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Biomedical subjects

S Stein

Publications and source records attributed to S Stein.

At least 145 records · Page 8Linked to original sources
PubMed1985

Effects of unemployment on mental and physical health.

From a prospective study of the impact of stress on health in 300 men assessed every six months, men who became unemployed after entering the study were compared with an equal number, matched for age and race, who continued to work. Psychological and health data after unemployment were compared between the two groups by multivariate analysis of variance and covariance. After unemployment, symptoms of somatization, depression, and anxiety were significantly greater in the unemployed than employed. Large standard deviations on self-esteem scores in the unemployed group suggested that some men coped better than others with job-loss stress. Further analysis showed those with higher esteem had more support from family and friends than did those with low self-esteem. Furthermore, unemployed men made significantly more visits to their physicians, took more medications, and spent more days in bed sick than did employed individuals even though the number of diagnoses in the two groups were similar.

Adult↗
PubMed1984

Identification of the alpha subunit half-cystine specifically labeled by an affinity reagent for the acetylcholine receptor binding site.

Nicotinic acetylcholine receptors contain a readily reducible disulfide bond at the periphery of the acetylcholine binding site. Following reduction of this disulfide, the binding site is susceptible to affinity labeling by electrophilic reagents with quaternary ammonium moieties. We reduced purified receptor from Torpedo californica electric tissue and affinity alkylated it with 4-(N-maleimido)benzyltri[3H]methylammonium iodide. The label was incorporated solely into the alpha subunit of the receptor. Isolated, labeled alpha subunit was cleaved with CNBr, and the fragments were separated by reverse-phase high-performance liquid chromatography. A uniquely labeled CNBr fragment was isolated, and its partial sequence was determined by automated Edman degradation. This CNBr fragment was cleaved at tryptophan residues, the subfragments were separated, and the labeled subfragments were partially sequenced. From our protein sequence information, we identify the labeled CNBr fragment as residues 179 to 207 of the sequence of alpha predicted from the cDNA sequence (Noda, M., Takahashi, H., Tanabe, T., Toyosato, M., Furutani, Y., Hirose, T., Asai, M., Inayama, S., Miyata, T., and Numa, S. (1982) Nature (Lond.) 299, 793-797). From the cycle of the Edman degradation in which radioactive residues are released, we conclude that Cys 192 and, possibly in addition, Cys 193 are the residues specifically labeled by 4-(N-maleimido)benzyltri[3H]methylammonium iodide. They are, therefore, close to the acetylcholine binding site.

Affinity Labels↗
PubMed1984

Use of high-performance liquid chromatography for preparing samples for microsequencing.

A method has been developed for the microsequencing of protein at subnanomole levels. The protein is carboxymethylated and freed of salts and reagents by reversed-phase chromatography prior to automated Edman degradation on a gas-phase sequencer. The carboxymethylated protein can also be fragmented chemically or enzymatically for further sequence analysis. The analytical techniques used to monitor the progress of the reactions all have picomole level sensitivity.

Amino Acid Sequence↗
PubMed1984

Isolation of proteins from crude mixtures with silica and silica-based adsorbents.

Silica and silica-based adsorbents have been used to isolate specific proteins from crude mixtures. Acid-activated Nugel silica and Nugel SP-Silica were used to extract human immune interferon from the conditioned medium of mixed lymphocyte cultures. Human interleukin-2 was extracted from the conditioned medium of Jurkat cells with LiChroprep RP-8. In each case, batch absorption was accomplished by gentle stirring in a microcarrier vessel. The adsorbate was collected by sedimentation, and either batch-eluted or packed into a column for gradient elution. A high degree of concentration and purification was achieved with a high recovery of biological activity.

Adsorption↗
PubMed1984

Constraints on the processing of indirect speech acts: evidence from aphasiology.

The ability of anterior aphasics and patients with right-hemisphere damage to comprehend both the literal and nonliteral readings of indirect speech acts was examined. Subjects viewed videotaped episodes in which one actor asked another "Can you X?" and the second actor responded with either an action or a simple "Yes." Subjects judged whether the response was appropriate given its context. Anterior aphasics could comprehend the nonliteral but not the literal reading, supporting models that posit that people have direct access to nonliteral but conventional readings. Patients with right-hemisphere damage could appreciate the direct reading, but failed to distinguish between appropriate and inappropriate action-responses. This finding suggests that it may be possible to dissociate the pragmatic and syntactic aspects of comprehension of indirect speech acts.

Aphasia↗
PubMed1984

Characterization of small amounts of peptides and proteins.

The use of microchemical methods for the characterization of both natural and recombinant proteins of biomedical importance is discussed. The methods include gel electrophoresis, high-performance liquid chromatography, protein fragmentation, amino acid analysis and automated Edman degradation. Each procedure is applicable at the picomole level.

