Effects of size on the dynamics of dislocations in ice single crystals.

Single crystals of ice subjected to primary creep in torsion exhibit a softening behavior: the plastic strain rate increases with time. In a cylindrical sample, the size of the radius affects this response. The smaller the radius of the sample becomes while keeping constant the average shear stress across a section, the softer the response. The size-dependent behavior is interpreted by using a field dislocation theory, in terms of the coupled dynamics of excess screw dislocations gliding in basal planes and statistical dislocations developed through cross slip occurring in prismatic planes. The differences in the results caused by sample height effects and variations in the initial dislocation microstructure are discussed.

Treatment of localized prostate cancer using a combination of high dose rate Iridium-192 brachytherapy and external beam irradiation: initial Australian experience.

Combination high dose rate brachytherapy (HDRB) and external beam radiation therapy is technically and clinically feasible as definitive treatment for localized prostate cancer. We report the first large Australian experience using this technique of radiation dose escalation in 82 patients with intermediate- and high-risk disease. With a median follow up of 3 years (156 weeks), complications were low and overall prostate-specific antigen progression-free survival was 91% using the American Society for Therapeutic Radiology and Oncology consensus definition. The delivery of hypofractionated radiation through the HDRB component shortens overall treatment time and is both biologically and logistically advantageous. As a radiation boost strategy, HDRB is easy to learn and could be introduced into most facilities with brachytherapy capability.

Long-term effects of the mammary carcinogen 7,12-dimethylbenz(a) anthracene on hypothalamic gonadotropin-releasing hormone and its pituitary receptor gene expression, during the promotion stage, in female Sprague-Dawley rats.

A single intragastric administration of 7,12-dimethylbenz(a)anthracene (DMBA) has been shown to induce mammary tumors in young cycling female Sprague-Dawley rats. The appearance of these tumors is preceded by a series of neuroendocrine disturbances, including attenuation of the preovulatory luteinizing hormone (LH) surge and amplification of the preovulatory 17beta-estradiol surge, and gonadotropin-releasing hormone (GnRH) released in vitro. In this study, we examined the hypothesis that DMBA administration decreases levels of GnRH mRNA in the preoptic area-anterior hypothalamus (POA-AH) and GnRH receptor (GnRH Rc) mRNA and protein in the anterior pituitary gland. Sprague-Dawley rats, 55-60 days of age with regular estrous cycles, received a single dose of 15 mg DMBA in 1 ml sesame oil delivered by intragastric intubation. A first series of experiments was performed for the measurement of hypothalamic GnRH mRNA and pituitary GnRH Rc mRNA levels. A second series of experiments was performed for the measurement of pituitary GnRH receptor. In both experiments, animals were sacrificed by decapitation at 11.00, 16.00, 18.00 and 20.00 h on each day of the 7th or 8th estrous cycle (28-32 days) after treatment. GnRH and GnRH receptor mRNAs were quantified using solution hybridization-RNase protection assay. The GnRH Rc was quantified using the 125I-D-Ala6-N-Met-Leu6-des-Gly10-ethylamide GnRH. DMBA-treatment produced no significant effect on the overall mean values of GnRH mRNA. GnRH mRNA levels in control rats rose significantly between 16.00 and 20.00 h on proestrus and between 18.00 and 20.00 h on diestrus I. DMBA-treated rats had a surge in GnRH mRNA levels at 18.00 h on proestrus, and showed additional surges at 18.00h on diestrus II and estrus. GnRH receptor mRNA content in the anterior pituitary gland surged at 16.00h on certain days of the cycle in both groups of rats. In control rats, only the surge on diestrus II proved significant, whereas DMBA-treated rats exhibited significant surges on diestrus I, diestrus II and proestrus. GnRH receptor mRNA values were significantly lower on both days of diestrus in DMBA-treated rats compared with controls. GnRH Rc peptide content, like GnRH receptor in RNA surged at 16.00h in both groups with the exception of a marked fall on proestrus day for DMBA treated rats. A reduction in the amplitude of the surge was also seen on the day of estrous and to a lesser extend on the day of diestrus DII in DMBA treated animal. Overall, there was a disruption of the GnRH Rc pattern which culminate on the day of proestrus in DMBA-treated animals. Interestingly, the daily rise between 11.00 and 16.00h which is the more pronounced on the day of proestrus in control animals, was completely blunted in DMBA-treated rats. Overall, the results are consistent with the hypothesis that the carcinogen attenuates, directly or indirectly, preovulatory biosynthesis of the GnRH receptor and LH release. Obviously, the changes in GnRH might occur simultaneously, independently from mammary tumorigenesis, but may play a role, in association with others DMBA-induced neuroendocrine disorders, in the promotion stage of mammary tumors in the Sprague-Dawley female rat.

