Risk factors for mortality in patients with tuberculosis admitted to intensive care units

OBJECTIVE

The purpose of this study is to investigate the mortality of patients with tuberculosis (TB) who need to be admitted to the intensive care unit (ICU) and to analyze the risk factors for mortality.

PATIENTS AND METHODS

A retrospective analysis was conducted to collect clinical data of patients with TB who were hospitalized in the ICU at Hebei Chest Hospital between 2015 and 2020. Subsequent to data collection, a rigorous statistical analysis was conducted.

RESULTS

A total of 99 patients with TB were admitted to the ICU of Hebei Chest Hospital from 2015 to 2020. After 28 days, 78 of the 99 eligible participants in this study died, while 21 survived. The mortality rate of patients with TB in the ICU was 78.79%. There was a significant difference in the length of stay in ICU, shock, drug, acute physiology, and chronic health evaluation (APACHE) II, procalcitonin, C-reactive protein, and albumin (p < 0.05). Further analysis indicated that the length of stay in the ICU, shock, APACHE II, and albumin were considered independent risk factors for mortality.

CONCLUSIONS

In China, the mortality rate of patients with TB requiring admission to the ICU is very high. In these patients, a prolonged ICU stay, a high APACHE II score, the onset of shock in the ICU, and a low albumin level have a significant impact on the risk of mortality.

[Construction and evaluation of a nomogram for predicting the prognosis of patients with colorectal cancer with peritoneal carcinomatosis treated with cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy]

Objectives: To construct a nomogram incorporating important prognostic factors for predicting the overall survival of patients with colorectal cancer with peritoneal metastases treated with cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC), the aim being to accurately predict such patients' survival rates. Methods: This was a retrospective observational study. Relevant clinical and follow-up data of patients with colorectal cancer with peritoneal metastases treated by CRS + HIPEC in the Department of Peritoneal Cancer Surgery, Beijing Shijitan Hospital, Capital Medical University from 2007 January to 2020 December were collected and subjected to Cox proportional regression analysis. All included patients had been diagnosed with peritoneal metastases from colorectal cancer and had no detectable distant metastases to other sites. Patients who had undergone emergency surgery because of obstruction or bleeding, or had other malignant diseases, or could not tolerate treatment because of severe comorbidities of the heart, lungs, liver or kidneys, or had been lost to follow-up, were excluded. Factors studied included: (1) basic clinicopathological characteristics; (2) details of CRS+HIPEC procedures; (3) overall survival rates; and (4) independent factors that influenced overall survival; the aim being to identify independent prognostic factors and use them to construct and validate a nomogram. The evaluation criteria used in this study were as follows. (1) Karnofsky Performance Scale (KPS) scores were used to quantitatively assess the quality of life of the study patients. The lower the score, the worse the patient's condition. (2) A peritoneal cancer index (PCI) was calculated by dividing the abdominal cavity into 13 regions, the highest score for each region being three points. The lower the score, the greater is the value of treatment. (3) Completeness of cytoreduction score (CC), where CC-0 and CC-1 denote complete eradication of tumor cells and CC-2 and CC-3 incomplete reduction of tumor cells. (4) To validate and evaluate the nomogram model, the internal validation cohort was bootstrapped 1000 times from the original data. The accuracy of prediction of the nomogram was evaluated with the consistency coefficient (C-index), and a C-index of 0.70-0.90 suggest that prediction by the model was accurate. Calibration curves were constructed to assess the conformity of predictions: the closer the predicted risk to the standard curve, the better the conformity. Results: The study cohort comprised 240 patients with peritoneal metastases from colorectal cancer who had undergone CRS+HIPEC. There were 104 women and 136 men of median age 52 years (10-79 years) and with a median preoperative KPS score of 90 points. There were 116 patients (48.3%) with PCI≤20 and 124 (51.7%) with PCI>20. Preoperative tumor markers were abnormal in 175 patients (72.9%) and normal in 38 (15.8%). HIPEC lasted 30 minutes in seven patients (2.9%), 60 minutes in 190 (79.2%), 90 minutes in 37 (15.4%), and 120 minutes in six (2.5%). There were 142 patients (59.2%) with CC scores 0-1 and 98 (40.8%) with CC scores 2-3. The incidence of Grade III to V adverse events was 21.7% (52/240). The median follow-up time is 15.3 (0.4-128.7) months. The median overall survival was 18.7 months, and the 1-, 3- and 5-year overall survival rates were 65.8%, 37.2% and 25.7%, respectively. Multivariate analysis showed that KPS score, preoperative tumor markers, CC score, and duration of HIPEC were independent prognostic factors. In the nomogram constructed with the above four variables, the predicted and actual values in the calibration curves for 1, 2 and 3-year survival rates were in good agreement, the C-index being 0.70 (95% CI: 0.65-0.75). Conclusions: Our nomogram, which was constructed with KPS score, preoperative tumor markers, CC score, and duration of HIPEC, accurately predicts the survival probability of patients with peritoneal metastases from colorectal cancer treated with cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy.

[Clinicopathological characteristics of gastric SMARCA4-deficient undifferentiated/rhabdoid carcinoma]

Objective: To investigate the clinicopathological features and immunohistochemical phenotypes of gastric SMARCA4-deficient undifferentiated carcinoma, and to discuss the daily diagnostics of this entity and analyze its prognosis. Methods: The cases of gastric SMARCA4-deficient undifferentiated carcinoma diagnosed at the Department of Pathology, Peking University Cancer Hospital, China from January 2010 to August 2022 were collected. The histological sections were reviewed, the immunohistochemical results and clinicopathological features were analyzed, and relevant literature was reviewed. Results: Pure foci of undifferentiated carcinoma were seen in 7 cases, and 1 case was accompanied by a moderately differentiated tubular adenocarcinoma component. Undifferentiated carcinoma foci showed similar sheet-like or solid diffuse growth pattern, medium-sized tumor cells characterized by 1-2 nucleoli, and abundant cytoplasm and rhabdoid appearance. The average patient age was 65±8 years. Six patients were male and 2 were female. Immunohistochemical staining showed that undifferentiated carcinoma of all 8 tumors were negative for SMARCA4 (BRG1). Among 7 patients who underwent SMARCA2 (BRM) and SMARCB1 (INI1) staining, 4 cases showed loss of BRM expression, 2 cases showed weakly positive staining, and 1 case was diffusely positive, but all 7 cases were diffusely strong positive for INI1. The neuroendocrine marker, synaptophysin, was weakly positive in 5 cases, while CgA and CD56 were negative in 8 cases. Ki-67 index was more than 70%. Two cases were mismatch repair deficient and showed the loss of MLH1/PMS2 expression, while 1 case showed only MSH2 loss. PD-L1 staining showed that combined positive score (CPS)≥1 in 4 cases (CPS ranging from 1 to 55) and CPS<1 in the other 3 cases. Four patients had clinical stage Ⅳ disease. Two of them died within 3 months after diagnosis. Conclusions: Gastric SMARCA4-deficient undifferentiated carcinoma/rhabdoid carcinoma is a rare group of highly malignant tumors with a poor prognosis. Loss of the core subunit of SWI/SNF complex may be associated with the development of dedifferentiated histological pattern and aggressive tumor progression, which may be more frequently accompanied with mismatch repair deficiency.

