Synthesis of cerium, zirconium, and copper doped zinc oxide nanoparticles as potential biomaterials for tissue engineering applications

A novel eco-friendly high throughput continuous hydrothermal flow system was used to synthesise phase pure ZnO and doped ZnO in order to explore their properties for tissue engineering applications. Cerium, zirconium, and copper were introduced as dopants during flow synthesis of ZnO nanoparticles, Zirconium doped ZnO were successfully synthesised, however secondary phases of CeO and CuO were detected in X-ray diffraction (XRD). The nanoparticles were characterised using X-ray diffraction, Brunauer-Emmett-Teller (BET), Dynamic Light scattering Measurements, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and RAMAN spectroscopy was used to evaluate physical, chemical, and structural properties. The change in BET surface area was also significant, the surface area increased from 11.35 (ZnO_2) to 26.18 (ZrZnO_5). However. In case of CeZnO_5 and CuZnO_5 was not significant 13.68 (CeZnO_5) and 12.16 (CuZnO_5) respectively. Cell metabolic activity analysis using osteoblast-like cells (MG63) and human embryonic derived mesenchymal stem cells (hES-MP) demonstrated that doped ZnO nanoparticles supported higher cell metabolic activity compared to cells grown in standard media with no nanoparticles added, or pure zinc oxide nanoparticles. The ZrZnO_5 demonstrated the highest cell metabolic activity and non-cytotoxicity over the duration of 28 days as compared to un doped or Ce or Cu incorporated nanoparticles. The current data suggests that Zirconium doping positively enhances the properties of ZnO nanoparticles by increasing the surface area and cell proliferation. Therefore, are potential additives within biomaterials or for tissue engineering applications.

Global fine-resolution data on springtail abundance and community structure

Springtails (Collembola) inhabit soils from the Arctic to the Antarctic and comprise an estimated ~32% of all terrestrial arthropods on Earth. Here, we present a global, spatially-explicit database on springtail communities that includes 249,912 occurrences from 44,999 samples and 2,990 sites. These data are mainly raw sample-level records at the species level collected predominantly from private archives of the authors that were quality-controlled and taxonomically-standardised. Despite covering all continents, most of the sample-level data come from the European continent (82.5% of all samples) and represent four habitats: woodlands (57.4%), grasslands (14.0%), agrosystems (13.7%) and scrublands (9.0%). We included sampling by soil layers, and across seasons and years, representing temporal and spatial within-site variation in springtail communities. We also provided data use and sharing guidelines and R code to facilitate the use of the database by other researchers. This data paper describes a static version of the database at the publication date, but the database will be further expanded to include underrepresented regions and linked with trait data.

The anti-malarial drug atovaquone potentiates platinum-mediated cancer cell death by increasing oxidative stress

Platinum chemotherapies are highly effective cytotoxic agents but often induce resistance when used as monotherapies. Combinatorial strategies limit this risk and provide effective treatment options for many cancers. Here, we repurpose atovaquone (ATQ), a well-tolerated & FDA-approved anti-malarial agent by demonstrating that it potentiates cancer cell death of a subset of platinums. We show that ATQ in combination with carboplatin or cisplatin induces striking and repeatable concentration- and time-dependent cell death sensitization in vitro across a variety of cancer cell lines. ATQ induces mitochondrial reactive oxygen species (mROS), depleting intracellular glutathione (GSH) pools in a concentration-dependent manner. The superoxide dismutase mimetic MnTBAP rescues ATQ-induced mROS production and pre-loading cells with the GSH prodrug N-acetyl cysteine (NAC) abrogates the sensitization. Together, these findings implicate ATQ-induced oxidative stress as key mediator of the sensitizing effect. At physiologically achievable concentrations, ATQ and carboplatin furthermore synergistically delay the growth of three-dimensional avascular spheroids. Clinically, ATQ is a safe and specific inhibitor of the electron transport chain (ETC) and is concurrently being repurposed as a candidate tumor hypoxia modifier. Together, these findings suggest that ATQ is deserving of further study as a candidate platinum sensitizing agent.

Enhancing bifunctional catalytic activity of cobalt–nickel sulfide spinel nanocatalysts through transition metal doping and its application in secondary zinc–air batteries

Transition metal-doped cobalt–nickel sulfide spinel (Ni_1.29Co_1.49Mn_0.22S₄) nanocatalysts for secondary Zn–air batteries with an efficient and stable electrochemical performance.

Abstract C114: The role of LKB1 and TP53 mutation status in determining sensitivity of non-small cell lung cancer cells to the metabolic inhibitors; metformin, phenformin and 2-DG

Lung cancer is the leading cause of cancer related death worldwide and adenocarcinoma is the most prevalent subtype. LKB1 (STK11) is the second most commonly altered tumour suppressor in adenocarcinoma and is inactivated in 17% of samples (1). LKB1 is a master kinase that phosphorylates up to 13 downstream targets involved in cell polarity and metabolism. It has been reported that LKB1 mutated cells are more sensitive to the metabolic inhibitor phenformin (2). We aimed to further investigate this by testing the toxicity of 3 metabolic inhibitors (metformin, phenformin and 2-DG) in LKB1 mutated (n = 8) and LKB1 WT (n = 4) NSCLC cell lines, as well as in isogenic cell lines with or without WT LKB1 expression (A549-wtLKB1, A549-mutLKB1).

There was a wide range of sensitivity [IC50 values: metformin 1.22 mM–34.37 mM; phenformin 0.01–1.39 mM; 2-DG 1.86–15.18 mM] to the inhibitors in the 12 NSCLC cell lines. The IC50values for the LKB1 WT cell lines fell within the range of IC50 values for the LKB1 mutated cell lines. IC50 data was analysed using ANOVA with LKB1, KRAS, and TP53 mutation status as factors and interpreting the partial eta squared (η2) using Cohen's rule of thumb to assess the effect size. By this analysis, LKB1 mutation status had a small effect in determining sensitivity to metformin or phenformin and TP53 mutation status had a large impact, with WT TP53 cells being more sensitive.

