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Biomedical subjects

C King

Publications and source records attributed to C King.

At least 145 records · Page 8Linked to original sources
PubMed1986

Opioid peptides in rat islets of Langerhans. Immunoreactive met- and leu-enkephalins and BAM-22P.

Previous studies have shown that met- and leu-enkephalins are present in extracts of whole pancreas obtained from guinea pigs and human cadavers. The present studies demonstrate that immunoreactive methionine (met)- and leucine (leu)-enkephalins present in rat pancreas are localized in islets of Langerhans. Immunohistochemical staining of fixed, whole pancreas indicated that only islet endocrine cells were heavily stained when any of four different met- and leu-enkephalin-directed antisera or an anti-BAM-22P (bovine adrenal medulla docosapeptide) antiserum was used. The peptides were characterized by a combination of gel-filtration chromatography, high-performance liquid chromatography (HPLC), and specific radioimmunoassay. Free met-enkephalin content in extracts of rat islets was 90-fold enriched over content in extracts of whole pancreas (1.72 +/- 0.35 versus 0.019 +/- 0.007 pmol/mg protein). Treatment with trypsin and carboxy-peptidase-B of high-molecular-weight peptides extracted from pancreas or islets resulted in release of additional met-enkephalin immunoreactivity, which was 39-fold enriched in islets compared with pancreas (5.90 +/- 0.58 and 0.153 +/- 0.032 pmol/mg protein, respectively). Total islet content (per milligram protein) of met-enkephalin-containing peptides was similar to that reported elsewhere for bovine hypothalamus. The immunohistochemical data as well as the enrichment of extractable enkephalins in islets compared with whole pancreas indicate that essentially all the met-enkephalin present in pancreas is localized in islets, while the presence of BAM-22P immunoreactivity in islets is consistent with biosynthesis of enkephalins in islet cells via a preprohormone, such as that described in the bovine adrenal medulla and rat brain.

Animals↗
PubMed1985

Alternative statistical models for the examination of clinical positron emission tomography/fluorodeoxyglucose data.

This article describes a method for partitioning metabolic variability found in positron emission tomography/[18F]fluorodeoxyglucose studies. For the 15 subjects examined, 74.8% of the total metabolic variability could be ascribed to individual differences in global metabolic rate, whereas 15.8% of the total variability was consistent regional variation or pattern across subjects. Subsequently, the method of Q-component analysis is described for the identification of strong- and weak-pattern subjects. In addition, a standardization procedure that amplifies the observed pattern by removing systematic individual differences is described. Finally, the implications of these findings and methods for future and clinical studies are discussed.

Adolescent↗
PubMed1985

Comparison of creatinine as determined with the Ames Seralyzer and by three Jaffé-based methods.

We compared results for urinary creatinine, serum creatinine, and creatinine clearance, as determined with the Ames Seralyzer, with results determined with the Beckman ASTRA, the DuPont aca, and Technicon's AutoAnalyzer and SMAC. Results for urinary creatinine from the Seralyzer differed significantly (p less than 0.05) from those obtained with the ASTRA and AutoAnalyzer, but not with the aca. The Seralyzer results for serum creatinine were at least 1.0 mg/L higher (p less than 0.05) than by the other three methods. Results for creatinine clearance from the Seralyzer were 8 to 11 mL/min lower (p less than 0.05) than results by the other three methods. These differences are related to the positive interference by bilirubin in the Seralyzer creatinine method. We also evaluated 23 other compounds for interference with these methods for creatinine.

Autoanalysis↗
PubMed1984

The role of aortic chemoreceptors during acute anemia.

The importance of aortic chemoreceptors in the circulatory and metabolic responses during acute anemia was studied in anesthetized dogs. Data were obtained from nine dogs in which the aortic chemoreceptors were surgically denervated prior to induction of anemia, and from seven sham-operated dogs. Cardiac output (QT), limb blood flow (QL), limb and whole body oxygen uptake (VO2) were determined at normal hematocrit (Hct) and at 30 min of anemia (Hct = 13%) produced by isovolemic dextran-for-blood exchange. At 30 min of anemia, QT was increased from 91 to 186 mL . kg-1 . min-1 (p less than 0.01) and from 99 to 153 mL . kg-1 . min-1 (p less than 0.01) in the sham and denervated groups, respectively. The increase in QT during anemia was less (p less than 0.05) in the aortic-denervated series. Limb flow was also increased during anemia in both groups (p less than 0.01); the mean value of 89 mL . kg-1 . min-1 in the denervated group was less than that of 130 mL . kg-1 . min-1 observed in the sham animals (p less than 0.05). Whole body VO2 decreased (p less than 0.05) in the denervated group at 30 min of anemia; limb VO2 was maintained at the preanemic control value in both groups. The data indicate that during acute anemia the aortic chemoreceptors contribute to the increase in QT.

Acute Disease↗
PubMed1984

Role of the hypophysis in regulation of pancreatic and gastric somatostatin.

