[Bacillus Calmette-Guerin maintenance treatment in non-invasive bladder tumors: 1 year follow-up results of multicenter URO-BCG-4 trial]. / Traitement d'entretien par BCG-thérapie des tumeurs de vessie n'infiltrant pas le muscle (TVNIM): résultats à un an de l'étude multicentrique URO-BCG-4.

INTRODUCTION: Intravesical instillations of BCG remains the gold standard for intermediate and high risk NMIBC management. Maintenance treatment is recommended, however, the frequency of side effects responsible for the discontinuation of maintenance therapy over four out of five patients before the third year suggest a reduction or even spacing instillations. The objective of the study URO-BCG-4 was the evaluation of a new maintenance schedule by intravesical instillations of BCG combined reduced dose (third dose) and a decrease number of instillations per cycle (two or three). MATERIAL AND METHODS: Multicenter study of the French Association Oncologic Committee (12 university hospital centers), randomized, prospective, comparing reference diagram of BCG maintenance therapy one third of usual dose (group I) to a regimen combining third dose and decrease the number of instillations per cycle (two instead of three) (group II). We present the preliminary results at 1year of this Program of Clinical Research (CHU Rouen Promoter 2003-081). RESULTS: The rate of recurrence was respectively 9 and 7% (P=0.678) in groups I and II. The rate of tumor progression are 3 and 2.8% in groups I and II (P=1). Tolerance of intravesical instillations of BCG scored according to the WHO classification (Geneva 1979) was similar in the two groups. CONCLUSION: The decrease in the BCG dose (third dose) and the changes in the number and rate of instillations did not alter free tumor recurrence survival. The toxicity of intravesical instillations of BCG was identical in both groups. The use of the WHO classification has shown its limitations in the study of side effects of BCG as too complex and often not exhaustive. The rate of increase muscle was comparable in the two groups; however, a larger clinical experience is required.

An insight into an intriguing oxidative biotransformation pathway of 5-O-caffeoylquinic acid by a gut bacterium.

Microbiota is known to play a pivotal role in generating bioavailable and bioactive low-molecular-weight metabolites from dietary polyphenols. 5-O-caffeoylquinic acid (5-CQA), one of the main polyphenols found in human diet, was submitted to a resting cell biotransformation study using three gut bacteria species Lactobacillus reuteri, Bacteroides fragilis and Bifidobacterium longum. These bacteria were selected according to their belonging to the main phyla found in human gut microbiota. Our study highlighted the ability of only one of the strains studied, L. reuteri, to bioconverse 5-CQA into various metabolites due to the expression of the cinnamoyl esterase enzyme as the first step. Interestingly, one known natural compound, esculetin, was described for the first time as a 5-CQA-derived metabolite after conversion by a gut bacterium, the other metabolites had already been reported. This evidence highlighted an interesting oxidative pathway occurring in vivo by intestinal microbiota leading to esculetin. This molecule was also identified after electrochemical and enzymatic oxidations of caffeic acid. The oxidation capacity of L. reuteri led to less diverse metabolites in comparison to those obtained either electrochemically and enzymatically where dimers and trimers were reported. Thus, esculetin may have interesting and benefical biological effects on gut microbiota, which should be further evaluated. Novel synbiotics could be formulated from the association of L. reuteri with 5-CQA.

Endocytosis of major histocompatibility complex class I molecules is induced by the HIV-1 Nef protein.

Like other pathogenic viruses, HIV-1 down-modulates surface expression of major histocompatibility complex class I (MHC-I) molecules in infected cells, thus impairing lysis by cytotoxic T lymphocytes. We have observed that this phenomenon depends on the expression of Nef. nef is an early gene of primate lentiviruses, which is necessary for maintaining high virus loads and inducing AIDS. Nef is not necessary for viral replication in vitro and stimulates the endocytosis of CD4. We show that the expression of MHC-I at the surface of lymphoid, monocytic and epithelial cells was reduced in the presence of Nef protein from various HIV-1 strains. Whereas MHC-I protein synthesis and transport through the endoplasmic reticulum and cis Golgi apparatus occurred normally in Nef(+) cells, surface MHC-I molecules were rapidly internalized, accumulated in endosomal vesicles and were degraded. The stimulation of MHC-I endocytosis by Nef represents a previously undocumented viral mechanism for evading the immune response.

