Search PubMed⌕ Search

Biomedical subjects

P Thomas

Publications and source records attributed to P Thomas.

At least 73 records · Page 4Linked to original sources
PubMed2004

[Difficulties associated with Lambert-Eaton syndrome].

INTRODUCTION: The diagnosis and treatment of the neurological paraneoplastic syndromes associated with lung cancer can pose a challenge both to general physicians and neurologists as well as pulmonologists. CASE REPORT: A 53 year-old heavy smoker presented with a Lambert-Eaton myasthenic syndrome (LEMS). Bronchoscopy was normal but radiological examinations revealed a lymph node in site 4R. The pathological diagnosis after mediastinoscopy was negative. Twenty-five months later, an opacity on chest X-ray led to a biopsy which revealed a squamous cell carcinoma. A lobectomy was performed for a pT2N0M0 lesion. A significant improvement of neurological symptoms was seen. The myasthenic syndrome reappeared 21 months later. A local and general relapse was diagnosed. The patient died 10 months later despite chemotherapy. CONCLUSION: LEMS occurs because of an immunological reaction against voltage-dependent calcium channels. LEMS is generally associated with small cell lung cancer occurring in three percent of cases. However, the case that we report shows the unusual association of LEMS with non small-cell lung cancer and highlights the difficulties associated in the management of this condition.

Fatal Outcome↗
PubMed2004

Comparison of DNA damage and repair following radiation challenge in buccal cells and lymphocytes using single-cell gel electrophoresis.

PURPOSE: To develop a reproducible single-cell gel electrophoresis assay for DNA damage and repair in buccal mucosa and sublingual exfoliated cells. MATERIALS AND METHODS: Buccal mucosa and sublingual cells and lymphocytes from six individuals (three males, three females, aged 34-45 years) were challenged with increasing doses of gamma-rays. DNA strand breaks and DNA repair were measured using the single-cell gel electrophoresis assay. RESULTS: Baseline DNA strand breaks were significantly greater in buccal mucosa and sublingual cells compared with lymphocytes. Buccal mucosa and sublingual cells did not differ from each other with respect to induction of DNA strand breaks by 2 or 4 Gy gamma-rays. However, they showed a smaller increase in gamma-ray-induced DNA strand breaks compared with lymphocytes (32-53% less than lymphocytes; ANOVA p<0.0001). Unlike lymphocytes, which repaired 83% of DNA strand breaks, buccal mucosa and sublingual cells exhibited only a minimal capacity for DNA repair (approximately 0-14% of the level in lymphocytes). CONCLUSIONS: Buccal mucosa and sublingual cells exhibit an apparent resistance to the expression of radiation-induced DNA strand breaks in vitro and an apparent lack of DNA strand break repair in the single-cell gel electrophoresis assay.

Adult↗
PubMed2004

Isolation of Bacillus pumilus from in vitro grapes as a long-term alcohol-surviving and rhizogenesis inducing covert endophyte.

AIMS: To isolate and characterize the alcohol-surviving covert bacterium associated with grape tissue culture. METHODS AND RESULTS: Single colony was isolated by plating the spent rectified spirit used during grape culturing and the organism was identified as Bacillus pumilus using partial 16S rDNA sequence data. Spotting tests (1 microl) using 3-day-old broth culture having a spore content of 20-30% showed similar bacterial survival in 25-90% (v/v) aqueous ethanol for 14 days. Survival in 90% ethanol and 90% rectified spirit appeared affected thereafter with no colony growth from 1 microl samples after 4 months. Plating the samples at this stage gave similar CFU ml(-1) for 25, 50 and 70% ethanol, a significant reduction in 80% ethanol and very few colonies in 90% ethanol and rectified spirit. B. pumilus-inoculated grape microcuttings showed substantial endophytic colonization of original cuttings (7.4 x 10(6) CFU g(-1)) followed by the sprout (5.9 x 10(5)) and roots (2.0 x 10(4)). The bacterium although a poor root colonizer, induced early rooting and more roots in vitro. Inoculation at ex vitro planting resulted in significantly more roots, root weight and shoot growth. CONCLUSIONS: Bacillus pumilus could remain as a covert endophyte in grape tissue cultures and survive in aqueous ethanol for extended periods. 90% ethanol was the most effective bactericidal concentration. The bacterium showed endophytic colonization and root and shoot growth promotion. SIGNIFICANCE AND IMPACT OF THE STUDY: The revelation that general recommendation of 70-80% ethanol may not be the most effective bactericidal concentration for all bacteria, elucidation of the possibility of covert bacterial survival in vitro plant cultures and isolation of a potential plant growth promoting endophyte in grape.

