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Biomedical subjects

N Gallagher

Publications and source records attributed to N Gallagher.

At least 19 recordsLinked to original sources
PubMed2003

Small- and intermediate-conductance calcium-activated K+ channels provide different facets of endothelium-dependent hyperpolarization in rat mesenteric artery.

Activation of both small-conductance (SKCa) and intermediate-conductance (IKCa) Ca2+-activated K+ channels in endothelial cells leads to vascular smooth muscle hyperpolarization and relaxation in rat mesenteric arteries. The contribution that each endothelial K+ channel type makes to the smooth muscle hyperpolarization is unknown. In the presence of a nitric oxide (NO) synthase inhibitor, ACh evoked endothelium and concentration-dependent smooth muscle hyperpolarization, increasing the resting potential (approx. -53 mV) by around 20 mV at 3 microM. Similar hyperpolarization was evoked with cyclopiazonic acid (10 microM, an inhibitor of sarcoplasmic endoplasmic reticulum calcium ATPase (SERCA)) while 1-EBIO (300 microM, an IKCa activator) only increased the potential by a few millivolts. Hyperpolarization in response to either ACh or CPA was abolished with apamin (50 nM, an SKCa blocker) but was unaltered by 1-[(2-chlorophenyl) diphenylmethyl]-1H-pyrazole (1 microM TRAM-34, an IKCa blocker). During depolarization and contraction in response to phenylephrine (PE), ACh still increased the membrane potential to around -70 mV, but with apamin present the membrane potential only increased just beyond the original resting potential (circa -58 mV). TRAM-34 alone did not affect hyperpolarization to ACh but, in combination with apamin, ACh-evoked hyperpolarization was completely abolished. These data suggest that true endothelium-dependent hyperpolarization of smooth muscle cells in response to ACh is attributable to SKCa channels, whereas IKCa channels play an important role during the ACh-mediated repolarization phase only observed following depolarization.

Animals↗
PubMed2003

A phase II/III study comparing intravenous ZD9331 with gemcitabine in patients with pancreatic cancer.

ZD9331 is a novel antifolate inhibitor of thymidylate synthase (TS). This multicentre, randomised, phase II/III study compared the efficacy and safety of ZD9331 with gemcitabine in 55 patients with chemonai;ve, locally advanced or metastatic pancreatic cancer. Patients received intravenous (i.v.) ZD9331 (n=30), on days 1 and 8 of a 3-week cycle or i.v. gemcitabine (n=25), once a week for 7 weeks followed by a 1-week rest, then on days 1, 8 and 15 of a 4-week cycle. Objective tumour response and clinical benefit response (CBR) were similar for both groups. More ZD9331 patients were alive at the data cut-off point compared with gemcitabine patients (13 and 8%, respectively). Median survival (152 versus 109 days, respectively) and time to progression (70 versus 58 days, respectively) were longer in the ZD9331 group. Nausea and vomiting (grade 1/2) were the most common toxicities in both groups. These results suggest that, in pancreatic cancer, ZD9331 is equivalent to gemcitabine and may offer a promising alternative to current therapies.

Adult↗
PubMed1998

Mortality and rebleeding following Transjugular Intrahepatic Portosystemic Stent Shunt for variceal haemorrhage.

The present study investigates clinical factors associated with decreased survival following Transjugular Intrahepatic Portosystemic Stent Shunt (TIPSS). Sixty-seven patients underwent TIPSS for bleeding related to portal hypertension, 42 (63%) on an urgent basis. TIPSS was successfully placed in 65 (97%) patients with no fatal procedural complications. Thirty day mortality was 21%, there being several predictive factors: transfer from another institution, urgency of procedure, sepsis, encephalopathy, higher mean serum bilirubin and low serum albumin. However, using regression analysis, 30 day mortality was predicted independently only by severe liver disease (Child-Pugh C, P= 0.003) and older age (P= 0.003). When stratified by Child-Pugh class, cumulative survival rates at 1 year for class A, B and C were 100, 90 and 34%, respectively. Only three of 25 patient deaths were due to variceal rebleeding. Thirty (46%) patients had a total of 41 rebleeding episodes, with mean time to first rebleed of 4.8 months (range, 3 days-38 months). Cumulative rebleeding rate at 1 year was 25%. Log-rank analysis did not reveal a significant difference in overall survival between rebleeders and non-rebleeders (P= 0.125). When investigated, shunt abnormalities (stenosis, occlusion) were identified in all cases of rebleeding. Our findings confirm TIPSS can be safe and effective in the control of refractory variceal haemorrhage. However, prognosis remains poor for patients with advanced liver disease, particularly if older and in the emergency setting. Vigilant surveillance and high rate of intervention is necessary to maintain shunt patency. Consideration could be given to elective shunt surgery instead of TIPSS for patients with recurrent bleeding and good prognosis liver disease.

