Polymorphism in 3'-untranslated region of toll-like receptor 4 gene is associated with protection from hepatitis B virus recurrence after liver transplantation

BACKGROUND

Hepatitis B virus (HBV) recurrence is one of the more severe complications following liver transplantation. Toll-like receptors (TLRs) play a key role in human immunity by recognizing various bacteria, viruses, fungi, and parasites. Single nucleotide polymorphisms (SNPs) in the TLRs are thought to have an impact on the susceptibility to some pathogens. This study focused on the association between polymorphisms in the TLRs and HBV recurrence after liver transplantation in Han Chinese patients.

METHODS

A total of 41 tag SNPs in TLRs were detected by the snapshot technique in 125 patients with primary HBV-related diseases receiving liver transplantation in our center from 2004 to 2008.

RESULTS

By comparing the genetic variations and clinical data between the HBV recurrence patients and nonrecurrence patients, we found that the variant genotype of rs11536889 (TLR4) was significantly associated with HBV recurrence after liver transplantation (P = 0.040, odds ratio was 0.390, 95% confidence interval 0.159-0.957).

CONCLUSION

Our findings indicate that polymorphism in 3'-untranslated regions of the TLR4 gene may be related to protection from HBV recurrence after liver transplantation in Han Chinese patients.

Partial cancerous changes eventually developing into superficial spreading cancer over 18 months

In this report, we describe a patient presenting with the superficial spreading type of early gastric cancer (egc) accompanied by cancerous ulcers. Disease progression and treatment outcome are discussed. After symptoms persisted for more than 1 year, the patient underwent total gastrectomy with D2 lymph node dissection. The patient was diagnosed with superficial spreading cancer (ssc), accompanied by an extensive iic lesions. The progression of this patient suggests that the co-occurrence of cancerous ulcers may contribute to egc development to some extent. As is known, egc often develops into advanced gastric cancer with time. However, in our case, we observed a process during which partial cancerous changes developed into ssc over 18 months. Superficial spreading cancer should be considered an egc variant, which may have the ability to spread superficially along the stomach wall without invading the muscularis propria. But we speculate that, if gene expression changes for some reason, the malignant ssc cells may acquire the ability to grow deeply into the stomach wall. Eventually, Borrmann type iv gastric cancer may develop.

Neuroglobin-overexpression alters hypoxic response gene expression in primary neuron culture following oxygen glucose deprivation

Neuroglobin (Ngb) is a tissue globin specifically expressed in neurons. Our laboratory and others have shown that Ngb overexpression protects neurons against hypoxia/ischemia, but the underlying mechanisms remain poorly understood. Recent studies demonstrate that hypoxia/ischemia induces a multitude of spatially and temporally regulated responses in gene expression, and initial evidence suggested that Ngb might function in altering biological processes of gene expression. In this study, we asked how Ngb may help regulate genes responsive to hypoxia. Expression of hypoxic response genes following oxygen-glucose deprivation (OGD) was examined using mRNA arrays in neuroglobin-overexpressing transgenic (Ngb-Tg) and wild type (WT) mouse neurons. From a total of 113 genes on the microarray, mRNA expression of 65 genes was detected. Under rest condition, 14 genes were downregulated in Ngb-Tg neurons compared to WT. In WT neurons, after 4-h OGD followed by 4-h reoxygenation (O4/R4), 20 genes were significantly downregulated, and only Fos mRNA was significantly increased. However, out of the 20 downregulated genes in WT neurons, 12 of them were no longer significantly changed in Ngb-Tg neurons: Add1, Arnt2, Camk2g, Cstb, Dr1, Epas1, Gna11, Hif1a, Il6st, Khsrp, Mars and Rara. Among these 12 genes, 8 (Add1, Camk2g, Cstb, Dr1, Epas1, Gna11, Hif1a, Khsrp) were already reduced in Ngb-Tg neurons compared to WT under rest conditions. Additionally, three genes that initially showed no changes in WT neurons (Ctgf, Egfr and Pea15) were downregulated after OGD in the Ngb-Tg neurons. These findings suggest that Ngb overexpression modulates mRNA expression of multiple hypoxic response genes in the early phase after OGD/reoxygenation. Further studies on these gene networks and interactions may lead to better understanding of Ngb in signaling pathways that contribute to neuroprotection.