Bacillus↗
PubMed2004

Snowdome, skiers and boarders: accident and emergency experience.

A prospective case series was compiled of all people presenting to the accident and emergency department with an injury caused by snowboarding or skiing, during the first year of opening of the Milton Keynes snowdome. The aim was to analyse the types of injuries associated with recreational snowboarding and to compare these with the injuries seen in skiing. Of the snowboarders, 23 (86%) were males, and the mean age was 24 years. Of the skiers, 13 (81%) were males, and the mean age was 34 years. Forty-three injuries required orthopaedic review, and 12 were admitted for further management. Significant differences were noted between the patterns of injuries in snowboarding and skiing. The snowboarders had a higher incidence of upper limb injuries (96 vs. 62%) and a lower incidence of lower limb injuries (4 vs. 38%) compared to the skiers. This study demonstrates that the opening of a leisure facility has a significant impact on the local accident and emergency department. Snowboarding is associated with a unique pattern of injuries, the knowledge of which should influence education and accident prevention.

Adolescent↗
PubMed2004

Glutamate and tachykinin receptors in central sensitization of withdrawal reflexes in the decerebrated rabbit.

This study assessed the involvement of NMDA and group I metabotropic glutamate receptors, and tachykinin NK1 and NK3 receptors, in central sensitization of withdrawal reflexes in the decerebrated rabbit. Reflexes evoked in the ankle flexor tibialis anterior and the knee flexor semitendinosus by electrical stimulation at the base of the toes were enhanced for 29-63 min after application of 20% mustard oil to the tips of the toes. Selective antagonists of mGlu1, mGlu5, NMDA and NR2B-subunit-containing NMDA glutamate receptors, as well as NK1, and NK3 receptors, and a non-selective blocker of all tachykinin receptors, were assessed for their effects on the magnitude and duration of the increase in reflexes induced by mustard oil. Dizocilpine, an antagonist of all NMDA receptors (1 mg intrathecal) abolished facilitation of tibialis anterior reflexes and significantly reduced the magnitude and duration of increase of the semitendinosus response. The NR2B-subtype selective antagonist CP-101,606 decreased the magnitude of facilitation of both reflexes but had no effect on duration of enhancement. Selective antagonists for the mGlu1 (CPCCOEt, 1-3 mg intrathecal), mGlu5 (MPEP, 0.2-1 mg intrathecal), NK1 (L-733,060, 0.3 mg intrathecal) or NK3 (SR 142,801, 1 mg kg(-1) i.v.) receptors had no effect on the amplitude or duration of sensitization. However, the non-selective tachykinin receptor blocker ZD-6021 (0.3 mg intrathecal) reduced the amplitude but not the duration of sensitization in the flexor reflexes. Combination of ZD-6021 with CP-101,606 (doses as above) decreased both aspects of the sensitization response. Dizocilpine reduced reflexes evoked from the heel per se, and dizocilpine, CP-101,606 and ZD-6021 reduced arterial blood pressure. Otherwise the drugs used had no effects on baseline variables. The present data confirm the importance of NMDA receptors as a critical part of the process of central sensitization, provide no evidence for a role of metabotropic glutamate receptors, and show that simultaneous blockade of all tachykinin receptors is required to reveal their role in hyperalgesia. The data further indicate that a combined pharmacological approach offers a potential way forward for the development of new antihyperalgesic agents.

Animals↗
PubMed2004

Serum procalcitonin and C-reactive protein as markers of sepsis and outcome in patients with neurotrauma and subarachnoid haemorrhage.

