Concurrent IMRT and weekly cisplatin followed by GDP chemotherapy in newly diagnosed, stage IE to IIE, nasal, extranodal NK/T-Cell lymphoma

On the basis of the benefits of frontline radiation in early-stage, extranodal natural killer (NK)/T-cell lymphoma (ENKTL), we conducted the trial of concurrent chemoradiotherapy (CCRT) followed by three cycles of gemcitabine, dexamethasone and cisplatin (GDP). Thirty-two patients with newly diagnosed, stage IE to IIE, nasal ENKTL received CCRT (that is, all patients received intensity-modulated radiotherapy 56 Gy and cisplatin 30 mg/m² weekly, 3–5 weeks). Three cycles of GDP (gemcitabine 1000 mg/m² intravenously (i.v.) on days 1 and 8, dexamethasone 40 mg orally on days 1–4 and cisplatin 75 mg/m² i.v. on day 1 (GDP), every 21 days as an outpatient were scheduled after CCRT. All patients completed CCRT, which resulted in 100% response that included 24 complete responses (CRs) and eight partial responses. The CR rate after CCRT was 75.0% (that is, 24 of 32 responses). Twenty-eight of the 32 patients completed the planned three cycles of GDP, whereas four patients did not because they withdrew (n=1) or because they had an infection (n=3). The overall response rate and the CR rate were 90.6% (that is, 29 of 32 responses) and 84.4% (that is, 27 of 32 responses), respectively. Only two patient experienced grade 3 toxicity during CCRT (nausea), whereas 13 of the 30 patients experienced grade 4 neutropenia. The estimated 3-year overall survival and progression-free rates were 87.50% and 84.38%, respectively. In conclusion, CCRT followed by GDP chemotherapy can be a feasible and effective treatment strategy for stage IE to IIE nasal ENKTL.

Synthesis of carboxylic block copolymers via reversible addition fragmentation transfer polymerization for tooth erosion prevention

Dental professionals are seeing a growing population of patients with visible signs of dental erosion. The approach currently being used to address the problem typically leverages the enamel protection benefits of fluoride. In this report, an alternative new block copolymer with a hydrophilic polyacrylic acid (PAA) block and a hydrophobic poly(methyl methacrylate) (PMMA) block was developed to similarly reduce the mineral loss from enamel under acidic conditions. This series of PMMA-b-PAA block copolymers was synthesized by reversible addition fragmentation transfer (RAFT) polymerization. Their structures were characterized by gel permeation chromatography (GPC) and (1)H nuclear magnetic resonance (NMR) spectra. The molar fractions of acrylic acid (AA) in the final block copolymer were finely controlled from 0.25 to 0.94, and the molecular weight (Mn) of PMMA-b-PAA was controlled from 10 kDa to 90 kDa. The binding capability of the block copolymer with hydroxyapatite (HAP) was investigated by ultraviolet-visible spectroscopy (UV-Vis) and Fourier transform infrared (FTIR) spectroscopy. FTIR spectra confirmed that the PMMA-b-PAA block copolymer could bind to HAP via bridging bidentate bonds. Both UV-Vis and FTIR spectra additionally indicated that a high polymer concentration and low solution pH favored the polymer binding to HAP. The erosion-preventing efficacy of the PMMA-b-PAA block copolymer in inhibiting HAP mineral loss was quantitatively evaluated by atomic absorption spectroscopy (AAS). Based on the results, polymer treatment reduced the amount of calcium released by 27% to 30% in comparison with the unprotected samples. Scanning electron microscope (SEM) observations indicated that PMMA-b-PAA polymer treatment protected enamel from acid erosion. This new amphiphilic block copolymer has significant potential to be integrated into dentifrices or mouthrinses as an alternative non-fluoride ingredient to reduce tooth erosion.

A new variable for SRS plan quality evaluation based on normal tissue sparing: the effect of prescription isodose levels

OBJECTIVE

A new dosimetric variable, dose-dropping speed (DDS), was proposed and used to evaluate normal tissue sparing among stereotactic radiosurgery (SRS) plans with different prescription isodose lines.

