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1.
Zhonghua Yu Fang Yi Xue Za Zhi ; 56(12): 1834-1837, 2022 Dec 06.
Article in Chinese | MEDLINE | ID: mdl-36536574

ABSTRACT

Between August and September, 2021, this study included 605 SARS-CoV-2 natural infection cases and 589 SARS-CoV-2 breakthrough cases from Nanjing and Yangzhou, as well as 690 inactivated COVID-19 vaccine recipients from Changzhou, China. In SARS-CoV-2 natural infection cases, the age range was 19-91 years (median age: 66 year), and the medians(Q1,Q3) of IgG titers were 0.19 (0.06-1.31), 3.70 (0.76-69.48), 15.31 (2.59-82.16), 4.41 (0.99-31.74), 2.31 (0.75-13.83), 2.28 (0.68-9.94) and 2.80 (1.00-9.53) at one to seven weeks after SARS-CoV-2 infection, respectively. In SARS-CoV-2 breakthrough cases, the age range was 18-76 years (median age: 45 year), and the medians(Q1,Q3)of IgG titers were 1.93 (0.34-26.67), 38.87 (7.90-121.0), 75.09 (11.85-123.70), 21.97 (5.20-95.58), 13.97 (3.47-46.82), 9.56 (2.48-33.38) and 4.38 (1.87-11.00) at one to seven weeks after SARS-CoV-2 infection, respectively. In inactivated COVID-19 vaccine recipients, the age range was 18-87 years (median age: 47 years), and the medians(Q1,Q3)of IgG titers were 16.22 (15.84-33.42), 5.35 (2.96-13.23), 3.30 (2.18-6.18), 3.14 (1.16-5.70), 2.77 (1.50-4.52), 2.72 (1.76-4.36), 2.01 (1.27-3.51) and 1.94 (1.35-3.09) at one to eight months after SARS-CoV-2 infection, respectively. The results suggested that IgG antibodies increased gradually within two weeks after SARS-CoV-2 infection, then declined gradually at three to seven weeks in SARS-CoV-2 natural infection cases. In SARS-CoV-2 breakthrough cases, IgG antibodies increased rapidly within two weeks, then declined gradually at three to seven weeks after SARS-CoV-2 infection. Additionally, IgG antibodies decreased rapidly within three months, then decreased gradually and remained at a low level within three months after immunization.


Subject(s)
COVID-19 Vaccines , COVID-19 , Humans , Aged , Middle Aged , Young Adult , Adult , Aged, 80 and over , Adolescent , SARS-CoV-2 , Kinetics , Antibodies, Viral , Immunoglobulin G
2.
Zhonghua Liu Xing Bing Xue Za Zhi ; 43(8): 1301-1308, 2022 Aug 10.
Article in Chinese | MEDLINE | ID: mdl-35981994

ABSTRACT

Objective: To analyze the impact of metabolic risk factors on the epidemiological characteristics of the reactivation of inactive HBsAg carriers (IHC) and provide effective intervention measures to standardize the management of chronic hepatitis B infections. Methods: Based on the chronic hepatitis B infection cohort established in 2010 in Jiangsu province, six follow-up visits from 2012 to 2020 were conducted to analyze the characteristics and influencing factors of the hepatitis B reactivation of IHC and the impact of metabolic risk factors, including obesity, high blood pressure, diabetes and hyperglycemia. Results: From 2012 to 2020, 2 527 IHC and 17 730 person-years were observed during a median follow-up period of 7.0 person-years. Ninety-eight cases of hepatitis B reactivation, with a cumulative reaction rate, was 3.9%, and the incidence density was 5.53/1 000 person-years. Multivariate Cox proportional risk regression analysis showed that age and baseline HBV DNA were independent risk factors of HBV reactivation. Compared with the patients ≥60 years, 40-49 age group (aHR=2.16, 95%CI:1.20-3.90) and 20-29 age group (aHR=5.48, 95%CI:2.07-14.48) were significantly associated with hepatitis B reactivation. Compared with the HBV DNA negative patients at baseline, the risk of hepatitis B reactivation was higher in the group with low HBV DNA level 100-1 999 IU/ml (aHR=1.67, 95%CI:1.11-2.52). Stratification analysis results showed that compared with those without metabolic risk factors, in the ≥50 age group, patients with ≥2 metabolic risk factors showed adjusted HR of 2.73 (95%CI:1.08-6.96). Conclusions: The risk of hepatitis B being reactive is the persistent existence of IHC in communities in Jiangsu province, especially young adults, low-level HBV DNA carriers, and IHC with ≥2 metabolic risk factors. Follow-up for these IHC should be strengthened to reduce the risk of disease progression by antiviral treatment at the right time.


