Apocynin ameliorates cognitive deficits in streptozotocin-induced diabetic rats

AIMS

The aim was to investigate the improvement properties of apocynin and its potential mechanism on diabetes-associated cognitive decline.

METHODS

In this study, the model of diabetic rat was established by STZ (50 mg/kg) and treated with apocynin (16 mg/kg/d for 12 weeks). The cognitive ability was evaluated by Morris water maze test. The indicators of oxidative stress (SOD and MDA) were analyzed by spectrophotometer. The inflammatory cytokines were measured by real time-PCR and ELISA. The protein expressions of Nrf-2, HO-1, Bcl-2 and Bax were determined by Western blot.

RESULTS

Treatment with apocynin ameliorated diabetes-related learning and memory injury, as represented by decreasing escape latency and enhancement of the number of times of crossing platform, in the Morris water maze test. In hippocampus, apocynin markedly augmented SOD activity and inhibited MDA level to alleviate oxidative stress. Moreover, apocynin obviously relieved inflammatory reaction by suppressing TNF-α, IL-1β and IL-6 concentrations. Concomitantly, apocynin also statistically enhanced Nrf-2 and HO-1 protein expression to improve DACD. Lastly, apocynin notably ameliorated Bax/Bcl-2 ratio by regulating Bax and Bcl-2 protein expression to mitigate apoptosis.

CONCLUSION

Our results have shown that apocynin may be a valid therapeutic agent against DACD via modulation of antioxidant, anti-inflammatory, and anti-apoptosis (Tab. 1, Fig. 18, Ref. 35).

Development of a prognostic model based on an immunogenomic landscape analysis of colorectal cancer

Screening and therapeutic programs for colorectal cancer (CRC) are invasive or not effective and unable to meet patient needs. Major advances in immunogenomics may change this status but need more exploration. Differentially expressed genes and immune-related genes (IRGs) were identified by computational methods. A prognostic model was established and validated based on survival-related IRGs via stepwise multivariate Cox regression analysis. Nine IRGs were selected and identified as survival-related genes. A 7-gene prognostic model could offer a preliminary and valid determination of risk in CRC patients. The area under the curve of the receiver operating characteristic was 0.672. The 7-gene prognostic model might be used as a novel prognostic tool in CRC patients.

LncRNA SBF2-AS1 promotes hepatocellular carcinoma metastasis by regulating EMT and predicts unfavorable prognosis

OBJECTIVE

Recent studies have furthered our understanding of the function of long noncoding RNAs (lncRNAs) in numerous biological processes, including cancer. The present study aimed to investigate the expression of lncRNA SBF2-AS1 (SBF2-AS1) in patients with hepatocellular carcinoma (HCC) and to investigate its effect on HCC cells.

PATIENTS AND METHODS

Using quantitative reverse transcription-polymerase chain reaction, we detected SBF2-AS1 expression in HCC cell lines and primary tumor tissues. The associations between SBF2-AS1 expression and the clinicopathological factors and outcome of HCC patients were statistically analyzed. MTT assay and transwell assay were performed to determine the proliferation, migration and invasion, respectively. In addition, we evaluated the activation of Mesenchymal-epithelial transition (EMT) pathway by Western blot.

RESULTS

We found that SBF2-AS1 expression levels were significantly up-regulated in HCC tissues and cell lines compared with the corresponding noncancerous liver tissues and normal hepatic cell line. In addition, high SBF2-AS1 expression levels were correlated with vein invasion (p = 0.008) and TNM stage (p = 0.013). Furthermore, Kaplan-Meier survival analysis indicated that high expressions of SBF2-AS1 were correlated with shorter overall survival of HCC patients. Univariate and multivariate analysis identified high SBF2-AS1 expression as an unfavorable prognostic factor for overall survival. Further functional analysis demonstrated that knockdown of SBF2-AS1 significantly inhibited HCC cells proliferation, migration and invasion. Mechanistically, we found that SBF2-AS1 could promote the activation of EMT pathway, which was demonstrated by measuring the expression levels of EMT-related markers.

CONCLUSIONS

SBF2-AS1 might be considered as a novel molecule involved in HCC development, which provides a potential therapeutic target for HCC.

