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M Torra

Publications and source records attributed to M Torra.

30 records · Page 2Linked to original sources

Accumulation of hexachlorobenzene in humans: a long standing risk.

1. Hexachlorobenzene (HCB) internal dose in the general population of Barcelona (Spain) was estimated after new indications of the carcinogenicity of this chemical in humans were recently reported. Hospital blood bank facilities and randomly selected volunteers were used for HCB analyses in serum (n = 100) and cerumen (n = 25). Other main organochlorine residues often found in human tissues and blood (pp DDE, beta-HCH,) were also determined. 2. HCB serum levels currently found (Range 0.7-19.7 ng Ml-1; X +/- s.d.: 4.13 +/- 3.61; GM: 3.05) were compared to those found in a similar survey made in 1986 on the same population. The serum HCB levels showed a significant decrease (P < 0.001) when compared to the former results and correlated with age (P < 0.001) suggesting a progressive preponderance of a stable blood-adipose equilibrium with fewer variations due to recent and variable intake of the chemical. 3. Cerumen analyses revealed detectable concentrations of HCB in all samples (Range: 160-4790 ng g-1 in extractable lipid basis) and confirmed the suitability of this matrix to assess the body burden of residues accumulated in adipose and lipid-rich tissues. The set of results shows that, although HCB exposure has been reduced, the overall population under study still accumulates significant amounts of this possible carcinogen.

Cerumen↗

Evaluation of serum zinc-binding capacity during childbirth, in newborn infants and during the menstrual cycle.

This is a study of the value of total serum zinc, serum zinc per g of protein, serum zinc-binding capacity and serum zinc-binding capacity per g of protein in 102 pregnant women during childbirth and in the cord blood of their newborn infants. A control group is established by analyzing these parameters in 10 healthy non-pregnant women on the first day of menstruation and on the day of ovulation during two consecutive menstrual cycles. The total serum zinc and serum zinc per g of protein values found were significantly higher in cord blood than in maternal blood, and the binding capacity of zinc and of zinc per g protein were significantly higher in maternal blood. There is a negative correlation between total zinc and binding capacity and total zinc and binding capacity per g protein both in maternal and in cord blood. In the control group, the values of total zinc and zinc per g protein vary from one menstrual cycle to the next and between the different phases of each cycle. Zinc-binding capacity per g protein during ovulation is significantly lower than during menstruation. These results allow us to conclude that the rise of zinc-binding capacity and zinc-binding capacity per g protein in maternal blood during childbirth, and during menstruation in the control group, can be due to the effect of progesterone. The fact that zinc-binding capacity and zinc-binding capacity per g of protein are higher in maternal blood than in cord blood would confirm the existence of mechanisms which tend to increase binding of zinc in the fetus.

Adult↗

Distribution and changes of glycoconjugates in rat colonic mucosa during development. A histochemical study using lectins.

A study was made of the modifications of glycoconjugates in rat colonic mucosa during development. Sections of the caecum, and proximal and distal portions of the colon from Sprague Dawley rats at different stages of development (embryos, fetuses, suckling, weaning and adult rats) were examined. The sections were incubated with a battery of eight fluoresceinated lectins: DBA, SBA, WGA, LFA, PNA, GS-I, UEA-I and Con A. Some sections were treated with neuraminidase, and others were submitted to sequential saponification-neuraminidase treatment prior to incubation with the lectin (WGA, PNA or LFA). The intensity of the fluorescence was evaluated and graded from absent (-) to very positive (4+). Gradual and progressive changes were seen in colonic glycoconjugates during development. These changes revealed a unique developmental pattern for each lectin, which was independent for each cellular compartment (goblet cells, luminal surface and supranuclear region). Local and regional differences, observed between the different colonic sections, were already present from early stages of development. Moreover, our study showed that for several glycoconjugates, the differentiation process in colonic mucosa began in the distal region and continued through to the proximal region, the former being the first to reach the adult pattern. In the caecum, some lectins maintained a fetal pattern throughout all the periods of development up to the adult stage.

Animals↗

Inhibition of intratesticular testosterone synthesis by inorganic lead.

The alterations in testicular testosterone synthesis produced by exposure to inorganic lead were investigated in BALB/c+ mice. Lead concentration in blood and testes and the levels of testosterone and delta 4-androgen biosynthesis pathway precursors (4-androstenedione, 17-hydroxyprogesterone, and progesterone) were measured in animals which were exposed to lead acetate in the drinking water (366 mg/l, 0.97 +/- 0.12 mg lead/animal/day) during 6 months. The results showed a significant reduction of the intratesticular testosterone levels after 30 days of exposure and of the androstenedione levels after 150 days. Intratesticular progesterone and hydroxyprogesterone levels showed no changes during the assay.

Androgens↗

Serum selenium concentration of a healthy northwest Spanish population.

Selenium (Se) is an essential element, cofactor for glutathione peroxidase (GSHPx) activity, whose deficiency may induce modifications in the cellular antioxidative status and induce the appearance of different diseases. Current views suggest that a serum Se concentration inferior to 45 micrograms/L may correlate with an increased risk of coronary hearth diseases, coronary atherosclerosis and cancer. Since the Se concentration in human blood varies between geographical areas, we initiated a study to evaluate the Se status in the general healthy population of Barcelona. Serum Se concentration was investigated in a random sample of 150 subjects (age range 18-70 yr) by graphite furnace atomic spectrometry (FLAAS). L'vov platform, Zeeman background correction, and other specifications of stabilized temperature platform furnace (STPF) concept were followed. The results show that in the general population of Barcelona, Se serum concentration ranges between 60 and 106 micrograms/L (X = 80.7 +/- 10 micrograms/L). These values can be considered within the safe limits, since no subject was found with a concentration lower than the threshold of 45 micrograms/L.

Adolescent↗

[Prevalence of obesity in the population assisted at primary health care services in Girona, 1995-1999].

OBJECTIVES: To estimate the prevalence of obesity and overweight in the population of Girona (Spain) between 1995 and 1999 and to divide the prevalences in geographical areas according to age and sex. METHODS: Height and weight were directly measures in 24,554 health care consumers older than 14 years (10,595 men and 13,959 women) treated in four primary health care areas: Girona 1, Girona 4, Salt and Camprodon and in one primary health care center in the province of Girona. Body mas index (BMI) was calcuted by dividing weight in kilograms bye height in meters squared. Obesity was defined as grades II and III of Garrow's index (BMI >= 30 kg/m2) and overweight as degree I (25 kg/m2 >= BMI < 30 kg/m2). Because the sample was not randomized, the prevalences were adequately weighted. The comparison between prevalences in two different primary health care areas for each sex (in the same Garrow's index and age group) was carried out using a parametric test of differences in proportions (Student's t-test). A hierarchical logistic regression was used to compare prevalences in the same grade Garrow's index, controlling for age and sex. RESULTS: The prevalence of obesity was estimated as 15.6% in men aged from 20-74 years (from 14.0% in Girona 1 to 22.4% in Camprodon) and 17.5% for women (15.6% in Girona 1, 22.7% in Camprodon). The weighted mean was 16.7%. The prevalence of overweight was 44% in men and 33% in women and the weighted mean was 37.8%. The prevalence of obesity was graduated with statistically significant differences between Girona 1, Salt, Girona 4, Camprodon and Sils. CONCLUSIONS: The estimates of the prevalences of obesity and overweight obtained in this study were closer to those of other studies in similar populations than previously believed. Indeed, the prevalences may be similar to those of the European Union and, in some age groups, to those of the United States.

Adolescent↗