Posterior tibial artery flap versus radial forearm flap in oral cavity reconstruction and donor site morbidity

The repair of soft tissue defects after oral cavity cancer resection is challenging. The aim of this study was to compare the outcomes and donor site morbidity of the radial forearm free flap (RFF) and posterior tibial artery perforator flap (PTAF) for oral cavity reconstruction after cancer ablation. All patients who underwent oral cavity reconstruction with a RFF or PTAF between January 2017 and December 2019 were included retrospectively in this study. All flaps were harvested with a long adipofascial extension. The donor site defects were closed with a triangular full-thickness skin graft harvested adjacent to the flap. Flap outcomes and donor site complications were recorded and compared. The study included 145 patients; 30 underwent reconstruction with a RFF and 115 with a PTAF. No significant difference between the PTAF and RFF was observed concerning the flap survival rate (98.3% vs 96.7%), flap harvest time (53.39 vs 49.28 min), hospital stay (12.3 vs 15.2 days), or subjective functional and cosmetic outcomes. The PTAF showed a larger vascular calibre (P < 0.05), greater flap thickness (P = 0.002), and lower frequency of surgical site infection (P = 0.055) when compared to the RFF. No significant difference was observed between the pre- and postoperative ranges of ankle and wrist movements. The PTAF is an excellent alternative to the RFF for the repair of oral cavity defects, with the additional advantages of a well-hidden scar on the lower extremity, larger vascular calibre, and lower frequencies of postoperative donor site morbidities.

[Relationship between selenium and the risk for oral cancer: a case-control study]

Objective: To explore the relationship between selenium and the risk for oral cancer. Methods: We performed a case-control study in 325 cases of newly diagnosed primary oral cancer from the First Affiliated Hospital of Fujian Medical University and 650 controls from the same hospital and community. Unconditional logistic regression and stratification analyses were used to explore the association between selenium and oral cancer. Adjusted OR and corresponding 95%CI were calculated. The analyses on multiple interactions between selenium and smoking or drinking status, and fruit or fish intake frequencies were conducted. Results: The level of serum selenium was 112.42 (80.98-145.06) μg/L in the case group, which was lower than 164.85 (144.44-188.53) μg/L in control group, the difference was statistical significant (P<0.01). There was a negative correlation between serum selenium level and the risk for oral cancer regardless of smoking and drinking status, and fruits and fish intake frequencies (P<0.05). There were multiple interactions between serum selenium level and smoking or drinking status, and fruit and fish intakes. Conclusions: The high level of serum selenium is a protective factor for the incidence of oral cancer, and serum selenium has multiple interactions with smoking or drinking status, and fruit and fish intakes. Therefore, reducing tobacco use and alcohol consumption and increasing the intakes of fruit and fish can reduce the risk for oral cancer to some extent.

[Association of single nucleotide polymorphisms of TBX5 gene and environmental exposure index with susceptibility to oral cancer]

Objective: To explore the association of TBX5 polymorphisms and environmental exposure index with susceptibility to oral cancer. Methods: A case-control study was conducted to collect 300 oral cancer patients hospitalized in the Department of Oral and Maxillofacial Surgery, the First Affiliated Hospital of Fujian Medical University from September 2010 to December 2016. A total of 445 non-tumor patients were selected as the control group. Questionnaires were used to collect the information of all subjects and 5 ml peripheral blood was collected to detect single nucleotide polymorphisms (SNPs) of the rs10492336 locus of TBX5 gene. According to the environmental exposure index score, subjects were divided into two groups, low risk group (0-2.31) and high risk group (2.32-11.76). To analyze the association of TBX5 gene rs10492336 SNPs, environmental exposure index and oral cancer and its interactions. Results: The age of all subjects in the case group and control group were (56.19±13.10) years and (54.56±12.48) years old. Compared with CC genotype, the OR (95%CI) values of the co-dominant genetic model AC genotype and the dominant genetic model AC+AA genotype were 0.69 (0.49-0.98) and 0.70 (0.51-0.97), respectively. Compared with the low risk group, the OR (95%CI) risk of oral cancer in the high risk group was 3.72 (2.55-5.43). The results of gene-environment interaction analysis showed that compared with the group with CC genotype and high risk of environmental exposure index, the OR (95%CI) value of oral cancer in the group with AC+AA genotype and low risk of environmental exposure index was 0.18(0.10-0.31). Furthermore there was a multiplicative interaction between rs10492336 SNPs and environmental exposure index (β=-0.405, P<0.001). Conclusion: This study suggests that the TBX5 gene rs10492336 SNPs and environmental exposure index were associated with oral cancer. And there was a multiplication interaction between rs10492336 SNPs and environmental exposure index.

[Intervention study of compassion fatigue of oncology nurses in Balint group activities]

Objective: To explore the effectiveness of Balint group on compassion fatigue among oncology nurses. Methods: From January to December 2016, 35 oncology nurses from one general hospital were enrolled. 18 cases were allocated in the observation group and 17 cases in the control group by computer randomization. Nurses in the observation group were received a total of 8 times Balint Group activities, with 2 times a month and 1.5 hours each time, which is aiming to discuss difficult cases encountered in the clinic to help nurses have a deeper experience and a better understanding of the emotions and behaviors, fantasies and needs between nurse-patient interaction. Nurses in the control group without intervention. All the Participants were requested to complete the survey of the Professional Quality of Life (ProQOL) , the Jefferson Scale of Empathy-Health Professionals (JSE-HP) , and the General Health Questionnaire (GHQ) at pre and post intervention. Results: Before intervention, two group of nurses in age, working years, marriage, and education were not statistically significant (P>0.05). There was no difference in the scores of empathy, compassion satisfaction, secondary traumatic stress, and General health (P>0.05). After intervention, the scores of JSE-HP and its three dimensions of perspective taking, emotional care, and trans-positional consideration in the observation group had significantly higher than the control group (P<0.05). The level of compassion satisfaction in the observation group was higher, and the general health status was lower (P<0.05). There was no statistically difference in the level of burnout and secondary traumatic stress between two groups (P>0.05) . Conclusion: Balint group has a positive role in promoting nurses'empathetic skills, compassion satisfaction and mental health.

MiR-93 inhibition ameliorates OGD/R induced cardiomyocyte apoptosis by targeting Nrf2

OBJECTIVE

To identify the expression changes of microRNA 93 (miR-93) in oxygen-glucose deprivation/reoxygenation (OGD/R) injury in cardiomyocytes and its mechanism of mediating OGD/R and inducing apoptosis.

MATERIALS AND METHODS

Primary cardiomyocytes were extracted and OGD/R model in cardiomyocytes was established in vitro. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect the expressions of miR-93, and Western blot assay was applied to measure the protein levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and caspase-3. Flow cytometry was utilized to examine the cardiomyocyte apoptosis rate.

RESULTS

The apoptosis rate was increased after OGD/R in cardiomyocytes, accompanied by remarkable rise of miR-93 expression. After transfection of miR-93 antagomir, the apoptosis rate of cardiomyocyte induced by OGD/R was down-regulated, and the expression of cleaved caspase-3 was decreased. Meanwhile, the results of qRT-PCR and Western blot showed that the levels of Nrf2 mRNA and protein expression were up-regulated after the miR-93 level was inhibited, and luciferase reporter assay affirmed that Nrf2 was a target molecule for OGD/R-induced apoptosis mediated by miR-93.

CONCLUSIONS

miR-93 mediates OGD/R-induced hypoxia/reoxygenation injury apoptosis in cells by targeting Nrf2.

