Neuroprotective effect of astaxanthin against glutamate-induced cytotoxicity in HT22 cells: Involvement of the Akt/GSK-3β pathway

Oxidative stress (OS) mediated the pathogenesis of Alzheimer's disease (AD). Astaxanthin (ATX) has been reported to exert antioxidant activities as well as neuroprotective effects in vivo and in vitro. But it is still unknown whether the Akt/glycogen synthase kinase-3β (GSK-3β) signaling mediated the neuroprotective effect of ATX in HT22 cells. Flow cytometric analysis was used to evaluate reactive oxygen species (ROS) generation. Caspase and PARP activity was measured. The expressions of heme oxygenase-1 (HO-1), nuclear factor-E2-related factor 2 (Nrf2), Bcl-2, Bax, apoptosis-inducing factor (AIF), cytochrome-c (Cyto-c), p-Akt and p-GSK-3β were evaluated to elucidate the underlying mechanism. Our results showed that ATX significantly attenuated glutamate-induced cell viability loss and lactate dehydrogenase (LDH) release, decreased the expression of caspase-3/8/9 activity and cleaved PARP, and suppressed the intracellular accumulation of ROS in HT22 cells after exposure to glutamate. ATX also increased the mitochondrial expression of AIF, Cyto-c as well as Bax while decreased Bcl-2. Moreover, ATX also induced the HO-1 expression in a dose and time-dependent manner, increased the antioxidant-responsive element (ARE) activity and nuclear Nrf2 expression. Furthermore, treatment with ATX restored the p-Akt and p-GSK-3β (Ser9) as well as HO-1 expression reduced by glutamate. This protective effect was partially blocked by the inhibitors lithium chloride treatment in HT22, indicating the involvement of Akt/GSK-3β inactivation during the neuroprotective effect of ATX. Our results provide the first evidence that ATX can protect glutamate-induced cytotoxicity in HT22 via attenuating caspase activation and mitochondrial dysfunction and modulating the Akt/GSK-3β signaling, indicating ATX may be useful for the treatment of neurodegenerative disorders such as AD.

Parallel enzyme-linked immunosorbent assay screening for human immunodeficiency virus among blood donors in five Chinese blood centres: a retrospective analysis

AIMS

To evaluate the strategy of parallel screening with different enzyme-linked immunosorbent assays (ELISA) among Chinese blood donors.

BACKGROUND

Parallel screening with ELISA has been the main strategy to detect human immunodeficiency virus (HIV) in blood donations in China for more than a decade. The performance of the strategy should be analysed.

METHODS

A total of 821,927 donations collected from five Chinese blood centres in 2008-2010 were tested using two third-generation ELISAs by different manufacturers licenced and confirmed by the Western blot (WB) in this study. The confirmatory positive predictive values (PPV), false positive rates (FPR), false negative rates (FNR) and potential risks for transfusion resulting from single or sequential ELISA screening were evaluated.

RESULTS

A total of 5318 (0·647%) of donations screened HIV reactive and were discarded. WB confirmatory results on 1668 available samples suggested that PPVs for dual ELISA, one round ELISA reactive and grey zone samples were 75·1, 0·7 and 0·5%, respectively. Eight out of 1124 one round ELISA reactive and 1 out of 195 grey zone samples were WB confirmed positive. All but one ELISA assay displayed comparable PPVs but variable FPRs and FNRs that differed by blood centre.

CONCLUSIONS

In the absence of nucleic acid testing (NAT), parallel ELISA screening prevented a substantial number of HIV infected donations from entering the Chinese blood supply. However, the loss of false positive donors should be re-evaluated especially given the frequently reported blood supply shortage in China.

Antisense proline-arginine RAN dipeptides linked to C9ORF72-ALS/FTD form toxic nuclear aggregates that initiate in vitro and in vivo neuronal death

Expanded GGGGCC (G4C2) nucleotide repeats within the C9ORF72 gene are the most common genetic mutation associated with both amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Sense and antisense transcripts of these expansions are translated to form five dipeptide repeat proteins (DRPs). We employed primary cortical and motor neuron cultures, live-cell imaging, and transgenic fly models and found that the arginine-rich dipeptides, in particular Proline-Arginine (PR), are potently neurotoxic. Factors that anticipated their neurotoxicity included aggregation in nucleoli, decreased number of processing bodies, and stress granule formation, implying global translational dysregulation as path accountable for toxicity. Nuclear PR aggregates were also found in human induced motor neurons and postmortem spinal cord tissues from C9ORF72 ALS and ALS/FTD patients. Intronic G4C2 transcripts, but not loss of C9ORF72 protein, are also toxic to motor and cortical neurons. Interestingly, G4C2 transcript-mediated neurotoxicity synergizes with that of PR aggregates, suggesting convergence of mechanisms.

Comparisons of sarcopenia prevalence based on different diagnostic criteria in Chinese older adults

The study aimed to describe the prevalence of sarcopenia and discussed the applicability of different diagnostic criteria in Chinese older adults. 286 Chinese adults (136 men and 150 women) aged 60-88 were recruited. The prevalence of sarcopenia were calculated using different diagnostic criteria. Physical functioning was compared in sarcopenic and non-sarcopenic older adults. Compared with the standard of EWGSOP (European Working Group on Sarcopenia in Older People), the prevalence of sarcopenia was higher when the IWGS (International Working Group on Sarcopenia) standard was applied (Men: 7.4% vs. 0.8%; Women: 4.7% vs. 0%). If the AWGS (Aisa Working Group on Sarcopenia) standard was applied, the prevalence was 5.9% in men and 0.7% in women. In conclusion, the prevalence of sarcopenia in Chinese older adults ranged from 0% to around 10% when the diagnostic criteria of IGWS, EWGSOP and AGWS were applied. Further studies are still needed to investigate appropriate diagnostic criterion of sarcopenia for Chinese population.

Oncogenic and tumor suppressive roles of microRNAs in apoptosis and autophagy

MicroRNAs (miRNAs), small and non-coding endogenous RNAs ∼22 nucleotides (nt) in length, have been known to regulate approximately 30 % of human gene expression at the post-transcriptional and translational levels. Accumulating data have demonstrated that certain miRNAs could exert an oncogenic and/or tumor suppressive function and might play essential roles in the regulation of apoptosis and autophagy in cancer. In this review, we summarize that certain oncogenic and tumor suppressive miRNAs could modulate apoptotic pathways in different types of cancer. Subsequently, we demonstrate that other miRNAs might play regulatory roles in the autophagic pathways of cancer. A limited number of oncogenic/tumor suppressive miRNAs could regulate apoptosis and autophagy, respectively, and cooperatively. Taken together, these findings would provide a new clue to elucidate more apoptotic and/or autophagic mechanisms of miRNAs for designing potential novel therapeutic strategies in cancer.

