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Biomedical subjects

A Roy

Publications and source records attributed to A Roy.

At least 469 records · Page 26Linked to original sources
PubMed1983

Regulation of adenylate cyclase synthesis in Escherichia coli: nucleotide sequence of the control region.

The regulatory region of the cya gene from Escherichia coli has been characterized by nucleotide sequence analysis and genetic approaches. Two promoters, P1 and P2, organized in that order with respect to the beginning of the cya open reading frame, were identified. Using cya-lac operon and protein fusions, it was possible to show that both promoters are active in vivo. P1 activity seemed sensitive to catabolite repression whereas activity of the stronger promoter, P2, did not respond to inhibition by glucose. No effect of cAMP or its receptor, catabolite activator protein (CAP), could be found although the DNA sequence reveals a consensus CAP site downstream of P2. The 548 nucleotides situated at the 3' end of the sequence carry an open reading frame which can tentatively be assigned to the beginning of adenylate cyclase. Among noteworthy features of the corresponding sequence are an UUG codon as the putative start site of cyclase, and a long hydrophobic stretch of amino acids resembling leader peptides in secreted or membrane proteins.

Adenylyl Cyclases↗
PubMed1983

The effect of monoacetin and calcium chloride on acid-base balance and survival in experimental sodium fluoroacetate poisoning.

Sodium fluoroacetate (compound "1080") was injected intravenously, 3 mmol/kg, to artificially-ventilated anesthetized cats. Blood pressure, ECG, acid-base parameters and serum ionized calcium were monitored in four groups of cats. Group A served as control. Group B cats were treated with calcium chloride to restore normal values of serum ionized calcium. Group C was given monoacetin (glyceryl monoacetate), 0.5 ml/kg every 30 min. Both monoacetin and calcium chloride were given to cats in group D. Fluoroacetate poisoning caused significant decrease in ionized calcium and severe metabolic acidosis with increased levels of lactate and pyruvate. The lactate to pyruvate ratio remained normal as long as there was no significant drop in blood pressure. Correction of blood ionized calcium prolonged survival from 94 to 166 min (group B). Monoacetin prolonged average survival time to 166 min. Metabolic acidosis was aggravated in monoacetin-treated animals (group C). Combined treatment with monoacetin and calcium chloride did not prolong mean survival time above 166 min.

Acid-Base Imbalance↗
PubMed1983

Fluoroacetamide poisoning in man: the role of ionized calcium.

Two cases are reported of severe acute fluoroacetamide poisoning in man, with successful treatment of the life-threatening cardiac arrhythmias by the administration of calcium chloride. The arrhythmias were preceded by prolongation of the QT interval in the ECG. Calcium chloride therapy restored to normal the markedly prolonged QT interval.

Adolescent↗
PubMed1983

Early parental death and adult depression.

In a matched controlled clinical study of 300 neurotic depressives collected over 6 years, 13% had experienced parental death before 17 years of age compared with 10.7% of the controls; this difference was not significant. There were no significant differences between the two groups when maternal or paternal death was examined separately either before 11 or 17 years of age. Thus the experience of parental death as a child is not in itself a risk factor for neurotic depression as seen in psychiatric patients.

Adolescent↗
PubMed1983

Life events precipitating mania.

A study of 20 manic patients, with patient and matched control comparisons, showed a two fold increase in life events during the 4 month period before admission to hospital. Life events, independent of affective illness and having significant objective negative impact (i.e. traumatic) were significantly more common. These findings are considered in relation to social relationships, family history of affective illness and the use of psychotropic medication.

Adult↗
PubMed1983

Depression in chronic schizophrenia.

Eighteen depressed chronic schizophrenic out-patients were matched with non-depressed schizophrenic out-patients. The depressed schizophrenics had had significantly more psychiatric admissions, past depression, past treatment for depression, significantly more had attempted suicide, lived alone, had low self-esteem, had early parental loss and had had more life events in the six months before the onset of depression. Depressive disorder in schizophrenic out-patients well controlled by neuroleptics may occur in those who are at risk for depression and experience an excess of life events.

Adult↗
PubMed1982

Risk factors for suicide in psychiatric patients.

In a matched controlled study of 90 psychiatric patient suicides, I found that significantly more of the suicides suffered from chronic schizophrenia (33.3%) or recurrent affective disorder (18.8%) and had made a previous suicide attempt (46.6%). The suicides were young and significantly more were unmarried (84.5%), unemployed (66%), living alone, (55.5%) and depressed (65.5%), and 44.4% had a primary diagnosis of depressive disorder. Of the 75 outpatient suicides, 58% had seen a psychiatrist within the previous week, 61 of the 75 (81.3%) had been admitted in their last episode of contact, and 44% of these suicided within a month of discharge.

Adolescent↗
PubMed1982

The cya locus of Escherichia coli K12: organization and gene products.

The cya gene region of Escherichia coli K12 has been cloned into plasmid pBR322. Detailed analysis of the locus, using in vitro recombination techniques as well as specific labelling of gene products has given information on the organization and products of the region. The cya gene is preceded by two DNA segments which behave as promoters of equivalent strength; a divergent, very strong, promoter is also present in the same control region. The former pair of promoters direct transcription of the cya gene which is expressed as a 95,000 dalton polypeptide; the latter promoter controls synthesis of a 40,000 dalton polypeptide. The cya gene product can complement a cya delta mutation when fully expressed or when expressed as a protein truncated at its carboxy terminal end.

Bacterial Proteins↗
PubMed1982

Suicide in chronic schizophrenia.

A matched controlled study of 30 chronic schizophrenic suicides is presented. Eighty per cent were male and committed suicide at a mean age of 25.8 years after a mean duration of illness of 4.8 years. Significantly more of the suicides had a chronic relapsing schizophrenic illness; 23.3 per cent committed suicide while in-patients, and 50 per cent of the out-patients committed suicide within three months of discharge from in-patient care. Significantly more of the suicides had a past history of depression (56.6 per cent), were depressed in the last episode of contract (53.3 per cent), had their last admission for depression or suicidal ideation (55.2 per cent) and were unemployed (80 per cent).

Adult↗
PubMed1981

Role of past loss in depression.

Among 187 depressives, 83 had parental loss before 17 years of age. Parental loss was not related to younger age or to a previous episode of depression. In a matched, controlled study of 102 of the depressives, parental loss before 17 years of age was significantly associated with depression.

Adolescent↗