MHC-I-restricted presentation of HIV-1 virion antigens without viral replication.

Dendritic cells and macrophages can process extracellular antigens for presentation by MHC-I molecules. This exogenous pathway may have a crucial role in the activation of CD8+ cytotoxic T lymphocytes during human viral infections. We show here that HIV-1 epitopes derived from incoming virions are presented through the exogenous MHC-I pathway in primary human dendritic cells, and to a lower extent in macrophages, leading to cytotoxic T-lymphocyte activation in the absence of viral protein synthesis. Exogenous antigen presentation required adequate virus-receptor interactions and fusion of viral and cellular membranes. These results provide new insights into how anti-HIV cytotoxic T lymphocytes can be activated and have implications for anti-HIV vaccine design.

Angiotensin II modulates steroidogenesis in granulosa and theca in the rabbit ovary: its possible involvement in atresia.

Accumulating evidence has shown the ovary of mammals to contain an intrinsic renin-angiotensin system that has been ascribed an autocrine-paracrine role. The present study in the female rabbit ovary investigated the putative in vitro action of angiotensin II (A II) on basal and gonadotropin-induced steroidogenesis. Ovarian follicles from immature female rabbits treated with pregnant mare's serum gonadotropin (PMSG) were dissected out and a complete separation of the theca interna from the granulosa layer was performed, to demonstrate that A II affects separately the two individual cellular components of the follicular wall. We could show that theca is a source of estradiol whose production under human chorionic gonadotropin (hCG) stimulation was reduced by A II. At the same time, A II increased the in vitro hCG-stimulated secretion of testosterone by theca. In granulosa, A II decreased hCG-stimulated aromatization of androstenedione to estradiol but did not alter the release of hCG-stimulated progesterone production. These results suggest that A II could induce locally an increase in follicular fluid androgen/estrogen ratio and possibly participate in causing atresia.

Evidence for peptidergic innervation of the endocrine optic gland in Sepia by neurons showing FMRFamide-like immunoreactivity.

The innervation of the endocrine optic gland of Sepia, which controls sexual maturation, was studied by immunocytochemistry. Anti-FMRFamide (Phe-Met-Arg-Phe-NH2) serum revealed immunoreactive neurons in the olfactory and basal-dorsal lobe of the supra-esophageal brain mass. The axons of these neurons form a network from which fibers run to the optic gland. The fibers form many varicosities on the glandular cells, indicating synaptic innervation. Apparently, the two brain lobes containing the immunopositive cells function as a unit where visual and olfactory cues are integrated to regulate the endocrine activity of the optic gland.

[Initial subretinal localization of acute myeloblastic leukemia (AML5) recurrence]. / Localisation sous-rétinienne inaugurale d'une rechute de leucémie aiguë myéloblastique (LAM5).

BACKGROUND: Reduced visual acuity in patients with acute leucemia can result from many causes including an ocular localization. CASE REPORT: A patient previously treated for acute myeloblastic leucemia-5 (AML5) developed bilateral vision impairment related to a subretinal localization of the leucemia. Meningeal and bone marrow relapse followed. The subretinal localization responded only to massive systemic steroid treatment. DISCUSSION: Although asymptomatic, ocular localizations are frequent in leucemia. Their prognostic impact depends on the ocular structure involved and on the chronology of onset--early or late in the leucemia course. The underlying pathophysiological mechanism of ocular involvement remains unexplained but hyperleucocytosis at presentation may be a risk factor and would justify at least systematic specialized examinations and discussion of prophylactic treatment.

