Site-specific interactions of copper(II) ions with heparin revealed with complementary (SRCD, NMR, FTIR and EPR) spectroscopic techniques

The interactions between Cu(II) ions and heparin were investigated using several complementary spectroscopic techniques. NMR indicated an initial binding phase involving specific coordination to four points in the structure that recur in slightly different environments throughout the heparin chain; the carboxylic acid group and the ring oxygen of iduronate-2-O-sulfate, the glycosidic oxygen between this residue and the adjacent (towards the reducing end) glucosamine and the 6-O-sulfate group. In contrast, the later binding phase showed little structural specificity. One- and two-dimensional correlated FTIR revealed that complex out of phase (asynchronous) conformational changes also occurred during the titration of Cu(II) ions into heparin, involving the CO and N-H stretches. EPR demonstrated that the environments of the Cu(II) ions in the initial binding phase were tetragonal (with slightly varied geometry), while the later non-specific phases exhibited conventional coordination. Visible spectroscopy confirmed a shift of the absorbance maximum. Titration of Cu(II) ions into a solution of heparin indicated (both by analysis of FTIR and EPR spectra) that the initial binding phase was complete by 15-20 Cu(II) ions per chain; thereafter the ions bound in the non-specific mode. Hetero-correlation spectroscopy (FTIR-CD) improved resolution and assisted assignment of the broad CD features from the FTIR spectra and indicated both in-phase and more complex out of phase (synchronous and asynchronous, respectively) changes in interactions within the heparin molecule during the titration of Cu(II) ions.

Could BNP screening of acute chest pain cases lead to safe earlier discharge of patients with non-cardiac causes? A pilot study

BACKGROUND

The assessment of chest pain relies on clinical assessment and markers of cell necrosis such as Troponin T (TnT). B-type natriuretic peptide (BNP) is also raised in myocardial ischaemia and therefore may be useful in deciding if acute chest pain is of cardiac origin or not.

AIM

To investigate the role of BNP in the assessment of unselected patients presenting with acute chest pain.

METHODS

A prospective observational study of 100 patients presenting with chest pain to the Acute Medical Admissions Unit was carried out. All patients had BNP and TnT levels measured. The primary outcome was categorization of chest pain as cardiac or non-cardiac. This was determined by the discharge diagnosis. BNP cutoffs were derived from a receiver operated characteristic (ROC) curve. The sensitivity, specificity, positive predictive accuracy (PPA) and negative predictive accuracy (NPA) were all calculated for BNP, TnT and for the composite of BNP and TnT.

RESULTS

Mean BNP in patients with cardiac chest pain was significantly greater than mean BNP for patients with non-cardiac chest pain (P </= 0.0001). BNP was significantly more sensitive than TnT (P = 0.003). However TnT was more specific than BNP (98% vs. 75%, P </= 0.0001). Combining BNP and TnT increased sensitivity from 55.6% to 95.6%.

CONCLUSION

Our findings suggest that BNP is more sensitive but less specific than TnT in the diagnostic assessment of acute chest pain. However, combining BNP and TnT was a very satisfactory rule out test (negative predictive accuracy 96%) for excluding chest pain that had a cardiac origin.

Apparent Contrasting Rates of Pharyngitis and Pyoderma in Regions where Rheumatic Heart Disease is Highly Prevalent

BACKGROUND

The aim of the study was to describe the epidemiology of pharyngitis and pyoderma in a Central Australian Aboriginal community with a high prevalence of rheumatic heart disease (RHD) and compare it to communities in the Top End of the Northern Territory.

METHODS

Following ethics approval and community consultation, selected households were enrolled and visited over a 13-month period. People were asked if they had a sore throat and/or skin sores and asked about current or recent use of antibiotics; all throats and any pyoderma lesions were swabbed for bacterial culture. Beta-haemolytic streptococci (BHS), including group A streptococcus (GAS), were identified in the central laboratory using standard methods. Household crowding was also assessed. Results were then compared to those from the Top End study.

RESULTS

Sore throat was relatively common (480 episodes per 100 person years), although there was only one case of GAS pharyngitis in 326 consultations. Only 5.5% of children <15 years had pyoderma during the course of the study. This is the opposite picture to that reported in the Top End where symptomatic pharyngitis is rare and pyoderma is common.

CONCLUSIONS

Although the data are limited, the epidemiology of pharyngitis and pyoderma in this Central Australian Aboriginal community appears to be more akin to that seen in temperate climates rather than tropical Top End communities. In this community, RHD preventative measure should continue to include aggressive treatment of pharyngitis according to recommendations.

