内田 雅士

Abstract Background Neutropenia can easily progress to febrile neutropenia and is a risk factor for life-threatening infections. Predicting and preventing severe neutropenia can help avoid such infections. Aim This study aimed to develop an optimal model using advanced statistical methods to predict neutropenia after 5-fluorouracil/cisplatin chemotherapy for esophageal cancer and to create a nomogram for clinical application. Method Patients who received 5-fluorouracil/cisplatin chemotherapy at Chiba University Hospital, Japan, between January 2011 and March 2021 were included. Clinical parameters were measured before the first, second, and third chemotherapy cycles and were randomly divided by patient into a training cohort (60%) and test cohort (40%). The predictive performance of Logistic, Stepwise, Lasso, and GLMMLasso models was evaluated by the area under the receiver-operating characteristic curve (AUC). A nomogram based on GLMMLasso was developed, and the accuracy of probabilistic predictions was evaluated by the Brier score. Results The AUC for the first cycle of chemotherapy was 0.781 for GLMMLasso, 0.751 for Lasso, 0.697 for Stepwise, and 0.669 for Logistic. The respective AUCs for GLMMLasso in the second and third cycles were 0.704 and 0.900. The variables selected by GLMMLasso were cisplatin dose, 5-fluorouracil dose, use of leucovorin, sex, cholinesterase, and platelets. A nomogram predicting neutropenia was created based on each regression coefficient. The Brier score for the nomogram was 0.139. Conclusion We have developed a predictive model with high performance using GLMMLasso. Our nomogram can represent risk visually and may facilitate the assessment of the probability of chemotherapy-induced severe neutropenia in clinical practice.

Introduction. The aim of this study was to evaluate the practicality of the signal transducer and activator of transcription (STAT) 3 polymorphisms as a predictive biomarker and sorafenib trough concentration as a monitoring biomarker for hand-foot skin reaction (HFSR) in patients with hepatocellular carcinoma (HCC). Methods. In total, 43 Japanese HCC patients were included. Sorafenib concentrations were measured, if possible, on days 8, 29, 35, and 57. The sorafenib concentration on day 8 (Cday8) was used for the analysis of HFSR occurring up to day 29. The median concentration for each patient (Cmedian) was used for HFSR occurring up to day 57 (study period). The STAT3 single nucleotide polymorphism (SNP) rs4796793 was determined using cell-free DNA extracted from plasma. Result. The Cday8 tended to be higher in the HFSR onset or grade ≥ 2 HFSR severity group than in the non-HFSR or grade ≤ 1 HFSR severity group. The Cmedian was significantly higher in the HFSR onset or grade ≥ 2 group than in the non-HFSR or grade ≤ 1 HFSR group. The Cmedian thresholds for predicting HFSR onset and severity were 3.62 μg/mL and 6.10 μg/mL, respectively. There was no association between STAT3 rs4796793 and HFSR onset or severity. In multivariate analysis, Cmedian values ≥ 3.62 μg/mL and >6.10 μg/mL were associated with the increased risk of HFSR onset (odds ratio: 16.6, p < 0.01) and severity (odds ratio: 15.7, p < 0.01), respectively. Conclusion. Monitoring of the sorafenib trough concentration may be practical for avoiding HFSR.

OBJECTIVES: A marked prolongation of the prothrombin time-international normalized ratio (PT-INR) is frequently observed during biliary obstruction in patients using warfarin. The objective of this study was to identify factors associated with PT-INR prolongation during biliary obstruction in patients using warfarin. METHODS: Among 44 patients using warfarin who had biliary obstruction, we retrospectively investigated warfarin doses and laboratory data before and during biliary obstruction. The primary outcome was the association between changes in PT-INR (ΔPT-INR) and changes in laboratory data before and during biliary obstruction. RESULTS: Median PT-INR was 1.59 (IQR 1.38-1.95) before biliary obstruction and 2.27 (IQR 1.60-3.49) during biliary obstruction, indicating significant prolongation during the obstruction (P < 0.001). ΔPT-INR showed strong positive correlations with change in total bilirubin (ΔT-Bil; ρ = 0.692, P < 0.001) and change in conjugated bilirubin (ΔC-Bil; ρ = 0.731, P < 0.001). ΔPT-INR showed a weak negative correlation with the change in albumin (ΔAlb; ρ =  -0.371, P < 0.05). When ΔPT-INR was used as the dependent variable in multiple linear regression analysis, ΔT-Bil, ΔC-Bil, and ΔAlb were significantly associated with ΔPT-INR. CONCLUSIONS: PT-INR was prolonged during biliary obstruction in patients using warfarin, and changes in bilirubin levels were associated with ΔPT-INR. If biliary obstruction with markedly elevated bilirubin levels occurs, measuring PT-INR could lead to safer warfarin therapy.

