Implications of the Collar Sign in Incompletely Occluded Aneurysms after Pipeline Embolization Device Implantation: A Follow-Up Study

BACKGROUND AND PURPOSE

The angiographic collar sign has been recently described in patients with incompletely occluded aneurysms after Pipeline Embolization Device implantation. The long-term implications of this sign are unknown. We report angiographic outcomes of patients with the collar sign with follow-up of up to 45 months and the implications of this angiographic finding.

MATERIALS AND METHODS

We performed a retrospective review of a prospectively maintained data base of patients who underwent Pipeline Embolization Device implantation for an intracranial aneurysm at our institution between January 2014 and December 2016. We included patients with a collar sign at the initial follow-up angiogram after Pipeline Embolization Device implantation.

RESULTS

A total of 198 patients with 285 aneurysms were screened for the collar sign on initial and subsequent follow-up angiograms. There were 226 aneurysms (79.3%) with complete occlusion at the first follow-up. Of 59 incompletely occluded aneurysms, 19 (32.2%) aneurysms in 17 patients were found to have a collar sign on the first angiographic follow-up (median, 6 months; range, 4.2-7.2). Ten (52.6%) aneurysms underwent retreatment with a second Pipeline Embolization Device, which resulted in aneurysm occlusion in 1 (10%) patient. There were only 3 (15.8%) aneurysms with complete occlusion at the last follow-up, 2 (10.5%) of which had a single Pipeline Embolization Device implantation and another single (5.3%) aneurysm with a second Pipeline Embolization Device implantation.

CONCLUSIONS

A collar sign on the initial angiogram after Pipeline Embolization Device placement is a predictor of poor aneurysm occlusion. Because the occlusion rates remain equally low regardless of retreatment in patients with a collar sign, radiologic follow-up may be more appropriate than retreatment.

Cortical stroke affects activity and stability of theta/delta states in remote hippocampal regions

Cognitive impairment is a common outcome of ischemic stroke. Our previous work has shown that an experimental stroke in the cortex reduces activity in remote hippocampal layers in rats. This study seeks to uncover the underlying functional connections between these areas by analyzing changes to oscillatory activity, signal power, and communication. We induced an ischemic stroke in the left somatosensory cortex of rats and used linear micro-electrode arrays to simultaneously record from cortex and hippocampus under urethane anesthesia at two weeks and one month after stroke. We found significant increase in signal power, as well as an increase in the number of brain state changes in response to stroke. Our results suggest that the cortex modulates the activity and stability of hippocampal oscillations, which is disrupted following cortical stroke that can lead to cognitive impairment.

Influence of coronal bowing on the lower alignment and the positioning of component in navigation and conventional total knee arthroplasty

BACKGROUND

Coronal alignment is an important factor for the function and longevity of total knee arthroplasty (TKA). Coronal bowing of the lower extremity is common among Asians and it may pose a risk for malalignment of the lower leg and malposition of component.

HYPOTHESIS

We hypothesized that coronal bowing itself has a risk for malalignment of the lower leg and malposition of femoral/tibial components and that navigation TKA is beneficial for patients with coronal bowing. We investigated the incidence of femoral/tibial bowing in patients treated with TKA and compared the radiographic parameters between the navigation group and the conventional group. Additionally, the influence of coronal bowing on these radiographic parameters was investigated.

MATERIALS AND METHODS

We enrolled 35 patients with knee osteoarthritis and 70 bilateral simultaneous TKAs. The patients underwent TKA with the use of a computer tomography-free navigation in one knee and conventional TKA in the contralateral knee. Preoperative coronal bowing were measured, and the subjects were divided into 2 subgroups, i.e. the bowing group and the non-bowing group. Lateral bowing was expressed as plus (+) and medial bowing was expressed as minus (-). Various radiographic parameters, including coronal bowing, lower leg alignment, component position, and outliers were compared between the navigation group and the conventional group.

RESULTS

Femoral bowing varied from -7.4° to 10.9° with an average of 3.0°. Tibial bowing varied from -4.1° to 4.6° with an average of 0.4°. The femoral component was placed more properly in the navigation group. Number of outlier regarding to the coronal femoral component angle to the femoral mechanical axis was 14 cases (37.8%) in the bowing group and 6 cases (18.2%) in the non-bowing group (P=0.04).