Complement factor H polymorphisms, renal phenotypes and age-related macular degeneration: the Blue Mountains Eye Study

Complement factor H (CFH) is a key regulator of the alternative pathway of complement and its mutations have been associated with membranoproliferative glomerulonephritis type II, atypical hemolytic uremic syndrome and age-related macular degeneration (AMD), suggesting that alternative pathway dysregulation is a common pathogenetic feature of these ocular and renal conditions. In this study we tested the hypothesis that common CFH variants have a global role in renal function in the Australian population-based Blue Mountains Eye Study (BMES). We replicated the association of I62V with estimated glomerular filtration rate (GFR; P=0.017) and creatinine clearance (CRCL; P=0.015). The minor allele of I62V (G) was deleterious: adding one copy of the G allele decreased GFR/CRCL by approximately 0.98 ml min(-1) per 1.73 m(2) (95% confidence interval (CI): 0.97, 0.99). We also replicated the association of Y402H with AMD and provided an unbiased estimate of population attributable risk (PAR). The minor allele of Y402H (C) was deleterious: the odds ratio estimate of CC genotype compared to TT was 1.87 (95% CI: 1.44, 2.45). The PAR of the C allele was estimated as 0.22 (95% CI: 0.15, 0.28). In summary, in the BMES population we confirmed the association between I62V and renal function, as measured by the estimated GFR, plus the association of Y402H with both early- and late-stage AMD.

[DNA methylation in cotton hybrids and their parents]

The possible role of methylation in the performance of heterosis has been analyzed in many crops. To further study this possibility, we investigated both the differences in cytosine methylation patterns between cotton heterotic hybrid/nonheterotic hybrids and their parental lines and the change in methylation level from seedling stage to flowering stage by using the methylation-sensitive amplified polymorphism (MSAP) method. The results showed that the number of demethylation loci in highly heterotic hybrids was greater that in lowly heterotic hybrids, and the level of DNA cytosine methylation in cotton at the seedling stage is higher than that at the flowering stage. The altered methylation patterns at low-copy genomic regions can be confirmed by DNA gel blot analysis. A total of 39 fragments that showed different methylation patterns were cloned and sequenced. The methylation status of these genes was modified differentially in hybrid and parents, suggesting that these genes might play a role in the performance of heterosis.

Aziridinyl quinone antitumor agents based on indoles and cyclopent[b]indoles: structure-activity relationships for cytotoxicity and antitumor activity

A large number of aziridinyl quinones represented by series 1-9 were studied with respect to their DT-diaphorase substrate activity, DNA reductive alkylation, cytostatic/cytotoxic activity, and in vivo activity. As a result, generalizations have been made with respect with respect to the following: DT-diaphorase substrate design, DT-diaphorase-cytotoxicity quantitative structure-activity relationship (QSAR), and DNA reductive alkylating agent design. A saturating relationship exists between the substrate specificity for human recombinant DT-diaphorase and the cytotoxicity in the human H460 non-small-cell lung cancer cell line. The interpretation of this relationship is that reductive activation is no longer rate-limiting for substrates with high DT-diaphorase substrate specificities. High DT-diaphorase substrate specificity is not desirable in the indole and cylopent[b]indole systems because of the result is the loss of cancer selectivity along with increased toxicity. We conclude that aziridinyl quinones of this type should possess a substrate specificity (V(max)/K(M)) < 10 x 10(-4) s(-1) for DT-diaphorase in order not to be too toxic or nonselective. While some DNA alkylation was required for cytostatic and cytotoxic activity by series 1-9, too much alkylation results in loss of cancer selectivity as well as increased in vivo toxicity. Indeed, the most lethal compounds are the indole systems with a leaving group in the 3alpha-position (like the antitumor agent EO9). We conclude that relatively poor DNA alkylating agents (according to our assay) show the lowest toxicity with the highest antitumor activity.

Recognition and cleavage at the DNA major groove

DNA recognition agents based on the indole-based aziridinyl eneimine and the cyclopent[b]indole methide species were designed and evaluated. The recognition process involved either selective alkylation or intercalating interactions in the major groove. DNA cleavage resulted from phosphate backbone alkylation (hydrolytic cleavage) and N(7) -alkylation (piperidine cleavage). The formation and fate of the eneimine was studied using enriched 13C NMR spectra and X-ray crystallography. The aziridinyl eneimine specifically alkylates the N(7) position of DNA resulting in direction of the aziridinyl alkylating center to either the 3'- or 5'-phosphate of the alkylated base. The eneimine species forms dimers and trimers that appear to recognize DNA at up to three base pairs. The cyclopent[b]indole quinone methide recognizes the 3'-GT-5' sequence and alkylates the guanine N(7) and the thymine 6-carbonyl oxygen causing the hydrolytic removal of these bases. In summary, new classes of DNA recognition agents are described and the utility of 13C-enrichment and 13C NMR to study DNA alkylation reactions is illustrated.