HIV Tat protein affects circadian rhythmicity by interfering with the circadian system

OBJECTIVES

Sleep disorders are common in patients with HIV/AIDS, and can lead to poor quality of life. Although many studies have investigated the aetiology of these disorders, it is still unclear whether impaired sleep quality is associated with HIV itself, social problems, or side effects of antiretroviral therapy (ART). Moreover, despite its known neurological associations, little is known about the role of the trans-activator of transcription (Tat) protein in sleep disorders in patients with HIV/AIDS. The purpose of this study was to test the hypothesis that the sleep quality of patients with HIV/AIDS affected by an altered circadian rhythm correlates with cerebrospinal HIV Tat protein concentration.

METHODS

Ninety-six patients with HIV/AIDS between 20 and 69 years old completed the Pittsburgh Sleep Quality Index. Their circadian rhythm parameters of blood pressure, Tat concentration in cerebrospinal fluid, melatonin concentration, CD4 cell count and HIV RNA viral load in serum were measured.

RESULTS

The circadian amplitude of systolic blood pressure and the score for sleep quality (Pittsburgh Sleep Quality Index) were negatively correlated with HIV Tat protein concentration, while the melatonin value was positively correlated with Tat protein concentration.

CONCLUSIONS

The HIV Tat protein affects circadian rhythmicity by interfering with the circadian system in patients with HIV/AIDS and further increases the melatonin excretion value. A Tat protein-related high melatonin value may counteract HIV-related poor sleep quality during the progression of HIV infection. This study provides the first clinical evidence offering an explanation for why sleep quality did not show an association with progression of HIV infection in previous studies.

Association of serum homocysteine levels with the severity and calcification of coronary atherosclerotic plaques detected by coronary CT angiography

AIM

In this study, we aim to evaluate the association of risk factors including homocysteine (Hcy) with the severity and burden of coronary atherosclerotic plaques detected by computed tomography angiography (CTA).

METHODS

Six hundred fifty-nine subjects who underwent CTA for the assessment of coronary artery disease (CAD) were studied. All the subjects enrolled had no clinical cardiovascular disease symptoms. Logistic regression showed apart from age, hypertension, smoking, triglyceride, low-density lipoprotein (LDL) cholesterol, and total bilirubin, Hcy was an independently risk factor of the severity of coronary disease. And Hcy was also found an independent predictor for the presence of calcified plaque. When the participants were divided into 4 groups according to serum Hcy quartiles (Q1-Q4 groups), both the percentage of patients with >50% stenosis and the percentage of patients with calcified plaque were higher in Q4 compared to other groups. The OR of Hcy (>15 µmol/L) for >50% stenosis was 2.212 (95% CI=1.119 to 4.375, P=0.022) and the OR for Hcy (>15 µmol/L) for calcification was 1.668 (95% CI=1.030 to 2.699, P=0.037) respectively.

CONCLUSION

Our study shows Hcy is independently associated with both the severity and calcified plaque detected by CTA. Hcy may provide additional information about CAD in the subjects without clinical symptoms.

In silico analysis and experimental validation of azelastine hydrochloride (N4) targeting sodium taurocholate co-transporting polypeptide (NTCP) in HBV therapy

OBJECTIVES

The aim of this study was to explore sodium taurocholate co-transporting polypeptide (NTCP) exerting its function with hepatitis B virus (HBV) and its targeted candidate compounds, in HBV therapy.

MATERIALS AND METHODS

Identification of NTCP as a novel HBV target for screening candidate small molecules, was used by phylogenetic analysis, network construction, molecular modelling, molecular docking and molecular dynamics (MD) simulation. In vitro virological examination, q-PCR, western blotting and cytotoxicity studies were used for validating efficacy of the candidate compound.

RESULTS

We used the phylogenetic analysis of NTCP and constructed its protein-protein network. Also, we screened compounds from Drugbank and ZINC, among which five were validated for their authentication in HepG 2.2.15 cells. Then, we selected compound N4 (azelastine hydrochloride) as the most potent of them. This showed good inhibitory activity against HBsAg (IC50 = 7.5 μm) and HBeAg (IC50 = 3.7 μm), as well as high SI value (SI = 4.68). Further MD simulation results supported good interaction between compound N4 and NTCP.

CONCLUSIONS

In silico analysis and experimental validation together demonstrated that compound N4 can target NTCP in HepG2.2.15 cells, which may shed light on exploring it as a potential anti-HBV drug.

Novel gammaherpesvirus functions encoded by bovine herpesvirus 6 (bovine lymphotropic virus)

The genus Macavirus of the subfamily Gammaherpesvirinae includes viruses that infect lymphoid cells of domestic and wild ruminants and swine, causing asymptomatic latent infections in reservoir hosts. Here, we describe the genome of bovine herpesvirus 6 (BoHV-6), a macavirus ubiquitous in healthy cattle populations. The BoHV-6 genome exhibited architecture conserved in macaviruses, including a repetitive H-DNA region and unique 141 kbp L-DNA region predicted to encode 77 genes. BoHV-6 encoded, in variable genomic regions, a novel complement of genes relative to other characterized macaviruses, probably contributing to distinctive aspects of BoHV-6 infection biology and host range. Most notably, BoHV-6 encoded the first herpesviral protein (Bov2.b2) similar to cellular ornithine decarboxylase, an enzyme that catalyses the first and rate-limiting step in the biosynthesis of polyamines. Bov2.b2 conceivably mediates a novel mechanism by which BoHV-6 promotes cell-cycle-dependent viral replication.

Cab45S inhibits the ER stress-induced IRE1-JNK pathway and apoptosis via GRP78/BiP

Disturbance of endoplasmic reticulum (ER) homeostasis causes ER stress and leads to activation of the unfolded protein response, which reduces the stress and promotes cell survival at the early stage of stress, or triggers cell death and apoptosis when homeostasis is not restored under prolonged ER stress. Here, we report that Cab45S, a member of the CREC family, inhibits ER stress-induced apoptosis. Depletion of Cab45S increases inositol-requiring kinase 1 (IRE1) activity, thus producing more spliced forms of X-box-binding protein 1 mRNA at the early stage of stress and leads to phosphorylation of c-Jun N-terminal kinase, which finally induces apoptosis. Furthermore, we find that Cab45S specifically interacts with 78-kDa glucose-regulated protein/immunoglobulin heavy chain binding protein (GRP78/BiP) on its nucleotide-binding domain. Cab45S enhances GRP78/BiP protein level and stabilizes the interaction of GRP78/BiP with IRE1 to inhibit ER stress-induced IRE1 activation and apoptosis. Together, Cab45S, a novel regulator of GRP78/BiP, suppresses ER stress-induced IRE1 activation and apoptosis by binding to and elevating GRP78/BiP, and has a role in the inhibition of ER stress-induced apoptosis.

