Non-invasive prenatal gene diagnosis has been developed rapidly in the recent years, and numerous medical researchers are focusing on it. Such techniques could not only achieve prenatal diagnosis accurately, but also ...Non-invasive prenatal gene diagnosis has been developed rapidly in the recent years, and numerous medical researchers are focusing on it. Such techniques could not only achieve prenatal diagnosis accurately, but also prevent tangential illness in fetuses and thus, reduce the incidence of diseases. Moreover, it is non-invasive prenatal gene diagnosis that prevents potential threaten and danger to both mothers and fetuses. Therefore, it is welcomed by clinical gynecologist and obstetrian, researchers of medical genetics, and especially, pregnancies. This review article touches briefly on the advanced development of using cell-free DNA, RNA in maternal plasma and urine for non-invasive prenatal gene diagnosis.展开更多
AIM: To validate a non-invasive method to detect gastric mucosal atrophy in a Chilean population with high prevalence of gastric cancer and a poor survival rate. METHODS: We first determined the optimal cut-off level ...AIM: To validate a non-invasive method to detect gastric mucosal atrophy in a Chilean population with high prevalence of gastric cancer and a poor survival rate. METHODS: We first determined the optimal cut-off level of serum pepsinogen (PG)-1, PG-1/PG-2 ratio and 17-gastrin in 31 voluntary symptomatic patients (mean age: 66.1 years), of them 61% had histologically confirmed gastric atrophy. Then, in a population-based sample of 536 healthy individuals (209 residents in counties with higher relative risk and 327 residents in counties with lower relative risk for gastric cancer), we measured serum anti-H pylori antibodies, PG and 17-gastrin and estimated their risk of gastric cancer. RESULTS: We found that serum PG-1 < 61.5 μg/L, PG-1/PG-2 ratio < 2.2 and 17-gastrin > 13.3 pmol/L had a high specificity (91%-100%) and a fair sensitivity (56%-78%) to detect corpus-predominant atrophy. Based on low serum PG-1 and PG-1/PG-2 ratio together as diagnostic criteria, 12.5% of the asymptomatic subjects had corpus-predominant atrophy (0% of those under 25 years and 20.2% over 65 years old). The frequency of gastric atrophy was similar (12% vs 13%) but H pylori infection rate was slightly higher (77% vs 71%) in the high-risk compared to the low-risk counties. Based on their estimated gastric cancer risk, individuals were classified as: low-risk group (no H pylori infection and no atrophy; n = 115; 21.4%); moderate-risk group(H pylori infection but no atrophy; n = 354, 66.0%); and high-risk group (gastric atrophy, with or without H pylori infection; n = 67, 12.5%). The high-risk group was significantly older (mean age: 61.9 ± 13.3 years), more frequently men and less educated as compared with the low-risk group. CONCLUSION: We propose to concentrate on an upper gastrointestinal endoscopy for detection of early gastric cancer in the high-risk group. This intervention model could improve the poor prognosis of gastric cancer in Chile.展开更多
This study examined the methylation difference in AIRE and RASSF1A between maternal and placental DNA, and the implication of this difference in the identification of free fetal DNA in maternal plasma and in prenatal ...This study examined the methylation difference in AIRE and RASSF1A between maternal and placental DNA, and the implication of this difference in the identification of free fetal DNA in maternal plasma and in prenatal diagnosis of trisomy 21. Maternal plasma samples were collected from 388 singleton pregnancies, and placental or chorionic villus tissues from 112 of them. Methylation-specific PCR （MSP） and methylation-sensitive restriction enzyme digestion followed by fluorescent quantitative PCR （MSRE ＋ PCR） were employed to detect the maternal-fetal methylation difference in AIRE and RASSF1A. Diagnosis of trisomy 21 was established according to the ratio of fetal-specific AIRE to RASSF1A in maternal plasma. Both methods confirmed that AIRE and RASSF1A were hypomethylated in maternal blood cells but hypermethylated in placental or chorionic villus tissues. Moreover, the differential methylation for each locus could be seen during the whole pregnant period. The positive rates of fetal AIRE and RASSF1A in maternal plasma were found to be 78.1% and 82.1% by MSP and 94.8% and 96.9% by MSRE ＋ PCR. MSRE ＋ PCR was superior to MSP in the identification of fetal-specific hypermethylated sequences （P〈0.05）. Based on the data from 266 euploidy pregnancies, the 95% reference interval of the fetal AIRE/RASSF1A ratio in maternal plasma was 0.33-1.77, which was taken as the reference value for determining the numbers of fetal chromosome 21 in 102 pregnancies. The accu-racy rate in 98 euploidy pregnancies was 96.9% （95/98）. Three of the four trisomy 21 pregnancies were confirmed with this method. It was concluded that hypermethylated AIRE and RASSF1A may serve as fetal-specific markers for the identification of fetal DNA in maternal plasma and may be used for noninvasive prenatal diagnosis of trisomy 21.展开更多
