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Biomedical subjects

T Mathew

Publications and source records attributed to T Mathew.

At least 19 recordsLinked to original sources

Subclinical hypothyroidism, arterial stiffness, and myocardial reserve.

CONTEXT: Subclinical hypothyroidism (SCH) is associated with increased risk of cardiac disease; its impact on arterial function is less clear. OBJECTIVE: The objective of the study was the assessment of arterial and cardiac function. DESIGN: The study was a 6-month controlled observational study using pulse wave analysis and tissue Doppler dobutamine stress echocardiography. SETTING: The study was conducted at a thyroid clinic. PATIENTS: Nineteen female SCH patients with raised TSH, normal free T(4), and no cardiovascular disease [aged 49.2 +/- 3.8 yr; body mass index (BMI) 29.9 +/- 6.7 kg/m(2)] were recruited from the thyroid clinic, and 10 female controls (aged 50.2 +/- 3.4 yr; BMI 29.7 +/- 7.2 kg/m(2)) also participated in the study. INTERVENTIONS: Incremental doses of l-thyroxine were used. MAIN OUTCOME MEASURES: Indices of vascular stiffness and left ventricular echocardiographic function were measured. RESULTS: Baseline augmentation gradient was elevated in SCH, compared with controls [10.3 +/- 5.1 (sd) mm Hg vs. 8.0 +/- 4.2, P < 0.05]; when euthyroid (mean T(4) dose 114 mug/d), it fell to 8.8 +/- 5.3 mm Hg (P < 0.05). Heart rate-corrected augmentation index was 26.7 +/- 9.9 vs. 18.8 +/- 9.9% (P < 0.02), falling to 19.7 +/- 9.6% (P < 0.001) after treatment. Time of travel of the reflected wave was 139.3 +/- 11.7 msec, compared with 141.5 +/- 8.8 msec in controls (P < 0.05), increasing to 144.9 +/- 11.9 msec (P < 0.05). There were no differences in resting global, regional left ventricular function, or regional myocardial velocities during maximal dobutamine stress between SCH patients and controls, or in treated patients, compared with baseline. CONCLUSIONS: Arterial stiffness was increased in SCH and improved with l-thyroxine, which may be beneficial, whereas myocardial functional reserve was similar to controls and remained unaltered after treatment.

Arteries↗

Spontaneous tumour lysis syndrome associated with non-Hodgkin's lymphoma--a case report.

Spontaneous tumour lysis syndrome is characterized by hyperuricemia, hyperkalemia, hyperphosphatemia, metabolic acidosis and hypocalcemia, that occur even prior to the treatment of a neoplasm. This rare occurrence was encountered in a patient with non-Hodgkin's lymphoma (NHL), of follicular cell type. Conservative but intensive treatment led to complete resolution. Subsequent chemotherapy was well tolerated.

Acidosis, Lactic↗

Neurological manifestations of Ehlers-Danlos Syndrome.

Ehlers-Danlos Syndrome (EDS) is more identified for its cutaneous features but its neurological manifestations have not received the focused attention. Four patients of Ehlers-Danlos Syndrome (EDS) with neurological manifestations were evaluated for phenotypic data. These four men were from three families and two had consanguineous parentage. The mean age at onset and presentation of neurological symptoms were 10.5 years and 19 years respectively. Patient 1 presented with bilateral optic atrophy, sensorineural deafness, cerebellar ataxia and neuropathy. Patient 2 had marfanoid habitus, chorea and cerebellar ataxia. Patient 3 had action and percussion myotonia, wasting and weakness of sternocleidomastoid and distal limb muscles. Patient 4 had action myotonia, mirror movements of both hands and neuropathy. MRI of brain showed right parietal polymicrogyria. Neuroaxis involvement at multiple levels in EDS may have prognostic significance.

Adolescent↗

Candida tropicalis causing prosthetic valve endocarditis.