Taurine improves functional and histological outcomes and reduces inflammation in traumatic brain injury

We investigated the effect of taurine on inflammatory cytokine expression, on astrocyte activity and cerebral edema and functional outcomes, following traumatic brain injury (TBI) in rats. 72 rats were randomly divided into sham, TBI and Taurine groups. Rats subjected to moderate lateral fluid percussion injury were injected intravenously with taurine (200mg/kg) or saline immediately after injury or daily for 7days. Functional outcome was evaluated using Modified Neurological Severity Score (mNSS). Glial fibrillary acidic protein (GFAP) of the brain was measured using immunofluorescence. Concentration of 23 cytokines and chemokines in the injured cortex at 1 and 7days after TBI was assessed by Luminex xMAP technology. The results showed that taurine significantly improved functional recovery except 1day, reduced accumulation of GFAP and water content in the penumbral region at 7days after TBI. Compared with the TBI group, taurine significantly suppressed growth-related oncogene (GRO/KC) and interleukin (IL)-1β levels while elevating the levels of regulated on activation, normal T cell expressed and secreted (RANTES) at 1day. And taurine markedly decreased the level of 17 cytokine: eotaxin, Granulocyte colony-stimulating factor (G-CSF), Granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon-gamma (IFN-γ), IL-1α, IL-1β, IL-4, IL-5, IL-6, IL-10, IL-12p70, IL-13, IL-17, leptin, monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-α), vascular endothelial growth factor (VEGF), and only increased the level of MIP-1α in a week. The results suggest that taurine effectively mitigates the severity of brain damage in TBI by attenuating the increase of astrocyte activity and edema as well as pro-inflammatory cytokines.

Population Structures of 'Candidatus Liberibacter asiaticus' in Southern China

Huanglongbing (HLB) is a highly detrimental citrus disease associated with 'Candidatus Liberibacter asiaticus', a nonculturable alpha-proteobacterium. Characterization of the bacterial populations is important for development of disease management strategies. In this study, the 'Ca. L. asiaticus' populations in eight provinces in southern China where HLB is endemic were analyzed based on tandem repeat number (TRN) variations in a previously characterized genomic locus CLIBASIA_01645. Of the 224 HLB samples collected, 175 (78.3%) samples yielded single polymerase chain reaction (PCR) amplicons (the single amplicon group, SAG) and 49 (21.7%) samples produced multiple PCR amplicons (the multiple amplicon group, MAG). Variations in SAG are summarized by Nei's diversity index (H) and ratio of TRN ≤ 10/TRN > 10 genotypes (R10). Variations in the MAG are described by the percentage of occurrence (PMAG). At an orchard-level comparison, the 'Ca. L. asiaticus' population from a Guangdong orchard (n = 24) showed H = 0.50, R10 = 23, and PMAG = 0, significantly different from that of the non-Guangdong orchards in Yunnan (n = 23), H = 0.83, R10 = 2.3, and PMAG = 11.5, and in Hainan (n = 35), H = 0.88, R10 = 1.5, and PMAG = 16.7. In a region-level consideration, the Guangdong 'Ca. L. asiaticus' population (n = 78) was H = 0.77, R10 = 25, and PMAG = 1.3, whereas the non-Guangdong population (n = 84) was H = 0.91, R10 = 1.6, and PMAG = 26.9. Overall, significant differences were observed between the 'Ca. L. asiaticus' population from Guangdong Province and those from the other provinces. A strong aggregation of TRN = 6, 7, and 8 genotypes is characteristic to the 'Ca. L. asiaticus' population in Guangdong. Referenced to genome annotation, we propose that rearrangement of tandem repeats at locus CLIBASIA_01645 could be associated with bacterial environmental adaptation.

Atorvastatin overcomes gefitinib resistance in KRAS mutant human non-small cell lung carcinoma cells

The exact influence of statins on gefitinib resistance in human non-small cell lung cancer (NSCLC) cells with KRAS mutation alone or KRAS/PIK3CA and KRAS/PTEN comutations remains unclear. This work found that transfection of mutant KRAS plasmids significantly suppressed the gefitinib cytotoxicity in Calu3 cells (wild-type KRAS). Gefitinib disrupted the Kras/PI3K and Kras/Raf complexes in Calu3 cells, whereas not in Calu3 KRAS mutant cells. These trends were corresponding to the expression of pAKT and pERK in gefitinib treatment. Atorvastatin (1 μM) plus gefitinib treatment inhibited proliferation, promoted cell apoptosis, and reduced the AKT activity in KRAS mutant NSCLC cells compared with gefitinib alone. Atorvastatin (5 μM) further enhanced the gefitinib cytotoxicity through concomitant inhibition of AKT and ERK activity. Atorvastatin could interrupt Kras/PI3K and Kras/Raf complexes, leading to suppression of AKT and ERK activity. Similar results were also obtained in comutant KRAS/PTEN or KRAS/PIK3CA NSCLC cells. Furthermore, mevalonate administration reversed the effects of atorvastatin on the Kras/Raf and Kras/PI3K complexes, as well as AKT and ERK activity in both A549 and Calu1 cells. The in vivo results were similar to those obtained in vitro. Therefore, mutant KRAS-mediated gefitinib insensitivity is mainly derived from failure to disrupt the Kras/Raf and Kras/PI3K complexes in KRAS mutant NSCLC cells. Atorvastatin overcomes gefitinib resistance in KRAS mutant NSCLC cells irrespective of PIK3CA and PTEN statuses through inhibition of HMG-CoA reductase-dependent disruption of the Kras/Raf and Kras/PI3K complexes.

Effects of pulsed Nd:YAG laser on tensile bond strength and caries resistance of human enamel

This study aims to evaluate the effects of pulsed Nd:YAG laser on the tensile bond strength (TBS) of resin to human enamel and caries resistance of human enamel. A total of 201 human premolars were used in this in vitro study. A flat enamel surface greater than 4 × 4 mm in area was prepared on each specimen using a low-speed cutting machine under a water coolant. Twenty-one specimens were divided into seven groups for morphology observations with no treatment, 35% phosphoric acid etching (30 seconds), and laser irradiation (30 seconds) of pulsed Nd:YAG laser with five different laser-parameter combinations. Another 100 specimens were used for TBS testing. They were embedded in self-cured acrylic resin and randomly divided into 10 groups. After enamel surface pretreatments according to the group design, resin was applied. The TBS values were tested using a universal testing machine. The other 80 specimens were randomly divided into eight groups for acid resistance evaluation. Scanning electron microscope (SEM) results showed that the enamel surfaces treated with 1.5 W/20 Hz and 2.0 W/20 Hz showed more etching-like appearance than those with other laser-parameter combinations. The laser-parameter combinations of 1.5 W/15 Hz and 1.5 W/20 Hz were found to be efficient for the TBS test. The mean TBS value of 14.45 ± 1.67 MPa in the laser irradiated group was significantly higher than that in the untreated group (3.48 ± 0.35 MPa) but lower than that in the 35% phosphoric acid group (21.50 ± 3.02 MPa). The highest mean TBS value of 26.64 ± 5.22 MPa was identified in the combination group (laser irradiation and then acid etching). Acid resistance evaluation showed that the pulsed Nd:YAG laser was efficient in preventing enamel demineralization. The SEM results of the fractured enamel surfaces, resin/enamel interfaces, and demineralization depths were consistent with those of the TBS test and the acid resistance evaluation. Pulsed Nd:YAG laser as an enamel surface pretreatment method presents a potential clinical application, especially for the caries-susceptible population or individuals with recently bleached teeth.

