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1.
The tumor suppressor gene p16 (CDKN2/MTS-1/INK4A) is an important component of the cell cycle and inactivation of the gene has been found in a variety of human cancers. In order to investigate the role of p16 gene in the tumorigenesis of hepatocellular carcinoma (HCC), 48 cases of HCC were analysed for p16 alterations by: methylation-specific PCR (MSP) to determine the methylation status of the p16 promoter region; comparative multiplex PCR to detect homozygous deletion; PCR-SSCP and DNA sequencing analysis to identify mutation of the p16 gene. We found high frequency of hypermethylation of the 5' CpG island of the p16 gene in 30 of 48 cases (62.5%) of HCC tumors. Moreover, homozygous deletion at p16 region were present in five of 48 cases (10.4%); and missense mutation were detected in three of 48 cases (6.3%). The overall frequency of p16 alterations, including homozygous deletion, mutation and hypermethylation, in HCC tumors was 70.8% (34 of 48 cases). These findings suggest that: (a) the inactivation of the p16 is a frequent event in HCC; (b) the p16 gene is inactivated by multiple mechanisms including homozygous deletion, promoter hypermethylation and point mutation; (c) the most common somatic alteration of the p16 gene in HCC is de novo hypermethylation of the 5' CpG island; and (d) in contrast to other studies, high frequency of genomic alterations are not uncommon in the 9p21 of the p16 gene. Our results strongly suggest that the p16 gene plays an important role in the pathogenesis of HCC.  相似文献   

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Thymic epithelial tumours are broadly classified into thymomas and thymic carcinomas. Although both tumours occasionally show invasive growth, they exhibit different clinical and biological findings. The oncogene and anti-oncogene in thymic epithelial tumours have not been evaluated fully. We investigated the expression of p53 protein by immunohistochemical analysis using the anti-p53 polyclonal antibody (CM-1) in 17 thymomas and 19 thymic carcinomas. We also examined p53 gene (exon 5-8) mutation in 18 thymic carcinomas by using polymerase chain reaction-single-strand conformation polymorphism methods and direct sequencing. Of the thymoma cases, only one invasive thymoma showed focal nuclear staining. Fourteen of the 19 thymic carcinomas (74%) showed nuclear staining. Point mutations of the p53 gene were recognized in only 2 of the 18 thymic carcinomas (11%). One was the mutation C to T transition in the first letter of codon 222 in exon 6, which results in the amino acid substitution from proline to serine. Another was a silent mutation. p53 protein accumulation is highly frequent in thymic carcinomas but not in thymomas, and gene mutation is uncommon in thymic carcinomas.  相似文献   

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This epidemiological study investigated the reasons why children in Northern Ireland who need orthodontic treatment do not receive treatment even when it is provided free by the state. A total of 1584 15- and 16-year-olds were examined in 23 high schools with the Index of Orthodontic Treatment Need. The characteristics of the adolescents who had received orthodontic treatment were compared with those who had a definite need for treatment and yet did not receive treatment or advice. One in 10 of the adolescents examined had an unmet need for orthodontic treatment. Logistic regression analysis was used to assess the influence of 11 variables including socioeconomic status, religion, and standard of dental health on the uptake of orthodontic care. This analysis revealed that the only significant predictors of whether an adolescent received orthodontic treatment was the dental attendance pattern of the adolescent, the adolescent's dental health, and the dental attendance pattern of the adolescent's mother. Those adolescents who had good dental health, who regularly attended a dentist, and whose mother regularly attended a dentist were more likely to receive orthodontic treatment.  相似文献   

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Distortion-product otoacoustic emissions (DPOAEs) have been shown to be ideally sensitive to interruptions of the cochlear blood flow. However, a 15- to 30-second latency typically occurs between cessation of circulation and measurable DPOAE level changes. DPOAEs can also be characterized by phase measures. The aim of the present study was to determine in 10 rabbits the effects on DPOAE phase of repetitively compressing the internal auditory artery. In contrast to the delays measured by DPOAE level, phase changes were detected 1 to 5 seconds after internal auditory artery compression. These data suggest that the essentially "real time" monitoring of cochlear function with DPOAE phase can be used to ensure hearing preservation during surgery involving the porus acousticus and skull base.  相似文献   

