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Biomedical subjects

L Thomas

Publications and source records attributed to L Thomas.

At least 55 records · Page 3Linked to original sources
PubMed2005

A prospective study of the incidence of complications associated with dermatological surgery.

BACKGROUND: Dermatological surgery is a relatively new and expanding subspecialty within dermatology. Little information is available about complications in this kind of surgery in the European setting. OBJECTIVES: The aim of this study was to assess the incidence of anaesthetic, haemorrhagic and infectious complications in dermatological surgery and to highlight the factors associated with these complications. METHODS: Data were collected prospectively over a 3-month period for all surgical procedures performed by a network of dermatologists (n = 84 dermatologists) in France, including the excision of all benign or malignant tumours but excluding sebaceous cysts and pyodermas. Information was collected regarding dermatologists, patients, procedures and complications. RESULTS: A total of 3788 surgical procedures were available for review; 236 complications, mostly minor, occurred in a total of 213 surgical procedures (6%), bleeding being the most common (3%). Vaso-vagal syncope was the main anaesthetic complication (51 of 54). Infectious complications occurred in 79 patients (2%). Superficial suppuration accounted for 92% of surgical site infections. Only one patient had a systemic infection. Complications requiring additional antibiotic treatment or repeat surgery accounted for only 22 cases of 3788 (1%). No statistically significant correlation was found with the characteristics of the dermatologists, especially with respect to their training or amount of surgical experience. Similarly, no link could be established between complications and surgical conditions. Multivariate analysis showed that anaesthetic or haemorrhagic complications were independent factors for infectious complications. Sex, administration of an anticoagulant or immunosuppressant, type of procedure performed and duration exceeding 24 min were independent factors for haemorrhagic complications. CONCLUSIONS: This study shows a low rate of complications associated with dermatological surgery performed by dermatologists under local anaesthesia on an outpatient basis.

Adolescent↗
PubMed2005

Is buscopan effective in meat bolus obstruction?

OBJECTIVE: To assess the efficacy of hyoscine butyl bromide (buscopan) in relieving oesophageal meat bolus obstruction. DESIGN: Retrospective review of case notes. SETTING: Secondary otorhinolaryngology care. PARTICIPANTS: Twenty-nine patients who presented to the Accidents & Emergency department satisfying, inclusion criteria: (i) >or=16 years old, (ii) patients with only meat bolus obstruction and (iii) had either only buscopan or no medications. Exclusion criteria were: (i) <16 years of age, (ii) patients who received any medications other than or in addition to buscopan, (iii) other foreign body obstructions and (iv) any patient in whom the approximate time of resolution of obstruction was not documented. RESULTS: Twenty-nine patients with 31 episodes of obstruction were analysed. Twenty-two episodes were treated with buscopan and in 18 (82%) the obstruction was relieved. Two had spontaneous relief >24 h later and two had surgical disimpaction. In nine episodes, where no medications were given, seven (78%) cleared spontaneously and two had surgical removal. Fisher's exact test failed to show any significant difference between the two groups. The study groups were too small and power calculation showed that the number required for statistically validated result would be 140 in each group. CONCLUSION: Routine use of buscopan in oesophageal obstruction especially in the upper two-thirds needs to be reviewed because of the possibility of side-effects and lack of objective evidence of its efficacy.

Adolescent↗
PubMed2005

Antimicrobial activity of chlorhexidine diacetate and benzalkonium chloride against Pseudomonas aeruginosa and its response to biocide residues.

