Isolation of Helicobacter pylori after transport from a regional laboratory of gastric biopsy specimens in saline, Portagerm pylori or cultured on chocolate agar.

Multiple gastric biopsies were taken from 288 patients in Port Lincoln, South Australia. One biopsy was used for a CLOtest and the other three were transported to a central laboratory in Adelaide in physiological saline, Portagerm pylori transport medium or after culture on a chocolate agar plate which was placed in a Biobag. Helicobacter pylori was isolated from 18.3% of patients. There was a 95.7% concordance between culture results and the CLOtest result. Recovery rates after transport on chocolate agar, Portagerm pylori and in saline were 90.2, 90.2 and 84.3%, respectively.

[Effect of nifedipine on arterial pressure and control of the cardiac reflex]. / Effet de la nifédipine sur la pression artérielle et le contrôle cardiaque réflexe.

Nine patients with untreated essential hypertension (random blood pressure 173/109 +/- 14/7 mmHg) were studied before and after 16 weeks' treatment with oral nifedipine 10 mg three times a day. Direct continuous measurement of the systolic and diastolic blood pressures showed that both values were significantly reduced during the 24 hour period. Nifedipine did not change the variability of the blood pressure. There was no significant change in the heart rate after treatment with nifedipine. Long-term nifedipine induced an increase in blood flow in the forearm and decreased the vascular resistances which confirmed the vasodilator effects of the drug. The absolute responses of the blood pressure during postural changes, the hand grip test and cold pressor test were reduced but the treatment did not change the percentage increase in blood pressure during these tests. Long-term nifedipine therapy did not affect the plasma renin activity. The sensitivity and characteristics of the baroreflex response to intravenous phenylephrine were measured. After long-term nifedipine therapy we observed a normalisation of the sino-aortic baroreflex and an increase in its sensitivity. Normalisation of the blood pressure by nifedipine induced a significant reduction in the index of left ventricular mass.

The effect of nifedipine on arterial pressure and reflex cardiac control.

Nine patients with untreated essential hypertension (mean casual blood pressure 173/109 +/- 14/7 mm Hg) (+/- SD) were studied in the control state and after 16 weeks of treatment with nifedipine, 10 mg orally every 8 hours. Direct arterial blood pressure monitored continuously over 24 hours showed that nifedipine significantly reduced systolic and diastolic blood pressure throughout the day and the night. The variability of blood pressure was not altered by nifedipine therapy. There was no significant change in heart rate after nifedipine therapy. Chronic nifedipine therapy increased forearm blood flow and decreased forearm vascular resistance, consistent with its action as a vasodilator. The absolute blood pressure responses to tilt, handgrip and cold were reduced, but the percent increase in pressure was not altered by therapy. Plasma renin activity was not altered by chronic nifedipine therapy. At each study, the sensitivity and setting of the baroreflex response to i.v. phenylephrine was measured. After chronic nifedipine therapy there was resetting of the sinoaortic baroreflex and an increase in its sensitivity. Successful control of blood pressure with nifedipine led to a significant reduction in the left ventricular mass index.

The effect of nifedipine on arterial pressure and reflex cardiac control.

Nine patients with untreated, essential hypertension (mean casual blood pressure 173/109 +/- 14/7 mmHg (+/- s.d.] were studied in the control state and then following 16 weeks treatment with nifedipine 10 mg orally 8 hourly. Direct arterial blood pressure was monitored continuously over 24 hours and demonstrated that nifedipine significantly reduced systolic and diastolic blood pressure throughout the day and the night. The variability of blood pressure was not altered by nifedipine therapy. There was no significant change in heart rate after nifedipine therapy. At each study the sensitivity and setting of the baroreflex response to intravenous phenylephrine was measured. Following chronic nifedipine therapy there was re-setting of the sino-aortic baroreflex and an increase in its sensitivity.

Cardiovascular response in black and white hypertensives.

Sixteen untreated black patients with mild-to-moderate hypertension and no evidence of target organ damage were matched for age, sex, casual blood pressure (BP), and socioeconomic status with 16 white hypertensives. All patients were studied under standardized conditions in the hospital where they underwent continuous intraarterial ambulatory monitoring of BP and assessment of BP control mechanisms. BP characteristics over prolonged periods of recording were similar for both groups, as were sinoaortic baroreflex activity and pressor response to isometric and dynamic exercise and to cold. Fasting cholesterol and triglyceride levels in both groups were similar. Resting plasma renin activity (PRA) was significantly lower in blacks, but no difference was observed in resting plasma norepinephrine levels. Urinary excretion of NA+ and K+ was also similar in both groups. Thus, results showed that casual BPs matched for black and whites, and recorded over a prolonged period, were similar in pattern, variability, and response to pressor stimuli. It appears that, if BP contributes to the different patterns of morbidity in blacks and whites, it is more likely to be the actual level of BP rather than differences in BP characteristics.

Assessment of left-ventricular mass and its response to antihypertensive treatment.

50 patients with mild to moderate essential hypertension underwent M-mode echocardiography and continuous intra-arterial ambulatory monitoring of blood pressure. Indices of left-ventricular (LV) mass were derived from echocardiographic data by standard formulae. 43 of the patients were followed up for 12+/-7 months with repeat M-mode echocardiography, and casual blood-pressure measurements. 25 of these patients received antihypertensive therapy and 18 were untreated. Mean 24 h systolic blood pressure was significantly correlated with echocardiographic LV mass; mean 24 h diastolic blood pressure was also correlated, but the relation was weaker. In the treated group there was a significantly greater fall in blood pressure and LV mass index than in the untreated group, and there was a significant correlation between the fall in systolic blood pressure and the fall in LV mass index in the treated group. Systolic blood pressure appears to be an important factor in the pathogenesis of LV hypertrophy, and in hypertensive patients changes in LV mass assessed by echocardiography correlate with changes in blood pressure.

The relationship between ambulatory blood pressure and echocardiographically assessed left ventricular hypertrophy.

1. Continuous intra-arterial ambulatory monitoring of blood pressure was recorded in 46 patients with mild to moderate hypertension under standardized conditions. M-mode echocardiography was performed after recording and left ventricular mass index calculated by standard formulae. 2. Systolic blood pressure from continuous recording was significantly correlated with left ventricular mass index (mean 24 h: r = 0.543, n = 45, P less than 0.001). Diastolic blood pressure exhibited a weaker but still significant correlation with left ventricular mass index (mean 24 h: r = 0.318, n = 45, P less than 0.05). Casual systolic blood pressure was significantly correlated with left ventricular mass index (r = 0.476, n = 46, P less than 0.001) but casual diastolic blood pressure did not correlate with left ventricular mass index (r = 0.245, n = 46). Awake blood pressure variability, age, resting plasma renin activity and resting plasma noradrenaline levels did not have a significant correlation with left ventricular mass index. 3. Nine patients were treated for 16 weeks with once-daily timolol and repeat ambulatory monitoring and M-mode echocardiography was performed with the same protocol. 4. Once-daily timolol provided good 24 h control of blood pressure and repeat echocardiography showed a reduction in left ventricular mass index in that group of patients (t = 2.59, P less than 0.05).