Vitamin K (Menaquinone-4) Metabolism in Liver Disease

We measured menaquinone-4 (MK-4) and MK-4 epoxide concentrations in plasma and liver tissue after intravenous injection of 200 μg/kg MK-4 in 42 patients who underwent hepatectomy. They were classified into normal (N; n = 10), chronic hepatitis (CH; n = 12), and liver cirrhosis (LC; n = 20) groups, on the basis of the diagnosis given by the pathologist after examining resected liver specimens. The plasma MK-4 epoxide concentration reached maximum level (C_max) 60 min after MK-4 injection. The C_max in groups LC and CH were 85.9 and 126.3 nmol/l, respectively, which is significantly reduced compared with that of group n (184.4 nmol/l) (p < 0.01 and p < 0.05, respectively). The MK-4 concentrations in liver tissues of 24 patients 60 min after MK-4 injection were 2.77 in group N, 3.79 in group CH, and 3.83 nmol/ g in group LC, and the MK-4 epoxide concentrations were 4.01, 3.09, and 2.62 nmol/g in the respective groups. Consequently, the ratio of MK-4 epoxide to total MK-4 (MK-4 + MK-4 epoxide) in groups CH and LC was significantly lower than in group n (p < 0.01). It is concluded that the C_max of MK-4 epoxide after MK-4 injection may serve as an indicator of liver function and that the low ratio of MK-4 epoxide to total MK-4 in the liver shows impairment in vitamin K metabolism.     

Alpha-tocopherol (vitamin E) and beta-carotene supplementation does not affect the risk for large abdominal aortic aneurysm in a controlled trial.

Antioxidants may retard atherogenesis and limit inflammatory processes involved in aneurysm formation. We evaluated effects of alpha-tocopherol and beta-carotene supplementation on incidence of large abdominal aortic aneurysm (AAA) in a randomised, double-blind, placebo-controlled trial. Subjects (n=29133) were 50-69-years-old male smokers, participants in the Finnish alpha-Tocopherol, beta-Carotene Cancer Prevention (ATBC) Study. They were randomised to receive either 50 mg/day of alpha-tocopherol, or 20 mg/day of beta-carotene, or both, or placebo in a 2x2 design. Incidence of AAA was evaluated from mortality and hospital registers. During 5.8 years of follow-up, 181 men were diagnosed with either ruptured AAA (n=77) or nonruptured large AAA treated with aneurysmectomy (n=104). Relative risk (RR) for AAA was 0.83 (95% confidence interval [CI] 0.62-1.11) among men receiving alpha-tocopherol compared with those who did not, and 0.93 (95% CI 0.69-1.24) among men receiving beta-carotene compared with those who did not. A modest though nonsignificant decrease in risk for nonruptured AAA was observed among alpha-tocopherol supplemented men (RR 0.71, 95% CI 0.48-1.04) compared with men not receiving alpha-tocopherol. For beta-carotene, RR for nonruptured AAA was 0.86 (95% CI 0.59-1.27) compared with men not receiving beta-carotene. Neither antioxidant affected risk for ruptured AAA. In conclusion, long-term supplementation with alpha-tocopherol or beta-carotene had no preventive effect on large AAA among male smokers.     

Vitamin B(12) supplementation did not improve cognition but reduced delirium in demented patients with vitamin B(12) deficiency

To examine the effects of vitamin B₁₂ supplementation on the cognitive function, delirium, and neuropsychiatric symptoms of mild to moderate dementia patients with vitamin B₁₂ deficiency. Thirty consecutive mild to moderate dementia cases aged over 60 years with low serum B₁₂ (<200 pmol/l) were given vitamin B₁₂ supplementation for 40 weeks. The Mattis Dementia Rating Scale (MDRS), Category Verbal Fluency Test (CVFT), Delirium Rating Scale (DRS), Mini-Mental State Examination (MMSE), and the Neuropsychiatric Inventory (NPI) were performed at baseline, and after 6, 16, and 40 weeks. No significant changes in cognitive function and behavioral symptoms were detected between baseline and 40 weeks. DRS scores decreased significantly at 6 and 40 weeks (median change of −1 at both follow-ups, p = 0.006 and 0.04, respectively). Cognitive function of mild to moderately demented older people with vitamin B₁₂ deficiency did not significantly change with vitamin B₁₂ supplementation over a 10-month period. The supplementation reduced delirium associated with dementia.     