A novel kind of multi-core magnetic composite particles, the surfaces of which were respectively mo- dified with goat-anti-mouse IgG and antitransferrin receptor（anti-CD71）, was prepared. The fetal nucleated red blo...A novel kind of multi-core magnetic composite particles, the surfaces of which were respectively mo- dified with goat-anti-mouse IgG and antitransferrin receptor（anti-CD71）, was prepared. The fetal nucleated red blood cells（FNRBCs） in the peripheral blood of a gravida were rapidly and effectively enriched and separated by the mo- dified multi-core magnetic composite particles in an external magnetic field. The obtained FNRBCs were used for the identification of the fetal sex by means of fluorescence in situ hybridization（FISH） technique. The results demonstrate that the multi-core magnetic composite particles meet the requirements for the enrichment and speration of FNRBCs with a low concentration and the accuracy of detetion for the diagnosis of fetal sex reached to 95%. Moreover, the obtained FNRBCs were applied to the non-invasive diagnosis of Down syndrome and chromosome 3p21 was de- tected. The above facts indicate that the novel multi-core magnetic composite particles-based method is simple, relia- ble and cost-effective and has opened up vast vistas for the potential application in clinic non-invasive prenatal diag- nosis.展开更多
Background: Although vitiligo shows a similar clinical picture to other disorders in which patients exhibit depigmented spots, there are few reports on the differentiation of these conditions from each other. Purpose:...Background: Although vitiligo shows a similar clinical picture to other disorders in which patients exhibit depigmented spots, there are few reports on the differentiation of these conditions from each other. Purpose: We aimed to investigate the differences and similarities between vitiligo and nevus depigmentosus in children based on the clinical course and characteristics. Materials and Methods: We conducted an examination of the disease type, treatment, progress, and differentiation of 85 cases of vitiligo and nevus depigmentosus that developed before 15 years of age among patients who visited the Osaka University Department of Dermatology with a chief complaint of white patches from January 2010 to March 2017. Results: The median age at the onset of symptoms of 79 patients with vitiligo was 4.5 years and while that of 6 patients with nevus depigmentosus was 0.8 years, indicating that the onset of nevus depigmentosus occurred earlier. While vitiligo often developed in the head and neck regions, with a tendency for depigmented spots in multiple regions, nevus depigmentosus did not show this tendency in these regions. Upon performing Wood’s lamp observation in 38 cases of vitiligo, 35 cases were found to be fluorescent chalky white and in 3 cases histologically diagnosed as vitiligo, no clear fluorescent color was observed. All 6 patients diagnosed with nevus depigmentosus exhibited a non-fluorescent off-white color under a Wood’s lamp. Conclusions: This study indicates that non-invasive observation using a Wood’s lamp is useful in the differential diagnosis of pediatric leukoderma, in addition to the subsequent clinical course, such as the presence or absence of lesional repigmentation and/or enlargement.展开更多
This paper presents a novel approach with Graphene devices that are highly sensitive in detecting IR energy. Current non-imaging techniques like ultrasonography have been proposed for thyroid diagnosis with limitation...This paper presents a novel approach with Graphene devices that are highly sensitive in detecting IR energy. Current non-imaging techniques like ultrasonography have been proposed for thyroid diagnosis with limitations on ability to detect low-temperature distribution around the hot spot at the starting stage of the thyroid hyperthyroidism. The energy distribution around hotspot is minimal at the beginning stage. This detection may require ultra-high sensitive materials to the IR energy. A computer modeling using COMSOL software shows the thermal energy simulation of a thyroid gland with single or multiple active nodules. Data collection of the energy levels and condition of thyroid in the human body support the work investigated in this study. The study conducted here has shown as low as 0.1 - 5 mW IR power can be detected based on the Graphene device sensitivity. The paper details the simulation and approach for this non-invasive diagnosis.展开更多
