Polymorphisms at GSTM1 and GSTP1 gene loci and risk of prostate cancer in a South Indian population

Inter-individual differences in cancer susceptibility may be mediated in part through polymorphic variability in the bioactivation and detoxification of carcinogens. The glutathione S-transferases (GSTs), which are active in detoxification of wide variety of carcinogens, have been consistently implicated as cancer susceptibility genes in this context. We here assessed the association of GSTM1 and GSTP1 polymorphisms with susceptibility to prostate cancer in a case-control study of 75 patients and 100 age-matched controls in a South Indian population. The GSTM1 null polymorphism was detected by PCR and the GSTP1 Ile105Val polymorphism by PCR-RFLP using peripheral blood DNA. There was no significant link between the null genotype of GSTM1 and risk of prostate cancer (OR-1.79; 95% CI-0.78-4.11; P-0.18). However, the GSTP1 Ile/Val genotype was significantly associated with a decreased risk for prostate cancer (OR-0.36; 95% CI-0.18-0.73; P<0.001). Analysis of the variant GSTM1 and GSTP1 genotypes in combination did not reveal any significant difference between cases and controls, even with a stratified analysis tumor grades. Thus our study indicates that the GSTP1 Ile/Val genotype may decrease risk of prostate cancer in the South Indian population.

n-Heptane under Pressure: Structure and Dynamics from Molecular Simulations

Atomistic molecular dynamics simulations have been performed in the isothermal-isobaric ensemble to explore the phase behavior of n-heptane. Motivated by recent high-pressure spectroscopic experiments on n-heptane, the present work aims at understanding the liquid-solid and the alluded to solid-solid transitions upon increasing pressure. Starting from the stabilized solid phase at 300 K and 10 kbar, we have investigated the range of these two transitions by a gradual decrease and increase of pressure, respectively. Although the solid-liquid transition has clear signatures such as the formation of gauche defects along the molecular backbone, the present model does not show any sign of a first-order solid-solid transition at high pressures. However, interesting changes in the environment around methyl groups and in their dynamics are observed. These have been substantiated by calculations of the vibrational density of states obtained from a normal-mode analysis and from the simulation trajectory.

Knowledge and practice of breast cancer screening amongst public health nurses in Singapore

AIM OF STUDY

The study aimed to examine the knowledge and practice of breast cancer screening amongst Public Health nurses who are patient educators.

METHOD

A self-administered questionnaire was sent to all 447 nurses in the Public Health Service to assess their knowledge and practice of breast cancer screening. Response rate was 96.4%. Knowledge scores ranged from 0-17 with one point given to a correct knowledge question, zero for wrong answer.

RESULTS

Median knowledge score was nine and 58.3% of nurses scored > or = 9. Statistically significant factors influencing knowledge scores were related to the nursing profession, namely nursing qualifications, current nursing post and current workplace. 76.2% of Nursing Officers/Higher Nursing Officers and 74.5% of midwives had knowledge scores > or = 9 compared with 57.3% of staff nurses and 40.8% of assistant nurses (p < 0.01). 60.1% of nurses who were taught breast-self examination scored > or = 9 (p < 0.05). As for practice, 93.7% of nurses did breast-self-examination, 54.1% had clinical breast examination in the past one year and 50.2% had mammogram done. On multivariate analysis, significant factors affecting practice of clinical breast examination were marital status (Prevalence Rate Ratio 1.94, 95% Confidence Interval 1.20-3.15), doctor's gender (PRR 1.35, CI 1.04-1.75) and those affecting mammogram were age group (PRR 1.78, CI 1.27-2.48), marital status (PRR 1.63, CI 1.03-2.59), history of breast disease (PRR 1.51, CI 1.06-2.16).

CONCLUSIONS

The majority of nurses had certain misconceptions in the knowledge of breast cancer and breast cancer screening. A higher proportion of nurses in the Family Health Service had higher knowledge scores than other nurses in the Public Health Service. Most of the nurses did breast-self-examination. Having ever married and the availability of a female doctor influenced the nurses attending clinical breast examination. Nurses who were > or = 50 years old, ever married and those with a positive history of breast disease were more likely to have mammography done.