Differential expression and analysis of target regulation of microRNAs in alcohol-dependent rats

This study analyzed the differential expression of miRNAs related to alcohol dependence in rats undergoing continued consumption and withdrawal. Furthermore miRNAs were sought and evaluated for potential use as biomarkers for diagnosis. This study used Exiqon miRCURYTM LNA miRNA microarray on alcohol-dependent and normal rats for the expression of microRNAs in perfluorinated compounds, and the stem-loop qPCR method to validate its expression in brain tissue. We forecast the relevant target genes of differentially expressed miRNA and drew the regulatory network. Comparison of the differential expression between brain tissue and plasma was carried out and the correlation and analyzed.65 miRNA with differential expression with threshold of 1.5 were screened out; among them, most miRNA with differential expression in the dependent group had relatively high expression values. The target genes were found with great confidence: PIK3CA, MAPK, NTF, BDNF, NGFR, IGF-1, and the pair consisting of miRNA- mRNA. Among the three groups, the expression levels of miR-101b (F=8.12, P less than0.05) showed significant difference; no significant difference was found in the expression levels of miRNA in plasma among the groups (F=1.23, P>0.05). No consistency was shown in the changing trend of miRNA in PFC and plasma (r= -.004, p>0.05). The genetic regulatory network of neurotrophic factors, its receptors and the protein kinases that influence metabolism may mediate the incidence of alcohol-dependence. There is a lack of conformity between the expression of miR-101b in the prefrontal cortex and the plasma.

Effect of tissue frozen on quantitative optical properties using optical coherence tomography

The purpose is to demonstrate the optical charactering concerning nasopharyngeal tissue of pig by fresh sections and frozen correlating sections with optical coherence tomography (OCT). After being imaged on a fresh specimen, samples are then stored in low temperature refrigerators (-80°C) for one year for the second OCT measurement. The OCT structure of the epithelium, lamina propria, and the basement membrane are still resolvable; the median scattering coefficients and anisotropy factors fitting from OCT images based on the multiple scattering effects for epithelium are 27.6  mm^-1 [interquartile range (IQR) 23.6 to 29.3  mm^-1] versus 22.5  mm^-1 (IQR 20.5 to 24.4  mm^-1), 0.86 (IQR 0.81 to 0.9) versus 0.88 (IQR 0.87 to 0.9) for fresh and frozen tissue, respectively; and 10.2  mm^-1 (IQR 8.1 to 13.6  mm^-1) versus 9.6  mm^-1 (IQR 8.1 to 13.8  mm^-1), 0.96 (IQR 0.93 to 0.98) versus 0.92 (IQR 0.9 to 0.98) for lamina propria, respectively. The results show that the frozen storage method can be used for OCT research.

[Tea, coffee intakes and risk of oral squamous cell carcinoma: a case-control study]

Objective: To evaluate the effects of tea and coffee intakes on oral squamous cell carcinoma (OSCC) stratified by milk intake. Methods: A case-control study involving 593 OSCC patients confirmed by pathological diagnoses and 1 128 gender-age frequency matched controls was conducted in Fujian province during September 2010-March 2016. Unconditional logistic regression was used to calculate adjusted odds ratios (aORs) and corresponding 95% confidence intervals (CIs) to assess the effects of coffee, tea intakes and related variables on OSCC. Additive interaction was estimated by relative excess risk interaction (RERI), attributable proportions interaction (API) and synergy index (SI). Results: Tea intake was significantly associated with decreased risk of OSCC: the adjusted ORs were 0.54 for all subjects (95%CI: 0.41-0.71), 0.47 for milk consumers (95%CI: 0.31-0.71) and 0.57 for non-milk consumers (95%CI: 0.40-0.81). Moreover, starting tea drinking at age ≥25 years, moderate tea concentration and water temperature, drinking green tea and oolong tea showed effects to decrease the risk for OSCC in three groups. Additionally, there was a tendency of a reduced risk with increased daily tea drinking and longer tea-drinking period (all trend P<0.05). No significant association was observed between coffee intake and OSCC. A multiplicative but not additive interactions was found between tea drinking and milk intake. Additionally, we did not observe multiplicative and additive interaction between coffee drinking and milk intake. Conclusion: Tea drinking is a protective factor for OSCC, and there is a multiplicative interaction between tea drinking and milk intake. Therefore, tea drinking and increasing intake of milk can reduce the risk of OSCC at certain extent.

[Pickled food, fish, seafood intakes and oral squamous cell carcinoma: a case-control study]

Objective: To investigate the effects between fish, seafood and pickled food intakes on oral squamous cell carcinoma (OSCC). Methods: A case-control study was carried out in Fujian area during September 2010 to December 2016, in which 604 newly diagnosed primary OSCC cases confirmed by pathological diagnosis were collected from hospital and 1 343 control subjects were enrolled from community and healthy hospital population. Demographic data, history of smoking drinking and tea drinking, oral hygiene status and dietary behaviors (fish, seafood and pickled food intakes) were collected by in-person interviews using a standard questionnaire.Using unconditional logistic regression to estimate adjusted odds ratios (ORs) and corresponding 95% confidence intervals (CIs) to assess the effects of fish, seafood and pickled food intakes on OSCC. Analysis stratified by smoking, alcohol drinking and bad prosthesis to explore the possible difference in association between subgroups. Multiplicative interactions and additive interactions between fish and bad prosthesis, seafood and alcohol drinking, pickled food and bad prosthesis were assessed by unconditional logistic regression, relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP) and synergy index (S). Results: The average age of case group and control group were separately (58.69±13.92) years old and (59.27±11.37) years old (χ(2)=4.75, P=0.191). The people whose fish and seafood intakes ≥3 times/week had the lower risk of OSCC, the adjusted OR (95%CI) values were 0.63 (0.52-0.77) and 0.51 (0.41-0.64); The stratified analysis indicated that the people having bad prosthesis had the lower risk of OSCC if they eating fish ≥3 times/week, and the adjusted OR (95%CI) values was 0.53 (0.39-0.71); the people having bad prosthesis had the higher risk of OSCC if they eating pickled food ≥3 times/week, the adjusted OR (95%CI) values was 1.37 (1.02-1.88). Regularly eating seafood can decrease the risk of OSCC for non-smokers, smokers, non-drinkers, drinkers, people without bad prosthesis and had bad prosthesis, the adjusted OR (95%CI) values were 0.49 (0.36-0.68), 0.52 (0.37-0.73), 0.41 (0.31-0.55), 0.77 (0.51-0.96), 0.49 (0.36-0.67), 0.59 (0.42-0.83). Crossover analysis showed fish and bad prosthesis exist multiplication interaction relationship (adjusted OR=0.66, 95%CI: 0.44-0.97) and additional interaction relationship (RERI=-0.81, 95%CI:-1.43--0.19; AP=-0.76, 95%CI:-1.35--0.17; S=0.08, 95%CI: 0.01-0.98); pickled food and bad prosthesis exist multiplication interaction relationship (adjusted OR=1.63, 95%CI: 1.06-2.51) and addition interaction relationship (RERI=0.65, 95%CI:0.08-1.22; AP=0.36, 95%CI:0.10-0.62; S=5.19, 95%CI:1.32-54.49). Conclusion: Reducing the consumption of pickled food, quitting smoking and limiting alcohol consumption, and regularly eating fish and seafood can prevent the occurrence of OSCC.

Analysis on the relationship and mechanism of high blood pressure and vascular aging on the condition that the gender and age matches

OBJECTIVE

The relationship between hypertension and the mechanism of the expression of T-lymphocyte Kv1.3 channels in vascular aging has been analyzed in this study based on the gender and age matches' principle.