Cell lineMutation statusIC50 (mM) ± SEMMetforminPhenformin2-DGA549LKB1 (Q37*), KRAS (G12S)1.22 ± 0.120.01 ± 0.0012.14 ± 0.26A427LKB1 ∆, KRAS (G12D)11.56 ± 0.460.65 ± 0.022.45 ± 0.06H1395LKB1 E57fs*, TP53 (C242F)17.99 ± 1.460.54 ± 0.0215.18 ± 1.08H1755LKB1 P281fs*, TP53 (C242F)27.73 ± 1.290.66 ± 0.022.21 ± 0.13H2030LKB1 E317*, TP53 (G262V)34.37 ± 4.181.39 ± 0.298.89 ± 2.10H2126LKB1 ∆, TP53 (E62*)16.33 ± 1.020.80 ± 0.0414.90 ± 1.19H23LKB1 W332*, TP53 (G738C)24.42 ± 3.381.10 ± 0.021.86 ± 0.26H460LKB1 Q37*, KRAS (Q61H)14.15 ± 0.600.35 ± 0.032.52 ± 0.31H1299TP53 deletion16.19 ± 1.090.46 ± 0.036.41 ± 0.47CORL10512.41 ± 0.790.64 ± 0.055.17 ± 0.26Calu6KRAS (Q61K), TP53 (R196*)16.94 ± 1.91.01 ± 0.059.09 ± 0.62NBE120.48 ± 1.160.66 ± 0.014.84 ± 0.32

To further investigate the effect of TP53 status, we transfected isogeneic A549 cells (A549-wtLKB1, A549-mutLKB1) with a vector expressing SV40 large T antigen to inhibit TP53 function. Loss of TP53 function increased resistance in both A549-wtLKB1 (metformin IC50: 5.42 versus 1.92 mM, p < 0.001; phenformin IC50: 0.57 versus 0.02 mM, p <0.001) and A549-mutLKB1 (metformin IC50: 3.99 versus 1.10 mM, p < 0.001; phenformin IC50: 0.53 versus 0.01 mM, p = 0.04) cells. As TP53 is the most commonly mutated tumour suppressor gene in lung adenocarcinoma (46%) (1), our results suggest that TP53 mutation status may be an important factor when considering treatment of NSCLC with metabolic inhibitors.

1.

TCGA. Comprehensive molecular profiling of lung adenocarcinoma. Nature. 2014;511(7511):543-50.

2.

Shackelford David B, Abt E, Gerken L, Vasquez Debbie S, Seki A, Leblanc M, et al. LKB1 Inactivation Dictates Therapeutic Response of Non-Small Cell Lung Cancer to the Metabolism Drug Phenformin. Cancer Cell. 2013 2/11/;23(2):143-58.

Citation Format: Fiona F. Cahill, Sivan Bokobza, Aoife Devery, Neele Drobnitzky, Yanyan Jiang, Luiza Madia Lourenco, Nuramalina Mumin, Anika Weber, Thomas Ashton, Anderson J. Ryan. The role of LKB1 and TP53 mutation status in determining sensitivity of non-small cell lung cancer cells to the metabolic inhibitors; metformin, phenformin and 2-DG. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C114.

Increasing productivity, reducing cost and improving quality in elective surgery in New Zealand: the Waitemata District Health Board joint arthroplasty pilot

BACKGROUND

In 2010, Waitemata District Health Board piloted a new model of care for total hip and knee arthroplasties. The pilot was incentive based and clinically led. The participating surgeons and anaesthetists were responsible for increasing surgical throughput. The pilot aimed to increase productivity, reduce cost and increase quality for patients.

AIM

To compare costs and outcomes for elective hip and knee arthroplasties carried out at the pilot site (Waitakere Hospital) compared with the main District Health Board hospital site (North Shore Hospital (NSH)).

METHODS

A retrospective matched cohort study of hip and knee replacements discharged between 1 July 2010 and 31 March 2011, comparing costs and outcomes at the pilot site compared with the NSH site. Only non-complex procedures were included, and routinely collected data were used.

RESULTS

One hundred and seventy-seven hip replacements (77 NSH, 100 pilot) and 158 knee replacements (88 NSH, 70 pilot) were analysed. Total inpatient event costs were 12% and 17% lower for hip and knee replacements, respectively, at the pilot site compared with NSH. Significant reduction in operation length (39% hip, 36% knee) and length of stay (38% hip, 39% knee) were found in the pilot groups compared with NSH.

CONCLUSION

Implementation of an innovative new model in a public hospital setting has produced significant increases in productivity and reduced overall costs. This model could potentially be used in other public healthcare settings for non-complex elective surgery.

Molecular detection of exercise-induced free radicals following ascorbate prophylaxis in type 1 diabetes mellitus: a randomised controlled trial

AIMS/HYPOTHESIS

Patients with type 1 diabetes mellitus are more susceptible than healthy individuals to exercise-induced oxidative stress and vascular endothelial dysfunction, which has important implications for the progression of disease. Thus, in the present study, we designed a randomised double-blind, placebo-controlled trial to test the original hypothesis that oral prophylaxis with vitamin C attenuates rest and exercise-induced free radical-mediated lipid peroxidation in type 1 diabetes mellitus.

