Effects of BNT162b2 mRNA Covid-19 vaccine on vascular function

The effects of Covid-19 vaccines on vascular function are still controversial. We evaluated the effects of BNT162b2 vaccine (BioNTech and Pfizer) on endothelial function assessed by flow-mediated vasodilation (FMD) and vascular smooth muscle function assessed by nitroglycerine-induced vasodilation (NID). This study was a prospective observational study. A total of 23 medical staff at Hiroshima University Hospital were enrolled in this study. FMD and NID were measured before vaccination and two weeks and six months after the 2nd dose of vaccination. FMD was significantly smaller two weeks after the 2nd dose of vaccination than before vaccination (6.5±2.4% and 8.2±2.6%, p = 0.03). FMD was significantly larger at six months than at two weeks after the 2nd dose of vaccination (8.2±3.0% and 6.5±2.4%, p = 0.03). There was no significant difference between FMD before vaccination and that at six months after the 2nd dose of vaccination (8.2±2.6% to 8.2±3.0%, p = 0.96). NID values were similar before vaccination and at two weeks, and six months after vaccination (p = 0.89). The BNT162b2 Covid-19 vaccine temporally impaired endothelial function but not vascular smooth muscle function, and the impaired endothelial function returned to the baseline level within six months after vaccination.

A Body Shape Index as a Simple Anthropometric Marker of Abdominal Obesity and Risk of Cardiovascular Events

BACKGROUND

A Body Shape Index (ABSI) has been reported to have associations with cardiovascular risk factors. However, there is no information on the association between ABSI and incidence of cardiovascular events.

METHODS

We investigated the associations between ABSI and first major cardiovascular events (death from cardiovascular disease, nonfatal acute coronary syndrome, and nonfatal stroke) in 1857 subjects from the database of Flow-Mediated Dilation Japan registry and from Hiroshima University Vascular Function registry.

RESULTS

The areas under the curves of ABSI to predict the first major cardiovascular events were superior to BMI (men: P=0.032, women: P=0.015) and waist circumference in women (men: P=0.078, women: P=0.002). The subjects were divided into two groups based on the cutoff value of ABSI for predicting first major cardiovascular events: a low ABSI group (<0.0822 in men and <0.0814 in women) and a high ABSI group (≥0.0822 in men and ≥0.0814 in women). During a median follow-up period of 41.6 months, 56 subjects died (23 from cardiovascular causes), 16 had nonfatal acute coronary syndrome, and 14 had nonfatal stroke. The Kaplan-Meier curves for first major cardiovascular events were significantly different between the two groups (men, P<0.001; women, P<0.001). Multivariate analysis revealed that high ABSI remained an independent predictor of first major cardiovascular events (men: hazard ratio, 2.33; 95% CI, 1.07 to 5.06; P=0.033; women: hazard ratio, 8.33; 95% CI, 1.06 to 65.49; P=0.044).

CONCLUSIONS

High ABSI is independently associated with incidence of cardiovascular events. ABSI calculation should be performed for evaluation of risk of cardiovascular events.

Role of Small Dense Low-density Lipoprotein Cholesterol in Cardiovascular Events in Patients with Coronary Artery Disease and Type 2 Diabetes Mellitus Receiving Statin Treatment

AIM

There is little information on the relationships of serum small dense low-density lipoprotein cholesterol (sdLDL-C) levels and serum triglyceride (TG) levels with cardiovascular events in patients with coronary artery disease (CAD) and type 2 diabetes mellitus (DM) who are receiving statins. The aim of this study was to evaluate the relationships of serum TG levels and sdLDL-C levels as residual risks for cardiovascular events in patients with CAD and type 2 DM who were being treated with statins.

METHODS

The subjects were divided into four groups based on TG levels and sdLDL-C levels: sdLDL-C of ＜40.0 mg/dL and TG of ＜150 mg/dL, sdLDL-C of ≥ 40.0 mg/dL and TG of ＜150 mg/dL, sdLDL-C of ＜40.0 mg/dL and TG of ≥ 150 mg/dL, and sdLDL-C of ≥ 40.0 mg/dL and TG of ≥ 150 mg/dL. During a median follow-up period of 1419 days, cardiovascular events occurred in 34 patients.

RESULTS

The incidences of cardiovascular events were significantly higher in patients with sdLDL-C of ≥ 40.0 mg/dL and TG of ＜150 mg/dL and in patients with sdLDL-C of ≥ 40.0 mg/dL and TG of ≥ 150 mg/dL, but not in patients with sdLDL-C of ＜40.0 mg/dL and TG of ≥ 150 mg/dL, than in patients with sdLDL-C of ＜40.0 mg/dL and TG of ＜150 mg/dL.

CONCLUSIONS

Under the condition of treatment with statins, patients with CAD and type 2 DM who had sdLDL-C levels of ≥ 40.0 mg/dL had a high risk for cardiovascular events even though serum TG levels were controlled at ＜150 mg/dL.

Seasonal variations in endothelium-dependent flow-mediated vasodilation and endothelium-independent nitroglycerine-induced vasodilation

Cardiovascular mortality has been shown to vary seasonally. However, it has not been determined whether vascular function is affected by the season. The purpose of this study was to investigate the associations of vascular function with season and outdoor temperature. Between April 2007 and March 2022, measurements of flow-mediated vasodilation (FMD) of the brachial artery as an index of endothelial function and nitroglycerine-induced vasodilation (NID) as an index of endothelium-independent vasodilation were performed in 2190 subjects. There was no significant seasonal difference in FMD (spring, 3.9 ± 3.1%; summer, 3.5 ± 3.0%; fall, 3.7 ± 3.0%; winter, 3.6 ± 3.2%; P = 0.14). There was no significant correlation between FMD and daily mean outdoor temperature (r = -0.02, P = 0.25). Multivariate analyses revealed that neither season (β = -0.020, P = 0.31) nor outdoor temperature (β = 0.005, P = 0.81) was significantly associated with FMD after adjustment for other confounding factors. There were significant seasonal differences in NID (spring, 12.8 ± 6.3%; summer, 12.0 ± 6.1%; fall, 11.7 ± 6.1%; winter, 12.3 ± 5.9%; P = 0.02). However, multivariate analysis revealed that there was no significant association between season and NID after adjustment for other confounding factors (β = -0.012, P = 0.56). There was no significant correlation between NID and daily outdoor mean temperature (r = -0.03, P = 0.17). Multivariate analysis revealed that outdoor temperature was not significantly associated with NID (β = -0.006, P = 0.78). There was no significant association of FMD or NID with season or outdoor temperature, suggesting that it is not necessary to take into account the effects of season and outdoor temperature on vascular function when interpreting the results of FMD and NID measurements. Public trials registry number: UMIN000039512.

Non-enzymatic reactions in biogenesis of fungal natural products

Fungi have long been regarded as abundant sources of natural products (NPs) exhibiting significant biological activities. Decades of studies on the biosynthesis of fungal NPs revealed that most of the biosynthetic steps are catalyzed by sophisticated enzymes encoded in biosynthetic gene clusters, whereas some reactions proceed without enzymes. These non-enzymatic reactions complicate biosynthetic analysis of NPs and play important roles in diversifying the structure of the products. Therefore, knowledge on the non-enzymatic reactions is important for elucidating the biosynthetic mechanism. This review focuses on non-enzymatic reactions we recently encountered during biosynthetic studies of four types of NPs (viridicatins, Sch210972, lentopeptins, and lentofuranine).

Association of cumulative low-density lipoprotein cholesterol exposure with vascular function

BACKGROUND

The relationship between cumulative low-density lipoprotein cholesterol (LDL-C) exposure and progression of atherosclerosis remains uncertain.

OBJECTIVE

The aim of this study was to determine the relationship between cumulative LDL-C level and flow-mediated vasodilation (FMD), nitroglycerine-induced vasodilation (NID) and the presence of plaque in the common carotid artery (CCA).

METHODS

This was a cross-sectional study. We measured FMD in 8208 subjects, NID in 1822 subjects, and CCA plaque in 591 subjects who were not taking lipid-lowering drugs. The subjects were divided into four groups based on cumulative LDL-C exposure: <4000 mg·year/dL, 4000-4999 mg·year/dL, 5000-5999 mg·year/dL, and ≥6000 mg·year/dL.

RESULTS

The odds ratio of the lower quartile of FMD in the cholesterol-year-score <4000 mg·year/dL group was significantly higher than the odds ratios in the other groups. The odds ratio of the lower quartile of NID in the <4000 mg·year/dL group was significantly higher than the odds ratios in the 5000-5999 mg·year/dL and ≥6000 mg·year/dL groups. The odds ratio of the prevalence of CCA plaque in the <4000 mg·year/dL group was significantly higher than that in the ≥6000 mg·year/dL group.

