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Biomedical subjects

P Samuel

Publications and source records attributed to P Samuel.

At least 37 records · Page 2Linked to original sources
PubMed1998

Effect of multiple doses of oral isradipine on atrioventricular conduction in patients with first-degree atrioventricular block.

The purpose of this study was to investigate the effect of multiple doses of orally administered isradipine on atrioventricular nodal conduction in patients with first-degree atrioventricular block. Forty-eight patients with a P-R interval > or =0.22 seconds on a surface electrocardiogram (ECG) (first-degree atrioventricular block) with or without a bundle-branch block were randomized to one of four groups for 6 weeks of treatment with either placebo or 5.0 mg/d, 7.5 mg/d, or 10.0 mg/d isradipine. P-R interval prolongation was assessed at baseline and posttreatment using resting 12-lead ECGs and 24-hour Holter monitoring. The effect of isradipine on the following parameters were assessed: systolic and diastolic blood pressures, heart rate, respiration rate, oral temperature, and weight. Neither isradipine nor placebo treatment had a statistically significant treatment effect on the change from baseline in P-R interval, QRS duration, Q-T interval (uncorrected), or sinus heart rate at week 7 as measured by 12-lead ECG. All treatment groups, however, had small, statistically insignificant decreases from baseline in the mean P-R interval. The largest decrease (from 0.26 seconds at baseline to 0.22 seconds at week 7) was recorded for the 7.5 mg/d isradipine group, which also had the greatest posttreatment decreases in QRS duration, sinus heart rate, and systolic and diastolic blood pressures. The treatment groups did not differ significantly with respect to the change from baseline to study end in P-R interval prolongation or degree of atrioventricular block (as measured by 24-hour Holter monitoring), radial pulse rate, respiration rate, weight, or oral temperature. In this study, isradipine did not have a negative dromotropic effect on the atrioventricular node. The trend toward a posttreatment decrease in P-R interval suggests that isradipine may actually improve atrioventricular nodal conduction in patients with first-degree atrioventricular block and thus may be used safely in this population.

Administration, Oral↗
PubMed1998

U-shape relationship between change in dietary cholesterol absorption and plasma lipoprotein responsiveness and evidence for extreme interindividual variation in dietary cholesterol absorption in humans.

A possible relationship between change in dietary cholesterol absorption and plasma lipoprotein responsiveness was examined in 18 normal subjects fed low fat low cholesterol, high fat low cholesterol, and high fat high cholesterol diets. For the group, neither dietary cholesterol nor dietary fat affected the percentage dietary cholesterol absorption, whereas dietary cholesterol intake raised total and LDL-C and dietary fat raised total, LDL, and HDL-C. On a fixed diet there was approximately a 2-fold variation among subjects in percentage dietary cholesterol absorption. Subjects also varied in response to dietary cholesterol and fat with regard to dietary cholesterol absorption and plasma lipoprotein responsiveness. There was a U-shaped parabolic relationship between dietary cholesterol-induced percent change in LDL-C and the change in percentage dietary cholesterol absorption (R2 = 0.62, P = 0.005). A similar but weaker relationship characterized the responsiveness of HDL-C (R2 = 0.38, P = 0.05). For the group, increased cholesterol intake raised dietary cholesterol mass absorption from 1.6 to 4.6 mg/kg per day, but the range of increase was from 1 to 4.7 mg/kg per day. Increased fat intake also affected dietary cholesterol mass absorption with most subjects displaying a strong inverse relationship between fat intake and mass absorption (r = -0.77, P < 0.003). In summary: i) the percentage change in dietary cholesterol absorption in response to dietary cholesterol does appear to regulate diet responsiveness of LDL and HDL-C, and ii) the large variability in percent absorption and changes in percentage and mass absorption in response to dietary cholesterol suggest the presence of genetically determined differences among individuals in the regulation of dietary cholesterol absorption.

Adult↗
PubMed1997

Leucocytopenia after rifampicin and ofloxacin therapy in leprosy.

New antimycobacterial agents and combined treatment regimens are being introduced for the treatment of leprosy. Ofloxacin is one such broad spectrum antimicrobial agent. In this study rifampicin plus ofloxacin were administered daily for 4 weeks (daily supervised dose). Two patients (and possibly a third patient who refused all investigations) out of 125 patients developed leucocytopenia during the third week of therapy. It was associated with fever, malaise, nausea and loss of appetite. They recovered after cessation of drug treatment. Patients receiving ofloxacin should be monitored for constitutional symptoms suggestive of this complication even though the risk of such complication may be minimal.

Adolescent↗
PubMed1997

Swimming for laryngectomy patients.

We describe how to start up and run a swimming club for laryngectomy patients. We detail the precautions required, and present the benefits to patients. This paper is based on the experience acquired through contact with the Sunderland Laryngectomy Swimming Club.

Humans↗
PubMed1997

A visit to Trinidad & Tobago.