AIM: To identify the independent predictors of hepatic fibrosis in 69 children with nonalcoholic steatohepatitis (NASH) due to nonalcoholic fatty liver disease (NAFLD). METHODS: All patients with clinically suspected ...AIM: To identify the independent predictors of hepatic fibrosis in 69 children with nonalcoholic steatohepatitis (NASH) due to nonalcoholic fatty liver disease (NAFLD). METHODS: All patients with clinically suspected NASH underwent liver biopsy as a confirmatory test. The following clinical and biochemical variables at baseline were examined as likely predictors of fibrosis at histology: age, body mass index (BMI), systolic blood pressure (SBP), dyastolic blood pressure (DBP), fasting glucose, fasting insulin, homeostatic model assessment for insulin resistence (HOMA-IR), cholesterol, tryglicerides, alanine aminotransferase (ALT), aspartate aminotransferase (AST), AST/ALT ratio, gamma glutamil transferase (GT), platelet count, prothrombin time (PT). RESULTS: At histology 28 (40.6%) patients had no fibrosis and 41 (59.4%) had mild to bridging fibrosis. At multivariate analysis, BMI > 26.3 was the only independent predictor of fibrosis (OR = 5.85, 95% CI = 1.6-21). CONCLUSION: BMI helps identify children with NASH who might have fibrotic deposition in the liver.展开更多
The impact of arterial narrowing/blocking caused by plaque buildup in arteries leads to many life-threatening consequences. This is recognized as a cause in heart attacks and peripheral vascular disease. Diagnosing th...The impact of arterial narrowing/blocking caused by plaque buildup in arteries leads to many life-threatening consequences. This is recognized as a cause in heart attacks and peripheral vascular disease. Diagnosing the illness is only feasible after symptoms have presented to the patient. Currently, the standard for visualizing coronary arteries is through angiography, which may have complications, and impact on the healthcare system. Furthermore, cardiac catheterization may also places high health risks, given its overall invasiveness. Cardiac arrhythmias, infection, and contrast dye nephrotoxicity are recognized complications within this process. Therefore, a noninvasive approach may have potentials to reduce patient complications, finances surrounding healthcare, and more efficient patient care through earlier screening and diagnosing. This research addresses a new approach using photoacoustic (PA) imaging. The transmission properties of atherosclerosis within walls of arteries, can be exploited using photo acoustics, to better visualize and characterize the degree and severity of atherosclerosis. The delivered energy is absorbed by components of the vascular tissue converted into heat, leading to transient thermos elastic expansion, which creates an acoustic emission. The thermal response was analyzed for its fall and recovery times that are attributed to the artery fat type. The control parameters, including the frequency, penetration depth, energy levels, and tissue layer sizes, for multilayered structures were considered. The structures investigated were fatty infiltrate within the artery, blood, bones, and skin, within frequency range from 1 MHz to 3 MHz, and typical tissue sizes in the milli to centimeter range. As high as 14 MPas in the acoustic pressure at 1 MHz, resulted in temperature difference of up to 3.4 K. When the operating frequency was altered to 2 MHz, the temperature changed to 23 K. Furthermore, when the frequency was changed to 3 MHz, the temperature moved to 43 K. The changes in temperatures were for nearly 1 second duration. The results obtained in this study suggest that there is high potential for practical models using flexible substrate with infra-red sensors and acoustic devices.展开更多
Oral potential malignant disorders (OPMDs), a series of local diseases with carcinogenic potential occurred in oral mucosa, have the possibility of developing into oral cancer. Effective diagnosis and surveillance at ...Oral potential malignant disorders (OPMDs), a series of local diseases with carcinogenic potential occurred in oral mucosa, have the possibility of developing into oral cancer. Effective diagnosis and surveillance at the early stage of OPMDs may be of help for interrupting the malignant transformation. In this review, we introduced the available non-invasive approaches of detecting the suspicious lesions, including vital staining, oral cytology, optical detection, saliva biomarkers detection, and image analysis, which can enhance the detection efficiency for the early diagnosis and surveillance of OPMDs. However, limitations which restrict the clinical application of these approaches still exist. How to improve the sensitivity and specificity of these techniques deserves further detailed study.展开更多
