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Biomedical subjects

J Johnson

Publications and source records attributed to J Johnson.

At least 595 records · Page 33Linked to original sources
PubMed1984

Anteroposterior gradients in cerebral glucose use in schizophrenia and affective disorders.

Local cerebral uptake of deoxyglucose labeled with fluorine 18 was measured by positron emission tomography in 16 patients with schizophrenia and 11 patients with affective disorder. Patients received no medication a minimum of 14 days and an average of 39.8 days. The subjects were administered the deoxyglucose 18F just before receiving a 34-minute 1/s series of unpleasant electrical stimuli to the right forearm while resting with eyes closed in a darkened, acoustically attenuated psychophysiologic testing chamber. Following monitored stimulation in the controlled environment, subjects were scanned and images converted to values of glucose use in micromoles per 100 g per minute according to Sokoloff's model. Data were analyzed with a four-way analysis of variance (ANOVA) with independent groups (normals, schizophrenics, and affectives) and repeated measures for slice level (supraventricular, midventricular, and infraventricular), hemisphere (right, left), and anteroposterior position (four sectors). Both normal subjects and patients showed a significant anteroposterior gradient in glucose use with highest values in the frontmost sector. Patients both with schizophrenia and with affective illness showed less of an anteroposterior gradient especially at superior levels, which was statistically confirmed by ANOVA. Absolute glucose levels in patients, which were actually higher in posterior regions rather than lower in frontal regions, were the largest contributors to the effect. Neither group differences in whole brain glucose use nor left-right asymmetries reached statistical significance. These results are consistent with our earlier reports of a relative hypofrontal function in schizophrenia compared with controls. This report extends this finding to affective illness, sharing a lack of diagnostic specificity with many biologic measures.

Adult↗
PubMed1984

Effects of anxiety and depression on anagram performance, ratings of cognitive interference, and the negative subjective evaluation of performance.

Studied whether any differential effects of anxiety and depression could be discerned in the anagram performance, ratings of cognitive interference, and subjective evaluation of anagram performance displayed by college students. Seventy-two undergraduates (36 male, 36 female) were selected to participate in the present experiment on the basis of their scores on the State-Trait Anxiety Inventory (A-Trait) and/or the Beck Depression Inventory. Results showed that depressed-anxious and anxious Ss displayed a tendency toward reduced efficiency in anagram solution, rated themselves as having experienced significantly more cognitive interference during the anagram task, and displayed a significantly more negative subjective evaluation of their anagram performance than did control Ss. Quasi-F analyses revealed that these results were related significantly to the anxiety factor common to both depressed-anxious and anxious Ss. Implications of these results for future research on anxiety and depression were discussed.

Anxiety↗
PubMed1984

Positron emission tomographic image measurement in schizophrenia and affective disorders.

Two analytical methods for assessing regional glucography with positron emission tomography were compared in 16 patients with schizophrenia and 11 patients with affective disorders. Patients were off all medication a minimum of 14 days and an average of 39.8 days. The subjects were administered fluorine-18-labeled 2-deoxyglucose just before receiving a 34-minute one-per-second series of unpleasant electrical stimuli to their right forearm while resting with their eyes closed in a darkened, acoustically attenuated psychophysiological testing chamber. Following monitored stimulation in the controlled environment, the subjects were scanned and the images were converted to values of glucose use in micromoles per 100 grams per minute, according to Sokoloff's model. Data were analyzed by a four-way analysis of variance (ANOVA) for independent groups (normal subjects, schizophrenic patients, and patients with affective disorders) and for repeated measures of slice level (supraventricular, midventricular , and infraventricular ), hemisphere (right, left), and anteroposterior position (four sectors). Normal individuals and patient groups both showed a significant anteroposterior gradient in glucose use, with the highest values in the sector farthest to the front. Patients with schizophrenia and those with affective illnesses showed less of an anteroposterior gradient than normal individuals, especially at superior levels, which was statistically confirmed by ANOVA. Neither the group differences in whole-brain glucose use nor the left-right asymmetries reached statistical significance. A second technique, involving reconstruction of the lateral cortical surface, also revealed differences between schizophrenics and normal individuals in the superior frontal cortex. These results are consistent with our earlier reports of a relative hypofrontal function in schizophrenia compared with controls; they also extend the finding to the affective illnesses, the other group of major psychoses.