METHODS

40 plans were generated for 8 intracranial SRS cases, prescribing to isodose levels (IDLs) ranging from 50% to 90% in 10% increments. Whilst maintaining similar coverage and conformity, plans at different IDLs were evaluated in terms of normal tissue sparing using the proposed DDS. The DDS was defined as the greater decay coefficient in a double exponential decay fit of the dose drop-off outside the planning target volume (PTV), which models the steep portion of the drop-off. Provided that the prescription dose covers the whole PTV, a greater DDS indicates better normal tissue sparing.

RESULTS

Among all plans, the DDS was found to be the lowest for the prescription at 90% IDL and the highest for the prescription at 60% or 70%. The beam profile slope change in the penumbra and its field size dependence were explored and given as the physical basis of the findings.

CONCLUSION

A variable was proposed for SRS plan quality evaluation. Using this measure, prescriptions at 60% and 70% IDLs were found to provide best normal tissue sparing.

ADVANCES IN KNOWLEDGE

A new variable was proposed based on which normal tissue sparing was quantitatively evaluated, comparing different prescription IDLs in SRS.

Associations of blood glucose and prevalent diabetes with risk of cardiovascular disease in 500 000 adult Chinese: the China Kadoorie Biobank

AIMS

To examine the relationship of self-reported diabetes, and of random blood glucose levels among individuals without known diabetes, with the prevalence of cardiovascular disease in Chinese adults.

METHODS

We examined cross-sectional data from the China Kadoorie Biobank of 0.5 million people aged 30-79 years recruited from 10 diverse regions of China in the period 2004-2008. Logistic regression was used to estimate the odds ratios of prevalent cardiovascular disease associated with self-reported diabetes, and with measured random blood glucose levels among participants with no history of diabetes, adjusting simultaneously for age, sex, area, education, smoking, alcohol, blood pressure and physical activity.

RESULTS

A total of 3.2% of participants had self-reported diabetes (men 2.9%; women 3.3%) and 2.8% had screen-detected diabetes (men 2.6%; women 2.8%), i.e. they had no self-reported history of diabetes but a blood glucose level suggestive of a diagnosis of diabetes. Compared with individuals without a history of diabetes, the odds ratios associated with self-reported diabetes were 2.18 (95% CI 2.06-2.30) and 1.88 (95% CI 1.75-2.01) for prevalent ischaemic heart disease and stroke/transient ischaemic attack, respectively. Among participants without self-reported diabetes there was a positive association between random blood glucose and ischaemic heart disease and stroke/transient ischaemic attack prevalence (P for trend <0.0001). Below the diabetic threshold (<11.1 mmol/l) each additional 1 mmol/l of random blood glucose was associated with 4% (95% CI 2-5%) and 5% (95% CI 3-7%) higher odds of prevalent ischaemic heart disease and stroke/transient ischaemic attack, respectively.

CONCLUSIONS

In this adult Chinese population, self-reported diabetes was associated with a doubling of the odds of prevalent cardiovascular disease. Below the threshold for diabetes there was still a modest, positive association between random blood glucose and prevalent cardiovascular disease.

Inhibition of ANKRD1 sensitizes human ovarian cancer cells to endoplasmic reticulum stress-induced apoptosis

High expression of Ankyrin Repeat Domain 1 (ANKRD1) in ovarian carcinoma is associated with poor survival, and in ovarian cancer cell lines is associated with platinum resistance. Importantly, decreasing ANKRD1 expression using siRNA increases cisplatin sensitivity. In this study, we investigated possible mechanisms underlying the association of ANKRD1 with cisplatin response. We first demonstrated that cisplatin-induced apoptosis in ovarian cancer cell lines was associated with endoplasmic reticulum (ER) stress, evidenced by induction of Glucose-Regulated Protein 78 (GRP78), growth arrest- and DNA damage-inducible gene 153 (GADD153) and increased intracellular Ca(2+) release. The level of sensitivity to cisplatin-induced apoptosis was associated with ANKRD1 protein levels and poly (ADP-ribose) polymerase (PARP) cleavage. COLO 316 ovarian cancer cells, which express high ANKRD1 levels, were relatively resistant to cisplatin, and ER stress-induced apoptosis, whereas OAW42 and PEO14 cells, which express lower ANKRD1 levels, are more sensitive to ER stress-induced apoptosis. Furthermore, we show that overexpression of ANKRD1 attenuated cisplatin-induced cytotoxicity, and conversely siRNA knockdown of ANKRD1 sensitized ovarian cancer cells to cisplatin and ER stress-induced apoptosis associated with induction of GADD153, and downregulation of BCL2 and BCL-XL. Taken together, these results suggest that ANKRD1 has a significant role in the regulation of apoptosis in human ovarian cancer cells, and is a potential molecular target to enhance sensitivity of ovarian cancer to chemotherapy.

