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Biomedical subjects

E Dunn

Publications and source records attributed to E Dunn.

90 records · Page 5Linked to original sources
PubMed1975

The benefits of corticosteroids in endotoxic shock.

The experiments reported here were undertaken to study the effects of pharmacological doses of corticosteroids administered alone or in conjunction with prolonged (12-hour) assisted circulation in 22 dogs subjected to LD50-60 Escherichia coli endotoxin. The most striking findings were lengthened survival time, higher cardiac output, decreased fluid requirement, and minimal evidence of pulmonary congestion or injury in the animals treated with steroids only. Unexplained mesenteric infarction prematurely terminated the experiments in animals undergoing assisted circulation. The benefits of corticosteroids in experimentally induced endotoxic shock are clearly demonstrated in these experiments. Further studies are needed to clarify the supportive role of assisted circulation in endotoxic shock and to determine any possible advantage of hypothermia over normothermia during its course.

Animals↗
PubMed1974

Regulatory aspects of L-glutamate transport in Aspergillus nidulans.

Wild-type cells of Aspergillus nidulans synthesize a transport system which appears to be specific for l-glutamate and l-aspartate. The system is energy dependent and concentrates l-glutamate at least 60-fold. In cells grown in the presence of 1% sucrose, l-glutamate uptake activity is regulated by ammonium control, although it is not certain whether this is at the level of transcription or translation. Mutants that are insensitive to ammonium control of certain other unrelated systems, e.g., nitrate reductase, are also insensitive, except in the case of one class of ammonium-insensitive mutants, to ammonium control of l-glutamate transport. The activity of this transport system is specifically impaired in a mutant at the aauA locus. This mutation results in poor growth with l-glutamate or l-aspartate as the sole carbon or nitrogen source and is recessive in the heterozygous diploid aauA1/+ for transport and growth characteristics. The likelihood that the mutation results in a defect of the transport mechanism rather than abnormal ammonium control is discussed.

Amino Acids↗
PubMed1973

Ammonium regulation in Aspergillus nidulans.

l-Glutamate uptake, thiourea uptake, and methylammonium uptake and the intracellular ammonium concentration were measured in wild-type and mutant cells of Aspergillus nidulans held in various concentrations of ammonium and urea. The levels of l-glutamate uptake, thiourea uptake, nitrate reductase, and hypoxanthine dehydrogenase activity are determined by the extracellular ammonium concentration. The level of methylammonium uptake is determined by the intracellular ammonium concentration. The uptake and enzyme characteristics of the ammonium-derepressed mutants, meaA8, meaB6, DER3, amrA1, xprD1, and gdhA1, are described. The gdhA mutants lack normal nicotinamide adenine dinucleotide phosphate-glutamate dehydrogenase (NADP-GDH) activity and are derepressed with respect to both external and internal ammonium. The other mutant classes are derepressed only with respect to external ammonium. The mutants meaA8, DER3, amrA1, and xprD1 have low levels of one or more of the l-glutamate, thiourea, and methylammonium uptake systems. A model for ammonium regulation in A. nidulans is put forward which suggests: (i) NADP-GDH located in the cell membrane complexes with extracellular ammonium. This first regulatory complex determines the level of l-glutamate uptake, thiourea uptake, nitrate reductase, and xanthine dehydrogenase by repression or inhibition, or both. (ii) NADP-GDH also complexes with intracellular ammonium. This second and different form of regulatory complex determines the level of methylammonium uptake by repression or inhibition, or both.

Aspergillus↗
PubMed1967

Heterologous antilymphocyte globulin: studies in vitro.

Incubation of dog-lymphocyte cultures with globulin from antiserum to lymphocytes resulted in a greater percentage of transformed cells than incubation with phytohemagglutinin. Viability counts demonstrated that this globulin and phytohemagglutinin had approximately equal degrees of cytotoxicity.

Animals↗
PubMedDate not supplied

Genome-wide analysis of deoxyribonucleic acid in endometrial cancer using comparative genomic hybridization microarrays.

The aim of this study was to identify amplified oncogenes in endometrial cancer using array-based comparative genomic hybridization (array CGH). Despite its prevalence, the molecular mechanisms of endometrial carcinogenesis are still poorly understood. The selected array CGH allows the simultaneous examination of 58 oncogenes commonly amplified in human cancers and is capable of achieving increased mapping resolution compared with conventional CGH. A subset of 8 specimens from a bank of 60 malignant and normal specimens was selected for array analysis to identify potential genes of interest. TaqMan polymerase chain reaction was carried out on the 60 specimens to examine if aberrations at the genomic level correlated with gene expression and to compare expression in normal and malignant samples. Oncogenes amplified in the endometrial cancers included AR, PIK3CA, MET, HRAS, NRAS, D17S1670, FGFR1, CTSB, RPS6KB1, LAMC2, MYC, PDGFRA, FGF4/FGF3, PAKI, and FGR. Three genes were examined at the messenger RNA level. AR and PIK3CA were higher in normal specimens, and MET was higher in malignant samples, suggesting a role for MET in endometrial cancer. Newer arrays examining more genes and larger sample numbers are necessary to elucidate the carcinogenic pathway in endometrial cancer.

