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Biomedical subjects

H D'Souza

Publications and source records attributed to H D'Souza.

11 recordsLinked to original sources
PubMed2005

Lead in paint and soil in Karnataka and Gujarat, India.

Blood lead surveys in several areas of India have found very high percentages of children with elevated blood lead levels. Fifty-three percent of children under 12 years of age in a seven-city screening had blood lead levels equal to or greater than 10 microg/dL, the level currently considered elevated by the U.S. Centers for Disease Control and Prevention (CDC). A number of these surveys focused on populations near lead smelters or in areas with high lead levels from combustion of lead-containing gasoline. There is little information available, however, on the levels of lead in paint in India and in soil. Field portable X-ray fluorescence analyzers were used to determine environmental lead levels in paint, dust, air, soil, and other bulk samples near several lead-using industries and in the residential environments of children with very high blood lead levels, at least four times as high as the CDC limit. Soils near industrial operations, such as secondary lead smelters, and battery dismantling units contained levels up to 100,000 ppm of lead. Four of 29 currently available paints from five manufacturers measured 1.0 mg/cm2 or above--the current U.S. definition of lead-based paint in housing-after the application of a single coat; four others measured at least 1.0 after three coats, and three others likely reached this level after the application of an additional one or two coats. In 5 of 10 homes of the elevated blood lead children, three or more locations in or around the home were found to have lead paint levels of 1.0 mg/cm2 or higher. Soil exceeding the U.S. standard for residential areas (400 ppm) was found at only one of the houses. Other sources of lead exposure, including traditional ayurvedic medicine tablets, were also observed. Similar surveys would be useful elsewhere in India and in other developing countries.

Data Collection↗
PubMed2004

Study of the relative response factors of various gas chromatograph-flame ionisation detector systems for measurement of C2-C9 hydrocarbons in air.

The assumption of an instrument response that is linear with carbon number is frequently used to quantify atmospheric non-methane hydrocarbons (NMHCs) when using gas chromatography (GC) and detection by flame ionisation detector (FID). In order to assess the validity of this widely used method the results of intercomparison measurements by 14 laboratories across Europe were evaluated. The intercomparison measurements were made on synthetic, gravimetrically-prepared, gas mixtures containing 30 hydrocarbons (C2-C9) in the low ppbv range, using various different GC-FID systems. The response per carbon atom of GC-FID systems to individual NMHCs, relative to that of butane, were found to differ by more than 25% across different systems. The differences were mostly caused by analytical errors within particular GC-FID systems and to a more minor degree by systematic deviations related to the molecular structure. (Correction factors due to the molecular structure would lessen the differences, e.g. by about 5% for olefin compounds.) The differences were larger than 10% even after elimination of obvious outliers. Thus, calibration of GC-FID systems with multicomponent NMHC mixtures is found to be essential whenever the accuracy of NMHC measurements is required to be better than about 10%. If calibration by multicomponent gas mixtures is not possible and effective carbon atom response factors are used to quantify the individual NMHC compounds then the particular analytical system should be carefully characterised and its responses to individual compounds be verified.

Air↗
PubMed2004

Portable lead analyzer to locate source of lead.

OBJECTIVE: To investigate the sources of lead in the environment in children with elevated blood, with the help of a Field Portable X-Ray Fluorescence Analyzer. METHODS: One hundred and seven school children were chosen for this study on a random basis, from Mangalore and Karnataka. Their blood lead was analyzed. Of the cases analyzed, 10 students whose blood lead level was more than 40 microg/dl were investigated using a field portable X-Ray Fluorescence Analyzer. This is the first time such a device has been available for this purpose in India. RESULTS: The 'likely' source of lead exposure could be determined in eight cases which was from the immediate environment of the children like 'lead-based' paint on surfaces in the house, on playground and other exterior equipment; lead storage batteries, contaminated dust and soil and other lead-containing substances. CONCLUSION: The use of an X-Ray Fluorescence Analyser appeared to be useful in determining the source of lead.

Child↗
PubMed1999

Variation in the isocentre of a Philips linear accelerator (SL-20) used for stereotactic radiosurgery/stereotactic radiotherapy.

