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Biomedical subjects

K Carney

Publications and source records attributed to K Carney.

28 records · Page 2Linked to original sources
PubMed1983

Selective posttransplantation bilateral native nephrectomy. Indications and results.

Twenty-five patients underwent bilateral native nephrectomy one to 68 months (mean, 15.6 months) following renal transplantation. The indications were erythrocytosis in two patients, recurrent urinary tract infection in three, medically uncontrolled hypertension in 18, and hypertension and urinary tract infection in two. One patient died two months after the nephrectomy, and one allograft was lost because of acute tubular necrosis. Both patients with erythrocytosis had prompt return of the hematocrit level and RBC mass to normal. Native nephrectomy eradicated the infection in each of the five patients with recurrent urinary tract infections. Results of nephrectomy for hypertension were classified as excellent in six patients, good in nine, and poor in four. Native renal-vein renin ratios of patients with excellent or good responses were not statistically different when compared with those of poor responders.

Adult↗
PubMed1983

The effects of ATP-MgCl2 and dipyridamole in cold-storage preservation.

The effects of ATP-MgCl2 and dipyridamole were evaluated in a canine model. Twenty-five adult mongrel dogs were divided into five equal groups. All dogs underwent left nephrectomy and 30 min of warm ischemia followed by Collins' C-4 flush and 24 hr of cold-storage preservation. Heterotopic autotransplantation and immediate contralateral nephrectomy were then performed. Group A served as controls; Group B was pretreated with intravenous ATP-MgCl2 (2.5 mM); Group C with intravenous dipyridamole (10 mg), and Group D with both ATP-MgCl2 (2.5 mM) and dipyridamole (10 mg). Group E was treated with ATP-MgCl2 (2.5 mM) at the time of transplantation. All kidneys underwent cortical biopsies at the end of preservation and 1 hr after restoration of blood flow for determinations of AMP, ADP, and ATP. In Groups A and E there were no survivors, whereas Groups B, C, and D had 40, 60, and 40% graft survival. In Groups B and D, ATP and energy charge (EC) were greater than that of controls after 24 hr of preservation, with Group D values being significantly greater (P less than 0.01). AMP and ADP levels were significantly greater (P less than 0.02) in Group C when compared to Group A. One hour posttransplantation biopsies demonstrated greater ability to regenerate cortical nucleotides in the surviving animals, but no absolute value could be identified as a predictor of viability. In conclusion, pretreatment with ATP-MgCl2 or dipyridamole maintains intracellular nucleotide levels and has a beneficial effect on graft survival in ischemically injured kidneys undergoing cold-storage preservation.

Adenine Nucleotides↗
PubMed1982

Potentiation of the carotid artery occlusion reflex by a cholinergic system in the posterior hypothalamic nucleus.

Bilateral occlusion of the common carotid arteries of urethane-anesthetized rats evoked a pressor response of 14 +/- 1 mm Hg. Injection into the lateral cerebral ventricle of neostigmine (0.2-1.0 microgram) or physostigmine (10-15 microgram) caused a dose-dependent increase in basal blood pressure and in the magnitude of the carotid artery occlusion (CAO) pressor reflex. Neostigmine (1 microgram) and physostigmine (15 microgram) caused nearly maximal and approximately equal degrees of cholinesterase inhibition in several brain regions. The recovery of the cardiovascular parameters and of brain cholinesterase activity was significantly faster following physostigmine compared to neostigmine. Prior intracerebroventricular injection of atropine (0.3 microgram) or hemicholinium-3 (20 microgram) prevented the increases in basal pressure and the CAO pressor response. Potentiation of the CAO reflex also followed injection of physostigmine or neostigmine into the posterior hypothalamic nucleus and of injection of physostigmine intravenously. Injection of atropine bilaterally into ther posterior hypothalamic nucleus prior to intravenous injection of physostigmine prevented the potentiation of the CAO reflex but not the increase in basal blood pressure. These results indicate that acetylcholine in the posterior hypothalamic nucleus serves as a neurotransmitter in a pathway which can potentiate the pressor response to carotid artery occlusion and thus modulate baroreceptor reflexes.

Acetylcholine↗
PubMed1982

Peptic ulcer disease following transplantation: the role of cimetidine.

