Insulin Dosing and Glycemic Outcomes Among Steroid-treated Hospitalized Patients

ObjectiveTo determine the optimal insulin-to-steroid dose ratio for the attainment of glycemic control in hospitalized patients.MethodsWe retrospectively studied data collected from the electronic health records within an academic medical center from 18 599 patient-days where patients were treated concurrently with insulin and steroids. Multivariate logistic regression analyses, which included demographic and clinical variables, were performed to assess the relationships between the exposures of total and basal insulin-to-steroid ratios and the outcomes of glycemic control (all blood glucose readings on the following patient-day were >70 and ≤180 mg/dL) and hypoglycemia within 3 subgroups of steroid dosing: low (≤10-mg prednisone equivalent dose [PED]), medium (from >10-mg to ≤40-mg PED), and high (>40-mg PED).ResultsIncreased insulin-to-steroid ratio was associated with increased odds of both glycemic control and hypoglycemia. The optimal total insulin-to-steroid ratio for attaining glycemic control was 0.294 U/kg/10-mg PED in the low-dose subgroup, 0.257 U/kg/10-mg PED in the medium-dose subgroup, and 0.085 U/kg/10-mg PED in the high-dose subgroup. The optimal basal insulin-to-steroid ratio was 0.215 U/kg/10-mg PED in the low-dose subgroup, 0.126 U/kg/10-mg PED in the medium-dose subgroup, and 0.036 U/kg/10-mg PED in the high-dose subgroup.ConclusionIncreasing insulin-to-steroid ratios are positively associated with glycemic control and hypoglycemia. Our study suggests that approximately 0.3 U/kg/10-mg PED is an optimal dose for low- and medium-dose steroids, whereas approximately 0.1 U/kg/10-mg PED is an optimal dose for high-dose steroids. Further prospective studies are needed to identify insulin regimens that will optimize glycemic control in steroid-treated patients while minimizing the risk of hypoglycemia.     

Dietary Iodine Affected the GSH-Px to Regulate the Thyroid Hormones in Thyroid Gland of Rex Rabbits

Iodine (I) is an essential trace element that can influence animal health and productivity. In this study, we investigated the effects of dietary iodine on the antioxidant indices of organ (liver and thyroid gland) and messenger RNA (mRNA) expression of glutathione peroxidase (GSH-Px) in Rex rabbits. A total of 120 4-month-old Rex rabbits (2235.4 ± 13.04 g BW) were divided into four equal groups, and their diets were supplemented with iodine (0, 0.2, 2, or 4 mg/kg dry matter (DM)). The iodine concentration in basal diet (control group) was 0.36 mg/kg DM. In most of measured parameters, supplemental iodine exerted no significant effect. Growth and slaughter performance and organ weight were not influenced significantly by iodine supplementation. Serum T₃ was significantly lower in 2-mg I group than in 0.2 and 4-mg I groups (P < 0.05). Superoxide dismutase (SOD), GSH-Px, methane dicarboxylic aldehyde (MDA), and thyroperoxidase (TPO) in the serum and liver were not influenced (P > 0.05). Conversely, serum catalase (CAT) was significantly reduced (P < 0.05). In the thyroid, GSH-Px was higher in the 2-mg I group than in the 0.2- and 4-mg I groups (P < 0.05). RT-PCR results showed that the mRNA expression level of GSH-Px in the liver was not significantly influenced (P > 0.05). In the thyroid gland, the mRNA expression level of GSH-Px was higher in the 2-mg I group than in the 4-mg I group (P < 0.05), which agreed with the activity of GSH-Px. In conclusion, iodine supplementation exerted no effect on the performance and antioxidant capacity of the body, but dietary iodine influenced serum T₃ or GSH-Px in the thyroid gland. Thus, on the basis of serum T₃ and GSH-Px levels in the thyroid gland, we hypothesized that GSH-Px secretion was increased by adding dietary iodine in the thyroid, which may inhibit the H₂O₂ generation and further influence the thyroid hormone synthesis.     

Interplay between the cpSRP pathway components, the substrate LHCP and the translocase Alb3: An in vivo and in vitro study

The chloroplast signal recognition particle (cpSRP) and its receptor, cpFtsY, posttranslationally target the nuclear-encoded light-harvesting chlorophyll-binding proteins (LHCPs) to the translocase Alb3 in the thylakoid membrane. In this study, we analyzed the interplay between the cpSRP pathway components, the substrate protein LHCP and the translocase Alb3 by using in vivo and in vitro techniques. We propose that cpSRP43 is crucial for the binding of LHCP-loaded cpSRP and cpFtsY to Alb3. In addition, our data suggest that a direct interaction between Alb3 and LHCP contributes to the formation of this complex.

