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Background: Hypertension leads to cardiac structural and functional changes, commonly assessed by echocardiography. In this study, we assessed the predictive performance of different echocardiographic parameters including left ventricular hypertrophy (LVH) on future cardiovascular outcomes in elderly hypertensive patients without heart failure., Methods: Data from LVH substudy of the Second Australian National Blood Pressure trial were used. Echocardiograms were performed at entry into the study. Cardiovascular outcomes were identified over short term (median 4.2 years) and long term (median 10.9 years). LVH was defined using threshold values of LV mass (LVM) indexed to either body surface area (BSA) or height(2.7): >115/95g/m(2) (LVH-BSA(115/95)) or ≥49/45g/m(2.7) (LVH-ht(49/45)) in males/females, respectively, and ≥125g/m(2) (LVH-BSA(125)) or ≥51g/m(2.7) (LVH-ht(51)) for both sexes., Results: In the 666 participants aged ≥65 years in this analysis, LVH prevalence at baseline was 33%-70% depending on definition; and after adjusting for potential risk factors, only LVH-BSA(115/95) predicted both short- and long-term cardiovascular outcomes. Participants having LVH-BSA(115/95) (69%) at baseline had twice the risk of having any first cardiovascular event over the short term (hazard ratio, 95% confidence interval: 2.00, 1.12-3.57, P = 0.02) and any fatal cardiovascular events (2.11, 1.21-3.68, P = 0.01) over the longer term. Among other echocardiographic parameters, LVM and LVM indexed to either BSA or height(2.7) predicted cardiovascular events over both short and longer term., Conclusions: In elderly treated hypertensive patients without heart failure, determining LVH by echocardiography is highly dependent on the methodology adopted. LVH-BSA(115/95) is a reliable predictor of future cardiovascular outcomes in the elderly., (© American Journal of Hypertension, Ltd 2016. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Objectives: To assess the association between parental education and under-five mortality, using the Integrated Management of Childhood Illness (IMCI) data from rural Bangladesh. It also investigated whether the association of parental education with under-five mortality had changed over time., Study Design: This study was nested in the IMCI cluster randomized controlled trial., Methods: Participants considered for the analysis were all children aged under five years from the baseline (1995-2000) and the final (2002-2007) IMCI household survey. The analysis sample included 39,875 and 38,544 live births from the baseline and the final survey respectively. The outcome variable was under-five mortality and the exposure variables were mother's and father's education. Data were analysed with logistic regression., Results: In 2002-2007, the odds of the under-five mortality were 38% lower for the children with mother having secondary education, compared to the children with uneducated mother. For similar educational differences for fathers, at the same time period, the odds of the under-five mortality were 16% lower. The association of mother's education with under-five mortality was significantly stronger in 2002-2007 compared to 1995-2000., Conclusions: Mother's education appears to have a strong and significant association with under-five mortality, compared to father's education. The association of mother's education with under-five mortality appears to have increased over time. Our findings indicate that investing on girls' education is a good strategy to combat infant mortality in developing countries., (Copyright © 2015 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.)

Objectives: Current blood pressure (BP) management guidelines recommend that treatment thresholds for BP be based on absolute cardiovascular disease (CVD) risk rather than on elevated BP levels alone. Clinicians are concerned that delayed pharmacotherapy in individuals with high BP, but low CVD risk, may increase long-term CVD events. To investigate this, we examined differences in CVD events within the Second Australian National BP study (ANBP2) for those previously on pharmacotherapy and those who were not, as well as fatal events in the 6-year post-trial period., Methods: Population consisted of ANBP2 participants without a prior CVD event. Adjusted Cox-regression hazard models were used to assess the effects of prior BP pharmacotherapy use on cardiovascular endpoints within ANBP2. An extended 6-year follow-up analysis for cardiovascular and all-cause mortality was also conducted., Results: We found a higher in-trial CVD and all-cause mortality rate and incidence of new-onset diabetes for those on previous treatment versus those who were treatment-naive. We investigated whether this was an effect of the in-trial protocol, but this did not explain the observed differences. No difference in CVD or all-cause mortality at 10 years was observed between 'treatment-naive' and 'previous treatment' groups., Conclusion: We found no long-term adverse mortality associated with treatment naivety of elevated BP in an elderly hypertensive cohort, but this finding is likely to be confounded as seen by the lower in-trial mortality in the 'treatment-naive' group. Legacy effects need to be explored in randomized trials of middle-aged populations where the clinical concern lies.

