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In Africa, achieving sustainable agricultural intensification-increasing agricultural output without deleterious environmental impacts or converting more land for cultivation-will depend greatly on the actions of smallholder farmers and the policies that influence them. Whatever the future holds, the vast majority of farmers right now are small. Using multiple lines of evidence across disciplines, we examine trends in productivity of land and fertilizers in Malawi. Unfortunately, our effort uncovers disturbing trends that indicate intensification and sustainability are at risk. Two time-series datasets of satellite-based vegetative indices show a generally flat but highly variable trend in the productivity of agricultural land with epochs of steep decline. This is notably despite substantial (and successful) government effort to promote fertilizer use. We also compile evidence from several studies over three decades that use field-level data from farmers and suggest substantial declining maize yield response to fertilizer over time. These trends are consistent with soil degradation, the disappearance of fallow land and minimal investment in rehabilitation practices in densely populated areas, putting agricultural productivity in jeopardy. These signs of the harmful impacts that narrow approaches to productivity improvement may be having in Malawi are an early warning sign to policy makers in Malawi and around the continent that a more holistic and nuanced strategy is necessary for sustainable intensification in agriculture., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier B.V.)

Introduction: The medical radiation sciences' (MRS) MedRadJournalClub attracts a global group of participants to monthly sessions to discuss selected journal articles. The September 2017 session explored the experiences of MRS professionals working with lesbian, gay, bisexual, and transgender (LGBT) patients. The aim of the chat was to establish staff educational preparation, how participants' organizations approached the issue, and what participants would do differently at work or at home in relation to this patient population after the chat., Method: Data were extracted using the Twitter advanced search function with #MedRadJClub from the 19th to 23rd September 2017. The data were reviewed and categorized for themes. Tweets related to shared LGBT resources were captured, verified, and counted separately., Results: 44 participants took part in the September Twitter chat. After data cleaning, 127 tweets were included for analysis with a further 16 tweets sharing LGBT resources. Almost all of the participants disclosed that they had no undergraduate education or workplace training in the care of LGBT patients. Workplaces of a limited few participants had specific approaches to improve experiences for this patient population. Many participants were eager to advocate for changes in their workplaces after the Twitter chat., Conclusion: There is still work to be carried out to educate MRS professionals to enhance their LGBT patients' experience and improve workplaces. Positive changes in education and a more inclusive clinical environment will ultimately improve care for LGBT patients., (Copyright © 2018. Published by Elsevier Inc.)

