长白山落叶松癌肿菌生物学特性

本文介绍韦氏小毛盘菌Lachnellula willkommii(Hartig)Dennis在长白落叶松上部分生物学特性的研究方法和结果。

Bacterial infections in cirrhotic patients with hepatocellular carcinoma

AIMS To establish the prevalence of bacterial infection in cir- rhotic patients with hepatocellular carcinoma(HCC). METHODS All 719 cirrhotic patients with HCC were investigat- ed retrospectively for the prevalence of bacterial infections. RESULTS The incidence of bacterial infection was 15.4% (111/719).According to Child-Pugh classification,the inci- dences of bacterial infection in class A,B and C were 2.3%,8. 0%,and 26.4 %,respectively.The bacterial infection increased with the severity of cirrhosis and severe bacterial infections usual- ly occurred in Child-Pugh class B and C patients. CONCLUSIONS The susceptibility of HCC patients to bacterial infection is mainly due to the underlying cirrhosis and not to the HCC itself.

Detection and location of Helicobacter pylori in human gastric carcinomas

AIM: To define the infection status of Helicobacter pylori in 109 patients with gastric cancers and H pylori localization in gastric carcinoma tissues in South China. METHODS: The incidence of H pylori infection in gastric carcinomas was estimated by polymerase chain reaction (PCR), simultaneously; both morphological features and the localization of H pylori in gastric carcinomas were demonstrated by Warthin-Starry (WS) staining. The relationships between H pylori infection and the clinical-pathologic factors of gastric carcinomas were analyzed by software SPSS10.0. RESULTS: H pylori was found in 42 (39.03%) and 58 (53.21%) cases of 109 patients with gastric carcinomas by PCR and WS, respectively. H pylori infection rate detected in gastric carcinomas by WS was higher than that by PCR (X2=9.735, P<0.005<0.01). WS stain showed that H pylori existed in the gastric antrum mucus, mucosal gland of normal tissues adjacent to gastric carcinomas and the gland, mucus pool of cancer tissues. The positive rate of H pylori in normal tissues adjacent to carcinomas was higher than that in cancer tissues (X2=15.750, P<0.005 <0.01). No significant differences in age, sex, site, histological types and lymph node metastasis were found between H pylori-positive gastric carcinomas and H pylori-negative cases by both methods, but there were statistically significant differences of H pylori positive rate between early and advanced stage of gastric carcinomas (X2= 4.548 or 5.922, P= 0.033 or 0.015<0.05). CONCLUSION: These results suggested that H pylori infection might play a certain role in the early stage of carcinogenesis of human gastric mucosa epithelia.

Loss of FHIT expression in gastric mucosa of patients with family histories of gastric cancer and Helicobacter pylori infection

AIM: To answer the question whether FHIT gene expression is affected by the family history of gastric carcinoma and the presence of Helicobacter pylori (Hpylori) in the gastric mucosa of patients with dyspepsia.METHODS: FHIT gene expression in two different topographic sites of the gastric mucosa of twenty-one patients with dyspepsia and with or without familial gastric carcinoma, infected or not infected with H pylori, was evaluated by reverse transcription-PCR (RT-PCR) and IMAGE QUANT methods. A rapid urease test and histopathological examination were used to determine H pylori colonization.RESULTS: In the gastric mucosa of patients with family histories of gastric carcinoma, the amount of FHIT protein mRNA was reduced down to 32%, and for patients with H pylori colonization, to 24% in comparison to controls with dyspepsia and without cancer in the family. FHIT expression was independent of the topography of specimens (corpus vsantrum), and for the control patients it was less sensitive to infection with H pylori. A considerable statistical difference in FHIT levels was observed in the gastric mucosa from the corpus of patients with family histories of gastric carcinoma in respect to H pylori colonization (P = 0.06). Macroscopic evaluation of the gastric mucosa demonstrated that pathologic changes classified according to the Sydney system had no significant influence on FHIT expression within each tested group of patients.CONCLUSION: Loss of FHIT expression was observed in patients with dyspepsia and family histories of gastric carcinoma, especially those infected with H pylori. Such results may constitute an early indication of the development of gastric carcinoma, which is associated with family factors including heredity and H pylori infection. The loss of the FHIT gene may serve as a marker for early diagnosis and prevention of gastric carcinoma, especially in context of early monitoring of H pylori infection in individuals with a record of familial stomach cancer.

Chemotherapy with enteric-coated tegafur/uracil for advanced hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide, including Japan. Although the development of imaging modalities has made the early diagnosis of HCC possible, surgically resectable cases are relatively uncommon because of hepatic function reserve and/or an advanced stage at presentation. Several modalities, such as transcatheter arterial chemoembolization, percutaneous ethanol injection, microwave coagulation therapy and radiofrequency ablation are reportedly useful in treating patients with non-resectable disease. However, unfortunately, many HCC patients have tumor recurrence. The overall prognosis of patients with HCC is very poor, and treatment of the advanced form is still problematic. In this article, we review the clinical efficacy and toxicity of enteric-coated tegafur/uracil in the treatment of patients with advanced non-resectable HCC.