METHODS

All data were collected from hospitalised diabetic patients. The electron paramagnetic resonance spectroscopic detection of spin-trapped alpha-phenyl-tert-butylnitrone (PBN) adducts was combined with the use of supporting markers of lipid peroxidation and non-enzymatic antioxidants to assess exercise-induced oxidative stress in male patients with type 1 diabetes (HbA(1c) 7.9 +/- 1%, n = 12) and healthy controls (HbA(1c) 4.6 +/- 0.5%, n = 14). Following participant randomisation using numbers in a sealed envelope, venous blood samples were obtained at rest, after a maximal exercise challenge and before and 2 h after oral ingestion of 1 g ascorbate or placebo. Participants and lead investigators were blinded to the administration of either placebo or ascorbate treatments. Primary outcome was the difference in changes in free radicals following ascorbate ingestion.

RESULTS

Six diabetic patients and seven healthy control participants were randomised to each of the placebo and ascorbate groups. Diabetic patients (n = 12) exhibited an elevated concentration of PBN adducts (p < 0.05 vs healthy, n = 14), which were confirmed as secondary, lipid-derived oxygen-centred alkoxyl (RO.) radicals (a(nitrogen) = 1.37 mT and abeta(hydrogen) = 0.18 mT). Lipid hydroperoxides were also selectively elevated and associated with a depression of retinol and lycopene (p < 0.05 vs healthy). Vitamin C supplementation increased plasma vitamin C concentration to a similar degree in both groups (p < 0.05 vs pre-supplementation) and attenuated the exercise-induced oxidative stress response (p < 0.05 vs healthy). There were no selective treatment differences between groups in the primary outcome variable.

CONCLUSIONS/INTERPRETATION

These findings are the first to suggest that oral vitamin C supplementation provides an effective prophylaxis against exercise-induced free radical-mediated lipid peroxidation in human diabetic blood.

CLINICAL TRIALS REGISTRATION NUMBER

ISRCTN96164937.

Prognostic significance of admission heart failure in patients with non-ST-elevation acute coronary syndromes (from the Canadian Acute Coronary Syndrome Registries)

We evaluated the in-hospital and 1-year outcomes and predictors of admission heart failure in patients with non-ST-elevation acute coronary syndromes (NSTE-ACSs) without previous heart failure. We analyzed 4,825 patients with NSTE-ACS without a history of congestive heart failure who were included in the multicenter Canadian ACS Registries. Patients in Killip's class II/III on admission (n = 559, 11.6%) were compared with patients in Killip's class I. Patients with heart failure on admission were older (72 [64, 79] vs 64 [54, 73] years, p < 0.0001), with higher baseline creatinine levels (96 vs 88 mmol/dl, p <0.0001), more diabetes (32.2% vs 22.8%, p < 0.0001), hypertension (58% vs 52.4%, p = 0.014), previous myocardial infarction (MI; 38.9% vs 30.3%, p < 0.0001), previous stroke (13.5% vs 7.4%, p < 0.0001), and had more ST depression on admission (27.7% vs 17.3%, p < 0.0001). In-hospital treatment was similar except for a lower rate of aspirin therapy and fewer coronary interventions. Crude event rates were significantly higher in patients with heart failure (in-hospital death 3.6% vs 1.1%, p < 0.0001; death or MI 7.9% vs 4.7%, p = 0.0011; stroke 1.1% vs 0.4%, p = 0.03). One-year event rates were also higher in patients with heart failure (death 14.6% vs 4.4%, p < 0.0001; MI 9.3% vs 6.6%, p = 0.03; death or MI 21.5% vs 10.3%, p < 0.0001). Variables independently associated with heart failure were age (odds ratio 1.57, 95% confidence interval 1.43 to 1.73), diabetes mellitus (odds ratio 1.53, 95% confidence interval 1.24 to 1.89), admission ST depression (odds ratio 1.52, 95% confidence interval 1.22 to 1.90), previous MI, and baseline creatinine. Heart failure on admission was an independent predictor of in-hospital death, death or MI, and stroke and of 1-year death and death or MI. In conclusion, in patients with NSTE-ACS, heart failure on admission is associated with increased short- and long-term rates of death and MI.

Effects of dietary carbohydrate on delayed onset muscle soreness and reactive oxygen species after contraction induced muscle damage

BACKGROUND

Delayed onset muscle soreness (DOMS) occurs after unaccustomed exercise and has been suggested to be attributable to reactive oxygen species (ROS). Previous studies have shown increased ROS after lengthening contractions, attributable to invading phagocytes. Plasma glucose is a vital fuel for phagocytes, therefore carbohydrate (CHO) status before exercise may influence ROS production and DOMS.

OBJECTIVE

To examine the effect of pre-exercise CHO status on DOMS, ROS production, and muscle function after contraction induced muscle damage.

METHOD

Twelve subjects performed two downhill runs, one after a high CHO diet and one after a low CHO diet. Blood samples were drawn for analysis of malondialdehyde, total glutathione, creatine kinase, non-esterified fatty acids, lactate, glucose, and leucocytes. DOMS and muscle function were assessed daily.

RESULTS

The high CHO diet resulted in higher respiratory exchange ratio and lactate concentrations than the low CHO diet before exercise. The low CHO diet resulted in higher non-esterified fatty acid concentrations before exercise. DOMS developed after exercise and remained for up to 96 hours, after both diets. A biphasic response in creatine kinase occurred after both diets at 24 and 96 hours after exercise. Malondialdehyde had increased 72 hours after exercise after both diets, and muscle function was attenuated up to this time.

CONCLUSIONS

Downhill running resulted in increased ROS production and ratings of DOMS and secondary increases in muscle damage. CHO status before exercise had no effect.