Angiotensin-(1-7) does not affect vasodilator or TPA responses to bradykinin in human forearm

Studies in isolated vessels and rat models of hypertension suggest that angiotensin (Ang)-(1-7) potentiates the vasodilator effect of bradykinin, possibly through ACE inhibition. We therefore tested the hypothesis that Ang-(1-7) potentiates the vasodilator or tissue plasminogen activator (TPA) response to bradykinin in the human forearm vasculature. Graded doses of Ang-(1-7) (10, 100, and 300 pmol/min), bradykinin (47, 94, and 189 pmol/min), and Ang I (1, 10, and 30 pmol/min) were administered through the brachial artery to 8 normotensive subjects in random order. Thirty minutes after initiation of a constant infusion of Ang-(1-7) (100 pmol/min), bradykinin and Ang I infusions were repeated. There were no systemic hemodynamic effects of the agonists. Bradykinin significantly increased forearm blood flow (P<0.001, from 3.8+/-0.5 to 13.9+/-3.1 mL/min per 100 mL at 189 pmol/min) and net TPA release (P=0.007, from 1.1+/-1.0 to 23.6+/-6.2 ng/min per 100 mL at 189 pmol/min), whereas Ang I caused vasoconstriction (P=0.003, from 3.3+/-0.4 to 2.5+/-0.3 mL/min per 100 mL at 30-pmol/min dose). There was no effect of Ang-(1-7) on either forearm blood flow (P=0.62, 3.3+/-0.4 to 3.5+/-0.4 mL/min per 100 mL at 300 pmol/min) or TPA release (P=0.52, from 0.7+/-0.8 to 1.0+/-0.7 ng/min/100 mL at 300 pmol/min). Moreover, there was no effect of 100 pmol/min Ang-(1-7) on the vasodilator [P=0.46 for Ang-(1-7) effect] or TPA [P=0.82 for Ang-(1-7) effect] response to bradykinin or the vasoconstrictor response to Ang I [P=0.62 for Ang-(1-7) effect]. These data do not support a role of Ang-(1-7), given at supraphysiological doses, in the regulation of human peripheral vascular resistance or fibrinolysis.     

血管紧张素-(1-7)对二肾一夹高血压大鼠血压及血管活性物质的影响

目的观察急性血管紧张素-(1-7)[Ang-(1-7)]干预后二肾一夹(2KlC)高血压大鼠血压的变化过程,以及Ang-(1-7)对血压相关血管活性物质的影响。方法建立2KlC高血压大鼠模型后2周,经颈内静脉予Ang-(1-7)短期干预,同时多导电生理仪记录有创颈动脉压演变。放免法测定血浆AngⅡ,酶法测定血清一氧化氮(NO)、氧自由基(O2-)浓度及血清总一氧化氮合酶(NOS)、超氧化物歧化酶(SOD)活力,酶免疫法测定血浆前列腺素E2(PGE2)。结果Ang-(1-7)可造成2KlC大鼠血压降低。与降低血压状态相伴随,血清NO及血浆PGE2浓度显著升高(P<0.01),血清O2-浓度显著降低(P<0.01),血浆AngⅡ水平及血清NOS、SOD活力未受Ang-(1-7)影响。结论在高肾素-血管紧张素系统(RAS)活性状态下,Ang-(1-7)降压机制与循环NO、PGE2浓度升高及O2-浓度降低有关。     

Short-term supplementation therapy does not affect elastin degradation in severe alpha(1)-antitrypsin deficiency. The American-Italian AATD Study Group

We evaluated the ability of intravenous supplementation therapy with alpha(1)-antitrypsin (AAT) to reduce the rate of urinary excretion of desmosine (DES), a specific marker of elastin degradation, in eight men and four women with emphysema due to severe, congenital deficiency of AAT (range 17-69 mg/dl). Nine were former cigarette smokers, two were current smokers, and one reported never smoking; their mean age was 54 (SD 12) yr and their mean FEV(1) was 41 (18%) of predicted. Urinary DES was measured by isotope dilution and HPLC. Prior to the start of AAT supplementation, mean DES excretion was 13.0 (5.0) microg/g creatinine, 73% higher than in healthy nonsmokers. During 8 wk of supplementation therapy, mean urinary DES excretion was 13.0 (5.9) microg/g creatinine, unchanged from the baseline period (p = 0.85 by repeated measures ANOVA). We conclude that baseline levels of elastin degradation in emphysematous patients with severe AAT deficiency were abnormally high and that 8 wk of AAT supplementation therapy did not appreciably reduce the rate of elastin degradation. These findings raise the possibilities that protective levels of AAT in the lungs are insufficient or that elastin degradation in the lungs of these subjects is not dependent upon neutrophil elastase at this time.     

