Ultrasonographic evaluation of the caudal vena cava in dogs with right-sided heart disease.

INTRODUCTION/OBJECTIVES: In humans with impaired right-sided cardiac function, the caudal vena cava (CVC) diameter serves as a marker of venous congestion. This study aimed to investigate whether ultrasonographic CVC variables could identify the presence of right-sided congestive heart failure (R-CHF) in dogs with right-sided heart disease (RHD). ANIMALS: Fifty client-owned control dogs and 67 dogs with RHD were enrolled. The dogs with RHD were subdivided into the non-R-CHF (n = 43) and R-CHF (n = 24) groups. MATERIALS AND METHODS: We measured and compared the ultrasonographic CVC variables and echocardiographic variables among the groups. Receiver operating characteristic (ROC) curve analysis was performed to calculate the sensitivity and specificity of the variables at optimal cutoff values. RESULTS: We obtained the highest accuracies of the ratio of the shortest diameter (SD) of the minimal CVC area to the aorta diameter (Ao) during inspiration [SD(min)/Ao] and of the ratio of SD(min) to the longest diameter of the minimal CVC area during inspiration [LD(min),SD/LD(min)], with high sensitivities, specificities, and an area under the ROC curve greater than 0.925. CONCLUSIONS: In addition to the echocardiographic assessment of right-sided cardiac function, the CVC variables in this study, especially SD(min)/Ao and SD/LD(min), would be useful diagnostic indices for identifying R-CHF in dogs with RHD.

Benign hilar bile duct strictures resected as perihilar cholangiocarcinoma.

BACKGROUND: Differentiation between perihilar cholangiocarcinoma (PHCC) and benign strictures is frequently difficult. The aim of this study was to investigate the incidence and long-term outcome of patients with tumours resected because of suspicion of PHCC, which ultimately turned out to be benign (malignancy masquerade). METHODS: Patients who underwent surgical resection with a diagnosis of PHCC between 2001 and 2016 were reviewed retrospectively. RESULTS: Among 707 consecutive patients, 685 had PHCC and the remaining 22 (3·1 per cent) had benign biliary stricture. All patients with benign disease underwent major hepatectomy, with no deaths. Preoperative histological assessment using bile duct biopsy or aspiration cytology had a high specificity (90 per cent), low sensitivity (62 per cent) and unsatisfactory accuracy (63 per cent). Despite the increasing use of histological assessment, the incidence of benign strictures resected did not decrease over time, being 0·9 per cent in 2001-2004, 4·0 per cent in 2005-2008, 3·8 per cent in 2009-2012 and 2·9 per cent in 2013-2016. The final pathology of benign strictures included IgG4-related sclerosing cholangitis (9 patients), hepatolithiasis (4), granulomatous cholangitis (3), non-specific chronic cholangitis (3), benign strictures after cholecystectomy (2), and a benign stricture possibly caused by parasitic infection (1). The 10-year overall survival rate for the 22 patients with benign stricture was 87 per cent, without recurrence of biliary stricture. CONCLUSION: The incidence of benign strictures resected as PHCC as a proportion of all resections was relatively low, at 3·1 per cent. Currently, unnecessary surgery for suspected PHCC is unavoidable.