Background and Objectives: Evidence relating the rate of change in renal function, measured as eGFR, after antihypertensive treatment in elderly patients to clinical outcome is sparse. This study characterized the rate of change in eGFR after commencement of antihypertensive treatment in an elderly population, the factors associated with eGFR rate change, and the rate's association with all-cause and cardiovascular mortality., Design, Setting, Participants, & Measurements: Data from the Second Australian National Blood Pressure study were used, where 6083 hypertensive participants aged ≥65 years were enrolled during 1995-1997 and followed for a median of 4.1 years (in-trial). Following the Second Australian National Blood Pressure study, participants were followed-up for a further median 6.9 years (post-trial). The annual rate of change in the eGFR was calculated in 4940 participants using creatinine measurements during the in-trial period and classified into quintiles (Q) on the basis of the following eGFR changes: rapid decline (Q1), decline (Q2), stable (Q3), increase (Q4), and rapid increase (Q5)., Results: A rapid decline in eGFR in comparison with those with stable eGFRs during the in-trial period was associated with older age, living in a rural area, wider pulse pressure at baseline, receiving diuretic-based therapy, taking multiple antihypertensive drugs, and having blood pressure <140/90 mmHg during the study. However, a rapid increase in eGFR was observed in younger women and those with a higher cholesterol level. After adjustment for baseline and in-trial covariates, Cox-proportional hazard models showed a significantly greater risk for both all-cause (hazard ratio, 1.28; 95% confidence interval, 1.09 to 1.52; P=0.003) and cardiovascular (hazard ratio, 1.40; 95% confidence interval, 1.11 to 1.76; P=0.004) mortality in the rapid decline group compared with the stable group over a median of 7.2 years after the last eGFR measure. No significant association with mortality was observed for a rapid increase in eGFR., Conclusions: In elderly persons with treated hypertension, a rapid decline in eGFR is associated with a higher risk of mortality., (Copyright © 2015 by the American Society of Nephrology.)

