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Biomedical subjects

J M Becker

Publications and source records attributed to J M Becker.

At least 199 records · Page 11Linked to original sources
PubMed1983

Hostile words and assaultive behavior on an acute inpatient psychiatric unit.

This report analyzes the relationship of hostile verbalizations to assaultive acts committed by 110 male schizophrenic patients on an acute psychiatric unit. It was found that patients who were verbally assaultive and threatening also tended to be physically assaultive. Assaults rarely occurred in the absence of verbal threats or abuse, and 32 per cent of violent patients could be identified on the basis of the occurrence of hostile verbalizations.

Acute Disease↗
PubMed1983

Polyoxin D inhibits growth of zoopathogenic fungi.

We demonstrated that polyoxin D at millimolar concentrations caused marked morphological alterations of the human pathogens Candida albicans and Cryptococcus neoformans. C. albicans incubated in the presence of this drug grew in long chains that were severely swollen. Polyoxin D inhibited the growth of C. neoformans and killed cells of both the yeast and the hyphal phase of C. albicans. These observations give the first evidence that polyoxin antibiotics can kill zoopathogenic fungi.

Antifungal Agents↗
PubMed1983

Synthesis and biological activity of tripeptidyl polyoxins as antifungal agents.

Three tripeptidyl polyoxins were synthesized and found to inhibit Candida albicans. Compared with the naturally occurring polyoxin D, the three synthetic polyoxins had little effect on chitin synthetase when assayed with a C. albicans membrane preparation. However, all the compounds inhibited growth, affected cell morphology in a manner similar to that of polyoxin D, and were hydrolyzed by cell extracts of C. albicans. Hydrolysis did not occur extracellularly, and at least one of the synthetic polyoxins, leucyl-norleucyl-uracil polyoxin C, inhibited peptide uptake, suggesting entrance into the cell via the peptide transport system. Thus, the intact tripeptidyl polyoxins are inactive prodrugs that are converted to active moieties by cellular enzymes.

Antifungal Agents↗
PubMed1983

Postprandial inhibition of canine enteric interdigestive myoelectric complex.

Our aim was to determine whether the passage of postprandial duodenal chyme into the jejunum activates jejunal feedback mechanisms that inhibit the interdigestive myoelectric complex (IMC) of the canine small bowel. In five conscious dogs with 75-cm Vella loops of proximal jejunum and recording electrodes on the duodenum and the loop, intestinal myoelectric activity was recorded for approximately 4 h during fasting. The dogs were then given either a 200-g liver meal orally or they underwent perfusion of the jejunal loop with postprandial duodenal chyme collected from a donor dog given an identical liver meal. Before feeding, IMCs occurred at mean intervals of 126 +/- 16 (SE) min in the duodenum and 88 +/- 10 min in the loop. Feeding by mouth completely inhibited the IMCs in the duodenum but failed to inhibit the IMCs in the loop. However, perfusion of the jejunal loop with duodenal chyme suppressed the IMCs in both the loop and the duodenum. We concluded that postprandial inhibition of duodenal IMCs is mediated in part by neural and/or hormonal factors activated by chyme in the jejunum, whereas local factors inhibit jejunal IMCs. An enteric phase of postprandial IMC inhibition is postulated.

Animals↗
PubMed1983

Antral control of canine gastric emptying of solids.

We wondered whether antral mucosal nerves sense the size of particles in gastric chyme and then activate motor mechanisms that allow only small particles to empty. Four conscious dogs with duodenal Thomas cannulas were fed 100 g of bovine liver, half of which was labeled with cyano[57Co]cobalamin. Duodenal chyme was then collected in 15-min periods for 5 h and poured through a stack of sieves of decreasing pore size, and the percentage of radioactivity recovered on each sieve was determined per hour. Five studies were carried out on each dog before and beginning 2 wk after antral mucosal neurolysis, during which the antral mucosal nerves were divided by dissecting the entire antral mucosa circumferentially free from the surrounding antral muscularis. In the control tests, nearly all liver (93%) emptied as particles less than 1.4 mm in diameter, but the percentage emptied as larger particles increased in the 3rd through 5th postprandial h. After antral mucosal neurolysis, the increase in the percentage of larger particles emptied occurred sooner and to a greater extent, but the overall rate of emptying of liver was not changed. We concluded that antral mucosal nerves have a role in regulating the size of gastric particles emptied, but a minor one.

Animals↗
PubMed1983

Intestinal pacing for canine postgastrectomy dumping.

