Effect of partial replacement of sugar with stevia on the quality of kulfi.

Stevia is a natural sweetener obtained from the leaf of Stevia rebaudiana plant. Its refined extract powder is 130-300 times sweeter than sucrose. Besides, it prevents diabetes, decreases weight, prevents tooth decay, increases digestion etc. Dietetic kulfi was produced, in which 50, 60 and 70% sugar was replaced with 0.05, 0.06 and 0.07% refined stevia extract powder respectively. At higher levels of sugar replacement there was a significant decrease in specific gravity, melting rate, carbohydrate percentage and total calorie content and a significant increase in freezing point, hardness and fat, protein, ash and moisture percentage. Kulfi prepared by replacing half the sugar content with stevia was adjudged on par with the control in sensory characteristics. Above 50% sugar replacement resulted in bitterness, lack of brownish appearance and presence of icy texture.

Unusual location for Castleman's disease.

OBJECTIVE: We present the first reported case of persistent, posterior triangle lymphadenopathy in a child, caused by Castleman's disease. CASE REPORT: A seven-year-old boy presented with a painless swelling in the posterior triangle of his left neck, with no compression of the surrounding structures. A histological diagnosis of Castleman's disease was made. Eventual treatment was by complete excision. At six-month follow up, there were no signs of recurrence. CONCLUSION: The causes of persistent cervical lymphadenopathy in children are many. Most are not significant, but some are life-threatening. Castleman's disease should be considered as a possible diagnosis in persistent childhood lymphadenopathy.

Methanococcus jannaschii flap endonuclease: expression, purification, and substrate requirements.

The flap endonuclease (FEN) of the hyperthermophilic archaeon Methanococcus jannaschii was expressed in Escherichia coli and purified to homogeneity. FEN retained activity after preincubation at 95 degrees C+ for 15 min. A pseudo-Y-shaped substrate was formed by hybridization of two partially complementary oligonucleotides. FEN cleaved the strand with the free 5' end adjacent to the single-strand-duplex junction. Deletion of the free 3' end prevented cleavage. Hybridization of a complementary oligonucleotide to the free 3' end moved the cleavage site by 1 to 2 nucleotides. Hybridization of excess complementary oligonucleotide to the free 5' end failed to block cleavage, although this substrate was refractory to cleavage by the 5'-3' exonuclease activity of Taq DNA polymerase. For verification, the free 5' end was replaced by an internally labeled hairpin structure. This structure was a substrate for FEN but became a substrate for Taq DNA polymerase only after exonucleolytic cleavage had destabilized the hairpin. A circular duplex substrate with a 5' single-stranded branch was formed by primer extension of a partially complementary oligonucleotide on virion phiX174. This denaturation-resistant substrate was used to examine the effects of temperature and solution properties, such as pH, salt, and divalent ion concentration on the turnover number of the enzyme.