Background: We have previously developed a score for predicting cardiovascular events in the intermediate term in an elderly hypertensive population. In this study, we aimed to extend this work to predict 10-year cardiovascular and all-cause mortality in the hypertensive aged population., Methods: Ten-year follow-up data of 5,378 hypertensive participants in the Second Australian National Blood Pressure study who were aged 65-84 years at baseline (1995-2001) and without prior cardiovascular events were analyzed. By using bootstrap resampling variable selection methods and comparing the Akaike and Bayesian information criterion and C-indices of the potential models, optimal and parsimonious multivariable Cox proportional hazards models were developed to predict 10-year cardiovascular and all-cause mortality. The models were validated using bootstrap validation method internally and using the Dubbo Study dataset externally., Results: The final model for cardiovascular mortality included detrimental (age, smoking, diabetes, waist-hip ratio, and disadvantaged socioeconomic status) and protective factors (female sex, alcohol consumption, and physical activity). The final model for all-cause mortality also included detrimental (age, smoking, random blood glucose, and disadvantaged socioeconomic status) and protective factors (female sex, alcohol consumption, body mass index, and statin use). Blood pressure did not appear in either model in this patient group. The C-statistics for internal validation were 0.707 (cardiovascular mortality) and 0.678 (all-cause mortality), and for external validation were 0.729 (cardiovascular mortality) and 0.772 (all-cause mortality)., Conclusions: These algorithms allow reliable estimation of 10-year risk of cardiovascular and all-cause mortality for hypertensive aged individuals., (© American Journal of Hypertension, Ltd 2014. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: The Modifications of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) are 2 equations commonly used to estimate glomerular filtration rate (eGFR). The predictive performance offered by these equations, particularly in relation to clinical outcomes in elderly hypertensive patients, is not clear., Methods: The Second Australian National Blood Pressure Study cohort was used to investigate the predictive performance of these 2 equations for long-term outcomes (median 10.8 years) in elderly treated hypertensive patients. Both equations were used to calculate eGFR in 6,083 patients aged ≥65 years and classified as having chronic kidney disease (CKD) or no CKD (eGFR ≥60ml/min/1.73 m2)., Results: More patients were classified as having no CKD using the CKD-EPI equation compared with the MDRD equation (72.1% vs. 69.4%; P = 0.001). Both equations performed similarly in risk prediction of all-cause and cardiovascular mortality with decreased eGFR, except for patients with baseline eGFR of 45-59ml/min/1.73 m2, where the CKD-EPI equation predicted higher risk of all-cause mortality compared with those with no CKD. However, the magnitude of difference in risk prediction was too small to be clinically meaningful. Both equations showed similar predictive performance. However, we observed longer survival and no higher risk in those who were reclassified as having no CKD using the CKD-EPI equation, but these patients were classified earlier as having CKD using the MDRD equation., Conclusions: There was no clinically relevant difference in predictive performance for long-term survival by eGFR calculated using either of these equations in this elderly hypertensive population., (© American Journal of Hypertension, Ltd 2014. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

The objective of this study was to examine the cost-effectiveness of angiotensin-converting enzyme inhibitor (ACEI)-based treatment compared with thiazide diuretic-based treatment for hypertension in elderly Australians considering diabetes as an outcome along with cardiovascular outcomes from the Australian government's perspective.We used a cost-utility analysis to estimate the incremental cost-effectiveness ratio (ICER) per quality-adjusted life-year (QALY) gained. Data on cardiovascular events and new onset of diabetes were used from the Second Australian National Blood Pressure Study, a randomized clinical trial comparing diuretic-based (hydrochlorothiazide) versus ACEI-based (enalapril) treatment in 6083 elderly (age ≥65 years) hypertensive patients over a median 4.1-year period. For this economic analysis, the total study population was stratified into 2 groups. Group A was restricted to participants diabetes free at baseline (n = 5642); group B was restricted to participants with preexisting diabetes mellitus (type 1 or type 2) at baseline (n = 441). Data on utility scores for different events were used from available published literatures; whereas, treatment and adverse event management costs were calculated from direct health care costs available from Australian government reimbursement data. Costs and QALYs were discounted at 5% per annum. One-way and probabilistic sensitivity analyses were performed to assess the uncertainty around utilities and cost data.After a treatment period of 5 years, for group A, the ICER was Australian dollars (AUD) 27,698 (&OV0556; 18,004; AUD 1-&OV0556; 0.65) per QALY gained comparing ACEI-based treatment with diuretic-based treatment (sensitive to the utility value for new-onset diabetes). In group B, ACEI-based treatment was a dominant strategy (both more effective and cost-saving). On probabilistic sensitivity analysis, the ICERs per QALY gained were always below AUD 50,000 for group B; whereas for group A, the probability of being below AUD 50,000 was 85%.Although the dispensed price of diuretic-based treatment of hypertension in the elderly is lower, upon considering the potential enhanced likelihood of the development of diabetes in addition to the costs of treating cardiovascular disease, ACEI-based treatment may be a more cost-effective strategy in this population.

