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Biomedical subjects

A Nasser

Publications and source records attributed to A Nasser.

At least 19 recordsLinked to original sources
PubMed2001

Effects of kaliuretic peptide on sodium and water excretion in persons with congestive heart failure.

Kaliuretic peptide, a 20-amino acid peptide hormone synthesized in the heart, enhances urine flow twofold, whereas atrial natriuretic peptide (ANP) enhances urine flow four- to 11-fold in healthy persons. The present investigation was designed to (1) determine whether kaliuretic peptide may have beneficial diuretic effects in persons with congestive heart failure (CHF), and (2) compare its beneficial effects with ANP in the treatment of CHF. Kaliuretic peptide (100 ng/kg body weight/min) given intravenously for 60 minutes to subjects with New York Heart Association class III CHF increased urine flow fourfold (p <0.001), which was maximal 212 hours after its infusion was stopped. Kaliuretic peptide enhanced sodium excretion threefold in subjects with CHF (p <0.01). Kaliuretic peptide increased the urinary excretion rate of potassium ion and fractional excretion of potassium 3.5- and twofold (p <0.05), respectively. ANP (same concentration) did not significantly enhance urine flow. ANP enhanced sodium excretion two- to sixfold in half of the CHF subjects, whereas it had no effect on sodium excretion in the other half. ANP did not significantly increase fractional excretion of sodium but did increase fractional excretion of potassium (p <0.05) during the first 20 minutes of its infusion. ANP-infused patients with CHF became hypotensive. None became hypotensive secondary to kaliuretic peptide. These data indicate that the diuretic properties of kaliuretic peptide in persons with CHF, as opposed to those of ANP, are not diminished (but rather are increased) compared with their effects in healthy persons. In patients with CHF, kaliuretic peptide causes a natriuresis-a feature not observed in those without sodium retention.

Adult↗
PubMed1999

Adjunctive abciximab improves outcomes during recanalization of totally occluded saphenous vein grafts using transluminal extraction atherectomy.

Degenerative disease of aortocoronary saphenous vein grafts is a major cause of late morbidity and mortality in patients after coronary bypass surgery. We previously described a technique for recanalization of totally occluded grafts using extraction atherectomy (TEC) as a primary modality. While success was comparable to overnight urokinase, distal embolization, no-reflow, and non-Q myocardial infarction were common. Recently, abciximab has been used adjunctively in angioplasty and stenting with a reduced incidence of periprocedural complications. In order to determine whether abciximab can reduce the incidence of distal embolization, no-reflow, and myocardial infarction during TEC in totally occluded saphenous vein grafts, we compared patients treated with adjunctive abciximab with control subjects not receiving the drug. Male patients with previous coronary bypass surgery, class III-IV angina, and totally occluded saphenous vein grafts serving a vascular territory with ischemia not approachable by standard catheter-based techniques underwent TEC with or without adjunctive abciximab. Recanalization of the graft was achieved in 8/10 (80%) of subjects without abciximab, but complete success was achieved in only 5/10 (50%). In contrast, all procedures in the abciximab group were completely successful, without embolization or no-reflow. Our results suggest that TEC with adjunctive abciximab may be a highly effective approach for management of totally occluded saphenous vein grafts.

Abciximab↗
PubMed1999

Cholesterol in peripheral vascular disease--a suitable case for treatment?

