Intraoperative serum lactate levels as a prognostic predictor of outcome for emergency abdominal surgery: a retrospective study.

BACKGROUND: The relationship between intraoperative lactate levels and prognosis after emergency gastrointestinal surgery remains unclear. The purpose of this study was to investigate the prognostic value of intraoperative lactate levels for predicting in-hospital mortality, and to examine intraoperative hemodynamic managements. METHODS: We conducted a retrospective observational study of emergency GI surgeries performed at our institution between 2011 and 2020. The study group comprised patients admitted to intensive care units postoperatively, and whose intraoperative and postoperative lactate levels were available. Intraoperative peak lactate levels (intra-LACs) were selected for analysis, and in-hospital mortality was set as the primary outcome. The prognostic value of intra-LAC was assessed using logistic regression and receiver operating characteristic (ROC) curve analysis. RESULTS: Of the 551 patients included in the study, 120 died postoperatively. Intra-LAC in the group who survived and the group that died was 1.80 [interquartile range [IQR], 1.19-3.01] mmol/L and 4.22 [IQR, 2.15-7.13] mmol/L (P < 0.001), respectively. Patients who died had larger volumes of red blood cell (RBC) transfusions and fluid administration, and were administered higher doses of vasoactive drugs. Logistic regression analysis showed that intra-LAC was an independent predictor of postoperative mortality (odds ratio [OR] 1.210, 95% CI 1.070 -1.360, P = 0.002). The volume of RBCs, fluids transfused, and the amount of vasoactive agents administered were not independent predictors. The area under the curve (AUC) of the ROC curve for intra-LAC for in-hospital mortality was 0.762 (95% confidence interval [CI], 0.711-0.812), with a cutoff value of 3.68 mmol/L by Youden index. CONCLUSIONS: Intraoperative lactate levels, but not hemodynamic management, were independently associated with increased in-hospital mortality after emergency GI surgery.

Development of glomerular hyperfiltration, a multiphasic phenomenon.

The trajectory of glomerular filtration rate (GFR) in relation to glomerular hyperfiltration (GHF) has been unknown. It was evaluated retrospectively in 23,982 GHF-free health examinees who were followed for 2-10 yr (mean: 5.1 yr). GFR was estimated by the serum creatinine concentration, and GHF was defined as age- and sex-specific estimated GFR (eGFR) ≥ 95% of the Japanese general population. The temporal profile of eGFR was plotted in a GHF-centered way, which was fitted to a random coefficient linear mixed model. Of the 23,982 subjects, 797 and 23,185 subjects developed or did not develop GHF, respectively, so that they were termed as the GHF(+) and GHF(-) groups. At baseline, median eGFR was significantly elevated in the GHF(+) group compared with in the GHF(-) group: 94.1 versus 77.3 mL/min/1.73 m2 (P < 0.001). Elevation of basal eGFR lasted for a mean (SD) of 3.3 (1.9) yr in the GHF(+) group; mean eGFR then rose to the GHF range, which was 108.5 mL/min/1.73 m2. The eGFR decline after the peak was steeper in the GHF(+) group than in the GHF(-) group: -0.984 versus -0.497 mL/min/1.73 m2/yr (P < 0.001). Baseline eGFR, but no other variable, well predicted incident GHF, with an area under the receiver operating characteristic curve of 0.87 (95% confidence interval: 0.86-0.88). In conclusion, GHF occurs as a chronic, multiphasic phenomenon: initially with a sustained GFR elevation for years, followed by a GFR surge to the GHF range, which was accompanied by accelerated GFR declining.

Postchallenge hyperglycemia in subjects with low body weight: implication for small glucose volume.