Identification of novel caspase/autophagy-related gene switch to cell fate decisions in breast cancers

OBJECTIVES

Caspases, a family of cysteine proteases with unique substrate specificities, contribute to apoptosis, whereas autophagy-related genes (ATGs) regulate cytoprotective autophagy or autophagic cell death in cancer. Accumulating evidence has recently revealed underlying mechanisms of apoptosis and autophagy; however, their intricate relationships still remain to be clarified. Identification of caspase/ATG switches between apoptosis and autophagy may address this problem.

MATERIALS AND METHODS

Identification of caspase/ATG switches was carried out using a series of elegant systems biology & bioinformatics approaches, such as network construction, hub protein identification, microarray analyses, targeted microRNA prediction and molecular docking.

RESULTS

We computationally constructed the global human network from several online databases and further modified it into the basic caspase/ATG network. On the basis of apoptotic or autophagic gene differential expressions, we identified three molecular switches [including androgen receptor, serine/threonine-protein kinase PAK-1 (PAK-1) and mitogen-activated protein kinase-3 (MAPK-3)] between certain caspases and ATGs in human breast carcinoma MCF-7 cells. Subsequently, we identified microRNAs (miRNAs) able to target androgen receptor, PAK-1 and MAPK-3, respectively. Ultimately, we screened a range of small molecule compounds from DrugBank, able to target the three above-mentioned molecular switches in breast cancer cells.

CONCLUSIONS

We have systematically identified novel caspase/ATG switches involved in miRNA regulation, and predicted targeted anti-cancer drugs. These findings may uncover intricate relationships between apoptosis and autophagy and thus provide further new clues towards possible cancer drug discovery.

Identification of microRNA-regulated autophagic pathways in plant lectin-induced cancer cell death

OBJECTIVES

Plant lectins, carbohydrate-binding proteins of non-immune origin, have recently been reported to induce programmed cell death (including apoptosis and autophagy) in many types of cancer cells. MicroRNAs (miRNAs), small, non-coding endogenous RNAs, ~22 nucleotides (nt) in length, have been well characterized to play essential roles in regulation of the autophagy process in cancer; however, how these miRNAs regulate autophagic pathways in plant lectin-induced cancer cells, still remains an enigma.

MATERIALS AND METHODS

Identification of microRNA-regulated autophagic pathways was carried out using a series of elegant systems - biology and bioinformatics approaches, such as network construction, hub protein identification, targeted microRNA prediction, microarray analyses and molecular docking.

RESULTS

We computationally constructed the human autophagic protein-protein interaction (PPI) network, and further modified this network into a plant lectin-induced network. Subsequently, we identified 9 autophagic hub proteins and 13 relevant oncogenic and tumour suppressive miRNAs, that could regulate these aforementioned targeted autophagic hub proteins, in human breast carcinoma MCF-7 cells. In addition, we confirmed that plant lectins could block the sugar-containing receptor EGFR-mediated survival pathways, involved in autophagic hub proteins and relevant miRNAs, thereby ultimately culminating in autophagic cell death.

CONCLUSIONS

These results demonstrate that network-based identification of microRNAs modulate autophagic pathways in plant lectin-treated cancer cells, which may shed new light on the discovery of plant lectins as potent autophagic inducers, for cancer drug discovery.

First-degree relatives of patients with early-onset gastric carcinoma show even at young ages a high prevalence of advanced OLGA/OLGIM stages and dysplasia

BACKGROUND

First-degree relatives (FDRs) of early-onset gastric carcinoma (EOGC) patients are at increased risk of cancer development. OLGA/OLGIM (Operative Link on Gastritis/Intestinal Metaplasia Assessment) classifications have been proposed for the identification of individuals at high risk of gastric cancer development.

AIM

To estimate the prevalence and severity of premalignant conditions and lesions in FDRs of EOGC patients.

METHODS

A case-control study was conducted encompassing 103 FDRs of EOGC patients (cases) and 101 age- and gender-matched controls, all submitted to upper GI endoscopy and OLGA and OLGIM used for staging as well as modified versions with exclusion of the biopsies from incisura angularis in the analysis.

RESULTS

Helicobacter pylori infection was present in 82% of cases (P = 0.001). Atrophy was present in 70% of cases (OLGA stages I-IV). High-risk stages (III-IV) were identified only in cases (19%) (P < 0.001). Dysplasia was diagnosed only in cases (n = 7, P = 0.007). The application of OLGIM, modified OLGA and modified OLGIM classifications led to downgrade of stages in comparison with the original OLGA classification (27%, 15% and 30% respectively). In all classification systems, dysplastic lesions clustered (86%) in high-risk stages.

CONCLUSIONS

FDRs of EOGC patients have, even at young ages, a high prevalence of H. pylori infection, high-risk OLGA and OLGIM stages and dysplasia. These patients should undergo accurate endoscopic observation with at least four biopsies in antrum and corpus to allow adequate staging and follow-up of premalignant conditions and lesions scored in high-risk stages, in accordance with international guidelines recently proposed.

Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS): a new autosomal dominant syndrome

OBJECTIVE

The purpose of this study was the clinical and pathological characterisation of a new autosomal dominant gastric polyposis syndrome, gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS).

METHODS

Case series were examined, documenting GAPPS in three families from Australia, the USA and Canada. The affected families were identified through referral to centralised clinical genetics centres.

RESULTS

The report identifies the clinical and pathological features of this syndrome, including the predominant dysplastic fundic gland polyp histology, the exclusive involvement of the gastric body and fundus, the apparent inverse association with current Helicobacter pylori infection and the autosomal dominant mode of inheritance.

CONCLUSIONS

GAPPS is a unique gastric polyposis syndrome with a significant risk of gastric adenocarcinoma. It is characterised by the autosomal dominant transmission of fundic gland polyposis, including areas of dysplasia or intestinal-type gastric adenocarcinoma, restricted to the proximal stomach, and with no evidence of colorectal or duodenal polyposis or other heritable gastrointestinal cancer syndromes.

Caspase-mediated programmed cell death pathways as potential therapeutic targets in cancer

The caspase family is well characterized as playing a crucial role in modulation of programmed cell death (PCD), which is a genetically regulated, evolutionarily conserved process with numerous links to many human diseases, most notably cancer. In this review, we focus on summarizing the intricate relationships between some members of the caspase family and their key apoptotic mediators, involving tumour necrosis factor receptors, the Bcl-2 family, cytochrome c, Apaf-1 and IAPs in cancer initiation and progression. We elucidate new emerging types of cross-talk between several caspases and autophagy-related genes (Atgs) in cancer. Moreover, we focus on presenting several PCD-modulating agents that may target caspases-3, -8 and -9, and their substrates PARP-1 and Beclin-1, which may help us harness caspase-modulated PCD pathways for future drug discovery.