PATIENTS AND METHODS

Thirty patients have been consecutively chosen with vascular aging caused by hypertension (group A), while 30 cases of high blood pressure not merged with vascular aging (group B) were chosen, and 30 cases of healthy volunteers (group C), conforming to gender and age 1:1 and the closest matching principle, were studied. The aim of this study was to separate the peripheral blood mononuclear cells and give intervention of 0.2 nmol/L ANGII to CD4 + T-lymphocytes, and store them in the incubator 48 h. The difference of Kv1.3 channel current of CD4 + T-lymphocyte, mRNA, angiotensin receptor (AT1R) protein mRNA, and IFN-γ density has also been compared.

RESULTS

The membrane capacitance, peak current, and current density of group A, are higher than those of the other two groups, and the differences have statistical significance (p<0.05). After adding ANGII intervention to group A, the expression levels of T-lymphocyte Kv1.3 potassium channels mRNA, AT1R mRNA, and IFN-γ are significantly increased, so that the difference has statistical significance p<0.05, while the other two groups have no significant change (p>0.05). The levels of Kv1.3 potassium channels, AT1R mRNA, and IFN-γ of group A before and after the intervention are significantly higher than those of the other two groups, and the differences are statistically significant (p<0.05).

CONCLUSIONS

Vascular aging caused by hypertension may be linked to the increase of Kv1.3 potassium channel activity of T-lymphocyte, while ANGII can improve the high expression of Kv1.3 potassium channel and AT1R, to stimulate lymph cells to secrete IFN-γ.

A comprehensive evaluation of application of light-cured colored compomer for deciduous teeth

Twinky Star colored compomer produced by VOCO GmbH is a new type of filling material designed with seven different colors. Previous studies have shown that using the colored filling material can induce children’s curiosity and increase the acceptance for dental treatment. However, few studies have been conducted to evaluate it. Hence, the present study was designed to assess the mechanical and adhesive properties of this new compomer, examine its biological safety, and evaluate the effects of its clinical application on children’s adherence to dental treatment and the subsequent therapeutic outcomes. We found that Twinky Star compomer has a high compressive strength, good biaxial flexural strength, low wear rate, and good adhesive properties, and had little in vitro cytotoxic effects and did not cause apparent hemolysis in vivo. Finally, application of the compomer helped to improve children’s acceptance of treatment without affecting the subsequent therapeutic outcomes in the follow-up examinations. To summarize, the findings suggest that Twinky Star compomer meets the performance requirements for dental fillings, and can be recommended for future clinical application.

Tea consumption and its interactions with tobacco smoking and alcohol drinking on oral cancer in southeast China

BACKGROUND/OBJECTIVES

Epidemiological results on the association between tea consumption and oral cancer remain controversial. We aimed to evaluate the exact relationship between tea consumption and oral cancer in Chinese population.

SUBJECTS/METHODS

A large-scale case-control study was conducted on 586 oral cancer patients and 1024 controls frequency-matched by age and gender. Epidemiological data were collected through face-to-face interviews with a structure questionnaire. Unconditional logistic regression model was used to assess the effect of tea consumption on oral cancer stratified by smoking, alcohol drinking and demographics. Quantity of tea consumed (ml/day) was categorized into five subgroups based on quartiles and then its interactions was evaluated with tobacco smoking and alcohol drinking at each subgroup.

RESULTS

Tea consumption showed an inverse association with oral cancer for non-smokers or non-alcohol drinkers (the odds ratios (ORs) were 0.610 (95% confidence interval (CI): 0.425-0.876) and 0.686 (95% CI: 0.503-0.934), respectively). For smokers or alcohol drinkers, decreased risk was only observed in those who consumed >800 ml/day. Furthermore, oolong tea consumption was associated with decreased risk of oral cancer in smokers or alcohol drinkers but not in non-smokers or non-alcohol drinkers. Tea consumption combined with smoking or/and alcohol drinking had a greater risk than tea consumption alone, but the risk was roughly reduced from zero to Q4 (>800 ml/day). Additionally, when stratified by demographics, the protective effect of tea was especially evident in females, urban residents, normal body mass index population (18.5-23.9), farmers, office workers and those aged <60 years.

CONCLUSIONS

Tea consumption protects against oral cancer in non-smokers or non-alcohol drinkers, but this effect may be obscured in smokers or alcohol drinkers. Additionally, demographics may modify the association between tea consumption and oral cancer.

Influence of oral hygiene and its interaction with standard of education on the risk of oral cancer in women who neither smoked nor drank alcohol: a hospital-based, case-control study

We know of only limited data about the role of oral hygiene and the risk of oral cancer with different standards of education. The aim of this study was to assess the association between oral hygiene and risk of oral cancer, with stratification by standard of education, in Chinese women. We organised a case-control study with 250 women with oral cancer and 996 age-matched controls in Fujian, China. Data were collected by personal interview using a structured questionnaire. We used unconditional logistic regression with stratification by educational standard to estimate the odds ratios (OR) and 95% CI. Tooth-brushing twice a day or more was inversely related to the risk of oral cancer in women with high school education or above (OR 0.50; 95% CI 0.25 to 0.98), but not in those who were illiterate or had primary-middle school education. Wearing dentures showed an increased risk only in less well-educated women: the OR were 2.23 (95% CI 1.14 to 4.34) for the illiterate and 1.68 (95% CI 1.08 to 2.62) for the primary-middle school group. The loss of more than five teeth and oral ulceration were associated with increased risks of oral cancer in all three groups. There was also a multiplicative interaction between oral hygiene and standard of education for risk of oral cancer (p=0.001). Our results suggest that oral hygiene seems to have a critical role in the risk of oral cancer in Chinese women, but this effect may be modified by their educational standard.

Acupoint herbal patching for allergic rhinitis: a systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Acupoint herbal patching (AHP) is extensively used in treatment of allergic rhinitis in China. However, existing systematic review is insufficient.

OBJECTIVE OF REVIEW

To evaluate the effectiveness and safety of AHP in treating allergic rhinitis.

SEARCH STRATEGY

We searched seven electronic databases for randomised controlled trials (RCTs) from inception until August 2014.

EVALUATION METHOD

Two authors selected studies, extracted data and evaluated risk of bias independently. The Cochrane risk of bias tool was applied to assess the methodological quality of the included trials, and RevMan 5.2 software was utilised to perform data analysis.

RESULTS

Twenty RCTs involving 2438 participants were included. Most of them were evaluated as high risk of bias. Acupoint herbal patching significantly decreased the recurrence rate at 6 months compared with Western medicine (RR 0.52; 95% CI 0.42-0.64), and similar effect was found for AHP plus Western medicine versus Western medicine (RR 0.53; 95% CI 0.44-0.65). Acupoint herbal patching appeared to be more effective than placebo in improving total clinical symptoms and signs after treatment and at 6 months, and in improving quality of life at <3 months and over 3 months. No severe adverse effects were found in the AHP groups.

CONCLUSIONS

Acupoint herbal patching alone or combined with Western medicine appears to be more effective than placebo or Western medicine, respectively. Acupoint herbal patching seems to be a safe treatment. However, the findings should be interpreted with caution. Further large-scale, rigorously designed trials are warranted to confirm the findings.

