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Biomedical subjects

M J Robinson

Publications and source records attributed to M J Robinson.

At least 91 records · Page 5Linked to original sources

Sexually transmitted cytomegalovirus proctitis in a woman.

A heterosexual woman with cytomegalovirus (CMV) proctitis after anal intercourse is presented. Whereas CMV infection typically occurs in immunosuppressed patients, including patients with acquired immune deficiency syndrome (AIDS), this patient has no evidence of immunodeficiency, and is human immunodeficiency virus (HIV) negative during 8 months of follow-up since onset of proctitis. A review of the literature reveals no other report of sexually transmitted CMV proctitis in an immunocompetent woman after anal intercourse.

Adult↗

Familial fibromuscular dysplasia presenting as sudden death.

Fibromuscular dysplasia involving the aorta, its main arch branches, and the coronary arteries is infrequent. Familial occurrence of arterial fibromuscular dysplasia is rarely recognized in infancy. We report three infant siblings with this disorder who presented with sudden unexpected death secondary to acute myocardial infarction as a complication of fibromuscular dysplasia involving the aorta, its main arch branches, and the major coronary arteries. This condition must be considered in the differential diagnosis of identifiable causes of the sudden infant death syndrome.

Adult↗

Vitamin D nutrition and vitamin D metabolism in the premature human neonate.

The effect of supplementation with daily doses of vitamin D2 (1000 IU or 3000 IU, 25-75 micrograms, 63-189 nmol) has been studied in 39 premature neonates, initial gestational age 25-32 weeks. The initial mean plasma 25-hydroxyvitamin D was 25.8 nmol/l (10.3 ng/ml) but in 12 infants, most of whom were born in the winter months, the level was less than 15 nmol/l (6 ng/ml), and in seven babies plasma 1,25-dihydroxyvitamin D was less than 48 pmol/l (20 pg/ml). These findings suggest a considerable degree of maternal vitamin D-deficiency. Maximum attained concentrations of 25-hydroxyvitamin D on treatment were 77.3 nmol/l (30.9 ng/ml), high dose and 86.8 nmol/l (34.7 ng/ml), low dose, the mean rate of increase was greatest during the first two weeks (2.2 nmol/l/d; 0.88 ng/ml/d) and declined over the next 4 weeks. Mean maximum concentrations of 1,25-dihydroxyvitamin D2 were 283 pmol/l, (121 pg/ml), high dose and 309 pmol/l (129 pg/ml), low dose. Apart from a minor contribution to the initial plasma 1,25-dihydroxyvitamin D concentration, no effect of gestational age could be discerned in any of the measured variables. The endogenous pool of 1,25-dihydroxyvitamin D3 decayed with a T 1/2 of 22.5 d, indicating that vitamin D supplementation of these infants was necessary to avoid vitamin D-deficiency.

Calcifediol↗

Neonatal tuberculosis.

Tuberculosis rarely presents in the neonatal period. Though treatable, it may be fatal despite modern treatment. The diagnosis of congenital tuberculosis should be considered in any neonate with pneumonia that fails to respond to conventional treatment, particularly in a child from an ethnic or socioeconomic environment where tuberculosis is prevalent.

Adult↗

Comparison of EMT blood pressure measurements with an automated blood pressure monitor: on scene, during transport, and in the emergency department.

Auscultation or palpation of blood pressure in critically ill patients by emergency medical technicians (EMTs) can be difficult, if not impossible, because of ambient noise, motion artifact, limited access to patients, or weak pulses. Automated blood pressure monitors (ABPMs) have been designed to overcome these problems during field emergencies and patient transport. Our study compared blood pressure measurements taken by EMTs with measurements provided by a Lifestat ABPM. Measurements in emergency patients on scene, during transport, in the emergency department (ED), and in a controlled environment were compared. Measurements in the various sites were obtained from 57 patients, and provision was made for two measurements at each site. Comparison of on-scene systolic blood pressures yielded a mean absolute systolic difference of 10.46 +/- 1.42 mm Hg and a mean absolute diastolic difference of 9.33 +/- 1.32 mm Hg. During transport systolic pressures showed a mean absolute difference of 11.50 +/- 1.72 mm Hg, and diastolic pressures showed a mean absolute difference of 7.59 +/- 1.16 mm Hg. Mean absolute differences in the ED were 11.23 +/- 1.49 mm Hg systolic and 8.37 +/- 1.25 mm Hg diastolic. Ninety comparison measurements in a controlled environment yielded a mean absolute systolic difference of 8.74 +/- 0.87 mm Hg and a mean absolute diastolic difference of 7.97 +/- 0.72 mm Hg. Comparison of mean diastolic pressure differences between EMT and ABPM measurements in various settings revealed some small, but statistically significant, discrepancies that were not considered clinically relevant.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗

Histone acetylation and deacetylation in senescent human diploid fibroblasts.