Background: The Use of Multidrug Pill In Reducing cardiovascular Events (UMPIRE) trial, showed that access to a cardiovascular polypill (aspirin, statin and two blood pressure lowering drugs) significantly improved adherence, lowered systolic blood pressure (SBP) and low-density lipoprotein cholesterol (LDLc) in patients with or at high risk of cardiovascular disease (CVD). We aimed to analyze the within-trial cost-effectiveness of the polypill strategy versus usual care in India., Methods: Relative effectiveness and costs of polypill versus usual care groups in UMPIRE were estimated from the health sector perspective. Only direct medical costs were considered. The effectiveness of the polypill was reported as a percentage increase in adherence and mean reductions in SBP, and LDL-c, over the 15-month trial period. Healthcare resource utilization and costs were collected for each patient during the trial. Polypill price was constructed using a range of scenarios: $0.06-$0.94/day. The cost-effectiveness of the polypill was measured as the additional cost for 10% increase in adherence, and per unit reduction in SBP and LDL-c., Results: Overall, the mean cost per patient was significantly lower with the polypill strategy (-$203 per person, (95% CI: -286, -119, p < 0.01). In scenario analyses that varied polypill price assumptions, incremental cost-effectiveness ratios for a polypill strategy ranged between cost-saving to $75 per 10% increase in adherence for polypill price of $0.94 per day., Conclusions: The polypill strategy was cost-saving compared to usual care among patients with or at high risk of CVD in India., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background and Aims: Elevated urinary 11-dehydro thromboxane B 2 (TxB 2 ), a measure of thromboxane A 2 formation in vivo, predicts future atherothrombotic events. To further understand this relationship, the genetic determinants of 11-dehydro TxB 2 and their associations with cardiovascular morbidity were investigated in this study., Methods: Genome-wide and targeted genetic association studies of urinary 11-dehydro TxB 2 were conducted in 806 Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) participants., Results: The strongest associations were in PPARGC1B (rs4235745, rs32582, rs10515638) and CNTN4 (rs10510230, rs4684343), these 5 single nucleotide polymorphisms (SNPs) were independently associated with 11-dehydro TxB 2 formation. Haplotypes of 11-dehydro TxB 2 increasing alleles for both PPARGC1B and CNTN4 were significantly associated with 11-dehydro TxB 2 , explaining 5.2% and 4.5% of the variation in the whole cohort, and 8.8% and 7.9% in participants not taking aspirin, respectively. In a second ASCOT population (n = 6199), addition of these 5 SNPs significantly improved the covariate-only Cox proportional hazards model for cardiovascular events (chisq = 14.7, p=0.01). Two of the risk alleles associated with increased urinary 11-dehydro TxB 2 were individually associated with greater incidences of cardiovascular events - rs10515638 (HR = 1.31, p=0.01) and rs10510230 (HR = 1.25, p=0.007); effect sizes were larger in those not taking aspirin., Conclusions: PPARGC1B and CNTN4 genotypes are associated with elevated thromboxane A 2 formation and with an excess of cardiovascular events. Aspirin appears to blunt these associations. If specific protection of PPARGC1B and CNTN4 variant carriers by aspirin is confirmed by additional studies, PPARGC1B and CNTN4 genotyping could potentially assist in clinical decision making regarding the use of aspirin in primary prevention., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: Fixed dose combinations of cardiovascular therapy ('polypills') have now been launched in several dozen countries. There is considerable clinical interest in the effects of switching to polypill-based care from typical current treatment regimens, especially if polypills contain components at sub-maximal dosage., Methods: The SPACE Collaboration includes three trials of polypill based care vs usual care in patients with established CVD or at high calculated risk. Individual patient data for 3140 trial participants were combined. Patients were categorized according to the potency of the statin and the number of BP lowering medications they were taking at baseline. Effects on adherence to anti-platelet medication, systolic blood pressure (SBP) and LDL cholesterol stratified by baseline potency of medication were determined using fixed effects models., Results: Randomisation to the polypill group was associated with improved SBP at 12months, but this improvement varied according to baseline BP regimen: -3.3, -5.9, -2.5 and +1mmHg for patients taking 0, 1, 2 and 3+ BP lowering medications at baseline. For changes in LDL cholesterol at 12months, significant improvements in LDL cholesterol were seen for those taking no statin (-0.21mmol/L; 95% CI: -0.34 to -0.07), less potent statin (-0.16mmol/L; 95% CI: -0.29 to -0.04) and equipotent statins (-0.14mmol/L; 95% CI -0.26 to -0.02) at baseline., Conclusion: The adherence benefits of polypills tend to offset the loss of potency from use of individual components with lower dose potency, and to facilitate improvements in multiple risk factors., (Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.)

