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Nickel (Ni) is the most common contact allergen among the general population in the industrialized world. Ni has been shown to exhibit immunomodulatory, if not immunotoxic, effects in several experiments conducted on humans and on rodents. This study tests the incidence of different infectious diseases in 100 patients with Ni hypersensitivity and compares it to data from 100 healthy volunteers. One hundred subjects with Ni hypersensitivity were enrolled. A group of 100 matched healthy volunteers with negative European standard patch test were enrolled as healthy controls. In patients with Ni hypersensitivity a higher incidence of recurrent herpes labialis (RHL), urinary tract infections (RUTI), genital candidiasis, and upper respiratory tract infections (RURTI) was detected. Fifteen patients with nickel allergic hypersensitivity (NAH) followed a Ni-poor diet. After a one-year diet a net reduction of incidence of RHL was found. Indeed, the number of episodes of RHL per year decreased from 6 +/- 2.75 to 2.4 +/- 1.2. Conversely, among the matched control group with NAH following a normal daily dietary nickel intake the RHL number did not show any statistically significant changes (6.1 +/- 1.7 vs 6 +/- 1.5 ). In conclusion, our study demonstrates a higher incidence of recurrent infections among patients with NAH. A low-Ni diet reduces the number of RHL episodes per year.

The growing interest in glycoconjugates expressed and released by the epithelium of the intestinal mucosa is tightly related to the multiple functional roles attributed to sialic acid and its derivatives. In the present work, biotin and HRP conjugated lectins were used to detect the sialylation pattern and to identify specific structural features of sialoderivatives in the rat colon. In particular, the occurrence and distribution of sialic acids linked a2,6 to D-Gal/D-GalNAc and a2,3 to D-Gal were directly demonstrated with SNA and MAL II binding, respectively. In addition, in order to by-pass the specificity problems of SNA and MAL II as histochemical reagents, as well as to look for additional and complementary information about acetylation degree and sites, we combined sialidase digestion, potassium hydroxide deacetylation, and differential periodate oxidation with PNA and DBA binding. The data showed the distribution and structure of sialic acidß- D-Gal(1-3)-D-GalNAc and sialic acid-D-GalNac sequences, which proved to be widely distributed as cellular components or secretory products in surface goblet cells and crypt cells of the colonic epithelium. A high degree of O-acetylation, with acetyl groups mainly at 9 and 4 positions, was found, showing an increasing gradient from the proximal to distal portion of the colon. These results, which largely reproduce the sialylation pattern in other species, contribute new insights in defining the tissue specific expression of sialoderivatives in the colonic mucosa, and testify to their high heterogeneity which the wide range of sialic acid functional correlates in the intestinal tract depend on.

The occurrence of phthalate esters in freshwater and marine aquacultural species like rainbow trout Oncorhynchus mykiss and shi drum Umbrina cirrosa, respectively, were determined by immunohistochemical approach. The results showed a similar distribution in the gastrointestinal tract of both species. In particular, intense immunoreactivity was found at gastric gland level. In the intestinal tract, goblet cells failed to stain, whereas enterocytes showed the highest binding of phthalates restricted to the apical cytoplasm. This distribution of phthalate esters at gastric gland and enterocyte level may have implications for the physiology of the digestive process and intestinal biotransformation. Phthalates are confirmed to be widely diffused contaminants, absorbed via the alimentary canal; thus a multidisciplinary approach could be useful to examine sea and freshwater environments

Lectin cytochemistry was performed in vitro on primary cultures from the rat submandibular gland. For this purpose, prepubertal rats (17, 27, 33 days old) of both sexes were used. Several types of medium supplements were tested and it was found that cells survived until 15 days in presence of all medium supplements and extracellular matrix gel. The binding patterns of all FITC/TRITC-labeled lectins, with and without prior sialidase digestion and deacetylation, were analyzed in a confocal laser scanning microscope. In particular, the occurrence of C4 acetylated sialic acid linked to ß-galactose at day 27 and the presence of fucose residues at day 33 indicated that lectin probes applied to cultured cells give results similar to those obtained in intact tissues and can be used as markers of growth and differentiation.

The regional distribution and relative occurrence of phthalates were studied immunohistochemically by confocal laser scanning microscopy in the alimentary tract of the green frog, Rana esculenta, using an antibody against o-phthalate esters. Many positive sites indicating the basal presence of phthalate esters were identified. The immunoreactive cells were located in the gastric glands of the stomach and in the intestinal epithelium regions with variable frequencies. The regional distribution of phathalate-accumulating cells resembled that of fish and demonstrated that these endocrine disruptors not only enter via the alimentary canal, but also bioaccumulate inside cells specialized in secretion as well as absorption functions.

We evaluated, by confocal laser scanning microscopy, the actin cytoskeleton of immortalized rat Py1a osteoblasts treated with phthalate esters (butyl benzyl phthalate, BBP and dibutyl phthalate, DBP), endocrine disruptors with estrogenic activity. We observed some peculiar modifications of actin cytoskeleton and cells changing from a spindle shape to a rounded form. In particular, F-actin formed thick bundles around the cell membrane but only a weak labeling was observed in rounded cells. Also influence on apoptosis and short-term effects on FGF-2 were studied. It was found that BBP and DBP exert their action in a similar way, act in a transient manner and do not induce apoptosis.

An ultrastructural analysis of lectin receptors on th e submandibular glands fro m mice of both sexes was performed utilizing horseradish pero xidase-labell ed lectins in conjunction with antiperox idase antibody and protein A-gold . Both qu alitati ve and quantit ati ve sexrelated differe nces in terminal suga r expression within secre tory gran ul es were detected. Following sia lidase digestion. also suhtenninal acceptor suga rs for terminal siali c ac ids, proved to be differentiall y ex pressed in the submandibular g land s of mal es and fema le s. Heteroge neo us distributi on of sialoglycoconjugates characteri zed bv the terminal disaccharide sialic acid-/3- galactose was f~ llIndt o occur in female ac inar ce lls. Also DBA reacti ve sites indicating the presence of terminal CI.-N-ace tylgalactosamin e discriminated betwee n male and female ac in ar sec re tor y glycoco nju ga tes. This difference was emphasized by sialidase pretreatment that ev idenced a marked occurrence of sialic acid subtended to u- N-ace tvlga lac tosamine in males in contrast to a modest pr es-e ~ce in fe males. The different sial ylation pa tt e rn s of acinar cell sec reto ry prod uc ts, pro bab ly related to a different exp ressio n of 0- and N-linked sia logl ycoconjugates, g iv e in sig ht into th e sex ual dimorphism of the mouse submandibular gland known until rece ntl y for the convoluted granular tubules.