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Biomedical subjects

D Barron

Publications and source records attributed to D Barron.

36 records · Page 2Linked to original sources
PubMed1995

Fatal morphine poisoning in a child due to accidental oral ingestion.

A case of fatal intoxication of an 8 year old child due to accidental oral ingestion of morphine is presented. Following a tonsillectomy and release from the hospital the decedent was prescribed meperidine syrup 50 mg per teaspoon (tsp) to be taken 2 tsps every 4 h. A pharmacist when filling her prescription mistakenly dispensed Roxanol which contained 20 mg/ml morphine sulfate. She took 1 or 2 tsp of the prescription prior to bed and was found dead the next morning. Autopsy findings were unremarkable. Quantitation by gas chromatography/mass spectrometry (GC/MS) yielded the following morphine results: blood, 0.128 mg/l; bile, 135 mg/l and stomach contents, 16 mg/l (2.3 mg total). Based upon the clinical history, autopsy and toxicology finding the cause of death was determined to be poisoning by morphine and the manner of death accidental.

Administration, Oral↗
PubMed1995

Growth retardation and hyperglycemia in insulin-like growth factor binding protein-1 transgenic mice.

Transgenic mice that constitutively overexpressed rat insulin-like growth factor binding protein-1 (IGFBP-1) were generated to determine the effects of overexpression of IGFBP-1 on growth and development. In offspring of three of the founders that showed high levels of expression, birth weight was significantly reduced to approximately 83-92% of the weight of their nontransgenic littermates. The transgenic mice gained less weight and were approximately 3.5-8 g lighter than nontransgenic littermates at 40 days of age. The difference in body weight between transgenic and wild-type mice was most apparent around the time of weaning when transgenic mice showed a more marked growth deceleration than wild-type mice. No significant catch-up growth was apparent over the first 3 months of life. In addition, offspring of all three high-expressing founders demonstrated fasting hyperglycemia. The transgene was highly expressed in the brain, uterus, lung, kidney, and heart, but little expression was detected in the liver. The weight of the brain relative to body weight was significantly reduced in transgenic mice compared with wild-type mice, whereas the relative weight of most other organs was similar to wild-type mice. These data demonstrate that IGFBP-1 may function to inhibit IGF action in vivo and that this inhibition selectively impairs development of organs such as the brain.

Animals↗
PubMed1989

Neutrophilic eccrine hidradenitis: a case report and review of the literature.

Neutrophilic eccrine hidradenitis (NEH) is a recently recognized dermatosis occurring in patients receiving chemotherapy for a variety of malignancies. We report the second pediatric case. An 11-year-old boy with non-Hodgkin's lymphoma developed widespread erythematous papulopustules beginning two days after receiving high-dose cytarabine (Ara-C) in preparation for a bone marrow transplant. The lesions spontaneously regressed in two weeks. Histologic examination revealed a neutrophilic infiltrate around and within the eccrine ducts and secretory coils. Bacterial, fungal, and viral cultures were negative. These findings are characteristic of NEH. The condition should be differentiated from infectious dermatoses that may require treatment.

Child↗
PubMed1988

Fecal protoporphyrin excretion in erythropoietic protoporphyria: effect of cholestyramine and bile acid feeding.

The effect of cholestyramine and bile acid feeding upon fecal, red blood cell, and plasma protoporphyrin levels was evaluated in a patient with erythropoietic protoporphyria and evidence of hepatic damage. After a basal period on a controlled diet, bile acids alone were administered (300-900 mg) daily for 9 days, followed by cholestyramine (12 g) plus bile acids (900 mg) daily for 7 days, and cholestyramine alone (12 g) daily for 6 days. There was no substantial change in either the red blood cell or plasma protoporphyrin concentrations during any treatment period. However, cholestyramine and cholestyramine combined with bile acids caused a threefold increase in fecal protoporphyrin excretion, whereas bile acids alone had no effect in this regard. After 1 yr of cholestyramine therapy, fecal excretion of protoporphyrin remained elevated with concurrent improvement in liver function tests and photosensitivity. This study indicates that cholestyramine but not bile acids can substantially increase protoporphyrin excretion and therefore may be capable of ameliorating the hepatotoxicity that may occur in selected patients with erythropoietic protoporphyria.

Bile Acids and Salts↗
PubMed1988

Dissociation constants and assay of weak bases in non-aqueous solvents.

A method is described for evaluating standard cell potentials of specific electrode pair systems in anhydrous acetic acid and acetonitrile. The dissociation constants (K(HB+)) in acetonitrile and the overall dissociation constants (K(B)) and (K(BHClO4)) in anhydrous acetic acid of a series of bases of pharmaceutical interest have been determined. Simple potentiometric and visual titration methods are proposed for the assay of bases and their mixtures.

Journal Article↗
PubMed1987

Enzymatic assay for flavonoid sulfotransferase.

A novel enzyme assay for flavonoid sulfotransferase is described. It makes use of tetrabutylammonium dihydrogen phosphate which forms a pair of ions with the flavonoid sulfate esters formed. This renders the sulfate ester soluble in organic solvents such as ethyl acetate, whereas the sulfate donor, 3'-phosphoadenosine-5'-phosphosulfate, remains in the aqueous reaction mixture. The procedure is simple, rapid, and reproducible. It eliminates the need for chromatographic separation of the reaction products, except when their identification is required, and is suitable for use in the purification and kinetic studies of sulfotransferases.