Background: Globally, most patients with hypertension are treated with monotherapy, and control rates are poor because monotherapy only reduces blood pressure by around 9/5 mm Hg on average. There is a pressing need for blood pressure-control strategies with improved efficacy and tolerability. We aimed to assess whether ultra-low-dose combination therapy could meet these needs., Methods: We did a randomised, placebo-controlled, double-blind, crossover trial of a quadpill-a single capsule containing four blood pressure-lowering drugs each at quarter-dose (irbesartan 37·5 mg, amlodipine 1·25 mg, hydrochlorothiazide 6·25 mg, and atenolol 12·5 mg). Participants with untreated hypertension were enrolled from four centres in the community of western Sydney, NSW, Australia, mainly by general practitioners. Participants were randomly allocated by computer to either the quadpill or matching placebo for 4 weeks; this treatment was followed by a 2-week washout, then the other study treatment was administered for 4 weeks. Study staff and participants were unaware of treatment allocations, and masking was achieved by use of identical opaque capsules. The primary outcome was placebo-corrected 24-h systolic ambulatory blood pressure reduction after 4 weeks and analysis was by intention to treat. We also did a systematic review of trials evaluating the efficacy and safety of quarter-standard-dose blood pressure-lowering therapy against placebo. This trial is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12614001057673. The trial ended after 1 year and this report presents the final analysis., Findings: Between November, 2014, and December, 2015, 55 patients were screened for our randomised trial, of whom 21 underwent randomisation. Mean age of participants was 58 years (SD 11) and mean baseline office and 24-h systolic and diastolic blood pressure levels were 154 (14)/90 (11) mm Hg and 140 (9)/87 (8) mm Hg, respectively. One individual declined participation after randomisation and two patients dropped out for administrative reasons. The placebo-corrected reduction in systolic 24-h blood pressure with the quadpill was 19 mm Hg (95% CI 14-23), and office blood pressure was reduced by 22/13 mm Hg (p<0·0001). During quadpill treatment, 18 (100%) of 18 participants achieved office blood pressure less than 140/90 mm Hg, compared with six (33%) of 18 during placebo treatment (p=0·0013). There were no serious adverse events and all patients reported that the quadpill was easy to swallow. Our systematic review identified 36 trials (n=4721 participants) of one drug at quarter-dose and six trials (n=312) of two drugs at quarter-dose, against placebo. The pooled placebo-corrected blood pressure-lowering effects were 5/2 mm Hg and 7/5 mm Hg, respectively (both p<0·0001), and there were no side-effects from either regimen., Interpretation: The findings of our small trial in the context of previous randomised evidence suggest that the benefits of quarter-dose therapy could be additive across classes and might confer a clinically important reduction in blood pressure. Further examination of the quadpill concept is needed to investigate effectiveness against usual treatment options and longer term tolerability., Funding: National Heart Foundation, Australia; University of Sydney; and National Health and Medical Research Council of Australia., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Aims: To conduct a prospective, individual participant data (IPD) meta-analysis of randomised controlled trials comparing a polypill-based approach with usual care in high risk individuals., Methods and Results: Three trials comparing polypill-based care with usual care in individuals with CVD or high calculated cardiovascular risk contributed IPD. Primary outcomes were self-reported adherence to combination therapy (anti-platelet, statin and ≥ two blood pressure (BP) lowering agents), and difference in mean systolic BP (SBP) and LDL-cholesterol at 12 months. Analyses used random effects models. Among 3140 patients from Australia, England, India, Ireland, New Zealand and The Netherlands (75% male, mean age 62 years), median follow-up was 15 months. At baseline, 84%, 87% and 61% respectively were taking a statin, anti-platelet agent and at least two BP lowering agents. At 12 months, compared to usual care, participants in the polypill arm had higher adherence to combination therapy (80% vs. 50%, RR 1.58; 95% CI, 1.32 to 1.90; p < 0.001), lower SBP (-2.5 mmHg; 95% CI, -4.5 to -0.4; p = 0.02) and lower LDL-cholesterol (-0.1 mmol/L; 95% CI, -0.2 to 0.0; p = 0.04). Baseline treatment levels were a major effect modifier for adherence and SBP (p-homog < 0.0001 and 0.02 respectively) with greatest improvements seen among those under-treated at baseline., Conclusions: Polypill therapy significantly improved adherence, SBP and LDL-cholesterol in high risk patients compared with usual care, especially among those who were under-treated at baseline., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Aims: Cardiovascular polypills are a novel strategy in the prevention of cardiovascular disease. Based on considerations about the effectiveness, the individual pills of a polypill are taken at different times of the day. This study aimed therefore to compare the use of a polypill in the morning, in the evening or the individual components taken at their usual times on cardiovascular risk factors and patient acceptability., Methods: The study was a randomized three-period crossover trial. Seventy-eight patients with established cardiovascular disease were randomly allocated to the use of polypill (aspirin 75 mg, simvastatin 40 mg, lisinopril 10mg and hydrochlorothiazide 12.5mg) in the morning, in the evening or use of the individual agents taken at different time points (Trial: NCT01506505)., Results: Using the polypill in the evening resulted in a 0.2 mmol/L (95%-confidence interval (CI): 0.1 to 0.3) lower fasting LDL-cholesterol compared to the use in the morning, and not statistically significantly different mean 24-hour systolic BP (mean difference: 0.7 mmHg; 95%-CI; -2.1 to 3.4). Compared to the use of the individual agents, the mean LDL-cholesterol was 0.2 mmol/L (95%-CI: 0.1 to 0.3) higher when using the polypill in the morning, but not statistically significantly different when used in the evening (mean difference: -0.1 mmol/L; 95%-CI: -0.1 to 0.0). Furthermore, there were no differences in mean 24-hour systolic BP with morning use (mean difference: 0.4 mmHg; 95%-CI; -1.5 to 2.3) or evening use (mean difference: 1.0mmHg; 95%-CI; -0.8 to 2.8) of the polypill compared to the individual agents. The adherence was 5.2% (95%-CI: 1.4 to 9.1) higher with morning use of the polypill and 5.0% (95%-CI: 1.5 to 8.5) higher with evening use compared to the individual agents. Treatment with the polypill was preferred by 92% of the participants., Conclusion: The use of a polypill in the evening was more effective in lowering LDL-cholesterol, and resulted in not statistically significantly different ambulatory BP levels compared to the use of a polypill in the morning. Therapy with a polypill was associated with an increased adherence. The polypill is highly preferred by patients, demonstrating a potential role for the polypill in the prevention of cardiovascular disease., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Background: An international collaboration of investigators will assess the benefits and risks of fixed dose combination (FDC) based care compared with usual care in populations at high risk of cardiovascular disease (CVD). Several trials are being conducted, as the effectiveness and economic impact of a FDC-based strategy may vary substantially between countries, given the varying influence of the health-care system within which the intervention is delivered., Methods: Individual patient data (IPD) will be provided by participating trials for combined IPD meta-analysis., Results: Primary outcomes will include self-reported current use of antiplatelet, statin, and combination (≥ 2) blood pressure lowering therapies at 12 months, and change in systolic blood pressure (SBP) and LDL cholesterol from baseline to 12 months. Non-inferiority margins of 3 mm Hg for SBP and 0.3 mmol/L for LDL cholesterol have been pre-specified. Secondary outcomes will include change in cholesterol fractions, diastolic blood pressure and creatinine from baseline to 12 months, quality of life, new onset diabetes mellitus, mortality (cardiovascular, non-cardiovascular and all cause) and a composite outcome of cardiovascular events (including all coronary heart disease events, heart failure events leading to death or requiring hospital admission, cerebrovascular events and peripheral arterial events)., Conclusion: The SPACE group of trials will assess, in a variety of healthcare settings, whether a FDC strategy for delivery of preventive medication has the potential to significantly improve prevention of cardiovascular disease in patients at high risk., (© 2013.)

