A mechanistic study on the inhibition of α-chymotrypsin by a macrocyclic peptidomimetic aldehyde.

Here we describe an NMR and X-ray crystallography-based characterisation of the mechanism by which a new class of macrocyclic peptidomimetic aldehyde inhibits α-chymotrypsin. In particular, a (13)C-labelled analogue of the inhibitor was prepared and used in NMR experiments to confirm formation of a hemiacetal intermediate on binding with α-chymotrypsin. Analysis of an X-ray crystallographic structure in complex with α-chymotrypsin reveals that the backbone adopts a stable ß-strand conformation as per its design. Binding is further stabilised by interaction with the oxyanion hole near the S1 subsite and multiple hydrogen bonds.

The Epstein-Barr virus encoded latent membrane protein 2A augments signaling from latent membrane protein 1.

The frequent coexpression of the EBV-encoded latent membrane proteins LMP1 and LMP2A/B in virus-associated tumors suggests that these two proteins may cooperate in the transformation process. While LMP2A is unable to directly activate the NF-kappaB and AP-1 pathways, we found that coexpression of LMP2A with LMP1 resulted in a significant enhancement of LMP1-mediated activation of these pathways. This enhancement was found to be critically dependent on the tyrosine residues present within the ITAM motif (Y74/Y85) and, to a lesser extent, the tyrosine at position 112 (Y112). Subsequent analysis revealed that LMP2A is able to stabilize and modulate the turnover of LMP1 by extending its half-life. This ability does not require a direct physical interaction between the two proteins but rather, results from an indirect effect of LMP2A on the turnover of the LMP1 protein. This study highlights an important role for LMP2A as a modulator of LMP1 activity in epithelial cells.

What do young adolescent New Zealanders eat? Nutrient intakes of a nationwide sample of form 1 children.

AIM: To determine the nutrient intakes of a nationwide sample of form 1 children (aged 10-11 years), and to identify possible areas of nutritional concern. METHOD: Ten form 1 classes (322 children) were chosen as a nationally representative but nonrandom sample. A 24-hour dietary record was used to obtain quantitative information on all food and beverages consumed. Mean daily intakes were compared with Australian recommended dietary intakes (RDIs) for ages 8 to 11 years. Mean percentage contributions made by selected macronutrients to total energy intake, were compared to targets set for adult New Zealanders. RESULTS AND DISCUSSION: The final sample comprised 251 children (114 boys, 137 girls) aged 10 to 11 years. Mean energy intake was 8.32 MJ/d (boys) and 7.97 MJ/d (girls). These intakes were within the Australian recommended range for 10 to 11 year olds. Snacks contributed a mean of 30 percent to the daily energy intake of this sample. The mean percentage of daily energy from total fat was 36% (boys) and 35% (girls), close to the target set for adult New Zealanders. However, polyunsaturated fatty acids (PUFA) provided only 4% of mean daily energy compared to the 8% recommended for adults. Sugar intake was considered too high, with total sugars contributing one quarter of daily energy. This group would probably benefit from increased consumption of complex carbohydrate including fibre, and less refined sugar. Nearly half of the girls sampled had a calcium intake less than 70% of the Australian RDI. This result is of concern with respect to maintaining positive calcium balance for achievement of peak bone mass. Mean sodium intake was high at approximately 100 mmol/d, despite no information on salt added during cooking and before eating. Intake of zinc and vitamin B6 was considered to be too low with over one-third of the sample consuming less than 70% of the Australian RDI.

EDI experts realistic and optimistic.

Recently, Healthcare Financial Management contacted five EDI experts to discuss a variety of issues related to EDI and the healthcare industry. Their answers to our questions, presented below, are both optimistic and realistic. Our experts feel that EDI can transform the healthcare industry into a model of efficiency, but their enthusiasm is tempered by the realization that politics, bureaucracy, budgets, and resistance to change can take a toll on even the most ardent of EDI supporters. Nevertheless, they believe that EDI can and will work. In the pages that follow, they discuss why, how, and when.

How to maintain control over the work of accounts receivable service firms.

Healthcare organizations that enter agreements with accounts receivable consulting firms should insist on various contractual safeguards. These controls allow a hospital to reject any recommendation without incurring extra costs; approve the format of bills sent to potential payers and review copies of bills later produced; insist that consultants identify themselves to payers as hospital representatives, not employees; and protect their interests in other ways.

Risk sharing: health care's latest challenge.

With pressure building to reduce healthcare costs, relations between providers and insurers in the years ahead increasingly will focus on risk sharing and utilization controls. Fixed price agreements and managed care plans are two approaches expected to come into wider use. To cope with coming utilization reviews and efforts to manage outpatient care, hospitals will need information systems allowing them to evaluate patient mixes and service intensities.

Geometrical aspects of sorted patterned ground in recurrently frozen soil.

A model for sorted patterned ground shows that some types arise from density-driven Rayleigh free convection that occurs during thawing of water-saturated recurrently frozen soils. The regularly spaced convection cells result in an uneven melting of the underlying ice front. Frost action causes stones to be upthrusted and to form in a pattern on the ground surface that mirrors the corrugation in the underlying ice front. The implications of the water circulation direction in the cells on the sorting process are considered.