ANTECEDENTES: La diferenciación entre colangiocarcinoma perihilar (perihilar colangiocarcinoma, PHCC) y estenosis benignas es con frecuencia difícil. El objetivo de este estudio fue investigar la incidencia y el resultado a largo plazo de los tumores resecados con sospecha diagnóstica de PHCC, que finalmente resultaron ser benignos (malignidad enmascarada). MÉTODOS: Se revisaron retrospectivamente los pacientes con diagnóstico de PHCC que se sometieron a resección quirúrgica entre 2001 y 2016. RESULTADOS: Entre 707 pacientes consecutivos, 685 pacientes presentaban PHCC y los 22 restantes (3,1%) tenían una estenosis biliar benigna. Todos los pacientes con patología benigna se sometieron a una hepatectomía mayor, sin mortalidad. La evaluación histológica preoperatoria mediante biopsia de conducto biliar o citología por aspiración tuvo una alta especificidad (90%), una baja sensibilidad (62%) y una exactitud diagnóstica insatisfactoria (63%). A pesar del uso creciente de la evaluación histológica, la incidencia de estenosis benignas resecadas no disminuyó con el tiempo, con un 0,9% en 2001-2004, un 4,0% en 2005-2008, un 3,8% en 2009-2012 y un 2,9% en 2013-2016. La patología final de las estenosis benignas incluyó colangitis esclerosante relacionada con IgG4 (n = 9), hepatolitiasis (n = 4), colangitis granulomatosa (n = 3), colangitis crónica no específica (n = 3), estenosis benignas tras una colecistectomía (n = 2) y una estenosis benigna posiblemente causada por una infección parasitaria (n = 1). Los resultados a largo plazo de los 22 pacientes con estenosis benigna fueron mejores (tasa de supervivencia a 10 años; 87,4%) sin recidiva de la estenosis biliar. CONCLUSIÓN: La incidencia de pacientes con estenosis benignas resecadas como PHCC en comparación con todas las resecciones fue relativamente baja, del 3,1%. Actualmente, la cirugía "innecesaria" por sospecha de PHCC es inevitable.

Modulation of extrasynaptic GABAA alpha 5 receptors in the ventral hippocampus normalizes physiological and behavioral deficits in a circuit specific manner.

Hippocampal hyperactivity is correlated with psychosis in schizophrenia patients and likely attributable to deficits in GABAergic signaling. Here we attempt to reverse this deficit by overexpression of the α5-GABAA receptor within the ventral hippocampus (vHipp). Indeed, this is sufficient to normalize vHipp activity and downstream alterations in dopamine neuron function in the MAM rodent model. This approach also attenuated behavioral deficits in cognitive flexibility. To understand the specific pathways that mediate these effects, we used chemogenetics to manipulate discrete projections from the vHipp to the nucleus accumbens (NAc) or prefrontal cortex (mPFC). We found that inhibition of the vHipp-NAc, but not the vHipp-mPFC pathway, normalized aberrant dopamine neuron activity. Conversely, inhibition of the vHipp-mPFC improved cognitive function. Taken together, these results demonstrate that restoring GABAergic signaling in the vHipp improves schizophrenia-like deficits and that distinct behavioral alterations are mediated by discrete projections from the vHipp to the NAc and mPFC.

Prepatterning of Papilio xuthus caterpillar camouflage is controlled by three homeobox genes: clawless, abdominal-A, and Abdominal-B.

Color patterns often function as camouflage to protect insects from predators. In most swallowtail butterflies, younger larvae mimic bird droppings but change their pattern to mimic their host plants during their final molt. This pattern change is determined during the early fourth instar by juvenile hormone (JH-sensitive period), but it remains unclear how the prepatterning process is controlled. Using Papilio xuthus larvae, we performed transcriptome comparisons to identify three camouflage pattern-associated homeobox genes [clawless, abdominal-A, and Abdominal-B (Abd-B)] that are up-regulated during the JH-sensitive period in a region-specific manner. Electroporation-mediated knockdown of each gene at the third instar caused loss or change of original fifth instar patterns, but not the fourth instar mimetic pattern, and knockdown of Abd-B after the JH-sensitive period had no effect on fifth instar patterns. These results indicate the role of these genes during the JH-sensitive period and in the control of the prepatterning gene network.

Major hepatectomy with or without pancreatoduodenectomy for advanced gallbladder cancer.

