Age determination of plutonium material by alpha spectrometry and thermal ionization mass spectrometry

Age is a key parameter to deduce the history of a plutonium material. An experimental method using both alpha spectrometry and thermal ionization mass spectrometry has been developed for the age determination of plutonium material. This method is based on the parent/daughter pair 241Pu/241Am ratio and has been validated using several plutonium source of known age. The results obtained are in good agreement with the last purification date of plutonium source.

Optical coherence tomography differs in neuromyelitis optica compared with multiple sclerosis

BACKGROUND

Neuromyelitis optica (NMO) is associated with destructive inflammatory lesions, resulting in necrosis and axonal injury. Disability from multiple sclerosis (MS) is due to a combination of demyelination and varying axonal involvement. Optical coherence tomography (OCT), by measuring retinal nerve fiber layer (RNFL) as a surrogate of axonal injury, has potential to discriminate between these two conditions.

METHODS

Included were 22 subjects with NMO or NMO spectrum disorders and 47 with MS. Seventeen subjects with NMO and all with MS had a remote history of optic neuritis (ON) in at least one eye, at least 6 months before OCT. Linear mixed modeling was used to compare the two diagnoses for a given level of vision loss, while controlling for age, disease duration, and number of episodes of ON.

RESULTS

After ON, NMO was associated with a thinner mean RNFL compared to MS. This was found when controlling for visual acuity (56.7 vs 66.6 microm, p = 0.01) or for contrast sensitivity (61.2 vs 70.3 microm, p = 0.02). The superior and inferior quadrants were more severely affected in NMO than MS.

CONCLUSIONS

Optic neuritis (ON) within neuromyelitis optica (NMO) is associated with a thinner overall average retinal nerve fiber layer compared to multiple sclerosis, with particular involvement of the superior and inferior quadrants. This suggests that NMO is associated with more widespread axonal injury in the affected optic nerves. Optical coherence tomography can help distinguish the etiology of these two causes of ON, and may be useful as a surrogate marker of axonal involvement in demyelinating disease.

Association study of IFNAR2 and IL10RB genes with the susceptibility and interferon response in HBV infection

A recent genome-wide association study discovered that two polymorphisms, interferon (IFN) alpha receptor 2 (IFNAR-2) F8S and interleukin 10 receptor (IL10RB) K47E, were associated with susceptibility to hepatitis B virus (HBV) infection in Africa. Here, we reevaluate the effects of the two polymorphisms on HBV susceptibility in the Chinese Han population, and extended the study to look at their association with IFN response in chronic hepatitis B (CHB). We included 341 patients with CHB and 341 unrelated controls presenting with asymptotic HBV self-limited infection, who were well matched in age and sex. In the CHB group, 101 patients had been treated with peg-IFN-alpha-2a for 48 weeks and followed up for 24 weeks to determine the clinical response, resulting 34 individuals with sustained virological response (SVR) and 67 individuals with nonsustained response (NR). Subgroups in the CHB group were divided according to the viral loads, HBeAg and maternal HBsAg status. The association with the susceptibility to HBV infection was only observed for IL10RB K47E when we compared the individuals with persistent HBV infection through nonmaternal transmission to the controls with asymptomatic self-limited HBV infection. Further, we found that the IFNAR2-8SS genotype was associated with HBeAg negative patients (OR = 0.316, 95% CI: 0.121-0.825, P = 0.019) and that the IFNAR2-8F allele was associated with the risk to high viral loads (OR = 1.667, 95% CI: 1.148-2.420, P = 0.007). In addition, the IFNAR2-8FF genotype predisposed to higher MxA gene induction and correlated with sustained IFN response (OR = 0.348, 95% CI: 0.129-0.935, P = 0.036). Haplotype analysis based on polymorphisms of three single-nucleotide polymorphisms, MxA - 88 G/T, IFNAR-2 F8S and IL10RB K47E showed that the haplotype distribution was significantly different between the SVR and NR groups (P = 0.040). This study suggests that IFNAR2 may play an important role in determining IFN response and clinical phenotypes of HBV infection in the Chinese Han population.