[Study on the negative regulation of TIPE2 from peripheral blood mononuclear cells on tissue factor in patients with bronchial asthma]

Objective: To investigate the expression of tumor necrosis factor alpha-inducible protein 8 like-2 (TIPE2) and tissue factor (TF) in patients with bronchial asthma. And to explore the regulation of TIPE2 on TF. Methods: Sixty-five asthmatic patients and 40 healthy controls were selected from the First Affiliated Hospital of Zhengzhou University from July to November, 2017. The expression of TIPE2 and TF in peripheral blood mononuclear cells of asthmatic patients and healthy controls were detected by Western blot.The level of TF protein in plasma was detected by enzyme-linked immunosorbent assay. The changes of TIPE2 and TF mRNA expression in THP-1 cells stimulated by house dust mite extract were detected by real-time fluorescence quantitative PCR (RT-PCR). The recombinant adenovirus Adv-TIPE2 was constructed and transfected into THP-1 cells and the effect of over-expression TIPE2 on TF expression in THP-1 cells was detected by RT-PCR. Results: The relative level of TIPE2 protein in asthmatic patients and healthy controls was 0.025±0.010 and 0.087±0.070, while that of TF was 0.40±0.27 and 0.15±0.10, respectively. Compared with healthy controls, the levels of TIPE2 protein decreased and TF protein increased in asthmatic patients, the differences were statistically significant (t=-5.06, 9.04, P<0.05) . TIPE2 protein level was negatively correlated with TF protein level (r=-0.460 3, P<0.05). The house dust mite extract reduced the expression level of TIPE2 mRNA in THP-1 cells, but increased the level of TF mRNA expression. When the concentration was 1 μg/ml, the change of TIPE2 mRNA was the most obvious at 4 h (P<0.05). The recombinant adenovirus Adv-TIPE2 was successfully constructed. The level of TF mRNA expression in THP-1 cells over-expressing TIPE2 gene was reduced (P<0.05). Conclusion: TIPE2, a negative regulator of inflammation, has a negative control effect on TF, and may be involved in the hyper-coagulable state of bronchial asthma by regulating TF expression.

[ATP-P2X7R signalling pathway and its effects in parasitic diseases]

ATP (Adenosine triphosphate) is an important endogenous damage - associated molecular pattern (DAMP). P2X₇R is an ATP-gated cation channel. ATP-P2X₇R plays a vital role in the pathophysiology of many diseases because P2X₇R is distributed on various immune cells. ATP-P2X₇R signal transduction pathway has been implicated to participate in the body's immune defense against pathogens. This paper reviews the recent progress regarding ATP-P2X₇R and its effects on parasitic diseases.

Primary cultures of mouse small intestinal epithelial cells using the dissociating enzyme type I collagenase and hyaluronidase

The epithelium is a highly dynamic system, which plays a crucial role in the homeostasis of the intestinal tract. However, studies on the physiological and pathophysiological functions of intestinal epithelial cells (IECs) have been hampered due to lack of normal epithelial cell models. In the present study, we established a reproducible method for primary culture of mouse IECs, which were isolated from the viable small intestinal crypts of murine fetuses (on embryonic day 19), using type I collagenase and hyaluronidase in a short span of time (≤20 min). With this method, continuously growing mouse IECs, which can be subcultured over a number of passages, were obtained. The obtained cell lines formed a tight cobblestone-like arrangement, displayed long and slender microvilli, expressed characteristic markers (cytokeratin 18 and Notch-1), and generated increasing transepithelial electrical resistance and low paracellular permeability during in vitro culture. The cells also had enzymatic activities of alkaline phosphatase and sucrase-isomaltase, and secreted various cytokines (IL-1β, IL-6, IL-8, and monocyte chemoattractant protein-1), responding to the stimulation of Escherichia coli. These results show that the primary-cultured mouse IECs obtained by the method established here had the morphological and immunological characteristics of IECs. This culture system can be a beneficial in vitro model for studies on mucosal immunology and toxicology.

Genetic diversity and phylogeographic structure of Bactrian camels shown by mitochondrial sequence variations

The Bactrian camel includes various domestic (Camelus bactrianus) and wild (Camelus ferus) breeds that are important for transportation and for their nutritional value. However, there is a lack of extensive information on their genetic diversity and phylogeographic structure. Here, we studied these parameters by examining an 809‐bp mtDNA fragment from 113 individuals, representing 11 domestic breeds, one wild breed and two hybrid individuals. We found 15 different haplotypes, and the phylogenetic analysis suggests that domestic and wild Bactrian camels have two distinct lineages. The analysis of molecular variance placed most of the genetic variance (90.14%, P < 0.01) between wild and domestic camel lineages, suggesting that domestic and wild Bactrian camel do not have the same maternal origin. The analysis of domestic Bactrian camels from different geographical locations found there was no significant genetic divergence in China, Russia and Mongolia. This suggests a strong gene flow due to wide movement of domestic Bactrian camels.