Alpha(2)-antiplasmin gene deficiency in mice does not affect neointima formation after vascular injury

The hypothesis that alpha(2)-antiplasmin (alpha(2)-AP), the main physiological plasmin inhibitor, plays a role in neointima formation was tested with use of a vascular injury model in wild-type (alpha(2)-AP(+/+)) and alpha(2)-AP-deficient (alpha(2)-AP(-/-)) mice. The neointimal and medial areas were similar 1 to 3 weeks after electric injury of the femoral artery in alpha(2)-AP(+/+) and alpha(2)-AP(-/-) mice, resulting in comparable intima/media ratios (eg, 0.43+/-0.12 and 0.42+/-0.11 2 weeks after injury). Nuclear cell counts in cross-sectional areas of the intima of the injured region were also comparable in arteries from alpha(2)-AP(+/+) and alpha(2)-AP(-/-) mice (78+/-19 and 69+/-8). Fibrin deposition was not significantly different in arteries of both genotypes 1 day after injury, and no mural thrombosis was detected 1 week after injury. Fibrinolytic activity in femoral arterial sections, as monitored by fibrin zymography, was higher in alpha(2)-AP(-/-) mice 1 week after injury (P<0.001) but was comparable in both genotypes 2 and 3 weeks after injury. Staining for elastin did not reveal significant degradation of the internal elastica lamina in either genotype. Immunocytochemical analysis revealed a comparable distribution pattern of alpha-actin-positive smooth muscle cells in both genotypes. These findings indicate that the endogenous fibrinolytic system of alpha(2)-AP(+/+) mice is capable of preventing fibrin deposition after vascular injury and suggest that alpha(2)-AP does not play a major role in smooth muscle cell migration and neointima formation in vivo.     

Block of I(Ks) does not induce early afterdepolarization activity but promotes beta-adrenergic agonist-induced delayed afterdepolarization activity

INTRODUCTION: An early afterdepolarization (EAD)-induced triggered beat is thought to precipitate torsade de pointes (TdP) in the long QT syndrome (LQTS). Previous studies demonstrated the development of EAD activity and dispersion of repolarization under LQT2 (reduced I(Kr)) and LQT3 (augmented late I(Na)), but not LQT1 (reduced I(Ks)), conditions. The present study examines these electrophysiologic characteristics during I(Ks) block. METHODS AND RESULTS: Canine epicardial (Epi), M, and endocardial (Endo) tissues and Purkinje fibers isolated from the canine left ventricle were studied using standard microelectrode recording techniques. The I(Ks) blocker chromanol 293B (293B, 30 microM), produced a homogeneous rate-independent prolongation of action potential duration (APD) in Epi, M, and Endo, but little to no APD prolongation in Purkinje. Chromanol 293B 1 to 30 microM failed to induce EADs or delayed afterdepolarizations (DADs) in any of the four tissue types. Isoproterenol (ISO, 0.1 to 1.0 microM) in the presence of 293B 30 microM significantly prolonged the APD of the M cell (basic cycle length > or = 1 sec), abbreviated that of Purkinje, and caused little change in that of Epi and Endo. The combination of 293B 30 microM and ISO 0.2 microM did not induce EADs in any of the four tissue types, but produced DAD activity in 4 of 8 Epi, 7 of 10 M cells, and 3 of 8 Endo. CONCLUSION: Our results indicate that I(Ks) block alone or in combination with beta-adrenergic stimulation does not induce EADs in any of the four canine ventricular tissue types, but that the combination of the two induces DADs as well as accentuated dispersion of repolarization.     

Comparison of N-glycan pattern of recombinant human coagulation factors II and IX expressed in Chinese hamster ovary (CHO) and African green monkey (Vero) cells

