Amino acid sequence of a mouse mucosal mast cell protease

The amino acid sequence has been determined of a mouse mucosal mast cell protease isolated from the small intestines of mice infected with Trichinella spiralis. The active protease contains 226 residues. Those corresponding to the catalytic triad of the active site of mammalian serine proteases (His-57, Asp-102, and Ser-195 in chymotrypsin) occur in identical positions. A computer search for homology indicates 74.3% and 74.1% sequence identity of the mouse mast cell protease compared to those of rat mast cell proteases I and II (RMCP I and II), respectively. The six half-cystine residues in the mouse mast cell protease are located in the same positions as in the rat mast cell proteases, cathepsin G, and the lymphocyte proteases, suggesting that they all have identical disulfide bond arrangements. At physiological pH, the mouse and rat mucosal mast cell proteases have net charges of +3 and +4, respectively, as compared to +18 for the protease (RMCP I) from rat connective tissue mast cells. This observation is consistent with the difference in solubility between the mucosal and connective tissue mast cell proteases when the enzymes are extracted from their granules under physiological conditions.     

Treatment of intact hepatocytes with synthetic diacyl glycerols mimics the ability of glucagon to cause the desensitization of adenylate cyclase

Incubation of intact hepatocytes with either of the synthetic diacyl glycerols 1-oleoyl-2-acetyl glycerol (OAG) or dihexanoyl glycerol (DHG) caused the transient uncoupling of the ability of glucagon to stimulate adenylate cyclase in membranes prepared from those cells. No change occurred in either the activity of the catalytic unit of adenylate cyclase or the coupling of Gs to adenylate cyclase. Diacyl glycerol action appeared to mimic glucagon-mediated desensitization of adenylate cyclase, suggesting that protein kinase C activation may provide the molecular trigger for glucagon desensitization.     

A molecular cytogenetic approach to studying platinum resistance

The technique of comparative genomic hybridisation (CGH) has until recently been used to screen for common genomic abnormalities in fresh tumour material; it has identified previously unrecognised regions of amplification associated with poor prognosis subtypes of breast cancer and lymphoma. Our group has applied this technique to resistant cell lines and their sensitive counterparts in order to define chromosomal abnormalities associated with acquired drug resistance. We have demonstrated the applicability of this technique to the study of drug resistance using cell lines with known mechanisms of resistance. The ability to detect novel genomic alterations in cell lines with novel mechanisms of resistance was also demonstrated. We subsequently examined the CGH profiles of seven different cell lines made resistant to three platinum analogues and showed the most consistent abnormalities to involve over-representation of regions 4q and 6q. More recently, we have applied the CGH technique to a series of testicular germ cell tumours (TGCTs) collected as formalin-fixed paraffin-embedded biopsy specimens from patients, both pre- and post-therapy using a platinum-based regimen (POMB/ACE). Previous reports have shown over-representation of X, 7q, 8q and 12p and loss of 13q to occur in 25% of primary TGCTs. Over-representation of 12p was confirmed in the majority of these biopsy samples; deletion of 13q was noted in the initial biopsies of several patients. We also demonstrated alterations of 4p, 4q, 5q and 6q in this series of patients. Newly acquired deletions of 2q and 18q and amplifications of 8q were frequently observed in post-chemotherapy samples from resistant tumours. The CGH studies on these patients with TGCT will not only enable us to correlate our observations on clinical material with those from long-term cell lines, but should also identify sites of key genes involved in clinical platinum resistance.     

Revisiting the use of Iprodione and Trichoderma in the integrated management of onion white rot

The biocontrol properties of Trichoderma species are well documented, but their effectiveness in antagonism of the problematic Sclerotium cepivorum, the causal agent of white rot in Allium species, appears limited with reports of significant control only relating to deliberately-mutated strains of Trichoderma. Our previous studies have indicated the possibility of using selected naturally-occurring strains of the antagonist in the suppression of other diseases; now in vitro and controlled environment in vivo studies have indicated that a degree of control of Onion White Rot is possible, and that the selected antagonist strains can be used in integrated treatments with Iprodione to good effect. The possible value of such treatments is considered in light of other approaches to the suppression of this continuing problem.     

Ground wētā in vines of the Awatere Valley,Marlborough: biology,density and distribution

The endemic New Zealand ground wētā (Hemiandrus sp. ‘promontorius’) has a Naturally Uncommon conservation status. This is because of the paucity of information on its density and distribution. Here, the biology, density and distribution of a population of this wētā found in and around vineyards in the Awatere Valley, Marlborough was studied. Wētā density was assessed in vineyards, paddocks and shrublands in this valley. Soil moisture, penetration resistance, pH and organic matter were recorded at locations with and without wētā. Wētā density in vineyards was significantly higher than in either paddocks or shrub habitats. In vineyards, the density of this insect was significantly higher under-vines than in the inter-rows. Higher numbers of this wētā were found in moist soils that required lower force to burrow. Females laid an average of 55 eggs between March and April, which hatched in September. These findings highlight the intersection between agriculture and conservation.     

