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Biomedical subjects

A L Wright

Publications and source records attributed to A L Wright.

125 records · Page 7Linked to original sources
PubMed1986

A comparative analysis of cord blood and adult lymphocytes: interleukin-2 and interferon production, natural killer cell activity, and lymphocyte populations.

A comprehensive comparative analysis of lymphocyte populations, natural killer cell activity, and interleukin-2 (IL-2) and interferon production was performed on cord blood and adult peripheral blood mononuclear cell populations. Analysis of the cell types present demonstrated significantly lower percentages of T3+, T8+, and Leu 11+ cells for the cord blood samples compared to the adult samples. Also, both natural killer cell activity and gamma interferon production were significantly lower in the cord blood group. These findings may correlate with the increased susceptibility of young infants to infection. Differences between the two groups were not evident for the percentages of T4+ cells, B cells, and large granular lymphocytes. IL-2 production by cells stimulated with concanavalin A and a phorbol ester was higher in cord blood. Individually, half of the cord blood samples contained more IL-2 than any of the adult samples. This result could be caused either by greater production of IL-2 by the cord blood samples or by greater utilization of IL-2 by the adult samples.

Antigens, Surface↗
PubMed1986

Influence of hexachlorobenzene on thyroids of male hamsters.

The effect of hexachlorobenzene (HCB) on thyroid function in hamsters was explored and compared with that of 3-amino-1,2,4-triazole. Both chemicals caused thyroid enlargement but whereas 3-amino-1,2,4-triazole depressed serum thyroxine (T4) levels and elevated triiodothyronine (T3), HCB depressed T3 with little effect on T4.

Animals↗
PubMed1985

Electrically evoked activity in the human external anal sphincter.

Following electrical stimulation of perianal skin, short latency evoked electromyographic (EMG) responses from the external and sphincter have been interpreted as the electrophysiological correlate of the anal reflex. Delayed responses in patients with idiopathic faecal incontinence have been interpreted as evidence for denervation of the external anal sphincter. Electrically evoked responses were studied in normal subjects, either before and during spinal anaesthesia (n = 8), or before and during competitive neuromuscular blockade (n = 4), instituted for operative purposes. Short latency responses persisted unchanged in either latency or duration during spinal anaesthesia whereas long latency responses were completely abolished. Both short and long latency responses were abolished during competitive neuromuscular blockade. Short latency responses are not spinal reflex in nature, but due to stimulus activation of alpha-motoneuronal terminal branches. Delayed responses in incontinent patients cannot be interpreted as evidence for pudendal neuropathy. Long latency (i.e. greater than 40 ms) responses demand a functional sacral spinal cord and represent the true anal reflex. Their wide range of latency in normal subjects suggests this measurement will be of little use in confirming the presence or absence of pudendal neuropathy, and that other measures of neuropathy may be more appropriate.

Adolescent↗
PubMed1983

The effect of pulmonary hypertension on systolic function of the right ventricle.

This study sought to determine if the right ventricular ejection fraction (RVEF) could be used to diagnose pulmonary hypertension noninvasively. The right ventricular ejection fraction was measured with gated blood pool radionuclide ventriculography and compared to hemodynamic measurements made within 48 hours in 57 subjects. There was a significant inverse relationship between the RVEF and pulmonary artery pressure (r = .57, p less than .001) and the sensitivity of RVEF greater than .45 in diagnosing pulmonary hypertension was .76. Other significant determinants of right ventricular function, including right coronary disease, left ventricular function and tricuspid regurgitation, were also considered.

Cardiac Output↗
PubMed1982

An improved method of right ventricular gated equilibrium blood pool radionuclide ventriculography.