Adult↗
PubMed1984

The Genain Quadruplets: electrophysiological, positron emission, and X-ray tomographic studies.

Four 51-year-old monozygotic quadruplets concordant for schizophrenia, originally studied at the National Institute of Mental Health 25 years ago, were restudied with topographic electroencephalography (EEG), evoked potentials (EPs), computed tomography (CT scans), polysomnographic sleep recordings, and positron emission tomography (PET) with 18F-2-deoxyglucose. EEG and EP findings were consistent with those from other groups of patients with schizophrenia and showed great similarity within the quadruplets. CT scans revealed uniformly small lateral ventricles. PET scans replicated earlier findings of relatively low glucose use in the frontal lobes but did not show strong familial concordance.

Brain↗
PubMed1984

13C NMR studies of glycolysis in intra- and extra-erythrocytic Babesia microti.

Metabolism in the erythrocytes of normal mice and mice infected with Babesia microti has been monitored non-invasively by high resolution 13C NMR spectroscopy. The conversion of [U-13C]glucose to lactate in both normal and infected cells together with the effect of the trypanocidal drug, 4,4'-diamidinodiazoaminobenzene diaceturate, on glycolytic rates were monitored. These studies show that erythrocytes utilize [U-13C]glucose at a rate of 3 X 10(-12) mumol cell-1 min-1 at 35 degrees C while parasitized cells consume 2.9 X 10(-11) mumol cell-1 min-1 and produce lactate as the sole end-product. This rate decreases to 9 X 10(-12) mumol cell-1 min-1 on the addition of 0.75 mM drug.

Animals↗
PubMed1984

Monoclonal antibodies to human urokinase identify the single-chain pro-urokinase precursor.

Monoclonal antibodies have been obtained that recognize either the A or B chain of human urinary urokinase. These antibodies identify human urokinase-producing cells and the product of urokinase mRNA. Anti-urokinase monoclonal antibodies precipitate an approximately equal to 54,000-dalton protein synthesized in vitro in a rabbit reticulocyte cell-free system. This pro-urokinase appears to be the precursor of both A and B chains of human urinary urokinase. Urokinase mRNA in human kidney constitutes only 0.1% or less of total poly(A)+ RNA.

Animals↗
PubMed1984

Effects of antidepressants on skilled performance.

Effects of amitriptyline 50 mg, desipramine 100 mg, and zimelidine 200 mg alone and in combination with ethanol 0.8 g/kg were investigated in healthy, male volunteers. Amitriptyline increased body sway and impaired tracking as well as information processing. It had an additive deleterious pharmacodynamic interaction with ethanol. Desipramine and zimelidine were free of adverse effects on performance and did not have significant interactions with ethanol. The dose of ethanol used in the present study did not inhibit biotransformation of the antidepressants.

Adult↗
PubMed1984

The site of renin in the human uterus.

Renin has been known to be present in the human uterus for many years. The study reported in this paper deals with the identification of the site of renin in the human uterus by the peroxidase-antiperoxidase technique, using anti-human renin. Cells containing renin granules have been demonstrated only in patients complaining of menorrhagia. The cells occur singly and in clusters in the interarteriolar connective tissue within myometrium adjacent to the endometrium. The cells bear a striking resemblance to those of the juxta-glomerular apparatus of the kidney.

Adult↗
PubMed1984

Imaging ovarian tumours by nuclear magnetic resonance.

The application of nuclear magnetic resonance imaging to the diagnosis of ovarian tumours has been studied in a group of seven patients with ovarian masses and several healthy volunteers who provided examples of normal pelvic anatomy. In three patients, benign unilocular ovarian cysts were demonstrated and in three patients, recurrent ovarian tumours were identified and the extent of the tumours defined. One patient with bilateral ovarian endometriomas was imaged. Endometrial cysts, like masses in other systems which contain blood or lipid-rich material, show high-density images whereas malignant tumours show tissue densities closer to those of normal tissues. The potential value of this technique in the assessment of pelvic disease is discussed.

