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Biomedical subjects

R W Reid

Publications and source records attributed to R W Reid.

At least 19 recordsLinked to original sources
PubMed1994

The in vitro differential binding of benzoylecgonine to pigmented human hair samples.

Only fragmentary information on the relationship between hair pigmentation (melanin) and the cocaine/benzoylecgonine content of hair samples is available. The in vitro incorporation of benzoylecgonine into the shafts of black, brown, and blond samples of human hair was accomplished. Post digestion analysis and wash samples demonstrate the relative incorporated ions of benzoylecgonine to be black > brown > blond. Melanin content seems to be important. Lightly pigmented blond hairs may be less appropriate samples for benzoylecgonine and cocaine analysis.

Binding Sites↗
PubMed1992

Retrospective serologic survey for the presence of feline immunodeficiency virus antibody: a comparison of ELISA and IFA techniques.

A total of 878 samples from the New York State Diagnostic Laboratory (NYSDL), dating from January 1984 to May 1987, were examined to detect antibodies to feline immunodeficiency virus (FIV). We used 2 screening methods; an indirect immunofluorescence assay (IFA) and an enzyme-linked immunosorbent assay (ELISA). Of these, 211 samples were from cats that tested negative for feline leukemia virus (FeLV) and exhibited disease signs consistent with immunodeficiency disease; 19 (9.0%) serum samples were determined to be positive. An additional 508 samples were from cats that tested FeLV-negative and were asymptomatic; 6 (1.2%) sera were determined to be positive. The final 159 samples were from FeLV-positive cats and included symptomatic and asymptomatic animals; this population of cats produced 6 (3.8%) positives. Additionally, 521 samples from the Cornell Feline Health Center (CFHC) serum bank, dating back to 1966, were tested to determine the earliest sample in which FIV antibodies could be detected. Five (2.7%) 1971 and 3 (3.3%) 1969 CFHC samples tested positive. The IFA for FIV antibody proved to be a sensitive (97.4%) and specific (100%) test. The ELISA also had high sensitivity (100%) and specificity (99.6%); however, the IFA proved to be more specific than the ELISA when assaying FeLV-positive cats.

Animals↗
PubMed1991

Direct diagnosis of tuberculosis by computer assisted pattern recognition gas chromatographic analysis of sputum.

Chemical detection of tuberculosis (TB) products in sputum was attempted by using gas chromatographic analysis in conjunction with different pattern recognition computer models. For the chromatographic separations, we used a 2 mm x 1.8 m packed column and a 0.25 mm x 30 m fused silica capillary column to analyse the methylated glycosides and fatty acid methyl ester derivatives. Three computer pattern recognition methods were applied: error score, TB score and discriminant analysis. These methods predicted the presence of active TB most often in sputa of active TB patients and less so in those from inactive, suspected and non-TB patients, in that order. Although the best true positive of 75% was obtained from the TB score method and best true negative of 98% from discriminant analysis, the accompanying false positive and false negative results (36% and 50%, respectively) were unacceptable. The use of capillary column or fatty acid methyl ester derivatives of the samples did not improve on the predictive values of chromatograms obtained from the packed column on trimethylsilylglycosidic derivatives. Additional work is needed before this method can have a direct clinical application.

Chromatography, Gas↗
PubMed1991

Naloxone increases water and electrolyte excretion after water loading in patients with cirrhosis and ascites.

Endogenous opioids may be involved in the pathogenesis of ascites and edema in patients with liver cirrhosis. We administered the opioid antagonist naloxone (5 mg bolus followed by a 0.06 mg/min infusion) to eight male patients with alcoholic cirrhosis and ascites and to five healthy age- and sex-matched control subjects and determined the effects of naloxone on water and electrolyte excretion after a nonsustained water load (20 ml/kg). In comparison with saline vehicle infusion carried out in the same subjects, naloxone administration resulted in a 50% increase in urine output and creatinine clearance and twofold increases in sodium and potassium excretion in patients with cirrhosis. Fractional sodium and potassium excretion, minimal urinary osmolality, plasma vasopressin and aldosterone levels, arterial blood pressure, and heart rate were not affected by naloxone treatment. The diuretic effect of naloxone was not observed in control subjects. Plasma naloxone levels were about six times higher in patients with cirrhosis than in control subjects (probably because of impaired metabolism of the drug) but only a weak correlation was found between drug levels and the degree of diuresis observed. The diuretic effect of naloxone may be related to an increase in glomerular filtration rate, possibly in conjunction with altered tubular reabsorption.

