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Biomedical subjects

A Mehta

Publications and source records attributed to A Mehta.

At least 19 recordsLinked to original sources

Paediatric Northern Score centile charts for the chest radiograph in cystic fibrosis.

AIM: To create the first national centile charts for the chest radiograph Northern Score using the UK Cystic Fibrosis (CF) Database (UKCFD). MATERIALS AND METHODS: All active patients for 2002 from the UKCFD were analysed in 1-year cohorts from 0 to 18 years. Northern Score results from the annual review forms were used to construct centile lines for the 5th, 25th, 50th, 75th, 95th centiles. RESULTS: There were 1806 patients with recorded Northern Score data for 2002 (927 male patients, male:female ratio 1.05). The centile chart demonstrates a quasi-linear rise throughout childhood. A Northern Score in excess of age in years equates to >95th centile in school-aged CF patients. CONCLUSION: This centile chart provides a disease-specific reference range for monitoring individual patients or for evaluating therapeutic change using the dominant chest radiograph scoring system in the UK. Patients, parents and clinicians may find these useful during the annual review process.

Aging↗

Evaluation of the efficacy and safety of etoricoxib compared with naproxen in two, 138-week randomised studies of patients with osteoarthritis.

OBJECTIVES: To assess the efficacy and safety of etoricoxib 60 mg once daily and naproxen 500 mg twice daily over a 138-week treatment period in patients with osteoarthritis (OA). METHODS: Two 1-year randomised, double blind, parallel group two-part base studies (part I 12 weeks; part II 40 weeks), followed by an 86-week extension, in patients with OA (hip or knee) were conducted at 80 clinical centres (19 countries). The studies had identical designs. Patients taking placebo in part I received etoricoxib or naproxen (1:1 ratio) in part II and the extension; patients taking etoricoxib or naproxen in part I continued to receive the same treatment throughout the entire length of the studies. Co-primary efficacy end points were patient global assessment of disease status, and WOMAC questionnaire pain subscale and physical function subscale (100 mm VAS). Efficacy over 138 weeks was assessed by graphical analysis. Safety was assessed by observation of adverse experiences and laboratory and physical evaluations. RESULTS: 997 patients entered (615 completed) the base studies. Of these patients, 463 patients entered the extensions. A total of 161 and 152 patients in the etoricoxib and naproxen groups, respectively, completed 138 treatment weeks. Etoricoxib and naproxen showed similar efficacy throughout the 138 weeks of treatment. For etoricoxib and naproxen, respectively, WOMAC pain assessments were 67 and 67 mm (baseline); 28 and 29 mm (1 year), and 34 and 33 mm (138 weeks). Results for the other efficacy end points were similar to those seen with the WOMAC pain assessments. Both etoricoxib and naproxen were generally well tolerated. CONCLUSION: Both etoricoxib and naproxen demonstrated long-term clinical efficacy for the treatment of OA. Etoricoxib and naproxen were generally well tolerated.

Adult↗

Nanofabrication of a space-variant optical transmission filter.

A space-variant optical transmission filter is demonstrated for which a simplified process is used to tailor the spatial response of the filter across the surface of a single wafer. A multilayer stack, of alternating high or low refractive index dielectric materials, was used to produce a narrow transmission notch in the center of a wide stop band. Subsequent patterning and etching of arrays of holes through the volume of the dielectric stack was performed to control the fill factor of the dielectric in the layers. The position of the transmission notch within the reflection spectrum was varied across the device surface by adjusting the hole diameter of the hole arrays. Experimental and numerical simulation were used to confirm the space-variant transmission characteristics of a single-wafer sample with two zones of different hole diameter arrays in the 1550 nm wavelength regime.

Journal Article↗

Agalsidase alpha and hearing in Fabry disease: data from the Fabry Outcome Survey.