BACKGROUND: The indications for major hepatectomy for gallbladder cancer either with or without pancreatoduodenectomy remain controversial. The clinical value of these extended procedures was evaluated in this study. METHODS: Patients who underwent major hepatectomy for gallbladder cancer between 1996 and 2016 were identified from a prospectively compiled database. Postoperative outcomes and overall survival were compared between patients undergoing major hepatectomy alone or combined with pancreatoduodenectomy (HPD). RESULTS: Seventy-nine patients underwent major hepatectomy alone and 38 patients had HPD. The patients who underwent HPD were more likely to have T4 disease (P < 0·001), nodal metastasis (P = 0·015) and periaortic nodal metastasis (P = 0·006), but were less likely to receive adjuvant therapy (P = 0·006). HPD was associated with a high incidence of grade III or higher complications (P = 0·002) and death (P = 0·037). Overall survival was longer in patients who underwent major hepatectomy alone than in patients who underwent HPD (median survival time 32 versus 10 months; P < 0·001). In multivariable analysis, surgery in the early period (1996-2006) (P = 0·002), pathological T4 disease (P = 0·005) and distant metastasis (P < 0·001) were associated with shorter overall survival, and cystic duct tumour (P = 0·002) with longer overall survival. CONCLUSION: Major hepatectomy alone for gallbladder cancer contributes to favourable overall survival with low morbidity and mortality, whereas HPD is associated with poor overall survival and high morbidity and mortality rates. HPD may eradicate locally spreading gallbladder cancer; however, the indication for the procedure is questioned from an oncological viewpoint.

Relationships between blood pressure lowering therapy and cardiovascular events in hypertensive patients with coronary artery disease and type 2 diabetes mellitus: The HIJ-CREATE sub-study.

OBJECTIVE: The effects of intensive blood pressure (BP) lowering for hypertensive patients with coronary artery disease (CAD) and diabetes mellitus on their clinical outcomes have not been fully evaluated. The aim was to explore the optimal systolic BP target in such patients in a substudy of a prospective, randomized trial. METHODS: Of a total of 2049 hypertensive patients with CAD who were enrolled in the HIJ-CREATE study, type 2 diabetes was diagnosed in 780 (38.1%). Titration of antihypertensive agents was performed to reach the target BP of <130/85 mmHg. The primary endpoint was the occurrence of a first major adverse cardiovascular event (MACE). Achieved BP was defined as the mean value of systolic BP in patients who did not develop MACEs and as the mean value of systolic BP prior to MACEs in those who developed MACEs during follow-up. RESULTS: During a median follow-up of 4.2 years, the primary outcome occurred in 259 (33.2%) diabetic patients and in 293 (23.1%) non-diabetic patients (p < 0.0001). The diabetic patients were divided into quartiles based on the mean systolic BP during follow-up. The relationships between achieved BP and the incidence of MACEs did not follow a J-shaped curve. Intensive systolic BP lowering to less than 120 mmHg did not correlate with an increased risk of MACEs. CONCLUSIONS: Our results suggest that the intensive BP lowering may not impair patients' clinical courses even in a high-risk population. The establishment of an optimal management strategy for hypertensive patients with diabetes and CAD is essential.

Ethanol ablation for refractory bile leakage after complex hepatectomy.

BACKGROUND: Only a few reports exist on the use of ethanol ablation for posthepatectomy bile leakage. The aim of this study was to assess the value of ethanol ablation in refractory bile leakage. METHODS: Medical records of consecutive patients who underwent a first hepatobiliary resection with bilioenteric anastomosis between 2007 and 2016 were reviewed retrospectively, with special attention to bile leakage and ethanol ablation therapy. Bile leakage was graded as A/B1/B2 according to the International Study Group of Liver Surgery definition. Absolute ethanol was injected into the target bile duct during fistulography. RESULTS: Of the 609 study patients, 237 (38·9 per cent) had bile leakage, including grade A in 33, grade B1 in 18 and grade B2 in 186. Left trisectionectomy was more often associated with grade B2 bile leakage than other types of hepatectomy (P < 0·001). Of 186 patients with grade B2 bile leakage, 31 underwent ethanol ablation therapy. Ethanol ablation was started a median of 34 (range 15-122) days after hepatectomy. The median number of treatments was 3 (1-7), and the total amount of ethanol used was 15 (3-71) ml. Complications related to ethanol ablation included transient fever (27 patients) and mild pain (13). Following ethanol ablation, bile leakage resolved in all patients and drains were removed. The median interval between the first ablation and drain removal was 28 (1-154) days. CONCLUSION: Ethanol ablation is safe and effective, and may be a treatment option for refractory bile leakage.