CONCLUSIONS

Endothelial dysfunction occurred from cumulative LDL-C exposure of 4000 mg·year/dL, vascular smooth muscle dysfunction occurred from cumulative LDL-C exposure of 5000 mg·year/dL, and prevalence of CCA plaque occurred from cumulative LDL-C exposure of 6000 mg·year/dL. CLINICAL TRIAL REGISTRY INFORMATION: http://www.umin.ac.jp (UMIN000012950, UMIN000012951, and UMIN000012952, UMIN000003409).

Percentage of mean arterial pressure as a marker of atherosclerosis for detecting patients with coronary artery disease

The percentage of mean arterial pressure (%MAP) is the height of the mean arterial waveform divided by the peak amplitude of the waveform of pulse volume recording. The purpose of this study was to determine whether the cutoff value of 45% for %MAP at the ankle, which is recommended for the diagnosis of lower extremity artery disease, in combination with ankle-brachial index (ABI) is useful for detecting patients with clinical coronary artery disease (CAD) and investigate the optimal cutoff value of %MAP to diagnose patients with CAD.　We measured ABI and %MAP in 2213 subjects　(mean age: 61.2 ± 15.5 years). Multivariate analysis revealed that %MAP ≥ 45% was significantly associated with a higher risk of CAD after adjusting for traditional cardiovascular risk factors (odds ratio [OR], 2.14; 95% confidence interval [CI], 1.43-3.21; p < 0.001). However, the association was no longer significant after adjusting for ABI (OR, 1.39; 95% CI, 0.83-2.33; p = 0.21), whereas ABI was significantly associated with CAD (OR, 0.98; 95% CI, 0.97-0.99; p = 0.005). The optimal cutoff value of %MAP derived from a receiver operating characteristic curve to diagnose CAD was 40.3%. Multivariate analysis revealed that %MAP ≥ 40.3% was significantly associated with a higher risk of CAD (OR, 1.63; 95% CI, 1.19-2.24; p = 0.002) independent of ABI (OR, 0.98; 95% CI, 0.97-0.99; p = 0.002). The cutoff value of 40.3%, but not 45%, for %MAP may be useful for detecting patients with advanced atherosclerosis and for cardiovascular risk assessment independent of ABI. REGISTRATION INFORMATION: http://www.umin.ac.jp (University Hospital Medical Information Network Clinical Trials Registry) (UMIN000039512).

An Extended Follow-Up on Blood Pressure in a Patient With New-Onset Essential Hypertension: Early-Morning Home, Morning Home, and Office Readings

The patient was a 63-year-old man with a 24-year history of hypertension. During long-term follow-up, when outpatient clinic blood pressure and morning blood pressure are well-regulated, exceptionally elevated early-morning blood pressure does not play a significant role in the development of hypertensive target organ disease or cardiovascular disease.

Impact of overnight 1 mg dexamethasone on vascular function in patients with nonfunctioning adrenal adenomas

The purpose of this study was to evaluate the effects of administration of overnight 1 mg dexamethasone on vascular function in patients with nonfunctioning adrenal adenomas (NFA). Flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation (NID) were measured to assess vascular function in 22 patients with NFA who had hypertension and/or diabetes mellitus (DM) and 272 patients without adrenal incidentalomas who had hypertension and/or DM (control patients with hypertension and/or DM). FMD and NID were measured in the morning before and after administration of 1 mg of dexamethasone at 2300 h in 18 patients with NFA. There were no significant differences in FMD and NID between control patients with hypertension and/or DM and patients with NFA who had hypertension and/or DM (3.4 ± 2.8% vs. 2.9 ± 1.9% and 11.5 ± 5.7% vs. 11.4 ± 4.3%, P = 0.46, and P = 0.99, respectively). There were no significant differences in vascular function between control patients with hypertension and/or DM and patients with NFA who had hypertension and/or DM even after adjustment for cardiovascular risk factors. Overnight 1 mg dexamethasone increased FMD from 2.4 ± 1.9% to 5.3 ± 3.2% (P < 0.01) and increased NID from 12.1 ± 4.2% to 14.0 ± 2.8% (P < 0.01) in patients with NFA. The overnight 1 mg dexamethasone suppression test does not impair FMD and NID in patients with NFA. Decreases in circulating levels of cortisol may improve vascular function.Clinical Trial Registration: This study was approved by principal authorities and ethical issues in Japan (URL for Clinical Trial: http://www.umin.ac.jp/ctr/index.htm Registration Number for Clinical Trial: UMIN000039512).

Therapeutic Myogenesis Induced by Ultrasound Exposure in a Volumetric Skeletal Muscle Loss Injury Model

BACKGROUND

Low-intensity pulsed ultrasound (LIPUS) irradiation has been shown to induce various responses in different cells. It has been shown that LIPUS activates extracellular signal-regulated kinase 1/2 (ERK1/2) through integrin.

PURPOSE

To study the effects of LIPUS on myogenic regulatory factors and other related myogenesis elements in a volumetric skeletal muscle loss injury model.

STUDY DESIGN

Controlled laboratory study.

METHODS

C57BL/6J mice were subjected to full-thickness muscle defect injury of the quadriceps and treated with direct application of LIPUS 20 min/d or non-LIPUS treatment (control) for 3, 7, and 14 days. LIPUS was also applied to C2C12 cells in culture in the presence of low and high doses of lipopolysaccharides. The expression levels of myogenic regulatory factors and the expression levels of myokine-related and angiogenic-related proteins of the control and LIPUS groups were analyzed.

RESULTS

Muscle volume in the injury site was restored at day 14 with LIPUS treatment. Paired-box protein 7, myogenic factor 5, myogenin, and desmin expressions were significantly different between control and LIPUS groups at days 7 and 14. Myokine and angiogenic cytokine-related factors were significantly increased in the LIPUS group at day 3 and decreased with no significant difference between the groups by day 14. LIPUS induced different responses of myogenic regulatory factors in C2C12 cells with low and high doses of lipopolysaccharides. LIPUS promoted myogenesis through short-lived increase in interleukin-6 and heme oxygenase 1, together with activation of ERK1/2.

CONCLUSION

LIPUS had a constant effect on the variables of tissue damage, from macrotrauma to microtrauma, leading to efficient muscle regeneration.

CLINICAL RELEVANCE

The focus of therapeutic strategies with LIPUS has been not only for microvascular regeneration but also for skeletal muscle and related local tissue recovery from acute or chronic damage.

KCNJ5 mutation is a predictor for recovery of endothelial function after adrenalectomy in patients with aldosterone-producing adenoma

The relationship of KCNJ5 mutation with vascular function and vascular structure in aldosterone-producing adenoma (APA) patients before and after adrenalectomy remains unclear. The purpose of this study was to evaluate the influence of KCNJ5 mutation on vascular function and vascular structure in APA and the effects of adrenalectomy on vascular function and vascular structure in APA patients with and those without KCNJ5 mutation. Flow-mediated vasodilation (FMD), nitroglycerine-induced vasodilation (NID), brachial artery intima-media thickness (IMT), and brachial-ankle pulse wave velocity (baPWV) were measured to assess vascular function and vascular structure in 46 APA patients with KCNJ5 mutation and 23 APA patients without KCNJ5 mutation and in 69 matched pairs of patients with essential hypertension (EHT). FMD, NID, brachial IMT and baPVW were evacuated before adrenalectomy and at 12 weeks after adrenalectomy in APA patients with KCNJ5 mutation and APA patients without KCNJ5 mutation. FMD and NID were significantly lower in APA patients than in patients with EHT. There was no significant difference in FMD or NID between patients with and those without KCNJ5 mutation. In APA patients with KCNJ5 mutation, FMD and NID after adrenalectomy were significantly higher than those before adrenalectomy. In APA patients without KCNJ5 mutation, only NID after adrenalectomy was significantly higher than that before adrenalectomy. Endothelial function in APA patients with KCNJ5 mutation was improved by adrenalectomy in the early postoperative period. KCNJ5 mutation is a predictor for early resolution of endothelial function by adrenalectomy. This study was approved by principal authorities and ethical issues in Japan (URL for Clinical Trial: http://www.umin.ac.jp/ctr/index.htm Registration Number for Clinical Trial: UMIN000003409).

Lack of impact of ipragliflozin on endothelial function in patients with type 2 diabetes: sub-analysis of the PROTECT study

BACKGROUND

We assessed the impact of 24 months of treatment with ipragliflozin, a sodium-glucose cotransporter 2 (SGLT2) inhibitor, on endothelial function in patients with type 2 diabetes as a sub-analysis of the PROTECT study.

METHODS

In the PROTECT study, patients were randomized to receive either standard antihyperglycemic treatment (control group, n = 241 ) or add-on ipragliflozin treatment (ipragliflozin group, n = 241) in a 1:1 ratio. Among the 482 patients in the PROTECT study, flow-mediated vasodilation (FMD) was assessed in 32 patients in the control group and 26 patients in the ipragliflozin group before and after 24 months of treatment.

