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Biomedical subjects

J Walsh

Publications and source records attributed to J Walsh.

At least 217 records · Page 12Linked to original sources
PubMed1986

Carotid endarterectomy for amaurosis fugax without angiography.

Angiography has associated morbidity and mortality, but it is the road map for the vascular surgeon. Can blood vessels be safely operated on without first obtaining an angiogram? It was the purpose of this retrospective analysis to ascertain the need for and value of carotid angiography in patients with amaurosis fugax. Twenty-eight patients (18 men and 10 women) with an average age of 66.4 years (range 58 to 71 years) had histories consistent with amaurosis fugax and were operated on for it. They did not have a history of transient ischemic attacks or stroke. Histories were reviewed for cardiac disease, smoking, hypertension, and diabetes. All patients were studied by noninvasive methods (bidirectional Doppler analysis, oculoplethysmography, carotid phonoangiography, and real-time B-mode ultrasonography), cerebral computerized tomographic scan, and angiography. Nineteen of the 28 patients (11 men and 8 women) had fluorescein angiography. All preoperative computerized tomographic scans were negative. Findings on real-time B-mode ultrasonography suggested significant ulcerated plaque in all of the patients. Angiography could only confirm ulcerated areas in 17 of the 28 patients. Of the patients studied by fluorescein angiography, 17 of 19 (10 men and 7 women) had confirmed embolic lesions. Surgery confirmed ulcerative lesions in all of the 28 patients. Results of this study indicate that if a patient has a history consistent with amaurosis fugax, a negative computerized tomographic scan, and a positive real-time B-mode ultrasonogram, an angiogram may not be necessary.

Aged↗
PubMed1986

The rib cage in normal and emphysematous subjects: a roentgenographic approach.

The configuration and motion of the bony rib cage were studied from lateral chest roentgenograms in 10 young normal subjects (YN), 12 elderly normal subjects, and 12 hyperinflated emphysematous patients [chronic obstructive pulmonary disease subjects (COPD), mean total lung capacity (TLC) 133% of predicted]. The acute angles formed by the fourth through seventh ribs with an axial reference plane were measured at residual volume, functional residual capacity, and TLC in both supine and standing positions and correlated with corresponding lung volumes. both rib angles (RA) and changes in RA with lung volume were greatest with the fourth rib and decreased progressively going down (caudad) the chest. At TLC the RA of upper ribs was significantly less in EN and significantly greater in COPD than in YN. RA's were greater supine than standing. When RA information was used together with autopsy data on the angles formed by intercostal muscles with adjacent ribs, intercostal muscle lengths in hyperinflation could be calculated. Computed intercostal muscle length data suggested that hyperinflation should not be associated with degrees of intercostal muscle shortening or overstretching, that would interfere seriously with tension generation.

Adult↗
PubMed1986

[Neurologic manifestations of ciguatera. 3 cases with a neurophysiologic study and examination of one nerve biopsy].

Ciguatera is the commonest form of poisoning resulting from eating fish in the tropics. It has been recognised since the 15th century. The disease is due to the formation of ciguatoxin by a dinoflagellate, Gambierdiscus toxicus, loosely attached to algae growing on coral reefs. The toxin, which is harmless to the fish, is ingested by small herbivorous fish and passes up the food chain as these are eaten by carnivores. The toxic effects include gastroenteritis, itching of the skin, peripheral neuropathy and central nervous system dysfunction. Though most cases are mild, occasionally the disease is severe and even fatal. There is no effective specific treatment. Three cases, of which one died and which exhibited both peripheral and central nervous system involvement, are described. Histological changes in sural nerve fibers are described. There was striking oedema of the adaxonal Schwann cell cytoplasm. These histological changes are very similar to those seen following the injection of scorpion and spider venoms into the peripheral nerve of experimental animals. Both these venoms and ciguatoxin increase the permeability of the membrane to sodium.

Adult↗
PubMed1985

Vasoactive intestinal peptide: a neurotransmitter for relaxation of the rabbit internal anal sphincter.