A hypothesis that postchallenge hyperglycemia in subjects with low body weight (BW) may be due, in part, to small glucose volume (GV) was tested. We studied 11,411 nondiabetic subjects with a mean BW of 63.3 kg; 5,282 of them were followed for a mean of 5.3 yr. In another group of 1,537 nondiabetic subjects, insulin sensitivity, secretion, and a product of the two (index of whole body insulin action) were determined. Corrected 2 h-plasma glucose (2hPGcorr) during a 75-g oral glucose tolerance test in subjects with BW ≤ 59 kg was calculated as 2hPGcorr = δPG2h · ECW/[16.1 (males) or 15.3 (females)] + fasting PG (FPG), where δPG2h is plasma glucose increment in 2 h; ECW is extracellular water (surrogate of GV); FPG is fasting plasma glucose; and 16.1 and 15.3 are ECW of men and women, respectively, with BW = 59 kg. Multivariate analyses for BW with adjustment for age, sex, and percent body fat were undertaken. BW was, across its entire range, positively correlated with FPG (P < 0.01). Whereas BW was correlated with 2hPG and δPG in a skewed J-shape, with inflections at around 60 kg (P for nonlinearity < 0.01 for each). Nonetheless, in those with BW ≤ 59 kg, insulin sensitivity, secretion, and action were unattenuated, and incident diabetes was less compared with heavier counterparts. BW was linearly correlated with 2hPGcorr, i.e., the J-shape correlation was mitigated by the correction. In conclusion, postchallenge hyperglycemia in low BW subjects is in part due to small GV rather than impaired glucose metabolism.

[Successful Resuscitation Using Percutaneous Cardiopulmonary Support in a Woman with Acute Heart Failure during a Thyroid Storm].

Thyroid storm is a rare, life-threatening condition characterized by severe manifestations of thyrotoxico- sis. Acute heart failure is one of the well-known com- plications of thyrotoxicosis. Thyrotoxicosis-induced heart failure sometimes causes circulatory collapse with high mortality. A 43-year-old woman had palpitations and exertional dyspnea without medical history. She developed con- gestive heart failure, due to tachycardiac atrial fibrilla- tion with no acute ischemic changes. High serum level of FT3 and FT4, and low level of TSH were shown in thyroid function tests, and thyromegaly in carotid ultrasound test She was admitted to the intensive care unit for acute heart failure caused by thyroid storm. Two days after admission, cardiopulmonary resuscitation and endotracheal intubation were necessary due to sudden cardiac arrest Transthoracic echocardiogram showed normal cardiac function after successful resuscitation. Five days after admission, her condition deteriorated with severe cardiac dysfunction, and she received PCPS (percutaneous cardiopulmonary support) for cardiovascular collapse resulting in persistent tachy- cardiac atrial fibrillation. Ten days after initiation of PCPS, the patient's cardiovascular function improved with estimated left ventricular ejection fraction of 50 percent and she was weaned off PCPS. In the case of acute heart failure with untreated hyperthyroid and refractory atrial fibrillation, careful hemodynamic management is required to avoid cardio- vascular collapse.

Femoral nerve block-sciatic nerve block vs. femoral nerve block-local infiltration analgesia for total knee arthroplasty: a randomized controlled trial.

BACKGROUND: The use of femoral nerve block (FNB) combined with sciatic nerve block (SNB) after total knee arthroplasty (TKA) has recently become controversial. Local infiltration analgesia (LIA) has been reported to be effective for postoperative TKA pain control. We aimed to assess whether LIA with continuous FNB is as effective as SNB combined with continuous FNB. METHODS: This was a prospective, randomized, single-center, observer-blinded, parallel group comparison trial of 34 American Society of Anesthesiologists (ASA) physical status 1-3 patients who underwent TKA and fulfilled the inclusion and exclusion criteria. Patients were randomized into two groups: a periarticular LIA and FNB group (group L, n = 17), and an SNB and FNB group (group S, n = 17). In both groups, participants received FNB with 20 mL of 0.375% ropivacaine, and 5 mL h(-1) of 0.2% ropivacaine after surgery. In group L, participants received 100-ml injections of 0.2% ropivacaine and 0.5 mg epinephrine to the surgical region. In group S, participants received SNB with 20 ml of 0.375% ropivacaine. After TKA, Numeric Rating Scale (NRS) scores for the first 24 h post-operation were compared via repeated-measures analysis of variance (ANOVA) as the primary outcome. Other outcome measures included NRS score changes within groups, area under the curve for the NRS scores, total analgesic dose, change in knee flexion and extension, pain control satisfaction, nausea and vomiting, and hospital stay duration. RESULTS: NRS score changes were greater in group L than in group S (P < 0.01, ANOVA) and greater in group L than in group S at three postoperative time points: 3 h (P < 0.01), 6 h (P < 0.01), and 12 h (P = 0.013; Mann-Whitney U test). Changes in the mean NRS score were observed in each group (P < 0.01, Friedman test). No significant differences were detected in the other outcome measures (Mann-Whitney U, Wilcoxon signed-rank, and chi-squared tests). CONCLUSIONS: Sciatic nerve block with femoral nerve block is superior to local anesthetic infiltration with femoral nerve block for postoperative pain control within 3-12 h of total knee arthroplasty. TRIAL REGISTRATION: UMIN-CTR ID: 000013364 R: 000015591.