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STUDY OBJECTIVES: To determine the safety of early extubation (EE) after coronary artery surgery. DESIGN: Prospective randomized controlled trial. SETTING: The cardiac surgery operating room and ICU of a university-affiliated teaching hospital. PATIENTS: One hundred eligible patients presenting for elective coronary artery surgery. INTERVENTIONS: Patients randomized to the EE group were administered a reduced dose of fentanyl (15 microg/kg) and an anesthetic compatible with EE, while patients randomized to the conventional extubation (CE) group were given fentanyl (50 microg/kg). MEASUREMENTS AND RESULTS: The time to extubation in the EE group (median, 240 min; range, 30 to 930 min) was significantly less than the CE group (median, 420 min; range, 125 to 1,140 min) (p<0.01). Twenty patients were withdrawn from the study according to protocol guidelines. There were no cases of reintubation or complications attributable to EE. CONCLUSIONS: By using an appropriate anesthetic technique and postoperative management, EE can be achieved following coronary artery bypass surgery without major complications.  相似文献   

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To elucidate the prevalence and biologic significance of the c-myc gene in human hepatocellular carcinoma (HCC), DNA samples were taken from the paired tumorous and nontumorous tissues of 77 cases of resected primary HCC and were analyzed by Southern blot hybridization. We demonstrated modest, but significant c-myc amplification (group A) in 28 (36.4%) of the cases: 1.6- to 2.0-fold in 18, 2.1- to 3.0-fold in four, and > 3.0-fold in six. Compared to HCC without c-myc amplification (group B), group A HCC occurred more often in patients < 50 years old (54.5% vs 29.1%, p < 0.02) with serum alpha-fetoprotein (AFP) levels > 320 ng/mL (61.1% vs 14.6%, p < 0.00002). Group A HCC occurred more frequently in patients with hepatitis B virus infection than in those with hepatitis C virus infection (p < 0.03). Group A HCC was more likely to be poorly differentiated (44.8% vs 10.5%, p < 0.004) and associated with intrahepatic portal vein spread (57.1% vs 28.6%, p < 0.02). The c-myc amplification did not correlate with sex or tumor size. For small HCC, group A had a worse one-year survival rate than group B (72.2% vs 90.9%, p < 0.04). These findings suggest that c-myc amplification is not an uncommon event in human hepatocarcinogenesis, occurs more frequently in young patients who have an elevated serum AFP level or HBV infection, and is related to the biologic behavior of HCC.  相似文献   

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Excessive deposition of extracellular matrix or neomatrix is a characteristic of desmoplastic invasive breast carcinomas. Type I and III collagens are abundant neomatrix components. Archival breast tissue sections were studied using 35S-labeled cDNA probes for alpha 1(I) and alpha 1(III) procollagen and in situ hybridization. Among the 33 invasive breast cancers, hybridization was seen forming a gradient-like pattern in fibroblasts closest to tumor cells. In the 10 ductal carcinomas in situ studied, a ring-like pattern of hybridization was seen in proximity to the basement membrane zone. Adjacent normal and benign tissues did not demonstrate the patterns of hybridization described in malignant tissues. Gene expression for neomatrix interstitial collagens occurs before there is evidence of invasion in carcinoma of the breast.  相似文献   

