Comparative mouse skin tumorigenicity and induction of Ha-ras mutations by bay region diol epoxides of 5-methylchrysene and 5,6- dimethylchrysene

We compared the tumor-initiating activities toward mouse skin of two structurally related polycyclic aromatic hydrocarbon diol epoxides: racemic anti-1,2,3,4-tetrahydro-5,6-dimethylchrysene-1,2-diol-3,4- epoxide (5,6-diMeCDE) and racemic anti-1,2,3,4-tetrahydro-5- methylchrysene-1,2-diol-3,4-epoxide (5-MeCDE). Tumors induced by these diol epoxides were analysed for mutations in the Ha-ras gene. 5,6- diMeCDE is derived from the non-planar parent compound 5,6- dimethylchrysene, and reacts to approximately equal extents with dA and dG in DNA, whereas 5-MeCDE is derived from a nearly planar parent compound, 5-methylchrysene, and reacts mainly with dG in DNA. 5,6- diMeCDE, at initiating doses of 33, 100 or 400 nmol per mouse, induced 1.2, 2.2 and 6.2 skin tumors per mouse, respectively. It was significantly less tumorigenic than 5-MeCDE which induced 3.1, 7.5 and 9.1 skin tumors per mouse at the same doses. Tumors induced by 5,6- diMeCDE had a large number of CAA-->CTA mutations in codon 61 of the Ha- ras gene: 50, 55 and 75% of the tumors analysed had this mutation at the 33, 100 and 400 nmol doses. No mutations were found in codons 12 and 13 in the tumors induced by 5,6-diMeCDE. In contrast, CAA-->CTA mutations in codon 61 were rarely seen in tumors induced by 5-MeCDE. At the highest dose of 5-MeCDE, 20% of the tumors analysed had mutations at G of codons 12 and 13. The results of this comparative study support the hypothesis that mutations in the Ha-ras gene in mouse skin tumors induced by PAH diol epoxides occur as a result of their direct reaction with the gene. However, pathways other than the commonly observed Ha- ras codon 61 mutations are clearly important in mouse skin tumorigenesis by these diol epoxides.      

Erythropoietin and erythropoietin receptor expression in head and neck cancer: relationship to tumor hypoxia.

PURPOSE: Erythropoietin, an oxygen-regulated glycoprotein hormone, is a hematopoietic cytokine that stimulates erythropoiesis by binding to its cellular receptor [erythropoietin receptor (EPOR)]. The recombinant form of human erythropoietin is used to prevent or treat anemia in cancer patients. However, in a recent randomized, placebo-controlled trial involving patients receiving curative radiotherapy for squamous cell carcinoma of the head and neck, erythropoietin treatment was associated with poorer locoregional progression-free survival. The purpose of our study was to determine whether EPOR and its ligand erythropoietin are expressed in primary head and neck cancer. We also investigated the hypothesis that erythropoietin expression in malignant cells may be associated with the presence of tumor hypoxia, an important factor involved in resistance to radiation treatment, tumor aggressiveness, and poor prognosis. EXPERIMENTAL DESIGN: Twenty-one patients received an i.v. infusion of the hypoxia marker pimonidazole hydrochloride before multiple tumor biopsies. Contiguous sections from 74 biopsies were analyzed by immunohistochemistry for EPOR and erythropoietin expression and pimonidazole binding. RESULTS: EPOR expression was present in tumor cells in 97% of the biopsies. Coexpression of erythropoietin was observed in 90% of biopsies. Erythropoietin and pimonidazole adduct staining did not always colocalize within tumors, but there was a significant positive correlation between levels of microregional erythropoietin expression and pimonidazole binding. CONCLUSIONS: The coexpression of erythropoietin and EPOR in tumor cells suggests that erythropoietin may potentially function as an autocrine or paracrine factor in head and neck cancer. The expression of the hypoxia-inducible protein erythropoietin in tumor cells correlates with levels of tumor hypoxia.     

基于主成分分析下慢性阻塞性肺疾病急性加重频率的判别分析

目的 对慢性阻塞性肺疾病患者（COPD)）一般资料及临床资料进行主成分分析和判别分析,研究影响疾病急性加重频率的因素,以预测患者后续发病频率。 方法 选取我院2016年1月～2017年10月收治的350例COPD患者为研究对象,收集患者例入院时一般资料、24h内动脉血气分析,首次降钙素原（PCT）含量、C反应蛋白（CRP）含量及血常规,及入院结束治疗时的抗生素治疗时间、住院时间。对入选患者随访1年,并明确1年内慢性阻塞性肺疾病急性加重（AECOPD）次数,根据疾病加重次数将患者分为三组（A组：≤1次;B组：＜3次;C组：≥3次）。比较三组一般资料及临床资料的差异,利用因子分析提取上述临床指标及一般资料主成分,并利用主成分对AECOPD患者急性加重频数行判别分析,比较提取主成分前后判别分析率差异。结果 共纳入患者321例,其中A组105例、B组105例、C组111例,三组一般资料及临床资料除吸烟年无明显差异,其余指标组间比较,差异有统计学意义（P＜0.05）。从临床指标及一般资料中共提取5个主成分,综合信息提取率833%。一般资料及临床指标判别分析提示,总体判别正确率为748%,A、B、C组三组正确判别率分别为88.6%、65.7%、70.3%;利用提取的主成分进行判别分析提示,总体判别正确率72.0%,A、B、C组三组正确判别率分别为971%、60%、595%。结论 利用常见一般资料及临床资料进行判别分析,可预测患者发病频数,主成分分析的判别正确率与综合资料判别正确率间无明显差异。     