[Perioperative Management of Emergency Gastrointestinal Surgery in a Patient with Left Ventricular Non-compaction].

Left ventricular non-compaction (LVNC) is a rare congenital cardiomyopathy characterized by heart failure, arrhythmia, and embolic events. A 65-year-old man, previously diagnosed as LVNC, was admitted to the emergency department with severe abdominal pain. He was diagnosed as appendicitis and treated conservatively with antibiotics. The echocardiogram examination showed left ventricular ejection fraction of less than 25%, and his B-type natriuretic peptide assay was > 5,000 pg x ml(-1) on admission. Ten days after admission, he underwent emergency surgery for suspected perforation of vermiform appendix. Transesophageal echocardiography (TEE) was used for real-time evaluation of cardiac function and restrictive fluid management during surgery. He was transferred to intensive care unit (ICU) for postoperative care, and extubated 16 hours after surgery. On the third postoperative day, he was discharged from ICU without any complications. We consider that perioperative hemodynamic management with TEE may be useful for gastrointestinal tract surgeries in patients with severe cardiac disease, such as LVNC.

Hemoglobin Glycation Index: A Novel Risk Factor for Incident Chronic Kidney Disease in an Apparently Healthy Population.

CONTEXT: Chronic kidney disease (CKD) is a worldwide health problem. Recent literature has shown an association of hemoglobin glycation index (HGI) and CKD in patients with dysglycemia. OBJECTIVE: The aim of this study was to reveal the impact of HGI as a predictor for incident CKD in the general population. METHODS: CKD was defined as dipstick proteinuria or estimated glomerular rate (eGFR) < 60 mL/min/1.73 m2. Impact of HGI on incident CKD was assessed using the data from CKD-free health examinees (N = 23 467, 4.1% with diabetes) followed for a mean of 5.1 years: Cox proportional hazards model was employed with multivariate adjustment for age, systolic blood pressure, eGFR, fasting plasma glucose, body mass index, log[alanine aminotransferase], log[triglycerides], high-density lipoprotein cholesterol, platelet counts, smoking, and sex. Elevated level of HGI in subjects with CKD was ascertained after propensity score matching of another group of health examinees (N = 2580, 7.6% with diabetes). RESULTS: In the former group, CKD developed in 2540 subjects and HGI was the second most robust predictor for CKD, following low eGFR. With adjustment for the 11 covariates, the hazard ratio of HGI (95% CI) for CKD was 1.293 (1.238 to 1.349) (P < .0001). The population attributable risk of HGI for CKD was 4.2%. In the latter group, among 708 subjects matched 1:1 for 9 covariates, HGI was significantly elevated in subjects with CKD (median [interquartile range] -0.208 [-0.504 to -0.156] vs -0.284 [-0.582 to 0.052], P = .03). CONCLUSION: HGI was a novel risk factor for CKD in the general population.

ExcA proteins of IncI1 plasmid R64 and IncIγ plasmid R621a recognize different segments of their cognate TraY proteins in entry exclusion.

Entry exclusion is a process whereby plasmid transfer between donor and recipient cells harboring identical or closely related conjugative plasmids is inhibited. Exclusion proteins in the recipient cells are responsible for entry exclusion. Although IncI1 Plasmid R64 and IncIγ plasmid R621a exhibit similar genome structure in replication, transfer, and leading regions, they belong to different incompatibility and exclusion groups. The amino acid sequences of TraY and ExcA proteins are significantly different between R64 and R621a. In the present study, TraY proteins of R64 and R621a were exchanged. Transfer of R64 derivative carrying R621a TraY was inhibited by recipient R621a ExcA but not R64 ExcA and transfer of R621a derivative carrying R64 TraY was inhibited by recipient R64 ExcA but not R621a ExcA. This indicates that R64 and R621a TraY proteins in the donor cells are the targets of cognate ExcA proteins in the recipient proteins. Since two segments, an internal and a C-terminal segment, were found to vary between R64 and R621a TraY proteins, various chimera TraY proteins were constructed. Conjugation experiments suggested that the R64 internal variable segment recognizes R64 ExcA protein and the R621a C-terminal variable segment recognizes R621a ExcA protein.

