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Biomedical subjects

J Healey

Publications and source records attributed to J Healey.

36 records · Page 2Linked to original sources
PubMed1990

Mechanism of synergistic induction of hepatic heme oxygenase by glutethimide and iron: studies in cultured chick embryo liver cells.

Heme oxygenase, the rate controlling enzyme for heme catabolism, is inducible by a variety of treatments, some of which induce by a heme-dependent mechanism and others by a heme-independent mechanism. This work shows that, in cultured chick embryo liver cells, synergistic induction of heme oxygenase by iron, added with the phenobarbital-like drug, glutethimide was heme-dependent. Addition of an inhibitor of heme biosynthesis abolished the synergistic induction of heme oxygenase providing evidence for the heme-dependent mechanism of induction. Glutethimide and iron appeared to induce at the transcriptional level since both heme oxygenase mRNA and protein levels correlate with changes in heme oxygenase activity.

Animals↗
PubMed1990

ECG evidence of limited myocardial infarction following coronary occlusion treated by early intravenous rt-PA infusion.

Serial 12-lead surface electrocardiograms (ECGs) were analysed in 110 patients with first evolving myocardial infarction entered in a double-blind placebo-controlled trial of intravenous rt-PA within 2.5 h (mean 1.9 +/- 0.5 (SD)) of pain onset. ECG analysis was performed by two 'blinded' analysts. QRS scoring (by the modified Selvester method) was used as an index of myocardial necrosis. Patient results were analysed according to infarct location. There was no difference between the two treatment groups in ST-segment elevation or QRS score at entry or up to 24 h after symptom onset. However from 24 h, QRS score was lower in patients with anterior infarction given rt-PA than in those given placebo: 5.4 +/- 2.8 vs 7.7 +/- 4.1 (P = 0.02) at 48 h; 4.7 +/- 3.2 vs 8.0 +/- 4.0 (P = 0.01) at 4-10 days; and 4.6 +/- 3.9 vs 7.5 +/- 3.9 (P = 0.01) at 21 days. For patients with inferior infarction, rt-PA treatment also resulted in a lower QRS score although this was not significantly different from the score of the placebo group (P = 0.07). Comparison of QRS scores with ejection fraction measured from the contrast ventriculogram taken at 21 days showed a moderate correlation (r = 0.46) in patients with anterior infarction but a poor correlation in patients with inferior infarction. These ECG results indicate that in evolving anterior myocardial infarction, there is limitation of infarct size from early rt-PA infusion.

Double-Blind Method↗
PubMed1989

Immunochemical detection of different isoenzymes of cytochrome P-450 induced in chick hepatocyte cultures.

This study investigated whether the same cytochrome P-450 (P-450) isoenzymes were inducible in cultures of chick-embryo hepatocytes as in the liver of chicken embryos. We purified two isoenzymes of cytochrome P-450 from the livers of 17-day-old-chick embryos: one of molecular mass approx. 50 kDa induced in vivo by the phenobarbital-like inducer glutethimide, and the second of approx. 57 kDa induced by 3-methylcholanthrene. Rabbit antiserum against the 50 kDa protein inhibited benzphetamine demethylase activity in hepatic microsomes (microsomal fractions) from glutethimide-treated chick embryo. Antiserum to the 57 kDa protein inhibited ethoxyresorufin de-ethylase activity in hepatic microsomes from methylcholanthrene-treated chick embryo. Cultured chick hepatocytes were treated with chemicals known to induce isoenzymes of P-450 in rodent liver. The induced P-450s were quantified spectrophotometrically and characterized by immunoblotting and enzyme assays. From these studies, chemical inducers were classified into three groups: (i) chemicals that induced a P-450 isoenzyme of 50 kDa and increased benzphetamine demethylase activity: glutethimide, phenobarbital, metyrapone, mephenytoin, ethanol, isopentanol, isobutanol, lindane, lysodren; (ii) chemicals that induced a P-450 isoenzyme of 57 kDa and increased ethoxyresorufin de-ethylase activity: 3-methylcholanthrene and 3,3',4,4'-tetrachlorobiphenyl; and (iii) the mono-alpha-substituted 2,3',4,4',5-pentabromobiphenyl, which induced both proteins and both activities. The immunochemical data showed that chick-embryo hepatocytes in culture retain the inducibility of glutethimide- and methylcholanthrene-induced isoenzymes of P-450 that are inducible in the liver of the chicken embryo.