Aged↗
PubMed1988

Identifying Mycobacterium tuberculosis cultures by gas-liquid chromatography and a computer-aided pattern recognition model.

A procedure that uses gas-liquid chromatography and a pattern recognition computer model was developed for distinguishing cultures of Mycobacterium tuberculosis from cultures of other mycobacteria, common bacteria, and fungi. In this procedure, a sample of a culture preparation is methanolyzed and trimethylsilylated sequentially and injected into a gas chromatograph equipped with a flame ionization detector. A pattern recognition procedure computes an error score by comparing the gas-liquid chromatography peak responses of a culture to those of a standard M. tuberculosis culture. Ten M. tuberculosis cultures were used in the development of the pattern recognition model. Computed error scores of 5 or less were established for identifying an M. tuberculosis culture. The method was evaluated with two sets of test samples, non-M. tuberculosis and M. tuberculosis cultures. Sample identification was correct for all 14 M. tuberculosis cultures (M. tuberculosis or non-M. tuberculosis), 45 fungal cultures, 94 bacterial cultures, and all but 1 of 18 cultures of mycobacteria other than tuberculosis (MOTT). The false prediction represented an isolate of M. fortuitum. For M. tuberculosis, fungal, bacterial, and MOTT cultures, the ranges of error scores were 1 to 5, 16 to 33, 13 to 34, and 4 to 26, respectively. Therefore, we have demonstrated that this diagnostic model can distinguish M. tuberculosis from non-M. tuberculosis cultures with a high degree of accuracy.

Bacteria↗
PubMed1986

Effect of acute postinfusion lipemia and free fatty acids on myocardial contractility: assessment with radionuclide ventriculography.

Equilibrium gated radionuclide ventriculography was used to evaluate the effect of intravenous fat-emulsion overload and excess of free fatty acids (FFA) on left ventricular ejection fraction (LVEF) in 20 patients with and without coronary artery disease (CAD). Fifteen of these patients had normal (greater than 50%) baseline LVEF and 5 had low (less than 50%) baseline LVEF. From 100 to 150 ml of 20% artificial fat emulsion (Liposyn) was infused over 20-25 min. At the end of the infusion, triglyceridemia reached 820 +/- 220 mg% and left ventricular ejection fraction decreased from baseline 62 +/- 19% (mean +/- SD) to 58 +/- 16% (P less than 0.05, paired t-test). After completion of Liposyn infusion, 5,000 U of heparin was administered intravenously and monitoring of LVEF was continued. One and one-half hours following heparin administration, plasma FFA levels reached 3.7 + 2.0 mmol/l and LVEF rose to 69 +/- 19% (P less than 0.001, paired t-test). Our data indicate that acute intravenous fat overload can suppress and high pathophysiologic levels of FFA can increase LVEF. This effect is more uniform and statistically more reliable in patients with normal LVEF. The study failed to demonstrate any significant difference in the effect of this pharmacologic intervention between patients with and without CAD.

Aged↗
PubMed1985

The effects of acute hypertriglyceridemia and high levels of free fatty acids on left ventricular function.

The effects of acute hypertriglyceridemia and of high levels of free fatty acids on the left ventricular ejection fraction were studied by radionuclide ventriculography in 20 subjects with and without coronary artery disease. An infusion of approximately 125 ml of a 20% fat emulsion over 25 minutes resulted in an increase of plasma triglycerides to the mean of 820 mg/dl and a fall of the left ventricular ejection fraction from the baseline mean of 62% to 58% (p less than 0.05). Ninety minutes after the intravenous administration of 5000 units of heparin, plasma free fatty acids rose to the mean of 4.6 mmol/L and the mean left ventricular ejection fraction increased to 69% (p less than 0.001). The observed changes in blood lipids were not associated with clinical or ECG evidence of myocardial ischemia. We conclude that acute hypertriglyceridemia causes slight depression of left ventricular performance, while high levels of free fatty acids augment it. However, neither hypertriglyceridemia per se nor its rapid conversion to free fatty acids are likely to cause angina in stable patients with coronary artery disease.