Subject(s)
Hepatitis B, Chronic , Hepatitis B , Cohort Studies , DNA, Viral , Hepatitis B/epidemiology , Hepatitis B Surface Antigens , Hepatitis B virus/genetics , Hepatitis B, Chronic/epidemiology , Humans , Risk Factors , Young Adult
3.
Eur Rev Med Pharmacol Sci ; 23(15): 6394-6403, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31378877

ABSTRACT

OBJECTIVE: We aimed to explore the role of microRNA-449b-5p in osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and its mechanism of action. MATERIALS AND METHODS: Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) assay was used to detect the expression levels of microRNA-449b-5p and osteogenic markers including RUNX2, OCN during BMSCs differentiation. The microRNA-449b-5p mimic and microRNA-449b-5p inhibitors were transfected into BMSCs to achieve microRNA-449b-5p overexpression and knockdown, then the expressions of osteogenic markers were detected by qRT-PCR. The ALP activity staining and the alizarin red staining were used to detect the activity of ALP and the mineralization ability of cells after overexpression and knockdown of microRNA-449b-5p. Binding sites for microRNA-449b-5p and Satb2 were predicted by TargetScan, the PicTar and microRNAanda programs, and confirmed by dual-luciferase reporter gene assay. The relationship between microRNA-449b-5p and Satb2 was analyzed by QRT-PCR and Western blot. The microRNA-449b-5p inhibitor and shSATB2 lentivirus were simultaneously transfected in BMSCs, and the expression levels of RUNX2, OCN and ALP were detected by qRT-PCR and ALP activity assays. RESULTS: microRNA-449b-5p expression gradually decreased during osteogenic differentiation. Overexpression of microRNA-449b-5p inhibited BMSCs differentiation by down-regulating ALP activity, RUNX2, and OCN expression, while the opposite result was observed after knockdown of microRNA-449b-5p. MicroRNA-449b-5p can bind to the 3'UTR end of Satb2, which was involved in the osteogenic differentiation of microRNA-449b-5p-regulated BMSCs, and silencing of Satb2 can abolish the positive effect of the microRNA-449b-5p inhibitor on osteoblasts differentiation. CONCLUSIONS: microRNA-449b-5p could aggravate osteoporosis by inhibiting osteogenic differentiation of BMSCs through targeting Satb2.


Subject(s)
Cell Differentiation/physiology , Matrix Attachment Region Binding Proteins/metabolism , Mesenchymal Stem Cells/metabolism , MicroRNAs/metabolism , Osteogenesis/physiology , Osteoporosis/metabolism , Transcription Factors/metabolism , Animals , Cells, Cultured , Disease Progression , Protein Binding/physiology , Rats
4.
Eur Rev Med Pharmacol Sci ; 23(13): 5823-5830, 2019 Jul.
Article in English | MEDLINE | ID: mdl-31298353

