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Biomedical subjects

J J de Castro

Publications and source records attributed to J J de Castro.

At least 19 recordsLinked to original sources
PubMed2001

Relationship between the number and impact of stressful life events and the onset of Graves' disease and toxic nodular goitre.

BACKGROUND: In the last few decades, several studies have suggested a possible association between Stressful Life Events (SLEs) and the onset of Graves' Disease (GD). However, others have criticised this association and it has not yet been possible to prove it unequivocally. At present, we are not aware of studies correlating SLE and non autoimmune thyrotoxicosis. OBJECTIVE: To assess possible associations between SLEs, the onset of GD and the onset of non autoimmune thyrotoxicosis (toxic nodular goitre, TNG). DESIGN: A case-control retrospective study. PATIENTS: This study included 93 subjects, divided into three groups of 31 each: GD, TNG and control (CG). The GD and TNG patients had thyroid disease diagnosed within the last 12 months, with clinical and biochemical confirmation. In the CG, psychopathological and endocrine disturbances had been ruled out. All three groups consisted of nine males (29%) and 22 females (71%). The mean age was 38.4 +/- 10.9 years in the GD group, 48.3 +/- 11.1 years in the TNG group and 41.1 +/- 11.8 years in the CG group. SLEs were evaluated (number and impact) for the 12 months preceding the onset of symptoms of thyroid disease. MEASUREMENTS: SLE occurrences and their impact on each group of cases were measured. To assess SLEs, we used the Life Experiences Survey (LES). Our statistical analysis included descriptive techniques and parametric and/or nonparametric comparative tests. P < 0.01 was considered statistically significant. Odds ratios were also calculated. RESULTS: Patients with GD had a significantly greater number of SLEs compared to the TNG group and the CG (P < 0.001). The number and impact of negative SLEs were significantly higher in GD compared to TNG and CG (P < 0.001). The difference between TNG and CG was not significant (P > 0.01). GD had a higher impact of positive SLEs than TNG (P = 0.004), and no significant differences were found between the GD group and CG. Neutral SLEs were similar in the three groups. CONCLUSIONS: These results suggest that SLEs are a precipitating factor of the onset of GD. We also demonstrated that SLEs do not seem to have any conclusive relationship with the onset of TNG.

Adult↗
PubMed1998

Effect of different East Coast fever control strategies on disease incidence in traditionally managed Sanga cattle in Central Province of Zambia.

A clinical trial, including five East Coast fever (ECF) control strategies (involving tick control and/or immunisation by infection-and-treatment) in five different groups of traditionally managed Sanga cattle, was conducted in Central Province of Zambia over 2.5 years between 1992 and 1995. Two groups were kept under intensive tick control by weekly acaricide treatment by hand spray; (one immunised and one non-immunised), two groups were under no tick control (one immunised and one non-immunised), and a fifth, immunised group was maintained under strategic tick control (18 sprays yr-1). ECF-specific mortality was highest in the non-immunised and non-treated group, while no difference in ECF-specific mortality could be observed between animals treated for ECF by immunisation or by tick control. Acaricide treatment and/or immunisation reduced the risk of clinical ECF by 92%. The results of an artificial challenge experiment at the end of the field trial indicated that about 60% of the animals in the control group had become infected with Theileria parva without showing clinical signs. ECF incidence in non-vaccinated cattle markedly declined six months after immunisation--suggesting that the carrier state induced by immunisation did not lead to a persistent high incidence, and might accelerate the progress to endemicity.

Animals↗
PubMed1998

An outbreak of East Coast fever in a herd of Sanga cattle in Lutale, Central Province of Zambia.

An outbreak of East Coast fever (ECF) occurred in an experimental herd of Sanga cattle maintained under a traditional rangeland grazing system at Lutale, Central Province of Zambia. Two groups of cattle had been kept under different tick-control regimens for several years prior to the introduction of the disease and epidemiological information on the outbreak were recorded. Weekly tick control was no sufficient to achieve full protection against Theileria parva infection. Systematic body temperature monitoring seems to be a good method for early detection of infection resulting in an important reduction of the case fatality rate after treatment with anti-theilerial drugs.

Animals↗
PubMed1998

Secular trends of weight, height and obesity in cohorts of young Portuguese males in the District of Lisbon: 1960-1990.