<title>Abstract</title><sec> <title>Background</title> Voriconazole (VRCZ) is the first-line therapy for chronic pulmonary aspergillosis and is available in both intravenous and oral formulations. The bioavailability of the oral form is estimated to be over 90% in healthy volunteers. Some drugs are reported to interact with enteral nutrition (EN), but there are few reports about the trough levels of VRCZ during EN therapy. Here, we describe changes in the VRCZ trough levels in a patient receiving continuous EN therapy. </sec><sec> <title>Case presentation</title> The patient was a 58-year-old man with esophageal cancer and a history of partial pulmonary resection due to aspergilloma. He was taking oral VRCZ tablets and his VRCZ trough level was about 2 μg/mL before esophageal cancer surgery. Following esophagectomy, VRCZ was restarted on postoperative day 16. Crushed VRCZ tablets were administered via a jejunostomy tube because of swallowing difficulty. He was also receiving EN, which was interrupted only during the administration of VRCZ. When we checked his VRCZ level 5 days after restarting VRCZ, the trough level was 0.80 μg/mL. After increasing the VRCZ dose, reducing EN, and changing the administration route from jejunostomy tube to oral, his trough level increased to 1.87 μg/mL. </sec><sec> <title>Conclusions</title> A decrease in the VRCZ trough level was observed when VRCZ was administered via a jejunostomy tube while the patient was receiving continuous EN. Careful monitoring of VRCZ levels is needed in such cases. </sec>

<title>Abstract</title><sec> <title>Background</title> The blood concentration of cyclosporine (CyA) is frequently elevated following the transfusion of red blood cell concentrate (RCC) to patients after allogeneic hematopoietic stem cell transplantation (HSCT). The aim of this retrospective study was to identify the variable factors affecting changes in the blood concentration of CyA before and after transfusion of RCC. </sec><sec> <title>Methods</title> We enrolled 105 patients (age, 5–66 years) who received both CyA and transfusion after HSCT. The ratio of the measurement after transfusion to the measurement before transfusion was calculated for the hematocrit and blood concentration/dose ratio of CyA (termed the HCT ratio and the CyA ratio, respectively). </sec><sec> <title>Results</title> The blood concentration/dose ratio of CyA was increased after transfusion compared with before transfusion (<italic>P</italic> &lt; 0.001). The HCT ratio was significantly correlated with the CyA ratio (<italic>P</italic> = 0.23, <italic>P</italic> &lt; 0.001). The HCT ratio, concomitant medication that could elevate CyA concentration after RCC transfusion, and difference in the alkaline phosphatase level between before and after transfusion (ΔALP) were explanatory variables associated with the variation in the CyA ratio. There was no correlation between the CyA concentration after transfusion and the change in the estimated glomerular filtration rate. </sec><sec> <title>Conclusions</title> A change in the blood concentration/dose ratio of CyA was found to be associated with a change in the HCT, concomitant medication that could elevate CyA concentration after RCC transfusion, and ALP levels. If the HCT level rises significantly after RCC transfusion, clinicians and pharmacists should pay attention to changes in the blood CyA concentration. </sec>

