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Pierre Thomas

Publications and source records attributed to Pierre Thomas.

At least 19 recordsLinked to original sources
PubMed2007

Petrotoga halophila sp. nov., a thermophilic, moderately halophilic, fermentative bacterium isolated from an offshore oil well in Congo.

A novel thermophilic, moderately halophilic, rod-shaped bacterium, strain MET-B(T), with a sheath-like outer structure (toga) was isolated from an offshore oil-producing well in Congo, West Africa. Strain MET-B(T) was a Gram-negative bacterium with the ability to reduce elemental sulfur, but not sulfate, thiosulfate or sulfite into sulfide. The optimum growth conditions were 60 degrees C, pH 6.7-7.2 and 4-6 % NaCl. The DNA G+C content was 34.6 mol%. Strain MET-B(T) was phylogenetically related to members of the genus Petrotoga; Petrotoga miotherma, Petrotoga olearia and Petrotoga mexicana were the closest relatives, with type strains exhibiting more than 99 % identity in an analysis of small-subunit rRNA gene sequences. The values for DNA-DNA relatedness between the type strains of these three species and strain MET-B(T) were less than 42 %. As MET-B(T) was found to be genetically and physiologically different from other species of the genus Petrotoga, this strain is proposed as representing a novel species, for which the name Petrotoga halophila sp. nov. is proposed. The type strain is MET-B(T) (=DSM 16923(T)=CCUG 50214(T)).

Bacterial Typing Techniques↗
PubMed2006

Tindallia texcoconensis sp. nov., a new haloalkaliphilic bacterium isolated from lake Texcoco, Mexico.

A new alkaliphilic and moderately halophilic, strictly anaerobic, fermentative bacterium (strain IMP-300(T)) was isolated from a groundwater sample in the zone of the former soda lake Texcoco in Mexico. Strain IMP-300(T) was Gram-positive, non-sporulated, motile and rod-shaped. It grew within a pH range from 7.5 to 10.5, and an optimum at 9.5. The organism was obligately dependent on the presence of sodium salts. Growth showed an optimum at 35 degrees C with absence of growth above 45 degrees C. It fermented peptone and a few amino acids, preferentially arginine and ornithine, with production of acetate, propionate, and ammonium. Its fatty acid pattern was mainly composed of straight chain saturated, unsaturated, and cyclopropane fatty acids. The G + C content of genomic DNA was 40.0 mol%. Analysis of the 16S rRNA gene sequence indicated that the new isolate belongs to the genus Tindallia, in the low G + C Gram-positive phylum. Phylogenetically, strain IMP-300(T) has Tindallia californiensis, as closest relative with a 97.5% similarity level between their 16S rDNA gene sequences, but the DNA-DNA re-association value between the two DNAs was only 42.2%. On the basis of differences in genotypic, phenotypic, and phylogenetic characteristics, strain IMP-300(T) is proposed as a new species of the genus Tindallia, T. texcoconensis sp. nov. (type strain IMP-300(T ) = DSM 18041(T) = JCM 13990(T)).

Alkalies↗
PubMed2006

Predictive validation study of the Edinburgh Postnatal Depression Scale in the first week after delivery and risk analysis for postnatal depression.

BACKGROUND: Postnatal depression is a major public health problem. The aim of this study is to validate the use of the Edinburgh Postnatal Depression Scale (EPDS) in the early postpartum, and to identify the markers for risk of postnatal depression. METHODS: 815 women filled out an EPDS and general information questionnaire between the third and the fifth day postpartum. The women with an EPDS score of >8 and a randomized control group from those with scores of <8 were contacted 8 weeks postpartum. 363 women therefore had a structured diagnostic interview by telephone at 8 weeks postpartum (MINI-DSM-IV), without knowledge of their EPDS scores, to screen for a major or minor depressive episode. RESULTS: The sensitivity of EPDS was measured as 0.82 [0.78-0.86], with a positivity threshold of 9.5/30. For an estimated prevalence for all depressive episodes of 16.1%, the positive predictive value of EPDS was measured as 42.8% [39.1-46.5%]. Multivariate risk analysis using logistical regression identified the following as risk markers for postnatal depression: previous history of depression (postnatal or other), unemployment, premature delivery or stopping breast-feeding in the first month for non-medical reasons. CONCLUSION: The use of EPDS between the third and fifth day postpartum is valid. An EPDS score of >10 should be completed by a clinical assessment and suitable management. The risk markers identified here are clinical indices that can be used for first-line early screening by non-psychiatric health workers.