DISCUSSION

In conclusion, coronal femoral bowing has an important effect on femoral bone cut in TKA. The navigated TKA was more consistent than conventional TKA in aiding proper alignments of femoral component.

LEVEL OF EVIDENCE

Level II, comparative prospective study.

Usefulness of long tibial axis to measure medial tibial slope for opening wedge high tibial osteotomy

PURPOSE

To assess which tibial slope measurements on knee, whole leg radiographs and three-dimensional reconstructed computed tomography (CT) were useful in clinical practice before and after opening wedge high tibial osteotomy.

METHODS

Medial and lateral tibial slopes on knee, whole leg radiographs and three-dimensional reconstructed CT were measured in 50 patients with knee osteoarthritis. To investigate the intraobserver reproducibility and interobserver reliability for each medial and lateral tibial slope on knee, whole leg radiographs and CT, the measurements were repeated twice by two observers. The statistical differences between the medial and lateral tibial slopes obtained by the three methods, and the differences and correlation coefficients for the medial and lateral tibial slopes between knee or whole leg radiographs and CT were calculated.

RESULTS

The reproducibility and reliability of medial and lateral tibial slopes on CT were superior to those on whole leg or knee radiographs. The medial and lateral tibial slopes on whole leg radiographs had better reproducibility and reliability than those on knee radiographs. The mean medial tibial slopes on knee, whole leg radiographs and CT were 9.3 ± 3.4°, 12.3 ± 4.3° and 11.0 ± 3.9°, respectively. The mean lateral tibial slopes were 7.9 ± 3.1°, 9.6 ± 3.6° and 9.3 ± 2.9°, respectively. The medial tibial slopes on knee, whole leg radiographs and CT were significantly higher than the lateral tibial slopes (p < 0.01 for all).

CONCLUSIONS

Tibial slope measurements using CT required time and specialized software. Therefore, measurements of the medial tibial slope using the long tibial axis on whole leg radiographs were more reproducible and reliable and could be an alternative to CT in clinical practice.

LEVEL OF EVIDENCE

III.

Impairment of host resistance to helminthes with age in murine small intestine

Age-associated alterations of Th2 immune responses against nematode parasites are largely unknown. We investigated primary and memory responses against two types of gastrointestinal nematode parasites, Heligmosomoides polygyrus (Hp) and Nippostrongylus brasiliensis (Nb), in aged mice. The small intestinal gene expression of Th2 cytokines was almost unchanged after primary (Nb and Hp) and secondary infection (Hp) in aged mice in contrast to strongly increased small intestinal gene expression of Th2 cytokines in young (3-month-old) mice. Mucus production decreased (Nb), and worm expulsion was impaired (Nb and Hp) compared with the young mice. Immunofluorescent staining revealed that after Hp infection, the number of alternatively activated macrophages, which are induced by Th2 cytokines, was lower in the aged mice. On the other hand, the number of CD4(+) T cells recruited to the worm cysts was normal compared with the young mice. These results suggest that migration of CD4(+) T cells to the host-parasite interface is not affected by ageing. Alterations in Th2 immune responses in aged mice might be due to inappropriate or insufficient activation of CD4(+) T cells in the submucosa.

Synthesis of 17-membered azalides from a 16-membered macrolide utilizing amide-selective silane reduction

Novel 17-membered azalides of N-methylated amine type were synthesized and their antibacterial activity was evaluated.

Reproducibility of condylar twist angle measurement using computed tomography and axial radiography of the distal femur

INTRODUCTION

It is essential to understand rotational alignment of the distal femur when performing total knee arthroplasty (TKA). Several rotational landmarks including condylar twist angle (CTA) are used for preoperative planning and during TKA. Axial radiography of the distal femur is used for measuring the CTA, and assessing rotational alignment in TKA. The aim of this study was to investigate the reliability and the reproducibility of the CTA using two different methods and evaluate if CTA differed between varus and valgus knees and between normal and osteoarthritic knees.

MATERIALS AND METHODS

CTA were obtained from 144 knees (77 patients) having total knee or hip arthroplasty using computed tomography (CT) and axial radiography. Subjects were divided into five groups based on femorotibial angle (FTA) and into four groups based on the severity of knee osteoarthritis. The intra-observer and inter-observer reliabilities of these methods and inter-method differences were evaluated.

