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Biomedical subjects

J M Thomas

Publications and source records attributed to J M Thomas.

At least 19 recordsLinked to original sources
PubMed2006

Surgical management of soft tissue sarcoma in patients over 80 years.

AIMS: To report outcome on patients over 80years of age with soft tissue sarcoma (STS), with respect to surgical treatment, co-morbidity, complications and survival. METHODS: From a prospective database of 3400 patients with STS presenting over a 13-year period, all patients over 80years of age were identified and reviewed, with respect to tumour characteristics morbidity, mortality and outcome. RESULTS: 128 patients over 80years were treated for STS with 63 referred for treatment of primary disease, of whom 50 underwent resectional surgery. The remaining 65 patients were treated for recurrent or incompletely excised disease. Of the 50 patients treated primarily with surgery, 56% of tumours where high grade and 56% were greater than 10cm in diameter. The overall complication rate was 34%, with a 30-day mortality of 4%. Two- and 5-year survival rates were 56% and 46%, with a local recurrence rate of 22% at a mean follow-up of 22months. CONCLUSION: This patient group presented with poor prognosis tumours that were associated with poor outcomes in the medium to long term. Age need not be considered a contra-indication to radical surgery with curative intent.

Age Factors↗
PubMed2006

Incidence, mortality and survival in cutaneous melanoma.

Cutaneous melanoma remains a challenge despite increased levels of awareness, education and targeted health policies. Worldwide incidence rates for cutaneous melanoma have risen faster than those for any other malignancy in Caucasian populations over the last 30 years. Despite improving survival rates (defined as the ratio of those who survive the disease against incidence) over this period, mortality rates, generally, have continued to climb. Mortality from melanoma is greater than that caused by all other types of skin cancer, especially in men. In Britain the percentage of increase in the male age standardised mortality rate surpassed that of all other malignancies assessed (1993-2002) by Cancer Research UK. A literature-based study was conducted with review of publications identified through Medline and EMBase, 1980-December 2005, databases. We present a review of the current literature on incidence, mortality and survival rates of melanoma including a discussion on the aetiological factors, behaviour modification associated with public education campaigns and recent health policies and the effect these are having on melanoma figures. It is likely that any fall in mortality rates from melanoma in the near future will be secondary to early detection. Changes resulting from primary prevention are unlikely to be noticeable for several decades.

Adolescent↗
PubMed2006

Quantitative analysis of chimerism using a short tandem repeat method on a fluorescent automated DNA sequencer.

Stem cell transplantation (SCT) is the treatment of choice for a number of malignant and nonmalignant diseases. Monitoring of SC engraftment or microchimerism (MC) is important for diagnosis of relapse, rejection or graft vs. host disease (GVHD). The goal of this study was to develop a sensitive and relatively simple method for MC lineage analysis using the Visible Genetics fluorescence automated sequencer. Sensitivity of the method was studied by polymerase chain reaction (PCR) amplification of informative short tandem repeats (STR) using donor/recipient DNA mixtures as the templates and DNA extracted from donor and recipient CD3+, CD19+ and CD15+ cells mixed at various ratios. Semi-quantitative analysis was performed using the Visible Genetics software and percent of donor specific signal was calculated. The sensitivity of this method varied from 0.8% to 6.2% for both DNA and cellular MC in CD3+, CD19+ and CD15+ subsets. Regression analysis revealed linearity (r = 0.94) between the number of donor cells in the mixture and intensity of MC fluorescent signal. These data indicate that the Visible Genetics polyacrylamide gel sequencer can be successfully used for MC analysis in SC recipients providing a relatively high level of sensitivity.

Antigens, CD↗
PubMed2006

Nanoscale scanning transmission electron tomography.

Electron tomography enables the study of complex three-dimensional objects with nanometre resolution. In materials science, scanning transmission electron microscopy provides images with minimal coherent diffraction effects and with high atomic number contrast that makes them ideal for electron tomographic reconstruction. In this study, we reviewed the topic of scanning transmission electron microscopy-based tomography and illustrated the power of the technique with a number of examples with critical dimensions at the nanoscale.