Structured summary

MINT-7992851: Alb3 (uniprotkb:Q8LBP4) physically interacts (MI:0915) with cpSRP43 (uniprotkb:O22265) by two hybrid (MI:0018)MINT-7992897: cpSRP43 (uniprotkb:O22265) and Alb3 (uniprotkb:Q8LBP4) physically interact (MI:0915) by bimolecular fluorescence complementation (MI:0809)MINT-7993251: SRP43 (uniprotkb:O22265) binds (MI:0407) to LHCP (uniprotkb:P27490) by pull down (MI:0096)MINT-7993207: cpSRP43 (uniprotkb:O22265) physically interacts (MI:0915) with ftsY (uniprotkb:O80842), LHCP (uniprotkb:P27490), SRP-54 (uniprotkb:P37106) and Alb3 (uniprotkb:Q8LBP4) by pull down (MI:0096)MINT-7993272: Alb3 (uniprotkb:Q8LBP4) and LHCB (uniprotkb:P27490) physically interact (MI:0915) by bimolecular fluorescence complementation (MI:0809)MINT-7992960: cpSRP43 (uniprotkb:O22265) binds (MI:0407) to Alb3 (uniprotkb:Q8LBP4) by pull down (MI:0096)MINT-7993236: Alb3 (uniprotkb:Q8LBP4) binds (MI:0407) to LHCP (uniprotkb:P27490) by pull down (MI:0096)MINT-7993166: cpSRP43 (uniprotkb:O22265) physically interacts (MI:0915) with LHCP (uniprotkb:P27490) and Alb3 (uniprotkb:Q8LBP4) by pull down (MI:0096)MINT-7993118: cpSRP43 (uniprotkb:O22265) physically interacts (MI:0915) with Alb3 (uniprotkb:Q8LBP4), SRP-54 (uniprotkb:P37106) and LHCP (uniprotkb:P27490) by pull down (MI:0096)MINT-7993046: cpSRP43 (uniprotkb:O22265) physically interacts (MI:0915) with ftsY (uniprotkb:O80842), SRP-54 (uniprotkb:P37106) and Alb3 (uniprotkb:Q8LBP4) by pull down (MI:0096)MINT-7993004: cpSRP43 (uniprotkb:O22265) physically interacts (MI:0915) with SRP54 (uniprotkb:P37106) and Alb3 (uniprotkb:Q8LBP4) by pull down (MI:0096)     

Hemoglobin Maintenance with use of Extended Dosing of Epoetin Alfa in Patients with Diabetes and Anemia of Chronic Kidney Disease

ObjectiveTo compare the efficacy of extended epo-etin alfa dosing in maintaining hemoglobin (Hb) concentrations in patients with and without diabetes as the primary cause of chronic kidney disease.MethodsWe undertook a post hoc analysis of the Clinical Evaluation of PROCRIT® for Maintenance Phase Treatment of Patients With Anemia Due to Chronic Kidney Disease (PROMPT) study. The study patients had chronic kidney disease but were not receiving dialysis, had stable Hb levels of ≥ 11.0 g/dL, and had been receiving epoetin alfa for ≥ 2 months. Patients received 1 of 4 epoetin alfa dosing regimens administered subcutaneously for up to 16 weeks: 10,000 U once weekly (QW), 20,000 U every 2 weeks (Q2W), 30,000 U every 3 weeks (Q3W), or 40,000 U every 4 weeks (Q4W). The primary end point was the percentage of patients able to achieve Hb maintenance, defined as a mean Hb level of ≥ 11.0 g/dL from week 2 to final measurement.ResultsAmong 445 evaluable patients, 201 had diabetes and 244 did not have diabetes. Mean baseline Hb was 11.9 g/dL in both groups. The percentage of patients achieving Hb maintenance, stratified by epoetin alfa dosing regimen, was similar in patients with and those without diabetes: QW (90.2% versus 96.5%), Q2W (91.1% versus 87.9%), Q3W (80.0% versus 75.7%), or Q4W (79.2% versus 72.5%). The incidence of adverse events was low and comparable between patients with and those without diabetes.ConclusionApproximately 90% of patients with and without diabetes in the QW and Q2W groups and more than 70% in the Q3W and Q4W groups maintained mean Hb levels of ≥ 11.0 g/dL from week 2 to final measurement. These results demonstrated that patients with diabetes responded in a similar manner as patients without diabetes to extended dosing of epoetin alfa up to Q4W. (Endocr Pract. 2007;13:251-259)     