Use of Physiologic Pacing After the Canadian Trial of Physiologic Pacing

The Canadian trial of physiologic pacing (CTOPP), published in 2000, demonstrated a reduction in atrial fibrillation (AF), stroke and death with preservation of atrioventricular synchrony, though only the lower rate of AF was statistically significant. The purpose of this study was to determine the effect of CTOPP on pacing mode selection in our region. The British Columbia Cardiac Registry contains prospectively entered data covering a population of 4 millions (M) and 17 implanting centers. It was examined for mode selection trends from 1997 to 2002. At examination, there were data on 22,446 pulse generators (PG) and 29,898 leads. New implant rates per M population were 1997:473; 1998:456; 1999:505; 2000:513; 2001:486; 2002:510. PG replacements also increased, resulting in a total implant rate of 667 PG per M in 2002. Over the 6-year period, DDD use decreased from 321 to 306, but DDDR use, more than doubled from 317 to 750 PG/year. VVI use steadily decreased from 741 to 410 PG/year, while VVIR use increased more modestly from 1997 to 1999, then remained stable. During the 6-year period bracketing CTOPP, use of modes maintaining AV synchrony increased by over 32%, to 53% of PG implanted in 2002. Our PG implant rate was much higher than expected from prior retrospective surveys, and similar to rates in Belgium, France, and Germany. CTOPP did not decrease our use of physiologic pacing but, instead, was associated with a brief pause, then progressively increased in both academic and community centers. Patients' need and widely accepted standards of care proved more important in clinical decision making than the results of a flawed randomized trial.

A multicenter disease management program for hospitalized patients with heart failure

BACKGROUND

Despite the availability of proven therapies, outcomes in patients with heart failure (HF) remain poor. In this 2-stage, multicenter trial, we evaluated the effect of a disease management program on clinical and economic outcomes in patients with HF.

METHODS AND RESULTS

In Stage 1, a pharmacist or nurse assessed each patient and made recommendations to the physician to add or adjust angiotensin-converting enzyme (ACE) inhibitors and other HF medications. Before discharge (Stage 2), patients were randomized to a patient support program (PSP) (education about HF, self-monitoring, adherence aids, newsletters, telephone hotline, and follow-up at 2 weeks, then monthly for 6 months after discharge) or usual care. In Stage 1 (766 patients) ACE inhibitor use increased from 58% on admission to 83% at discharge (P < .0001), and the daily dose (in enalapril equivalents) increased from 11.3 +/- 8.8 mg to 14.5 +/- 8.8 mg (P < .0001). In Stage 2 (276 patients) there was no difference in ACE inhibitor adherence, but a reduction in cardiovascular-related emergency room visits (49 versus 20, P = .030), hospitalization days (812 versus 341, P = .003), and cost of care (2,531 Canadian dollars less per patient) in favor of the PSP.

CONCLUSION

Simple interventions can improve ACE inhibitor use and patient outcomes.

Detection of p53 mutations in precancerous gastric tissue

Intestinal-type gastric cancer is preceded by gastritis and intestinal metaplasia. There is uncertainty regarding the stage at which genetic alterations in the p53 gene occur. Reactive oxygen species (ROS) may participate in the production of mutations and the inactivation of p53 is due to infection by the bacterium Helicobacter pylori. We have investigated whether alterations of the p53 gene can be detected in gastritis and intestinal metaplasia using the restriction site mutation assay. We also assessed the potential contribution of ROS to p53 inactivation using electron spin resonance spectroscopy (ESR) and correlated with the presence of H. pylori. In all, 35% of the gastritis samples and 45% of the intestinal metaplasia samples were found to contain mutations in exons 5–8 of the p53 gene. Electron spin resonance spectroscopy analysis showed a significant increase in free radical levels in gastritis samples compared with normal, intestinal metaplasia and cancer samples, suggesting that free radicals present in gastritis may contribute to p53 mutations. There was no significant difference in free radical levels between the H. pylori-positive and -negative groups. However, a small subpopulation of the H. pylori-negative patients had much higher levels of free radicals. This suggests a more prominent role for other factors in ROS production.

Lack of benefit of dietary advice to men with angina: results of a controlled trial

OBJECTIVE

To see whether mortality among men with angina can be reduced by dietary advice.

DESIGN

A randomized controlled factorial trial.

SETTING

Male patients of general practitioners in south Wales.

SUBJECTS

A total of 3114 men under 70 y of age with angina.

INTERVENTIONS

Subjects were randomly allocated to four groups: (1) advised to eat two portions of oily fish each week, or to take three fish oil capsules daily; (2) advised to eat more fruit, vegetables and oats; (3) given both the above types of advice; and (4) given no specific dietary advice. Mortality was ascertained after 3-9 y.

RESULTS

Compliance was better with the fish advice than with the fruit advice. All-cause mortality was not reduced by either form of advice, and no other effects were attributable to fruit advice. Risk of cardiac death was higher among subjects advised to take oily fish than among those not so advised; the adjusted hazard ratio was 1.26 (95% confidence interval 1.00, 1.58; P=0.047), and even greater for sudden cardiac death (1.54; 95% CI 1.06, 2.23; P=0.025). The excess risk was largely located among the subgroup given fish oil capsules. There was no evidence that it was due to interactions with medication.

CONCLUSIONS

Advice to eat more fruit was poorly complied with and had no detectable effect on mortality. Men advised to eat oily fish, and particularly those supplied with fish oil capsules, had a higher risk of cardiac death. This result is unexplained; it may arise from risk compensation or some other effect on patients' or doctors' behaviour.

Cost-effectiveness of palivizumab in New Zealand

OBJECTIVE

To establish the preterm infant hospitalization risks from respiratory syncytial virus (RSV) in New Zealand and the net cost per hospitalization averted by palivizumab.

METHODS

The 437 infants born < 32 weeks' gestation in 1997 and treated at five major neonatal units were identified. Subsequent admissions during the next 2 years for bronchiolitis, pneumonia and croup were tracked, and information collected on RSV tests performed. Data on the length of stay and hospital costs were used to calculate the potential net cost per hospitalization averted associated with the use of palivizumab and the number needed to treat (NNT) to prevent one hospitalization.