RESULTS

The mean CTA was 7.02° with axial radiography, and 6.87° with CT images. There were no significant differences among the five FTA groups and among the four osteoarthritis groups. In total, intra-/inter-observer, and inter-method intraclass correlation coefficients were substantial or almost perfect in the scoring system of Landis et al. However, discrepancies ≥ 2° between the two methods were observed in more than 20% of knees.

CONCLUSION

The CTA should be reassessed by more than two observers or two methods for precise preoperative TKA planning in cases where it is difficult to identify the bony landmarks for CTA measurements.

LEVEL OF EVIDENCE

Level III.

Five- to ten-year outcome following medial opening-wedge high tibial osteotomy with rigid plate fixation in combination with an artificial bone substitute

Between 2003 and 2007, 99 knees in 77 patients underwent opening wedge high tibial osteotomy. We evaluated the effect of initial stable fixation combined with an artificial bone substitute on the mid- to long-term outcome after medial opening-wedge high tibial osteotomy (HTO) for medial compartmental osteoarthritis or spontaneous osteonecrosis of the knee in 78 knees in 64 patients available for review at a minimum of five years (mean age 68 years; 49 to 82). The mean follow-up was 6.5 years (5 to 10). The mean Knee Society knee score and function score improved from 49.6 (SD 11.4, 26 to 72) and 56.6 (SD 15.6, 5 to 100) before surgery to 88.1 (SD 12.5, 14 to 100) and 89.4 (SD 15.6, 5 to 100) at final follow-up (p < 0.001) respectively. There were no significant differences between patients aged ≥ 70 and < 70 years. The mean standing femorotibial angle was corrected significantly from 181.7° (SD 2.7°, 175° to 185°) pre-operatively to 169.7° (SD 2.4°, 164° to 175°) at one year's follow-up (p < 0.001) and 169.6° (SD 3.0°, 157° to 179°) at the final follow-up (p = 0.69 vs one year). Opening-wedge HTO using a stable plate fixation system combined with a bone substitute is a reliable procedure that provides excellent results. Although this treatment might seem challenging for older patients, our results strongly suggest that the results are equally good.

Vegfrecine, an inhibitor of VEGF receptor tyrosine kinases isolated from the culture broth of Streptomyces sp

A new inhibitor of VEGF receptor tyrosine kinases, vegfrecine (1), was isolated from the culture broth of Streptomyces sp. MK931-CF8. The molecular structure of 1 was determined by NMR and MS analysis combined with synthesis. Compound 1 showed potent inhibitory activity against vascular endothelial growth factor receptor (VEGFR) tyrosine kinases in in vitro enzyme assays, but platelet-derived growth factor receptors (PDGFRs), fibroblast growth factor receptor (FGFR), and epidermal growth factor receptor (EGFR) responded only weakly. Compound 1 is a promising new selective VEGFR inhibitor for investigating new treatments of cancer and inflammatory diseases.

NAD(P)H quinone oxidoreductase 1 (NQO1)-bioactivated pronqodine A regulates prostaglandin release from human synovial sarcoma cells

Natural products have contributed to the elucidation of biological mechanisms as well as drug discovery research. Even now, the expectation for natural products is undiminished. We screened prostaglandin release inhibitors that had no effect on in vitro cyclooxygenase activity derived from natural product sources and discovered pronqodine A. Using spectral analysis and total synthesis, the structure of pronqodine A was shown to be a benzo[d]isothiazole-4,7-dione analogue. Evaluation of the biological activity of pronqodine A revealed that the NAD(P)H dehydrogenase quinone 1 (NQO1) converted pronqodine A into a two-electron reductive form. The reductive form underwent autoxidation and reversed to its native form immediately with the generation of reactive oxygen species. Further investigations proved that pronqodine A inhibited cyclooxygenase enzyme activity only in the presence of NQO1. Pronqodine A acts as a potential bioreductive compound, inhibiting prostaglandin release in selectively activated NQO1-expressing cells.

