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Biomedical subjects

J Cox

Publications and source records attributed to J Cox.

At least 19 recordsLinked to original sources
PubMed1992

The Canadian Cardiovascular Society grading scale for angina pectoris: is it time for refinements?

OBJECTIVE: To appraise the measurement properties of the Canadian Cardiovascular Society (CCS) classification of stable angina pectoris. DATA SOURCES: Relevant articles were identified through a MEDLINE search (1976 to November 1991). Bibliographies of retrieved articles were also reviewed. STUDY SELECTION: Studies chosen directly addressed the validity and reliability of the CCS scale. Recent studies and reviews of related topics (for example, silent ischemia) are selectively cited. DATA SYNTHESIS: No data address the scale's applicability, that is, how clinicians typically assign angina grades in practice. Comprehensiveness would be improved by coverage of the patient's perceptions of symptom burden; mixed exertional and rest symptoms; episodic or changing symptoms; and modifying factors. Reliability was assessed in one study with two clinicians; the interobserver, chance-corrected agreement on patient grading was 60%. Content validity (the ability of the scale to measure what it claims) is threatened by the unproven assumption of symptomatic or physiologic equivalence among diverse levels of different activities within any given grade of angina. Construct validity is uncertain, given weak relations between angina grade and noninvasive markers of ischemia, anatomical disease, or prognosis. The scale's responsiveness (the ability to detect the smallest clinically important changes) is limited by the reliance on four coarse gradations based on only ambulation or stair-climbing. CONCLUSIONS: The CCS scale for stable angina might be made more useful by developing measurements for patients' self-rated symptom burden and the changes they deem important; by adding items on clinical instability (that is, progressive symptoms or pain at rest); and by empirically testing the current scale to eliminate redundant or inconsistent elements.

Angina Pectoris↗
PubMed1992

The increase in blood pressure with age and body mass index is overestimated by conventional sphygmomanometry.

This cross-sectional study investigated whether the technique of blood pressure measurement used (conventional sphygmomanometry vs. ambulatory monitoring) affects the relation between blood pressure and both age and body mass index. Two independent data sets were analyzed. The first comprised 328 subjects (48% men) drawn from the population of a small Belgian town, and the second comprised 776 Irish bank employees (51% men). Age ranged from 17 years to 81 years, and body mass index (weight (kg)/height (m)2) ranged from 16.6 to 40.2. Twenty-four-hour ambulatory blood pressure was lower than blood pressure measured by a nurse in both the Belgian population sample (118/71 mmHg vs. 122/73 mmHg) and the Irish employees (118/72 mmHg vs. 119/76 mmHg). When blood pressure was measured by an observer, the well-established relations between systolic and diastolic blood pressure and both age and body mass index were evident. When the analyses were repeated using 24-hour measurements, the increment (cross-sectionally assessed) in blood pressure with age was weaker, especially in young and middle-aged subjects (20-60 years), while the increase in blood pressure with body mass index was also reduced. The within-subject differences between the conventional and ambulatory blood pressure measurements increased with older age and greater body mass index. Several other relations with blood pressure as the response variable may require revision in light of the present findings.

Adult↗
PubMed1992

The HMG domain of lymphoid enhancer factor 1 bends DNA and facilitates assembly of functional nucleoprotein structures.

The high mobility group (HMG) domain is a DNA-binding motif that is associated with several eukaryotic regulatory proteins, including the lymphoid enhancer-binding factor LEF-1 and the testis-determining factor SRY. Here, we provide evidence that DNA binding by the HMG domain of LEF-1 involves primarily minor groove contacts and induces a bend of approximately 130 degrees in the DNA helix. Bending was also found to accompany sequence-specific DNA binding by the SRY-HMG domain. Examining possible regulatory roles of HMG domain-induced DNA bends, we found that LEF-1 can function in a manner similar to bacterial integration host factor and facilitate communication between widely separated protein-binding sites in a recombination assay. Together with the previous observation that LEF-1 by itself is unable to augment basal promoter activity, these data suggest that HMG domain proteins can serve as "architectural" elements in the assembly of higher-order nucleoprotein structures.