Adenocarcinoma↗
PubMedDate not supplied

Willingness to pay to shorten waiting time for cataract surgery.

We interviewed persons who had recently been placed on a public waiting list for cataract surgery in Manitoba, Canada; Barcelona, Spain; and Denmark. The majority of the respondents were unwilling to pay higher taxes to reduce the length of the waiting list or to pay more out of pocket to have the surgery performed earlier in the private sector. Less than 2 percent actually had the surgery done in the private sector. We conclude that in spite of expressed public dissatisfaction with waiting lists in all three sites, a majority of the respondents did not support the actions that could have reduced their own wait.

Aged↗
PubMedDate not supplied

Teaching cards for respiratory nurses.

The provision of information to patients with chronic respiratory problems is arguably one of the most important aspects of care. Mindful of the paucity of relevant information on this for respiratory nurses, the authors set out to compile teaching cards which would act as guidelines for nursing interventions with respiratory patients. The cards, the authors claim, are useful for nurses working in hospitals or patients' homes.

Education, Nursing, Continuing↗
PubMedDate not supplied

Laparoscopic placement and revision of peritoneal dialysis catheters.

Chronic peritoneal dialysis is an option for many patients with end stage renal disease. Laparoscopy offers an alternative approach in the management of dialysis patients. Over an 18-month period, laparoscopy was used for placement or revision of seven peritoneal dialysis catheters. All were placed in patients with end stage renal disease for chronic dialysis. Two catheters were initially placed using the laparoscope, and in five other patients, the position of the catheter was revised. Of the two patients who had their catheters placed initially, one patient had a previous lower mid-line incision and underwent laparoscopic placement of a catheter and lysis of pelvic adhesions. The second patient had hepatitis C and chronically elevated liver function tests. He underwent laparoscopic placement of a peritoneal dialysis catheter and liver biopsy. Five patients had laparoscopic revision for non-functional catheters. Four were found to have omental adhesions surrounding the catheter. Three patients were found to have a fibrin clot within the catheter, and in one patient the small bowel was adhered to the catheter. All seven patients had general endotracheal anesthesia. There were no operative or anesthetic complications. The average operative time was 56 minutes. Four patients had their procedure in an ambulatory setting and were discharged home the same day. One patient was admitted for 23-hour observation, and two patients had their procedure while in the hospital for other reasons. In follow-up, there was one early failure at two weeks, which required removal of the catheter for infection. One catheter was removed at the time of a combined kidney/pancreas transplant eight months after revision. The other five catheters are still functional with an average follow-up of ten months. These results suggest that laparoscopy is another method for placement of peritoneal dialysis catheters and more importantly for revision in patients with nonfunctional catheters secondary to adhesions. It also provides an opportunity to evaluate the abdomen and perform concomitant procedures.

Catheterization↗
PubMedDate not supplied

Deep venous thrombosis prophylaxis is not indicated for laparoscopic cholecystectomy.

OBJECTIVES: Recent publications have discussed the risk of deep venous thrombosis during laparoscopic cholecystectomy and the need for routine deep venous thrombosis (DVT) prophylaxis. The purpose of this study was to determine the incidence of clinically detectable DVT in patients undergoing laparoscopic cholecystectomy without a standard DVT prophylaxis regimen. MATERIALS AND METHODS: We performed completed laparoscopic cholecystectomy in 587 patients over a 4-year period. Eighteen of these patients received some form of perioperative DVT prophylaxis, and 569 patients did not. Routine screening with a duplex Doppler was not used. Patients were followed postoperatively for 4 weeks after discharge from the hospital. RESULTS: In an average of 4 weeks follow-up, 31 complications and 4 deaths were reported. These complications included wound infection (16), postoperative bleeding (3), persistent pain (3), pneumonia (3), retained CBD stones (2), asthma (1), papillary stenosis (1), ileus (1), and intraoperative bowel injury (1). None of the 587 patients in this study had symptoms of DVT or pulmonary embolism. DISCUSSION: Despite the fact that DVT in this patient population is rare, many reports suggest the use of routine DVT prophylaxis with sequential compression devices (SCDs) or low-molecular-weight heparin (LMWH). Because no clinically detectable evidence was found of DVT in our study group despite the lack of any perioperative DVT prophylaxis, we question whether routine DVT prophylaxis is indicated or cost effective for routine laparoscopic cholecystectomy. A large prospective trial addressing this question is needed.

Adolescent↗