Background: The Integrated Management of Childhood Illness (IMCI) strategy includes guidelines for the management of sick children at first-level facilities. These guidelines intend to improve quality of care by ensuring a complete assessment of the child's health and by providing algorithms that combine presenting symptoms into a set of illness classifications for management by IMCI-trained service providers at first-level facilities., Objectives: To investigate the sustainability of improvements in under-five case management by two cadres of first-level government service providers with different levels of pre-service training following implementation of IMCI training and supportive supervision., Methods: Twenty first-level health facilities in the rural sub-district of Matlab in Bangladesh were randomly assigned to IMCI intervention or comparison groups. Health workers in IMCI facilities received training in case management and monthly supportive supervision that involved observations of case management and reinforcement of skills by trained physicians. Health workers in comparison facilities were supervised according to Government of Bangladesh standards. Health facility surveys involving observations of case management were carried out at baseline (2000) and at two points (2003 and 2005) after implementation of IMCI in intervention facilities., Findings: Improvement in the management of sick under-five children by IMCI trained service providers with only 18 months of pre-service training was equivalent to that of service providers with 4 years of pre-service training. The improvements in quality of care were sustained over a 2-year period across both cadres of providers in intervention facilities., Conclusion: IMCI training coupled with regular supervision can sustain improvements in the quality of child health care in first-level health facilities, even among workers with minimal pre-service training. These findings can guide government policy makers and provide further evidence to support the scale-up of regular supervision and task shifting the management of sick under-five children to lower-level service providers., (Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine © The Author 2013; all rights reserved.)

Objectives: In hypertensive persons aged 60 years or below, visit-to-visit SBP variability is directly associated with cardiovascular events, especially stroke. It is unclear whether such a relationship exists for older persons. We investigated whether there is a relationship between visit-to-visit SBP variability and cardiovascular events in an elderly population, and identified the factors associated with increased SBP variability., Methods: Information from 49771 visits of 5880 patients aged at least 65 years being treated for hypertension in the Second Australian National Blood Pressure study was used. Patients were followed for 4.1 (median) years and had eight (median) doctor visits during the study. SBP variability was defined as within-individual SD of SBP across study follow-up visits., Results: Increased visit-to-visit SBP variability was found to be a strong predictor for future cardiovascular events in this elderly population. The hazard ratio (95% confidence interval) for any first fatal/nonfatal cardiovascular event for highest decile compared with lowest decile of SBP variability was 2.18 (1.52-3.13) after adjusting for sex, age, treatment including other baseline variables, and average on-treatment SBP. A similar effect was observed for stroke (hazard ratio 2.78, 1.28-6.05), myocardial infarction (hazard ratio 4.11, 1.87-9.06), and heart failure (hazard ratio 4.79, 1.82-12.62). Highest SBP variability was also a predictor of post-trial fatal cardiovascular events. Increased visit-to-visit SBP variability was related to age, pulse pressure, changing physicians, smoking, treatment allocation, and the use of multiple BP-lowering drugs., Conclusion: These findings suggest that reducing visit-to-visit SBP variability might be an important objective in addition to conventional blood pressure-lowering in elderly hypertensive patients.