Urothelial eddies in papillary urothelial neoplasms: a distinct morphologic pattern with low risk for progression

We encountered an undescribed histologic feature of papillary urothelial neoplasms: “urothelial eddy”, which was histologically reminiscent of squamous eddy of irritated follicular keratosis of the skin. A review of 756 patients with transurethral resection of bladder tumor revealed 10 patients (1.3%) of papillary urothelial neoplasms with urothelial eddies. All cases were male with a median age of 65 years. Urothelial eddies were characterized by small ovoid nests of ovoid to spindle cells arranged in an onion-skin pattern with fine cytoplasmic processes within wide intercellular space. The cytoplasmic processes mimicked intercellular bridges but ultrastructurally were cytoplasmic microvillous projections. They were of papillary urothelial neoplasm of low malignant potential in seven patients and low-grade urothelial carcinoma in three patients. Nine patients presented as non-invasive tumor and one patient showed microinvasion within papillary stalks. Six patients showed an inverted growth pattern. Their immunoprofile was more similar to that of conventional urothelial carcinoma rather than squamous cell carcinoma: high expressions of GATA3, S100P, uroplakin III, and cytokeratin 7; and low expressions of high molecular weight cytokeratin and p53. The Ki-67 labeling index was low (mean and median values, 2% each). During the follow-up period (mean, 88.7 months), four patients, including the microinvasive patient, showed recurrence with the same grade and stage but neither progressed into muscle-invasive tumor nor caused death. Our results suggest that urothelial eddy is a rare aberrant histology of papillary urothelial neoplasms with indolent behavior and should be discriminated from squamous differentiation of urothelial carcinoma, which has a poor prognosis.     

Distinguishing true from false positives in genomic studies: p values

Distinguishing true from false positive findings is a major challenge in human genetic epidemiology. Several strategies have been devised to facilitate this, including the positive predictive value (PPV) and a set of epidemiological criteria, known as the “Venice” criteria. The PPV measures the probability of a true association, given a statistically significant finding, while the Venice criteria grade the credibility based on the amount of evidence, consistency of replication and protection from bias. A vast majority of journals use significance thresholds to identify the true positive findings. We studied the effect of p value thresholds on the PPV and used the PPV and Venice criteria to define usable thresholds of statistical significance. Theoretical and empirical analyses of data published on AlzGene show that at a nominal p value threshold of 0.05 most “positive” findings will turn out to be false if the prior probability of association is below 0.10 even if the statistical power of the study is higher than 0.80. However, in underpowered studies (0.25) with a low prior probability of 1 × 10^?3, a p value of 1 × 10^?5 yields a high PPV (>96 %). Here we have shown that the p value threshold of 1 × 10^?5 gives a very strong evidence of association in almost all studies. However, in the case of a very high prior probability of association (0.50) a p value threshold of 0.05 may be sufficient, while for studies with very low prior probability of association (1 × 10^?4; genome-wide association studies for instance) 1 × 10^?7 may serve as a useful threshold to declare significance.     

Loop myopexy with true muscle transplantation for very large angle heavy eye syndrome patient

A 42-year-old man presenting with complaints of squint for last 20 years. His visual acuity was 20/400 in right eye (RE) and 20/30 in left eye (LE) with glasses. His refraction was RE -16.75/-2.5 D cycl 180 and LE was -14.5/-1.5 D cycl 180. His axial length was 31.23 mm In RE and 29.72 mm in LE. On examination we found he had RE large esotropia with hypotropia measuring 130 pd base out and 40 pd base up in RE. A computerized tomography scan revealed that the superior rectus (SR) was shifted nasally, and lateral rectus (LR) was shifted inferiorly. A RE medial rectus (MR) recession and LR resection with muscle transplantation on the MR was done. A loop myopexy was done to correct the path of the LR and SR. The patient had only 18 pd eso and 20 pd hypo on follow-up after 3 months. Loop myopexy in conjunction with muscle transplantation is a safe and effective procedure for large angle esotropia associated with heavy eye syndrome.     

TIBIA AS DONOR SITE FOR ALVEOLAR BONE GRAFTING IN PATIENTS WITH CLEFT LIP AND PALATE: LONG TERM EXPERIENCE

Tibial bone grafts were studied in 137 patients with clefts of the lip and palate. Twenty-one had clefts of the lip and primary palate and 116 had complete unilateral clefts of the lip and palate. Bone grafting was performed secondarily or late secondarily. Bone was harvested from the proximal part of the tibia distal to the tuberosity through an incision about 15 mm long. The mean follow-up time after bone grafting was 5.5 years (range 2-11). There were no operative, or early or late postoperative complications reported (such as haematoma, fracture, or shortening of the limb). Harvesting time was about 15 minutes. The possibility of operating with two teams makes the total operating time shorter. Bleeding was negligible (less than 15 ml) and the amount of bone obtained was always sufficient. Patients were mobilised the next day and were back to full physical activity by one month. Indications for tibial bone grafting included facilitation of tooth eruption into the graft, giving bony support to the neighbouring teeth, making it possible to insert a titanium fixture, raising the alar base of the nose, and closing an oronasal fistula. Compared with iliac, cranial, mandibular, and costal donor sites, using the tibia took less time, gave less bleeding, made it possible for two teams to operate simultaneously, gave a smaller scar, and there were minimal complications and satisfactory quantity and quality of bone in all cases. The results suggested that the tibia is an excellent choice of graft for residual alveolar clefts in patients with cleft lip and palate.