Molecular phylogeny of the Bactrian camel based on mitochondrial Cytochrome b gene sequences

The Bactrian camel is an important domesticated animal providing milk, meat, and other products in desert countries. In this study, 111 individuals representing 11 domestic Bactrian camel breeds from China, Mongolia, Russia, and one wild Bactrian camel group from Mongolia were selected for the preparation of mitochondrial DNA. The 1140-bp fragments of the cytochrome b gene (Cytb) were amplified by polymerase chain reaction and sequenced directly. Sequences of the 92 domestic and 19 wild Bactrian camel samples were analyzed with DNASTAR, and a phylogenic tree was constructed using MEGA. The analysis revealed sixteen haplotypes among the samples that were divided into two haplogroups: a domestic haplogroup (H1-H13, H15, and H16) and a wild haplogroup (H14). Haplotype diversity values were from 0.356 in the HosZogdort, to 0.889 in the Sunit Bactrian camel breed. The Sunit breed displayed the highest nucleotide diversity value (0.00115), and the HosZogdort breed had the lowest value (0.00031). All domestic Bactrian camels formed a single monophyletic lineage that is the sister group to wild Bactrian camels, a finding consistent with a single domestication event and independent maternal inheritance since domestication. In addition, the most common mitochondrial haplotypes (H1, H3, and H4) were shared between Chinese, Mongolian, and Russian domestic Bactrian camels, which indicated that there was no distinguishing geographic structure among the domestic breeds from these three regions. These findings provide important insights into patterns of relatedness among Bactrian camels from the Chinese, Mongolian, and Russian regions.

Repairs of Partial Oblique Tendon Injuries: A Biomechanical Evaluation

This study evaluated the tensile properties of oblique partial tendon lacerations and the effects of peripheral sutures on their strength. Seventy-four fresh pig flexor digitorum profundus tendons were divided into eight groups and were transected across 90% of their diameter. The lacerations in the tendons of five of the groups were at 0°, 15°, 30°, 45°, and 60° to their transverse cross-section, respectively. In the other three groups the lacerations were 0°, 45°, and 60° to the cross-section and were repaired with running peripheral sutures. The tendons were subjected to load-to-failure tests in a tensile testing machine to determine the initial, 1 and 2 mm gap formation forces, and the ultimate strength. Obliquity of tendon lacerations affected the strength of partially lacerated tendons. The tendons with 45° and 60° oblique lacerations had a significantly lower ultimate strengths than those with transverse (0°), or 15° or 30° oblique lacerations. Running peripheral sutures significantly increased both the gap formation forces and the ultimate strength of the tendons with oblique partial lacerations.

Androgen deprivation in LNCaP prostate tumour xenografts induces vascular changes and hypoxic stress, resulting in promotion of epithelial-to-mesenchymal transition

Background:

When single-agent androgen deprivation therapy (ADT) is administered for locally advanced prostate cancer, men usually relapse within 1–2 years with more malignant castrate-resistant disease. The reason for this is currently unknown. We now hypothesise that an initial treatment response that increases tumour hypoxia drives selection of more malignant tumours.

Methods:

The LNCaP prostate tumour xenografts were analysed for physiological (oxygen and vasculature) and genetic (PCR array) changes during longitudinal treatment with ADT (bicalutamide, 6 or 2 mg kg⁻¹ daily for 28 days).

Results:

Bicalutamide caused an immediate (within 24 h) dose-dependent fall in oxygenation in LNCaP-luc prostate tumours with a nadir of ≤0.1% oxygen within 3–7 days; this was attributed to a significant loss of tumour microvessels (window chamber study). The hypoxic nadir persisted for 10–14 days. During the next 7 days, tumours regrew, oxygenation improved and the vasculature recovered; this was inhibited by the VEGF inhibitor B20.4.1.1. Gene expression over 28 days showed marked fluctuations consistent with the physiological changes. Accompanying the angiogenic burst (day 21) was a particularly striking increase in expression of genes associated with epithelial-to-mesenchymal transition (EMT). In particular, insulin-like growth factor 1 (IGF-1) showed increases in mRNA and protein expression.