Identification of rare HIV-1 Group N, HBV AE, and HTLV-3 strains in rural South Cameroon.

Surveillance of emerging viral variants is critical to ensuring that blood screening and diagnostic tests detect all infections regardless of strain or geographic location. In this study, we conducted serological and molecular surveillance to monitor the prevalence and diversity of HIV, HBV, and HTLV in South Cameroon. The prevalence of HIV was 8.53%, HBV was 10.45%, and HTLV was 1.04% amongst study participants. Molecular characterization of 555 HIV-1 specimens identified incredible diversity, including 7 subtypes, 12 CRFs, 6 unclassified, 24 Group O and 2 Group N infections. Amongst 401 HBV sequences were found a rare HBV AE recombinant and two emerging sub-genotype A strains. In addition to HTLV-1 and HTLV-2 strains, sequencing confirmed the fifth known HTLV-3 infection to date. Continued HIV/HBV/HTLV surveillance and vigilance for newly emerging strains in South Cameroon will be essential to ensure diagnostic tests and research stay a step ahead of these rapidly evolving viruses.

Changes in standing body sway of pregnant women after long-term bed rest.

Pregnant women tend to fall and increased body postural instability, namely body sway, may be one of the causative factors. We had a clinical impression that pregnant women after long-term bed rest tend to fall. We hypothesised that such women may show increased body sway, which we attempted to determine. Pregnant women (n = 161) were divided into three groups: (i) women with preterm labour after 2-week bed rest, (ii) those after 4-week bed rest, and (iii) those without bed rest or preterm labour. Body sway was analysed using stabilometry, that is, computed analysis of movement of the centre of gravity. The 3 groups fundamentally showed the same stabilometric measurements. Women with oedema showed greater medial-lateral sway than those without it. Factors other than oedema yielded no differences in stabilometric parameters. Long-term bed rest fundamentally did not increase body sway to the extent that stabilometry could reveal it. It may be prudent to consider that pregnant women with oedema tend to fall.

Liver regeneration following experimental major hepatectomy with choledochojejunostomy.

BACKGROUND: Surgical treatment for perihilar cholangiocarcinoma frequently involves hepatectomy and extrahepatic bile duct resection with a choledochojejunostomy (CJ). Cholangitis owing to bilioenteric anastomosis is a common complication. The impact of CJ or regurgitating cholangitis on the liver regeneration process after major hepatectomy is unknown. METHODS: Rats underwent 70 per cent hepatectomy (Hx group) or hepatectomy with CJ (Hx + CJ group). The intrahepatic inflammatory response, hepatic regeneration rate, and expression of regeneration-associated genes in the liver and blood were compared between these two groups. RESULTS: Levels of hepatobiliary markers in the blood were significantly higher 4 and 7 days after operation in the Hx + CJ group than the Hx group. Intrahepatic expression of inflammation-associated genes, such as interleukin 6 and tumour necrosis factor α, was also significantly higher in the Hx + CJ group on days 4 and 7. A progressive periportal inflammatory response was identified in the Hx + CJ group by histological examination. The hepatic regeneration rate was significantly lower in the Hx + CJ group than in the Hx group on day 2 (mean(s.d.) 14·2(6·3) versus 21·4(2·6) per cent; P = 0·013) and day 4 (32·4(5·3) versus 41·3(4·4) per cent; P = 0·004). Gene expression levels of hepatic regeneration-promoting factors such as hepatocyte growth factor were significantly lower in the Hx + CJ group than the Hx group on day 1. CONCLUSION: CJ perturbs early liver regeneration after hepatectomy. An excessive inflammatory response in the liver and suppression of liver regeneration-associated factors may play a role. Surgical relevance Patients with perihilar cholangiocarcinoma may need major hepatectomy with extrahepatic bile duct resection and choledochojejunostomy. This carries a substantial risk of postoperative complications including liver failure. A rat model of partial hepatectomy with choledochojejunostomy was established. The molecular mechanisms underlying liver regeneration, and perturbation of this process by duodenobiliary reflux via the choledochojejunostomy, are described. The results give insight into the pathophysiological events following major hepatectomy with extrahepatic bile duct resection and choledochojejunostomy. This may help to develop a treatment strategy to reduce postoperative liver failure.

