Huge Anterior Mediastinal Teratoma Leading to Orthopnea in a Young Patient

The anterior mediastinal cysts and masses (AMCM) can be of varied origin and presentation. Although the space in the mediastinum is limited the cysts and masses can grow to a large size before the presentation. They displace the adjacent structures and then can grow into the pleural cavities thereby acquiring a large size. We share our experience of a case of a huge anterior mediastinal cystic mass in a young female who had a characteristic presentation of sudden onset breathlessness in the supine position and immediate relief in the sitting position. The patient recovered well after surgical treatment.

Chemical modifications and dissociation characteristics of tyrosine and tryptophan residues in alpha-crystallin.

A quantitative estimation of surface accessibility of aromatic residues in alpha-crystallin from goat lens has been accomplished by chemical modifications using different specific reagents having varying sizes. Results of modification of tyrosine residues with N-acetylimidazole and tetranitromethane when combined with those of ionization studies carried out with hydroxyl ions having the smallest size reveal different classes of tyrosine residues in the native protein: 78 +/- 2 residues have been found to be easily available for modification; among the rest, 94 +/- 2 residues appear to be comparatively less exposed to the reagents while 28 +/- 2 residues are found to be completely unavailable for modification in the native protein and are modified only when the protein is denatured. Modification of tryptophan residues with H2O2 also indicates different classes of these residues available for oxidation at different concentrations of the oxidant. 34 +/- 2 residues of tryptophan are found to be easily oxidized at a lower concentration of H2O2 during the first phase of the reaction. The remaining tryptophan residues appear to be less exposed to the reagent. This is also corroborated from the studies of reactivities of these residues towards another specific but bulkier reagent, 2-hydroxy-5-nitrobenzyl bromide. These surface exposed aromatic residues in alpha-crystallin may be considered to be vulnerable to in vivo oxidative modifications forming insoluble aggregates which may finally contribute to the formation of cataract.

Identification and characterization of some PR-proteins induced by kitazin and Rhizoctonia solani causing sheath blight of rice.

Significant reduction (68.38%) in sheath blight disease of rice was noticed when foliar spray of a systemic fungicide, kitazin (480 micrograms mg-1), was applied twice at an interval of 2 days before inoculation. SDS-PAGE analysis of proteins of Rhizoctonia-infected rice leaf sheaths revealed the presence of 16 proteins ranging from 20 to 90 kDa (approx.). Six were identified as constitutive defense proteins (increased after infection), 6 as secondary defense proteins (formed de novo) and the rest 4 appeared non-defense proteins. Non-inoculated kitazin-treated leaf sheaths showed 15 proteins of which 5 were constitutive and 4 secondary defense proteins (both are PR-proteins). Among the PR-proteins, five beta-1,3-glucanases and one chitinase was identified and characterized. One rice chitinase (MW 20 kDa) and 2 glucanases (60 & 69 kDa) showed serological relationships with tobacco chitinase (32 kDa) and tobacco glucanase (33 kDa) respectively. The implications of results have been discussed in relation to biotic and abiotic induction of PR-proteins in rice.