Effect of atorvastatin on plasma NT-proBNP and inflammatory cytokine expression in patients with heart failure

The aim of this study was to explore the effect of atorvastatin intervention on plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) and inflammatory cytokine levels in patients with heart failure (HF). One hundred and twenty-three HF patients were selected from our hospital and randomly divided into control (N = 61) and observation (N = 62) groups; the former received conventional treatment, while the latter were given conventional treatment combined with atorvastatin. Plasma NT-proBNP, inflammatory cytokines [high-sensitive C-reactive protein (hs-CRP), interleukin (IL)-6, IL-10] and cardiac function [left ventricular end-diastolic dimension (LVEDD), left ventricular ejection fraction (LVEF), end-diastolic maximum flow rate ratio (E/A)] were compared among groups. The effective rate of treating HF significantly increased after atorvastatin treatment. The plasma NT-proBNP, IL-6, IL-10, hs-CRP, and LVEDD levels significantly decreased (P < 0.05), while the LVEF and E/A levels significantly increased (P < 0.05) in the observation group compared to the control group and before intervention. The NT-proBNP and cytokine levels significantly differed among patients with different classes of heart function (P < 0.05); the NT-proBNP and cytokine levels increased with the severity of heart function. Pearson's correlation analysis revealed a negative correlation between the NT-proBNP and inflammatory cytokine levels and LVEF and E/A values, and a positive correlation between these factors and LVEDD (P < 0.05). In conclusion, atorvastatin significantly improves cardiac function; the mechanism atorvastatin action was related to the decrease in plasma NT-proBNP and inflammatory cytokine levels.

PTEN degradation after ischemic stroke: a double-edged sword

Tumor suppressor phosphatase and tensin homolog (PTEN) is highly expressed in neurons and PTEN inhibition has been reported to be neuroprotective against ischemic stroke in experimental models. On the other hand, PTEN deletion has been shown to lead to cognitive impairment. In the current study, we examined the expression and functions of PTEN in an ischemic stroke rodent model. We found rapid S-nitrosylation and degradation of PTEN after cerebral ischemia/reperfusion injury. PTEN degradation leads to activation of Akt. PTEN partial deletion or PTEN inhibition increased the expression of GABAA receptor (GABAAR) γ2 subunit and enhanced GABAA receptor current. After cerebral ischemia, increased expression of GABAAR γ2 subunit was observed in the ischemia region and the penumbra area. We also observed PTEN loss in astrocytes after cerebral ischemia. Astrocytic PTEN partial knockout increased astrocyte activation and exacerbated ischemic damage. We speculated that ischemic stroke induced neuronal PTEN degradation, hence enhanced GABAA receptor-medicated neuronal activity inhibition which could attenuate excitotoxicity and provide neuroprotection during the acute phase after stroke, while inhibiting long-term functional recovery and contributing to vascular cognitive impairment after stroke. On the other hand, ischemic stroke induced astrocytic PTEN loss and enhanced ischemic damage and astrogliosis. Taken together, our study indicates that ischemic stroke induces rapid PTEN degradation in both neurons and astrocytes which play both protective and detrimental action in a spatiotemporal- and cell-type-dependent manner. Our study provides critical insight for targeting PTEN signaling pathway for stroke treatment.

Analysis of oxidative modification of proteins

Protein oxidation has been implicated in a variety of degenerative diseases as well as in the aging process. This unit describes techniques for the quantification of various protein oxidation products, including protein carbonyls, loss of protein thiol groups, dityrosine and nitrotyrosine, and isoaspartate formation. Such oxidatively modified products may also be used as biomarkers for the assessment of oxidative stress during aging and/or disease.

Suicide prevention: increasing education and awareness

Suicide is a serious and complex public health problem. Health care providers, including both psychiatrists and primary care physicians, are just beginning to understand the intricacies involved in suicide and its prevention. Suicide rates continue to rise, making the education of the public and physicians regarding awareness and prevention, recognition of a wide range of risk factors, and research into suicide prevention strategies very important.

Integration of suicide prevention into outpatient management of bipolar disorder

Suicide prevention is a critical objective in the treatment of bipolar disorder. This article describes practical mechanisms by which monitoring and management of suicide risk can be integrated into the routine care of patients with bipolar disorder. Suicide risk is assessed in terms of inclination (the drive to commit a self-destructive act) and opportunity (access to lethal means). Intervention strategies are adapted to the needs of bipolar patients across 3 phases of treatment: the acute episode; the continuation phase, when symptom reduction has occurred but adaptive recovery has not; and the maintenance phase, in which optimization of adaptive function and vigilance against impending relapse are paramount. Integration of suicide prevention into the outpatient management plan begins with a routine discussion of suicide risk at the initiation of a treatment relationship, even in the absence of other known risk factors. This discussion paves the way for ongoing assessment of suicidality. Just as the recommended routine monitoring of every euthymic bipolar patient includes at least some minimal assessment for prodromal symptoms of acute mania or depression, every clinical visit can include sufficient probes to determine the need for new interventions specific to suicide prevention. Ongoing assessment of risk and protective factors can be linked to a range of individualized interventions designed to meet the varying needs of patients over time. The intensity of monitoring and interventions reflects the clinician's knowledge of risk factors and may be life saving, but it is also important that patients and others involved in their care understand that monitoring cannot guarantee safety.

Prevention of flight activity prolongs the life span of the housefly, Musca domestica, and attenuates the age-associated oxidative damamge to specific mitochondrial proteins

The purpose of this study was to explore the mechanisms by which oxidative stress affects the aging process. The hypothesis that the rate of accumulation of oxidative damage to specific mitochondrial proteins is linked to the life expectancy of animals was tested in the housefly. The rate of oxygen consumption and life expectancy of the flies were experimentally altered by confining the flies in small jars, where they were unable to fly. Prevention of flight activity decreased the rate of oxygen utilization of flies and almost tripled their life span as compared to those permitted to fly. Rate of mitochondrial H(2)O(2) generation at various ages was lower in the low activity flies than in the high activity flies. Oxidative damage to mitochondrial proteins, adenine nucelotide translocase, and aconitase, detected as carbonyl modifications, was attenuated; and the loss in their functional activity occurring with age was retarded in the long-lived low activity flies as compared to the short-lived high activity flies. The two proteins were previously identified to be the only mitochondrial proteins exhibiting age-related increases in carbonylation. Results support the hypothesis that accrual of oxidative damage to specific protein targets and the consequent loss of their function may constitute a mechanism by which oxidative stress controls the aging process.

Effects of aging and hyperoxia on oxidative damage to cytochrome c in the housefly, Musca domestica

Cytochrome c is a component of the mitochondrial electron transport chain, where it transfers electrons from ubiquinol-cytochrome c reductase to cytochrome c oxidase. Autoxidation of some of the components of the electron transport chain is the main source of intracellular O(2)(-*)/H(2)O(2) production in aerobic organisms. Because cytochrome c is located on the outer surface of the inner mitochondrial membrane, it is likely to be constantly exposed to H(2)O(2), secreted by mitochondria into the cytosol. The specific objective of this study was to determine whether cytochrome c in the flight muscle mitochondria of the housefly is oxidatively damaged during aging and/or under severe oxidative stress induced by exposure of flies to 100% oxygen. Results of two independent methods, namely tritiated borohydride labeling for determining carbonylation and mass spectral analysis for the measurement of molecular mass, indicated that neither the carbonyl level nor the molecular mass of cytochrome c was affected by aging or hyperoxia. Thus, either cytochrome c is resistant to oxidative damage in vivo or the oxidized cytochrome c is promptly degraded. These findings also support the concept that protein oxidative damage during aging and under oxidative stress is selective.

Gel electrophoretic quantitation of protein carbonyls derivatized with tritiated sodium borohydride

A method for the quantitation of protein carbonyls, which have been widely employed as markers of protein oxidative damage, is described. Protein carbonyls were derivatized with tritiated sodium borohydride and the tritiated proteins were separated on SDS-PAGE. Protein bands, visualized by Coomassie blue staining, were then excised and incubated in 30% H2O2 at 60 degrees C for 48 h. Tritium, incorporated into the proteins, was quantitated by liquid scintillation counting after gel solubilization by H2O2. This method can be applied to the measurement of carbonylation of specific proteins as it employs SDS-PAGE and has the advantage that unreacted NaB3H4 in the labeling reaction mixture need not be removed. The present method, when combined with immunochemical detection of protein carbonyls, should be very useful in the quantitation of oxidative damage to individual proteins.

