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Biomedical subjects

C Meyers

Publications and source records attributed to C Meyers.

At least 73 records · Page 4Linked to original sources

Interleukin-2.

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Chemical Phenomena↗

Psychosomatic disorders in general practice: comparisons of treatment with flupenthixol, diazepam and sulpiride.

One hundred and thirteen patients diagnosed as suffering from one of four common psychosomatic syndromes (psychogenic headache, cardiac neurosis, functional disturbance of the colon, or pruritus) were treated by two groups of general practitioners with flupenthixol or diazepam or sulpiride. Flupenthixol was compared with diazepam in 58 patients in one group of Belgian practices, and with sulpiride in 55 patients in another group of practices and assessed over a 4-week period for therapeutic response and adverse effects. Flupenthixol was given in a dosage of 0.5 to 2 mg a day, diazepam in a dosage of 2.5 to 10 mg a day and sulpiride 100 to 200 mg a day, in identical capsules. In the flupenthixol/diazepam comparison, there were 7 drop-outs (3 flupenthixol, 4 diazepam). Marked or moderate reduction in global assessment of illness occurred in both treatment groups, but there was no significant difference in the therapeutic effect of the two drugs. The incidence of side-effects was low and similar in the two groups. In the flupenthixol/sulpiride comparison, there were 10 drop-outs (7 flupenthixol, 3 sulpiride). A significant reduction in symptoms occurred in both treatment groups, but this was more rapid in the flupenthixol group. Side-effects were infrequent and mild in both groups.

Adult↗

Biologically active synthetic fragments of epidermal growth factor: localization of a major receptor-binding region.

A primary receptor-binding region of mouse epidermal growth factor (EGF) was identified by comparing the relative affinities of selected synthetic fragments with overlapping sequences in the EGF receptor-binding assay, using human foreskin fibroblasts. Only synthetic peptides containing the amino acid residues 20-31 in the mouse EGF sequence showed the ability to compete with 125I-labeled EGF in binding to EGF receptors. The affinities of the cyclic EGF fragment [Ala20]EGF-(14-31) and the linear [(S-acetamidomethyl)-Cys20,31]-EGF-(20-31) were approximately 1/10(4) of the affinity of EGF. Despite their reduced receptor affinities, these two peptides exhibited the in vitro biological activities of native EGF, while fragments from other regions of the EGF molecule were devoid of these biological properties. The peptides induced DNA synthesis in human foreskin fibroblasts as measured by [3H]thymidine incorporation into DNA. They also induced EGF receptor clustering and activated the EGF-sensitive kinase, enhancing the autophosphorylation of EGF receptors in a dose-related manner. Moreover, a major antigenic determinant of EGF for rabbit anti-EGF antibodies was identified within this same localized region of the EGF molecule by competition experiments utilizing the synthetic EGF fragments. The predominant EGF antigenic determinant(s) was also found within the fragment [(S-acetamidomethyl)Cys20,31]-EGF-(20-31). The accessibility of the residues in positions 20-31 for antibody recognition is consistent with the conclusion that these residues constitute or contain a major receptor-binding region for EGF.

Binding, Competitive↗

Structure-activity relationships of eighteen somatostatin analogues on gastric secretion.

1. The effect of somatostatin and eighteen somatostatin analogues on pentagastrin-stimulated gastric acid and pepsin secretion was investigated in the conscious vagotomized cat prepared with chronic gastric fistulae. The majority of the analogues are peptides where D-amino acids are incorporated into the molecule instead of the natural L-isomers. 2. The ID50 for cyclic-somatostatin inhibition of near-maximal gastric acid secretion stimulated by pentagastrin 8 microgram kg-1 hr-1 was found to be 1.29 +/- 0.13 n-mole kg-1 hr-1. Pentagastrin-stimulated pepsin secretion had a lower threshold to somatostatin inhibition than did acid secretion. 3. D-Phe6, D-Phe7, D-Thr10, D-Thr12 and D-Phe6-D-Trp8 analogues all show low biological activity against the secretion of gastric acid and pepsin, growth hormone, insulin and glucagon. None of these analogues are antagonists of the cyclic-somatostatin inhibition of gastric secretion, suggesting that they have low affinity for this somatostatin receptor. 4. The analogues under investigation show parallel changes in activity against gastric and growth hormone secretion, suggesting a similarity between the gastric and growth hormone receptors for somatostatin. 5. D-Cys14 analogues are equipotent with or have a greater potency than cyclic-simatostatin in inhibiting the secretion of gastric acid, growth hormone and glucagon but show low insulin inhibiting activity.