Journal Article↗
PubMed1984

CO2 laser surgery of the cervix, vagina, and vulva.

The gynecologic laser surgeon must be an expert colposcopist and skilled in the use of the surgical microscope. Surgical protocols for CO2 laser surgery of the cervix, vagina, and vulva are outlined and techniques discussed. Indications for its use, including treatment of cervical intraepithelial neoplasia, condylomata acuminata, and genital herpes are described and illustrated.

Biopsy↗
PubMed1984

Future concerns and recent life events of elderly community residents.

Fifty-eight elderly community residents completed a 37-item inventory that measured their level of concern about potentially stressful events or emotions. Afterwards, they indicated whether selected life events had actually occurred in the last six months. All data were intercorrelated to determine if there were relationships between total scores, personal characteristics, and recent life events. Results showed elderly persons in this sample to be most worried about immediate economic survival and disability. Those in poorer health who had less education, were living with their children, and had less tenure in the neighborhood evidenced greater total concern.

Aged↗
PubMed1983

Purification and properties of a type beta transforming growth factor from bovine kidney.

Type beta transforming growth factor (TGF-beta) has been purified 200 000-fold from bovine kidneys. This peptide is characterized by its ability to induce anchorage-dependent normal rat kidney cells to grow in soft agar in the presence of epidermal growth factor (EGF); TGF-beta is not mitogenic for cells grown in monolayer culture. Purified TGF-beta does not compete with EGF for binding to membrane receptors. The concentration of TGF-beta required to elicit a half-maximal response for formation of colonies greater than 3100 micron2 in the soft agar assay is 2-3 pM (55 pg/mL) when assayed in the presence of 0.8 nM EGF (5 ng/mL). The four-step purification procedure which includes chromatography of acid--ethanol tissue extracts on polyacrylamide sizing gels, cation exchange, and two steps of high-pressure liquid chromatography results in a 10% overall yield of colony-forming activity with a recovery of 3-4 micrograms/kg. Amino acid analysis of purified TGF-beta shows 16 half-cystine residues per mole. Analysis of the purified polypeptide by electrophoresis on sodium dodecyl sulfate-polyacrylamide gels indicates that TGF-beta is composed of two closely related polypeptide chains cross-linked by disulfide bonds. In the absence of beta-mercaptoethanol, the colony-forming activity is associated with a single silver-staining band of molecular weight 25 000; in the presence of beta-mercaptoethanol, the TGF-beta is converted to an inactive species that migrates as a single band of molecular weight 12 500-13 000. Sequence analysis indicates that at least the first 15 N-terminal amino acids of the two TGF-beta subunits are identical.

Amino Acid Sequence↗
PubMed1983

Impact on nursing home staff of training about death and dying.

The aim of the study was to test an educational program for nursing home personnel concerning working with dying patients. Ten community nursing homes were randomly assigned to experimental (training) or control (no training) conditions. Staff members in all homes were pretested on their anxieties about death, attitudes, knowledge, and skill in working with the dying. After training, experimental staff members (N = 296) had more fear of their own deaths and less fear of the dying of others than control subjects (N = 290). Also, trained staff had better attitudes toward caring for the dying patient and dealing with the family, as well as improved knowledge and skill. Data support the value of training, even though sessions may temporarily increase anxiety of staff members about their own deaths.

Anxiety↗
PubMed1983

Abdominal abscess. A surgical strategy.

To reassess the role of laparotomy and extraserosal drainage in the treatment of patients with abdominal abscess, we analyzed the course of 79 patients who underwent 97 operations to treat 120 abdominal abscesses during a five-year period. In 66 clinical episodes the abscess was drained by the most direct approach. Sepsis resolved with a single operation In 80% of these patients, five patients (8%) required a second operation for drainage for an abscess, and eight patients (12%) died. In 31 clinical episodes, the abscess was drained by a laparotomy. Sepsis resolved with a single operation in 61% of these patients, seven patients (21%) had a second abscess, six patients (19%) required a second operation to drain a metachronous abscess, and six patients (19%) died. When the location or number of abscesses was diagnosed incorrectly, the success rate of therapy fell substantially. Since most abdominal abscesses can now be accurately diagnosed preoperatively, most abscesses should be drained by a direct approach. Exploratory laparotomy is indicated when preoperative localization is unsuccessful, when sepsis has not resolved after other methods of drainage, or when the patient has a concomitant abdominal condition that must be treated surgically.

Abdomen↗
PubMed1983

Cimetidine in the treatment of Zollinger-Ellison syndrome.

