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Biomedical subjects

M Feldman

Publications and source records attributed to M Feldman.

At least 235 records · Page 13Linked to original sources
PubMed1988

Life events stress and psychosocial factors in men with peptic ulcer disease. II. Relationships with serum pepsinogen concentrations and behavioral risk factors.

We examined in a controlled study whether psychologic disturbances in men with peptic ulcer disease were related to other potential ulcer "risk factors" (serum pepsinogen concentrations, cigarette smoking, and intake of alcohol, aspirin, or coffee). Psychopathology in general, personality features of hostility, irritability, and hypersensitivity, and impaired coping ability (low ego strength) each correlated significantly with serum pepsinogen concentration in ulcer patients (p less than or equal to 0.005). Cigarette smoking and intake of alcohol and aspirin were increased in ulcer patients but unrelated to psychopathology. Depression was the variable that best discriminated ulcer patients from nonulcer controls; a negative perception of life events, number of relatives with ulcer, and serum pepsinogen I concentration also had a major, unique discriminating value, whereas smoking played a relatively minor role independent of the other variables examined. Our study supports the concept that several interacting factors (psychologic, behavioral, and genetic/physiologic) are likely involved in peptic ulcer disease. Emotional stress may predispose to ulcers by producing gastric hypersecretion, as manifested by hyperpepsinogenemia.

Acetaminophen↗
PubMed1988

Comparison of gastric acid secretion rates and serum pepsinogen I and II concentrations in Occidental and Oriental duodenal ulcer patients.

The purpose of these controlled studies was to determine the prevalence of acid-pepsinogen hypersecretion in 173 patients with duodenal ulcer disease [88 Americans (75 men, 13 women) and 85 Chinese (66 men, 19 women)]. One-half to two-thirds of duodenal ulcer patients of either sex had acid hypersecretion or hyperpepsinogenemia, or both. When Chinese and American duodenal ulcer patients were compared, the two ethnic groups had similar serum pepsinogen I and II concentrations and similar maximal acid outputs per kilogram body weight. In contrast, Chinese duodenal ulcer patients had significantly lower basal acid outputs per kilogram body weight than American duodenal ulcer patients. We conclude that acid-pepsinogen hypersecretion is present in the majority of American and oriental duodenal ulcer patients.

Adult↗
PubMed1988

Apomorphine-induced nausea in humans: release of vasopressin and pancreatic polypeptide.

Based on studies in animals and humans, it has been suggested that nausea activates the hypothalamo-neurohypophyseal system with resultant increases in circulating concentrations of oxytocin or vasopressin. The purpose of these studies was to determine in humans whether nausea is associated with increases in circulating concentrations of neurohypophyseal hormones or various enteropancreatic peptides (vasoactive intestinal polypeptide, substance P, or pancreatic polypeptide). Nausea, induced by intravenous infusion of apomorphine, was associated with fivefold to 75-fold increases in plasma vasopressin concentrations in 7 subjects (mean increase, 41-fold), with no change in plasma oxytocin levels. Furthermore, nausea was associated with sevenfold to 16-fold increases in plasma pancreatic polypeptide concentrations (mean increase, ninefold), with no change in plasma levels of vasoactive intestinal polypeptide or substance P. In 1 subject refractory to nausea, there was no increase in plasma vasopressin or pancreatic polypeptide concentrations with apomorphine. These studies indicate that nausea in humans is associated with vasopressin and pancreatic polypeptide release.

Adult↗
PubMed1988

Reversal of the metastatic phenotype in Lewis lung carcinoma cells after transfection with syngeneic H-2Kb gene.

High metastatic clones of the murine 3LL carcinoma express greatly reduced levels of H-2Kb major histocompatibility complex class I antigens, while low metastatic clones of the same tumor express high levels of H-2Kb. Induced expression of this antigen after transfection with the H-2Kb gene resulted in conversion of a metastatic to a non- or low-metastatic phenotype. Unlike the parental cells, transfected cells are potent inducers of H-2Kb-restricted syngeneic cytotoxic lymphocytes that kill the Kb-positive clones and cross-react with parental nontransfected cells. Preimmunization of mice with Kb-positive transfectants conferred protection against metastatic spread of malignant cells. Moreover, immunotherapy of metastasis was achieved by immunization with the H-2Kb-transfected cells of animals already carrying a growing local tumor of the parental cells.