Multicenter study of street foods in 13 towns on four continents by the food and environmental hygiene study group of the international network of pasteur and associated institutes.

An international multicenter study of ready-to-eat foods, sandwiches, and ice creams or sorbets sold in the streets and their vendors was carried out to assess the microbiological quality of these foods and to identify characteristics of the vendors possibly associated with pathogens. Thirteen towns in Africa, America, Asia, and Oceania were involved in the study. A single protocol was used in all 13 centers: representative sampling was by random selection of vendors and a sample of foods bought from each of these vendors at a time and date selected at random. Microbiological analyses were carried out using standardized Association Française de Normalisation methods, and the use of a standardized questionnaire to collect data concerning the characteristics of the vendors. Fifteen surveys were carried out, with 3,003 food samples from 1,268 vendors. The proportion of unsatisfactory food samples was between 12.7 and 82.9% for ice creams and sorbets and between 11.3 and 92% for sandwiches. For ice creams and sorbets, the sale of a large number of units (>80 per day) increased the risk of unsatisfactory food by a factor of 2.8 (95% confidence interval [CI]: 1.5 to 5.1), lack of training in food hygiene by 6.6 (95% CI: 1.1 to 50). and by a factor of 2.8 (95% CI: 1.4 to 5.4) for mobile vendors. These risk factors were not identified for sandwiches, this difference may be due to the presence of a cooking step in their preparation. These results show that the poor microbiological quality of these street foods constitutes a potential hazard to public health, that the extent of this hazard varies between the cities studied, and that vendors' health education in food safety is a crucial factor in the prevention of foodborne infections.

Reaction of the uranyl(VI) ion (UO(2)(2+)) with a triamidoamine ligand: preparation and structural characterization of a mixed-valent uranium(V/VI) oxo-imido dimer.

The synthesis and structural characterization of a mixed-valent uranium(V/VI) oxo-imido complex are reported. Reaction of the uranyl chloride complex [K(18-crown-6)](2)[UO(2)Cl(4)] (1) with the triamidoamine ligand Li(3)[N(CH(2)CH(2)NSiBu(t)Me(2))(3)] yields oxo-imido [K(18-crown-6)(Et(2)O)][UO(mu(2)-NuCH(2)CH(2)N(CH(2)CH(2)NSiBu(t)Me(2))(2))](2) (2) as the major isolated uranium product in moderate yield. The reaction that forms 2 involves activation of both the triamidoamine ligand and the uranyl dioxo unit of 1. An X-ray crystal structure determination of 2 reveals a dimeric complex in which the coordination geometry at each uranium center is that of a capped trigonal bipyramid. The multidentate triamidoamine ligand coordinates to uranium through the capping amine and two of the three pendant amido ligands, while the third pendant amido donor has been activated to generate a bridging imido ligand by loss of the silyl substituent. One of the uranyl oxo groups is retained as a terminal ligand to complete the coordination sphere for each uranium center. The oxo and imido nitrogen may be regarded as the axial ligands of the trigonal bipyramid, while the two amido ligands and the other imido donor occupy equatorial coordination sites. The central amine of the tripodal set serves as the capping ligand. Distortion of the axial O-U-N angle from 180 degrees emanates from the proximity of the capping amine and the bridging interaction to the other uranium center. The structure and bonding in 2 are assessed in the context of metal-ligand multiple bonding in high-valent actinide complexes. The possibility of valence averaging [5.5/5.5 vs 5.0/6.0] via delocalization or rapid intramolecular electron-transfer dynamics of the unpaired electron is also discussed in the context of crystallographic, spectroscopic (NMR, IR, Raman, and EPR), and electrochemical data. Crystal data for 2: triclinic space group P1 macro, a = 12.1144(6) A, b = 12.6084(6) A, c = 14.5072(7) A, alpha = 101.374(1) degrees, beta = 103.757(1) degrees, gamma = 109.340(1) degrees, z = 1, R1 = 0.0523, wR2 = 0.1359.

