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Biomedical subjects

K Thomas

Publications and source records attributed to K Thomas.

At least 19 recordsLinked to original sources
PubMed2006

A phase I/II study of lomustine and temozolomide in patients with cerebral metastases from malignant melanoma.

Temozolomide is an alkylating agent with activity in the treatment of melanoma metastatic to the brain. Lomustine is a nitrosurea that crosses the blood brain barrier and there is evidence to suggest that temozolomide may reverse resistance to lomustine. A multicentre phase I/II study was conducted to assess the maximum-tolerated dose (MTD), safety and efficacy of the combination of temozolomide and lomustine in melanoma metastatic to the brain. Increasing doses of temozolomide and lomustine were administered in phase I of the study to determine the MTD. Patients were treated at the MTD in phase II of the study to six cycles, disease progression or unacceptable toxicity. Twenty-six patients were enrolled in the study. In phase I of the study, the MTD was defined as temozolomide 150 mg m(-2) days 1-5 every 28 days and lomustine 60 mg m(-2) on day 5 every 56 days. Dose-limiting neutropaenia and thrombocytopaenia were observed at higher doses. Twenty patients were treated at this dose in phase II of the study. No responses to therapy were observed. Median survival from starting chemotherapy was 2 months. The combination of temozolomide and lomustine in patients with brain metastases from melanoma does not demonstrate activity. The further evaluation of this combination therefore is not warranted.

Administration, Oral↗
PubMed2006

Social deprivation and survival on renal replacement therapy in England and Wales.

This study examines the association between social deprivation and patient characteristics and outcomes in a nationally representative cohort of incident renal replacement therapy (RRT) patients. All Caucasian patients reported to the UK Renal Registry between 1997 and 2004 by centers in England and Wales with high data completeness were included. Social deprivation was assessed using the Townsend index. Socially deprived patients were more likely to be referred late. They were less likely to receive peritoneal dialysis (25.1 vs 34.8% on day 1, P trend <0.0001) or a renal transplant (5.3 vs 12.4% at 1 year, P trend <0.0001), and were less likely to attain UK Renal Association standards for hemoglobin and phosphate at 1 year. Crude survival decreased significantly with increasing deprivation for patients under the age of 65 years, but not for those aged 65 years and above (likelihood ratio for age-social deprivation interaction P<0.0001). Social deprivation was significantly associated with poorer survival after adjustment for age, gender, and cause of renal failure. After adjusting for baseline co-morbidity, social deprivation was no longer associated with poorer survival. Baseline differences in co-morbidity seem to explain poorer crude survival in incident Caucasian RRT patients from socially deprived areas in England and Wales. Differences also exist in some processes of care and intermediate outcomes, which may be amenable to intervention.

Aged↗
PubMed2006

Risk factors associated with pelvic inflammatory disease.

OBJECTIVE: To investigate factors associated with pelvic inflammatory disease (PID). METHODS: A case-control study was used to investigate demographic and behavioural factors, and causative agents associated with PID. RESULTS: A total of 381 participants were recruited: 140 patients, and 105 and 136 controls in tubal ligation and general practice groups, respectively. When compared with a PID-free tubal ligation control group, increased risk of PID was associated with: age <25 years; age at first sexual intercourse <20 years; non-white ethnicity; not having had children; a self-reported history of a sexually transmitted disease; and exposure to Chlamydia trachomatis. When compared with a general practice control group, increased risk was associated with: age <25 years; age at first sexual intercourse <15 years; lower socioeconomic status; being single; adverse pregnancy outcome; a self-reported history of a sexually transmitted disease; and exposure to C trachomatis. Of the cases, 64% were not associated with any of the infectious agents measured in this study (idiopathic). CONCLUSIONS: A high proportion of cases were idiopathic. PID control strategies, which currently focus on chlamydial screening, have to be reviewed so that they can prevent all cases of PID. Behavioural change is a key factor in the primary prevention of PID, and potential modifiable risk factors were associated with PID.

Adolescent↗
PubMed2006

Scrub typhus among hospitalised patients with febrile illness in South India: magnitude and clinical predictors.

