Enhanced immunological and detoxification responses in Pacific oysters, Crassostrea gigas, exposed to chemically dispersed oil.

The aim of this study was to evaluate the effects of chemically dispersed oil on an economically and ecologically important species inhabiting coasts and estuaries, the Pacific oyster Crassostrea gigas. Studies were carried out with juveniles, known to generally be more sensitive to environmental stress than adults. A set of enzyme activities involved in immune defence mechanisms and detoxification processes, i.e. superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), catecholase-type phenoloxidase (PO), laccase-type PO and lysozyme were analysed in different oyster tissues, i.e. the gills, digestive gland and mantle, and in the plasma and the haemoycte lysate supernatant (HLS) of the haemolymph. Results indicated that total PAH body burdens were 2.7 times higher in the presence than in the absence of the chemical dispersant. After 2 days of exposure to chemically dispersed oil, alkylated naphthalenes accounted for 55% of the total PAH body burden, whereas alkylated fluorenes and alkylated dibenzothiophenes accounted for 80% when the chemical dispersant was absent. Importantly, a higher number of enzyme activities were modified when oil was chemically dispersed, especially in the plasma and gills. Moreover, independently of the presence or absence of chemical dispersant, oil exposure generally inhibited enzyme activities in the gills and plasma, while they were generally activated in the mantle and haemocytes. These results suggest that the gills and plasma constitute sensitive compartments in C. gigas, and that the mantle and haemocytes may play an important role in protection against xenobiotics. Among the six enzyme activities that were analysed in these body compartments, five were modulated in the chemical dispersion (CD) treatment while only half of the enzyme activities were modulated in the mechanical dispersion treatment. Furthermore, CD treatment effects were often observed following exposure, but also during depuration periods. These results suggest that immune and/or detoxification responses are likely to be affected when dispersants are used to treat oil spills in shallow waters.

Vitamin D receptor gene start codon polymorphism (FokI) and bone mineral density in healthy male subjects.

OBJECTIVE: The genetic factors determining peak bone mineral density (BMD) in men are not well characterized. Recent studies have investigated the relationship between the start codon polymorphism (SCP) of the vitamin D receptor (VDR) gene and BMD in different populations. We have now examined the relationship between SCP of the VDR gene and BMD in a group of healthy Caucasian men from the north-east of England. SUBJECTS: Ninety-six healthy men (median age 50, range 40.0-77.0 years). MEASUREMENTS: Analysis of the FokI genotypes of SCP of the VDR and measurements of BMD at the femoral neck and lumbar spine were performed. RESULTS: FF, Ff and ff VDR FokI genotypes were found to have the highest, intermediate and the lowest lumbar spine BMD, respectively (Mean +/- SD, for FF 1.07 +/- 0.14, Ff 1.05 +/- 0.16 and ff 0.95 +/- 0.10 g/cm2). There was a significant difference in spine BMD between FF and ff genotypes (P < 0.05, analysis of variance [ANOVA]), but no such difference was apparent between Ff and ff (P > 0.05, ANOVA). Interestingly, there was no association between FokI polymorphism and femoral neck BMD (Mean +/- SD, for FF 0.85 +/- 0.12, Ff 0.87 +/- 0.15 and ff 0.83 +/- 0.15 g/cm2). The distribution of FokI VDR genotypes approached Hardy-Weinberg equilibrium and was similar to that reported for women from different ethnic groups, as the prevalence of FF and ff genotypes was 44% and 16%, respectively. CONCLUSION: The study shows that in this population of healthy men there is a weak association between lumbar spine bone mineral density and FokI restriction fragment length polymorphism at the translation initiation site of the vitamin D receptor gene.

Vitamin D binding protein gene in male osteoporosis: association of plasma DBP and bone mineral density with (TAAA)(n)-Alu polymorphism in DBP.

Vitamin D binding protein (DBP) is a major carrier protein for the vitamin D metabolites, but may also play an important role in osteoclast differentiation. Polymorphisms of the DBP gene have been reported, including (TAAA)(n)-Alu repeat polymorphisms downstream of intron 8. We have examined the relationship between polymorphisms of the DBP gene and bone mineral density (BMD) and vertebral fractures in a group of 26 men with vertebral fractures but no underlying secondary cause of osteoporosis (median age 64, ages 27-72 years) and 21 male control subjects (median age 65, ages 40-77 years). There was no apparent effect of DBP phenotype on BMD, but there was a relationship between certain genotypes of (TAAA)(n)-Alu repeats and reduced BMD and vertebral fracture. Lumbar spine and femoral neck BMD were significantly lower in men with 10/8 genotype than 10/10 genotype (P < 0.05). Furthermore, the predominant genotype in men with vertebral fractures was 10/8, whereas the most common genotype in control subjects was 10/10 (odds ratio 56; 95% confidence interval 7-445). Plasma DBP was higher in men with 10/8 genotype than those with 10/10 genotype (P < 0.05), and patients with vertebral fractures were found to have higher levels than control subjects (P < 0.0005). Although our study is small because of the relative rarity of idiopathic osteoporosis in men, the results suggest that (TAAA)(n)-Alu polymorphism may have an important effect on plasma levels of DBP, bone density and fracture risk in men.

Protein kinase C dependent induction of pp125FAK in monocytes by colony stimulating factor-GM: evidence for a synergistic effect by the cytokine and 1,25 dihydroxyvitamin D3.

The differentiation of monocytes into osteoclasts has been recently achieved in vitro in a suitable milieu containing morphogens that includes 1,25 dihydroxyvitamin D3, colony stimulating factors, interleukins and the presence of cells of osteoblastic lineage. However, the precise role of these factors in the osteoclastic differentiation process has not yet been examined. Since our previous studies have shown that osteoclasts express a much higher level of focal adhesion kinase (pp125FAK) than cells of macrophage/monocytic lineage, the present study was carried out to ascertain which morphogens are involved in increasing the expression of the kinase during the differentiation of monocytes to osteoclasts. We demonstrate that a marked increase in the expression of pp125FAK occurs only after prolonged exposure to hCSF-GM and combination of hCSF-GM and 1,25 (OH)2 D3. The hCSF-GM was found to be a more potent stimulator of pp125FAK induction than 1,25 (OH)2 D3; interestingly, the presence of both hCSF-GM and 1,25 (OH)2 D3 showed co-operative effect. Furthermore, the presence of a protein kinase C inhibitor, bisindolylmaleimide (GF 109203X), blocked hCSF-GM-mediated induction of focal adhesion kinase, implicating an important role for protein kinase C in the induction of pp125FAK.

Plantar acral melanoma--an experience from a regional cancer centre, India.

This is a retrospective analysis of all plantar acral melanomas treated at the Cancer Institute (WIA) Madras between January 1981 and December 1990. Acral melanomas constitute 26% of all melanomas in this population, the sole of the foot being the dominant site (35 of 36 cases). We have found that it is more common in the lower socioeconomic strata, occurs often over weight bearing areas and is usually advanced at presentation. The projected five year survival was 51% while the five year disease free survival was only 22%. Pathological nodal status was found to be the only factor significantly influencing survival in this study. Wide local excision was found to give results equivalent to radical amputation and is strongly recommended since it gives a much better quality of life with a disease that has an overall dismal prognosis.