Helium ion microscopy for high-resolution visualization of the articular cartilage collagen network

The articular cartilage collagen network is an important research focus because network disruption results in cartilage degeneration and patient disability. The recently introduced helium ion microscope (HIM), with its smaller probe size, longer depth of field and charge neutralization, has the potential to overcome the inherent limitations of electron microscopy for visualization of collagen network features, particularly at the nanoscale. In this study, we evaluated the capabilities of the helium ion microscope for high-resolution visualization of the articular cartilage collagen network. Images of rabbit knee cartilage were acquired with a helium ion microscope; comparison images were acquired with a field emission scanning electron microscope (FE-SEM) and a transmission electron microscope (TEM). Sharpness of example high-resolution helium ion microscope and field emission scanning electron microscope images was quantified using the 25-75% rise distance metric. The helium ion microscope was able to acquire high-resolution images with unprecedented clarity, with greater sharpness and three-dimensional-like detail of nanoscale fibril morphologies and fibril connections, in samples without conductive coatings. These nanoscale features could not be resolved by field emission scanning electron microscopy, and three-dimensional network structure could not be visualized with transmission electron microscopy. The nanoscale three-dimensional-like visualization capabilities of the helium ion microscope will enable new avenues of investigation in cartilage collagen network research.

Are current definitions of sarcopenia applicable for older Chinese adults?

This study aims to explore whether the current definitions of sarcopenia are applicable to the older Chinese population. Participants were 783 Chinese adults recruited from four regions in Mainland China: Jinan, Guangzhou, Xi'an, and Chengdu. Body composition was measured by dual energy x-ray absorptiometry. Handgrip strength, body weight, and height were measured by trained technicians, and demographic data were collected through questionnaires. Relative appendicular skeletal muscle, skeletal muscle index (SMI=100 × skeletal muscle mass/ body mass) and residuals methods were applied to identify sarcopenia. Compared with young adults, no significant decrease was found in the relative appendicular skeletal muscle (ASM/height2) in older adults. If the criterion of two standard deviations below the mean value of ASM/height2 in young adults is used, none of older adults in this study could be diagnosed with sarcopenia. In addition, compared with the ASM/height2 and residuals methods, SMI shows higher discriminating power in the identifying persons with low handgrip strength. The data suggest that ASM/height2 method may not be appropriate for diagnosis of sarcopenia in Chinese population. However, whether SMI is a better choice remains inconclusive. Prospective studies are needed to clearly define sarcopenia in Chinese population.

Photonic generation of triangular waveform signals by using a dual-parallel Mach-Zehnder modulator

A photonic approach to generate triangular waveform signals is proposed and analyzed. With active bias control, two sub-MZMs (MZ-a and MZ-b) of a dual-parallel Mach-Zehnder modulator (DP-MZM) operate at minimum transmission point, leaving the main MZM (MZ-c) at quadrature transmission point. Triangular waveform can be observed by a parameter setting of modulation index. The proposal is first analyzed and then validated by simulation. The key significance of the scheme is that it is capable of generating triangular waveform signals via a sinusoid local oscillator.

Chinese parents' perceptions of their children's weights and their relationship to parenting behaviours

PURPOSE

The purpose of this study is to examine Chinese parents' perceptions of their children's weights and explore the parenting behaviours associated with these perceptions.

METHODS

A total of 2143 adolescents and 1869 parents were recruited from secondary schools in Ganzhou and Shantou in China. The adolescents' actual weights and heights were measured by trained testers. The self-reported parents' weights and heights, parental perception of the adolescents' weights, adolescents' perception of their own weights, parenting behaviours and demographic information were collected through the questionnaires distributed to the respondents.

RESULTS

The results based on Kappa statistics show only a slight agreement between parental perception of their children's weights and the adolescents' actual weights (Kappa = 0.221). The results from the logistic regression show that the parents' gender [odds ratio (OR) = 0.80, 95% confidence interval (CI): 0.64-1.00], adolescents' gender (OR = 1.61, 95% CI: 1.29-2.01) and perception of their own weights (OR = 0.30, 95% CI: 0.24-0.38) are associated with the parents' perception of their children's weights. Statistically significant difference in several parenting behaviours was found between the parents with correct and incorrect perceptions of their children's weight.

DISCUSSION AND CONCLUSION

Misconceptions about their children's weights are prevalent among Chinese parents. The association between parents' perception of their children's weight and parenting behaviours suggests that the accurate classification of children's weights could help prevent childhood obesity.

Infection of immunocompromised patients by avian H9N2 influenza A virus

Avian influenza A (H9N2) virus is transmitted sporadically from avian species to human causing mild diseases in immunocompetent person. We report two cases of human infection in immunocompromised patients in Hong Kong between 2008 and 2009. One patient had uneventful recovery with viral shedding at day 10 after symptom onset despite her underlying acute lymphoblastic leukaemia. The other patient with post-bone marrow transplant chronic graft-versus-host disease and bronhioltis obliterans went into respiratory failure. Genetic analysis revealed that these cases were caused by different genetic variants which are circulating in poultry in this region. Review of literature identified another 9 human cases reported in Southern China since 1988. It is possible that human infection with H9N2 is more common than what has been recognized. Continuous surveillance of H9N2 influenza virus infection in human is warranted.

Excess fluoride interferes with chloride-channel-dependent endocytosis in ameloblasts

Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene cause cystic fibrosis (CF). Both CF and dental fluorosis result in protein retention in mature enamel. We hypothesized that excess fluoride might cause protein retention by interfering with CFTR function, resulting in abnormal expression of proteases and pathological endocytosis. Millimolar concentrations of fluoride reduced uptake of Emdogain, an enamel matrix derivative, in ameloblast-like PABSo-E cells, while stimulating an acidic intracellular environment at the same time. When CFTR function was inhibited by either an siRNA or a chloride channel inhibitor, CFTRinh-172, fluoride's effect on Emdogain uptake was partially blocked. Treatment of cells with CFTR siRNA down-regulated expression of proteases MMP20 and KLK4 and increased intracellular pH. We conclude that excess fluoride inhibits endocytic activity of ameloblasts through the CFTR chloride channel or other chloride channels. The intracellular pH might be the key mechanism by which abnormal proteolytic activity and defective endocytosis cause the residual protein observed in enamel of patients with CF and dental fluorosis.

Is antiepileptic drug use related to depression and suicidal ideation among patients with epilepsy?