Effects of light regime and oxygen profile on transformation of oxolinic acid in pond sediment

This study investigated the effects of light (visible light - 5800 lux, 24 h) or dark regime and aerobic or anaerobic condition on the decay of added oxolinic acid (OA) at 5, 10 and 20 mg L⁻¹ in eel pond sediment. An asymptotic decaying exponential model C_t = C_min + C_o × exp (−k × t) was used to facilitate quantitative approach to OA transformation, where C_t is the concentration of OA after t days, C_min the estimated level-off concentration of OA residue, C_o the concentration of added OA and k the decaying coefficient. OA decayed faster under light (C_min = 4.6 mg L⁻¹) than under dark (C_min = 7.8 mg L⁻¹) and also decayed faster under aerobic (C_min = 4.0 mg L⁻¹) than under anaerobic condition (C_min = 8.5 mg L⁻¹). C_min increased with C_o. Sundrying and tilling eel pond bottom should be able to reduce OA residue significantly.     

Effect of host sex on passive immunity in mice infected with Nematospiroides dubius

Dobson C. & Owen M. E. 1978. Effect of host sex on passive immunity in mice infected with Nematospiroides dubius. International Journal for Parasitology8: 359–364. Female C₃H but not Quackenbush (Q) mice harboured fewer Nematospiroides dubius than male C₃H and Q mice. Both strains lost worms 21 days after infection. C₃H and Q mice became progressively immune to infection following 4 sequential doses of N. dubius larvae and showed a sex resistance to infection. Hypothymic nu/nu CBA Balb/c mice did not show these effects on N. dubius infection. The reciprocal transfer of male and female immune mesenteric lymph node cells (IMLNC) to syngeneic male and female recipients showed that the female environment enhanced the protective qualities of both male and female IMLNC but the male environment suppressed these effects. Gonadectomized male and female recipients of male and female IMLNC had levels of infection similar to the entire female recipients. Serum from immune female donor mice protected both male and female recipients better than immune serum from male donors, but female mice in each treatment group were better protected than male mice. Immune serum transferred greater levels of protection then IMLNC to recipient mice against N. dubius infections. These data are consistent with the conclusion that the male environment suppresses lymphocyte activity and the production of protective antibodies and additionally may depress the effectiveness of sensitized lymphocytes and antibodies in ejecting N. dubius. On the other hand the female environment does not appear to adversely affect the mobilization of the protective immune response and may enhance immune effector mechanisms in protecting mice against N. dubius infections.     

Study on Hydrological Functions of Litter Layers in North China

Canopy interception, throughfall, stemflow, and runoff have received considerable attention during the study of water balance and hydrological processes in forested ecosystems. Past research has either neglected or underestimated the role of hydrological functions of litter layers, although some studies have considered the impact of various characteristics of rainfall and litter on litter interception. Based on both simulated rainfall and litter conditions in North China, the effect of litter mass, rainfall intensity and litter type on the maximum water storage capacity of litter (S) and litter interception storage capacity (C) were investigated under five simulated rainfall intensities and four litter masses for two litter types. The results indicated: 1) the S values increased linearly with litter mass, and the S values of broadleaf litter were on average 2.65 times larger than the S values of needle leaf litter; 2) rainfall intensity rather than litter mass determined the maximum interception storage capacity (C_max); C_max increased linearly with increasing rainfall intensity; by contrast, the minimum interception storage capacity (C_min) showed a linear relationship with litter mass, but a poor correlation with rainfall intensity; 3) litter type impacted C_max and C_min; the values of C_max and C_min for broadleaf litter were larger than those of needle leaf litter, which indicated that broadleaf litter could intercepte and store more water than needle leaf litter; 4) a gap existed between C_max and C_min, indicating that litter played a significant role by allowing rainwater to infiltrate or to produce runoff rather than intercepting it and allowing it to evaporate after the rainfall event; 5) C_min was always less than S at the same litter mass, which should be considered in future interception predictions. Vegetation and precipitation characteristics played important roles in hydrological characteristics.     