[Clinical, biological and developmental aspects of alcoholic ketoacidosis]. / Aspects cliniques, biologiques et évolutifs de l'acidocétose alcoolique.

OBJECTIVES: To review cases of alcoholic ketoacidosis in order to better ascertain therapeutic management. METHODS: The medical files of 32 alcoholic patients with ketoacidosis hospitalized in the Saint-Pierre general hospital of the Reunion island from January 1, 1991 through 31 August 1994 were analyzed. RESULTS: There were 18 women and 14 men, mean age 47 years. The first clinical signs were predominated by digestive (n = 22) or neurological disorders (n = 10). Acidosis was severe (mean pH = 7.12) and always associated with a wide anion gap (mean anion gap = 35). There were 3 types of glycemic status: hypoglycemia 10 cases, normal or subnormal glycemia in 19 cases (mean glycemia = 9.3 mmol/l) and hyperglycemia above 20 mmol/l in 3 cases. Hypophosphatemia, elevated serum lactate levels and cytolytic hepatitis were the main abnormalities associated. CONCLUSION: Short-term outcome was favorable in all cases after rehydration. The use of insulin may be dangerous and needs to be avoided.

Children's and adults' assignment of blame for personal injury.

The present study examined the effect of outcome foreseeability on blame attributions. While most previous studies on assignment of blame for negative outcomes in interpersonal events have focused solely on blame attributed to the perpetrator of the misdeed, the present study examined assignment of blame to the victim as well. Preschoolers (n = 18) were exposed to stories in which an actor with positive or negative motives brought about a foreseeable or unforeseeable injury to another child. Responses to these stories were also obtained from an adult sample (n = 21) to provide a basis for comparison. The analyses of the results indicated, as expected, that children's blame attributions were influenced less by outcome foreseeability than were adults'. Furthermore, children were more likely to assign blame to single, personal sources for unforeseeable outcomes than were adults.

The waved with open eyelids (woe) locus is a hypomorphic mouse mutation in Adam17.

The waved with open eyes (woe) locus is a spontaneous recessive mouse mutation that exhibits wavy fur, eyelids open at birth, and enlarged heart and esophagus. In this study, we confirmed the previously identified woe phenotypes and additionally identified anterior eye segment defects, absence of the meibomian glands, and defects in the semilunar cardiac valves. Positional cloning identified a C794T substitution in the Adam17 gene that ablates a putative exonic splicing enhancer (ESE) sequence in exon 7 resulting in aberrant Adam17 splicing. The predominant woe transcript, Adam17(Delta)(exon7), lacks exon 7 resulting in an in-frame deletion of 90 bp and a putative Adam17(Delta252-281) protein lacking residues 252-281 from the metalloprotease domain. Western blot analysis in woe identified only the precursor form of Adam17(Delta252-281) protein. Absence of cleavage of the prodomain renders Adam17(Delta252-281) functionally inactive; however, constitutive and stimulated shedding of Adam17 substrates was detected in woe at significantly reduced levels. This residual Adam17 shedding activity in woe most likely originates from full-length Adam17(T265M) encoded by the Adam17(C794T) transcript identified expressed at severely reduced levels. These results show that even small amounts of functional Adam17 allow woe mice to survive into adulthood. In contrast to Adam17(-/-) mice that die at birth, the viability of woe mice provides an excellent opportunity for studying the role of Adam17 throughout postnatal development and homeostasis.

Distribution of mutation frequencies among Salmonella enterica isolates from animal and human sources and genetic characterization of a Salmonella Heidelberg hypermutator.