The circular smooth muscle of the rabbit internal anal sphincter, tested in vitro, exhibited spontaneous resting tonus and relaxed with neural stimuli of 0.05-0.5-ms duration and 1-10-Hz frequency. The relaxation was abolished by tetrodotoxin (10(-6) M) but not by atropine or propranolol at the same molar concentration, suggesting that the inhibitory neural fibers mediating relaxation are nonadrenergic and noncholinergic. One-hour incubation in physiologic solution containing 8% of rabbit vasoactive intestinal peptide (VIP) antiserum significantly reduced the relaxation induced by electrical stimulation. The reduction was greater for the shorter duration stimuli, ranging from 80% to 50% for 0.05-ms stimuli to 35%-11% for 0.5-ms stimuli. Control strips were relaxed in a dose-dependent fashion by 10(-9)-10(-6) M VIP; the antiserum at the concentration used completely blocked the relaxation produced by 10(-7) M VIP and reduced the relaxation produced by 10(-6) M VIP. Adenosine triphosphate also relaxed the internal anal sphincter in a dose-dependent manner. Prolonged inhibitory nerve stimulation (0.5 ms, 10 Hz, 30-min train) caused significant reduction in the relaxation induced by exogenous VIP, whereas the relaxation induced by adenosine triphosphate was unaffected. These data are consistent with VIP being an inhibitory neurotransmitter responsible for relaxation of the internal anal sphincter.

Adenosine Triphosphate↗
PubMed1985

Government subsidy of critical-need occupations: the case of nurses.

This paper undertakes an econometric evaluation of governmental policies aimed at increasing the labor force supply of nurses and at effecting greater hospital substitution among auxilliary health personnel, in times of nurse shortage. The methodology is to employ a simultaneous equation, multi-nurse econometric model which is estimated by a three-stage least-squares procedure incorporating use of logit transformation to deal with limited dependent variables and use of weighted least squares to deal with heteroskedasticity.

Analysis of Variance↗
PubMed1985

Wound closure of the myelomeningocoele defect.

Our experience with 74 neonates with myelomeningocoele is reported. Management in the first phase of the study period consisted of primary closure in 37 patients by wide undermining and skin advancement, marked by a high wound-complication rate. Latissimus dorsi muscle closure, either "reverse" or advanced, was performed in a transitional phase in 5 patients, characterized by increased operative time and blood loss. In the last portion of the study period, 32 patients were managed by immediate dural closure and skin grafts either simultaneously or on a delayed basis at 48 to 72 hours with a low incidence of graft loss, CSF leak, or sepsis. Back ulceration and follow-up in either the primary closure or the skin-grafted group has been infrequent.

Female↗
PubMed1985

Intermittent claudication: a double-blind crossover trial of pentoxifylline.

The influence of the xanthine derivative pentoxifylline ('Trental' or BL191; Hoechst-Roussel) on exercise tolerance was measured in 38 subjects with stable, severe to moderately severe, intermittent claudication who completed a randomised, double-blind, placebo controlled, cross-over clinical trial. Patients received placebo tablets or 400 mg slow-release pentoxifylline tablets ('Trental 400') twice a day for one week, followed by three times daily for seven weeks, and then crossed over to receive the alternate preparation for another eight weeks. Claudication distance and walking distance were measured on a treadmill before starting treatment and again at four-week intervals during the trial. At the same times, red blood cell filterability, plasma fibrinogen concentration and blood viscosity, resting and post-ischemic calf muscle blood flow, and the resting and post-exercise ankle/brachial systolic pressure ratio were also measured. In this study, the observed effects of pentoxifylline treatment were no greater than those of placebo, even though serum levels of pentoxifylline and its hydroxy-metabolite were within the anticipated range. This was shown by a 'therapeutic effect ratio' of 0.98 for treadmill claudication distance and 0.96 for treadmill walking distance after within-patient analysis at the end of the cross-over (where a ratio of 1.0 means the test drug and placebo effects are identical). These ratios have 95% confidence limits of 0.72-1.34 and 0.74-1.25, respectively.