ALTERATIONS WITH AGING OF THE ENDOCRINE AND NEUROENDOCRINE CIRCADIAN SYSTEM IN HUMANS

This was an open-label study in 19 children aged 9–13 years, weighing 27–44 kg, with bronchial asthma. Twenty-four-hour steady-state concentrations of theophylline and its metabolites 1,3-dimethyl uric acid, 3-methyl xanthine and 1-methyl uric acid were assessed after daily dosing of 600 mg (ca18 mg/kg/day) of the sustainedrelease theophylline micro-pellet sprinkle system BY158K, for 4 days. The dosing regimen used was an unequal twice-daily dose of 200 mg in the morning after breakfast and 400 mg in the evening after dinner. Twenty-four-hour peak expiratory flow (PEF) profiles were compared before treatment and at steady-state, along with lung function parameters after bronchial provocation. Mean values±SD (n=16) of the steady-state characteristics were C_min6.8±2.1 mg/1, C_max14.5±4.8 mg/1 and C_av10.S±2.9 mg/1, the plateau time was 11.7±4.8 hr and peak-trough fluctuation and swing were 72±21 and 118±52%, respectively. There was an excellent reproducibility of theophylline pre-dose levels at corresponding time points of the 24-hr sampling period [r=0.864 (p< 0.001)]. Mean values±SD of the 24 hr average serum metabolite levels were 0.9±0.2 mg/1 for 1, 3-dimethyl uric acid, 0.6±0.1 mg/1 for 3-methyl xanthine and 0.4±0.1 mg/1 for 1-methyl uric acid. Lung function (n=17) following bronchial provocation, improved in 10 children after theophylline treatment of 4 days, remained stable in 2 patients and deteriorated in 5 patients. Serum theophylline profiles and PEF profiles ran largely in parallel over the 24-hr period. Six children exhibited typical theophylline induced side-effects, headache (n=3), nausea (n=4), dizziness (n=l), vomiting (n=4), sleep disturbances (n=1), pallor (n=1) and tremor(n=1), necessitating in 3 children one dose omission/reduction (n=2) or subsequent dose reduction (n=1). It has been shown that a twice daily dosing regimen with unequal doses of anhydrous theophylline (BY158K) is well suited to this population of fast metabolisers. The patients were well protected throughout the day, including the critical early morning hours.     

Resveratrol and para-coumarate serve as ring precursors for coenzyme Q biosynthesis

Coenzyme Q (Q or ubiquinone) is a redox-active polyisoprenylated benzoquinone lipid essential for electron and proton transport in the mitochondrial respiratory chain. The aromatic ring 4-hydroxybenzoic acid (4HB) is commonly depicted as the sole aromatic ring precursor in Q biosynthesis despite the recent finding that para-aminobenzoic acid (pABA) also serves as a ring precursor in Saccharomyces cerevisiae Q biosynthesis. In this study, we employed aromatic ¹³C₆-ring-labeled compounds including ¹³C₆-4HB, ¹³C₆-pABA, ¹³C₆-resveratrol, and ¹³C₆-coumarate to investigate the role of these small molecules as aromatic ring precursors in Q biosynthesis in Escherichia coli, S. cerevisiae, and human and mouse cells. In contrast to S. cerevisiae, neither E. coli nor the mammalian cells tested were able to form ¹³C₆-Q when cultured in the presence of ¹³C₆-pABA. However, E. coli cells treated with ¹³C₆-pABA generated ¹³C₆-ring-labeled forms of 3-octaprenyl-4-aminobenzoic acid, 2-octaprenyl-aniline, and 3-octaprenyl-2-aminophenol, suggesting UbiA, UbiD, UbiX, and UbiI are capable of using pABA or pABA-derived intermediates as substrates. E. coli, S. cerevisiae, and human and mouse cells cultured in the presence of ¹³C₆-resveratrol or ¹³C₆-coumarate were able to synthesize ¹³C₆-Q. Future evaluation of the physiological and pharmacological responses to dietary polyphenols should consider their metabolism to Q.     

A 52-week,open-label study evaluating the safety and efficacy of tabalumab,an anti-B-cell–activating factor monoclonal antibody,for rheumatoid arthritis

Introduction

The objective of this study was to evaluate the long-term safety and efficacy of tabalumab, a monoclonal antibody that neutralizes membrane-bound and soluble B-cell-activating factor, in rheumatoid arthritis (RA) patients.

Methods

Patients with RA who completed one of two 24-week randomized controlled trials (RCTs) participated in this 52-week, flexible-dose, open-label extension study. Patients in RCT1 received intravenous placebo, 30-mg tabalumab or 80-mg tabalumab every 3 weeks, and patients in RCT2 received subcutaneous placebo or 1-, 3-, 10-, 30-, 60- or 120-mg tabalumab every 4 weeks (Q4W). Regardless of prior treatment, all patients in this study received subcutaneous 60-mg tabalumab Q4W for the first 3 months, then a one-time increase to 120-mg tabalumab Q4W (60-mg/120-mg group) and a one-time decrease to 60-mg tabalumab Q4W per patient was allowed (60-mg/120-mg/60-mg group).