Amycolamicin: a novel broad-spectrum antibiotic inhibiting bacterial topoisomerase

The abuse of antibacterial drugs imposes a selection pressure on bacteria that has driven the evolution of multidrug resistance in many pathogens. Our efforts to discover novel classes of antibiotics to combat these pathogens resulted in the discovery of amycolamicin (AMM). The absolute structure of AMM was determined by NMR spectroscopy, X-ray analysis, chemical degradation, and modification of its functional groups. AMM consists of trans-decalin, tetramic acid, two unusual sugars (amycolose and amykitanose), and dichloropyrrole carboxylic acid. The pyranose ring named as amykitanose undergoes anomerization in methanol. AMM is a potent and broad-spectrum antibiotic against Gram-positive pathogenic bacteria by inhibiting DNA gyrase and bacterial topoisomerase IV. The target of AMM has been proved to be the DNA gyrase B subunit and its binding mode to DNA gyrase is different from those of novobiocin and coumermycin, the known DNA gyrase inhibitors.

The extent of degeneration of cruciate ligament is associated with chondrogenic differentiation in patients with osteoarthritis of the knee

OBJECTIVE

Degeneration in cruciate ligaments results from abnormal biomechanical stress and the aging process. Such degeneration is a common outcome in patients with osteoarthritis (OA) of the knee and contributes to the progression of OA. However, to date, there are no specific markers that can predict the extent of ligament degeneration. We hypothesized that the extent of degeneration has correlations to increased chondrogenic potential.

METHODS

Twenty anterior cruciate ligaments (ACLs) and 30 posterior cruciate ligaments (PCLs) from 30 knees of 28 adult patients with OA at the time of total knee arthroplasty were used for the study. Degeneration was histologically assessed using a grading system. Expressions of Scleraxis (as a ligament cell marker) and Sry-type HMG box 9 (SOX9) (as a chondrogenic marker) were immunohistochemically assessed in each grade.

RESULTS

We found the opposite expression pattern between Scleraxis and SOX9 according to the grade. The percentage of Scleraxis-positive cells decreased significantly by grade (60.9±23.7 in grade 1, 39.7±30.5 in grade 2, and 13.9±27.1 in grade 3, P<0.0001). In contrast, the percentage of SOX9-positive cells increased significantly by grade (2.5±4.9 in grade 1, 17.5±13.4 in grade 2, and 50.9±27.1 in grade 3, P<0.0001). Furthermore, co-localized expression of both Scleraxis and SOX9 was demonstrated in chondrocyte-like cells.

CONCLUSIONS

This study indicates that chondrogenic differentiation is associated with the progression of degeneration in human ligaments. Our results suggest that the expression of SOX9 as a chondrogenic marker could be an indicator for the extent of degeneration in human ligaments. It remains to be elucidated whether suppression of chondrogenic differentiation can prevent progression of the degenerative process of cruciate ligaments in patients with OA.

The relationship between recurrences and immunosuppression on living donor liver transplantation for hepatocellular carcinoma

OBJECTIVES

Living donor liver transplantation (LDLT) offers timely transplantation for patients with hepatocellular carcinoma (HCC). If ABO-incompatible LDLT is feasible, the needs for pretransplantation treatments may be eliminated. It is known that negative impacts of immunosuppression are limited among LDLT for HCC, however, we believe that excessive immunosuppression is one of the risk factors for recurrence. We compared the impacts of immunosuppression for LDLT with hepatectomy outcomes for HCC.

METHODS

From 1991 to 2010, we performed 144 LDLTs including 14 patients with HCC. Seven met the Milan criteria. Immunosuppressive therapies were based on tacrolimus plus methylprednisolone plus CD25 antibody. For ABO-incompatible cases, we also used mycophenolate mofetil and rituximab. Five cases underwent strong imunosuppressive therapy (steroid pulse or rituximab) within 180 days. In addition, we performed hepatectomy for 180 HCC cases from 1997 to 2010.

RESULTS

Overall survival rates of the LDLT cohort and hepatectomy groups were similar, but disease-free 5-year survival rates (DFS) of the LDLT cohort were significantly better than those of the hepatectomy group (total = 54.4% versus 27.4%, within the Milan criteria cases, 71.4% versus 33.8%). Thus, the negative impact of immunosuppression on recurrence was less than the benefit of a whole liver resection. Among strongly immunosuppressed cases, 5-years DFS rates were significantly worse than among other immunosuppressed cases (20.0% versus 76.2%). Upon univariate analysis, the factors associated with HCC recurrence were alpha-fetoprotein levels and steroid doses within 180 days, but multivariate analysis did not show a predictor for recurrence.