Animals↗

An in vivo model for testing inhibition of arginine-induced insulin and glucagon release by somatostatin analogs.

An animal model for testing the in vivo potency of somatostatin analogs in inhibiting the release of insulin and glucagon is described. The secretion of these pancreatic hormones was stimulated in rat by infusion of arginine. The plasma insulin level increased almost to a maximum after an infusion of 10 min, while plasma glucagon rose more slowly, reaching its maximum only after a 30 min infusion. Concomitant infusion of graded doses of somatostatin (2.5, 10, 40 and 160 microgram/100 g BW) for 30 min inhibited both insulin and glucagon release in a dose-dependent manner, enabling us to test somatostatin analogs for insulin and glucagon-suppressive activity in a semi-quantitative manner. Using this animal model, 3 analogs of somatostatin [D-Cys14]-, [Ala2, D-Cys14]- and [D-Trp8, D-Cys14]somatostatin were tested in a 4-point assay. They all showed dissociated activity in inhibiting the secretion of glucagon more than that of insulin.

Animals↗

Radiographic findings in herpetic esophagitis.

The authors report a case of classic esophagitis simulating candidiasis radiographically. Endoscopy provided pathological conformation of herpes infection, showing typical multinucleated cells with intranuclear inclusion bodies.

Biopsy↗

Diverticulum of the hepatic duct: a rare anomaly.

A diverticulum of the hepatic duct was found in a 25-year-old woman. Cholangiography revealed that the diverticulum was cystic in nature and contained several stones. Since the intrahepatic ducts are never seen at surgery, the authors stress the importance of preoperative and operative cholangiography in locating such anomalies.

Adult↗

Enzymes as reagents in peptide synthesis: enzymatic removal of amine protecting groups.

A model system is described for the enzymatic deprotection of suitably masked amino groups during stepwise peptide synthesis. Nitrophenyl esters of amino acids, N-protected with trypsin-labile benzyloxycarbonylarginyl groups, were prepared as crystalline, analytically pure picrate salts in a standardized procedure. These intermediates were shown to react with amino compounds to form the expected peptide linkages. A pair of diasteriomeric peptides prepared in this way and featuring benzyloxycarbonylarginyl-L-, AND -D-glutaminyl sequences, respectively, were subjected to tryptic digestion. In both cases, a specific cleavage of the arginyl bond was achieved; however, the peptide containing the L-glutaminyl residue was deprotected much more rapidly than its diasteriomer containing the D-glutaminyl residue. The hydrolysis of the former isomer was not noticeably impeded by the presence of the latter. The results of these studies suggest that C-activated amino-acid derivatives, N-protected with trypsin-labile groups, are readily prepared in convenient form and that the peptide derivatives prepared from these intermediates are readily freed of their amino-protecting groups under mild, aqueous conditions with a potentially useful degree of stereospecificity. Theoretical implications of this first enzyme-catalyzed step in the repetitive cycle of peptide elaboration are discussed along with the procedural advantages implicit in the alternation of strongly and weakly basic groups in the protected and unprotected peptide intermediates, respectively.

Acylation↗

[Influence of traumatizing factors during captivity on somatic and psychiatric morbidity in former prisoners of war].

This study tries to evidence the effect of past traumatic experiences of the present somatic and psychiatric morbidity of the former POW. One hundred POWs hospitalized at the Ste-Ode Center for former prisonners of war and political prisonners having spent five years in the German and Austrian camps were submitted to a semi-structured interview. The number of traumatic experiences spontaneously reported has been compared with the present score on the Cornell Index form N2. The results show a relation between both data: a former POW who had undergone a minimum number of traumas significantly appears to be anxious, asthenic, nervous, with a predisposition to depression and psychosomatic disorders.

Aged↗