Pharmacokinetics of 20(S)-25-methoxyl-dammarane-3beta, 12beta, 20-triol and its active metabolite after oral and intravenous administration in rat

The pharmacokinetics behaviour of 20(S)-25-methoxyl-dammarane-3beta, 12beta, 20-triol (25-OCH3-PPD) and its active metabolite after oral and intravenous administration in rats were studied. Rats were administered 2.5, 5.0, and 10 mg kg(-1) 25-OCH3-PPD orally after an overnight fasting or by intravenous injection of 5 mg kg(-1) 25-OCH3-PPD via the tail vein. Plasma concentration-time profiles of 25-OCH3-PPD and its active metabolite 25-O-demethylated (25-OH-PPD) in rats were monitored by liquid chromatography-tandem mass spectroscopy (HPLC-MS-MS). The 25-O-demethylated metabolite appears to be a pathway in the phase I metabolism of 25-OCH3-PPD in rats. The plasma concentration of the metabolite was higher than that of the parent compound.

Optical coherence tomography is less sensitive than visual evoked potentials in optic neuritis

OBJECTIVES

Determine the utility of optical coherence tomography (OCT) to detect clinical and subclinical remote optic neuritis (ON), its relationship to clinical characteristics of ON and visual function, and whether the retinal nerve fiber layer (RNFL) thickness functions as a surrogate marker of global disease severity.

METHODS

Cross-sectional study of 65 subjects with at least 1 clinical ON episode at least 6 months prior. Measures included clinical characteristics, visual acuity (VA), contrast sensitivity (CS), OCT, and visual evoked potentials (VEP).

RESULTS

Ninety-six clinically affected optic nerves were studied. The sensitivity of OCT RNFL after ON was 60%, decreasing further with mild onset and good recovery. VEP sensitivity was superior at 81% (p = 0.002). Subclinical ON in the unaffected eye was present in 32%. VEP identified 75% of all subclinically affected eyes, and OCT identified <20%. RNFL thickness demonstrated linear correlations with VA (r = 0.65) and CS (r = 0.72) but was unable to distinguish visual categories <20/50. RNFL was thinner with severe onset and disease recurrence but was unaffected by IV glucocorticoids. OCT measurements were not related to overall disability, ethnicity, sex, or age at onset. The greatest predictor for RNFL in the unaffected eye was the RNFL in the fellow affected eye.

CONCLUSIONS

Visual evoked potentials (VEP) remains the preferred test for detecting clinical and subclinical optic neuritis. Optical coherence tomography (OCT) measures were unrelated to disability and demographic features predicting a worse prognosis in multiple sclerosis. OCT may provide complementary information to VEP in select cases, and remains a valuable research tool for studying optic nerve disease in populations.

Induction of protective cytotoxic T-cell responses by a B-cell-based cellular vaccine requires stable expression of antigen

B cell-based cellular vaccines represent a promising approach to active immunotherapy of cancer complementing the use of dendritic cells, especially in pediatric patients and patients with low bone marrow reserves. B cells can be easily prepared in large numbers and readily home to secondary lymphoid organs, the primary site of induction of cytotoxic T lymphocyte (CTL) responses. However, most B cell-based vaccines tested so far failed to induce functional and protective CTLs in in vivo models. Here we demonstrate that B cells activated via the Toll like receptor-9 (TLR-9) and CD40 up-regulate surface expression of MHC and costimulatory molecules, produce IL-12, and exhibit potent antigen-presenting properties in vitro. Importantly, while administration of peptide-coated or transiently transfected B cells fails to induce immune responses, therapeutic immunization with low numbers of genetically modified B cells stably expressing antigen results in an induction of functional CTLs and protection against the growth of tumor in an animal model. Following activation, B cells partially loose their ability to home to organized lymphoid tissue due to the shedding of CD62L; however, this property can be restored by expression of protease-resistant mutant of CD62L. In summary, the data presented in this report suggest that genetically modified activated B cells represent a promising candidate for a cancer vaccine eliciting functional systemic CTLs.