Adolescent↗
PubMed2006

Absence and myoclonic status epilepticus precipitated by antiepileptic drugs in idiopathic generalized epilepsy.

Aggravation of idiopathic generalized epilepsy (IGE) syndromes by inappropriate antiepileptic drugs (AEDs) is increasingly recognized as a serious and common problem. Precipitation of status epilepticus (SE) by inappropriate medication has rarely been reported. We retrospectively studied all adult patients with IGE taking at least one potentially aggravating AED, who developed video-EEG documented SE over 8 years, and whose long-term outcome was favourable after adjustment of medication. We identified 14 patients (seven male patients) aged 15-46 years with a mean duration of epilepsy of 16.4 years. Video-EEG demonstrated typical absence SE (ASE) in five, atypical ASE in five, atypical myoclonic SE (MSE) in three and typical MSE in one. Epilepsy had been misclassified as cryptogenic partial in eight cases and cryptogenic generalized in four. The correct diagnosis proved to be juvenile absence epilepsy (JAE) in six patients, juvenile myoclonic epilepsy (JME) in four, epilepsy with grand mal on awakening (EGMA) in two and childhood absence epilepsy (CAE) in two. All patients had been treated with carbamazepine (CBZ) and had experienced seizure aggravation or new seizure types before referral. Seven patients had polytherapy with phenytoin (PHT), vigabatrin (VGB) or gabapentin (GBP). Potential precipitating factors included dose increase of CBZ or of CBZ and PHT; initiation of CBZ, VGB or GBP; and decrease of phenobarbital. Withdrawal of the aggravating agents and adjustment of medication resulted in full seizure control. This series shows that severe pharmacodynamic aggravation of seizures in IGE may result in ASE or MSE, often with atypical features.

Adolescent↗
PubMed2006

Relationship between posttrauma GABA plasma levels and PTSD at 1-year follow-up.

OBJECTIVE: Gamma-aminobutyric acid (GABA) exerts a prominent effect on central adrenergic stress responses in times of high stress and has been associated with acute posttraumatic stress disorder (PTSD). The authors examined the association between low posttrauma plasma GABA levels and long-term PTSD. METHOD: Plasma GABA levels were measured in 78 victims of road traffic accidents who met criteria for trauma exposure on arrival at a trauma department and were admitted for at least 3 days. Patients were assessed for PTSD and major depressive disorder at 6-week and 1-year follow-ups. RESULTS: At 6 weeks and at 1 year, mean posttrauma GABA levels were significantly lower among subjects who met all or nearly all criteria for PTSD than among those who did not. Among patients who met all or nearly all criteria for PTSD at 6 weeks, 75% of those with posttrauma GABA levels above 0.20 mmol/ml no longer met criteria at 1 year. By contrast, among patients whose GABA levels were below 0.20 mmol/ml, 80% met all or nearly all criteria for PTSD at 1 year. Two-thirds of patients who met all or nearly all criteria for PTSD at 1 year also met criteria for major depressive disorder. CONCLUSIONS: A plasma GABA level above 0.20 mmol/ml may protect against chronic PTSD and may represent a marker of recovery from trauma.

Accidents, Traffic↗
PubMed2005

Tonic status epilepticus in patients with idiopathic generalized epilepsy.

RATIONALE: Tonic status epilepticus (TSE) in patients with idiopathic generalized epilepsy (IGE) is not well recognized. The objective of this study is to report episodes of TSE in patients with IGE. METHODS: We retrospectively reviewed the clinical and EEG evaluation of three IGE patients who presented TSE. RESULTS: The three patients had mainly clinical features of IGE, but had developed, in addition, focal discharges, diffuse EEG abnormalities and some focal or diffuse neuropsychological dysfunction. The tonic attacks eventually responded to treatment, but were not completely controlled in any of the patients. DISCUSSION: The continuum between IGE and secondary generalized epilepsy is demonstrated in these patients. Most of their clinical and EEG features are however, in keeping with an idiopathic generalized epileptic process with additional focal and diffuse components. Recognition of the significance of TSE in such patients has important therapeutic and prognostic implications. [Published with video sequences].

