Noninvasive Assessment of Advanced Fibrosis Based on Hepatic Volume in Patients with Nonalcoholic Fatty Liver Disease

Background/Aims

Noninvasive liver fibrosis evaluation was performed in patients with nonalcoholic fatty liver disease (NAFLD). We used a quantitative method based on the hepatic volume acquired from gadoxetate disodium-enhanced (Gd-EOB-DTPA-enhanced) magnetic resonance imaging (MRI) for diagnosing advanced fibrosis in patients with NAFLD.

Methods

A total of 130 patients who were diagnosed with NAFLD and underwent Gd-EOB-DTPA-enhanced MRI were retrospectively included. Histological data were available for 118 patients. Hepatic volumetric parameters, including the left hepatic lobe to right hepatic lobe volume ratio (L/R ratio), were measured. The usefulness of the L/R ratio for diagnosing fibrosis ≥F3–4 and F4 was assessed using the area under the receiver operating characteristic (AUROC) curve. Multiple regression analysis was performed to identify variables (age, body mass index, serum fibrosis markers, and histological features) that were associated with the L/R ratio.

Results

The L/R ratio demonstrated good performance in differentiating advanced fibrosis (AUROC, 0.80; 95% confidence interval, 0.72 to 0.88) from cirrhosis (AUROC, 0.87; 95% confidence interval, 0.75 to 0.99). Multiple regression analysis showed that only fibrosis was significantly associated with the L/R ratio (coefficient, 0.121; p<0.0001).

Conclusions

The L/R ratio, which is not influenced by pathological parameters other than fibrosis, is useful for diagnosing cirrhosis in patients with NAFLD.

A higher incidence of cleavage failure in oocytes containing smooth endoplasmic reticulum clusters

PURPOSE

In human oocytes, sERCs are one of the dysmorphic phenotypes that have been reported. Significantly reduced pregnancy rates and a comparatively higher number of abnormities in live births appear to be associated with the presence of sERCs in oocytes. However, some reports have shown that healthy babies can be born, without any reduced pregnancy rates, from oocytes observed to contain sERCs. Thus, the clinical and scientific significance of oocytes that harbor sERCs remains controversial.

METHODS

The presence of sERCs was evaluated using a time-lapse system while studying the dynamic changes within oocytes and embryos. Logistic regression analysis was carried out to explore the independent variables for meiotic and mitotic cleavage failure..

RESULTS

The incidence of mitotic cleavage failure and the incidence of meiotic cleavage failure during the second polar body extrusion in oocytes with sERCs were found to be significantly higher than that in oocytes without sERCs. Furthermore, ICSI was found to have a greater frequency of meiotic failure than IVF.

CONCLUSIONS

In cases of cleavage failure, an embryonic cell could become tetraploid and may induce abnormal chromosomal configurations. Some cells exposed to cleavage failure may become trophectoderm cells and form placental abnormalities. Even if they develop into trophectoderm cells, the ICM can be susceptible to further cleavage failure and may in turn cause further aneuploidy. For these reasons, it is important to monitor pregnancies and births derived from oocytes that contained sERCs.

Influence of the reference scan and scan time on the arterial phase of liver magnetic resonance imaging

The controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) technique can decrease scan time. The purpose of this study was to determine whether an arterial phase scan can be performed in 5 s using the CAIPIRINHA short-scan and a reference scanning technique. The generalized autocalibrating partially parallel acquisition (GRAPPA), the CAIPIRINHA routine (CAIPI-routine), and the CAIPIRINHA short-scanning (CAIPI-short) methods were compared. The scan time for each method was preset to 20 s, 15 s, and 10 s, respectively. The reference scan had a scan time of 5 s. A phantom study was used to compare the influence of artifacts during the reference scan. For comparison, the phantom was moved during the last 5 s. In the clinical studies of suspected chronic liver diseases, magnetic resonance imaging of the liver is usually performed while the patient is breath-hold. The motion artifacts of each method were compared. Artifacts were reduced in reference scans using the CAIPIRINHA method. At 5 s after initiation, the rate of change in the standard deviation value was within 30% compared to that of the original image. Motion artifacts due to the influence of the reference scan when a patient failed to hold their breath did not complicate image evaluation. The proportion of motion artifacts for each sequence was as follows: GRAPPA, 5.8%; CAIPI-routine, 1.9%; and CAIPI-short, 0.7%. The arterial phase can be scanned in 5 s using the CAIPI-short and reference scan techniques.