We measured the kinetics of histone H4 hyperacetylation and kinetics of deacetylation for all core histones in young and senescent human diploid fibroblast-like cells. Both cell populations contained a fraction of histone H4 characterized by very rapid acetylation and deacetylation. The kinetics of these reactions were similar in young and senescent cells. The distribution of acetylated species of core histones was also similar in young and senescent human diploid fibroblast-like cells. These results indicated that previously-reported alterations in chromatin template activity in senescent cells were due to a mechanism other than histone acetylation.

Acetylation↗

High-frequency positive-pressure ventilation in neonates.

Twenty-five newborn infants with severe respiratory failure responding poorly to conventional mechanical ventilation were switched to high-frequency positive-pressure ventilation (HFPPV) at 90 to 180 cycle/min (mean 158), an estimated tidal volume less than or equal to 3 ml/kg body weight, an inspiratory time of 0.1 sec, and a PEEP of 3 to 17 cm H2O. In all infants, HFPPV increased PaO2 (mean 66 torr) and decreased PaCO2 (mean 14 torr) within 1 h. Fourteen hours after onset of treatment, the FIO2 requirement had decreased from 1.0 to 0.6 in all infants. Mean airway pressure (Paw) with HFPPV was usually less than or equal to Paw during conventional ventilation. In spite of the often high level of PEEP used, pneumothorax occurred in only 2 infants and bronchopulmonary dysplasia in 1. Eighteen (72%) infants survived and none died of respiratory failure. The use of HFPPV might be beneficial in neonates with severe respiratory failure that responds poorly to conventional therapy.

Bronchopulmonary Dysplasia↗

Paracetamol metabolites in the neonate following maternal overdose.

A case of paracetamol overdose in a 36 week pregnant woman is described. The baby was delivered by Caesarian section 6 h after the overdose. The mother but not the baby was treated with N-acetylcysteine and neither suffered liver damage. The plasma paracetamol half-life was prolonged to 10 h in the neonate compared to 2.5 h in the mother and was unaffected by a two volume exchange transfusion. The pattern of urinary metabolites in the neonate was similar to that observed in the mother, but there was a marked delay in the time taken to reach peak plasma concentrations of metabolites. This is consistent with a very slow biotransformation of the drug and may explain the relative resistance of very young children to the hepatotoxicity of paracetamol. There was no evidence of limited or decreasing capacity in sulphate conjugation nor was sulphation the major metabolic pathway. In retrospect both the obstetrical intervention and the exchange transfusion were unnecessary.

Acetaminophen↗

Neonatal fat embolism and agglutination of intralipid.

Pulmonary fat embolism in a preterm infant receiving Intralipid intravenously is described. Serum obtained at the time of clinical deterioration agglutinated Intralipid. This coincided with the onset of septicaemia and with a raised serum C reactive protein concentration. Subsequent clinical improvement was associated with reduction in the C reactive protein concentration and nonagglutination of Intralipid.

Agglutination↗

Kinetics of histone hyperacetylation and deacetylation in human diploid fibroblasts.

We have utilized sodium butyrate-treated normal human diploid fibroblasts to study core histone hyperacetylation kinetics. We report a small, distinct population of core histone characterized by a very rapid rate of hyperacetylation (t1/2 approximately equal to 10-15 min for monoacetylated histone H4) compared to the slower rate (t1/2 approximately equal to 140-200 min for monoacetylated H4) observed for bulk histone. Two rates of core histone deacetylation were also detected and we demonstrated that the rapidly hypermodified histone H4 population was also rapidly deacetylated. The kinetics of histone H4 hyperacetylation and deacetylation in these cells were not significantly altered, regardless of whether cultures were exponentially growing, confluent or arrested in an essentially non-mitotic state.

Acetylation↗