Adult↗
PubMed2004

Long-term behavioural alterations in female rats after a single intense footshock followed by situational reminders.

Post-traumatic stress disorder (PTSD) affects a vulnerable sub-population of individuals exposed to a traumatic event. This psychopathology induces long-lasting hypothalamo-pituitary-adrenal (HPA) axis hypoactivity, hyperarousal and avoidance of trauma-like situation. PTSD also manifests a high co-morbidity with anxiety disorders. The aim of the present study was to characterise long-term biobehavioural alterations in female rats in an animal model of PTSD consisting in an intense footshock (2 mA, 10s) followed by three weekly situational reminders. This procedure induced several long-term alterations: increased anxiety behaviour, reduced time spent in an 'aversive-like' context, altered social behaviour and blunted corticosterone response to stress. These results demonstrate that exposure to an intense footshock associated with repeated situational reminders elicited long-term disturbances which lasted more than 1 month after the footshock administration. Our findings suggest that this paradigm could provide a useful animal model of PTSD.

Animals↗
PubMed2004

Low posttrauma GABA plasma levels as a predictive factor in the development of acute posttraumatic stress disorder.

BACKGROUND: Gamma amino-butyric acid (GABA) regulates the intensity and the duration of the central hyperadrenergic response in times of high stress and has been negatively associated with anxiety, depression, and sleep problems. We hypothesized that individuals with low plasma GABA levels may be more prone to develop posttraumatic stress disorder (PTSD) in the aftermath of trauma exposure. METHODS: To test this hypothesis, we measured plasma GABA levels in a population of 108 road traffic accident victims on arrival at a traumatology department and assessed them for PTSD 6 weeks later. RESULTS: The mean GABA level (nmol/mL) in the PTSD group (n = 55; M =.20; SD =.08) was significantly lower compared with members of the trauma-exposed group who did not develop PTSD [n = 17; M =.30; SD =.09), t(70) = 3.94, p =.0002]. CONCLUSIONS: Provided that GABA levels in the brain are genetically predetermined, our results would suggest that individuals with low plasma GABA levels are premorbidly more vulnerable to stress-related disorders such as acute PTSD. If replicated, plasma GABA levels measured in the aftermath of trauma exposure might help to identify individuals at high risk for developing PTSD.

Acute Disease↗
PubMed2004

Clostridium tunisiense sp. nov., a new proteolytic, sulfur-reducing bacterium isolated from an olive mill wastewater contaminated by phosphogypse.

A new sporulated fermentative bacterium designated strain E1(T) (T=type strain), was isolated from an anaerobic mud of an olive mill wastewater basin contaminated by phosphogypse produced by a Tunisian factory. Strain E1(T) was a motile Gram-positive slightly curved rod with spherical terminal spore swelling the cell. It grew between 18 degrees C and 43 degrees C with an optimum at 37 degrees C and pH 7.8 (range 5.5-8.7), without NaCl (range 0-3%). Strain E1(T) was a chemoorganotrophic anaerobic bacterium fermenting only proteins and amino acids. Yeast extract was required for growth. Elemental sulfur was used as terminal electron acceptor. The G+C content of the DNA was 32.6 mol%. The closest phylogenetical relatives of strain E1(T) were Clostridium thiosulfatireducens and C. subterminale (97.3% similarity for partial rRNA gene sequences). DNA-DNA hybridization values between strain E1(T) and both species were 17% and 20.8%, respectively. On the basis of differences in genotypic and phenotypic characteristics, strain E1(T) (DSM 15206(T), CIP 107666(T)) is proposed as the type strain of a new species, C. tunisiense sp. nov. GenBank accession number for the 16S rRNA gene sequence of strain E1(T) is AY187622.

Journal Article↗
PubMed2004

Petrotoga mexicana sp. nov., a novel thermophilic, anaerobic and xylanolytic bacterium isolated from an oil-producing well in the Gulf of Mexico.