OBJECTIVE: To examine the secular trend of weight, height and obesity among young Portuguese males at the time of military inspection for national conscription purposes in the region of Lisbon, during the last thirty years. DESIGN: Cross-sectional study, based on the review of military census files. SETTING: Military selection centre of Lisbon. SUBJECTS AND METHODS: In Portugal, military service is obligatory and medical inspections are carried out every year on males at the age of twenty. For study purposes, representative samples were taken from the young male population undergoing inspection for the Armed Forces on a five year basis, between 1960 and 1990 in the region of Lisbon. Weight and height were evaluated by a trained team, using standard measurement instruments and procedures. RESULTS: A progressive and significant increase in weight, height and BMI of the young male population was found between 1960 and 1990. For certain variables the increase was also statistically significant within a five-year period, as it was the case for height between 1965-1980 and for weight between 1985-1990. The increase in BMI experienced some minor fluctuation along the reference period, however, it was statistically significant between 1985-1990. The increase in weight and in BMI was greater in the highest percentiles and particularly noticeable between 1985 and 1990. The percentage of young males with BMI over 25 kg/m2 was of 8.1% in 1960 and of 18.0% in 1990, while those having a BMI over 27 kg/m2 varied between 3.6% and 6.4% in the same period, respectively. The percentage of young adult males with BMI higher than 25 kg/m2 doubled between 1960 and 1990.

Adult↗
PubMed1997

Sustainable tick and tickborne disease control in livestock improvement in developing countries.

Tick and tickborne disease (TTBD) control is a major component of animal health programmes protecting livestock, thereby enhancing global food security. The present methods for TTBD control are reviewed and an integrated use of the tools is recommended with a broader view of how to link TTBD control to the control of other parasitic diseases. The work of FAO in this field is presented and it is advocated that, although there are still areas that need further investigation, a stage has been reached where robust integrated TTBD control schemes, based on ecological and epidemiological knowledge of ticks and their associated diseases, can be promoted and implemented. Major challenges are the implementation of these policies in the field through the continuation of the present on-going programme in Africa and support to Latin America and Asia. The importance of involving all parties, governments, international and private organisations and the agrochemical industry in developing sustainable, cost-efficient control programmes is stressed and a global strategy is proposed. The main thrust should now be to convince policy makers on the adoption of the strategies and veterinarians and farmers on their implementation.

Africa↗
PubMed1997

Effect of different East Coast Fever control strategies on fertility, milk production and weight gain of Sanga cattle in the Central Province of Zambia.

Five different East Coast Fever (ECF) (Theileria parva infection) control strategies, based on tick control and/or ECF immunization, were tested in groups of traditionally managed Sanga cattle in the Central Province of Zambia over a period of 2.5 years. Two groups were kept under intensive tick control (sprayed weekly), one group immunized and one non-immunized. Two further groups were under no tick control, one group immunized and one non-immunized, while a fifth group was immunized against ECF and maintained under strategic tick control (18 sprays per year). Tick control increased milk production and weight gain but not fertility. Immunization had neither marked detrimental nor beneficial effects on the cattle productivity. The combination of strategic tick control and immunization resulted in the highest level of production and at the same time reduced the potential risk from other tick-borne diseases.

Animal Husbandry↗
PubMed1997

A comparison of the insulin tolerance/glucagon test with the short ACTH stimulation test in the assessment of the hypothalamo-pituitary-adrenal axis in the early post-operative period after hypophysectomy.

OBJECTIVE: The insulin tolerance test (ITT) is the established reference test for assessing the hypothalamo-pituitary-adrenal (HPA) axis. Various authorities, however, have suggested that the 250 microgram short ACTH stimulation test may be used to assess the HPA axis in place of the ITT in suspected hypopituitarism, although a number of other studies have suggested that the test may be unreliable in this setting. In this study, the ITT (or glucagon test) has been compared with the 250 microgram short ACTH stimulation test in patients with pituitary tumours pre-operatively and within 2 weeks of trans-sphenoidal hypophysectomy. DESIGN: An ITT, or a glucagon test when the ITT was contraindicated, and the 250 micrograms short ACTH stimulation test, were performed in all the patients before (an ITT in 18 and a glucagon test in three patients) and within 2 weeks after trans-sphenoidal hypophysectomy (an ITT in 16 and a glucagon test in five patients). PATIENTS: Twenty-one patients with pituitary disorders (15 with acromegaly, one with a prolactinoma and five with non-functioning tumours) were studied; four had a microadenoma, two a mesoadenoma and 15 a macroadenoma. MEASUREMENTS: Serum cortisol was measured by radioimmunoassay. A normal response was defined as a rise in serum cortisol to 580 nmol/l or above for all the tests. RESULTS: Before surgery, three of 18 patients (17%) had a discrepancy between the ITT and the 30 minute short ACTH stimulation test and one of three between the glucagon test and the 30 minute short ACTH stimulation test. Combined together, pre-operatively, four of 21 patients (19%) had discrepant results. In the early post-operative period, the discrepancy between ITT and the 30 minute short ACTH stimulation test was higher with four of 16 patients (25%) showing discordant results; one of the five patients tested had a discrepancy between the glucagon test and the 30 minute short ACTH stimulation test. On combining the tests, the post-operative discrepancy was five of 21 patients (24%). CONCLUSIONS: The 250 microgram short ACTH stimulation test produces discordant results from the ITT in a clinically significant proportion of affected patients when assessing the HPA axis, although the rate of discordance varies according to the criteria used for normality for both the tests. We suggest that the ITT should remain the preferred test for assessing ACTH secretory capacity compared with the standard 250 microgram short ACTH stimulation test, both in the preoperative and in the early post-trans-sphenoidal hypophysectomy period.