Risk factors for overweight and obesity: results from the 2001 National Health Survey

OBJECTIVES

A significant rise in the proportion of overweight and obese adults has produced a serious health epidemic in Australia and worldwide. The current research aimed to identify sociodemographic and behavioural predictors of overweight and obesity among a large representative sample of Australian adults.

STUDY DESIGN

We used the National Health Survey conducted by the Australian Bureau of Statistics in 2001. The survey involved a stratified multistage area sample of private dwellings and face-to-face interviews.

METHODS

We analysed data from 8643 females and 7600 males who responded to the 2001 National Health Survey. Multinomial logistic regression examined the association of being overweight or obese versus a healthy weight with a range of sociodemographic and behavioural variables.

RESULTS

Fewer females than males were overweight while similar proportions were obese. For females and males, overweight and obesity were significantly associated with older age, being born in Australia, not being in a marriage-like relationship, low education, physical inactivity, and being a non/ex-smoker. High household incomes are protective from obesity but not from being overweight. Additionally, females with high levels of area social disadvantage and males in professional or white-collar occupations were more likely to be overweight or obese than a healthy weight.

CONCLUSIONS

Reductions in mortality and morbidity associated with overweight and obesity may be achieved by targeting health promotion strategies to high-risk groups such as those who are older, single, Australian born, socioeconomically disadvantaged, physically inactive, and non-smokers.

Quantum computing based on vibrational eigenstates: pulse area theorem analysis

In a recent paper [D. Babikov, J. Chem. Phys. 121, 7577 (2004)], quantum optimal control theory was applied to analyze the accuracy of quantum gates in a quantum computer based on molecular vibrational eigenstates. The effects of the anharmonicity parameter of the molecule, the target time of the pulse, and the penalty function on the accuracy of the qubit transformations were investigated. We demonstrate that the effects of all the molecular and laser-pulse parameters can be explained utilizing the analytical pulse area theorem, which originates from the standard two-level model. Moreover, by analyzing the difference between the optimal control theory results and those obtained using the pulse area theorem, it is shown that extremely high quantum gate fidelity can be achieved for a qubit system based on vibrational eigenstates.

An Australian guideline for rheumatic fever and rheumatic heart disease: an abridged outline

Acute rheumatic fever (ARF) and rheumatic heart disease (RHD) are diseases of poverty. They occur at world-record rates in Indigenous Australians, yet individual cases are often poorly managed, and most jurisdictions with high rates of these diseases do not have formal control strategies in place. New Australian guidelines formulated in 2005 by the National Heart Foundation of Australia and the Cardiac Society of Australia and New Zealand for diagnosis and management of ARF and RHD are a valuable resource for clinicians and policymakers. Key recommendations of the guidelines include: New diagnostic criteria for ARF in high-risk populations, including Indigenous Australians, which include echocardiographic evidence of subclinical valvular disease, and polyarthralgia or aseptic monoarthritis as major manifestations. Clear guidance about treatment of ARF. Non-steroidal anti-inflammatory drugs should be withheld until the diagnosis is confirmed, and corticosteroids may be an option in severe acute carditis. Most cases of chorea do not require medication, but use of carbamazepine or sodium valproate is recommended if medication is needed. Clear guidance about dose, dosing frequency and duration of secondary prophylaxis. Benzathine penicillin G is the preferred medication for this purpose. Establishment of a coordinated control program for all regions of Australia where there are populations with high prevalence of ARF and RHD. Key elements and indicators for evaluation are recommended. Active screening and legislated notification of ARF and RHD, where possible. Development of a structured care plan for all patients with a history of ARF or with established RHD, to be recorded in the patient's primary health care record.

Diabetes in Indigenous Australians: possible ways forward

Reducing the burden of diabetes will require action well beyond the health service sphere.

Rheumatic fever and social justice

High rates of this disease are the face of Indigenous disadvantage.

Perioperative Erythropoietin Efficacy in Renal Transplantation

BACKGROUND

There is no consensus on the usage of erythropoietin in the immediate postoperative period to prevent anemia and delayed graft function.

METHODS

A retrospective case note audit of renal transplants included hemoglobin (Hb) and serum creatinine (Scr) values preoperatively as well as at days 7, 14, 30, 60, and 90. Patients were categorized as those receiving erythropoietin during the first 6 months posttransplant (Epo+ve) and those not receiving any erythropoietin (Epo-ve).

