Resonant Inelastic X-Ray Scattering Reveals Hidden Local Transitions of the Aqueous OH Radical.

Resonant inelastic x-ray scattering (RIXS) provides remarkable opportunities to interrogate ultrafast dynamics in liquids. Here we use RIXS to study the fundamentally and practically important hydroxyl radical in liquid water, OH(aq). Impulsive ionization of pure liquid water produced a short-lived population of OH(aq), which was probed using femtosecond x-rays from an x-ray free-electron laser. We find that RIXS reveals localized electronic transitions that are masked in the ultraviolet absorption spectrum by strong charge-transfer transitions-thus providing a means to investigate the evolving electronic structure and reactivity of the hydroxyl radical in aqueous and heterogeneous environments. First-principles calculations provide interpretation of the main spectral features.

Risk of death from cardiovascular disease following breast cancer: a systematic review.

PURPOSE: Breast cancer incidence and survival is high, which results in high prevalence of breast cancer survivors. The risk of (death from) cardiovascular disease (CVD) is higher in patients exposed to cardiotoxic treatments, in particular if they have pre-existing CVD risk factors. This study systematically summarized the risk of death from CVD following breast cancer. METHODS: Databases of Medline, Embase, and the Cochrane Library were systematically searched using the following terms and synonyms: breast cancer, cardiovascular disease, and cause of death. Articles reporting on both risk and risk factors of CVD mortality following breast cancer were eligible for inclusion. The methodological quality of each article was assessed using the Newcastle Ottawa quality assessment scale for cohort studies. RESULTS: Fourteen articles were included assessing the risk of CVD mortality among 1,217,910 women with breast cancer. The methodological quality was high for the majority of the studies. Studies were heterogeneous in design, study population, length of follow-up, CVD outcomes, and risk factors. 1.6-10.4% of all women with breast cancer died of CVD. Women with breast cancer had a higher risk of CVD mortality than women from the general population. The risk of CVD mortality was higher among women with breast cancer with older age at diagnosis, left-sided tumor, diagnosis in an earlier calendar period, and black ethnic origin. CONCLUSIONS: CVD is an important cause of death following breast cancer. Identification of patients at high risk of CVD is important to optimize CVD prevention and tailor breast cancer treatment.

Haemoglobin disorders in Australia: where are we now and where will we be in the future?

Inherited disorders of haemoglobin (Hb), such as thalassaemia and sickle cell disease (SCD) are common and responsible for significant morbidity and mortality on a global scale. As Australia becomes increasingly ethnically diverse, their prevalence will increase. However, we lack important demographic and epidemiological data to manage these disorders and their consequences and to support affected individuals and communities. Thalassaemia and SCD are lifelong conditions. Affected individuals have reduced life expectancies, poorer quality of life and complex healthcare needs. Treatment strategies currently focus on prenatal diagnosis, red blood cell transfusion, iron chelation, management of iron-related complications, haemopoietic stem cell transplantation (HSCT) and hydroxyurea. Currently, the only curative therapy is HSCT; however, gene therapy offers the possibility of cure and trials are currently underway. These therapies are associated with significant complications and substantial costs; there is also evidence of variation in approaches to diagnosis and care. Optimal strategies for many aspects of management are not yet defined and more research is necessary to inform clinical care and health service delivery.

Practical management of myelofibrosis with ruxolitinib.

Treatment for the majority of patients with myelofibrosis is primarily based on symptom control as curative allogeneic stem cell transplantation is typically offered only to younger patients, especially those with poor prognosis disease. Around 50% of patients with myelofibrosis have the JAK2(V617F) mutation, but almost all patients have aberrant activation of the JAK-STAT signalling pathway. Recent efforts have focussed on the clinical use of JAK2 inhibitors to treat myelofibrosis. In this article, we present our recommendations for the practical management of myelofibrosis with ruxolitinib, a selective inhibitor of both JAK1 and JAK2. Ruxolitinib can significantly improve the quality of life of patients with myelofibrosis. There is also increasing evidence of a positive impact on survival. Consistent with the physiological role of JAK signalling the major toxicity of ruxolitinib is cytopenia. Managing cytopenia is key to maximising the therapeutic benefit of ruxolitinib. Further research into the safety of ruxolitinib in patients with thrombocytopenia is warranted, as is its role in special subgroups of patients, such as those undergoing stem cell transplantation and those experiencing thrombosis as a major manifestation of myelofibrosis.