[Delayed augmentation effect of cytokine production after hyperthermia stimuli].

Heatstroke is considered an important condition that may contribute to endothelial cell damage. The aim of this study was to assess temporal profiles of the cytokine (IL-6 and IL-8) and mRNA production when endothelial cells undergo higher temperature stimuli. In the first group, human umbilical vascular endothelial cells (HUVECs)were cultured at 4 different temperatures (37, 38, 39 or 40 degrees C) for 1, 3 and 5 h. In the second group, HUVECs were cultured at 37 degrees C for 4 h or 23 h, after stimulation by heating for one hour at the same culture temperatures used in the first group (37 degrees C to 40 degrees C). After culturing, IL-6 and IL-8 mRNA and protein levels were measured. It has been found the cytokine mRNA levels being significantly higher (p < 0.001) in all cells incubated at higher temperatures than those in the control (cultivation at 37 degrees C). At the same time, the productionof IL-6 and 8 at a higher temperature (39, 40 degrees C) was significantly lower (p < 0.001) than at 37 degrees C (control), and the decrease was temperature dependent. However, IL-6 and IL-8 levels were significantly greater in the cells at 23 h after transient hyperthermic (40 degrees C, 1 h) stimulation than in control ones (p < 0.001).After a transient hyperthermia, the production of the cytokines in HUVECs is initially inhibited and then augmented. The results indicated that tissue injury might continue to develop after a hyperthermic event. There might be a potent risk for underestimation of cytokine induced tissue injury in the acute phase of a heatstroke.

Interleukin-18 is elevated in the horny layer in patients with atopic dermatitis and is associated with Staphylococcus aureus colonization.

BACKGROUND: An increase in interleukin (IL)-18 production from epidermal cells has been reported in an atopic dermatitis (AD) mouse model, and subsequent topical application of Staphylococcus aureus results in severe dermatitis. OBJECTIVES: To reveal the relationship between S. aureus colonization of skin lesions and keratinocyte IL-18 production, particularly in AD with relatively low serum IgE levels. We also aimed to establish a simple and noninvasive method of assaying IL-18 produced by epidermal keratinocytes to evaluate local skin inflammation and therapeutic effects in patients with AD. METHODS: IL-18 in the horny layer of the skin was collected via a tape-stripping method and measured in 95 patients with AD and 40 healthy controls by enzyme-linked immunosorbent assay (ELISA). Clinical severity, blood data and S. aureus skin colonization were evaluated before and after treatment. RESULTS: IL-18 levels in the horny layer were significantly higher in the skin lesions of patients with AD than in healthy controls and correlated with SCORAD, levels of serum IL-18, IgE, lactate dehydrogenase, thymus and activation-regulated chemokine, blood eosinophils and transepidermal water loss. In the AD group with serum IgE < 1500 IU mL(-1) , significantly higher IL-18 levels were observed in the horny layer of patients colonized with S. aureus compared with those who were not. CONCLUSIONS: Epidermal IL-18 production was associated with the severity of AD. Staphylococcus aureus colonization seems to contribute to this IL-18 production, especially in the AD group with relatively low IgE production. Tape stripping provides an easy and noninvasive method to assess epidermal IL-18 production by ELISA.

High resolution, low hν photoelectron spectroscopy with the use of a microwave excited rare gas lamp and ionic crystal filters.

The need for not only bulk sensitive but also extremely high resolution photoelectron spectroscopy for studying detailed electronic structures of strongly correlated electron systems is growing rapidly. Moreover, easy access to such a capability in one's own laboratory is desirable. Demonstrated here is the performance of a microwave excited rare gas (Xe, Kr, and Ar) lamp combined with ionic crystal filters (sapphire, CaF(2), and LiF), which can supply three strong lines near the photon energy of hnyu hν=8.4, 10.0, and 11.6 eV, with the hν resolution of better than 600 µeV for photoelectron spectroscopy. Its performance is demonstrated on some materials by means of both angle-integrated and angle-resolved measurements.

