Metagenomic sequencing revealed the regulative effect of Danshen and Honghua herb pair on the gut microbiota in rats with myocardial ischemia injury

In recent years, more and more evidence has shown that the disorder of gut microbiota (GM) is closely correlated with myocardial ischemia (MI). Even though the Danshen and Honghua herb pair (DHHP) is widely used in treating cardiovascular disease in China and exhibits obvious clinical efficacy on MI, the anti-MI mechanism of DHHP remains and needs to be explored in depth. Thus, in this study, we investigated whether the amelioration effect and molecular mechanism of DHHP on MI were related to regulating GM through pharmacodynamics evaluation and metagenomic sequencing. Histopathological testing results showed that DHHP treatment could alleviate the pathological changes of myocardial tissue in the acute MI (AMI) rats induced by isoproterenol (ISO), especially structural disorder, irregular distribution, and enlargement of the myocardial space. These pathological changes were all alleviated to some extent by DHHP treatment. Biochemical analysis results suggested that compared with the control group, the serum levels of AST, CTn-I, CK-MB, and TNF-α in model group rats were notably decreased, and the CAT and SOD levels in serum were markedly increased. These abnormal trends were significantly reversed by DHHP treatment. Furthermore, metagenomic sequencing analysis results indicated that DHHP could improve disorders in the composition and function of GM in AMI rats, mainly reflected in increasing diversity and richness, and obviously enhancing the abundance of Bacteroides fluxus, B. uniformis, B. stercoris, Roseburia hominis, Schaedlerella arabinosiphila, and R. intestinalis, and reducing the abundance of Enterococcus avium and E. canintestini, which were associated with purine metabolism, tyrosine metabolism, cyanoamino acid metabolism, and glutathione metabolism. In conclusion, DHHP may attenuate ISO-induced MI by regulating the structure, composition, and function of GM, thus contributing to further our understanding of the anti-MI mechanisms of DHHP and providing new therapeutic ideas and diagnostic targets for the clinical studies of MI.

[Prevalence of albuminuria and its association with cardiovascular diseases in Chinese residents aged over 35 years]

Objective: To investigate the prevalence of albuminuria in Chinese residents aged >35 years and its potential association with cardiovascular disease (CVD). Methods: A total of 34 647 Chinese subjects aged ≥35 years were selected by stratified multi-stage random sampling from 2012 to 2015. Data were collected through questionnaires, physical examinations, and laboratory tests. Albuminuria was categorized into 3 types according to urinary albumin-to- creatinine ratio: normal (<30 mg/g), microalbuminuria (MAU, 30-300 mg/g), and macroalbuminuria (≥300 mg/g). Measurement data were expressed as x¯±s, and t-tests were used for comparisons between indicators. Qualitative data were expressed as rate or constituent ratio, and the χ² test or Kruskal-Wallis test was used to examine differences. Logistic regression was used for multivariate analyses. SAS 9.4 software was used for statistical analyses, and P<0.05 was considered statistically significant. Results: The prevalence of abnormal albuminuria was 19.1%; the prevalence was 17.2% for MAU and lower in males (13.8%) than females (20.1%, P<0.01). The risk of CVD was higher among subjects with MAU (OR=1.23, 95%CI 1.12-1.35) and macroalbuminuria (OR=1.86, 95%CI 1.50-2.32). When MAU was complicated by hypertension and diabetes mellitus, the CVD risk was 1.76 times higher. Conclusions: The prevalence of MAU is high among Chinese subjects aged 35 years and over. Those with MAU have higher CVD risk, especially those with hypertension and diabetes mellitus.

[Current status of hypertension prevalence, treatment and control rate among young and middle-aged population in China]

Objective: To estimate the prevalence, awareness, treatment and control rate of hypertension among young and middle-aged population in China. Methods: The analysis was based on the results of 2012-2015 China Hypertension Survey, which was a cross-sectional stratified multistage random sampling survey. A total of 229 593 subjects were included in the final analysis. The data including sex, age, living in urban and rural areas, prevalence of hypertension, history of stroke, family history of coronary heart disease and drinking, physical examination, heart rate were collected. Hypertension was defined as mean systolic blood pressure (SBP) ≥140 mmHg (1 mmHg=0.133 kPa), and (or) diastolic blood pressure (DBP) ≥90 mmHg, and (or) self-report a history of hypertension, and (or) use of antihypertensive medicine within 2 weeks before survey. Prehypertension was defined as SBP between 120-139 mmHg, and (or) DBP between 80-89 mmHg. Control of hypertension was considered for hypertensive individuals with SBP<140 mmHg and DBP<90 mmHg. The prevalence of prehypertension, hypertension, awareness, treatment, control rate were calculated, and the control rate among those with antihypertensive medication was also calculated. Results: The prevalence of prehypertension and hypertension was 43.8% (95%CI: 42.3%-45.4%), and 22.1% (95%CI: 20.8%-23.3%), respectively. The prevalence of prehypertension and hypertension was significantly higher among male than female across different age groups. The awareness, treatment, control rate of hypertension and control rate among treated hypertensive participants were 43.8%, 33.2%, 16.7%, and 40.2%, respectively. The prevalence was higher, and the control rate was lower among individuals with higher heart rate. Conclusion: The prevalence of prehypertension and hypertension among young and middle-aged population is high, the awareness, treatment and control rate need to be further improved in this population. The prevention and treatment of hypertension should be strengthened in the future to improve the control rate of hypertension in China.