Animals↗
PubMed1988

Esophageal achalasia syndromes.

Esophageal achalasia, characterized by failure of the lower esophageal sphincter to relax normally with swallowing and esophageal aperistalsis, may be primary or secondary to another disorder (in the United States most often cancer). Primary achalasia is of unclear etiology but almost certainly is a disorder of the innervation of the smooth muscle portion of the esophagus. This article reviews the classification and clinical features of achalasia syndromes, as well as current concepts of pathogenesis, diagnosis, complications, and therapy of this group of disorders.

Deglutition↗
PubMed1988

Inhibitory effect of isoprenaline on gastric acid secretion in the rat. The role of endogenous histamine.

In dogs beta-adrenoreceptor agonists inhibit gastric acid secretion stimulated by exogenous gastrin to a much greater extent than acid secretion stimulated by exogenous histamine. One possible explanation for this observation is that endogenous histamine is important in gastrin-mediated acid secretion and that isoprenaline and related beta-adrenoreceptor agonists block gastric mucosal histamine release. This possibility was tested in the present study in gastric lumen-perfused anaesthetized rats. Intravenous infusion of isoprenaline (12 microgram kg-1 h-1) inhibited maximal, pentagastrin-stimulated acid output by 50-70% (P less than 0.01), but had no significant inhibitory effect on the maximal acid secretory response to histamine. In contrast to its inhibitory effect on gastrin-stimulated acid output, isoproterenol had no effect on gastric histamine output during pentagastrin infusion. We conclude that isoprenaline selectively inhibits gastrin-stimulated acid secretion in the rat, as in the dog, and by a mechanism other than inhibiting gastric histamine release.

Animals↗
PubMed1988

Effect of GABA on basal and vagally mediated gastric acid secretion and hormone release in dogs.

To stimulate peripheral gamma-aminobutyric acid (GABA) receptors, GABA, which does not cross the blood-brain barrier, was administered to dogs with vagally innervated gastric fistulas at intravenous doses of 0, 0.66, 2, 6, 18, and 54 micrograms.kg-1.min-1. Mean gastric acid output increased from zero basally to 3.0 +/- 1.4 mmol/h during infusion of 54 micrograms.kg-1.min-1 GABA. Plasma somatostatin-like immunoreactivity decreased significantly below basal levels during infusion of 54 micrograms.kg-1.min-1 GABA (P less than 0.05). To stimulate central nervous system GABA receptors as well as peripheral GABA receptors, progabide, a GABA-receptor agonist, which readily crosses the blood-brain barrier, was injected intravenously. Mean acid output was 3.5 +/- 1.3 mmol/h after 20 mg/kg progabide and 0.6 +/- 0.5 mmol/h after its vehicle (P less than 0.05). Basal serum gastrin concentration increased significantly after progabide injection. Acid output during insulin-induced hypoglycemia was inhibited 59% by 30 mg/kg intravenous progabide. Progabide infusion also diminished or abolished circulating gastrin, somatostatin, and pancreatic polypeptide responses during insulin-induced hypoglycemia (P less than 0.05). Further studies were performed in dogs with a gastric fistula and a vagally denervated Heidenhain pouch to confirm that GABA-receptor stimulation affects acid secretion via peripheral pathways. Intravenous injection of baclofen (0.5 mg/kg), a GABAB-receptor agonist, increased acid secretion significantly from the gastric fistula and the Heidenhain pouch. These studies suggest that GABA may play a role in regulating gastric acid secretion and gastrointestinal and pancreatic endocrine function by both central and peripheral mechanisms.

Animals↗
PubMed1988

Basal and PGE2-stimulated duodenal bicarbonate secretion in the rat in vivo.

We studied basal and prostaglandin E2 (PGE2)-stimulated duodenal HCO3- transport in the rat in vivo both in the presence and absence of a concentration gradient for HCO3- from blood to lumen. Basal HCO3- transport was not reduced when the luminal solution was changed from one containing 0 mM HCO3- to one containing 22 mM HCO3- either at pH 9.0 or 7.5. Thus basal duodenal HCO3- transport in rats is independent of a blood-to-lumen HCO3- concentration gradient, which indicates an energy-dependent process with little passive flux of HCO3-. Luminal or intravenous administration of PGE2 significantly (P less than 0.01) increased HCO3- secretion into a HCO3(-)-free luminal solution but had no effect on HCO3- secretion into luminal solutions containing 22 mM HCO3-, either at pH 9.0 or 7.5. Therefore prostaglandins may act by increasing passive flux of HCO3- rather than by stimulating energy-dependent duodenal HCO3- transport.

