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Biomedical subjects

J Flynn

Publications and source records attributed to J Flynn.

At least 91 records · Page 5Linked to original sources
PubMed1988

Prophylactic indomethacin for prevention of intraventricular hemorrhage in premature infants.

The impact of early prophylactic use of intravenous indomethacin on the incidence and severity of periventricular-intraventricular hemorrhage and patent ductus arteriosus in 199 oxygen-requiring premature infants (less than or equal to 1300 g birth weight) was prospectively investigated. The trial was controlled, the infants were randomized, and the investigators were unaware of the group assignments. Patients with minimal (grade I) or no periventricular-intraventricular hemorrhage determined by prestudy echoencephalography were randomized within two birth weight subgroups (500 to 899 and 900 to 1300 g) to receive either prophylactic indomethacin (n = 99) or an equal volume of saline-vehicle placebo (n = 100). The first dose (0.2 mg/kg) was given within 12 hours of delivery and two subsequent doses (0.1 mg/kg) were administered at 12 hourly intervals. Prophylactic indomethacin significantly reduced the incidence of grades II to IV periventricular-intraventricular hemorrhage. Intraventricular hemorrhage was half as common in infants given prophylactic indomethacin as in control infants (23% v 46%, P less than .002). The reduction was manifested in both birth weight subgroups. Results of this study also confirmed a lower incidence of clinically significant patent ductus arteriosus in infants who received prophylactic indomethacin in contrast to those who received placebo (11% v 42%, P less than .001). No significant differences were found between treatment and control groups in the duration of oxygen therapy, mechanical ventilation, or hospitalization or in the incidence of pneumothorax, chronic lung disease, sepsis, necrotizing enterocolitis, retinopathy of prematurity, or death. Early prophylactic indomethacin initiated within 12 hours of delivery is effective in reducing the incidence of intraventricular hemorrhage as well as clinically significant patent ductus arteriosus in very low birth weight premature infants.

Birth Weight↗
PubMed1988

Ibuprofen reduces the lung lymph flow changes associated with inhalation injury.

Inhalation injury was produced in sheep which were chronically prepared for study. The injury was induced by insufflating them with smoke from burning cotton cloth. One group of animals was treated with the cyclooxygenase inhibitor ibuprofen and another group was untreated. Eight hr following the administration of smoke, there was an elevation of lung lymph flow in both groups. These changes were not as severe in the animals which were treated with ibuprofen. The pulmonary changes which occur following smoke inhalation injury are associated with elevations of the metabolites of arachidonic acid, especially those generated by the cyclooxygenase pathway. These metabolites in some way contribute to the pathophysiological changes induced by the inhalation of smoke, since they are reduced by the administration of a cyclooxygenase inhibitor.

Animals↗
PubMed1987

Microtubule gelation-contraction: essential components and relation to slow axonal transport.

Preparations of microtubule proteins isolated by assembly and disassembly undergo gelation-contraction after addition of adenosine triphosphate (ATP). A particulate fraction from these preparations that is required, along with purified tubulin, to produce ATP-dependent microtubule gelation-contraction in vitro has been isolated. The particulates exhibited microtubule-stimulated adenosine triphosphatase activity and moved slowly (about 1 micrometer per minute) along microtubule walls in the presence of ATP. The particulates contained tubulin, neurofilament, and spectrin polypeptides. The composition, solubility, and motility of the particulates are consistent with those of slow component a of axonal transport.

Adenosine Triphosphatases↗
PubMed1987

Transcutaneous oxygen monitoring and retinopathy of prematurity.

This study was performed to determine whether the use of continuous tcPO2 monitoring could reduce the incidence of ROP in preterm infants receiving oxygen therapy. Two hundred and ninety-six infants with birth weights less than or equal to 1300 grams were randomly assigned to a continuous monitoring (CM) or a standard care (SC) group. CM infants had tcPO2 monitored continuously as long as they required supplemental oxygen while SC infants had tcPO2 monitored only during the more acute state of their illness. Management of both groups was otherwise identical. One hundred and one of 148 infants in the CM and 113 of 148 patients in the SC groups survived. Mean birth weights and gestational age were similar in both groups. Duration of mechanical ventilation and oxygen therapy was also similar. The overall incidence of ROP was 51% in the CM and 59% in the SC group. As birth weight for infants greater than or equal to 1000 grams increased a higher risk for developing ROP was noted in the SC group. Four infants in the CM and 5 in the SC group developed cicatricial ROP. These results suggest that continuous tcPO2 monitoring may reduce the incidence of ROP in infants with birth weights greater than 1000 grams, but not in the smaller infants in whom this complication occurs more frequently and is more severe.