RESULTS

Estimated RSV readmission risk before 1 year corrected age in infants < 32 weeks' gestation discharged home on oxygen, and those " 28 weeks' gestation, or between 29 and 31 weeks' gestation with or without chronic lung disease was 42%, 23%, 19%, 10% and 8%, respectively. The NNT with palivizumab to prevent one hospitalization ranged from six to 26 across subgroups. Mean (range) net cost per hospitalization averted was 60,000 New Zealand dollars ($28,000-$166,700). In no subgroup would prophylaxis result in net cost saving. Prophylaxis for all NZ infants " 28 weeks' gestation would cost approximately $1,090,000 net and prevent 29 hospitalizations annually, being equivalent to $37,000 net per hospitalization averted, with eight infants treated to prevent one hospitalization. Alternative assumptions about cost and efficacy failed to alter these findings.

CONCLUSION

If value is placed on preventing morbidity, the priority groups for palivizumab prophylaxis are preterm infants discharged home on oxygen, followed by preterm infants of 28 weeks' gestation or less.

Commercially available folic acid supplements and their compliance with the British Pharmacopoeia test for dissolution

A recent report suggested that some folic acid preparations available in the United States failed to meet the specifications for dissolution specified by the US Pharmacopoeia (USP), of 70 per cent drug release in the first hour of testing. The Teratology Society recommends that women of childbearing age should take a daily supplement of 400 microg folic acid when they are trying to conceive, to reduce the risk of foetal neural tube defects. The consequence of this failure to meet the USP requirements may be that an inadequate dose of folate may be absorbed and thus the expected level of protection against neural tube defects not afforded. The purpose of the present study was to examine a number of brands of folic acid (400 microg), available commercially in the United Kingdom, for compliance with the British Pharmacopoeia (BP) test for dissolution. Ten tablets (or capsules) from each of 11 brands were tested using dissolution apparatus compliant with BP requirements, using 0.1 M sodium hydroxide as the dissolution medium. The results indicated that four of the brands failed to release 70 per cent of the nominal drug content in the first hour of test and thus did not comply with the test. Two of the seven brands that passed the test went on to release more than 150 per cent of the nominal 400 microg drug content. These results highlight the problems of dose uniformity and the potential health risks of slow dissolution and under-dosing in commercially available folic acid dosage forms.

The rocky road to health reform: some lessons from New Zealand

Ongoing structural change has been a feature of the New Zealand health system throughout the 1990s. As we enter the new millennium a new government is now embarking upon yet another round of reform. I look back on the past few years and consider what lessons might be learned about the process of health policy-making in New Zealand. They include the need for a clear vision about the goals of health policy, the importance of consulting with key stakeholders at an early stage, the problems of implementing change too speedily, and the need to allow sufficient time for systems to mature before replacing them with new structures.

The oxidative mechanism of heparin interferes with radical production by glucose and reduces the degree of glycooxidative modifications on human serum albumin

Among substances which may prove useful in preventing or reducing the progression of glycooxidative modifications of proteins, heparin plays a unique role. To elucidate the mechanism whereby heparin may favourably influence the protein structure during glycation, human serum albumin (HSA) was glycated with both 25 and 50 mM glucose in the absence and presence of 12 microg.mL(-1) low-molecular-mass heparin. Glycation caused: (a) modifications of fluorescence emission and excitation spectra consistent with the covalent attachment of glucose to protein; (b) a significant increase in the esterase activity of HSA on p-nitrophenyl acetate; (c) a reduced susceptibility to tryptic digestion and (d) enhanced formation of high-molecular mass aggregates of HSA. These alterations were accompanied by oxidative reactions, as the EPR spectra showed a clear-cut radical signal, dependent on glucose concentration, further confirmed by measurement of the carbonyl content of HSA, as an indirect proof of oxidative damage. In the presence of heparin all the above alterations, especially at 25 mM glucose, turned out to be antagonized. The effects of heparin were dependent on its specific binding to HSA, which triggered an oxidative mechanism strikingly different from that caused by glucose. In the presence of heparin, only the radical species catalyzed by heparin was detected across all samples of glycated HSA, irrespective of glucose concentration. In addition, at 25 mM glucose, enhancement of the oxidative capacity of heparin was also observed. The results demonstrate that the oxidative mechanism sustained by heparin mediates biological effects that may be beneficial in reducing the extent of glycooxidative damage on HSA.

Public purchasing and private priorities for healthcare in New Zealand

The 1993 Health and Disability Services Act heralded a range of structural reforms in the New Zealand health care system. Despite these reforms considerable resources being spent on convincing consumers of their merits, have failed to gain widespread public approval. This paper examines two key issues that have arisen during the reform process. These are the difficulties associated with trying to set priorities in ways which are effective and politically acceptable, and the relationship between the public and private sectors. Unacknowledged conflicts of interest have helped to undermine the priority setting process. The discussion suggests that it may be increasingly difficult for any government in future to determine the allocation of resources without taking private sector interests and rising public concern into account. It remains to be seen which of these factors is more powerful.

Priority-setting in New Zealand: translating principles into practice

In May 1998 the New Zealand Health Funding Authority released a discussion paper which proposed a principles-based approach to setting purchasing priorities that incorporates the economic methods of programme budgeting and marginal analysis, and cost-utility analysis. The principles upon which the process was to be based are effectiveness, cost, equity of health outcomes, Maori health and acceptability. This essay describes and critiques issues associated with translating the principles into practice, most particularly the proposed methods for evaluating the effectiveness and measuring the cost of services. It is argued that the proposals make an important contribution towards the development of a method for prioritizing services which challenges our thinking about those services and their goals, and which is systematic, explicit, and transparent. The shift towards 'thinking at the margin' and systematically reviewing the value for money of competing claims on resources is likely to improve the quality of decision-making compared with the status quo. This does not imply that prioritization can, or should, be undertaken by means of any simple formula. Any prioritization process should always be guided by informed judgement. The approach is more appropriate for some services than for others. Key methodological issues that need further consideration include the choice of instrument for measuring health gains, the identification of marginal services, how to combine qualitative and quantitative information, and how to ensure consistency across different levels of decision-making.