A case of uremia-associated pleural effusion in a peritoneal dialysis patient

The development of pleural effusions in ESRD patients is a relatively common occurrence. Uremia, currently a rare cause of effusion, can lead to the development of hemorrhagic pleural fluid collections in patients who are underdialyzed. Uremic pleural effusions should be considered when common etiologies of effusions such as volume overload, congestive heart failure (CHF), infection, and malignancy have been excluded. Uremia-associated serosal injury allows transudation of fluid into the pleural space, and defective platelet function contributes to the hemorrhagic nature of the effusion. Although uremic effusions may occur less frequently in peritoneal dialysis patients, we present a patient who developed this complication due to a peritoneal dialysis regimen that was inadequate by current Dialysis Outcomes Quality Initiative guidelines. The pleural effusion resolved with an intensified dialysis regimen in the absence of a change in the underlying volume status.

Abdominal thrombotic and ischemic manifestations of the antiphospholipid antibody syndrome: CT findings in 42 patients

PURPOSE

To determine the abdominal computed tomographic (CT) findings in patients with antiphospholipid antibody syndrome (APS).

MATERIALS AND METHODS

Retrospective review of medical records from two university medical centers from 1994 through 1997 revealed 215 patients who had a hypercoagulable state attributed to primary or secondary APS. Abdominal CT findings in these patients were reviewed for evidence of large-vessel occlusion or visceral ischemia.

RESULTS

In 42 (19.5%) of 215 patients with APS (age range, 32-65 years; mean age, 42 years), abdominal thromboses or ischemic events were detected at CT. Twenty-two (52%) had major vascular thromboses, including those in the inferior vena cava (n = 10), portal and superior mesenteric veins (n = 7), splenic vein (n = 4), and aorta (n = 1). Thirty-six (86%) patients had abdominal visceral ischemia resulting in renal infarction (n = 22), bowel ischemia (n = 13), splenic infarction (n = 6), pancreatitis (n = 3), hepatic infarction (n = 1), and/or hepatic dysfunction with portal hypertension (n = 1). In some patients, more than one abdominal organ and/or vessel was involved.

CONCLUSION

Patients who have circulating antiphospholipid antibodies are at risk for major abdominal vascular thromboses and organ infarction. Radiologists must be familiar with this syndrome; they may be the first physicians to suggest the diagnosis on the basis of findings of unusual or recurrent sites of thrombosis, especially in young patients.

Microfabricated reaction and separation systems

Over the past year there have been a number of recent advances in the fields of miniaturized reaction and separation systems, including the construction of fully integrated 'lab-on-a-chip' systems. Microreactors, which initially targeted DNA-based reactions such as the polymerase chain reaction, are now used in several other chemical and biochemical assays. Miniaturized separation columns are currently employed for analyzing a wide variety of samples including DNA, RNA, proteins and cells. Although significant advances have been made at the component level, the realization of an integrated analysis system still remains at the early stages of development.

Evolution and characterization of tetraonine endogenous retrovirus: a new virus related to avian sarcoma and leukosis viruses

In a previous study, we found avian sarcoma and leukosis virus (ASLV) gag genes in 19 species of birds in the order Galliformes including all grouse and ptarmigan (Tetraoninae) surveyed. Our data suggested that retroviruses had been transmitted horizontally among some host species. To further investigate these elements, we sequenced a replication-defective retrovirus, here named tetraonine endogenous retrovirus (TERV), from Bonasa umbellus (ruffed grouse). This is the first report of a complete, replication-defective ASLV provirus sequence from any bird other than the domestic chicken. We found a replication-defective proviral sequence consisting of putative Gag and Env proteins flanked by long terminal repeats. Reverse transcription-PCR analysis showed that retroviral gag sequences closely related to TERV are transcribed, supporting the hypothesis that TERV is an active endogenous retrovirus. Phylogenetic analyses suggest that TERV may have arisen via recombination between different retroviral lineages infecting birds. Southern blotting using gag probes showed that TERV occurs in tetraonines but not in chickens or ducks, suggesting that integration occurred after the earliest phasianid divergences but prior to the radiation of tetraonine birds.