Mitochondrial adenine nucleotide translocase is modified oxidatively during aging

The purpose of this study was to test the hypothesis that elevation in protein oxidative damage during the aging process is a targeted rather than a stochastic phenomenon. Oxidative damage to proteins in mitochondrial membranes in the flight muscles of the housefly, manifested as carbonyl modifications, was detected immunochemically with anti-dinitrophenyl antibodies. Adenine nucleotide translocase (ANT) was found to be the only protein in the mitochondrial membranes exhibiting a detectable age-associated increase in carbonyls. The age-related elevation in ANT carbonyl content was correlated with a corresponding loss in its functional activity. Senescent flies that had lost the ability to fly exhibited a relatively higher degree of ANT oxidation and a greater loss of functional activity than their cohorts of the same age that were still able to fly. Exposure of flies to 100% oxygen resulted in an increase in the level of ANT carbonyl content and a loss in its activity. In vitro treatment of mitochondria with a system that generated hydroxyl free radicals caused an increase in ANT carbonyl level and a decrease in ANT exchange activity. ANT was also the only mitochondrial membrane protein exhibiting adducts of the lipid peroxidation product 4-hydroxynonenal. Results of this study indicate that proteins in mitochondrial membranes are modified selectively during aging.

Identification of oxidized proteins based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunochemical detection, isoelectric focusing, and microsequencing

It has been demonstrated that an age-associated increase in protein oxidation is a highly selective rather than random phenomenon. Addition of carbonyl groups is a widely used marker for the detection of oxidative damage to the proteins. Carbonyls can be detected immunochemically using antibodies against dinitrophenylhydrazine (DNPH), a reagent that specifically reacts with protein carbonyl groups. In this paper, a procedure for the identification of oxidized proteins during aging or under pathological conditions is described. Protein samples were treated with DNPH and then separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), followed by immunochemical detection. Proteins exhibiting positive immunostain were then purified by SDS-PAGE followed by isoelectric focusing. The focused protein band was further concentrated by another run of SDS-PAGE and transferred onto Immobilon-P membrane. The identity of the protein was revealed by automated Edman microsequencing and a computer database search. This method is successfully demonstrated for the identification of housefly arginine kinase, a cytosolic protein that is involved in the energy metabolism of insect muscle cells.

Macromolecular carbonyls in human stratum corneum: a biomarker for environmental oxidant exposure?

The presence of stratum corneum carbonyls may serve as an intrinsic dosimeter for environmental oxidative damage to skin. To investigate the accumulation of carbonyls in human stratum corneum, skin was tape-stripped, then tapes were sequentially incubated with 2,4-dinitrophenyl hydrazine (DNPH), rat anti-DNP, mouse anti-rat IgG conjugated with alkaline phosphatase, p-nitrophenyl phosphate and absorbance (405 nm) measured and carbonyls estimated. Stratum corneum exposed in vitro to oxidants: hypochlorous acid (1, 10, 100 mM), ozone (0, 1, 5, 10 ppm for 2 h) or UV light (280-400 nm; 0, 4, 88, or 24 J/cm2) contained increased carbonyls. Furthermore, stratum corneum carbonyls were elevated in tanned compared with untanned sites: dorsal hand (0.43 +/- 0.06 nmol/cm2) vs. lower arm (0.32 +/- 0.04, mean +/- S.E.M., n = 11; P < 0.003) and lower back (0.26 +/- 0.02) vs. buttock (0.21 +/- 0.02; n = 6, P < 0.01) indicating in vivo oxidative damage.

UV-irradiation depletes antioxidants and causes oxidative damage in a model of human skin

The degree to which antioxidant loss occurs in human skin after UV irradiation is unknown, as is the cascade of events that might occur. We have, therefore, evaluated a tissue culture model of human skin for its usefulness for studying oxidative injury by UV-irradiation. Human skin equivalents, a tissue culture model, were irradiated using a full solar UV spectrum (UVA and UVB, 280-400 nm) (0 to 16.8 J/cm2, 0-12 minimal erythemal dose, MED), then incubated from 1 to 24 h. Ubiquinol was the most UV-light sensitive antioxidant and was depleted by 2.1 J/cm2 (1.5 MED, p < .004); ubiquinone decreased with 4.2 J/cm2 (3 MED, p < .0007). A linear decrease in alpha-tocopherol occurred--approximately 1.7 pmol tocopherol/cm2 surface were destroyed per J/cm2 UV-light. Urate was depleted by irradiation with 8.4 J/cm2 (6 MED), while ascorbate was depleted by 16.8 J/cm2 (12 MED). Cellular protein carbonyls and lactic dehydrogenase (LDH) leakage into the medium were only increased at 1 h incubation following exposure to 16.8 J/cm2 (12 MED). At 24 h incubation, PGE2 was increased in the medium of cells exposed to UV-irradiation at 0.35 J/cm2 (0.25 MED) compared with sham-exposed cells (p < .04); higher UV exposures lead to significant increases in both PGE2 (p < .001) and LDH (p < .001) in the medium. In conclusion, human skin equivalents respond to suberythemal levels of UV-irradiation by increasing production of PGE2; higher levels of UV-irradiation (at least 1 MED) were needed to deplete cellular antioxidants and induce immediately detectable oxidative damage.

The lipoic acid analogue 1,2-diselenolane-3-pentanoic acid protects human low density lipoprotein against oxidative modification mediated by copper ion

1,2-Diselenolane-3-pentanoic acid, in which the sulfur atoms of alpha-lipoic acid are replaced with selenium, displayed markedly different antioxidant properties when compared to alpha-lipoic acid. 1,2-Diselenolane-3-pentanoic acid was unable to inhibit protein oxidative modification of human low density lipoprotein (LDL) and bovine serum albumin induced by copper ion or hydroxyl radical, whereas alpha-lipoic acid showed significant protection. However, 1,2-diselenolane-3-pentanoic acid was able to inhibit the formation of lipid peroxidation products in LDL after oxidation by copper, while alpha-lipoic acid did not. Hence the diselenium compound exerts its effects in a lipophilic environment whilst lipoic acid exerts its effects in a hydrophilic environment. These differences in antioxidant activities of the two compounds may be explained, at least in part, by their differing partition coefficients.

Oxidative damage during aging targets mitochondrial aconitase

The mechanisms that cause aging are not well understood. The oxidative stress hypothesis proposes that the changes associated with aging are a consequence of random oxidative damage to biomolecules. We hypothesized that oxidation of specific proteins is critical in controlling the rate of the aging process. Utilizing an immunochemical probe for oxidatively modified proteins, we show that mitochondrial aconitase, an enzyme in the citric acid cycle, is a specific target during aging of the housefly. The oxidative damage detected immunochemically was paralleled by a loss of catalytic activity of aconitase, an enzyme activity that is critical in energy metabolism. Experimental manipulations which decrease aconitase activity should therefore cause a decrease in life-span. This expected decrease was observed when flies were exposed to hyperoxia, which oxidizes aconitase, and when they were given fluoroacetate, an inhibitor of aconitase. The identification of a specific target of oxidative damage during aging allows for the assessment of the physiological age of a specific individual and provides a method for the evaluation of treatments designed to affect the aging process.

