p53 gene mutations are rare in human papillomavirus-associated colon cancer

Recent studies suggest that infection with high risk human papillomavirus (HPV) is a common event in colon tumors. Infection by oncogenic HPV may result in functional inactivation of the p53 protein in absence of mutations. Thus far no studies have been made to examine the frequency of p53 mutations in HPV-associated colon cancer. The purpose of this study was to investigate the interrelationship between p53 mutations and HPV infection. The 'hot-spot' region of the p53 gene for mutations was analyzed by PCR-SSCP and direct sequencing in HPV-positive tumor samples. Only 2 mutations were identified in 56 samples. This rate was much lower than reported for sporadic colon tumors. Our results indicate an inverse relationship between p53 mutations and HPV infection and suggest that p53 inactivation caused by HPV infection may play a role in the pathogenesis of colon cancer.     

Plasminogen activator inhibitor-1 4G/5G polymorphism in Turkish children with cerebral infarct and effect on factor V 1691 A mutation

The thrombotic risk of carrying plasminogen activator inhibitor-1-675 4G allele was found to be controversial in previous studies. The aim of this study was to evaluate the possible effect of plasminogen activator inhibitor-1 4G/5G polymorphism in the pathogenesis of childhood stroke. The case-control study included 43 patients with cerebral infarct who were below the age of 18 years (range, 10 months to 18 years) and 113 healthy unrelated individuals without family histories of thrombosis. Plasminogen activator inhibitor-1 4G/5G polymorphism was analyzed according to a previously described method. There was no statistically significant difference in patient and control groups for the distribution of plasminogen activator inhibitor-1 4G/5G polymorphism (P = .75) (allele frequency 4G controls: 0.50; patients: 0.53). However, there was a significant difference for the factor V (FV) 1691 A mutation for both groups (P = .0007).     

P53 codon 72 polymorphism in breast cancer

Increased and deregulated proliferative activity due to abnormalities in the cell cycle modulators are frequently observed in cancer. A sequence polymorphism at codon 72 of the p53 gene results in either a proline or an arginine and may induce different functional activities. This polymorphism has been shown to have varying ethnic and geographical distribution. It has been reported that the p53 Arg homozygous genotype could be a potential genetic risk factor for cancer. However, not all investigations have been consistent and this hypothesized association remains controversial. The purpose of this study was to investigate the genotype frequencies and association of the p53 codon 72 polymorphism with breast cancer in Turkish patients. A group of 115 patients with breast cancer and a control group of 76 healthy individuals were enrolled in the study. A significantly higher prevalence of homozygosity for the p53 Arg allele was observed in the patients as compared to the controls. Statistical analysis suggested a strong association between the Arg/Arg genotype and breast cancer.     

Hounsfield Units: A new indicator showing maxillary resistance in rapid maxillary expansion cases?

Objective:To determine if density measurements of several maxillary regions in Hounsfield Units (HU) and outcomes of rapid maxillary expansion (RME) are correlated. Is correlation powerful enough to give us direct information about maxillary resistance to RME?Materials and Methods:Twenty-two computed tomographic (CT) scans (14 years) are used in this archive study. Two CT records were collected, one before RME (T₁) and one after 3 months of retention period (T₂). Maxillary measurements were made using dental and skeletal landmarks in first molar and first premolar slides to measure the effects of RME. Density of midpalatal suture (MPSD) and segments of maxillary bone is measured in HU at T₁. Correlation analysis was conducted between density measurements and maxillary variables. Regression analysis was then performed for variables that showed positive correlation.Results:There was no correlation between density and skeletal measurements. Intermolar angle (ImA) in molar slice showed statistically significant correlation with density measurements. The ImA variable showed the highest correlation with MPSD in frontal section (r  =  0.669, P < .01).Conclusions:There is correlation of 32.1–43.3% between density measurements and ImA increase. Our density measurements explain a certain percentage of ImA increase, but density is not the only and definitive indicator of changes after RME.     