Journal Article↗
PubMed2006

[Control of hypertension in nursing homes].

In a cross sectional study we determined prevalence of hypertension among institutionalized old subjects. Prevalence of hypertension was 69%. Among detected hypertensive patients, 76% received an antihypertensive drug treatment. 61% of the declared hypertensive patients and 80% of the treated hypertensive patients had their blood pressure controlled. The general practitioners should better detect and treat this common geriatric problem associated with a high comorbidity.

Aged, 80 and over↗
PubMed2006

Multiple cardiovascular involvement in a case of relapsing polychondritis.

Relapsing polychondritis is a multisystem disease characterized by recurrent inflammation of the cartilaginous tissue. Cardiovascular manifestations of relapsing polychondritis are rare but are the second most common cause of death in these patients. We report a case of relapsing polychondritis who underwent aortic valve replacement uneventfully but presented six months later with myocardial infarction due to bilateral coronary ostial stenosis.

Adult↗
PubMed2005

Risk and predictors of fatigue after infectious mononucleosis in a large primary-care cohort.

BACKGROUND: Fatigue has been found to complicate infectious mononucleosis (IM) when patients are directly asked about it. We do not know whether such fatigue is clinically significant, nor whether IM is a specific risk for fatigue (or whether it can follow other common infections). Various risk markers for post-infectious fatigue have been identified, but findings are inconsistent. AIM: To determine the risk of clinically reported fatigue (compared with depression) after IM (compared with both influenza and tonsillitis) in patients attending primary care, and to examine risk markers for post-IM fatigue. DESIGN: Comparison of matched primary-care cohorts. METHODS: We identified 1438 adult patients with a positive heterophil antibody test for IM from the UK General Practice Research Database. These patients were individually matched on age, sex and practice to two comparison groups; one with a clinical diagnosis of influenza and the other of tonsillitis. RESULTS: The odds ratios (ORs) (95%CI) for reported fatigue after IM vs. influenza and tonsillitis were 4.4 (2.9-6.9) and 6.6 (4.2-10.4), respectively. Risk markers for post-IM fatigue included female sex and premorbid mood disorder. By comparison, the ORs for depression after IM vs. influenza and tonsillitis were 1.6 (0.9-2.6) and 2.3 (1.4-3.9), respectively. DISCUSSION: IM is a specific and significant risk for clinically reported fatigue, which is both separate from, and more common than, depression. Female sex and premorbid mood disorder are risk markers for fatigue. These can be used both to target prevention strategies and to explore aetiological mechanisms.

Adolescent↗
PubMed2005

Computational approaches to the determination of active site structures and reaction mechanisms in heterogeneous catalysts.

We apply quantum chemical methods to the study of active site structures and reaction mechanisms in mesoporous silica and metal oxide catalysts. Our approach is based on the use of both molecular cluster and embedded cluster (QM/MM) techniques, where the active site and molecular complex are described using density functional theory (DFT) and the embedding matrix simulated by shell model potentials. We consider three case studies: alkene epoxidation over the microporous TS-1 catalyst; methanol synthesis on ZnO and Cu/ZnO and C-H bond activation over Li-doped MgO.

Carbon↗
PubMed2005

Delay in referral to a specialist soft-tissue sarcoma unit.