AIMS: The aims of this study were to evaluate the antimicrobial activity of chlorhexidine diacetate (CHX) and benzalkonium chloride (BZK) for strains of Pseudomonas aeruginosa exhibiting increased minimum inhibitory concentrations (MIC) for CHX, and to determine whether residues of chlorhexidine digluconate (CHG) and Hibiscrub (Hib, a formulation containing CHG) affect the susceptibility of P. aeruginosa to these biocides and a number of antibiotics. METHODS AND RESULTS: The bactericidal activity of CHX and BZK was evaluated for strains of P. aeruginosa exhibiting increased MIC for CHX with established suspension and surface disinfection tests. None of the strains of P. aeruginosa exhibiting raised MIC for CHX was less sensitive than the parent strain to CHX or BZK in either method. A test was designed to investigate the effects of dried CHG and Hib residues on P. aeruginosa cells. Exposure of P. aeruginosa to dried residues of CHG or Hib did not result in the organism becoming less sensitive to either biocide or a number of antibiotics. CONCLUSIONS: Pseudomonas aeruginosa strains with raised MIC to CHX were no less sensitive than the parent strain to CHX and BZK in bactericidal investigations. Exposure to dried residues of CHG and Hib did not render P. aeruginosa less sensitive to either of these agents or a number of antibiotics. SIGNIFICANCE AND IMPACT OF THE STUDY: An increase in the MIC for a biocide in a micro-organism does not necessarily result in a failure of the biocide to effectively kill the organism. The residue that remains after the use of an antimicrobial agent can be at a far lower concentration than that initially applied and this study highlights the necessity for further investigations into the effect of residues, at low concentration, on bacterial populations and their role, if any, in the continued problem of antibiotic resistance.

Anti-Bacterial Agents↗
PubMed2005

Avoiding alar necrosis with post-nasal packs.

Foley's catheter is used for post-nasal packing in severe epistaxis. Various methods have been described for securing the catheter in position, all of which can be associated with patient discomfort, risk of alar necrosis or unsightliness. We describe a new method to secure the Foley's catheter without these problems. The ribbon gauze used for anterior nasal packing is tied over the catheter in multiple knots to secure it in place. This has been successfully tried on over 50 patients.

Acute Disease↗
PubMed2004

Bismuth citrate in the quantification of inorganic phosphate and its utility in the determination of membrane-bound phosphatases.

This paper describes a rapid and sensitive method to determine inorganic phosphate, even in the presence of labile organic phosphate compounds and large quantities of proteins. The method eliminates the use of sodium arsenite, a highly toxic compound, substituting bismuth citrate for it to stabilize the phosphomolybdic acid complex formed during the interaction of inorganic phosphate and molybdate reduced by ascorbic acid. This method has also been adapted to microplates and has been used to determine the activities of Na/K ATPase and alkaline phosphatase of intestinal basolateral and luminal plasma membranes.

Alkaline Phosphatase↗
PubMed2004

[Management of soft tissue sarcomas in first isolated local recurrence: a retrospective study of 83 cases].

PURPOSE: To analyse the management and clinical outcome of patients treated for a first isolated local recurrence of soft tissue sarcoma (trunk or extremities) and to identify prognosis factors. PATIENTS AND MATERIAL: This is a retrospective study of 83 adult patients treated between 1980 and 1999. Mean tumor size was 6 cm. Most sarcomas were located in extremities (N =74), were deep (N =60), and proximal (N =53). Thirty involved nerves or vessels. Histologic subtypes were mainly grade 2 (42%) or 3 (36%) histocytofibrosarcomas (49%) and liposarcomas (20%). Surgical treatment of recurrences consisted in wide excision (32 cases), marginal resection (46 cases), five patients requiring amputation. Final results were R0 (N =33), R1 (N =47) or R2 (N =3) resection. Beside surgery, six patients received neoadjuvant and seven others adjuvant chemotherapy. Twenty-three patients received postoperative external beam radiotherapy (EBRT) (mean dose 55 Gy) and 26 interstitial (192)Ir low dose rate brachytherapy (BCT) (mean dose 45 Gy for BCT alone, 22 Gy when associated with EBRT), 19 patients being re-irradiated. RESULTS: Mean follow up was 59 months. Thirty-seven (45%) tumors relapsed, 62% locally as first event. Nineteen patients developed secondary distant metastases. Multivariate analysis showed only tumour depth (P =0.05) and re-resection for primary R1 resection for the recurrence (P =0.018) being independent prognosis factors for tumour control, radiotherapy (EBRT and/or BCT) being significant in univariate analysis (P =0.05). Overall survival rate was 73, 54, and 47% at respectively 3, 5 and 10 years, and was 65, 35 and 32% after a further local recurrence. Multivariate analysis showed trunk (P =0.0001) or inferior extremity locations (P =0.023), symptomatic (P =0.001), high grade (P =0.01), deep (P = 0.01) tumours, and the occurrence of a further local failure (P =0.004) as unfavourable characteristics for overall survival. CONCLUSION: Because of the high relapse rate in this series, a first isolated local recurrence of STS increases mainly the risk of a subsequent local relapse. Quality of local treatment for the first local relapse is decisive. When a conservative treatment is feasible, it should combine surgical resection and radiotherapy, brachytherapy being the best suited in previously irradiated patients. Efforts have to be pursued to increase quality of the treatment of primary tumours, at best performed in centers that have expertise in this field.