First Report of Sclerotinia sclerotiorum Causing Sclerotinia Blight on Peanut (Arachis hypogaea) in Northeastern China

Peanut, Arachis hypogaea L., is an important source of vegetable oil and protein in China with a planting area of 5 million ha and annual production of 16.2 million metric tons. In September of 2012, typical symptoms of Sclerotinia blight were first observed on peanut in Shuangcheng, Heilongjiang Province, China. Approximately 50% of the plants in a field were infected. Symptoms began as a chlorotic wilt on the foliage and developed into necrosis of basal stems and developed very quickly in the field. In advanced stages of the disease, stems and branches became bleached and eventually died. White, fluffy mycelium and black irregular sclerotia (3.5 to 5.4 mm diameter) were observed on the infected stems. Infected branches and pegs were shredded, and most pods dropped on the soil during harvest. To isolate the causal agent of the disease, sclerotia were collected from the field. Twenty sclerotia were surface disinfected in 1% NaOCl for 3 min, rinsed three times with sterile water, placed on potato sucrose agar (PSA) with 100 μg/ml streptomycin, and then incubated at 22°C in the dark for 10 days. Fungal DNA was extracted from mycelia with a TIANGEN DNAsecure Plant Kit (Beijing) and amplified by PCR with the universal fungal primer ITS1 and ITS4. PCR products of five replicates were sequenced and subjected to an NCBI BLAST search. The BLAST search revealed that our sequences (GenBank Accession No. KC935388) had 100% identity with reported sequences of Sclerotinia sclerotiorum. The isolates were identified as S. sclerotiorum (Lib.) de Bary based on mycelia, sclerotia, and rDNA sequence analysis. To conduct pathogenicity tests, nine potted peanut plants (1 month old) were each inoculated with a 5-mm-diameter disk of colonized PSA by placing the inoculum on the base of the stem. Plants were inoculated with a plug of non-colonized PSA as controls. All inoculated plants were covered with a plastic bag for 5 days to maintain high humidity and incubated at 22 to 24°C in the growth chamber with a 12-h photoperiod. After 2 days, the inoculated plants showed water-soaked brown symptoms on the stem base and whole plants wilted after 5 days under high moisture conditions. The symptoms were identical to those observed on peanut plants in Shuangcheng, Heilongjiang Province, whereas the control plants remained symptom-free. Re-isolation of the fungus from the inoculated plants confirmed that the causal agent was S. sclerotiorum. S. sclerotiorum has been reported on peanut in the United States and Argentina (1,2,3). To our knowledge, this is the first report of S. sclerotiorum as a pathogen causing Sclerotinia blight on peanut in northeastern China. References: (1) A. Marinelli et al. Int. J. Pest Manage. 44:251, 1998. (2) J. E. Woodward et al. Plant Dis. 90:111, 2006. (3) J. E. Woodward et al. Plant Dis. 92:1468, 2008.

PD-1/PDL1 and CD28/CD80 pathways modulate natural killer T cell function to inhibit hepatitis B virus replication