ABSTRACT

OBJECTIVE: Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide. The pathogenesis of NSCLC has not yet been fully understood, and the therapeutic efficacy of current anti-NSCLC medication remains unsatisfactory. Previous studies indicated that miR-296-3p was down-regulated in NSCLC, suggesting that miR-296-3p may participate in the pathogenesis of NSCLC; however, the specific mechanisms still need to be further explored. The aim of this work is to investigate the roles of miR-296-3p in NSCLC and the related mechanism. PATIENTS AND METHODS: Thirty NSCLC tissue and paired adjacent tissue were collected, and Real Time-quantitative Polymerase Chain Reaction (RT-qPCR) was performed to examine the expression of miR-296-3p in cancer tissue and the adjacent tissue. Next, A549 cells were cultured and transfected with miR-296-3p mimics, and cell migration and invasion were determined using scratch wound-healing and transwell assays. Moreover, Western blot assay was performed to determine the effect of miR-296-3p on the expression of Rab-like 3 (RABL3), Matrix metallopeptidase (MMP)-2, Janus kinase (JAK) and Signal transducer and activator of transcription 3 (STAT3); next, Dual-Luciferase reporter assay has been conducted to prove the direct targeting relationship between miR-296-3p and RABL3. Finally, the cells of different treatments were subcutaneously implanted into nude mice to investigate the effect of miR-296-3p mimics in the xenograft mice tumor models. RESULTS: Our data indicated that miR-296-3p was significantly down-regulated and RABL3 was markedly up-regulated in NSCLC tissue compared with the adjacent tissue. Moreover, transient over-expression of miR-296-3p in A549 cells induced a significant decrease in the proliferation and invasion ability of A549 cells, as well as decreased expression of RABL3, MMP-2, JAK and STAT3. Furthermore, the Dual-Luciferase reporter assay confirmed that RABL3 is a direct target of miR-296-3p. Finally, the results of animal studies indicated that miR-296-3p can regulate the tumorigenesis of A549 cells in vivo. CONCLUSIONS: Our findings proved that miR-296-3p may play a role as a tumor suppressor in NSCLC both in vitro and in vivo, and we first reported that miR-296-3p can regulate the migration and invasion of A549 cells via targeting RABL3. Our data suggested that miR-296-3p may serve as a potential therapeutic target for treating NSCLC.


Subject(s)
Carcinoma, Non-Small-Cell Lung/metabolism , Lung Neoplasms/metabolism , MicroRNAs/metabolism , rab GTP-Binding Proteins/metabolism , Animals , Carcinoma, Non-Small-Cell Lung/pathology , Carcinoma, Non-Small-Cell Lung/surgery , Cell Movement , Cell Proliferation , Cells, Cultured , Down-Regulation/genetics , Humans , Lung Neoplasms/pathology , Lung Neoplasms/surgery , Male , Mice , Mice, Inbred BALB C , Mice, Nude , MicroRNAs/genetics , Neoplasms, Experimental/metabolism , Neoplasms, Experimental/pathology , Neoplasms, Experimental/surgery , rab GTP-Binding Proteins/genetics
5.
Zhonghua Liu Xing Bing Xue Za Zhi ; 38(2): 179-184, 2017 Feb 10.
Article in Chinese | MEDLINE | ID: mdl-28231662

ABSTRACT

Objective: To understand the epidemiological characteristics and influencing factors related to HBeAg sero-clearance in chronic hepatitis B patients so as to provide evidence for regular management on chronic HBV patients. Methods: From 2012 to 2014, a cohort study was conducted among HBeAg positive chronic HBV patients in Jiangsu province. Association between the characteristics and incidence of HBeAg sero-clearance was analyzed by Cox regression method. The changing trend on HBV DNA between patients with HBeAg sero-clearance and those with persistent HBeAg positive status was compared by repeated measure data variance analysis method. Results: In 2012, there were 721 HBeAg positive hepatitis B patients aged (45.2 ± 14.2) years enrolled in this study. By 2014, the follow-up observation period was 1 058 person-years, and 393 cases had lost their HBeAg status, with the rate as 37.2/100 person-years. The HBeAg sero-clearance rate was 32.4/100 person-years in hepatitis B patients who received antiviral treatment. The probability of HBeAg clearance in HBeAg positive hepatitis B patients aged ≥60 year (62.0/100 person-years) was higher than those of aged <20 year (7.0/100 person-years). The rate of HBeAg sero-clearance in HBeAg positive patients with HBV DNA <20 000 IU/ml (75.8/100 person-years) was higher than those whose HBV DNA were ≥200 000 IU/ml (16.1/100 person-years). By Cox regression analysis, the HBV DNA level was an important influencing factor on the progress of HBeAg sero-clearance. Patients with HBV DNA levle as ≥200 000 IU/ml, had a lower HBeAg clearance rate (HR=0.18, 95%CI: 0.13-0.23, P<0.001). Compared to the persistent HBeAg positive group, HBV DNA showed a more dramatic fall in the HBeAg-lost group (P<0.001). Conclusion: The rate of HBeAg sero-clearance among HBeAg positive hepatitis B patients was correlated with age and HBV DNA status of the patients that called for comprehensive management and intervention programs to develop for the HBeAg positive hepatitis B patients with different characteristics.