Management of systemic AL amyloidosis: recommendations of the Myeloma Foundation of Australia Medical and Scientific Advisory Group.

Systemic AL amyloidosis is a plasma cell dyscrasia with a characteristic clinical phenotype caused by multi-organ deposition of an amyloidogenic monoclonal protein. This condition poses a unique management challenge due to the complexity of the clinical presentation and the narrow therapeutic window of available therapies. Improved appreciation of the need for risk stratification, standardised use of sensitive laboratory testing for monitoring disease response, vigilant supportive care and the availability of newer agents with more favourable toxicity profiles have contributed to the improvement in treatment-related mortality and overall survival seen over the past decade. Nonetheless, with respect to the optimal management approach, there is a paucity of high-level clinical evidence due to the rarity of the disease, and enrollment in clinical trials is still the preferred approach where available. This review will summarise the Clinical Practice Guidelines on the Management of Systemic Light Chain (AL) Amyloidosis recently prepared by the Medical Scientific Advisory Group of the Myeloma Foundation of Australia. It is hoped that these guidelines will assist clinicians in better understanding and optimising the management of this difficult disease.

Influence of Selective Carbon 1s Excitation on Auger-Meitner Decay in the ESCA Molecule.

Two-dimensional spectral mapping is used to visualize how resonant Auger-Meitner spectra are influenced by the site of the initial core-electron excitation and the symmetry of the core-excited state in the trifluoroethyl acetate molecule (ESCA). We observe a significant enhancement of electron yield for excitation of the COO 1s → π* and CF3 1s → σ* resonances unlike excitation at resonances involving the CH3 and CH2 sites. The CF3 1s → π* and CF3 1s → σ* resonance spectra are very different from each other, with the latter populating most valence states equally. Two complementary electronic structure calculations for the photoelectron cross section and Auger-Meitner intensity are shown to effectively reproduce the site- and state-selective nature of the resonant enhancement features. The site of the core-electron excitation and the respective final state hole locality increase the sensistivity of the photoelectron signal at specific functional group sites. This showcases resonant Auger-Meitner decay as a potentially powerful tool for selectively probing structural changes at specific functional group sites of polyatomic molecules.

Health of adults living with a clinically significant haemoglobinopathy in New South Wales, Australia.

AIM: To comprehensively review the health needs of patients living with clinically significant haemoglobinopathies (thalassaemia and sickle-cell disease (SCD)) in New South Wales, Australia. METHODS: A survey-based health needs assessment was undertaken in outpatients cared for at five tertiary institutions in metropolitan and regional centres. Sixty-three of 121 adults (approximately 80-90% of adult patients with transfusion-requiring haemoglobinopathies in New South Wales) completed an in-house and commercial health-related quality assessment survey (SF-36v2). RESULTS: Subjects came from more than eight world regions, with those with SCD being more likely to be born outside of Australia than subjects with thalassaemia (P < 0.001, likelihood ratio 20.64) as well as more likely to have been refugees (26% vs 2%). The population contained socially disadvantaged subjects with 13 subjects (20.6%) having incomes below the Australian poverty line. Complications of thalassaemia were comparable to previous international reports although our subjects had a high rate of secondary amenorrhea (>12 months = 27%) and surgical splenectomy (55.6%). Use of hydroxyurea in SCD was less than expected with only 46.6% of subjects having prior use. Lack of universal access to magnetic resonance imaging-guided chelation (international best practice) was evident, although 65.5% had been able to access magnetic resonance imaging through clinical trial, or self-funding. CONCLUSIONS: Patients with SCD and thalassaemia experience considerable morbidity and mortality and require complex, multidisciplinary care. This study revealed both variance from international best practice and between specialist units. The results of this research may provide the impetus for the development of clinical and research networks to enable the uniform delivery of health services benchmarked against international standards.