Conclusions:

Hypoxic stress caused by ADT promotes EMT, providing a mechanism for the cause of malignant progression in prostate cancer.

Blockade of IL-6 signal exacerbates acute inflammatory bowel disease via inhibiting IL-17 producing in activated CD4+ Th17 population

BACKGROUND

Inflammatory bowel disease (IBD) is a common disease in human resulted from a various of factors including genetic background, immune system and environment factors.

OBJECTIVES

Recent studies suggest pro-inflammatory cytokine IL-17 producing cell subset was involved in the disease development and the maintenance of IBD. And the differentiated and activation of IL-17 producing cells were mostly dependent on the cytokines profile secreted by innate cells in intestinal tissues. In this study, we examined the functions of IL-6 signal in regulatory of IL-17 production in acute IBD model.

MATERIALS AND METHODS

Wildtype mice were treated with anti-IL-6 neutralizing antibodies to block IL-6 signal And then treated with DSS to induce acute IBD.

RESULTS

Mice treated with anti-IL-6 neutralizing antibodies show severe colitis and high level of pro-inflammatory cytokine IL-17 production in DSS-induced acute IBD model when compared with control group. Our research suggested blockade of IL-6 signal pathways in acute colitus model resulted in specific activation of IL-17 producing cell population. Furthermore, CD44+ activated Th17 cell population and CD44- IL-17 producing T cells exhibited different susceptibility to IL-6 signal in our model.

CONCLUSIONS

Blockade of IL-6 signal in DSS-induced acuted IBD model increased IL-17 production level specifically in CD44- T cells and reduced CD44+ Th17 cell population.

The effects of angiotensin-converting enzyme-inhibitory peptide LAP on the left common carotid artery remodeling in spontaneously hypertensive rats

OBJECTIVE

To investigate the protective effect of angiotensin-converting enzyme (ACE)-inhibitory peptide LAP on the left common carotid artery remodeling in spontaneously hypertensive rats (SHRs).

METHODS

A cohort of male SHRs were randomly divided into three groups (n = 10 for each group): pseudo-experimental group, enalapril-treated group as a positive control group, ACE-inhibitory peptide LAP-treated group. After the experiment, the left common carotid artery from each rat was removed for morphological evaluation.

RESULTS

It was observed that the vascular medial thickness, media thickness/lumen diameter, medial cross-sectional area and mean nuclear area of smooth muscle cells of the left common carotid artery in the LAP group or enalapril group were significantly lower than those in the pseudo-experimental group, while there was no significant difference in these parameters observed between the LAP group and enalapril group. Additionally, the vascular area percentage of collagen fibers of the left common carotid artery in the LAP group and enalapril group was significantly lower than that of the pseudo-experimental group.

CONCLUSIONS

The protective vessel remodeling effect in SHRs was observed with ACE-inhibitory peptide LAP in SHRs by decreasing blood pressure, inhibiting smooth muscle cell hypertrophy and reducing the proliferation of collagen fibers.

Interleukin-18 and IL18 -607A/C and -137G/C gene polymorphisms in patients with penicillin allergy

This study investigated the association between polymorphisms (-607A/C and -137G/C) in the promoter region of the IL18 gene (which encodes interleukin [IL]-18) and serum levels of IL-18, using standard genotyping techniques (sequence specific primer-polymerase chain reaction) and an enzyme-linked immunosorbent assay, respectively, in patients allergic to penicillin. A higher frequency of A alleles and the AA genotype was found at position -607A/C in patients allergic to penicillin than in control subjects. For the -137G/C position, the C allele was more frequent in patients allergic to penicillin than in control subjects. Haplotype analysis showed that the -607A/-137C haplotype was more frequent in patients allergic to penicillin than in control subjects. The patients had a significantly higher serum IL-18 level than the control subjects. In conclusion, IL18 -607A/C and -137G/C promoter polymorphisms are associated with susceptibility to penicillin allergy. In particular, the -137G/C position appears to play an important role in IL18 expression.