Subject(s)
Antiviral Agents/therapeutic use , DNA, Viral/blood , Hepatitis B e Antigens/blood , Hepatitis B virus/drug effects , Hepatitis B, Chronic/drug therapy , Hepatitis B, Chronic/epidemiology , Adult , Aged , Aged, 80 and over , Cohort Studies , Female , Hepatitis B , Hepatitis B virus/isolation & purification , Hepatitis B, Chronic/blood , Hepatitis B, Chronic/virology , Humans , Incidence , Male , Middle Aged , Viral Load
6.
Zhonghua Liu Xing Bing Xue Za Zhi ; 38(2): 194-199, 2017 Feb 10.
Article in Chinese | MEDLINE | ID: mdl-28231665

ABSTRACT

Objective: To investigate the clinical features and viral load of persons infected with HCV and the risk factors for severe outcomes. Methods: Medical testing and questionnaire survey were conducted on 465 cases who were infected with HCV, 20-30 years back. HCV RNA, alanine transaminase (ALT), aspartate transaminase (AST), albumin, globulin and bilirubin were tested for these subjects. Factors as demography, tobacco and alcohol consumption, SNP of rs7453920 and rs2856718 on HLA-DQ gene of subjects with HCV RNA, were analyzed by multiple logistic regression method to explore the risk factors for severe outcomes among the patients. Result: Totally, 465 subjects had symptoms as hypodynamic (15.70%, 73/465), digestive system (17.63%, 82/465), and arthrodynia (10.32%, 48/465). HCV RNA was positive in 68.60% (319/465) of the subjects with median viral load as 76.01×10(4) copies/ml (min-max: 592 copies/ml -1.08×10(10) copies/ml). Totally, 11.83% (55/465) of the cases appeared having liver inflammation by routine ultrasound exams. ALT and AST was seen higher than 80 (IU/L) in 12.70% (59/465) and 11.18% (52/465) of the subjects, separately. Factors as being male (OR =2.298, 95%CI: 1.247-4.238), GA genotype compared with AA type in rs2856718 (OR=1.716, 95%CI: 1.070-2.752), alcohol intake ≥7 times per-week (OR=2.966, 95% CI: 0.979-8.988) etc., were independently related to HCV RNA sustained positivity. Factors as: being male (OR=1.694, 95%CI: 0.975-2.942), in 50-59 years age group (OR=2.414, 95%CI: 1.156-5.042), having other liver diseases (OR=2.592, 95% CI: 1.105-6.079) and carrying positive HCV RNA (OR=3.479, 95% CI: 1.648-7.343) etc. were independent risk factors for abnormal liver function. Conclusion: High rates of carrying sustained positive HCV RNA and abnormal liver function appeared in subjects who got the HCV infection 20-30 years ago. Factors as being male, in old age, being frequent alcohol taker, GA genotype in rs2856718 and with other liver diseases etc. were related to higher risk for developing severe outcomes.


Subject(s)
Hepacivirus/isolation & purification , Hepatitis C/epidemiology , RNA, Viral/analysis , Adult , Alanine Transaminase/metabolism , Aspartate Aminotransferases/metabolism , Bilirubin/blood , China/epidemiology , Female , Genotype , HLA-DQ Antigens , Hepacivirus/genetics , Hepatitis C/diagnosis , Humans , Liver Function Tests , Male , Middle Aged , Polymerase Chain Reaction/methods , Prognosis , Risk Factors , Viral Load
7.
Zhonghua Liu Xing Bing Xue Za Zhi ; 38(1): 43-48, 2017 Jan 10.
Article in Chinese | MEDLINE | ID: mdl-28100375