CONCLUSION

Patients who are strongly immunosuppressed may have several negative impacts for recurrences. More careful indications must be selected for ABO-incompatible cases.

Curing bacteria of antibiotic resistance: reverse antibiotics, a novel class of antibiotics in nature

By screening cultures of soil bacteria, we re-discovered an old antibiotic (nybomycin) as an antibiotic with a novel feature. Nybomycin is active against quinolone-resistant Staphylococcus aureus strains with mutated gyrA genes but not against those with intact gyrA genes against which quinolone antibiotics are effective. Nybomycin-resistant mutant strains were generated from a quinolone-resistant, nybomycin-susceptible, vancomycin-intermediate S. aureus (VISA) strain Mu 50. The mutants, occurring at an extremely low rate (<1 × 10(-11)/generation), were found to have their gyrA genes back-mutated and to have lost quinolone resistance. Here we describe nybomycin as the first member of a novel class of antibiotics designated 'reverse antibiotics'.

Navigated opening wedge high tibial osteotomy improves intraoperative correction angle compared with conventional method

PURPOSE

The correction angle after high tibial osteotomy (HTO) depends on an accurate preoperative planning and an accurate intraoperative technique. We hypothesized that the use of a navigation system in opening wedge HTO would improve the intraoperative target angles in the coronal and sagittal planes.

METHODS

Postoperative femoro-tibial angle (FTA) and tibial posterior slope (TPS) in 28 knees with navigated opening wedge HTO were compared to those in 31 knees with the conventional method. Intraoperative correction angle was determined by the predicted medial opening width in the conventional group, and by the change of hip-knee-ankle angle in the navigated group. We defined lateral unstable knee as the knees with lateral cortex breakage or lateral tibial plateau fracture.

RESULTS

Mean postoperative FTA was higher in the conventional group than in the navigated group (P < 0.037). In the conventional group, 4 lateral unstable knees were corrected to 174.6°. In the navigated group, 5 lateral unstable knees were corrected to 170.3° and no knees showed FTA > 173°. Mean change in TPS was greater in the conventional group than in the navigated group (P = 0.001).

CONCLUSION

The navigation system in opening wedge HTO might reduce undercorrection in the knees with lateral cortex breakage or lateral tibial plateau fracture, and provide the better intraoperative FTA and TPS.

LEVEL OF EVIDENCE

III.

Reminiscence of our research on membrane phospholipids in mammalian cells by using the novel technology

By using "our devised up-to-the-second technique" over 30 years ago, we succeeded in the first isolation in the world of the three different kinds of mammalian cell mutants defective in the biosynthesis on each of phosphatidylserine (PS), cardiolipin (CL) and sphingomyelin (SM) from the parental CHO cells. As the results, we found that during the biosyntheses of PS and SM, the biosynthetic precursor or the final lipids are transported from their synthesized intracellular organelles to the plasma membranes via the other intracellular organelles. We further clarified the presence of the reversed routes for PS and SM from the plasma membranes to their synthesized organelles too. Our first epoch-making finding is not only the cycling inter-conversion reactions between PS and PE catalyzed by PSS-II and PSD but also their simultaneous transferring between MAM and Mit (found by O. Kuge). Our second finding is "the ceramide-trafficking protein (CERT)" working as the specific transfer protein of ceramide from the ER to the Golgi apparatus, during the SM biosynthesis (by K. Hanada). As for their new biological roles, we clarified possible contribution of PS and/or PE to the fusion process between viral envelope and endosomal membrane, releasing the genetic information of the virus to the host cytoplasm. CL is contributing to the functional NADH-ubiquinone reductase activity by keeping the right structure of Coenzyme Q9 for its functioning. SM and cholesterol form the microdomain within the plasma membrane, so-called "the raft structure" where the GPI-anchored proteins are specifically located for their functioning.

