Conjugation of trypsin by temperature-sensitive polymers containing a carbohydrate moiety: thermal modulation of enzyme activity

Given the substantial increase in the numbers of community psychiatric nurses (CPNs) in England in the last 15 years this paper asks the question: is CPN activity where it should be? In-other words is activity distributed around the country according to need? Various indicators of need are suggested including population age structure, deprivation indices and suicide rates. We find no evidence -- based on information from scatterplots, Spearman correlations and more innovative measures of inequality -- that CPNs are distributed according to need. If this is confirmed by further research it is cause for alarm -- CPNs should be where they are most needed.     

Continuous purification of porcine lipase by rotating annular size-exclusion chromatography

Non-accidental head injury, be it shaking, impact(s) or a combination of the two, is characterised by subdural and/or subarachnoid haemorrhages with retinal haemorrhages, but minimal or absent external cranio-facial trauma. The classical assault scenario depicts the infant being gripped around the head, face, chest and abdomen and shaken or being gripped by a limb and swung. This gripping might be expected to leave physical evidence in the form of bruising. A study was undertaken to establish the prevalence, distribution and pathological association of external bruising in 24 cases of fatal non-accidental head injury in children. At autopsy, 17 cases had new external bruises, 15 old external bruises and 13, a combination of both. However, seven (29%) cases showed no fresh external bruising and five (21%) showed no external bruising at all. Thus, external bruising may be absent in children with fatal intracranial injury. The face was shown to be the commonest site of bruising followed by the forehead and buttocks. Limb, chest and abdominal bruising were found to be uncommon. Retinal haemorrhages were confirmed in 23 (96%) cases. It is hypothesised that bruising, when present, may be a result of abuse in the form of punches and slaps rather than due to gripping during the assault. We discuss why gripping does not necessarily result in external bruising.     

Solution of free radical polymerization

The steady state approximation in free radical polymerization is known to break down during the operation of commercial reactors, in which case the unsteady mole balance of polymer radicals have to be solved numerically. We observed that the differential equations governing the zeroth, first, and second moments of polymer radicals in free radical polymerization are nonlinear in nature. The numerical solution of these is “stiff” because the concentration of polymer radicals is very small. Assuming an isothermal reactor, in the absence of the gel effect, these differential equations can be transformed in a suitable new domain where they are linear and can be solved analytically. We have subsequently developed a computer program for nonisothermal reactors in the presence of the gel effect using the analytical solution between any time increment. The results have been compared with those obtained from the fourth order Runge-Kutta technique. We show that when the temperature changes are fast, the Runge-Kutta technique cannot handle the stiffness, and the results begin to deviate from the exact solution. We find that our computer program is computationally efficient in handling this stiffness, takes considerably less time, and can be adapted to any personal computer.     

Selective plasticization of the ionic domains in a segmented thermoplastic ionene cationomer

The use of zinc stearate as an ionic plasticizer has been demonstrated to function effectively in a segmented ionene cationomer thereby permitting its melt processability. The ionene polymer is prepared by reacting dimethylamino-terminated polytetramethylene oxide (PTMO) oligomers with various benzyl dihalide compounds, leading to a segmented cationomer. Since the unplasticized ionene polymer undergoes degradation near the softening temperature (ca. 180°C), an ionic plasticizer was incorporated as a means of lowering the softening temperature to prevent degradation and permit melt processability. Zinc stearate was utilized in this study as it has been demonstrated to function well in other ionomers (essentially anionomers) in this capacity. Through the utilization of melt rheological and solid-state morphological investigations, it has been clearly shown that zinc stearate will function effectively as an ionic plasticizer in these quite different ionomer materials by lowering the softening temperature to ca. 120°C, thereby permitting melt processability. In addition, due to the crystallization of the zinc stearate following cooling, this same species also serves to enhance the mechanical properties in the solid state.     

Paget bone disease involving young adults in 3 generations of a Korean family

Pancreatic cancer is an aggressive disease with a dismal prognosis. It has long been regarded as one of the most difficult cancers to accurately diagnose and stage preoperatively. The purpose of this review is to provide an update of the state-of-the-art for early detection, diagnosis, and staging of pancreatic cancer. These methods include spiral CT scans, magnetic resonance imaging, positron emission tomography (PET) imaging, laparoscopy, endoscopic ultrasound, CA 19-9 serology, fine needle aspiration cytology, ERCP brush cytology, and screening for p53 and ras oncogenes. These advanced techniques should help us to detect pancreatic cancers in high-risk populations at a curative stage and to decrease pancreaticoduodenectomies for benign disease which could otherwise be treated with less morbid procedures. In addition, these tests will help reliably diagnose pancreatic cancer preoperatively.     

Peptide-mass fingerprinting and the ideal covering set for protein characterisation

The rules that govern the dynamics of protein characterisation by peptide-mass fingerprinting (PMF) were investigated through multiple interrogations of a nonredundant protein database. This was achieved by analysing the efficiency of identifying each entry in the entire database via perfect in silico digestion with a series of 20 pseudo-endoproteinases cutting at the carboxy terminal of each amino acid residue, and the multiple cutters: trypsin, chymotrypsin and Glu-C. The distribution of peptide fragment masses generated by endoproteinase digestion was examined with a view to designing better approaches to protein characterisation by PMF. On average, and for both common and rare cutters, the combination of approximately two fragments was sufficient to identify most database entries. However, the rare cutters left more entries unidentified in the database. Total coverage of the entire database could not be achieved with one enzymatic cutter alone, nor when all 23 cutters were used together. Peptide fragments of > 5000 Da had little effect on the outcome of PMF to correctly characterise database entries, while those with low mass (near to 350 Da in the case of trypsin) were found to be of most utility. The most frequently occurring fragments were also found in this lower mass region. The maximum size of uncut database entries (those not containing a specific amino acid residue) ranged from 52,908 Da to 258,314 Da, while the failure rate for a single cutter in identifying database entries varied from 10,865 (8.4%) to 23,290 (18.1%). PMF is likely to be a mainstay of any high-throughput protein screening strategy for large-scale proteome analysis. A better understanding of the merits and limitations of this technique will allow researchers to optimise their protein characterisation procedures.