Prophylactic and curative effects of Bacopa monniera in gastric ulcer models.

Bacopa monniera Wettst. (BM, syn. Herpestis monniera L; Scrophulariaceae), is an Ayurvedic drug used as a rasayana. Its fresh juice was earlier reported to have significant antiulcerogenic activity. In continuation, methanolic extract of BM (BME) standardized to bacoside-A content (percentage-38.0 ± 0.9), when given in the dose of 10–50 mg/kg, twice daily for 5 days, showed dose-dependent anti-ulcerogenic on various gastric ulcer models induced by ethanol, aspirin, 2 h cold restraint stress and 4 h pylorus ligation. BME in the dose of 20 mg/kg, given for 10 days, twice daily showed healing effects against 50% acetic acid-induced gastric ulcers. Further work was done to investigate the possible mechanisms of its action by studying its effect on various mucosal offensive acid-pepsin secretion and defensive factors like mucin secretion, mucosal cell shedding, cell proliferation and antioxidant activity in rats. BME 20 mg/kg showed no effect on acid-pepsin secretion, increased mucin secretion, while it decreased cell shedding with no effect on cell proliferation. BME showed significant antioxidant effect per se and in stressed animals. Thus, the gastric prophylactic and curative effects of BME may be due to its predominant effect on mucosal defensive factors.     

On the computation of the tertiary structure of globular proteins—IV. Use of secondary structure information

The distance geometry approach for computing the tertiary structure of globular proteins emphasized in this series of papers (Goelet al., J. theor. Biol. 99, 705–757, 1982) is developed further. This development includes incorporation of some secondary structure information—the location of alpha helices in the primary sequence—in the algorithm to compute the tertiary structure of alpha helical globular proteins. An algorithm is developed which estimates the interresidue distances between chain-proximate helices. These distances, in conjunction with the global statistical average distances obtainable from a database of real proteins and determined by the primary sequence of the protein under study, are used to determine the tertiary structure. Five proteins, parvalbumin, hemerythrin, human hemoglobin, lamprey hemoglobin, and sperm whale myoglobin, are investigated. The root mean square (RMS) errors between the calculated structures and those determined by X-ray diffraction range from 4.78 to 7.56 Å. These RMSs are 0.21–2.76 Å lower than those estimated without the secondary structure information. Contact maps and three-dimensional backbone representations also show considerable improvements with the introduction of secondary structure information.     

Simulation of cellular compaction and internalization in mammalian embryo development as driven by minimization of surface energy

A model based upon minimization of surface energy is proposed as an explanation for compaction and internalization of cells during mammalian embryo development. The model is used to simulate and graphically display these phenomena on a computer.     

Nonionic contrast media: economic analysis and health policy development.

The replacement of old radiologic contrast media with supposedly safer but more expensive media has created a dilemma for radiologists and hospital administrators. To quantitate the nature of this trade-off we performed a cost-utility analysis using optimistic assumptions that favoured the new media. A complete conversion to the new media would result in an incremental cost of at least $65,000 to gain 1 quality-adjusted life-year (QALY). For a selective strategy in which only high-risk patients would receive the new media the cost would be about $23,000 per QALY gained. However, the incremental cost for low-risk patients is over $220,000 per QALY gained. Conversion to the new contrast media, although not necessarily the most efficient use of scarce resources, has already occurred in Ontario, primarily because of press publicity, pressure from insurers and a political unwillingness of policymakers to decide the fate of identifiable victims. We found that funding of a new intervention associated with a high cost-utility ratio rather than interventions with lower ratios might save some identifiable victims at the expense of a larger number of unidentifiable ones.     

Fine needle aspiration cytologic diagnosis of the solitary cold thyroid nodule. Comparison with ultrasonography, radionuclide perfusion study and xeroradiography

Thirty-six cases of solitary and scintigraphically "cold" thyroid nodules were studied by fine needle aspiration (FNA) cytology, ultrasonography, radionuclide perfusion study (RPS) and xeroradiography with the aim of differentiating the neoplastic from the nonneoplastic nodules. Histologic study of the excised specimens provided the definitive diagnosis in all cases. Of the techniques used in this study, FNA cytology and RPS had the highest sensitivities and specificities. Ultrasonography and xeroradiography were of limited use due to their low sensitivity rates.     

Micropropagation of Sterculia urens Roxb. — an endangered tree species

An in vitro procedure for large scale multiplication of Sterculia urens Roxb. (Gum Kadaya Tree) has been developed using cotyledonary node segments. An average of 4.0 shoots per node were obtained on Murashige and Skoog's (MS) medium containing 2.0 mgl^–1 6-benzyl amino-purine (BAP) within 21 days of initial culture. Upon subsequent subculture 16 shoots/node could be harvested every three weeks and upto three times. Sixty per cent of the shoots were successfully rooted. Rooted plantlets were transferred to plastic pots containing soil under mist house conditions before they were finally exposed to an external environment. Fifty seven per cent of the plantlets survived in nursery sheds.     

ABC transporters mined through comparative transcriptomics associate with organ-specific accumulation of picrosides in a medicinal herb,Picrorhiza kurroa

Protoplasma - Picrorhiza kurroa Royle ex Benth is a valuable medicinal herb of North-Western Himalayas due to presence of two major bioactive compounds, picroside-I and picroside-II used in the...     

A novel cyclomaltodextrin glucanotransferase from Bacillus firmus that degrades raw starch

Summary An alkalophilic Bacillus firmus secreting the enzyme cyclomaltodextrin glucanotransferase was isolated from soil. The enzyme attacked raw starch to produce cyclodextrins. Maximum cyclodextrins were produced from tapioca starch followed by potato and corn starch. About 49 % of tapioca starch (at 10 and 50 g/l) was converted to cyclodextrins. The main reaction products were and -cyclodextrins with 40 % and 8 % yield respectively. On prolonged incubation small amount of -cyclodextrin was also produced. The ratio of cyclodextrins was dependent on the initial substrate concentration as well as reaction time.NCL communication number 6203