AIM:To evaluate the usefulness of stool-PCR test for diagnosis of Helicobacter pylori(H pylori)infection in pediatric populations. METHODS:Based on endoscopic features(including nodular gastritis,erosive duodenitis an...AIM:To evaluate the usefulness of stool-PCR test for diagnosis of Helicobacter pylori(H pylori)infection in pediatric populations. METHODS:Based on endoscopic features(including nodular gastritis,erosive duodenitis and ulcer)and/or a positive rapid urease test(RUT)obtained during endoscopy,28 children from a group of children admitted to the Children's Medical Center of Tehran for persistent upper gastrointestinal problems were selected to compare biopsy-based tests with stoolPCR.Their gastric activity and bacterial density were graded by the updated Sydney system,and their first stool after endoscopy was stored at-70℃.Biopsies were cultured on modified campy-blood agar plates and identified by gram-staining,biochemical tests,and PCR.Two methods of phenol-chloroform and boiling were used for DNA extraction from H pylori isolates. Isolation of DNA from stool was performed using a stool DNA extraction kit(Bioneer Inc,Korea).PCR was performed using primers for detection of vacA,cagA,and 16srRNA genes in both isolates and stool. RESULTS:Sixteen out of 28 child patients(57%) were classified as H pylori positive by biopsy-based tests,of which 11(39%)were also positive by stoolPCR.Sensitivity and specificity of stool-PCR was 62.5% and 92.3%respectively.H pylori was observed in histological sections for 10 out of 11 stool-positivepatients.Association was observed between higher score of H pylori in histology and positivity of stoolPCR.Also association was observed between the more severe form of gastritis and a positive stool-PCR. CONCLUSION:Association between higher score of H pylori in histology and a positive stool-PCR make it a very useful test for detection of H pylori active infection in children.We also suggest that a simple stool-PCR method can be a useful test for detection of H pylori virulence genes in stool.展开更多
The diagnosis of liver cirrhosis in patients with chronic hepatitis C has not always been easy, since the gold standard method is the liver biopsy, which is an invasive procedure with interobserver accuracy problems a...The diagnosis of liver cirrhosis in patients with chronic hepatitis C has not always been easy, since the gold standard method is the liver biopsy, which is an invasive procedure with interobserver accuracy problems and there have been reports of complications including records of deaths due to hemoperitoneum. Cirrhosis changes the prognosis of the subject with hepatitis C and requires a different clinical management. This study aimed to identify clinical and laboratory variables associated with the diagnosis of cirrhosis in the ultrasonography of patients infected with hepatitis C. In a case-control study, we evaluated 70 cirrhotic patients with chronic hepatitis C compared to a control group of 70 non-cirrhotic people with positive HCV. The results showed, through logistic regression analysis, that the variables blood donor and professional athlete, adjusted for alcohol consumption, showed OR 0.24 and 0.18, with p values of 0.044 and 0.035, respectively. We conclude that the diagnosis of cirrhosis in patients with chronic hepatitis C remains challenging, but the patients with the condition of blood donor or professional athlete prove to be less likely to cirrhosis in ultrasonography in the initial consultation.展开更多
文摘Non-invasive prenatal gene diagnosis has been developed rapidly in the recent years, and numerous medical researchers are focusing on it. Such techniques could not only achieve prenatal diagnosis accurately, but also prevent tangential illness in fetuses and thus, reduce the incidence of diseases. Moreover, it is non-invasive prenatal gene diagnosis that prevents potential threaten and danger to both mothers and fetuses. Therefore, it is welcomed by clinical gynecologist and obstetrian, researchers of medical genetics, and especially, pregnancies. This review article touches briefly on the advanced development of using cell-free DNA, RNA in maternal plasma and urine for non-invasive prenatal gene diagnosis.
