[Safety and health in workers employed in industry. Data from Industrial Accidents Compensation Board (INAIL) and National Social Security Institute (INPS), Veneto Region, 1994-2002]. / Sicurezza e salute dei lavoratori dell'Industria attraverso i dati INAIL e INPS, Veneto, 1994-2002.

BACKGROUND: A decreasing time trend for occupational injuries and sickness absence would be the effect of the new legislation (D.Lgs. 626/94 and successive laws) on prevention in occupational settings. Conversely, the reduction of INPS disability would reflect a health improvement due to non-occupational causes. OBJECTIVES: The aim of the study was to investigate the efficacy of the new legislation among employees in industry (where the law was mainly applied), via the time trend of three standardized rates in the Veneto Region. METHODS: The numerator for the rate of occupational accidents (cases occurring in industry workers in the Veneto Region, broken down for sex, age and calendar years) was supplied by INAIL. The denominator for the above rate, as well as numerators and denominators for disability and sickness absence were supplied by INPS. Data were available from 1994 to 2002 for accidents and disability, and from 1997 to 2002 for sickness absence. In every year from 1994 to 2002, the rates were standardized for age and sex with the direct method, using an internal "standard" population. The time trend of year-specific standardized rates was analyzed by Joinpoint regression software. RESULTS: Among industrial workers in the Veneto Region, occupational accidents increased by 0.4% yearly, while disability decreased by 2.56% from 1994 to 2002. Sick absence increased up to 1999, then decreased. CONCLUSIONS: This epidemiological pattern is difficult to explain. The increase in accidents could be due to the increase of non-European Union workers and/or to the fact that accidents on the way to or from work were recognized as occupational accidents by INAIL starting from 2000. Both these phenomena could have contributed to increase the rate that was otherwise diminishing. On the other hand, this same situation could be due to insufficient efficacy of the legislation (D.Lgs. 626/94 and successive laws) for preventing occupational accidents and diseases.

Localization of tubulin mRNA during ascidian development.

In ascidians determination of the nervous system is known to occur at the gastrula stage, when the chorda-endoderm and ectoderm come in contact. In situ hybridization with beta-tubulin cDNA showed that tubulin transcripts were concentrated in presumptive neural cells at the early gastrula stage and continued to increase in these cells throughout neurulation. In the young larvae, the tubulin transcripts were also detectable in the adhesive papillae cells, in mesenchyme cells, muscle cells and button cells. The results suggest that expression of tubulin mRNA could be used as a marker for neural determination at early stages and, at later stages, as a marker for all cell types that elaborate many microtubules.

Behavior of endodermal "button cells" during metamorphosis of ascidian larvae.

Swimming larvae of Phallusia mamillata are known to have "button cells" of endodermal origin between the ventral surface of the pharynx and the epidermis, that are stainable by various techniques. By immunofluorescence with anti-tubulin antibody and confocal laser microscopy, we obtained a bright reaction at one pole of the cells, suggesting the presence of a cap of tubulin and of microtubules overlaying the nucleus. During metamorphosis the microtubule-rich pseudopods at their base reach the epidermis, especially in the area near the adhesive papillae. Then they emigrate through the epidermis and become roundish again.

The effect of l-thyroxine on the metamorphosis of Ascidia malaca.

Larvae of Ascidia malaca, both before and after hatching, were treated with L-thyroxine solutions. The effect of the thyroid hormone was to induce the onset of metamorphosis and then to cause the rate at which body reorganization occurred to increase. In treated larvae the resorption of the tail occurred only few hours after hatching, and a beating heart appeared form 10 to 15 h earlier than in the control larvae. These results are discussed in the context of a probable relationship between the occurrence of a hormonal metamorphic factor and the button cells of the trunk.

Electrical response to fertilization in ascidian oocytes.

The fertilization potential of the ascidian oocyte has been studied using two intracellular electrodes. Two classes of oocyte were observed; low resting potential (RP) oocytes of -20 to -35 mV and high RP oocytes of -80 to -90 mV. The two types have comparable membrane resistance, falling in the range of 100-300 M omega, and both may be fertilized and develop normally, although the fertilization potential (FP) is different in the two cases. High RP oocytes give rise to step-like regenerative potentials which attain positive values, whereas low RP oocytes give rise to slower depolarizations that reach zero level. In both cases the FP was sometimes preceded by a small-step depolarization as normally observed in the sea urchin. Irrespective of the original RP, the membrane resistance always decreased to 1-10% of its initial value during the first few minutes of the FP plateau. In contrast when the membrane was depolarized to a comparable potential by current injection the membrane resistance did not decrease. Polyspermic fertilization was induced by removing the extracellular coats, aging the oocytes and using high densities of sperm. The FP in monospermic and polyspermic oocytes were comparable and we could not correlate additional sperm interactions with additional electrical events. Our results suggest that the plasma membrane in ascidian oocytes lacks intrinsic mechanisms, electrical or otherwise, to prevent polyspermic fertilization.

Experimental activation of ascidian eggs.

The effects of the ionophore A23187 on the activation of the eggs of Ascidia malaca have been studied. No common external ion in the sea water is found to be essential for the activation but lanthanum and manganese inhibit the response. These observations support the interpretation that activation of these eggs results from changes in free intracellular calcium levels. This has led to the prediction of two other activating treatments, namely high external calcium and addition of theophylline.

"BEP" RNAs and proteins are situated in the animal side of sea urchin unfertilized egg, which can be recognized by female pronuclear localization.

Microsurgery experiments demonstrate that the animal side of the unfertilized sea urchin Paracentrotus lividus egg coincides with the side of the egg pronucleus location. It is demonstrated by means of in situ hybridization and immunostaining of whole mounts of animal or vegetal halves that the previously identified bep 1 and bep4 RNAs and their proteins are located in the animal part of the unfertilized egg and much less in the vegetal part. The addition of Fabs against BEP1 and BEP4 causes exogastrulation.

Decline in the exposure to hepatitis A and B infections in children in Naples, Italy.

In May 1988, the hepatitis A antibody (anti-HAV) and hepatitis B virus (HBV) markers were studied by radioimmunoassay in 484 apparently healthy children between the ages of 7 and 12, attending a primary school in Naples, Italy. The overall anti-HAV prevalence was 11.2%, increasing from 5.2 in 7-year-old children to 28.2% in children between the ages of 11 and 12 years old. The overall prevalence of the hepatitis B surface antigen (HBsAg) and of other HBV markers were 0.8 and 6.8 respectively. Compared with a similar previous study conducted in Naples in 1980, the results show a significant reduction in the prevalence of anti-HAV in each of the two age-groups (P less than 0.01), in the prevalence of any HBV marker in the 11 to 12-year-old group, as well as in the total population (P less than 0.05). The findings of the present study indicate that today, children in Naples are less exposed to the hepatitis A virus than in the past, most likely because of improvements in both the socioeconomic conditions and in health education during recent years. These same reasons, as well as decreased family size and a lower prevalence of HBeAg among HBsAg carriers could explain the decline, although to a lesser degree, of exposure to HBV infection.