Hypermutation is an important mechanism used by different Salmonella enterica subspecies enterica to regulate genetic stability in adaptation to changing environments, including antimicrobial treatments and industrial processes. Strong hypermutator strains generally contain a mutation in genes of the methyl mismatch repair (MMR) system and have mutation frequencies up to 1000-fold higher than wild type strains. The objectives of this study were to determine the distribution of mutation frequencies from a collection of 209 Salmonella strains, to genetically characterize a strong mutator, and to study MMR mutated protein-DNA binding interactions. Only one strain of S. Heidelberg was determined to have a hypermutator phenotype by virtue of its high mutation rate. Sequencing of genes of the MMR system showed a 12bp deletion in the mutS gene was present. The MMR mutated protein-DNA binding interactions were studied by bioanalysis, using the available crystal structure of a similar MutS protein from Escherichia coli. This analysis showed the small deletion in the Salmonella MutS was localized within the core domain. A retardation assay with MutS from hypermutable and wild type strains showed this mutation has no effect on MutS DNA binding. A better understanding of the genetic mechanisms of hypermutation will help to anticipate the behavior of hypermutator strains in various conditions.

Seasonal variations in planktonic community structure and production in an Atlantic coastal pond: the importance of nanoflagellates.

The structure and summertime production of planktonic communities and the role of nondiatom planktonic cells were studied in coastal ponds, which are areas traditionally used for fattening and greening table-sized oysters. The abundance and biomass of nano-microplanktonic protists were determined at weekly intervals between February 1998 and February 1999 in a coastal pond without oysters in the French Atlantic coast near La Rochelle. The production of these microbiotas was determined in the summer period. The structure of plankton communities revealed the following observations: (1) microphytoplanktonic cells were mostly diatoms and dinoflagellates, (2) microzooplanktonic cells were mainly ciliates, and (3) nanoplanktonic cells were represented by pigmented (80-90% of the nanoplankton biomass) and colorless nanoflagellates. Diatoms were dominated by Naviculiineae. Dinoflagellates were dominated by Peridiniales. Oligotrichida were predominant in the ciliate community. Protist biomass levels were nine times higher from April to August (summer period 1033 microg C L(-1)) than from September to March (winter period 114 microg C L(-1)). Whatever the season, nanoflagellates were dominant in the water column (66 and 53% of the entire protist biomass in the summer and winter periods, respectively). Nanoflagellates represented the highest production of nano-microplanktonic communities (76% of carbon protist production) in the coastal pond in summer and showed the shortest generation time (7.1 h). Dinoflagellates came after nanoflagellates in production (19.5% of carbon protist production). Diatoms represented only a supplementary carbon resource available for higher trophic levels, whereas, until now, they were considered as the principal food of oysters in coastal ponds. Ciliates were a small source of carbon, but their growth rate was high. We suggest, first, that nanoflagellates represented the primary resource available in the pond and could constitute an important food resource for higher trophic levels, such as oysters, farmed in this type of pond. Overall, the system appeared to be more autotrophic than heterotrophic. Because inorganic nutrients are quickly exhausted in a semiclosed pond, pigmented flagellates dominated the carbon biomass, production and biomass of bacteria were high (thus, the microbial food web appeared to be active in this pond), and mixotrophy seemed to be an important trophic mode there.

Cognitive-motivational influences on the task-related help-seeking behavior of black children.

The present study examined the relation between children's mastery motivation, self-assessment of performance, and task-related help-seeking behavior during task performance. Average-achieving black American children, varying in mastery motivation as measured by subscales of the Harter's Intrinsic-Extrinsic Orientation in the Classroom Scale, performed a multitrial verbal task and were given the opportunity to seek help on each trial after making a tentative response and assessing their performance by rating their confidence in the correctness of the response. A response-contingent payoff system was implemented to encourage children to restrict their help seeking to those instances in which they perceived that they could not make a correct response without assistance. As predicted, children's self-assessments of performance, regardless of their accuracy, appeared to influence help seeking more than the actual performance outcomes. Neither children's self-assessments of performance nor their overall rate of help seeking varied with level of measured mastery motivation. However, the type of help sought varied as expected with mastery motivation. Children characterized by high intrinsic orientations toward independent mastery in academic achievement contexts sought indirect help (i.e., hints) more often than they sought direct help (i.e., answers), whereas children characterized by low intrinsic orientations toward independent mastery showed no preference. These differences in motivational orientation influenced requests for help only when children perceived their initial solutions to be incorrect. These findings are discussed in the context of the analyses of help seeking as an instrumental learning and achievement strategy. The implications of the findings for analyses of black children's achievement styles are highlighted.

