An epidemiological study was conducted on 353 students to determine the potential relationships between oral saprophytism with Candida albicans and dental status. For each student included, an interview, a dental examination, a mycological investigation and determination of oral pH were conducted. Various factors liable to affect the presence of oral fungus were investigated using the chi(2) test. 58.6% of samples were positive when cultured, with C. albicans in 93.7% of cases. The mean DMF index was 7.6. C. albicans was more frequently isolated in men, smokers, when pH was lower than 7, when dental plaque was abundant and when the time since the teeth had last been brushed was more than 8 h. DMF and F indexes were greater when C. albicans was present but not when it was abundant, while decay was more often present in subjects with abundant C. albicans. Although the specific role of the various factors is difficult to establish, the results suggest that further research to elucidate the possible role of C. albicans in caries aetiology would be valuable.

A SW-NE-oriented structural crustal section of northern Calabria (Southern Italy) extending from back-are (SW 'internal') up to foreland (NE. 'external') areas illustrates the tectonic evolution of this key sector of the Central Mediterranean Calabrian Are.The outcropping terrains of this part of Calabria show a thrust sheet pile of basement units ('Calabrian basement Complex'), which are from top to bottom: a Hercynian assemblage of gneisses, granites, and metapelites ('Calabride' Units), with a partly detached Jurassic-Paleogene cover and former foredeep sequences, a series of Alpine metamorphic units comprising a Cretaceous to Paleogene metapelitic/ophiolitic/carbonate assemblage ('Liguride' Units). This highly tectonized and cataclastic assemblage overlies a Triassic carbonate series that outcrops in a number of tectonic windows along the internal, Tyrrhenian side of the Are. Our field studies revealed that these can be assigned to the 'San Donato-Campotenese Unit' that shows a comprehensive Triassic pelitic to carbonatic platform series, more extensively outcropping in the northern part of the area. Along the external part of the section, well data show that the basement assemblage tectonically overlies a deformed carbonate unit and its Paleogene-Lower Miocene cover. These data confirm the hypothesis that the Calabrian basement was first deformed during Late Eocene (eo-Alpine phase) times and later overthrusted Tethyan carbonate platform areas, already deformed in the Apennine Chain.Highly detailed tectonostratigraphic studies of the Calabrian intra-arc and fore-are basins, previously published and recently calibrated with a regional interpretation of the available two-dimensional and three-dimensional seismic and well database, showed that the subsequent Late Neogene evolution was characterized by the activity of a number of oblique crustal shear zones that controlled the evolution of a wide range of thrust belt basins. Basin inversion phases during middle Messinian, middle Pliocene and middle Pleistocene times resulted in the widespread occurrence of thin-skinned and thick-skinned oblique back thrusting and the generation of regional passive roof duplex structures, all of these common along the margins and within the Calabrian Element.Our integrated interpretation of field geology, subsurface data and magnetotelluric analysis resulted in a comprehensive crustal section showing the following main features: (1) The superficial Calabrian basement Complex (assembled up to Eocene times) is a relatively thin thrust sheet (ca 1.5-2 km in thickness) overlying all deeper units. (2) Below this, an Early Miocene thrust stack in the subsurface shows a number of opposite (internal. W and external, E) verging tectonic units. The carbonate platform units outcropping in this northern sector of the Calabrian Are form the top part of this subsurface thrust stack. (3) Below the subsurface thrust stack, a number of antiformal geometries are present, which, in our opinion, are the fundamental crustal terranes of which the Calabrian Are is composed, juxtaposed by oblique crustal shear zones in Miocene-Recent times. The main branches of these shear zones, which root into a number of deep thick-skinned overthrusts, dissect and deform the Early Miocene thrust sheet pile and are represented by main transpressive fault zones in the surface. Three main subsurface terranes can be recognized: one internal, overlain by an internally verging thrust stack, one central overlain by a number of externally verging thrust sheets, and one externally in continuity with the foreland area. (4) Externally, a regional thin-skinned thrust sheet ('Metaponte Nappe') composed of a tectonic assemblage of Eocene and Late Neogene terrains shows a retrovergent internal margin that partly masks the surface trace of one of the major shear zones, and an external flat lying overthrust upon the Gulf of Taranto-Salentino foreland platform unit.Finally, we present an evolutionary model describing the Eocene to Recent evolution of this sector of the Central Mediterranean Mountain Chain. (C) 2000 Elsevier Science B.V. All rights reserved.