Background: We sought to determine the incidence of newly diagnosed diabetes in treated elderly hypertensive patients and the prognostic impact of diabetes on long-term survival., Methods: The Second Australian National Blood Pressure (ANBP2) study randomized 6,083 hypertensive patients aged 65-84 years to angiotensin-converting enzyme inhibitor (ACEI) or thiazide diuretic-based therapy and followed them for a median of 4.1 years. Long-term survival was determined in 5,678 patients over an additional median of 6.9 years after ANBP2 (post-trial)., Results: After ANBP2, the cohort was classified into preexisting (7.2%), newly diagnosed (5.6%), and no diabetes (87.2%) groups. A 44% higher incidence of newly diagnosed diabetes was observed in patients randomized to thiazide diuretic compared with ACEI-based treatment. The other predictors of newly diagnosed diabetes were having a higher body mass index, having a higher random blood glucose, and living in a regional location compared to major cities (a geographical classification based on accessibility) at study entry. After completion of ANBP2, compared with those with no diabetes, the preexisting diabetes group experienced higher cardiovascular (hazards ratio (HR) = 1.65; 95% confidence interval (CI) = 1.03-2.65) and all-cause mortality (HR = 1.40; 95% CI = 1.02-1.92) when adjusted for age, sex, and treatment. A similar pattern was observed after including the post-trial period for cardiovascular (HR = 1.52; 95% CI = 1.20-1.93) and all-cause mortality (HR = 1.50; 95% CI = 1.29-1.73). However, when the newly diagnosed group was compared with the no diabetes group, no significant difference was observed in cardiovascular (HR = 0.33; 95% CI = 0.11-1.05) or all-cause mortality (HR = 0.76; 95% CI = 0.47-1.23) either during the ANBP2 trial or including post-trial follow-up (cardiovascular: HR = 0.82; 95% CI = 0.58-1.17; all-cause mortality: HR = 1.04; 95% CI = 0.85-1.27)., Conclusions: Long-term presence of diabetes reduces survival. Compared with thiazide diuretics, ACEI-based antihypertensives may delay the development of diabetes in those at risk and thus potentially improve cardiovascular outcome in the elderly.

High blood pressure (BP) is highly prevalent among the elderly, and even with pharmacological therapy BP is difficult to control to guideline recommended levels. Although poor compliance to therapy is associated with less BP control, little is known regarding other barriers to attaining on-treatment target BP. This study examined factors associated with achieving on-treatment target BP in 6010 hypertensive participants aged 65-84 years from the Second Australian National Blood Pressure study. Participants were followed for a median of 4.1 years, with BP monitored every 6 months. 'Target BP' was defined as a reduction of systolic/diastolic BP of at least 20/10 mm Hg and BP <160/90 mm Hg from randomization in two consecutive follow-up visits. Cox regression was used to identify factors associated with achieving target BP from a number of baseline and in-study factors. Mean BP at randomization was 168/91 mm Hg and patients had a median of 9 (range: 2-20) study visits. Target BP was achieved in 50% of patients. Demographic factors associated with achieving target BP were male gender, living in a regional area; and clinical factors included history of antihypertensive therapy, increased plasma creatinine, lower pretreatment pulse pressure and in-study use of multiple BP-lowering drugs. Those aged >80 years and seeking care from multiple doctors (hazard ratio 0.40, 95% confidence interval 0.36-0.45, P<0.001) were less likely to achieve target BP. These findings identify clinical markers that can be targeted for intervention, but also demographic factors related to service delivery, which may provide further opportunity for achieving better BP control in hypertensive elderly.

Background: Quality hospital care is important in ensuring that the needs of severely ill children are met to avert child mortality. However, the quality of hospital care for children in developing countries has often been found poor. As the first step of a country road map for improving hospital care for children, we assessed the baseline situation with respect to the quality of care provided to children under-five years age in district and sub-district level hospitals in Bangladesh., Methods: Using adapted World Health Organization (WHO) hospital assessment tools and standards, an assessment of 18 randomly selected district (n=6) and sub-district (n=12) hospitals was undertaken. Teams of trained assessors used direct case observation, record review, interviews, and Management Information System (MIS) data to assess the quality of clinical case management and monitoring; infrastructure, processes and hospital administration; essential hospital and laboratory supports, drugs and equipment., Results: Findings demonstrate that the overall quality of care provided in these hospitals was poor. No hospital had a functioning triage system to prioritise those children most in need of immediate care. Laboratory supports and essential equipment were deficient. Only one hospital had all of the essential drugs for paediatric care. Less than a third of hospitals had a back-up power supply, and just under half had functioning arrangements for safe-drinking water. Clinical case management was found to be sub-optimal for prevalent illnesses, as was the quality of neonatal care., Conclusion: Action is needed to improve the quality of paediatric care in hospital settings in Bangladesh, with a particular need to invest in improving newborn care.