OBJECTIVES: To derive a clinical algorithm for diagnosis of scrub typhus among patients hospitalized with febrile illness and to determine predictors of bad prognosis. METHODS: Patients hospitalized with febrile illness of 5-30 days duration were evaluated for common aetiologies. Sera were tested for antibodies (IgM and IgG) to Orientia tsutsugamushi using ELISA kit. RESULTS: Among 207 patients, 50 had elevated levels of IgM antibodies. The data of these patients were compared with that of 16 controls having febrile illnesses in whom rickettsial infection was ruled out. Transaminase elevation (>twice normal) was present in 90% and was significantly (P=0.004) more common in those with scrub typhus. If a combination of elevated transaminases, thrombocytopenia and leukocytosis is used, the specificity and positive predictive value are about 80%. Case fatality rate was 14%. Univariate analysis showed that hyperbilirubinemia (>1.5mg%) has a RR of 9 (95% CI=1.48-58.5) and elevated creatinine level (>1.4 mg%) had a RR of 43.99 (95% CI=3.65-530.5) for death. Elevated creatinine level was found to be an independent predictor of mortality (P=0.02). CONCLUSION: In developing countries with limited diagnostic facilities, it is prudent to recommend empiric therapy in patients with undifferentiated febrile illness having evidence of multiple system involvement especially if there is transaminase elevation. Elevated creatinine may predict bad outcome.

Adolescent↗
PubMed2005

Quantification of 2,4-D on solid-phase exposure sampling media by LC-MS-MS.

Three types of solid-phase chemical exposure sampling media: cellulose, polyurethane foam, and XAD-2, were analyzed for 2,4-dichlorophenoxyacetic acid (2,4-D) and the amine salts of 2,4-D. Individual samples were extracted into acidified methanol, and the extracts were analyzed via liquid chromatography-tandem mass spectrometry using electrospray ionization and a C(8) reversed-phase LC column. (13)C 2,4-D and a labeled benzoic acid (13)C or d5) were employed as the surrogate and internal standard, respectively. Over a three-year study of pesticide exposure among agricultural workers involving a high volume of analyses, values of average % recovery for (13)C 2,4-D on personal exposure samples ranged from 87 to 98 with a % relative standard deviation ranging from 7 to 12. The performance of the method compares favorably with that of the current National Institute for Occupational Safety and Health-recommended approach for the analysis of 2,4-D on these types of exposure sampling matrices.

2,4-Dichlorophenoxyacetic Acid↗
PubMed2005

Predictors of multi-organ dysfunction in heatstroke.

BACKGROUND: Heatstroke is a medical emergency that results from failure of thermoregulatory mechanism coupled with an exaggerated acute phase response, causing an elevation in core body temperature that rises above 40 degrees C, producing multi-organ dysfunction. It carries a high mortality rate, and in survivors, a risk of permanent neurological damage. OBJECTIVE: To investigate predictors of multiple organ dysfunction syndrome in patients presenting with heatstroke. METHODS: We investigated 28 patients admitted to a hospital in southern India during the period January 1998 to December 2001. Using a standard form, we collected data on the patients' characteristics, laboratory data, and outcome, and compared those with multiple organ dysfunction with those without such dysfunction. RESULTS: We found that more than three quarters of the studied patients developed multiple organ dysfunction, with the most common dysfunction being respiratory failure. Among the selected predictors, metabolic acidosis 14 of 16 patients, 87.5%; p = 0.011, elevated CPK 17 of 19 patients, 89.5%; p = 0.005, and liver enzymes elevated more than twice the normal (11 of 18 patients, 61%; p = 0.02) had the highest correlation with dysfunction of two or more organs. CONCLUSIONS: The high mortality observed in heatstroke is secondary to multi-organ dysfunction, and among the various parameters assessed, high levels of CPK (>1000 IU/l), metabolic acidosis, and elevated liver enzymes are predictive. Aggressive measures to lower the body temperature with other supportive therapy could substantially reduce the mortality.

Acidosis↗
PubMed2005

Predictors of mortality in mechanically ventilated patients.

OBJECTIVES: There are scarce data from India validating scoring systems used to predict outcome in patients requiring mechanical ventilation. This study prospectively compared the organ system failure (OSF), the acute physiology and chronic health evaluation (APACHE) II, and the APACHE III, scores on patients requiring mechanical ventilation in the medical intensive care unit, to predict outcome. METHODS: 200 consecutive patients requiring mechanical ventilation in a medical intensive care unit were recruited. OSF, APACHE II, and APCHE III scores were calculated at admission and daily for one week or until discharge in all patients. Other variables recorded include age, sex, diagnosis, oxygen therapy before ventilation, complications on ventilation, duration in hospital before ventilation, duration of ventilation, type of respiratory failure, alveolar arterial oxygen gradient, P/F ratio, use of tracheostomy, time on ventilator before tracheostomy, muscle relaxant used, fluid balance, inotrope support. Logistic regression analysis and area under the curve were computed to determine which variables independently predict outcome. RESULTS: Of the 200 patients, at discharge 143 patients (71.5%) had died. The factors that independently predicted outcome among these patients on mechanical ventilation were the type of respiratory failure (type I) OR = 2.7 (p = 0.02), the use of inotropes OR 2.4 (p = 0.04), and the APACHE II score OR = 1.8 (p = 0.008) for every five point increase in APACHE II score. CONCLUSIONS: Type 1 respiratory failure, the use of inotropes, and the APACHE II score measured at admission are significant independent predictors of mortality in the patients on mechanical ventilation.