Introduction. An epidemiological study was conducted in 82 institutionalized adults in Sao Tome e Principe to determine the dental status and the oral fungal flora.Materials and methods. For each adult included, a dental examination and a swab of inferior molar teeth with culture on chromagar(R) medium were conducted.Results. The average number per person of Decayed, Missing, Filling (mean DMF index) was 13 (extremes: from 0 to 32) and 37.8% of population were colonized with fungal species: 25.6% with yeasts only, 3.7% with filamenteous fungi and 8.5% with both of them. 13.4% were colonized with Candida albicans.Conclusion. Despite the lack of dental treatment, the dental health of this population is currently good with low caries but many avulsions. Oral fungal flora is poor and C. albicans is not the most important species as in industrialized countries. The data illustrate treatment needs in these people and that minimal improvements could considerably improve their dental health.

Introduction. La flore fongique buccale de 300 enfants Beninois a ete identifiee pour evaluer son role eventuel comme facteur de risque de la carie dentaire, au meme titre que Streptococcus mutans et Lactobacillus. Materiels et methodes. Apres ecouvillonnage des molaires inferieures et ensemencement sur milieu chromagar®, 11 % des enfants se sont averes porteurs de champignons (5 % hebergeaient Candida albicans et 6 % hebergeaient des especes filamenteuses diverses). Conclusion. La colonisation fongique buccale s'est averee peu importante, notamment pour C. albicans et l'origine de la biodiversite des champignons filamenteux reste a determiner. Aucune relation entre la presence buccale de C. albicans et l'existence de carie dentaire n'a pu etre mise en evidence.

Dental caries is becoming increasingly common in developing countries but very few attempts have been made to assess its prevalence accurately. We therefore carried out an epidemiological survey in 1998 in the south of Benin, to estimate the prevalence of dental caries in 300 school children, both boys and girls, aged 12 to 14 years. Each child underwent a dental examination and interview and the data obtained were recorded in a personal clinical record. We determined DMF index for various subgroups of children. We then analyzed DMF index and its correlation with sex, age, socioeconomic level, the urban or rural origin of the child, diet and daily dental hygiene practices. We found that mean DMF index at age 12 years was 0.83 (38.7% had dental caries and 4.4% had fillings), and thus, 61. 3% of the children were free of dental caries. We also found that 80% of the children had an accumulation of tartar. More boys than girls had dental caries. Rural children were less likely to have dental caries than urban children. The prevalence of caries appears to be low despite poor dental hygiene and a lack of dental treatment. These results conflict with those of most other studies. However, they should be interpreted with caution because the population studied was very homogeneous (selection bias), the age of the children could be no more than approximate (some were probably younger than 12 and others older than 14, because the registry system is inaccurate), there had been health education classes in some schools before the survey and it was difficult to define socioeconomic level and a sugary diet. For example, the lower socioeconomic level (no TV, radio, electricity or tap water) was probably an accurate representation of children from the rural area, whereas urban children were proud of being well-equipped and may have had a tendency to exaggerate. The prevalence of dental caries in this population is currently as low as that for most pre-industrial African countries. To avoid problems in the future, dental health services require reorganization and should stress measures for preventing dental caries: changes in dietary habits, the promotion of traditional tooth brushing practices, the systematic surveillance of dental caries at school and the removal of tartar.

Introduction. Oral fungal flora of three hundred Benin children were isolated to determine an eventuel role in dental carie,Materials and methods. After swabing of inferior molar teeth and culture on chromaga(R) medium, 11% of children were colonized with fungal species: 5% with Candida albicans and 6% with filamenteous fungus.Conclusion. Oral fungal flora appears relatively weak and further studies are needed to determine the biodiversity of filamenteous fungal Species. The role of C. albicans in dental caries is not determined in this Study.

