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Biomedical subjects

V Miller

Publications and source records attributed to V Miller.

At least 127 records · Page 7Linked to original sources

Evaluation of fat utilization in paediatric Crohn's disease using 13C-labelled fat.

Carbon-13 breath tests provide a safe and noninvasive way of assessing nutrient absorption and utilization. Disordered protein and carbohydrate metabolism have been reported in children with Crohn's disease, but little is known about their fat utilization. To assess fat oxidation, 13C-Hiolein was administered to 11 children with active Crohn's disease (age range, 10.5-16.9 years; mean, 12.6) before and after treatment with steroids. Expired breath samples were collected at hourly intervals for 12 h, and 13CO2 excretion was measured by mass spectrometry. The mean 95% confidence interval (CI) time to peak 13CO2 excretion was 9 h (range, 7.73-9.97) before treatment and 6.95 h (range, 5.75-8.15) after treatment (p < 0.02). Mean 95% CI cumulative 13CO2 excretion up to peak time (7 h) was 47.53% (range, 24-69%) before treatment and 68.7% (range, 35-80.5%) after treatment with steroids (p < 0.02). Our results demonstrated impaired lipid utilization during active disease and improvement following steroid treatment. The oral 13C-Hiolein test is simple and noninvasive, and its results are reproducible. It provides a new method for estimating fat utilization in paediatric patients, along with the possibility of discriminating between patients with and without impaired utilization during the acute phase of the disease.

Adolescent↗

Diffuse juvenile non-adenomatous polyposis: a rare cause of severe hypoalbuminaemia in childhood.

Hypoalbuminaemia is a well-recognized complication of juvenile polyposis, which is often not clinically apparent. We describe a child with diffuse colonic non-adenomatous polyposis who presented with generalized oedema and severe hypoalbuminaemia. The site of the protein loss was the polyps, and the problem resolved after colectomy. This is a case of unusually severe hypoalbuminaemia complicating juvenile polyposis.

Adenomatous Polyposis Coli↗

A radioreceptor assay for TNF alpha-binding proteins.

A radioreceptor assay for tumour necrosis factor alpha (TNF alpha)-binding proteins was development that is suitable for use with synovial fluids and sera. This assay, an alternative to the commonly used enzyme-linked immunosorbent assays (ELISAs), is not specific for soluble tumour necrosis factor alpha receptors (sTNF-R), but detects any molecules that might compete with TNF alpha for receptor binding. It also detects molecules that might bind TNF alpha and thereby interfere with subsequent binding to receptor. In a preliminary study, the assay was used to determine levels of TNF alpha-binding activity in a test group of synovial fluids from patients with rheumatoid arthritis (RA), osteoarthritis (OA) or psoriatic arthritis (PA). Levels of binding activity were much higher than those reported for sTNF-R alone in other studies [1, 2]. Our results indicated that there may be other molecules associated with the inflamed synovium that can interfere with the binding of TNF to its receptors and so attenuate its effect in diseases such as RA.

Arthritis, Psoriatic↗

Selenium and glutathione peroxidase status in paediatric health and gastrointestinal disease.

To examine the effect of paediatric GI disease on selenium concentration in plasma and glutathione peroxidase activity in plasma and red cells, results in children with Crohn's disease (n = 39), cystic fibrosis (n = 14), intractable diarrhoea (n = 13), and biliary atresia (n = 10) were compared with those from 86 healthy children undergoing routine operations. In Crohn's disease, plasma selenium concentrations were rarely low, but glutathione peroxidase activity was increased in the plasma and reduced in the red cells. Selenium concentration and glutathione peroxidase activity increased with steroid treatment but decreased with a selenium-deficient elemental diet. Plasma selenium concentration was normal in children with cystic fibrosis but very low in severely malnourished children with biliary atresia and intractable diarrhoea. Selenium concentration and glutathione peroxidase activity should be monitored in children with severe malnutrition or requiring prolonged nutritional support. Supplementation is recommended in cases of severe selenium depletion.

Adolescent↗

An open triple crossover study comparing water absorption from potable water, Lucozade, and Dioralyte using the stable isotope 18O.

Nine volunteer children aged 6-9 years were randomised in a Latin square design to receive one of three oral solutions [Lucozade (Beechams), Dioralyte (Rorer Pharmaceuticals), and potable water] labeled with the stable isotope 18O. After administration, breath CO2 was collected using a face mask for a period of 120 min. Mass spectrometric analysis gave the enrichments of 18O in CO2 at parts per million levels. Analysis showed the accumulation of the tracer (and, by inference, absorption from the gut) to be quickest from Dioralyte and slowest from Lucozade. We hope to use this technique to investigate the absorption of water from oral rehydration solutions in infants with dehydration due to gastroenteritis.

Breath Tests↗

Dietary intake and nutritional treatment in childhood Crohn's disease.