文摘AIM: To validate a non-invasive method to detect gastric mucosal atrophy in a Chilean population with high prevalence of gastric cancer and a poor survival rate. METHODS: We first determined the optimal cut-off level of serum pepsinogen (PG)-1, PG-1/PG-2 ratio and 17-gastrin in 31 voluntary symptomatic patients (mean age: 66.1 years), of them 61% had histologically confirmed gastric atrophy. Then, in a population-based sample of 536 healthy individuals (209 residents in counties with higher relative risk and 327 residents in counties with lower relative risk for gastric cancer), we measured serum anti-H pylori antibodies, PG and 17-gastrin and estimated their risk of gastric cancer. RESULTS: We found that serum PG-1 < 61.5 μg/L, PG-1/PG-2 ratio < 2.2 and 17-gastrin > 13.3 pmol/L had a high specificity (91%-100%) and a fair sensitivity (56%-78%) to detect corpus-predominant atrophy. Based on low serum PG-1 and PG-1/PG-2 ratio together as diagnostic criteria, 12.5% of the asymptomatic subjects had corpus-predominant atrophy (0% of those under 25 years and 20.2% over 65 years old). The frequency of gastric atrophy was similar (12% vs 13%) but H pylori infection rate was slightly higher (77% vs 71%) in the high-risk compared to the low-risk counties. Based on their estimated gastric cancer risk, individuals were classified as: low-risk group (no H pylori infection and no atrophy; n = 115; 21.4%); moderate-risk group(H pylori infection but no atrophy; n = 354, 66.0%); and high-risk group (gastric atrophy, with or without H pylori infection; n = 67, 12.5%). The high-risk group was significantly older (mean age: 61.9 ± 13.3 years), more frequently men and less educated as compared with the low-risk group. CONCLUSION: We propose to concentrate on an upper gastrointestinal endoscopy for detection of early gastric cancer in the high-risk group. This intervention model could improve the poor prognosis of gastric cancer in Chile.
基金supported by grants from Health Department of Hubei Province (No. QJX2008-28)Science and Technology Bureau of Wuhan (No. 200760423158)Population and Family Planning Commission of Wuhan, China (No. WRJK0906)
文摘This study examined the methylation difference in AIRE and RASSF1A between maternal and placental DNA, and the implication of this difference in the identification of free fetal DNA in maternal plasma and in prenatal diagnosis of trisomy 21. Maternal plasma samples were collected from 388 singleton pregnancies, and placental or chorionic villus tissues from 112 of them. Methylation-specific PCR （MSP） and methylation-sensitive restriction enzyme digestion followed by fluorescent quantitative PCR （MSRE ＋ PCR） were employed to detect the maternal-fetal methylation difference in AIRE and RASSF1A. Diagnosis of trisomy 21 was established according to the ratio of fetal-specific AIRE to RASSF1A in maternal plasma. Both methods confirmed that AIRE and RASSF1A were hypomethylated in maternal blood cells but hypermethylated in placental or chorionic villus tissues. Moreover, the differential methylation for each locus could be seen during the whole pregnant period. The positive rates of fetal AIRE and RASSF1A in maternal plasma were found to be 78.1% and 82.1% by MSP and 94.8% and 96.9% by MSRE ＋ PCR. MSRE ＋ PCR was superior to MSP in the identification of fetal-specific hypermethylated sequences （P〈0.05）. Based on the data from 266 euploidy pregnancies, the 95% reference interval of the fetal AIRE/RASSF1A ratio in maternal plasma was 0.33-1.77, which was taken as the reference value for determining the numbers of fetal chromosome 21 in 102 pregnancies. The accu-racy rate in 98 euploidy pregnancies was 96.9% （95/98）. Three of the four trisomy 21 pregnancies were confirmed with this method. It was concluded that hypermethylated AIRE and RASSF1A may serve as fetal-specific markers for the identification of fetal DNA in maternal plasma and may be used for noninvasive prenatal diagnosis of trisomy 21.
文摘A novel kind of multi-core magnetic composite particles, the surfaces of which were respectively mo- dified with goat-anti-mouse IgG and antitransferrin receptor（anti-CD71）, was prepared. The fetal nucleated red blood cells（FNRBCs） in the peripheral blood of a gravida were rapidly and effectively enriched and separated by the mo- dified multi-core magnetic composite particles in an external magnetic field. The obtained FNRBCs were used for the identification of the fetal sex by means of fluorescence in situ hybridization（FISH） technique. The results demonstrate that the multi-core magnetic composite particles meet the requirements for the enrichment and speration of FNRBCs with a low concentration and the accuracy of detetion for the diagnosis of fetal sex reached to 95%. Moreover, the obtained FNRBCs were applied to the non-invasive diagnosis of Down syndrome and chromosome 3p21 was de- tected. The above facts indicate that the novel multi-core magnetic composite particles-based method is simple, relia- ble and cost-effective and has opened up vast vistas for the potential application in clinic non-invasive prenatal diag- nosis.