α-Galactosylceramide (α-GalCer)-activated natural killer T (NKT) cells have antiviral properties against hepatitis B virus (HBV). However, α-GalCer activation of NKT cells can induce anergy. We hypothesized that this effect may be overcome by a treatment strategy that includes manipulation of CD28/CD80 costimulatory and PD-1/PDL1 coinhibitory signals of NKT cells, thereby enhancing the anti-HBV effect of α-GalCer. We established a transgenic mouse model of chronic HBV infection and investigated hepatic NKT cell frequencies, functions and expression of immunomodulatory factors. Our results showed that compared with uninfected control mice, hepatic NKT cells from HBV transgenic mice displayed lower frequencies (7.91% vs 16.74%, P < 0.05), impaired capabilities to produce interferon (IFN)-γ (5.6% vs 1.4%, P < 0.05) and interleukin (IL)-4 (6.8% vs 0.3%, P < 0.05), higher expression of PD-1 (9.64% vs 6.36%, P < 0.05) and lower expression of CD28 (5.05% vs 28.88%, P < 0.05). However, when hepatic mononuclear cells (MNCs) were isolated from HBV transgenic mice, α-GalCer exposure in culture remarkably upregulated both PD-1(+) NKT cells (P < 0.05) and CD28(+) NKT cells (P < 0.05). Furthermore, when HBV transgenic mice were treated with combination therapies consisting of α-GalCer and anti-PDL1 monoclonal antibody (mAb) and/or anti-CD80/anti-CD28 mAbs, IFN-γ(+) NKT cell frequency was selectively increased (P < 0.05) and HBV replication was suppressed; these effects were accompanied by varying degrees and types of liver damage. Surprisingly, activating CD28/CD80 signal in HBV transgenic mice was more effective but caused less liver injury than blocking PD-1/PDL1 signal in modulating αGalCer-activated NKT cell function to inhibit HBV infection. Our findings also show that combined therapy with blocking PD-1/PDL1 and activating CD28/CD80 signal in the presence of aGalCer cannot superimpose the effect of antivirus. α-GalCer combination therapy that modulates the CD28/CD80 pathways of NKT cells may represent a promising approach to inhibit HBV replication in chronically infected patients.

The impact of intensifying acid suppression on sleep disturbance related to gastro-oesophageal reflux disease in primary care

BACKGROUND

Sleep disturbance is common in patients with GERD but there has been little evaluation of this problem in primary care in patients already taking therapy.

AIM

To evaluate the impact of administering a questionnaire (PASS test) to identify patients with sleep problems and evaluate the efficacy of esomeprazole to improve sleep disturbance in patients with GERD.

METHODS

This was a primary care based cluster-randomised, open-label study where practices were assigned to intervention or control groups. PASS test failures continued current therapy (control) or were switched to 4 weeks' once-daily esomeprazole 20 or 40 mg (intervention). Patients were evaluated at the end of 4 weeks and the outcomes that were assessed were the sleep questions from the Quality of Life in Reflux and Dyspepsia (QOLRAD) questionnaire and the presence or absence of sleep disturbance from the PASS test questionnaire.

RESULTS

A total of 1388 patients with evaluable data at 4 weeks were included in the analysis and 825 reported GERD-related sleep disturbance at baseline. At 4 weeks, 161 of 291 of control patients (55%) reported continued sleep disturbance compared to 120 of 534 (22.5%) of intervention patients [number needed to treat of 3: 95% confidence intervals (CI): 2.5-4]. There was a mean improvement in QOLRAD scores related to sleep in the intervention patients compared to control patients (mean improvement = 4.91; 95% CI: 3.73-6.09).

CONCLUSION

A PASS strategy identifies GERD patients with sleep disturbance in primary care that will benefit from a change in acid-suppressive therapy. ClinicalTrials.gov identifier: NCT00392002; study code: D9612L00096.

Zoledronate inhibits phosphate and bone morphogenetic protein 2-induced extracellular calcification of vascular smooth muscle cells in vitro

The aim of this study was to explore the effects of the bisphosphonate zoledronate on calcification induced by inorganic phosphate (Pi) and/or bone morphogenetic protein 2 (BMP-2) and the underlying mechanisms. Primary vascular smooth muscle cells (VSMCs) from rats were treated with 3 mM Pi or 3 mM Pi/BMP-2, with and without addition of zoledronate; 1.4 mM Pi served as a control. Calcium deposits, expression of core binding factor α-1 (Cbfa-1), osteopontin (OPN), parathyroid pituitary-specific transcription factor (Pit)-1 and Pit-2, and Pi uptake of VSMCs was determined. The calcification of VSMCs induced by elevated Pi or Pi/BMP-2 was significantly inhibited by zoledronate. The expression of Cbfa-1, OPN and Pit-1 was increased significantly after treatment with an elevated level of Pi or Pi/BMP-2, and this expression was significantly suppressed by addition of zoledronate. Pi uptake of VSMCs increased following treatment with elevated Pi and significantly decreased by addition of zoledronate. These results indicated that zoledronate effectively inhibited calcification induced by Pi/BMP-2, and this may have been achieved by means of the downregulation of expression of calcification-related proteins and uptake of Pi.