Objectives: To investigate the association of polymorphisms in complement factor H (CFH) and coronary heart disease (CHD) using meta-analysis., Background: Age-related macular degeneration (AMD) and CHD may share partially overlapping pathogenesis. A non-synonymous SNP (rs1061170/Y402H) in CFH encoding complement factor H (fH) is robustly associated with increased AMD risk but associations with CHD risk have been inconsistent., Methods: We conducted de novo genotyping and genetic association analyses of incident and prevalent CHD in four studies, and in silico analysis of the same association in a further four cohorts. We pooled these data with information from all published studies using random effects meta-analysis, including a total of 48,646 participants of which 9097 were CHD cases. We also evaluated the association of Y402H with known risk factors for CHD by pooling results from new and in silico studies providing relevant data., Results: CFH genotype was not associated with CHD. Compared to the reference TT homozygote group the pooled odds ratio (OR) for individuals homozygous for the C allele was 1.02, 95% CI (0.91, 1.13) and that for heterozygote TC individuals was 1.04 (0.98, 1.10). There was no association of CFH with systolic and diastolic blood pressure, total-, LDL- and HDL-cholesterol, or body mass index. Individuals who were CC compared to TT had higher triglyceride levels: pooled mean difference 0.06 (0.02, 0.10) mmol/L, p=0.005., Conclusions: The AMD-associated CFH genotype is not associated with CHD. With the possible exception of triglycerides, this CFH SNP was not associated with a wide range of other CHD risk factors., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