Depression and suicide are increased in patients with epilepsy. The U.S. Food and Drug Administration warns that antiepileptic drugs (AEDs) are associated with increased risk of suicidality. This study examines the relationship among depression, suicidal ideation, and AEDs in a prospective cohort of 163 patients with epilepsy from a registry at the University of Florida (January 2006 to August 2008). The Neurological Disorders Depression Inventory for Epilepsy (NDDI-E) was used to measure mood and suicidal ideation across two time points (median = 154 days). Groups included: (1) No AED Change, (2) New AED Added, (3) AED Dose Increased, (4) AED Reduced/Stopped, (5) Multiple AED Changes, and (6) Combined Any AED Change (groups 2-5 combined). No group had worsening mood or suicidal ideation. Significant improvements in proportions of depression and suicidal ideation were seen only for the No AED Change group, which differed only with the AED Dose Increased group with respect to suicidal ideation.

Effect of citrus juice and SLCO2B1 genotype on the pharmacokinetics of montelukast

Previously the authors found that a common polymorphism, rs12422149 (SLCO2B1{NM_007256.2}:c.935G>A), in the gene coding for OATP2B1, was associated with absorption of and response to montelukast in humans. In vitro studies showed that citrus juice could reduce the permeability of montelukast consistent with known inhibition of organic anion-transporting polypeptides. To study the clinical significance of c.935G>A, the authors conducted a single-dose, pharmacokinetic study of montelukast co-ingested with citrus juice. On average, co-ingestion with either orange juice or 4× concentrated grapefruit juice had a minimal effect on the area under the plasma concentration-time curve from time zero extrapolated to infinite time (AUC(0→∞)) of montelukast relative to co-ingestion with Gatorade control (n = 24). However when the data were stratified by genotype at c.935 (G/G n = 21, A/G n = 5), a significant reduction in AUC(0→∞) was detected with orange juice in G/G homozygotes (AUC(0→∞), G/G, Gatorade = 2560 ± 900 ng·h·mL(-1) vs AUC(0→∞), G/G, orange juice = 2010 ± 650 ng·h·mL(-1), P = .032). Significantly, A/G heterozygotes showed reduced AUC(0→∞) relative to G/G homozygotes, independent of treatment (AUC(0→∞), G/G, combined treatments = 2310 ± 820 ng·h·mL(-1) vs AUC(0→∞), A/G, combined treatments = 1460 ± 340 ng·h·mL(-1), P = 2.0 × 10(-5)) replicating previous observations.

Serum concentrations of selected endogenous estrogen and estrogen metabolites in pre- and post-menopausal Chinese women with osteoarthritis

The purpose of this study was to investigate whether serum levels of selected endogenous estrogens and their metabolites are involved in the pathogenesis of osteoarthritis in pre- and post-menopausal women with osteoarthritis. Sixty-four patients with osteoarthritis (OA) of the knee, 48 patients with rheumatoid arthritis (RA) of the knee, and 48 healthy women were included in this study. Serum concentrations of estradiol and estrogen metabolites, such as 2- hydroxyestrone, 2-hydroxyestradiol, and 16α-hydroxyestrone, were measured by high performance liquid chromatography-mass spectrometry. Our results show that the serum concentrations of free estradiol and total 2-hydroxyestrone were significantly lower in pre-menopausal women with OA compared to the levels detected in the control groups (RA and healthy women). While serum concentrations of free and total estradiol in post-menopausal women with OA was significantly decreased compared to those of the control groups, the level of total 2-hydroxyestradiol significantly increased in postmenopausal women. Furthermore, the total 2-hydroxyestrone concentration positively correlated with the total estradiol level in pre-menopausal women with OA. In addition, the total 2- hydroxyestradiol level positively correlated with free and total estradiol levels in post-menopausal women with OA. In conclusion, estradiol and estrogen metabolites, including 2-hydroxyestrone and 2-hydroxyestradiol, were found in the sera of pre- and post-menopausal women with OA. Except for free and total estradiol deficiency, a decreased serum level of total 2- hydroxyestrone in pre-menopausal women and an increased total 2-hydroxyestradiol level in post-menopausal women with OA may also correlate with the pathogenesis of female OA.

Bacterial community dynamics in two full-scale wastewater treatment systems with functional stability

AIMS

To characterize the bacterial community dynamics over 1 year in two full-scale wastewater treatment systems operated under constant conditions and exhibiting stable performance.

METHODS AND RESULTS

Functional stability was defined and quantified by the effluent concentration of biological oxygen demand, total nitrogen and ammonia. Community dynamics were investigated using specific PCR followed by terminal restriction fragment length polymorphism (T-RFLP) of the 16S rRNA gene. The T-RFLP results indicated that during the period of functional stability, the bacterial community structures in two full-scale wastewater treatment systems were not stable, and the average change rates every 15 days of the two systems were 22.6 ± 6.9 and 21.6 ± 7.3%, respectively. The corresponding species with dominant T-RFs were determined by clonal sequencing and T-RFLP. Based on Pareto-Lorenz distribution curves, it was observed that only a small number of micro-organisms were numerically dominant in the two systems.

CONCLUSIONS

The results of this study showed that, throughout the period of the study, the bacterial community structure changed significantly in two full-scale wastewater treatment systems despite the stable function.

SIGNIFICANCE AND IMPACT OF THE STUDY

The findings enrich the theory involving the relation between bacterial community dynamics and functional stability in full-scale wastewater treatment plants.

A clinical analysis of diabetic patients with hand ulcer in a diabetic foot centre

AIMS

The aim of the study was to explore the prevalence and clinical characteristics of hand ulcer in hospitalized patients with diabetes.

METHODS

We analysed 17 subjects with hand ulcer among diabetic inpatients, who were admitted to the Diabetic Foot Care Center, Department of Endocrinology and Metabolism at the West China Hospital of Sichuan University from April 2003 to December 2008.

RESULTS

The prevalence of diabetic hand ulcer among hospitalized patients (0.37%) was significantly lower than that of diabetic foot ulcers (9.7%, P = 0.000). The mean age was 62.1 +/- 9.4 years. The average known durations of diabetes and glycated haemoglobin (HbA(1c)) were 5.3 +/- 4.9 years and 10.9 +/- 2.4%, respectively. All patients lived in the subtropical zone. Fifteen patients (88.2%) were diagnosed with diabetic peripheral neuropathy. Ten patients had hand infection. After therapy, the ulcers healed in 13 patients (76.5%) and none of them experienced amputation. The average hospital stay for patients with local infection was characteristically longer than that for patients without infection (P = 0.012). The prognosis of the hand ulcer was poorer in the patients who had diabetes for > 3 years compared with those who had diabetes for < 3 years (P = 0.009).

CONCLUSIONS

Diabetic hand ulcer is a relatively rare complication of diabetes in South-West China. Long duration of diabetes, poorly controlled blood glucose, minor trauma and delayed treatment are the risk factors. Diabetic peripheral neuropathy may play an important role in the pathogenesis of hand ulcer. Early control of blood glucose with insulin and early anti-microbial therapy with appropriate antibiotics are crucial. Debridement and drainage are necessary for hand abscesses.

