鼻咽癌切除术后患者血浆DNA的快速变化

摘要：目的监测鼻咽癌病人于肿瘤切除手术期间和术后,其血浆DNA浓度的变化,以了解血浆DNA在体内的动态变化情况。方法静脉抗凝血分离血浆,从血浆中提取DNA,用实时定量PCR方法分别测定手术前、后鼻咽癌病人血浆DNA的浓度。结果肿瘤手术初期,病人血浆DNA的浓度会快速升高,随后其水平会迅速下降,DNA在血浆中的半衰期为126min;当血浆DNA水平降到最低时,其水平又会再次升高,至2385：min后出现第二个峰值。结论癌症病人游离DNA可以极其迅速地从血循环中被清除,第二个峰值的水平可能对评估组织损伤严重程度具有一定的临床意义,此研究为进一步研究血浆肿瘤DNA在其他肿瘤中的变化奠定了基础。     

A study of the knowledge and attitude towards pulse polio immunization in semi urban areas of South India

Background

The government of India launched the pulse polio immunization (PPI) programme in 1995 with the aim of eradicating poliomyelitis by the end of 2000. Despite this, 733 children with polio were reported in 2009 alone. Therefore, there is a need to understand the reason underlying such high numbers of cases after so many years of programme implementation. This study was performed to assess the knowledge of the general population about poliomyelitis and PPI and their attitude and practice towards PPI.

Method

This cross-sectional study was undertaken in two semi- urban areas of Mangalore city. Only houses in which children under five lived were included in the study. Data was collected by interviewing any adult member of the household using a pretested questionnaire.

Results

The literacy rate of study participants was 99%. Only 35(10.9%) participants knew the correct mode of transmission of polio. More than one quarter of the study population were under the misconception that polio is a curable disease. The primary source of information about PPI in majority of participants was the television (n = 192; 60%). Two-hundred and eighty eight (90%) participants knew that the purpose of PPI was to eradicate polio. Only 128 (40%) participants knew that polio drops can be given to children with mild illnesses and an identical number of participants knew that hot food stuff should not be given for at least half an hour following vaccination administration. Misconceptions such as PPI causing vaccine overdose was identified among 7 (2.2%) participants, it is a substitute for routine immunization was believed among 30 (9.4%) participants and that oral polio vaccine prevents other diseases was seen among 76 (23.7%) participants. The educational status of the participants was significantly associated with their awareness level (χ² =13.668, DF=6, P=0.033).

Conclusion

This study identified a few important misconceptions associated with polio and PPI which need to be addressed by large scale awareness campaigns in order to achieve polio eradication in the near future.     

Chronic mercury exposure at different concentrations produces opposed vascular responses in rat aorta

Mercury chloride exposure for 30 days decreases NO bioavailability and increases oxidative stress. However, the mechanisms underlying the effects of mercury on the cardiovascular system are not completely understood, and it is not known if they are dose‐dependent or if some concentrations have no harmful effects. Thus, we investigated the effects of chronic exposure to doses low (half) and high (2.5‐fold higher) than that needed to obtain 29 nmol/L of HgCl₂ on the vascular function. Three‐month‐old male Wistar rats received intramuscular (i.m.) HgCl₂ for 30 days and were divided in three groups: lower (Low Hg); higher (High Hg); and saline was used as the control. High Hg exposure increased the contractile response to phenylephrine (PHE) in aortic rings, but Low Hg reduced it. The hyporesponsiveness in the Low Hg rats was blunted by endothelial denudation and NOS inhibition with l ‐NAME (100 μmol/L). The phosphorylated‐eNOS/eNOS protein ratio increased in the aortas of Low Hg rats. In the High Hg group, endothelial denudation increased the PHE‐induced contractions, while l ‐NAME had no effects and indomethacin (10 μmol/L), losartan (10 μmol/L) and apocynin (30 μmol/L) reduced this response. In the High Hg group, protein levels of the NADPH oxidase subunit gp91phox and cyclooxygenase‐2 increased. Our results support previous suggestions that High Hg increases oxidative stress that might activate an inflammatory cascade and the renin‐angiotensin system. However, very low Hg concentrations below the level considered safe still reduced vascular reactivity, suggesting the need for special attention to continuous exposure as a putative cause of increased cardiovascular risk.     

Visual outcome and progression of retinopathy after cataract surgery in diabetic patients

Purpose: Diabetes mellitus is a major cause of visual impairment in developed countries through retinopathy and is frequently complicated by cataract formation. The present study examines the visual outcome of cataract surgery in diabetic patients.
Methods: A retrospective study was performed over a 26 month period in a general hospital eye clinic. Eighty-five consecutive diabetic patients who underwent cataract surgery were categorized according to their type of diabetes, duration and treatment, operative technique, pre-operative visual acuity (VA) and degree of retinopathy. Visual acuity and retinopathy status were recorded at a minimum of 4 months postoperatively. Factors affecting visual outcome and progression of retinopathy were then examined.
Results: Of the 107 eyes of the 85 consecutive cases, 55 were without retinopathy (NR), 21 had background retinopathy (BDR), six had background retinopathy with macular oedema (BDR/MO), four had proliferative retinopathy and 12 cases had inadequate fundal view. In the NR and BDR groups, 90 and 81% of patients, respectively, had improved VA compared with 33% of patients with BDR/MO. Retinopathy progressed in 50% of BDR/MO patients compared with progression in 9 and 19% of NR and BDR patients, respectively.
Conclusion: The present study illustrates the poor visual outcome in patients with severe, untreated retinopathy, particularly maculopathy, following cataract surgery. Larger prospective studies are needed to better define risk groups and pre-operative treatment strategies.     