Decalpenic acid, a novel small molecule from Penicillium verruculosum CR37010, induces early osteoblastic markers in pluripotent mesenchymal cells

Osteoblasts are the cells responsible for bone formation during embryonic development and adult life. Small compounds that could induce osteoblast differentiation might be promising sources of therapies for bone diseases such as osteoporosis. During screening for inducers of osteoblast differentiation of mouse pluripotent mesenchymal C3H10T1/2 cells, we isolated a small compound from the fermentation broth of Penicillium verruculosum CR37010. This compound, named decalpenic acid, bears a decalin moiety with a tetraenoic acid side chain. Treatment of C3H10T1/2 cells with decalpenic acid alone induced the expression of early osteoblast markers, such as alkaline phosphatase activity and osteopontin mRNA, but did not induce the late osteoblast marker osteocalcin mRNA or adipocyte markers under our experimental conditions.

The synthesis of paleic acid, an antimicrobial agent effective against Mannheimia and Pasteurella, and its structurally related derivatives

A synthetic route to paleic acid 1, antimicrobial agent effective against Mannheimia haemolytica and Pasteurella multocida, has been established. The absolute configuration of the secondary hydroxyl group was controlled by a catalytic asymmetric alkylation of an aldehyde using a chiral titanium sulfonamide complex and the cis double bond was installed using a Wittig reaction. This synthetic route was also applied to the preparation of structurally related analogs, which were used in structure-activity relationship studies for antibacterial activity.

Structure-activity relationship of boronic acid derivatives of tyropeptin: proteasome inhibitors

The structure-activity relationship of the boronic acid derivatives of tyropeptin, a proteasome inhibitor, was studied. Based on the structure of a previously reported boronate analog of tyropeptin (2), 41 derivatives, which have varying substructure at the N-terminal acyl moiety and P2 position, were synthesized. Among them, 3-phenoxyphenylacetamide 6 and 3-fluoro picolinamide 22 displayed the most potent inhibitory activity toward chymotryptic activity of proteasome and cytotoxicity, respectively. The replacement of the isopropyl group in the P2 side chain to H or Me had negligible effects on the biological activities examined in this study.

Biological activities of pargamicin A, a novel cyclic peptide antibiotic from Amycolatopsis sp

The time-kill studies using pargamicin A against Staphylococcus aureus and Enterococcus faecalis were performed. The effects of the incorporation of radioactive precursors into macromolecules, membrane potential and function using fluorescent dyes were also examined. These studies revealed that rapid bactericidal activity of pargamicin A correlates with the perturbation of bacterial cell membrane potential and membrane function.

Quality of life and problems affecting recipients more than 10 years after living donor liver transplantation

BACKGROUND

We initiated living donor liver transplantation (LDLT) in 1991, allowing us to examine issues related to long-term survival. The aim of this study was to review the long-term outcomes of LDLT in children.

PATIENTS AND METHODS

We performed 116 LDLT from 1991 to present, including 17 recipients who survived >10 years. They were evaluated for growth, immunosuppressive therapy, complications, and quality of life (QOL).

RESULTS

The average age at LDLT was 5.4 years (range, 6 months to 17 years), with a present average age of 17.2 years (range, 11-28 years). At the time of LDLT, 6 recipients had growth retardation with body weights low for age by 2 standard deviations (SD). However, 4 of 6 recipients who underwent LDLT before age of 2 years caught up, reaching average heights and body weights for their ages. Among 6 recipients who were diagnosed with acute rejections by biopsy >5 years after LDLT, 5 improved after steroid pulse therapy. One recipient with a steroid-resistant acute rejection was administered deoxyspergualin after steroids. Chronic rejection was not observed in this series. One recipient has not required immunosuppressive therapy for >4 years with a good present condition.

CONCLUSION

The majority of LDLT recipients achieved a good QOL during long-term survival; they are pursuing normal studies.

Synthesis of boronic acid derivatives of tyropeptin: proteasome inhibitors

Boronic acid derivatives of tyropeptin were synthesized with TP-110 as the lead compound. Due to the lability of the aminoboronic acid moiety, careful design of the deprotection and coupling sequence was required. Liquid-liquid partition chromatography was found to be a powerful tool for purification of compounds of this class. The obtained derivatives showed potent inhibitory activities against the human 20S proteasome in vitro.