ABSTRACT

Objective: To understand characteristics and influencing factors of reversion of HBeAg in chronic hepatitis B patients with HBeAg sero-conversion, and provide epidemiological evidence for the regular management of chronic hepatitis B patients. Methods: From 2012 to 2014, a cohort study was conducted among the chronic hepatitis B patients with sero-conversion of HBeAg in Jiangsu province. Association between participants' demographics, ALT, HBV DNA and incidence of HBeAg reversion was analyzed by Cox regression model. HBV DNA changing trend between patients with HBeAg reversion and patients with persistent HBeAg sero-conversion was compared by repeated measure data variance analysis. Results: In 2012, there were 5 068 HBeAg seroconverted chronic hepatitis B patients aged (51.9 ± 12.8) years enrolled. By 2014, HBeAg had reversed in 121 cases with the rate of 1.3/100 person-years. The probability of HBeAg reversion decreased with the age of the patients. By Cox regression analysis, HBV DNA level was an important influencing factor for the progress of HBeAg reversion. The patients with HBV DNA≥200 000 IU/ml had a higher HBeAg reversion rate DNA (3.8/100 person-years) than those with HBV DNA <2 000 IU/ml (1.1 person-years) (HR=3.44, 95% CI: 1.91-6.20, P=0.000). Compared with the persistent HBeAg sero-conversion group, HBV DNA and ALT showed a more dramatic increase in the HBeAg reversion group (P=0.000). Conclusions: There was a certain HBeAg reversion rate in chronic hepatitis B patients with HBeAg sero-conversion. Younger chronic CHB patients with HBeAg sero-conversion and those with higher HBV DNA lever had higher HBeAg reversion rate. Following up and management of chronic CHB patients with HBeAg sero-conversion is important and helpful for the control of hepatitis B.


Subject(s)
DNA, Viral/blood , Hepatitis B e Antigens/blood , Hepatitis B virus/immunology , Hepatitis B, Chronic/epidemiology , Adult , Aged , Antiviral Agents , Cohort Studies , Female , Hepatitis B e Antigens/genetics , Hepatitis B virus/genetics , Hepatitis B, Chronic/blood , Hepatitis B, Chronic/immunology , Hepatitis B, Chronic/virology , Humans , Incidence , Male , Middle Aged , Seroconversion
8.
Zhonghua Liu Xing Bing Xue Za Zhi ; 37(10): 1345-1349, 2016 Oct 10.
Article in Chinese | MEDLINE | ID: mdl-27765123

ABSTRACT

Objective: To evaluate the effects of blocking transmission of HBV from mother to infant in Jiangsu, and discuss influencing factors related to development of chronic HBV infection in children of HBsAg positive mother. Methods: HBsAg positive mothers delivered during 2010-2015 in three counties of Jiangsu (Zhangjiagang, Danyang and Taixing) and their neonates were included in the study. The neonates were vaccinated with hepatitis B vaccine (10 µg) and hepatitis B immunoglobin (100 units) within 24 hours after birth. Blood samples were collected from the infants 7 months later, and serum HBsAg, anti-HBs and anti-HBc were detected by Abbott particles chemiluminescence. Results: A total of 2 099 children aged 7-52 months were surveyed, of whom 34 (1.62%) developed chronic HBV infection. Logistic regression analysis showed that mother HBeAg positivity (RR=4.997, 95% CI: 2.408-10.370) was the independent risk factors of mother-to-infant transmission of HBV, while elder delivery age (RR=0.264, 95% CI: 0.101-0.691) was independent protective factors of HBV transmission. Among the other 2 065 uninfected children, 9.7% had anti-HBs level less than 10 mIU/ml, 35.4% between 10 and 100 mIU/ml, and 54.9% higher than 100 mIU/ml. The anti-HBs positive rate was 90.3% and the anti-HBc positive rate was 13.7%. The positive rate and geometric mean titers (GMT) of anti-HBs reached the peaks at 7-12 months after birth, and decreased with the age. Conclusions: The current immunological strategy of Jiangsu has good protective efficacy for the interruption of perinatal transmission of HBV. Mother HBeAg positivity is the major risk factor for perinatal blocking failure. Children with effective immunization still need to be monitored for anti-HBs and revaccinated if necessary.


