Search PubMed⌕ Search

Biomedical subjects

A Goldstein

Publications and source records attributed to A Goldstein.

At least 199 records · Page 11Linked to original sources

Porcine pituitary dynorphin: complete amino acid sequence of the biologically active heptadecapeptide.

The full primary structure of the very potent opioid peptide dynorphin, from porcine pituitary, has been determined. It is (H)Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Ile-Arg-Pro-Lys-Leu-Lys-Trp-Asp-Asn-Gln(OH). The synthetic peptide with this sequence behaves identically to natural dynorphin in a number of ways, and it has the same potency in the guinea pig ileum myenteric plexus--longitudinal muscle bioassay. The potency is accounted for by the first 13 residues.

Amino Acid Sequence↗

Immunoreactive dynorphin in mammalian spinal cord and dorsal root ganglia.

The distribution of immunoreactive dynorphin (ir-dynorphin) has been determined in dorsal and ventral aspects of spinal cord and in dorsal root ganglia of rabbit and rat. Concentrations are highest in dorsal root, with intermediate levels in ventral cord and low levels in dorsal root ganglia of both species. Levels of ir-dynorphin are relatively uniform over examined segments (vertebrae C2-S3) of rabbit spinal cord and dorsal root ganglia. Gel permeation chromatography of extracts from rabbit dorsal and ventral spinal cord and dorsal root ganglia revealed at least three immunoreactive components of differing molecular size in all three structures. Multiple unilateral or bilateral dorsal rhizotomy (vertebrae C5-T1) in rat did not affect levels of ir-dynorphin in spinal cord. As reported [Goldstein, A. & Ghazarossian, V. E. (1980) Proc. Natl. Acad. Sci. USA 77, 6207-6210], midthoracic spinal transection was without effect. Within the spinal cord, the neuropeptide appears, most probably, to be contained in short-axoned neurons. We surmise that this potent opioid peptide may participate in the processing of sensory information in spinal cord.

Animals↗

Dynorphin immunocytochemical localization in brain and peripheral nervous system: preliminary studies.

Using antisera specific for the opioid peptide dynorphin, we have carried out immunocytochemical studies of the distribution in rat brain and periphery. In the central nervous system, cells that stain positively for dynorphin are found in the supraoptic nucleus, with less-well-stained cells in the paraventricular nucleus of the hypothalamus. Few positive fibers were detected in brain, suggesting problems with fixation and preservation of antigenicity. In pituitary no staining was seen in the anterior and intermediate lobes but heavy staining was detected in the posterior lobe. In the guinea pig, adrenal chromaffin cells stained with dynorphin antisera. Staining of these cells could be blocked with excess of dynorphin-(1-13) or either enkephalin. Radioimmunoassays revealed a great excess of the enkephalins in the adrenal, suggesting cross competition between dynorphin antiserum and adrenal medullary enkephalin. Finally, the dynorphin antiserum stained a complex of fibers in guinea pig ileum. Staining of these fibers could be blocked by moderate amounts of enkephalin as well as by smaller amounts of dynorphin-(1-13). We conclude that in some places (brain and pituitary) dynorphin exists separately from leucine-enkephalin. In other parts of brain and in the periphery the relationship between dynorphin and the enkephalins is very complex and requires further study and improved antisera.

Animals↗

Resonance by rod-shaped reflectors in ultrasound test objects.

Rod-shaped reflectors such as those used in the AIUM test object resonate at medical ultrasound frequencies, producing artifacts posterior to the reflector. Rods of various diameters and materials were examined to determine their resonant properties, and the effect of the Plexiglas scanning surface of the enclosure on image quality was studied. A theory predicting the resonant frequencies of rods is proposed, and methods of eliminating resonance artifacts are discussed.

Health Physics↗

Diurnal rhythm of plasma immunoreactive beta-endorphin and its relationship to sleep stages and plasma rhythms of cortisol and prolactin.

To determine the diurnal rhythm of plasma beta-endorphin (beta-End), 10 healthy male volunteers between the ages of 20 and 32 yr were studied in a sleep laboratory setting for a 24-h period. Blood samples were taken through an indwelling catheter at 0800, 1000, 1400, 1800, 2200, 2300, and 2400 h and then half-hourly until 0730 h, and they were then assayed for total beta-End-like immunoreactivity (ir beta-End), PRL, and cortisol. Subjects were habituated by spending the night before the study in the sleep laboratory with an indwelling catheter and electrodes for sleep recording in place. There was a clear diurnal variation of ir beta-End, with lowest levels between 2200 and 0330 h and highest levels between 0400 and 1000 h. There was no evidence for direct entrainment with sleep stage. There was a close correlation with cortisol levels, suggesting a similar secretory pattern for beta-End and PRL in only 5 of the subjects. Because the beta-End antiserum used has a cross-reactivity of 30% with beta-lipotropin gel permeation chromatography was done on extracts of plasma taken at 1400, 2400, 0400, and 0730 h for each subject. The peak in the beta-End elution position showed a clear diurnal variation similar to that of ir beta-End.