Mechanisms of carbon dioxide acquisition and CO2 sensing in marine diatoms: a gateway to carbon metabolism

Diatoms are one of the most successful marine eukaryotic algal groups, responsible for up to 20% of the annual global CO2 fixation. The evolution of a CO2-concentrating mechanism (CCM) allowed diatoms to overcome a number of serious constraints on photosynthesis in the marine environment, particularly low [CO2]aq in seawater relative to concentrations required by the CO2 fixing enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO), which is partly due to the slow diffusion rate of CO2 in water and a limited CO2 formation rate from [Formula: see text] in seawater. Diatoms use two alternative strategies to take up dissolved inorganic carbon (DIC) from the environment: one primarily relies on the direct uptake of [Formula: see text] through plasma-membrane type solute carrier (SLC) 4 family [Formula: see text] transporters and the other is more reliant on passive diffusion of CO2 formed by an external carbonic anhydrase (CA). Bicarbonate taken up into the cytoplasm is most likely then actively transported into the chloroplast stroma by SLC4-type transporters on the chloroplast membrane system. Bicarbonate in the stroma is converted into CO2 only in close proximity to RubisCO preventing unnecessary CO2 leakage. CAs play significant roles in mobilizing DIC as it is progressively moved towards the site of fixation. However, the evolutionary types and subcellular locations of CAs are not conserved between different diatoms, strongly suggesting that this DIC mobilization strategy likely evolved multiple times with different origins. By contrast, the recent discovery of the thylakoid luminal θ-CA indicates that the strategy to supply CO2 to RubisCO in the pyrenoid may be very similar to that of green algae, and strongly suggests convergent coevolution in CCM function of the thylakoid lumen not only among diatoms but among eukaryotic algae in general. In this review, both experimental and corresponding theoretical models of the diatom CCMs are discussed.This article is part of the themed issue 'The peculiar carbon metabolism in diatoms'.

Evolutionarily distinct strategies for the acquisition of inorganic carbon from seawater in marine diatoms

The acquisition of dissolved inorganic carbon (DIC) in CO2-limited seawater is a central issue to understand in marine primary production. We previously demonstrated the occurrence of direct HCO3- uptake by solute carrier (SLC) 4 transporters in a diatom, a major marine primary producer. Homologs of SLC are found in both centric and pennate marine diatoms, suggesting that SLC transporters are generally conserved. Here, the generality of SLC-mediated DIC uptake in diatoms was examined using an SLC inhibitor, diisothiocyano-2,2'-stilbenedisulfonic acid (DIDS), and an inhibitor of external carbonic anhydrase, acetazolamide. DIDS suppressed high-DIC-affinity photosynthesis in the pennate diatom Phaeodactylum tricornutum and the centric diatom Chaetoceros muelleri, but there was no effect on either the pennate Cylindrotheca fusiformis or the centric Thalassiosira pseudonana. Interestingly, the DIC affinity of DIDS-insensitive strains was sensitive to treatment with up to 100 μM acetazolamide, displaying a 2-4-fold increase in K0.5[DIC]. In contrast, acetazolamide did not affect the DIDS-sensitive group. These results indicate the occurrence of two distinct strategies for DIC uptake-one primarily facilitated by SLC and the other being passive CO2 entry facilitated by external carbonic anhydrase. The phylogenetic independence of these strategies suggests that environmental demands drove the evolution of distinct DIC uptake mechanisms in diatoms.

Molecular aspects of the biophysical CO2-concentrating mechanism and its regulation in marine diatoms

Diatoms operate a CO2-concentrating mechanism (CCM) that drives upwards of 20% of annual global primary production. Recent progress in CCM research in the marine pennate diatom Phaeodactylum tricornutum revealed that this diatom directly takes up HCO3- from seawater through low-CO2-inducible plasma membrane HCO3- transporters, which belong to the solute carrier (SLC) 4 family. Apart from this, studies of carbonic anhydrases (CAs) in diatoms have revealed considerable diversity in classes and localization among species. This strongly suggests that the CA systems, which control permeability and flux of dissolved inorganic carbon (DIC) by catalysing reversible CO2 hydration, have evolved from diverse origins. Of particular interest is the occurrence of low-CO2-inducible external CAs in the centric marine diatom Thalassiosira pseudonana, offering a strategy of CA-catalysed initial CO2 entry via passive diffusion, contrasting with active DIC transport in P. tricornutum. Molecular mechanisms to transport DIC across chloroplast envelopes are likely also through specific HCO3- transporters, although details have yet to be elucidated. Furthermore, recent discovery of a luminal θ-CA in the diatom thylakoid implied a common strategy in the mechanism to supply CO2 to RubisCO in the pyrenoid, which is conserved among green algae and some heterokontophytes. These results strongly suggest an occurrence of convergent coevolution between the pyrenoid and thylakoid membrane in aquatic photosynthesis.