The incidence of endocarditis produced by the so-called "opportunists" as a complication of prosthetic valve surgery is progressively increasing in frequency and gradually transforming the clinical picture habitually associated with this disease. Candida endocarditis is an unusual but severe complication caused by Candida albicans or other fungal species. This case and a review of the literature indicate that Candida endocarditis treated with amphotericin B and prosthetic valve replacement may recur months after treatment, and that late recurrent Candida endocarditis, which is difficult to diagnose and treat, may be best prevented by lifelong antifungal suppressive therapy.

Adult↗

Unexpected presentations--four cases of lead poisoning.

OBJECTIVE: To describe the clinical presentation and response to treatment of four patients who presented with abdominal pain and were diagnosed to have lead poisoning. METHODS: After ruling out the more obvious causes of abdominal pain by barium studies, gastrointestinal endoscopies, and biochemical studies, blood lead levels were estimated by atomic absorption spectrophotometry. The patients were treated with oral d-penicillamine. RESULTS: The four patients had blood lead levels from 79 microg/dL to 365 microg/dL. All four of them showed marked improvement in their clinical condition and lowering of blood lead levels on follow up. CONCLUSIONS: Clinicians need to develop a high index of suspicion of lead poisoning as a possible cause of unexplained abdominal pain or altered sensorium, especially against a background of environmental lead contamination in India.

Abdominal Pain↗

A comparative study of the intestinal parasites prevalent among children living in rural and urban settings in and around Chennai.

A comparative analysis of the various intestinal parasites detected among children attending schools was carried out in a rural and urban location in and around Chennai. A total of 324 stool samples were examined by routine microscopy using normal saline and Lugol's iodine preparation as well as by saturated sodium chloride flotation technique. All suspicious samples were subjected to zinc sulphate concentration technique as well as modified Ziehl Neelson stain and Trichrome stains to identify the other uncommon intestinal parasites. Out of 125 specimens tested from the rural location, the overall prevalence of intestinal parasites was 91%. Ascaris lumbricoides was the most common helminthic parasite detected (52.8%) followed by Trichuris trichura (45.6%), Ancylostoma duodenale (37.6%), Strongyloides stercoralis (3.2%) and Hymenolepis nana (1.6%). Giardia lamblia was the most common protozoan parasite detected (16%), followed by Entamoeba histolytica (4%). In contrast under urban settings, out of the 199 stool specimens tested the positivity rate was 33%. Giardia was the most common parasite detected (22.6%) followed by Entamoeba histolytica (10.6%). All other intestinal parasites such as T. trichura (2.01%), H. nana (1.01%) and A. lumbricoides (0.50%) were found to have much lower prevalence in comparison to the rural area tested. Enterobius vermicularis (0.50%) was also detected. Ancylostoma duodenale and Strongyloides stercoralis were not encountered at all in the urban setting studied.

Adolescent↗

Acid-catalyzed isomerization of pivalaldehyde to methyl isopropyl ketone via a reactive protosolvated carboxonium ion intermediate.

Quantitative rearrangement of pivalaldehyde to methyl isopropyl ketone is observed in acids such as trifluoromethanesulfonic acid, anhydrous HF, and trifluoroethyl alcohol-BF3 but not in trifluoroacetic acid. Studies in a mixture of trifluoroacetic acid and trifluoromethanesulfonic acid show that acids with H(o) < or = -11 are able to carry out complete isomerization. These results and density functional theory calculations at the B3LYP/6-31G level suggest that protonated pivalaldehyde undergoes further protosolvation at higher acidities to a reactive superelectrophilic species resulting in rearrangement. A mechanism for the pivalaldehyde rearrangement to methyl isopropyl ketone in strong protic acids involving a reactive protosolvated superelectrophilic intermediate is suggested. Aspects of the related mechanism of the reaction with isobutane with CO in HF/BF3 medium leading to methyl isopropyl ketone are also discussed.

Journal Article↗

Streptococcus agalactiae endocarditis.