Birth Weight↗
PubMed1987

Translation of mouse testis poly(A)+ mRNAs for testis-specific protein, protamine 1, and the precursor for protamine 2.

Since previous studies have suggested that the mammalian protamine mRNAs are translated poorly in cell-free systems, we directly measured the efficiency of translation of mouse protamine 1 mRNA. We found that mouse testis poly(A)+ mRNA stimulates the synthesis in the wheat germ and reticulocyte cell-free systems of three prominant translation products which can be resolved by electrophoresis through acid urea polyacrylamide gels containing 8 M urea. These translation products have been identified as testis-specific protein, protamine 1, and the precursor to protamine 2 by several criteria, including labeling with amino acids, [35S]cysteine, and [3H]leucine, which are known to be specific to some of these proteins from the nucleotide sequences of recombinant DNAs. Surprisingly, the mobility of the testis-specific protein translation product is slightly reduced and the mobility of both protamine translation products is drastically reduced unless the extracts of cell-free translations are coelectrophoresed with the appropriate carrier. The fraction of [35S]cysteine- labeled protamine 1 translation product was compared with the fraction of testis poly(A)+ mRNA as protamine 1 mRNA which we measured in dot blots with the use of an SP6 RNA polymerase transcript for protamine 1. The results demonstrate that protamine 1 mRNA is translated only slightly less efficiently than the average testis poly(A)+ mRNA.

Animals↗
PubMed1987

High levels of dietary fat: alteration of hepatic promutagen activation in the rat.

Male Ola:Sprague-Dawley rats were fed diets containing either low or high levels of fats. After being fed these diets for 4 weeks, the rats were killed and individual hepatic postmitochondrial (S9) fractions were prepared. The ability of these fractions to convert the heterocyclic aromatic amines (HAAs)--2-amino-3-methylimidazo[4,5-f]quinoline; 2-amino-3,4-dimethylimidazo[4,5-f] quinoline; and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (compounds produced during the cooking of proteinaceous food)--to bacterial mutagens was studied, with the use of Salmonella typhimurium TA98 as indicator. Fractions from rats fed high-fat diets exhibited a greater ability to activate the HAAs than did those from rats fed the low-fat diet. The magnitude of the increase was dependent on the type of fat used.

Animals↗
PubMed1987

Influence of transcutaneous oxygen monitoring on the incidence of retinopathy of prematurity.

This study was performed to determine whether the use of continuous transcutaneous oxygen tension (tcPO2) monitoring could reduce the incidence of retinopathy of prematurity in preterm infants receiving oxygen therapy. A total of 296 infants with birth weights less than or equal to 1,300 g were randomly assigned to a continuous monitoring or a standard care group. Infants in the continuous monitoring group had tcPO2 monitored continuously as long as they required supplemental oxygen, and infants in the standard care group had tcPO2 monitored only during the more acute state of their illness. Management of both groups was otherwise identical. Of 148 infants in the continuous monitoring group, 101 survived; of the 148 patients in the standard care group, 113 survived. Mean birth weights and gestational ages were similar for both groups. Duration of mechanical ventilation and oxygen therapy was also similar. The overall incidence of retinopathy of prematurity was 51% in the continuous monitoring group and 59% in the standard care group. As birth weight for infants greater than or equal to 1,000 g increased, a higher risk of retinopathy of prematurity developing was noted in the standard care group. Cicatricial retinopathy of prematurity developed in four infants in the continuous monitoring group and five in the standard care group. These results suggest that continuous tcPO2 monitoring may reduce the incidence of retinopathy of prematurity in infants with birth weights greater than 1,000 g but not in the smaller infants in whom this complication occurs more frequently and is more severe.

Birth Weight↗
PubMed1986

The effect of various dietary fibres on tissue concentration and chemical form of mercury after methylmercury exposure in mice.

The whole-body retention of mercury after exposure of BALB/c mice to methylmercury was measured in animals fed fibre-free, 5% pectin, 5% cellulose or 5, 15 or 30% wheat bran diets. The rate of elimination of mercury was dependent on the diet fed, with dietary bran increasing the rate of elimination. The incorporation of 15 or 30% bran in the diet of the mice decreased the total mercury concentration in the brain, blood and small intestine, although the effects were significant only in those animals on 30% bran diet. The fibres had little effect on mercury levels in other tissues. The proportion of mercury found in the mercuric form was significantly greater in liver, kidneys and gut of mice fed bran. The results suggest that dietary bran may reduce the levels of mercury in the brain after methylmercury exposure and may therefore reduce the neurotoxic effects of the organomercurial. We suggest that wheat bran exerts its effects on mercury retention and brain level via a modification of the metabolic activity of the gut microflora.

