Growth phenotypes and biosafety profiles in poliovirus-receptor transgenic mice of recombinant oncolytic polio/human rhinoviruses

The use of oncolytic recombinant polioviruses has an important therapeutic potential in the treatment of human gliomas. This study was carried out to assess parameters of the utility of the oncolytic poliovirus/human rhinovirus type 2 chimeras (PV/HRV2). The prototype PV/HRV2 chimera was constructed containing the complete genome of wild-type PV type 1 (Mahoney) [PV1(M)] in which the cognate IRES was replaced with that of HRV2 [called PV1(RIPO)]. A derivative of PV1(RIPO) is PV1(RIPOS) in which the capsid coding region (P1) was replaced with the capsid-coding region of the PV type 1 (Sabin) [PV1(S)] vaccine strain. In addition, a third PV/HRV2 chimera was constructed containing the complete genome of PV1(S) in which the cognate IRES was replaced with that of HRV2 [termed PVS(RIPO)]. To analyze the growth phenotypes of PV/HRV2 recombinants [PV1(RIPO), PV1(RIPOS), PVS(RIPO)], one-step growth experiments were performed in four human cell lines at three different temperatures. To address the safety profile, PVS(RIPO) was injected into the brain of CD155 tg mice at the dose 10(7) PFU. Then, clinical signs, persistence of the virus in the CNS and genetic stability of PVS(RIPO) replicating in the CNS were evaluated. The data obtained in the present study suggest (i) a correlation between temperature-sensitive (ts) phenotype in both neuronal and non-neuronal cell lines and neuroattenuation in experimental animals, (ii) that PVS (RIPO) is genetically stable on replication in the CNS of poliovirus-susceptible mice. These findings highlight the safety of intracerebral inoculation of PVS(RIPO) for the treatment of human glioma.     

Evaluation of linear array human papillomavirus genotyping using automatic optical imaging software

Variations in biological behavior suggest that each carcinogenic human papillomavirus (HPV) type should be considered individually in etiologic studies. HPV genotyping assays might have clinical applications if they are approved for use by the FDA. A widely used genotyping assay is the Roche Linear Array HPV genotyping test (LA). We used LA to genotype the HPV isolates from cervical specimens from women with the full spectrum of cervical disease: cervical cancer, cervical intraepithelial neoplasia (CIN), and HPV infections. To explore the feasibility and value of the automated reading of the LA results, we custom-designed novel, optical imaging software that provides optical density measurements of LA bands. We compared unmagnified visual examination with the automated measurements. The two measurements were highly associated. By either method, the threshold between a negative and a positive result was fairly sharp, with a clear bimodal distribution. Visually, most positive results were judged to be strong or medium, with fewer equivocal results categorized as weak (9.5% of positive samples), very weak (6.5% of positive samples), or extremely weak (7.7% of positive samples). The automated measurements of the intensities were significantly associated with the strength of the visual categories (P < 0.001). At the extremes of the automated signal intensities (≤20 units or ≥120 units), the bands were almost always categorized visually as negative and positive, respectively. In the equivocal zone (20 to 119 units), specimens were more increasingly likely to be judged to be visually positive as the number of other, definite infections on the same strip increased (P for trend < 0.001). Multiple, concurrent infections comprise ≥25% of HPV infections; thus, any systematic visual tendency that influences their evaluation when the result is equivocal should be minimized. Therefore, automated reading is probably worth development if easy-to-calibrate hardware and software can be optimized.     

Reciprocal tachycardias using accessory pathways with long conduction times.

Three patients with reentrant tachycardia are described who had an accessory pathway with a very long conduction time that was incorporated in the tachycardia circuit. The accessory pathway was able to conduct in one direction only, in retrograde manner in two patients and in anteriograde manner in the remaining patient. Evidence is presented that reveals that in the first two patients the accessory pathway was septally located, had completely bypassed the normal atrioventricular (A-V) conduction system, had properties of decremental conduction, and had an atrial exit close to the coronary sinus and a ventricular exit relatively far from the atrioventricular A-V ring. In the third patient, who manifested wide QRS complex during tachycardia, the ventricular end of the accessory pathway seemed to be located close to the right ventricular apex. The atrial end of the pathway could not be localized exactly.     