Wnt/beta-catenin signaling has been implicated in taste papilla development; however, its role in epithelial maintenance and tumor progression in the adult tongue remains elusive. We show Wnt/beta-catenin pathway activation in reporter mice and by nuclear beta-catenin staining in the epithelium and taste papilla of adult mouse and human tongues. beta-Catenin activation in APC(min/+) mice, which carry a mutation in adenomatous poliposis coli (APC), up-regulates Sonic hedgehog (Shh) and Jagged-2 (JAG2) in the tongue epithelium without formation of squamous cell carcinoma (SCC). We demonstrate that Shh suppresses beta-catenin transcriptional activity in a signaling-dependent manner in vitro and in vivo. A similar regulation and function was observed for JAG2, suggesting that both pathways negatively regulate beta-catenin, thereby preventing SCC formation in the tongue. This was supported by reduced nuclear beta-catenin in the tongue epithelium of Patched(+/-) mice, exhibiting dominant active Shh signaling. At the invasive front of human tongue cancer, nuclear beta-catenin and Shh were increased, suggesting their participation in tumor progression. Interestingly, Shh but not JAG2 was able to reduce beta-catenin signaling in SCC cells, arguing for a partial loss of negative feedback on beta-catenin transcription in tongue cancer. We show for the first time that the putative Wnt/beta-catenin targets Shh and JAG2 control beta-catenin signaling in the adult tongue epithelium, a function that is partially lost in lingual SCC.

Background: To compare patterns of coronary artery disease in British South Asian and White European men., Methods: 41 South Asian and 42 European men (mean age 64+/-9 years) with coronary artery disease were studied. All had similar symptoms. Vessel reference diameter and degree of stenosis were calculated using quantitative coronary angiography. Extent of atherosclerotic disease in the LAD was assessed using calcification scores (CAC) measured by multislice Computed Tomography. Fasting bloods and blood pressure were measured. The LAD was subdivided into four 2.5 cm segments for analysis., Results: Most atherosclerosis occurred in the proximal LAD segment, South Asian men had more proximal LAD stenosis than European men (50% vs. 37%, p=0.036), but CAC scores were similar. South Asians with CAC scores in the lowest tertile (0-22 HU), had significantly narrower LAD diameters than Europeans (2.8 mm vs. 3.8 mm, p=0.004, adjusted for body surface area and age). This ethnic difference was not explained by measured risk factors, including diabetes. In contrast, ethnic differences in LAD diameter were abolished in the upper tertiles of CAC scores (23-2416 HU) (South Asians: 3.0 mm, Europeans: 3.1 mm, p=0.6). Calcification scores were negatively correlated with LAD diameter in Europeans (rho=-0.38, p=0.016) but not in South Asians (rho=-0.06, p=0.72)., Conclusions: Increased LAD stenosis, despite equivalent levels of calcified disease, in South Asians is attributable to narrower arteries. Reduced LAD diameter is associated with advanced disease in Europeans but not in South Asians, indicative of ethnic differences in vascular remodelling.