Animals↗
PubMed1986

Effects of plant-derived flavonoids and polyphenolic acids on the activity of mutagens from cooked food.

The ability of 3 plant flavonoids (morin, myricetin and quercetin) and 4 polyphenolic acids (caffeic acid, chlorogenic acid, ellagic acid and ferulic acid) to inhibit the genotoxic effects of a number of cooked-food mutagens (IQ, MeIQ, MeIQx, Trp-P-1 and Trp-P-2), was investigated in a bacterial mutation assay using Salmonella typhimurium TA98 as indicator and hepatic S9 mixes from either SWR mice or Syrian hamsters as metabolic activating systems. Although the polyphenolic acids failed to have an effect, the flavonoids generally inhibited IQ, MeIQ, MeIQx and Trp-P-1 induced mutagenesis in a dose-dependent manner, irrespective of the source of S9. This was not the case with Trp-P-2 where the flavonoids were only observed to inhibit when SWR mouse S9 but not Syrian hamster S9 was used. Of the 3 compounds, myricetin and quercetin were superior to morin in their inhibitory capacity.

Animals↗
PubMed1986

Metabolic conversion of IQ and MeIQ to bacterial mutagens.

The metabolic conversion of 2-amino-3-methyl- and 2-amino-3,4-dimethyl-imidazo[4,5-f]quinoline (IQ and MeIQ respectively) to bacterial mutagens was studied using a bacterial mutation assay. Studies were performed using S9 fractions derived from either corn oil (uninduced) or Aroclor-1254-treated Sprague-Dawley rats. Aroclor 1254 treatment lowered the S9 protein concentration required for optimum levels of mutagenesis, enhanced the numbers of mutants observed and altered the effects of metabolic inhibitors and cofactors added to the assay. Studies with uninduced preparations revealed that IQ and MeIQ exhibited similar responses to the effects of metabolic inhibitors and cofactors involved in detoxication reactions. Both IQ and MeIQ activation appeared to be inhibited by the biogenic amines tryptamine and tyramine and inactivated by conjugation with either acetyl coenzyme A or glutathione.

Acetyl Coenzyme A↗
PubMed1986

The computer in quality control of hemodialysis patient care.

A computerized, custom-designed medical information system (MIS) has been used for more than eight years in the care of patients with chronic renal failure treated by hemodialysis in a Cincinnati medical center. A comprehensive clinical data base that forms the core of the system readily serves the need for sophisticated quality control analysis. Application of the MIS in the day-to-day management of patients in one limited care dialysis clinic is detailed, with particular attention to its capacity to contribute to the quality of care of the individual patient. Data can be stored in the system periodically with relative ease; this enables physicians, nurses, and other personnel concerned with patient care to monitor the quality of procedures and treatments used in their patients. The system is shown to be cost-effective.

Blood Pressure↗
PubMed1986

Effect of first and subsequent use of hemodialyzers on patient well-being. Analysis of the incidence of symptoms and events and description of a syndrome associated with new dialyzer use.

To determine the effect of multiple dialyzer use on intradialytic symptoms, data from 26,592 successive dialyses on 147 patients were analyzed. Over the 26-month period of study 4,933 new dialyzers were used. All symptoms, considered together, occurred 1.3 times more frequently during the initial than during the subsequent use of the dialyzer. No symptom occurred more frequently in the second or subsequent use of the dialyzer. Concurrent chest and back pain were 41 times more frequent when the dialyzer was used for the first time. A syndrome associated with the first use of the dialyzer is described.

Back Pain↗
PubMed1986

Fatal metabolic acidosis, hyperglycemia, and coma after steroid therapy for Kearns-Sayre syndrome.

Two adolescent boys with Kearns-Sayre syndrome (progressive external ophthalmoplegia, heart block, elevated CSF protein, and ragged-red muscle fibers) developed lethargy, increasing somnolence, polydipsia, polyphagia, and polyuria after a brief course of steroid therapy. Both had hyperglycemia and acidosis. Nonketotic, lactic acidosis was present in one and ketosis in the other. Severe respiratory failure developed, and both patients died. Postmortem revealed fatty infiltration of the pancreas in addition to a diffuse spongiform encephalopathy.

Acidosis↗