PURPOSE: Anastomotic leakage is a potential complication after colorectal surgery. We investigated the effects of oral antibiotics and a low-residue diet on the incidence of anastomotic leakage after left-sided colorectal surgery. METHODS: Outcomes were retrospectively compared between 64 patients who underwent mechanical bowel preparation alone (group A) and 183 patients who underwent mechanical bowel preparation with addition of oral kanamycin and metronidazole (group B) on the day before left-sided colorectal surgery. After surgery, patients in group A received a normal diet containing dietary fiber and those in group B received a low-residue diet. The primary outcome was the incidence of anastomotic leakage. Secondary outcomes were rates of other postoperative complications, length of postoperative hospital stay, and laboratory data. RESULTS: Anastomotic leakage, surgical site infection, and diarrhea were less common in group B than in group A (4.9% vs 18.8%, 6.6% vs 23.4%, and 25.7% vs 43.8%, respectively). Postoperative C-reactive protein levels were significantly lower in group B. The median postoperative hospital stay was significantly shorter in group B than in group A (8 days vs 9 days, P = 0.010). Adaptive double least absolute shrinkage and selection operator regression revealed that use of preoperative oral antibiotics and a postoperative low-residue diet were associated with lower incidence of anastomotic leakage (odds ratio 0.163, 95% confidence interval 0.062-0.430; P < 0.001). CONCLUSION: Oral antibiotics and a low-residue diet reduced the incidence of anastomotic leakage and shortened the postoperative hospital stay by 1 day.

BACKGROUND: Vancomycin (VCM) is eliminated mainly by diafiltration under continuous hemodiafiltration (CHDF), but the contribution of adsorption to CHDF clearance (CLCHDF ) of VCM using a polyacrylonitrile and sodium methallyl sulfonate copolymer membrane coated with polyethylenimine (AN69ST) or a polymethylmethacrylate (PMMA) membrane is unknown. This study sought to investigate the contribution of diafiltration and adsorption to the CLCHDF of VCM using AN69ST and PMMA membranes in vitro. METHODS: An in vitro CHDF circuit model was developed. The initial concentration of VCM was 50 μg/mL and human serum albumin (HSA) was prepared at a concentration of 0, 2.5, or 5.0 g/dL. The effluent flow rate (Qe) was set at 800, 1500, or 3000 mL/h. The CLCHDF , diafiltration rate, and adsorption rate of VCM were calculated. RESULTS: Total CLCHDF of VCM using the AN69ST membrane increased and decreased with increasing Qe and HSA concentration, respectively. Diafiltration and adsorption rates were 82.1 ± 9.8% and 12.1 ± 6.1% under all conditions, respectively. Total CLCHDF using the PMMA membrane increased with increasing Qe. Diafiltration and adsorption rates were 89.2 ± 20.4% and 4.6 ± 17.0% under all conditions, respectively. The observed CLCHDF values significantly correlated with the predicted CLCHDF , calculated according to a previous study as the product of Qe and the plasma unbound fraction. CONCLUSIONS: Diafiltration predominantly contributed to CLCHDF of VCM using AN69ST and PMMA membranes. When diafiltration rather than adsorption mainly contributes to the CLCHDF of VCM, the CLCHDF could be predicted from the Qe and HSA concentration, at least in vitro.

Vancomycin (VM) is used as empirical therapy for bacterial meningitis (BM). We investigated the relationship of the microbiological efficacy of VM for BM with VM minimum inhibitory concentration (MICVM), serum VM trough concentration (VMser) and cerebrospinal fluid (CSF) protein (P)/serum albumin (SA) ratio, which may reflect the extent of blood-brain barrier (BBB) disruption. Twelve BM patients were enrolled and VM was microbiologically effective in seven (58.3%). VMser, MICVM, and CSF-P/SA ratio were not associated with the microbiological efficacy of VM. The microbiological efficacy of VM was significantly associated with CSF-P/SA ratio multiplied by VMser relative to the MICVM (η = 0.61, p = 0.04). These results indicate that the parameter combining VMser, MICVM, and the extent of BBB disruption could be associated with the microbiological efficacy of VM in BM patients.