Fabry disease is an X-linked lysosomal storage disorder characterized by multi-organ dysfunction, including hearing loss - mainly sensorineural. The recent introduction of enzyme replacement therapy (ERT) has resulted in improvements in renal and cardiac function, pain and quality of life. One study has also suggested small improvements in high-frequency hearing. In this paper, we study the effect of ERT on hearing in patients in the Europe-wide database - the Fabry Outcome Survey (FOS). Twenty-six patients in FOS had pure-tone audiometry performed up to 6 months before starting ERT with agalsidase alpha and after a median of 12 months of treatment. We assessed changes in hearing thresholds, expressed as deviations from the 50th centile of the normal population (International Organization for Standardization ISO 7029) to correct for age-related non-specific hearing deterioration. Hearing did not change significantly in ears with normal hearing (less than 10 dB deviation from the 50th centile of ISO 7029) or those with severe hearing loss (more than 40 dB deviation from the 50th centile of ISO 7029) at baseline. In ears with a mild or moderate hearing loss at baseline, hearing thresholds, expressed as deviations from the normal 50th centile, improved significantly by 4-7 dB at most frequencies (P < 0.05). Agalsidase alpha stabilizes, and possibly improves, hearing in Fabry patients who have not already progressed to severe hearing loss. Further follow-up of these patients will determine the longer-term effects of ERT.

Adult↗

Hearing loss in Fabry disease: data from the Fabry Outcome Survey.

Hearing loss is a common symptom in Fabry disease, but neither its natural course nor its aetiology has been defined precisely. The aim of this study was to provide a detailed epidemiological description of hearing impairment in patients in the Fabry Outcome Survey (FOS), which is the largest available database of Fabry patients. Questionnaires were completed by 566 Fabry patients, of whom 316 reported ear-related symptoms. Pure-tone audiograms from 86 patients, performed before starting enzyme replacement therapy, were analysed and compared with age- and sex-specific normal values (International Organization for Standardization, ISO 7029). When compared to an age-matched population (ISO 7029), 74% of patients had a threshold elevated above the 95th centile in at least one tested frequency. All frequencies were affected to a similar degree. However, only 14 patients (16%) were clinically affected by hearing impairment according to the age-independent World Health Organization (WHO) classification (mean threshold at 0.5, 1 and 2 kHz worse than 25 dB). Hearing loss was sensorineural in 63 patients (73%) of whom 7 patients (8%) had also a conductive component. One patient had a purely conductive hearing loss. Episodes of sudden hearing loss seemed to occur more frequently than in the general population. Men were affected earlier and more severely than women. Hearing in Fabry disease is significantly worse than in an age-matched general population but leads to clinically relevant hearing impairment in only 16% of cases. It resembles accelerated presbycusis with an additional Fabry-specific strial-type hearing loss.

Adolescent↗

Hyperhidrosis: a new and often early symptom in Fabry disease. International experience and data from the Fabry Outcome Survey.

Hypohidrosis is a classic feature of Fabry disease; in contrast, hyperhidrosis has only been rarely described. The aim of the study is to characterise the baseline descriptive data on hyperhidrosis (frequency, age at onset, sex ratio and outcome with and without enzyme replacement therapy) in hemizygous male and heterozygous female patients with Fabry disease. We describe case histories of five patients with Fabry disease and hyperhidrosis seen at three different centres. We have also analysed a cohort of 21 paediatric patients in the UK and a large European cohort of patients enrolled in the Fabry Outcome Survey (FOS). Five patients (three female, two male) with hyperhidrosis were originally identified, although each had additional symptoms related to Fabry disease. The age at onset of hyperhidrosis was less than 18 years in four cases. In the cohort of 21 paediatric patients (12 female, nine male), one female had hyperhidrosis; the age at onset of this symptom was 11 years. In the FOS cohort, 66 of 714 patients with Fabry disease had hyperhidrosis (44 of 369 females, 11.9%; 22 of 345 males, 6.4%). The female predominance was observed in seven of nine countries from which data were analysed. Hyperhidrosis is an increasingly recognised feature of the Fabry disease phenotype. It is more prevalent in females than in males and often appears in childhood or adolescence. The efficacy of enzyme replacement therapy on this recently recognised symptom should be assessed.