Base Sequence↗
PubMed1992

Solitary rectal ulcer: an unusual cause of rectal bleeding in children.

The solitary rectal ulcer syndrome (SRUS) is a disease which is commonly diagnosed in adults but only rarely described in children. Rectal prolapse and intussusception are frequently associated with this entity. A relationship between SRUS and chronic constipation due to spastic pelvic floor syndrome (SPFS) is often observed. Thus biofeedback defaecation training is an efficient treatment of both conditions. We describe two paediatric patients suffering from SRUS associated with SPFS who showed complete recovery after biofeedback defaecation training.

Child↗
PubMed1992

Twenty-four hour blood pressure monitoring in the Syst-Eur trial.

This article describes the objectives and protocol of a study on ambulatory blood pressure in elderly patients with isolated systolic hypertension. This study constitutes an optional side-project to the Syst-Eur trial. The multicentre Syst-Eur trial investigates whether antihypertensive treatment of elderly patients with isolated systolic hypertension will influence the incidence of stroke. Secondary endpoints include cardiovascular events, such as myocardial infarction. The main objective of the side-project is to investigate whether ambulatory blood pressure monitoring will improve the prediction of cardiovascular complications based on blood pressure measurement in the clinic. The side-project also provides the opportunity to evaluate the diurnal profile of blood pressure in elderly patients with isolated systolic hypertension randomized to placebo or active antihypertensive treatment.

Aged↗
PubMed1992

The diurnal blood pressure profile. A population study.

This population study included 399 subjects, of whom 370 (93%) showed a significant diurnal blood pressure (BP) rhythm. The nocturnal BP fall was normally distributed and averaged 16 +/- 9 mm Hg systolic and 14 +/- 7 mm Hg diastolic (mean +/- SD). The amplitude of the diurnal BP curve followed a positively skewed distribution, with a mean of 16 +/- 5 mm Hg for systolic BP and 14 +/- 4 mm Hg for diastolic BP. The daily BP maximum occurred at 15:54 +/- 4:47 for systolic BP and at 15:11 +/- 4:20 for diastolic BP. Thirty-four subjects were reexamined after a median interval of 350 days. The test for the presence of a significant diurnal rhythm was discordant in only two subjects. Repeatability (twice the standard deviation of the differences between paired recordings expressed as a percentage of the mean) varied from 11 to 25% for the 24 h, daytime, and overnight BP, and from 76 to 138% for the parameters describing the diurnal BP rhythm. In nine subjects with an initial night/day ratio of mean BP less than 0.78, the nighttime BP was significantly increased at the repeat examination, whereas the opposite tendency was observed in nine subjects with an initial ratio greater than 0.87. In conclusion, the distribution of the nocturnal BP fall is unimodal. The reproducibility of the ambulatory BP is satisfactory for the level of BP and for the presence of a diurnal BP rhythm, but not for the parameters of the diurnal BP curve. Thus, one 24 h recording is insufficient to fully characterize an individual's diurnal BP profile.

Adult↗
PubMed1992

Syst-Eur--a multicenter trial on the treatment of isolated systolic hypertension in the elderly: first interim report.

Syst-Eur is a multicenter placebo-controlled outcome trial designed by the European Working Party on High Blood Pressure in the Elderly to investigate the effect of antihypertensive treatment on the incidence of stroke in elderly patients with isolated systolic hypertension (ISH). Eligible patients must be at least 60 years old and have a systolic blood pressure averaging 160-219 mm Hg with a diastolic blood pressure less than 95 mm Hg. The present paper is an interim report on the first 316 patients randomized into this trial. The placebo (n = 170) and active treatment (n = 146) groups were similar at randomization with respect to age (73 +/- 8 years; mean +/- SD), sitting blood pressure (178 +/- 12 mm Hg systolic; 85 +/- 7 mm Hg diastolic), percentage of men (34%), and percentage of patients with cardiovascular complications (29%). After randomization blood pressure fell more (p less than 0.001) in patients on active treatment than in those in the placebo group (19 +/- 20 mm Hg systolic; 6 +/- 10 mm Hg diastolic vs. 7 +/- 19 and 1 +/- 10 mm Hg for sitting blood pressure). This first interim report on the Syst-Eur trial demonstrates that a multinational trial in elderly patients with ISH is feasible and that a significant blood pressure difference between the two treatment groups can be achieved and maintained. New centers are being recruited in order to randomize a total of 3,000 patients.