RESULTS

HbA1c levels significantly decreased after 24 months of treatment compared to the baseline value in the ipragliflozin group, but not in the control group. However, there was no significant difference between the changes in HbA1c levels in the two groups (7.4 ± 0.8% vs. 7.0 ± 0.9% in the ipragliflozin group and 7.4 ± 0.7% vs. 7.3 ± 0.7% in the control group; P = 0.08). There was no significant difference between FMD values at baseline and after 24 months in both groups (5.2 ± 2.6% vs. 5.2 ± 2.6%, P = 0.98 in the ipragliflozin group; 5.4 ± 2.9% vs. 5.0 ± 3.2%, P = 0.34 in the control group). There was no significant difference in the estimated percentage change in FMD between the two groups (P = 0.77).

CONCLUSIONS

Over a 24-month period, the addition of ipragliflozin to standard therapy in patients with type 2 diabetes did not change endothelial function assessed by FMD in the brachial artery.

TRIAL REGISTRATION

Registration Number for Clinical Trial: jRCT1071220089 ( https://jrct.niph.go.jp/en-latest-detail/jRCT1071220089 ).

Endothelial Function Is Preserved in Patients with Wild-Type Transthyretin Amyloid Cardiomyopathy

Heart failure (HF) is associated with endothelial dysfunction. Vascular function per se plays an important role in cardiac function, whether it is a cause or consequence. However, there is no information on vascular function in patients with wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM). The purpose of this study was to evaluate vascular function in patients with ATTRwt-CM. We measured flow-mediated vasodilation (FMD) as an index of endothelial function and nitroglycerine-induced vasodilation (NID) as an index of vascular smooth muscle function and brachial artery intima-media thickness (bIMT) and brachial-ankle pulse wave velocity (baPWV) as indices of arterial stiffness in 22 patients with ATTRwt-CM and in 22 one-by-one matched control patients using vascular function confounding factors. FMD was significantly greater in patients with ATTRwt-CM than in the controls (5.4 ± 3.4% versus 3.5 ± 2.4%, p = 0.038) and the N-terminal pro-brain natriuretic peptide (NT-proBNP) level was significantly greater in patients with ATTRwt-CM than in the controls (2202 ± 1478 versus 470 ± 677 pg/mL, p < 0.001). There were no significant differences in NID, bIMT or baPWV between the two groups. There was a significant relationship between NT-proBNP and FMD in patients with ATTRwt-CM (r = 0.485, p = 0.022). NT-proBNP showed no significant relationships with NID, bIMT or baPWV. Conclusions: Endothelial function was preserved in patients with ATTRwt-CM. Patients with ATTRwt-CM may have compensatory effects with respect to endothelial function through elevation of BNP.

Genetic Risk of Primary Aldosteronism and Its Contribution to Hypertension: A Cross-Ancestry Meta-Analysis of Genome-Wide Association Study

BACKGROUND

Hypertension imposes substantial health and economic burden worldwide. Primary aldosteronism (PA) is one of the most common causes of secondary hypertension, causing cardiovascular events at higher risk compared with essential hypertension. However, the germline genetic contribution to the susceptibility of PA has not been well elucidated.

METHOD

We conducted a genome-wide association analysis of PA in the Japanese population and a cross-ancestry meta-analysis combined with UK Biobank and FinnGen cohorts (816 PA cases and 425 239 controls) to identify genetic variants that contribute to PA susceptibility. We also performed a comparative analysis for the risk of 42 previously established blood pressure-associated variants between PA and hypertension with the adjustment of blood pressure.

RESULTS

In the Japanese genome-wide association study, we identified 10 loci that presented suggestive evidence for the association with the PA risk (P<1.0×10^-6). In the meta-analysis, we identified 5 genome-wide significant loci (1p13, 7p15, 11p15, 12q24, and 13q12; P<5.0×10^-8), including 3 of the suggested loci in the Japanese genome-wide association study. The strongest association was observed at rs3790604 (1p13), an intronic variant of WNT2B (odds ratio, 1.50 [95% CI, 1.33-1.69]; P=5.2×10^-11). We further identified 1 nearly genome-wide significant locus (8q24, CYP11B2), which presented a significant association in the gene-based test (P=7.2×10^-7). Of interest, all of these loci were known to be associated with blood pressure in previous studies, presumably because of the prevalence of PA among individuals with hypertension. This assumption was supported by the observation that they had a significantly higher risk effect on PA than on hypertension. We also revealed that 66.7% of the previously established blood pressure-associated variants had a higher risk effect for PA than for hypertension.

CONCLUSIONS

This study demonstrates the genome-wide evidence for a genetic predisposition to PA susceptibility in the cross-ancestry cohorts and its significant contribution to the genetic background of hypertension. The strongest association with the WNT2B variants reinforces the implication of the Wnt/β-catenin pathway in the PA pathogenesis.

Reactive Azlactone Intermediate Drives Fungal Secondary Metabolite Cross-Pathway Generation

Pathogenic fungi of Aspergillus section Fumigati are known to produce various secondary metabolites. A reported isolation of a compound with an atypical carbon skeleton called fumimycin from A. fumisynnematus prompted us to examine a related fungus, A. lentulus, for production of similar products. Here we report the isolation of fumimycin and a related new racemic compound we named lentofuranine. Detailed analyses revealed that both compounds were assembled by a nonenzymatic condensation of a polyketide intermediate from the terrein biosynthetic pathway and a highly reactive azlactone intermediate produced by an unrelated nonribosomal peptide synthetase carrying a terminal condensation-like domain. While highly reactive azlactone is commonly used in chemical synthesis, its production by a conventional non-metalloenzyme and employment as a biosynthetic pathway intermediate is unprecedented. The observed unusual carbon skeleton formation is likely due to the reactivity of azlactone. Our finding provides another example of a chemical principle being aptly exploited by a biological system.

Effect of exposure to radiation caused by an atomic bomb on endothelial function in atomic bomb survivors

Background

The purpose of this study was to evaluate the effects of exposure to radiation caused by an atomic bomb in atomic bomb survivors on vascular function and vascular structure and to evaluate the relationships of radiation dose from the atomic bomb with vascular function and vascular structure in atomic bomb survivors.

Methods

Flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation (NID) as indices of vascular function, brachial-ankle pulse wave velocity (baPWV) as an index of vascular function and vascular structure, and brachial artery intima-media thickness (IMT) as an index of vascular structure were measured in 131 atomic bomb survivors and 1,153 control subjects who were not exposed to the atomic bomb. Ten of the 131 atomic bomb survivors with estimated radiation dose in a cohort study of Atomic Bomb Survivors in Hiroshima were enrolled in the study to evaluate the relationships of radiation dose from the atomic bomb with vascular function and vascular structure.

Results

There was no significant difference in FMD, NID, baPWV, or brachial artery IMT between control subjects and atomic bomb survivors. After adjustment of confounding factors, there was still no significant difference in FMD, NID, baPWV, or brachial artery IMT between control subjects and atomic bomb survivors. Radiation dose from the atomic bomb was negatively correlated with FMD (ρ = -0.73, P = 0.02), whereas radiation dose was not correlated with NID, baPWV or brachial artery IMT.

Conclusion

There were no significant differences in vascular function and vascular structure between control subjects and atomic bomb survivors. Radiation dose from the atomic bomb might be negatively correlated with endothelial function.

Effect of ipragliflozin on carotid intima-media thickness in patients with type 2 diabetes: a multicenter, randomized, controlled trial

AIMS

To examine the effects of a 24-month treatment with ipragliflozin on carotid intima-media thickness (IMT) in type 2 diabetes patients.

METHODS AND RESULTS

In this multicenter, prospective, randomized, open-label, and blinded-endpoint investigator-initiated clinical trial, adults with type 2 diabetes and haemoglobin A1C (HbA1c) of 6.0-10.0% (42-86 mmol/mol) were randomized equally to ipragliflozin (50 mg daily) and non-sodium-glucose cotransporter-2 (SGLT2) inhibitor use of standard-care (control group) for type 2 diabetes and were followed-up to 24 months. The primary endpoint was the change in mean common carotid artery IMT (CCA-IMT) from baseline to 24 months. A total of 482 patients were equally allocated to the ipragliflozin (N = 241) and control (N = 241) groups, and 464 patients (median age 68 years, female 31.7%, median type 2 diabetes duration 8 years, median HbA1c 7.3%) were included in the analyses. For the primary endpoint, the changes in the mean CCA-IMT from baseline to 24 months were 0.0013 [95% confidence interval (CI), -0.0155-0.0182] mm and 0.0015 (95% CI, -0.0155-0.0184) mm in the ipragliflozin and control groups, respectively, with an estimated group difference (ipragliflozin-control) of -0.0001 mm (95% CI, -0.0191-0.0189; P = 0.989). A group difference in HbA1c change at 24 months was also non-significant between the treatment groups [-0.1% (95% CI, -0.2-0.1); P = 0.359].