Subject(s)
Hepatitis B/transmission , Infectious Disease Transmission, Vertical/prevention & control , Child , Female , Follow-Up Studies , Hepatitis B Antibodies , Hepatitis B Surface Antigens , Hepatitis B Vaccines , Hepatitis B virus , Humans , Immunization, Secondary , Infant , Infant, Newborn , Mothers , Pregnancy , Risk Factors , Surveys and Questionnaires , Vaccination
9.
Zhonghua Liu Xing Bing Xue Za Zhi ; 37(11): 1463-1467, 2016 Nov 10.
Article in Chinese | MEDLINE | ID: mdl-28057135

ABSTRACT

Objective: To understand epidemiological characteristics and influencing factors of hepatitis B virus (HBV) carriers progressing to chronic hepatitis B in Jiangsu, and provide evidence for regular management of HBV carriers. Methods: From 2012 to 2014, a cohort study was conducted among the HBV carriers in an area in Jiangsu province. Association between HBV carriers' demographics, HBeAg level and HBV DNA detection result and incidence of chronic hepatitis B was analyzed by Cox regression analyses. Results: In 2012, a total of 4 069 HBV carriers aged (52.0±12.8) years were surveyed. By 2014, chronic hepatitis B had developed in 1 444 cases, with the rate of 21.0/100 person-years. Cox regression analysis indicted that, in addition to gender, HBV DNA level was an important influencing factor for the incidence of chronic hepatitis B (P<0.05). In HBeAg positive carriers progressing to chronic hepatitis, 40.7% had HBeAg seroconversion, and reversion of HBeAg occurred in 1.7% of HBeAg negative carriers. Conclusion: Chronic hepatitis B developed in more than 1/5 (21.0/100 person-years) of HBV carriers in the surveyed area in Jiangsu. It is suggested to conduct regular ALT, HBV DNA detection and B ultrasonic examination in HBV carriers for the early detection of chronic hepatitis B.


Subject(s)
Hepatitis B virus , Cohort Studies , Hepatitis B e Antigens , Hepatitis B, Chronic , Humans , Incidence
10.
Epidemiol Infect ; 143(13): 2827-36, 2015 Oct.
Article in English | MEDLINE | ID: mdl-25600557

ABSTRACT

Limited information is available on the prevalence of hepatitis C virus (HCV) in the general population in China. A community-based epidemiological study was conducted in three counties in eastern China. A total of 149 175 individuals were investigated in 60 communities in three counties in Jiangsu province, eastern China, of whom 1175 subjects [0·79%, 95% confidence interval (CI) 0·74-0·83] were HCV antibody positive. The prevalence was low in children (0·09%, 95% CI 0·04-0·17), but increased progressively from adolescents (0·20%, 95% CI 0·15-0·28) to adults aged ⩾21 years (95% CI 0·15-1·64). Women had a higher prevalence of HCV infection than men in most age groups. In a multilevel regression analysis, age, sex, education, occupation, blood transfusion [odds ratio (OR) 2·91, 95% CI 1·09-5·37], invasive testing (OR 1·28, 95% CI 1·14-1·61), and dental therapy (OR 2·27, 95% CI 1·41-3·42) were associated with HCV infection. In conclusion, although the prevalence of HCV in this population was lower than reported from national levels, the total reservoir of infection is significant and warrants public health measures, such as health education to limit the magnitude of the problem.


Subject(s)
Hepatitis C/epidemiology , Adolescent , Adult , Aged , Child , China/epidemiology , Female , Humans , Male , Middle Aged , Prevalence , Risk Factors
11.
Meat Sci ; 63(4): 427-32, 2003 Apr.
Article in English | MEDLINE | ID: mdl-22062511

ABSTRACT

To determine the effects of globin moiety denaturation and pH on the ability of metmyoglobin (MetMb) to undergo reduction, MetMb isolated from porcine hearts was denatured in 8.5M urea. Both native and denatured MetMb solutions were serially reduced with Na(2)S(2)O(4) (0, 7.5, 15, 18.75, 22.5, 26.25, 30, 30.75, and 45 umol). Reduction was conducted at pH 5, 5.2, 5.4, 5.6, 6, 6.2, 6.4, 6.6, and 7. After reduction, absorbance was determined at 635 nm and the percent of the original MetMb which was reduced was calculated. The average percent MetMb reduced from the native and denatured forms was 35 and 25%, respectively. pH significantly influenced the percentage of MetMb reduced, especially when pH was <6. If the MetMb was denatured prior to reduction, the influence of pH on its ability to undergo reduction was slight. The percentage of denatured MetMb reduced was higher at pH 7 than at all other pHs. High pH enhanced the ability of MetMb to undergo reduction; while low pH decreases it. Low pH may have denatured the native globin moiety.