PUMA mediates EGFR tyrosine kinase inhibitor-induced apoptosis in head and neck cancer cells

Overexpression of epidermal growth factor receptor (EGFR) is found in over 80% of head and neck squamous cell carcinomas (HNSCC) and associated with poor clinical outcomes. EFGR selective tyrosine kinase inhibitors (TKIs) or antibodies have recently emerged as promising treatments for solid tumors, including HNSCC, though the response rate to these agents is low. p53 upregulated modulator of apoptosis (PUMA), a BH3-only Bcl-2 family protein, is required for apoptosis induced by p53 and various chemotherapeutic agents. In this study, we show that PUMA induction is correlated with EGFR-TKI sensitivity, and is mediated through the p53 family protein p73beta and inhibition of the PI3K/AKT pathway. In some HNSCC cells, the gefitinib-induced degradation of oncogenic Delta Np63 seems to facilitate p73-mediated PUMA transcription. Inhibiting PUMA expression by small hairpin RNA (shRNA) impairs gefitinib-induced apoptosis. Furthermore, PUMA or BH3 mimetics sensitize HNSCC cells to gefitinib-induced apoptosis. Our results suggest that PUMA induction through p73 represents a new mechanism of EGFR inhibitor-induced apoptosis, and provide potential ways for enhancing and predicting the sensitivity to EGFR-targeted therapies in HNSCC.

SMAC/Diablo mediates the proapoptotic function of PUMA by regulating PUMA-induced mitochondrial events

p53-upregulated modulator of apoptosis (PUMA) is a BH3-only Bcl-2 family protein and an essential mediator of DNA damage-induced apoptosis. PUMA is localized in the mitochondria and induces apoptosis through the mitochondrial pathway. However, the mechanisms of PUMA-induced apoptosis remain unclear. In this study, we found that second mitochondria-derived activator of caspase (SMAC)/Diablo, a mitochondrial apoptogenic protein, mediates the proapoptotic function of PUMA by regulating PUMA-induced mitochondrial events. SMAC is consistently released into the cytosol in colon cancer cells undergoing PUMA-induced apoptosis. In SMAC-deficient cells, execution of PUMA-induced apoptosis is abrogated, in company with decreases in caspase activation, cytosolic release of cytochrome c and collapse of mitochondrial membrane potential. Reconstituting SMAC expression restored these events in the SMAC-deficient cells. Furthermore, SMAC and agents that mimic the inhibitor of apoptosis proteins (IAPs) inhibition function of SMAC significantly sensitize cells to PUMA-induced apoptosis. These results demonstrate an important role of SMAC in executing DNA damage-induced and PUMA-mediated apoptosis and suggest that SMAC participates in a feedback amplification loop to promote cytochrome c release and other mitochondrial events in apoptosis.

Efficient femtosecond green-light source with a diode-pumped mode-locked Yb3+:KY(WO4)2 laser

Efficient generation of femtosecond pulses at 524 nm is demonstrated by the extracavity frequency doubling of the output of a diode-pumped femtosecond Yb3+:KY(WO4)2 laser using a periodically poled LiTaO3 crystal. An average second-harmonic power of 120 mW is produced at an internal conversion efficiency of 40%. The temporal characteristics of the frequency-doubled pulses as a function of focusing conditions in a thick nonlinear crystal are investigated experimentally, and pulses as short as 225 fs are generated at a pulse repetition frequency of 86 MHz.

Extended operation of synchronously pumped optical parametric oscillators to longer idler wavelengths

A synchronously pumped optical parametric oscillator, based on periodically poled lithium niobate, has operated at idler wavelengths out to 7.3 microm . Directly measured idler output powers (average) are 4.2 mW at 6.1 microm, 0.5 mW at 7.0 microm, and 0.04 mW at 7.25 microm . Characterization of the idler output indicates essentially bandwidth-limited and diffraction-limited operation.

Mutations in a newly identified GTPase gene cause autosomal dominant hereditary spastic paraplegia

The hereditary spastic paraplegias (HSPs; Strümpell-Lorrain syndrome, MIM number 18260) are a diverse class of disorders characterized by insidiously progressive lower-extremity spastic weakness (reviewed in refs. 1-3). Eight autosomal dominant HSP (ADHSP) loci have been identified, the most frequent of which is that linked to the SPG4 locus on chromosome 2p22 (found in approximately 42%), followed by that linked to the SPG3A locus on chromosome 14q11-q21 (in approximately 9%). Only SPG4 has been identified as a causative gene in ADHSP. Its protein (spastin) is predicted to participate in the assembly or function of nuclear protein complexes. Here we report the identification of mutations in a newly identified GTPase gene, SPG3A, in ADHSP affected individuals.

