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Biomedical subjects

J H Johnson

Publications and source records attributed to J H Johnson.

At least 163 records · Page 9Linked to original sources
PubMed1980

The reliability of diagnoses by technician computer, and algorithm.

Described a computer-assisted system for intake assessment. Previous evaluation studies are reviewed. Two experiments (N = 30; N = 35) are reported that compared the reliability of a diagnostic procedure that involves technicians, a structured interview schedule, and a computerized diagnostic program with diagnoses made by clinicians. Results show that the computer-assisted technician approach is as reliable as the conventional method.

Diagnosis, Computer-Assisted↗
PubMed1980

Urinary ascites in the newborn.

Seven cases of neonatal urinary ascites secondary to obstructive uropathy are reported. In 2 the bladder had perforated; in 4 there was perirenal extravasation; in 1 the site of leakage was not determined. A localised parenchymal perforation was found in 3 kidneys. Treatment was by temporary urinary diversion followed by operative relief of the obstruction. Six patients survive in good health; 1 infant died from causes unrelated to the ascites or the urinary tract. It is suggested that spontaneous urinary tract perforation with the development of ascites is often beneficial in the long term since it decompresses the obstructed system and lessens renal parenchymal damage.

Ascites↗
PubMed1980

Cell membrane phospholipids and their constitutent fatty acids in dividing and nondividing cells of Micrococcus lysodeikticus.

Changes occurring in the cell membrane of nondividing cells of Micrococcus lysodeikticus disIIp+ grown in the presence of the mucopeptide synthesis inhibitor D-cycloserine include (a) an increae in the relative amount of diphosphatidylglycerol with a concomitant decrease in the relative content of phosphatidylglycerol, (b) a small increase in the relative palmitic acid content of phosphatidylinositol, and (c) leakage of membrane components into the growth medium. Growth of the organism in the presence of both D-cycloserine and D-alanine (which prevents the effects of D-cycloserine on cell division and mucopeptide synthesis) prevents the above changes in the cell membrane, demonstrating that secondary damage to the cell membrane can occur as a rsult of inhibition in mucopeptide synthesis. Growth of the organism in the presence of D-cycloserine and pantoyl lactone prevents the leakage of membrne components and cell division inhibition. Possible relationships of these changes to cell division are discussed.

Alanine↗
PubMed1980

Demonstration of a pancreatic proelastase 2-alpha 1-protease inhibitor complex in normal human plasma.

A peak of immunoreactive pancreatic elastase 2 with a molecular weight consistent with that of a complex of elastase 2 and alpha 1-protease inhibitor (also referred to as alpha 1-antitrypsin) can be detected by radioimmunoassay in normal human serum or plasma (Geokas et al., J. Biol. Chem. 252:61-67, 1977). This material has been purified by gel filtration on Sephadex G-200 and by ion-exchange chromatography on DEAE-cellulose. The alpha 1-protease inhibitor-bound immunoreactive elastase 2 has been dissociated by incubation with hydroxylamine, and the resulting immunoreactive product isolated by gel filtration on Sephadex G-100. The dissociated immunoreactive elastase 2 was shown by affinity chromatography on turkey egg white inhibitor-bound agarose, before and after activation by bovine trypsin, to consist only of proelastase 2. A second peak of immunoreactive material associated with the high molecular weight fraction of plasma has been shown to result from a specific interaction of the 125I-labeled phenylmethanesulfonyl-elastase 2 employed as tracer in the radioimmunoassay with alpha 2-macroglobulin, resulting in apparent immunoreactivity. These results demonstrate that all of the detectable immunoreactive pancreatic elastase 2 in normal human plasma is proelastase 2 bound to alpha 1-protease inhibitor.

Chromatography, Affinity↗
PubMed1980

Importance of time-related parameters of pre-optic electrical stimulation in the release of LH in the pentobarbital-blocked pro-oestrous rat.

The effectiveness of pre-optic stimulation in overcoming the pentobarbital blockade of ovulation in the rat has long been recognized and employed in neuroendocrine investigations. Although some reports have appeared comparing certain aspects of electrical stimulation in effectiveness in releasing LH, no complete study in female rats has been reported. The present study utilized regularly cycling rats of the Charles River CD strain in which ovulation was blocked by the injection of sodium pentobarbital on the afternoon of pro-oestrus. Electrical stimulation was delivered through bipolar platinum electrodes stereotaxically positioned in the preoptic area, and LH was measured in plasma samples obtained at the onset of stimulation and 10, 20, 30, 45, 60, 80, 120 and 150 min thereafter. LH release was established in response to a baseline set of parameters: 15 HZ, 1.5 mA and 1.5 ms per phase, 30 s on/off for 60 min. Stimulations employing equi-coulombic increments of 1/3 introduced in each parameter in turn were compared in groups of 4-6 animals. Use of small increments in each parameter allowed the detection of those parameters to which the pre-optico-hypothalamo-pituitary system is most sensitive over the range studied, namely duration: of each pulse and of the overall stimulation period. This observation may be explained in terms of characteristics of the pituitary responsiveness.