Trinidad & Tobago are the two most southerly of the Caribbean islands off the coast of Venezuela. Trinidad is industrial, having natural deposits of oil, gas and bitumen, while Tobago is a tropical holiday island, sometimes known as Robinson Crusoe Island. The population of 1.3 million represents races from Africa, India, Europe and Asia, who live and work together harmoniously; Trinidadian women are renowned for their beauty, resulting from this rich mix. The centre of Trinidad is heavily forested and-apart from the capital, Port-of-Spain-the towns are small and rural in character. Fruit grows abundantly, especially mangoes, bananas, pineapples, citrus fruits, paw-paw and coconuts.

Breast Feeding↗
PubMed1996

Effectiveness of MDT in multibacillary leprosy.

The study on the use of World Health Organization multidrug therapy (WHO/MDT) under field conditions was initiated in December 1981, and included 1067 multibacillary (MB) patients treated with two MDT regimens. The first was a THELEP-recommended regimen which consisted of 600 mg of rifampin (RFP) and 600 mg of clofazimine (CLO) given under supervision on two consecutive days monthly and 225 mg of diacetyl diaminodiphenylsulfone (DADDS) bimonthly plus dapsone (DDS) 100 mg daily unsupervised. The second regimen was the conventional MDT: patients received RFP 600 mg and CLO 300 mg supervised once a month, daily 100 mg of DDS and 50 mg of CLO unsupervised. A zero relapse rate was obtained after more than 10 years (a total of 8244 person-years) of follow up. Both regimens were well tolerated with few complications and a high acceptability, even among women. The fall in the bacterial index (BI) was 0.5 - 1.0+ in positive patients. CLO discoloration began to decrease after 3 months and disappeared within 1 year after it was discontinued. Seventy-two patients (67%) developed reactions during the treatment period; a further 12 patients developed post-treatment reactions during the surveillance period. This study vindicates MDT treatment for MB patients as recommended by WHO under field conditions.

Drug Therapy, Combination↗
PubMed1990

Effect of isradipine, a new calcium antagonist on the lipid profile in patients with hypertension.

The effect of isradipine versus hydrocholorothiazide on the lipid profile of 44 hypertensive patients was investigated in a double-blind, randomized trial. Lipid profiles included total cholesterol, serum triglycerides, high density lipoprotein-cholesterol (HDL), HDL subclasses (HDL2 and HDL3), low density lipoprotein cholesterol (LDL), very low density lipoprotein cholesterol (VLDL), Apolipoprotein A-1 and Apolipoprotein B. Isradipine had no effect on the lipid profile in 52 week studies. Hydrochlorothiazide increased serum triglycerides in 11 of 13 patients by a mean of 8% for the group (p less than 0.05) in 52 week studies, and total cholesterol by a mean of 9 and 16% respectively (p less than 0.01) in 2 of 13 patients, with no difference in other lipid or lipoprotein parameters in short or long term experiments.

Antihypertensive Agents↗
PubMed1989

Dyslipoproteinemia in murine systemic lupus erythematosus.

Dyslipoproteinemia, a feature of systemic lupus erythematosus may contribute to premature atherosclerosis. In order to develop an experimental model for this dyslipoproteinemia we measured plasma concentrations of lipoproteins in juvenile NZB/W (lupus) and NZB/B (control) mice. Additionally to evaluate the effects of a diet rich in n - 3 fatty acids we measured lipoprotein concentrations in mice on normal or menhaden oil-enriched diets. The lupus mice had elevated triglycerides compared to the controls, similar to that seen in human SLE patients (161 +/- 31 vs 113 +/- 13 mg/dl, P less than 0.003). In contrast, the menhaden oil diet fed NZB/W mice had triglycerides similar to the NZB/B control fed group. In the NZB/W murine SLE model, dyslipoproteinemia is an early sign of disease as has been shown in man, therefore this model will be useful in elucidating the mechanism of dyslipoproteinemia in SLE.

Animals↗
PubMed1988

Effects of isradipine, a new calcium antagonist, versus hydrochlorothiazide on serum lipids and apolipoproteins in patients with systemic hypertension.

The effect of isradipine versus hydrochlorothiazide on the lipid profile of 44 hypertensive patients was investigated in a double-blind, randomized, 2-center trial. Lipid profiles included total cholesterol, serum triglycerides, high density lipoprotein (HDL) cholesterol, HDL subclasses, (HDL2 and HDL3), low density lipoprotein cholesterol, very low density lipoprotein cholesterol, apolipoprotein A-1 and apolipoprotein B. Isradipine had no effect on the lipid profile in short- (4 and 10 week) or long-term (52 week) studies. Hydrochlorothiazide increased serum triglycerides in 11 of 13 patients by a mean of 8% for the group (p less than 0.05) in long-term (52 week) studies, and total cholesterol by a mean of 9 and 16%, respectively (p less than 0.01) in 2 of 13 patients, with no difference in other lipid or lipoprotein parameters in short- or long-term studies.

Adult↗
PubMed1988

Dyslipoproteinemia in pediatric systemic lupus erythematosus.