Enrichment of membrane curvature-sensing proteins from Escherichia coli using spherical supported lipid bilayers.

Bacteria display dynamically organized curved membrane structures, especially during cell division. The importance of membrane curvature-sensing (MCS) proteins for the recognition and regulation of biological membrane morphologies has predominately been investigated in eukaryotic cells. Recently, a technique for screening MCS proteins from solutions that contain peripheral membrane proteins was developed, and MCS protein candidates were identified from mammalian cells. The technique uses differently sized spherical supported lipid bilayers (SSLBs), which consist of spherical SiO2 particles covered with a lipid bilayer. To discriminate between proteins possessing the MCS property, SSLBs with the same surface area were used in a comparative sedimentation assay with shotgun proteome analysis. In this study, to prove that the technique could be applied to other samples, MCS proteins in Escherichia coli were investigated. Through a comparative proteomic study, 35 and 47 proteins were enriched as candidate MCS proteins preferentially bound to SSLBs of 100 nm and 1000 nm, respectively. Among the identified MCS candidate proteins, FtsZ and SecA were further examined for their MCS properties using the two SSLB sizes, which revealed a high binding affinity for the low membrane curvature (large SSLB). This is the first study to explore MCS proteins in prokaryotic cells and the MCS property of the SecA protein. The results demonstrate a method to enrich MCS proteins that could be utilized to better elucidate membrane dynamics and protein function expression on curved membrane structures in prokaryotic cells.

Hepatic Steatosis and High-Normal Fasting Glucose as Risk Factors for Incident Prediabetes.

Context: The role of hepatic steatosis (HS) in the initial stages of developing type 2 diabetes remains unclear. Objective: We aimed to clarify the impact of HS indexed by Fatty Liver Index (FLI) and high-normal fasting plasma glucose (FPG) as risk factors for incident prediabetes in a nonobese cohort. Methods: Data from 1125 participants with ADA-defined normal glucose metabolism (median age 52 years; BMI 23.1 kg/m2) were used for retrospective analysis. In the entire population, correlation between normal FPG and FLI was evaluated by multiple regression adjusted for age and sex. Follow-up data from 599 participants in whom 75-g OGTT was repeated 3.7 years later showed that 169 developed prediabetes. This was analyzed by the multivariate Cox proportional hazards model. Results: In the entire population, FLI was positively correlated with FPG (P < 0.01): mean FLI increased from 15.8 at FPG 4.2 mmol/L to 31.6 at FPG 5.5 mmol/L. Analysis of the 599 participants (2061 person-years) by Cox model, adjusted for sex, age, family history of diabetes, ISIMATSUDA, and Stumvoll-1, clarified an increased risk of prediabetes with high-normal FPG and FLI. Risk was increased 2.2 times with FLI ≥ 16.5 vs FLI < 16.5, P < 0.001, and increased 2.1 times in participants with FPG ≥ 5.3 mmol/L, P < 0.001. Cutoff values (unadjusted) were obtained by ROC at the point of the largest Youden's index using the entire range of the variables. Conclusion: Even among nonobese individuals, HS indexed by FLI and a high-normal FPG (≥ 5.3 mmol/L) are risk factors for prediabetes, independently from insulin.

Transplantation of mature adipocyte-derived dedifferentiated fat (DFAT) cells improves urethral sphincter contractility in a rat model.

OBJECTIVES: To examine the effects of mature adipocyte-derived dedifferentiated fat (DFAT) cell transplantation on urethral tissue regeneration and sphincter function. METHODS: Sixteen female Sprague-Dawley rats underwent vaginal distension (VD) for 3 h. Subsequently, green fluorescence protein (GFP)-labeled DFAT cells (1×10(6) in 20 µL saline, DFAT group, n=8) or saline (20 µL, control group, n=8) were injected into paraurethral connective tissue. Two weeks following VD, leak point pressure (LPP) was measured and an immunohistochemical analysis of the urethra was performed to evaluate urethral sphincter regeneration. RESULTS: The VD model was characterized by atrophy of the urethral sphincter and showed a decrease in LPP. DFAT cell transplantation resulted in a significant improvement of LPP (DFAT group: 37.3±6.4 vs control group: 21.7±5.7 mmHg, P<0.01). Immunohistochemistry revealed that the striated muscle thickness and smooth muscle α-actin-positive area were significantly (P<0.05) larger in the DFAT group than in the control group. DFAT cell transplantation enhanced macrophage accumulation followed by an increased number of cells in the proliferative state. Transplanted DFAT cells were observed in the damaged smooth muscle layer and showed positive staining for smooth muscle α-actin, suggesting conversion into the smooth muscle cell phenotype. CONCLUSIONS: DFAT cell transplantation promotes sphincter muscle regeneration and improves LPP in the rat VD model.