APACHE↗
PubMed2005

Disease and injury among participants in the Agricultural Health Study.

The Agricultural Health Study (www.aghealth.org) is a cohort of 89,658 pesticide applicators and their spouses from Iowa and North Carolina assembled between 1993 and 1997 to evaluate riskfactorsfor disease in ruralfarm populations. This prospective study is just now reaching sufficient maturity for analysis of many disease endpoints. Nonetheless, several analyses have already provided interesting and important leads regarding disease patterns in agricultural populations and etiologic clues for the general population. Compared to the mortality experience of the general population in the two states (adjusted for race, gender, age and calendar time), the cohort experienced a very low mortality rate overall and for many specific causes and a low rate of overall cancer incidence. A few cancers, however, appear elevated, including multiple myeloma and cancers of the lip, gallbladder, ovary, prostate, and thyroid, but numbers are small for many cancers. A study of prostate cancer found associations with exposure to several pesticides, particularly among individuals with a family history of prostate cancer. Links to pesticides and other agricultural factors have been found for injuries, retinal degeneration, and respiratory wheeze. Methodological studies have determined that information collected by interview is unbiased and reliable. A third round of interviews scheduled to begin in 2005 will collect additional information on agricultural exposures and health outcomes. The study can provide data to address many health issues in the agricultural community. The study investigators welcome collaboration with interested scientists.

Accidents, Occupational↗
PubMed2005

The use of a structured form during urology out-patient consultations -- a randomised controlled trial.

OBJECTIVES: To compare the completeness of documentation in the medical record using a structured form (SF) versus a traditional medical record (TMR). METHODS: Randomised controlled trial comparing the use of SF and TMR in urology out-patient clinics for documentation of 15 items of clinical information, time taken to complete and acceptability to clinicians assessed by a self-completion questionnaire.in a teaching and district general hospitals. RESULTS: Four hundred new urology patient consultations, 11 clinicians. Completeness of information was compared between groups based on the medical record alone (SF vs. TMR), medical record plus letter to GP and letter alone. SFs were significantly (p<0.0001) more complete than TMRs for the majority of the items in all three groups. There was no significant difference in the time taken to document information using either type of record. The clinicians generally found the SF acceptable for routine use. CONCLUSIONS: Structured forms significantly improved the completeness of documentation for new out-patient consultations in urology.

Ambulatory Care↗
PubMed2004

A multi-laboratory evaluation of a common in vitro pepsin digestion assay protocol used in assessing the safety of novel proteins.

Rationale. Evaluation of the potential allergenicity of proteins derived from genetically modified foods has involved a weight of evidence approach that incorporates an evaluation of protein digestibility in pepsin. Currently, there is no standardized protocol to assess the digestibility of proteins using simulated gastric fluid. Potential variations in assay parameters include: pH, pepsin purity, pepsin to target protein ratio, target protein purity, and method of detection. The objective was to assess the digestibility of a common set of proteins in nine independent laboratories to determine the reproducibility of the assay when performed using a common protocol. Methods. A single lot of each test protein and pepsin was obtained and distributed to each laboratory. The test proteins consisted of Ara h 2 (a peanut conglutin-like protein), beta-lactoglobulin, bovine serum albumin, concanavalin A, horseradish peroxidase, ovalbumin, ovomucoid, phosphinothricin acetyltransferase, ribulose diphosphate carboxylase, and soybean trypsin inhibitor. A ratio of 10U of pepsin activity/microg test protein was selected for all tests (3:1 pepsin to protein, w:w). Digestions were performed at pH 1.2 and 2.0, with sampling at 0.5, 2, 5, 10, 20, 30, and 60min. Protein digestibility was assessed from stained gels following SDS-PAGE of digestion samples and controls. Results. Results were relatively consistent across laboratories for the full-length proteins. The identification of proteolytic fragments was less consistent, being affected by different fixation and staining methods. Overall, assay pH did not influence the time to disappearance of the full-length protein or protein fragments, however, results across laboratories were more consistent at pH 1.2 (91% agreement) than pH 2.0 (77%). Conclusions. These data demonstrate that this common protocol for evaluating the in vitro digestibility of proteins is reproducible and yields consistent results when performed using the same proteins at different laboratories.

Clinical Laboratory Techniques↗
PubMed2004

Acute urinary retention: a review of the aetiology and management.

Acute retention of urine (AUR) is a common urological emergency characterised by a sudden inability to pass urine associated with lower abdominal pain. In recent years, the natural history and incidence of AUR has become better understood, however, further research into methods to prevent it and evaluation of the impact an episode of AUR has on the patient is required. This review provides an overview of the current management of AUR in men and the impact of the condition on patients' quality of life.

