Atrial fibrillation and risk of dementia in non-demented elderly subjects with and without mild cognitive impairment (MCI).

MCI is regarded as a precursor of dementia, but not all patients with MCI actually develop dementia. As Alzheimer and vascular dementia (AD and VD, respectively) are thought to share many common etiopathogenetic mechanisms, we investigated whether the vascular risk factor atrial fibrillation affect the risk of conversion to dementia for different MCI subtypes diagnosed according to international criteria. One-hundred-eighty elderly outpatients with MCI and 431 elderly outpatients with a normal cognition were followed-up for a mean of 3 and 4 years, respectively. The risk of conversion to dementia associated with atrial fibrillation was studied in both samples using a Cox proportional-hazards model adjusted for sociodemographic and medical variables. Overall conversion rate to dementia was 10.5 (8.0-13.8) per 100 person-years in the MCI group and 2.2 (1.5-3.1) per 100 person-years in the normal cognition group. Atrial fibrillation was significantly associated with conversion to dementia (hazard ratio=HR=4.63, 95% confidence interval=Cl=1.72-12.46) in the MCI group, but not in the cognitively normal group (HR=1.10, 95% Cl=0.40-3.03). Current diagnostic criteria for MCI subtypes define heterogeneous populations, but atrial fibrillation can be useful in identifying people with increased risk of conversion to dementia.

Risk factors for dementia: data from the Conselice study of brain aging.

Among the age-related diseases, the development of cognitive impairments, in particular dementia, is the most devastating for the individual and has great social and healthcare costs. Accurate information is needed about the prevalence and incidence of cognitive disorders and the physiology of the aging brain. In particular, only scarce data are available about the relationship between aging, cognitive status and nutritional factors. In order to address these issues, we planned the Conselice Study, a longitudinal study of physiological and pathological brain aging. The center involved in the study was the municipality of Conselice, (Province of Ravenna), in the Northern-Italian Region Emilia-Romagna. A total of 1,016 subjects aged 65 years and over was enrolled at baseline. Information about cognitive status at 4-years of follow-up was collected from 940 of them. These data have been used to estimate prevalence and incidence of dementia in the elderly Italian population and to investigate the possible role of homocysteine as a predictor of dementia.

Characterisation of immunodominant protein encoded by the F1L gene of orf virus strains isolated in Italy.

We analysed the molecular properties of the immunodominant protein of different orf virus strains isolated in Italy. The F1L encoding genes and the deduced amino acid sequences of all strains were determined and compared, and they showed several mutations. Structural analysis was carried out in order to assess the influence of amino acid variations on protein structure demonstrating a conservation of the secondary structure. Western blot analysis and immunogold electron microscopy showed that all orf virus strains were antigenically identical. The results of our study confirmed the immunogenicity of the F1L protein; furthermore, our data suggest a possible involvement of the protein in the virus cycle.

Viral encephalopathy and retinopathy of farmed marine fish species in Italy.

Viral encephalopathy and retinopathy, otherwise known as fish encephalitis or viral nervous necrosis (VNN), is an emerging problem in several farmed marine fish species in various geographic areas all over the world. Since summer 1995, heavy losses affecting mainly juvenile and adult sea bass (Dicentrarchus labrax) have been observed in several on-growing facilities in Italy. Dying fish show abnormal swimming behaviour and, at temperatures higher than 20-22 degrees C, mortality rates range between 15 and 50%. Neither significant external nor internal gross pathological signs, except frequent abnormal swim bladder hyperinflation, were detected. Histological investigations reveal vacuolations in the grey matter of the brain and spinal cord and in the granular layers of the retina. Serial tissue sections examined by an immunohistochemical method carried out with antisera against fish nodaviruses showed a positive reaction. Additionally, spherical virus-like particles 22-25 nm in diameter were detected by electron microscopy in negative stained preparations of brain tissues, and the same samples gave a positive reverse transcription-polymerase chain reaction (RT-PCR) for the T4 region of the fish nodavirus gene. These results indicate that both juvenile and adult sea bass subject to mass mortality in Italy since summer 1995 are infected with a fish nodavirus and strongly suggest that the identified virus is the cause of the observed mortality.

