Paget-Schroetter Syndrome: Review of Pathogenesis and Treatment of Effort Thrombosis

Effort thrombosis, or Paget-Schroetter Syndrome, refers to axillary-subclavian vein thrombosis associated with strenuous and repetitive activity of the upper extremities. Anatomical abnormalities at the thoracic outlet and repetitive trauma to the endothelium of the subclavian vein are key factors in its initiation and progression. The role of hereditary and acquired thrombophilias is unclear. The pathogenesis of effort thrombosis is thus distinct from other venous thromboembolic disorders. Doppler ultrasonography is the preferred initial test, while contrast venography remains the gold standard for diagnosis. Computed tomographic venography and magnetic resonance venography are comparable to conventional venography and are being increasingly used. Conservative management with anticoagulation alone is inadequate and leads to significant residual disability. An aggressive multimodal treatment strategy consisting of catheter-directed thrombolysis, with or without early thoracic outlet decompression, is essential for optimizing outcomes. Despite excellent insights into its pathogenesis and advances in treatment, a significant number of patients with effort thrombosis continue to be treated suboptimally. Hence, there is an urgent need for increasing physician awareness about risk factors, etiology and the management of this unique and relatively infrequent disorder

Classification of Subjects as Slow or Rapid Inactivators of Isoniazid Oral Administration of a Slow-release. Preparation of Isoniazid and Determination of the Ratio of Acetyisoniazid to Isoniazid in Urine

A simple method for classifying subjects as slow or rapid inactivators of isoniazid has beenevaluated on large numbers of patients. The method consists of determining the ratio of acetylisoniazid to isoniazid in a 24-26 h. urine collection following the oral administration of a slow-release preparation of isoniazid 30 mg./kg. body-weight. In a group of 101 patients, there was 100 per cent agreement between the classification based on this method and that based on a standard method, consisting of estimation of the serum isoniazid concentration, 4½ h. after an intramuscular dose of ordinary isoniazid 3 mg./kg. body-weight. Subsequent studies in other patients have confirmed that the method is efficient, and demonstrated that the classification is highly reproducible

Inactivators of Isoniazid, Based on The Ratio of The Urinary Excretion of Acetylisoniazid To Isoniazid

Following an intramuscular injection of isoniazid 3 mg/kg body-weight, the urinary excretion of isoniazid and acetylisoniazid during the periods 0-1, 1-2, 2-3 and 3-4 h was determined for 124 patients with pulmonary tuberculosis. On the same occasion, the serum isoniazid concentration at 4½ h was determined by microbiologic assay. The ratios of acetylisoniazid to isoniazid in the urine collections at 2, 3 and 4 h. were bimodally distributed. Rules were derived from these. ratios for classifying subjects as slow or rapid inactivators of isoniazid. There was 100% agreement between the classification based on each of these ratios and that based on the serum isoniazid concentration at 4½ h

A Modified Method for the Estimation of Acetylisoniazid in Urine

The method of Venkataraman et al. (1968) for the direct estimation of acetylisoniazid in urine has been modified to make it suitable for application to urine specimens containing sugar. The urine is first extracted with a mixture of chloroform and n-butanol, the organic phase re-extracted with dilute sulphuric acid, and the original method then applied to the acid extract. With the modified method, recoveries of acetylisoniazid were quantitative, both in the presence and the absence of glucose. Interference due to hydrazones and isonicotinyl glycine was substantially reduced by the modification, while that due to isoniazid remained the same. There was little or no interference from isonicotinic acid, with either the original or the modified method

Blue luminescence of Au nanoclusters embedded in silica matrix

Photoluminescence study using the 325 nm He-Cd excitation is reported for the Au nanoclusters embedded in SiO2 matrix. Au clusters are grown by ion beam mixing with 100 KeV Ar+ irradiation on Au [40 nm]/SiO2 at various fluences and subsequent annealing at high temperature. The blue bands above ~3 eV match closely with reported values for colloidal Au nanoclusters and supported Au nanoislands. Radiative recombination of sp electrons above Fermi level to occupied d-band holes are assigned for observed luminescence peaks. Peaks at 3.1 eV and 3.4 eV are correlated to energy gaps at the X- and L-symmetry points, respectively, with possible involvement of relaxation mechanism. The blue shift of peak positions at 3.4 eV with decreasing cluster size is reported to be due to the compressive strain in small clusters. A first principle calculation based on density functional theory using the full potential linear augmented plane wave plus local orbitals (FP-LAPW+LO) formalism with generalized gradient approximation (GGA) for the exchange correlation energy is used to estimate the band gaps at the X- and L-symmetry points by calculating the band structures and joint density of states (JDOS) for different strain values in order to explain the blueshift of ~0.1 eV with decreasing cluster size around L-symmetry point.Comment: 13 pages, 7 Figures Only in PDF format; To be published in J. of Chem. Phys. (Tentative issue of publication 8th December 2004

Multi-phonon Raman scattering in GaN nanowires

UV Raman scattering studies show longitudinal optical (LO) mode up to 4th order in wurtzite GaN nanowire system. Frohlich interaction of electron with the long range electrostatic field of ionic bonded GaN gives rise to enhancement in LO phonon modes. Good crystalline quality, as indicated by the crystallographic as well as luminescence studies, is thought to be responsible for this significant observation. Calculated size dependence, incorporating size corrected dielectric constants, of electron-phonon interaction energy agrees well with measured values and also predict stronger interaction energy than that of the bulk for diameter below ~3 nm.Comment: 13 pages, 5 figures, Journa