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Biomedical subjects

R Fox

Publications and source records attributed to R Fox.

At least 271 records · Page 15Linked to original sources
PubMed1985

Omental protection of autogenous arterial reconstruction following femoral prosthetic graft infection.

Vascular graft infections in the femoral region that require synchronous revascularization are generally reconstructed with prosthetic grafts via extra-anatomic routes. If in situ revascularization is required, then autologous tissue provides optimal results. A particular challenge in this circumstance is achieving soft tissue coverage of the reconstruction where wide and radical débridement has removed the tissues ordinarily used for this purpose. If muscle flaps are not available or possible, the use of omentum is advocated. The omentum can be easily reached from behind the inguinal ligament and transposed on its bipedicled vascular base for coverage of vital structures in the femoral triangle, thereby obliterating dead space and providing a surface for both temporary and permanent skin coverage. The procedure is quite simple, can be performed rapidly, and should be considered for use in the dire situation that requires soft tissue coverage of exposed vessels in extraperitoneal locations.

Blood Vessel Prosthesis↗
PubMed1985

Relationship of increased lung serotonin levels to endotoxin-induced pulmonary hypertension in sheep. Effect of a serotonin antagonist.

A persistent pulmonary artery hypertension, increased airways resistance, increased vascular permeability to protein, and hypoxia are characteristic of sepsis-induced ARDS in humans and are present in the late phase injury response seen in sheep after endotoxin. Our purpose was to determine the role of serotonin, 5-HT, in the steady-state pulmonary hypertension and decreased arterial oxygen tension seen beginning approximately 3 h after Escherichia coli endotoxin injury (2 micrograms/kg) in the adult sheep. Plasma 5-HT levels remained constant, whereas lung lymph values increased from a baseline of 60 +/- 40 to 180 +/- 70 and 270 +/- 90 ng/ml at 1-h and at 3- to 5-h periods, respectively, after endotoxin. Platelet count decreased significantly only at the 3-h time period. Ketanserin, a 5-HT antagonist, was infused (0.15 mg/kg/h) in 7 sheep during endotoxin injury. The degree of early pulmonary hypertension and hypoxia was not affected by ketanserin. Mean values for pulmonary artery pressure and arterial oxygen tension were 40 +/- 8 mmHg and 70 +/- 8 torr for endotoxin alone and 38 +/- 7 mmHg and 72 +/- 7 torr for the ketanserin group. Steady-state, protein-rich pulmonary perfusion was also not altered, being increased 3-fold in both groups. Pulmonary hypertension and hypoxia were significantly attenuated, however, at the 3- to 5-h period with ketanserin, compared with endotoxin alone, the pulmonary artery pressure decreasing from 29 +/- 5 to 22 +/- 4 mmHg and the PaO2 increasing from 75 +/- 4 to 83 +/- 5 torr.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Extraglandular Warthin's tumors.

Warthin's tumor or papillary cystadenoma lymphomatosum (PCL) represents a clinically significant entity, not because of pernicious behavior, but because its cytohistological characteristics tell us much about the development and morphology of the parotid region. Three cases operated on in which PCL developed in an extraglandular location from the parotid, formed the basis for a series of observations on what is known about: 1. etiology of PCL; 2. the nature of the lymphocytic components; 3. the relatively high incidence of bilateral and multiple occurrence, as well as male predominance. These studies employed immunohistological techniques using a series of monoclonal antibodies.

Adenolymphoma↗
PubMed1985

Industrial exposure to organophosphorus compounds. Studies of a group of workers with a decrease in esterase-staining monocytes.

When an automated counting instrument using an esterase stain was employed, decreased monocyte counts were observed in a group of process workers exposed to organophosphate esters. Their monocyte counts were not found to be depressed with manual counting or with an automated counter using another staining method. The apparent depression was transient. In these workers and a comparison group, theoretical adverse consequences of decreased monocyte esterase and also possible changes in other esterases were explored. No anergy was seen with mumps or staphylococcal phage lysate hypersensitivity skin tests. Histology of the mumps reaction was similar in both groups. The depressed monocyte counts were significantly associated with a mild reduction in erythrocyte cell acetylcholinesterase, but no reduction was seen in plasma pseudocholinesterase or lymphocyte neurotoxic esterase.

Adult↗
PubMed1985

Effect of hydroxyl radical scavenging on endotoxin-induced lung injury.