The N-glycan patterns of recombinant human coagulation factors II (rF-II) and IX (rF-IX), derived from both transfected Chinese hamster ovary (CHO) cells and African green monkay (Vero) cells produced at industrial scale, were analyzed by binding to carbohydrate-specific lectins and were compared with the glycan structure of human plasma-derived coagulation factors. Human plasma-derived coagulation factors II (hpF-II) and IX (hpF-IX) exhibited complex-type glycan structures with carbohydrate chains capped with (2–6)-sialic acid. Terminal galactose-(1–4)-N-acetylglucosamine units were detected in hpF-IX. Both CHO cell-derived rF-II and rF-IX exhibited complex-type glycosylation and contained (2–3)-sialic acid in addition to terminal galactose-(1–4)-N-acetylglucosamine. Vero cell-derived rF-IX exhibited a complex-type glycan structure similar to that of CHO cell-derived rF-IX. In contrast, rF-II produced by Vero cells exhibited a glycan microheterogeneity composed of hybrid-type glycosylation containing high-mannose structures and complex-type glycosylation containing (2–3)-sialic acid. Galactose-(1–4)-N-acetylglucosamine structures and a low concentration of (2–6)-sialic acid were detected in both microheterogeneity fractions of Vero cell-derived rF-II. Although different in their carbohydrate structures, coagulation factors II and IX obtained recombinantly from both transformed CHO cells and Vero cells exhibited coagulation activities comparable with the plasma-derived proteins.     

Passive smoking does not increase hydrogen peroxide (H2O2) levels in exhaled breath condensate in 9-year-old healthy children

Environmental tobacco smoke, also called passive smoking, was shown to have adverse effects on the health of children. Hydrogen peroxide (H2O2) is proposed as a sensitive marker of oxidative injury and inflammatory processes in the airways, being increased in adult active cigarette smokers. We tested whether passive smoking had an influence on H2O2 exhalation in healthy children. Thirty healthy passive smoking and 24 nonexposed healthy children aged 9 years were included in the study. Exhaled breath condensate (EBC) was obtained by spontaneous tidal volume breathing with EcoScreen (Jaeger, Germany). All subjects underwent flow-volume measurements immediately after EBC collection. Levels of H2O2 were measured fluorimetrically with the homovanillic acid method. Lung function did not differ between the passive smoking and nonexposed children groups. In the passive smoking group, EBC H2O2 concentration (median and range) was 0.32 (0.00-1.20) microM, and did not differ significantly (P >0.05) from that found in the nonexposed group, i.e., 0,22 (0.00-0.68) microM. Exhaled H2O2 did not correlate with spirometric parameters (FEV1, FEV1%FVC, and MEF50%FVC) in either group. We conclude that passive smoking does not increase H2O2 exhalation in healthy children.     

No differences in physical activity in (un)diagnosed asthma and healthy controls

To establish whether asthma affects physical activity levels in children (aged 7-10 years) we evaluated physical activity levels in children with undiagnosed asthma (UDA), diagnosed asthma (DA), and healthy controls (HCs). A cross-sectional community-based study was performed which included a parental questionnaire on their child's respiratory health, and testing of airway reversibility and bronchial hyperresponsiveness (BHR). DA was defined as the parents' confirmation of a physician's diagnosis of asthma in the past 12 months. UDA was defined by asthma symptoms combined with airway reversibility or BHR in children without a physician's diagnosis of asthma. Physical activity was measured during 5 days with an accelerometer and a diary, and with the habitual activity estimation scale which reviews the physical activity during the past 2 weeks. The final study population comprised 1,614 children of whom 81 (5%) had DA, 130 (8%) UDA, and 202 HCs. Baseline FEV(1) % was lowest in children with UDA (UDA FEV(1) 94% predicted, DA FEV(1) 98% predicted, HCs FEV(1) 100% predicted). Using the three methods, no differences were found in the physical activity between children with UDA, DA, and HCs. Childhood asthma does not appear to be associated with a decreased level of daily physical activity in our study population.     

A calcium-containing electrolyte-balanced hydroxyethyl starch (HES) solution is associated with higher factor VIII activity than is a non-balanced HES solution,but does not affect von Willebrand factor function or thromboelastometric measurements - results of a model of in vitro haemodilution

Background

Hydroxyethyl starch (HES) is known to impair blood coagulation. The impact of calcium-containing, balanced carrier solutions of HES on coagulation is controversial. We investigated the effects of increasing degrees of haemodilution with modern 6%, electrolyte-balanced HES vs non-balanced HES on coagulation in vitro, and compared the balanced HES to a balanced crystalloid solution for an internal control.

Materials and methods

Blood samples from ten healthy volunteers were diluted in vitro by 20%, 40% and 60% with either calcium-containing balanced 130/0.42 HES, non-balanced 130/0.4 HES or balanced crystalloid. In all samples, blood counts, prothrombin time ratio, activated partial thromboplastin time, ionized calcium, factor VIII activity, von Willebrand factor antigen, von Willebrand factor collagen binding activity, and von Willebrand factor activity were determined, and activated rotational thromboelastometry (EXTEM and FIBTEM assays) was performed.