Effects of the inhibition of cyclo-oxygenase 1 or 2 or 5-lipoxygenase on the activation of the hypothalamic-pituitary-adrenal axis induced by interleukin-1beta in the male Rat.

The limited entry of interleukin-1beta (IL-1beta) into the central nervous system has led to the hypothesis that IL-1beta acts, through IL-1beta receptors located notably on endothelial cells, on the release of prostaglandins which in turn stimulate the hypothalamic-pituitary-adrenal (HPA) axis. We used cyclo-oxygenase-1 (COX-1) and cyclo-oxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) inhibitors, before the injection of IL-1beta, to explore the role of arachidonic acid metabolic pathways on HPA axis activation. Adult male rats were i.m injected 20 min before i.p injection of IL-1beta, with (i): a COX-1/COX-2 inhibitor (ketoprofen); (ii) a COX-2 selective inhibitor (NS 398); or (iii) a 5-LOX inhibitor (BW A4C). Following this, rats were killed 90 min after i.p. IL-1beta injection and analysis for plasma adrenocorticotropic hormone (ACTH) and corticosterone concentrations and determination of anterior pituitary pro-opio melanocortin (POMC) gene transcription was conducted. Administration of the COX-1/COX-2 inhibitor led to a complete blockage of ACTH and corticosterone secretion and POMC gene transcription. The COX-2 inhibitor led to a complete blockade of ACTH secretion and POMC gene transcription but had no effect on corticosterone secretion. The 5-LOX inhibitor had no significant effect on any parameter. These results demonstrate the crucial role of eicosanoid pathways in mediating the stimulation of the HPA axis induced by IL-1beta. Moreover, we found a clear dissociation of the effect of the blockage of COXs upon ACTH and corticosterone secretion, suggesting that IL-1beta may act at the brain as well as at the adrenal cortex to stimulate the secretion of corticosterone.

[Molecular genetics of pigmentary retinopathies: identification of mutations in CHM, RDS, RHO, RPE65, USH2A and XLRS1 genes]. / Génétique moléculaire des rétinopathies pigmentaires: identification de mutations des gènes CHM, RDS, RHO, RPE65, USH2A et XLRS1.