BACKGROUND: Soft-tissue sarcoma is a rare neoplasm which can occur almost anywhere in the body. There are no specific symptoms and signs and the disease can mimic more common benign and malignant conditions. It is not surprising, therefore, that diagnosis and referral to a specialist unit is often delayed. METHODS: A prospective audit was undertaken in 216 patients referred to a specialist unit with suspected or proven soft-tissue sarcoma over a 12 month period. All patients were interviewed to determine the chronology of symptoms and signs, and the referral and diagnostic pathway. Delay in referral was defined as three months or greater from first presentation to a doctor to review at our unit. RESULTS: There were 159 patients with previously untreated soft-tissue sarcomas. Thirty-one patients had delays in referral, and the overall median delay was 14 months (range 4-96 months). The delay was caused by the general practitioner in 13 patients, the patient (after general practitioner referral) on two occasions, by the hospital or referring specialist in seven patients, and was multifactorial in nine patients. CONCLUSIONS: A fifth of patients with soft-tissue sarcoma encountered important delays in referral to this specialist unit. This duration of delay is likely to have had a detrimental effect on treatment options and outcomes, including survival in some patients.

Adult↗
PubMed2005

Prognostic factors in advanced synovial sarcoma: an analysis of 104 patients treated at the Royal Marsden Hospital.

AIMS: Key prognostic factors at diagnosis of synovial sarcoma are well defined from the literature. There are few data regarding prognostic parameters in the setting of advanced disease. Our aim was to look specifically at a cohort of patients with advanced synovial sarcoma and to identify potential prognostic factors. PATIENTS AND METHODS: One hundred and four patients with advanced synovial sarcoma were identified from the Royal Marsden Hospital's sarcoma database between 1978 and 2003. Patient data were analysed retrospectively. Most patients were aged between 20 and 50 years at diagnosis. Seventy-one patients were deceased at the time of analysis. Ninety-two patients received chemotherapy for management of advanced disease (most commonly doxorubicin + ifosfamide). RESULTS: Median survival following development of advanced disease was 22 months. Predictors of survival with advanced disease were age <35 years (P = 0.03) and response to first-line chemotherapy (P = 0.05). The response rate to doxorubicin plus ifosfamide was 58.6%, and this was superior to either agent when given singly. Metastasectomy was not associated with improved prognosis in this series. CONCLUSIONS: Synovial sarcoma is a chemosensitive soft tissue sarcoma. Compared with historical controls, survival with advanced disease seems to have improved over the years, possibly as a result of better use of chemotherapy. Age <35 years and response to first-line chemotherapy predict for improved survival with advanced disease.

Adult↗
PubMed2005

Surgical management of primary and recurrent retroperitoneal liposarcoma.

BACKGROUND: Surgery plays a dominant role in the initial and subsequent treatment of retroperitoneal liposarcoma (RPLS). This study was a review of outcomes of patients treated at the Royal Marsden Hospital. METHODS: Records of all patients who had surgery for RPLS since 1990 were reviewed, with particular attention to local recurrence and disease-specific survival. Patients with primary RPLS and those with recurrent RPLS, who had palliative surgery after a variable number of operations performed elsewhere, were considered separately. RESULTS: Seventy-two patients had surgery for primary RPLS, over half of whom underwent resection of a contiguous organ to achieve clearance. Follow-up of at least 12 months was available for 58 patients. Thirty-four patients had no evidence of recurrence after median follow-up of 26 (range 12-151) months. Low-grade tumour and macroscopic clearance of tumour were significantly associated with a reduced risk of local recurrence and improved survival. Forty-seven patients had palliative surgery for recurrent RPLS. Median survival from time of last operation to death was 27 (range 0-79) months. Follow-up was to a median of 68 (range 14-261) months. CONCLUSION: Patients with low-grade RPLS that has been completely resected at the initial operation have the most favourable prognosis. Palliative resection is worthwhile to treat troublesome symptoms of recurrence.

Adult↗
PubMed2005

Imaging features of retroperitoneal and pelvic schwannomas.