Hepatic fat quantification using the two-point Dixon method and fat color maps based on non-alcoholic fatty liver disease activity score

AIM

The two-point Dixon method for magnetic resonance imaging (MRI) is commonly used to non-invasively measure fat deposition in the liver. The aim of the present study was to assess the usefulness of MRI-fat fraction (MRI-FF) using the two-point Dixon method based on the non-alcoholic fatty liver disease activity score.

METHODS

This retrospective study included 106 patients who underwent liver MRI and MR spectroscopy, and 201 patients who underwent liver MRI and histological assessment. The relationship between MRI-FF and MR spectroscopy-fat fraction was used to estimate the corrected MRI-FF for hepatic multi-peaks of fat. Then, a color FF map was generated with the corrected MRI-FF based on the non-alcoholic fatty liver disease activity score. We defined FF variability as the standard deviation of FF in regions of interest. Uniformity of hepatic fat was visually graded on a three-point scale using both gray-scale and color FF maps. Confounding effects of histology (iron, inflammation and fibrosis) on corrected MRI-FF were assessed by multiple linear regression.

RESULTS

The linear correlations between MRI-FF and MR spectroscopy-fat fraction, and between corrected MRI-FF and histological steatosis were strong (R²  = 0.90 and R²  = 0.88, respectively). Liver fat variability significantly increased with visual fat uniformity grade using both of the maps (ρ = 0.67-0.69, both P < 0.001). Hepatic iron, inflammation and fibrosis had no significant confounding effects on the corrected MRI-FF (all P > 0.05).

CONCLUSIONS

The two-point Dixon method and the gray-scale or color FF maps based on the non-alcoholic fatty liver disease activity score were useful for fat quantification in the liver of patients without severe iron deposition.

Abstract P2-05-24: Prognostic value of circulating PIK3CA mutations revealed with digital PCR in patients with HER2-positive advanced breast cancer: Results of West Japan Oncology Group study 6110BTR

This abstract was withdrawn by the authors.

The Beneficial Effect of Carboxylated Poly-L-Lysine on Cryosurvival of Vitrified Early Stage Embryos

BACKGROUND

In the vitrification of embryos, dimethyl sulfoxide (DMSO) is one of the most effective cryoprotectant agents (CPAs), but cytotoxic effects of DMSO on embryos are well known. Carboxylated poly-L-lysine (CPLL) has been identified as an effective cryoprotectant of cultured cell lines and mammalian oocytes.

OBJECTIVE

To evaluate the efficacy and safety of CPLL as a CPA for developmental stage embryos.

MATERIALS AND METHODS

Mouse 8-cell embryos and blastocysts were vitrified with ethylene glycol (EG), DMSO/EG, or CPLL/EG and the developmental potency assessed in vitro.

RESULTS

In 8-cell embryos, there were no differences between the levels of survival and developmental progress into the blastocyst stage in each solution. At the blastocyst stage, the proportion of dead cells was significantly higher in the EG compared with other solutions. In contrast, there were no differences between the DMSO/EG and CPLL/EG.

CONCLUSION

These results indicate that CPLL can be used as a replacement for DMSO in the vitrification of mouse embryos.

Unilateral Leg Swelling Caused by Common Femoral Vein Compression by a Hip Ganglion Cyst in the Groin

Background

As a rare cause of unilateral leg swelling, extrinsic vein compression caused by intraperitoneal, retroperitoneal, or inguinal lesions has been noted. A rare case of leg swelling as a cause of extrinsic compression of common femoral vein from a ganglion cyst in the groin is presented.