Results

There were 182 patients enrolled: 60 mg (n = 60), 60/120 mg (n = 121) and 60/120/60 mg (n = 1). Pretabalumab baseline disease activity was generally higher in the 60-mg/120-mg group. There was a higher frequency of serious adverse events and treatment-emergent adverse events, as well as infections and injection-site reactions, in the 60-mg/120-mg group. One death unrelated to the study drug occurred (60-mg/120-mg group). In both groups, total B-cell counts decreased by approximately 40% from the baseline level in the RCT originating study. Both groups demonstrated efficacy through 52 weeks of treatment relative to baseline pretabalumab disease activity based on American College of Rheumatology criteria improvement ≥20%, ≥50% and ≥70%; European League against Rheumatism Responder Index in 28 joints; Disease Activity Score in 28 joints–C-reactive protein; and Health Assessment Questionnaire–Disability Index.

Conclusions

With long-term, open-label tabalumab treatment, no unexpected safety signals were observed, and B-cell reductions were consistent with previous findings. Despite differences in RCT originating studies, both groups demonstrated an efficacy response through the 52-week extension.

Trial registration

ClinicalTrials.gov Identifier: {"type":"clinical-trial","attrs":{"text":"NCT00837811","term_id":"NCT00837811"}}NCT00837811 (registered 3 February 2009).

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-014-0415-2) contains supplementary material, which is available to authorized users.     

Simultaneous determination of hydroxocobalamin and its cyanide complex cyanocobalamin in human plasma by high-performance liquid chromatography application to pharmacokinetic studies after high-dose hydroxocobalamin as an antidote for severe cyanide poisoning

Hydroxocobalamin (OHCbl) is a powerful antidote for cyanide poisoning, via the formation of non-toxic cyanocobalamin (CNCbl). Plasmatic cobalamins were measured at 361 nm, after enrichment and purification on a short C₁₈ precolumn (1% acetic acid; 1 ml min⁻¹; 2 min), by back-flush elution on a C₁₈ ODS-2 column [0.1 M sodium dihydrogenphosphate-methanol (63:27, v/v) (pH 4.0); 0.80 ml min⁻¹]. The precision was 3.21 and 3.54% for 10 μM OHCbl and CNCbl, respectively. The method was used to study the pharmacokinetics of OHCbl and the formed CNCbl in severely poisoned patients.     

高压氧联合支气管肺泡灌洗对重型颅脑损伤肺部感染患者临床疗效及血清sTREM-1、HMGB1、CRP/Alb水平的影响

摘要 目的：探讨高压氧（HBO）联合支气管肺泡灌洗对重型颅脑损伤肺部感染（PI）患者临床疗效及血清可溶性髓系细胞触发受体-1（sTREM-1）、高迁移率族蛋白B1（HMGB1）、C反应蛋白/白蛋白（CRP/Alb）水平的影响。方法：选取2019年9月-2022年9月安徽中医药大学附属六安医院收治的72例重型颅脑损伤PI患者为研究对象,按随机数字表法分为观察组和对照组,每组各36例。对照组采用支气管肺泡灌洗治疗,观察组采用HBO联合支气管肺泡灌洗治疗。收集两组临床资料,对比两组临床疗效、治疗前后临床体征[体温、动脉血氧分压（PaO₂）,血白细胞计数（WBC）]、临床肺部感染评分（CPIS）、全身炎症反应综合征修正（ASS）评分、格拉斯哥昏迷评分（GCS）、血清指标（sTREM-1、HMGB1、CRP/Alb）。结果：观察组治疗总有效率94.44%高于对照组的77.78%（P＜0.05）;治疗后观察组体温、WBC、CPIS评分、ASS评分低于对照组,PaO₂、GCS评分高于对照组（P＜0.05）;治疗后观察组血清sTREM-1、HMGB1、CRP/Alb水平低于对照组（P＜0.05）。结论：HBO联合支气管肺泡灌洗治疗重型颅脑损伤PI能减轻炎症反应,降低PI程度,减轻临床体征,提高临床疗效。     

LD-Aminopterin in the Canine Homologue of Human Atopic Dermatitis: A Randomized,Controlled Trial Reveals Dosing Factors Affecting Optimal Therapy

Background

Options are limited for patients with atopic dermatitis (AD) who do not respond to topical treatments. Antifolate therapy with systemic methotrexate improves the disease, but is associated with adverse effects. The investigational antifolate LD-aminopterin may offer improved safety. It is not known how antifolate dose and dosing frequency affect efficacy in AD, but a primary mechanism is thought to involve the antifolate-mediated accumulation of 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR). However, recent in vitro studies indicate that AICAR increases then decreases as a function of antifolate concentration. To address this issue and understand how dosing affects antifolate efficacy in AD, we examined the efficacy and safety of different oral doses and schedules of LD-aminopterin in the canine model of AD.