Australian guidelines for the assessment of iron overload and iron chelation in transfusion-dependent thalassaemia major, sickle cell disease and other congenital anaemias.

Iron overload is the most important cause of mortality in patients with thalassaemia major. Iron chelation is therefore a critical issue in the management of these patients and others with transfusion-dependent haemoglobinopathies and congenital anaemias. In recent years, significant developments have been made in the assessment of iron overload, including the use of magnetic resonance imaging for measuring liver and cardiac iron. Advances in the modalities available for iron chelation, with the advent of oral iron chelators including deferiprone and deferasirox in addition to parenteral desferrioxamine, have expanded treatment options. A group of Australian haematologists has convened to formulate guidelines for managing iron overload on the basis of available evidence, and to describe best consensus practice as undertaken in major Australian Haemoglobinopathy units. The results of their discussions are described in this article, with the aim of providing guidance in the management of iron overload in these patients.

Overview of endocrinopathies associated with ß-thalassaemia major.

BACKGROUND: Thalassaemia major is a common and serious medical problem worldwide that is associated with a range of complications, including effects on multiple endocrine pathways. Minimizing or preventing comorbidities is important for these individuals who need life-long multidisciplinary care and treatment. However, there are limited overviews of the endocrine complications associated with this illness, nor any consensus regarding management guidelines. METHOD: A retrospective cohort analysis of ß-thalassaemia patients attending an ambulatory transfusion clinic at Royal Prince Alfred Hospital was conducted from June 2008. RESULTS: All of our subjects (n=29) had at least one endocrinopathy present with 16 patients (55%) having three or more (≥3) endocrinopathies. Hypogonadism was the most prevalent followed by osteoporosis and growth failure (less than 3rd centile) with a frequency of 16/29 (55%), 14/29 (48%) and 10/29 (35%) patients respectively. Those with more endocrinopathies (≥3) had a longer duration of transfusion therapy when compared with those with fewer endocrinopathies. CONCLUSION: A summary of our clinical guidelines, which have been used to monitor and manage these complications, is presented along with a discussion on the results and pathophysiology of the associated endocrinopathies.

Observation of the fastest chemical processes in the radiolysis of water.

Elementary processes associated with ionization of liquid water provide a framework for understanding radiation-matter interactions in chemistry and biology. Although numerous studies have been conducted on the dynamics of the hydrated electron, its partner arising from ionization of liquid water, H2O+, remains elusive. We used tunable femtosecond soft x-ray pulses from an x-ray free electron laser to reveal the dynamics of the valence hole created by strong-field ionization and to track the primary proton transfer reaction giving rise to the formation of OH. The isolated resonance associated with the valence hole (H2O+/OH) enabled straightforward detection. Molecular dynamics simulations revealed that the x-ray spectra are sensitive to structural dynamics at the ionization site. We found signatures of hydrated-electron dynamics in the x-ray spectrum.

Molecular structure determination from x-ray scattering patterns of laser-aligned symmetric-top molecules.

We investigate the molecular structure information contained in the x-ray diffraction patterns of an ensemble of rigid CF(3)Br molecules aligned by an intense laser pulse at finite rotational temperature. The diffraction patterns are calculated at an x-ray photon energy of 20 keV to probe molecular structure at angstrom-scale resolution. We find that a structural reconstruction algorithm based on iterative phase retrieval fails to extract a reliable structure. However, the high atomic number of Br compared with C or F allows each diffraction pattern to be treated as a hologram. Using this approach, the azimuthal projection of the molecular electron density about the alignment axis may be retrieved.