INTRODUCTION: The purpose of this study was to explore factors influencing meropenem pharmacokinetics (PKs) in critically ill patients by developing a population PK model and to determine the optimal dosing strategy. METHODS: This prospective observational study involved 12 critically ill patients admitted to the intensive care unit and treated with meropenem 1 g infused over 1 h every 8 h. Blood samples were collected on days 1, 2, and 5 immediately prior to dosing, and at 1, 2, 4, and 6 h after the start of infusion. Population PK parameters were estimated using nonlinear mixed-effects model software. RESULTS: Meropenem PK was adequately described using a two-compartment model. Typical values of total and inter-compartmental clearance were 9.30 L/h and 9.70 L/h, respectively, and the central and peripheral compartment volumes of distribution were 12.61 L and 7.80 L, respectively. C-reactive protein (CRP) was identified as significant covariate affecting total meropenem clearance. The probability of target attainment (PTA) predicted by Monte Carlo simulations varied according to the patients' CRP. The PTA of 100% time above the minimum inhibitory concentration ≤2 mg/L for bacteria was achieved after a dose of 1 and 2 g infused over 4 h every 8 h in patients with CRP of 30 and 5 mg/dL, respectively. CONCLUSION: The findings of this study suggest that CRP might be helpful in managing meropenem dosing in critically ill patients. Higher doses and extended infusion may be required to achieve optimal pharmacodynamic targets.

We have reported that acrolein-conjugated low-density lipoprotein (Acro-LDL) uptake by scavenger receptor class A type 1 (SR-A1) can mediate macrophage foam cell formation. The purpose of this study was to determine which amino acid residues of apoB protein in LDL are conjugated with acrolein. Acro-apoB was prepared by incubation of LDL with acrolein (10 to 60 μM) at 37 °C for 7 days. Identification of acrolein-conjugated amino acid residues in apoB was performed using LC-MS/MS. The levels of acrolein-conjugated amino acid residues of apoB as well as crosslinking apoB increased in proportion to acrolein concentration. The level of LDL uptake by macrophages was parallel with the acrolein-conjugated monomer apoB. Acrolein-conjugated amino acid residues in apoB were C212, K327, K742, K949, K1087, H1923, K2634, K3237 and K3846. The NH2-teriminal four amino acid residues (C212, K327, K742 and K949) were located at the scavenger receptor SR-A1 recognition site, suggesting that these four acrolein-conjugated amino acids are involved in the rapid uptake of Acro-LDL by macrophages. It is proposed that the rapid uptake of LDL by macrophages is dependent on acrolein conjugation of four amino acids residues at the scavenger receptor recognition site of apoB in LDL.

<title>Abstract</title><sec> <title>Background</title> Generic drugs are heavily promoted in Japan. The aim of this retrospective single-center study was to clarify whether the frequency and reason that patients request a switch from a generic drug to the original drug differ according to therapeutic category and dosage form. </sec><sec> <title>Methods</title> This study was performed at Chiba University Hospital. Prescription inquiries about 121 generic drugs from community pharmacies over a 3-year period (from July 2014 to June 2017) were analyzed. </sec><sec> <title>Results</title> Approximately 30% of the requests were related to the efficacy, safety, and comfort of the generic drug. The most cited motive was “patient’s desire with no reason given” at 44.5%. According to multiple logistic regression analysis, therapeutic categories and dosage forms were associated with the requests. The median request frequency differed according to therapeutic category and dosage form. The frequency was highest for “agents affecting the central nervous system” and “tablets and capsules”, respectively. Among the therapeutic categories, “agents affecting the central nervous system” had the highest median number of requests related to “decreased effectiveness”; “cardiovascular agents” had the highest median number of requests related to “physician’s instruction”; and “agents for the epidermis” had the highest median number of requests related to “uncomfortable to use”. Among dosage forms, the odds ratio for patients’ original drug request for “liniment and patch” was about 1.5 times that for “tablets and capsules”. “Liniment and patch” had the highest median frequency of requests related to “decreased effectiveness”, “uncomfortable to use”, and “patient’s desire with no reason given”. </sec><sec> <title>Conclusions</title> The request frequency and reason differed according to therapeutic category and dosage form. Pharmacists should advise each patient properly about the choice and switching of drug brands, taking into account the therapeutic category and dosage form, especially liniments and patches. </sec>