Adult↗

The use of the multiplicity survey to identify migrants.

New approaches must be developed and tested to meet the needs for current data on population movement. One such approach is the survey with multiplicity (social networks). It allows respondents to report events (in this case, migration) that occurred to specified relatives living elsewhere. In order to test the value of the approach on a limited, exploratory basis, a two-stage research design was employed. A sample of persons resident in Cranston, Rhode Island who had changed address in the three years preceding the survey, was first identified and information was gathered in Round I on their mobility and on their relatives living in the State. In turn, these relatives (Round II) were asked about the mobility of their parents, siblings, and children. (The responses from Round II should have included the migrants in Round I.) Evaluation of the accuracy of Round II responses in comparison to those obtained in Round I was undertaken in terms of kin relationships, recency of move, and type of move. The results indicate that respondents had a low awareness of their relatives' movements, that moves of females were more likely to be reported than those of males, that recent moves were more frequently cited and that moves between communities were more likely to be reported than intracity mobility.

Adult↗

Levels of immunoreactive dynorphin in brain and pituitary of Brattleboro rats.

The very potent opioid peptide, dynorphin, has recently been shown by radioimmunoassay and immunocytochemical techniques to be selectively concentrated in the pars nervosa of pituitary, suggesting a possible association of dynorphin with the neurohypophyseal hormones, vasopressin and oxytocin. In this study, we report that pituitary and brain contents of immunoreactive dynorphin in homozygote Brattleboro rats (unable to synthesize vasopressin) are similar to those in heterozygote animals and in normal Long-Evans rats. Thus, the syntheses of immunoreactive dynorphin and vasopressin in the hypothalamo-hypophyseal tract appear to be independently regulated.

Animals↗

Epidural analgesia and cardiac output in severe pre-eclamptics.

Labour and delivery cardiac output was assessed by thermal dilution in ten severe pre-eclamptics who received lumbar epidural analgesia. Control cardiac output was 8.8 litres/min which remained statistically unchanged following administration of lumbar epidural analgesia. At birth and delivery of the placenta, there was a moderate increase in cardiac output which increased significantly (28%) by 15 min after delivery of the placenta. Subsequently over the next hour, cardiac output returned toward baseline levels. Mother and fetus were stable throughout and infant Apgar scores were good. These results emphasise that lumbar epidural analgesia has little effect on cardiac output in severe pre-eclamptics.

Adolescent↗

Transducer beam pattern test object.

A new test object has been developed that generates images of transducer beam patterns on B-mode hardcopy. The extent and depth of the transducer focal zone are measured from these images. The predictions made from test object images were verified in the clinical images obtained from two 3.5-MHz focused transducers. Using the test object images, we have found that we can make a more rational selection of transducer for each clinical situation.

Humans↗

A follow-up study of heroin addicts five years after first admission to a methadone treatment program.

A random sample (n = 260) of the first 799 admissions to the Santa Clara County Methadone Treatment Program was sought for interview five years after the date of their first dose; 80% were successfully located. Data from the year prior to entering methadone treatment were compared to data from the year prior to the follow-up interview. The two specific areas showing the most dramatic improvement were in heroin use and employment. During the year prior to the follow-up interview, 24% of the subjects with known outcome had no heroin use; 19% were abstinent from both heroin and methadone and at risk (not in jail or other treatment) for the entire year. Unemployment dropped from 51% to 19%. Subjects drank significantly more alcohol during the year prior to interview, with a 48% increase in the number of daily drinkers. Little or no change was seen in the use of other drugs, in the percentage of subjects with an arrest or jail time, or in the number living with an addicted person. Time in treatment was not a predictor of successful outcome and subjects who had left methadone treatment were doing at least as well as those continuously in methadone treatment.

Adolescent↗

Human leukocyte A and B antigens in patients with prostatic adenocarcinoma.

An increasing number of diseases has been associated with specific human leukocyte antigens. A total of 100 white men with adenocarcinoma of the prostate was serotyped for 32 A and B antigens. Compared to a control population of 169 white subjects relative risks of 2 or more were associated with the antigens A11 and A29. Relative risks of 0.20 or less were associated with the antigens AW23, BW21 and BW22. None of these relative risks was significant statistically. We were unable to demonstrate a significant human leukocyte A or B antigen association with adenocarcinoma of the prostate.

Adenocarcinoma↗