Occult hepatocellular carcinoma: a case report of a special icteric-type hepatoma and literature review

Hepatocellular carcinoma (HCC) presenting with obstructive jaundice due to bile duct tumour thrombi is classified as icteric-type hepatoma. This report describes a case of unusual icteric-type HCC with common bile duct thrombus, which is herein named 'occult HCC', as no detectable primary lesion in liver was defined pre-operatively and intra-operatively. A thrombectomy followed by a T biliary drainage tube placement was carried out, and the final post-operative pathological evaluation demonstrated the tumour thrombus originated from a moderately differentiated HCC. The clinicopathological features and logical clinical interventions of this rare type of HCC were discussed with a review of the literature. The HCC patients with bile duct thrombi receiving palliative biliary drainage alone had a poor outcome. With respect to improving prognosis, a curative resection of primary HCC and tumour thrombi was suggested on the basis of performing an intensive post-operative monitoring for early detection of primary liver lesion.

Multidrug resistant gram-negative bacilli as predominant bacteremic pathogens in liver transplant recipients

BACKGROUND

Bacteremias, which are often caused by gram-negative bacteria, are the most frequently occurring infectious complications after liver transplantation (LT). The aim of this study was to investigate bacteremic incidence, pathogenic spectrum, risk factors for bacteremia due to multidrug resistant (MDR) gram-negative bacilli, and its impact on mortality after LT.

METHODS

A cohort analysis of prospectively recorded data was done in 475 LT recipients, who were divided into 3 categories: cases with gram-negative bacteremia, cases with MDR gram-negative bacteremia, and cases without bacteremia as controls.

RESULTS

In 475 LT recipients, there were 152 (32.0%) patients with gram-negative bacillus bacteremia in the first 6 months after LT. Out of 152 patients, there were 225 bacteremic episodes, which accounted for 69.7% in a total 323 bacteremic episodes. A total of 190 bacteremic episodes were caused by Stenotrophomonas maltophilia, Enterobacteriaceae, Ochrobactrum anthropi, Pseudomonas, and Acinetobacter baumanii, all of which were the most frequent gram-negative isolates in this study, and MDR bacilli constituted 56.3%. The most frequent source was intravascular catheters. There were 70 patients with MDR gram-negative bacillus bacteremia. Independent risk factors for bacteremia due to MDR gram-negative bacillus were as follows: post-LT abdominal infection (P<0.0001, odds ratio [OR] 0.066, 95% confidence interval [CI] 0.019-0.226), post-LT reoperative episodes (P<0.0001, OR 10.505, 95% CI 3.055-36.121), or one or more episodes of acute rejection (P=0.042, OR 4.457, 95% CI 0.988-20.103). In the first 6 months after LT, MDR gram-negative bacillus bacteremia-related mortality was significantly higher than that due to antibiotic-susceptible bacillus (38.6% vs. 14.6%, P<0.001).

CONCLUSION

Post-LT bacteremias caused by MDR gram-negative bacilli are common, and associated with allograft acute rejection, post-LT reoperation, and abdominal infection. The increasing isolates of MDR gram-negative bacilli pose a great challenge for clinical treatment.

The antibacterial mechanism of carvacrol and thymol against Escherichia coli

AIMS

To investigate the antibacterial mechanism of carvacrol and thymol against Escherichia coli.

METHODS AND RESULTS

The time-kill curve results showed that carvacrol and thymol at 200 mg l(-1) could inhibit the growth of E. coli. Flow cytometry and fluorescent dyes were used to explore the effect of two components on membrane permeability and membrane potential. In membrane permeability experiment, the mean fluorescence intensity of cells treated with 200 mg l(-1) carvacrol or thymol were lower than nonexposed cells. The ratio of red to green fluorescence intensity of DiOC2(3) reflected the change of membrane potential. Carvacrol and thymol at 200 mg l(-1) caused the ratio of red/green decreasing from 0.42 of control to 0.08 and 0.07, respectively.

CONCLUSIONS

Carvacrol and thymol had desired antimicrobial effect on E. coli. The antibacterial effects were attributed to their ability to permeabilize and depolarize the cytoplasmic membrane.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study showed the potential use of flow cytometry as a suitable method to investigate the mode of antibacterial action of essential oil components.