千葉大学医学部附属病院では2016年4月から病院薬局製剤(以下、院内製剤)の使用患者の調査と医師による有効性および安全性の評価を行っている。本研究では2018年12月までを対象に院内製剤のクラス分類、投与経路、診療科、管理方法と有効性および安全性評価の実施の関連を明らかにすることを目的とした。全体の74.9%の製剤に対し有効性および安全性の評価が行われていた。クラス分類、投与経路、診療科、管理方法により評価実施率は異なった。いずれの因子も評価の実施との関連がみられたが、因子間の関連が強く各因子の影響の大きさは不明だった。しかし、使用患者の事前把握やストックの有無、分割使用といった管理方法とそれらの組み合わせが影響する可能性が示されたことから、院内製剤の有効性および安全性評価を実施するために、薬剤師は主体的に管理体制構築にかかわる必要があると考えられた。(著者抄録)

WHAT IS KNOWN AND OBJECTIVE: Vitamin K deficiency is known to cause impaired coagulation. We report a case of marked prolongation of the prothrombin time-international normalized ratio (PT-INR) associated with warfarin and vitamin K deficiency caused by endoscopic nasobiliary drainage (ENBD). CASE PRESENTATION: Oral administration of warfarin was initiated in a 67-year-old man after left hemihepatectomy. He developed a biliary fistula after surgery that was treated by ENBD, which resulted in significant prolongation of the PT-INR. WHAT IS NEW AND CONCLUSION: The effect of warfarin was enhanced in this patient due to reduced absorption of vitamin K as a result of external biliary drainage.

Background Elevated blood concentration of tacrolimus is frequently observed following transfusion of red blood cell concentrate in patients after allogeneic hematopoietic stem cell transplantation. Objective The aim of this retrospective study was to clarify the effects of transfusion of red blood cell concentrate on the blood concentration of tacrolimus. Setting Chiba University Hospital in Japan. Method Fifty-two patients (aged 0-65 years) receiving both tacrolimus and transfusion after allogeneic hematopoietic stem cell transplantation were enrolled. The ratio of measurement after transfusion to measurement before transfusion was calculated for hematocrit and blood concentration/dose ratio of tacrolimus (termed the hematocrit ratio and the tacrolimus ratio, respectively). Main outcome measure Change in blood concentration/dose ratio of tacrolimus and variable factors associated with variation in tacrolimus ratio. Results The blood concentration/dose ratio of tacrolimus was increased after transfusion compared with before transfusion (p < 0.001). A statistically significant correlation was seen between the hematocrit ratio and tacrolimus ratio (r = 0.32, p < 0.001). Hematocrit ratio, age or body surface area, and difference in aspartate aminotransferase level before and after transfusion were associated with the variation in tacrolimus ratio. There was no correlation between tacrolimus ratio and change in serum creatinine or potassium level in the short term. Conclusion Change in the blood concentration/dose ratio of tacrolimus was associated with change in the hematocrit ratio after transfusion, and more attention is required for children or patients with small body surface area. Dose adjustment of tacrolimus is required if the blood concentration of tacrolimus is much higher than the target concentration.

BACKGROUND: Although continuous hemodiafiltration (CHDF) is often performed in critically ill patients during sepsis treatment, the pharmacokinetics of vancomycin (VCM) during CHDF with a polymethylmethacrylate hemofilter (PMMA-CHDF) have not been revealed. In this study, the authors aimed to describe the population pharmacokinetics of VCM in critically ill patients undergoing PMMA-CHDF and clarify its hemofilter clearance (CLhemofilter). METHODS: This single-center, retrospective study enrolled patients who underwent intravenous VCM therapy during PMMA-CHDF at the intensive care unit of Chiba University Hospital between 2008 and 2016. A population analysis was performed, and CLhemofilter was assessed. RESULTS: Twenty-five patients were enrolled. Median body weight (BW) and Sequential Organ Failure Assessment (SOFA) score were 63 kg and 15, respectively. Mean conditions for CHDF were 107.5 ± 18.3 mL/min for blood flow rate and 26.3 ± 6.3 mL/kg/h for effluent flow rate. The mean parameter estimates were distribution volume of the central compartment (V1), 59.1 L; clearance of the central compartment (CL1), 1.35 L/h; distribution volume of the peripheral compartment (V2), 56.1 L; and clearance of the peripheral compartment (CL2), 3.65 L/h. BW and SOFA score were significantly associated with V1 (P < 0.05) and CL1 (P < 0.05), respectively, and were thus selected as covariates in the final model. The estimated dosage of VCM to achieve a target area under the concentration-time curve/minimum inhibitory concentration ≥400 was 27.1 mg/kg for loading and 9.7 mg/kg every 24 hours for maintenance; these dosages were affected by BW and SOFA score. Mean CLhemofilter obtained from 8 patients was 1.35 L/h, which was similar to CL1. CONCLUSIONS: The authors clarified the pharmacokinetics and CLhemofilter of VCM in PMMA-CHDF patients. The PK of VCM in patients undergoing CHDF appeared to vary not only with the CHDF setting and BW but also with SOFA score.