The release of oxygen radicals, in particular the hydroxyl radical, from sequestered neutrophils produces acute lung injury after a number of insults. Our purpose was to determine whether hydroxyl radical, OH., is responsible for the lung injury from endotoxin characterized by (1) pulmonary leukostasis, (2) increased thromboxane production leading to pulmonary hypertension and hypoxia, and (3) increased protein permeability. This hypothesis was tested by infusion of a selective OH. scavenger, dimethyl thiourea (0.75 gm/kg), into unanesthetized sheep before endotoxin and comparison of the response to that seen with endotoxin alone. Pulmonary vascular integrity was measured by the use of lung lymph flow, QL, and lymph protein transport. Thromboxane A2 was measured as TxB2 and prostacyclin as 6-keto-PGF1 alpha. We found no difference in the degree of leukopenia and hypoxia after endotoxin or the levels of TxB2, 6-keto-PGF1 alpha, and pulmonary hypertension with dimethyl thiourea, compared with endotoxin alone. The permeability injury was also identical, with a twofold to threefold increase in protein-rich lymph seen in both groups. It appears that OH. does not play a major causative role in either phase of endotoxin lung injury.

6-Ketoprostaglandin F1 alpha↗
PubMed1984

Anuloaortic ectasia: a clinical and echocardiographic study.

Twenty-six patients with an aortic root diameter greater than or equal to 3.7 cm by 2-dimensional echocardiography (2-D echo) were studied. Group I consisted of 14 patients (mean age 50 +/- 14 years) with idiopathic anuloaortic ectasia and group II consisted of 12 patients (mean age 60 +/- 12 years) with secondary causes of aortic root dilatation. Patients in group I had a significantly larger aortic root diameter at the level of the aortic valve (5.0 +/- 0.7 cm) and 2 cm above the aortic valve (5.3 +/- 1.2 cm) as assessed by echo than did patients in group II (4.1 +/- 0.3 and 4.4 +/- 0.4 cm, respectively, p less than 0.025). The diameter of descending thoracic aorta was slightly larger in patients in group II (3.1 +/- 0.8 vs 2.7 +/- 0.5 cm, difference not significant). Over a mean follow-up period of 18 months, in group I, aortic dissection developed in 3 patients and severe aortic regurgitation and congestive heart failure in 2; 7 patients had aortic root grafting, aortic valve replacement or both. The 3 patients in group I with aortic dissection had an aortic root diameter greater than or equal to 5.3 cm, but 4 asymptomatic patients also had a diameter greater than 5 cm. Only 1 patient in group II required surgery for aortic dissection. Thus, 2-D echo is useful in identifying and following high-risk patients with anuloaortic ectasia.

Adult↗
PubMed1984

Location of myocardial necrosis as an independent determinant of left ventricular performance: analysis of 96 patients.

This study determines whether the location of myocardial scarring has an effect independent of its size on left ventricular (LV) ejection fraction (EF) in patients with coronary artery disease. Two groups of patients were studied: Group I (n = 44) had resting thallium-201 perfusion defects involving the anterior wall or septum or both, and Group II (n = 52) had perfusion defects involving the inferior wall or posterior wall or both. The thallium images were divided into 5 segments in each of 3 projections, and the thallium score was determined from the number of abnormal segments and the degree of reduction of thallium uptake; the higher the score, the more severe the perfusion deficit. If the thallium score was less than or equal to 10, EF was 45 +/- 14% (mean +/- standard deviation) in Group I and 47 +/- 11% in Group II (p = not significant [NS]). If the thallium score was greater than 10, EF was 30 +/- 12% in Group I and 32 +/- 11% in Group II (NS). Similarly, EF was not significantly different between the 2 groups when the perfusion defects were assessed by the number of abnormal segments. In each group EF was significantly lower as the number of abnormal segments increased or as the thallium score was higher (p less than 0.01). The results were unchanged when patients with resting ischemic defects or women were excluded. Thus, the location of myocardial scar itself is not important in determining LV function. However, the size of the scar is important in determining LVEF.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Improved patient selection for enzymatic lysis of peripheral arterial and graft occlusions.

Intraarterial thrombolysis by remote intravenous or direct intraarterial infusion of streptokinase is possible. The latter may be more effective with a lesser potential for systemic hemorrhagic complications because of the smaller dose administered directly in the area. Fifty patients with prosthetic graft, embolic, and renal artery occlusions were evaluated. Embolic occlusion responded dramatically, particularly since lytic therapy was initiated at an early stage. Patients with severe ischemia or those with simple localized occlusion were best treated by surgical means. Successful thrombolysis was also obtained with renal artery occlusions combined with percutaneous transluminal angioplasty. The management of patients with prosthetic graft occlusion by lytic therapy is complex. Optimal results can be obtained in patients presenting with occluded grafts after the immediate postoperative period and in those in whom previous satisfactory runoff has been demonstrated. Failure of lysis in this group is associated with a high incidence of limb loss due to unreconstructable obliterative disease. Successful lysis of occluded prosthetic grafts will often require corrective angioplasty or surgical revision.

Adult↗
PubMed1984

Stereopsis during continuous head motion.