A novel mechanism whereby BRCA1/1a/1b fine tunes the dynamic complex interplay between SUMO-dependent/independent activities of Ubc9 on E2-induced ERalpha activation/repression and degradation in breast cancer cells

BRCA1 dysfunction is associated with hormone-responsive cancers. We have identified a consensus SUMO modification site in the amino-terminal region of BRCA1/1a/1b proteins and the mutation in this potential SUMO acceptor site (K 109 to R) impaired their ability to bind and repress ligand-dependent ERalpha transcriptional activity in breast cancer cells. Furthermore, we have found SUMO E2-conjugating enzyme Ubc9 to bind BRCA1 proteins. We have mapped BRCA1 [within amino acids (aa) 1-182] as the minimum domain that is sufficient for in vitro binding to Ubc9 as well as for regulating ERalpha activity. BRCA1 Mutant #1 (K109 to R) was impaired in its ability to both bind, as well as modulate Ubc9 mediated SUMO-dependent/independent E2-induced ERalpha transcriptional activity in breast cancer cells. Similarly, BRCA1 cancer-predisposing mutation (61Cys-Gly) abrogated the ability to both bind Ubc9 as well as inhibit ERalpha activity suggesting physiological significance. Addition of BRCA1 but not Mutant #1 to E2-induced ERalpha in the presence of SUMO-1 and Ubc9 resulted in the degradation of ERalpha suggesting BRCA1 to be a putative SUMO-1 and Ubc9-dependent E3 ubiquitin ligase for ERalpha. This is the first report demonstrating the participation of Ubc9 in BRCA1 E3 ubiquitin ligase mediated degradation of ERalpha. These results suggest a novel function for BRCA1 in regulating the dynamic cycles of SUMO and ubiquitin modifications required for ERalpha turn over and deregulation of this molecular switch due to lack of BRCA1 results in ERalpha-negative/positive breast cancers. This study will help in designing novel BRCA1 function-based targeted treatment for breast cancers.

Distribution of pathogenic Yersinia enterocolitica in China

Yersinia enterocolitica (1,295 strains) was isolated from diarrhea patients, livestock, poultry, wild animals, insect vectors, food, and the environment. They were studied for epidemiology distribution using bacterial biochemical metabolism tests, their virulence genes, and pulsed-field gel electrophoresis (PFGE) sub-typing. The data showed that 416 of the 1,295 strains were pathogenic, where the pathogenic Chinese isolates were of serotypes O:3 and O:9. These two serotypes were found in livestock and poultry, with swine serving as the major reservoir. The geographic distribution of pathogenic isolates was significantly different, where most of the strains were isolated from the cold northern areas, whereas some serotype O:3 strains were recovered from the warm southern areas. By the analysis of the data of the Ningxia Hui Autonomous Region, we find the phenomenon of 'concentric circle distribution' around animal reservoirs and human habitation. The clustering of PFGE showed that the patterns of the pathogenic strains isolated from diarrhea patients were identical compared to those from the animals in the same area, thus, suggesting that the human infection originated from the animals.

Radioprotection by fullerenols ofStylonychia mytilusexposed to γ-rays

The aim was to study the protective effects of fullerenols, C60(OH)x, on Stylonychia mytilus cells exposed to 60Co gamma-rays and the probable mechanisms of fullerenols protection. Ciliated protozoans Smytilus, kept in solutions of fullerenols at different concentrations, were irradiated with 60Co gamma-rays to various dose levels. Surviving cells were counted each day over 5 days after irradiation, and the surviving fraction was calculated. The relations of the surviving fraction to radiation dose and to fullerenols concentration were studied. Superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA) and lipofusion (LIP) levels in S. mytilus were also measured. The surviving fraction of S. mytilus decreased with increasing gamma-ray doses from 100 to 2000 Gy. Fullerenols enhanced the surviving fraction, except for the highest gamma-ray dose level. The maximum protection by fullernols occurred at a concentration of 0.10 mg ml(-1). However, fullerenols at concentration of 0.25 mg ml(-1) yielded a surviving fraction lower than that for the control sample. Fullerenols at a concentration of 0.10 mg ml(-1) increased the SOD and CAT activities in the gamma-ray plus fullerenols (gamma + F) group compared with the levels in both the gamma-ray (gamma) group (p < 0.01) and the control group (p < 0.01). The MDA and LIP levels in the gamma + F groups (p < 0.01) were significantly lower than that in both the control group (p < 0.05) and the gamma group (p < 0.01). At a concentration of 0.25 mg ml(-1), fullerenols reduced the SOD and CAT activities, but increased the MDA and LIP level compared with the control. There was no significant difference in SOD and CAT activities between the gamma + F group and gamma group. While the MDA and LIP level in the gamma + F and gamma groups were similar at a dose of 500 Gy, the LIP level in the gamma + F group was significantly higher than that in the gamma group (p < 0.01) at a dose of 2000 Gy. Fullerenols are good radiation protectors for the protozoan S. mytilus exposed to gamma-rays. The effectiveness of radioprotection depends on both fullerenols concentration and gamma-ray dose. The protective effect of fullerenols on damage induced by gamma-rays seems to be mediated, at least in part, through their anti-oxidative and radical scavenging activities.

