Quantitative relationships between the measurable transport resistances of membrane carriers: theory and experiment

A theoretical analysis is made of the possible quantitative relationships between the transport resistances that characterise membrane carrier systems. It is shown that there exist only five possible patterns in which to rank the four transport resistances. Symbolising these as A, B, C and D, the five possible patterns are (i) A = B = C = D; (ii) A = B much greater than C, D; (iii) A = B much greater than C = D; (iv) A = B = 2C = 2D; (v) A = 2B = 2C much greater than D. A survey of the available experimental data shows that pattern (ii) is the most prevalent, pattern (v) is often found and pattern (iii) has been identified. None of the ten transport systems so far analysed experimentally failed to fit one of the predicted patterns.     

The case for cloud computing in genome informatics

With DNA sequencing now getting cheaper more quickly than data storage or computation, the time may have come for genome informatics to migrate to the cloud.     

Inhibition of Membrane-Active Peptides by Fatty Acid–Peptide Hybrids

Nine fatty acid–peptide hybrid molecules were constructed using the general formula CH₃(CH₂) _n CO-Phe Asp Cys-amide and tested for their ability to inhibit cell lysis induced by the membrane-active peptide melittin. All of these molecules, where n = 4–14, inhibited the action of melittin to some extent, but the longer carbon chains were most effective. Several potential inhibitors were also constructed with conservative substitutions in the peptide portion of the molecule. All were effective to varying degrees. We concluded that in the hexapeptide inhibitor published by Blondelle et al. (1993), the role of the first three residues is only to provide hydrophobic interaction with the melittin and has no particular amino acid sequence specificity. Some of these inhibitors were found to inhibit the lytic activity of a melittin analogue which had only superficial sequence similarity to melittin and also a truncated form of melittin, indicating the generality of the action of the inhibitors.Deceased 5/4/98     

Detection of Staphylococcal Enterotoxin A,B, and C in Milk By an Elisa Procedure

Enterotoxigenic reference strains of Staphylococcus aureus were cultivated in sterile whole and skim milk for 18 h at 37°G. Staphylococcal enterotoxin A, B, and C were detected directly in the milk by an enzyme linked immunosorbent assay (ELISA), sensitive down to 1 ng/ml. Enterotoxins in the range of 1 ng–20 µg/ml milk were detected without any concentration or extraction. Skim and whole milk were almost identical as medium for enterotoxin production.     

Regulation of G(1) cell-cycle progression by oncogenes and tumor suppressor genes.

Progression of resting quiescent G(0) cells into early G(1) and transition across the restriction point are highly regulated processes. Mutation of proto-oncogenes and tumor suppressor genes regulating these transitions are targeted during oncogenesis. Recent work has underscored the importance of the G(0) to early G(1) transition and metabolism to neoplastic cells.     

Sampling for Explosives-Residues at Fort Greely,Alaska

Fort Greely, Alaska has an extensive complex of weapon training and testing areas located on lands withdrawn from the public domain under the Military Lands Withdrawal Act (PL106-65). The Army has pledged to implement a program to identify possible munitions contamination. Because of the large size (344,165,000 m²) of the high hazard impact areas, characterization of these constituents will be difficult. We used an authoritative sampling design to find locations most likely to contain explosives-residues on three impact areas. We focused our sampling on surface soils and collected multi-increment and discrete samples at locations of known firing events and from areas on the range that had craters, pieces of munitions, targets, or a designation as a firing point. In the two impact areas used primarily by the Army, RDX was the most frequently detected explosive. In the impact area that was also used by the Air Force, TNT was the most frequently detected explosive. Where detected, the explosives concentrations generally were low (<0.05 mg/kg) except in soils near low-order detonations, where the explosive-filler was in contact with the soil surface. These low-order detonations potentially can serve as localized sources for groundwater contamination if positioned in recharge areas.