The induction effects of pyrazole and dexamethasone (known to be specific to P450 2E1 and 3A enzymes, respectively), given alone or simultaneously, were studied in rat liver and kidney microsomes. Pyrazole treatment induced the catalytic activity and the amount of P450 2E1 enzyme in both organs. Immunoreactive P450 2E1 and 4-nitrophenol 2-hydroxylation increased 8- and 13-fold, respectively (versus control), in the kidney, but only 2.4- and 2.7-fold (versus control) in the liver after pyrazole treatment. As assessed by nifedipine oxidation activity, dexamethasone treatment increased the P450 3A catalytic activity approximately 4-fold (versus control) in the liver, but not in the kidney, suggesting that P450 3A was not inducible in the kidney. Pyrazole decreased P450 3A activity in the liver but did not modify it in the kidney. A combination of both chemicals induced both enzymes, but to a lesser extent than treatment with each single chemical compound. Furthermore, the 2-hydroxylation of p-nitrophenol, considered one of the most specific substrates for monitoring the level of P450 2E1, was mediated also by P450 3A, at least in dexamethasone-treated rats. Finally, this experimental work demonstrated that P450 3A induction is organ-specific, and it also demonstrated the lack of specificity of p-nitrophenol as a P450 2E1 substrate.

4-Nitrophenol 2-hydroxylation activity was previously shown to be mainly catalyzed by P450 2E1 in animal species and humans. As this chemical compound is widely used as an in vitro probe for P450 2E1, this study was carried out to test its catalytic specificity. First, experiments were carried out on liver microsomes and hepatocyte cultures of rat treated with different inducers. Liver microsomes from pyrazole- and dexamethasone-treated rats hydroxylated p-nitrophenol with a metabolic rate increased by 2.5- and 2.7-fold vs control. Dexamethasone treatment increased the hepatic content of P450 3A but not that of P450 2E1. Two specific inhibitors of P450 3A catalytic activities, namely, ketoconazole and troleandomycin (TAO), inhibited up to 50% of 4-nitrophenol hydroxylation in dexamethasone-treated rats but not in controls. Hepatocyte cultures from dexamethasone-treated rats transformed p-nitrophenol into 4-nitrocatechol 7.8 times more than controls. This catalytic activity was inhibited by TAO. Similarly, hepatocyte cultures from pyrazole-treated rats hydroxylated p-nitrophenol with a metabolic ratio increased by about 8-fold vs control. This reaction was inhibited by diethyl dithiocarbamate and dimethyl sulfoxide, both inhibitors of P450 2E1. Second, the capability of human P450s other than P450 2E1 to catalyze the formation of 4-nitrocatechol was examined in a panel of 13 human liver microsomes. Diethyl dithiocarbamate and ketoconazole reduced 4-nitrophenol hydroxylase activity by 77% (+/- 11) and 13% (+/- 16), respectively. Furthermore, the residual activity following diethyl dithiocarbamate inhibition was significantly correlated with seven P450 3A4 catalytic activities. Finally, the use of human cell lines genetically engineered for expression of human P450s demonstrated that P450 2E1 and 3A4 hydroxylated 4-nitrophenol with turnovers of 19.5 and 1.65 min-1, respectively. In conclusion, P450 3A may make a significant contribution to 4-nitrophenol hydroxylase activity in man and rat.

Pyrazole, acetone, and ethanol are known to induce cytochrome P450 2E1 (CYP2E1) and fatty acid (omega-1)-hydroxylation in rat liver microsomes. However, the nature of the P450 enzyme involved in this (omega-1)-hydroxylation has not been clearly established in extrahepatic tissues such as kidney. Four enzymatic activities (hydroxylations of chlorzoxazone, 4-nitrophenol, and two fatty acids) were assayed in kidney microsomal preparations of rats treated with CYP2E1 inducers. Per os treatment resulted in large increases (threefold to fivefold) in the chlorzoxazone and 4-nitrophenol hydroxylations, and up to a ninefold increase when ethanol was administered by inhalation. However, neither the omega-hydroxylation nor the (omega-1)-hydroxylation of fatty acids was modified. Immunoinhibition specific to CYP2E1 did not significantly decrease the omega and (omega-1)-lauric acid hydroxylations, while the polyclonal anti-CYP4A1 antibody inhibited in part both the omega- and (omega-1)-hydroxylations. Chemical inhibitions using either CYP2E1 competitive inhibitors (such as chlorzoxazone, DMSO, and ethanol) or P450 mechanism-based inhibitors (such as diethyldithiocarbamate and 17-octadecynoic acid) led to a partial inhibition of the hydroxylations. All these results suggest that fatty acid (omega-1)-hydroxylation, a highly specific probe for CYP2E1 in rat and human liver microsomes, is not mediated by CYP2E1 in rat kidney microsomes. In contrast to liver, where two different P450 enzymes are involved in fatty acid omega- and (omega-1)-hydroxylations, the same P450 enzyme, mainly a member of the CYP4A family, was involved in both hydroxylations in rat renal microsomes.