CIGARETTE SMOKE-INDUCED HYPERCAPNIC EMPHYSEMA IN C3H MICE IS ASSOCIATED WITH INCREASES OF MACROPHAGE METALLOELASTASE AND SUBSTANCE P IN THE LUNGS

The authors tested whether macrophage metalloelastase (MMP-12) and substance P (SP) were increased in the cigarette smoke (CS)-exposed female C3H/HeN mice with hypercapnic emphysema. The authors found that as compared to control (filtered air), 16 weeks of CS exposure significantly up-regulated mRNA and protein levels of MMP-12, the ratio of MMP-12/tissue inhibitor of matrix metalloproteinase-1, and SP/preprotachykinin-A (a precursor to SP) in the lungs. Importantly, a significant correlation was found between MMP-12 and SP, and between MMP-12/SP and the degrees of hypoxemia/hypercapnia denoted in CS-exposed mice. These data suggest a possible involvement of SP and MMP-12 in the pathogenesis of severe COPD.

Multi-mJ, 200-fs, cw-pumped, cryogenically cooled, Yb,Na:CaF2 amplifier

Using a novel (to our knowledge) broadband Yb-doped Yb3+,Na+:CaF2 crystal cooled in a closed loop to 130 K we demonstrate a chirped pulse regenerative laser amplifier delivering the energy of up to 3 mJ at a repetition rate of 1 kHz and an average output power of 6 W at 20 kHz. The gain narrowing in the laser crystal is compensated by shaping the amplitude of the seed pulse spectrum. As the result, at the highest amplified pulse energy we obtain a 12 nm FWHM bandwidth supporting a 130 fs pulse duration, assuming ideal compression. Amplified pulses were recompressed from 250 ps to 195 fs with a 1700 lines/mm transmission grating compressor.

Molecular cloning and characterization of a novel glyoxalase I gene TaGly I in wheat (Triticum aestivum L.)

Methylglyoxal is a kind of poisonous metabolite that can react with RNA, DNA and protein, which generally results in a number of side advert effects to cell. Glyoxalase I is a member of glyoxalase system that can detoxify methylglyoxal. An EST encoding a glyoxalase I was isolated from a SSH (suppression subtractive hybridization)-cDNA library of wheat spike inoculated by Fusarium graminearum. The corresponding full length gene, named TaGly I, was cloned, sequenced and characterized. Its genomic sequence consists of 2,719 bp, including seven exons and six introns, and its coding sequence is 929 bp with an open reading frame encoding 291 amino acids. Sequence alignment showed that there were two glyoxalase I domains in the deduced protein sequence. By using specific primers, TaGly I was mapped to chromosome 7D of wheat via a set of durum wheat 'Langdon' D-genome disomic-substitution lines. The result of Real-time quantitative polymerase chain reaction demonstrated that TaGly I was induced by the inoculation of Fusarium graminearum in wheat spikes. Additionally, it was also induced by high concentration of NaCl and ZnCl2. When TaGly I was overexpressed in tobacco leaves via Agrobacterium tumefaciens infection, the transgenic tobacco showed stronger tolerance to ZnCl2 stress relative to transgenic control with GFP. The above facts indicated that TaGly I might play a role in response to diverse stresses in plants.