This prospective study evaluated serum procalcitonin (PCT) and C-reactive protein (CRP) as markers for systemic inflammatory response syndrome (SIRS)/sepsis and mortality in patients with traumatic brain injury and subarachnoid haemorrhage. Sixty-two patients were followed for 7 days. Serum PCT and CRP were measured on days 0, 1, 4, 5, 6 and 7. Seventy-seven per cent of patients with traumatic brain injury and 83% with subarachnoid haemorrhage developed SIRS or sepsis (P=0.75). Baseline PCT and CRP were elevated in 35% and 55% of patients respectively (P=0.03). There was a statistically non-significant step-wise increase in serum PCT levels from no SIRS (0.4+/-0.6 ng/ml) to SIRS (3.05+/-9.3 ng/ml) to sepsis (5.5+/-12.5 ng/ml). A similar trend was noted in baseline PCT in patients with mild (0.06+/-0.9 ng/ml), moderate (0.8+/-0.7 ng/ml) and severe head injury (1.2+/-1.9 ng/ml). Such a gradation was not observed with serum CRP There was a non-significant trend towards baseline PCT being a better marker of hospital mortality compared with baseline CRP (ROC-AUC 0.56 vs 0.31 respectively). This is the first prospective study to document the high incidence of SIRS in neurosurgical patients. In our study, serum PCT appeared to correlate with severity of traumatic brain injury and mortality. However, it could not reliably distinguish between SIRS and sepsis in this cohort. This is in part because baseline PCT elevation seemed to correlate with severity of injury. Only a small proportion of patients developed sepsis, thus necessitating a larger sample size to demonstrate the diagnostic usefulness of serum PCT as a marker of sepsis. Further clinical trials with larger sample sizes are required to confirm any potential role of PCT as a sepsis and outcome indicator in patients with head injuries or subarachnoid haemorrhage.

APACHE↗
PubMed2004

Marker-based cloning of the region containing the UhAvr1 avirulence gene from the basidiomycete barley pathogen Ustilago hordei.

Race-cultivar specialization during the interaction of the basidiomycete smut pathogen Ustilago hordei with its barley host was described in the 1940s. Subsequent genetic analyses revealed the presence of dominant avirulence genes in the pathogen that conform to the gene-for-gene theory. This pathosystem therefore presents an opportunity for the molecular genetic characterization of fungal genes controlling avirulence. We performed a cross between U. hordei strains to obtain 54 progeny segregating for three dominant avirulence genes on three differential barley cultivars. Bulked segregant analysis was used to identify RAPD and AFLP markers tightly linked to the avirulence gene UhAvr1. The UhAvr1 gene is located in an area containing repetitive DNA and this region is undetectable in cosmid libraries prepared from the avirulent parental strain. PCR and hybridization probes developed from the linked markers were therefore used to identify cosmid clones from the virulent (Uhavr1) parent. By walking on Uhavr1-linked cosmid clones, a nonrepetitive, nearby probe was found that recognized five overlapping BAC clones spanning 170 kb from the UhAvr1 parent. A contig of the clones in the UhAvr1 region was constructed and selected probes were used for RFLP analysis of the segregating population. This approach genetically defined an approximately 80-kb region that carries the UhAvr1 gene and provided cloned sequences for subsequent genetic analysis. UhAvr1 represents the first avirulence gene cloned from a basidiomycete plant pathogen.

Base Sequence↗
PubMed2004

[Treatment protocol for long-term anti-epilepsy drugs in adults with refractory partial epilepsy].

The primary goals of antiepileptic treatment are complete cessation of seizure without any adverse reaction. In adult refractory focal epilepsies, a rational approach is based on adequate syndromic categorization and accurate knowledge of the pharmacological properties of antiepileptic drugs, whose number has significantly increased in recent years. Since 1991 nine new antiepileptic medications have been marketed in France, i. e. by order of appearance, vigabatrin (Sabril), felbamate (Taloxa), gabapentin (Neurontin), lamotrigine (Lamictal), tiagabine (Gabitril), fosphenytoin (a water-soluble phenytoin prodrug, Prodilantin), topiramate (Epitomax), oxcarbazepine (Trileptal) and levetiracetam (Keppra). Efficacy of these new compounds in focal epilepsies is proven, and in some patients with middle-severity focal epilepsy, clinical benefit is significant. Improvement is especially significant in terms of tolerability, ease of use and reduced interaction potential. However, some of these drugs (tiagabine, topiramate) may have an unfavorable short-term tolerance profile, while others (felbamate, lamotrigine) expose patients to a potential risk of severe acute idiosyncratic reactions. Increased availability of new drugs and the fact that drug monitoring has been claimed to be of little or no value in newly-marketed drugs have paradoxically strongly complicated therapeutic options. Moreover, only a few patients with truly refractory focal epilepsy can be made seizure-free by these new compounds, and the search for more effective anticonvulsants should continue in addition with alternative therapies or surgery.

