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Biomedical subjects

D J Ross

Publications and source records attributed to D J Ross.

61 records · Page 4Linked to original sources

An enzyme mechanism in explanation of pain in angina pectoris.

The effect of catecholamines, represented by epinephrine and norepinephrine, on the activity of phospholipase A2 from bee venom was studied. It was shown that the hydrolysis of l-alpha-lecithin to lysolecithin and a fatty acid was considerably activated by preincubation of the lecithin with the biogenic amine. On the other hand, addition of nitroglycerin or propranolol to the enzyme solution considerably curtailed activation by the catecholamines. The pharmacological effect of the split products of l-alpha-lecithin, free fatty acids (FFA), and lysolecithin in the nascent state on the myocardial cell membrane might be more plausible than the commonly accepted theory that the FFA derive from lipolysis of remote fat deposits. Certain arrhythmias and ion imbalances might be caused by catecholamine activation of phospholipase A2. Of great pharmacological interest is the observation that this activation is inhibited by a beta-adrenergic blocking agent without the presence of cyclic adenosine monophosphate as a messenger. The reaction may serve as a model for the study of the pharmacological influence of nitroglycerin and propranolol on angina pectoris.

Angina Pectoris↗

Nurses decrease barriers to health care by "hyperlinking" multiple-diagnosed women living with HIV/AIDS into care.

The Well-Being Institute (WBI), a community-based nursing organization in Detroit, Michigan, has developed and put into practice innovative intervention and service delivery models to assist HIV-positive women who have a history of substance abuse and mental illness. These multiple-diagnosed women are known to have special problems and barriers to accessing health care. The service delivery model is based on "hyperlinking" women into hard-to-get health care appointment slots through nurses' personal contacts in health care clinics. The intervention model is the personalized nursing LIGHT model. This article describes the service delivery and intervention models and discusses outcomes of the WBI Women's Intervention Program in practice. The program locates HIV-positive, substance-abusing women; enrolls them in primary medical and mental health care; and helps retain them in health care. The results of the model in practice demonstrate its success in hyperlinking hard-to-reach and hard-to-serve HIV-positive women with health care and other needed services and resources. In addition, these multiple-diagnosed women have shown positive effects with respect to improved sense of well-being and decreased psychosocial distress.

Adult↗

Differential soluble interleukin-2R levels in bilateral bronchoalveolar lavage after single lung transplantation.

Preliminary reports suggest that measurement of the soluble 55 kd subunit of the interleukin-2 receptor may facilitate the diagnosis of allograft rejection in solid organ transplants. Levels of soluble interleukin-2 receptor in serum or plasma have previously lacked sufficient sensitivity and specificity for the diagnosis of acute allograft rejection. Because single lung transplantation is preferentially performed for nonseptic end-stage pulmonary and cardiopulmonary maladies, we questioned whether the pattern of soluble interleukin-2 receptor recovery in bronchoalveolar lavage fluid obtained from both the native and transplanted lungs may enhance correct diagnosis. Fifty-three consecutive fiberoptic bronchoscopic procedures were performed with bilateral bronchoalveolar lavage fluid. Transbronchoscopic biopsies were histologically classified by the International Society for Heart Transplantation Working Formulation for Standardized Nomenclature. "Soluble interleukin-2 receptor index" was calculated as the quotient of soluble interleukin-2 receptor (in units per milliliter) by enzyme-linked immunosorbent assay, divided by protein (in milligrams per milliliter) to correct for differences in bronchoalveolar lavage fluid techniques and cellularity. Soluble interleukin-2 receptor indexes were significantly increased in the allograft bronchoalveolar lavage fluid during histologic grade A (acute rejection) versus normal transbronchoscopic biopsy specimens (3395 +/- 1298 U/mg versus 76 +/- 21 U/mg) associated with an increased transplanted/native lung ratio (69.9 +/- 46 versus 2 +/- 1 [mean +/- standard error of the mean]) (one-way analysis of variance, p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

Obstructive flow-volume loop contours after single lung transplantation.

The development of spirometric airflow obstruction may be a diagnostic dilemma in recipients of single lung allografts. The contribution of bronchial anastomotic stenosis to the observed spirometric obstruction may be clinically difficult to distinguish from that of obliterative bronchiolitis. Similarly, differentiating the "normal" obstructive defect after single lung transplantation for emphysema from obliterative bronchiolitis may be clinically challenging. We retrospectively reviewed the maximum inspiratory and expiratory flow-volume loop contours of lung transplant recipients with either obliterative bronchiolitis (n = 7) or bronchoscopically diagnosed severe bronchial anastomotic stenosis (n = 3). Five patients underwent single lung transplantation for obstructive native lung diseases and underwent observation before and after development of obliterative bronchiolitis. Bronchial anastomotic stenosis-maximum inspiratory and expiratory flow-volume loops were analyzed both before and after correction of stenosis by niobium: yttrium-aluminum-garnet laser photoresection or endobronchial silicone stent placement. Measures of airflow derived from maximum inspiratory and expiratory flow-volume loops, such as peak expiratory flow, peak inspiratory flow, forced expiratory flow at 50% vital capacity, forced inspiratory flow at 50% vital capacity, and forced expiratory volume in 1 second/peak expiratory flow ratio could not differentiate patients with bronchial anastomotic stenosis versus obliterative bronchiolitis. The most clinically useful index was the maximum inspiratory and expiratory flow-volume contour, which was characterized by terminal plateaus during exhalation and inhalation in patients with bronchial anastomotic stenosis. This index was reflected in a lower forced inspiratory flow at 75% vital capacity and forced inspiratory flow at 75% vital capacity/peak inspiratory flow ratio in bronchial anastomotic stenosis that increased after elimination of the anastomotic obstruction.(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Obstruction↗

Transesophageal echocardiographic assessment of pulmonary venous flow after single lung transplantation.

Transesophageal echocardiography was used to evaluate pulmonary venous flow velocity and pulmonary venous diameter of both the transplanted and native lungs in six single lung transplant recipients. Mean pulmonary venous velocity (50 +/- 10 versus 27 +/- 8 cm/sec) and pulmonary venous diameter (1.39 +/- 0.16 versus 0.98 +/- 0.18 cm) were significantly greater in the transplanted lung than in the native contralateral lung. An index of allograft perfusion, QD-transesophageal echocardiography (pulmonary venous velocity x pulmonary venous diameter), correlated highly with previously measured technetium 99m-labeled macroaggregated albumin quantitative lung perfusion studies (r = 0.94). A pressure gradient in pulmonary venous flow velocity across the left atrial anastomosis was detected in two patients (8 and 12 mm Hg). Analysis of previous resting supine and upright incremental hemodynamic exercise testing showed no significant differences in these two patients with respect to maximum oxygen uptake, mean pulmonary arterial pressure, pulmonary capillary wedge pressure, cardiac index, or pressure-flow relationships. Therefore these left atrial anastomotic gradients did not appear to adversely affect the pulmonary vascular response to incremental exercise. Transesophageal echocardiography may be an invaluable technique in the expedient evaluation of cardiac function and allograft perfusion after lung transplantation.

Adult↗