Endocannabinoids contribute to metabotropic glutamate receptor-mediated inhibition of GABA release onto hippocampal CA3 pyramidal neurons in an isolated neuron/bouton preparation.

Retrograde synaptic signaling by endogenous cannabinoids (endocannabinoids) is a recently discovered form of neuromodulation in various brain regions. In hippocampus, it is well known that endocannabinoids suppress presynaptic inhibitory neurotransmitter release in CA1 region. However, endocannabinoid signaling in CA3 region remains to be examined. Here we investigated whether presynaptic inhibition can be caused by activation of postsynaptic group I metabotropic glutamate receptors (mGluRs) and following presynaptic cannabinoid receptor type 1 (CB1 receptor) using mechanically dissociated rat hippocampal CA3 pyramidal neurons with adherent functional synaptic boutons. Application of group I mGluR agonist (RS)-3,5-dihydroxyphenylglycine (DHPG) reversibly suppressed spontaneous inhibitory postsynaptic currents (IPSCs). In the presence of tetrodotoxin (TTX), frequency of miniature IPSCs was significantly reduced by DHPG, while there were no significant changes in minimum quantal size and sensitivity of postsynaptic GABA(A) receptors to the GABA(A) receptor agonist muscimol, indicating that this suppression was caused by a decrease in GABA release from presynaptic nerve terminals. Application of CB1 synthetic agonist WIN55212-2 (mesylate(R)-(+)-[2,3-dihydro-5-methyl-3-[4-morpholino)methyl]pyrrolo-[1,2,3-de]-1,4-benzoxazin-6-yl](1-naphthyl)methanone) or endocannabinoid 2-arachidonoylglycerol also suppressed the spontaneous IPSC. The inhibitory effect of DHPG on spontaneous IPSCs was abolished by SR-141716 (5-(4-chlorophenyl)-1-(2,4-dichloro-phenyl)-4-methyl-N-(piperidin-1-yl)-1H-pyrazole-3-carboxamide), a CB1 receptor antagonist. Furthermore, postsynaptic application of GDP-betaS blocked the DHPG-induced inhibition of spontaneous IPSCs, indicating the involvement of endcannabinoid-mediated retrograde synaptic signaling. These results provide solid evidence for retrograde signaling from postsynaptic group I mGluRs to presynaptic CB1 receptors, which induces presynaptic inhibition of GABA release in rat hippocampal CA3 region.

Changes in Fungicide Resistance Frequency and Population Structure of Pyricularia oryzae after Discontinuance of MBI-D Fungicides.

The changes in fungicide resistance frequency and population structure of the rice blast fungus Pyricularia oryzae were monitored after the discontinuance of melanin biosynthesis inhibitor targeting scytalone dehydratase (MBI-D) fungicides use in Saga Prefecture, Japan. After discontinuance in 2003, the frequency of resistant isolates decreased from 71.8% in 2002 to 25% in 2003, and became undetectable in 2007. The initial marked decrease was due to a decline of isolates possessing the predominant haplotype, although the haplotypic diversity among resistant isolates remained high from 2003 to 2005. These results revealed that resistant isolates were less fit in comparison with sensitive isolates in the absence of MBI-D fungicide pressure under field conditions. Pairwise FST values indicated that the change in population structure after MBI-D discontinuance was explainable by a rapid change in the proportions of resistant and sensitive subpopulations. Depending upon the existence of fitness cost and rapid changes in population structure, it may be possible to reintroduce MBI-D fungicides in areas where resistance has already developed, although we speculate that fitness cost related to MBI-D resistance may be small based on our present results and previous findings.

Over-expression of polycomb group protein EZH2 relates to decreased expression of p16 INK4a in cholangiocarcinogenesis in hepatolithiasis.