Animals↗
PubMed1980

Blockade of ovulation by methadone in the rat: a central nervous system-mediated acute effect.

Morphine blocks ovulation in the rat and is associated with irregular menstrual cycles in humans. Methadone, the synthetic narcotic used to treat heroin addiction, was tested in rats for its ability to block ovulation. Equal doses of methadone were administered subcutaneously at 13:00, 14:00 and 15:00 hr on proestrus. Three different total (cumulative) doses were tested: 6, 9 and 15 mg/kg, in Wistar and Sprague-Dawley rats. The 6 mg/kg dose was ineffective, 9 mg/kg affected by Sprague-Dawley, whereas the 15 mg/kg dose blocked ovulation in both strains. Injection of saline at 13:00, 14:00 and 15:00 hr, or of the narcotic antagonist naltrexone at 12:00 had no effect on ovulation. Naltrexone prevented the blockade of ovulation by methadone, implicating narcotic receptors in the mediation of this action of methadone. Electrochemical stimulation of the medial preoptic area of the brain, or administration of exogenous luteinizing hormone overcame methadone's blockade of ovulation suggesting that the drug is acting via the central nervous system. The results of these studies suggest that menstrual dysfunction may not be a major problem in the clinical application of methadone.

Animals↗
PubMed1980

Lithium toxicity in cattle.

Eighteen mixed-breed beef cattle died as the result of consuming "tacky lithium grease" discarded from a rubber reclaiming plant. Four experimental groups of mature cattle were given oral doses of a lithium salt at levels of 0, 20, 500, and 700 mg/kg body weight. Although all animals in the 250 mg/kg group showed signs of intoxication, the signs were mild and transient. Doses of 500 and 700 mg/kg proved toxic and fatal. Signs, serum levels, and tissue-organ deposition were dose and time-related. Signs of intoxication were salivation, depression, anorexia, hypodipsia, anuria, and diarrhea. The high dose group also showed severe depression and ataxia. The highest mean lithium serum values were 19, 40, and 54 ppm for the 250, 500, and 700 mg/kg groups, respectively. Postmortem and histopathologic examinations revealed dose-related gastroenteritis, slight interstitial nephritis, and hepatic cirrhosis. Tissue residues of lithium were in striated muscle (86.8 ppm), heart (79.3 ppm), liver (68.7 ppm), kidney (67.1 ppm) , and brain (51.8 ppm), in the high dose group. Since serum levels of cattle consuming the "tacky lithium grease" were 0.49 ppm of lithium, we believe other contaminants in this discarded grease may have caused or enhanced the toxic effect of lithium.

Animals↗
PubMed1979

Orgotein in equine navicular disease: a double blind study.

Fourteen horses (7 treated with orgotein and 7 treated with a placebo) with navicular disease were studied on a double blind basis. All 14 horses had clinical and radiographic evidence of navicular disease. Orgotein and the placebo were administered by juxtabursal injection. Of the 7 orgotein-treated horses, 3 responded but none of the 7 placebo-treated horses responded. The difference was statistically significant (P less than 0.05).

Animals↗
PubMed1979

Imagery in the associative learning of schizophrenics.

The present experiment is similar to Bower's (1970) study on imagery as a relational organizer in paired-associate (PA) learning with normals. Three groups of 20 schizophrenic patients learned three different lists of 30 word-word paired-associates, which used either interactive imagery, separation imagery, or rote repetition encoding. Ss were tested on stimulus recognition and paired-associate recall, given recognition. Differences in stimulus recognition and paired-associate recall were not significant across the three encoding methods. Results suggest that schizophrenics are unable to benefit from imaginal cues to facilitate learning in a manner similar to normals. These results are interpreted as providing additional support for the notion that the schizophrenics' cognitive deficit is associated with the relational organizing process of learning.

Adult↗
PubMed1979

A study of mental status and anamnestic factors related to the decision for inpatient or outpatient treatment.

Reviewed previous studies of the determinants of disposition decision-making. Experimental flaws in these studies are indicated. A study of the intake decision process and its relationship to mental status and anamnestic variables obtained during the intake examination is presented (N = 523). Results suggest that diagnoses of psychosis and personality disorder are rleated to inpatient care, while the diagnosis of neurosis is related to outpatient care. In addition, depressed/suicidal symptomatology is found to be related to inpatient treatment, while a previous history of either sexual maladjustment or stubbornness/retardation is found to be related to outpatient care. Results are discussed in terms of universal and local criteria that are involved in intake decision-making.

Adult↗