Aged↗
PubMed1992

[Comparative histological study of the reproductive system of the female llama (Lama guanicoe glama). I. Ovary].

In the present study a cytological, histological and morphometrical comparison between the ovaries of the llama, the cow and the sheep is presented, at two phases of the ovarian cycle. There were found differences in the amount of primordial and primary follicles, the size of secondary follicles and follicular cells, and type and distribution of the connective tissue inside the stroma of the ovary. It would be necessary to study the fine structure of the ovary and the so-called "embryological remnants", for its permanent appearance in most (50%) of the ovaries.

Animals↗
PubMed1992

Vitamin-D-fortified liquid milk--a highly effective method of vitamin D administration for house-bound and institutionalised elderly.

The aim of the study was to assess the efficacy and acceptability of vitamin-D-fortified liquid milk in the management of hypovitaminosis D in an elderly institutionalised population. The design was a single-blind randomised controlled study. In phase I, patients were encouraged to drink an increased quantity of either fortified or unsupplemented milk for 3 months. In phase II, patients were continued on either fortified or on unsupplemented milk which was given as part of the everyday diet for a further 6 months with no extra encouragement of any patient to take additional amounts. Ninety-eight patients (mean age 84 years) from extended care wards at the Department of Medicine for the Elderly, St. James's Hospital, Dublin, Ireland, participated in the study. Seventy-eight patients completed phase I, and 62 completed phase II. A general biochemical screen and 25-hydroxy vitamin D measurements were performed at entry and repeated 3 and 9 months later. The average milk intake per patient in phase I was 454 ml/day in the unsupplemented group and 359 ml/day in the fortified milk group. In phase II, the average daily milk intake per patient was 235 ml in the unsupplemented milk group and 140 ml in the fortified milk group. Seventy-four patients (94%) of the total who completed phase I had serum vitamin D baseline levels below the normal range. In the fortified milk group, mean vitamin D levels rose from 2.4 to 14.80 ng/ml (p < 0.001) at the end of phase I and remained significantly elevated at 10.2 ng/ml (p < 0.001) at the end of phase II.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Cumulative sums in quantifying circadian blood pressure patterns.

The plotting of cumulative sums (cusums), a technique of proven value in the detection of trends in data collected at intervals of time, may be modified to analyze circadian blood pressure patterns quantitatively. Mean 24-hour ambulatory blood pressure is taken as the reference value and is subtracted from each pressure value. The products of the remainders and the corresponding time intervals are summed in sequence and are plotted against time to form a modified cusum plot. The slope of the plot over any given time period equals the difference between mean blood pressure during that period and mean 24-hour blood pressure. Crest and trough blood pressures (the mean blood pressures of the 6-hour periods of highest and lowest pressures) may be identified as the 6-hour periods where plot slopes are most steeply ascending and descending, respectively. The magnitude of the circadian blood pressure change, defined as the difference between crest and trough blood pressure, is calculated from the difference between crest and trough plot slopes. The height of the cusum plot, which reflects pressure alteration extent and duration, may also be used as a measure of circadian pattern. The modified cusums technique and cusum-derived statistics are illustrated using ambulatory blood pressure profiles of hypothetical and actual hypertensive subjects. Independence from fixed time periods improves precision and reproducibility. Cusum-derived statistics are simply calculated from raw ambulatory data and should prove useful in the quantitative analysis of circadian blood pressure profiles.

Adult↗
PubMed1992

Aluminium administered in drinking water but not in the diet influences biopterin metabolism in the rodent.