Dietary intake was assessed in 24 children with active Crohn's disease. Seventeen of the children were sex and height matched with healthy siblings of other patients. The mean energy intake was 1,764 KJ/day (420 kcal/day) lower in patients during relapse than controls (p < 0.05). All 24 children entered a randomised controlled trial of high-dose steroids compared to an elemental diet. The elemental diet was well tolerated orally in most cases; only one patient required nasogastric administration. There was a similar improvement in disease activity and duration of remission in both groups regardless of the site of disease. Subsequent growth velocity was significantly better in the group treated with the elemental diet despite a greater and more sustained increase in energy intake in the group treated with steroids. Reintroduction of specific foods in the elemental diet group initially caused symptoms in three children but were subsequently tolerated. During remission, there was no significant difference in energy intake, but vegetables were consumed significantly less frequently (p < 0.01) and confectionery significantly more frequently (p < 0.05) when patients were compared with their own siblings.

Adolescent↗

Modification of the Fe Protein of Nitrogenase in Natural Populations of Trichodesmium thiebautii.

The Fe protein of nitrogenase in the marine nonheterocystous cyanobacterium Trichodesmium thiebautii is interconverted between two forms, which is reminiscent of the ADP-ribosylation described in the purple bacterium Rhodospirillum rubrum. In natural populations of T. thiebautii during the day, when nitrogenase activity (NA) is present and while photosynthetic rates are high, a low-molecular-mass form of the Fe protein is present. In the late afternoon, the low-molecular-mass form is partially converted to a higher-molecular-mass form (approximately equal distribution of high- and low-molecular-mass forms of the Fe protein subunits), concurrent with cessation of NA. Some of the higher-molecular-mass form persists through the night until the very early morning, when the lower-molecular-mass form appears. New synthesis of both the Fe and MoFe proteins of nitrogenase appears to occur at this time. The higher-molecular-mass form of the Fe protein is also produced rapidly in response to artificially elevated external O(2) levels (40%) during the day. T. thiebautii is capable of recovery of NA in less than 1 h following exposure to 40% O(2), which is correlated with the return of the Fe protein to the lower-molecular-mass form. Recovery from exposure to O(2) is not dependent upon protein synthesis. The modification of the Fe protein is clearly involved in regulation of NA during the diel cycle of NA in T. thiebautii but may also be involved in protecting the Fe protein during transient O(2) concentration increases.

Journal Article↗

Insulin like growth factor-I, insulin like growth factor binding protein-1, and insulin in childhood Crohn's disease.

Twenty nine children with Crohn's disease were studied before and after treatment with steroids or an elemental diet to assess the effect of disease activity and treatment on serum insulin like growth factor I (IGF-I), insulin like growth factor binding protein (IGFBP-1), and insulin concentrations. The median serum IGF-I concentration was lower in patients with active disease than in matched controls, and lower in stunted than well grown patients, but insulin and IGFBP-1 concentrations were not significantly different between any group. After four weeks of either treatment there was an increase in the median serum IGF-I concentration; this was greater in the steroid group than the elemental diet group. The median serum insulin concentration increased and median serum IGFBP-1 concentration decreased in the steroid treated group but not in the elemental diet group. These changes were accompanied by a greater and more sustained increase in energy intake in the steroid group. Despite this the median height velocity SD score was greater in the elemental diet group than in the steroid group.

Adolescent↗

Autonomic modulation of contractions to endothelin-1 in canine coronary arteries.

Endothelin-1 contracts vascular smooth muscle and inhibits release of neurotransmitter from adrenergic and cholinergic neurons. Experiments were designed to investigate the interaction of these mechanisms in a blood vessel that receives both adrenergic and cholinergic innervation. Rings cut from canine left anterior descending coronary arteries were suspended in organ chambers for the measurement of isometric force. In some rings, the endothelium was removed. Endothelin-1 caused concentration-dependent increases in tension in all rings. During electrical stimulation (1 Hz, 9 V, 2 msec), the contractions to endothelin-1 were reduced significantly. In rings without endothelium, this decrease was greater in the presence of atropine (10(-6) M) and was eliminated by a combination of phentolamine (10(-5) M) and propranolol (5 x 10(-6) M). Contractions to endothelin-1 during electrical stimulation in rings with endothelium were significantly less than those without endothelium. This difference was eliminated by atropine and NG-monomethyl L-arginine (10(-4) M). The presynaptic effects of endothelin-1 were studied by measurement of tritium-labeled norepinephrine. Phasic electrical stimulation induced release of norepinephrine; this was inhibited by endothelin-1 at high concentrations (4 x 10(-7) M) in the presence of atropine. These results suggest that the major effect of endothelin-1 is postsynaptic in canine coronary arteries. However, contractions to endothelin-1 may be modulated by the level of sympathetic and parasympathetic tone. In situations in which innervation to the coronary arteries is altered, for example, in hearts used for transplantation, the contractile effects of endothelin-1 would prevail.

Animals↗

The role of dipyridamole in the therapy of vascular disease.