Adult↗
PubMed2004

[Cost-effectiveness of epilepsy surgery in a cohort of patients with medically intractable partial epilepsy--preliminary results].

OBJECTIVE: Patients with medically intractable epilepsy are potential candidates for surgery if the epileptogenic tissue is localized and resectable. Surgical therapy can eliminate seizures but is very expensive. We followed a prospective adult cohort of intractable epileptic patients in order to perform a cost-effectiveness analysis. POPULATION AND METHODS: Adult patients with a suspected partial medically intractable and operable epilepsy were eligible for evaluation, explorations and/or surgery. Clinical and economical data were collected at the inclusion and every 6 months over at least two years. Two patient groups were analyzed: some underwent a surgery, others did not. Clinical data were compared between both groups. As the data collection was not yet complete, we compared the surgery to a continuation of the preoperative medical management in a cost-effectiveness analysis. Direct medical and nonmedical costs were evaluated according to a societal perspective. The effectiveness was defined as one year without seizure. We assessed the incremental cost-effectiveness ratio (ICER) for the first two years after the surgery. We also modeled long-term costs and effectiveness and extrapolated the results over the patients' lifetime with a Markov model. We computed the ICER and performed a sensitivity analysis. Indirect costs were measured in physical units and intangible costs were assessed with quality-of-life measures (QOLIE-31, SEALS). Data were compared before and after surgery. RESULTS: Among the 286 patients included, 119 did not enter in the analysis: 7 were not eligible, 44 not operable, 31 did not present a follow-up, 37 still underwent exams. Finally, 89 underwent a surgical treatment, and 78 were medically treated. Disease was more severe in surgical patients than in medical patients: seizures frequency, depressive disorders and cognitive impairment were greater. One year after the surgery, 83% patients were seizure free. During the year before inclusion and the year after surgery, direct costs were mainly due to hospitalization. During the second year after surgery, the cost of antiepileptic drugs predominated. One additional year without seizure costs 23 531 euro one year after surgery and 9533 euro two years after surgery. In a long-term perspective, the surgery became cost-effective between 7 and 8 years after the surgery. CONCLUSION: Surgical therapy is a cost-effective treatment in a middle-term even without indirect costs consideration.

Adolescent↗
PubMed2004

Bone density, parathyroid hormone, calcium and vitamin D nutritional status of institutionalized elderly subjects.

INTRODUCTION: Osteoporosis is characterized by a decrease in bone mass and a change in bone microarchitecture. This causes skeletal fragility and may result in fractures. Fractures of the femur neck (FM) are frequent and have major consequences in terms of morbidity and mortality in elderly subjects. We carried out a cross-sectional study to evaluate bone and nutritional status in an elderly population from a same geriatrics department. AIMS OF THE STUDY: We aimed to screen for nutritional deficiencies and to measure bone mineral density (BMD) in the femur neck by dual-energy X-ray absorptiometry (DEXA). RESULTS: The study included 64 white Caucasian subjects, 44 of whom were women. The mean age of the subjects was 80.6 +/- 7.1 years. The mean time since the menopause was 31.45 +/- 7.8 years and 31 subjects presented previous fractures, 12 of which concerned the FM. Mean body mass index (BMI) was 25.8 +/- 4.4 and mean calcium intake was 670 +/- 258.3 mg/d. Mean PTH level was 48.5 +/- 30.34. Thirty-five subjects presented vitamin D deficiencies (mean concentration 8.56 +/- 5.2 microg/L), and 11 of these patients had associated secondary hyperparathyroidism. Fifty-four subjects had osteoporosis (T score <-2.5 standard deviation). Mean bone mineral density (BMD) was 0.596 +/- 0.157 g/cm2 for the femur neck (T score = -3.15 +/- 1.39 standard deviation) and 0.501 +/- 0.169 g/cm2 for the trochanter (T score = - 2.55 +/- 1.68 standard deviation). CONCLUSIONS: Vitamin D deficiency and low calcium intake were observed in a large number of elderly subjects. The patients with the lowest BMD values had secondary hyperparathyroidism.

