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J Diamant

Publications and source records attributed to J Diamant.

12 recordsLinked to original sources
PubMed2001

Pooling of Chlamydia laboratory tests to determine the prevalence of ocular Chlamydia trachomatis infection.

With the Global Elimination of Trachoma by 2020 program underway, it has become increasingly important to identify the prevalence of ocular chlamydia infection in communities. DNA amplification tests are the gold standard, but are prohibitively expensive. In the present paper, we investigate whether pooling multiple specimens into a single test is feasible. The conjunctivae of 170 children in western Nepal were examined and swabbed. The prevalence of chlamydial infection was estimated in two ways using the ligase chain reaction: by testing all 170 specimens individually, and by testing 34 pools of 5 specimens each. We show that the confidence interval for 34 pooled specimens approaches that of doing all 170 specimens as the prevalence decreases. We also determine the optimal number of specimens to pool into a single test to minimize the confidence interval of the estimate. If the population prevalence is expected to be around 10%, then 14 specimens should be pooled per test. Even at 50% prevalence, costs can be reduced by pooling two samples per test.

Child↗
PubMed1994

Severe metabolic alkalosis.

Our patient's acid-base disturbance may be among the highest recorded in nonfatal cases of metabolic alkalosis. This case also shows that life-threatening alkalemia can be safely and effectively treated by defining and removing the causes of alkalosis and applying aggressive supportive therapy with fluid repletion and potassium and electrolyte replacement. The need for potentially dangerous therapy such as exogenous acid administration, dialysis, or forced mechanical depression of respiration should not routinely be used on the basis of blood pH alone, and it should never replace thoughtful, organized supportive care.

Alkalosis↗
PubMed1975

Plasma catecholamine response of coronary-prone subjects (type A) to a specific challenge.

Plasma norepinephrine (NE) and epinephrine (E) were assayed in 15 men prone to develop coronary heart disease (type-A behavior pattern) and in 15 coronary-disease-resistant men (type-B behavior pattern) under resting, noncompetitive conditions and also immediately before, during, and after participation in a nonphysical competitive struggle. The average concentration of catecholamines was virtually the same in both groups under resting conditions. Under competitive conditions the NE concentration of the coronary-susceptible group rose an average of 30%, while that of the resistant group remained essentially unchanged. E concentration remained unchanged in both groups.

Competitive Behavior↗
PubMed1975

A precise catecholamine assay for small plasma samples.

The time, temperature, and pH of the trihydroxyindole reaction were controlled to minimize interference between norepinephrine (NE) and epinephrine (E) so that, in plasma catecholamine assay within normal human physiologic range, NE contributes less than 1 per cent to the fluorescence produced from E, and E contributes only 0.5 to 10 per cent to NE fluorescence; assay and blank measurements show superior stability. Elution from alumina and instrumental factors, such as optical filters, were optimized so that a single 5 ml. plasma sample sufficed for triplicate analyses of both NE and E, with duplicate blanks for each. This triplicate fluorescence assay was combined with duplicate recovery measurements of radioactive catecholamines added in tracer quantities to the plasma so as to make possible reliable estimates of the precision of measurement of each individual sample. The mean levels found for men aged 40 to 60 years from antecubital vein blood drawn during the subject's working hours (but after a brief rest) were, for NE 0.38 ng. per milliliter, range 0.15 to 0.54 ng. per millilter, and for E 0.09 ng./ml, range 0.01 to 0.27 ng. per millilter. The high precision and small amounts of blood required by this method made possible the measurement of basal plasma levels of E and NE in rats under two-stage phenobarbital anesthesia. The mean levels for 13 male and 4 female Long-Evans-stain rats weighing 250 to 350 grams were, for NE 0.26 ng. per millilter, range 0.16 to 0.37 ng. per millilter, and for E 0.36 ng. per millilter, range 0.14 to ng. per millilter. These rat values are called basal because they are only 1/5 to 1/10 as large as values obtained on plasma secured by single-stage pentobarbital anesthesia or from unanesthetized rats. Eight to 11 ml. of whole blood obtained from each rat were sufficient for individual analyses, an improvement over most other reported methods which require blood from a number of animals to be pooled. The average precision of an individual determination of NE was plus or minus 10 per cent in the range of 0.20 to 0.40 ng. per millilter. The average recovery for NE was 65 per cent and for E it was 55 per cent. Major factors influencing recovery were quantitatively investigated and discussed.

Adult↗
PubMedDate not supplied

Neurogenic hypercholesterolemia: influence of autonomic drugs.

Eleven substances capable of either augmenting or depleting the alpha- and - beta-adrenergic capacities of the autonomic nervous system were administered to rats exhibiting hypothalamic hypercholesterolemia and to normal controls. Only the beta-adrenergic blocking agents propranolol and possibly 6-OH dopamine were observed to alter (raise) the serum cholesterol concentration, and this occurred in both experimental and control animals. Neither atropine, nor the serotonin-depleting agent, rho-chlorophenylalanine, nor the serotonin-antagonist cyproheptadine, were observed to alter serum cholesterol level. Such absence of effect was also noted with metaraminol, phenoxybenzamine, isoproterenol, epinephrine, reserpine, and alpha-methyl tyrosine.

Adrenergic alpha-Agonists↗