Capillary electrophoresis of human follicular fluid

Some of the major serum proteins that are also found in follicular fluid, including transferrin, alpha-macroglobulin and albumin, are thought to play a role in oocyte maturation. This study set out to identify proteins in human follicular fluid by capillary zone electrophoresis and to investigate their relationship to follicular/oocyte maturity and fertility outcome. 176 individual follicular fluid samples, from 30 women undertaking in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI), were run using an optimized capillary zone electrophoresis method that gave a good separation of sixteen peaks in most samples. Nine of the peaks were identified and quantified but seven remain unknown and require further proteomic identification. Of the identified protein peaks, levels of each were corrected for follicular volume and total content calculated. No significant difference in protein levels was found with regard to oocyte recovery and fertilization. Protein concentrations tended to decrease as the follicular sphere increased whilst total content in follicular fluid increased in proportion to size. This is consistent with simple transudation across a sphere surface area which does not increase in proportion to the follicular fluid. This is not true of the concentration and content pattern of other proteins/biomolecules which are produced by follicular cells locally. In conclusion, neither concentration nor absolute levels of nine major proteins identified in follicular fluids correlated with oocyte presence and fertility outcome. Future work to remove more concentrated proteins (e.g. albumin) would enhance separation of smaller peaks and identification of the unknown molecules.

Feline programmed death and its ligand: characterization and changes with feline immunodeficiency virus infection

Programmed death (PD)-1 and its ligand, PD-L1, are co-stimulatory molecules expressed on T cells and antigen-presenting cells, respectively, that modulate T cell receptor signals. Altered PD expression or signalling contributes to pathogen persistence in chronic infections. The sequence of the feline PD genes was derived from gene amplification with primers conserved across human and canine homologs, and by sequence extension through rapid amplification of cDNA ends. Feline PD-1 was similar to that of other mammalian species and consisted of extracellular, transmembrane and cytoplasmic regions. Functional motif analysis of the translated amino acid sequence predicted immunoreceptor tyrosine-based inhibitory and switch motifs, and a SH3-binding region, in the cytoplasmic tail. PD-1 and PD-L1 were expressed in resting lymphocytes and dendritic cells, and up-regulated on mitogen-activated or irradiated lymphocytes of both CD4 and CD8-positive subsets. In vitro infection with the feline immunodeficiency virus (FIV) significantly decreased PD-1, but not PD-L1, gene expression in lymphocytes at 24h, and decreased expression of both genes at 168h. No significant changes in gene or protein expression from FIV infection were noted in dendritic cells. Blood lymphocytes from cats chronically FIV-infected expressed significantly higher PD protein than lymphocytes from FIV-negative cats. These findings indicate that both feline PD-1 and PD-L1 are expressed by resting lymphocytes and dendritic cells. Apoptosis and cell activation increased protein expression on lymphocytes, while in vitro acute FIV infection decreased PD-1 gene expression. Increased PD levels in lymphocytes from chronically FIV-infected cats suggests that alterations in T cell co-signalling may contribute to immune dysfunction in lentiviral infection.

Structure and sequence variation of the canine perforin gene

Lymphocyte-mediated cytotoxicity is essential to control viral infections, limit lymphocyte expansion and activation, and survey for malignant cells. Humans with defects in lymphocyte cytotoxicity have reduced perforin function resulting in uncontrolled lymphocyte expansion, leading to excessive histiocyte activation and a hemophagocytic disorder. Dog breeds such as Bernese mountain dogs (BMD) have a high incidence of reactive and malignant diseases affecting histiocytes. This study addressed the hypothesis that changes in the perforin gene contribute to the development of hemophagocytic histiocytic sarcoma (HHS) in BMD. Canine perforin DNA was amplified and sequenced through multiple PCR assays from healthy and diseased dogs, and the gene structure determined by rapid amplification of cDNA ends. The coding component of the gene consists of 1679bp, with two exons of 536bp and 1143bp separated by an intron of 865bp. Gene configuration and location differ from that in other species although the coding sequence is highly conserved. Three silent single nucleotide polymorphisms (SNP) were identified. Analysis of their distribution indicated a consistent genotype among 6 middle-aged to older BMD without histiocytic diseases. Among samples from 10 dogs with HHS and 10 without histiocytic diseases SNP occurred with variable frequency. It was concluded that changes in the amino acid sequence of perforin were not associated with HHS but that a constellation of SNP may characterize BMD without histiocytic disease. Investigation of more dogs is required to confirm a specific genotype. Future studies should focus on the potential contribution of reduced perforin expression and/or function to HHS in dogs.

Intracellular oxidative stress and cadmium ions release induce cytotoxicity of unmodified cadmium sulfide quantum dots

OBJECTIVE

To fully understand the cytotoxicity of after-degradation QDs, we synthesized CdS QDs and investigated its toxicity mechanism.

METHODS

Biomimetic method was proposed to synthesize cadmium sulfide (CdS) QDs. Thereafter MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay was conducted to evaluate their cytotoxicity. To investigate the toxicity mechanism, we subsequently conducted intracellular reactive oxygen species (ROS) measurement with DCFH-DA, glutathione (GSH) measurement with DTNB, and cellular cadmium assay using atomic absorption spectrometer. Microsized CdS were simultaneously tested as a comparison.

RESULTS

MTT assay results indicated that CdS QDs are more toxic than microsized CdS especially at concentrations below 40 microg/ml. While microsized CdS did not trigger ROS elevation, CdS QDs increase ROS by 20-30% over control levels. However, they both deplete cellular GSH significantly at the medium concentration of 20 microg/ml. In the presence of NAC, cells are partially protected from CdS QDs, but not from microsized particles. Additionally, nearly 20% of cadmium was released from CdS nanoparticles within 24h, which also accounts for QDs' toxicity.

CONCLUSION

Intracellular ROS production, GSH depletion, and cadmium ions (Cd(2+)) release are possible mechanisms for CdS QDs' cytotoxicity. We also suggested that with QD concentration increasing, the principal toxicity mechanism changes from intracellular oxidative stress to Cd(2+) release.

Prophylactic total gastrectomy (PTG) for hereditary diffuse gastric cancer (HDGC): the Newfoundland experience with 23 patients

BACKGROUND

Hereditary diffuse gastric cancer (HDGC) results from truncating mutations of the CDH1 (E-cadherin) gene. It is an autosomal dominant cancer susceptibility syndrome with a lifetime risk of diffuse gastric cancer (DGC) of 60-80%, with a mean age of onset of 37 years. There exists no adequate screening test for DGC. Early intramucosal diffuse/signet-ring cell carcinomas have been found in prophylactic total gastrectomy (PTG) specimens following normal preoperative endoscopy. Total gastrectomy has been advocated on a prophylactic basis. The aim of this study was to report our experience with PTG in 23 patients from the Canadian province of Newfoundland and Labrador. This is the largest series worldwide.

METHODS

A retrospective study of consecutive patients undergoing PTG for HDGC was performed. All patients were confirmed to have a truncating mutation of the CDH1 gene.