Aged↗
PubMed1985

Spurious hyperphosphatemia due to hyperlipidemia.

A patient had hyperlipidemia associated with apparent hyperphosphatemia. Further tests on his serum and on the lipemic sera from 15 additional patients revealed a method-dependent overestimation of inorganic phosphorus values. The degree of overestimation was found to correlate positively with the serum triglyceride concentration. Unexplained elevation of the serum phosphorus level should alert the physician to the possibility of spurious hyperphosphatemia due to hyperlipidemia.

Aged↗
PubMed1984

The dexamethasone suppression test and depressive symptoms in early and late withdrawal from alcohol.

Results of the dexamethasone suppression test (DST) in 30 alcoholic patients tested on day 5 and again on day 25 after their last drink are presented. Nineteen patients (63%) failed to suppress cortisol on day 5; three (11%) failed to suppress cortisol on day 25. Depressive symptoms, measured by the Beck Depression Inventory, were significantly correlated with DST results; the lifetime diagnosis of depressive illness was not. The authors conclude that the DST is not useful in detecting primary affective disorders during the early phase of withdrawal from alcohol.

Adult↗
PubMed1984

Calcium-complexing versus vasorelaxant effect of acetate, lactate, and other bases.

The calcium-complexing abilities of acetate, bicarbonate, lactate, succinate, and citrate were quantified, and were found to differ substantially. Acetate was a more potent vasodilator than lactate, and the vasorelaxant potencies of acetate and lactate failed to correlate with their calcium-complexing ability. The vasodilator action of acetate was not abolished after correction for complexing of ionized calcium. Strips constricted with vasopressin were especially sensitive to the vasodilator effects of acetate.

Acetates↗
PubMed1984

Gas-liquid chromatography for rapid diagnosis and monitoring of invasive candidal infections and candidemia.

Gas-liquid chromatography was performed on serum samples obtained from selected patients with infectious diseases. The characteristic chromatographic profile was seen in serum samples from 21 patients with either documented invasive candidiasis or candidemia. Serum samples from ten normal controls, three patients with candidal colonization, and 11 clinically noninfected patients, seven of whom had fevers attributable to malignancies, showed normal chromatograms. The eradication of Candida from deep tissue and/or bloodstream was reflected promptly by a normalization of the chromatograms in all six cases. Use of amphotericin B was safely avoided in three patients with candidemia whose follow-up chromatograms became normal following the discontinuation of intravenous catheterization. This test promises to be useful in the diagnosis and therapeutic monitoring of invasive candidal infections and candidemia.

Candida↗
PubMed1981

Detection of pentazocine and tripelennamine in urine.

Pentazocine and tripelennamine can be identified in urine as a part of routine screening for drug abuse. Pentazocine, pentazocine hydrate, and tripelennamine can be detected by thin-layer chromatography of chloroform/isopropanol extracts of heat- and acid-hydrolyzed urine. Gas chromatography is used for confirmation. Gas chromatographic/mass spectrometric studies (chemical ionization mode) show that such extracts contain major molecular (M+) ions of m/e 256, 286, and 304, indicating the presence of tripelennamine, pentazocine, and pentazocine hydrate, respectively.

Chromatography, Gas↗
PubMed1975

Second thoughts on dementia. Evaluation and management of patients with mild dementia.

The early recognition of dementia along with consideration of differential diagnosis and elucidation of its underlying causes is of paramount importance because many of these conditions are remediable, given proper diagnosis and adequate treatment. The purpose of this article is to emphasize possible alternatives to the grim sentence of slowly progressive irreversible deterioration of personality and intellect when the verdict of dementia is pronounced.

Aged↗