CONCLUSION

Twenty-four months of ipragliflozin treatment did not affect carotid IMT status in patients with type 2 diabetes recruited in the PROTECT study, relative to the non-SGLT2 inhibitor-use standard care for type 2 diabetes.

Cytotoxic Homo- and Hetero-Dimers of o-toluidine, o-anisidine, and Aniline Formed by In Vitro Metabolism

Several aromatic amine compounds are urinary bladder carcinogens. Activated metabolites and DNA adducts of polycyclic aromatic amines, such as 4-aminobiphenyl, have been identified, whereas those of monocyclic aromatic amines, such as o-toluidine (o-Tol), o-anisidine (o-Ans), and aniline (Ani), have not been completely determined. We have recently reported that o-Tol and o-Ans are metabolically converted in vitro and in vivo to cytotoxic and mutagenic p-semidine-type dimers, namely 2-methyl-N⁴-(2-methylphenyl) benzene-1,4-diamine (MMBD) and 2-methoxy-N⁴-(2-methoxyphenyl) benzene-1,4-diamine (MxMxBD), respectively, suggesting their roles in urinary bladder carcinogenesis. In this study, we found that when o-Tol and o-Ans were incubated with S9 mix, MMBD and MxMxBD as well as two isomeric heterodimers, MMxBD and MxMBD, were formed. Therefore, any two of o-Tol, o-Ans, and Ani (10 mM each) were incubated with the S9 mix for up to 24 h and then subjected to LC-MS to investigate their metabolic kinetics. Metabolic conversions to all nine kinds of p-semidine-type homo- and hetero-dimers were observed, peaking at 6 h of incubation with the S9 mix; MxMxBD reached the peak at 6.1 ± 1.4 μM. Homo- and hetero-dimers containing the o-Ans moiety in the diamine structure showed a faster dimerization ratio, whereas levels of these dimers, such as MxMxBD, markedly declined with further incubation. Dimers containing o-Tol and Ani were relatively stable, even after incubation for 24 h. The electron-donating group of the o-Ans moiety may be involved in rapid metabolic conversion. In the cytotoxic assay, dimers with an o-Ans moiety in the diamine structure and MMBD showed approximately two- to four-fold higher cytotoxicity than other dimers in human bladder cancer T24 cells. These chemical and biological properties of homo- and hetero-dimers of monocyclic aromatic amines may be important when considering the combined exposure risk for bladder carcinogenesis.

Relationship of Daily Coffee Intake with Vascular Function in Patients with Hypertension

We evaluated the relationship of daily coffee intake with endothelial function assessed by flow-mediated vasodilation and vascular smooth muscle function assessed by nitroglycerine-induced vasodilation in patients with hypertension. A total of 462 patients with hypertension were enrolled in this cross-sectional study. First, we divided the subjects into two groups based on information on daily coffee intake: no coffee group and coffee group. The median coffee intake was two cups per day in the coffee group. There were significant differences in both flow-mediated vasodilation (2.6 ± 2.8% in the no coffee group vs. 3.3 ± 2.9% in the coffee group, p = 0.04) and nitroglycerine-induced vasodilation (9.6 ± 5.5% in the no coffee group vs. 11.3 ± 5.4% in the coffee group, p = 0.02) between the two groups. After adjustment for confounding factors, the odds ratio for endothelial dysfunction (OR: 0.55, 95% CI: 0.32–0.95) and the odds ratio for vascular smooth muscle dysfunction (OR: 0.50, 95% CI: 0.28–0.89) were significantly lower in the coffee group than in the no coffee group. Next, we assessed the relationship of the amount of daily coffee intake with vascular function. Cubic spline curves revealed that patients with hypertension who drank half a cup to 2.5 cups of coffee per day had lower odds ratios for endothelial dysfunction assessed by flow-mediated vasodilation and vascular smooth muscle dysfunction assessed by nitroglycerine-induced vasodilation. Appropriate daily coffee intake might have beneficial effects on endothelial function and vascular smooth muscle function in patients with hypertension.

Alkaloid Biosynthetic Enzyme Generates Diastereomeric Pair via Two Distinct Mechanisms

Ergopeptines constitute one of the representative classes of ergoline alkaloids and carry a tripeptide extension on the lysergic acid core. In the current study, we discovered and structurally characterized newly isolated ergopeptine-like compounds named lentopeptins from a filamentous fungus Aspergillus lentulus, a close relative of A. fumigatus. Interestingly, in lentopeptins, the common lysergic acid moiety of ergopeptines is replaced by a cinnamic acid moiety at the N-terminus of the peptide segment. Moreover, lentopeptins lack the C-terminal proline residue necessary for the spontaneous cyclization of the peptide extension. Herein, we report the atypical lentopeptin biosynthetic pathway identified through targeted deletion of the len cluster biosynthetic genes predicted from the genome sequence. Further in vitro characterizations of the thiolation-terminal condensation-like (T-C_T) didomain of the nonribosomal peptide synthetase LenA and its site-specific mutants revealed the mechanism of peptide release via diketopiperazine formation, an activity previously unreported for C_T domains. Most intriguingly, in vitro assays of the cytochrome P450 LenC illuminated the unique mechanisms to generate two diastereomeric products. Lentopeptin A forms via a stereospecific hydroxylation, followed by a spontaneous bicyclic lactam core formation, while lentopeptin B is produced through an initial dehydrogenation, followed by a bicyclic lactam core formation and stereospecific hydration. Our results showcase how nature exploits common biosynthetic enzymes to forge new complex natural products effectively (213/250).

Poor tooth brushing behavior is associated with high risk of cardiovascular events: A prospective observational study

BACKGROUNDS

Poor oral care is associated with cardiovascular disease. The aim of this study was to determine the impact of tooth brushing behavior on the incidences of future cardiovascular events in a general population including patients with cardiovascular disease.

METHODS

This was a prospective observational study which included 692 participants (437 men and 255 women, mean age, 63 ± 16 years). The participants were divided into three groups according to the frequency and duration of tooth brushing: low frequency and short duration group (<twice/day and <2 min/procedure), low frequency or short duration group (<twice/day or <2 min/procedure), and non-low frequency and non-short duration group (≥twice/day and ≥2 min/procedure). We assessed the associations of tooth brushing behavior with major adverse cardiovascular events (MACEs) including death from cardiovascular causes, acute myocardial infarction, hospitalization for heart failure, and stroke.

RESULTS

During a median follow-up period of 28.5 (15.4-35.1) months, 32 events occurred (10 deaths from cardiovascular causes, one acute myocardial infarction, 13 hospitalizations for heart failure, and eight strokes). Kaplan-Meier curves for MACEs among the groups were significantly different (P = 0.001). After adjustment for cardiovascular risk factors, the combination of low frequency and short duration of tooth brushing was significantly associated with high incidences of MACEs compared with the incidences of MACEs for the combination of non-low frequency and non-short duration of tooth brushing (hazard ratio, 3.06; 95% confidence interval, 1.24-7.63; P = 0.02).

CONCLUSIONS

The combination of decreased frequency and duration of tooth brushing is associated with a higher risk of cardiovascular events.

CLINICAL TRIAL REGISTRATION INFORMATION

URL for Clinical Trial: http://UMIN; Registration Number for Clinical Trial: UMIN000003409.

Serum Potassium Levels of 4.5 to Less Than 5.0 mmol/L Are Associated with Better Vascular Function

Aim: An experimental study showed that potassium inhibits the formation of reactive oxygen species by vascular cells. The purpose of this study was to investigate the association between serum potassium levels and vascular function.

Methods: We measured flow-mediated vasodilation (FMD) as an index of endothelial function in 3045 subjects (1964 men; mean age, 62.3±13.8 years) and nitroglycerine-induced vasodilation (NID) as an index of vascular smooth muscle function in 1578 subjects (1001 men; mean age, 61.8±16.3 years).

Results: In the 3045 subjects, there was a significant positive correlation between FMD and serum potassium levels (r=0.09,P＜0.001). Multivariate analysis revealed that serum potassium levels were significantly associated with FMD (β=0.109,P＜0.001). When subjects were divided into two groups based on treatment with drugs that could alter serum potassium levels, the association between serum potassium levels and FMD was significant both in subjects with (β=0.096,P＜0.001) and subjects without (β=0.123,P＜0.001) treatment with drugs that could alter serum potassium levels. In the 1578 subjects, there was a significant positive correlation between NID and serum potassium levels (r=0.11,P＜0.001). Multivariate analysis revealed that serum potassium levels were significantly associated with NID (β=0.098,P＜0.001). The association between serum potassium levels and NID was significant both in subjects with (β=0.121,P=0.001) and subjects without (β=0.083,P=0.03) treatment with drugs that could alter serum potassium levels.