ASC-dependent RIP2 kinase regulates reduced PGE2 production in chronic periodontitis

Levels of prostaglandin E(2) (PGE(2)) and its processing enzyme, prostaglandin-endoperoxide-synthase-2/ cyclooxygenase-2 (PTGS2/COX-2), are elevated in actively progressing periodontal lesions, but suppressed in chronic disease. COX-2 expression is regulated through inflammatory signaling that converges on the mitogen-activated protein kinase (MAPK) pathway. Emerging evidence suggests a role for the inflammatory adaptor protein, ASC/Pycard, in MAPK activation. We postulated that ASC may represent a mediator of the MAPK-mediated regulatory network of PGE(2) production. Using RNAi-mediated gene slicing, we demonstrated that ASC regulates COX-2 expression and PGE(2) production in THP1 monocytic cells following infection with Porphyromonas gingivalis (Pg). Production of PGE(2) did not require the inflammasome adaptor function of ASC, but was dependent on MAPK activation. Furthermore, the MAP kinase kinase kinase CARD domain-containing protein RIPK2 was induced by Pg in an ASC-dependent manner. Reduced ASC and RIPK2 levels were revealed by orthogonal comparison of the expression of the RIPK family in ASC-deficient THP1 cells with that in chronic periodontitis patients. We show that pharmacological inhibition of RIPK2 represses PGE(2) secretion, and RNAi-mediated silencing of RIPK2 leads to diminished MAPK activation and PGE(2) secretion. These findings identify a novel ASC-RIPK2 axis in the generation of PGE(2) that is repressed in patients diagnosed with chronic adult periodontitis.

Social partnering significantly reduced rapid eye movement sleep fragmentation in fear-conditioned, stress-sensitive Wistar-Kyoto rats

Negative emotionality affects sleep-wake behavior in humans and rodents, and the Wistar-Kyoto (WKY) rat strain is known for its stress-sensitive phenotype. Analyzing rapid eye movement sleep (REMS) microarchitecture by separating REMS into single (siREMS; inter-REM episode interval>3 min) and sequential (seqREMS; interval≤3 min) episodes, we previously reported that cued fear conditioning (CFC) increased REMS fragmentation in WKY compared to Wistar rats by increasing the number of seqREMS episodes. Since social support affects fear responsiveness in humans, we hypothesized that social interaction with a naive partner would affect the sleep-wake response to CFC in WKY rats. Thus, male WKY rats were assigned to either the social support or the social isolation group. Animals were fear-conditioned to 10 tones (800 Hz, 90 dB, 5 s), each co-terminating with a mild foot shock (1.0 mA, 0.5 s), at 30-s intervals. All subjects underwent a tone-only test both 24 h (Day 1) and again two weeks (Day 14) later. Social partnering was achieved by providing the fear-conditioned rat with 30 min of interaction with its naive partner immediately after CFC and during the tone presentations on Day 1 and Day 14. The results indicate that while CFC increased freezing behavior in socially isolated WKY rats, it increased grooming behavior in socially partnered rats. Socially partnered rats had increased sleep efficiency during the light phase and spent less time in NREMS during the dark phase. The number of siREMS episodes increased during both the light and dark phases in partnered rats, and the number of seqREMS episodes increased in socially isolated rats. Our findings suggest that social partnering may protect WKY rats from the REMS fragmentation that is observed following CFC in isolation.

Quorum-sensing system in Acidithiobacillus ferrooxidans involved in its resistance to Cu²⁺

AIMS

 The purpose of this study was to search for the relationship between quorum sensing (QS) and Cu²⁺ resistance in Acidithiobacillus ferrooxidans.

METHODS AND RESULTS

 Resistance to Cu²⁺ of A. ferrooxidans significantly decreased with the treatment dose of a synthetic QS blocker (5Z)-4-bromo-5-(bromomethylene)-2(5H)-furanone (FUR). Relative differences in expression of the QS genes afeI, afeR and Cu²⁺ resistance-associated genes afe0329, afe0454 were examined in the presence of Cu²⁺ and/or FUR compound. The expression of QS genes afeI and afeR increased significantly with 50 mmol l⁻¹ Cu²⁺ in the culture, while for samples treated with both 50 mmol l⁻¹ Cu²⁺ and 0.01 μg ml⁻¹ FUR compound, they showed little changes compared with control, and the expression of afe0329 and afe0454 genes increased slightly either. These results showed that QS system was positively related to the mechanism of Cu²⁺ resistance.