A novel anaerobic, thermophilic, xylanolytic, motile rod-shaped bacterium with a sheath-like outer structure (toga) was isolated from a Mexican oil well in the Gulf of Mexico. Strain MET12T was a Gram-negative bacterium, reducing elemental sulfur, thiosulfate and sulfite to hydrogen sulfide. Its optimum growth conditions were 55 degrees C, pH 6.6, 3% NaCl and 0.15% MgCl2.6H2O. The DNA G+C content was 36.1 mol%. Phylogenetically, strain MET12T was related to members of genus Petrotoga, with similarities to Petrotoga mobilis, Petrotoga sibirica, Petrotoga miotherma and Petrotoga olearia varying from 97.6 to 98.8%. However DNA-DNA relatedness values between these species and strain MET12T were lower than 70%. As strain MET12T (=DSM 14811T=CIP 107371T) was genomically and phenotypically different from existing Petrotoga species, it is proposed as the type strain of a novel species, Petrotoga mexicana sp. nov.

Gram-Negative Anaerobic Straight, Curved, and Heli↗
PubMed2004

Petrobacter succinatimandens gen. nov., sp. nov., a moderately thermophilic, nitrate-reducing bacterium isolated from an Australian oil well.

A novel Gram-negative, aerobic and moderately thermophilic bacterium, strain 4BON(T), was isolated from a non-water-flooded Australian terrestrial oil reservoir. Cells were non-spore-forming straight rods, which were motile by means of a polar flagellum. The optimum growth conditions were 55 degrees C, pH 6.9 and 0.5 % NaCl. Strain 4BON(T) was oxidase- and catalase-positive; it grew on fumarate, pyruvate, succinate, formate, ethanol and yeast extract in the presence of oxygen or nitrate as terminal electron acceptor. Nitrate was reduced to nitrous oxide. The DNA G+C content of the strain was 58.6 mol%. The closest phylogenetic relative of strain 4BON(T) was Hydrogenophilus thermoluteolus (similarity of 91.8 %), of the beta-Proteobacteria. As strain 4BON(T) is physiologically and phylogenetically different from H. thermoluteolus, it is proposed that it be assigned to a novel species of a novel genus, Petrobacter succinatimandens gen. nov., sp. nov. The type strain is 4BON(T) (=DSM 15512(T)=CIP 107790(T)).

Australia↗
PubMed2004

Pseudoxanthomonas mexicana sp. nov. and Pseudoxanthomonas japonensis sp. nov., isolated from diverse environments, and emended descriptions of the genus Pseudoxanthomonas Finkmann et al. 2000 and of its type species.

Three mesophilic bacteria (strains AMX 26B(T), UR374_02 and 12-3(T)) isolated respectively from an anaerobic digester, human urine and urban riverside soil were characterized. Cells were Gram-negative, motile, non-sporulating, straight to curved rods with one polar flagellum and had a strictly respiratory metabolism with O(2) as the preferential terminal electron acceptor. Phylogenetic analysis based on 16S rRNA gene sequences revealed that all strains clustered within the Xanthomonadaceae branch of the Proteobacteria. Isolates AMX 26B(T) and UR374_02 exhibited 100 % 16S rRNA gene sequence similarity and both were related to strain 12-3(T) (99.6 % similarity). The closest relative of all the isolates was Pseudoxanthomonas broegbernensis DSM 12573(T) (similarity 97.1-97.5 %), and they were equidistantly related to Xanthomonas species (95.4-96.6 %), Stenotrophomonas species (95.3-96.1 %) and Pseudoxanthomonas taiwanensis ATCC BAA-4040(T) (95.3-95.4 %). Chemotaxonomic and biochemical data (branched-chain cellular fatty acid pattern without C(13 : 0) iso 3-OH, ubiquinone with eight isoprenoid units, limited range of substrates used, ability to reduce nitrite but not nitrate with the production of N(2)O) supported their affiliation to the genus Pseudoxanthomonas. The results of DNA-DNA hybridization and/or phenotypic analysis allowed them to be differentiated from the two Pseudoxanthomonas species with validly published names and showed that strain 12-3(T) was genomically and phenotypically distinct from the other two isolates. On the basis of these results, two novel species of the genus Pseudoxanthomonas are proposed: Pseudoxanthomonas mexicana sp. nov., consisting of strains AMX 26B(T) (=ATCC 700993(T)=CIP 106674(T)=JCM 11524(T)) (type strain) and UR374_02 (=DSM 15133), and Pseudoxanthomonas japonensis sp. nov., consisting of strain 12-3(T) (=CCUG 48231(T)=CIP 107388(T)=JCM 11525(T)). The report of these two novel species leads to the emendation of the description of the genus Pseudoxanthomonas and the re-evaluation of the phenotype of P. broegbernensis DSM 12573(T) necessitates the emendation of its description.