Conclusions: Serum potassium levels of 4.5-＜5.0 mmol/L are associated with better vascular function regardless of the presence or absence of treatment with drugs that could alter serum potassium levels.

Falsely normalized ankle-brachial index despite the presence of lower-extremity peripheral artery disease: two case reports

Background

The ankle-brachial index measurement is used for screening and diagnosis of lower-extremity peripheral artery disease and cardiovascular risk assessment. However, the value is occasionally unreliable since the oscillometric ankle-brachial index can be elevated and falsely normalized despite the presence of lower-extremity peripheral artery disease because of the incompressibility of infrapopliteal arteries at the ankle, potentially leading to a missed diagnosis of lower-extremity peripheral artery disease or underestimation of cardiovascular risk.

Case presentation

We report two cases of lower extremity peripheral artery disease with normal ankle-brachial index (a 76-year-old Asian man and a 66-year-old Asian man). In both cases, the ankle-brachial index was within the normal range (1.00–1.40) despite the presence of lower-extremity peripheral artery disease, whereas upstroke time at the ankle calculated from the pulse volume waveform simultaneously obtained by plethysmography during the ankle-brachial index measurement was prolonged (≥ 180 milliseconds). Diagnostic imaging tests revealed the presence of occlusive arterial disease in the lower extremity and severe calcification of infrapopliteal arteries.

Conclusions

In both cases, the oscillometric ankle-brachial index might have been falsely normalized despite the presence of lower-extremity peripheral artery disease because of calcified incompressible infrapopliteal arteries. Sole reliance on the ankle-brachial index value may lead to a missed diagnosis of lower-extremity peripheral artery disease or underestimation of cardiovascular risk. Upstroke time at the ankle was helpful for suspecting the presence of lower-extremity peripheral artery disease in both patients with normal ankle-brachial index. In addition to history-taking and vascular examination, upstroke time at the ankle should be carefully checked for accurate diagnosis of peripheral artery disease and cardiovascular risk assessment in patients with normal ankle-brachial index.

Toward Engineered Biosynthesis of Drugs in Human Cells

Biosynthetic genes are not only responsible for the formation of bioactive substances but also suited for other applications including gene therapy. To test the feasibility of human cells producing antibiotics in situ when provided with a heterologous biosynthetic gene, we focused on cytochrome P450, the class of enzymes important in conferring bioactivity to natural product precursors. We selected Fma-P450 that plays a central role in the fumagillin antimicrobial biosynthesis in Aspergillus fumigatus to examine fungal metabolite production by HeLa cells that express fma-P450 heterologously. Here we show that HeLa cells harboring fma-P450 can biosynthesize 5-hydroxyl-β-trans-bergamoten and cytotoxic 5-epi-demethoxyfumagillol when supplemented with the nontoxic precursor β-trans-bergamotene. While the production level was insufficient to effect cell death, we demonstrate that programming human cells to autogenerate antibiotics by introducing a heterologous biosynthetic gene is feasible.

Short stature is associated with low flow-mediated vasodilation in Japanese men

An inverse association between height and the risk of cardiovascular disease has been reported. The objective of this study was to examine the association between height and endothelial function assessed by flow-mediated vasodilation (FMD). We evaluated cross-sectional associations of height with FMD in 7682 Japanese men. All participants were divided into four groups based on height: <155.0 cm, 155.0-164.9 cm, 165.0-174.9 cm, and ≥175.0 cm. Subjects in a lower quartile of FMD were defined as subjects having low FMD values. Univariate regression analysis revealed that height was significantly correlated with FMD (r = 0.14, p < 0.001). FMD values were 4.6 ± 3.1% in the <155.0 cm group, 5.2 ± 3.1% in the 155.0-164.9 cm group, 5.7 ± 3.1% in the 165.0-174.9 cm group and 6.1 ± 3.2% in the ≥175.0 cm group. FMD significantly increased in relation to an increase in height. Multiple logistic regression analysis revealed that higher height groups were significantly associated with a decreased risk of low FMD value compared with the <155.0 cm group after adjustments for age, presence of hypertension, dyslipidemia, diabetes, current smoking, and brachial artery diameter. FMD was low in subjects with a short stature compared with that in subjects with tall stature. Individuals with a short stature may require intensive interventions to reduce the risk of cardiovascular events.Clinical Trial Registration Information: URL for Clinical Trials: http://www.umin.ac.jp Registration Number for Clinical Trials: UMIN000012952.

A 5-kV pulse generator with a 100-kV/µs slew rate based on series-connected 1700-V SiC MOSFETs for electrical insulation tests

This study demonstrates a high-slew-rate 5-kV pulse generator for electrical insulation tests. Electrical equipment, such as electrical actuators and traction drive motors, are exposed to severe electrical stress because recent switching inverters have high-frequency outputs with high supply voltages using wide-bandgap power devices. For an advanced electrical insulation test, a high-voltage pulse generator is required with a high slew rate; however, such generators suffer from large switching noise, followed by measurement noise, such as ground voltage fluctuations and radiation noise, hindering the detection of partial discharge (PD) phenomena. In this study, we propose a 5-kV pulse generator based on series-connected 1700-V silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs). Four 1700-V SiC MOSFETs are connected in series as a 5-kV SiC switching module, constituting a half-bridge configuration for the pulse generator. The obtained switching waveforms exhibit fast rise times of 48 ns under 5 kV and 6.2 ns under 400 V with a low voltage overshoot and ringing owing to superior device characteristics and reduced parasitic inductances. Because of the low switching noise, we detect a clear PD signal with a 1500-V pulse when using the fabricated pulse generator for a PD test of a twisted pair. The proposed pulse generator uses a hard switching configuration such that the pulse generator can vary the pulse width from 150 ns to DC and increase the switching pulse cycle beyond 1 MHz by changing the control signals of the SiC MOSFETs.

Relationship between hemoglobin A1c level and flow-mediated vasodilation in patients with type 2 diabetes mellitus receiving antidiabetic drugs

Aims/Introduction

Diabetes mellitus is associated with endothelial dysfunction. However, it is still controversial as to whether antidiabetic drug treatment affects endothelial function. The purpose of this study was to evaluate the relationships of the hemoglobin A1c (HbA1c) level with flow‐mediated vasodilation (FMD) and nitroglycerine‐induced vasodilation (NID) in patients with type 2 diabetes mellitus who are receiving antidiabetic drugs.

Materials and Methods

The FMD was measured in 866 patients with type 2 diabetes mellitus who were receiving antidiabetic drugs (625 men and 241 women; mean age: 62 ± 10 years). The patients were divided into four groups according to HbA1c levels: <6.5, 6.5–6.9, 7.0–7.9, and ≥8.0%.

Results

There was an inverted U‐shaped pattern of association of the HbA1c level with the FMD at an HbA1c level of about 7% of the peak of FMD in patients with type 2 diabetes mellitus who were receiving antidiabetic drugs. The FMD was significantly smaller in the HbA1c <6.5% group than in the HbA1c 6.5–6.9% group and the HbA1c 7.0–7.9% group (P < 0.001 and P < 0.001, respectively). The FMD values were similar in the HbA1c <6.5% group and HbA1c ≥8.0% group (P = 0.10). There were no significant differences in NID among the four groups (P = 0.98).

Conclusions

These findings suggest that a low HbA1c <6.5% as well as a high HbA1c ≥8.0% is associated with endothelial dysfunction in patients with type 2 diabetes mellitus who are receiving antidiabetic drugs and that vascular smooth muscle function is similar in such patients regardless of the HbA1c level.

Upstroke time as a marker of atherosclerosis in patients with diabetes mellitus who have a normal ankle-brachial index

We measured upstroke time in 509 patients with diabetes who had a normal ankle-brachial index (ABI) (1.00 ≤ ABI ≤ 1.40) (443 men and 66 women; mean age: 67.6 ± 10.8 years). The prevalence of cardiovascular disease was significantly higher in patients with prolonged upstroke time at the ankle than in patients with normal upstroke time. The association between prolonged upstroke time and a higher risk of cardiovascular disease remained significant after adjusting for confounders.

Stair climbing activity and vascular function in patients with hypertension

We evaluated the relationship between daily stair climbing activity and vascular function as assessed by flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation (NID). This study was a cross-sectional study. A total of 374 patients with hypertension were enrolled. The subjects were divided into three groups based on their daily stair climbing habit: no stairs group, climbing stairs to the 2nd-floor group, and climbing stairs to the ≥3rd-floor group. There was a significant difference in FMD between the ≥3rd-floor group and the other two groups (3.3 ± 2.5% vs. 2.3 ± 2.7% and 2.4 ± 2.7%, p = 0.02, respectively). FMD values were similar in the no stairs group and the 2nd-floor group (p = 0.96). There was a significant difference in NID between the no stairs group and the other two groups (7.4 ± 4.2% vs. 10.9 ± 5.3% and 11.3 ± 5.1%, p < 0.001, respectively). NID values were similar in the second-floor group and the ≥3rd-floor group (p = 0.86). These findings suggest that both endothelial function and vascular smooth muscle function are impaired in individuals who do not climb stairs and that endothelial function but not vascular smooth muscle function is impaired in individuals who climb stairs to the second floor compared with individuals who climb stairs to the ≥3rd floor. Stair climbing activity, a simple method for assessing daily physical activity, may reflect vascular function in patients with hypertension.