The antiplatelet agent dipyridamole is FDA-approved as an adjunct to warfarin for the prevention of thromboembolism in patients receiving prosthetic heart values. It is also prescribed in several other situations, although data supporting these uses remain equivocal. Dipyridamole does not appear to be superior to aspirin alone in the management of patients with cerebral or coronary artery disease nor in maintaining the patency of autologous grafts. Its role in the management of patients who fail aspirin or other antithrombotic therapy remains to be examined. The drug may offer long-term advantages in the prevention of atherogenesis, but this use also warrants future investigation.

Animals↗

Estrogens, lipids, and heart disease.

The routine prescription of hormone replacement therapy for elderly women to prevent heart disease is not indicated. Until better data are available, the use of estrogens primarily to prevent heart disease probably should be reserved for women at high risk by virtue of their LDL/HDL ratio or the presence of manifest coronary heart disease. There is no reason to give progestins to the woman without a uterus; unopposed oral estrogen should improve lipoproteins within a few weeks, and this change, if sustained, should reduce risk. The management of a woman with an intact uterus is more problematic given the unknowns about progestin's long-term effects on lipids or the heart and the unwillingness of many elderly women to resume regular (or irregular) bleeding. There are, however, many proven benefits of hormone replacement therapy, including the prevention of osteoporosis and urogenital atrophy. Decisions about when it is too late to start estrogen, or when it is time to stop it, will need to be made on a case-by-case basis.

Age Factors↗

Whole body protein turnover in childhood Crohn's disease.

In order to investigate the effects of treatment on protein metabolism in childhood Crohn's disease whole body protein turnover was measured using a primed constant intravenous infusion of L-[1-13C]leucine and mass spectrometry in 10 children with active disease. Mean rates of protein synthesis and breakdown markedly decreased after treatment with steroids (four) or an elemental diet (six). This suggests that protein synthesis and breakdown are increased during active Crohn's disease in children and are reduced after induction of remission regardless of the type of treatment.

Adolescent↗

[Coronary transluminal angioplasty after the use of thrombolytic therapy in acute myocardial infarction].

PURPOSE: To present the Cardiology Institute of Rio Grande do Sul experience with percutaneous coronary angioplasty (PTCA), after thrombolytic therapy in acute myocardial infarction (AMI). METHODS: Fifty-three patients with transmural AMI in whom early successful intravenous streptokinase recanalization was followed by PTCA. The mean age was 50 years, male patients were more frequent, the predominant area of infarct was anterior wall and more frequently the "culprit" coronary was the left anterior descendent. The main indication of PTCA was uniarterial lesion with less than 20 mm of length. RESULTS: The success comes out in 44 patients (81.5%). Ten patients (18.5%) were considered unsuccessful and were referred to emergency bypass graft surgery. The in-hospital AMI rate after PTCA was 5.5%. In the follow-up the reestenoses rate was 11% and reocclusion was 3.7%. New PTCA was necessary in 3 patients (5.5%) and in one, by-pass graft (1.8%). CONCLUSIONS: PTCA is an important and secure modality of complementary therapy after thrombolytic therapy with low morbidity and mortality.

Adult↗

Progestins and breast cancer: an epidemiologic review.

OBJECTIVE: To provide a worldwide review of all studies that have examined the relationship between progestins, as contained in both contraceptive and postmenopausal replacement therapies, and breast cancer risk. An overview of utilization patterns for progestins, as well as a review of possible biological mechanisms for progestins' action on breast tissue, are also presented. DATA IDENTIFICATION: All major epidemiologic studies conducted since 1980 have been identified through MEDLINE searches through the published literature and personal communications with prominent researchers in the area. STUDY SELECTION: Only studies that specifically examined the effects of progestin use are discussed here; these include investigations of progestins, in combination or singularly, as the main hypothesis or a subgroup analysis. RESULTS: The majority of studies have examined combination estrogen and progestin products (oral contraceptives), and subgroup analyses of progestins have been impeded by low statistical power and the fact that each progestin possesses different types of pharmacological activity. Only a few studies of long-acting injectable progestins exist, confirming a general lack of specific information on the progesterone-breast cancer relationship. Investigations of the effect on breast cancer of the addition of progestins to postmenopausal replacement therapy have also produced inconsistent results. CONCLUSIONS: To date, there is no consistent evidence of an association between progestins and breast cancer. There is need for further study, particularly of patients in potentially high-risk groups, including those with (1) extended hormone exposure before age 25 and/or first full term pregnancy and (2) exposure in the postmenopausal period.

Breast Neoplasms↗

Assessing for abuse: self-report versus nurse interview.

Estimates are that 1.8 million women are physically abused each year by their husbands. To prevent abuse and promote physical safety, routine assessment is essential. Planned Parenthood of Houston and Southeast Texas added four self-reported abuse assessment questions to their standard intake form completed by all initial and annual-visit clients. After one month of self-report by 477 women, the prevalence of physical abuse was 7.3%. To compare self-report to nurse interview assessment, the same four questions were asked of 300 women coming to the same clinic for initial or annual visits. The reported prevalence of abuse after a nurse interview was 29.3%.

Adolescent↗