Search PubMed⌕ Search

Biomedical subjects

M Feldman

Publications and source records attributed to M Feldman.

At least 343 records · Page 19Linked to original sources
PubMed1983

The automated metabolic profile.

The automated metabolic profile provides the physician with a comprehensive review and graphic display of the patient's nutritional status, energy expenditure, substrate utilization, and nutritional requirements. A paramedical assistant performs all data acquisition, anthropometric and indirect calorimetric measurements. Data reduction is performed on a standard microcomputer system utilizing off-the-shelf peripherals. A standardized graphic sheet is used for the printout. The automated metabolic profile is utilized before initiation of nutritional therapy and subsequently to record the progress. Its use optimizes the clinical management of patients needing both ventilatory and nutritional support. By its use, total parenteral nutrition can be tailored to the requirements of the critically ill patient.

Anthropometry↗
PubMed1983

Sex-associated differences in the immune response against fetal major histocompatibility antigens. II. Association of the female IgG1 with H-2K-encoded alloantigens.

Alloantibodies against the H-2b haplotype were produced in C3HeB female and male parental mice in response to transplantation of F1 fetal tissue (bones). In testing IgG1 and IgG2 antibodies by means of the FACS II we found striking sex-associated differences in the isotypes produced: female mice produced much more IgG1 than male mice, although they produced comparable amounts of IgG2. Using protein-A-sepharose-purified fractions of IgG1 and IgG2, raised in the parental females we found the specificity of this extra IgG1 to be directed against the H-2Kb private determinants, in contrast to the IgG2 which was found to be specific for H-2Kb, H-2Db and I-Ab subregion alloantigens. The relevance of the association between H-2K alloantigens and IgG1, in context of the fetal-maternal relationship is discussed.

Animals↗
PubMed1983

Elimination of endogenous xenotropic retroviruses from peritoneal macrophages in virus-induced T cell lymphoma.

Peritoneal macrophages did not support the replication of 136 . 7 and 4SP, T cell lymphoma-inducing viruses, either in vivo or in vitro. Interestingly, endogenous xenotropic viruses, which were detected in more than 50% of the tested samples of peritoneal macrophages of normal C57BL/6 mice, were eliminated from peritoneal macrophages removed from 136 . 7- or 4SP-inoculated, T cell lymphoma-bearing mice. This elimination occurred about 2 weeks after virus inoculation. X-irradiation (400 rads) seemed to accelerate the elimination of xenotropic viruses from the peritoneal macrophages of mice inoculated with the radiation-dependent variant, the 4SP virus. The significance of this elimination of viruses from macrophages following inoculation with T cell lymphoma-inducing viruses is discussed.

Animals↗
PubMed1983

Sex-related differences in gastrin release and parietal cell sensitivity to gastrin in healthy human beings.

We compared serum gastrin concentrations and gastric acid secretion basally and in response to a mixed meal in age-matched women and men. Women had significantly higher basal serum gastrin concentrations (P < 0.01) and two- to threefold higher food-stimulated serum gastrin concentrations (P < 0.001) than men. Basal and food-stimulated serum gastrin concentrations in women did not fluctuate significantly during the menstrual cycle. Sex-related differences in food-stimulated serum gastrin concentrations were not due to differences in antral pH because pH after the meal in women and men had been kept constant at 5.0 by in vivo intragastric titration with sodium bicarbonate. Studies using an antibody that reacts only with potent gastrin heptadecapeptide species (G-17-I and II) indicated that women also had threefold higher serum G-17 concentrations after the meal than men (P < 0.005). Elevated serum G-17 concentrations after the meal in women were due to increased release of G-17 rather than slower clearance of G-17 from the circulation.Despite elevated serum gastrin concentrations in response to food, women secreted approximately the same amount of acid relative to their maximal secretory capacity as men. Furthermore, during exogenous G-17 infusion, which led to identical serum gastrin concentrations in women and men, the dose-response curve for acid secretion in women was shifted significantly to the right of the G-17 dose-response curve in men (P < 0.02). The dose of G-17 that stimulated half of peak acid secretion was two to three times higher in women than in men, reflecting significantly reduced sensitivity of parietal cells to gastrin in women (P < 0.05). Our studies suggest that, compared with men, women release greater amounts of gastrin but are at the same time less sensitive to stimulation of acid secretion by gastrin.