Arylsulfotransferase↗
PubMed1986

Surface alterations in dialysis roller pump inserts: a scanning electron microscopy study.

Scanning electron microscopy has been used in a study of particle spalling from silicone and PVC elastomer inserts of dialysis roller pumps. In an experimental circuit using Isoton II, pump occlusion, pressure, pump revolutions and temperature were monitored. Scanning electron microscopy was performed on inserts exposed to 1-10 h of pumping using Silastic (medical grade) and a Watson-Marlow MHRE pump, with PVC and Pivipol, a polyurethane coated PVC (Bellco) using a Bellco BL705N pump. Changes included longitudinal splits (single and multiple), superficial cracks (random and orientated), deformations of normal surface pattern, holes, craters and detaching particles. There was an increase in these abnormalities with time for all types of pump insert, the changes being most marked for the Silastic/Watson-Marlow pump combination and least prevalent with the PVC/Bellco pump combination.

Humans↗
PubMed1986

Particle spallation induced by blood pumps in hemodialysis tubing sets.

The repeated flexion and compression of pump segments by the rollers of peristaltic pumps results in cracking and abrasion of the inner surfaces of the pump segment, leading to shedding of particles into the extracorporeal circuit. A series of studies to assess the rate of particle release from silicone rubber, polyvinyl chloride (PVC), and Pivipol, a coextruded polyurethane-coated PVC tubing, when these materials were used with blood pumps of the type found in hemodialysis units, was undertaken. The studies show that with all tubing/pump combinations there is an overall increase in the total number of particles released, but an analysis of the particle size distribution indicates that the majority of the particles are less than 16 micron in diameter. The rate of increase may be reduced, however, by decreasing the occlusion pressure.

Analysis of Variance↗
PubMed1986

Changes in peripheral T-cell subsets and natural-killer cytotoxicity in relation to colorectal cancer surgery.

Surgery for cancer in man is followed by immunosuppression, and immunosuppressed cancer patients have advanced stage and poor prognosis. Yet surgery continues to offer the best chance for cure for patients with solid tumors. Since natural-killer cells appear to play a major role in control of tumor metastases in experimental animals, we studied peripheral blood T-cell subsets and natural-killer cytotoxicity of 75 patients with colorectal cancer preoperatively and between 1 and 3 months postoperatively. There was no relationship between preoperative lymphocyte, T-cell, helper-cell, suppressor-cell, or natural-killer cell number or natural-killer cytotoxicity and stage of disease. One to 3 months following surgery natural-killer cells had increased more than 50% from 218 to 325 cells/cmm (T = 2.07, P = 0.0459). Natural killer cytotoxicity increased proportionally. Lymphocytes, T cells, suppressor cells, and helper cells increased insignificantly. The results suggest that potentially curative excision of solid tumors in man is eventually followed by return of immune function reflected by increased numbers of natural-killer cells.

Colonic Neoplasms↗
PubMedDate not supplied

Microcratering within the lunar regolith--a theory and observation.

Since the Apollo 11 mission to the moon, there has been substantial analysis of the lunar rocks and soil grains, utilizing more recent advances in electron probe technologies. It is the objective of this research to revisit the theories concerning the microcratering within the lunar regolith. Recent theories have included the idea that the microcratering phenomenon was caused by meteoric impacting onto the lunar surface during early lunar history. Other theories have suggested that the microcratering was a result of secondary ejector associated with micrometeoric and meteoric impact. This research team suggests that microcratering may have been associated with primordial dust during and before the formation of our solar system.

Microscopy, Atomic Force↗
PubMedDate not supplied

Modulation of cancer cell multidrug resistance by an extract of Ficus citrifolia.

Multidrug resistance due to P-glycoprotein is a serious impediment to successful chemotherapy of cancer. Previous studies have shown that natural compounds such as prenyl flavonoids are able to modulate the multidrug resistance phenotype of P-glycoprotein-positive cancer cells. A fraction from the dichloromethane extract of a common Guadalupe Ficus, Ficus citrifolia was studied for its direct interaction with the purified C-terminal cytosolic domain of P-glycoprotein, and for its induced accumulation and cytotoxicity of vinblastine and daunomycin in two model cell lines overexpressing P-glycoprotein, namely K562/R7 and MESSA/Dx5. The fraction bound with high affinity to P-glycoprotein C-terminal cytosolic domain and was as efficient as cyclosporin A to increase intracellular accumulation of daunomycin in K562/R7 leukemic cells. Moreover, the fraction markedly enhanced the cytotoxic effect of vinblastine on the growth of MESSA/Dx5 cells. These results suggest that Ficus citrifolia possesses important therapeutic potential for improving the efficacy of cancer chemotherapy.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMedDate not supplied

SIDS and infant positioning: implications for critical care.

This article will briefly review the literature that led to the AAP's recommendations of supine and side-lying positions for infants and explore the challenges and the controversy associated with changing standards and practices. It will discuss specific considerations for the critical care nurse and suggest points to consider in implementing any practice changes for seriously ill or critically ill infants.

Critical Care↗