文摘Background: Although vitiligo shows a similar clinical picture to other disorders in which patients exhibit depigmented spots, there are few reports on the differentiation of these conditions from each other. Purpose: We aimed to investigate the differences and similarities between vitiligo and nevus depigmentosus in children based on the clinical course and characteristics. Materials and Methods: We conducted an examination of the disease type, treatment, progress, and differentiation of 85 cases of vitiligo and nevus depigmentosus that developed before 15 years of age among patients who visited the Osaka University Department of Dermatology with a chief complaint of white patches from January 2010 to March 2017. Results: The median age at the onset of symptoms of 79 patients with vitiligo was 4.5 years and while that of 6 patients with nevus depigmentosus was 0.8 years, indicating that the onset of nevus depigmentosus occurred earlier. While vitiligo often developed in the head and neck regions, with a tendency for depigmented spots in multiple regions, nevus depigmentosus did not show this tendency in these regions. Upon performing Wood’s lamp observation in 38 cases of vitiligo, 35 cases were found to be fluorescent chalky white and in 3 cases histologically diagnosed as vitiligo, no clear fluorescent color was observed. All 6 patients diagnosed with nevus depigmentosus exhibited a non-fluorescent off-white color under a Wood’s lamp. Conclusions: This study indicates that non-invasive observation using a Wood’s lamp is useful in the differential diagnosis of pediatric leukoderma, in addition to the subsequent clinical course, such as the presence or absence of lesional repigmentation and/or enlargement.
文摘This paper presents a novel approach with Graphene devices that are highly sensitive in detecting IR energy. Current non-imaging techniques like ultrasonography have been proposed for thyroid diagnosis with limitations on ability to detect low-temperature distribution around the hot spot at the starting stage of the thyroid hyperthyroidism. The energy distribution around hotspot is minimal at the beginning stage. This detection may require ultra-high sensitive materials to the IR energy. A computer modeling using COMSOL software shows the thermal energy simulation of a thyroid gland with single or multiple active nodules. Data collection of the energy levels and condition of thyroid in the human body support the work investigated in this study. The study conducted here has shown as low as 0.1 - 5 mW IR power can be detected based on the Graphene device sensitivity. The paper details the simulation and approach for this non-invasive diagnosis.
文摘AIM: To identify the independent predictors of hepatic fibrosis in 69 children with nonalcoholic steatohepatitis (NASH) due to nonalcoholic fatty liver disease (NAFLD). METHODS: All patients with clinically suspected NASH underwent liver biopsy as a confirmatory test. The following clinical and biochemical variables at baseline were examined as likely predictors of fibrosis at histology: age, body mass index (BMI), systolic blood pressure (SBP), dyastolic blood pressure (DBP), fasting glucose, fasting insulin, homeostatic model assessment for insulin resistence (HOMA-IR), cholesterol, tryglicerides, alanine aminotransferase (ALT), aspartate aminotransferase (AST), AST/ALT ratio, gamma glutamil transferase (GT), platelet count, prothrombin time (PT). RESULTS: At histology 28 (40.6%) patients had no fibrosis and 41 (59.4%) had mild to bridging fibrosis. At multivariate analysis, BMI > 26.3 was the only independent predictor of fibrosis (OR = 5.85, 95% CI = 1.6-21). CONCLUSION: BMI helps identify children with NASH who might have fibrotic deposition in the liver.