Adolescent↗

Hepatic veno-occlusive disease due to tacrolimus in a single-lung transplant patient.

Hepatic veno-occlusive disease is defined as nonthrombotic fibrous obliterative endophlebitis of small centrilobular hepatic venules. Clinically, patients present with elevated liver enzymes and a triad of jaundice, hepatomegaly and ascites. Although reported as a complication of other solid organ and stem cell transplantation, there have been no reported cases to date of veno-occlusive disease following lung transplantation. The present authors report a case of veno-occlusive disease following single-lung transplantation in a patient on a triple-drug immunosuppressive regimen composed of tacrolimus, mycophenolate mofetil and prednisone. The diagnosis was established by transjugular liver biopsy and by discontinuing tacrolimus; there was clinical regression of symptoms and serological return to baseline.

Female↗

A micromachined electrochemical sensor for free chlorine monitoring in drinking water.

In this work, we designed, fabricated and tested a disposable, flow-through amperometric sensor for free chlorine determination in water. The sensor is based on the principle of an electrochemical cell. The substrate, as well as the top microfluidic layer, is made up of a polymer material. The advantages include; (a) disposability from low cost; (b) stable operation range from three-electrode design; (c) fluidic interconnections that provide on line testing capabilities; and (d) transparent substrate which provides for future integration of on-chip optics. The sensor showed a good response and linearity in the chlorine concentration ranging from 0.3 to 1.6 ppm, which applies to common chlorination process for drinking water purification.

Chlorine↗

Placental site trophoblastic tumour--a case report.

Placental site trophoblastic tumour is a rare form of gestational trophoblastic disease, which seldom metastasizes. It is chemoresistant though has an excellent prognosis after complete resection of the tumour. Its characterization is thus important for treatment and further management. We present an unusual case who presented with ascites of non-neoplastic origin and was found to have metastases to the lymph node.

Adult↗

Enzyme replacement therapy and renal function in 201 patients with Fabry disease.

AIM: Fabry disease is a rare lysosomal storage disorder caused by deficient activity of alpha-galactosidase A, resulting in progressive cellular accumulation of glycolipids, which may ultimately result in endstage renal disease. We examined the effects of enzyme replacement therapy (ERT) with Agalsidase-alpha on renal function using data from a large international database, the Fabry Outcome Survey (FOS). METHODS: This analysis was based on 1,040 serum creatinine measurements in 201 patients with Fabry disease, aged 20 - 60 years, with serum creatinine concentrations of less than 2 mg/dl and duration of ERT of up to 4.7 years. Both pretreatment and treatment data were used to examine independent predictors of changes in serum creatinine. In a second approach longitudinal serum creatinine measurements from 1 year before treatment, at baseline and 1 and 2 years after the start of treatment were analyzed in 20 patients with chronic kidney disease (CKD) Stage 2 and 3. RESULTS: We found an independent negative association between serum creatinine and time on Agalsidase-alpha treatment (p < 0.05). Renal function declined significantly (p < 0.05) in the year before treatment. After 1 year of treatment, however, the decline in estimated glomerular filtration rate had been halted, and renal function was preserved for up to 2 years. CONCLUSIONS: In conclusion, ERT with Agalsidase-alpha is associated with decrease of serum creatinine and may prevent the deterioration of renal function in patients with Fabry disease.

Adult↗

CFTR, chloride concentration and cell volume: could mammalian protein histidine phosphorylation play a latent role?