Comparison between copper-mediated and hypochlorite-mediated modifications of human low density lipoproteins evaluated by protein carbonyl formation

The purpose of this study was to evaluate the mechanisms of apolipoprotein B (apoB) modification during oxidation of human low density lipoproteins (LDL) mediated either by copper or by hypochlorite (HOCl). The kinetics of protein carbonyl formation, the relationship of apoB carbonyl formation to lipid peroxidation, and the loss of apoB lysine residues were determined. During copper-mediated LDL oxidation, apoB carbonyls appeared to increase slowly, displayed saturation kinetics in response to increasing copper concentrations, and correlated with lipid peroxidation. During HOCl-mediated LDL oxidation, apoB carbonyls increased with increasing HOCl concentrations reaching plateau with time; however, lipid peroxidation was not observed. During copper-mediated but not during HOCl-mediated LDL oxidation, LDL vitamin E was depleted. ApoB carbonyls formed more efficiently during copper-mediated LDL oxidation at low (< 5 microM) copper concentrations compared with higher copper concentrations or during HOCl-mediated LDL oxidation. The differences in oxidation kinetics between copper- and HOCl-mediated LDL oxidation support the concept that the binding of copper to LDL is a site specific process, and suggest that HOCl modifies apoB amino acids randomly.

Apolipoprotein B carbonyl formation is enhanced by lipid peroxidation during copper-mediated oxidation of human low-density lipoproteins

To determine whether lipid peroxidation is required for apolipoprotein B (apoB) carbonyl formation of human low-density lipoproteins (LDL) during copper-mediated oxidation, we investigated oxidation of native and probucol-preloaded LDL by measuring thiobarbituric acid-reactive substances (TBARS) and apoB carbonyls. Probucol was used because it is known to inhibit lipid peroxidation, but not protein modification. During copper-mediated oxidation, apoB carbonyls formed in a time-dependent manner; high copper concentrations (> or = 30 microM) resulted in saturation of apoB carbonyl content. ApoB carbonyl formation and lipid peroxidation were linearly related during incubation of LDL with copper for 3 h. During Cu(2+)-mediated LDL oxidation of probucol-LDL, TBARS production was very low, nonetheless apoB carbonyls increased significantly, and vitamin E was depleted. Bovine serum albumin (fatty acid free; BSA) oxidation in the presence of trace amounts of LDL, linoleic acid, or tert-butyl hydroperoxide was used to further understand the role of lipid peroxidation in apoB carbonyl formation. Protein carbonyl formation during BSA incubation with copper (either Cu+ or Cu2+) was trivial; however, further addition of linoleic acid (1:1, m/m), trace amounts of LDL (10 micrograms/ml), or tert-butyl hydroperoxide (1:1, m/m) markedly increased protein carbonyl formation. These results demonstrate that lipid peroxidation enhances copper-mediated carbonyl formation and suggest that copper ions react with LDL lipid hydroperoxides producing the necessary reactive species.

Antioxidant activity of diethyldithiocarbamate

Diethyldithiocarbamate (DDC), a potent copper chelating agent, has long been used for the treatment of oxygen toxicity to the central nervous system, as an immunomodulator to treat cancer, and in HIV-infected patients. We evaluated the antioxidant properties of DDC, including its scavenging of reactive oxygen species, its reducing properties, its iron-chelating properties, and its protective effects on oxidant-induced damage to brain tissue, protein, human LDL, and DNA. It is found that DDC is a powerful reductant and antioxidant since it scavenges hypochlorous acid, hydroxyl radical and peroxynitrite; it chelates, then oxidizes ferrous ions; it blocks the generation of hydroxyl radicals and inhibits oxidative damage to deoxyribose, protein, DNA, and human LDL. These findings may provide an explanation for the apparent beneficial effects of DDC against oxidative stress-related diseases that have been observed in experimental and clinical studies.

Efficacy of hypochlorous acid scavengers in the prevention of protein carbonyl formation

We observed that protein (bovine serum albumin) carbonyl content increases upon hypochlorite oxidation, and this increase is inhibited in a concentration-dependent manner in the presence of hypochlorite scavengers. Based on this observation, we tested whether some known hypochlorite scavengers (lipoic acid, cysteine, and glutathione) and some other antioxidants (uric acid, ascorbic acid, alpha-tocopherol, and probucol) could prevent protein carbonyl formation. N-acetylcysteine, dihydrolipoic acid, cysteine, and glutathione (reduced form, GSH), which otherwise could not be tested in a previously reported 5-thio-2-nitrobenzoic acid test system, were successfully evaluated in our assay. The hypochlorite scavenging capacity of different compounds, compared by determining the IC50 (concentration which produces 50% inhibition), showed that the compounds tested have the following potency: dihydrolipoic acid > GSH, N-acetylcysteine > cysteine > S-methyl glutathione > lipoic acid, ascorbic acid > cystine, GSSG, and uric acid. No scavenging ability was observed for either alpha-tocopherol or probucol.

Efficacy of Bio-Catalyzer alpha.rho no.11 (Bio-Normalizer) supplementation against peroxyl radical-induced oxidative damage in rat organ homogenates

To better delineate the antioxidant potential of Bio-Catalyzer alpha.rho No.11 (Bio-Normalizer), a natural food supplement recently proposed as an antioxidant agent, we investigated the efficacy of Bio-Normalizer supplementation to protect rat organ homogenates against oxidative damage induced in vitro by peroxyl radicals generated in the hydrophobic or in the hydrophilic phase. Bio-Normalizer supplementation efficiently protected rat kidney homogenates against the accumulation of thiobarbituric reactive substances (TBARS), the formation of protein carbonyl derivatives and the depletion of alpha-tocopherol induced by peroxyl radicals generated from the hydrophobic azo-initiator 2,2'-azobis (2,4-dimethylvaleronitrile) (AMVN). It also protected the heart but not the liver or the brain homogenates. Bio-Normalizer supplementation did not have effect in any organ homogenates when peroxyl radicals were generated from the hydrophilic azo-initiator 2,2'-azobis (2-amidinopropane) dihydrochloride) (AAPH). In vitro direct addition of aqueous solutions of Bio-Normalizer to the organ homogenates was ineffective against AMVN or AAPH-induced oxidative damage. Our findings expand previous reports on the antioxidant activity of Bio-Normalizer. They confirm that supplemented Bio-Normalizer protects against peroxyl radical-induced oxidative damage and suggest that its antioxidant action depends on in vivo bioactivation, it is organ specific and it is limited to damage induced by peroxyl radicals generated in the hydrophobic phase.

Elucidation of antioxidant activity of dihydrolipoic acid toward hydroxyl radical using a novel hydroxyl radical generator NP-III

The photosensitive organic hydroperoxide, NP-III, which produces hydroxyl radicals on illumination by UVA light, was used to examine the antioxidant activity of dihydrolipoic acid toward hydroxyl radical. Apolipoprotein (apo-B) of human low density lipoprotein (LDL), and bovine serum albumin (BSA), were irradiated with UVA in the presence of NP-III and dihydrolipoic acid. The oxidation of BSA and apo-B of LDL by NP-III was completely inhibited by dihydrolipoic acid. ESR studies using dimethylpyrroline oxide (DMPO) as a spin trapping reagent also revealed that in the presence of dihydrolipoic acid, the DMPO-OH adduct produced from the irradiation of NP-III and DMPO completely disappeared. Hence, the scavenging activity of dihydrolipoic acid is not due to its chelating activity toward transition metals (ferrous ions). The results lead us to conclude that dihydrolipoic acid is an efficient hydroxyl radical scavenger through the direct reaction of dihydrolipoic acid with hydroxyl radical.

