Photocatalytic conversion of gaseous nitrogen trichloride into available chlorine--experimental and modeling study

In water, chlorine reacts with nitrogen-containing compounds to produce disinfection byproducts such as nitrogen trichloride which induces ocular and respiratory irritations in swimming pool workers. A technical solution has been used to reduce NCl3 exposure to acceptable levels, by adding a stripping step to the water recycling loop. The pollutants extracted are currently rejected into the atmosphere without treatment. However, the physical properties of NCl3 could be harnessed to induce its controlled degradation by direct or indirect light. This paper describes the way to transform NCl3 into oxidizing chlorine by photocatalysis under laboratory conditions. Photocatalytic oxidation efficiently degrades gaseous nitrogen trichloride, producing compounds such as HClO. About 60% of NCl3 decomposed was converted into HClO which could be used as a disinfection compound. A kinetic model is proposed for the photocatalytic process based on a convection/diffusion model. The Langmuir-Hinshelwood model was applied to the chemical part of the mechanism. The apparent quantum yield was also estimated to assess the optimal irradiance for NCl3 transformation. The results show that photocatalysis performs much better than photolysis alone for NCl3 removal, i.e. at least 25 times more efficient.

[Precariousness, DRG's and health planning: pilot study at the Lariboisière hospital in Paris]

OBJECTIVES

This paper considers the specific administrative procedures set up by managers of public healthcare establishments and those responsible for health and welfare policies to care for low-income pregnant women for whom 100% of the "price per act" (T2A) is refunded. What are the limitations and what improvements can be suggested?

PATIENTS AND METHOD

The results are based on an analysis of data from semi-structured interviews, legislation and documents.

RESULTS

The State, health insurance systems, public health establishments, local authorities, charities and outpatient services are involved in handling low-income parturients in different services and different establishments, both locally and regionally. A health and welfare policy comprising specific, coordinated actions and measures has been developed. The T2A "price per act" system may threaten its survival: the limited number of front-line facilities is often saturated and demand is increasing, treatment is often reduced to reactive management leading to unwanted readmissions, ethics are sometimes called into question and there is a risk of patient selection.

DISCUSSION AND CONCLUSION

This pilot study provided some encouraging information but also indicated the limitations of the approach adopted. However, it was still of interest to see whether it was possible to use this approach, which did not require considerable resources, to reveal useful markers. This appeared to be the case. Regional Health Agencies (ARS) and local authorities could support the system. Additional funding is needed.

Neurotensin induces mating in Saccharomyces cerevisiae cells that express human neurotensin receptor type 1 in place of the endogenous pheromone receptor

Heterologous expression of the human neurotensin receptor type I (hNT1-R) has been achieved in the yeast Saccharomyces cerevisiae. Immunoanalysis of membranes prepared from cells expressing a c-myc-tagged version of hNT1-R revealed multiple c-myc cross-reacting polypeptides of high molecular mass, suggesting that hNT1-R was glycosylated in yeast. High-affinity binding sites for 125I-labeled-[monoiodo-Tyr3]neurotensin ([125I-Tyr3]NT) were detected on hNT1-R-expressing cells with Kd and Bmax values of 3.2 nM and of 500 receptors per cell, respectively. Competition binding studies of neurotensin with SR142948 and SR48692, two nonpeptidic antagonists of hNT1-R, indicated that the yeast-produced recombinant receptor displayed the same pharmacological properties as hNT1-R expressed in mammalian cells. Interestingly, neurotensin activated the pheromone pathway in hNT1-R-expressing cells in a dose-dependent fashion, as revealed by a beta-galactosidase activity assay with a pheromone-responsive Fus1:lacZ construct. Mutational inactivation of the SST2 and STE2 genes increased the level of beta-galactosidase activity in response to neurotensin by twofold. Recombinant hNT1-R-producing cells, which lacked the endogenous G-protein-coupled receptor for the alpha pheromone, mated with wild-type MATalpha haploid cells in response to neurotensin, leading to bona fide diploid zygote formation. This is the first report of a mammalian receptor that can replace the endogenous pheromone receptor when produced in yeast, by signaling a fully effective, agonist-induced, mating process.

