Identification and validation of genes involved in the pathogenesis of colorectal cancer using cDNA microarrays and RNA interference.

PURPOSE: The purpose of this study was to profile gene expression changes in colorectal tumors to identify new targets and strategies for the management of this disease. EXPERIMENTAL DESIGN: cDNA microarray analysis was used to detect differences in gene expression between normal tissue and colon tumors and polyps isolated from 20 patients. To identify genes that are important in regulating the growth properties of colorectal cancer, RNA interference (RNAi) was used to disrupt expression of several of the overexpressed genes in a colon tumor cell line, HCT116, which showed similar patterns of gene expression as many of the patient tumors. RESULTS: Expression changes of > or =2-fold in approximately one-third of the patients were consistently observed for 2632 of a total of 9592 genes (574 up-regulated genes and 2058 down-regulated genes). Subsequent analysis of 13 genes by quantitative real-time PCR confirmed the reliability of this analysis. RNAi-mediated disruption of the expression of one of these genes, survivin, a potent inhibitor of apoptosis, severely reduced tumor growth both in vitro and in an in vivo xenograft model. CONCLUSIONS: The combined use of microarray analysis and RNAi provides an excellent system to define the role of specific genes that are up-regulated in cancer lead to the increased in vitro and in vivo growth of colon tumors.     

Dibenzo[a,l]pyrene-induced DNA adduction, tumorigenicity, and Ki-ras oncogene mutations in strain A/J mouse lung

Dibenzo[a,l]pyrene (DB[a,l]P), an environmental polycyclic aromatic hydrocarbon, is the most potent carcinogen ever tested in mouse skin and rat mammary gland. In this study, DB[a,l]P was examined for DNA adduction, tumorigenicity, and induction of Ki-ras oncogene mutations in tumor DNA in strain A/J mouse lung. Groups of mice received a single i.p. injection of 0.3, 1.5, 3.0, or 6.0 mg/kg DB[a,l]P in tricaprylin. Following treatment, DNA adducts were measured at times between 1 and 28 days, while tumors were counted at 250 days and analyzed for the occurrence of point mutations in codons 12 and 61 of the Ki-ras oncogene. DB[a,l]P in strain A/J mouse lung induced six major and four minor DNA adducts. Maximal levels of adduction occurred between 5 and 10 days after injection followed by a gradual decrease. DB[a,l]P-DNA adducts in lung tissue were derived from both anti- and syn-11,12- dihydroxy-13,14-epoxy- 11,12,13,14-tetrahydrodibenzo[a,l]pyrene (DB[a,l]PDE) and both deoxyadenosine (dAdo) and deoxyguanosine (dGuo) residues in DNA as revealed by cochromatography. The major adduct was identified as a product of the reaction of an anti-DB[a,l]PDE with dAdo in DNA. DB[a,l]P induced significant numbers of lung adenomas in a dose- dependent manner, with the highest dose (6.0 mg/kg) yielding 16.1 adenomas/mouse. In tricaprylin-treated control animals, there were 0.67 adenomas/mouse. Based on the administered dose, DB[a,l]P was more active than other environmental carcinogens including benzo[a]pyrene. As a function of time-integrated DNA adduct levels, DB[a,l]P induced lung adenomas with about the same potency as other PAHs, suggesting that the adducts formed by DB[a,l]P are similar in carcinogenic potency to other PAHs in the strain A/J mouse lung model. Analysis of the Ki- ras mutation spectrum in DB[a,l]P-induced lung tumors revealed the predominant mutations to be G-->T transversions in the first base of codon 12, A-->G transitions in the second base of codon 12, and A-->T transversions in the second or third base of codon 61, concordant with the DNA adduct profile.      

