PubMed Health⌕ Search

Biomedical subjects

J Benjamin

Publications and source records attributed to J Benjamin.

At least 37 records · Page 2Linked to original sources
PubMed1988

Prostaglandins, H2-receptor antagonists and peptic ulcer disease.

Peptic ulcer develops when offensive factors overwhelm defensive processes in the gastroduodenal mucosa. Offensive factors include NSAIDs, hydrochloric acid-peptic activity, bile reflux, and some products of the lipoxygenase pathway such as leukotriene B4; whereas defensive processes are largely mediated by prostaglandins through poorly understood mechanisms uniformly termed cytoprotection. Cytoprotection, a physiological process working through the products of arachidonic acid metabolism, may result from the net effect of the protective actions of prostaglandins versus the damaging actions of leukotrienes. Some prostaglandins also have antisecretory effects. Therefore the peptic ulcer healing effects of prostaglandin analogues, all of which have significant antisecretory activity, may be more due to their antisecretory effects than primarily to their effects on mucosal defences. Certain drug-induced gastroduodenal lesions, e.g. NSAID-induced ulcers, which are often unresponsive to H2-receptor antagonists, have been healed and their recurrence prevented by the use of PGE1 and PGE2 analogues. All the prostaglandin analogues investigated to date in humans have the potential for inducing abortion, an important side effect which may limit their worldwide use. The optimal prostaglandin analogue for ulcer healing should not induce abortion and should be potently cytoprotective. The predominant damaging agent in the development of peptic ulcer disease is gastric hydrochloric acid. Thus, the worldwide established efficacy and safety of H2-receptor antagonists such as cimetidine, ranitidine, famotidine and most recently of roxatidine acetate suggest that these agents have become the standard by which other forms of anti-ulcer therapy should be judged.

Histamine H2 Antagonists↗
PubMed1987

Biomechanical evaluation of various forms of fixation of transverse patellar fractures.

A study was undertaken to evaluate the strength and ease of application of four different forms of patellar fracture fixation. Modified tension band, screw fixation, Lotke longitudinal anterior band (LAB), and Magnusson wiring were examined using a Materials Testing System. Using cadaver lower extremities, the tibia was mounted in a fixed base and the tibiofemoral joint was fixed at 36 degrees. Tension was applied to the patella through the quadriceps tendon and fracture displacement was measured with linear motion transducers. Based on the results, we recommend screw fixation for transverse patellar fractures in patients with adequate bone stock. In patients with patellar fractures with comminution and/or osteopenia, modified tension band fixation is recommended. Simple wiring techniques alone may not provide sufficient fixation to allow immediate range of motion.

Biomechanical Phenomena↗
PubMed1986

Renal disease associated with toluene inhalation.

A 32-year old woman developed severe quadriparesis, hypokalemia, and distal renal tubular acidosis following paint sniffing for one week. A review of literature indicated that a spectrum of renal diseases may develop in association with inhalation of toluene-containing substances. Toluene inhalation should be considered in the differential diagnosis in any young patient who presents with an unexplained renal disorder.

Acidosis, Renal Tubular↗
PubMed1979

Protection against alloxan-induced diabetes by various urea derivatives: relationship between protective effects and reactivity with the hydroxyl radical.

Several urea derivatives (monomethylurea, monoethylurea and diethylurea) give i.p. to mice 30 min before alloxan (75 mg/kg i.v.) were able to prevent the diabetogenic actions of alloxan. Protection by these agents correlated reasonably well with their capacity to react with (scavenge) the hydroxyl radical. Protection did not correlate with the capacity of the above agents to cause a transient hyperglycemia at the point of alloxan administration, which might have also been a potential means of protection. These data extend previously published data on the capacity of hydroxyl radical scavengers to protect against alloxan and add evidence to the concept that the hydroxyl radical, generated within the beta cells, is the species derived from alloxan responsible for the damage to beta cells.

Animals↗
PubMed1976

A comparison of pulmonary function in male smokers and nonsmokers.

Results of certain tests of pulmonary function, including a questionnaire, single-breath N2 test of closing capacity, forced expiration, and diffusing capacity were significantly different in groups of male smokers and nonsmokers. The influence of age on these smoking-related changes of pulmonary function was evaluated. The analyses indicated that (1) some tests including number of symptoms; closing capacity, i.e., closing volume plus residual volume as a percentage of total lung capacity; residual volume as a percentage of total lung capacity; Phase III of the single-breath N2 test, and steady-state diffusing capacity (ml of CO/mm Hg - min) revealed significant differences between adjusted mean smoker and nonsmoker values but did not reveal differences associated with age. (2) Tests of forced expiration (1-sec forced expiratory volume/vital capapity, reciprocal of the maximal mid-expiratory flow, maximal flow at 50 per cent of vital capacity; and moments) however, revealed differences between smoker and nonsmoker means )adjusted and unadjusted), as well as increasing smoker-nonsmoker differences with increasing age. It is suggested that the first group of tests probably measured an all-or-none response that occurred with the onset of smoking and was not affected by duration of smoking. The second group of tests probably measured the effects of continued smoking and indicated increasing abnormality associated with longer exposure (years of smoking). Test showing age-related differences between smokers and nonsmokers may reflect cummulative, irreversible changes in pulmonary function to a greater extent than test that do not.

Adolescent↗
PubMed1975

Vascular interdependence in postmortem human lungs.

Interdependence of arteries and the surrounding lung was estimated in excised, postmortem human lungs. At low vascular pressures, vessel diameter increased as the lung was inflated. At high vascular pressures, vessel diameter decreased as the lung was inflated. Compared to the effects of interdependence in excised dog lobes, those in human lungs at low transpulmonary pressures were small. The following conclusions were reached: (1) the diameter of intrapulmonary arteries is stabilized (more constant with changes in intravascular pressure) when the lung has a high transpulmonary pressure; (2) increases in pulmonary vascular resistance at high lung volumes may be related to extra-alveolar, as well as intra-alveolar, vessel compression; (3) interdependence in human lungs differs markedly from interdependence in dog lungs.

Adolescent↗