Patients with systemic lupus erythematosus are at increased risk for premature atherosclerosis. We examined one possible etiologic factor, dyslipoproteinemia, both before and after corticosteroid therapy. We identified 2 distinct patterns of dyslipoproteinemia. One is attributable to active disease; the other is attributable, in part, to corticosteroid therapy. The dyslipoproteinemia of active disease consists of depressed high density lipoprotein cholesterol and apoprotein A-I with elevated very low density lipoprotein cholesterol and triglyceride, while the dyslipoproteinemia after corticosteroid therapy consists of increased total cholesterol, very low density lipoprotein cholesterol, and triglyceride. The possible pathophysiologic mechanisms responsible for these patterns, as well as the possible roles in premature atherosclerosis seen in systemic lupus erythematosus patients, are discussed.

Adolescent↗
PubMed1988

The effect of inhaled steroids on the upper respiratory tract.

The incidence of upper respiratory tract Candidiasis secondary to steroid aerosol treatment is disputed, and varies from series to series. We found a very low incidence of thrush, but a significant number of abnormalities of the upper respiratory tract in a random selection of asthmatics on steroid inhaler. A minority had positive Candida cultures, but 37 per cent had symptoms which were minor and self-limiting, but a complaint of hoarseness in asthmatics on steroid inhalers should be referred to a laryngologist, even if there is no evidence of fungal infection in order to ascertain the nature of the laryngeal abnormality, such as adductor cord paralysis, or even carcinoma. This study also implies that the history from a patient with laryngeal or pharyngeal symptoms is incomplete unless the patient's aerosol medication is also taken into account, as signs and symptoms in this group of patients are usually reversible when alternative treatment for asthma is instituted.

Adolescent↗
PubMed1988

Isradipine (PN 200-110) versus hydrochlorothiazide in mild to moderate hypertension. A multicenter study.

The effects of 10 weeks of treatment with isradipine (ISRP), a new dihydropyridine Ca antagonist, was evaluated in a prospective, randomized, double-blind, parallel group, hydrochlorothiazide (HCTZ) controlled study in patients with mild to moderate hypertension. Of 98 patients enrolled, 73 completed the study and were deemed valid for efficacy analyses; 36 in the ISRP group and 37 in the HCTZ group. Monotherapy with ISRP significantly (P less than 0.001) decreased (mean +/- SD) sitting systolic blood pressure (BP) from 146 +/- 11 mm Hg to 128 +/- 11 mm Hg and diastolic BP from 100 +/- 4 mm Hg to 83 +/- 5 mm Hg. Heart rate during the plateau period was not significantly different (76 +/- 11 vs 78 +/- 11 bpm) between the ISRP and HCTZ groups. These reductions in BP were comparable to monotherapy with HCTZ. The mean reduction in diastolic BP with ISRP (17 +/- 6 mm Hg) was significantly (P less than 0.05) greater than that with HCTZ (14 +/- 5 mm Hg). The mean doses for ISRP and HCTZ were 12 mg/day and 60 mg/day, respectively. There was no significant difference in frequency of common side effects (headache, nausea, fatigue, dizziness, palpitations) between the two groups. However, transient or intermittent peripheral edema occurred more frequently in ISRP group. Four patients in ISRP group (two due to edema and two due to palpitations) and two patients in HCTZ group (due to poor BP control) were discontinued from the study. Our results indicate that ISRP in doses of 5 to 10 mg bid is as effective as HCTZ as monotherapy in the treatment of mild to moderate hypertension.

Blood Pressure↗
PubMed1988

[Madreporic, polarized total arthroplasties of the hip. Apropos of 2688 cases].

This paper reports an experience over ten years with cementless total hip arthroplasty in a series of 2688 personal cases commencing in 1975. Stress is laid on the results over a period greater than 5 years and up to 10 years as much on the long-term effects on the host bone as on the implant itself. The causes of failure of biological anchorage by endosteal osteogenesis are analysed. Various phenomena, particularly the reaction of the cortices to stress, several cases of bony resorption with debris due to wear and fatigue fractures of the stem of the prosthesis have been seen. These and the problems posed by the occasional need for extraction have led to the progressive development of the prosthesis, resulting in 1983 in a new type of anchorage with a polarised surface and a better-balanced prosthesis in relation to stress and extractability.

Adult↗
PubMed1987

Infection rate in total hip arthroplasty as a function of air cleanliness and antibiotic prophylaxis. 10-year experience with 2,384 cementless Lord madreporic prostheses.

To separate the respective effects of sterile air and antibiotic prophylaxis in orthopedic surgery, the authors reviewed 2,384 cementless total hip replacements performed from 1975 to 1984 for incidence of deep sepsis. During this period, a conventionally ventilated room (100 particle-forming units (pfu)/m3) and a laminar vertical flow (1 pfu/m3) were alternately used, without significant difference in the sepsis rate. Beginning in 1979, a prophylactic antibiotic regimen was added, which from 1979 to 1984 reduced the incidence of deep sepsis from 2.78% to 0.52%. There was also a change in common infecting organisms, from sensitive to resistant strains, which is not an insignificant consequence.

Air Microbiology↗