan metabolic ratio (dextromethorphan/dextrorphan). We developed and tested a method to determine debrisoquin phenotype on the basis of the metabolic ratio in saliva. Each of 62 normal volunteers was given a 50 mg capsule of dextromethorphan hydrobromide and collected urine (0 to 8 hours) and saliva (at 3 hours). Dextromethorphan and dextrorphan in saliva and urine were assayed by HPLC. The distributions of paired urinary and 3-hour salivary metabolic ratios of samples from 61 subjects were compared. The urinary and salivary metabolic ratios were distributed trimodally and bimodally, respectively. The Spearman rank correlation coefficient for logarithm of urinary metabolic ratio vs that of salivary metabolic ratio was 0.704. All the poor metabolizers identified by urinary metabolic ratio were also identified by the metabolic ratio in saliva at 3 hours (100% concordance). This study demonstrates that salivary analysis for determination of dextromethorphan metabolic phenotype is feasible.

A population-based assessment of the use and effectiveness of thrombolytic therapy. The Corpus Christi Heart Project.

Little is known regarding the use and effectiveness of thrombolytic therapy in community settings, especially regarding the receipt of therapy by Mexican Americans. Thus, we examined the factors associated with receipt of thrombolysis and the survival experience of recipients and nonrecipients in the Corpus Christi Heart Project. The Corpus Christi Heart Project is a population-based surveillance program for hospitalized myocardial infarction among Mexican-American and non-Hispanic white women and men residing in Corpus Christi, Texas. Multivariate regression analyses were used to identify factors associated with receipt of thrombolytic therapy and to assess the association between receipt of thrombolytic therapy and mortality. During a 2-year period, 1199 patients hospitalized for myocardial infarction were identified; 159 (13.3%) received thrombolysis. Among "ideal" candidates for thrombolytic therapy, 74 (35.1%) of 211 received such therapy. Women were less likely to receive thrombolysis than men, and Mexican Americans were less likely to received thrombolysis than non-Hispanic whites. Patients for whom there was a delay of more than 4 hours between onset of symptoms and arrival at the hospital were also less likely to receive thrombolysis. Recipients of thrombolytic therapy experienced lower mortality over 56 months following myocardial infarction than did nonrecipients (20.5 versus 33.2%, P < 0.01). Use of thrombolytic therapy was less frequent among women and Mexican Americans than among men and non-Hispanic whites, and was limited by delay between onset of symptoms and arrival at the hospital.(ABSTRACT TRUNCATED AT 250 WORDS)

Childhood sexual trauma and psychosocial functioning in adults with schizophrenia.

OBJECTIVE: This study explored the association between sexual abuse in childhood and the severity of psychosocial deficits in adults with schizophrenia. METHODS: The Quality of Life Scale, which assesses current interpersonal and work function, and the NEO personality inventory, which assesses personality dimensions relevant to social functioning, were administered to 54 individuals who had been diagnosed as having schizophrenia. Nineteen of the individuals reported having been sexually abused as children, and 35 reported no history of abuse. RESULTS: A multiple analysis of variance indicated that there were differences between the group of individuals who had a history of sexual trauma and the group that did not. Subsequent univariate analysis of variance indicated that the individuals with a history of abuse had poorer current role functioning and fewer of the basic psychological building blocks necessary for sustaining intimacy. They also demonstrated higher levels of neuroticism, which is a measure of vulnerability to emotional turmoil. The two groups did not differ in frequency of interpersonal contacts or level of extroversion. CONCLUSIONS: Sexual abuse in childhood is associated with poorer psychosocial functioning in adults with schizophrenia.

Higher levels of social support predict greater survival following acute myocardial infarction: the Corpus Christi Heart Project.

Although low levels of social support have been related to mortality from coronary heart disease, little is known about the role of social support among Mexican Americans. The authors therefore examined the relationship between social support and long-term survival in the Corpus Christi Heart Project. They developed a social support scale that used data collected during in-hospital interviews of 292 Mexican Americans and 304 non-Hispanic Whites who survived a myocardial infarction for more than 28 days. The scale incorporated three measures: marital status; if not married, whether living alone; and whether advised to seek help. During an average follow-up period of 43 months, 115 participants died. Survival following myocardial infarction was greater for those with high or medium social support than for those with low social support. With age, gender, ethnicity, education, employment, smoking, diabetes, hypertension, and hypercholesterolemia included in a proportional hazards regression model, the relative risk of mortality was 1.89 (95% CI, 1.20-2.97) for those with low social support. But when the two ethnic groups were analyzed separately, low social support was no longer a significant predictor of mortality for non-Hispanic Whites, whereas for Mexican Americans, the relative risk of mortality was 3.38 (95% CI, 1.73-6.62) for those with low social support.

Urologic complications associated with pelvic fractures.

Patients with a history of lower abdominal trauma need to be assessed for concomitant urologic complications. Assessment of the genitourinary tract should be performed in an orderly progression to insure complete information. This article provides an overview of the evaluation, treatment, and complications associated with the bladder and male urethral injuries most commonly associated with pelvic fractures. Nursing considerations are presented for the immediate and long-term care of this patient grouping.