A considerable body of evidence indicates that the intracellular chloride concentration ([Cl-]i) is an important regulatory signal in epithelial ion transport. [Cl-]i regulates the open channel probability of sodium and chloride channels, the rate of chloride channel recycling to the apical membrane, cell volume homeostasis, the activity of sodium-coupled chloride entry pathways and G-protein activity. Cell volume goes awry in epithelial cells bearing mutant forms of the cystic fibrosis (CF) transmembrane conductance regulator protein (CFTR); however, the pathways that mediate this [Cl-]i effect at the apical membrane of polarized epithelia are unknown. Recently, we proposed a mechanism for the transduction of in vitro chloride concentration into a phosphorylation signal to proteins within the apical membrane of respiratory epithelia. Our studies show that an apically enriched plasma membrane fraction from a variety of species, including sheep, human and mouse airway, contains at least two membrane-bound protein kinases which exhibit a number of novel properties. Firstly, the phosphate is located on histidine residues within different families of proteins; one kinase(s) utilizes GTP rather than ATP as a phosphate donor and each kinase has its own unique profile of membrane protein phosphorylation (which itself varies with anion species). Secondly, both kinases mediate Cl- -dependent phosphorylation of an apical membrane protein around the established physiological values for [Cl-]i in airway epithelial cells ( approximately 40 mM); associated phosphatases also alter the net phosphoprotein profile of the apical membrane. These findings are reviewed and their potential roles explored in relation to the pathogenesis of CF using the control of cell volume as a model for disrupted cellular function in CF-affected epithelia.

AMP-Activated Protein Kinases↗

Needlestick injuries in a tertiary care centre in Mumbai, India.

Accidental exposure from blood/body fluid of patients is a risk to healthcare workers (HCWs). Percutaneous injury is the most common method of exposure to blood-borne pathogens. A policy was formulated at our institute, a tertiary care centre in central Mumbai, and we report a six-year (1998--2003) ongoing surveillance of needlestick injuries. Of the 380 HCWs who reported needlestick injuries, 45% were nurses, 33% were attendants, 11% were doctors and 11% were technicians. On source analysis, 23, 15 and 12 were positive for Hepatitis B surface antigen (HBsAg), human immunodeficiency virus (HIV) and hepatitis C virus (HCV), respectively. Immediate action following potential exposure included washing the wound with soap and water, encouraging bleeding and reporting the incident to the emergency room. Analysis of the source of injuries revealed that known sources accounted for 254 injuries, and unknown sources from garbage bags and Operating Theatre instruments accounted for 126 injuries. Most needlestick injuries occurred during intravenous line insertion (N=112), followed by blood collection (N=69), surgical blade injury (N=36) and recapping needles (N=36). Immediate postexposure prophylaxis (PEP) for HCWs who sustained injuries with hepatitis-B-virus-positive patients included booster hepatitis B immunization for those positive for antiHBs. A full course of immunization with hepatitis B immunoglobulin was given to those who were antiHBs negative. All staff who sustained injury with HIV were given immediate antiretroviral therapy (AZT 600 mg/day) for six weeks. Subsequent six-month follow-up showed zero seroconversion.

Accidents, Occupational↗

Behavioral responses to injections of muscimol into the subthalamic nucleus: temporal changes after nigrostriatal lesions.

Changes in cellular activity in the subthalamic nucleus are a cardinal feature of Parkinson's disease and occur in rodents after lesions of the nigrostriatal pathway, a model of Parkinson's disease. GABA-ergic neurons from the globus pallidus provide a major input to the subthalamic nucleus. Previous electrophysiological studies revealed temporal changes in the activity of pallidal neurons after nigrostriatal lesions in rats. However, little is known about the impact of these changes on GABAergic transmission in the subthalamic nucleus. We have examined the behavioral responses to a local administration of the GABA A agonist muscimol into the subthalamic nucleus. Muscimol (0.01 and 0.1 microg) induced orofacial dyskinesia in normal rats; this response was blunted 2 weeks but enhanced 2 months after a unilateral lesion of the nigrostriatal pathway. The early decrease in the behavioral response occurred at a time when increased expression of mRNA for glutamic acid decarboxylase, the enzyme of GABA synthesis, and burst firing have been reported in the globus pallidus, suggesting an adaptive post-synaptic response to increased GABAergic transmission in the subthalamic nucleus. In contrast, we now show that glutamic acid decarboxylase mRNA is unchanged in the globus pallidus at the later time point, when electrophysiological changes also subside in this region. The increased behavioral response at this later time point may reflect a decreased activity in GABAergic inputs to the subthalamic nucleus. The results show time-dependent changes in behavioral responses to GABA A receptor stimulation in the subthalamic nucleus which may reflect adaptive changes in postsynaptic inhibitory responses after dopaminergic lesions.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗

Successful treatment of hairy cell leukemia variant with rituximab.