Polycomb group protein EZH2 and Bmi1 are reportedly involved in the progression of malignant tumours. We examined the participation of EZH2 in multi-step cholangiocarcinogenesis in hepatolithiasis with respect to tumour suppressor gene p16 INK4a. We examined 20 hepatolithiatic livers with intrahepatic cholangiocarcinoma (ICC) and 10 histologically normal livers. Neoplastic biliary lesions were classified into biliary intraepithelial neoplasm (BilIN-1, 2 and 3) and invasive carcinoma. We selected 15 foci of invasive carcinoma, 8 BilIN-3 (carcinoma in situ), 12 BilIN-2 (high-grade dysplasia), 32 BilIN-1 (low-grade dysplasia) and 37 non-neoplastic biliary epithelia from these livers. Expression of p16 INK4a, EZH2 and Bmi1 were surveyed in these foci. P16 INK4a promoter methylation was examined in microdissected tissues. Taking advantage of two cell lines of CC (HuCTT-1 and TFK-1) and small interfering RNA (siRNA), the effects of the knockdown of EZH2 on p16 INK4a methylation of CC cells were examined. Expression of p16 INK4a, which was frequent in BilIN1, was decreased in BilIN-2/3 and invasive carcinoma, while EZH2 expression showed step-wise increase from BilIN-1, -2 and -3 to invasive carcinoma (p < 0.01). P16 INK4a promoter hypermethylation was related to aberrant expression of EZH2. The knockdown of EZH2 in cultured CC cells decreased p16 INK4a methylation and decreased binding of EZH2 to the p16 INK4a gene promoter. The latter suggested that direct binding of EZH2 is involved in the regulation of the p16 INK4a gene. Our data suggest that over-expression of EZH2 may induce hypermethylation of p16 INK4a promoter followed by decreased expression of p16 INK4a in the multi-step cholangiocarcinogenesis through intraepithelial neoplasm in hepatolithiasis.

Allelic diversification at the wx locus in landraces of Asian rice.

To examine continuous variation of amylose levels in Asian rice (Oryza sativa) landraces, the five putative alleles (Wx a, Wx in, Wx b, Wx op, and wx) at the wx locus were investigated in near-isogenic lines (NILs). Apparent amylose levels ranged from 0.5 to 29.9% in the NILs, showing a positive relation with the levels of Wx gene product, granule-bound starch synthase (GBSS) as well as the enzymatic activity per milligram starch granule. Only opaque (Wx op) accessions had an enzymatic activity per GBSS that was reduced to half the level of the others. Nucleotide sequences in the Wx gene were compared among 18 accessions harboring the five different alleles. Each of the Wx alleles had a unique replacement, frame-shift or splice donor site mutation, suggesting that these nucleotide changes could be reflected in phenotype alterations. A molecular phylogenetic tree constructed using the Wx gene indicated that ssp. japonica forms a distinct clade, whereas ssp. indica forms different clades together with the wild progenitor. Unexpectedly, the wx allele of 160 (indica from Taiwan) joined the japonica lineage; however, comparisons using linked genes for two Taiwanese accessions revealed that the wx gene was the product of gene flow from japonica to indica. Therefore, the japonica lineage frequently included Wx in, Wx b and wx, while Wx a and Wx op were found in the other lineages, strongly suggesting that allelic diversification occurred after divergence of the two subspecies. The present results were discussed in relation to the maintenance of agronomically valuable genes in various landraces.

Differential expression of two fructokinases in Oryza sativa seedlings grown under aerobic and anaerobic conditions.

Fructokinases (EC 2.7.1.4) may play an important role in carbohydrate metabolism of Oryza sativa L. (rice) seedlings under anoxia. We present here the molecular and biochemical characterizations of two rice fructokinases, namely OsFK1 and OsFK2. The results show that, at both a transcriptional and a transductional level, OsFK1 is preferentially expressed under aerobic conditions, whereas OsFK2 is induced under anoxia. Substrate inhibition was demonstrated for OsFK1, while OsFK2 appears to be largely unaffected by fructose concentrations up to 10 mM. Sugar modulation of anoxia-induced proteins has been proposed, but our results on rice calli treated with or without glucose (10, 30 or 90 mM) for different time indicate that neither OsFK1 nor OsFK2 are sugar-regulated. We propose that OsFK2 plays a major role in fructose phosphorylation under anoxic conditions.