To investigate the neurotoxic effects of aluminium (Al) Al was administered: 1) in the diet of the rat (30 mg Al/kg body weight for 6 weeks); 2) as a suspension of aluminium acetate in drinking water of the rat for 3 months and 3) in a long-term study in the mouse in which aluminosilicates were incorporated into a pelleted diet (1035 mg/kg of food over 23 months). In the latter treatment, increased Al was combined with a reduction in calcium and magnesium; a treatment designed to increase absorption of Al into the body. Administration of Al in the drinking water significantly reduced total brain biopterins and BH4 synthesis. However, no significant affect of Al in the diet on total biopterins or BH4 synthesis was found either in the rat or in the long-term study in the mouse. In addition, in the mouse no significant effects of the Al diet on levels of noradrenaline, serotonin, dopamine, 5-HIAA or CAT could be demonstrated. Hence, the occurrence of brain alterations may depend on the Al species present and the method of administration. Al salts in drinking water may increase brain tissue levels compared with the administration of a more insoluble species. Since alterations in biopterin metabolism are also a feature of Alzheimer's disease (AD) these results support the hypothesis that Al in the water supply may be a factor in AD.

Aluminum↗
PubMed1992

Ambulatory blood pressure monitoring in elderly patients with isolated systolic hypertension.

OBJECTIVES: This study compared clinic and ambulatory blood pressure measurement and the reproducibility of these measurements in older patients with isolated systolic hypertension (ISH). PATIENTS: Eighty-seven patients aged greater than or equal to 60 years with ISH on clinic measurement were followed in the placebo run-in phase of the Syst-Eur trial. METHODS: Clinic blood pressure was defined as the mean of two blood pressure readings on each of three clinic visits (six readings in total). Ambulatory blood pressure was measured over 24 h using non-invasive ambulatory blood pressure monitors. RESULTS: Daytime ambulatory systolic pressure was, on average, 21 mmHg lower than the clinic blood pressure, whereas diastolic pressure was, on average, similar with both techniques of measurement. In the 42 patients who had repeat measurements, clinic blood pressure levels nad the amplitude of the diurnal blood pressure profile (fitted by Fourier analysis) were equally reproducible. However, both were less reproducible than ambulatory blood pressure levels. The repeatability coefficients, expressed as per cent of near maximum variation (four times the standard deviation of a given measurement), were 52% and 45% for the clinic systolic and diastolic pressures, 56% and 42% for the amplitude of the diurnal profile, and 29% and 26% for mean 24-h pressures. CONCLUSIONS: In older patients with ISH, clinic and ambulatory systolic blood pressure measurements may differ largely: the prognostic significance of this difference remains to be elucidated. Furthermore, in these patients the level of pressure is more reproducible by daytime ambulatory blood pressure measurement than by clinic measurement.

Aged↗
PubMed1992

[SYST-EUR: a multicenter trial of treatment of systolic hypertension in aged subjects. An initial report].

Syst-Eur is a multicentre placebo-controlled outcome trial, designed by the European Working Party on High Blood Pressure in the Elderly (EWPHE), to investigate the effect of antihypertensive treatment on the incidence of stroke in elderly patients with isolated systolic hypertension (ISH). Eligible patients must be at least 60 years old and have a systolic blood pressure averaging 160-219 mmHg with a diastolic blood pressure less than 95 mmHg. The present paper in an interim report on the first 316 patients randomized into this trial. The placebo (N = 170) and active treatment (N = 146) groups were similar at randomization with respect to age (73 +/- 8 years; mean +/- standard deviation), sitting blood pressure (178 +/- 12/85 +/- 7 mmHg), percentage men (34%) and percentage of patients with cardiovascular complications (29%). After randomization blood pressure fell more (p < 0.001) on active treatment than in the placebo group (19 +/- 20/6 +/- 10 mmHg versus 7 +/- 19/1 +/- 10 mmHg for the sitting blood pressure). This first interim report on the Syst-Eur trial demonstrates that a multinational trial in elderly patients with ISH is feasible and that a significant blood pressure difference between the 2 treatment groups can be achieved and maintained. New centres are being recruited in order to randomize a total of 3,000 patients.