[Effects of heat stress on DA mediated PI signal transduction system in rat striatum]

Objective. To study the effects of heat stress on dopamine (DA) and related phosphatidylinositol (PI) signal transduction system members: PLA2, PI, Ca2+ in rat striatum. Method. Male Wistar rats were randomly divided into control group and heat stressed group. Heat stressed rats were placed in small hot chambers and taken out as soon as their rectal temperatures (Tr) reached the preset temperature. Then the animals were killed and their striatums were taken out. Fluorospectrophotometry, HPLC, Fura-2/AM fluoresence labelled method and acidalkaline titration were used to measure the content of DA, PI, [Ca2+]i and the enzyme activity of PLA2. Result. During heat stress, when rats' Tr reached 41.0 degrees C or higher, with increase of Tr, DA content increased continuously. When Tr = 43.0 degrees C, DA content was significantly higher than control. When Tr = 41.0 degrees C PLA2 activity was higher than control significantly, PI content of heat stressed group decreased significantly than control. [Ca2+]i increased significantly when Tr = 42.0 degrees C as compared with control. But if DA receptor2 (D2R) antagonist was given an hour before heat stress, [Ca2+]i decreased and Tr took a longer time to get to 42.0 degrees C. Conclusion. During heat stress, DA mediated PI signal transduction system was activated. The increase of [Ca 2+]i might be mediated by D2R, and D2R antagonist may improve thermotolerance.

[Determination of the point of gene mutation in two types of tissue from the aminoglycoside antibiotics induced deaf patients]

OBJECTIVE

To elucidate the gene mutation presents in hair follicle cells, just as blood cells, in the aminoglycoside antibiotics induced deaf patients(AAID).

METHOD

Mitochondrial DNA of blood cells and/or hair follicle cells from 8 members of 3 aminoglycoside antibiotics induced deafness families were analysed using PCR-SSCP and Alw 26 I digestian.

RESULT

Our result showed that a gene mutation at nucleotide 1555 in 12 S rRNA of mitochondrial DNA appeared in blood cells and/or hair follicle cells of 7 subjects among those 8 members. Only a father with normal hearing did't exhibit such a mutation.

CONCLUSION

This indicated that hairs could be used as a sample instead of blood to perform gene examination for AAID.

SeO(2) induces apoptosis with down-regulation of Bcl-2 and up-regulation of P53 expression in both immortal human hepatic cell line and hepatoma cell line

An immortal human hepatic cell line HL-7702 and human hepatoma cell line SMMC-7721 were treated with 3-30 microM SeO(2). SeO(2) at 30 microM markedly inhibited cell proliferation and viability, and prompted apoptosis of both normal hepatic and hepatoma cells after 48h treatment. SeO(2) could also down-regulate the Bcl-2 level, greatly in HL-7702 and slightly in SMMC-7721 cells, but up-regulate wild type P53 level a little in HL-7702 and significantly in SMMC-7721 cells. The Bcl-2/P53 value was closely correlated with the apoptotic rate as well as SeO(2) concentrations.

Bioeffects of positive and negative acoustic pressures in mice infused with microbubbles

This study provided one test of the hypothesis that hemorrhage in tissues containing ultrasound (US) contrast agents results from inertial cavitation. The test relied on the prediction of classical cavitation theory that the response of microbubbles to negative pressures is much greater than it is for positive pressures. An endoscopic electrohydraulic lithotripter was used to generate a spherically diverging positive pressure pulse. A negative pressure pulse was produced by reflection of the positive pulse from a pressure release interface. Mice were injected with approximately 0. 1 mL of Albunex(R) and exposed to 100 pulses at either + 3.6 MPa or -3.6 MPa pressure amplitude. For comparison, mice were also exposed to the same acoustic fields without injection of contrast agents. Sham animals experienced the same protocols, with or without Albunex(R) injections, but were not exposed to the lithotripter fields. Following exposure, mice were scored for hemorrhage to various organs and tissues. When Albunex(R) was present in the vasculature, negative pressure pulses produced significantly more hemorrhage than positive pressures in tissues such as the kidney, intestine, skin, muscle, fat, mesentery and stomach.