Understanding the morphology and function of heart valves is important to the study of underlying causes of heart failure. Existing techniques such as those based on echocardiography are limited by the relatively low signal-to-noise ratio (SNR), attenuation artefacts, and restricted access. The alternative of cardiovascular MR imaging offers versatility and accuracy in 3D localisation, but is hampered by large movements of the valves throughout the cardiac cycle. This paper presents a motion-compensated adaptive imaging approach for MR valve imaging. To illustrate its clinical potential, 3D motion of the aortic valve plane is first captured through a single breath-hold COMB tag pre-scan and then tracked in real-time with an automatic method based on multi-resolution image registration. Motion-compensated coverage of the aortic valve is then acquired prospectively, thus allowing its clear 3D reconstruction and visualisation. To provide isotropic voxel coverage of the imaging volume, retrospective projection onto convex sets (POCS) super-resolution enhancement is applied to the slice-select direction. In vivo results demonstrate the effectiveness of the proposed motion-compensation and super-resolution schemes for depicting the structure of the valve leaflets throughout the cardiac cycle. The proposed method fundamentally changes the way MR imaging is performed by transforming it from a spatially to materially localised imaging method. This also has important implications for quantifying blood flow and myocardial perfusion, as well as tracking anatomy and function of the heart.

Background: Increased platelet activation occurs in ischemic heart disease (IHD), but increased platelet activation is also seen in cerebrovascular atherosclerosis and peripheral artery disease. It is not clear therefore whether platelet activation is an indicator of IHD or a marker of generalized atherosclerosis and inflammation. South Asian subjects are at high risk of IHD, but little is known regarding differences in platelet and leukocyte function between European and South Asian subjects., Methods: Fifty-four male subjects (age 49-79 years) had coronary artery calcification measured by multislice computed tomography (CT), aortic atherosclerosis assessed by measurement of carotid-femoral pulse wave velocity (aortic PWV), and femoral and carotid atherosclerosis measured by B-mode ultrasound. Platelet and leukocyte activation was assessed by flow cytometry of platelet-monocyte complexes (PMC), platelet expression of PAC-1 binding site and CD62P, and expression of L-selectin on leukocytes., Results: Elevated circulating PMC correlated significantly with elevated aortic PWV and PMC were higher in subjects with femoral plaques. In contrast PMC did not differ by increasing coronary artery calcification category or presence of carotid plaques. Higher numbers of PMC were independently related to elevated levels of C-reactive protein (CRP), higher aortic PWV, hypertension and smoking in a multivariate model. Markers of platelet and leukocyte activation did not differ significantly by ethnicity., Conclusions: Increased PMC are related to the extent of aortic and femoral atherosclerosis rather than coronary or carotid atherosclerosis. The association between elevated CRP and increased PMC suggests that inflammation in relation to generalized atherosclerosis may play an important role in PMC activation.

Objectives: Carotid endoluminal intervention is an alternative to surgery but carries a risk of embolic stroke even with distal protection devices. We investigated the clinical features and degree of stenosis related to number and size of emboli during carotid angioplasty., Design: An experimental ex vivo study., Materials: An ex vivo pulsatile flow model was used in which temperature, velocity, flow, pressure and viscosity characteristics were designed to simulate the carotid circulation., Methods: Carotid endarterectomy specimens excised as intact cylinders (n = 28) were subjected to a standardised angioplasty procedure using radiological guidance. Emboli collected in filters placed distally were counted and sized using microscopy., Results: Median number of emboli during angioplasty was 133 (range 15-1331). Median size of the largest embolus was 700 microns (range 75-2400). Severity of stenosis correlated with increased maximum size (r = 0.55, p = 0.012). Statin therapy >4 weeks pre-operatively was associated with reduced emboli number and size (54 (range 15-748) vs 247 (range 37-1331) [p = 0.023] and 400 microm (range 75-2400) vs 1300 microm (range 600-2200) [p = 0.022])., Conclusions: In this model a wide range of emboli number and size were produced. Number and size of embolic particles were highest in patients with high-grade stenoses not receiving statin therapy.