Endometriosis↗
PubMed1984

Stupor: a review of 25 cases.

Twenty-five cases of stupor referred to a psychiatric teaching hospital over 15 years are reviewed. Ten cases presented with a depressive syndrome, four cases with catatonic phenomena and a further 10 cases with established organic aetiology; one case was considered to be psychogenic in origin. The overall mortality was high (16%), attributable to the basic pathology. Compared with earlier series there was a reduction in cases with catatonic features with a corresponding increase in the proportion of organic cases.

Adolescent↗
PubMed1984

Penetration of cefoperazone into surgical wound drainage in patients undergoing head and neck surgery.

Cefoperazone penetration into skeletal muscle and wound drainage in patients undergoing major surgery of the head and neck was measured by high-pressure liquid chromatography. Cefoperazone (2 g) was infused over 30 min before surgery and every 8 h for three postoperative doses. Simultaneous samples of serum and sternomastoid muscle were collected in 18 patients at 135 to 480 min after infusion. Mean cefoperazone concentrations in muscle tissue were 17.1% of those in simultaneously collected serum. Steady-state wound drainage concentrations after the fourth dose of cefoperazone averaged 55.2 micrograms/ml at 1 to 2 h and 62.1 micrograms/ml at 2 to 3 h. Simultaneous steady-state serum and wound fluid samples were obtained at regular intervals in six patients. In all patients, the peak level in wound fluid exceeded 25 micrograms/ml. Thus, cefoperazone reaches interstitial fluid concentration in soft tissue that exceeds the MICs required to inhibit the usual pathogens found at the site of wound infection after head and neck surgery.

Cefoperazone↗
PubMed1984

Non immune hydrops fetalis.

With the decline in the frequency of rhesus isoimmunisation, hydrops fetalis secondary to other factors is becoming increasingly recognised. We describe a case in association with chorioangioma of the placenta. The causes of non immune hydrops are reviewed and the problems of management discussed.

Cerebral Hemorrhage↗
PubMed1984

Etoposide-induced blood-brain barrier disruption. Effect of drug compared with that of solvents.

The intracarotid infusion of the anti-neoplastic compound, etoposide, has been shown to exert a dose-dependent effect on blood-brain barrier (BBB) permeability. Etoposide, however, is formulated in a complex solvent solution containing alcohol, Tween 80, polyethylene glycol 300, and citric acid. To investigate the contribution of the solvent solution to BBB disruption, the authors studied Sprague-Dawley rats after the internal carotid artery infusion of the solvent solution with and without the addition of etoposide. Experiments were performed at four doses of drug and/or solvent. Disruption of the BBB was evaluated qualitatively by the appearance of the systemically administered dye, Evans blue, in the cerebral hemispheres and quantitatively by the ratio of gamma counts of the technetium-labeled chelate of diethylenetriaminepentaacetic acid (99mTc-DTPA) in the ipsilateral:contralateral hemisphere. Significant barrier opening was obtained in all four groups of animals infused with solvent plus etoposide. In the corresponding groups of rats infused with the solvent solution alone, BBB disruption was markedly lower. Only in the group infused with the largest dose of solvent was the hemispheric ratio of 99mTc-DTPA significantly different from saline-infused animals. Each of the groups with solvent plus etoposide had 99mTc-DTPA ratios significantly different from the control group. Intracarotid infusion and subsequent BBB disruption were well tolerated by the animals receiving either solvent alone or solvent and etoposide. Disruption of the BBB secondary to the intracarotid infusion of etoposide is primarily caused by the drug itself and not by the solvent solution.

Animals↗
PubMed1984

Identification of subsets of lymphocytes infiltrating head and neck tumor tissue: a preliminary report.

Monoclonal antibodies reactive to distinct subclasses of lymphocytes were used to identify lymphocytes infiltrating tissue obtained from patients with squamous cell carcinoma of the head and neck. The majority of lymphocytes present were T-cells with very few B-lymphocytes and natural killer cells present. A variety of patterns of infiltration and relationship of T-helper to T-suppressor lymphocytes was noted. Long-term follow-up studies will be required to determine the clinical significance of infiltration by different T-lymphocyte subclasses.

Adult↗