Human population dynamics revisited with the logistic model: how much can be modeled and predicted?

"We revive the logistic model, which was tested and found wanting in early-20th-century studies of aggregate human populations, and apply it instead to life expectancy (death) and fertility (birth)....For death...the logistic portrays the situation crisply. Human life expectancy is reaching the culmination of a two-hundred year-process that forestalls death until about 80 for men and the mid 80s for women. No breakthroughs in longevity are in sight unless genetic engineering comes to help. For birth, the logistic covers quantitatively its actual morphology. However, because we have not been able to model this essential parameter in a predictive way over long periods, we cannot say whether the future of human population is runaway growth or slow implosion... From a niche point of view, resources are the limits to numbers, and access to resources depends on technologies. The logistic makes clear that for homo faber, the limits to numbers keep shifting. These moving edges may most confound forecasting the long-run size of humanity."

Astaxanthin production by a Phaffia rhodozyma mutant on grape juice.

During fermenter cultivation of Phaffia rhodozyma on a grape juice medium, the presence of glucose initially delayed fructose utilization, although fructose was consumed before glucose depletion. Total pigment and astaxanthin production were growth associated and reached maximum values of 15.9 µg/ml and 9.8 µg/ml, respectively, after depletion of the carbon source. The total cellular pigment and astaxanthin content increased during the stationary growth phase due to a decrease in biomass, reaching final values of 2120 µg/g and 1350 µg/g, respectively, without the volumetric concentration in the culture changing. The final cell yield was 0.33 g/g sugar utilized. High sugar concentrations in shake-flasks as well as O2 limitation decreased the astaxanthin content of the cells. Addition of yeast extract to a grape juice minimal medium markedly increased the maximum specific growth rate, total pigment and astaxanthin content of the cells. An excess of ammonia decreased the intracellular astaxanthin content, which reached a maximal value in cultures with no residual glucose or ammonia.

Selection and evaluation of astaxanthin-overproducing mutants of Phaffia rhodozyma.

Mutagenesis of Phaffia rhodozyma with NTG yielded a mutant with an astaxanthin content of 1688 µg (g dry biomass)(-1), a cell yield coefficient of 0.47 on glucose and a maximum specific growth rate of 0.12 h(-1). Re-mutation of the mutant decreased the cell yield and maximum specific growth rate but increased the astaxanthin content. The use of mannitol or succinate as carbon sources enhanced pigmentation, yielding astaxanthin contents of 1973 µg g(-1) and 1926 µg g(-1), respectively. The use of valine as sole nitrogen source also increased astaxanthin production, but severely decreased the maximum specific growth rate and cell yield coefficient. The optimum pH for growth of P. rhodozyma was between pH 4.5 and 5.5, whereas the astaxanthin content remained constant above pH 3.

Chemostat cultivation of Candida blankii on sugar cane bagasse hemicellulose hydrolysate.

A Candida blankii yeast isolate was grown in sugar cane bagasse hemicellulose hydrolysate at 38 degrees C in carbon-limited chemostat culture. The pretreatment of the acid hydrolysate prior to microbial cultivation consisted of partial neutralization with ammonia and sodium hydroxide, plus the addition of phosphorus, which was the only other growth-limiting nutrient apart from nitrogen. The cell yield coefficient on nitrogen was 16.78. The critical dilution rate was higher (0.35 h(-1)) in diluted hydrolysate than in undiluted hydrolysate (0.21 h(-1)). In undiluted hydrolysate at a dilution rate of 0.1 h(-1) and pH 4, where aseptic procedures proved unnecessary, the cell and protein yield coefficients were 0.53 and 0.26, respectively, and no residual carbon substrates (D-xylose, L-arabinose, D-glucose, and acetic acid) were detected. The cell yield on oxygen increased linearly as a function of dilution rate. The cellular content of protein, carbohydrate, and RNA also increased with an increase in dilution rate, whereas the DNA content decreased slightly. C. blankii has considerable potential for the production of single cell protein from hemicellulose hydrolysate, because of its ability to utilize all of the major carbon substrates in the hydrolysate at a low pH and at a relatively high temperature with a high protein yield.

Effect of temperature and pH onCandida blankii in chemostat culture.

The growth characteristics ofCandida blankii as a function of temperature and pH in a simulated bagasse hemicellulose hydrolysate were determined in chemostat culture. The highest maximum specific growth rate of 0.44h(-1) was reached at 38°C and at pH 5.5, with a sharp decrease in growth rate on either side of this temperature. Growth occurred at 46°C but not at 48°C. The protein and cell yields varied little below 40°C and the respective values were 0.22 and 0.5 g/g at 38°C. At the lower pH values, a severe linear decrease in cell and protein yields occurred, whereas a small increase in these yields at decreasing pH values was found when acetic acid was omitted from the medium. In the presence of acetic acid, a very sharp decrease in the growth rate at pH values below pH 4.5 was noted, despite the very low residual acetic acid concentrations, of less than 50 mg/l, in the culture.