Animals↗
PubMed1984

'The hidden society': the practical use of multi-dimensional scaling to illuminate the pattern of relationships between long-stay psychiatric residents.

This paper briefly reports testing the use of multi-dimensional scaling as a method to illuminate the complex pattern of relationships existing between patients in a long-stay psychiatric setting. The results did not support the hypothesis that recently formed rehabilitation groups in the hostel would serve to explain the pattern of relationships between patients. The results did, however, promote a more informed discussion regarding the origin and implications of patient relationships in long-stay psychiatric care, which served to revise staff ideas and options regarding the organization of care. Relationships between long-stay disabled psychiatric patients are notoriously opaque to observers. The use of multi-dimensional scaling helped make them more transparent.

Choice Behavior↗
PubMed1984

Development of motor co-ordination by normal left-handed children.

Ninety-six normal left-handed children were tested for motor co-ordination on a series of timed repetitive tasks, alternating left and right hands, feet and fingers. Preferred hand advantage could be demonstrated to the same degree for the left hand of these children as it had been for the preferred right hand in previously studied groups of the same age (Denckla 1973, 1974). The only test (finger to thumb successive opposition) that failed to show a preferred hand advantage in left-handers also had failed to show such an advantage among right-handers. This same test was performed more rapidly by left-handed girls than boys, as it had been by right-handed girls. However, left-foot superiority appeared to be less well established among left-handers than superiority of the right foot among right-handers, and at a later age. Left-handed children were less likely than their right-handed counterparts to choose their preferred hand when trying out a new task. Writing posture, i.e. whether inverted or straight, could not be established unambiguously for the left-handed children up to the age of 10, and often differed for writing and printing.

Child↗
PubMed1978

Binding of Triton X-114 to mammalian serum albumins at critical micelle concentration.

When the nonionic detergent Triton X-114 binds to different mammalian serum albumins, remarkably little variation occurs in the number bound at the critical micelle concentration of the detergent. Average molar ratios range from 4.0 to 6.3; mean body weights range from 0.25 to 600 kg. Measured values of the extinction coefficients reported here also show remarkably little variation. These results support the view that the folding of these serum albumins is similar.

Animals↗
PubMedDate not supplied

Progressive coxa valga after childhood excision of the hip abductor muscles.

To our knowledge, progressive coxa valga, femoral anteversion, and hip subluxation after surgical resection of soft tissue tumors of the gluteal muscles have not been described. The importance of this paper is to document proximal femoral deformity and hip subluxation in children after tumor resection of the hip abductor muscles, to provide guidelines for diagnosis and management of this problem, and to avoid late complications of progressive joint incongruity. Late deformity was seen in two cases after limb salvage surgery for a soft tissue buttock tumor. In both cases, the gluteus medius and minimus muscles were completely resected and the tensor fascia lata and gluteus maximus were partially resected. The ages of the patients at initial treatment were 4 months old and 5 years old, and both patients were followed for a minimum of 4 years. Valgus deformity was seen as early as 15 months. One patient has had a varus osteotomy to correct severe coxa valga and hip subluxation; the other patient with moderate deformity is being followed clinically and radiographically.

Bone Diseases, Developmental↗
PubMedDate not supplied

Ewing's sarcoma in a patient with congenital optic atrophy.

PURPOSE: The authors report Ewing's sarcoma in a patient with congenital optic atrophy. Congenital optic atrophy is an autosomal dominant disorder with variable expression. It manifests itself within the first decade of life and is accompanied by changes in visual acuity. This condition has not been known to cause a predisposition toward malignancy. PATIENT AND METHODS: In this article, a 16-year-old girl with dominant optic atrophy and Ewing's sarcoma is described. RESULTS: After tumor resection, the patient was successfully treated for Ewing's sarcoma with chemotherapy and radiation therapy. Today she has no evidence of malignancy. However, she continues to have deterioration of her visual acuity. CONCLUSION: This report of cancer in a child with dominant optic atrophy suggests the possible need for a higher degree of suspicion of malignancy in these patients.

Adolescent↗