Results

Haemodilution impaired coagulation in a dilution-dependent manner as determined by both conventional laboratory assays and thromboelastometry. Ionized calcium increased with balanced HES (p≤0.004), but decreased with non-balanced HES (p≤0.004). Prothrombin time ratio (p≤0.002) and factor VIII levels (p=0.001) were better preserved with balanced HES than with non-balanced HES in dilutions ≥40%. Thromboelastometry showed no differences between values in blood diluted with the balanced or non-balanced HES.

Discussion

In vitro, a balanced calcium-containing carrier solution of 6% HES 130/0.42 preserved coagulation better than did non-balanced HES 130/0.4 as quantified by conventional coagulation assays, but not in activated thromboelastometry. One explanation could be the increased ionized calcium levels after dilution with calcium-containing carrier solutions.     

Dalteparin sodium (fragmin) administration following acute infarction does not affect myocardial perfusion and function in swine

Background: Heparin and low molecular weight heparin (LMWH) derivatives are considered angiogenic factors in ischemic and infarcted myocardium. However, the effect of dalteparin sodium (fragmin®, a LMWH derivative) on angiogenesis post infarction has not yet been investigated. Purpose. To assess the effect of systemically-administered dalteparin sodium on left ventricular perfusion and function during remodeling in swine subjected to acute microembolization infarction (MI). Methods. MI was induced in 12 anesthetized female pigs which randomly received dalteparin sodium (12,500U) or placebo through intra-peritoneal osmotic pump, for one week, beginning immediately after the MI. Myocardial perfusion and function were measured using radionuclear scan and echocardiography, respectively, at baseline, immediately post MI, and at 2 and 4 weeks post MI. Dobutamine stress echocardiography was performed 4 weeks post MI. Serum level of basic fibroblast growth factor (bFGF) was analyzed using a commercially available ELISA kit. Results. No differences were observed in myocardial perfusion at all time points following MI. No significant changes were observed in myocardial function and wall motion during the 4 weeks follow-up period, or after dobutamine administration. Serum bFGF did not change throughout the study period. Conclusion. Under the setting of the current experiment, one week of dalteparin sodium administration does not affect myocardial perfusion and function following acute infarction in swine, either at rest or following pharmacological stress.     

Failure of GLP-l(7–36)amide to affect glycogenesis in rat skeletal muscle

Summary Glucagon-like peptide-1(7–36)amide has been described as exerting potent glycogenic action and as stimulating glycolysis in skeletal muscle. We exposed isolated rat soleus muscle strips to various concentrations of glucagon-like peptide-1(7–36) amide (10⁻¹¹–10⁻⁶ mol/l) or insulin (10⁻¹⁰–10⁻⁷ mol/l) and determined the respective effects on glucose metabolism. Insulin markedly increased the rate of glucose incorporation into glycogen with a maximal effect at 10⁻⁸ mol/l insulin (348 ± 46 % of intraindividual control experiment, p < 0.005), while glucagon-like peptide-1(7–36)amide was without an effect (e. g. 10⁻¹¹ mol/l, 96 ± 10 %; 10⁻⁹ mol/l, 104 ± 9 %; 10⁻⁷ mol/l, 121 ± 13 %; not significant). Likewise, glucagon-like peptide-1(7–36)amide did not affect the rate of ³H-2-deoxy-glucose transport or glycogen content of soleus muscle strips. The rates of aerobic or anaerobic glycolysis were also not increased. The findings were independent of peptide source and of employed muscle size. Our results do not suggest any effect of glucagon-like peptide-1(7–36)amide on skeletal muscle glucose metabolism and, hence, are in contrast to data derived from similar experiments by others. [Diabetologia (1995) 38: 864–867] Received: 29 December 1994 and in revised form: 13 March 1995     

An avian influenza virus A(H7N9) reassortant that recently emerged in the United States with low pathogenic phenotype does not efficiently infect swine

In 2017, outbreaks of low and highly pathogenic avian H7N9 viruses were reported in four States in the United States. In total, over 270 000 birds died or were culled, causing significant economic loss. The potential for avian‐to‐swine transmission of the U.S. avian H7N9 was unknown. In an experimental challenge in swine using a representative low pathogenic H7N9 (A/chicken/Tennessee/17‐007431‐3/2017; LPAI TN/17) isolated from these events, no infectious virus in the upper and minimal virus in the lower respiratory tract was detected, nor was lung pathology or evidence of transmission in pigs observed, indicating that the virus cannot efficiently infect swine.