Adenoma↗
PubMed1997

Long-term studies on the economic impact of ticks on Sanga cattle in Zambia.

Three different tick control policies were tested in groups of traditionally managed Sanga cattle in the Central Province of Zambia over a period of 3 years. One group was given strategic tick control using 12 pyrethroid acaricide spray applications between the onset and the end of the wet season (October to March). The productivity of this herd was compared with that of a group with no tick control and a group under an intensive tick control regimen of spraying every week in the wet season and every 2 weeks in the dry season (36 applications per year). The highest output was associated with intensive tick control, followed by strategic control and then no tick control policies. However, when the costs of tick control were taken into account, the strategic tick control policy produced the best economic result, followed by the intensive and then the no tick control policies. Neither the strategic nor the intensive tick control policy was sufficient to prevent the transmission of East Coast fever (ECF) infection when this disease was introduced to the area.

Animals↗
PubMed1993

Tick resistance to acaricides in western Ethiopia.

A survey of acaricide resistance was performed on ticks collected from 18 dairy farms and 6 veterinary clinics in western Ethiopia. Boophilus decoloratus collected from most of the dairy farms were resistant to toxaphene, but no resistance was detected in ticks collected from indigenous cattle. There is a need in Ethiopia to replace toxaphene on dairy farms and formulate a rational tick control policy for the whole country.

Animals↗
PubMed1993

Host resistance to ticks (Acari: Ixodidae) in different breeds of cattle at Bako, Ethiopia.

European cattle breeds are being introduced into Ethiopia in an effort to improve the productivity of indigenous breeds. The Ethiopian cattle breeds Horro and Boran were compared for tick burdens with their crosses with Friesian, Jersey and Simmental. Horro animals had the lowest tick burdens and the Horro x Friesian the highest. Adaptation to their environment and long-term natural selection for tick resistance in Horro cattle is the most likely explanation. Repeatability of tick burdens in all animals considered as one herd were only statistically significant for Boophilus decoloratus, the most abundant tick species. Statistically significant correlations between burdens of female B. decoloratus, Amblyomma cohaerens and Rhipicephalus praetextatus were observed and the addition of the males resulted in all inter-species correlations becoming significant. Care should be taken when crossing Ethiopian with more productive European cattle breeds in order not to lower their tick and disease resistance.

Adaptation, Physiological↗
PubMed1993

Host resistance in cattle tick control.

Cattle ticks are an important constraint on the livestock industry, particularly in tropical and subtropical areas, mainly because of the diseases they transmit and the costs of control. Conventional control is by means of acaricides; although there are still serious drawbacks, these can be minimized by a strategic approach. In this review Julio de Castro and Robin Newson look at alternatives. One is to make use of the host's innate abilities. In the simplest situation, where no control measures are applied, the animals develop their own protective immunity against ticks and tick-borne diseases (TBDs). Alternatively, breeds of cattle with naturally high resistance to ticks can be used, enhanced by selection. Methods of immunizing cattle against ticks are also under development. Ideally, ticks should be managed at an economically acceptable level by a combination of techniques, supported where necessary by vaccination against TBDs.

Journal Article↗
PubMed1991

Towards the selection of cattle for tick resistance in Africa.

Half-body tick collections and visual assessment of tick burdens were performed monthly over six months on 100 bulls at the Kenya National Boran Stud, Mutara Ranch, Kenya. Boophilus decoloratus predominated among several tick species infesting the animals. Burdens of B. decoloratus and total tick burdens were highly correlated. Rankings of relative tick resistance among bulls were consistent from month to month. Rankings based on visual assessment were very close to those based on actual tick burdens. Animals with thin skins appeared to carry fewer ticks, but tick burden bore no relationship to coat colour. The results suggest that simple visual inspection of total tick burdens may be a suitable basis for the selection of tick resistance in cattle.