Cytoreductive surgery with intraperitoneal hyperthermic chemotherapy for disseminated peritoneal cancer of gastrointestinal origin

No standard effective treatment exists for peritoneal carcinomatosis of gastrointestinal origin. The pharmacokinetic advantage of intraperitoneal chemotherapy and the synergy of heat and certain anticancer agents have prompted researchers to investigate intraperitoneal hyperthermic chemotherapy in treating disseminated peritoneal cancers. We have conducted a large Phase II trial to determine the safety and efficacy of aggressive cytoreductive surgery and intraperitoneal hyperthermic chemotherapy (IPHC) in treating peritoneal carcinomatosis of gastrointestinal origin. Patients with disseminated peritoneal carcinomatosis of gastrointestinal origin with or without malignant ascites were eligible. After aggressive surgical debulking, patients were administered a 2-hour heated (40.5 degrees C) intraperitoneal perfusion with mitomycin C. The major response variable monitored was overall survival. Patients were assessed for toxicity after IPHC administration using the National Cancer Institute Common Toxicity Criteria. Eighty-four patients with peritoneal carcinomatosis of gastrointestinal origin were evaluated for survival and toxicity (colon, n = 38; appendix, n = 22; stomach, n = 19; other gastrointestinal, n = 5). Thirty-nine (46%) patients had malignant ascites at the time of therapy. The operative mortality (30-day) was 6 per cent. Hematologic toxicity was the most common toxicity but was of mild to moderate severity (7 and 4% of patients had grade 3/4 white blood cell or platelet toxicity, respectively). The overall median survival was 14.3 months. The median survival of patients with peritoneal carcinomatosis of appendiceal, colorectal, and gastric origins were 31.1+, 14.6, and 10.1 months, respectively. Significant differences in median survival were seen in patients without and with malignant ascites (27.7 vs 7.6 months; P = 0.0004) and R0/R1 (complete gross tumor resection) versus R2 (gross residual tumor) surgical resection status (28.5+ vs 10.8 months, P = 0.0002). These data suggest that aggressive cytoreductive surgery with IPHC using mitomycin C is safe and effective in treating peritoneal carcinomatosis of gastrointestinal origin. Additional studies and broader applications of this treatment are encouraged.     

幽门螺杆菌中国菌株致病相关基因cagA、iceA、vacA及HP0519分布分析

目的分析中国不同人群及不同胃部疾病病例来源的幽门螺杆菌致病相关基因cagA、iceA、vacA及HP0519的分布.方法采用特异引物聚合酶链式反应（PCR）方法分析150株幽门螺杆菌上述基因的多态性分布特点,并对其分布作初步统计分析.结果93%（139/150）中国菌株cagA基因3′端重复序列的PCR产物具有东方菌株特征.75%（113/150）菌株iceA基因为iceA1,19%（29/150）为iceA2,不同地区间iceA基因的分布差异无统计学意义.云南菌株iceA1、iceA2的分布与菌株分离个体的种族特点及临床疾病类型无显著关系.96%中国菌株（144/150）vacA基因s区的等位基因为s1;m区等位基因m2、m1b和m1b-m2的比例分别为57%（85/150）、27%（41/150）和11%（16/150）,仅2株福建菌株为m1a.不同地区间vacA s1、m2、m1b分布的差异无统计学意义.云南菌株m1b-m2的分布高于福建和北京菌株.云南菌株vacA s区等位基因的多样性与分离个体的种族及临床疾病类型无显著关系.vacA m区等位基因的多样性与分离个体的临床疾病类型无显著关系,但不同民族间m2的分布有显著差异,白族人群m2的分布显著少于汉族和纳西族.93%（140/150）的中国菌株HP0519基因具有24 bp和15 bp DNA插入和缺失的多态性特点.不同地区间HP0519基因的多态性无显著不同.云南菌株HP0519的多态性与菌株分离个体的临床疾病类型无显著关系,但来源不同民族菌株的HP0519基因存在差异.结论幽门螺杆菌中国菌株cagA 3′端JF/TR特异引物的扩增结果具有东亚菌株特点.中国菌株vacA基因多为s1,其分布与菌株分离个体的临床疾病类型无关.中国菌株vacA基因m区的分布具有多样性.中国菌株HP0519基因具有24 bp和15 bp插入和缺失的多态性特点.     