RESULTS

Hb decreased from 12.4 +/- 1.6 g/L preoperatively to 9.5 +/- 1.5 g/L at day 14 and then rose to 10.5 +/- 1.6 g/L at 1 month and 12.4 +/- 1.7 g/L at 3 months. There was no difference in absolute Hb values in three transplant groups. Scr decreased from 597.0 +/- 200.1 mmol/L preoperatively to 254.1 +/- 196.9 mmol/L at day 14 and continued to fall to 163.8 +/- 98.9 mmol/L at 1 month and 147.8 +/- 66.9 mmol/L at 3 months. There was no difference in absolute Hb values and delayed graft function in the three transplant groups.

CONCLUSION

With respect to anemia and delayed graft function, the use of erythropoietin in the first 3 months had little impact. We suggest that such an expensive medication may be safely omitted in the immediate postoperative period.

Impact of consuming a milk drink containing a probiotic on mood and cognition

OBJECTIVE

The impact on mood and memory of consuming a probiotic containing milk drink, or a placebo, was examined as, previously, a poor mood has been found to correlate with the frequency of constipation.

DESIGN

A double-blind placebo-controlled trial with random allocation of subjects.

SETTING

Subjects went about their normal life in the community apart from three visits to the laboratory.

SUBJECTS

One hundred and thirty-two healthy members of general population, mean age 61.8 years, volunteered in response to local media coverage. One hundred and twenty-four finished the trial.

INTERVENTION

For a 3-week period, either a probiotic containing milk drink, or a placebo, were consumed daily. Mood and cognition were measured at baseline, and after 10 and 20 days of consumption.

RESULTS

At baseline those who reported themselves to be less frequently constipated were more clearheaded, confident and elated. Although the taking of the probiotic did not generally change the mood, this appeared to be a reflection of the generally good mood in this sample. When those in the bottom third of the depressed/elated dimension at baseline were considered, they selectively responded by reporting themselves as happy rather than depressed after taking the probiotic. The intervention did not, however, influence the reported frequency of defaecation, probably a reflection of the initially low incidence of constipation. An unexpected and possibly chance finding was that the consumption of probiotics resulted in a slightly-poorer performance on two measures of memory.

CONCLUSIONS

The consumption of a probiotic-containing yoghurt improved the mood of those whose mood was initially poor. This improvement in mood was not, however, associated with an increased frequency of defaecation.

Normal mode analysis using the driven molecular dynamics method. II. An application to biological macromolecules

The driven molecular-dynamics (DMD) method, recently proposed by Bowman, Zhang, and Brown [J. Chem. Phys. 119, 646 (2003)], has been implemented into the TINKER molecular modeling program package. The DMD method yields frequencies and normal modes without evaluation of the Hessian matrix. It employs an external harmonic driving term that can be used to scan the spectrum and determine resonant absorptions. The molecular motions, induced by driving at resonant frequencies, correspond to the normal-mode vibrations. In the current work we apply the method to a 20-residue protein, Trp-cage, that has been reported by Neidigh, Fesinmeyer, and Andersen [Nature Struct. Biol. 9, 425 (2002)]. The structural and dynamical properties of this molecule, such as B-factors, root-mean square fluctuations, anisotropies, vibrational entropy, and cross-correlations coefficients, are calculated using the DMD method. The results are in very good agreement with ones calculated using standard normal-mode analysis method. Thus, the DMD method provides a viable alternative to the standard Hessian-based method and has considerable potential for the study of large systems, where the Hessian-based method is not feasible.

LMSD: LIPID MAPS structure database

The LIPID MAPS Structure Database (LMSD) is a relational database encompassing structures and annotations of biologically relevant lipids. Structures of lipids in the database come from four sources: (i) LIPID MAPS Consortium's core laboratories and partners; (ii) lipids identified by LIPID MAPS experiments; (iii) computationally generated structures for appropriate lipid classes; (iv) biologically relevant lipids manually curated from LIPID BANK, LIPIDAT and other public sources. All the lipid structures in LMSD are drawn in a consistent fashion. In addition to a classification-based retrieval of lipids, users can search LMSD using either text-based or structure-based search options. The text-based search implementation supports data retrieval by any combination of these data fields: LIPID MAPS ID, systematic or common name, mass, formula, category, main class, and subclass data fields. The structure-based search, in conjunction with optional data fields, provides the capability to perform a substructure search or exact match for the structure drawn by the user. Search results, in addition to structure and annotations, also include relevant links to external databases. The LMSD is publicly available at