Animals↗
PubMed1991

[Arterial pressure and race. A study in pauper children attending schools in an urban strip in Lisbon].

OBJECTIVE: To determine whether race is a factor of blood pressure levels in school-age children of similar social status, and to investigate other potential determinants of the levels of blood pressure. DESIGN: Inquiry in schools of the suburbs of Lisbon. SETTING: Three schools, four medical observers (general practitioners with school-health functions). SUBJECTS: Three hundred ninety seven children, aged 6-14 years, both sexes, 296 being white and 101 non-white. INTERVENTIONS: Inquiry to the following individual characteristics--sex, age, race, birthplace, type of housing, house availability of water, electricity and waste water, type of transportation to school, number of cohabitans, family income, school marks. Individual determination of systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), weight and height. MEASUREMENTS AND MAIN RESULTS: Blood pressure values were cross-analyzed with all the determined variables, and the virtual correlations were checked. Main results as follows: Race does not influence either SBP or DBP. In this age group, sex does not influence blood pressure values. The used markers of socioeconomical status have equally no influence on blood pressure. Age has only a significant repercussion on SBP. No significant correlation was found between height and blood pressure. Body weight, however, influence either SBP or DBP. SBP was found to be lower in the second of two successive measurements, and the difference increases with age. CONCLUSIONS: In this school-aged biracial population, body weight seems to be the major factor of blood pressure levels, in the sense-bigger weight, higher SBP and DBP.

Adolescent↗
PubMed1990

[The effectiveness of amiodarone seems to depend highly on the pathology underlying the arrhythmia].

STUDY OBJECTIVE: To evaluate the efficacy of amiodarone in tachyarrhythmias occurring acutely, in patients with different nosological entities of the heart. DESIGN: A retrospective study. SETTING: Emergency-room patients and ward-patients, in an Internal Medicine Department of a University Hospital. PATIENTS: Sequential sample of 148 patients with acute tachyarrhythmias, 138 out of them supraventricular (atrial fibrillation--116 cases; paraoxysmal supraventricular tachycardia--14 cases, and atrial flutter--8 cases). INTERVENTIONS: 81 patients had been treated with amiodarone; 67 patients had received several other antiarrhythmic drugs. MEASUREMENTS AND MAIN RESULTS: A favourable result of antiarrhythmic treatment was achieved in 84% of the patients who received amiodarone and in only 57% of those having been treated with the other antiarrhythmic drugs (p less than 0.025). A clearly distinct benefit of amiodorone was seen in the subgroup of patients with mitral stenosis, when compared with the whole of the other treatments (p less than 0.001). Amiodarone results were also better than the other antiarrhythmic ones in hypertensive patients (p less than 0.05). There was no difference between amiodarone and the remaining compounds in patients suffering from ischaemic heart disease, congestive heart failure and chronic obstructive lung disease. No adverse side effects were verified is this short term treated sequence of patients. CONCLUSIONS: Amiodarone seems, in this study, to be a very effective antiarrhythmic drug for the treatment of supraventricular tachyarrhythmias. Its efficacy was superior in cases where the underlying disease was mitral stenosis or arterial hypertension. So, effectiveness of the compound seems to depend on the nature of the subjacente cardiac disease. The short term tolerability has been excellent. However, the small number of patients studied claims for bigger scaled similar investigations.

Acute Disease↗
PubMed1989

Resistance in cattle against Rhipicephalus appendiculatus with an assessment of cross-resistance to R. pulchellus (Acari: Ixodidae).

A comparison of the yield of engorged nymphs of Rhipicephalus appendiculatus and R. pulchellus was carried out between cattle highly resistant to R. appendiculatus but susceptible to R. pulchellus, and cattle and rabbits susceptible to both species. Resistant cattle yielded fewer and smaller R. appendiculatus nymphs than either susceptible cattle or rabbits. More nymphs of both tick species dropped from susceptible cattle but no differences were detected in the mean weight of engorged R. pulchellus nymphs fed on R. appendiculatus-resistant and susceptible cattle, although resistant animals yielded more nymphs of R. pulchellus than of R. appendiculatus. An acute inflammatory reaction, accompanied by intense pruritus and grooming, was observed in the ears of the resistant cattle infested with R. appendiculatus, but no reaction was detected in the opposite ears where R. pulchellus was feeding. The low cross-resistance between these two closely related tick species suggests that different antigens may be involved in the development of resistance in cattle to different tick species.

Animals↗