[Intensive chemotherapy and autograft of hematopoietic stem cells in the treatment of metastatic cancer: results of the national protocol Pegase 04]

We report hereby the results of the french multicentric randomized PEGASE 04 protocol established to evaluate the impact on survival of high-dose chemotherapy over conventional chemotherapy for MBC patients.

PATIENTS AND METHODS

Inclusion criteria were: age < or = 60 year, PS < 2, adenocarcinoma initially metastatic or in first relapse, chemosensitive disease. Randomization was done after 4-6 courses of conventionnal chemotherapy between high-dose (Mitoxantrone, 45 mg/m2, Cyclophosphamide: 120 mg/kg, Melphalan: 140 mg/m2), and the pursuit of the same conventionnal chemotherapy. Between 09/92 and 12/96, 61 chemosensitive patients were enrolled: 29 were referred to standard chemotherapy, 32 to intensive therapy. At randomization, 13 pts (21.3%) were in complete response and 48 in partial response.

RESULTS

The median progression-free survivals were 20 and 35.3 months in the standard and intensive groups (p=0.06). The relapse rates were respectively 79.3% vs 50.8% at 3 years and 90.8% vs 90.7% at 5 years. The median overall survivals were 20 and 43.4 months, with an overall survival rate of 18.5% vs 29.8% at 5 years (p=0.12).

CONCLUSION

The CMA regimen could prolong the progression-free survival of MBC patients, however without any significant impact on overall survival.

Neurotensin is an antagonist of the human neurotensin NT2 receptor expressed in Chinese hamster ovary cells

The human levocabastine-sensitive neurotensin NT2 receptor was cloned from a cortex cDNA library and stably expressed in Chinese hamster ovary (CHO) cells in order to study its binding and signalling characteristics. The receptor binds neurotensin as well as several other ligands already described for neurotensin NT1 receptor. It also binds levocabastine, a histamine H1 receptor antagonist that is not recognised by neurotensin NT1 receptor. Neurotensin binding to recombinant neurotensin NT2 receptor expressed in CHO cells does not elicit a biological response as determined by second messenger measurements. Levocabastine, and the peptides neuromedin N and xenin were also ineffective on neurotensin NT2 receptor activation. Experiments with the neurotensin NT1 receptor antagonists SR48692 and SR142948A, resulted in the unanticipated discovery that both molecules are potent agonists on neurotensin NT2 receptor. Both compounds, following binding to neurotensin NT2 receptor, enhance inositol phosphates (IP) formation with a subsequent [Ca2+]i mobilisation; induce arachidonic acid release; and stimulate mitogen-activated protein kinase (MAPK) activity. Interestingly, these activities are antagonised by neurotensin and levocabastine in a concentration-dependent manner. These activities suggest that the human neurotensin NT2 receptor may be of physiological importance and that a natural agonist for the receptor may exist.

Molecular cloning of a levocabastine-sensitive neurotensin binding site

A search for sequences homologous to the neurotensin receptor cDNA in a rat hypothalamic library has identified a novel neurotensin receptor (NTR-2). The 1539 bp cDNA encodes a 416 amino acid protein and shows highest homology to the previously cloned neurotensin receptor (NTR-1) (64% homology and 43% identity). Binding and pharmacological studies demonstrate that NTR-2 expressed in COS cells recognizes neurotensin (NT) with high affinity as well as several other agonists and antagonists. However, a fundamental difference was found; unlike NTR-1, NTR-2 recognizes, with high affinity, levocabastine, a histamine H1 receptor antagonist previously shown to compete with NT for low-affinity binding sites in brain.

Adiposity indices and clinical opinion

The comparison of various adiposity indices in children and adolescents shows that there is a great similarity between the indices, and also between their ability to distinguish extreme groups. The adiposity indices used are highly correlated with weight and subscapular skinfold thickness, and are not generally independent of height. Differences in these correlations appear during the period of puberty. Discrimination of obese and non-obese subjects by the indices and by clinical opinion agrees in 65%-75% of instances, with no one index agreeing better than the others.