From 1977 to 1983 we used cimetidine as primary therapy for 17 patients with the Zollinger-Ellison syndrome. All patients were treated with oral doses of cimetidine, 300 to 600 mg, four times a day, unless symptoms of hyperacidity developed or until evidence of a potentially resectable tumor became available, at which time they underwent definitive therapy. Eleven (65 percent) had no response to cimetidine therapy, 7 of whom had symptomatic recurrent ulcers, 3 of whom had esophagitis, and 2 of whom had severe diarrhea. Eight of these patients were treated with total gastrectomy, two with successful tumor resection, and one with parietal cell vagotomy (which facilitated the control of hyperacidity with cimetidine). All operations except one were performed electively and there was no operative mortality.

Adolescent↗
PubMed1983

Pig brain contains cholecystokinin octapeptide and several cholecystokinin desoctapeptides.

A sequential method employing methanol extraction of the COOH-terminal fragment of cholecystokinin (CCK) from pig brain followed by HCl extraction of the more basic CCK peptides was used as the first step in purification of these peptides. Recovery was monitored with two different assays, one directed to the COOH terminus of CCK and the other to the NH2 terminus. The amino acid content and sequence were determined for each of five peptides after purification. The only peptide containing COOH-terminal immunoreactivity was CCK-octapeptide (CCK8). The other four peptides did not contain CCK8 and had lost one or two additional amino acids, perhaps as a consequence of the action of carboxypeptidases. These peptides were shown to be CCK33-desnonapeptide, CCK39-desnonapeptide and -desdecapeptide, and a large molecular weight precursor, CCK58-desnonapeptide, containing 19 amino acids (Ala-Val-Gln-Lys-Val-Asp-Gly-Glu-Ser-Arg-Ala-His-Leu-Gly-Ala-Leu-Leu-Ala-Arg) NH2-terminal to CCK39. The three NH2-terminal fragments of CCK58, CCK39, and CCK33 were about equally prominent. The brain, unlike the gut, appears to cleave CCK8 rapidly from a precursor peptide but to process the NH2-terminal portions of the molecule more slowly and incompletely.

Amino Acid Sequence↗
PubMed1983

Resection of gastrinomas.

Exploratory laparotomy and a search for gastrinomas was performed in 52 patients with the Zollinger-Ellison syndrome (ZES). Gastrinoma tissue was resected in 11 patients (21%), 6 (12%) of whom appear to have been cured. After surgery, serum gastrin levels in these six patients have remained normal from 10 months to 10 years. In the 46 other patients, tumor was unresectable because of metastases or multiple primary tumors (21 patients; 40%) or inability to find the tumor at laparotomy (21 patients; 40%). Multiple pancreatic islet cell adenomata were found in six of seven patients with multiple endocrine neoplasia (MEN), indicating that patients with this condition usually have diffuse involvement of the pancreas. The results of CT scans correlated with findings at laparotomy in 13 of 16 patients. The smallest tumor detected by CT scans was 1 cm in diameter. CT technology is more accurate in finding gastrinomas now than in the past and has a useful role in preoperative evaluation. The possibility of resection should be seriously considered in every patient with Zollinger-Ellison syndrome. Abdominal CT scans, transhepatic portal venous sampling, and laparotomy should be used to find the tumor and to determine whether it is resectable. Using presently available methods, it should be possible to cure about 25% of patients with gastrinomas who do not have MEN and over 70% of those without MEN who appear to have a solitary tumor. Total pancreatectomy may be necessary to cure some patients with MEN, but that operation is rarely justified. The morbidity and mortality of surgical attempts at curing this disease have become minimal; we have had no deaths or serious complications following such operations in over 10 yrs. Total gastrectomy and indefinite use of H2-receptor blocking agents are the therapeutic options for patients with unresectable gastrinomas. Because H2-receptor blocking agents fail to control acid secretion in many patients after several yrs of therapy, total gastrectomy is indicated in a large proportion of patients whose tumors cannot be resected. Total gastrectomy in patients with ZES is also safe using current techniques; our last death following this operation for ZES occurred 15 yrs ago.

Adenoma, Islet Cell↗
PubMed1983

Classical "parietal" neglect syndrome after subcortical right frontal lobe infarction.

The classical unilateral neglect syndrome is usually associated with lesions of the nondominant inferior parietal lobe. Symptoms typically include a disturbance of orienting and attending to sensory events. We examined three patients with a "parietal" neglect syndrome: CT-documented infarctions that involved only the subcortical right frontal lobe and basal ganglia. There was no CT abnormality in the nondominant parietal lobe. Our data support the view that for polymodal cortical association areas such as the parietal lobe, which connect a variety of distant cerebral areas including the frontal lobe and basal ganglia, damage in a part of the network may be associated with different aspects of the neglect syndrome.

Aged↗