Risk of death from cardiovascular disease following breast cancer in Southeast Asia: a prospective cohort study.

Breast cancer incidence and survival is high in Southeast Asia. As such, many women diagnosed with breast cancer are at risk of dying of other causes. Given the increased risk of cardiotoxicity induced by breast cancer treatments, it is important to identify patients at high risk of cardiovascular disease (CVD) mortality. The aim of this study was to investigate if this risk varies by age and ethnicity. Patient details were obtained from 5,868 Chinese, Malay, and Indian women diagnosed with in situ or non-metastasized invasive breast cancer at the National University Hospital of Singapore and KK Women's and Children's Hospital in Singapore. Death causes were obtained from the National Registry of Births and Deaths. Flexible parametric survival models estimated CVD mortality rates and hazard ratios. During a median follow-up of six years, 1,010 deaths occurred of which 6.8% were due to CVD. CVD mortality rates of older women peaked within the first year following diagnosis and increased over time since diagnosis. Indian had more than double the risk of CVD mortality than Chinese, independent of age at diagnosis and stage. Taking ethnicity and age into account may promote CVD risk stratification and management in (Southeast Asian) women with breast cancer.

Multiple myeloma causes clonal T-cell immunosenescence: identification of potential novel targets for promoting tumour immunity and implications for checkpoint blockade.

Tumour-induced dysfunction of cytotoxic T cells in patients with multiple myeloma (MM) may contribute to immune escape and be responsible for the lack of therapeutic efficacy of immune checkpoint blockade. We therefore investigated dysfunctional clonal T cells in MM and demonstrated immunosenescence but not exhaustion as a predominant feature. T-cell clones were detected in 75% of MM patients and their prognostic significance was revalidated in a new post-immunomodulatory drug cohort. The cells exhibited a senescent secretory effector phenotype: KLRG-1+/CD57+/CD160+/CD28-. Normal-for-age telomere lengths indicate that senescence is telomere independent and potentially reversible. p38-mitogen-activated protein kinase, p16 and p21 signalling pathways known to induce senescence were not elevated. Telomerase activity was found to be elevated and this may explain how normal telomere lengths are maintained in senescent cells. T-cell receptor signalling checkpoints were normal but elevated SMAD levels associated with T-cell inactivation were detected and may provide a potential target for the reversal of clonal T-cell dysfunction in MM. Low programmed death 1 and cytotoxic T-lymphocyte-associated antigen 4 expression detected on T-cell clones infers that these cells are not exhausted but suggests that there would be a suboptimal response to immune checkpoint blockade in MM. Our data suggest that other immunostimulatory strategies are required in MM.

Hetero-site-specific X-ray pump-probe spectroscopy for femtosecond intramolecular dynamics.

New capabilities at X-ray free-electron laser facilities allow the generation of two-colour femtosecond X-ray pulses, opening the possibility of performing ultrafast studies of X-ray-induced phenomena. Particularly, the experimental realization of hetero-site-specific X-ray-pump/X-ray-probe spectroscopy is of special interest, in which an X-ray pump pulse is absorbed at one site within a molecule and an X-ray probe pulse follows the X-ray-induced dynamics at another site within the same molecule. Here we show experimental evidence of a hetero-site pump-probe signal. By using two-colour 10-fs X-ray pulses, we are able to observe the femtosecond time dependence for the formation of F ions during the fragmentation of XeF2 molecules following X-ray absorption at the Xe site.

Phospho-flow detection of constitutive and cytokine-induced pSTAT3/5, pAKT and pERK expression highlights novel prognostic biomarkers for patients with multiple myeloma.