Case presentation

A 38 year old man was referred with a 3 week history of left leg swelling. Following a radiological diagnosis of common femoral vein compression from a cystic groin mass, he firstly underwent needle aspiration. Although the lesion became somewhat smaller, his left leg was still swollen, and he underwent surgical excision of the lesion 2 days after needle aspiration. Histopathological features of the cystic wall were consistent with those of a ganglion cyst. He was discharged from the hospital with complete improvement of the leg swelling, and has remained free from recurrence 1 year after surgery.

Conclusion

Femoral vein compression by a ganglion cyst in the groin is a very rare pathology; however, it should be kept in mind in the differential diagnosis of unilateral leg swelling.

•

Ganglion cyst in the groin is a benign hip joint related lesion.

•

Extrinsic compression of common femoral vein by a ganglion cyst in the groin is a rare cause of unilateral leg swelling.

•

Surgical excision of a ganglion cyst in the groin is more curative than needle aspiration.

Thylakoid luminal θ-carbonic anhydrase critical for growth and photosynthesis in the marine diatom Phaeodactylum tricornutum

The algal pyrenoid is a large plastid body, where the majority of the CO2-fixing enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) resides, and it is proposed to be the hub of the algal CO2-concentrating mechanism (CCM) and CO2 fixation. The thylakoid membrane is often in close proximity to or penetrates the pyrenoid itself, implying there is a functional cooperation between the pyrenoid and thylakoid. Here, GFP tagging and immunolocalization analyses revealed that a previously unidentified protein, Pt43233, is targeted to the lumen of the pyrenoid-penetrating thylakoid in the marine diatom Phaeodactylum tricornutum The recombinant Pt43233 produced in Escherichia coli cells had both carbonic anhydrase (CA) and esterase activities. Furthermore, a Pt43233:GFP-fusion protein immunoprecipitated from P. tricornutum cells displayed a greater specific CA activity than detected for the purified recombinant protein. In an RNAi-generated Pt43233 knockdown mutant grown in atmospheric CO2 levels, photosynthetic dissolved inorganic carbon (DIC) affinity was decreased and growth was constantly retarded; in contrast, overexpression of Pt43233:GFP yielded a slightly greater photosynthetic DIC affinity. The discovery of a θ-type CA localized to the thylakoid lumen, with an essential role in photosynthetic efficiency and growth, strongly suggests the existence of a common role for the thylakoid-luminal CA with respect to the function of diverse algal pyrenoids.

Randomized phase III study of bevacizumab plus FOLFIRI and bevacizumab plus mFOLFOX6 as first-line treatment for patients with metastatic colorectal cancer (WJOG4407G)

BACKGROUND

FOLFIRI and FOLFOX have shown equivalent efficacy for metastatic colorectal cancer (mCRC), but their comparative effectiveness is unknown when combined with bevacizumab.

PATIENTS AND METHODS

WJOG4407G was a randomized, open-label, phase III trial conducted in Japan. Patients with previously untreated mCRC were randomized 1:1 to receive either FOLFIRI plus bevacizumab (FOLFIRI + Bev) or mFOLFOX6 plus bevacizumab (mFOLFOX6 + Bev), stratified by institution, adjuvant chemotherapy, and liver-limited disease. The primary end point was non-inferiority of FOLFIRI + Bev to mFOLFOX6 + Bev in progression-free survival (PFS), with an expected hazard ratio (HR) of 0.9 and non-inferiority margin of 1.25 (power 0.85, one-sided α-error 0.025). The secondary end points were response rate (RR), overall survival (OS), safety, and quality of life (QoL) during 18 months. This trial is registered to the University Hospital Medical Information Network, number UMIN000001396.

RESULTS

Among 402 patients enrolled from September 2008 to January 2012, 395 patients were eligible for efficacy analysis. The median PFS for FOLFIRI + Bev (n = 197) and mFOLFOX6 + Bev (n = 198) were 12.1 and 10.7 months, respectively [HR, 0.905; 95% confidence interval (CI) 0.723-1.133; P = 0.003 for non-inferiority]. The median OS for FOLFIRI + Bev and mFOLFOX6 + Bev were 31.4 and 30.1 months, respectively (HR, 0.990; 95% CI 0.785-1.249). The best overall RRs were 64% for FOLFIRI + Bev and 62% for mFOLFOX6 + Bev. The common grade 3 or higher adverse events were leukopenia (11% in FOLFIRI + Bev/5% in mFOLFOX6 + Bev), neutropenia (46%/35%), diarrhea (9%/5%), febrile neutropenia (5%/2%), peripheral neuropathy (0%/22%), and venous thromboembolism (6%/2%). The QoL assessed by FACT-C (TOI-PFC) and FACT/GOG-Ntx was favorable for FOLFIRI + Bev during 18 months.