Volume Elastic Modulus, Vascular Function, and Vascular Structure in Patients with Cardiovascular Risk Factors

Aims: Volume elastic modulus (V _E ), an index of arterial elasticity, and arterial diameter of the brachial artery can be automatically measured by a newly developed oscillometric device. We investigated the associations of V _E with flow-mediated vasodilation (FMD), an index of endothelium-dependent vasodilation, nitroglycerine-induced vasodilation (NID), an index of endothelium-independent vasodilation, and intima-media thickness (IMT) of the brachial artery and association of oscillometrically measured brachial artery diameter with ultrasonographically measured brachial artery diameter in patients with cardiovascular risk factors.

Methods: Oscillometric measurements of V _E and brachial artery diameter and ultrasound measurements of brachial artery diameter, FMD, NID, and IMT of the brachial artery were performed in 50 patients with cardiovascular risk factors.

Results: The mean values were 2.1±0.4 mmHg/% for V _E , 0.31±0.05 mm for brachial IMT, 4.48±0.70 mm for oscillometric brachial artery diameter, and 4.30±0.55 mm for ultrasound brachial artery diameter. V _E significantly correlated with brachial IMT (r=0.51, P ＜0.001), whereas there was no significant correlation of V _E with FMD (r=-0.08, P =0.58) or NID (r=0.07, P =0.61). Multivariate analysis revealed that V _E was significantly associated with brachial IMT (β=0.33, P =0.04). Oscillometric brachial artery diameter significantly correlated with ultrasound brachial artery diameter (r=0.79, P ＜0.001). The Bland-Altman plot showed good agreement between oscillometric brachial artery diameter and ultrasound brachial artery diameter (mean difference, -0.17 mm; limits of agreement, -1.03 mm to 0.69 mm).

Conclusions: In patients with cardiovascular risk factors, V _E may represent atherosclerotic structural alterations of the vascular wall but not vascular function. The accuracy of oscillometric measurement of brachial artery diameter is acceptable.

Low-intensity pulsed ultrasound decreases major amputation in patients with critical limb ischemia: 5-year follow-up study

Various therapeutic strategies for angiogenesis are performed to improve symptoms in patients with critical limb ischemia (CLI). Pre-clinical studies have shown that low-intensity pulsed ultrasound (LIPUS) exposure induces angiogenesis. LIPUS may be a new stratergy for treatment of CLI. The purpose of this pilot trial was to evaluate outcomes in patients with CLI who were treated with LIPUS. Fourteen patients with CLI, who were not candidates for angioplasty or surgical revascularization, were enrolled in this study. Historical control data were obtained from the Hiroshima University PAD database. The primary endpoints were major amputation and death. The outcomes were compared in 16 lower limbs of the 14 patients with CLI who were treated with LIPUS and in 14 lower limbs of 14 patients with CLI as historical controls. All patients were followed for after 5 years after treatment with LIPUS. The mean duration of LIPUS exposure in the LIPUS group was 381± 283 days. During the 5-year follow-up periods, there were 3 major amputations and 7 deaths in the LIPUS group and there were 14 major amputations and 7 deaths in the historical control group. The overall amputation-free survival rate was significantly higher in patients who were treated with LIPUS than in historical controls. There was no significant difference between overall mortality-free survival rates in the LIPUS group and historical control group. LIPUS is a noninvasive option for therapeutic angiogenesis with the potential to reduce the incidence of major amputations in patients with CLI.

Artesunate inhibits intestinal tumorigenesis through inhibiting wnt signaling

Artesunate (ART) is a clinically approved antimalarial drug and was revealed as a candidate of colorectal cancer chemopreventive agents in our drug screening system. Here, we aimed to understand the suppressive effects of ART on intestinal tumorigenesis. In vitro, ART reduced T-cell factor/lymphoid enhancer factor (TCF/LEF) promoter transcriptional activity. In vivo, ART inhibited intestinal polyp development. We found that ART reduces TCF1/TCF7 nuclear translocation by binding the Ras-related nuclear protein (RAN), suggesting that ART inhibits TCF/LEF transcriptional factor nuclear translocation by binding to RAN, thereby inhibiting Wnt signaling. Our results provide a novel mechanism through which artesunate inhibits intestinal tumorigenesis.

Inconvenient relationship of haemoglobin A1c level with endothelial function in type 2 diabetes in a cross-sectional study

OBJECTIVE

The aim of this study was to determine the relationship of haemoglobin A1c (HbA1c) level with flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation (NID) in patients with type 2 diabetes.

DESIGN

Cross-sectional study.

SETTING

22 university hospitals and affiliated clinics in Japan.

PARTICIPANTS

1215 patients with type 2 diabetes including 349 patients not taking antidiabetic drugs.

MEASURES

We evaluated FMD and HbA1c level. All patients were divided into four groups based on HbA1c level: <6.5%, 6.5%-6.9%, 7.0%-7.9% and ≥8.0%.

RESULTS

An inverted U-shaped pattern of association between HbA1c level and FMD was observed at the peak of HbA1c of about 7%. FMD was significantly smaller in the HbA1c <6.5% group than in the HbA1c 6.5%-6.9% group and HbA1c 7.0%-7.9% group (p<0.001 and p<0.001), and FMD values were similar in the HbA1c <6.5% group and HbA1c ≥8.0% group. There were no significant differences in NID values among the four groups. After adjustments for confounding factors, FMD was significantly smaller in the HbA1c <6.5% group than in the HbA1c 6.5%-6.9% and HbA1c 7.0%-7.9% group (p=0.002 and p=0.04). In patients not taking antidiabetic drugs, FMD was also significantly smaller in the HbA1c <6.5% group than in the HbA1c 6.5%-6.9% group and HbA1c 7.0%-7.9% group (p<0.001 and p=0.02), and there were no significant differences in NID values among the four groups.

CONCLUSIONS

These findings suggest that there is an inverted U-shaped pattern of association between FMD and HbA1c and that a low HbA1c level of <6.5% is associated with endothelial dysfunction.

TRIAL REGISTRATION NUMBER

UMIN000012950, UMIN000012951, UMIN000012952 and UMIN000003409.

Regenerative medicine for radiation emergencies

Hiroshima University is a 'medical institution for tertiary radiation emergencies' and a 'medical support organization as a part of the International Atomic Emergency Agency Emergency Preparedness Response-Response and Assistance Network (IAEA EPR-RANET)'. To establish a system of regenerative medicine for radiation emergencies with treatment by implantation of various types of cells derived from induced pluripotent stem (iPS) cells, it is necessary to establish methods of defense against and treatment for radiation-induced damage from nuclear power plant accidents and nuclear terrorism. It is also necessary to develop cell therapy, cellular repair technology and regenerative biotechnology as regenerative medicine for radiation emergencies. Such applications have not been established yet. To develop a regenerative medical system, by using the existing one, for radiation emergencies, we will attempt to manage the cell-processing center to establish a safe and secured iPS cell bank for radiation medicine. By using this iPS cell bank as the central leverage, we will develop an education program for radiation emergency medicine and construct a network of regenerative medicine for radiation emergency medicine.

Lower triglyceride levels are associated with better endothelial function

BACKGROUND

Increased serum triglyceride levels are independently associated with endothelial dysfunction. However, there is little evidence to define normal levels of triglycerides and there is little information on endothelial function in subjects with extremely low levels of triglycerides.

OBJECTIVE

The purpose of this study was to determine the relationship between triglycerides, especially low levels of triglycerides, and vascular function.

METHODS

We measured flow-mediated vasodilation (FMD) in 7047 subjects and nitroglycerine-induced vasodilation (NID) in 1017 subjects. We divided the subjects into eight groups by triglyceride levels: <50 mg/dL, 50-69 mg/dL, 70-89 mg/dL, 90-109 mg/dL, 110-129 mg/dL, 130-149 mg/dL, 150-199 mg/dL, and ≥200 mg/dL.