A new type of tripropeptin with anteiso-branched chain fatty acid from Lysobacter sp. BMK333-48F3

Branched chain amino acids are often utilized as the precursors of many lipid-containing bacterial secondary metabolites. The effect of isoleucine on the composition of the mixture of cyclic lipopeptide antibiotics, tripropeptins from Lysobacter sp. BMK333-48F3 was evaluated. As expected, a novel tripropeptin analog with an anteiso-branched fatty acid was produced. The new compound, TPPaiC shows potent antibacterial activity against Gram-positive bacteria including MRSA and VRE. On the other hand, no increase was observed in the production of other tripropeptins by the addition of isoleucine.

A free radical scavenger, edaravone, prevents ischemia-reperfusion injury in liver grafts from non-heart-beating donors

BACKGROUND

Due to the increase in liver transplantation, the donor shortage has become a serious problem, requiring marginal, non-heart-beating donors (NHBDs). The aims of this study were to evaluate the cytoprotective effect of edaravone, a free radical scavenger, on warm ischemia-reperfusion (I/R) injury of liver grafts from NHBDs.

METHODS

Rat livers were harvested from heart-beating donors (HB group) or from NHBDs undergoing cardiac arrest for 30 minutes led by thoracotomy (NHB group), and reperfused for 60 minutes with Krebs-Henseleit bicarbonate buffer after cold preservation for 6 hours. In another group (ED group), warm ischemic livers from NHBDs were reperfused with buffer containing edaravone (1 mg/L) after cold preservation.

RESULTS

In the ED group, portal flow volume, bile production, and energy charge were significantly ameliorated. Lipid peroxidation, elevation of hepatic enzymes, and release of tumor necrosis factor-alpha and interleukin-1 beta were significantly alleviated, compared with the NHB group.

CONCLUSIONS

These results suggested that edaravone has suppressive effects on warm I/R injury in liver grafts from NHBDs.

Continuous low-dose human atrial natriuretic peptide promotes diuresis in oliguric patients after living donor liver transplantation

Human atrial natriuretic peptide (ANP) is beneficial for the prophylaxis of acute renal failure (ARF) after liver transplantation (OLT). We evaluated renal function in OLT patients with or without ARF, describing cases unresponsive to loop diuretics successfully treated with continuous low-dose ANP infusion without hemodialysis. Twenty-seven consecutive adult-to-adult living donor liver transplantations (LDLTs) were performed in 26 patients. One case was excluded due to the need for continuous hemodialysis (HD) during the operation. Of the 26 cases, 6 (23%, group 2) developed ARF in the first 30 days after LDLT; the other 20 were ARF-free (group 1). The median follow-up was 24 months. No patient required either continuous or intermittent HD. Only one patient died due to multiple liver abscesses. Mean preoperative serum creatinine (sCr) value and intraoperative blood loss in group 2 were significantly higher than those in group 1. Three cases in group 2 failed to improve on high-dose loop diuretics with low-dose dopamine, exhibiting fluid overload. The remaining three cases in group 2 responded to conventional diuretic treatments. Continuous low-dose ANP was started 2, 4, or 5 days after LDLT, and urine output significantly increased after ANP administration. The serum creatinine values were 1.1, 1.2, and 1.1 at 1 month and 1.0, 0.9, and 0.6 mg/dL at 6 months after LDLT. Massive blood loss during the operation caused ARF, but did not affect renal function after LDLT. Continuous low-dose ANP improved renal function and diuresis for oliguric ARF patients, preventing the need for HD or continuous venovenous hemodialysis.

Migrastatin acts as a muscarinic acetylcholine receptor antagonist

Migrastatin and its analogs have various biological activities such as inhibition of cell migration and anchorage-independent growth of cancer cells. Although its biosynthesis and chemical synthesis have been under investigation, little is known about the biological target of migrastatin. Here, we found that migrastatin inhibited intracellular calcium mobilization induced by carbachol in neuroblastoma SK-N-SH cells without affecting Ca2+ mobilization and cAMP accumulation induced by ligands of other receptors. The binding of [3H] N-methylscopolamine, an antagonist for muscarinic receptor was also inhibited by migrastain. Functionally, migrastatin inhibited Ca2+ mobilization induced by carbachol in primary cultures of smooth muscle cells of rat bladder. This study reveals that migrastatin acts as a muscarinic acetylcholine receptor antagonist.