New Zealand: long-term care in a decade of change

Long-term care in New Zealand incorporates a mix of public and private funding and provision. After a decade of structural change, the purchasing of almost all publicly funded health and social care is now the responsibility of one central agency. Services for older persons are poorly integrated, and there are problems of access to and quality of some services. Efforts are being made to address these problems. The challenge now is to ensure that this groundwork is not lost amid the turmoil of yet another round of restructuring by an enthusiastic, newly elected government.

Electron spin resonance spectroscopy, exercise, and oxidative stress: an ascorbic acid intervention study

Oxygen free radicals are highly reactive species that are produced in increased quantities during strenuous exercise and can damage critical biological targets such as membrane phospholipids. The present study examined the effect of acute ascorbic acid supplementation on exercise-induced free radical production in healthy subjects. Results demonstrate increases in the intensity of the alpha-phenyl-tert-butylnitrone adduct (0.05 +/- 0.02 preexercise vs. 0.19 +/- 0.03 postexercise, P = 0.002, arbitrary units) together with increased lipid hydroperoxides (1.14 +/- 0.06 micromol/l preexercise vs. 1.62 +/- 0.19 micromol/l postexercise, P = 0.005) and malondialdehyde (0.70 +/- 0.04 micromol/l preexercise vs. 0.80 +/- 0.04 micromol/l postexercise, P = 0.0152) in the control phase. After supplementation with ascorbic acid, there was no significant increase in the electron spin resonance signal intensity (0.02 +/- 0. 01 preexercise vs. 0.04 +/- 0.02 postexercise, arbitrary units), lipid hydroperoxides (1.12 +/- 0.21 micromol/l preexercise vs. 1.12 +/- 0.08 micromol/l postexercise), or malondialdehyde (0.63 +/- 0.07 micromol/l preexercise vs. 0.68 +/- 0.05 micromol/l postexercise). The results indicate that acute ascorbic acid supplementation prevented exercise-induced oxidative stress in these subjects.

Cardiac pacing in Canada in 1998: working towards optimal pacing therapy. Canadian Working Group on Cardiac Pacing

The Canadian Working Group on Cardiac Pacing (CWGCP) was formed in 1996 with the primary goal of promoting optimal pacing therapy in Canada. In 1997, the CWGCP conducted a survey of pacing practices across Canada. Ninety-two of 125 implanting programs (74%) responded. Implant rates vary by province--from 39 per 100,00 population in Ontario to 63 per 100,000 population in Nova Scotia and Prince Edward Island. Variations in regional implant rates persist even after correcting for the age of the population. Physiological pacing was used for 35% of all implants in Canada in 1996/97. There were marked differences across Canada in the mode of pacing selected. In western Canada, 39.5% of pacing systems implanted were physiological compared with 18.2% in Atlantic Canada and 29% in Quebec. There were also differences in follow-up practices. Approximately 40% of centres follow patients with single chamber pacemakers annually, whereas most other centres still follow these patients every six months. Economic constraints, the size of pacing programs and the involvement of committed pacing physicians are factors that may influence the regional differences in cardiac pacing across Canada.

Electron spin resonance spectroscopic detection of oxygen-centred radicals in human serum following exhaustive exercise

Free radicals or oxidants are continuously produced in the body as a consequence of normal energy metabolism. The concentration of free radicals, together with lipid peroxidation, increases in some tissues as a physiological response to exercise - they have also been implicated in a variety of pathologies. The biochemical measurement of free radicals has relied in the main on the indirect assay of oxidative stress by-products. This study presents the first use of electron spin resonance (ESR) spectroscopy in conjunction with the spin-trapping technique, to measure directly the production of radical species in the venous blood of healthy human volunteers pre- and post-exhaustive aerobic exercise. Evidence is also presented of increased lipid peroxidation and total antioxidant capacity post-exercise.

Contracting for health services in New Zealand: a transaction cost analysis

The splitting of the functions of purchaser and provider in the New Zealand health system in 1993 necessitated the use of explicit contracts between the two parties. This paper examines contracting experiences during the first two years of operation. The study focuses on four services: rest homes, primary care clinics, surgical services, and acute mental health services. The insights of transaction cost economics form the theoretical framework. The objective of this study was to examine whether the transaction costs associated with contracting vary across the four different services, and whether different types of contracts and contractual relationships are emerging as transactors attempt to reduce these costs. Information was collected in a series of 53 interviews with purchasers and providers, together with any relevant documentation. The results suggest that the costs of contracting are indeed greater for some services than for others. Other variables such as the style of negotiations, the type and specificity of contracts and the degree of monitoring also differ across the four services. At this early stage of the reform process, there was little evidence that purchasers and providers were attempting to reduce transaction costs by negotiating more flexible, longer-term, relational contracts. The main benefit from contracting to date has been improved accountability of service providers.

Health care costs of obesity in New Zealand

OBJECTIVE

To estimate the costs of health care that are attributable to obesity in New Zealand.

METHODS

The 1991 health care costs of non-insulin dependent diabetes, coronary heart disease, hypertension, gallstone disease, post-menopausal breast cancer and colon cancer were estimated and multiplied by the population attributable factor for obesity for each condition. The relative risk estimates were taken from the literature, the obesity prevalence from a 1990 New Zealand survey, and the costs and volumes of services were taken from a variety of sources and covered hospital (inpatient and outpatient) services, general practitioner consultations, pharmaceuticals, laboratory tests and ambulance services. Calculations were conservative and net of goods and services tax.

