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A Aznarez

Publications and source records attributed to A Aznarez.

6 recordsLinked to original sources

Quality evaluation of newborn screening programs.

In the last four decades in many countries and regions all over the world newborn screening programs have been developed. Traditionally, most programs focus on phenylketonuria and congenital hypothyroidism. However, with development of new technologies, screening for a large variety of other disorders has become available. The decision-making process on what to screen or not to screen for is usually driven by personal interest of the professionals involved, by local legislation and access to funding, resulting in large differences among countries. In general, quality evaluation is only applied to the pure laboratory analytical phase. Less attention is given to the pre-analytical phase (e.g. timely sampling, maximum coverage) and the post-analytical phase (follow-up and treatment, evaluation of long-term effects, cost-effectiveness, etc.). In order to gain more insight into the current situation worldwide we developed a questionnaire which was sent to leading screening centers in more than 30 countries. As expected, the results show large differences in degree of organization, turnover times, completeness of coverage and follow-up. There appears to be no relationship between screening procedures and the degree of legislation or the system of funding. In presenting the more detailed results we hope to be of service to program organizers.

Asia↗

Are there any differences in the parathyroid response in the different types of renal osteodystrophy?

With the purpose of studying the curve of parathyroid response to variations of serum calcium during dialysis, we studied 20 patients on haemodialysis: 10 women and 10 men, with different forms of bone disease diagnosed by bone biopsy (adynamic bone disease, mild hyperparathyroidism, severe hyperparathyroidism). In all patients, we performed parathyroid stimulation by 4 h dialysis with 1 mEq/l of Ca2+ in the dialysate, and an inhibition test in another dialysis session with 4 mEq/l of Ca2+, with a 48 h interval. Ca2+ and intact parathyroid hormone (iPTH) were measured prior to dialysis and every hour subsequently, to obtain a Ca2+-iPTH for each patient. The analysis of the curves was made using Brown's four-parameter model. Stimulation and inhibition levels were similar in all groups, but basal iPTH and the response profiles obtained varied in the different histological groups. Basal, maximal and minimal iPTH were lower in adynamic forms than in the other two groups (P<0.04), and basal calcium was higher than basal calcium of severe hyperparathyroidism, expressing a basal inhibition status. In severe hyperparathyroidism, basal calcium was lower than the set-point, showing a permanent stimulation, and the slope was higher than in other groups, showing more sensitivity to serum calcium variations. The set-point of severe hyperparathyroidism was significantly higher than the set-point of mild and adynamic forms. In conclusion, the functional parathyroid study showed a different response in the different forms of renal osteodystrophy.

Adult↗

99Tc(m)-MIBI scanning of the thyroid gland in patients with markedly decreased pertechnetate uptake.

Diffusely reduced 99Tc(m)-pertechnetate uptake is a relatively infrequent but annoying finding that impairs evaluation of the thyroid gland. We studied 32 female patients aged 19-85 years with markedly reduced pertechnetate uptake. The following causes of reduced pertechnetate uptake were recognized: treatment with iodinated pharmaceuticals (n = 15), suppression therapy with T4 (n = 11), subacute thyroiditis (n = 5) and massive tumour replacement (n = 1). 99Tc(m)-MIBI thyroid scintigraphy was performed within 24 h of the pertechnetate study. The results were correlated with neck ultrasound, serum TSH (n = 25) and surgical findings in patients who had been operated on. The technique identified the following conditions: normally sized thyroids (n = 4), diffuse goitres (n = 8), multinodular goitres (n = 17) and solitary thyroid nodules (n = 3). Moreover, substernal goitres were identified in nine patients. This condition was confirmed at surgery in seven patients. Ultrasonography was concordant in 29 of 32 patients in terms of thyroid size and structure, but failed to demonstrate substernal thyroid tissue. Our results suggest that 99Tc(m)-MIBI scintigraphy may contribute to the diagnosis of thyroid pathology and treatment planning in patients with diffusely decreased 99Tc(m)-pertechnetate uptake.

Adult↗

Indium-111 leukocyte imaging. The skeletal photopenic lesion.

Photon-deficient lesions in the skeleton occasionally are seen in In-111 leukocyte imaging. Although the findings usually indicate past surgery, previous infections, or radiation therapy effect, they may be due to metastatic disease or active or partially treated infection.

Adult↗

Clastogenic action of a dimethyl p-benzoquinone of animal origin.

The cytogenetic action of a volatile dimethyl p-benzoquinone found in the natural secretion of an arachnid (Acanthopachylus aculeatus Kirby) was studied in cultured human peripheral leukocytes and in mouse bone-marrow cells. Continuous and pulse treatments carried out in vitro, as well as experiments performed in vivo, induced different chromatid and chromosome aberrations suggesting that this chemical has clastogenic properties. The biology of the animal and the possible role of one of the components of its secretion as a natural mutagenic agent are discussed.

Animals↗