Bacterial meningitis is a life-threatening condition. Vancomycin (VCM) is one of the antibiotics used as empirical therapy for bacterial meningitis. It is essential to maintain an adequate concentration of VCM in cerebrospinal fluid (CSF) to treat bacterial meningitis effectively. VCM administered intravenously must pass the blood-brain barrier (BBB) to enter the CSF and the extent of VCM penetration into CSF varies widely among patients. Previous report indicated that CSF albumin level is useful for estimation of VCM CSF penetration. However, CSF albumin level is not measured in routine practice. We focused on CSF protein concentration that is generally examined at the beginning of diagnosis and treatment of bacterial meningitis. We examined the relationship between CSF protein concentration/serum albumin ratio and the extent of VCM penetration into CSF. This retrospective study involved 7 patients admitted to our hospital who were treated with VCM for suspected bacterial meningitis. The VCM concentrations in serum and CSF were 17.6 ± 7.2 μg/mL and 3.31 ± 3.14 μg/mL, respectively. The serum VCM concentrations showed no significant correlation with CSF VCM concentrations. On the other hand, the protein concentration in CSF/serum albumin ratio showed a strong positive correlation with the VCM CSF/serum ratio (r = 0.877, p < 0.005). Our study indicates that the ratio of CSF protein concentration/serum albumin is likely useful for estimating the approximate VCM CSF/serum ratio. This could contribute to an improvement in the treatment of bacterial meningitis.

INTRODUCTION: Dyslipidemia is one of the onset and risk factors of chronic kidney disease and renal function drop is seen in lipoprotein abnormal animal models. However, the detailed molecular mechanism of renal lipotoxicity has not been clarified. Therefore, the present study aimed to investigate the influence of cholesterol overload using mouse kidney tissue and kidney-derived cultured cells. METHODS: C57BL/6 mice were fed normal diet (ND) or 1.25% cholesterol-containing high-cholesterol diet (HCD) for 11 weeks, and we used megalin as a proximal tubule marker for immunohistology. We added beta-very low density lipoprotein (βVLDL) to kidney-derived cells and examined the effect of cholesterol overload on megalin protein and mRNA expression level, cell proliferation and cholesterol content in cells. RESULTS: In the kidney of HCD mice, the gap between glomerulus and the surrounding Bowman's capsule decreased and the expression level of megalin decreased. After βVLDL treatment to the cells, the protein expression and mRNA expression level of megalin decreased and cell proliferation was restrained. We also observed an increase in cholesterol accumulation in the cell and free cholesterol/phospholipid ratios increased. CONCLUSIONS: These findings suggest that the increased cholesterol load on kidney contribute to the decrease of megalin and the overloaded cholesterol is taken into the renal tubule epithelial cells, causing suppression on cell proliferation, which may be the cause of kidney damage.