文摘The impact of arterial narrowing/blocking caused by plaque buildup in arteries leads to many life-threatening consequences. This is recognized as a cause in heart attacks and peripheral vascular disease. Diagnosing the illness is only feasible after symptoms have presented to the patient. Currently, the standard for visualizing coronary arteries is through angiography, which may have complications, and impact on the healthcare system. Furthermore, cardiac catheterization may also places high health risks, given its overall invasiveness. Cardiac arrhythmias, infection, and contrast dye nephrotoxicity are recognized complications within this process. Therefore, a noninvasive approach may have potentials to reduce patient complications, finances surrounding healthcare, and more efficient patient care through earlier screening and diagnosing. This research addresses a new approach using photoacoustic (PA) imaging. The transmission properties of atherosclerosis within walls of arteries, can be exploited using photo acoustics, to better visualize and characterize the degree and severity of atherosclerosis. The delivered energy is absorbed by components of the vascular tissue converted into heat, leading to transient thermos elastic expansion, which creates an acoustic emission. The thermal response was analyzed for its fall and recovery times that are attributed to the artery fat type. The control parameters, including the frequency, penetration depth, energy levels, and tissue layer sizes, for multilayered structures were considered. The structures investigated were fatty infiltrate within the artery, blood, bones, and skin, within frequency range from 1 MHz to 3 MHz, and typical tissue sizes in the milli to centimeter range. As high as 14 MPas in the acoustic pressure at 1 MHz, resulted in temperature difference of up to 3.4 K. When the operating frequency was altered to 2 MHz, the temperature changed to 23 K. Furthermore, when the frequency was changed to 3 MHz, the temperature moved to 43 K. The changes in temperatures were for nearly 1 second duration. The results obtained in this study suggest that there is high potential for practical models using flexible substrate with infra-red sensors and acoustic devices.
文摘Oral potential malignant disorders (OPMDs), a series of local diseases with carcinogenic potential occurred in oral mucosa, have the possibility of developing into oral cancer. Effective diagnosis and surveillance at the early stage of OPMDs may be of help for interrupting the malignant transformation. In this review, we introduced the available non-invasive approaches of detecting the suspicious lesions, including vital staining, oral cytology, optical detection, saliva biomarkers detection, and image analysis, which can enhance the detection efficiency for the early diagnosis and surveillance of OPMDs. However, limitations which restrict the clinical application of these approaches still exist. How to improve the sensitivity and specificity of these techniques deserves further detailed study.
文摘AIM:To evaluate the usefulness of stool-PCR test for diagnosis of Helicobacter pylori(H pylori)infection in pediatric populations. METHODS:Based on endoscopic features(including nodular gastritis,erosive duodenitis and ulcer)and/or a positive rapid urease test(RUT)obtained during endoscopy,28 children from a group of children admitted to the Children's Medical Center of Tehran for persistent upper gastrointestinal problems were selected to compare biopsy-based tests with stoolPCR.Their gastric activity and bacterial density were graded by the updated Sydney system,and their first stool after endoscopy was stored at-70℃.Biopsies were cultured on modified campy-blood agar plates and identified by gram-staining,biochemical tests,and PCR.Two methods of phenol-chloroform and boiling were used for DNA extraction from H pylori isolates. Isolation of DNA from stool was performed using a stool DNA extraction kit(Bioneer Inc,Korea).PCR was performed using primers for detection of vacA,cagA,and 16srRNA genes in both isolates and stool. RESULTS:Sixteen out of 28 child patients(57%) were classified as H pylori positive by biopsy-based tests,of which 11(39%)were also positive by stoolPCR.Sensitivity and specificity of stool-PCR was 62.5% and 92.3%respectively.H pylori was observed in histological sections for 10 out of 11 stool-positivepatients.Association was observed between higher score of H pylori in histology and positivity of stoolPCR.Also association was observed between the more severe form of gastritis and a positive stool-PCR. CONCLUSION:Association between higher score of H pylori in histology and a positive stool-PCR make it a very useful test for detection of H pylori active infection in children.We also suggest that a simple stool-PCR method can be a useful test for detection of H pylori virulence genes in stool.
文摘The diagnosis of liver cirrhosis in patients with chronic hepatitis C has not always been easy, since the gold standard method is the liver biopsy, which is an invasive procedure with interobserver accuracy problems and there have been reports of complications including records of deaths due to hemoperitoneum. Cirrhosis changes the prognosis of the subject with hepatitis C and requires a different clinical management. This study aimed to identify clinical and laboratory variables associated with the diagnosis of cirrhosis in the ultrasonography of patients infected with hepatitis C. In a case-control study, we evaluated 70 cirrhotic patients with chronic hepatitis C compared to a control group of 70 non-cirrhotic people with positive HCV. The results showed, through logistic regression analysis, that the variables blood donor and professional athlete, adjusted for alcohol consumption, showed OR 0.24 and 0.18, with p values of 0.044 and 0.035, respectively. We conclude that the diagnosis of cirrhosis in patients with chronic hepatitis C remains challenging, but the patients with the condition of blood donor or professional athlete prove to be less likely to cirrhosis in ultrasonography in the initial consultation.