Methods and Findings

This was a multi-center, double-blind trial involving 75 subjects with canine AD randomized to receive up to 12 weeks of placebo, once-weekly (0.007, 0.014, 0.021 mg/kg) or twice-weekly (0.007 mg/kg) LD-aminopterin. The primary efficacy outcome was the Global Score (GS), a composite of validated measures of disease severity and itch. GS improved in all once-weekly cohorts, with 0.014 mg/kg being optimal and significant (43%, P<0.01). The majority of improvement was seen by 8 weeks. In contrast, GS in the twice-weekly cohort was similar to placebo and worse than all once-weekly cohorts. Adverse events were similar across all treated cohorts and placebo.

Conclusions

Once-weekly LD-aminopterin was safe and efficacious in canine AD. Twice-weekly dosing negated efficacy despite having the same daily and weekly dose as effective once-weekly regimens. Optimal dosing in this homologue of human AD correlated with the concentration-selective accumulation of AICAR in vitro, consistent with AICAR mediating LD-aminopterin efficacy in AD.     

Association Study of a Functional Variant on ABCG2 Gene with Sunitinib-Induced Severe Adverse Drug Reaction

Sunitinib is a tyrosine kinase inhibitor and used as the first-line treatment for advanced renal cell carcinoma (RCC). Nevertheless, inter-individual variability of drug’s toxicity was often observed among patients who received sunitinib treatment. This study is to investigate the association of a functional germline variant on ABCG2 that affects the pharmacokinetics of sunitinib with sunitinib-induced toxicity of RCC patients in the Japanese population. A total of 219 RCC patients were recruited to this pharmacogenetic study. ABCG2 421C>A (Q141K) was genotyped by using PCR-Invader assay. The associations of both clinical and genetic variables were evaluated with logistic regression analysis and subsequently receiver operating characteristic (ROC) curve was plotted. About 43% (92/216) of RCC patients that received sunitinib treatment developed severe grade 3 or grade 4 thrombocytopenia according to the National Cancer Institute-Common Terminology Criteria for Adverse Events version 3.0, the most common sunitinib-induced adverse reaction in this study. In the univariate analysis, both age (P = 7.77x10^-3, odds ratio (OR) = 1.04, 95%CI = 1.01–1.07) and ABCG2 421C>A (P = 1.87x10^-2, OR = 1.71, 95%CI = 1.09–2.68) showed association with sunitinib-induced severe thrombocytopenia. Multivariate analysis indicated that the variant ABCG2 421C>A is suggestively associated with severe thrombocytopenia (P = 8.41x10^-3, OR = 1.86, 95% CI = 1.17–2.94) after adjustment of age as a confounding factor. The area under curve (AUC) of the risk prediction model that utilized age and ABCG2 421C>A was 0.648 with sensitivity of 0.859 and specificity of 0.415. Severe thrombocytopenia is the most common adverse reaction of sunitinib treatment in Japanese RCC patients. ABCG2 421C>A could explain part of the inter-individual variability of sunitinib-induced severe thrombocytopenia.     

Hydrocarbon monooxygenase in Mycobacterium: recombinant expression of a member of the ammonia monooxygenase superfamily