Streptococcus agalactiae (S. agalactiae) is a rare cause of infective endocarditis, which is associated with a high mortality rate. Endocarditis in adults is generally related to immunocompromised states. We hereby report the case of a 35 year old man who presented with fever and delirium in whom aortic valve endocarditis due to S. agalactiae was detected. Though most patients with S. agalactiae endocarditis need surgical intervention along with antibiotics, our patient improved with medical therapy alone.

Adult↗

Rapid identification of fluconazole resistance using Chrom agar Candida.

All though extremely rare 10 years ago, antifungal drug resistance is becoming a major problem in certain populations, especially in those infected with HIV. This study was undertaken to study the resistance of Candida species isolated in our hospital to Fluconazole using Chrom agar Candida. The Candida strains which were routinely isolated from clinical specimens like blood, urine, sputum, pus, fluid and homograft isolates were included in the study. 142 Candida isolates were tested by using Chrom agar Candida incorporated with Fluconazole. 16 strains were found to be resistant to Fluconazole and 126 strains sensitive to Fluconazole. Nine were C. tropicalis, 3 C. krusei, 2 C. guillermondii, 1 Geotrichum candidum and one was an unidentified strain of Candida. The MIC of the 16 strains were done using RPMI 1640 medium by macro broth dilution method. MIC of 9 strains was 64 & > 64 ug/ml of 6 strains 32 ug/ml and 1 strain 16 ug/ml.

Agar↗

Rapid identification of fluconazole resistance using Chromagar Candida.

Although extremely rare 10 years ago, antifungal drug resistance is becoming a major problem in certain populations, especially in those infected with HIV. This study was undertaken to study the resistance of Candida species isolated in our hospital to Fluconazole using Chrom agar Candida. The Candida strains which were routinely isolated from clinical specimens like blood, urine, sputum, pus, fluid and homograft isolates were included in the study. 142 Candida isolates were tested by using Chrom agar Candida incorporated with fluconazole. 16 strains were found to be resistant to Fluconazole and 126 strains sensitive to Fluconazole. Nine were C tropicalis, 3 C krusei, 2 C guillermondii, 1 Geotrichum candidum and one was an unidentified strain of Candida. The MIC of the 16 strains were done using RPMI 1640 medium by macro broth dilution method. MIC of 9 strains was 64 & > 64 micrograms/ml of 6 strains 32 micrograms/ml and 1 strain 16 micrograms/ml.

Antifungal Agents↗

Intraoperative somatosensory evoked potential findings in acute and chronic spinal canal compromise.

STUDY DESIGN: Early and long-term postoperative outcome were analyzed by retrospective record review and compared with results of intraoperative somatosensory evoked potential (SEP) findings in 70 patients with chronic lumbar stenosis. SUMMARY OF BACKGROUND DATA: Adverse SEP changes occur in up to 2% of patients during scoliosis surgery and may reverse with intraoperative intervention. Little is known about the short- or long-term results of intraoperative intervention based on adverse SEP changes in patients with chronic lumbar stenosis during lumbar decompression and fusion. OBJECTIVE: To compare intraoperative SEP changes with immediate and long-term neurologic outcome in patients undergoing lumbar decompression, instrumentation and fusion for chronic lumbar stenosis and to determine whether the early correlation between intraoperative SEP deterioration and clinical outcome persisted. METHODS: Monitoring SEPs using an alternating arm and leg stimulation paradigm allowed rapid identification of intraoperative changes. Retrospective record review was conducted without knowledge of intraoperative SEP findings. Clinical and SEP findings were then compared, to determine whether the strong association between intraoperative SEP results and early clinical outcome persisted. RESULTS: Nine of 12 patients who had unilateral intraoperative SEP deterioration that resolved with intervention had no adverse sequelae; the remaining three had new ipsilateral weakness that persisted during a 9-24-month follow-up. Intraoperative SEPs deteriorated in 15% of patients with normal and abnormal baseline SEPs. Intraoperative SEP deterioration could not be predicted by preoperative radicular pain, focal symptomatology or baseline SEP findings. 80% of patients with normal SEPs but only 54% with abnormal SEPs had immediate and sustained pain relief. SEP deterioration that reversed with surgical intervention or high-dose steroids resulted in no adverse neurologic outcome. CONCLUSIONS: Acute, unilateral, unresolved intraoperative SEP deterioration was associated with long-term ipsilateral weakness not predicted by clinical or neurologic findings before surgery. Clinical improvement persisted in 92% of patients, 4% were unchanged, and 4% had persistent neurologic changes during an average 12-month follow-up period. The findings underscore the need for monitoring SEPs during surgery in all patients undergoing invasive lumbar surgery and for rapid identification and intervention should a unilateral SEP change persist.