Adult↗
PubMed2004

Dermoscopy of Bowen's disease.

BACKGROUND: Dermoscopy improves the diagnostic accuracy in pigmented skin lesions, but it is also useful in the evaluation of nonpigmented skin tumours as it allows the recognition of vascular structures that are not visible to the naked eye. Bowen's disease (BD) or squamous cell carcinoma in situ is usually nonpigmented, but may also rarely be pigmented. Objective To describe the dermoscopic features in a series of pigmented and nonpigmented BD. METHODS: Dermoscopic images of 21 histopathologically proven BD were evaluated for the presence of various dermoscopic features. Each lesion was photographed using the Dermaphot (Heine Optotechnik, Herrsching, Germany), at 10-fold magnification, and the colour slides were scanned to digital format using a Kodak Photo CD system. RESULTS: The majority of cases of BD revealed a peculiar dermoscopic pattern characterized by glomerular vessels (90%) and a scaly surface (90%). In addition, in pigmented BD small brown globules regularly packed in a patchy distribution (90%), and structureless grey to brown pigmentation (80%) were observed. CONCLUSIONS: Dermoscopy can be helpful for diagnosing BD because of the presence of repetitive morphological findings such as glomerular vessels and a scaly surface. In pigmented BD, small brown globules and/or homogeneous pigmentation can be seen as well.

Aged↗
PubMed2004

Naturally occurring fruit juices dislodge meat bolus obstruction in vitro.

Oesophageal meat bolus obstruction is often removed endoscopically/surgically with attendant morbidity and mortality. Anecdotal evidence suggests that fruit juices' enzymes may dissolve meat boluses. To assess this, an in vitro study was carried out. Cooked chicken was tightly packed between 10 and 8 mL markers of 80, 10 mL syringes. Two millilitres of fresh juice from lemons, papaya, kiwi fruits, pineapples, frozen and then thawed pineapple juice, processed pineapple juice, Coca-Cola and saliva were added to 10 syringes each. By 4 h, the meat boluses significantly moved in the pineapple juice both fresh and frozen and kiwi juice groups (P < 0.001), little movement in the Coca-Cola group (P < 0.05), and no movement in the saliva, processed pineapple juice, lemon juice and papaya groups. In conclusion, pineapples and kiwi fruits contain enzymes which can dislodge meat boluses. Freezing does not denature the enzyme and provides a convenient way of storing the juice.

Beverages↗
PubMed2004

Hereditary non-polyposis colorectal cancer and the role of hPMS2 and hEXO1 mutations.

Hereditary non-polyposis colorectal cancer (HNPCC) is an autosomal dominant, inherited condition that is characterized primarily by the development of early-onset colorectal cancer and a number of other epithelial malignancies. The underlying genetic basis of the disease is associated with a breakdown of DNA-mismatch repair. There are many genes involved in DNA-mismatch repair, and five of them have been implicated in HNPCC. Two of the genes (hMSH2 and hMLH1) account for the majority of HNPCC families (approximately 60%), and it is not known what the exact contributions of the remaining three genes (hPMS1, hPMS2, and hMSH6) are in relation to this condition. In addition, a sixth gene (hEXO1) has been associated with a disease phenotype that is consistent with HNPCC. Current estimates suggest that all four of these genes, combined, may account for up to 5% of families. In this report, we examine the contribution of hPMS2 and hEXO1 to a well-defined set of families that fulfill the diagnostic criteria for HNPCC. The genes, hPMS2 and hEXO1, were studied by denaturing high performance liquid chromatography (DHPLC) analysis in 21 families that have previously been determined not to have mutations in hMSH2 or hMLH1. hPMS2 accounts for a small proportion of HNPCC families, and none were deemed to be associated with hEXO1. Mutations in hPMS2 appear to account for a small proportion of families adhering to the Amsterdam II criteria, whereas hEXO1 does not appear to be associated with HNPCC.