AIM: To describe the imaging features of retroperitoneal and pelvic schwannomas. MATERIALS AND METHODS: The presenting cross-sectional imaging for 18 sequential patients with retroperitoneal or pelvic schwannomas was reviewed retrospectively. Note was made of tumour diameter, position, homogeneity, margin, shape, calcification and invasion into adjacent structures. Where MRI had been performed, T1 and T2 signal intensity relative to skeletal muscle, and the degree and pattern of enhancement with gadolinium, were also assessed. RESULTS: Imaging from 13 patients was available for review. The mean tumour diameter was 8.7 cm (range 4 to 15 cm); 9 schwannomas were located in the pelvis and 4 in the retroperitoneum; 12 cases showed smooth, regular margins and 1 case irregular, invasive margins. The tumours were homogeneous in 5 cases and heterogeneous with cystic change in 8; in 2 cases there was smooth expansion of a sacral nerve root exit foramen, and in 1 there was bony destruction of the sacrum and extension of tumour into the spinal canal. In 5 cases MRI was performed; on T1-weighted images all tumours were isointense; on T2-weighted images 4 tumours were hyperintense and 1 was isointense to skeletal muscle. In all cases the diagnosis was confirmed by core biopsy. CONCLUSION: Retroperitoneal and pelvic schwannomas typically form large, well-circumscribed masses in the retroperitoneum or presacral area, and frequently undergo cystic degeneration. They can occasionally cause bony changes in the spine, but otherwise do not invade or obstruct adjacent structures. Although they are rare, it is important for the radiologist to recognize the typical appearance of schwannomas because they can be mistaken for malignant tumours.

Adult↗
PubMed2005

Increased expression of unusual EP repeat-containing proteins in the midgut of the tsetse fly (Glossina) after bacterial challenge.

Proteins containing a glutamic acid-proline (EP) repeat epitope were immunologically detected in midguts from eight species of Glossina (tsetse flies). The molecular masses of the tsetse EP proteins differed among species groups. The amino acid sequence of one of these proteins, from Glossina palpalis palpalis, was determined and compared to the sequence of a homologue, the tsetse midgut EP protein of Glossina m. morsitans. The extended EP repeat domains comprised between 36% (G. m. morsitans) and 46% (G. p. palpalis) of the amino acid residues, but otherwise the two polypeptide chains shared most of their sequences and predicted functional domains. The levels of expression of tsetse EP protein in adult teneral midguts were markedly higher than in midguts from larvae. The EP protein was detected by immunoblotting in the fat body, proventriculus and midgut, the known major immune tissues of tsetse and is likely secreted as it was also detected in hemolymph. The EP protein was not produced by the bacterial symbionts of tsetse midguts as determined by genome analysis of Wigglesworthia glossinidia and immunoblot analysis of Sodalis glossinidius. Bacterial challenge of G. m. morsitans, by injection of live E. coli, induced augmented expression of the tsetse EP protein. The presence of EP proteins in a wide variety of tsetse, their constitutive expression in adult fat body and midguts and their upregulation after immunogen challenge suggest they play an important role as a component of the immune system in tsetse.

Amino Acid Motifs↗
PubMed2005

Incidence and outcome of critical illness amongst hospitalised patients with haematological malignancy: a prospective observational study of ward and intensive care unit based care.

To determine the incidence and outcome of critical illness amongst the total population of hospital patients with haematological malignancy (including patients treated on the ward as well as those admitted to the intensive care unit), consecutive patients with haematological malignancy were prospectively studied. One hundred and one of the 1437 haemato-oncology admissions (7%) in 2001 were complicated by critical illness (26% of all new referrals). Fifty-four (53%) of these critically ill patients survived to leave hospital and 33 (34%) were still alive after 6 months. The majority (77/101) were not admitted to the intensive care unit but were managed on the ward, often with the assistance of the intensive care team. Independent risk factors for dying in hospital included hepatic failure (odds ratio 5.3, 95% confidence intervals 1.3-21.2) and central nervous system failure (odds ratio 14.5, 95% confidence intervals 1.7-120.5). No patient with four or more organ failures or a Simplified Acute Physiology Score II >/= 65 survived to leave hospital. There was close agreement between actual and predicted mortality with increasing Simplified Acute Physiology Score II for all patients, including those not admitted to intensive care.

Adult↗