CONCLUSIONS

QS system in A. ferrooxidans involved in its resistance to Cu²⁺.

SIGNIFICANCE AND IMPACT OF THE STUDY

 The mechanisms of Cu²⁺ resistance in A. ferrooxidans could be revealed on a population level rather than on a single-cell level. Our work also provides useful data for further selection of A. ferrooxidans strains with suitable Cu²⁺ resistance that could probably increase the bioleaching efficiency.

The use of hepatitis B core antibody-positive donor livers does not appear to have a deleterious effect on graft survival in liver transplantation for hepatitis C

INTRODUCTION

The use of hepatitis B core antibody-positive donor livers (HBcAb(+)) has steadily increased. According to a recent multivariate analysis of United Network for Organ Sharing (UNOS) data, there was no significant increase in the risk of using these donors. The increased risk among the hepatitis C virus (HCV)-positive subgroup noted in a univariate model disappeared upon multivariate analysis. However, deeper scrutiny may show that HCV-positive recipients may be at increased risk with HBcAb(+) donor livers, as they require simultaneous treatment with two antiviral regimens there may be deleterious interactions between the two viruses. Thus, the issue of HBcAb(+) donors for HCV-positive recipients merits more detailed analysis.

METHODS

Using UNOS registry data of all liver transplantations performed during the Model for End-Stage Liver Disease era from February 2002 through November 2007, we analyzed graft survival using Kaplan-Meier and Cox regression analyses.

RESULTS

Of the 12,543 HCV-positive recipients, 2,543 received HBcAb(-) livers and 853 received HBcAb(+) livers. While Kaplan-Meier analysis showed significantly lower graft survival among HCV-negative recipients of HBcAb(+) livers (P = .0001), there was no significant effect on graft survival among the HCV-positive population (P = .2). To detect an early effect in HCV-positive recipients, we examined 1-year graft survival, observing no significant difference (P = .3). To exclude a possible late effect, we examined graft survival in the HCV-positive population conditional upon surviving at least 1 year after transplantation; no significant difference was observed (P = .6). The elimination of potentially confounding codiagnoses, such as hepatitis B virus, alcoholism, acute graft failure, and hepatocellular cancer did not alter the findings. On univariate analysis, the lack of a significant effect persisted among the HCV population. However, the significant effect observed in the univariate model for the HCV-negative population became insignificant when combined with other risk factors in the multivariate model.

CONCLUSION

The use of HBcAb(+) livers in recipients with HCV did not appear to have a significant impact on graft survival.

Mechanism of adhesion maintenance by methionine sulphoxide reductase in Streptococcus gordonii

Methionine sulphoxide reductase maintains adhesin function during oxidative stress. Using Streptococcus gordonii as a model, we now show the mechanistic basis of adhesin maintenance provided by MsrA. In biofilms, S. gordonii selectively expresses the msrA gene. When the wild-type strain was grown with exogenous hydrogen peroxide (H(2)O(2)), msrA-specific mRNA expression significantly increased, while acid production was unaffected. In the presence of H(2)O(2), a msrA-deletion mutant (ΔMsrA) showed a 6 h delay in lag phase growth, a 30% lower yield of H(2)O(2), significantly greater inhibition by H(2)O(2) on agar plates (reversed by complementation), 30% less adhesion to saliva-coated hydroxyapatite, 87% less biofilm formation and an altered electrophoretic pattern of SspAB protein adhesins. Using mass spectrometry, methionine residues in the Met-rich central region of SspB were shown to be oxidized by H(2)O(2) and reduced by MsrA. In intact wild-type cells, MsrA colocalized with a cell wall-staining dye, and MsrA was detected in both cell wall and cytosolic fractions. To maintain normal adhesion and biofilm function of S. gordonii in response to exogenous oxidants therefore msrA is upregulated, methionine oxidation of adhesins and perhaps other proteins is reversed, and adhesion and biofilm formation is maintained.

Immunostimulatory activities of specific bacterial secondary metabolite of Anoxybacillus flavithermus strain SX-4 on carp, Cyprinus carpio

AIMS

  To determine the capacity of secondary metabolite of strain SX-4, to enhance the nonspecific immunity and survival of carp (Cyprinus carpio), and to identify the constituents that are responsible.

