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Biomedical subjects

P Thomas

Publications and source records attributed to P Thomas.

At least 91 records · Page 5Linked to original sources
PubMed2003

[Surgery for oesophageal cancer: current controversies].

Any attempt to define the present role of surgery in the treatment of oesophageal cancer should integrate the dramatic changes that occurred within this disease over the last 2 decades: major shift in the histologic type of tumours, improved staging methods, spectacular reduction of operative risks, standardization of oncologic principles focusing on the completeness of resection, and development of multimodality therapeutic strategies. Surgery has still a pivotal role. Esophagectomy should be performed by trained surgeons in high-volume institutions. Radical surgery with en-bloc resection and 2 fields lymphadenectomy, should be encouraged in low-risk patients with subcarinal tumors. Although multimodality treatment strategy is commonly applied for locally advanced disease, few data support its superiority over surgical resection alone, followed by adjuvant therapy when appropriate. One may thus hypothesize that the risk/benefit ratio of such strategies is probably optimal in case of early stage tumors, and future studies may further clarify this issue. Conversely, locally advanced tumors, particularly those located in the upper mediastinum and the neck, may be managed alternatively without surgery. However, surgery remains an important tool to ensure optimal palliation of dysphagia, to achieve local control, and finally to improve quality of life. In that way, video-assisted techniques and/or trans hiatal approaches aiming to minimize the surgical insult may have a place in the treatment of patients who have substantially responded to induction therapy. Tumors located close to the pharyngo-oesophageal junction are best managed with chemotherapy and radiotherapy. Finally, salvage surgery may be considered in highly selected patients in case of non-response or local relapse without distant metastases.

Combined Modality Therapy↗
PubMed2003

Immuno-allergological properties of aluminium oxide (Al2O3) ceramics and nickel sulfate in humans.

For more than 30 years aluminium oxide (Al(2)O(3)) ceramics have been used for implants in maxillofacial and orthopaedic surgery. Up to now, there are no reports and also no investigations on hypersensitivity reactions. In order to evaluate the aspects of immuno-allergological reactivity to aluminium oxide ceramics, skin testing and in vitro lymphocyte activation studies were performed. The patch test reactivity to a standard series of contact allergens and to an aluminium oxide (Al(2)O(3)) disk was examined in a consecutive series of 250 patients frequenting a University Dermatology Clinic. Furthermore, peripheral blood mononuclear cells (PBMC) of 15 nickel-allergic and 15 non-allergic individuals were cultured with medium alone, with the pan T-cell mitogen phytohemagglutinine (PHA) or with nickel sulfate (NiSO(4)). By additional presence/absence of Al(2)O(3) disk its influence on the cytokine secretion pattern and proliferative response was investigated. The results show that in contrast to a high frequency of delayed-type hypersensitivity to standard contact allergens, no allergic skin reactions to Al(2)O(3) ceramics occured. The IL-4 and IFN-gamma production in vitro remained almost unchanged by the presence of Al(2)O(3) disk as well as the proliferative response of PBMC of non-allergic individuals. Cellular reactivity of nickel allergic and non-allergic donors was partly enhanced upon contact to Al(2)O(3) disks.

Allergens↗
PubMed2003

A methodological approach for the identification of arsenic bearing phases in polluted soils.

A methodological approach is used to characterize arsenic pollution in three soils and to determine arsenic speciation and association with solid phases in three polluted soils. HPLC-ICP-MS was used for arsenic speciation analysis, SEM-EDS and XRD for physical characterization of arsenic pollution, and sequential chemical extractions to identify arsenic distribution. Arsenic was concentrated in the finest size fractions also enriched in iron and aluminium. Total arsenic concentrations in soils are close to 1%. Arsenic was mainly present as arsenate, representing more than 90% of total arsenic. No crystallised arsenic minerals were detected by XRD analysis. SEM-EDS observations indicated arsenic/iron associations. Modified Tessier's procedure showed that arsenic was mainly extracted from amorphous iron oxide phase. The results of this methodological approach lead to predict the formation of iron arsenates in the case of one of the studied soils while arsenic sorption on iron amorphous (hydr)oxides seemed to be the determinant in the two other soils.

Arsenicals↗
PubMed2003

Recurrences following primary osteosarcoma in adolescents and adults previously treated with chemotherapy.