[Renin-angiotensin system of the uterus and ovary in mammalian females]. / Système rénine/angiotensine de l'utérus et de l'ovaire chez les femelles de mammifères.

The circulating reninangiotensin system (RAS) participates in the regulation of blood pressure and electrolyte metabolism. Renin, a proteolytic enzyme, synthesized in the kidney from its biological precursor, prorenin, cleaves its substrate angiotensinogen in the blood to form the active octapeptide, angiotensin II (AII). All the RAS components are present in the reproductive system of mammals. During pregnancy, the level of prorenin increases in the plasma. The ovary is the source of this prorenin during early pregnancy and maternal decidua later on. During the menstrual cycle, the thecal of preovulatory follicles synthesize prorenin, renin and AII. Thecal renin synthesis is controlled by LH/hCG as demonstrated in vivo and in vitro in the rabbit. Ovarian renin seems to be identical to kidney renin. Prorenin appears to be the major secretory product rather than renin, which remains intracellular. AT2-type angiotensin II-receptors are expressed in the rat on follicular granulosa cells and could be down-regulated by FSH. The bovine thecal cells also express AT2-receptors, up-regulated by LH. These data are consistent with an autrocrine or paracrine role for ovarian RAS. It has been implicated in neovascularization of the follicle and regulation of steroidogenesis by increasing the androgen/estrogen ratio, an index of follicular atresia.

The downregulation of CD4 and MHC-I by primate lentiviruses: a paradigm for the modulation of cell surface receptors.

The human and simian immunodeficiency viruses (HIV and SIV) downregulate the cell surface expression of CD4, their primary receptor, and of class I histocompatibility complex (MHC-I), a critical mediator of immune recognition. While the first of these effects seems important to preserve viral infectivity, the second likely promotes immune evasion. Three HIV-1 proteins, Nef, Env and Vpu, contribute to downregulate CD4, Env forms a complex with CD4 in the endoplasmic reticulum, thereby retaining the receptor in this compartment. Nef and Vpu, on the other hand, act as connectors between CD4 and specific intracellular trafficking pathways, targeting the receptor for degradation in the lysosome and the proteasome, respectively. Some of the downstream partners of the viral proteins in these events have been identified, and include the adaptor complex of clathrin-coated pits, the beta subunit of COP-I coatomer, and the ubiquitin pathway-related h-beta TrCP protein. HIV-induced MHC-I downregulation, mostly the effect of Nef, also reflects a redistribution of this receptor, with its accumulation in the Golgi. The modalities of this process, however, are as yet imperfectly understood. New evidence indicates that the mechanisms employed by primate lentiviruses to downmodulate CD4 and MHC-I are also exploited by a number of cellular regulatory processes.

Human immunodeficiency virus type I Nef independently affects virion incorporation of major histocompatibility complex class I molecules and virus infectivity.

We have recently reported that HIV-1 Net down-regulates the cell surface expression of major histocompatibility complex class I (MHC-I) molecules. MHC-I molecules are one of the predominant cellular proteins associated with HIV-1 virions. Wild-type or nef-mutated HIV-1 virions were analyzed by immunoelectronic microscopy and Western blot for particle-associated MHC-I molecules. The number of MHC-I molecules was significantly higher in HIV-1 virions produced in the absence of Nef than in wild-type virions, indicating that Nef affects the incorporation of MHC-I molecules into virions. Wild-type HIV particles have been shown to be more infectious than Nef- viruses. This difference was maintained when Nef+ and Nef virions devoid of MHC-I molecules were produced in Daudi-CD4 cells. Therefore, the enhancement of virion infectivity and the down-regulation of MHC-I represent independent biological properties of Nef.