An in vivo rat model for assessment of extrahepatic metabolism

INTRODUCTION

Xenobiotic metabolism in extrahepatic tissues has been extensively studied in vitro, but it is difficult to estimate in vivo the share of xenobiotic transformation in extrahepatic tissues for lack of a suitable approach. In this paper an in vivo rat model for assessment of extrahepatic metabolism is described, and the model was investigated using the conversion of lidocaine to monoethylglycinexylidide (MEGX).

METHODS

The rats were anesthetized with ethyl ether inhalation. The liver was exposed, the liver artery ligated, and the portal vein was clamped at its distal end. The left hepatic lobe was partly excised along its inferior margin, and a heparinized silicone catheter, diameter 0.2 cm, was inserted into the portal and left hepatic veins to allow the recirculation of portal vein blood. A sham operation was performed in the control group.

RESULTS

Phenol red test showed that hepatic blood supply was absolutely blocked in model rats. At 30 min after establishing the portal-cavum bypass, the renal function and electrolytes did not change, but serum glucose decreased by 64.4 +/- 30.4%; 30 min after intravenous administration of 1.0% lidocaine 2 mg x kg(-1), serum MEGX in model rats was 32.0 +/- 7.14% of that in the control group, which mostly existed in a free form and was not induced by phenobarbital pretreatment.

DISCUSSION

The model is easy to establish and provides an in vivo method to study the extrahepatic metabolism of xenobiotics.

[Protective effect of extract of folium ginkgo on repeated cerebral ischemia-reperfusion injury]

OBJECTIVE

To study the protective effect of extract of Folium Ginkgo (FGE) on repeated cerebral ischemia-reperfusion injury.

METHODS

The model in waking mice induced by repeated cerebral ischemia-reperfusion were used in the experiment to observe the effect of FGE on behavior, oxygen free radical metabolism and prostaglandin E2 (PGE2) content by step-through experiment, diving stand and colorimetric method.

RESULTS

FGE could obviously improve the learning ability and memory of model animals, and could lower obviously the content of malonyldialdehyde, nitric oxide and PGE2, restore the lowered activity of superoxide dismutase and catalase in cerebral tissue.

CONCLUSION

FGE has highly protective effect against repeated ischemia-reperfusion injury, the mechanism might be related with its action on anti-lipid oxidatin, improve the activity of antioxidase and inhibit the producing of PGE2.

Pulmonary function for pectus excavatum at long-term follow-up

PURPOSE

The aim of this article was to assess whether and to what extent pulmonary function recovered to normal degree postoperatively and to investigate the changes in pulmonary function after surgical correction and the value of surgical correction.

METHODS

A total of 27 patients who could be questioned and examined in person at the outpatient department of our hospital were included in this study. Of these patents, 24 were boys and 3 were girls. Their ages ranged from 3 to 16 years (mean, 8.67) at follow-up. The mean age at surgery was 4 years, and mean years of follow-up was 6.8. Pulmonary functional measurements included in vital capacity (VC), total lung capacity (TLC), residual volume (RV), functional residual capacity (FRC), RV-TLC ratio, maximal voluntary ventilation (MVV), force ventilatory capacity (FVC), forced expiratory volume in one second (FEV1), maximal midexpiratory flow curve (MMEF), maximal expiratory flow in 75% vital capacity (V75), maximal expiratory flow in 50% vital capacity (V50), maximal expiratory flow in 25% vital capacity (V25), and breathing reserve ratio (BR).

RESULTS

TLC, FRC, MVV, MMEF, V75, and V50 values were not different from the normal values. IVC, FVC, FEV1, and V25 values were decreased significantly compared with the normal values. The RV and RV-TLC were high in 87.5% cases.

CONCLUSIONS

Preoperative symptoms obviously improved after operation. There was little airway obstruction in the patients postoperatively. The patients with pectus excavatum should be operated on as soon as possible.

