[Enteroviruses receptors and cell entry]

Human enteroviruses, which belong to the family of Picornaviridae, are common infectious viral agents transmitted by fecal-oral or airway routes. These positive RNA viruses possess a high genetic diversity and variability. They can evolve through genetic mutations or recombination mechanisms that are associated to the emergence of new potential epidemic serotypes. Human enteroviruses use different cellular receptors: receptors and co-receptors that are directly related to the tropism and the epidemiologic characteristics of some enterovirus serotypes. The receptors onto the cell-surface settle within a capsid depression, called canyon, initiating the process of viral uncoating. For some enteroviruses, a co-receptor molecule allows the crossing of cell topological barriers that is required to initiate the target cell infection. After the attachment phase, enteroviruses use the endocellar signaling pathways to support and optimize their entry into target-cells via endocytic pathways. The clathrin coated pits and the caveolae are both major ways of enterovirus entry in the cell even if "new" endocytic pathways regulated by enzymes of theADP ribosylation factors family and of the Rho family small GTPases have been recently described. The viral genetic diversity allows the human enteroviruses to simultaneously or alternatively use several distinct endocytic pathways in accordance to the infected cell lines, and allows a rapid and efficient adaptation to cellular microenvironments and to multiple immune selection pressures developed during the pathophysiological course of human infection. In conclusion, entry mechanisms used by human enteroviruses to infect target cells are various but they are closely dependent on the cellular functions that will be driven towards viral benefits. In the present time, the attachment and entry phases of the human enteroviruses into the target cell represent major viral events that may be targeted for the development of further new antiviral strategies.

Detection of somatic phages, infectious enteroviruses and enterovirus genomes as indicators of human enteric viral pollution in surface water

In the present study, we aimed to determine whether the concentrations of somatic coliphages, infectious enteroviruses or the detection of enterovirus genomes were associated with the detection of human pathogenic viruses in surface water. Four French rivers were sampled monthly or semimonthly for the quantitative detection of somatic coliphages, infectious enteroviruses and the qualitative RT-PCR detection of enterovirus, hepatitis A virus, Norwalk I viruses, Norwalk II viruses, astrovirus and rotavirus genomes over 12 months. All the 68 water samples tested were positive for the quantitative detection of somatic coliphages (range of concentrations: 4 x 10(2) to 1.6 x10(5) FUl(-1)). Infectious enteroviruses were isolated by a cell culture system in only two (3%) of the 68 concentrated water samples tested, whereas enterovirus genomes were detectable in 60 (88%) of the same samples. A positive RT-PCR detection of the genome of hepatitis A virus, Norwalk-like virus genogroup II, astrovirus, rotavirus and Norwalk-like virus genogroup I was demonstrated, respectively, in 1.5% (1/68), 1.5% (1/68), 3% (2/68), 0% and 0% of the 68 concentrated water samples tested. All of these four water samples were positive for the detection of enterovirus genomes, whereas only one of them was positive for the isolation of enteroviruses on cell culture. Moreover, the genomic detection of human pathogenic viruses appeared not to be statistically associated with the concentration levels of somatic coliphages in the 68 concentrated water samples tested (Wilcoxon rank test; P=0.14). Taken together, our findings indicate that the quantitative detection of somatic coliphages and the isolation of enteroviruses on cell culture are not suitable parameters for the control of the viral contamination in surface water, whereas the detection of enterovirus genomes may be useful for predicting the presence of waterborne viruses.

In vitro and in vivo antifilarial activity of ethynesulfonamides, epoxyethanesulfonamides and carboxamide analogues

A series of 2-substituted trans-1,2-epoxyethanesulfonamides (1T), ethynesulfonamides (2), and their carboxamide analogues 3 (cis and trans) and 4 were evaluated for their antifilarial activity, first in vitro against the infective larvae of the filaria Molinema dessetae, then in vivo against the same filaria in Proechimys oris, its natural host. On the whole, compounds 2 displayed a high level of activity in vitro, while 4 showed a wider range and 3 were virtually inactive. The modest activity found within the series 1T was assumed to be due, in part, to the instability of the products under the conditions of the biological tests. Five new compounds within the series 1T, 2 and 4 showed a macrofilaricidal activity in vivo. There is no clear correlation between in vivo and in vitro data. It was observed, however, that within the series 2 and 4 all the compounds active in vivo were among the most potent compounds in vitro. Nevertheless, the in vitro model, although of limited value, could help in selecting compounds for further evaluation within a given series.