Esophageal and Gastric Varices↗
PubMed1996

Postpartum avulsion of the terminal ileal wall in Crohn's disease.

A case of acute perforation of the terminal ileum induced by avulsion of the bowel wall in a segment of acutely inflamed Crohn's disease is presented. This case is unusual in that the avulsion developed after delivery following the rapid retraction of the uterus which had been compressing a small localized perforation and abscess. A review of the literature has failed to demonstrate a similar case report.

Adult↗
PubMed1991

Kinetics and quality assurance: prescription therapy through kinetic modeling.

With recent startling statistics showing an increase in mortality risk of dialysis patients in the United States compared to other countries, managers and practitioners have been motivated to carefully examine not only the dialysis prescription, but what is actually delivered to the patient. In October 1990, prior to ANNA's Clinical Concerns in Nephrology meetings in Cincinatti and San Antonio, attendants were invited to participate in an education session examining the monitoring and evaluation of prescription therapy for peritoneal and hemodialysis. The title of the session was "The Nurse's Role in Prescription Therapy--What Does it Really Mean?" The sponsor was Fresenius USA, Inc. This educational offering gave the nephrology nurse the opportunity to learn how to manage the delivery of care based on the theory of kinetic modeling for peritoneal and hemodialysis therapy. Quality assurance indicators, data collection tools, and the latest technology were described for the monitoring and evaluation of the adequacy of therapy. The following article is adopted from the original transcripts of the five-member panel of experts who participated in the session. We appreciate the willingness of the speakers to share this timely and important material with the ANNA Journal readers.

Data Collection↗
PubMed1985

Fungal peritonitis in patients on peritoneal dialysis: incidence, clinical features and prognosis.

Fungal peritonitis occurred in 17 patients on chronic peritoneal dialysis. The incidence of infection per 100 patient-dialysis months was 0.36 for patients on intermittent peritoneal dialysis and 1.6 for patients on continuous ambulatory dialysis (p less than 0.005). Initial clinical findings included abdominal pain (76%), fever (59%), cloudy dialysate (76%) and poor dialysate outflow (6%). 15 patients received antibiotics within 4 weeks of developing peritonitis. All infections were caused by yeasts, with Candida parapsilosis and Candida albicans as the most common species. 14 patients were unable to continue peritoneal dialysis due to persistent or relapsing infection or the development of complications. 2 of the 3 patients who were able to continue peritoneal dialysis were treated with catheter replacement, intraperitoneal miconazole and oral ketoconazole.

Adult↗
PubMed1984

Characterization of a pancreatic tumor containing vasoactive intestinal peptide, neurotensin, and pancreatic polypeptide.

The biochemical characteristics of a pancreatic tumor from a patient with watery diarrhea, hypokalemia, hypochlorhydria, and steatorrhea is described Plasma concentrations of vasoactive intestinal peptide (VIP) were elevated 6-fold, those of neurotensin (NT) were elevated 10-fold, and those of pancreatic polypeptide (PP) were elevated 200-fold above the normal range. The pancreatic tumor removed was found to contain high concentrations of these peptides in a similar ratio to plasma. The tumor content of NT was 6 times higher than any previously reported, but no specific symptoms could be ascribed to NT. After removal of the tumor, plasma levels of VIP, NT, and PP returned to normal, and the diarrhea disappeared. Gel chromatography of plasma and tumor extracts indicated that all of the immunoreactive PP co-eluted with standard human PP. When the tumor extract was subjected to gel chromatography and high pressure liquid chromatography, two forms of VIP were detected, the major one resembling porcine VIP and a smaller more hydrophobic form detected by C- but not N-terminally directed VIP antisera. This smaller form was not present in normal ileum. Immunoreactive NT in plasma was predominantly an N-terminal fragment. High pressure liquid chromatography of the tumor extract revealed that approximately 75% of the NT immunoreactivity consisted of N-terminal fragments. In contrast, normal ileum contained only authentic NT-(1-13). Since N-terminal fragments of NT are thought to be biologically inactive, the nature of the immunoreactive NT should be determined before attempting to assign specific clinical symptoms to NT-secreting tumors.

Adenoma, Islet Cell↗
PubMed1981

Peritoneal dialysis fluid as a source of hepatitis antigen.

An epidemic of HBsAg positive hepatitis involving the dialysis unit of the Seattle Veterans Administration Medical Center is described. 6 patients and 4 staff members were affected: there were four patient deaths. The source of HBsAg was identified as a chronic in-center peritoneal dialysis patient in whom both serum and peritoneal fluid were persistently HBsAg positive. Surveillance data documented heavy population exposure to HBsAg at the time of this patient's presence in the dialysis setting. We have subsequently identified 2 other patients with HBsAg positive peritoneal effluent. Peritoneal dialysis of HBsAg positive individuals represents a significant risk for the transmission of HBsAg and clinical hepatitis.

Carrier State↗