Aged↗
PubMed1984

Inotropic effects of ionic contrast media: the role of calcium binding additives.

Renografin-76 (RG76) regularly depresses myocardial contractility during coronary angiography. Angiovist-370 (AV370) is a contrast medium similar to RG76 except the calcium sequestering agents sodium citrate and EDTA in RG76 have been replaced by calcium EDTA (an additive that does not bind additional calcium). To determine if the calcium sequestering agents contribute to the mechanical depression produced by ionic contrast media, this study compared the inotropic response of RG76 to that of AV370. Additionally, saline solutions containing sodium citrate + EDTA and calcium EDTA at concentrations found in the respective contrast media were also compared. In 10 open chest dogs the percent change and duration of the inotropic response following intracoronary injections of RG76 and AV370, as well as solutions of sodium citrate + EDTA and calcium EDTA were compared using Walton-Brodie strain gauges. Injections, 2 cc, of RG76 and AV370 produced a biphasic response characterized by an initial negative inotropic response followed by a more prolonged positive inotropic response. The magnitude (67 +/- 3% vs 59 +/- 2%; p less than 0.001) and duration (34 +/- 3 vs 24 +/- 2 sec; p less than 0.001) of the initial negative inotropic response was greater with RG76 than with AV370. The magnitude of the secondary positive inotropic response with RG76 was not different from that obtained with AV370 (31 +/- 12% vs 28 +/- 10%; p greater than 0.3). This positive response was not affected by beta-adrenergic blockage with 0.2 mg/kg of timolol.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Histological staining as a measure of stress in collagen fibers.

It has been reported previously that collagen fibers will stain either red or green by Masson's and other trichrome methods depending on whether they have been respectively stressed or relaxed prior to fixation. This was shown in skin [1, 2, 3] tendon [4, 5] bone [6] and films of collagen [7]. If this stain-stress dependence is of a unique quantitative nature, then staining could be used as a tension probe for collagen fibers. Relaxed and stressed collagen bundles of rat tail tendon and rat Achilles tendon have been stained using various staining periods, and results indicate that the change in staining may be associated with denser packing of the fibers in the bundle under stress rather than directly due to the stress itself. Denser packing may reduce the rate of penetration of the counterstain thus causing the staining differences. Since this rate of penetration is dependent on a number of other variables (unrelated to stress), it is concluded that collagen staining is not a reliable tension probe.

Achilles Tendon↗
PubMed1984

Primary gastrin cell hyperplasia. Report of five cases and a review of the literature.

Primary gastrin cell hyperfunction of the gastric antrum as a clinical syndrome consists of basal hypergastrinemia, an exaggerated gastrin response to feeding, the absence of any ectopic source of gastrin secretion, and peptic ulcer disease. The number of G-cells were quantitated in the gastric antrum of five patients with clinically diagnosed primary G-cell hyperfunction, and the results were compared to controls with a variety of gastric diseases. Patients with the clinical diagnosis of primary G-cell hyperfunction had a significantly increased number of antral G-cells (p less than 0.05). The clinical syndrome of primary G-cell hyperplasia appears to be associated with hyperplasia of G-cells rather than with the hypersecretion of gastrin by a normal number of G-cells.

Adult↗
PubMed1984

Nonspecific esterases of leukemia cell lines: evidence for activation of myeloid-associated zymogens in HL-60 by phorbol esters.

Myeloid leukemia cell line HL-60 contains fluoride-sensitive, myeloid-associated isoenzymes of nonspecific esterase that increase in activity when cultures are treated with phorbol ester. These isoenzymes are not detectable in B-lymphoblast cell line KLM-2, either in control or in phorbol-ester-treated cultures. No increased de novo synthesis of the isoenzymes is detectable in HL-60 treated with phorbol ester. The data suggest stimulated conversion of a preformed, myeloid-associated zymogen in HL-60.

Cell Line↗