Gated blood pool radionuclide ventriculography provides a means for obtaining repeated studies of both cardiac ventricles with a single dose of radionuclide. Quantitative assessment of right ventricular (RV) function using this technique has been complicated by several technical problems. We describe a new method of RV blood pool analysis which attempts to solve these problems using well-established concepts for left ventricular (LV) blood pool analysis: (1) variable regions of interest; (2) computer edge detection with operator intervention; and (3) computer selected background. Results showed a strong linear correlation between gated first pass RV ejection fraction (RVEF) and the gated blood pool RVEF (n = 22; r = 0.93; blood pool RVEF = 0.03 + 0.89 X first pass RVEF; Sy.x = 0.04). There was also a strong linear correlation between LV and RV stroke counts in patients without valvular regurgitation, intracardiac shunts, or ventricular aneurysms (n = 19; r =0.86; RV counts = 72 + 0.94 X LV counts; Sy.x = 116). In terms of both of these validation standards this method proved superior to three published methods of RV blood pool analysis that used hand-drawn regions, and is suitable for analysis of rest, exercise, and intervention studies of RV function.

Adult↗
PubMed1982

The normal right ventricular response to supine exercise.

Nine normal, healthy young males performed graded, maximal supine bicycle exercise with monitoring of hemodynamic and gated blood pool parameters. Right ventricular ejection fraction (RVEF) was greater than 0.45 in all acquisitions at rest (mean +/- SD = 0.53 +/- 0.05) and increased greater than 0.05 in all subjects with maximal exercise (mean +/- SD = 0.69 +/- 0.06 at stage 4). There was a very close correspondence between RV and LV stroke counts from the radionuclide angiograms at rest and all exercise levels in all patients. Cardiac output changes by radionuclide data from the RV correlated closely with those obtained by the Fick technique. Multivariate analysis of RVEF vs pulmonary artery pressure, total pulmonary resistance, and heart rate showed that RVEF was inversely related to total pulmonary resistance in these patients (n = 43 acquisitions, r = 0.61, RVEF = 0.75 -- 0.001 TPR in dynes-sec/cm5 Sy.x = 0.07) and positively related to heart rate (n = 43, 4 = 0.78, RVEF = 0.34 + 0.0025 x HR Sy.x = 0.05). RVEF was not significantly related to the other hemodynamic parameters. These results suggest that in normal subjects RV systolic function is afterload-dependent and that total pulmonary resistance may be a suitable afterload index. The results emphasize that heart rate must be considered when comparing RVEF changes.

Adult↗
PubMed1981

On the calculation of climacteric symptoms.

Survey techniques, which are widely used to estimate the prevalence of climacteric symptoms, are generally unable to distinguish symptoms which relate to physiological changes from those which may be attributable to other factors. New data collection techniques developed in a study of menopause among a group of American Indians are reported here, which permit the evaluation of the cause of the reported symptoms. Two classes of complaints were than calculated: "gross" symptoms and "climacteric" symptoms. It was found that differences between prevalence, as estimated by the two classes of complaints, were smallest for vasomotor symptoms and greatest for psychological complaints, reflecting presumed physiological relationships. Further, climacteric-related symptoms demonstrated a clearer relationship to factors hypothesized by other researchers as affecting the experience of climacteric symptoms. While not feasible for all studies, these techniques demonstrate that more accurate estimates of symptom experience are possible.

Climacteric↗
PubMed1981

Experimental zinc depletion and altered taste perception for NaCl in young adult males.

Taste perception for saltiness and bitterness was tested in five young men while fed a basal (15 mg Zn/day) and zinc depletion (0.25 mg Zn/day)) diet and in three young men during zinc repletion. The perceived intensity of five NaCl solutions ranging from 0 to 600 mM and five urea solutions also ranging from 0 to 600 mM were rated on a 17-point scale. The intensity ratings for the 75 and 150 mM NaCl solutions were significantly lower (p less than 0.05) during depletion than during the basal period; intensity ratings for 300 and 600 mM NaCl solutions did not change significantly. Bitterness perception was not altered with zinc depletion. The changes in perceived intensity that occurred were not related to parotid salivary zinc concentration, percentage change in plasma zinc with depletion, or the length of time required for depletion. The results suggest that zinc depletion may alter the taste perception of some moderately salty solutions.