Marked abnormal quadruple screen in a patient with severe preeclampsia at 20 weeks with a triploid fetus.

Severe preeclampsia rarely occurs prior to 20 weeks of gestation except in pregnancies with triploidy. The patient reported herein is a 29-year-old primigravida who developed severe preeclampsia at 20 weeks of gestation. Evaluation of the pregnancy demonstrated a markedly abnormal quadruple screen. Amniocentesis demonstrated a fetus with triploidy, despite a normal appearance.     

Prognostic implications of molecular and immunohistochemical profiles of the Rb and p53 cell cycle regulatory pathways in primary non-small cell lung carcinoma.

PURPOSE: Many studies have highlighted the aberrant expression and prognostic significance of individual proteins in either the Rb (particularly cyclin D1, p16INK4A, and pRb) or the p53 (p53 and p21Waf1) pathways in non-small cell lung cancer. We hypothesize that cumulative abnormalities within each and between these pathways would have significant prognostic potential regarding survival. EXPERIMENTAL DESIGN: Our study population consisted of 106 consecutive surgically resected cases of predominantly early-stage non-small cell lung cancer from the National Cancer Institute-Mayo Clinic series, and assessment of proteins involved both immunohistochemical (cyclin D1, p21Waf1, pRb, p16INK4A, and p53) and mutational analysis (p53) in relationship to staging and survival. RESULTS: Cyclin D1 overexpression was noted in 48% of the tumors, p16INK4A negative in 53%, pRb negative in 17%, p53 immunopositive in 50%, p53 mutation frequency in 48%, and p21(Waf1) overexpression in 47%, none with prognostic significance. Cyclin D1 overexpression in pRb-negative tumors revealed a significantly worse prognosis with a mean survival of 2.3 years (P = 0.004). A simultaneous p53 mutation dramatically reduced the mean survival time to 0.9 years (P = 0.007). Cyclin D1 overexpression with either a p53 mutation or a p53 overexpression was also associated with a significantly poorer prognosis (P = 0.0033 and 0.0063, respectively). CONCLUSIONS: Some cumulative abnormalities in the Rb and p53 pathways (e.g., cyclin D1 overexpression and p53 mutations) significantly cooperate to predict a poor prognosis; however, the complexity of the cell cycle protein interaction in any given tumor warrants caution in interpreting survival results when specific protein abnormalities are taken in isolation.     

Cytochrome P450 epoxygenases as EDHF synthase(s)

The metabolism of arachidonic acid by cytochrome P450 (CYP) epoxygenases generates epoxyeicosatrienoic acids (EETs) which affect numerous cellular process including Ca(2+) signaling and the activity of Ca(2+)-dependent K(+) channels. The expression of the CYP epoxygenase(s) that generate EETs in endothelial cells is not constitutive but is determined by a number of physical (fluid shear stress and cyclic stretch) and pharmacological stimuli which also affect responses attributed to an endothelium-derived hyperpolarizing factor (EDHF). This review summarizes the role played by EETs, and the enzymes that generate and metabolize them, in EDHF-mediated responses.     

Tubo-ovarian Abscess in Virginal Adolescent Females: A Case Report and Review of the Literature

BackgroundA tubo-ovarian abscess (TOA) is a serious complication of pelvic inflammatory disease (PID), predominantly polymicrobial and present in sexually active women. TOA in virginal adolescent females are extremely rare but have serious and lifelong consequences.CaseA 13 y.o. virginal female presented to the Emergency Room of a tertiary care pediatric hospital with abdominal pain and vomiting. Imaging suggested bowel compromise with potential perforation. An exploratory laparotomy revealed TOA which grew Escherichia Coli. This is the first reported case of Escherichia Coli TOA due to suspected bowel translocation.ConclusionReview of the literature identified 8 cases of TOA in virginal adolescents. Given the severity of outcomes following TOA, this pathology should be considered in the differential diagnosis of virginal adolescents who present with fever and abdominal pain. If suspected, a prompt gynecology consult should be initiated, followed by a first line antibiotic therapy and when indicated, surgical drainage.