In this retrospective analysis, we report on the detailed management of 33 recurrent osteosarcoma patients from a population of 81 adolescents and adults previously treated (between November 1979 and November 1998) at the La Timone Adults Hospital, for an extremity-localised osteosarcoma. The site of the first recurrence was limited to the lung in 24 patients (73%), was local in 4 patients (12%), at multiple sites in 4 patients (12%), and limited to the bone for 1 patient (3%). The median interval between the diagnosis of the primary osteosarcoma and the first recurrence was 16 months (range 4-108 months). For all patients, the treatment combined aggressive chemotherapy and surgical resection of the recurrences whenever possible. 19 patients (58%) achieved a second complete remission. The median follow-up time from the first recurrence was 18 months (range 4-150 months). For all patients, the median overall survival from first recurrence was 17 months (95% confidence interval (CI), 11-22 months) and the projected 3- and 5-year survival rates were 31.6 and 23.7%, respectively. Patients with a second complete remission had a better 5-year survival than patients without (44.6% versus 0%, P=0.001). The achievement of a second complete remission has an independent significant prognostic value for an improved survival. Aggressive surgery with the removal of recurrence sites combined with multi-agent chemotherapy can either cure patients with recurrent osteosarcoma or significantly prolong their survival.

Adolescent↗
PubMed2003

Complex chimeras to map ligand binding sites of GPCRs.

Family 1a GPCRs are thought to bind small molecule ligands in a pocket comprising sequences from non-contiguous transmembrane helices. In this study, receptor-ligand binding determinants were defined by building a series of complex chimeras where multiple sequences were exchanged between related G-protein coupled receptors. Regions of P2Y(1), P2Y(2) and BLT(1) predicted to interact with nucleotide and leukotriene ligands were identified and receptors were engineered within their transmembrane helices to transpose the ligand binding site of one receptor on to another receptor. Ligand-induced activation of chimeras was compared with wild-type receptor activation in a yeast reporter gene assay. Binding of ligand to a P2Y(2)/BLT(1) chimera confirmed that the ligand binding determinants of BLT(1) are located in the upper regions of the helices and extracellular loops of this receptor and that they had been successfully transferred to a receptor that normally binds unrelated ligands.

Amino Acid Sequence↗
PubMed2003

Desulfovibrio hydrothermalis sp. nov., a novel sulfate-reducing bacterium isolated from hydrothermal vents.

Mesophilic, hydrogenotrophic, sulfate-reducing bacteria were isolated from a deep-sea hydrothermal chimney sample collected at 13 degrees N on the East-Pacific Rise at a depth of 2,600 m. Two strains (BL5 and H9) were found to be phylogenetically similar to Desulfovibrio profundus (similarity >99%), whereas two other strains (H1 and AM13T) were found to be phylogenetically distinct (similarity 96.4%) from Desulfovibrio zosterae, their closest relative. Strain AM13T was characterized further. It was a barophilic, Gram-negative, non-sporulating, motile, vibrio-shaped or sigmoid bacterium possessing desulfoviridin. It grew at temperatures ranging from 20 to 40 degrees C, with an optimum at 35 degrees C in the presence of 2.5% NaCl. The pH range for growth was 6.7-8.2 with an optimum around 7.8. Strain AM13T utilized H2/CO2, lactate, formate, ethanol, choline and glycerol as electron donors. Electron acceptors were sulfate, sulfite and thiosulfate, but not elemental sulfur or nitrate. The G + C content of DNA was 47 mol%. Strain AM13T (= DSM 14728T = CIP107303T) differed from D. zosterae not only phylogenetically, but also genomically (DNA-DNA reassociation value between the two bacteria was 23.8%) and phenotypically. This isolate is therefore proposed as the type strain of a novel species of the genus Desulfovibrio, Desulfovibrio hydrothermalis sp. nov.

DNA, Bacterial↗
PubMed2003

Acetabular labrum and its tears.

Groin pain is a major cause of morbidity in athletes. Only in the last decade have acetabular labrum tears been recognised as a possible diagnosis. Awareness of this condition is important for appropriate management. The basic science and pathological and clinical features of acetabular labrum tears are reviewed, and diagnostic and treatment options are presented.

Acetabulum↗
PubMed2003

An exploratory study of the consistency of balance control and the mobility of people with Parkinson's disease (PD) between medication doses.

OBJECTIVE: To evaluate the consistency of balance control, mobility and perceived difficulties with functional tasks by people on carefully controlled anti-parkinsonian medication programmes, between doses on a single day and across days using standard clinical measures. DESIGN: Small group prospective study. SETTING: A hospital outpatient physiotherapy department. SUBJECTS: Subjects, recruited from a specialist Parkinson's disease (PD) clinic, had to be independently mobile, diagnosed with PD at least five years previously and on a stable drug regime. METHOD: Assessments (timed up and go, functional reach and a tap test) were completed 30 minutes prior to medication and hourly for 4 hours. They were repeated on a second day within a seven-day period. The self-assessment of functional disability was completed during the worst and best periods of the drug cycle. A general linear model (repeated measures analysis of variance) was used to analyse the data. RESULTS: Nine subjects (8 males) with PD (grade III Hoehn and Yahr, average duration of symptoms eight years), average age 72 years, were recruited to the study. Four subjects had worse Hoehn and Yahr scores (grade 4) during the worst phase of the L-dopa cycle. Balance and mobility data did not change significantly over the medication cycle. Tests on day 2 were similar to day 1 with only the tap test showing a significant mean difference (p = 0.02) (2.6, 95% confidence interval (CI) 0.5-4.8). Individuals perceived significantly greater difficulty (mean difference = 7.9, 95% CI 3.6-12.2) (p < 0.001) in achieving functional tasks at the end of dose than peak dose of the medication cycle. CONCLUSION: Measures of balance and mobility remained stable over the cycle. Fluctuations in the perception of difficulties with daily functional tasks were not accompanied by observed fluctuations in performance. The improvement in the mean of the tap test over the days could reflect a learning effect.

