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Biomedical subjects

A Roy

Publications and source records attributed to A Roy.

At least 343 records · Page 19Linked to original sources
PubMed1989

Diazepam-binding inhibitor and corticotropin-releasing hormone in cerebrospinal fluid.

Diazepam-binding inhibitor (DBI) is a neuromodulatory peptide for gamma-aminobutyric acid (GABA) neurotransmission. Cerebrospinal fluid (CSF) levels of DBI have been found to be elevated in depression. CSF levels of the peptide corticotropin-releasing hormone (CRH) have also been found to be elevated in depression. Therefore, we examined for a relationship between DBI and CRH in human CSF. We found significant positive correlations between CSF levels of DBI and CRH in depressed patients, pathological gamblers, and normal controls. These data, along with the elevated CSF levels of DBI in depression, suggest the possibility that DBI may have a role in coordinating responses to stress in humans in addition to its possible role in the pathophysiology of depression.

Adult↗
PubMed1989

Molecular characterization of two cya mutations, cya-854 and cyaR1.

The cya-854 mutation of Escherichia coli K-12 (E. Brickman, L. Soll, and J. Beckwith, J. Bacteriol. 116:582-587, 1973) has been shown to consist of a 200-base-pair deletion generating a new translation start that permits synthesis of the adenylate cyclase carboxy terminus. Contrary to expectations (C. Guidi-Rontani, A. Danchin, and A. Ullmann, J. Bacteriol. 148:753-761, 1981), cyaR1 results from the insertion of an IS1 element into the sequence coding for the catalytic center of the protein.

Adenylyl Cyclases↗
PubMed1989

Scintigraphic and ultrasound features of giant hemangiomas of the liver.

Giant hemangiomas of the liver are clinically distinct from smaller and more innocent hemangiomas as they are more prone to complications. On imaging with ultrasound, they can also be readily confused with hepatoma, metastatic disease, or focal nodular hyperplasia. Nine giant hemangiomas (maximal diameter greater than 8 cm) were studied by scintigraphy and ultrasound. In all instances, the fill-in of the lesion on [99mTc]RBC scintigraphy indicated the diagnosis of hemangioma, adding specificity to the screening sonographic study. The pattern of fill-in on scintigraphy also appeared to be size dependent with lesions less than 11 cm in diameter equilibrating uniformly, while larger abnormalities intensified in centripetal fashion.

Erythrocytes↗
PubMed1989

Mortality pattern in babies delivered by cesarean section and vaginal delivery.

A total of 7077 cases of delivery were studied in a rural based hospital where most of the mothers come without any antenatal care, from November, 1979 to December, 1980 to observe the mortality pattern in different types of delivery. Only live born babies were included in the study in which the mortality rate in elective cesarean section was found to be nearly equal to that in vaginal delivery. The percentage of mortality was higher (5.4%) in emergency cesarean section-the chief causes being asphyxia neonatorum, low gestational age and low birth weight.

Cesarean Section↗
PubMed1988

Survival of a dog with pneumonia caused by Mycobacterium fortuitum.

Pneumonia caused by Mycobacterium fortuitum was diagnosed in the left lung lobes of a 3-year-old male Samoyed. Unilateral pneumonectomy and antibiotic treatment (primarily amoxicillin trihydrate-clavulanate potassium and kanamycin) were associated with resolution of the pneumonia. In dogs, M fortuitum causes pulmonary disease that radiographically resembles bacterial pneumonia. Therefore, M fortuitum infection should be considered in dogs with radiographic signs of bronchopneumonia that worsen despite antibiotic treatment.

Animals↗
PubMed1988

High intercorrelations among urinary outputs of norepinephrine and its major metabolites. A replication in depressed patients and controls.

We examined the intercorrelations among urinary outputs of norepinephrine (NE) and its three major metabolites in unipolar depressed patients (n = 28) and normal controls (n = 24). Among the depressed patients, levels of NE correlated with normetanephrine (NM), 3-methoxy-4-hydroxyphenylglycol (MHPG), and vanillylmandelic acid (VMA), and VMA correlated with NM and MHPG. In the total group of depressed and control subjects (n = 52), the sum of NE and its major metabolites correlated with urinary outputs of NE, NM, MHPG, and VMA. These highly significant correlations among urinary outputs of NE and its major metabolites replicate a previous report of strong correlations among these same four urinary substances in a smaller group of depressed patients.

Adult↗
PubMed1988

Pathological gambling. A psychobiological study.

We investigated psychobiological substrates of pathological gambling by measuring levels of norepinephrine, monoamine metabolites, and peptides in cerebrospinal fluid, plasma, and urine. Pathological gamblers had a significantly higher centrally produced fraction of cerebrospinal fluid levels of 3-methoxy-4-hydroxyphenylglycol as well as significantly greater urinary outputs of norepinephrine than controls. These results suggest that pathological gamblers may have a functional disturbance of the noradrenergic system. This system has been postulated to underlie sensation-seeking behaviors, aspects of which are thought to be abnormal among pathological gamblers.

Adult↗
PubMed1988

Norepinephrine and its metabolites in cerebrospinal fluid, plasma, and urine. Relationship to hypothalamic-pituitary-adrenal axis function in depression.