Identifying check points in cell signal transduction pathways has led to the development of new cancer therapies; however, relatively few studies have determined the diagnostic and prognostic significance of analysing phosphorylated signaling proteins in patient blood and bone marrow (BM) samples. This is the first comprehensive phospho-flow study of both constitutive and cytokine-induced pSTAT3, pSTAT5, pAKT and phosphorylated extracellular signal-regulated kinase (pERK) expression in malignant plasma cells of patients with monoclonal gammopathies. In diagnostic BM samples from 65 patients with multiple myeloma (MM), interleukin (IL)-6-induced pSTAT3 proved to be a new and independent prognostic biomarker for improved survival. When combined with the International Staging System, 6 subgroups demonstrated stratified median survivals from 9 to 72 months (χ(2)=34.3; P<0.0001). In contrast, constitutive expression of pSTAT3, pSTAT5, pAKT and pERK did not assist the differential diagnosis nor determine prognosis. High pSTAT3 expression was dependent on existing CD45 expression and pSTAT5 appeared to regulate IgG production. Phospho-flow cytometry could be used to screen for personalized therapy, although the lack of clinical significance of constitutive pSTAT3 levels suggests that pSTAT3 blockade may not be clinically relevant in MM. This study has revealed novel prognostic biomarkers and insights into the biology of signaling pathways in patients with MM.

Gene regulation and deregulation: a beta globin perspective.

The study of the beta globin gene has provided great insights into the mechanisms of gene regulation and expression. In this review, we consider the normal regulation and expression of the beta globin gene and illustrate how the various steps may be affected, providing a basis for understanding the molecular pathophysiology of beta thalassemia. Mutations causing beta thalassemia can be classified as beta0 or B+ according to whether they abolish or reduce the production of beta globin chains. The vast majority of beta thalassemia is caused by point mutations, mostly single base substitutions, within the gene or its immediate flanking sequences. Rarely, beta thalassemia is caused by major deletions of the beta globin cluster. All these mutations behave as alleles of the beta locus but in several families the beta thalassemia phenotype segregates independently of the beta globin complex, and are likely to be caused by mutations in trans-acting regulatory factors.

Characterization of truncated insulin-like growth factor-binding protein-2 in human milk.

Truncated forms of insulin-like growth factor (IGF)-binding protein-2 (IGFBP-2) have been purified from human milk and shown to retain partial IGF-binding activity. By affinity chromatography on agarose-IGF-I and HPLC, truncated IGFBP-2 of apparent Mr 14,000-16,000 resolved into two peaks. Both peaks bound radioiodinated IGF-II on ligand blotting. Within both peaks, two sequences were identified, starting at Gly169 and Lys181 of hIGFBP-2 (predicted Mr, 13,786 and 12,502, respectively, if both extend to Gln289). Mass spectrometry of a fraction predominantly containing Gly169 peptides yielded two major species, 13,840 and 13,425 Mr. Prolonged incubation of radioiodinated recombinant human (rh) IGFBP-2 with human milk failed to reveal any degradation, suggesting the formation of the fragments within the mammary gland. By solution binding assay, truncated IGFBP-2 showed less than 10% binding of [125I]IGF-I and 25% binding of [125I]IGF-II at pH 7.0 compared with rhIGFBP-2. No binding activity was seen at pH 4.0, in contrast to intact IGFBP-2, which showed peak binding from pH 4.0 to at least pH 9.0. The IGF-II association constant for truncated IGFBP-2 (6.5 nM(-1)) was 10-fold lower than that for intact IGFBP-2 (58 nM(-1)). Des(1-6)-IGF-II was totally inactive in displacing IGF-II tracer from the IGFBP-2 fragment, but displaced tracer from rhIGFBP-2 with 10% the activity of IGF-II. Thus, the amino-terminal hexapeptide of IGF-II is required for interaction with the carboxy-terminal domain of IGFBP-2. The presence of active IGFBP-2 fragments in milk suggests a role for milk IGFBP-2 in modifying IGF activity in the neonatal gut.

Regulation of pulsatile growth hormone secretion by fasting in normal subjects and patients with acromegaly.

