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N Mores

Publications and source records attributed to N Mores.

28 records · Page 2Linked to original sources
PubMed1989

Effects of sustained-release verapamil on 24-hour ambulatory blood pressure and on pressor response to isometric exertion in hypertensive patients.

The antihypertensive effect of a drug should be present not only at rest, but also during usual daily activities and pressor stimuli. In our study, we tested the impact of a new formulation of sustained-release (SR) verapamil (240-mg tablets), given once or twice daily, on 24-h ambulatory blood pressure (BP) and on pressor response to isometric exercise (handgrip). Fourteen mildly to moderately essential hypertensive patients were included in a single-blind placebo-controlled trial. The mean titrated dose of verapamil required to normalize office BP was 430 +/- 28 mg/day. Mean 24-h waking (7 a.m.-11 p.m.) and sleeping (11 p.m.-7 a.m.) blood pressures were significantly lower after verapamil than after placebo. The absolute levels of BP achieved at peak of handgrip (30% of maximal voluntary contraction for 3 min) were significantly reduced by verapamil with respect to placebo. However, due to the lower starting values, the pressor increment to the isometric work was not significantly modified by the active treatment. In conclusion, SR verapamil seems to provide a blood pressure lowering effect during all times of the day. It attenuates the surges in BP associated with handgrip exercise.

Adult↗
PubMed1989

Peroxidative events in stored platelet concentrates.

Changes in metabolic and functional activity of platelets stored as platelet concentrates in plastic bags highly permeable to gases were investigated. The following parameters were measured daily: pH, pO2, pCO2, HCO3, glucose, lactic acid, lactic dehydrogenase, cellular ATP and platelet aggregation induced by different agents (collagen and ADP). As indexes of lipid peroxidative damage, the cellular levels of conjugated dienes, malonyldialdehyde and some antioxidant molecules such as coenzyme Q10 and vitamin E were determined. A marked increase in pO2, conjugated dienes, malonyldialdehyde, lactic acid and lactic dehydrogenase activity was observed during the preservation. Platelet ATP content was unmodified and a remarkable decrease in platelet aggregability was found. pCO2, cyclooxygenase activity, vitamin E, coenzyme Q10, bicarbonate and glucose showed a rapid fall. Our data seem to indicate a preservation of platelet metabolic activity and a correlation between increased lipid peroxidation and functional impairement.

Adenine↗
PubMed1988

Twenty-four-hour blood pressure monitoring after a single dose of sustained-release verapamil.

The antihypertensive effect of a single dose of 240 mg sustained-release (S-R) verapamil was investigated by ambulatory blood pressure (BP) monitoring in 13 patients with mild to moderate essential hypertension. Following a 2-week washout period, 24-hour BP monitoring was carried out with a Spacelabs ICR 5300 device following random administration of a tablet of S-R verapamil or placebo; BP recording was repeated after crossover 3 to 7 days later. Average whole-day systolic and diastolic BPs were significantly lower after verapamil (130.1 +/- 2.6/87.1 +/- 1.2 mmHg) than after placebo (142.1 +/- 3.3/95.8 +/- 2.1 mmHg) (p less than 0.01). Mean waking BP was 146.4 +/- 3.6/99.1 +/- 2.2 mmHg after placebo and 135.2 +/- 3.3/90.5 +/- 1.7 mmHg after verapamil (p less than 0.01); during sleeping hours BP was 133.8 +/- 3.1/88.7 +/- 2.6 mmHg following placebo and 122.2 +/- 2.3/80.9 +/- 1.8 mmHg following verapamil (p less than 0.01). Blood pressure profile was significantly reduced by verapamil up to 20 hours after tablet administration, while from 21 to 24 hours after drug intake BP values were similar to placebo. Response to verapamil was not correlated to the pretreatment BP values and to the patient's age. In summary, this study suggests that acute administration of 240 mg S-R verapamil in hypertensive patients produces a BP reduction during 24-hour, daytime, and nighttime periods. The hypotensive efficacy is preserved for many hours after tablet intake and seems to be due to individual variation in cardiovascular reactivity to the drug.

Adult↗
PubMed1988

Effect of sustained-release verapamil therapy on the blood pressure at rest and on the pressor response to isometric exertion in hypertensive patients.

The effect of a new formulation of verapamil sustained release (SR) 240 mg tablets on resting blood pressure (BP) and on the pressor response to isometric exertion have been examined in a single-blind, placebo-controlled, cross-over study in 12 hypertensive patients (mean age 45 years). SR verapamil and placebo were administered every 12 h for 6 consecutive weeks. At the end of each period of treatment BP and heart rate (HR) were measured at rest and during isometric exercise, performed as a handgrip (HG) test for 3 min at 30% of the maximum voluntary contraction. There was a significant reduction in resting systolic and diastolic BP, with no change in HR. BP and HR at peak exercise were lower after verapamil than after placebo, but the maximal absolute increase did not change during verapamil therapy. The results are compatible with a role of SR verapamil b.d. in reducing resting BP in hypertension, and in lowering very high pressure at the peak of a HG test, without modifying the physiological reactivity of cardiovascular system.