Aged↗
PubMed2003

Effect of vaccination with selective bacterins on conventional pigs infected with type 2 porcine circovirus.

The objective of this study was to determine whether vaccination with bacterins commonly used in the USA, when administered at a time typical of US protocol, enhances porcine circovirus type 2 (PCV2) replication and the incidence and severity of clinical signs and lesions characteristic of postweaning multisystemic wasting syndrome (PMWS) in conventional pigs. Sixty-one pigs free of PCV2 were randomly assigned to four groups. Groups 1 (n = 15) and 2 (n = 15) pigs served as sham-inoculated negative controls. Groups 3 (n = 14) and 4 (n = 17) pigs were inoculated intralymphoid with PCV2 field isolate ISU-40895. Pigs in groups 2 and 4 were vaccinated with Actinobacillus pleuropneumoniae (APP) and Mycoplasma hyopneumoniae (M. hyopneumoniae) bacterins 21 days before and again 1 day before inoculation with PCV2. Mild transient respiratory disease and diarrhea were observed from 13 to 34 days postinoculation (DPI) in pigs in groups 3 and 4. Half the pigs from each group were necropsied at 22 and 34 DPI, respectively. Moderately enlarged, tan-colored lymph nodes were observed in the majority of pigs in groups 3 and 4. There was a significantly (P < 0.05) longer length of viremia (2.14 +/- 0.26 versus 4.44 +/- 0.23 weeks), a higher copy number of the PCV2 genome in serum, a wider range of tissue distribution of PCV2 antigen, and an increased severity of lymphoid depletion in pigs vaccinated with commercial APP and M. hyopneumoniae vaccines and inoculated with PCV2 compared with PCV2-inoculated unvaccinated pigs. Swine producers and veterinarians may need to consider changes in vaccination protocols in herds with recurrent PCV2-associated PMWS.

Actinobacillus pleuropneumoniae↗
PubMed2003

[Epileptic Münchausen syndrome by idiosyncratic of effect antiepileptic drugs].

Between 1996 and 2000, a 36-year-old woman was admitted four times for the presumed diagnosis of status epilepticus. Major skin allergy followed by collapsus occurred each time after intravenous phenytoin therapy. Video-EEG demonstrated non epileptic, psychogenic seizure leading to the diagnosis of Münchausen syndrome by idiosyncratic reaction to antiepileptic drugs.

Adult↗
PubMed2003

Influence of antidepressant therapies on weight and appetite in the elderly.

OBJECTIVE: Determine the nutritional impact of antidepressant drugs in elderly. METHODS: The study included 139 independently mobile out-patients managed by the Poitiers geriatric day hospital for problems of loss of home support, rehabilitation and medical or psychological care, with a stable treatment for 3 months at the time of inclusion and over the 3 months of the study. The study addressed the time course of nutritional parameters from baseline to 3 months post-inclusion. The physical examination included monthly weighing of the patients, 3-monthly evaluation of nutritional status using the Mini Nutritional Assessment (MNA) instrument and serum albumin. RESULTS: 52 men (76.3 +/- 6.7 years [62-87]) and 87 women (81.0 +/- 7.2 years [65-100]) were included. Seventy-nine patients presented with dementia. Seventy-four patients were receiving an antidepressant, of which 54 serotonin reuptake inhibitors. The patients free from dementia and not receiving antidepressants had nutritional indices that did not vary over the study period. The dementia-free patients receiving antidepressants gained weight (1.44 kg) - 1.87 kg on serotonin reuptake inhibitors - showed an improvement in MNA of 0.76/30 and showed a significant improvement in serum albumin of 1.78 g/L. The demented patients not receiving antidepressants lost weight (-1.01 kg), MNA score fell and serum albumin significantly decreased. On antidepressants, the demented patients significantly gained weight (0.73 kg) while no deterioration in the other parameters reflecting undernutrition was observed. Conclusions. In the middle term, in elderly subjects, antidepressants do not induce undernutrition or weight loss. Irrespective of antidepressant type, those agents seem to prevent weight loss in elderly subjects presenting with dementia.

Aged↗