Adult↗
PubMed1983

Gastric bicarbonate secretion in humans. Effect of pentagastrin, bethanechol, and 11,16,16-trimethyl prostaglandin E2.

Although the stomach is mainly known for its ability to secrete hydrochloric acid, there is increasing evidence that the gastric mucosa also secretes bicarbonate. A simple method for simultaneous measurement of gastric HCO-3 secretion and H+ secretion was developed from a two-component model of gastric secretion. The method, which is based upon gastric juice volume, H+ concentration, and osmolality, was validated both in vitro and in vivo. In 14 healthy human beings, basal gastric HCO-3 secretion averaged 2.6 mmol/h (range, 0.7-8.7 mmol/h). Basal HCO-3 secretion was approximately 50% of basal H+ secretion and there was a significant correlation between basal HCO-3 and H+ secretion in individual subjects (r = 0.79). HCO-3 was secreted in basal nonparietal secretion at a concentration of approximately 90 mmol/liter. Intravenous pentagastrin infusion markedly stimulated H+ secretion but did not increase HCO-3 secretion. During pentagastrin infusion, the cholinergic agonist, bethanechol, significantly augmented H+ secretion (from 20.2 to 24.7 mmol/h) and increased HCO-3 secretion (from 2.2 to 4.2 mmol/h). A prostaglandin E2 analogue significantly reduced H+ secretion and increased HCO-3 secretion during pentagastrin infusion. The reduction in net gastric juice H+ output following prostaglandin E2 was due more to H+ secretory inhibition than to HCO-3 secretory stimulation. We conclude that the healthy human stomach actively secretes HCO-3 and that gastric HCO-3 secretion can be influenced by cholinergic stimulation and by prostaglandin E2.

Adult↗
PubMed1983

Disorders of gastrointestinal motility associated with diabetes mellitus.

Gastrointestinal symptoms such as vomiting, constipation, diarrhea, and fecal incontinence occur frequently in patients with diabetes mellitus. In a survey of 136 diabetic outpatients, 76% had one or more gastrointestinal symptoms, the commonest symptom being constipation (found in 60%). In many cases these symptoms are thought to be due to abnormal gastrointestinal motility that, in turn, may be a manifestation of diabetic autonomic neuropathy involving the gastrointestinal tract. The pathophysiology of these gastrointestinal symptoms, clarified in recent studies, and the clinical features and treatment of these problems in diabetic patients are reviewed.

Autonomic Nervous System Diseases↗
PubMed1983

Lack of a T-cell dependent subpopulation of macrophages in (dichloromethylene) diphosphonate-treated mice.

In Cl2MDP-osteopetrotic mice, one subpopulation of thioglycollate-induced peritoneal exudate macrophages (M phi) is missing. This subpopulation is precisely the one whose differentiation is known to be dependent on T-lymphocytes, as it is also missing in the athymic nu/nu mice. Cl2MDP-induced osteopetrosis being partially attributable to deficient osteoclastic bone resorption, raises the possibility that this missing M phi subpopulation might represent the precursors of osteoclasts. It is suggested from this work that the interplays between T-cells and M phi, so well known in immunity and inflammation, may also be relevant to osteoclastic differentiation and therefore, to bone remodeling.

Animals↗
PubMed1983

Effect of gastric alkalinization on serum gastrin concentrations in humans.

Previous studies have shown that alkalinizing the stomach with sodium bicarbonate for periods up to 3 h does not cause an increase in serum gastrin concentration. We evaluated the effect of a 5-h period of continuous intragastric alkalinization on serum gastrin concentration in 12 healthy humans and 12 asymptomatic duodenal ulcer patients. On the first day, intragastric pH was maintained between 6.0 and 7.0 for 5 h by infusing 0.3 N sodium bicarbonate into the stomach. On the second day, an identical amount of sodium bicarbonate was infused intravenously while intragastric pH was permitted to remain at its natural level for 5 h. Serum gastrin concentration was also measured in each subject and patient after infusion of a homogenized steak meal. In both healthy subjects and duodenal ulcer patients, mean serum gastrin concentrations were significantly (p less than 0.05) higher after 5 h of intragastric bicarbonate infusion than after 5 h of intravenous bicarbonate infusion during which intragastric pH remained at its natural level. Increases in serum gastrin concentration with alkalinization averaged 23% and 30% of the increases in serum gastrin after a homogenized steak meal in the same subjects and patients, respectively. We conclude that continuous gastric alkalinization for 5 h increases serum gastrin concentrations in humans.