Adult↗
PubMed1979

Action on alcohol.

Explore the source record for details and available documents.

Alcohol Drinking↗
PubMedDate not supplied

Urticaria and hidden salicylates.

A 23-month-old girl had a chronic urticaria resistant to antihistamine therapy. She was found to be using large quantities of a topical salicylate preparation which was being regularly applied to her pacifier. Once this habit was stopped, her urticaria cleared and has not recurred.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMedDate not supplied

The measurement of salivary cadmium by electrothermal atomic absorption spectrophotometry and its use as a biological indicator of occupational exposure.

We have examined the potential use of salivary cadmium measurements for the biological monitoring of occupational cadmium exposure, paying particular attention to the contamination risks associated with such measurements. We have developed a method for the direct determination of cadmium in saliva by graphite furnace atomic absorption spectrophotometry, which minimizes the risk of contamination during sample preparation and analysis. The limit of detection is 0.6 nmoll-1, which is sufficiently sensitive to discriminate between unexposed and occupationally exposed individuals. The method has been employed to measure cadmium levels in saliva samples collected by two different methods from an unexposed population, a group of ex-workers previously exposed to cadmium (Group 1), and two groups of currently exposed workers (Groups 2 and 3). Salivary cadmium levels were significantly raised in both of the groups of currently exposed individuals (group 2 median (Md) = 17 nmoll-1, group 3 Md = 70 nmoll-1, p greater than 0.0001), and in past workers with previous long-term exposure (Group 1 Md = 2.5 nmoll-1, p greater than 0.001) when compared with an unexposed population. The results suggest that the measurement of salivary cadmium may reflect recent exposure to the metal. However, considerable care must be taken in collecting samples because a risk of contamination during sampling is apparent with procedures commonly used for saliva collection, and for this reason the applicability of such measurements for biological monitoring is limited.

Cadmium↗
PubMedDate not supplied

Cytodiagnosis of in situ and early carcinoma of the upper gastrointestinal tract.

Three cases of adenocarcinoma of the stomach, two in situ and one superficially invasive, and one of superficially invasive squamous-cell carcinoma of the esophagus are presented to illustrate the problems encountered in the diagnosis of early lesions of the upper gastrointestinal (GI) tract and the contribution that cytodiagnosis can make. The symptomology and roentgenographic findings in these cases were largely nonspecific. While endoscopic biopsies were repeatedly negative in three of the four cases, endoscopic brushing cytology consistently indicated the presence of a malignancy. Surgery was finally performed on the basis of the cytologic findings, confirming the presence of early malignancy. The cytologic findings, with histologic correlations, are presented in an effort to define some specific criteria for the diagnosis of early malignancy of the upper GI tract.

Adenocarcinoma↗
PubMedDate not supplied

Fine needle aspiration cytology of extraskeletal chondrosarcoma.

The cytologic presentation of a case of extraskeletal chondrosarcoma diagnosed by fine needle aspiration in a 57-year-old asymptomatic female is described. A mass detected on routine chest X ray and defined by CAT scan was subjected to a preoperative percutaneous fine needle aspiration under fluoroscopic guidance; a core biopsy was also obtained. Cytologic findings included pleomorphic malignant cells, with occasional spindle-shaped forms and binucleated and multinucleated cells having various degrees of nuclear atypia. The sarcomatous nature of this neoplasm was readily recognized in the cytologic material, although histologic and ultrastructural studies, which are also illustrated, were necessary to establish its specific histologic type. The biopsy was interpreted as a probable chondrosarcoma, and an exploratory laparotomy revealed a soft tissue tumor arising in the retroperitoneum. A diagnosis of soft tissue chondrosarcoma was rendered. In retrospect, the distinctive cytologic findings in the aspirated material suggest that extraskeletal chondrosarcoma should be considered in the differential diagnosis of soft tissue tumors.

Chondrosarcoma↗