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Biomedical subjects

R J Mills

Publications and source records attributed to R J Mills.

15 recordsLinked to original sources

Ranitidine prevents duodenal ulcers associated with non-steroidal anti-inflammatory drug therapy.

The results of four similarly designed, randomized, double-blind, placebo-controlled studies conducted to evaluate ranitidine as prophylaxis for NSAID-associated damage are reviewed. A total of 673 patients receiving therapeutic dosages of NSAIDs for arthritic or musculoskeletal conditions also received either ranitidine 150 mg twice daily (n = 343) or placebo (n = 330) for four weeks (two studies) or eight weeks (two studies). Endoscopic grading of mucosal lesions was based on a modified Lanza scoring system. All patients had normal baseline endoscopies. After four weeks of treatment a significant protective effect against duodenal mucosal lesions including duodenal ulcers (three studies) and gastric mucosal lesions including gastric ulcers (one study) was observed in patients who received ranitidine compared with those who received placebo. A meta-analysis of the four studies confirmed that significantly fewer patients receiving ranitidine than placebo developed duodenal ulcers (1% vs. 6%, P = 0.01). Endoscopic data at eight weeks from the two longer-term studies showed that duodenal ulcers occurred in ranitidine- and placebo-treated patients at a rate of 1% (2/137) vs. 8% (10/126) (P = 0.02), respectively, in one trial, and 0% (0/57) vs. 8% (4/49) (P = 0.02), respectively, in the other trial. No protective effect in the stomach was evident at eight weeks. We conclude that ranitidine is effective in preventing NSAID-associated duodenal ulcers and may be appropriate prophylaxis for certain high-risk patients.

Adult

Effects of antihypertensive agents on circadian blood pressure and heart rate patterns. Review.

Blood pressure and heart rate exhibit a circadian rhythm, with both rising rapidly during the morning hours and then decreasing throughout the day to a nadir around 3 AM. Current evidence suggests a possible link between cardiovascular events, such as myocardial infarction and sudden cardiac death, which have been shown to occur most frequently during the morning hours, and the rapid rise in blood pressure and heart rate during this same time period. We review data from ambulatory blood pressure studies to ascertain which antihypertensive agents provide the most satisfactory control of blood pressure and heart rate during the hours of 6 AM to 12 noon. Of the forms of drug therapy studied, labetalol, a combined alpha- and beta-blocker, and two calcium channel blockers, nifedipine and verapamil, appear to be the most effective in blunting the rise in arterial blood pressure during these critical morning hours.

Antihypertensive Agents

Peak expiratory flow in normal Ethiopian children and adults in Addis Ababa.

The peak expiratory flow rate was determined using the Wright peak flow meter in normal Ethiopian children and adults residing in Addis Ababa (altitude 2500 m). The sample studied was of 84 boys, 69 girls (4-17 years) and 177 men, 148 women (18-70 years). Normality was determined by history alone. Linear multiple regression analysis was used to construct prediction equations that depended upon height and age. The results serve as reference values specifically for Ethiopians residing at altitude. Comparison of the PEFR values determined in 47 Caucasians (22 males, 27 females) working in Addis Ababa, with those from a group of Ethiopians matched for age and height indicated that the mean PEFR was significantly greater in the Caucasians by 7.3% in males and by 8.2% in females.

Adolescent

A critical appraisal of a rapid radiographic method of determining total lung capacity.

We have demonstrated that the total lung capacities of normal caucasian adults, can be satisfactorily estimated by means of a regression equation derived from a single set of three measurements taken from a specially exposed plain X-ray film of the chest. However, these equations differ from those found by workers who have studied patients with lung disease. It is concluded from this that different regression equations are to be expected for normal and diseased lungs, and that, the appropriate equation will depend not only on the presence of disease, but also on its type and severity. It is also concluded that the rapid radiographic method of estimating total lung capacity can make little contribution to the diagnostic assessment of lung disease. However, the regression equations appropriate to particular ethnic groups could be used to measure TLC in normal subjects rapidly and inexpensively in places where specialised respiratory equipment and trained personnel are lacking.

Adult

The effect of human pregnancy on the pulmonary transfer factor for carbon monoxide as measured by the single-breath method.

1. The pulmonary transfer factor for carbon monoxide was measured by the single-breath method in 21 pregnant women with no previous history of cardiac or respiratory disease. Measurements were made at monthly intervals throughout pregnancy and once post partum. 2. The transfer factor was higher in the first trimester of pregnancy than in the non-pregnant state. There was a fall in the transfer factor during pregnancy until 26 weeks gestation, after which no further decrease was observed. 3. The changes in transfer factor were not explained by alterations in haemoglobin concentration or alveolar volume. 4. Simultaneous serial estimation of plasma 17beta-oestradiol were performed in all the subjects. There was no obvious direct relation between changes in the concentration of this hormone and transfer factor measurements.

Adult

Large airways function during normal pregnancy.

Specific airways conductance and forced expiratory volume in one second were measured monthly from the first trimester until term in 30 subjects in the course of a normal pregnancy. Measurements were also made in the postpartum period. There was no significant change in these measurements either throughout pregnancy or compared with postpartum values. Our results suggested that the function of the larger pulmonary airways was not altered in pregnancy.

Adolescent

Cardiogenic oscillations of nitrogen and argon concentration in expired gas in man.

1. The cardiogenic oscillations in the concentration of nitrogen and argon in expired gas, which are seen after the inspiration from residual volume of pure oxygen or a bolus of argon, have been studied in normal subjects and in patients with atrial fibrillation. 2. In the upright position of the subject, the peaks of nitrogen and argon concentration coincide with ventricular systole, although there is a transit delay along the tracheobronchial tree before any change of concentration occurs at the mouth. 3. Studies in different postures demonstrated that the effect of the heart is predominantly due to a reduction in cardiac volume during systole with a decrease in airflow from regions adjacent to the heart. These areas contain a different concentration of nitrogen and argon in the alveolar air from the more apical regions. 4. It has been shown that the results are consistent with the present concepts of the influence of gravity on the distribution of inspired air.

Argon

The significance of variation in the selectivity of proteinuria.

The selectivity of proteinuria has been determined immunochemically at least 4 times over periods of 3 years or more in 27 children and adolescents who had been investigated by renal biopsy. Variations of the selectivity outside the limits of experimental error were observed in 14 patients, in 8 of whom there was a progressive decline. Six of these 8 had focal and segmental glomerular lesions, including one case of Alport's syndrome, and 2 had proliferative glomerulonephritis. Two different anomalies of relative IgG clearance were noted: in proliferative glomerulonephritis there was a constantly low clearance, and in focal glomerulosclerosis an elevated clearance increasing with time. Indirect evidence suggests that the latter may be due to the presence of low molecular weight IgG fragments in serum and urine.

Adolescent