FTIR-ATR spectroscopy for monitoring polyanhydride/anhydride-amine reactions

The reactivity of 1,3-bis(p-carboxyphenoxy) propane:sebacic acid anhydride copolymer (CPPSA1:6), myristic and benzoic anhydrides with amine nucleophiles were investigated in non-polar solvents. FTIR-ATR (attenuated total reflectance) spectroscopy was used to monitor the polyanhydride/anhydride reaction rates in dichloromethane, dichloroethane, chloroform, and 1,4-dioxane solutions at room temperature. The reaction kinetics was determined by measuring the anhydride peak loss with time. Aminolysis resulted from nucleophilic attack of the added amine on the carbonyl group of the anhydride moiety. Primary and secondary amines reacted to form amides and the reaction followed second-order kinetics. Second-order rate constants and reaction half-life (t(1/2)) were calculated from the semilog plots of [anhydride]/[amine] in 1,4-dioxane at room temperature. The aminolysis rate decreased with pK(a) of the amine reactant, and half-life (t(1/2)) decreased with increasing amine concentration, as expected. With trifluoroethylamine (pK(a) 5.8), myristic anhydride reacted about 6-fold faster than benzoic anhydride. The lower reaction rate of benzoic anhydride was due to the higher stability of the aromatic anhydride compared to aliphatic. The overall CPPSA1:6 copolymer reactivity was the sum of aliphatic-aliphatic (SA-SA), aliphatic-aromatic (SA-CPP), and aromatic-aromatic (CPP-CPP) anhydride linkage reactivities. Based on the monomer ratio, the probability of SA-SA, SA-CPP, and CPP-CPP dyads were calculated to be 0.74, 0.24, and 0.02, respectively. This indicated that CPPSA1:6 reactivity will mainly result from SA-SA and SA-CPP linkages. The second-order rate constants and t(1/2) obtained for CPPSA1:6 with TFEA were closer to those for myristic anhydride than benzoic anhydride with TFEA.

Electron acceleration and the propagation of ultrashort high-intensity laser pulses in plasmas

Reported are interactions of high-intensity laser pulses ( lambda = 810 nm and I</=3x10(18) W/cm(2)) with plasmas in a new parameter regime, in which the pulse duration ( tau = 29 fs) corresponds to 0. 6-2.6 plasma periods. Relativistic filamentation is observed to cause laser-beam breakup and scattering of the beam out of the vacuum propagation angle. A beam of megaelectronvolt electrons with divergence angle as small as 1 degrees is generated in the forward direction, which is correlated to the growth of the relativistic filamentation. Raman scattering, however, is found to be much less than previous long-pulse results.

Cospeciation and horizontal transmission of avian sarcoma and leukosis virus gag genes in galliform birds

In a study of the evolution and distribution of avian retroviruses, we found avian sarcoma and leukosis virus (ASLV) gag genes in 26 species of galliform birds from North America, Central America, eastern Europe, Asia, and Africa. Nineteen of the 26 host species from whom ASLVs were sequenced were not previously known to contain ASLVs. We assessed congruence between ASLV phylogenies based on a total of 110 gag gene sequences and ASLV-host phylogenies based on mitochondrial 12S ribosomal DNA and ND2 sequences to infer coevolutionary history for ASLVs and their hosts. Widespread distribution of ASLVs among diverse, endemic galliform host species suggests an ancient association. Congruent ASLV and host phylogenies for two species of Perdix, two species of Gallus, and Lagopus lagopus and L. mutus also indicate an old association with vertical transmission and cospeciation for these ASLVs and hosts. An inference of horizontal transmission of ASLVs among some members of the Tetraoninae subfamily (grouse and ptarmigan) is supported by ASLV monophyletic groups reflecting geographic distribution and proximity of hosts rather than host species phylogeny. We provide a preliminary phylogenetic taxonomy for the new ASLVs, in which named taxa denote monophyletic groups.