[Investigation on status of dyslipidemia in Chinese females aged 35 years or above]

Objective: To investigate the prevalence, awareness, treatment and control status of dyslipidemia among females aged ≥35 years old across China. Methods: Participants were selected by stratified multistage random sampling method in the "Twelfth Five-Year Plan" National Science and Technology Support Project "Survey on the Prevalence of Important Cardiovascular Diseases and Key Technology Research in China" project. This study is a retrospective, cross-sectional study. A total of 17 418 females aged 35 years and over were included in the current study. The basic information such as age, medical history and menopause was collected by questionnaire. The blood lipid parameters were derived from clinical laboratory examinations. The prevalence of dyslipidemia and the rate of awareness, treatment, and control of dyslipidemia were analyzed in females aged 35 years and over. Results: The age of participants was (56.2±13.0) years old, and the prevalence of dyslipidemia was 33.1% (5 765/17 418). The prevalence rates of high total cholesterol, hypertriglyceridemia, low HDL-C and high LDL-C were 9.7% (1 695/17 418), 11.1% (1 925/17 418), 10.9% (1 889/17 418) and 7.3% (1 262/17 418), respectively. The prevalence of dyslipidemia increased with age and the prevalence of dyslipidemia in women who were not married, Han, menarche age>16 years, obesity, central obesity, alcohol consumption, diabetes, hypertension and family history of cardiovascular disease were higher than those without such characteristics (P<0.05). There were 10 432 (59.9%) menopausal females in this cohort and prevalence of dyslipidemia of these participants was 38.8% (4 048/10 432), which was higher than that of non-postmenopausal females (24.6%, 1 717/6 986) (P<0.05). The awareness rates, treatment rates and control rates of dyslipidemia were 33.9% (1 953/5 765), 15.1% (870/5 765) and 2.5% (143/5 765) respectively among females aged 35 years and over in China. Conclusion: The prevalence of dyslipidemia in Chinese females aged 35 years and over is high, and its awareness, treatment, and control rates need to be optimized.

Synchronization between frontal eye field and area V4 during free-gaze visual search

Information flow between the prefrontal and visual cortices is critical for visual behaviors such as visual search. To investigate its mechanisms, we simultaneously recorded spike and local field potential (LFP) signals in the frontal eye field (FEF) and area V4 while monkeys performed a free-gaze visual search task. During free-gaze search, spike-LFP coherence between FEF and V4 was enhanced in the theta rhythm (4-8 Hz) but suppressed in the alpha rhythm (8-13 Hz). Cross-frequency couplings during the Cue period before the search phase were related to monkey performance, with higher FEF theta-V4 gamma coupling and lower FEF alpha-V4 gamma coupling associated with faster search. Finally, feature-based attention during search enhanced spike-LFP coherence between FEF and V4 in the gamma and beta rhythms, whereas overt spatial attention reduced coherence at frequencies up to 30 Hz. These results suggest that oscillatory coupling may play an important role in mediating interactions between the prefrontal and visual cortices during visual search.

[Study of genetic etiology in fetuses with severely short limbs in the first and second trimester using whole exome sequencing]

Objective: To investigate pathogenic genes related to the phenotype of fetus with severely short limbs in the first and second trimester by whole exome sequencing (WES). Methods: Thirteen fetuses with severely short limbs detected by ultrasonography in the first and second trimester admitted in Chinese PLA General Hospital from September 2016 to June 2018 were collected. All cases were performed induced abortion, 6 of which were carried out karyotype analysis of amniotic fluid at the same time. WES and copy number variations (CNV) were performed on specimens from fetal tissues after labor induction. The suspected pathogenic mutations were validated by Sanger sequencing reactions. Results: No abnormal karyotypes or pathological CNV were found. In 10 fetuses, pathogenic or possibly pathogenic mutations were detected in the following genes: COL2A1, FGFR3, COL1A1, COL1A2, DYNC2LI1 and TRIP11, all of which were essential to skeletal development. The diagnostic yield of WES in the fetuses with severe short limbs was 10/13. Conclusions: In the first and second trimester, most of the fetuses with extremely short limbs suffer from monogenic diseases. WES is likely to be a valuable diagnostic testing option for the fetuses with severe short limbs.