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It has been well documented that the liver is an exceptional organ in which the monoallelic expression of insulin-like growth factor 2 (IGF2) due to genomic imprinting is relaxed during the postnatal period, resulting in biallelic expression thereafter. In the present study, changes in the status of genomic imprinting were examined in 15 hepatocellular carcinomas (HCCs) as well as in 29 liver biopsies of chronic hepatitis or liver cirrhosis without clinical evidence of HCC, following screening for heterozygotes with an ApaI polymorphism in IGF2 in 34 HCCs and 80 such non-HCC cases. Extreme allelic-expression imbalance, leading to restoration of monoallelic IGF2 expression, was observed in 15 (100%) of 15 informative HCCs for the polymorphism with this monoallelic IGF2 expression appearing to be non-random from the paternal allele. Interestingly, the same allelic-expression imbalance was also present in a significant fraction of noncancerous liver specimens of patients with underlying disease known to be associated with HCC development. In contrast, the status of genomic imprinting of H19, another gene closely mapped at 11p15 under opposite imprinting, was strictly maintained in seven (100%) of seven cases informative for an RsaI polymorphism of H19. Together with the previous reports on altered genomic imprinting of IGF2 and H19 in embryonal lesions such as Wilms tumors as well as in lung cancers, the results suggest that perturbations of imprinting status occur as locus and tumor-type specific events in the development of human cancers.  相似文献   

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Hemopoietic alterations may occur during tumoral diseases, determining anemia. In most cases, serum EPO levels were lower than normal values. Hepatocellular carcinoma (HCC), one of the most frequent malignancies world-wide, is often characterized by mild anemia and increased serum EPO levels. We studied 30 HCC patients and 20 healthy subjects. We found that HCC patients presented higher serum EPO levels than healthy controls. In HCC patients, there was a significant inverse correlation between serum EPO levels and red blood cell count or hemoglobin levels. We postulated that the elevated serum EPO levels observed in these patients may be due to reduced hepatic clearance of EPO, and to the influence of cytokine-mediated inflammatory factors.  相似文献   

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Metallothionein (MT), an oncofocal gene product was strongly expressed in 35%-95% of hepatocytes in hepatocellular carcinoma (HCC) and MT-positive hepatocytes were localized mainly in the non-cancerous cirrhotic nodules but not in malignant hepatocytes. On the other hand, <10% hepatocytes showed weak staining for MT in chronic hepatitis and cirrhosis of liver. Strong expressions of MT in non-cancerous cirrhotic nodule in HCC and low expressions in liver cirrhosis without HCC indicate a relationship between malignant transformation of hepatocytes and the expression of MT.  相似文献   

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The extracellular matrix (ECM) located in and around tumors is different from normal organ stroma, and there is evidence that it is critically involved in carcinogenesis and malignant growth. Whereas an abnormal composition of ECM in hepatocellular carcinomas (HCC's) has previously been demonstrated, not much is known so far with respect to putative HCC precursor lesions. We have, therefore, systematically analyzed the immunohistochemical reactivity for two major ECM components, tenascin and type IV collagen, in three types of liver cell dysplasia (LCD), and compared the findings with patterns observed in HCC's of different types and grades. Tenascin reactivity was generally stronger in HCC's than in cirrhosis. In cirrhotic nodules harboring areas of LCD, tenascin expression was significantly lower in small cell LCD than in large cell LCD. Type IV collagen reactivity in and around HCC's decreased as a function of a lower differentiation grade. In both groups of cirrhosis, i.e. with or without HCC, cirrhotic nodules occupied by the small cell variant of LCD exhibited a significantly lower type IV collagen reactivity than those with large cell LCD or simple regenerative cells. Taken together these findings suggest that, similar to adenomatous hyperplasia, small cell LCD is characterized by an abnormal tenascin and type IV collagen expression, thus reflecting the defective ECM pattern observed in HCC's.  相似文献   

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The therapeutic modalities in patients with hepatocellular carcinoma (HCC) depend on the number, size and location of the lesions as well as the stage of the underlying liver disease and the physical condition of the patient. In patients with small and solitary lesions, resection, liver transplantation and in some cases percutaneous ethanol injection (PEI) can be curative. In more advanced stages of the disease with larger or multiple lesions, PEI and/or transarterial chemotherapy with or without embolization (TACE or TAC) can slow the progression of the disease. In disseminated disease, a radiotherapeutic approach can be taken in selected cases. The therapeutic strategy in patients with HCCs should be individualized, frequently involving a combination of therapeutic modalities. In contrast to the earlier dismal prognosis, for most HCC patients there is today a therapeutic strategy that results in prolongation of life and in some cases even cure.  相似文献   