Increased risk of hepatocellular carcinoma in male hepatitis B surface antigen carriers with chronic hepatitis who have detectable urinary aflatoxin metabolite M1

We followed 145 men with chronic hepatitis B virus (HBV) hepatitis for 10 years to determine whether exposure to aflatoxin, or concomitant exposure to hepatitis C virus (HCV), or family history of hepatocellular carcinoma (HCC) increased the risk of developing HCC. We collected 8 monthly urine samples before beginning follow-up and pooled them to detect aflatoxin metabolite M1 (AFM1). AFM1 was detected in 78 (54%) of the subjects. The risk of HCC was increased 3.3-fold (with a 95% confidence interval of 1.2-8.7) in those with detectable AFM1 (above 3.6 ng/L). This relative risk was adjusted for age and for HCV status. The attributable risk from exposure to detectable AFM1 was 0.553 (0.087, 0.94). The relative risk of fatal cirrhosis for those with elevated AFM1 was 2.8 (0.6, 14.3), and the odds of having a persistently elevated alanine transaminase (ALT) were 2.5-fold greater in those with detectable AFM1 (P =.007). Concomitant infection with HCV increased the risk of HCC 5.8-fold (2. 0-17), adjusted for age and AFM1 status. A family history of HCC increased the risk of HCC 5.6-fold, adjusted for age and AFM1. Four men with detectable AFM1 and HCC all had missense mutation in codon 249 of the p53 gene in cancer tissues. This study shows that exposure to AFM1 can account for a substantial part of the risk of HCC in men with chronic HBV hepatitis and adds importantly to the evidence that HCV and family history of HCC increase the risk of HCC in men with chronic HBV hepatitis.

Tumor necrosis factor-alpha-activated cell death pathways in NIT-1 insulinoma cells and primary pancreatic beta cells

Tumor necrosis factor-alpha (TNFalpha) is a potential mediator of beta cell destruction in insulin-dependent diabetes mellitus. We have studied TNF-responsive pathways leading to apoptosis in beta cells. Primary beta cells express low levels of the type I TNF receptor (TNFR1) but do not express the type 2 receptor (TNFR2). Evidence for TNFR1 expression on beta cells came from flow cytometry using monoclonal antibodies specific for TNFR1 and TNFR2 and from RT-PCR of beta cell RNA. NIT-1 insulinoma cells similarly expressed TNFR1 (at higher levels than primary beta cells) as detected by flow cytometry and radio-binding studies. TNF induced NF-kappaB activation in both primary islet cells and NIT-1 cells. Apoptosis in response to TNFalpha was observed in NIT-1 cells whereas apoptosis of primary beta cells required both TNFalpha and interferon-gamma (IFNgamma). Apoptosis could be prevented in NIT-1 cells by expression of dominant negative Fas-associating protein with death domain (dnFADD). Apoptosis in NIT-1 cells was increased by coincubation with IFNgamma, which also increased caspase 1 expression. These data show that TNF-activated pathways capable of inducing apoptotic cell death are present in beta cells. Caspase activation is the dominant pathway of TNF-induced cell death in NIT-1 cells and may be an important mechanism of beta cell damage in insulin-dependent diabetes mellitus.

[Characteristics of high frequency 249 codon mutation of p53 gene in hepatocellular carcinoma in prevalent area of China]

OBJECTIVE

To study the characteristic features of an unique hotspot missense mutation of the 249 codon of p53 gene demonstrated in human hepato-cellular carcinoma(HCC) in a region of high(Qidong) and low (Beijing) exposure to both hepatitis B virus (HBV) and aflatoxin B1 (AFB1) in China.

METHODS

Surgical samples from 97 HCC from Qidong and 22 from Beijing, China, collected in 1994 through 1997, were studied. The 249 codon mutation of p53 gene was detected by PCR followed by HaeIII RFLP analysis and DNA sequencing. Intracellular p53 protein level was determined by immunohistochemical staining.

RESULTS

High mutation rate of 249 codon of p53 gene was consistently found in recent years, with an average of 53.6% (52/97). No such mutation was identified in 22 Beijing HCC collected in the same time period. The genotype of p53 249 codon mutants which showed heterozygous profile was identified to be homozygous in nature following tumor tissue enrichment. Of 21 HCC shown to have 249 codon mutation, 20 exhibited high intranuclear accumulation of p53 protein. p53 protein staining was negative in the surrounding noncancerous hepatic tissue.

CONCLUSION

The high frequency of homozygous mutation of the 249 codon of p53 gene accompanied with p53 protein accumulation provides important enlightenment in the understanding of hepatocarcinogenesis and clinical application of gene therapy and/or immunotherapy for HCC.