RH-5992--an ecdysone agonist on model system of the silkworm Bombyx mori

RH-5992 is a novel synthetic non-steroidal ecdysteroid agonist with a high selectivity towards Lepidopteran species. The effect of ecdysone agonist RH-5992 on larval period, larval weight, silk gland weight and haemolymph protein profile were examined in the model organism, the larvae of silkworm, Bombyx mori. The LD50 values were found to be 16.21 and 12.01 micrograms/larva for 72 and 96 hr respectively. In the present study, three sublethal concentrations of 1/5th, 1/10th and 1/20th of LD50 at 72 hr were selected and applied on the mid-dorsal line of the silkworm B. mori. The maximum mortality of 35% was observed in the group which received the highest (3.2 micrograms/larva) concentration of RH-5992. The mortality rate was found to be dose dependent as well as time dependent. Interesting results were observed in haemolymph profile of the RH-5992 treated larvae as staining intensity of 30 kDa protein decreased significantly whereas the effect was not marked on other major proteins like storage proteins and vitellogenin polypeptides. From the results, it is confirmed that RH-5992 causes changes in larval characters and protein profile of silkworm B. mori. It is proposed that RH-5992 may cause negative effect specifically on reproductive characters like development of ovary and egg production due to decrease in 30 kDa protein.

The murine clan V(H) III related 7183, J606 and S107 and DNA4 families commonly encode for binding to a bacterial B cell superantigen

Superantigens, by virtue of their unconventional binding interactions with Ag receptors, can simulate a large subset of mature lymphocytes in the repertoire. Recent studies have documented that in vivo exposure to the model bacterial B cell superantigen, Staphylococcal protein A (SpA), induces large scale effects on murine B-cell clonal selection by mechanism(s) that include deletion of supra-clonal sets. While the structural bases for the immunomodulatory properties of several T-cell superantigens have been well characterized, the requirements for murine Fab-binding of SpA remain incompletely defined. To investigate these structural requirements, a series of direct binding and inhibition studies were performed with a large panel of Moabs of diverse variable region gene usage. These studies confirm previous reports that superantigen binding is completely restricted to the products of clan V(H) III-related families, that include the small S107 and J606 families, and we also demonstrated that usage of the related small DNA4 family commonly correlates with weaker binding activity. Furthermore, our results document that genes from the largest clan V(H) III family, 7183, commonly encode for Fab-mediated binding of SpA, while antibodies from five other VH families, J558, Q52, Sm7, VH11 and VH12, did not display Fab-mediated SpA binding activity. By contributing to the essential foundation for understanding of the structural basis for binding interactions, these findings will aid interpretation of evolving observations regarding the clonal fates induced by in vivo B-cell superantigen exposure.

Changes in embryonic protein profile and economic characters of Bombyx mori (Lepidoptera:Bombycidae) following UV irradiation

Eggs of B. mori were irradiated with UV (254.4 nm wavelength) for different durations. Increase in the time of exposure to UV decreased the percentage hatchability of the eggs, cocoon and pupal weights. The shell weight remained unaltered proving the stability of silk gland DNA. Irradiation of eggs also delayed the degradation/utilization of the embryonic proteins, viz. vitellin (heavy and light subunits), egg-specific protein and 30K protein.

Post traumatic rupture of the right main bronchus: a rare clinical entity?

Tracheobronchial disruption is an uncommon injury usually associated with severe blunt thoracic trauma and rarely occurs in isolation. We report a case of isolated rupture of the right main bronchus occurring after a crush injury without an associated pneumothorax. Difficulties in the diagnosis of this condition are briefly discussed and an algorithm of management presented.