Proliferative and inflammatory factors in the vitreous of patients with proliferative diabetic retinopathy

Purpose:

The purpose was to measure the concentrations of various cytokines and growth factors (including vascular endothelial growth factor [VEGF] and pigment epithelium-derived factor [PEDF]) in the vitreous of patients with proliferative diabetic retinopathy (PDR) and to investigate interaction between inflammatory and proliferative factors in the genesis of PDR.

Materials and Methods:

Vitreous samples from 32 eyes with PDR and 25 eyes without diabetes mellitus and signs of DR (control) were collected. Vitreous concentrations of VEGF, PEDF, monocyte chemotactic protein-1 (MCP-1), interleukin-4 (IL-4), IL-6, IL-8, IL-10, IL-17A, and secretory immunoglobulin A (sIgA) were simultaneously measured using enzyme-linked immunoassay.

Results:

Vitreous levels of VEGF, PEDF, IL-17A, IL-6, IL-8, IL-4, and sIgA were significantly (Π < 0.05) higher in eyes with PDR compared to control. The concentration of VEGF was more than 17-times higher than in control, and the concentration of PEDF was not changed oppositely and was also higher (1.45-times) compared to control, that may indicate disturbances of compensatory mechanisms in angiogenesis regulation in PDR. Significant (P < 0.05) positive correlations were observed between vitreous concentrations of VEGF and IL-17A (r = 0.45), VEGF and IL-8 (r = 0.48), VEGF and IL-4 (r = 0.51), PEDF and IL-17A (r = 0.48), PEDF and IL-8 (r = 0.59), MCP-1 and PEDF (r = 0.72), MCP-1 and IL-8 (r = 0.45), IL-4 and IL-17A (r = 0.65), IL-4 and IL-8 (r = 0.71), IL-8 and IL-17A (r = 0.59).

Conclusions:

Significantly raised levels of inflammatory and proliferative factors and numerous positive correlations between them may demonstrate a significant role of activation of vascular proliferation and local inflammation in the pathogenesis of PDR.     

Sensitivity and specificity of first screen mammography in the Canadian National Breast Screening Study: a preliminary report from five centers

Sensitivity and specificity of first screen mammography in a randomized screening trial at five centers are reported. A total of 23,101 women underwent mammography; in 139, breast cancer was detected at first screening; in 20, less than 12 months after first screening; and in 47, at second screening. All 206 cancer cases were histologically confirmed, and 174 were defined as being detectable at first screening. Average length of follow-up for all women was 3.2 years. Interpretations of first screen mammograms by the center radiologists were matched to known outcomes. Simultaneous blind review was performed by a single reference radiologist with mammograms from all 206 cancer cases and those of a random sample of 739 women not known to have breast cancer at 15 months or more after initial screening. Overall, the five screening centers achieved a sensitivity of 69% (range, 60%-78%), a specificity of 94% (range, 93%-96%), a positive predictive value of 8.6% (range, 3%-16%), and a negative predictive value of 99.7% (range, 99.6%-99.9%).     

Abnormal prothrombin in the plasma of rats carrying hepatic tumors

Vitamin K is required for the posttranslational formation of gamma- carboxyglutamyl residues in a number of plasma clotting factors. Interference with vitamin K action results in the appearance of abnormal (des-gamma-carboxy) forms of prothrombin in human plasma. Vitamin K-sufficient patients with primary hepatocellular carcinoma also secrete significant quantities of abnormal prothrombin; this response has now been studied in a rat model. Normal Buffalo strain rats had 9 micrograms/mL of circulating plasma abnormal prothrombin, whereas Buffalo strain rats carrying the transplantable Morris hepatoma tumor no. 7777 had 33 micrograms/mL at 3 weeks after transplant. Vitamin K-dependent carboxylase activity was normal in the liver of these rats, but very low in the tumor tissue. Rats carrying Morris hepatoma tumors no. 9618A and 5123D did not secrete significant amounts of abnormal prothrombin. Carboxylase activity in these tumors was 15 times that of the 7777 tumor. The data suggest that the secretion of abnormal prothrombin by hepatocellular tumors is the result of normal expression of the prothrombin gene by those tumors and a failure of the tumor to express the carboxylase gene.     

Diagnosis and treatment of a child with the syndrome of apparent mineralocorticoid excess type 1

We report the case of a 16-month-old boy who presented with chronic vomiting, failure to thrive, arterial hypertension and medullary nephrocalcinosis. Laboratory results revealed hypokulaeniin. metabolic alkalosis, increased urinary potassium excretion and ii hyporeninaeniic hypo~ildostei-onisiii. Chromatographic determination of urinary steroid metabolites showed a n abnormal elevation of tetrahydi-ocortisol and do-tetrahydrocortisol compared to tetrahydrocortisone; this pattern of urin- ary steroid excretion is essential for the diagnosis of the syndrome of apparcnt mineralocorticoid excess type I and believed to be a result of the underlying metabolic defect, a decreased activity of the II & hydroxysteroid dehydrogenase. A second variant, called syndrome of apparent mineralocorticoid excess type 2, has similiar clinical features but lacks the typical urinary steroid profile. Therapy with spironolaetone resulted in growth, weight gain and blood pressure control.