Abdominal Pain↗
PubMed2004

Genital syndromes and syndromic management of vaginal discharge in a community setting.

The objective of the study was to determine the community prevalence of genital syndromes in women and evaluate the syndromic management of vaginal discharge in this setting. A representative sample for the state of Tamilnadu was chosen using probability proportional to size cluster technique. Thirty clusters were selected from three districts. Demographic, sexual behaviour, risk factors, clinical and laboratory data were collected from the selected population using a structured questionnaire. Direct smear examination for Trichomonas vaginalis, culture for Neisseria gonorrhoeae and Haemophilus ducreyi, serological tests for syphilis (RPR and TPHA), hepatitis B (Hbs Ag ELISA), IgM and IgG antibodies to HSV2 (Novum diagnostics, Germany) and PCR test for detection of C. trachomatis from urine were done. There were 1157 women in the selected population. On examination, vaginal discharge was the most common genital syndrome (38.4%). The sensitivity, specificity, positive and negative predictive value of vaginal discharge as a marker for STD in women was found to be 43.3%, 61.6%, 10.7% and 91.1%, respectively. We concluded that treatment on the basis of syndromic management would result in over-treatment of 90% of women with vaginal discharge.

Adult↗
PubMed2004

A comparative study on idiopathic pulmonary fibrosis and secondary diffuse parenchymal lung disease.

BACKGROUND AND AIMS: Clinical characteristics of patients diagnosed to have Diffuse parenchymal lung disease (DPLD) were evaluated in this study. DESIGN AND SETTING: Retrospective evaluation, a tertiary care center in South India. MATERIAL AND METHOD: Subjects diagnosed to have DPLD over a five-year period were included in this study. Data pertained to clinical characteristics and lab parameters were obtained. STATISTICAL CONSIDERATIONS: t- test for Mean values and chi-square test for comparing proportions were used. RESULTS: There were 73 eligible patients included for evaluation. Secondary cause for DPLD was diagnosed in 40 (55%) and idiopathic pulmonary fibrosis (IPF) was diagnosed in 33 (45%). The mean age was 45+/-11 and 53+/-10 years, of these 5 (12%) and 17 (52%) were male subjects in the secondary DPLD and IPF group respectively. The mean age, dyspnoea, cough, clubbing and crepitations were noted to be higher in patients with IPF as compared to patients with secondary DPLD. Fifty patients were followed up for a mean of 13 months (28 secondary DPLD and 18 IPF). Follow up data was available in 46 patients. Of these subjects prednisone alone was initiated in 24 subjects and combination with azathioprine in 22. Subjective improvement in symptoms was noted in 29/46 (63%), 19 with secondary DPLD and 10 with IPF. CONCLUSION: symptoms and signs were noted more frequently with IPF, subjective improvement to treatment was noted in 63% and the best response was noted among patients diagnosed to have sarcoidosis. A prospective trial is needed to study the long term prognosis and therapeutic response among Indian patients.

Diagnosis, Differential↗
PubMed2003

Microbial quality of domestic and imported brands of bottled water in Trinidad.

A cross-sectional study was conducted to determine the microbial quality of domestic and imported brands of bottled water available in Trinidad, purchased from six geographical regions in Trinidad, and representing the whole island. A sample size of 344 bottles of water was determined by using a precision rate of 2% and a Type 1 error of 5%. The membrane filter technique was used with cultures grown on m-Endo agar and m-FC agar for total coliforms and thermotolerant coliforms, respectively. Aerobic plate count (APC) was determined on nutrient agar; Pseudomonas aeruginosa was detected on MacConkey agar, Escherichia coli was isolated on eosin methylene blue (EMB) and Salmonella spp. was assayed by using standard methods. Of the 344 water samples tested, 262 (76.2%) and 82 (23.8%) were domestic and imported brands, respectively. Eighteen (5.2%) of the 344 samples contained coliforms with a mean count of 0.88+/-6.38 coliforms per 100 ml, while 5 (1.5%) samples contained E. coli. The prevalence of total coliforms in domestic brands of bottled water was 6.9% (18 of 262) as compared with 0.0% (0 of 82) detected in imported brands. The difference was statistically significant (p=0.004). Similarly, the prevalence of aerobic bacteria in domestic brands of bottled water (33.6%) was significantly higher (p=0.001) than was found in imported brands (14.8%). Twenty-six (7.6%) of the total samples of water contained Pseudomonas species, but all were negative for thermotolerant coliforms and Salmonella spp. It was concluded that based on the recommended zero tolerance for coliforms in potable water, 5% of bottled water sold in Trinidad could be considered unfit for human consumption.

Bacteria↗