Background: WHO and UNICEF launched the Integrated Management of Childhood Illness (IMCI) strategy in the mid-1990s to reduce deaths from diarrhoea, pneumonia, malaria, measles, and malnutrition in children younger than 5 years. We assessed the effect of IMCI on health and nutrition of children younger than 5 years in Bangladesh., Methods: In this cluster randomised trial, 20 first-level government health facilities in the Matlab subdistrict of Bangladesh and their catchment areas (total population about 350 000) were paired and randomly assigned to either IMCI (intervention; ten clusters) or usual services (comparison; ten clusters). All three components of IMCI-health-worker training, health-systems improvements, and family and community activities-were implemented beginning in February, 2002. Assessment included household and health facility surveys tracking intermediate outputs and outcomes, and nutrition and mortality changes in intervention and comparison areas. Primary endpoint was mortality in children aged between 7 days and 59 months. Analysis was by intention to treat. This study is registered, number ISRCTN52793850., Findings: The yearly rate of mortality reduction in children younger than 5 years (excluding deaths in first week of life) was similar in IMCI and comparison areas (8.6%vs 7.8%). In the last 2 years of the study, the mortality rate was 13.4% lower in IMCI than in comparison areas (95% CI -14.2 to 34.3), corresponding to 4.2 fewer deaths per 1000 livebirths (95% CI -4.1 to 12.4; p=0.30). Implementation of IMCI led to improved health-worker skills, health-system support, and family and community practices, translating into increased care-seeking for illnesses. In IMCI areas, more children younger than 6 months were exclusively breastfed (76%vs 65%, difference of differences 10.1%, 95% CI 2.65-17.62), and prevalence of stunting in children aged 24-59 months decreased more rapidly (difference of differences -7.33, 95% CI -13.83 to -0.83) than in comparison areas., Interpretation: IMCI was associated with positive changes in all input, output, and outcome indicators, including increased exclusive breastfeeding and decreased stunting. However, IMCI implementation had no effect on mortality within the timeframe of the assessment., Funding: Bill & Melinda Gates Foundation, WHO's Department of Child and Adolescent Health and Development, and US Agency for International Development.

The structural gene for NAD+-dependent 3-hydroxyisobutyrate dehydrogenase (EC 1.1.1.31) from Pseudomonas putida E23 was cloned in Escherichia coli cells to obtain a large amount of the enzyme and its nucleotides were sequenced to study its structural relationship with other proteins. The gene encoded a polypeptide containing 295 amino acid residues and was in a cluster with the gene for methylmalonate semialdehyde dehydrogenase. Transformed E. coli cells overproduced 3-hydroxyisobutyrate dehydrogenase, and the recombinant enzyme was purified to homogeneity with a high yield. Lysine and asparagine residues, which are important in catalysis of the 3-hydroxyacid dehydrogenase family, are conserved in this enzyme.

The structural gene for NADP+-dependent serine dehydrogenase [EC 1.1.1.-] from Agrobacterium tumefaciens ICR 1600 was cloned into Escherichia coli cells and its complete DNA sequence was analyzed. The gene encodes a polypeptide containing 249 amino acid residues. The enzyme had high sequence similarity to short-chain alcohol dehydrogenases from bacteria and unknown proteins of Haemophilus influenzae, Escherichia coli, and Saccharomyces cerevisiae.

Strains of the fish pathogen Enterococcus seriolicida were identified as agglutinating and non-agglutinating, according to their reaction with anti-serum raised against type strain YT-3 (ATCC49156). The non-agglutinating strains are highly pathogenic in contrast to agglutinating strains. A 96 kDa immunoprotective glycoprotein G1 antigen from non-agglutinating Ent. seriolicida strain SS91-014 (N) was purified and characterized. The purification procedure entailed extraction of antigen by glass bead agitation, 80% (NH4)(2)SO4 precipitation, gel filtration and electroelution. An immunofluorescence microscopy study using monoclonal antibody M3A5 raised against G1 antigen revealed that G1 antigen is present only on the cell surface of non-agglutinating strains. Therefore, the G1 antigen of virulent Ent. seriolicida could be a potential candidate for protective vaccine against enterococcosis in fish.