千葉大学医学部附属病院では院外処方せんに関する問い合わせは薬剤部医薬品情報(DI)室を介して実施している。保険薬局からの問い合わせのうち約90%は医師に照会を行っているが、形式的に医師に確認をとる程度の軽微な内容も多く、医師・患者・保険薬局の負担となっていた。そこで、11項目の問い合わせ内容について問い合わせの受付時に医師に照会を行わず薬剤師の判断で対応するプロトコルを作成し、医師の合意の下、運用を開始した。プロトコル導入後、医師に照会することなく対応した問い合わせは全体の31.1%であり医師に照会した件数は11件/日減少した。医師への疑義照会の所要時間は中央値3.5分(値域1〜237分)であり、保険薬局・患者の待ち時間が短縮される事例があると考えられた。よってプロトコルに基づく運用は有用だと考えられた。(著者抄録)

The proliferation of vascular smooth muscle cells (SMCs) causes restenosis in biomaterial vascular grafts. The purposes of this study were to establish a suspension culture system for SMCs by using a novel substrate, low-acyl gellan gum (GG) and to maintain SMCs in a state of growth inhibition. When SMCs were cultured in suspension with GG, their proliferation was inhibited. Their viability was 70% at day 2, which was maintained at more than 50% until day 5. In contrast, the viability of cells cultured in suspension without GG was 5.6% at day 2. By cell cycle analysis, the ratio of SMCs in the S phase when cultured in suspension with GG was lower than when cultured on plastic plates. In SMCs cultured in suspension with GG, the ratio of phosphorylated retinoblastoma (Rb) protein to Rb protein was decreased and p27(Kip1) expression was unchanged in comparison with SMCs cultured on plastic plates. In addition, SMCs could be induced to proliferate again by changing the culture condition from suspension with GG to plastic plates. These results suggest that our established culturing method for SMCs is useful to maintain SMCs in a state of growth inhibition with high viability.

Protein-conjugated acrolein (PC-Acro) is detected in atherosclerotic lesions, and we demonstrated previously that acrolein-conjugated low-density lipoproteins induce macrophage foam cell formation. Although it has been suggested that beta-migrating very low-density lipoprotein (beta VLDL) is taken up by macrophages during atherogenesis, the modification of beta VLDL with acrolein and its localization on lesions are still unclear. The purpose of this study was to clarify the localization of PC-Acro in atherosclerotic lesions and to determine the role of acrolein-conjugated beta VLDL in atherogenesis. Male New Zealand white rabbits were fed 0.5% cholesterol-containing rabbit chow for 8 weeks, and used as an animal model of atherosclerosis. PC-Acro and malondialdehyde (MDA)-conjugated protein levels, which has been used widely as a means to detect oxidized low-density lipoprotein (LDL), in plasma were increased in the 0.5% cholesterol-containing diet-induced animal model of atherosclerosis, whereas their level was unchanged in the control diet fed rabbit. PC-Acro was detected in beta VLDL by western blot analysis, and acrolein-conjugated beta VLDL was effectively taken up by THP-1 macrophages. By immunohistochemical analysis, PC-Acro and macrophages were detected at the internal elastic lamina of the aorta, which was the initial lesion of atherosclerosis. These results suggest that acrolein-conjugated beta VLDL has an important role in the initiation of atherosclerosis via the induction of macrophage foam cell formation in the atherosclerotic lesion.

The proliferation of vascular smooth muscle cells (SMCs) contributes to atherosclerotic plaque formation and restenosis. Cyclin-dependent kinase inhibitors, such as p27(Kip1) and p21(Cip1), are known to play significant roles in the control of the aberrant proliferation of SMCs. Primary cultured SMCs stop proliferating immediately when cultured in three-dimensional matrices of type-I collagen "honeycombs" structures. To clarify whether p27(Kip1) and p21(Cip1) are involved in the proliferative inhibition of SMCs cultured in honeycombs, the characteristics of SMCs derived from the aorta of both wild-type mice (p27[+/+] SMCs) and p27(Kip1) knockout mice (p27[-/-] SMCs) were investigated. Although the growth of p27(-/-) SMCs cultured on plates was faster than that of p27(+/+) SMCs, the number of both p27(+/+) and p27(-/-) SMCs did not change when they were cultured in honeycombs. p21(Cip1) expression was decreased but maintained in p27(-/-) SMCs cultured on plates and in honeycombs. Knockdown of p21(Cip1) in p27(-/-) SMCs promoted proliferation on plates. On the contrary, p21(Cip1) knockdown had no effect on the proliferation of p27(-/-) SMCs cultured in honeycombs. In conclusion, p271(Kip1) and p21(Cip1) are insufficient for the proliferative inhibition of SMCs cultured in honeycombs. (C) 2015 Elsevier Inc. All rights reserved.