Adaptor Proteins, Signal Transducing↗
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

[Brachytherapy in soft tissue sarcomas].

Soft tissue sarcomas are rare tumors with a high risk or local recurrence and a risk of distant metastases. Standard treatment advocated is the combination of conservative resection and external radiotherapy. Brachytherapy is an integrated part of the multidisciplinary treatment. Brachytherapy can increase local control with good functional results. Primary exclusive brachytherapy has been used and is effective and safe in high grade sarcomas (randomized trial of MSKCC). Brachytherapy seems to be important as part of the treatment of central localization (shoulder, groin) and sarcomas with positive resection margins, but its relation with external radiotherapy has to be defined. Brachytherapy used with special guidelines allows to obtain an improved local control with an acceptable level of complication.

Brachytherapy↗
PubMed2003

[Randomised phase III trial of fotemustine versus fotemustine plus whole brain irradiation in cerebral metastases of melanoma].

PURPOSE: The main objective of this prospective multicenter randomised phase III study was to compare a combined regimen of fotemustine plus whole brain irradiation versus fotemustine alone in terms of cerebral response and time to cerebral progression in patients with melanoma brain metastases. PATIENTS AND METHODS: Seventy-six patients (instead of the 106 planned patients; study was stopped after the interim analysis) were randomised receiving either fotemustine (arm A, n = 39) or fotemustine and whole brain irradiation (arm B, n = 37). Fotemustine was administered intravenously at 100 mg m(-2) on day 1, 8 and 15, followed by a 5-week rest period, then every 3 weeks in non-progressive patients. In arm B, a concomitant whole brain irradiation was performed at the total dose of 37.5 Gy (2.5 Gy/d(-1), days 1-5, 3 consecutive weeks). RESULTS: Although patients who received fotemustine alone had worse prognostic factors, there was no significant difference in brain response (arm A: 7.4%, B: 10.0%) or control rates (objective response plus stable disease) after seven weeks (arm A: 30%, B: 47%) and overall survival (arm A: 86d, B: 105d). However, there was a significant difference in favour of arm B for the time to brain progression (p = 0.028, Wilcoxon test). CONCLUSION: Fotemustine plus whole brain irradiation delayed the time to brain progression of melanoma cerebral metastases compared to fotemustine alone but without a significant improvement in terms of objective control or overall survival.

Adult↗
PubMed2003

Changes in regional left atrial function with aging: evaluation by Doppler tissue imaging.

AIMS: This study applies pulsed wave Doppler tissue imaging and colour Doppler tissue imaging to study changes in atrial function with ageing. We tested the following hypotheses: (1) pulsed wave Doppler tissue imaging can detect global changes of left atrial function associated with ageing similar to standard echocardiographic methods, (2) colour Doppler tissue imaging can reproducibly detect regional changes in atrial function (wall motion) of the normal young and normal aging atrium. METHODS AND RESULT: We studied 92 healthy subjects, divided into Group B (>or=50 years) and Group A (<50 years). As a reference standard the conventional measures of atrial function were determined: peak mitral A wave velocity, A wave velocity time integral, atrial emptying fraction and atrial ejection force. Pulsed wave Doppler tissue imaging estimated atrial contraction velocity (A' velocity) in late diastolic and segmental atrial contraction was determined by colour Doppler tissue imaging. A' velocities were significantly higher in Group B vs Group A (9.8+/-1.8 vs 8.5+/-1.5cm/s; P=0.0005). A' velocity correlated with atrial fraction (r=0.28; P=0.007) and atrial ejection force (r=0.21; P=0.04). Age correlated significantly with atrial ejection force (r=0.47; P=0.0001), atrial fraction (r=0.61; P=0.0001) and A' velocity (r=0.4; P=0.0002). Longitudinal segmental atrial contraction using colour Doppler tissue imaging showed an annular to superior segment decremental gradient with contraction velocities higher in Group B vs Group A. CONCLUSION: Pulsed wave Doppler tissue imaging and colour Doppler tissue imaging are reproducible and readily obtained parameters that provide unique data about global and segmental atrial contraction. In this study, changes in atrial contraction with aging were consistent with increased atrial contribution to filling accomplished by augmented atrial contractility.

Adolescent↗