Animals↗
PubMed1988

Effect of immunization with prostaglandin metabolites on gastrointestinal ulceration.

Active immunization of rabbits with a 6-ketoprostaglandin F1 alpha-thyroglobulin conjugate induced gastrointestinal ulceration, whereas active immunization of rabbits with 13,14-dihydro-15-keto prostaglandin E2-thyroglobulin conjugate or with thyroglobulin alone did not result in ulceration. Passive immunization of a separate group of rabbits with 6-ketoprostaglandin F1 alpha-hyperimmune plasma, obtained from actively 6-ketoprostaglandin F1 alpha-immunized donor rabbits that had ulcers, induced gastric ulceration within 9 days, whereas passive immunization of rabbits with control plasma, obtained from donor rabbits actively immunized with thyroglobulin alone, did not induce ulceration. Ulcerogenic donor plasma containing antibody to 6-ketoprostaglandin F1 alpha neutralized the inhibitory actions of prostacyclin on adenosine diphosphate-induced platelet aggregation, indicating that this antibody cross-reacted with prostacyclin. In contrast, plasma containing antibodies to 13,14-dihydro-15-ketoprostaglandin E2 cross-reacted only slightly with prostaglandin E2. Thus antibodies to inactive metabolites of prostaglandins induce ulceration only if these antibodies cross-react with an endogenous, "cytoprotective" prostaglandin.

6-Ketoprostaglandin F1 alpha↗
PubMed1988

Neuropsychiatric, psychoeducational, and family characteristics of 14 juveniles condemned to death in the United States.

Of the 37 juveniles currently condemned to death in the United States, all of the 14 incarcerated in four states received comprehensive psychiatric, neurological, neuropsychological, and educational evaluations. Nine had major neurological impairment, seven suffered psychotic disorders antedating incarceration, seven evidenced significant organic dysfunction on neuropsychological testing, and only two had full-scale IQ scores above 90. Twelve had been brutally physically abused, and five had been sodomized by relatives. For a variety of reasons the subjects' vulnerabilities were not recognized at the time of trial or sentencing, when they could have been used for purposes of mitigation.

Adolescent↗
PubMed1988

Models of spinal cord injury: Part 3. Dynamic load technique.

Having previously studied a static load model of cord injury in rats, we report here an evaluation of a dynamic (weight drop) technique. Under general anesthesia, Sprague-Dawley rats were subjected to a laminectomy at T12, after which a 10-g weight was dropped onto a force transducer and impounder resting on the spinal cord; the weight drop distances varied in different groups from 0 (control) in increments of 2.5 cm to a maximal height of 17.5 cm. A strain gauge attached to the force transducer yielded an oscilloscopic wave form from which force of impact (peak force and impulse) was calculated. Eighty-six animals were used in this parametric study. The animals were observed for 4 weeks postinjury with two tests of motor recovery (Tarlov score for locomotion and the inclined plane test). After sacrifice at 4 weeks, the spinal cords were removed and, with the use of preset criteria, qualitative histopathological scoring of the extent of tissue damage was carried out. We found that the variable height of weight drop was capable of producing a graded injury that correlated with the force of injury (as measured by the force transducer) and with the outcome parameters of functional recovery and degree of morphological damage in the spinal cord. Histopathologically, there was a tendency to central cavitation of the cord. Both the static load and the dynamic load techniques seem to be valid models of spinal cord injury. Pathologically, however, the tissue damage after static load injury involved primarily the dorsal half of the cord. By contrast, the dynamic load technique produced central cavitation comparable to that observed in human spinal cord injury. In this respect, the dynamic model seems to be superior and its use is therefore recommended for studies of therapeutic intervention for spinal cord injury.

Animals↗
PubMed1988

Basal and sham-feeding-stimulated salivary flow in duodenal ulcer patients and healthy subjects.