Adult↗
PubMed1988

Casual versus 24-hour ambulatory blood pressure recording in the evaluation of chronic administration of sustained-release verapamil.

Although ambulatory blood pressure monitoring has been used widely for the evaluation of antihypertensive treatment, little information is available regarding the comparison between this method and casual BP measurement during drug trials. In our study, we tested the efficacy of a new formulation of verapamil, 240 mg sustained-release tablets, and compared the degree of BP reduction as detected by casual (standard mercury manometer) and by 24-hour ambulatory recording (Spacelab ICR 5300). A statistically significant fall in casual BP was observed after verapamil with respect to placebo. Moreover, 24-hour, waking and sleeping ambulatory BPs were significantly reduced by verapamil. The mean BP reduction was similar for office (20.1/16.1 +/- 4.3/3.1 mmHg) and for day-time ambulatory monitoring (13.4/10.7 +/- 4.2/1.9 1.9 mmHg), but no correlation was found between BP fall recorded by the two techniques for individual subjects. This study suggests that sustained-release verapamil is an effective antihypertensive drug. Individual mean BP reduction outside the clinic may not be predicted from office readings and therefore ambulatory BP recording seems to provide a better basis for testing the efficacy of drugs.

Adult↗
PubMed1987

Biochemistry of packed red blood cell concentrates stored in PAGGS-sorbitol solution for 42 days.

We investigated metabolic, blood gas and acid-base balance modifications of erythrocyte concentrates resuspended in PAGGS-sorbitol solution during 6 weeks of storage. Glucose utilization was impaired during the last 2 weeks, while the intraerythrocytic ATP level decreased only 50% from the 1st to the 6th week. The K+ and Hb concentration in the medium showed a progressive increase which was more pronounced during the last 2 weeks. The decrease in pH progressed to reach 6.27 at the 6th week of storage. Intraerythrocytic 2,3-DPG dropped rapidly in the course of the 1st week and the percentage of oxyhemoglobin showed a remarkable increase after the 1st week (90%). Our data suggest that erythrocyte concentrates in PAGGS-sorbitol should be transfused, for optimal efficacy, within 4 weeks.

Adenine↗
PubMed1987

Biochemical and functional changes of platelet stored for transfusional use.

A protocol for the biochemical study of platelet stored for transfusional use at 22 degrees C and under continuous shaking in a plastic bag highly permeable to gases and with a suitable area/volume ratio, is described. Plasmatic dextrose, lactic acid, lactic dehydrogenase activity, cellular ATP and malonyldialdehyde were monitored during the storage, as well as some acid-base indexes namely: pH, pCO2, HCO3-, pO2. The platelet functional status was checked as aggregating power induced by ADP and collagen and by beta-thromboglobulin release. The results obtained are indicative of a discrete maintenance of aerobic metabolism by platelets which are able to give up CO2 and take up O2 so that the plasmatic pH is constant during the storage. However, the malonyldialdehyde increase suggests that platelets become increasingly susceptible to peroxidative attacks. The aggregating response was dramatically reduced even on the third day of storage. The data obtained point out that, under the conditions reported, platelets can be transfused up to the third day of storage.

Blood Preservation↗
PubMed1986

Biochemical parameters to assess viability of blood stored for transfusional use.

Blood collected in citrate-phosphate-dextrose-adenine (CPDA-1) containing transfusional bags, was weekly tested throughout a 35 day period. Biochemical assays included plasmatic glucose, electrolytes, free Hb, acid-base balance and hemogasanalysis. Intraerythrocytic ATP and 2,3 DPG were also determined. Results show that an almost total 2,3 DPG depletion occurs during the first three weeks, whereas intracellular ATP are about 50% of the initial values, at the same time. Lowering of pH is also maximal at the third week. pCO2 variation pattern is biphasic: an early increase due to HCO3- titration by lactic acid arising from red cells glycolysis, followed by a decrease probably due to plastic bag permeability to CO2 itself. The percentage of O2Hb also rises during blood storage: this might be the combined result of increase in pO2 and decrease in 2,3 DPG content. A rise of free Hb was obtained; extracellular K+ levels underwent a sixfold increase in 35 days. The mechanism of relative variations of these parameters and the gas transport are discussed. Some of these parameters might be used as routine controls to asses viability and functional status of stored red cells for transfusional use.

Adenine↗
PubMedDate not supplied

Isolation and identification of chicken infectious anemia virus in Brazil.

Seven chicken infectious anemia virus (CIAV) isolates were obtained from seven broiler flocks with poor performance in two states of Brazil. All isolates induced thymus atrophy, bone-marrow aplasia, and low hematocrit values when inoculated into 1-day-old susceptible chicks. The CIAV isolates were resistant to treatment with chloroform and were able to pass through 50-nm-pore-size filters. CIAV-specific antigens could be demonstrated in tissues of experimentally infected chicks using a monoclonal antibody specific for CIAV. These characteristics of the virus and the virus-induced lesions demonstrate that CIAV is present in Brazil and that the virus is associated with production problems.

Anemia↗