Alanine dehydrogenase [EC 1. 4. 1. 1] was purified to homogeneity from a crude extract of Enterobacter aerogenes ICR 0220. The enzyme had a molecular mass of about 245 kDa and consisted of six identical subunits. The enzyme showed maximal activity at about pH 10.9 for the deamination of L-alanine and at about pH 8.7 for the amination of pyruvate. The enzyme required NAD+ as a coenzyme. Analogs of NAD+, deamino-NAD+ and nicotinamide guanine dinucleotide served as coenzymes. Initial-velocity and product inhibition studies suggested that the deamination of L-alanine proceeded through a sequential ordered binary-ternary mechanism. NAD+ bound first to the enzyme, followed by L-alanine, and the products were released in the order of ammonia, pyruvate, and NADH. The Km were 0.47 mM for L-alanine, 0.16 mM for NAD+, 0.22 mM for pyruvate, 0.067 mM for NADH, and 66.7 mM for ammonia. The Km for L-alanine was the smallest in the alanine dehydrogenases studied so far. The enzyme gene was cloned into Escherichia coli JM109 cells and the nucleotides were sequenced. The deduced amino acid sequence was very similar to that of the alanine dehydrogenase from Bacillus subtilis. However, the Enterobacter enzyme has no cysteine residue. In this respect, the Enterobacter enzyme is different from other alanine dehydrogenases.

NADP(+)-dependent serine dehydrogenase [EC 1.1.1.-], which catalyzes the oxidation of the hydroxyl group of serine to form 2-aminomalonate semialdehyde, was purified to homogeneity from a crude extract of Agrobacterium tumefaciens ICR 1600. The enzyme had a molecular mass of about 100 kDa and consisted of four identical subunits. In addition to L-serine, D-serine, L-glycerate, D-glycerate, and 2-methyl-DL-serine were substrates. However, O-methyl-DL-serine and L-threonine were inert. The enzyme showed maximal activity at about pH 9 for the oxidation of L-serine. The enzyme required NADP+ as a coenzyme, NAD+ was inert. The enzyme was not inhibited by EDTA, o-phenanthroline, or alpha,alpha'-dipyridyl, but was inhibited by HgCl2, p-chloromercuribenzoate, L-cysteine, D-cysteine, malonate, 2-methylmalonate, and tartronate. The Michaelis constants for L-serine, D-serine, and NADP+ were 42, 44, and 0.029 mM, respectively.

The NAD(+)-dependent 3-hydroxyisobutyrate dehydrogenase [EC 1.1.1.31] was purified to homogeneity from Pseudomonas putida E23. The enzyme was a tetramer (molecular mass, 120 kDa) consisted of identical subunits (molecular mass, 30 kDa). The enzyme was specific for NAD+ (Km, 0.44 mM). The maximal activity was obtained at about pH 10. The enzyme was specific for the L-isomer of 3-hydroxyisobutyrate. In addition to L-3-hydroxyisobutyrate, L-serine, 2-methyl-DL-serine, and 3-hydroxypropionate were substrates. The Km for L-3-hydroxyisobutyrate, L-serine, 2-methyl-DL-serine, and 3-hydroxypropionate were 0.12, 18, 44, and 83 mM, respectively. The enzyme was inhibited by p-chloromercuribenzoate, HgCl2, and AgNO3, but not by EDTA, alpha,alpha'-dipyridyl, and o-phenanthroline. The N-terminal 26 amino acid sequence was compared with the sequences deduced from the enzyme genes of rat liver and Pseudomonas aeruginosa.