The copper membrane monooxygenases (CuMMOs) are an important group of enzymes in environmental science and biotechnology. Areas of relevance include the development of green chemistry for sustainable exploitation of methane (CH₄) reserves, remediation of chlorinated hydrocarbon contamination and monitoring human impact in the biogeochemical cycles of CH₄ and nitrogen. Challenges for all these applications are that many aspects of the ecology, physiology and structure–function relationships in the CuMMOs are inadequately understood. Here, we describe genetic and physiological characterization of a novel member of the CuMMO family that has an unusual physiological substrate range (C₂–C₄ alkanes) and a distinctive bacterial host (Mycobacterium). The Mycobacterial CuMMO genes (designated hmoCAB) were amenable to heterologous expression in M. smegmatis—this is the first example of recombinant expression of a complete and highly active CuMMO enzyme. The apparent specific activity of recombinant cells containing hmoCAB ranged from 2 to 3 nmol min^–1 per mg protein on ethane, propane and butane as substrates, and the recombinants could also attack ethene, cis-dichloroethene and 1,2-dichloroethane. No detectable activity of recombinants or wild-type strains was seen with methane. The specific inhibitor allylthiourea strongly inhibited growth of wild-type cells on C₂–C₄ alkanes, and omission of copper from the medium had a similar effect, confirming the physiological role of the CuMMO for growth on alkanes. The hydrocarbon monooxygenase provides a new model for studying this important enzyme family, and the recombinant expression system will enable biochemical and molecular biological experiments (for example, site-directed mutagenesis) that were previously not possible.     

Influence of survivin (BIRC5) and caspase-9 (CASP9) functional polymorphisms in renal cell carcinoma development: a study in a southern European population

Renal cell carcinoma (RCC) is the most common cancer of the adult kidney and its incidence and mortality has increase in the last 20 years. The disruption of cellular death is one the mechanism involved in cancer development. This process is precise regulated by apoptotic and anti-apoptotic molecules. Survivin (BIRC5) is a member of the inhibitor of apoptosis protein family and has the ability to inhibit the activation of the pro-apoptotic caspase-9 (CASP9). Thus BIRC5 and CASP9 functional polymorphisms might modulate the apoptosis and consequently RCC development. Our purpose was to investigate the potential role of BIRC5?31G/C and CASP9+83C/T functional polymorphisms in the risk for the development of RCC and metastatic disease. We studied the BIRC5?31G/C and CASP9+83C/T functional polymorphisms by PCR–RFLP and allelic discrimination using the 7300 real-time polymerase chain reaction system, respectively, in 178 RCC patients and in 305 healthy individuals. Regarding the BIRC5?31G/C polymorphism, there is a trend to an overrepresentation of CC genotype in RCC group compared with normal controls (aOR, 1.94; P = 0.053). We observed, after gender stratification and age-adjustment, that BIRC5?31CC and CASP9+83CT/TT genotypes were associated with an increased risk for RCC development in the female group of our southern European study population (aOR = 3.85; P = 0.019; aOR = 2.98; P = 0.028; respectively). Concerning the waiting time for onset of metastatic disease, we observed that BIRC5?31CC homozygous developed metastasis 8 years earlier than the G carriers using a Cox proportional hazard model with gender as covariate (HR = 4.9, P = 0.038, P _bootstrap = 0.009). The Cox regression proportional hazard model was validated using bootstrap statistic with 1,000 samples of the same number of patients as the original dataset. Our results suggest that individual differences influence the susceptibility to RCC and tumor behavior. This genetic profile may help to define higher risk groups that would benefit from individualized chemoprevention strategies and therapies.     

Lizards on ice: Comparative thermal tolerances of the world's southernmost gecko

(1) We measured thermal tolerances (critical thermal minimum, CT_min and panting threshold, T_pant) for four populations of Homonota darwinii spanning most of the latitudinal range of the species. (2) CT_min differed across populations, but not latitudinally as predicted, likely because latitude was not as good a proxy for operative temperatures (T_e). (3) Some populations had subzero CT_min indicating supercooling or freeze tolerance—the first time either phenomenon has been reported for a gecko. (4) T_pant did not differ significantly among populations. (5) The thermal tolerance breadth appears to be correlated with thermal variability in the environment. (6) Annual T_e data indicate gecko retreats play a crucial role in surviving extreme surface temperatures (<0 or >50 °C).     

para-Aminobenzoic Acid Is a Precursor in Coenzyme Q6 Biosynthesis in Saccharomyces cerevisiae