RESULTS

FMD was significantly higher in subjects with triglyceride levels of <50 mg/dL than in subjects with triglyceride levels of 50-69 mg/dL, 70-89 mg/dL, 90-109 mg/dL, 110-129 mg/dL, 130-149 mg/dL, 150-199 mg/dL, and ≥200 mg/dL (p=0.002, p<0.001, p<0.001, p<0.001, p<0.001, p<0.001, and p<0.001, respectively). Using triglyceride levels of >200 mg/dL as a reference, the odds ratios for a lower quartile of FMD were significantly lower in the <50 mg/dL group, 50-69 mg/dL group, 70-89 mg/dL group, and 90-109 mg/dL group after adjustment for age, gender and other cardiovascular risk factors. There was a slight negative correlation between NID and triglycerides (r=-0.074; p=0.019). However, there was no significant differences in NID among the eight groups.

CONCLUSIONS

FMD values were highest in subjects with extremely low levels of triglycerides (<50 mg/dL). Lower triglyceride levels were associated with better endothelial function.

CLINICAL TRIAL REGISTRATION INFORMATION

http://www.umin.ac.jp (University Hospital Medical Information Network Clinical Trials Registry) (UMIN000012950).

o-Anisidine Dimer, 2-Methoxy-N4-(2-methoxyphenyl) Benzene-1,4-diamine, in Rat Urine Associated with Urinary bladder Carcinogenesis

Monocyclic aromatic amines, o-toluidine (o-Tol) and its structural analog o-anisidine (o-Ans), are IARC Group 1 and Group 2A urinary bladder carcinogens, respectively, and are involved in metabolic activation and DNA damage. Our recent study revealed that 2-methyl-N⁴-(2-methylphenyl) benzene-1,4-diamine (MMBD), a p-semidine-type homodimer of o-Tol, was detected and identified in an in vitro reaction of o-Tol with S9 mix and in vivo urinary samples of o-Tol-exposed rats. Potent mutagenic, genotoxic, and cytotoxic activities were reported with MMBD, suggesting its involvement in urinary bladder carcinogenesis. However, it remains unknown whether o-Ans is converted to active metabolites to induce DNA damage in a similar manner as o-Tol. In this study, we report that a novel o-Ans metabolite, 2-methoxy-N⁴-(2-methoxyphenyl) benzene-1,4-diamine (MxMxBD), a dimer by head-to-tail binding (p-semidine form), was for the first time identified in o-Ans-exposed rat urine. MxMxBD induced a stronger mutagenicity in N-acetyltransferase overexpressed Salmonella typhimurium strains and potent genotoxicity and cytotoxicity in human bladder carcinoma T24 cells compared with o-Ans. These results suggest that MxMxBD may to some extent contribute toward urinary bladder carcinogenesis. In addition to homodimerization, such as MxMxBD, heterodimerizations were observed when o-Ans was coincubated with o-Tol or aniline (Ani) in in vitro reactions with S9 mix. This study highlights the important consideration of homodimerizations and heterodimerizations of monocyclic aromatic amines, including o-Ans, o-Tol, and Ani, in the evaluation of the combined exposure risk of bladder carcinogenesis.

Finger blood flow after the cold challenge with primary Raynaud's syndrome: a case report

Background 

Raynaud’s syndrome is a commonly encountered disorder. The relationship between the grade of Raynaud’s phenomenon and severity of vasoconstriction is unclear. Recently, various methods including colour Doppler ultrasonography have been used for assessment of vascularity of the extremities including fingers.

Case summary 

A 53-year-old man had a 6-year history of Raynaud’s phenomenon with typical tri-coloured changes proceeding from white, blue to red and slight pain and slight paresthaesia in the fingers of both hands when his fingers were exposed to cold. He was diagnosed with primary Raynaud’s syndrome. After treatment with the calcium channel blocker amlodipine (5 mg once daily), a cold challenge did not induce Raynaud’s phenomenon on the fingers in the present patient. After the cold challenge, colour Doppler ultrasonography showed that vascularity was markedly decreased or was absent, whereas there was little difference in skin colour of the fingers.

Discussion 

In Raynaud's phenomenon, vasospasm may occur even if the symptoms are well-controlled with a calcium channel blocker. It is unlikely that clinical symptoms in patients with Raynaud’s syndrome always reflect the severity of vasoconstriction in their fingers.

Smoking status and endothelial function in Japanese men

It is established that smoking is a major risk factor of atherosclerosis. Endothelial dysfunction occurs in the initial step in the pathogenesis of atherosclerosis and plays a critical role in the development of atherosclerosis. The purpose of this study was to evaluate the association between smoking status and endothelial function in detail in men. We measured flow-mediated vasodilation (FMD) in 2209 Japanese men including 1181 men who had never smoked and 1028 current smokers. All of the participants were divided into five groups by smoking pack-years: never smoker group (= 0), light smoker group (> 0 to 10), moderate smoker group (> 10 to 20), heavy smoker group (> 20 to 30) and excessive smoker group (> 30). FMD significantly decreased in relation to pack-years (6.6 ± 3.4% in the never smoker group, 6.8 ± 3.0% in the light smoker group, 6.5 ± 2.9% in the moderate smoker group, 5.9 ± 2.9% in the heavy smoker group, and 4.9 ± 2.7% in the excessive smoker group; P < 0.001). After adjustment for age (≥ 65 years), body mass index, systolic blood pressure, low-density lipoprotein cholesterol, glucose, and year of recruitment, FMD was significantly smaller in the excessive smoker group than in the never smoker group as a reference group (OR 1.95, 95% CI 1.42 to 2.67; P < 0.001). These findings suggest that FMD decreases with an increase in the number of cigarettes smoked and that excessive smoking is associated with endothelial dysfunction. Cigarette smoking is harmful to vascular function in men who are heavy smokers.

Endothelial function is preserved in light to moderate alcohol drinkers but is impaired in heavy drinkers in women: Flow-mediated Dilation Japan (FMD-J) study

Light to moderate alcohol consumption has protective effects on all-cause death and coronary artery disease in women. It is thought that light to moderate alcohol consumption has a beneficial effect on vascular function in women. We measured flow-mediated vasodilation (FMD) in 702 women aged 17-86 years who provided information on alcohol consumption. We divided the subjects into four groups: non-drinkers (0 g/week), light drinkers (>0 to 140 g/week), moderate drinkers (>140 to 280 g/week) and heavy drinkers (>280 g/week). There was no significant difference in FMD among the four groups. Multivariate regression analysis revealed that alcohol consumption in non-drinkers and light drinkers was not an independent predictor of FMD (β = -0.001, P = 0.98). We compared 50 moderate drinkers and 50 non-drinkers matched for age and medical histories and 22 heavy drinkers and 22 non-drinkers in matched pair analysis. There was no significant difference in FMD between moderate drinkers and non-drinkers (8.2±4.3% vs. 8.1±3.5, P = 0.91), while FMD in heavy drinkers was significantly lower than that in non-drinkers (5.9±2.5% vs. 8.9±3.5%, P = 0.002). These findings suggest that heavy alcohol consumption is associated with endothelial dysfunction but that light to moderate alcohol consumption is not associated with endothelial dysfunction in women. Clinical trial registration information This study was approved by principal authorities and ethical issues in Japan (University Hospital Medical Information Network UMIN000012952, 01/12/2009). www.umin.ac.jp/.

Upstroke Time Is a Useful Vascular Marker for Detecting Patients With Coronary Artery Disease Among Subjects With Normal Ankle-Brachial Index

Background Upstroke time is the transit time from the nadir to peak of the waveform of pulse volume recording. The purpose of this study was to determine whether upstroke time at the ankle is a useful vascular marker for detecting patients with advanced atherosclerosis in combination with ankle-brachial index (ABI). Methods and Results We measured upstroke time and ABI in 2313 subjects (mean age, 61.2±15.3 years). The prevalence of coronary artery disease (CAD) was significantly higher in patients with prolonged upstroke time (≥180 ms) than in subjects with normal upstroke time (<180 ms) (29.6% versus 11.8%; P<0.001), with a significant association between prolonged upstroke time and an increased risk of CAD (odds ratio [OR], 1.61; 95% CI, 1.07-2.44; P=0.02). In 1954 subjects with normal ABI (1.00 ≤ ABI ≤ 1.40), the prevalence of CAD was significantly higher in patients with prolonged upstroke time than in subjects with normal upstroke time (29.5% versus 10.6%; P<0.001), with a significant association between prolonged upstroke time and CAD (OR, 2.33; 95% CI, 1.41-3.87; P=0.001), whereas there was no significant association between upstroke time and CAD in subjects with low ABI (<1.00) (OR, 1.24; 95% CI, 0.72-2.16; P=0.44). Conclusions Upstroke time may be a useful vascular marker for detecting patients with CAD, especially in subjects with normal ABI who are usually considered not to have advanced atherosclerosis by ABI measurement alone. More attention should be paid to upstroke time for detecting patients with advanced atherosclerosis. Registration URL: https://www.umin.ac.jp; Unique identifier: UMIN000039512.