Aged↗
PubMed1991

Disseminated toxoplasmosis in a severely immunodeficient patient: demonstration of cysts in bone marrow smears.

A 30-year-old woman was treated with unrelated HLA-compatible bone marrow transplantation for acute myeloid leukemia. Examination of her bone marrow smears because of fever and pancytopenia revealed the presence of Toxoplasma cysts. Although Toxoplasma cysts are rarely found in the bone marrow, bone marrow examination in the immunocompromised patient offers rapid diagnosis of systemic toxoplasmosis.

Adult↗
PubMed1991

Is prevention of vascular dementia possible? The Syst-Eur Vascular Dementia Project.

Vascular dementia (VD) is the second most common cause of dementia in the elderly after Alzheimer's disease (AD). Prevalence estimates from community surveys indicate that, on average, 5% of persons over 65 and 15 to 20% of people over 80 suffer from "severe dementia". Clinico-pathological studies have shown that AD accounts for 50 to 60% of the cases and VD for about 10 to 20%; 20% of the patients have both disorders. The incidence rate of VD ranges from 7 per 1,000 person-years in normal volunteers to 16 per 1,000 person-years in subjects with risk factors for strokes, particularly high blood pressure. The only effective therapeutic approach to VD is the prevention of strokes, mainly through the treatment of hypertension; however, none of the therapeutic trials has included VD prevention as one of its treatment goals. Syst-Eur Study is a European placebo controlled trial which aims to determine whether morbidity and mortality are changed when elderly patients (60 years and over) with isolated systolic hypertension are treated. In this trial, the incidence of VD will be carefully recorded during the five year follow-up of the expected 3,000 patients. The present side project to the Syst-Eur trial will specifically address the following questions: does antihypertensive treatment reduce the incidence of VD?, and how do the cognitive functions of elderly patients change when treated with active or placebo treatment? The protocol is based on the administration of the MMS (Folstein) once a year to all patients. If the MMS score is 23 or less, a set of criteria will be used to establish the diagnosis of vascular dementia. A pilot study has demonstrated the feasibility of the trial. The main study is in progress.

Aged↗
PubMed1991

Cardiovascular manifestations of Lyme disease.

Although the cardiac manifestations of Lyme disease may be diverse, in general they are treatable with currently available therapies. A high index of suspicion is required to make a diagnosis, especially for patients who may lack a suggestive history of tick exposure or residence in an endemic region. Lyme disease-related heart block may require pacemaker insertion and supportive care. The efficacy of antibiotics in the therapy of acute and chronic cardiac Lyme disease will require further study. Serologic testing and cardiac histopathology are the most precise methods of diagnosis. There is a need to develop more sensitive and specific diagnostic tests for Lyme disease and for Lyme carditis in particular.

Administration, Oral↗
PubMed1991

Ambulatory blood pressure monitoring in the evaluation of drug efficacy.

Conventional clinic measurement of blood pressure is influenced by many factors that make the technique unsuitable for the assessment of antihypertensive drug efficacy. The major drawback of conventional measurement is that it cannot indicate the duration of drug effect or the influence of antihypertensive drugs on nocturnal blood pressure. Noninvasive 24-hour ambulatory blood pressure measurement has a number of advantages over conventional measurement: it provides a profile of blood pressure over the 24-hour period; it detects white coat responders; it is free of regression to the mean and the placebo response, thereby making it possible to consider efficacy studies which need not have a placebo phase; it enables considerably more observations than is possible with clinic measurement by increasing the power of studies, which may reduce significantly the numbers of patients needed for antihypertensive drug studies. Twenty-four-hour ambulatory blood pressure measurement offers the opportunity to study antihypertensive drugs in fewer patients with greater accuracy than is possible with conventional clinic measurement and should be a mandatory requirement for such studies.

Ambulatory Care↗