CONCLUSION

FOLFIRI plus bevacizumab was non-inferior for PFS, compared with mFOLFOX6 plus bevacizumab, as the first-line systemic treatment for mCRC.

CLINICAL TRIALS NUMBER

UMIN000001396.

Association of the clinical efficacy of vancomycin with the novel pharmacokinetic parameter area under the trough level (AUTL) in elderly patients with hospital-acquired pneumonia

WHAT IS KNOWN AND OBJECTIVE

The pharmacokinetic-pharmacodynamic parameter that best predicts the efficacy of vancomycin is the ratio of the area under the concentration versus time curve (AUC) to the minimum inhibitory concentration (MIC). A 24-h AUC (AUC24 )/MIC ratio ≥ 400 was recommended in an American consensus review, but vancomycin treatment occasionally fails despite maintenance of AUC24 /MIC ≥ 400. We evaluated the association between clinical efficacy of vancomycin and two novel pharmacokinetic parameters, the 'area under the trough level' (AUTL) and the 'area above the trough level' (AATL), in hospitalized elderly patients with methicillin-resistant Staphylococcus aureus (MRSA) pneumonia.

METHODS

The subjects were hospitalized elderly patients who were administered vancomycin for treatment of MRSA pneumonia between 2006 and 2012 at Sasebo Chuo Hospital (Nagasaki, Japan). Pharmacokinetic parameters of vancomycin were estimated for each patient by Bayesian analysis using population pharmacokinetic parameters for Japanese patients. Based on the patient-specific parameters thus obtained, AUC24 values were calculated as the vancomycin dosage divided by vancomycin clearance. AUTL was calculated as the trough serum concentration multiplied by 24 h, whereas AATL was calculated by subtracting AUTL from AUC24 .

RESULTS AND DISCUSSION

Logistic regression analysis demonstrated that efficacy of vancomycin was more strongly associated with AUTL than AUC24 . The optimal cut-off value of AUTL was 331 μg∙h/mL, which means that the optimal cut-off value of the trough serum concentration was 13·8 μg/mL.

WHAT IS NEW AND CONCLUSION

Efficacy of vancomycin was associated with AUTL, a novel pharmacokinetic parameter. Determining the target AUTL or trough concentration may enhance the efficacy of vancomycin therapy in elderly patients with MRSA pneumonia. Given that nephrotoxicity may increase with a Ctrough in excess of 15 μg/mL, this level should ideally not be exceeded.

Quantitative Analysis of Carbon Flow into Photosynthetic Products Functioning as Carbon Storage in the Marine Coccolithophore, Emiliania huxleyi

The bloom-forming coccolithophore Emiliania huxleyi (Haptophyta) is a dominant marine phytoplankton, cells of which are covered with calcareous plates (coccoliths). E. huxleyi produces unique lipids of C37-C40 long-chain ketones (alkenones) with two to four trans-unsaturated bonds, β-glucan (but not α-glucan) and acid polysaccharide (AP) associated with the morphogenesis of CaCO3 crystals in coccoliths. Despite such unique features, there is no detailed information on the patterns of carbon allocation into these compounds. Therefore, we performed quantitative estimation of carbon flow into various macromolecular products by conducting (14)C-radiotracer experiments using NaH(14)CO3 as a substrate. Photosynthetic (14)C incorporation into low molecular-mass compounds (LMC), extracellular AP, alkenones, and total lipids except alkenones was estimated to be 35, 13, 17, and 25 % of total (14)C fixation in logarithmic growth phase cells and 33, 19, 18, and 18 % in stationary growth phase cells, respectively. However, less than 1 % of (14)C was incorporated into β-glucan in both cells. (14)C-mannitol occupied ca. 5 % of total fixed (14)C as the most dominant LMC product. Levels of all (14)C compounds decreased in the dark. Therefore, alkenones and LMC (including mannitol), but not β-glucan, function in carbon/energy storage in E. huxleyi, irrespective of the growth phase. Compared with other algae, the low carbon flux into β-glucan is a unique feature of carbon metabolism in E. huxelyi.