Bio-Catalyzer alpha . rho No. 11 (Bio-Normalizer) supplementation: effect on oxidative stress to isolated rat hearts

Bio-Catalyzer alpha . rho No. 11 (Bio-Normalizer), a natural health food product prepared by yeast fermentation of medicinal plants, has been recently reported to possess antioxidant properties. To better define its antioxidant action, we investigated the effects of orally supplemented Bio-Normalizer on oxidative damage in the rat heart. Hearts were isolated from control or Bio-Normalizer supplemented animals and 1) exposed to ischemia-reperfusion using the Langendorff technique, or 2) homogenized and exposed to peroxyl radicals generated from (2,2'-azobis (2,4'-dimethylvaleronitrile) (AMVN). During reperfusion following 40 minutes of ischemia, leakage of lactate dehydrogenase from hearts isolated from Bio-Normalizer supplemented rats was significantly lower than from hearts of control animals. Furthermore, lower levels of AMVN-induced accumulation of thiobarbituric acid reactive substances and of protein carbonyl derivatives were measured in homogenates prepared from hearts isolated from Bio-Normalizer supplemented rats than in samples from control animals. Our findings confirm an antioxidant action of Bio-Normalizer and show that it protects the heart against ischemia-reperfusion induced damage.

Ginkgo biloba extract (EGb 761) protects human low density lipoproteins against oxidative modification mediated by copper

The antioxidant effects of Ginkgo biloba extract (EGb 761) on copper-mediated human low density lipoprotein (LDL) oxidative modification were evaluated by several techniques. Human LDL (0.5 mg/ml) in phosphate buffered saline, pH 7.4, was incubated with 10 microM cupric sulfate at 37 degrees C under air for 8 hours and 24 hours in the presence of varying concentrations of EGb 761. Increases in LDL apoB carbonylation, lipid peroxidation, apoB electrophoretic mobility and LDL fluorescence were all inhibited when the incubation mixture contained EGb 761 at concentrations less than 100 micrograms/ml. This inhibition was EGb 761-concentration-dependent. Thus, EGb 761 has powerful antioxidant effects on copper-mediated LDL oxidative modification.

Oxidative DNA damage and senescence of human diploid fibroblast cells

Human diploid fibroblast cells cease growth in culture after a finite number of population doublings. To address the cause of growth cessation in senescent IMR-90 human fibroblast cells, we determined the level of oxidative DNA damage by using 8-oxoguanine excised from DNA and 8-oxo-2'-deoxyguanosine in DNA as markers. Senescent cells excise from DNA four times more 8-oxoguanine per day than do early-passage young cells. The steady-state level of 8-oxo-2'-deoxyguanosine in DNA is approximately 35% higher in senescent cells than in young cells. Measurement of protein carbonyls shows that senescent cells did not appear to have elevated protein oxidation. To reduce the level of oxidative damage, we cultured cells under a more physiological O2 concentration (3%) and compared the replicative life span to the cells cultured at the O2 concentration of air (20%). We found that cells grown under 3% O2 achieved 50% more population doublings during their lifetime. Such an extension of life span resulted from the delayed onset of senescence and elevation of growth rate and saturation density of cells at all passages. The spin-trapping agent alpha-phenyl-t-butyl nitrone (PBN), which can act as an antioxidant, also effectively delayed senescence and rejuvenated near senescent cells. The effect is dose-dependent and is most pronounced for cells at the stage just before entry into senescence. Our data support the hypothesis that oxidative DNA damage contributes to replicative cessation in human diploid fibroblast cells.

Elucidation of antioxidant activity of alpha-lipoic acid toward hydroxyl radical

The photosensitive organic hydroperoxide, NP-III, which produces hydroxyl radicals on illumination by UVA light, was used to examine the antioxidant activity of alpha-lipoic acid and its derivatives toward hydroxyl radical. Apolipoprotein (apo-B) of human low density lipoprotein (LDL) and bovine serum alubumin (BSA) were irradiated with UVA in the presence of NP-III and alpha-lipoic acid. The oxidation of BSA and the apo-B protein of LDL by NP-III was completely suppressed by alpha-lipoic acid. ESR studies using dimethylpyrroline oxide (DMPO) as a spin trapping reagent also revealed that in the presence of alpha-lipoic acid, the DMPO-OH adduct produced from the irradiation of NP-III and DMPO completely disappeared. DMPO-OH quenching experiments were performed in the presence or absence of desferoxamine but no change in the signal intensity was found. Hence, the quenching activity of alpha-lipoic acid is not due to its chelating activity toward transition metals (ferrous ions). The results lead us to conclude that alpha-lipoic acid is an efficient hydroxyl radical quencher owing to the disulfide bond in the dithiolane ring.

Induction of protein oxidation in human low density lipoprotein by the photosensitive organic hydroperoxide, N,N'-bis(2-hydroxyperoxy-2-methoxyethyl)-1,4,5,8-naphthalene-tetra-carb oxylic- diimide

We have developed a new molecular probe, N,N'-bis(2-hydroxyperoxy-2-methyoxyethyl)-1,4,5,8-naphthalen e-tetra-carboxylic- diimide (NP-III), that specifically generates hydroxyl radical upon irradiation with longer wavelength ultraviolet light (UVA). Hydroxyl radicals are generated only upon irradiation, thus NP-III is a new controllable hydroxyl radical source. Apolipoprotein (apo-B) of human low density lipoprotein (LDL), and bovine serum alubumin (BSA), were irradiated with UVA in the presence of NP-III and their oxidation was evaluated by two independent methods: assay of protein carbonyl groups and gel electrophoresis. NP-III oxidized apo-B and BSA in a time- and concentration-dependent manner. The results demonstrate that NP-III is a controllable, precise, and potentially tagetable source of hydroxyl radicals with which to induce protein oxidation.

Effects of oxygen radicals on the conformation of sulfhydryl groups on human polymorphonuclear leukocyte membranes

The healthy intact polymorphonuclear leukocytes (PMNs) were labeled with 4-maleimide-TEMPO spin labeling compound (MAL) to study the effects of oxygen radicals produced by phorbol myristate acetate (PMA)-stimulated PMNs on the conformation of sulfhydryl (SH) groups of PMN membrane proteins. The lipid peroxidation induced by PMA-stimulated PMNs was detected by evaluating the formation of malonaldehyde (MDA) with the thiobarbituric acid (TBA) test. From the experiments of luminol-dependent chemiluminescence (CL) and fluorometry, it was found that Chinese herbs schizandrin B (Sin B) and quercetin (Q) possessed scavenging properties for oxygen radicals produced during the PMN respiratory burst. These two herbs can also inhibit the conformation changes in SH binding sites on the PMN membrane proteins caused by oxygen radicals produced by the PMNs themselves. They also decreased the amount of MDA, which was a final product formed during lipid peroxidation.

ESR spin trapping studies on the free radicals in gasphase of cigarette smoking

Free radicals in the gasphase of cigarette smoke were determined by spin trapping agent PBN (N-tert-butyl-2-phenyl nitrone) and DMPO (5,5-dimethyl-1-pyrroline-oxide) on electron spin resonance spectrometer. They were identified according to the spectrum parameters calculated from the spectra. The free radicals mainly consist of alkoxyl and alkyl free radicals, of which alkoxyl free radicals make up 60-70% of the total spectral components. These free radicals are very active and reactive. They can damage cells and lead to some diseases. This work points out the importance of scavenging the free radicals of cigarette smoke to prevent diseases caused by them.