The Effect of Perfusion Prior to Cold Preservation and Addition of Biliverdin on the Liver Graft from Non-Heart-Beating Donors

AIM

Our aim was to improve the energy status and viability of a liver graft from a non-heart-beating donor (NHBD), we investigated the effects of perfusion prior to cold preservation and the addition of an antioxidant, biliverdin.

METHODS

Rats were divided into five groups: group 1: without 30 minutes warm ischemia (WI) and cold preservation (control group); group 2 without WI and with 6 hours of cold preservation in UW solution (HBD group); group 3 with WI and cold preservation (NHBD group); group 4 with 30 minutes perfusion prior to cold preservation (PRE group); and group 5 with addition of biliverdin to precold preservation perfusion (BV group). Oxygenated Klebs-Henseleit solution was used as the perfusate prior to and after preservation. Portal flow and bile production during reperfusion, energy charge (EC), ATP level, GOT, and TNF-alpha were measured as well as a histological evaluation.

RESULTS

Portal flow of the PRE and BV groups during 1 hour of reperfusion was higher than of that the NHBD group. Bile production of the PRE group was also higher than that of the NHBD group, but bile production in the BV group was comparable to the NHBD group. EC of the PRE group was higher than that of the NHBD group prior to and after reperfusion. The EC and ATP levels of the BV group after reperfusion were higher than those of the NHBD and PRE groups. The GOT and TNF-alpha were reduced in the BV group.

CONCLUSIONS

Precold preservation perfusion improves the viability of grafts from NHBDs. Furthermore, biliverdin exerted an additive effect to ameliorate energy status.

A New Teleocidin Analog from Streptomyces sp. MM216-87F4 Induces Substance P Release from Rat Dorsal Root Ganglion Neurons

A new teleocidin analog was isolated from the fermentation medium of Streptomyces sp. MM216-87F4 and its structure was elucidated as 14-O-(N-acetylglucosaminyl) teleocidin A (GlcNAc-TA). GlcNAc-TA induces the translocation of protein kinases Calpha and theta fused with enhanced green fluorescent protein (PKCalpha-EGFP and PKCtheta-EGFP) to the plasma membrane in stable transfectants, and reduces intracellular calcium mobilization induced by agonists of G-protein coupled receptors in various cell lines without causing irritation of the mouse ear. Further, GlcNAc-TA sensitizes the release of excitatory neuropeptides substance P induced by capsaicin from primary-cultured dorsal root ganglion (DRG) neurons of the rat and GlcNAc-TA alone also triggers substance P release in a dose-dependent manner. This study provides the first observation that a teleocidin analog without a free hydroxyl group at C-14 acts as a PKC activator and directly induces the release of excitatory neuropeptide.

New strategy for ABO-incompatible living donor liver transplantation with anti-CD20 antibody (rituximab) and plasma exchange

It is more difficult to control humoral rejection in living donor liver transplantations (LDLT) across the ABO blood group barrier than in matched or compatible combinations. We achieved excellent results in ABO-incompatible transplantation with novel immunosuppressive regimens and plasma exchange (PE). Among 82 LDLT were 10 cases of ABO-incompatible recipients, including three who were administered rituximab for rescue or prophylactic therapy. Pretransplantation PE was performed as necessary to maintain hemagglutinin titers below 1:16 and posttransplantation PE was performed when there were signs of hyperacute rejection associated with high titers. Induction immunosuppression consisted of FK506, steroid, mycophenolate mofetil (MMF), and rituximab. The first patient was administered rituximab with deoxyspergualin (DSG), steroid pulse therapy, and PE on postoperative day (POD) 7, because of biopsy-proven humoral acute rejection. The titers and LFTs improved drastically. The second and third patients were administered rituximab just after the operation with other routine immunosuppressants for prophylaxis of hyperacute rejection. The second patient showed a slight deterioration in LFTs with an elevated titer, which normalized after steroid pulse therapy and PE. The third patient had no episodes of rejection. At present, that is 27, 17, and 6 months after the operations respectively, the 3 transplant recipients are in stable condition.