Our aim was to determine whether or not postprandial retrograde duodenal pacing would abolish the canine postgastrectomy dumping syndrome. Five dogs underwent truncal vagotomy, distal hemigastrectomy, gastroduodenostomy, and circumferential proximal duodenal myotomy to facilitate pacing. Bipolar stimulating electrodes from an implanted pacing unit were attached to the bowel 35 cm distal to the gastroduodenostomy, and six monopolar recording electrodes were applied at 5-cm intervals proximal to the pacing electrodes. After recovery, gastric emptying was assessed in the fasted conscious dogs using 300-ml gastric instillates of 25% dextrose marked with [14C]polyethylene glycol, while pulse, hematocrit, and defecation were monitored. Each dog underwent five tests with and five tests without retrograde duodenal pacing. Without pacing, the dogs emptied a mean +/- SEM of 237 +/- 14 ml of the instillate by 20 min and developed tachycardia (change in pulse, 45 +/- 4), hemoconcentration (change in hematocrit, 8 +/- 1), and diarrhea in 13 of 25 tests. Retrograde duodenal pacing slowed gastric emptying (157 +/- 20 ml, p less than 0.05) and minimized the adverse cardiovascular sequelae (change in pulse, 25 +/- 5, change in hematocrit, 6 +/- 1; p less than 0.05) and the diarrhea (only 2 of 25 tests, p less than 0.01). We concluded that intestinal pacing ameliorated the postgastrectomy dumping syndrome in dogs. Such an approach may be applicable to humans.

Action Potentials↗
PubMed1983

Proximal gastric vagotomy and mucosal antrectomy: a possible operative approach to duodenal ulcer.

Our aim was to develop proximal gastric vagotomy with mucosal antrectomy as an operative approach to duodenal ulcer. We performed mucosal antrectomy in four dogs by excising the antral mucosa via a circular corporal myotomy, removing a circumferential band of corporal seromuscularis, anastomosing the corporal and pyloric mucosas endoantrally, and reapproximating the corporal and antral seromuscularis. Gastric emptying and serum gastrin were assessed before and 4 weeks after operation. A second operation, proximal gastric vagotomy, was then done, and the tests were repeated 4 weeks later. The concentration of gastrin in the serum during fasting was lower after mucosal antrectomy than before operation, as was the postprandial concentration; the values remained low after proximal gastric vagotomy. Gastric emptying of liquids and indigestible solids was unaltered by mucosal antrectomy or mucosal antrectomy plus proximal gastric vagotomy. The emptying of digestible solids was slowed somewhat by mucosal antrectomy to 75% of the control rate, but no further change was found after proximal gastric vagotomy. We concluded that mucosal antrectomy eliminated the gastrin-producing antral mucosa and, in combination with proximal gastric vagotomy, did not greatly alter gastric emptying of liquids or solids. The combined operation might have a role in the surgical treatment of duodenal ulcer.

Animals↗
PubMed1982

Photoinactivation of peptide transport in Saccharomyces cerevisiae.

Oligopeptides and dipeptides are transported into Saccharomyces cerevisiae by a carrier-mediated system. In the dark, leucyl-p-nitroanilide (Leu-p-NA) and leucyl-leucyl-4-azido-2-nitrophenylalanine [Leu-Leu-Phe-(4N3,2NO2)] are competitive inhibitors of peptide transport by S. cerevisiae cells. The photolysis of yeast cells in the presence of Leu-p-NA or Leu-Leu-Phe(4N3,2NO2) at 350 nm results in an irreversible inactivation of peptide transport. Protection against this inactivation is afforded by an excess of trimethionine, a transported peptide. Photolysis with Leu-p-NA or Leu-Leu-Phe(4N3,2NO2) does not affect amino acid or sugar transport, and cell viability is maintained throughout the irradiation procedure. A 5-min irradiation of S. cerevisiae with 2.4 microM Leu-p-NA or 15 microM Leu-Leu-Phe(4N3,2NO2) causes 50% inhibition of trimethionine uptake. p-Nitroaniline, a possible hydrolysis product generated from Leu-p-NA by cellular peptidase activity, has no effect on peptide transport. An exogenous energy source is not required for photoinactivation. The results suggest that a component(s) of the peptide transport system of S. cerevisiae is irreversibly modified by photolysis with Leu-p-NA or Leu-Leu-Phe-(4N3,2NO2) and provide the first example of the use of amino acid p-nitroanilides as photoaffinity labels.

Affinity Labels↗
PubMed1982

Hemofiltration treatment of psoriasis.

Eleven patients with severe psoriasis were treated with hemofiltration once weekly for 4 consecutive weeks. Hemofiltration is a method of extracorporeal dialysis that uses a pressure gradient, rather than passive diffusion, to remove small and medium molecular weight substances from the blood. Six of the patients had very substantial clearing of their psoriatic lesions. Five patients had little or no apparent benefit during the course of hemofiltration treatments. They subsequently had dramatic clearing, however, when previously ineffective topical therapy was resumed. No patient had worsening of his condition during the hemofiltration series, and there were no perceived adverse effects.

Adult↗
PubMed1982

The context of involuntary commitment on the basis of danger to others: a study of the use of the California 14-day certificate.