PURPOSE: To evaluate the occurrence and inheritance of various types of pigmentary retinopathy in patients followed at the outpatient clinic in the university hospital, Montpellier, France. To characterize genes and mutations causing these conditions. METHODS: Ophthalmic examination and various visual tests were performed. Mutations were sought from genomic DNA by PCR amplification of exons associated with single-strand conformation analysis and/or direct sequencing. RESULTS: Among 315 patients over an 8-year period, cases of retinitis pigmentosa (63.2%), Usher's syndrome (10.2%), Stargardt's disease (5.4%), choroideremia (3.2%), Leber's congenital amaurosis (3.2%), congenital stationary night blindness (2.9%), cone dystrophy (2.5%), dominant optic atrophy (1.9%), X-linked juvenile retinoschisis (1.6%), Best's disease (1.6%), and others (4.3%) were diagnosed. In retinitis pigmentosa, inheritance could be determined in 54.2% of the cases including dominant autosomic (26.6%), recessive autosomic (22.6%), and X-linked cases (5%) while it could not be confirmed in 45.7% of the cases (simplex cases in the majority). For the 6 examined genes, mutations were found in 22 out of 182 propositus (12.1%). Analysis of phenotype-genotype correlations indicates that in retinitis pigmentosa, RDS is more frequently associated with macular involvement and retinal flecks, RHO with regional disease, and RPE65 with the great severity of the disease with some cases of Leber's congenital amaurosis. CONCLUSIONS: Identification of genes may help in diagnosis and in genetic counseling, especially in simplex cases with retinitis pigmentosa. In this latter condition, molecular diagnosis will be necessary to rationalize future treatments.

A trigonal bipyramidal uranyl amido complex: synthesis and structural characterization of [Na(THF)2][UO2(N(SiMe3)2)3].

The synthesis and structural characterization of a rare example of a uranyl complex possessing three equatorial ligands, [M(THF)2][UO2(N(SiMe3)2)3] (3a, M = Na; 3b, M = K), are described. The sodium salt 3a is prepared by protonolysis of [Na(THF)2]2[UO2(N(SiMe3)2)4], whereas the potassium salt 3b is obtained via a metathesis reaction of uranyl chloride UO2Cl2(THF)2 (4) with 3 equiv of K[N(SiMe3)2]. A single-crystal X-ray diffraction study of 3a revealed a trigonal-bipyramidal geometry about uranium, formed by two axial oxo and three equatorial amido ligands, with average U=O and U-N bond distances of 1.796(5) and 2.310(4) A, respectively. One of the oxo ligands is also coordinated to the sodium counterion. 1H NMR spectroscopic studies indicate that THF adds reversibly as a ligand to 3 to expand the trigonal bipyramidal geometry. The degree to which the coordination sphere in 3 is electronically satisfied with only three amido donors is suggested by (1) the reversible THF coordination, (2) a modest elongation in the bond distances for a five-coordinate U(VI) complex, and (3) the basicity of the oxo ligands as evidenced in the contact to Na. The vibrational spectra of the series of uranyl amido complexes [UO2(N(SiMe3)2)n]2-n (n = 2-4) are compared, to evaluate the effects on the axial U=O bonding as a function of increased electron density donated from the equatorial region. Raman spectroscopic measurements of the nu 1 symmetric O=U=O stretch show progressive axial bond weakening as the number of amido donors is increased. Crystal data for [Na(THF)2][UO2(N(SiMe3)2)3]: orthorhombic space group Pna2(1), a = 22.945(1) A, b = 15.2830(7) A, c = 12.6787(6) A, z = 4, R1 = 0.0309, wR2 = 0.0524.

The prevalence of Mycobacterium tuberculosis drug resistance in New Caledonia, 1995-1996.

SETTING: Study of the susceptibility to anti-tuberculosis drugs of Mycobacterium tuberculosis strains isolated in New Caledonia, a French South Pacific Territory, where tuberculosis continues to be a public health problem. OBJECTIVE: To assess the stability of this susceptibility in order to justify both non-systematic susceptibility testing and the implementation of simplified chemotherapy regimens. METHODS: Over a period of nearly 2 years (1995-1996), every new case of tuberculosis confirmed by the laboratory was included in the study. A total of 105 strains were tested against five anti-tuberculosis drugs: isoniazid, rifampicin, ethambutol, pyrazinamide and streptomycin. RESULTS: No primary drug resistance was detected for the main drugs. One strain with acquired resistance to isoniazid and streptomycin was isolated from one of the 12 patients suffering a relapse of the disease. CONCLUSIONS: The results of this exhaustive study justify the non-systematic approach to susceptibility testing for new patients. However, for strains isolated from patients suffering from relapse or therapeutic failure, or who belong to a high risk population, drug susceptibility testing should be performed. This kind of management will aid in the detection of possible isoniazid and streptomycin resistance, thus avoiding the selection and possible emergence of strains resistant to rifampicin. The results of the study argue for the use of a fixed dose regimen using triple combination tablets of isoniazid, rifampicin and pyrazinamide (HRZ) for 2 months, followed by dual drug therapy (HR) for 4 months.