Heterocyclic derivatives of all-trans retinoic acid: in vitro effects on fibroblast/keratinocyte growth and differentiation, and in vivo effects on guinea-pig skin.

We investigated the biological effects of five all-trans retinoic acid derivatives, bearing heterocyclic ring systems in the side chain. Growth assays performed on submerged human fibroblast and keratinocyte cultures revealed that (E)4-[2-(5-terbuthyl-thiophen-2-yl)propenyl]benzoic acid (compound 5) is the best compound among the studied derivatives for it exhibits a weaker antiproliferative activity and induces, like all-trans retinoic acid does, a significant increase in fibroblast and keratinocyte growth. The morphological and morphometrical analyses of submerged human fibroblast cultures and human epidermis reconstructed in vitro showed that the compound 5 behaves similarly to all-trans retinoic acid: it induces a decrease in all the cell parameters of submerged fibroblast cultures, and modulates the differentiation of keratinocytes in in vitro reconstructed epidermis. Compound 5 induces thickening of epidermis in vivo, one of the most remarkable pharmacological effects of retinoids on skin, but compared to all-trans retinoic acid, it induces a weaker irritation on guinea-pig skin in terms of both erythema and scaling. Compound 5 could then represent a promising candidate for the treatment of certain dermatological diseases.

[Treatment plants: viruses in aerosols]. / Depuratori: virus nell'aerosol.

A survey was carried out on the animal virus occurrence in wastewater and aerosols, in 2 treatment plants. Forty-five samples of sewage (10 litres) and 118 aerosol (2.3 m3) were examined. Forty out of forty-five (88.9%) of sewage and four out of one hundred and eighteen of aerosol (3.4%) samples were positive for viruses. Thirty-three reovirus and nine enterovirus strains were recovered from the sewage, two reovirus and two enterovirus strains from aerosol. Among enterovirus strains 6 resulted coxsackievirus B5, 3 coxsackievirus B4, 1 poliovirus, 1 strains remained unidentified.

Bovine corneal stroma and epithelium reconstructed in vitro: characterisation and response to surfactants.

In order to define safety profiles and proper handling procedures for new industrial products, it is essential to determine their potential for ocular irritation. The Draize test is normally employed but it involves using rabbits. There is today a great need for all researchers to limit the use of animals for laboratory experiments and to encourage the development and adoption of alternative in vitro methods to evaluate the potential toxicity of new products. This study proposes a three-dimensional model of bovine corneal stroma and epithelium that is not only easy to reproduce but may also be used in the toxicological field as an alternative to animal experimentation. The data presented here show that this model allows the growth of epithelium similar in features to in vivo epithelium. Basal cells are cube-shaped, whereas superficial areas are horizontally longer; desmosomes and 64 kDa keratin, as a marker for differentiation of corneal epithelial cells, are both expressed; the basal lamina is synthesised also. The 3-[4,5-dimethylthiazol-2-yl]2,5-diphenyltetrazolium bromide (MTT) assay was carried out on the model to evaluate the toxicity of some surfactants: benzalkonium chloride, Triton X-100, sodium dodecylsulphate and Tween 20. Since the in vitro data fit very well the results of the Draize test in vivo as reported in the literature, the three-dimensional culture may be used to predict the potential cytotoxicity of surfactants.

Characterization and applications of human epidermis reconstructed in vitro on de-epidermized derma.

In recent years in vitro models have been developed to avoid the use of animals in cutaneous toxicological studies. Submerged human keratinocyte cultures in vitro could be so far employed as an alternative to animal testing and a good correlation between skin irritation and cytotoxicity has been demonstrated. Nevertheless, these submerged cultures are lacking in the stratum corneum which acts as a barrier to chemical toxicity, so that this type of culture is far from the in vivo situation. A better alternative method seems to be the use of in vitro reconstructed skin at the air-liquid interface that closely resembles the in vivo situation. In this work, in a first step we have characterized human epidermis reconstructed in vitro on de-epidermized derma (DED) after a two-week air exposure. Human skin reconstituted in vitro on DED was histologically similar to the in vivo skin. A stratified epidermis including the stratum corneum was obtained. The presence of basal lamina as well as of various important markers for epidermal differentiation (involucrin, K10 keratin, and filaggrin) were revealed. In a second step we have tested the cytotoxic and morphological effects of four surfactants on our model. A good rank correlation has been shown to exist between the irritation potency of surfactants on our model and reported ocular irritancy in vivo. From our results, in vitro reconstituted human skin could represent an attractive model for irritancy testing and could be an in vitro replacement for animal testing.