Conduction abnormalities in nonischemic dilated cardiomyopathy: basic mechanisms and arrhythmic consequences

Heart failure is associated with an increased risk of sudden death caused by ventricular tachyarrhythmias. The role of altered repolarization in the formation of arrhythmogenic substrates and triggers has been studied at multiple levels of integration, including molecular, cellular, tissue, and organ levels. Numerous studies have focused on conduction abnormalities in the context of ischemic heart disease and left ventricular dysfunction after myocardial infarction. However, ischemia alone, independent of left ventricular dysfunction, alters conduction by depressing membrane excitability and increasing tissue resistivity. In this review, we focus on the role of conduction abnormalities in the genesis of arrhythmias in nonischemic dilated cardiomyopathy and discuss their underlying cellular and molecular mechanisms, including changes in myocyte excitability, the extracellular matrix, and cell-to-cell coupling. We compare the nature of conduction slowing in ischemic and nonischemic heart failure and highlight the mechanistic differences between the two disease etiologies.     

What is adverse effect of wireless local area network,using 2.45 GHz,on the reproductive system?

Aim: To investigate the inflammatory effect and testicular damage on rats exposed to low level of electromagnetic fields (EMF) at 2.45?GHz microwave radiation.

Methods: Twenty two Wistar rats were divided into two groups. Group 1 was the control group and not exposed to EMF. Group 2 was exposed to low level EMF (average E-field 3.68?±?0.36 V/m, whole body average SAR, 0.0233 W/kg, in 10?g tissue) at 2.45?GHz for 1?hour/day for 30 consecutive days. At the end of the study, interleukin-6 (IL-6), interleukin-10 (IL-10), interleukin-32 (IL-32), C-reactive protein (CRP) were measured in rat serum and IL-6, IL-10, IL-32 were measured in rat testis tissue. Furthermore, testicular tissues were evaluated histopathologically in terms of spermatogenesis and coagulation necrosis.

Results: Serum IL-6 and CRP levels were found to be significantly different in the study group compared to the control group (p?<?.05), but no significant difference was found in serum IL-10, IL-32 levels and testis tissue IL-6, IL-10, IL-32 levels compared to the control group (p?>?.05). On the other hand, histopathological evaluation of testicular tissue revealed a significant difference in necrosis and spermatogenesis when compared with the control group (p?<?.05).

Conclusions: It may be concluded that low level EMF at 2.45?GHz increases inflammation and testicular damage and negative impact on male reproductive system function.     

Serum lactate levels and perfusion index: are these prognostic factors on mortality and morbidity in very low-birth weight infants?

Aim: Early hemodynamic assessment of global parameters in critically ill newborns fails and requires mostly invasive measurements in neonatal intensive care unit. Clinical signs are frequently used for assessment of peripheral perfusion. Perfusion index (PI) is a new noninvasive numerical value of peripheral perfusion. Serum lactate levels and PI are the indicators that are important in determining prognosis of preterm infants. In this study, we aimed to investigate the relationship of serum lactate levels and PI with mortality and morbidity in very low-birth weight infants (VLBW).

Study design: This study was conducted between July 2014 and July 2015 in a Level III NICU. The study enrolled preterm infants with a gestational age?≤?32 weeks, birth weight?≤?1500?g. Serum lactate levels from blood gases and PI, SpO2 measurements were recorded at 1st, 12th and 24th hours by using a new generation pulse-oximeter. Morbidities and mortalities were documented.

Results: A total of 60 VLBW infants were enrolled the study. Mean birth weight and gestational age were 991?±?288?g and 27.5?±?2.5 w, respectively. Retinopathy of prematurity (ROP) was significantly higher in the patients with high lactate levels (>4?mg/dl) at 1st hour and low-PI levels (<0.5) at 12th hour of life (p?=?0.042, p?=?0.015), respectively. Bronchopulmonary displasia (BPD) was significantly higher in the patients with low PI (Conclusion: High lactate levels (>?4?mg/dl) and low PI (相似文献