Adjuvant high-dose rate brachytherapy with or without external beam radiotherapy post-hysterectomy for endometrial cancer.

The purpose of this study was to evaluate patient selection, local control, survival and late toxicity of posthysterectomy adjuvant radiotherapy and compare adjuvant external beam therapy and high-dose rate (HDR) brachytherapy versus HDR brachytherapy alone. A retrospective analysis was performed on a series of 225 patients with endometrial cancer treated with external beam radiotherapy and HDR brachytherapy or HDR brachytherapy alone posthysterectomy from 1985 to June 1993. Of these 225 patients, 82 received external beam radiotherapy and brachytherapy and 143 received brachytherapy alone. The HDR fraction size was 8.5 Gy prescribed to the mucosal surface; two fractions were given after external beam and four fractions if brachytherapy alone was used. The median follow-up was 6.9 years. The patients who received combined external beam and brachytherapy had higher stage and grade tumors. The survival outcome was similar for either group when matched for stage. Overall relapse-free survival at five years was 96% and 81%, respectively for brachytherapy alone and combined adjuvant therapy. Pelvic recurrence was seen in 2.7% of patients. Toxicity was more common with external beam radiotherapy and brachytherapy compared to brachytherapy alone (45.1% vs 23.1%, P = 0.003). However, moderate or severe toxicity was rare but again was more common in the combined radiotherapy group (8.5% vs 2.1%, P = 0.04). There was a non-significant trend to increased toxicity after lymphadenectomy and external beam radiotherapy compared with patients who did not have a staging lymphadenectomy prior to external beam radiotherapy (62% vs 38%, P = 0.16). Adjuvant radiotherapy can be individualized and be based upon the information provided by the pathological specimens, which excluded external beam radiotherapy if a lymphadenectomy was performed and there was no evidence of extra-uterine disease. This study found more toxicity associated with adjuvant radiotherapy compared with other studies, but this may reflect different reporting criteria. There was more toxicity related to external beam radiotherapy and brachytherapy compared to brachytherapy alone. The two HDR brachytherapy protocols used in this series appear effective and safe.

High-dose-rate brachytherapy alone post-hysterectomy for endometrial cancer.

PURPOSE: To evaluate the outcome of post-hysterectomy adjuvant vaginal high-dose-rate (HDR) brachytherapy. METHODS AND MATERIALS: A retrospective analysis was performed on a series of 143 patients with endometrial cancer treated with HDR brachytherapy alone post-hysterectomy from 1985 to June 1993. Of these patients, 141 received 34 Gy in four fractions prescribed to the vaginal mucosa in a 2-week period. The median follow-up was 6.9 years. Patients were analyzed for treatment parameters, survival, local recurrence, distant relapse, and toxicity. RESULTS: Five-year relapse free survival and overall survival was 100% and 88% for Stage 1A, 98% and 94% for Stage IB, 100% and 86% for Stage IC, and 92% and 92% for Stage IIA. The overall vaginal recurrence rate was 1.4%. The overall late-toxicity rate was low, and no RTOG grade 3, 4, or 5 complications were recorded. CONCLUSION: These results are similar to reported international series that have used either low-dose-rate or HDR brachytherapy. The biological effective dose was low for both acute and late responding tissues compared with some of the HDR brachytherapy series, and supports using this lower dose and possibly decreasing late side-effects with no apparent increased risk of vaginal recurrence.