Tension-free vaginal mesh procedure for pelvic organ prolapse: a single-center experience of 310 cases with 1-year follow up.

OBJECTIVE: To prospectively evaluate the efficacy of a tension-free vaginal mesh (TVM) procedure for pelvic organ prolapse (POP). METHODS: Between December 2005 and April 2008, 310 female patients (mean age 67.2 years, range 42-84) with POP underwent TVM procedures at our institute. Fifty-six individuals were qualified as stage 2 according to the POP quantification system and 162 and 92 were stage 3 and 4, respectively. One hundred ninety-one patients underwent anterior TVM, and seven underwent posterior TVM. One hundred twelve cases underwent both anterior and posterior TVM procedures. Each patient was systematically assessed at 1, 3, 6 and 12 months after surgery. Quality of life (QOL) was also assessed by using the Short Form-36 and the prolapse-QOL questionnaires. RESULTS: Perioperative complications were the following: five bladder injuries (1.6%), no rectal injuries and three hemorrhages greater than 400 mL (1.0%). The anatomical cure rate (% stage 0 cases) at 3, 6 and 12 months after surgery were 94.1%, 93.5%, and 92.3%, respectively. Short Form-36 and prolapse-QOL parameters were significantly improved, and maintained during the follow-up period. Postoperative complications were the following: five pelvic hematomas (1.6%), one wound infection (0.3%), 10 vaginal mesh extrusions (3.2%), and three cases of pelvic pain (1.0%). Complications concerning lower urinary tract function were: eight cases of postoperative stress urinary incontinence (2.6%), three cases of transient urinary retention (1.0%), and two cases of de novo overactive bladder (0.6%). CONCLUSIONS: The TVM procedure provides a good outcome at 1 year with a low incidence of surgical complications and recurrence. Further evaluation with a longer follow up is needed.

[Effects of intravenous vasopressor on spread of spinal anesthesia with 0.5% hyperbaric bupivacaine for caesarean delivery].

BACKGROUND: It is known that when isobaric bupivacaine is applied for Caesarean delivery, phenylephrine is superior to ephedrine in preventing rostral spread of spinal anesthesia. In this study, we prospectively investigated whether phenylephrine can prevent rostral spread of spinal hyperbaric bupivacaine. METHODS: We randomly divided 32 patients undergoing Caesarean delivery into two groups: phenylephrine group and ephedrine group. In both groups, after the spinal injection of 2.0 ml of hyperbaric 0.5% bupivacaine, we started continuous intravenous infusion of phenylephrine or ephedrine. Blood pressure and heart rate were recorded every minute. Block height of cold sensation was assessed at 5, 10 and 15 minutes after the spinal injection. We measured umbilical artery pH after birth. Data were analyzed using a statistical software package. RESULTS: Block height was significantly lower with phenylephrine than with ephedrine at 10 and 15 minutes. Umbilical artery pH was significantly higher with phenylephrine than with ephedrine. Haemodynamic changes were significantly different between the two groups. There were no significant differences in age, BMI and spinal-delivery intervals. CONCLUSIONS: 1. Phenylephrine prevented rostral spread of spinal hyperbaric bupivacaine. 2. Haemodynamic changes were significantly different between the two groups. 3. Umbilical artery pH was significantly higher with phenylephrine than with ephedrine.

Mature, adipocyte derived, dedifferentiated fat cells can differentiate into smooth muscle-like cells and contribute to bladder tissue regeneration.