Relationship between cell number and clinical outcomes of autologous bone-marrow mononuclear cell implantation in critical limb ischemia

Cell therapy using intramuscular injections of autologous bone-marrow mononuclear cells (BM-MNCs) improves clinical symptoms and can prevent limb amputation in atherosclerotic peripheral arterial disease (PAD) patients with critical limb ischemia (CLI). The purpose of this study was to evaluate the effects of the number of implanted BM-MNCs on clinical outcomes in atherosclerotic PAD patients with CLI who underwent cell therapy. This study was a retrospective observational study with median follow-up period of 13.5 years (range, 6.8–15.5 years) from BM-MNC implantation procedure. The mean number of implanted cells was 1.2 ± 0.7 × 10⁹ per limb. There was no significant difference in number of BM-MNCs implanted between the no major amputation group and major amputation group (1.1 ± 0.7 × 10⁹ vs. 1.5 ± 0.8 × 10⁹ per limb, P = 0.138). There was also no significant difference in number of BM-MNCs implanted between the no death group and death group (1.5 ± 0.9 × 10⁹ vs. 1.8 ± 0.8 × 10⁹ per patient, P = 0.404). Differences in the number of BM-MNCs (mean number, 1.2 ± 0.7 × 10⁹ per limb) for cell therapy did not alter the major amputation-free survival rate or mortality rate in atherosclerotic PAD patients with CLI. A large number of BM-MNCs will not improve limb salvage outcome or mortality.

Daily Low-intensity Pulsed Ultrasound Ameliorates Renal Fibrosis and Inflammation in Experimental Hypertensive and Diabetic Nephropathy

The estimated morbidity rate of chronic kidney disease is 8% to 16% worldwide, and many patients with chronic kidney disease eventually develop renal failure. Thus, the development of new therapeutic strategies for preventing renal failure is crucial. In this study, we assessed the effects of daily low-intensity pulsed ultrasound (LIPUS) therapy on experimental hypertensive nephropathy and diabetic nephropathy. Unilateral nephrectomy and subcutaneous infusion of angiotensin II via osmotic mini-pumps were used to induce hypertensive nephropathy in mice. Immunohistochemistry revealed that daily LIPUS treatment ameliorated renal fibrosis and infiltration of inflammatory cells induced by angiotensin II. A similar therapeutic effect was also observed in mice with angiotensin II-induced hypertensive nephropathy in which splenectomy was performed. In addition, LIPUS treatment significantly decreased systolic blood pressure after 21 days. Subsequently, db/db mice with unilateral nephrectomy developed proteinuria; daily LIPUS treatment significantly reduced proteinuria after 42 days. In addition, immunohistochemistry revealed that renal fibrosis was significantly ameliorated by LIPUS treatment. Finally, LIPUS stimulation suppressed TGF-β1 (transforming growth factor-β1)-induced phosphorylation of Smad2 and Smad3 in HK-2 (human proximal tubular cell line) cells. LIPUS treatment may be a useful therapy for preventing the progression of renal fibrosis in patients with chronic kidney disease.

A Comparison of Adrenalectomy and Eplerenone on Vascular Function in Patients with Aldosterone-producing Adenoma

CONTEXT

It remains unclear whether adrenalectomy has more beneficial effects than treatment with a mineralocorticoid receptor antagonist on vascular function in patients with aldosterone-producing adenoma (APA).

OBJECTIVE

The aim of this study was to compare the effects of adrenalectomy and treatment with eplerenone on vascular function in patients with APA.

DESIGN, SETTING, AND PATIENTS

Flow-mediated vasodilation (FMD), as an index of endothelium-dependent vasodilation, and nitroglycerine-induced vasodilation (NID), as an index of endothelium-independent vasodilation, were measured to assess vascular function before and after a 3-month treatment with eplerenone and at 3 months after adrenalectomy in 23 patients with APA.

RESULTS

Flow-mediated vasodilation and NID after adrenalectomy were significantly higher than those before treatment with eplerenone (5.4 ± 2.6% vs 2.7 ± 1.9% and 14.8 ± 4.7% vs 9.6 ± 4.6%, P < 0.01, respectively) and those after treatment with eplerenone (5.4 ± 2.6% vs 3.1 ± 2.3% and 14.8 ± 4.7% vs 11.0 ± 5.3%, P < 0.01 and P = 0.03, respectively), while treatment with eplerenone did not alter FMD and NID compared with those before treatment with eplerenone. After adrenalectomy, the increase in FMD and NID were significantly correlated with a decrease in plasma aldosterone concentration and a decrease in the aldosterone-renin ratio. There were no significant relationships between FMD and changes in other parameters or between NID and changes in other parameters.

CONCLUSIONS

Adrenalectomy, but not treatment with eplerenone, improved vascular function in patients with APA. Adrenalectomy may be more effective than treatment with eplerenone for reducing the incidence of future cardiovascular events in patients with APA. Clinical Trial Information: URL for the clinical trial: http://UMIN; Registration Number for the clinical trial: UMIN000003409.

Pre-impaired fasting glucose state is a risk factor for endothelial dysfunction: Flow-mediated Dilation Japan (FMD-J) study

INTRODUCTION

Diabetes mellitus is associated with endothelial dysfunction. However, there is little information on the relationships of fasting blood glucose (FBG), including high normal blood glucose and impaired fasting glucose (IFG) with endothelial function. The purpose of this study was to evaluate the relationship between FBG level and flow-mediated vasodilation (FMD) using a large sample size.

RESEARCH DESIGN AND METHODS

This study was a cross-sectional study. We measured FMD in 7265 subjects at 31 general hospitals. The subjects were divided into four groups based on FBG levels: <100, 100-109, 110-125, and ≥126 mg/dL or known diabetes. The subjects were also divided into six groups based on FBG levels: <90, 90-94, 95-99, 100-109, 110-125, and ≥126 mg/dL or known diabetes.

RESULTS

FMD decreased in relation to increase in FBG level. There was a significant difference in FMD between the FBG of <100 mg/dL group and the other three groups (6.7±3.1% vs 5.9±2.8%, 5.7±3.1%, and 5.1±2.6%, respectively; p<0.001). After adjustment for confounding factors, the odds of having the lowest quartile of FMD were significantly higher in the FBG of 95-99, 100-104, 105-109, 110-125, and ≥126 mg/dL or known diabetes groups than in the FBG of the <90 mg/dL group.

CONCLUSIONS

These findings suggest that FBG of 100-109 mg/dL and FBG of 110-125 mg/dL are similarly associated with endothelial dysfunction and that a pre-IFG state (FBG of 95-99 mg/dL) is also a risk for endothelial dysfunction compared with FBG of <90 mg/dL.

TRIAL REGISTRATION NUMBER

UMIN000012950, UMIN000012951, UMIN000012952, and UMIN000003409.

Association of Body Mass Index with Endothelial Function in Asian Men

BACKGROUND

The association of body weight with cardiovascular events is still controversial. We evaluated the relationship between body mass index (BMI) and endothelial function.

METHODS

We measured flow-mediated vasodilation (FMD) and BMI in 7682 men. All participants were divided into four groups by BMI: underweight (<18.5 kg/m²), normal weight (18.5 to 24.9 kg/m²), overweight (25.0 to 29.9 kg/m²), and obesity (≥30.0 kg/m²).

RESULTS

Multiple logistic regression analysis revealed that overweight (OR: 1.30, 95% CI: 1.14-1.47; P < 0.001) and obesity (OR: 1.40, 95% CI: 1.09-1.80; P = 0.009) were associated with an increased risk of a low quartile of FMD. In 5571 younger adults (<60 years), overweight (OR: 1.34, 95% CI: 1.16-1.55; P < 0.001) and obesity (OR: 1.37, 95% CI: 1.04-1.81; P = 0.03) were associated with an increased risk of a low quartile of FMD, and underweight (OR: 0.56, 95% CI: 0.35-0.89; P = 0.01) was associated with a reduced risk of a low quartile of FMD. In 2111 older adults (≥60 years), underweight (OR: 2.16, 95% CI: 1.22-3.80; P = 0.008) was associated with an increased risk of a low quartile of FMD, and overweight and obesity were not associated with a risk of a low quartile of FMD.

CONCLUSIONS

In Asian men, endothelial function was impaired in the overweight and obesity groups compared with that in the normal weight group. The risk for endothelial dysfunction was higher in obese younger adults than in obese older adults. The association of BMI with endothelial function may be different in young and elderly men.

CLINICAL TRIAL REGISTRATION INFORMATION

http://www.umin.ac.jp (University Hospital Medical Information Network Clinical Trials Registry) (UMIN000012952).

Fluctuation of Blood Pressure in a Patient With Pheochromocytoma

Treatment with a combination of norepinephrine and doxazosin was effective in a patient with pheochromocytoma who had blood pressure fluctuation, hypotension, and recurrent syncope. After adrenalectomy, his blood pressure, heart rate, and plasma levels of catecholamines remained normal and stable without any medication. (Level of Difficulty: Beginner.)