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Biomedical subjects

L Rodrigues

Publications and source records attributed to L Rodrigues.

At least 19 recordsLinked to original sources
PubMed1992

Incidence of cancers of the larynx and lung near incinerators of waste solvents and oils in Great Britain.

The Small Area Health Statistics Unit (SAHSU) is a new independent facility for the investigation of disease near industrial installations in the UK. SAHSU analysed the incidence of cancers of the larynx and lung near the incinerator of waste solvents and oils at Charnock Richard, Coppull, Lancashire (which operated between 1972 and 1980) and nine other similar incinerators in Great Britain, after reports of a cluster of cases of cancer of the larynx near the Charnock Richard site. Postcoded cancer registration data were available for 1974-84 in England and Wales and 1975-87 in Scotland. Lag periods of 5 and 10 years were used between start-up (or first registration) of the incinerators and cancer incidence. Standardised observed/expected (O/E) ratios were assessed within 3 km and 3-10 km of each site and then aggregated over all sites. Expected values were based on national rates (regionally adjusted) with and without stratification by Carstairs' index, a measure of the socioeconomic profile of areas that uses census data for enumeration districts. Data were also assessed over a range of circles up to 10 km to test for trend in O/E ratios with distance. For Charnock Richard, none of the O/E ratios within 3 km or from 3-10 km differed significantly from unity, for either cancer or lag period. In the analysis of all sites with stratification by Carstairs' index, none of these O/E ratios differed significantly from unity for the two cancers. There was no evidence of decreasing risk with distance from the sites of either cancer. We conclude that the apparent cluster of cases of cancer of the larynx reported near Charnock Richard was unlikely to be due to its former incinerator.

Cluster Analysis↗
PubMed1992

The Small Area Health Statistics Unit: a national facility for investigating health around point sources of environmental pollution in the United Kingdom.

STUDY OBJECTIVE: The Small Area Health Statistics Unit (SAHSU) was established at the London School of Hygiene and Tropical Medicine in response to a recommendation of the enquiry into the increased incidence of childhood leukaemia near Sellafield, the nuclear reprocessing plant in West Cumbria. The aim of this paper was to describe the Unit's methods for the investigation of health around point sources of environmental pollution in the United Kingdom. DESIGN: Routine data currently including deaths and cancer registrations are held in a large national database which uses a post code based retrieval system to locate cases geographically and link them to the underlying census enumeration districts, and hence to their populations at risk. Main outcome measures were comparison of observed/expected ratios (based on national rates) within bands delineated by concentric circles around point sources of environmental pollution located anywhere in Britain. MAIN RESULTS: The system is illustrated by a study of mortality from mesothelioma and asbestosis near the Plymouth naval dockyards during 1981-87. Within a 3 km radius of the docks the mortality rate for mesothelioma was higher than the national rate by a factor of 8.4, and that for asbestosis was higher by a factor of 13.6. CONCLUSIONS: SAHSU is a new national facility which is rapidly able to provide rates of mortality and cancer incidence for arbitrary circles drawn around any point in Britain. The example around Plymouth of mesothelioma and asbestosis demonstrates the ability of the system to detect an unusual excess of disease in a small locality, although in this case the findings are likely to be related to occupational rather than environmental exposure.

Asbestosis↗
PubMed1992

A bright future for community nursing.

Lisa Rodrigues argues that health visitors and community nurses have a world to gain from the current flux in community health services. But they must actively seek out ways of working jointly with other agencies if they are not to be left on the sidelines.

Community Health Nursing↗
PubMed1992

[Primary effect of carotid body stimulation on left ventricular inotropism in swine].

The cardiovascular response to carotid body stimulation has been a interesting and simultaneously controversial subject. In fact, several authors described different responses depending on the animal species used (cat, dog, rabbit, monkey), time of stimulation (short-term v. long-term) and experimental conditions and procedures. According to our experience, the response to carotid body stimulation with cyanide, in normal breathing dogs, consists in hyperpnoea, bradycardia with arterial blood pressure fall (by means of longer diastolic periods), followed by a marked rise in arterial blood pressure and heart rate, after curarization. Concerning the inotropic response to carotid chemoreceptors stimulation, there exists some controversial and even antagonic opinions. In fact, some authors describe a positive inotropic effect, others a negative inotropic effect, and others still defend no inotropic response at all. In the present work, the authors try to contribute to the solution of this problem, studying a group of animals (pig) anaesthetised with chloralose, in which the major modulators of the inotropic response to carotid body stimulation (ventilation; heart rate; and ventricular load conditions) were controlled. To the evaluation of cardiac contractile state, indexes derived from the systolic isovolumic phase were used (maximum left ventricular pressure, dP/dtmax; dP/dtmin) in all the animals. In some animals, other indexes were also used (Vmax, Vpm, (dP/dt)/DP40, Tau and PB). The authors concluded that, in the present experimental conditions, the primary response to carotid body stimulation, in the pig, includes a positive inotropic effect.

Animals↗
PubMed1992

Determinants of survival in adult Brazilian AIDS patients, 1982-1989. The Brazilian State AIDS Program Co-Ordinators.