Tumor markers in serum, polyamines and modified nucleosides in urine, and cytogenetic aberrations in lymphocytes of workers exposed to polycyclic aromatic hydrocarbons

Some polycyclic aromatic hydrocarbons (PAHs) such as benzo(a)pyrene and benzo(a)anthracene are well-established genotoxic agents. Long-term exposure to PAHs may lead to proliferative cell disorders in humans, predominantly in the skin, lung, and bladder. The concentration of several tumor markers in serum, of polyamines and modified nucleosides in urine, and of cytogenetic endpoints in peripheral lymphocytes (sister-chromatid exchanges, high frequency cells [HFC], and micronuclei) were measured in 149 male workers exposed to PAHs in two coke oven and one graphite electrode plants, and in 137 controls. We have assessed whether these biomarkers were related to several parameters reflecting exposure to PAHs, i.e., the sum of the airborne concentration of 13 PAHs, 1-hydroxypyrene (1-OHP) concentration in postshift urine, benzo(a)pyrene-diolepoxide adducts to hemoglobin (BPDE-Hb adducts), and duration of exposure, taking also into account several possible confounding factors. HFC was the biomarker most consistently associated with the intensity of current exposure to PAHs. Smoking exerts an independent effect on the same parameter. On the basis of the logistic regression between the prevalence of abnormal HFC values and PAHs in air and 1-OHP in postshift urine found in nonsmokers, it is suggested that the latter should be kept below 6.4 micrograms/m3 and 2.7 micrograms/g creatinine, respectively. No relationship was found between the cytogenetic effects and BPDE-Hb adducts although both parameters are statistically correlated with the airborne PAH level. Some tumor markers in serum (carcinoembryonic antigen, tissue polypeptide antigen, sialic acid) and the urinary concentration of some polyamines were correlated with either PAHs in air or 1-OHP in urine. The associations, however, were very weak which suggests that these biomarkers have limited practical value for the health surveillance of groups of workers exposed to genotoxic PAHs.

The NHS R&D Information Systems Strategy (ISS)

Following a strategy study which reported in August 1992 the NHS R&D Information Systems Strategy (ISS), a strategic framework for information systems, has been developed to support research and development in the NHS. This paper summarizes its main features, illustrates the benefits which specific information systems will bring, and outlines how the products of the programme are disseminated and accessed.

Determinants of urinary thioethers, D-glucaric acid and mutagenicity after exposure to polycyclic aromatic hydrocarbons assessed by air monitoring and measurement of 1-hydroxypyrene in urine: a cross-sectional study in workers of coke and graphite-electrode-producing plants

A cross-sectional epidemiological study was performed on 286 workers from two coke oven and one graphite electrode plants. The aim was to evaluate the usefulness of monitoring 1-hydroxypyrene (1-HOP) in urine for assessing exposure to polycyclic aromatic hydrocarbons (PAHs), and that of the urinary excretion of thioethers and D-glucaric acid, and the mutagenic activity of urine as indicators or biological effects of PAHs. The results confirm that 1-HOP determination in urine probably reflects exposure to PAHs by all routes and is not significantly influenced by the smoking habit. In comparison with the total PAHs in the air and 1-hydroxypyrene in urine, taken as reference exposure parameters, the results indicate that urinary D-glucaric acid excretion is not positively influenced by PAHs exposure; thioethers determination in urine is of poor value, since the smoking habit is a strong confounding factor. The determination of urinary mutagenicity might contribute to the detection of groups of workers exposed to potentially genotoxic PAHs.