12.
Meat Sci ; 61(4): 419-24, 2002 Aug.
Article in English | MEDLINE | ID: mdl-22061072

ABSTRACT

From a series of experiments heating metmyoglobin solutions at pH 5.0 through 7.0, the effects of temperature and pH on the thermal stability of metmyoglobin were investigated. The percent metmyoglobin denatured at temperatures from 25 to 80 °C was determined. pHs lower than 6.5 caused metmyoglobin denaturation at various temperatures from 25 to 80 °C, but it was particularly apparent when pH was < 5.6. Thermal stability of metmyoglobin increased as pH increased. Metmyoglobin denaturation occurred at 55 °C at pH 5, however, denaturation did not occur until 60 °C at pHs from 5.3 to 7.0. A slower heating rate (0.9 °C/min) resulted in more metmyoglobin thermal denaturation than a faster heating rate (1.3 °C/min) when the temperature was above 55 to 60 °C. The denaturation caused by low pH alone was reversible, while that caused by high temperature was not. Techniques which increase muscle pH, such as the injection of sodium bicarbonate, could effectively improve the color condition of PSE meat.

13.
Meat Sci ; 57(2): 169-76, 2001 Feb.
Article in English | MEDLINE | ID: mdl-22061360

ABSTRACT

To evaluate factors affecting pork color, the gluteus medius (GM), longissimus lumborumetthoracis (LT), semimembranosus (SM), biceps femoris (BF), and triceps brachii (TRI) muscles from pork carcasses of varying ultimate pHs were allowed to bloom for 30 min. L*, a*, and b* values, hue angle, chroma and visual color were determined. Color was evaluated using HunterLab (illuminants A, C, D(65) and F) and Minolta (illuminants C and D(65)) Spectrocolorimeters. LT had the highest L* value (51.31; TR=39.93) and hue angle (59.36; TR=46.94), and the lowest a* (7.52; TR=12.88) value. L* value was unaffected by bloom time; hue angle stabilized after 5 min, a* and b* values after 10 min and chroma after 20 min. Using the Minolta/illuminant D65, visual color best correlated with b* and L* values (r=-0.94 and -0.89) of LT. Using the Hunter/illuminant C, visual color correlated with L* value of LT, GM, BF and SM (r >-0.90 for each). Overall, the instrumental measure that best related to visual color was L* value.

14.
Meat Sci ; 59(2): 153-63, 2001 Oct.
Article in English | MEDLINE | ID: mdl-22062673

ABSTRACT

These studies evaluated whether consumers detect differences among pork loin chops with low (1.05% fat), medium (2.33%) and high (3.46%) amounts of marbling when visually evaluated, when prepared under controlled conditions, and when prepared at home. Highly marbled chops appeared lighter colored, less lean, had less acceptable appearance, and were less likely to be purchased than leaner chops; they were juicier, more tender, oily and flavorful than leaner chops. These results indicate a disparity between purchase intent based on visual evaluation, and quality attributes of the cooked product. When evaluated at home, consumers rated the chops they chose (40% low, 40% medium marbled) as more tender, juicy and flavorful than chops they evaluated "blind" on-site suggesting that additional factors have a significant impact on stated purchase intent.

15.
Sci Sin B ; 29(2): 126-35, 1986 Feb.
Article in English | MEDLINE | ID: mdl-3749867

ABSTRACT

The interaction of cis-[Pt(NH3)2Cl2] with nucleosides, as constituents of DNA, was studied by spectrophotometric, 13C NMR and CNDO/2 methods. The apparent stability constants of the complexes formed and the initial rate of formation were determined. The sites of binding of nucleoside (or nucleotide) with Cisplatin were ascertained and the electronic structure of the model coordination compounds of Cisplatin and guanine was calculated by MO approach. On the basis of the obtained results, the mechanism of the antitumour action of Cisplatin was discussed, and a new possible mode of bonding of Cisplatin with DNA was proposed.


Subject(s)
Cisplatin , DNA , Nucleosides , Binding Sites , Chelating Agents , Chemical Phenomena , Chemistry , Models, Chemical
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