Coenzyme Q (ubiquinone or Q) is a crucial mitochondrial lipid required for respiratory electron transport in eukaryotes. 4-Hydroxybenozoate (4HB) is an aromatic ring precursor that forms the benzoquinone ring of Q and is used extensively to examine Q biosynthesis. However, the direct precursor compounds and enzymatic steps for synthesis of 4HB in yeast are unknown. Here we show that para-aminobenzoic acid (pABA), a well known precursor of folate, also functions as a precursor for Q biosynthesis. A hexaprenylated form of pABA (prenyl-pABA) is normally present in wild-type yeast crude lipid extracts but is absent in yeast abz1 mutants starved for pABA. A stable ¹³C₆-isotope of pABA (p- amino[aromatic-¹³C₆]benzoic acid ([¹³C₆]pABA)), is prenylated in either wild-type or abz1 mutant yeast to form prenyl-[¹³C₆]pABA. We demonstrate by HPLC and mass spectrometry that yeast incubated with either [¹³C₆]pABA or [¹³C₆]4HB generate both ¹³C₆-demethoxy-Q (DMQ), a late stage Q biosynthetic intermediate, as well as the final product ¹³C₆-coenzyme Q. Pulse-labeling analyses show that formation of prenyl-pABA occurs within minutes and precedes the synthesis of Q. Yeast utilizing pABA as a ring precursor produce another nitrogen containing intermediate, 4-imino-DMQ₆. This intermediate is produced in small quantities in wild-type yeast cultured in standard media and in abz1 mutants supplemented with pABA. We suggest a mechanism where Schiff base-mediated deimination forms DMQ₆ quinone, thereby eliminating the nitrogen contributed by pABA. This scheme results in the convergence of the 4HB and pABA pathways in eukaryotic Q biosynthesis and has implications regarding the action of pABA-based antifolates.     

Vancomycin Dosing in Neutropenic Patients

Background

To compare vancomycin pharmacokinetic parameters in patients with and without neutropenia.

Methods

Patients ≥18 years admitted on general wards were included. Routinely vancomycin trough and peak plasma concentrations were measured with a fluorescence polarization immunoassay. Pharmacokinetic parameters of individual patients were determined with maximum a posterior Bayesian estimation (MW Pharm 3.60). Neutropenia was defined as neutrophils <0.5×10⁹ cells/L.

Principal Findings

A total of 171 patients were included. Patients with neutropenia (n = 56) had higher clearance of vancomycin (CLva), 67 (±26) mL/min, compared to patients without neutropenia (n = 115), CLva 50 (±22) mL/min (p<0.001). No significant difference was found in serum creatinine and vancomycin volume of distribution. Neutropenia was positively associated with CLva, independently of relevant co-variables (B: 12.122, 95%CI: 1.095 to 23.149, p = 0.031). On average patients with neutropenia needed 33% higher doses of vancomycin to attain adequate exposure, i.e. AUC₂₄≥400 mg×h/L. Furthermore, 15 initially neutropenic patients in our study group received vancomycin for a second administration period. Ten patients received the second administration period during another neutropenic period and 5 patients during a non-neutropenic phase. All 5 patients with vancomycin during both neutropenic and non-neutropenic phase had higher CLva (91 (±26) mL/min) during the neutropenic period and lower CLva (45 (±10) mL/min) during the non-neutropenic phase (p = 0.009).

Conclusion

This study shows that most patients with neutropenia have augmented CLva. In a small group of patients that received vancomycin during two episodes, the augmented CLva seems to be reversible in the non-neutropenic period. Our data indicate that it is important to increase the daily dose with one third in patients with neutropenia (from 15 mg/kg twice daily to 13 mg/kg three times daily). Frequent performance of therapeutic drug monitoring in patients with neutropenia may prevent both therapy failure due to low AUCs and overcomes toxicity due to high vancomycin trough concentrations during recovery from neutropenia.     

Thermal conductance and basal metabolic rate are part of a coordinated system for heat transfer regulation

Thermal conductance measures the ease with which heat leaves or enters  an organism''s body. Although the analysis of this physiological variable in relation to climatic and ecological factors can be traced to studies by Scholander and colleagues, only small advances have occurred ever since. Here, we analyse the relationship between minimal thermal conductance estimated during summer (C_min) and several ecological, climatic and geographical factors for 127 rodent species, in order to identify the exogenous factors that have potentially affected the evolution of thermal conductance. In addition, we evaluate whether there is compensation between C_min and basal metabolic rate (BMR)—in such a way that a scale-invariant ratio between both variables is equal to one—as could be expected from the Scholander–Irving model of heat transfer. Our major findings are (i) annual mean temperature is the best single predictor of mass-independent C_min. (ii) After controlling for the effect of body mass, there is a strong positive correlation between log₁₀ (C_min) and log₁₀ (BMR). Further, the slope of this correlation is close to one, indicating an almost perfect compensation between both physiological variables. (iii) Structural equation modelling indicated that C_min values are adjusted to BMR values and not the other way around. Thus, our results strongly suggest that BMR and thermal conductance integrate a coordinated system for heat regulation in endothermic animals and that summer conductance values are adjusted (in an evolutionary sense) to track changes in BMRs.