Quantitative hypermethylation of NMDAR2B in human gastric cancer

NMDA receptor Type 2B (NMDAR2B) is a candidate TSG first identified in esophageal squamous cell carcinoma (ESCC). To evaluate NMDAR2B methylation in gastric cancer progression, we performed quantitative methylation-specific PCR (MSP), RT-PCR and immnunohistochemistry (IHC) in primary gastric tissues and colony formation assays in gastric cancer cell lines. We found that the expression of NMDAR2B was reactivated by the demethylating agent, 5-aza-2'-deoxycytidine, with or without trichostatin A in gastric cancer cell lines. Moreover, inactivation of NMDAR2B was found to be closely correlated with promoter methylation status in gastric cell lines and primary gastric tumors. IHC data also showed that NMDAR2B was specifically expressed in gastric epithelial cells and its expression was diminished or absent in gastric cancer epithelium. Quantitative analysis of NMDAR2B promoter methylation showed 61% (17/28) hypermethylation in primary gastric tumors versus 5% (1/20) in normal gastric tissues from nongastric cancer patients. Forced over-expression of NMDAR2B in gastric cancer cell lines significantly inhibited cell colony formation. Taken together, the above results suggest that NMDAR2B methylation is a common and important biologically relevant event in gastric cancer progression.     

Neither one‐time negative screening tests nor negative colposcopy provides absolute reassurance against cervical cancer

A population sample of 10,049 women living in Guanacaste, Costa Rica, was recruited into a natural history of human papillomavirus (HPV) and cervical neoplasia study in 1993–1994. At the enrollment visit, we applied multiple state‐of‐the‐art cervical cancer screening methods to detect prevalent cervical cancer and to prevent subsequent cervical cancers by the timely detection and treatment of precancerous lesions. Women were screened at enrollment with 3 kinds of cytology (often reviewed by more than one pathologist), visual inspection and cervicography. Any positive screening test led to colposcopic referral and biopsy and/or excisional treatment of CIN2 or worse. We retrospectively tested stored specimens with an early HPV test (hybrid capture tube test) and for >40 HPV genotypes using a research PCR assay. We followed women typically 5–7 years and some up to 11 years. Nonetheless, 16 cases of invasive cervical cancer were diagnosed during follow‐up. Six cancer cases were failures at enrollment to detect abnormalities by cytology screening; 3 of the 6 were also negative at enrollment by sensitive HPV DNA testing. Seven cancers represent failures of colposcopy to diagnose cancer or a precancerous lesion in screen‐positive women. Finally, 3 cases arose despite attempted excisional treatment of precancerous lesions. Based on this evidence, we suggest that no current secondary cervical cancer prevention technologies applied once in a previously under‐screened population is likely to be 100% efficacious in preventing incident diagnoses of invasive cervical cancer. © 2009 UICC     

249 TP53 mutation has high prevalence and is correlated with larger and poorly differentiated HCC in Brazilian patients

Background  

Ser-249 TP53 mutation (249^Ser) is a molecular evidence for aflatoxin-related carcinogenesis in Hepatocellular Carcinoma (HCC) and it is frequent in some African and Asian regions, but it is unusual in Western countries. HBV has been claimed to add a synergic effect on genesis of this particular mutation with aflatoxin. The aim of this study was to investigate the frequency of 249^Ser mutation in HCC from patients in Brazil.     

Accuracy of concurrent visual and cytology screening in detecting cervical cancer precursors in rural India

The high burden of cervical cancer and inadequate/suboptimal cytology screening in developing countries led to the evaluation of visual screening tests, like visual inspection with acetic acid (VIA) and Lugol's iodine (VILI). We describe the performance of VIA, VILI and cytology, carried out in a multinational project called "Screening Technologies to Advance Rapid Testing" in 5,519 women aged 30-49 years, in detecting cervical intraepithelial neoplasia (CIN). VIA, VILI and cytology were positive in 16.9%, 15.6% and 6.1% women, respectively. We found 57 cases of CIN2, 55 of CIN3 and 12 of cervical cancer; 90% of CIN3 and 43% CIN2 cases were positive for p16 overexpression and high-risk HPV infection, indicating a high validity of histological diagnosis. The sensitivity of VIA, VILI and cytology to detect high-grade CIN were 64.5%, 64.5% and 67.7%, respectively; specificities were 84.2%, 85.5% and 95.4%. A high proportion of p16 positive CIN 3 (93.8%) and 2 (76.9%) were positive on cytology compared with visual tests (68.8% and 53.8%, respectively) indicating a higher sensitivity of cytology to detect p16 positive high-grade CIN. However, the immediate availability of the results from the visual tests permits diagnosis and/or treatment to be performed in the same sitting, which can potentially reduce loss to follow-up when women must be recalled following positive cytology. Organizing visual screening services in low-resource countries may facilitate the gradual building of an infrastructure committed to screening allowing the eventual introduction of more sensitive, highly objective, reproducible and affordable human papillomavirus screening tests in future.