Bicarbonates↗
PubMed1983

Loss of expression of transplantation antigens encoded by the H-2K locus on Lewis lung carcinoma cells and its relevance to the tumor's metastatic properties.

The Lewis lung carcinoma 3LL, a C57BL/6 (H-2b)-originated spontaneous tumor that progresses at the site of transplantation in all mouse strains, produced lung metastases only in mice that shared the H-2D region and the non-H-2 genetic background with the tumor's strain of origin. In vitro cytotoxicity assays revealed that 3LL tumor cells were sensitive to lysis exerted by anti-H-2Db immune effector cells but were relatively resistant to lysis by anti-H-2Kb effector cells. In addition, the 3LL tumor cells could inhibit the anti-H-2Dd response against EL 4 (H-2b) target cells but had almost no inhibitory effect on the anti-H-2Kb response against the same targets. Immunization of C3HeB (H-2k) and B10.D2 (H-2d) mice with 3LL tumor cells resulted in antisera that could preferentially react with H-2Db-positive cells but reacted very weakly with H-2Kb-positive cells. The results indicate that 3LL tumor cells expressed H-2Db cell surface antigens at a high density and seemed to lack membrane glycoproteins that are encoded by the H-2Kb region.

Animals↗
PubMed1983

Alterations in major histocompatibility complex phenotypes of mouse cloned T10 sarcoma cells: association with shifts from nonmetastatic to metastatic cells.

The T10 sarcoma, induced in a (C57BL/6J X C3HeB/-FeJ)F1 (H-2b X H-2k) mouse, grows locally (L-T10) and generates spontaneous lung metastases (M-T10). L-T10 cells were found to express the H-2b haplotype, whereas M-T10 expressed both the H-2b and H-2k haplotypes. Most L-T10 cloned cells expressed the H-2b haplotype and were not metastatic. The minority expressed both H-2k and H-2b and were metastatic. Serial transplantations of H-2k-negative clones always ended in spontaneous expression of the H-2k haplotype concomitantly with the acquisition of metastatic potency. The expressed H-2k seemed to be associated with the metastatic properties inasmuch as an H-2b-positive--H-2k-negative clone, which had lost the expressed H-2b and was temporarily H-2 negative, remained nonmetastatic until reexpression of the two haplotypes occurred. Serial transfers of H-2k-positive clones resulted in the maintenance of the expressed H-2k haplotype and the retention of metastatic capacity. A shift toward increased metastatic capacity correlated with H-2k expression occurred during serial transfers of every clone tested. Expression of major histocompatibility complex components, rather than their loss, may potentiate the metastatic capacity of tumor cells.

Animals↗
PubMed1983

Use of chromatofocusing to distinguish estradiol receptor from ovarian-dependent and -independent rat mammary tumors.

Cytosol estradiol receptor from MTW9-D (ovarian dependent) and MTW9-MtT (ovarian independent) rat mammary tumors were fractionated by chromatofocusing, a procedure which separates proteins on an ion-exchange column as a function of isoelectric point. Receptor from MTW9-D usually fractionated as three peaks with mean pH at peak height of 7.5, 6.8, and 6.0. The intermediate peak at pH 6.8 was present in 90% of MTW9-D tumors examined but in only 20% of MTW9-MtT tumors. Treatment of cytosols with 20 mM sodium molybdate or 50 mM leupeptin did not change the chromatofocusing profiles. The pI 6.8 fraction of receptor bound quantitatively to DNA-cellulose after ammonium sulfate precipitation, while receptor in the other two peaks bound much less. The quantitative binding of a fraction of estradiol receptor characteristic of MTW9-D to DNA is consistent with the greater binding of unfractionated cytosol receptor from MTW9-D to DNA than the binding of receptor from MTW9-MtT. Sucrose gradient analysis of the pI 6.8 receptor showed a sedimentation coefficient slightly less than ovalbumin with a Stokes radius of 26 A as determined by agarose chromatography. The correlation of receptor binding to DNA with response to ovariectomy might make this form of receptor a potential marker of hormonal responsivity in mammary tumors.

Animals↗