Ovarian steroid modulation of neurokinin contents in hypothalamus, pituitary, trigeminal nucleus, and cervical spinal cord of the ovariectomized female rat.

Ovariectomized rats were treated with estradiol benzoate (EB) and progesterone in conditions known to negatively and positively regulate gonadotropin secretion. Injection with EB decreased the plasma concentration of substance P at the time of the positive feed-back exerted by EB on gonadotropin secretion, while having no effect on the plasma concentration of neurokinin A. In the hypothalamus, EB injection enhanced the substance P and neurokinin A content, while progesterone reduced the substance P content. In the anterior pituitary, the substance P content was increased after progesterone, and this increase was blocked by EB. Conversely, in the posterior pituitary, the substance P content was reduced after progesterone, and this effect was enhanced by EB. In the trigeminal nucleus, the substance P content was increased after progesterone and EB, while only progesterone affected neurokinin A content. Finally, in the cervical spinal cord, the substance P and neurokinin A contents were reduced after EB. We conclude that neurokinin contents are controlled by ovarian steroids not only in the hypothalamo-pituitary complex but also in the trigeminal nucleus and the cervical spinal cord.

The in vitro effect of substance P on the GnRH-induced LH release depends on the steroidal environment and is reverted by a NK1 receptor antagonist (RP 67580) in the cycling female rat.

A previously study reported that administration of substance P on the morning of the proestrous day induces an inhibition of afternoon gonadotropin preovulatory surges in the female rat. It has also been shown, with a non-peptide specific antagonist of the neurokinin 1 (NK1) receptor (RP 67580), that this effect is mediated by NK1 receptors. The present study used perifused anterior pituitaries from proestrous morning female rats and showed that the SP modulation of the GnRH-induced LH release is markedly dependent on the steroidal environment. In the absence of steroids or in the presence of 17beta estradiol, or a combination of 17beta estradiol and progesterone, SP inhibited the GnRH-induced LH release. In contrast, SP stimulated the GnRH-induced LH secretion in the presence of progesterone alone. However, the inhibitory or stimulatory effect of SP was antagonized by the specific NK1 receptor antagonist RP 67580.

Variations in levels of substance P-encoding beta-, gamma-preprotachykinin and substance P receptor NK-1 transcripts in the rat hypothalamus throughout the estrous cycle: a correlation between amounts of beta-preprotachykinin and NK-1 mRNA.

Using a sensitive RNase protection assay, the simultaneous quantification of hypothalamic beta-, gamma-preprotachykinin (PPT) and SP receptor NK-1 transcripts was performed throughout the estrous cycle. The amounts of these 3 transcripts were up-regulated during diestrus II-proestrus night (2-, 1.5- and 1.3-fold, respectively). These levels returned to low values during the proestrous day in the case of gamma-PPT mRNA and during the estrus-diestrus I night in the cases of beta-PPT and NK-1 mRNAs. These results implicate a differential regulation in amounts of the two alternatively spliced PPT transcripts. The 160 hypothalami of this study had been previously assayed for amounts of substance P (SP) and neurokinin A (NKA) peptides [P. Duval, V. Lenoir, S. Moussaoui, C. Garret and B. Kerdelhué, Substance P and neurokinin A variations throughout the rat estrous cycle; comparison with ovariectomized and male rats: I. Plasma, hypothalamus, anterior and posterior pituitary, J. Neurosci. Res., 45 (1996) 598-609]. Variations in mRNA and peptide levels were compared by statistical analysis. Surprisingly, variations in SP level paralleled those in beta-PPT mRNA level and variations in NKA level paralleled those of gamma-PPT mRNA level, although beta- and gamma-PPT transcripts encode both SP and NKA. Furthermore, the level of NK-1 mRNA was positively correlated with the level of beta-PPT mRNA (r = 0.90, P < 10(-58)) and with the level of SP peptide (r = 0.30, P < 10(-3)) but not with the level of NKA peptide. This analysis suggests that SP receptor NK-1 mRNA could be physiologically regulated by SP peptide in the rat hypothalamus.