RESULTS

A conservative estimate of the health care costs attributable to obesity for the six conditions was NZ$135 million. This represents about 2.5% of total health care costs which is similar to analyses from other countries.

CONCLUSIONS

The health care costs of obesity as estimated are considerable. However, the total cost of overfatness to the New Zealand population is far greater than this because lesser degrees of overfatness, the health care costs of other obesity-related conditions such as arthritis, the costs to individuals of weight-loss programs and the indirect and intangible costs were not included in the analysis. A substantial and wide-ranging public health effort is needed to turn around the increasing prevalence and costs of obesity.

Market concentration in secondary health services under a purchaser-provider split: the New Zealand experience

The separation of purchaser and provider in government-funded health systems enables competition to develop between providers. Competition is seen as a means to drive technical efficiencies by providers. While it is difficult to assess comprehensively the level of competition in a market taking into account contestability and substitutability effects, it is possible to measure the degree of market concentration. This paper employs the Hirschman-Herfindahl index to provide measures of market concentration in selected secondary health care markets in New Zealand immediately prior to (1992) and following (1994) implementation of a purchaser-provider split. The results show that, generally, the selected markets are highly concentrated and that there has been little change in the degree of concentration over the 2 year period under investigation. The paper also discusses some of the methodological problems associated with the measurement of market concentration and acknowledges the limitations of such measures as indicators of competition.

The purchaser-provider split in New Zealand: the story so far

In July 1993 some major structural changes were introduced into the New Zealand health system. The main feature was a separation of the purchasing and providing functions that had previously been performed by area health boards. This paper describes the reasons for and nature of the original (1991) proposals, together with changes that have been made subsequently. It discusses the nature of the contracting environment between purchasers and providers, including the integration of primary and secondary funding, the flexibility of contractual arrangements, and the degree of competition. Some information is provided on progress to date, including the impact on quality of services and accountability of providers, as well as some more tangible measures such as changes in throughput, waiting lists, and expenditure since the restructuring took place. The paper concludes that the success or failure of the purchaser-provider split in New Zealand appears to hang crucially on the contractual arrangements which are struck between purchasers and providers. In the longer term, purchasers are likely to encourage the vertical integration of primary and secondary care providers into managed care organisations styled along the lines of health maintenance organisations. Hence the purchaser-provider split may best be viewed as a temporary structure which provides a pathway towards the desired end, that is, more managed and coordinated patient care provided by vertically integrated organisations which were unlikely to emerge under the previous arrangements.

Shopping for health: purchasing health services through contracts

The 1993 New Zealand health service reforms were based on the purported efficiencies of the purchaser/provider split. Purchasers are required to contract for services that will maintain, improve and restore the health of the populations they serve. The purchasing role, which requires the development of contracting skills as well as the setting of strategic directions and priorities, is new and as yet poorly developed. This paper describes the role of purchasing agents in setting priorities, the different approaches that are being taken to contracting for services and some of the problems that have arisen in the first year of contracting. It explores the trade-off that is evident between the potential for improving efficiency through contestable contracting and the need to minimise transaction costs associated with the contracting process. The purchasers' accountability to the public and the Minister is analysed in the broader political context of the purchasers' role in shaping a public health service and improving the health of the population.

Preventing child pedestrian injury: pedestrian education or traffic calming?

The traditional approach to the prevention of child pedestrian injuries in New Zealand is pedestrian education. However, none of the programs currently being implemented in New Zealand have ever been shown to reduce injury rates. The allocation of scarce resources to pedestrian education must therefore be questioned. In this paper we estimate the number of serious child pedestrian injuries which might be prevented if the resources allocated to pedestrian education were allocated instead to environmental approaches, in particular, to traffic calming. It is estimated that approximately 18 hospitalisations of child pedestrians could be prevented each year under this alternative resource allocation, disregarding any other benefits of traffic calming. These results emphasise the need to consider the potential sacrifices involved in the allocation of scarce resources to child pedestrian education.

From evolution to revolution: restructuring the New Zealand health system

After a number of years of evolutionary changes to the New Zealand health system, the government announced a radical restructuring of all publicly funded health services in July 1991, to be implemented on 1 July 1993. The primary features of these changes are a splitting of the purchaser and provider roles, and a restructuring of health services along more business-like lines. The proposals have been highly contentious and have attracted little support from within the health sector. This paper outlines the reasons for and nature of the reforms and explores some of the issues behind the changes. These include problems of pricing services for purchasing purposes, the potential conflict between financial and social objectives, and questions of accountability of purchasers and providers. Considerable uncertainty surrounding these and other issues means that any potential efficiency gains cannot be guaranteed. The costs of the reform process have, however, already been high, both in financial terms and in terms of their impact on the morale of health workers.

The purchaser-provider split: implications for dental services

In July 1991, the National Government announced proposals for a radical restructuring of the New Zealand public health system, a central feature of which is the separation of the purchasing and providing roles currently performed by area health boards. While the competitive market model suggests that the split should improve the efficiency of public health services by effectively creating a market system, this paper suggests that, in practice, there are likely to be a number of obstacles. Other potential sources of efficiency are improved accountability, improved management, and integration of primary and secondary care. For dental health services, the separation of purchaser and provider should introduce greater flexibility into State-funded dental services by opening up options for alternative providers and methods of provision. Factors such as the number and structure of provider units; the contractual arrangements between these units and the RHAs, especially in respect of payment mechanisms; and the regulatory regime which covers these contractual arrangements will all affect service delivery. If real choices between types of providers and methods of provision eventually emerge, a major challenge for RHAs will be to monitor and enforce at reasonable cost any quality measures built into contracts.