A spatiotemporal characterization of the effect of p53 phosphorylation on its interaction with MDM2

The interaction of p53 and MDM2 is modulated by the phosphorylation of p53. This mechanism is key to activating p53, yet its molecular determinants are not fully understood. To study the spatiotemporal characteristics of this molecular process we carried out Brownian dynamics simulations of the interactions of the MDM2 protein with a p53 peptide in its wild type state and when phosphorylated at Thr18 (pThr18) and Ser20 (pSer20). We found that p53 phosphorylation results in concerted changes in the topology of the interaction landscape in the diffusively bound encounter complex domain. These changes hinder phosphorylated p53 peptides from binding to MDM2 well before reaching the binding site. The underlying mechanism appears to involve shift of the peptide away from the vicinity of the MDM2 protein, peptide reorientation, and reduction in peptide residence time relative to wild-type p53 peptide. pThr18 and pSr20 p53 peptides experience reduction in residence times by factors of 13.6 and 37.5 respectively relative to the wild-type p53 peptide, indicating a greater role for Ser20 phosphorylation in abrogating p53 MDM2 interactions. These detailed insights into the effect of phosphorylation on molecular interactions are not available from conventional experimental and theoretical approaches and open up new avenues that incorporate molecular interaction dynamics, for stabilizing p53 against MDM2, which is a major focus of anticancer drug lead development.     

Productivity cost due to maternal ill health in sri lanka

Background

The global impact of maternal ill health on economic productivity is estimated to be over 15 billion USD per year. Global data on productivity cost associated with maternal ill health are limited to estimations based on secondary data. Purpose of our study was to determine the productivity cost due to maternal ill health during pregnancy in Sri Lanka.

Methods and Findings

We studied 466 pregnant women, aged 24 to 36 weeks, residing in Anuradhapura, Sri Lanka. A two stage cluster sampling procedure was used in a cross sectional design and all pregnant women were interviewed at clinic centers, using the culturally adapted Immpact tool kit for productivity cost assessment. Of the 466 pregnant women studied, 421 (90.3%) reported at least one ill health condition during the pregnancy period, and 353 (83.8%) of them had conditions affecting their daily life. Total incapacitation requiring another person to carry out all their routine activities was reported by 122 (26.1%) of the women. In this study sample, during the last episode of ill health, total number of days lost due to absenteeism was 3,356 (32.9% of total loss) and the days lost due to presenteeism was 6,832.8 (67.1% of the total loss). Of the 353 women with ill health conditions affecting their daily life, 280 (60%) had coping strategies to recover loss of productivity. Of the coping strategies used to recover productivity loss during maternal ill health, 76.8% (n = 215) was an intra-household adaptation, and 22.8% (n = 64) was through social networks. Loss of productivity was 28.9 days per episode of maternal ill health. The mean productivity cost due to last episode of ill health in this sample was Rs.8,444.26 (95% CI-Rs.6888.74-Rs.9999.78).

Conclusions

Maternal ill health has a major impact on household productivity and economy. The major impact is due to, generally ignored minor ailments during pregnancy.     

Computer system for assisting with clinical interpretation of tumour marker data.

OBJECTIVE--To design and evaluate a computer advisory system for the treatment of gestational trophoblastic tumour. DESIGN--A comparison of clinicians'' treatment decisions with those of the computer system. Two datasets were used: one to calibrate the system and one to independently evaluate it. SETTING--Department of medical oncology. PATIENTS--Computerised records of 290 patients with low risk gestational trophoblastic tumour for whom the advisory system could predict the adequacy of treatment. The calibration set comprised patients admitted during 1979-86(227) and the test set patients during 1986-89(63). MAIN OUTCOME MEASURES--The system''s accuracy in predicting need to change treatment compared with clinicians'' actions. The mean time faster that the system was in predicting the need to change treatment. RESULTS--On the calibration dataset the system was 94% (164/174) accurate in predicting patients whose treatment was adequate, recommending change when none occurred in only 10 (6%) patients. In patients whose treatment was changed the system recommended change earlier than clinicians in 39/53 cases (74%), with a mean time advantage of 14.9 (SE 2.02) days. On the test dataset the system had an accuracy of 91% (31/34) in predicting treatment adequacy and a false positive rate of 9% (3/34). The system recommended change earlier than clinicians in 22/29 cases (76%), with a mean time advantage of 12.5 (2.22) days. CONCLUSIONS--The computer advisory system could improve patient management by reducing the time spent receiving ineffective treatment. This has implications for both patient time and clinical costs.