In acromegaly, GH hypersecretion occurs despite elevated insulin-like growth factor-I (IGF-I) levels, implying defective IGF-I feedback. To study the possible mechanisms of defective IGF-I negative feedback in acromegaly, we assessed parameters of pulsatile GH secretion during fasting-induced decrease in plasma IGF-I. Seven patients with active acromegaly and six normal controls were fasted for 6 days and GH secretory profiles were obtained by frequent (every 10 min) blood sampling for 24 h and analyzed by Cluster. Fasting resulted in similar decreases in IGF-I, body weight, and blood glucose levels, and increases in free fatty acid and beta-hydroxybutyrate in all subjects. Normal subjects showed increases in 24-h total and pulsatile GH production, GH pulse frequency, maximal pulse amplitude, interpulse and nadir levels, implying suppression of hypothalamic somatostatin secretion and increase in GH-releasing hormone (GHRH) pulse frequency. In acromegalic patients, GH (and, by inference, GHRH) pulse frequency was unchanged. Three patients had increases in GH production, interpulse, and nadir levels similar to the normals while the other four had no change or paradoxical decreases in these parameters. Percentage change in GH production was highly correlated with percentage change in interpulse and nadir levels in both normals and patients. Mean GH response to GHRH (0.33 micrograms/kg iv) did not change significantly in any group as a result of fasting. Our data suggest that in healthy humans IGF-I negative feedback on GH secretion involves suppression of GHRH pulse frequency. GH (and, by inference, GHRH) pulse frequency is resistant to decrease in IGF-I in acromegaly, suggesting that lowered sensitivity of GHRH neurons to IGF-I may be the mechanism of high GH pulse frequency in this disease.

Effects of a prolonged growth hormone (GH)-releasing peptide infusion on pulsatile GH secretion in normal men.

Bolus injection of the synthetic hexapeptide GH-releasing peptide-6 (GHRP-6) reliably promotes GH secretion. However, desensitization to the GH-releasing effects of GHRP has been shown to occur during short term iv infusion. To determine whether humans would remain responsive to prolonged exposure to GHRP and to study the mechanism of action of GHRP, we compared the effects of a 34-h iv infusion of either GHRP or normal saline on parameters of pulsatile GH concentration in nine healthy young men. Each infusion was administered from 0800 h on day 1 to 1800 h on day 2. GHRP was given as a 1 microgram/kg loading bolus, then at the rate of 1 microgram/kg.h. A 50-microgram iv bolus of TRH was given at 0800 h on day 2, followed by iv boluses of GH-releasing hormone (GHRH; 1 microgram/kg, iv, at 1000, 1200, and 1400 h) and then a bolus of GHRP (1 microgram/kg at 1600 h). The integrated GH concentration (IGHC) and parameters of pulsatile GH concentration were calculated for the period between 1400 h on day 1 to 0800 h on day 2, and IGHC was calculated for 2 h after each bolus of GHRP or GHRH. During GHRP infusion, there was a significant increase in IGHC (2908 +/- 450 vs. 1374 +/- 160 micrograms x min/L), maximum pulse amplitude (15.2 +/- 2.8 vs. 8.4 +/- 1.7 micrograms/L), and mean pulse amplitude (7.0 +/- 1.1 vs. 3.8 +/- 1.5 micrograms/L). Plasma insulin-like growth factor-I increased from 252 +/- 23 to 312 +/- 23 micrograms/L. There was no change in either GH pulse frequency or interpulse GH concentration. During GHRP infusion, the GH responses to the GHRH boluses were augmented; however, baseline TSH was lower, and the GH and TSH/PRL responses to GHRP and TRH, respectively, were smaller. We conclude that the pituitary remains sensitive to GHRP during a prolonged GHRP infusion. The mechanisms of the GHRP effect on GH secretion are uncertain, and the possibility that GHRP acts as a functional somatostatin antagonist is discussed. The contrasting effects of GHRP on GH and TSH/PRL secretion could be due to differential effects of GHRP on the pituitary and hypothalamus.