Aerobiosis↗
PubMed2004

Mahella australiensis gen. nov., sp. nov., a moderately thermophilic anaerobic bacterium isolated from an Australian oil well.

A novel Gram-positive, anaerobic and moderately thermophilic bacterium, strain 50-1 BON(T), was isolated from an Australian terrestrial oil reservoir. Cells were spore-forming straight rods, motile by peritrichous flagella. The optimum growth conditions were 50 degrees C, pH 7.5 and 0.1 % NaCl. Strain 50-1 BON(T) fermented arabinose, cellobiose, fructose, galactose, glucose, mannose, sucrose, xylose and yeast extract. Glucose was fermented mainly into lactate, formate, hydrogen and CO(2). The major end product of pyruvate fermentation was acetate together with H(2) and CO(2). Thiosulfate, sulfate, elemental sulfur and nitrate were not used as terminal electron acceptors. The DNA G+C content was 55.5 mol%. The closest phylogenetic relative of strain 50-1 BON(T) was Thermoanaerobacterium thermosulfurigenes (16S rRNA gene sequence similarity of 85.7 %). As strain 50-1 BON(T) was physiologically and phylogenetically different from members of the order 'Thermoanaerobacteriales', it is proposed that strain 50-1 BON(T) (=DSM 15567(T)=CIP 107919(T)) be classified as the type strain of a novel species of a new genus, Mahella australiensis gen. nov., sp. nov.

Anaerobiosis↗
PubMed2004

EEG diagnostic procedures and special investigations in the assessment of photosensitivity.

Photosensitivity can be assessed in laboratory conditions with different methods. The most common procedure is intermittent photic stimulation (IPS), whose effectiveness in detecting photosensitivity depends largely on methodologic aspects. Although IPS is a widespread and routinely used procedure in EEG laboratories, only recently has a standardization of the IPS method been proposed. Furthermore, other modalities of visual stimulation, including pattern stimulation and low-luminance visual stimulation (LLVS), have proven their usefulness in detecting photosensitivity. We provide an overview of the methodologic aspects and clinical implications of these procedures, resulting from recent consensus meetings, and the diagnostic usefulness of the LLVS technique in photosensitive individuals whose seizures are triggered particularly by television images. Finally, we briefly illustrate the potential of advanced neurophysiological (magnetoencephalography and high-density EEG) and functional imaging techniques in the investigation of the pathophysiologic mechanisms underlying photosensitivity.

Electroencephalography↗
PubMed2004

The choice of antiepileptic drugs in newly diagnosed epilepsy: a national French survey.

The choice of an antiepileptic drug (AED) in patients with epilepsy is mainly based on efficacy and safety of each drug. However, these criteria of drug selection should be further evaluated according to the epileptic syndromes, and adjusted to the sex and age of the patient. Unfortunately, very few studies have been conducted based on these latter criteria. We conducted a survey on the management of epilepsy treatment in adults. This survey was undertaken in France, and led to the establishment of a French consensus on antiepileptic drug treatment in adult patients with newly diagnosed epilepsy. Patients were grouped into 18 categories according to the epileptic syndrome (absence epilepsy, juvenile myoclonic epilepsy, undetermined idiopathic generalized epilepsy, symptomatic or cryptogenic partial epilepsy and unclassified epilepsy), and to the patient's gender and age. Our survey suggests that there is a consensus among French epileptologists for the choice of AEDs, mainly based on the epilepsy syndrome. Gender also plays a crucial role. Sodium valproate and lamotrigine are the two drugs of choice for generalized epilepsies, as well as for undetermined epilepsies. Lamotrigine is often prefered for women of childbearing age. First line AEDs in partial epilepsy are carbamazepine (particularly for men), lamotrigine (particularly for women), and gabapentin (in the elderly). In cases of failure and/or intolerance to one of these AED, the principal alternatives are oxcarbazepine, sodium valproate and topiramate.

Adolescent↗