Of 253 consecutive renal transplants performed in 209 patients between January 1971 and December 1980, symptomatic gastroduodenal ulcerations developed in 22 (8.7 percent). Time of presentation ranged from 5 days to 9 years (mean 225 days) following transplantation with 16 of these patients presenting within the first 3 months. Nine (Group I) patients were diagnosed before the administration of H2 antagonist cimetidine. Mode of presentation in this group was upper gastrointestinal bleeding in each instance. Thirteen patients (Group II) were diagnosed after the clinical use of cimetidine was established. The mode of presentation in this group was bleeding in 11 patients and abdominal pain in 2 patients. In Group I, one patient died from liver failure and an ulcer was not contributory. The remaining eight patients were treated with antacids and blood transfusions (mean 12.7 units). Five patients in this group demonstrated ulcer healing, whereas three patients (37.5 percent) required emergency operations with two postoperative deaths. In Group II, one patient died from hemorrhagic shock before therapy could be instituted. In the other 12 patients treatment consisted of antacids, cimetidine, and blood transfusions (mean 6.8 units). Ten patients had relief of symptoms, whereas two patients (16.7 percent) required emergency operations with no deaths. During cimetidine therapy, two patients had rejection episodes that were reversible, and the remaining patients had no significant alterations in renal function. To conclude, cimetidine is a safe and effective adjunct in the treatment of peptic ulceration in renal transplant recipients.

Cimetidine↗
PubMed1980

Modulatory effect of brain acetylcholine on reflex-induced bradycardia and tachycardia in conscious rats.

The effects of intracerebroventricular (i.c.v.) injection of physostigmine and hemicholinium-3 (HC-3) on reflex bradycardia and tachycardia have been studied in unanesthetized rats. The reflex increases and decreases in heart rate were elicited by i.v. injection of norepinephrine and sodium nitroprusside, respectively. Physostigmine (5-10 micrograms) increased basal mean arterial pressure (MAP), reduced basal heart rate (HR), enhanced the reflex bradycardia and reduced reflex tachycardia. Physostigmine did not modify either the pressor effect of norepinephrine, the depressor effect of sodium nitroprusside or the responsiveness of peripheral muscarinic receptors. Pretreatment (i.c.v.) with atropine (0.3 micrograms) completely abolished the effect of physostigmine on MAP, HR, reflex bradycardia and reflex tachycardia. Pretreatment (i.c.v.) with mecamylamine (50 micrograms) did not modify the effect of the cholinesterase inhibitor on MAP, HR and reflex tachycardia, but inverted its effect on reflex bradycardia. Injection of HC-3 (20 micrograms i.c.v.) did not modify MAP, but reduced HR and inhibited both reflex bradycardia and reflex tachycardia. The HC-3 bradycardic effect started within minutes and lasted for about 1 hr, while the depressor effect on the reflexes began only after 15 min and continued for several hours. In addition, i.c.v. pretreatment with HC-3 completely abolished all the effects of physostigmine on MAP, HR, reflex bradycardia and reflex tachycardia. These results suggest that brain acetylcholine has a modulatory effect on baroreceptor reflexes. This modulation operates through muscarinic receptors in reflex tachycardia and through both muscarinic and nicotinic receptors in reflex bradycardia.

Acetylcholine↗
PubMedDate not supplied

Economics of hospice care.

As an institution providing care for patients who are dying, hospice has expanded significantly since the opening of the first hospice in the United States in 1974. Many changes have occurred in that time, including the maturation of hospices and the introduction of third-party reimbursement under Medicare. This article examines literature on hospice from an economic perspective; the focus is on the characteristics of the hospice "industry," demand for hospice care, hospice as a supplier of care, and the cost of hospice care. Two major gaps in the research are the failure to categorize hospices by the type of reimbursement received and the emphasis on expenditures for care to the exclusion of consideration of the cost of producing hospice care.

Costs and Cost Analysis↗
PubMedDate not supplied

Hospice costs and medicare reimbursement: an application of break-even analysis.

The adequacy of Medicare reimbursement to cover hospice costs is examined using break-even analysis. Since hospice costs are high during the first few days after enrollment, a long period of enrollment is required for per diem reimbursement to cover costs. Under a variety of specifications, the length of stay required for the hospice to break even is greater than the median length of stay.

Aged↗