Sigmatropic reactions of the aziridinyl semiquinone species. Why aziridinyl benzoquinones are metabolically more stable than aziridinyl indoloquinones

Described herein is the chemistry of aziridinyl semiquinone species, which are formed upon one-electron metabolic reduction of aziridinyl quinone antitumor agents. The semiquinone species undergo a type of electrocyclic reaction known as a 1,5-sigmatropic shift of hydrogen. This reaction converts the aziridinyl group to both ethylamino and amino groups resulting in a loss of cytotoxicity. Since the radical anion conjugate base does not undergo ring opening as fast as the semiquinone, it was possible to determine the semiquinone pK(a) values by plotting the percent sigmatropic products versus pH. Aziridinyl quinones based on benzoquinones, such as DZQ and AZQ, possess semiquinone pK(a) values below neutrality. In contrast, an indole-based aziridinyl quinone possesses a semiquinone pK(a) value of 9.3. Single electron reduction of DZQ and AZQ by NADPH: cytochrome P-450 reductase at physiological pH therefore affords the radical anion without any sigmatropic rearrangement products. In contrast, the same reduction of an aziridinyl indoloquinone affords the semiquinone which is rapidly converted to sigmatropic rearrangement products. These findings suggest that aziridinyl quinone antitumor agents based on indoles will be rapidly inactivated by one electron-reductive metabolism. A noteworthy example is the indoloquinone agent EO9, which is rapidly metabolized in vivo. In contrast, benzoquinone-based aziridinyl quinone antitumor agents such as AZQ, DZQ, and the new benzoquinone analogue RH1 do not suffer from this problem.

[Clinical and pathological characteristics of gastric stump cancer and recurrent gastric stump cancer]

OBJECTIVE

To study early diagnosis and rational treatment of gastric stump cancer and recurrent gastric stump cancer.

METHODS

The data of 27 patients with gastric stump cancer and 23 patients with recurrent gastric stump cancer were analysed retrospectively during the past 20 years based on their clinical and pathological findings.

RESULTS

The onset time was 10 years or more for gastric stump cancer and less than 10 years for recurrent gastric stump cancer after gastrectomy. Gastroscopy was better than double contrast radiography in diagnosis. Partial resection of gastric stump was performed for patients with early cancer at the anastomotic stoma of gastrojejunostomy. Total resection of gastric stump was made for other patients. Lymph node of the mesojejunum were dissected routinely because their metastasis rate was about 40.0% in patients with cancer of anastomotic stoma. The effect of surgical treatment was poor for patients with advanced cancer.

CONCLUSIONS

Regular gastroscopy is useful in detecting gastric stump cancer in patients with gastric cancer after gastrectomy, or in those years after removal benign. Malignancy was more evident in recurrent gastric stump cancer than in primary gastric cancer. Prognosis is good for early stage cases and poor for late stage cases after surgical treatment.

Attenuation and loss of hormonal modulation of KGF (FGF-7)/KGF receptor expression and mitogenesis during mammary tumor progression

Keratinocyte growth factor (KGF), alone and in synergism with progesterone (P) and prolactin (PRL), is mitogenic for normal mammary epithelium (ME) in vitro. In addition, P can upregulate ME sensitivity to KGF by slowing KGF receptor (KGFR) mRNA turnover in vitro. These hormonal interactions with KGF in vitro raise the possibility that alterations in these interactions can play a role in hormone-dependent mammary tumor growth and progression. The effect of hormones on KGF mitogenesis and the regulation of KGFR expression was examined in pregnancy-dependent (PDT) and ovarian-independent (OIT) mouse mammary tumors. In serum-free, collagen gel cell culture, dose/response (2-20 ng/ml) and time course studies showed that KGF stimulated the proliferation of PDT (not OIT) cells but synergism with P or PRL was not observed. The level of KGFR mRNA in PDT cells was not significantly different from normal ME but in OIT it was reduced more than 90%. P did not affect KGFR mRNA turnover in cultured PDT cells. However, KGFR mRNA was more stable in PDT cells compared to normal ME; after 6 days culture in basal medium, KGFR mRNA levels declined 40% vs. 85% previously shown for normal ME. Determination of KGF mRNA levels in tissues showed that it was lower in PDT compared to normal mammary gland and not detectable in OIT. These data show that in PDT both KGF-stimulated mitogenesis and the regulation of KGFR expression are independent of hormones. OIT has progressed to independence from any KGF influence. Thus, a subset of hormonally regulated pathways related to epithelial/stromal cell interactions can be lost in hormone-dependent mammary tumors during tumor progression.