We assessed the prevalence of conventional risk factors for ischaemic heart disease in patients with peripheral vascular disease, and the scope for preventative treatment with lipid-lowering therapy in this group, by retrospectively reviewing 299 patients who had undergone peripheral angiography in 1996. A total of 278 patients had severe peripheral vascular disease; 44% were current smokers at the time of their angiogram, and 36% had a history of coronary artery disease (either myocardial infarction, coronary artery bypass surgery, coronary angioplasty or angina). Cholesterol had been measured in 80 (27%) patients, of whom 26 (9%) were receiving treatment for hypercholesterolaemia. Patients with a history of ischaemic heart disease were more likely to have had their cholesterol measured (50% vs. 15%; p < 0.001). Hypertension (defined as systolic > 160 mmHg or diastolic > 90 mmHg) was present in 44%. There was no difference in the distribution of risk factors between those with and those without known ischaemic heart disease. There is a high prevalence of modifiable risk factors for coronary disease in patients with severe peripheral vascular disease. Effective prevention is available for coronary artery disease, but we found low levels of treatment. There is considerable scope for intervention to reduce the risk of coronary disease in such patients.

Aged↗
PubMed1999

Sporothrix meningitis.

Sporothrix schenckii is a fungus commonly found in soil and on plants, wood splinters, rosebush thorns, and decaying vegetation. It is also carried by some wild and domestic animals and rodents. When this organism penetrates the skin of individuals handling contaminated substances, the cutaneous manifestation may be lymphangitic or fixed. The treatment of choice for the cutaneous form of the disease (sporotrichosis) is potassium iodide. If iodides are contraindicated or not tolerated, itraconazole may be used. Sporotrichosis can persist for years if unrecognized and can progress to systemic forms, including osteoarticular, pulmonary (may occur when the organism is inhaled), and meningeal involvement. Systemic forms can be life-threatening and very difficult to treat. Primary care providers must be familiar with this disorder and its presentation because it is easily mistaken for a bacterial infection and inappropriately treated.

Humans↗
PubMed1998

Effect of ketanserin on central haemodynamics and coronary circulation.

Ketanserin is a selective 5-hydroxytryptamine (5-HT2) antagonist with vasodilator properties in the systemic and pulmonary circulation. Ketanserin also can inhibit serotonin-induced coronary artery vasoconstriction during percutaneous transluminal coronary angioplasty (PTCA). The in vivo effect of ketanserin on the coronary arteries of patients with stable angina has not previously been reported. The effects of intravenous ketanserin on cardiac haemodynamics and coronary artery diameter were measured in 10 patients with stable angina undergoing diagnostic cardiac catheterisation. Ketanserin (10 mg, i.v.) was associated with significant reductions in systemic and pulmonary arterial pressure (p < 0.05) and total systemic (SVR) and pulmonary (PVR) vascular resistance (p < 0.05). No significant change in mean coronary artery diameter or coronary artery stenotic index was evident after ketanserin. Vasodepressor responses in the systemic and pulmonary arterial circulation were observed after ketanserin injection. We assume these responses to be a direct effect of ketanserin, although non-drug-induced changes over time cannot be excluded. No significant effect on coronary artery diameter was observed, presumably because circulating serotonin levels are low in patients with stable anginal symptoms.

Angina Pectoris↗
PubMed1996

Collaboration between a referring hospital and a tertiary care center in improving the transfer process for cardiac patients.

BACKGROUND: Transfer of cardiac patients between hospitals is a complex process with many implications for quality of care. In the case of heart disease, specialized procedures such as coronary angioplasty, coronary bypass surgery, and valve replacement or repair require the performance of cardiac catheterization and coronary arteriography in a catheterization laboratory, as well as the availability of cardiac surgical services. The Department of Veterans Affairs Medical Center (DVAMC) at Muskogee, Oklahoma, transfers most cardiac patients requiring specialized diagnostic procedures and advanced cardiac care to DVAMC at Oklahoma City, Oklahoma. Concerns about the inefficiency of the transfer process led to the launch of a quality improvement project in late 1992. CHANGES IN THE TRANSFER PROCESS: Greater emphasis was placed on medical aspects compared to administrative aspects of transfer, and ready access to the physicians at DVAMC at Oklahoma City was provided. RESULTS: The time from request for transfer to the actual transfer decreased. Before the quality improvement project, only 33% of transfers of cardiac patients were completed within 24 hours-versus 78% in 1993 and 1994, 89% in 1995, and 84% in the first half of 1996. In addition, DVAMC-Muskogee physician satisfaction regarding services at DVAMC-Oklahoma City improved. CONCLUSION: Ongoing discussion between the cardiology team at the accepting hospital and physicians at the referring hospital expanded the continuum of care to both hospitals. Priority of transfers could be upgraded at any time without unduly jeopardizing patient safety or increasing resource utilization at the receiving center.