Cost-effectiveness of alternative medications in the treatment of duodenal ulcer

This study examines the differential costs of various medications in the treatment of duodenal ulcer. Two approaches are taken. The first estimates the (differential) cost per year of life before relapse can be expected to occur, for five different medications. The second approach estimates the cost of treating a duodenal ulcer over a 5-year period during which ranitidine, cimetidine, or colloidal bismuth subcitrate (CBS) is used in the initial course of treatment. Expected rates of relapse and the probability of receiving maintenance therapy are taken into account. The results of both approaches suggest that CBS costs considerably less than other medications to achieve a similar outcome. It is concluded that, as well as the clinical benefits associated with slower relapse, the potential economic benefits of CBS are substantial.

A cost effectiveness analysis of the treatment of end stage renal failure

An economic evaluation of continuous ambulatory peritoneal dialysis (CAPD), home haemodialysis, incentre haemodialysis and transplantation was carried out using cost effectiveness analysis to evaluate the cost per life year saved. The probability that a person with end stage renal failure would change treatment modalities was used to calculate an average five year treatment profile. The present value of the cost per life year saved (expressed in 1988 $NZ) was $35,270 for incentre dialysis, $28,175 for home haemodialysis, $26,390 for CAPD at Middlemore Hospital, $25,395 for CAPD at Auckland Hospital and $18.463 for transplantation. This ranking was unchanged after various sensitivity analyses. This apparent ranking of the cost effectiveness of the different modalities cannot, however, be used to support a decrease in haemodialysis in favour of an increase in transplants and CAPD until marginal cost factors have been studied. It must also be recognised that social and medical characteristics define which treatments are appropriate for any patient so that the different modalities are not perfect substitutes for each other.

The efficacy of L-tryptophan in the reduction of sleep disturbance and depressive state in alcoholic patients

Alcoholic male inpatients (N = 76) served as subjects in this study which examined the effect of L-tryptophan on depressive state and sleep disturbance. All subjects were residents of a 6-week alcohol treatment program at a Veterans Administration Medical Center. Subjects' degree of depression (Zung's Depression Scale) and sleep satisfaction (Webb's Post-Sleep Inventory) were measured four times during the study, just prior to and following ingestion of a substance that was either 3 gms L-tryptophan or 3 gms of an identical-appearing placebo. Subjects in the L-tryptophan/placebo condition received the active substance for 4 days followed by the placebo with a 4-day washout period in between. A second group of subjects received the same regimen of reverse order and a third received placebos on both occasions. There were two additional control groups that received no substances. All subjects in the study reported decreased levels of depression due to nonspecific treatment effects. The subjects who took L-tryptophan in either sequence reported even lower levels of depression. Sleep disturbance was not affected by L-tryptophan since it was barely present when the study began. A phenomenon referred to as the interval effect is discussed and an alternative explanation for this effect is offered.

Trends in antihypertensive medication costs in a cohort of Aucklanders 1982-87

This study examines the trends in drug treatment and costs of hypertension in a cohort of 1600 adult Aucklanders between 1982 and 1987. In 1987 prices the average daily cost of antihypertensive drug treatment per person increased from 42 cents to 74 cents over the five year period. The increase in cost seen in antihypertensive therapy in this cohort is explained by the introduction of new and more expensive drugs rather than by increases in the proportion of the population being treated for hypertension, daily dosage, number of antihypertensives per individual or in real prices of antihypertensives.

Alcohol taxes: do the poor pay more than the rich?

Concern has often been expressed that alcohol taxes bear more heavily on the poor than on the rich, especially if these taxes are based on quantity rather than price. However, surprisingly little is known about how the tax burden is distributed across different income groups. Utilizing survey data from 3010 respondents in New Zealand, this study calculates exactly how much alcohol tax was paid by respondents in different income groups and in different types of households. These results were applied to household expenditure survey data to estimate the incidence of alcohol taxes across different households. The results suggest that, although in dollar terms the wealthiest households paid about four times as much alcohol tax as the poorest households, when expressed as a percentage of income, alcohol taxes are distributed proportionally across the lower income brackets but decline towards the upper end of the income scale. These taxes accounted for less than 1% of household income for all income groups. Households with children generally paid less alcohol tax than households without children. It is concluded that alcohol taxes in New Zealand do not seriously conflict with the broader equity objectives of government policy.

Estimated cost of alcohol to the New Zealand public hospital system

The abuse of alcohol imposes a heavy burden upon our public hospital system. Although a lack of conclusive evidence precludes any accurate estimated of the costs that are incurred, our broad estimates do give some indication of the extent of these costs. Taking into account only those health problems where alcohol is recorded as a causal factor gives an estimated cost of public hospital services of approximately $21 million per year in excess of any costs which might otherwise be expected to arise in the absence of alcohol. Expanding the definition of alcohol-related disorders according to the results of survey data increases the estimated cost to at least $52 million per year and possibly to $115 million or more. These costs are far outweighed by the non-medical costs of excessive drinking such as lost production, crime and a deterioration in the quality of life of alcohol abusers and their families.

Attenuation factors for certain tissues when the body is irradiated omnidirectionally

Experimental values of mean attenuation factors are reported for certain tissues in an anthropomorphic phantom irradiated omnidirectionally with gamma rays from sodium-24, radium-226, iodine-131 and xenon-133. The data are used to relate the mean absorbed dose to the whole body, bone marrow, gonads and skin to (a) the absorbed dose in air and (b) the exposure in air. Correlations are made for the degradation of the radiation by scatter and the photoelectron enhancement effect. It is proposed that for natural background gamma rays a mean attenuation factor of 0.7 may be used for bone marrow. The corresponding rad/R factor is 0.67. It is also estimated that the effective mean depth of bone marrow for omnidirectional irradiation is 5.0--5.5 cm.