Increased vagal (parasympathetic) stimulation of gastric secretion has been postulated in patients with duodenal ulcer disease. Since salivary secretion is influenced by parasympathetic nerves, we reasoned that duodenal ulcer patients also might have increased salivary secretion. Furthermore, if salivary secretion in duodenal ulcer patients is under nearly maximal parasympathetic stimulation basally, salivary volume might not increase with additional parasympathetic activation induced by sham feeding. To test these hypotheses, we measured basal and sham-feeding-stimulated salivary flow in duodenal ulcer patients and healthy subjects. Contrary to our hypotheses, both basal salivary flow and the salivary response to sham feeding were almost identical in duodenal ulcer patients and healthy subjects. Also, urogastrone concentrations in saliva were approximately the same in duodenal ulcer patients and normal subjects.

Duodenal Ulcer↗
PubMed1988

The c-fos proto-oncogene in murine 3LL carcinoma clones controls the expression of MHC genes.

The c-fos proto-oncogene and H-2K class I major histocompatibility antigens are differentially expressed in low-metastatic Lewis lung carcinoma clones, but not in high-metastatic clones. Interferons induce mRNA expression of fos and H-2 in non-expressor cells and elevate mRNA steady state levels of expressor cells. Transfection of non-expressor cells by v-fos or c-fos genes induces the transcription of H-2K mRNA and elevates the levels of H-2 proteins, but not of other gene products. These results, correlated with observations in other cell systems, suggest that the c-fos proto-oncogene controls the expression of MHC genes coding for class 1 antigens.

Actins↗
PubMed1988

Intralabyrinthine schwannoma.

In the case presented, an intralabyrinthine schwannoma was discovered during translabyrinthine eighth nerve section. Analysis of this case and the 22 previously reported cases of intralabyrinthine schwannoma highlights the difficulty in preoperative diagnosis of this lesion. Concerns are raised about the frequency with which this diagnosis may be missed and its implication in neurotologic surgery for vertigo.

Adult↗
PubMed1988

[Cystadenoma and cystadenocarcinoma of the pancreas].

In the past 28 years 298 pancreatic tumors have been observed, out of which 2% (6 cases) were cystadenomas and 1.3% (4 cases) were cystadenocarcinomas. Cystadenomas appear around the 6th decade of life, what constitutes an argument against its congenital origin. They are more frequent in woman (2 to 1). The histopathologic differentiation of the mucinous cystic neoplasma often forming papillae of the serous cystadenoma is useful because those are likely to become malignant. Association of pancreatic cystadenomas with different pathologies (biliary lithiasis, cancer of a different location, cysts in other organs, diabetes) has been observed, but these would be mere coincidences. Cystadenomas are frequently operative findings (3 cases) in patients who had been operated on for different reasons, but they may have different symptoms, mainly pain and a abdominal mass. Visual method of diagnosis are useful in preoperative diagnosis. In cystic formations of the pancreas with surgical possibilities, operative biopsy a must be preferred to that one obtained by means of pre-operating needle puncture. Surgical resection is the method to be chosen, either enucleation (1 case) or pancreatectomy (3 cases), being more important in mucinous cystadenoma because they may become malignant. Cystadenocarcinomas are not so frequent and seem to originate in benign cystadenomas. Palpable tumors, compression signs and pain are the late clinical manifestations. The resection is the treatment to be chosen although the most cases are unresectable. An external drainage is not a satisfactory operation but it sometimes helps to lessen the symptoms, and sometimes its posterior resection was possible.

Adult↗
PubMed1988

Antigen-tuftsin conjugate signals interleukin-1 synthesis and secretion.

The immunoglobulin heavy chain derived tetrapeptide, tuftsin (Thr-Lys-Pro-Arg), known for its phagocytosis-stimulating activity, was found to augment the antigen-presenting capacity of macrophages in culture, when applied simultaneously with antigen. Injection of antigens or antigens admixed with tuftsin had no immunogenic effect in vivo. On the other hand, antigen-tuftsin covalent conjugates, injected in aqueous solution intramuscularly or intravenously, significantly augmented antibody production. Studying the mechanism underlying these immunogenic effects, we demonstrate that tuftsin, when applied to macrophages together with, or conjugated to, antigens, signals de novo synthesis of mRNA encoding for interleukin-1 (IL-1), and induces secretion of IL-1 from the cells. We suggest that triggering the immunogenic processes by tuftsin conjugates is a consequence of up-regulation of IL-1 synthesis and secretion.

Animals↗