Acute Disease↗

Diagnosis and risk stratification of patients with anginal pain and non-diagnostic electrocardiograms.

Patients with acute chest pain suggestive of myocardial ischaemia, and normal or non-diagnostic electrocardiograms, form a difficult subgroup for diagnosis and early risk stratification. We prospectively evaluated the role of troponin T (cTnT), troponin I (cTnI), CKMB mass and myoglobin, in the diagnosis and risk stratification of 214 patients with acute chest pain of < or = 24 h and non-diagnostic or normal ECGs admitted directly to the Cardiac Unit of the Royal Victoria Hospital Belfast from the Mobile Coronary Care Unit or the Accident/Emergency Department. This was a single-centre prospective study, and follow-up (3 months) was complete for all patients. Blood was assessed for quantitative cTnT, cTnI, CKMB mass and myoglobin, and qualitative cTnT on admission and at 12 h. Diagnosis of index event and incidence of new cardiac events (death, non-fatal myocardial infarction, revascularization, or readmission for unstable angina) over 3 months were assessed. Based on standard criteria, myocardial infarction occurred in 37/214 (17%), and unstable angina in 72/214 (34%). At 12 h from admission, cardiac troponins had higher sensitivity for the diagnosis of acute coronary syndromes (myocardial infarction and unstable angina) than conventional markers (cTnI 48%, cTnT 38%, CKMB mass 30% or myoglobin 27%). At 3 months, a new cardiac event had occurred in 42/214 (20%). Significantly higher event rates occurred when any of the biochemical markers was elevated, but the statistical significance was highest for patients with elevated cTnI (p < 0.0001). Whilst gender, history of ischaemic heart disease (IHD), stress test response, cTnT, cTnI, CKMB mass and myoglobin were univariate predictors, cTnI at 12 h and stress test response were the only two independent significant predictors for a subsequent cardiac event at 3 months. Raised cTnI at 12 h after admission had the highest sensitivity for the diagnosis of acute coronary syndromes, and was independently associated with a 2-3 times increased risk of future cardiac events within 3 months among patients with acute chest pain suggestive of myocardial ischaemia but with normal or non-diagnostic ECGs.

Aged↗

On the equivalence of meta-analysis using literature and using individual patient data.

When data come from several independent studies for the purpose of estimating treatment control differences, meta-analysis can be carried out either on the best linear unbiased estimators computed from each study or on the pooled individual patient data modelled as a two-way model without interaction, where the two factors represent the different studies and the different treatments. Assuming that observations within and between studies are independent having a common variance, Olkin and Sampson (1998) have obtained the surprising result that the two meta-analytic procedures are equivalent, i.e., they both produce the same estimator. In this article, the same equivalence is established for the two-way fixed-effects model without interaction with the only assumption that the observations across studies be independent. A consequence of the equivalence result is that, regardless of the covariance structure, it is possible to get an explicit representation for the best linear unbiased estimator of any vector of treatment contrasts in a two-way fixed-effects model without interaction as long as the studies are independent. Another interesting consequence is that, for the purpose of best linear unbiased estimation, an unbalanced two-way fixed-effects model without interaction can be treated as several independent unbalanced one-way models, regardless of the covariance structure, when the studies are independent.

Analysis of Variance↗