Antiretrovirals are standard treatment for HIV-1-positive women during pregnancy in the UK, but little is known about maternal or fetal safety. In our cohort study of 214 pregnant women with HIV-1 infection, those who received no antiretroviral therapy had a rate of pre-eclampsia significantly lower (none of 61) than those on triple antiretroviral therapy (8 of 76; odds ratio 15.3, 95% CI 0.9-270, p=0.0087). However, the rate of pre-eclampsia in HIV-1-positive women on treatment did not differ from that in uninfected controls (12 of 214; p=0.2). The association of HIV-1-related immune deficiency with a low rate of pre-eclampsia, and the restoration of this rate in women treated with triple antiretroviral therapy to the expected rate indicates a pivotal role of the immune system in the pathogenesis of pre-eclampsia. The clinical presentation of pre-eclampsia and toxic effects of antiretroviral therapy could overlap and complicate diagnosis and management in these patients.

Carbon monoxide (CO) may be the cause of more than one-half of the fatal poisonings reported in many countries; fatal cases also are grossly under-reported or misdiagnosed by medical professionals. Therefore, the precise number of individuals who have suffered from CO intoxication is not known. The health effects associated with exposure to CO range from the more subtle cardiovascular and neurobehavioral effects at low concentrations to unconsciousness and death after acute or chronic exposure to higher concentrations of CO. The morbidity and mortality resulting from the latter exposures are described briefly to complete the picture of CO exposure in present-day society. The symptoms, signs, and prognosis of acute CO poisoning correlate poorly with the level of carboxyhemoglobin (COHb) measured at the time of hospital admission; however, because CO poisoning is a diagnosis frequently overlooked, the importance of measuring COHb in suspicious settings cannot be overstated. The early symptoms (headache, dizziness, weakness, nausea, confusion, disorientation, and visual disturbances) also have to be emphasized, especially if they recur with a regular periodicity or in the same environment. Complications occur frequently in CO poisoning. Immediate death is most likely cardiac in origin because myocardial tissues are most sensitive to the hypoxic effects of CO. Severe poisoning results in marked hypotension, lethal arrhythmias, and electrocardiographic changes. Pulmonary edema may occur. Neurological manifestation of acute CO poisoning includes disorientation, confusion, and coma. Perhaps the most insidious effect of CO poisoning is the development of delayed neuropsychiatric impairment within 2-28 days after poisoning and the slow resolution of neurobehavioral consequences. Carbon monoxide poisoning during pregnancy results in high risk for the mother by increasing the short-term complication rate and for the fetus by causing fetal death, developmental disorders, and chronic cerebral lesions. In conclusion, CO poisoning occurs frequently; has severe consequences, including immediate death; involves complications and late sequelae; and often is overlooked. Efforts in prevention and in public and medical education should be encouraged.

Production of reactive species has been associated with tissue injury in diverse human disorders and experimental models of disease. Peroxynitrite is a strong oxidant with multiple pathways of reactivity. One protein modification reaction that may be specific to peroxynitrite is the nitration of the ortho position of tyrosine residues and nitrotyrosine has been used as a marker for peroxynitrite-mediated oxidative stress. Nitrotyrosine was formed when peroxynitrite was reacted at physiological pH with fatty acid-free bovine serum albumin or with human plasma proteins. Nitrotyrosine was not formed when proteins were incubated with nitric oxide, nitrogen dioxide, or nitric oxide plus hydrogen peroxide in the presence of ferrous iron or ferrihorseradish peroxidase. Low-molecular-weight molecules such as uric acid, ascorbate, and sulfhydryls inhibited protein tyrosine nitration in the absence of bicarbonate. Addition of bicarbonate catalytically enhanced the yield of nitration and overcame the inhibition of these antioxidants. Bicarbonate/CO2 enhanced the yield of protein nitrotyrosine in a concentration-dependent manner. Catalysis of nitration is achieved by the interaction of CO2 with the peroxynitrite anion. A mechanism is proposed involving an ONOO(O)CO- intermediate, which readily nitrates tyrosine residues in a non-radical-dependent manner. Thus, peroxynitrite nitrates tyrosine residues by a mechanism that is catalyzed by CO2 under normal physiological conditions.