PURPOSE: We recently reported that mature, adipocyte derived, dedifferentiated fat cells show high proliferative activity and multilineage differentiation potential. In the current study we investigated whether such cells could differentiate into a smooth muscle cell lineage and contribute to bladder tissue regeneration in a mouse bladder injury model. MATERIALS AND METHODS: Human adipocyte derived dedifferentiated fat cells were cultured for 1 week under conditions favorable for smooth muscle cell differentiation and immunostained for alpha-smooth muscle actin. The expression of smooth muscle cell marker genes for differentiating dedifferentiated fat cells was measured by real-time reverse transcription-polymerase chain reaction. Green fluorescence protein labeled dedifferentiated fat cells were injected into cryo-injured bladder walls in mice. The ability of the fat cells to regenerate smooth muscle tissue was examined immunohistochemically 14 and 30 days after transplantation. RESULTS: Immunohistochemical analysis revealed that more than 50% of the fat cells were successfully differentiated into alpha-smooth muscle actin positive cells under the optimum culture condition of a medium containing 5% fetal bovine serum and 5 ng/ml transforming growth factor-beta1. Real-time reverse transcription-polymerase chain reaction revealed increased expression of SM22alpha, alpha-smooth muscle actin and smooth muscle-myosin heavy chain in dedifferentiated fat cells during week 1 of differentiation culture. Cells expressing alpha-smooth muscle actin plus green fluorescence protein were observed at the bladder wall injection sites in mice 14 and 30 days after transplantation. Alpha-smooth muscle actin positive areas in injured bladder tissue in mice with fat cell injection were significantly larger than those in saline injected control mice. CONCLUSIONS: These findings suggest that dedifferentiated fat cells can differentiate into smooth muscle cell lineages and contribute to the regeneration of bladder smooth muscle tissue.

Prognostic significance of the immunohistochemical expression of O6-methylguanine-DNA methyltransferase, P-glycoprotein, and multidrug resistance protein-1 in glioblastomas.

We studied the expression of O(6)-methylguanine-DNA methyltransferase (O(6)-MGMT), P-glycoprotein (Pgp), and multidrug resistance protein-1 (MRP-1) in 23 glioblastomas using RT-PCR, methylation-specific PCR, and immunohistochemistry, and analyzed their association with overall patient survival. Univariate analysis of collected data demonstrated that the expressions of O(6)-MGMT and MRP-1 detected by immunohistochemistry, in addition to the consistent factors, including preoperative Karnofsky performance scale (KPS), radical surgery, and tumor location and extension, were significant prognostic factors for the overall survival (OS) of patients with glioblastoma, who received nimustine (ACNU)-based chemotherapy in association with surgery and radiotherapy. Among them, following multivariate analysis, preoperative KPS, radical surgery, tumor location, and the expression of O(6)-MGMT remained as significant prognostic factors. These findings suggest that immunohistochemical analysis of O(6)-MGMT in patients with glioblastoma can be a useful method to predict the effects of chemotherapy and identify alternative chemotherapeutic regimens for O(6)-MGMT-positive patients.

[Clinical utility of epidural anesthesia during and after major spine surgery].

BACKGROUND: Spine surgery causes severe postoperative pain, but epidural anesthesia is not commonly used. The main reason is that it might cause some complications, such as motor block and infection. We compared the efficacy of epidural infusion with hypodermic infusion. METHODS: Thirty-two patients scheduled for spine surgery were included in the study. Patients were randomly assigned to receive either continuous epidural infusion (ropivacaine 0.18% and fentanyl 45.5 microg x ml(-1) at 2 ml x hr(-1)) or continuous hypodermic infusion via a patient-controlled analgesia system (morphine 0.04 mg x kg(-1) x ml(-1) at 0.5 ml x hr(-1); bolus: 0.5 ml x hr(-1)). We investigated pain and nausea by using visual analogue scale after surgery. RESULTS: Patient data did not differ between groups. Pain and nausea scores were significantly lower in the epidural infusion group than in the hypodermic infusion group. Epidural infusion did not cause any complications. The incidence of nausea in the hypodermic infusion group was 13 times as high as that in the epidural infusion group. Similarly, the incidence of nausea in female patients was 13 times as high as that in male patients. CONCLUSIONS: Continuous epidural infusion provides superior analgesia even if high-dose local anesthetics are not used. Besides, it decreases the incidence of nausea because systemic administration of opioids can be avoided.