RESULTS

Twenty-three patients underwent PTG between February 2006 and November 2008. Major complications were found in 4/23 patients (17%), with no mortality. Two of 23 patients (9%) had positive mucosal biopsies on preoperative EGD. Twenty-two of 23 patients (96%) had evidence of diffuse/signet-ring carcinoma on final standardized pathological evaluation. Therefore, 21/23 (91%) were not picked up by preoperative EGD screening.

CONCLUSIONS

PTG can be performed in patients with HDGC with a low rate of serious complications. Methods of reconstruction incorporating a pouch reservoir and preservation of the postgastric branches of the vagus nerves need to be explored. More refined penetrance estimates, effective screening protocols, and long-term psychological and functional outcomes following PTG require organized multicenter collaborative efforts.

Clara cell secretory protein is reduced in equine recurrent airway obstruction

Horses are prone to recurrent airway obstruction (RAO), an inflammatory lung disease induced by repeated exposure to environmental mold, dust, and bacterial components. Active disease manifests with mucus hyperproduction, neutrophilic inflammation, bronchoconstriction, and coughing. Chronically affected animals have lung remodeling characterized by smooth muscle hyperplasia, collagen deposition, lymphoid hyperplasia, and impaired aerobic performance. Clara cell secretory protein (CCSP) counters inflammation in the lung, hence we hypothesized that CCSP depletion is a key feature of RAO in horses. Recombinant equine CCSP and specific antiserum were produced, and percutaneous lung biopsies were obtained from 3 healthy horses and from 3 RAO-affected horses before and after induction of RAO. CCSP relative gene expression in tissue, as well as protein concentration in lung lavage fluid, was determined. Immunocytochemical analysis, using both light and immunogold ultrastructural methods, demonstrated reduced CCSP staining in lung tissue of animals with RAO. Immunogold label in Clara cell granules was less in animals with chronic RAO than in normal animals, and absent in animals that had active disease. Median lung lavage CCSP concentration was 132 and 129 ng/ml in healthy horses, and 62 and 24 ng/ml in RAO horses before and after challenge, respectively. CCSP lung gene expression was significantly higher in healthy animals than in animals with chronic RAO. Together, these preliminary findings suggest that reduced production of CCSP and subcellular changes in Clara cells are features of chronic environmentally induced lung inflammation in horses.

hCG beta expression by cervical squamous carcinoma--in vivo histological association with tumour invasion and apoptosis

AIMS

To investigate the correlation of beta-subunit of human chorionic gonadotrophin (hCG beta) expression by cervical carcinomas with measures of tumour apoptosis.

METHODS AND RESULTS

Eighty-nine cervical carcinoma patients' samples were subject to hCG beta immunohistochemistry and scored with respect to intensity of immunopositivity and percentage of positive cells. Apoptosis was evaluated by three independent parameters: morphological characteristics [haematoxylin and eosin (H&E)], terminal deoxynucleotidyl transferase biotin-dUTP nick end labelling (TUNEL) and poly (ADP-ribose) polymerase (PARP) immunopositivity. Of the 12 adenocarcinomas, only one (8%) was hCG beta+. However, 87% (61/70) of the squamous cell and 100% (7/7) of adenosquamous cell carcinomas were hCG beta+. hCG beta reactivity and intensity was predominantly confined to peripheral tumour cells at the stromal-epithelial interface. Correlation analysis showed that H&E and PARP apoptotic immunopositivity negatively correlated with hCG beta expression (P < 0.001 and P = 0.028 respectively), whereas TUNEL did not (P = 0.12). However, immunopositivity for apoptotic cells by TUNEL was significantly less in tumours where hCG beta expression was greater (scoring >or= 6) and vice versa. hCG beta immunopositivity was also observed in newly formed blood vessels, as well as tumour cells within lymphatic vessels. When tumour vascularization was taken into account, samples with noted vascularization positively correlated with hCG beta scoring.

CONCLUSIONS

hCG beta expression correlates with reduced tumour cell apoptosis and may be involved in tumour vascularization and dissemination.

Suppression of the internal electric field effects in ZnO/Zn(0.7)Mg(0.3)O quantum wells by ion-implantation induced intermixing

Strong suppression of the effects caused by the internal electric field in ZnO/ZnMgO quantum wells following ion-implantation and rapid thermal annealing, is revealed by photoluminescence, time-resolved photoluminescence, and band structure calculations. The implantation and annealing induces Zn/Mg intermixing, resulting in graded quantum well interfaces. This reduces the quantum-confined Stark shift and increases electron-hole wavefunction overlap, which significantly reduces the exciton lifetime and increases the oscillator strength.

The immunosuppressive and protective ability of glucose-regulated protein 78 for improvement of alloimmunity in beta cell transplantation

An insulinoma cell line, NIT-1, transfected with glucose-regulated protein 78 (GRP78) was established, namely NIT-GRP78, and used to study the immunosuppressive and protective ability of GRP78. In extended cytotoxic T lymphocyte (CTL) killing assay, NIT-1-primed lymphocytes were more cytotoxic in killing beta cells than NIT-GRP78-primed lymphocytes. Severe necrosis was observed only when the NIT-1-primed lymphocytes were cultured with NIT-1 beta cells, but not with NIT-GRP78 cells. In addition, an increase of interleukin (IL)-4 secretion from beta cell-primed splenocytes when GRP78 presence was observed in cytokine enzyme-linked immunosorbent assay (ELISA). Diabetic mice reached normoglycaemia promptly and gained weight after transplantation of either NIT-1 or NIT-GRP78 cells. However, the recipient mice transplanted with NIT-GRP78 cells lived much longer than those recipients transplanted with NIT-1 cells, which was due apparently to prolonged insulin production by the transplanted NIT-GRP78 cells. In fact, we observed a significant increase of insulin concentration after glucose stimulation of diabetic mice received NIT-GRP78 cells at day 7 post-transplantation. From the results we propose that GRP78 could have a dual function in both protecting NIT-1 cells from CTL-mediated lysis and stimulating a population of T helper 2 cells to down-regulate the immune response to the transplanted beta cells.

Cellular uptake of amelogenin, and its localization to CD63, and Lamp1-positive vesicles

Proteins of the developing enamel matrix include amelogenin, ameloblastin and enamelin. Of these three proteins amelogenin predominates. Protein-protein interactions are likely to occur at the ameloblast Tomes' processes between membrane-bound proteins and secreted enamel matrix proteins. Such protein-protein interactions could be associated with cell signaling or endocytosis. CD63 and Lamp1 are ubiquitously expressed, are lysosomal integral membrane proteins, and localize to the plasma membrane. CD63 and Lamp1 interact with amelogenin in vitro. In this study our objective was to study the molecular events of intercellular trafficking of an exogenous source of amelogenin, and related this movement to the spatiotemporal expression of CD63 and Lamp1 using various cell lineages. Exogenously added amelogenin moves rapidly into the cell into established Lamp1-positive vesicles that subsequently localize to the perinuclear region. These data indicate a possible mechanism by which amelogenin, or degraded amelogenin peptides, are removed from the extracellular matrix during enamel formation and maturation.