In order to assess the long term effects of antihypertensive treatment on left ventricular diastolic function, 26 hypertensive patients were followed up for a mean of 4.25 years with two-dimensional and Doppler echocardiography. A significant reduction in left ventricular mass index was first apparent after 9 months of therapy (mean (S.D.) 124 (22) vs. 114 (18) g/m2, P < 0.01), and this was maintained over the 4.25 year period (124 (22) vs. 117 (17) g/m2, p < 0.05). At 9 months there was no change in either isovolumic relaxation time (108 (26) vs. 108 (17) ms, P = N.S.) or left ventricular filling as assessed by peak flow velocity E/A ratio (0.94 (0.22) vs. 0.95 (0.27), P = N.S.). However, after 4.25 years there was a significant improvement in IVRT (108 (26) vs. 83 (11) ms, P < 0.01) with a trend towards an improved peak flow velocity E/A ratio, although this did not reach statistical significance (0.95 (0.27) vs. 1.02 (0.26), P = N.S.). Of the 14 patients who had an abnormal isovolumic relaxation time at baseline, 12 normalised and 2 improved. These findings suggest that left ventricular diastolic dysfunction in hypertension may be reversed by prolonged antihypertensive treatment.

Water-soluble fiber has been reported to reduce serum cholesterol and consequently, oat bran, which has a high soluble-fiber content, has been recommended as part of a lipid-lowering diet. However, a recent small study of 20 volunteers with low mean serum cholesterol concentrations (4.8 mmol/L) demonstrated no lipid-lowering effect of oat bran. The present study investigated 64 volunteers with cholesterol concentrations much more typical of the UK population (6 mmol/L). Subjects were randomly allocated to receive either a normal-sized helping of an oat-based cereal or a cereal containing no oats for 4 wk and then crossed over to the alternative regimen for a further 4 wk. Small (2.23% and 4.55%) but significant (P < 0.04 and P < 0.05) reductions in total and low-density-lipoprotein cholesterol, respectively, were observed in association with the consumption of oat-based cereal. These data support the view that consumption of oat-based cereals may well contribute usefully to a lipid-lowering diet.

Two free radical generating systems, xanthine oxidase/hypoxanthine or phenazine methosulfate/NADH, were exposed to air plus He, N2, or Ar at partial pressures ranging from 0.2 to 6.0 MPa, and the rates of production of superoxide, hydroxyl, singlet O2, and H2O2 were measured. All three inert gases acted similarly to enhance the production of superoxide radicals by facilitating interactions between iron and H2O2, or O2 and organic radicals. These reactions occurred at quite low gas partial pressures, only 0.28 MPa, and hydrostatic pressures of up to 6.0 MPa had no effect on radical reactions. Enhanced radical production may be the basis for the inhibition of cellular growth mediated by inert gases, and inert gas enhancement of O2 toxicity.

The effect of antihypertensive therapy on regression of left ventricular hypertrophy and left ventricular diastolic function was investigated in 25 hypertensive patients for up to 18 months after initiation of treatment. Left ventricular mass index was calculated by two-dimensional echocardiography and left ventricular diastolic function assessed by transmitral pulsed doppler ultrasound. Significant reduction in left ventricular mass index was observed after 9 months of treatment. Only 13 patients had a reduction in mass greater than the intraobserver variability of the technique. There was no change in doppler indices of left ventricular diastolic function. In 7 patients who were studied for a further 9 months after regression had occurred there was still no appreciable difference in left ventricular diastolic function. These findings indicate that there is no direct relation between left ventricular mass and abnormal left ventricular diastolic function.

A randomised double-blind cross-over study of increased oral potassium 64 mmol a day versus placebo was conducted in 20 young healthy males on normal sodium unrestricted diet. A significantly greater proportion had lower systolic and diastolic blood-pressures on potassium than on placebo. The mean diastolic pressure was significantly lowered, by 2.4 mm Hg, during potassium supplementation. Change in diastolic pressure correlated negatively with change in 24-hour urinary potassium and positively which change in 24-hour urinary sodium/potassium ratio in individual subjects.