Stereotactic irradiation, either in the form of stereotactic radiosurgery (SRS) or stereotactic radiotherapy (SRT) of brain lesions requires high precision and submillimetre accuracy in the isocentre, the main determinants being gantry and couch rotations. It is thus necessary to evaluate the isocentre variation due to gantry and couch rotations in the particular setup for SRS/SRT. This paper describes variation in the isocentre of a Philips (now Elekta) SL-20 linear accelerator modified for adapting a couch-mounted radiosurgery system. By considering the isocentre as defined by a mechanical index as the standard, the variations in the isocentre of the linear accelerator were independently measured for the gantry and for couch rotations. The variation in the isocentre for gantry rotation was found to be between 0.1 mm and 0.9 mm, conforming to the submillimetre accuracy required for SRS/SRT. However, the isocentre variation due to couch rotation varied considerably, possibly because the couch is of the RAM type. The isocentre variation due to couch rotation is rectified by microadjusting the couch mount at the time of treatment using a laser target localizing frame. It is our conclusion that a modified linear accelerator can be used for performing SRS/SRT after careful and separate evaluation of the isocentre stability due to gantry and couch rotations.

Brain Neoplasms↗
PubMedDate not supplied

Circumferential periosteal sleeve resection: results in limb-length discrepancy secondary to poliomyelitis.

We report the results of circumferential periosteal sleeve resection of lower-limb bones for mild degrees of limb-length discrepancy (mean, 3.5 cm) secondary to postpolio residual paralysis in 23 patients. Results were expressed by calculating percentage of length discrepancy of the operated-on limb with respect to the normal limb and gain in length in centimeters of the operated-on limb over the normal limb. All patients had a uniform trend of gain in length with response in the femur lasting for approximately 1 year, whereas that in the tibia persisted >2 years. Circumferential periosteal sleeve resection is a safe and reliable method of longitudinal bone-growth stimulation, providing consistent results, especially for mild to moderate discrepancies.

Child↗
PubMedDate not supplied

Rotation fasciocutaneous flap for neglected clubfoot: a new technique.

Skin necrosis and wound problems complicate surgical release of severe neglected clubfoot. This is primarily the result of excessive tension on the skin edges and a poor understanding of the abnormal vascular anatomy in clubfoot. We report a technique of primary skin closure by using a local-rotation fasciocutaneous flap. Posteromedial skin incision is taken. Posterior tibial artery perforators supplying the medial flap and saphenous vein are preserved. After soft-tissue release and correction of deformity, a defect appears in the posteromedial part of wound. Horizontal backcut is taken at proximal part of the incision and entire medial fasciocutaneous flap is rotated inferiorly to cover the defect. Triangular defect appearing proximally is sutured primarily or covered with skin graft. Primary uncomplicated wound healing was achieved within 2 weeks in all 20 rigid and neglected clubfeet (1-7 years) operated on with this technique. This flap is scientifically logical, technically easy, and ensures primary wound healing.

Child↗
PubMedDate not supplied

Musculoaponeurotic fibromatosis of both bones of forearm.

Desmoplastic fibroma is a rare primary tumour of bone. When it does occur, the sites of predilection are the long bones. The following is a case report of desmoplastic fibroma involving both bones of forearm in a 12 year old boy with a review of literature.

Bone Neoplasms↗
PubMedDate not supplied

Rotation fasciocutaneous flap for neglected club feet--a new technique.

Skin necrosis and wound problems complicate surgical release of severe neglected clubfoot. This is primarily due to excessive tension on the skin edges and a poor understanding of abnormal vascular anatomy in clubfoot. We report a technique of primary skin closure using a local rotation fasciocutaneous flap using the conventional posteromedial skin incision (Turco). Primary uncomplicated wound healing was achieved within 2 weeks in all 16 rigid and neglected clubfeet (1-7 years) operated by this technique. This flap is scientifically logical, technically easy and ensures primary wound healing.

Child↗
PubMedDate not supplied

Talectomy in arthrogryposis: analysis of results.

Talectomy is recommended as a primary or salvage procedure for management of rigid or recurrent equinovarus deformity in arthrogryposis. Twenty-one feet (11 children) that had undergone talectomy were reviewed at a mean follow-up of 11.1 years (range, 2-24). Fourteen (73.7%) feet were satisfactory at final review, whereas five (26.3%) had an unsatisfactory result. Attention to technical details and accurate positioning of calcaneus in the ankle mortise are the two important prerequisites to guarantee a satisfactory long-term result. Fusion of the tibiocalcaneal articulation in optimal position, either spontaneous or induced, is a favorable sign, as it ensures lasting correction of the deformity. The role of a tight and fibrotic tibialis anterior in causing recurrence of severe forefoot adduction and supination is discussed.

Arthrogryposis↗