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Hepatocellular carcinoma (HCC) represents one of the most common neoplasms worldwide. To date, curative treatment options include liver transplantation or resection. Unfortunately, most patients are detected with nonresectable or -transplantable HCC due to disease extension or comorbid factors, and are therefore candidates only for palliative treatments. Palliative medical treatments, including systemic chemotherapy, immunotherapy or hormonal manipulation, have a borderline activity on HCC and cannot be recommended outside clinical trials. A high response rate has been reported with local therapies such as transcatheter arterial embolisation, intra-arterial chemotherapy or percutaneous alcohol (ethanol) injection, but as there is no clear evidence of a survival advantage for these treatment modalities, further investigations are required. Multidisciplinary treatment, including preoperative cytoreduction or postoperative adjuvant therapy, is currently under investigation, with encouraging survival results. HCC patients should be evaluated within clinical trials, possibly randomised and with homogeneous prognostic factors, in order that we may find the answer to all these important questions.  相似文献   

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BACKGROUND: The p27KIP1 gene, whose protein product is a negative regulator of the cell cycle, is a potential tumor suppressor gene; however, no tumor-specific mutations of this gene have been found in humans. This study was undertaken to identify and to assess potential alterations of p27KIP1 gene expression in patients with benign prostatic hyperplasia (BPH) and patients with prostate cancer. METHODS: We analyzed 130 prostate carcinomas from primary and metastatic sites, as well as prostate samples from normal subjects and from patients with BPH. Immunohistochemistry and in situ hybridization were used to determine the levels of expression and the microanatomical localization of p27 protein and messenger RNA (mRNA), respectively. Immunoblotting and immunodepletion assays were performed on a subset of the prostate tumors. Associations between alterations in p27KIP1 expression and clinicopathologic variables were evaluated with a nonparametric test. The Kaplan-Meier method and the logrank test were used to compare disease-relapse-free survival. Prostate tissues of p27Kip1 null (i.e., knock-out) and wild-type mice were also evaluated. RESULTS: Normal human prostate tissue exhibited abundant amounts of p27 protein and high levels of p27KIP1 mRNA in both epithelial cells and stromal cells. However, p27 protein and p27KIP1 mRNA were almost undetectable in epithelial cells and stromal cells of BPH lesions. Furthermore, p27Kip1 null mice developed enlarged (hyperplastic) prostate glands. In contrast to BPH, prostate carcinomas were found to contain abundant p27KIP1 mRNA but either high or low to undetectable levels of p27 protein. Primary prostate carcinomas expressing lower levels of p27 protein appeared to be biologically more aggressive (two-sided P = .019 [Cox regression analysis]). CONCLUSIONS/IMPLICATIONS: On the basis of these results, we infer that loss of p27Kip1 expression in the human prostate may be causally linked to BPH and that BPH is not a precursor to prostate cancer.  相似文献   

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We studied the management of postoperative drainage after total knee replacement (TKR). 90 primary total knee joint arthroplasties were prospectively randomized into 3 groups: a) no drain, b) an autotransfusion system, c) a standard disposable closed suction drainage system. We monitored hemoglobin and hematocrit values, drainage volume and transfusions (homologous and autologous), range of knee motion, knee swelling and hospital stay. Parameters were recorded preoperatively, days 0-8 and 4 months postoperatively. No significant differences were seen between the groups in any of the parameters measured. The results show no benefit from using postoperative drainage systems in knee arthroplasties. Savings of SEK 400 (USD 55) per patient would have resulted if drains had not been used at all.  相似文献   

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