Helicobacter pyloriseroprevalence in patients with lung cancer

AIM:To assess Helicobacter pylori(Hpylon)seroprevalence in a cohort of Greek patients with lung cancer. METHODS:Seventy-two lung cancer patients(55 males and 17 females,aged 58.2±11.7 years)and 68,age and gender-matched,control subjects were enrolled.All subjects underwent an enzyme-linked immunosorbent assay IgG serologic test for Hpylori diagnosis. RESULTS:A correlation between age and HpyloriIgG level was detected for both lung cancer patients(r=0.42, P=0.004)and controls(r=0.44,P=0.004).Seropositivity for Hpyloridid not differ significantly between patients with lung cancer and controls(61.1% vs 55.9%,P>0.05). Concerning the mean serum concentration of IgG antibodies against Hpylori,no significant difference between the two groups was detected(32.6±19.1 vs 27.4±18.3 U/mL, P>0.05). CONCLUSION:No significant association between Hpylori infection and lung cancer was found.

Helicobacter infection in hepatocellular carcinoma tissue

AIM： To investigate whether Helicobacter species （Helicobacter spp.） could be detected in hepatocellular carcinoma （HCC） tissue.METHODS： Liver samples from 28 patients with hepatocellular carcinoma （HCC） diagnosed by histopathology were studied. Twenty-two patients with other liver diseases （5 with liver trauma, 7 with cavernous liver hemangioma, 6 with liver cyst and 4 with hepatolithiasis）, 25 patients with gastric cancer, 15 with colonic cancer and 15 with myoma of uterus served as controls. Two piceces of biopsy were obtained from each patient. One was cultured for Helicobacter spp. and extraction of DNA, the other was prepared for scanning electron microscopy （SEM） and in situ hybridization. The samples were cultured on Columbia agar plates with microaerobic techniques. Helicobacter spp. in biopsy from the studied subjects was detected by polymerase chain reaction （PCR） with Helicobacter spp. 16S rRNA primers. Amplified products were identified by Southern hybridization and sequenced further. Besides, other genes （vacA, cagA） specific for Helicobacter pylori （H pylorO were also detected by PCR. Helicobacter spp. in biopsies was observed by SEM. Transmission electron microscopy （TEM） was performed to identify the cultured positive Helicobacter spp. The presence of Helicobacter spp. was detected by in situ hybridization to confirm the type of Helicobacter. RESULTS： The positive rate of He/icobacter cultured in HCC and gastric cancer tissue was 10.7% （3/28） and 24%（6/25）, respectively. Helicobacter microorganisms were identified further by typical appearance on Gram staining, positive urease test and characteristic colony morphology on TEM. The bacterium was observed in adjacent hepatocytes of the two HCC samples by SEM.The number of cocci was greater than that of bacilli. The bacterium was also found in four gastric cancer samples. PCR showed that the positive rate of HCC and gastric cancer samples was 60.7% and 72% respectively, while the controls were negative （P〈 0.01）. The PCR-amplified products were identified by Southern hybridization and sequenced. The homology to 16S rRNA of H pylon was 97.80%. The samples were verified by in situ hybridization for Helicobacter spp. 16S rRNA-mRNA and proved to be Hpylori positive. There was no statistical significance between HCC and gastric cancer （P〉 0.05）, but the positive rate of HCC and controls had statistical significance （P〈0.01）. Only 3 HCC samples and 2 gastric cancer samples of the cagA genes were detected. None of the samples reacted with primers for vacA in the two groups. As for the genotype of H pylori, type II had preference over type I. CONCLUSION： Helicobacter infection exists in liver tissues of HCC patients. Helicobacter spp. infection is related with HCC, which needs further research.

In Vivo Selection of Phage Sequences and Characterization of Peptide-specific Binding to Breast Cancer Cells

OBJECTIVE To screen specific polypeptide target binding to breast cancer xenografts in vivo from a phage-displayed peptide library in order to provide peptide sequences for breast cancer tumor-targeting diagnosis and therapy. METHODS A mouse model for carrying breast cancer xenografts was established using Tientsin Albinao Ⅱ mice （TA Ⅱ）. A 12-peptide library was biopanned through 4 rounds. Phages were recovered and titrated from tumor xenografts and control tissue （liver）. The distribution of phages was detected by immunohistochemical staining. RESULTS Phage homing to breast cancer was enriched through 4 rounds of biopanning, being 14-fold of that recovered from liver tissue. A peptide sequence, ASANPFPTKALL was characterized by randomly picked-up clones which appeared most frequently. Immunohistochemical staining revealed phage localization in cancer xenografts 40 min after injection of the enriched phages. When a specific phage was tested individually, the phage reclaimed from breast cancer xenografts was 14 times as those from control tissues. CONCLUSION Tumor-specific homing peptides may provide an effective tool for breast cancer target therapy. The in vivo phage display selection technique employed in this study was feasible and applicable to screening peptides that home to breast cells.

Dysbiosis of gut microbiota in promoting the development of colorectal cancer

Gastrointestinal microbiome,containing at least 100 trillion bacteria,resides in the mucosal surface of human intestine.Recent studies show that perturbations in the microbiota may influence physiology and link to a number of diseases,including colon tumorigenesis.Colorectal cancer(CRC),the third most common cancer,is the disease resulting from multi-genes and multi-factors,but the mechanistic details between gut microenvironment and CRC remain poorly characterized.Thanks to new technologies such as metagenome sequencing,progress in large-scale analysis of the genetic and metabolic profile of gut microbial has been possible,which has facilitated studies about microbiota composition,taxonomic alterations and host interactions.Different bacterial species and their metabolites play critical roles in the development of CRC.Also,microbiota is important in the inflammatory response and immune processes deregulation during the development and progression of CRC.This review summarizes current studies regarding the association between gastrointestinalmicrobiota and the development of CRC,which provides insights into the therapeutic strategy of CRC.