Absorptiometry, Photon↗
PubMed2004

Selection of an ultraviolet disinfection system for a municipal wastewater treatment plant.

As part of an expansion to an average flow of 45.9 million gallons per day (174 mld), the Ypsilanti Community Utilities Authority wastewater treatment plant in the State of Michigan, USA, elected to install ultraviolet disinfection as a replacement for the existing chlorination process. This paper presents a unique methodology used in selecting the best system based on not only the life cycle costs, and O & M considerations but also the participation of the stakeholders. The Team members consisted of representatives of all departments at the Authority, and these Team members made the decision. The Team evaluated all criteria in the office, which was followed by verification at selected sites with similar types of equipment. The selected equipment then was pilot tested for validation of the dose-kill relationship under normal operation and also under reduced irradiation conditions. A low-pressure, high intensity system was selected, based on life-cycle cost, reliability, safety, and ease of operation. This paper describes the unique methodologies used in making that decision. The full-scale system is scheduled for start-up in Spring 2003.

Bioreactors↗
PubMed2003

A preliminary report on prevalence of acetabular labrum tears in sports patients with groin pain.

To the best of our knowledge, this prospective study is the first to investigate the prevalence of acetabular labrum tears in athletes presenting with groin pain. Eighteen athletes who presented to our sports clinic with groin pain, underwent clinical assessment and magnetic resonance arthrography (MRa) to detect presence or absence of acetabular labrum tears. Ethical committee approval and informed consent was obtained from each patient. In four out of these eighteen athletes (22%) the MRa demonstrated the presence of acetabular labrum tear. Three of them underwent arthroscopic debridement of their acetabular labrum tears and returned to their sporting activities within 8 months. Clicking sensation of the hip was a sensitive (100%) and specific (85%) clinical symptom to predict labral tears. The internal rotation-flexion-axial compression manoeuvre was sensitive (75%) but not specific (43%). The Thomas test was neither sensitive nor specific. The conclusion of the study is that acetabular labrum tears can be a common cause of groin pain in athletes. Sports clinicians managing athletes with groin pain have to be well aware of the condition.

Acetabulum↗
PubMed2003

Electrochemical properties and Fourier transform-infrared spectroscopic investigations of the redox behaviour of poly(indole-5-carboxylic acid) in LiClO4-acetonitrile solutions.

Electropolymerisation of indole-5-carboxylic-acid leads to the formation of electroactive polymer films. Potentiostatic deposition of the related polymer, poly(indole-5-carboxylic-acid), was carried out at a constant potential at 1.35 V versus SCE. The cyclic voltammogram of the resulting polymer in LiClO4 (0.15 mol dm(-3))/acetonitrile solution is characterized by two poorly resolved anodic and cathodic set peaks. FTIR spectroscopy was used to characterize both reduced and oxidized forms of poly(indole-5-carboxylic-acid). Assignments of the vibrational modes were proposed by comparison of the vibrational spectra of polyindole and polycyanoindole. The polymerization sites correspond to the 2 and 3 carbon positions of the pyrrole cycle. In the oxidized form of the polymer, the NH group is deprotonated while the quinoid form is present between the pyrrole rings.

Acetonitriles↗
PubMed2003

[Allergic reactions to implant materials].

The extent of the immune response upon implantation of metallic devices depends on the individual reactivity and on material characteristics. If specific T-cellular sensitization occurs or an allergy to metal preexists, hypersensitive reactions to implant components may develop. They include eczema, impaired wound healing, and sterile osteomyelitis. The existence of allergy-induced implant loosening is still an open question. Further improvement of clinical allergological diagnostics, better understanding of peri-implantar immune reactions, and interdisciplinary collection of epidemiological data concerning allergy to implants will contribute to a better knowledge about tolerance of implant material in humans.

Dermatitis, Allergic Contact↗