METHODS AND RESULTS

  A thermophilic strain SX-4 that is able to produce immunostimulatory metabolite was isolated from sludge sample of hot spring and identified by comparison with 16S rRNA sequences (99% of homology) as Anoxybacillus flavithermus. Bioactivity-guided fractionation of methanol extract from its cell-free culture, one bacterial peptide with the capacity of improving the nonspecific immune responses and disease resistance (relative per cent survival = 66·67%) was obtained and the compound was characterized as cyclo-(L-Pro-Gly) by IR, ESI-MS, (1) H NMR and (13) C NMR spectroscopic analyses. After intraperitoneal administration of this peptide, selected innate immune parameters including phagocytic activity, superoxide anion production, serum lysozyme activity and serum SOD activity, along with immune-related genes expression (i.e. interleukin-1β and inducible nitric oxide synthase), in the blood were found to be significantly increased.

CONCLUSIONS

  The bacterial peptide cyclo-(L-Pro-Gly) significantly enhances nonspecific immunity and survival of carp.

SIGNIFICANCE AND IMPACT OF THE STUDY

  There is a possibility of using cyclo-(L-Pro-Gly) as a better natural immunostimulant, which could have a promising role in aquaculture to prevent diseases and disease outbreaks.

Transretinal degeneration in ageing human retina: a multiphoton microscopy analysis

AIM

Retinal cell remodelling has been reported as a consistent feature of ageing. However, the degree to which this results in transretinal degeneration is unclear. To address this, the authors used multiphoton microscopy to quantify retinal degeneration in post-mortem human eyes of two age groups.

METHODS

Retinas from six young subjects (18-33 years old) and six older subjects (74-90 years old) were prepared as wholemount preparations. All retinas were stained with 4,6-diamidino-2-phenylindole and imaged by multiphoton confocal microscopy to quantify neuron densities in the retinal ganglion cell layer (RGCL), inner nuclear layer (INL) and outer nuclear layer (ONL). Neurons were counted using automated cell identification algorithms. All retinas were imaged hydrated to minimise tissue artefacts.

RESULTS

In both groups, 56% of the area within the central 4 mm eccentricity and 27% of the area with eccentricity between 4 mm and 7 mm were imaged. Compared with young subjects, the peak RGCL neuron loss in the aged subjects (25.5%) was at 1 mm eccentricity. INL and ONL neuron densities significantly decreased at 1-2 mm eccentricity (8.7%) and 0.5-4 mm eccentricity (15.6%) respectively (P <0.05). The reduction in neuron density in the INL corresponded, spatially, to the region with the greatest neuron loss in the RGCL and ONL.

CONCLUSIONS

This is the first study to correlate neurodegeneration in different populations of cells in the ageing retinas. These data confirm that the greatest neuronal loss occurs in the RGCL and ONL in human ageing retinas, whereas the INL is relatively preserved.

Topography of neuron loss in the retinal ganglion cell layer in human glaucoma

AIM

To determine if retinal ganglion cell (RGC) loss influences the loss of surrounding RGCs to generate clustered patterns of cell death in human glaucoma. It is hypothesised that retinal ganglion cell loss accelerates the loss of surrounding cells to generate, at a local, cellular scale, clustered patterns of retinal of RGC death. The absence of these interactions would result in a diffuse pattern RGC loss.

METHOD

Six glaucomatous retinas (67-83 years old) and six age-matched control retinas (61-89 years old) were prepared as wholemounts and stained by 4',6-diamidino-2-phenylindole (DAPI) solution (3 microg/ml in PBS). An area corresponding to central 14 degrees of the visual field was imaged. The nearest-neighbour distribution was determined for cells in both normal and glaucomatous RGCL.

RESULTS

Clustered RGC loss in human glaucoma was observed on a background of diffuse loss. The mean nearest-neighbour distance (NND) of the glaucomatous retinas was significantly higher than with controls (p<0.001). The distribution of NND in glaucomatous retinas was skewed to the higher values with a higher positive kurtosis relative to controls. The quantitative analysis of the pattern of cell loss is supported by the visual inspection of the patterns of cell loss.

DISCUSSION

The nearest-neighbour analysis is consistent with the presence of two patterns of cell loss in the RGCL in glaucoma. While the diffuse of cell loss can account for an overall reduction in the RGC population, an additional non-random pattern is consistent with the hypothesis that RGC loss has a local influence on the viability of surrounding cells.