Synthesis and anticholinesterase activity of huperzine A analogues containing phenol and catechol replacements for the pyridone ring

Based upon modeling results obtained using the crystal structure of huperzine A in complex with acetylcholinesterase (AChE), two novel analogues of this potent AChE inhibitor were designed with phenol or catechol rings replacing the pyridone ring. From the modeling studies, the catechol analogue appeared capable of replacing one of the crystallographic waters bridging huperzine with Tyr 130 and Glu 199 of AChE. The synthesis of these materials by use of a palladium catalyzed bicycloannulation strategy is detailed together with the results of AChE inhibition assays.

[The inhibitory effect of antisense--RNA of papillomavirus type 16 E6E7 genes on malignant phenotypes of cervical carcinoma cell line]

In our previous study, the malignant phenotypes of the NIH3T3 cells, transformed with HPV-16 E6E7 genes, could be inhibited by the antisense RNA of HPV-16 E6E7. In this study, the antisense RNA of HPV-16 E6E7 was induced into the cervical carcinoma cells, caski, which contained HPV-16 DNA. The results showed that the cellular growth velocity was down regulated by the antisense RNA of HPV-16 E6E7, the ability of forming cellular colonies in soft agar medium and the tumorigenicity in nude mice of CaSki cells were also inhibited by the antisense cellular colonies in soft agar median and the tumorigenicity in nude mice of Caski cells were also inhibited by the antisense RNA. In addition, the decrease of the expression of viral early genes in carcinoma cells was detected with Western blot assay. It denoted that the phenotypes and the carcinogenicity of tumor cells were inhibited by the associated antisense RNA, and this may be one of the pathways inducing tumor cells reversion.

Infection with human immunodeficiency virus and hepatitis viruses in Chinese drug addicts

The prevalence of antibody against hepatitis C virus (anti-HCV) and five hepatitis B virus markers (HBVM) was measured in 176 Chinese drug addicts, of whom 23 were AIDS patients. Of 176 drug addicts, 147 were members of ethnic minorities while 29 were Han, the majority ethnic group. The total prevalence rates of anti-HCV and HBVM were 35.8% and 50.6% respectively, significantly different (P < 0.01). Anti-HCV and HBVM were together found in 22.7%. Similar prevalence rates were found among the different ethnic groups. Among the ethnic minorities, there was a significantly higher prevalence rate of anti-HCV in intravenous drug addicts (IVDA, 51.1%) than in oral drug addicts (20.3%). Furthermore, the prevalence of anti-HCV was significantly higher in needle-sharing abusers (60.4%) than in non-needle sharing ones (37.1%, P < 0.05). The prevalence of HBVM was also significantly higher in needle-sharing abusers (69.8%) than in non-needle sharing ones (34.3%). Prevalence of HBsAg was significantly higher in drug abusers with AIDS (47.8%) than in IVDA only (16.1%). The anti-HCV positive rates among ethnic minority people were: for the Yi people 69.2%, the Hui 55.6%, the Bai 53.9%, the Dai 26.8% and the Wa 23.1%. No obvious difference was identified for HBVM. The prevalence rates of HCV, HBV and HCV + HBV in IVDA showed no significant difference (P > 0.05) between the two regions. HIV, HCV and HBV infections may promote each other and be related to needle-sharing behaviour in drug abuse and to different subcultures and living habits.

Fertilization-independent seed development in Arabidopsis thaliana

We report mutants in Arabidopsis thaliana (fertilization-independent seed:fis) in which certain processes of seed development are uncoupled from the double fertilization event that occurs after pollination. These mutants were isolated as ethyl methanesulfonate-induced pseudo-revertants of the pistillata phenotype. Although the pistillata (pi) mutant has short siliques devoid of seed, the fis mutants in the pi background have long siliques containing developing seeds, even though the flowers remain free of pollen. The three fis mutations map to loci on three different chromosomes. In fis1 and fis2 seeds, the autonomous endosperm nuclei are diploid and the endosperm develops to the point of cellularization; the partially developed seeds then atrophy. In these two mutants, proembryos are formed in a low proportion of seeds and do not develop beyond the globular stage. When FIS/fis plants are pollinated by pollen from FIS/FIS plants, approximately 50% of the resulting seeds contain fully developed embryos; these seeds germinate and form viable seedlings (FIS/FIS). The other 50% of seeds shrivel and do not germinate; they contain embryos arrested at the torpedo stage (FIS/fis). In normal sexual reproduction, the products of the FIS genes are likely to play important regulatory roles in the development of seed after fertilization.