OBJECTIVE: Little has been published about the length and determinants of survival for persons with AIDS in developing countries. This study examined the survival experience of Brazilian AIDS patients from 1982 to 1989. DESIGN: A retrospective cohort study involving record review of reported AIDS cases. METHODS: We obtained information about 2135 adult AIDS patients in Brazil. Local health officials supplied data regarding demographic and clinical characteristics and length of survival. Statistical techniques of survival analysis were applied. RESULTS: Median survival was 5.1 months, much shorter than in developed countries, and there was no improvement in survival for cases diagnosed more recently. Younger patients and those in the intravenous drug use exposure category lived longer than other AIDS patients. Those presenting with Kaposi's sarcoma, esophageal candidiasis, and tuberculosis fared relatively well, while those presenting with multiple diagnoses or toxoplasmosis did more poorly. CONCLUSIONS: These results tend to confirm the predictors of AIDS survival previously reported from developed countries and to document the poor survival of AIDS patients in the developing world.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Sudden infant deaths and cold weather: was the rise in infant mortality in 1986 in England and Wales due to the weather?

Using the daily number of deaths due to sudden infant death syndrome in England and Wales from 1979 to 1985, and the daily temperature recorded at the London Weather Centre, two models were constructed, one including a temperature term and one without it, and the models used to predict the mortality in 1986. It was found that the model using temperature had a slightly better predictive power and successfully accounted for the increased mortality in February 1986. Thus, we conclude that the excess mortality of February 1986 was associated with the unusually cold weather during that month.

Cold Climate↗
PubMed1990

Case-control designs in the study of common diseases: updates on the demise of the rare disease assumption and the choice of sampling scheme for controls.

In recent years the use of case-control designs has been extended to the study of common diseases. It has been shown that the rare disease assumption is not necessary, and that by a suitable choice of sampling scheme for controls, it is possible to obtain direct estimates of relative risk and relative rate, instead of relying on the odds ratio as an indirect estimate. The majority of papers addressing these issues are theoretical, and the arguments have been couched in mathematical terms. As such they are not readily accessible to many practising epidemiologists. This paper summarizes the discussion in a simplified manner. It describes the three different measures of relative incidence, namely the relative risk, the relative rate and the odds ratio, together with their corresponding case-control designs. The discussion is extended to show that the choice of the appropriate measure of relative incidence depends on the mode of action of the risk factor, as well as on characteristics of disease. We propose a classification scheme comprising five different categories of situation, and make recommendations regarding study designs for each.

Case-Control Studies↗
PubMed1989

Protection of cells against membrane damage by haemolytic agents: divalent cations and protons act at the extracellular side of the plasma membrane.

The protective effect of Ca2+, Zn2+ and H+ against membrane damage induced by different haemolytic agents has been studied by measuring monovalent cation leakage and haemolysis of erythrocytes, and phosphoryl[3H]choline and adenine nucleotide leakage from Lettre cells prelabelled with [3H]choline. The protective effect of Ca2+ and Zn2+ on erythrocytes damaged by Staphylococcus aureus alpha-toxin, Sendai virus or melittin is unaffected by the addition of A23187, even though this ionophore greatly increases the uptake of 45Ca2+ or 65Zn2+. The same result has been found for the protective effect of Zn2+ on Lettre cells damaged by S. aureus alpha-toxin, Sendai virus, melittin or Triton X-100. Leakage of phosphoryl[3H]choline from prelabelled Lettre cells is inhibited if extracellular pH is lowered; lowering the intracellular pH without affecting the extracellular pH, affords little protection. It is concluded that Ca2+, Zn2+ and H+ protect cells against membrane damage induced by haemolytic agents by an action at the extracellular side of the plasma membrane.

Animals↗
PubMed1989

[Breast reconstruction using skin expansion after radiotherapy: limitations of the procedure. Apropos of 10 cases].

The incidence of failure, be it partial or possibly total, in breast reconstruction after amputation and radiotherapy, appears to be too high in the author's experience. The analysis of ten of such cases focuses attention on what was really done concerning X-ray therapy. It is no longer acceptable to rely on a dose limit on of 50 GY for, expressed in this way, it is not sufficiently accurate. Attention is drawn to the need for a better knowledge of what has really been done before attempting breast reconstruction using temporary expansion.

Breast↗
PubMed1987

Fate of TR-2, the hepatic metabolite of the tremorgenic mycotoxin verruculogen, in sheep.

1. Verruculogen is eliminated in bile after transformation to TR-2, only a trace of which was excreted as such in faeces of sheep given verruculogen per os. Negligible TR-2 was present free in urine; no glucuronide was found. 2. An isomer of TR-2, a minor component of the bile of sheep given verruculogen, has been defined by 1H-n.m.r. spectroscopy and the isomerism involves the disposition of the two adjacent hydroxyl groups with a concomitant change in the conformation of the ring adjacent to the indole. 3. 14C-TR-2, added to the perfusate of isolated rat liver, was excreted unchanged in the bile, implying no significant loss of any biliary TR-2 subject to enterohepatic recycling in vivo. 4. 14C-TR-2 incubated anaerobically in sheep ileum contents was 95% transformed into more polar metabolites, the majority of the radiolabelled metabolites isolated being water soluble. 5. The principal fate of biliary TR-2 is as a metabolic substrate for the intestinal microflora.

Animals↗
PubMed1977

Echocardiographic evaluation of left-to-right shunt in ventricular septal defect and persistent ductus arteriosus.

Forty-five patients with either a ventricular septal defect or a persistent ductus arteriosus were assessed by echocardiography and cardiac catheterisation. Left atrial dimension was expressed either as a function of the body surface area (LAD cm per m2 BSA), or as a multiple of the aortic root dimension (LAD/AR), and was compared with the shunt size as determined by oximetry. A highly significant (P less than 0-001) regression relation was found for the group as a whole. A significant relation also existed for each individual group: ventricular septal defect, ventricular septal defect with pulmonary hypertension, and persistent ductus arteriosus. Regression equations were derived for the whole group. The value of echocardiography is in separating large from small shunts and in adding a dimension to the follow-up of the individual patient.

Adolescent↗