This study investigated the degree to which the processing of stereoscopic information is degraded by side-to-side head rotations of amplitudes and frequencies known to disrupt binocular correspondence. Forced-choice recognition thresholds were obtained for a briefly presented stereoscopic test stimulus, formed from a dynamic random-element stereogram, under conditions of active head rotation. Thresholds were not impaired by such head movements, a result consistent with the hypothesis that precise binocular correspondence is not essential for the processing of stereoscopic information.

Depth Perception↗
PubMed1984

The effect of testing method on stereoanomaly.

Previous tests of stereoanomaly (a deficit in stereopsis for a given disparity direction, crossed or uncrossed) have employed stimuli in which physical contours are presented with large disparities at exposure durations too brief for eye movements. This study investigated stereoanomaly using alternative testing methods with two types of stimuli: (1) stereoscopic contours formed from dynamic random-element stereograms presented both briefly and continuously, and (2) afterimages of retinally disparate physical contours. The results from three experiments show that most subjects who are classified as stereoanomalous under conditions of brief exposure perform normally under conditions that allow long inspection periods while eliminating eye movements. These results suggest that anomalies in stereopsis previously reported may depend on the method of testing rather than on deficits in underlying neural mechanisms.

Afterimage↗
PubMed1984

Spatial contrast sensitivity of the tree shrew.

Spatial contrast sensitivity functions (CSFs) were measured for 3 tree shrews. Our two-alternative forced-choice discrimination paradigm required the animals to discriminate a vertical sine-wave luminance grating from a homogeneous field of the same size (16 degrees) and mean luminance (35 cd/m2). Spatial frequencies tested ranged from 0.1 to 2.0 c/deg and grating contrast was varied trial-by-trial using a modified staircase technique. Small between-subject variations in the shape of the CSFs appeared to be correlated with our estimates of refractive error for each animal. In general, the CSFs were of the typical band-pass type with peak sensitivity occurring at approximately 0.7 c/deg. Estimates of grating acuity derived from the CSFs ranged from 1.2 to 2.4 c/deg and are within the limitations set by the eye size and retinal anatomy of the tree shrew.

Animals↗
PubMed1984

Advanced breast cancer: response to high dose oral medroxyprogesterone acetate.

We treated 105 patients with advanced breast cancer, using the progestational agent medroxyprogesterone acetate (MPA), 200 mg orally tds in a non-randomised trial. In general they were a poor risk population, since 78 had received prior endocrine therapy (21 more than one type) and 58 prior chemotherapy. Treatment was well tolerated. Side effects included weight gain, muscle cramps, fine tremor and fluid retention, but these were usually mild, resolved if the dose of drug was reduced, and only one patient stopped treatment because of toxicity. Seventeen patients died within six weeks of starting MPA, and disease progression occurred in a further 58. Nine have had stable disease for periods ranging from two to 11 months, and there were 21 who showed disease regression. Response to treatment continues in 13 of these patients, and at the time of writing the median duration of response is 10 months. Response rates were similar in pre- and post-menopausal patients. The dose of MPA was double to 400 mg tds in 16 patients whose disease had progressed on 200 mg tds, but no additional responses were seen in this group. Seven out of 24 (29%) patients who had not received prior endocrine therapy responded to high dose oral MPA, a response rate similar to that seen following other hormonal manipulations, but because the drug also has activity against hormone-resistant tumours and is well tolerated, it should have role in the treatment of advanced breast cancer.

Antineoplastic Agents↗
PubMed1984

The Indochinese: strategies for health survival.

Compounding the "culture shock" of the Indochinese refugees were added problems of unemployment, and lack of housing and educational facilities, all leading to emotional distress. Traditional service delivery systems failed to show interest, much less offer needed service to the refugees who were stereotyped as deviant, unmotivated and resistant. The limited service that was offered ignored significant ethno-cultural factors central to effective intervention. An innovative approach was required. This paper describes a unique service program in New York City undertaken by Fordham University Graduate School of Social Service, and supported with a federal government grant. It was designed to reduce the refugees' strain and facilitate their adjustment. It trained bi-lingual and bi-cultural manpower with special skills to offer systemic, integrated and comprehensive service. The project demonstrated, quantitatively and qualitatively, that substantial impact can be made on the problems of refugees by providing ethno-centric service patterns. It provided trainees with entry-level knowledge and skill in the human services while offering relevant and responsive services to reduce the emotional strain, facilitate adjustment and secure entitlements for the refugees. It was but minimally successful in impacting on the established public and private delivery systems.

Acculturation↗
PubMed1984

Physical fitness and personality characteristics of obese and nonobese retarded adults.

Performance on a test of submaximal cardiovascular endurance and on measures of self-concept and anxiety was studied with 22 obese and 20 nonobese mentally retarded adults. Results indicated that the endurance test successfully discriminated between the obese and nonobese groups while the personality measures did not. Implications of this finding for obesity treatment were discussed.

Adult↗