New antifilarial agents. 1. Epoxy sulfonamides and ethynesulfonamides

Two series of 2-substituted 1,2-epoxyethanesulfonamides 2 and ethynesulfonamides 5 were synthesized and evaluated for their antifilarial activity. The trans epoxides 2T were stereospecifically prepared by a Darzens reaction between aldehydes and halomethanesulfonamides. The cis isomers 2c were obtained from ethynesulfonamides 5 by semihydrogenation followed by KOCl epoxidation. 2-Substituted ethynesulfonamides 5 were synthesized from appropriate trans-ethenesulfonamides by a bromination/dehydrobromination sequence. These products, as well as several synthetic intermediates, were evaluated for antifilarial activity against Molinema dessetae either in vivo in its natural host, the rodent Proechimys oris, or in vitro by a new test using cultures of the infective larvae. Most of the epoxides 2T and acetylenic derivatives 5 bearing a 2-aryl substituent were active in vitro. Among these compounds, four epoxides 2T and one acetylenic derivative 5 showed marked macrofilaricidal activity in vivo without any microfilaricidal activity. The differences between the in vivo and in vitro results may be due, in part, to the low chemical stability of the epoxy sulfonamides 2T. Despite this limitation, the activities observed in this reliable animal model suggest further development and testing of both series 2T and 5 as macrofilaricides.

Altered pulmonary epithelial permeability in canine radiation lung injury

A radioaerosol scanning technique measuring regional clearance of sodium pertechnetate (99mTcO-4) and 99mTc-labeled diethylenetriaminepentaacetate (99mTc-DTPA) was used to assess changes in canine pulmonary epithelial permeability following lung irradiation. Doses of 2,000 cGy (11 dogs), 1,000 cGy (2 dogs), and 500 cGy (2 dogs) were given in one fraction to either the entire right hemithorax (500 cGy) or the right lower lung (1,000 and 2,000 cGy). Radioaerosol scans, chest roentgenograms, and computerized tomograms (CT) were obtained before and serially after irradiation. A dose of 2,000 cGy resulted in a decrease in regional pulmonary epithelial permeability to both 99mTcO4- and 99mTc-DTPA; both showed significant decreases from the 2nd wk postirradiation onward. In comparison, CT and chest roentgenogram did not become abnormal until 7.1 +/- 2.8 (SD) and 8.2 +/- 2.6 wk, respectively. Doses of 1,000 and 500 cGy produced reversible decreases in 99mTcO4- clearance. Lung morphology showed definite changes of radiation pneumonitis after 2,000 and 1,000 cGy but not after 500 cGy at approximately 9, 17, and 12 wk postirradiation, respectively. These results suggest that dose-dependent changes in pulmonary physiology may precede obvious structural alterations in radiation lung injury.

Diffuse alveolar septal amyloidosis presenting with recurrent hemoptysis and medial dissection of pulmonary arteries

An unusual case of recurrent hemoptysis in a 56-yr-old woman is presented. After all the usual investigations for hemoptysis, left lower lobectomy revealed medial dissection of small and medium-sized pulmonary arteries with evidence of amyloid deposition. The patient subsequently developed the clinical picture of diffuse alveolar septal amyloidosis in association with primary amyloidosis. Pulmonary artery dissection is briefly reviewed, and vascular amyloidosis is presented as the probable origin in this case.

Antiandrogenic activity of a series of des-A-steroid derivatives

In the search for new antiandrogens, a number of des-A-steroids were prepared by condensation of Grignard reagents with lactone 3. From the resulting key intermediates 5, various structural modifications were performed such as the introduction of an additional unsaturation to afford dienones 8 and aromatic derivatives 10 or the introduction of an alkyl substituent mostly in position 10 (11-13) but also in some cases in position 16 (22). In addition, 13-ethyl analogues were also prepared from lactone 4. The relative binding affinities (RBAs) for the androgen receptor of these compounds were determined under various conditions. Some compounds exhibit a capacity to interact with the receptor comparable to that of testosterone. One of the most potent compounds is 17beta-hydroxy-des-A-androsta-9,11-dien-5-one (8b), RBA value 73% of that of testosterone. More interestingly, several compounds were found to have an antiandrogenic profile in vitro and in vivo. One of the most effective compounds is 10-ethyl-17beta-hydroxy-des-A-estra-9-en-5-one (5c), which exhibits a strong local antiandrogenic activity in hamsters, without any significant systemic antiandrogenic effects. The corresponding 17beta-acetyl derivative (RU 38882) has been selected for extended pharmacological studies.