Stimulatory effect of a specific substance P antagonist (RPR 100893) of the human NK1 receptor on the estradiol-induced LH and FSH surges in the ovariectomized cynomolgus monkey.

Utilizing a human NK1 receptor antagonist (RPR 100893), the present in vivo study was designed to test the hypothesis that endogenous substance P (SP) modulates the action of 17beta-estradiol in inducing luteinizing hormone (LH) and follicle stimulating hormone (FSH) surges in ovariectomized cynomolgus monkey. Plasma concentrations of LH and FSH as well as NK1 receptor antagonist and SP were measured during the development of the negative and positive feedback phases which follow a single administration of estradiol benzoate (50 microg/kg) to long-term ovariectomized monkeys. Daily administration by gastric intubation of 1 mg/kg or 10 mg/kg of the NK1 receptor antagonist (RPR 100893) leads to detectable levels of the antagonist in the blood of treated animals for at least 6 hr after its administration. These levels are in agreement with the experimentally determined IC50 value of the antagonist. The most striking finding of this study is that LH and FSH releases are enhanced during the descending arm of the estradiol benzoate-induced LH and FSH surges, which suggests that endogenous SP normally has an inhibitory role during this time. The enhancement of LH release is approximately 50%, regardless of the amount of the NK1 antagonist used. However, the enhanced FSH release is more important. Furthermore, blockade of the NK1 receptor with the smaller dose of the antagonist leads to a small, but significant, increase in plasma levels of SP, indicating that blockade of SP receptors leads to an increased release of SP. Collectively, these results further substantiate the link which exists between the ovarian steroid 17beta-estradiol and SP systems. Also, for the first time, these results demonstrate an inhibitory involvement of the human NK1 receptor in the 17beta-estradiol-induced pseudo-ovulatory gonadotropin surges in the ovariectomized monkey.

Strategy for the detection of Helicobacter species by amplification of 16S rRNA genes and identification of H. felis in a human gastric biopsy.

The aim of the present work was to develop polymerase chain reactions (PCRs) based on the conserved nucleotide sequence of the 16S rRNA gene for detection of bacteria of the Helicobacter genus in human antral biopsy samples. The assay for Helicobacter spp was developed by amplifying a 399-bp 16S rRNA gene sequence specific to the genus Helicobacter. The identity of the amplicon was confirmed by hybridization with an internal probe and by restriction by endonuclease VspI showing two expected fragments of 295 and 104 base pairs. A total of 65 dyspeptic patients from France and New Caledonia were screened for Helicobacter spp infection through the use of the following diagnostic assays on biopsy specimens collected through endoscopy: direct detection of bacteria in histological sections by Giemsa and Warthin Starry staining, urease test and bacterial isolation, PCR for Helicobacter pylori ureC/glmM gene, and PCR targeted to 16S rRNA genes. The 16S rRNA gene PCR assay was able to detect down to 680 bacterial cells, as assessed by agarose gel electrophoresis, and down to 4 bacterial cells by hybridization of amplicon with the internal probe. The 16S rRNA PCR test was 100% specific and sensitive; results obtained with this test were in agreement with the visualization of bacteria by histology. Urease test and culture were 86.4% and 22.7% sensitive, and 96.5 and 100% specific, respectively. The H. pylori ureC/glmM gene-based PCR was 100% specific and only 95.4% sensitive, since one biopsy from a Melanesian patient contained a Helicobacter strain other than H. pylori. For this Melanesian patient, a branch-specific PCR targeting the epsilon branch of Proteobacteria was used to amplify a 967-bp amplicon. This amplicon was sequenced and matched with the H. felis sequence. This was confirmed using an H. felis-specific urease PCR test.