Among 140 depressed and control subjects, there were significant positive correlations between indexes of noradrenergic activity in cerebrospinal fluid (CSF), plasma, and urine. Among the depressed patients, CSF levels of the norepinephrine (NE) metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG) and urinary outputs of NE and its metabolites normetanephrine, MHPG, and vanillylmandelic acid correlated significantly with plasma cortisol levels in relation to dexamethasone administration. Also, CSF levels of MHPG were significantly higher among patients who were cortisol nonsuppressors than among either patients who were cortisol suppressors or controls. Urinary outputs of NE and normetanephrine were significantly higher among patients who were cortisol nonsuppressors than among controls. Patients who were cortisol suppressors had indexes of NE metabolism similar to those of controls. These results in the depressed patients extend recent observations suggesting that dysregulation of the noradrenergic system and hypothalamic-pituitary-adrenal axis occur together in a subgroup of depressed patients.

Adult↗
PubMed1988

TRH-induced prolactin release in unipolar depressed patients and controls.

We compared unipolar depressed patients (N = 32) with normal controls (N = 38) for their prolactin responses on the thyrotropin releasing hormone test. Depressed patients showed prolactin responses similar to sex matched controls. Among the depressed patients there were no significant differences for prolactin response between those with or without a blunted thyroid stimulating hormone response, dexamethasone suppressors or nonsuppressors, or between melancholic and nonmelancholic depressive subgroups.

Adult↗
PubMed1988

The CRH stimulation test in bereaved subjects with and without accompanying depression.

We studied recently bereaved individuals with the corticotropin-releasing hormone (CRH) stimulation test. Subjects with a bereavement complicated by a depressive illness (n = 9) had significantly higher basal plasma cortisol levels and smaller plasma adrenocorticotropic hormone (ACTH) responses to CRH than either subjects with an uncomplicated bereavement (n = 19) or normal controls (n = 34). Subjects with depressed bereavement showed ACTH responses to CRH similar to those of depressed patients (n = 30). Bereaved subjects who had received psychotropic medications in the past (n = 13), compared with those who had not (n = 15), showed significantly smaller plasma ACTH responses to CRH. Significantly more subjects with bereavement complicated by depression, as compared to subjects whose bereavement was uncomplicated, had a past history of treatment for depression. These results suggest that predisposed individuals may respond to the stress of bereavement with a depressive illness accompanied by dysregulation of the hypothalamic-pituitary-adrenal axis.

Adjustment Disorders↗
PubMed1988

Acting out hostility in normal volunteers: negative correlation with levels of 5HIAA in cerebrospinal fluid.

We examined relationships in normal volunteers between cerebrospinal fluid (CSF) concentrations of the serotonin metabolite 5-hydroxyindoleacetic acid (5HIAA) and scores on the Hostility and Direction of Hostility Questionnaire. There was a significant negative correlation between CSF 5HIAA levels and scores on the "urge to act out hostility" subscale, as well as a similar nonsignificant trend with CSF levels of homovanillic acid. These results suggest that among normal individuals reduced central serotonergic tone may be associated with impaired impulse control.

Adult↗
PubMed1988

Urinary-free cortisol in depressed patients and controls: relationship to urinary indices of noradrenergic function.

We measured urinary outputs of urinary-free cortisol in 28 medication-free depressed patients and 32 normal controls. Depressed patients had significantly greater urinary outputs of urinary-free cortisol than controls. Also, there were significant correlations among depressed patients, but not among controls, between urinary-free cortisol and urinary outputs of norepinephrine and its metabolite vanillylmandelic acid (VMA). These urinary data extend recent findings suggesting that dysregulation of both the hypothalamic-pituitary-adrenal axis and noradrenergic system occur together in depression.

Adult↗
PubMed1988

Aspects of the regulation of adenylate cyclase synthesis in Escherichia coli K12.

In Escherichia coli K12 expression of the adenylate cyclase gene is subject to multiple controls. In order to gain understanding of the regulation of adenylate cyclase synthesis, operon and protein fusions were constructed by in vitro recombination either into bacteriophage lambda or low-copy-number plasmids, or directly on the chromosome at the cya locus. The fusions were used in physiological experiments as probes to study transcriptional and translational controls of cya expression. It was found that adenylate cyclase synthesis was insensitive to glucose effects. As already described by other workers, the CAP-cAMP complex had a moderate negative control on cya expression. In addition it was observed that concomitant with a severe slackening of growth rate, specific to the growth of cya strains in rich medium, cya expression was considerably enhanced. This increase of adenylate cyclase synthesis did not appear to be directly dependent on the presence of a functional cAMP receptor (CAP), and seemed to be controlled at the level of transcription. Finally, translation of the cya message was very weak when compared to cya transcription (the mRNA level was the same in protein and operon fusions.

Adenylyl Cyclases↗
PubMed1988

Thyrotropin releasing hormone test in unipolar depressed patients and controls: relationship to clinical and biologic variables.

We compared unipolar depressed patients (n = 31) with controls (n = 38) for their responses to the thyrotropin releasing hormone (TRH) test. Depressed patients showed significantly smaller thyrotropin stimulating hormone (TSH) responses to TRH which correlated negatively with post-dexamethasone plasma cortisol levels. Depressed patients also showed significant negative correlations between delta max TSH and urinary outputs of norepinephrine and normetanephrine with similar trends with plasma levels of norepinephrine and 3-methoxy-4-hydroxyphenylglycol. Patients who showed a blunted TSH response, compared with those who did not, had significantly lower platelet serotonin uptake values. These results suggest that the blunted TSH response to TRH seen in depression may be associated with dysregulation of the cortisol, noradrenergic and serotonin systems.

Adult↗