Hairy cell leukemia (HCL) variant is a rare low-grade B-cell disorder affecting the elderly or middle-aged population with features intermediate between those of HCL and prolymphocytic leukemia. Unlike HCL, it is resistant to most conventional treatment. We report a case of a 53-year-old man who had refractory thrombocytopenia and lymphocytosis for 8 years. Investigations and analysis of spleen and bone marrow revealed a diagnosis of HCL variant. He opted for treatment with rituximab, a chimeric monoclonal antibody targeting CD 20. There was complete recovery of his full blood count and a bone marrow biopsy performed 3 months post-treatment showed complete remission. This is, to our knowledge, the first reported patient with HCL variant for whom treatment with rituximab was successful, and this treatment needs further investigation.

Antibodies, Monoclonal↗

Isolated central nervous system involvement in adult T-cell lymphoma/leukaemia.

Central nervous system (CNS) presentation of adult T-cell lymphoma/leukaemia is rare, and almost invariably associated with systemic disease. We report an unusual manifestation of adult T-cell lymphoma/leukaemia, with isolated CNS involvement and unusual imaging findings. We also describe objective response to antiviral therapy. To our knowledge, this is the first report of such presentation and response.

Adult↗

Natural history of the cerebrovascular complications of Fabry disease.

UNLABELLED: Fabry disease is a rare, X-linked lysosomal storage disease caused by an inborn deficiency of alpha-galactosidase A, which results in progressive accumulation of globotriaosylceramide in a range of cells and tissues. Neurological symptoms of Fabry disease, including peripheral neuropathy and cerebrovascular events, are among the most significant clinical aspects. In this paper we present the natural history and mechanisms involved in the cerebrovascular complications of Fabry disease using data reported in FOS-- the Fabry Outcome Survey--and other registries and clinical studies. We discuss ways in which these manifestations can be modified by intervention, including both general measures for cerebrovascular disease and enzyme replacement therapy. CONCLUSION: Data from FOS have provided important insights into the natural history of the cerebrovascular complications of Fabry disease. Furthermore, the database has demonstrated that significant renal or cardiac disease often co-exists with cerebrovascular disease, and may predispose patients with Fabry disease to neurological disability and stroke.

Adult↗

Genotype and phenotype in Fabry disease: analysis of the Fabry Outcome Survey.

AIM: Mutations of the gene (GLA) encoding alpha-galactosidase A are implicated in Fabry disease, a progressive, X-chromosomal inherited lysosomal storage disorder. FOS--the Fabry Outcome Survey - was established as a long-term surveillance study to describe the natural course of Fabry disease and its response to enzyme replacement therapy in a large cohort of European patients. Clinical phenotype, age of onset and course of Fabry disease are very variable, even within the same family, which makes it difficult to define a genotype-phenotype relationship by analysing individual patients. The FOS database contains detailed medical information on a large cohort of patients and thus has the potential to provide important information to address this question. METHODS: At the time of analysis, information on 545 patients belonging to 157 families from nine European countries had been entered into the FOS database. A GLA mutation has been reported in 365 individuals (65% and 68% of all males and females, respectively) in FOS. These data were used to analyse the relationship between genotype and phenotype in Fabry disease. RESULTS: A highly significant positive correlation was found between the age at entry into FOS and the FOS Severity Index in male patients with GLA missense mutations (p < 0.001) as well as in those carrying other types of mutations (p < 0.001). A positive correlation was also found between the age at entry into FOS and the number of affected organs in male patients with missense mutations, irrespective of whether the change in the amino acid side chain predicted in the alpha-galactosidase A protein was classified as a conservative or non-conservative change. CONCLUSION: The data presented here suggest that there is a correlation between genotype and clinical severity.

Age Distribution↗