Vascular smooth muscle cells (SMC) are able to proliferate when cultured on plates, but become differentiated when maintained in three-dimensional type I collagen matrices (honeycombs). SMC grown in honeycombs contained a low level of polyamines due to the presence of antizyme 1 (AZ1), a negative regulator of ornithine decarboxylase (ODC) and of polyamine uptake. To clarify the role of AZ1 in differentiation of SMC in honeycombs, an ODC gene was stably transfected into SMC (ODC-SMC). Although proliferation of ODC-SMC on plates was accelerated together with an increase in phosphorylated focal adhesion kinase (FAK) and a decrease in alpha-actin and myosin, maker proteins of differentiation, growth of ODC-SMC ceased in honeycombs similarly to normal SMC with a low level of phosphorylated FAK and a high level of alpha-actin and myosin. AZ1 expression in ODC-SMC on plates was low, but that in honeycombs was high. Antizyme in ODC-SMC in honeycombs not only decreased the level of ODC but also inhibited polyamine uptake activity. These results taken together suggest that low levels of polyamines caused by AZ1 in SMC in honeycombs inhibit phosphorylation of FAK and enhance expression of alpha-actin and myosin, resulting in differentiation through inhibition of focal adhesions.

Background: Dedifferentiated rabbit vascular smooth muscle cells (SMCs) exhibit similar features to differentiated SMCs when cultured in three-dimensional matrices of type-I collagen called "honeycombs," but the mechanism is unknown. The role of filamin, an actin-binding protein that links actin filaments in SMCs, was investigated. Methods: Filamin and other related proteins were detected by western blot analysis and immunofluorescence staining. Honeycomb size was measured to confirm the contraction of SMCs. Results: Full-length filamin was expressed in subconfluent SMCs cultured on plates; however, degradation of filamin, which might be regulated by calpain, was observed in confluent SMCs cultured on plates and in honeycombs. While filamin was co-localized with beta-actin in subconfluent SMCs grown on plates, filamin was detected in the cytoplasm in SMCs cultured in honeycombs, and degraded filamin was mainly detected in the cytoplasmic fraction of these cells. In addition, beta-actin expression was low in the cytoskeletal fraction of SMCs cultured in honeycombs compared with cells cultured on plates, and the size of the honeycombs used for culturing SMCs was significantly reduced. Conclusion: These data suggest that degradation of filamin in SMCs cultured in honeycombs induces structural weakness of beta-non-muscle actin filaments, thereby permitting SMCs in honeycombs to achieve contractility. Copyright (C) 2011 S. Karger AG, Basel

AIM: Kefiran is an exopolysaccharide produced by Lactobacillus kefiranofaciens, and has been proposed to have many health-promoting properties. We investigated the antiatherogenic effect of kefiran on rabbits fed a high-cholesterol diet. METHODS: Male New Zealand White rabbits were fed a 0.5% cholesterol diet without (control group, n = 7) or with kefiran (kefiran group, n = 8) for eight weeks. The aorta was analyzed by histochemistry and atherosclerotic lesions were quantified. Lipids and sugars in serum were measured. Foam cell formation of RAW264.7 by βVLDL derived from both groups of rabbits was also investigated. RESULTS: Cholesterol, triglyceride and phospholipids levels of serum and lipoprotein fractions were not significantly different between these groups. Atherosclerotic lesions of the aorta in the kefiran group were statistically lower than those of the control group, with marked differences in the abdominal aorta. T-lymphocytes were not detectable in the aorta of the kefiran group. Cholesterol contents in stools were almost identical in both groups. Cholesterol content in the liver of the kefiran group was statistically lower than in the control group. Galactose content of βVLDL derived from the kefiran group was higher, and the lipid peroxidation level was much lower than in the control group. RAW264.7 macrophages treated with βVLDL from the kefiran group showed a more spherical shape and accumulated statistically lower cholesterol than macrophages treated with βVLDL from the control group. CONCLUSION: Orally derived kefiran is absorbed in the blood. Kefiran prevents the onset and development of atherosclerosis in hypercholesterolemic rabbits by anti-inflammatory and anti-oxidant actions.