PubMed Health⌕ Search

Biomedical subjects

S Stein

Publications and source records attributed to S Stein.

At least 19 recordsLinked to original sources
PubMed1979

On betaH-Leu5-endorphin and schizophrenia.

A previously unknown peptide, betaH-Leu5-endorphin, has been reported in the dialysates of schizophrenic patients. Accordingly, hemofiltrates from two schizophrenic and two control patients were examined for the presence of betaH-Leu5-endorphin. The opioid peptides were detected by a radioreceptor assay after separation and identification by gel filtration and high-performance liquid chromatography. With a detection limit of 30 pmole/L of hemofiltrate, no betaH-Leu5-endorphin or Met5-endorphin was found in controls or in patients. Whatever the possible involvement of endorphins in schizophrenic behavior, they are not present at detectable levels in the hemofiltrates of two well-characterized schizophrenic patients, thereby casting doubt on a general relationship of Leu-endorphin and schizophrenia.

Adult↗
PubMed1979

Isolation of the opioid heptapeptide Met-enkephalin [Arg6,Phe7] from bovine adrenal medullary granules and striatum.

Bovine adrenal chromaffin granules have been shown to contain, in addition to Met-enkephalin and Leu-enkephalin, at least three small peptides with opiate receptor activity. One of these adrenal peptides has been purified to homogeneity and its sequence was shown to be Met-enkephalin-[Arg6,Phe&]. This heptapeptide was also found in beef striatal extracts in amounts comparable to those of Leu-enkephalin.

Adrenal Medulla↗
PubMed1979

Purification to homogeneity of camel pituitary pro-opiocortin, the common precursor of opioid peptides and corticotropin.

Pro-opiocortin was purified from camel pituitaries by procedures including high-performance liquid chromatography. The precursor relationship of the pure protein to the opioid peptides and to corticotropin was confirmed. Partial chemical analysis consisting of amino acid analysis and tryptic peptide mapping was carried out with the aid of sensitive fluorescence detection.

Adrenocorticotropic Hormone↗
PubMed1979

Alimentary tract complications after renal transplantation.

A computer analysis of post renal transplantation gastrointestinal problems was performed to identify important associated clinical factors. Thirty-seven per cent of all transplant recipients developed one or more significant problems. Hemorrhage, nondiverticular intestinal perforation, and esophagitis occurred most frequently in hospitalized patients. Pancreatitis, diverticulitis, and gastroduodenal perforation occurred characteristically in long-term survivors with well functioning allografts. Eleven of 32 HLA identical recipients treated with maintenance corticosteroids during stable kidney function developed gastrointestinal disease while only one of 13 HLA identical recipients not given maintenance steroids developed a problem, which strongly suggests a causal role for steroids in the development of late complications. The association of preexisting peptic ulcer and diverticular disease with hemorrhage and perforation supports previous recommendations that documented peptic ulcer disease or diverticulitis should be corrected surgically prior to transplantation.

Adolescent↗
PubMed1979

Carcinoma of choroid plexus in a premature infant.

A histologically proven case of choroid plexus carcinoma in a 5-week-old infant is presented. Computed tomography showed invasion through the ventricular wall, suggesting its malignant nature.

Adenocarcinoma, Papillary↗
PubMed1979

Separation of opioid peptides utilizing high performance liquid chromatography.

Chromatographic procedures have been developed for resolving all of the known enkephalins and endorphins on a single column. The effect of eluant pH on the retention times and separation of the enkephalins and beta-endorphin was determined. By combining these separations with a sensitive radioreceptor assay it is possible to assay all of the opioid peptides in the pituitary gland or in various regions of the brain from individual small laboratory animals.

Amino Acid Sequence↗
PubMed1978

Binding assay for opioid peptides with neuroblastoma x glioma hybrid cells: specificity of the receptor site.

A sensitive and rapid radioreceptor assay has been developed to monitor opioid peptides in column effluents. It is based on competitive binding to NG 108-15 cells using [3H-Tyr]Leu-enkephalin as the displaced ligand. The specificity of binding to the cells of naturally occurring opioid peptides and synthetic analogs has been shown to be similar to that found with synaptic plasma membranes.

Animals↗
PubMed1978

Characterization of pro-opiocortin, a precursor to opioid peptides and corticotropin.

The high molecular weight (approximately 30,000) precursor to opioid activity (pro-opiocortin) previously detected in extracts of rat pituitary was digested with trypsin and the resulting peptide mixture was resolved by high-performance reverse-phase chromatography. A peak of opioid activity was eluted at the position of the nonapeptide beta-LPH (61-69), which was also the same fragment obtained by trypsin digestion of betas-lipotropin or beta-endorphin. This identified the protein as a precursor to the endorphins and Met-enkephalin. No activity was detected in the position corresponding to the Leu5 analog of betas-LPH (61-69), thus ruling out the possibility of a beta-lipotropin-like precursor to Leu-enkephalin in pituitary extracts. Pro-opiocortin and beta-lipotropin are present in rat pituitary extracts in comparable amounts, approximately 10 pmol/mg of tissue.

Adrenocorticotropic Hormone↗
PubMed1978

High molecular weight opioid-containing proteins in striatum.

Striatal extracts of guinea pigs, rats, and cattle were found to contain two large proteins (greater than 40,000 and greater than 100,000 daltons) that on treatment with trypsin yield opioid peptides differing chromatographically from the opioid nonapeptide generated by trypsin digestion of endorphins, beta-lipotropin, or pro-opiocortin. Furthermore, the large opioid proteins found in the pituitary do not appear to be present in the striatum. These and other findings indicate that the striatal enkephalins are produced via a pathway from the one deduced from studies on the pituitary.

Animals↗