A thin-layer chromatographic assay was developed as an alternative method for the determination of cytochrome P450 2E1 (CYP2E1) in microsomes using [2-14C]chlorzoxazone. After incubation of microsomes with 0.125 microCi/mmol chlorzoxazone, chlorzoxazone and its single metabolite, 6-hydroxychlorzoxazone, were extracted using chloroform-2-propanol (85:15, v/v) and chromatographed on silica gel 60 F254 plates with acetone-hexane (45:55, v/v) as solvent . The plates were then exposed to X-ray film for 2 days to localize the radiolabelled chlorzoxazone and 6-hydroxychlorzoxazone. The metabolite and substrate regions were scraped and counted in a liquid scintillation analyzer. This method is sensitive enough to determine constitutive and induced CYP2E1 activities in liver or kidney microsomes. The precision of the method was similar to that of the HPLC method. The correlation coefficient between both methods was found to be 0.97 (n = 21). Therefore, the TLC method constitutes a valuable tool for the determination of chlorzoxazone metabolism in microsomes.

The Belvedere Spinello salt mine is located in the Catanzaro Province of Calabria in southern Italy. An extensive mining program has caused the development of underground cavities filled with brine and the migration of this brine has been of great environmental concern to the mine owners. This paper presents the results of a multidimensional interpretation of a two-phase resistivity and magnetotelluric (MT) survey that was performed in an attempt to determine the complex conductivity structure of the mine area and to gain information on brine development and migration pathways. Key resistivity soundings were interpreted using a 2.5D algorithm based on the Polozhii decomposition method. The MT data were interpreted using a 2D finite-element code. A conductivity model was developed, integrating available geological and drill-hole information. The interpretation of the MT data, collected five years after the acquisition of the resistivity data, shows a conductive feature of depth that is not resolved in the resistivity interpretation. This feature has been interpreted as a thick brine zone that has developed as a result of mining during the interval between the resistivity and the MT measurements.

In this study, microsomal cytochrome P-450 2E1 (CYP2E1) contents and activities were tested in liver, kidney and lung from Wistar rats after the following treatments (1) oral administration of a 10% ethanol solution for 4 weeks; (2) pair fed controls; (3) oral administration of a 5% acetone solution for 1 week; (4) inhalation of ethanol vapour for 4 weeks. CYP2E1 activity was measured using chlorzoxazone as substrate and CYP2E1 content was measured using Western blot analysis. In addition, the cellular distribution of CYP2E1 was studied in liver, lung and kidney by immunohistochemistry. Basal liver CYP2E1 was 10-20 times lower in lung and kidney than in liver. Inhalation was clearly the most efficient way of inducing CYP2E1, probably due to the continuous and high alcohol exposure. Among the organs tested, lung appeared to be the tissue least sensitive to induction even after ethanol inhalation, suggesting the absence of local induction. After ethanol intoxication, immunostaining was increased in the centrilobular region of the liver, in the alveolar cells of the lung and in the proximal convoluted tube of the kidney. The CYP2E1 activities decreased to control values in the three tissues tested, within 24 h after cessation of intoxication.

Geophysical methods provide the capability to map the lateral and vertical distribution of pollution in areas between boreholes drilled to determine the spread of contamination from a waste disposal site. In particular, when contamination causes an increase in dissolved salts in the groundwater, the consequent increase in its conductivity may be detected and monitored by electromagnetic (EM) methods.Transient electromagnetic (TEM) and Schlumberger DC sounding measurements have been made at a liquid waste disposal site and a landfill site. At both these sites, significant changes in conductivity near the sources of contamination have been detected by the TEM and DC methods, and the results generally correlate with the conductivity of groundwater sampled in the boreholes. The TEM and DC data are inverted assuming a layered earth model. Measurements at the landfill site are being made at approximately six-monthly intervals to test the application of the methods to the monitoring of the spread of the pollution plume. Data are also being collected over the same time intervals at another site prior to its being used as a landfill site. This will enable the discrimination of any seasonal change in the sub-surface conductivity from a change in conductivity caused by groundwater contamination once disposal of wastes begins.