Since hypophysectomy and GH deficiency are associated with decreases in hypothalamic content and release of SRIF, it was of interest to determine whether these hormonal alterations also affect peripheral tissue levels of SRIF. Hypophysectomized (hypox) rats were studied at various times after surgery and compared with age-matched controls. Pancreatic, gastric, and hypothalamic SRIF levels were measured by RIA and expressed as nanograms per mg protein or nanograms per organ. Decreased levels of hypothalamic SRIF were observed in hypox animals at all time periods after surgery. In contrast, pancreatic SRIF concentrations increased within 1 week of hypophysectomy, and the tissue content increased as much as 3-fold after 20 weeks. Measurement of the SRIF content of isolated rat islets of Langerhans revealed a 67% increased content/islet in hypox rats compared with controls. The gastric SRIF concentration was not changed early, but subsequently, the total organ content was significantly decreased compared with that in controls. The changes in stomach and pancreas SRIF contents became more marked with duration of pituitary deficiency. Studies in genetically dwarfed Snell mice, lacking primarily GH but also other anterior pituitary hormones, were similar to the findings noted in hypox rats; the SRIF concentration was significantly increased in the pancreas and decreased in the stomach and hypothalamus. It is probable that deficiencies in other hormones as well as GH are involved in producing the changes in pancreatic SRIF in hypox and dwarfed animals. This contention was supported in that replacement of T3 (5 micrograms/kg . day) reduced pancreatic SRIF concentration by 30%, while GH plus T3 produced a significantly greater (60%) decrease in pancreatic SRIF in hypox rats.

Aging↗
PubMed1982

Effects on sleep of phentolamine and epinephrine infused into the locus coeruleus of cats.

The sleep-wavefulness behavior of cats was studied after infusion of phentolamine (3 micrograms, bilateral) or epinephrine (60 micrograms, bilateral) into the locus coeruleus. The drugs exerted opposite effects: phentolamine increased rapid eye movement (REM) sleep and decreased light slow wave sleep; epinephrine decreased REM sleep, increased light slow wave sleep and augmented wakefulness. The REM-enhancing effect of phentolamine was due to more REM periods than in control experiments, with a shortening of the sleep cycle. Epinephrine, by contrast, resulted in fewer REM periods and a prolongation of the sleep cycle. The data support the hypothesis that pontine catecholamines inhibit REM sleep and facilitate wakefulness in cats, and implicate the rostral pons as an important site for the REM-increasing effect of systemically administered phentolamine.

Animals↗
PubMed1982

Intensive care unit bed extension for fluoroscopy.

Effective use of the 'C-arm' X-ray fluoroscopy machine in the intensive care unit (ICU) is often prevented by the design of the ICU bed. An inexpensive, easily constructed device is described which facilitates use of the 'C-arm' machine, yet permits the patient's monitoring and life-support apparatus to remain attached and functioning.

Beds↗
PubMed1982

Attentional deficits with and without hyperactivity: teacher and peer perceptions.

The present study assessed teacher and peer perceptions of boys classified according to DSM-III criteria for Attention Deficit with Hyperactivity (ADH) and Attention Deficit without Hyperactivity (AD). Teachers completed SNAP checklists (Pelham, Note 1) on all boys in their classrooms (219 boys). Twelve percent fit ADH criteria; less than 5% fit AD criteria. Teacher perceptions were assessed with the Conners Teacher Rating Scale. ADH and AD groups did not differ on the Inattention factor, although the AD group was rated significantly lower than the ADH group on Conduct Problems and Hyperactivity. These profiles were expected on the basis of DSM-III descriptions of ADH and AD; the ADH group seemed to resemble previous research samples of hyperactive children. Classroom peer perceptions, assessed with like-dislike nominations, did not discriminate between diagnostic groups. Both groups were perceived more negatively than the Comparison group, suggesting that both groups are "at risk."

Attention↗
PubMed1982

A new system for gray-level surface distribution maps of electrical activity.

This report describes an integrated anatomical, electrophysiological and data management system for presenting cortical surface distribution maps. Approximately equal area projections (lateral and top) were constructed from a cross-sectional whole head atlas. Anatomical landmarks (major sulcus and gyrus locations) were also located on the outline. The outline and weights for interpolation are stored in the computer, with software for map generation directly from multilead EEG or evoked potential data. Electrode position and number can be easily varied and mapped onto any shaped space using the same program. Data derived from other sources such as xenon blood flow, brain scans or positron emission tomography can similarly be presented. The program uses a laboratory computer and emphasizes simplicity of data management and a mapping algorithm which is applicable to many forms of data.

Brain↗
PubMed1982

Effects on sleep of acetylcholine perfusion of the locus coeruleus of cats.

The loci coeruleus of freely moving cats were perfused bilaterally with acetylcholine at a dose of 0.001 microgram/microliter per min, while the animals were recorded polygraphically. The controls consisted of experiments in which no perfusions were done, and experiments in which the loci coeruleus were perfused bilaterally with saline, 1 microliter/min. The acetylcholine produced a sharp inhibition of rapid eye movement (REM) sleep, prolonged the sleep cycle and the REM interval and decreased the number of REM periods and the mean duration of the REM episodes. Total sleep time was increased. This was entirely due to a specific elevation by acetylcholine of deep slow-wave sleep; light slow-wave sleep was not affected. The data support the Hobson-McCarley hypothesis of how the brain controls the REM state, and also suggest that cholinergic stimulation of the locus coeruleus may be important for the shift from REM sleep into slow-wave sleep.

Acetylcholine↗