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.

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.

Maturation of catalase precursor proceeds to a different extent in glyoxysomes and leaf peroxisomes of pumpkin cotyledons

As an approach to study the mechanism of the microbody transition (glyoxysomes to leaf peroxisomes) in greening pumpkin cotyledons, catalase molecules were purified from the two different types of microbody and their structural properties were compared. The purified glyoxysomal catalase was found to consist of four identical subunits (55 kDa), whereas the leaf peroxisomal catalase contains two different forms of monomeric subunit (55 and 59 kDa). These different catalase species cross-reacted with the rabbit antibody raised against the glyoxysomal enzyme. During gel filtration on an Ultrogel AcA 34 column, the leaf peroxisomal 55-kDa polypeptide eluted slightly faster than the leaf peroxisomal 59-kDa polypeptide. The profile of catalase activities exactly paralleled the elution pattern of the 55-kDa molecules, which indicated that the 59-kDa polypeptide was enzymically inactive. Peptide mapping analysis using Staphylococcus aureus protease V8 showed that the glyoxysomal 55-kDa polypeptide was identical to the leaf peroxisomal 55-kDa species, whereas the leaf peroxisomal 59-kDa polypeptide had a different primary structure from the 55-kDa polypeptide. In an in vitro translation system directed by mRNA isolated from etiolated and green cotyledons, glyoxysomal and leaf peroxisomal catalases were synthesized as the identical 59-kDa polypeptide. From peptide mapping analysis, the in vitro-translated 59-kDa polypeptide was found to have a nearly identical primary structure to that of the leaf peroxisomal 59-kDa species. In vivo pulse-chase labeling experiments using etiolated cotyledons showed the conversion of the 59-kDa polypeptide to the 55-kDa molecular species. The overall results strongly indicate that the 59-kDa polypeptide is a precursor form of catalase in pumpkin cotyledons.

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 F_ST 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.

A change of blood flow during strenuous physical exercises using cycle ergometer

Our purpose of the study is to measure the blood flow in the carotid artery during physical exercises. We have developed the blood flow velocimeter during physical exercises by using the non-invasive Doppler ultrasound method. We used it and measured blood flow in the carotid artery in which using a cycle ergometer and had two exercise tests in this report. The protocol exercise with transient response and ramp response were conducted. As a result, maximum blood flow velocities changed largely during physical exercises. In particular the maximum blood flow velocity was decreased during physical exercise in transient response. In addition, we could also detect arrhythmia that occurred in the subject immediately after exercise. For this reason, blood flow measurement during physical exercise maybe useful for the early detection of cardiovascular disease. Recently, the physical exercises are very popular for health maintenance.

Monitoring Carotid Blood Flow and ECG for Cardiovascular Disease in Elder Subjects

This report is to investigate the correlation between common carotid blood flow (CCBF) properties and the risk factors for cardiovascular disease. The measurement system was designed for simultaneously monitoring of CCBF and electrocardiogram (ECG) in order to get more valid information for detection and diagnosis of cardiovascular disease. In our study, blood flow velocimeter was developed to measure blood flow in carotid by using ultrasound Doppler technique. This measurement system is based on a continuous-wave (CW) Doppler ultrasound method with two semicircular piezoelectric (PZT) transducers, one continuously transmitting ultrasound, and the other continuously receiving the echoes. Eleven patients with cardiovascular disease underwent in the experiment. In the report, blood flow was compared with data from 25 healthy subjects which asymptomatic subjects putatively free of cardiovascular disease as controls. The maximum of CCBF velocity was 102.8 (SD 18.3) cm/s in the 25 healthy subjects. While, the maximum of CCBF velocities were 53.9 (SD 16.6) cm/s in the eleven cardiac patients. The data suggest that CCBF velocity decreased significantly in the cardiac patients and by simultaneously monitoring of CCBF and ECG were probably obtained more valid information to detect and diagnose cardiovascular disease at the early stage.