Academic Medical Centers↗
PubMed1984

Penetration of different human pathogenic viruses into sand columns percolated with distilled water, groundwater, or wastewater.

The adsorption of several enteroviruses and rotavirus SA11 to sand from an aquifer in the Federal Republic of Germany was estimated in sand-filled columns loaded with ca. 10(7) PFU and run at a velocity of 2.5 m/day for 12 h. After either distilled water, groundwater, secondary effluent, or tertiary effluent was percolated, the sand core was slowly extruded out of the column and cut in 1-cm slices. The slices were eluted with nutrient broth, and the amount of viruses in the broth was estimated. The best adsorption was promoted by groundwater and tertiary effluent, followed by distilled water and secondary effluent. Similar experiments, carried out at different percolation rates, indicated that a 50-day underground stay of recharged water probably suffices to eliminate viruses in the groundwater-recharged tertiary effluent. However, when viruses and sand were incubated in the presence of the surfactants sodium dodecyl sulfate, nonyl phenol, dodigen 226, or alkylbenzylsulfonate, the adsorption of the viruses was substantially diminished. Experiments in the presence of nonyl phenol seem to indicate that hydrophobic interactions are involved in the adsorption of viruses to sand.

Adsorption↗
PubMed1984

Simultaneous concentration of four enteroviruses from tap, waste, and natural waters.

The efficiency of virus recovery from water was investigated by using a method which enabled the concentration of a mixture of four enteroviruses with determination of their individual recovery efficiencies. The four viruses used (poliovirus 1, coxsackievirus A9, coxsackievirus B1, and echovirus 7) represented each of the four major subgroups of enteroviruses. This method, which was based on selective antibody neutralization, was used to investigate the effects of input water quality on enterovirus concentration by Balston filters (grade C; Balston, Inc., Lexington, Mass.) and organic flocculation. With tap water, the average recovery efficiency of the four viruses was 97%. Concentration from natural waters, including samples from two lakes (Lake Kinneret and the Hula Nature Reserve) and the Mediterranean Sea, resulted in similarly high average recovery efficiencies. Echovirus 7 was recovered with a slightly lower average efficiency from these types of water than were the other viruses. In comparison with other types of water, virus concentration from Jerusalem wastewater generally had a slightly lower efficiency of recovery, ranging from 63 to 75% for each of the viruses, with an overall average of 68%. The ability of each concentration step, membrane filtration or organic flocculation, to recover the viruses from water was assayed. For the filtration step, although there were not large differences in virus recoveries from tap water, echovirus 7 was recovered with the lowest efficiency (72%), and poliovirus 1 was recovered with the highest (87%) efficiency. Overall virus recovery by the filtration step was least efficient for wastewater (73%) and most efficient for seawater (107%).(ABSTRACT TRUNCATED AT 250 WORDS)

Enterovirus↗
PubMedDate not supplied

Experimental heterotopic bone transplant.

We studied the reaction in rats to implants of heterotopic bone in the paravertebral region, using three types of material: bone preserved in alcohol, homologous bone preserved in alcohol associated with autogenous cancellous bone obtained from the iliac crest of the same animal, and isolated autogenous cancellous bone. Thirty rats were operated on, ten in each group. Some were sacrificed after 6, 14 and 21 days. The excised grafts were histologically studied. Animals in the third group showed new bone formation even in the first days, those in the second group presented less intense bone formation and those in the first group showed only traces of new bone tissue in the third week.

Animals↗