Accelerated endothelialization and suppressed thrombus formation of acellular vascular grafts by modifying with neointima-inducing peptide: A time-dependent analysis of graft patency in rat-abdominal transplantation model.

Acellular blood vessels have clinical potential as tissue-engineered vascular grafts. However, neointima is hard to form on their luminal surface. We recently reported the integrin α4ß1 ligand peptide (Arg-Glu-Asp-Val) conjugated with a repetitive Pro-Hyp-Gly sequence as luminal surface modifier. By using this peptide, excellent patency of tissue-engineered small-caliber long-bypass grafts in minipig transplantation model was achieved. Here, the time-dependent change of the graft patency is investigated by using rat abdominal transplantation model. In vitro test showed that 86% of the endothelial cells were adhered to the peptide-modified graft surface, while cells were scarcely adhered on the unmodified and random peptide-modified surfaces. After transplantation in the abdominal aorta, the patency of unmodified and random peptide-modified grafts gradually decreased during two to three weeks and reached 20-40% in four weeks. In contrast, 80% of the modified grafts were patent without any thrombus formation at four weeks. These results suggest that the luminal surface modifier was bound to acellular surface through (Pro-Hyp-Gly)7 sequence and improved the in vivo graft patency by endothelialization and thrombus formation suppression.

Mature adipocyte-derived dedifferentiated fat cells exhibit multilineage potential.

When mature adipocytes are subjected to an in vitro dedifferentiation strategy referred to as ceiling culture, these mature adipocytes can revert to a more primitive phenotype and gain cell proliferative ability. We refer to these cells as dedifferentiated fat (DFAT) cells. In the present study, we examined the multilineage differentiation potential of DFAT cells. DFAT cells obtained from adipose tissues of 18 donors exhibited a fibroblast-like morphology and sustained high proliferative activity. Flow cytometric analysis revealed that DFAT cells comprised a highly homogeneous cell population compared with that of adipose-derived stem/stromal cells (ASCs), although the cell-surface antigen profile of DFAT cells was very similar to that of ASCs. DFAT cells lost expression of mature adipocytes marker genes but retained or gained expression of mesenchymal lineage-committed marker genes such as peroxisome proliferator-activated receptor gamma (PPARgamma), RUNX2, and SOX9. In vitro differentiation analysis revealed that DFAT cells could differentiate into adipocytes, chondrocytes, and osteoblasts under appropriate culture conditions. DFAT cells also formed osteoid matrix when implanted subcutaneously into nude mice. In addition, clonally expanded porcine DFAT cells showed the ability to differentiate into multiple mesenchymal cell lineages. These results indicate that DFAT cells represent a type of multipotent progenitor cell. The accessibility and ease of culture of DFAT cells support their potential application for cell-based therapies.

Expression of vascular endothelial growth factor-A and mRNA stability factor HuR in human astrocytic tumors.

High-grade astrocytic tumors, such as glioblastoma, possess rich vascular components, which are necessary for their growth. VEGF-A is considered to be the major mediator of angiogenesis in malignant neoplasms including high-grade astrocytic tumors. The upregulation of VEGF-A expression in tumor cells is induced by two mechanisms: the transcriptional activation and the post-transcriptional stabilization of VEGF-A mRNA. While the former mechanism mediated by hypoxia inducible factor-1 alpha (HIF-1alpha) has been revealed, the latter mediated by mRNA stability factor HuR remains unclear in astrocytic tumors. In the present study, we investigated the expression of VEGF-A and mRNA stability factor HuR in supratentorial astrocytic tumors of 27 adults using RT-PCR, ELISA, and immunohistochemistry. Furthermore, we studied the involvement of HuR in the upregulation of VEGF-A expression using malignant astrocytoma cell lines. In higher-grade astrocytic tumors, the level of VEGF-A and microvascular density were elevated, cytoplasmic expression of HuR, which potentially means the protection of VEGF-A mRNA from degradation by ribonucleases, appeared, and they were correlated positively. In in vitro experiments, the inhibition of the cytoplasmic translocation of HuR protein by leptomycin B (LMB) reduced the upregulation of VEGF-A expression in malignant astrocytic tumor cells under hypoxic conditions. These findings suggest that the expression of VEGF-A and cytoplasmic translocation of HuR relates to the histological grade, and that HuR is involved in the upregulation of VEGF-A expression, in human astrocytic tumors.