This study examines the applications of civil commitment criteria for prolonged (14-day) involuntary hospitalization of individuals judged to be dangerous to others by reason of mental illness. The California Civil Commitment Statute (Lanterman-Petris-Short, LPS) provides for such commitment, after a 72-hour period of observations. For a sample of 71 males on an acute inpatient unit, we examined the relationship between 14-day certification by reason of dangerousness to others (DO) under the LPS and measures of prehospitalization dangerousness, prior legal status, assaultive behavior in hospital, and mental status. The 31 per cent of subjects who were certified as DO were found to have been significantly more often held initially for 72-hour observation on the DO grounds than were patients who were certified for other reasons. However, subjects in the DO group were no different from the contrast groups on ratings of assaultiveness of preadmission behavior and of violent acts while in hospital. The implications of these results for the evaluation of civil commitment proceedings are discussed.

Adult↗
PubMed1982

Short-term civil commitment and the violent patient.

To explore the specificity of criteria for civil commitment for dangerousness, the authors examined the relationship between civil commitment for dangerousness to others under the California Civil Commitment Statute (the Lanterman-Petris-Short Act) and violent acts and behavioral ratings made immediately after commitment. Using a prospective design they evaluated 84 subjects. The ratings of violent acts for subjects considered dangerous to others were no different than those of a nondangerous control group. The subjects considered dangerous to others, however, differed on several subscales of the Brief Psychiatric Rating Scale. The authors discuss the implications of these results for civil commitment proceedings.

Adult↗
PubMed1982

Drift and dangerousness: social class differences between acute schizophrenics and their parents in relation to measures of violence.

Socio-economic differences between schizophrenics on an acute in-patient unit and their parents were studied in relation to indices of dangerousness and of psychiatric status. It was found that, whenever thier class of origin, a large proportion of patients had dropped in occupational attainment, relative to that of their parents, but that patients tended to be higher in education than their parents. Patients who had committed an assaultive act prior to admission were lower in social status than their parents.

Adult↗
PubMed1982

Effect of gastrointestinal hormones on the biliary sphincter of the opossum.

The smooth muscle sphincter enveloping the terminal portion of the common bile duct in the opossum exhibits spontaneous electrical activity and simultaneous rhythmic contractions. The aim of our study was to define the influence of four gastrointestinal hormones on biliary sphincter electrical and mechanical activity. An array of five monopolar extracellular electrodes was placed along the opossum choledochal sphincteric smooth muscle and contiguous duodenum. A catheter in continuity with a pressure transducer, drop counter, and saline reservoir was placed in the common duct for simultaneous measurement of ductal pressure and flow. The cystic and distal common hepatic ducts were then ligated to isolate the common bile duct from the gallbladder and liver. In each opossum, biliary sphincteric and duodenal myoelectric activity, common bile duct and gallbladder pressure, and common duct flow were recorded simultaneously before and after the intravenous administration of five different doses of an enteric hormone. Ten animals were given 0.1-10.0 international dog units per kilogram body wt of cholecystokinin, 10 received 0.01-1.00 microgram/kg body wt of cholecystokinin-octapeptide, 10 were given 0.1-10.0 micrograms/kg body wt of secretin, and 5 were given 0.1-10.0 micrograms/kg body wt of pentagastrin. Cholecystokinin, cholecystokinin-octapeptide, and pentagastrin all effected a significant increase in sphincter electrical spike activity and common duct pressure with a decrease in common duct flow. This contractile response was consistent at a wide range of hormonal levels. Secretin had little effect on biliary pressure, flow, and myoelectric activity. The data lend support to the concept that cholecystokinin and gastrin contract the biliary sphincter, metering bile flow at the time of gallbladder emptying in the opossum.

Action Potentials↗
PubMed1981

Peptidase activity in the inner membrane of Pseudomonas aeruginosa.

The location of peptidase activity within the cell envelope structure of Pseudomonas aeruginosa has been studied. Inner and outer membrane fractions were separated on the basis of buoyant density using two consecutive sucrose steps gradients and identified on the basis of known components. The inner membrane was shown to contain peptidase activity while the outer membrane contained none. These data support the hypothesis that P. aeruginosa transports intact peptides.

Cell Membrane↗
PubMed1981

Reconstructive gastric surgery.

Among 173 patients undergoing reconstructive gastric operations, including 115 patients who received Roux-en-Y gastrojejunostomy, 25 with jejunal interpositions, 11 with conversion of Billroth II to Billroth I, 8 with closure of gastroenterostomy, 5 with pyloric reconstruction and 9 with other operations, only 2 immediate postoperative mortalities occurred. A perfect or good result was obtained in 108 of 156 patients (69 per cent) at long term follow-up, while a fair result was achieved in 35 patients (22 per cent) and a poor result in 13 patients (9 per cent). We concluded that reconstructive gastric operations were safe and had clearly improved 7 of 10 patients in this series.

Adult↗