Antiproliferative activity and phototoxicity of some methyl derivatives of 5-methoxypsoralen and 5-methoxyangelicin.

The in vitro antiproliferative activity and in vivo phototoxicity of some methyl derivatives of 5-methoxypsoralen and 5-methoxyangelicin, i.e. 4,4'-dimethyl-5-methoxyangelicin (compound I), 3,4'-dimethyl-5-methoxyangelicin (compound II), 4,4'-dimethyl-5-methoxypsoralen (compound III); and 3,4'-dimethyl-5-methoxypsoralen (compound IV), have been investigated. The effects of the compounds were evaluated in vitro on HL60 and A431 cells, using 5-methoxypsoralen as the reference compound. In both cell lines compound I, II and III showed better antiproliferative activity than compound IV and 5-methoxypsoralen. Scanning electron microscopy revealed that all the compounds induced the formation of blebs and blisters on a A431 cell surface. Significant variations in the nuclear area strictly related to the toxicity of the compounds have been shown in both cell lines. Skin irritancy in vivo was evaluated by mean of histopathological responses on guinea-pig skin. For each compound a damage index was determined by morphometrical analysis of empty spaces in the epidermis. Histopathology revealed skin phototoxicity of compounds which lacked erythemogenic activity by visual scoring. By coupling cytotoxicity data in vitro to skin sensitization ones in vivo, compound I proved a promising candidate for use in clinical trials since due to a high inhibitory effect on the growth of human cell lines coupled to low skin phototoxicity.

Effects of benzopsoralen derivatives on HL60 and HeLa cells.

The effect of 4-hydroxymethyl-6,7,8,9-tetrahydro-2H-benzofuro-[3,2-g]-1-benzo piran-2-one (compound 1) and 4-hydroxymethyl-2H-benzofuro-[3,2g]-1-benzopiran-2-one (compound 2), two new benzopsoralen derivatives, was tested on HL60 and HeLa cell lines in the dark and by UVA irradiation; 8-methoxypsoralen was used as a reference compound. The action of the compounds was evaluated by means of the neutral red uptake assay, by means of ultrastructure, morphometry and interaction with human erythrocytes membrane. In both HL60 and HeLa cell lines benzopsoralen derivatives showed more antiproliferative activity after UVA irradiation, however less than 8-methoxypsoralen. Compound 1 was more effective than compound 2 both in the dark and after UVA irradiation. The ultrastructure showed a morphological rank damage caused by these compounds: compound 2 induced slight modifications in the cytoplasm organization, compound 1 induced some vacuolizations and 8-methoxypsoralen generated plenty of vacuoles and an empty space around the nucleus. Morphometrical data in HL60 cells turned out to be in accordance with the different action mechanisms existing between 8-methoxypsoralen and the two benzopsoralen derivatives; in HeLa cells we noted an increase in the nuclear area induced by all the three compounds. Only compound 1 caused the formation of echinocytes both in the dark and after UVA irradiation, suggesting the involvement of a mechanism not strictly related to DNA interaction and singlet oxygen production.

Effect of moderate physical training on serum lipids and lipoproteins.

Total cholesterol, triglycerides and HDL-, HDL2-, HDL3-cholesterol were evaluated in 81 subjects, 49 of them practised moderate physical activity, 32 were controls. Total cholesterol and triglycerides were evaluated enzymatically. The Abell method was applied to analyse HDL-cholesterol and the HDL3 subclass. A significant difference was observed between the plasmatic triglycerides of the active group and the control, indicating that even moderate physical activity can be associated with lower concentrations of triglycerides. The correlation coefficients calculated for the HDL-cholesterol and the HDL2-cholesterol subclass, respectively, with some anthropometric and physiological variables were, in most of the cases, not significant. The highest number of significant correlations was found in the HDL3-cholesterol subclass, but in that of the control group only.