Effect of NMDA on proliferation and apoptosis in hippocampal neural stem cells treated with MK-801

The purpose of the present study was to investigate effects of N-methyl-D-aspartate (NMDA) on proliferation and apoptosis of hippocampal neural stem cells (NSCs) treated with dizocilpine (MK-801). Cultures of hippocampal NSCs were randomly divided into four groups consisting of an untreated control, cells treated with MK-801, NMDA and a combination of MK801 and NMDA (M+N). Proliferative and apoptotic responses for each of the experimental groups were determined by MTS and flow cytometry. The results revealed that MK-801 and NMDA exerted significant effects on hippocampal NSCs proliferation. Cell survival rates decreased in MK-801, NMDA and M+N treated groups compared with the control group. Cells survival rates in NMDA and M+N treated groups increased compared with the MK-801 treated group. MK-801 and NMDA were demonstrated to significantly affect apoptosis in hippocampal NSCs. Total and early stages of apoptosis in MK-801 and NMDA groups significantly increased compared with the control group. Total and early apoptosis of NSCs in the M+N group significantly decreased compared with MK-801 and NMDA groups. Late apoptosis of NSCs in MK-801 and NMDA groups significantly decreased compared with the control group. Late apoptosis of NSCs in the M+N group significantly increased compared with MK-801 and NMDA groups. The present study revealed that MK-801 inhibited proliferation and increased apoptosis in hippocampal NSCs. NMDA may reduce the neurotoxicity induced by MK-801, which may be associated with its activity towards NMDA receptors and may describe a novel therapeutic target for the treatment of schizophrenia.

Dihydroartemisinin alleviates oxidative stress in bleomycin-induced pulmonary fibrosis

AIMS

Dihydroartemisinin has been shown to inhibit the development of pulmonary fibrosis in rats, but its mechanism has yet to be elucidated. This study aimed to determine the mechanisms of dihydroartemisinin in bleomycin-induced pulmonary fibrosis in a rat model.

MAIN METHODS

Morphological changes and collagen deposition were analyzed via hematoxylin-eosin staining and Masson staining and the expression of biotic-factor-related oxidative stress in lung tissues was assayed with standard assay kits. The expressions of α-SMA, E-cadherin, and Nrf2/HO-1 were detected by Western blot and RT-PCR, and the cell morphology and proliferation of cultured type II alveolar epithelial cells (AECs) were assessed via microscopy and immunocytochemical assay.

KEY FINDINGS

Dihydroartemisinin treatment significantly decreased the level of oxidative stress and collagen synthesis and inhibited AECs differentiation in bleomycin-induced pulmonary fibrosis compared to the control group (P < 0.001).

SIGNIFICANCE

Our results indicated that dihydroartemisinin might decrease oxidative damage to attenuate lung injury and fibrosis.

Expression of NR1 and apoptosis levels in the hippocampal cells of mice treated with MK‑801

The aim of the present study was to investigate the characteristics of N‑methyl‑D‑aspartate receptor R1 (NR1) expression and apoptosis in the nerve cells of the hippocampus in schizophrenia‑like mice. C57BL/6 mice were randomly allocated to the following groups: i) Blank group; ii) MK‑801 group; iii) MK‑801+NMDA group, according to body weight. The NMDAR antagonist, MK‑801 (0.6 mg/kg/d) was intraperitoneally injected daily for 14 days to induce a schizophrenia‑like phenotype mouse model, and the effect of the NMDA injection via the lateral ventricle was observed. The results demonstrated that the number of NR1 positive cells in the MK‑801 group increased in the CA1 and DG regions, indicating that NMDA may reverse this change. The level of damage decreased in the MK‑801 treated group when compared with the blank group in the CA3 region. The protein expression of NR1 increased however, at the mRNA expression level, NR1 was lower in the MK‑801 treated group when compared to the blank group; NMDA also reversed this change. In addition, early and total apoptosis detected in the hippocampal nerve cells was significantly increased in the MK‑801 group when compared with the blank group, which was reversible following treatment with NMDA. These results indicated that NMDA may regulate the expression of NR1 and suppress apoptosis in hippocampal nerve cells in schizophrenia‑like mice. Thus, NR1 may be a promising therapeutic target for the treatment of schizophrenia.

Analysis of Clinicopathological Features and Prognostic Factors in 39 Cases of Bladder Neuroendocrine Carcinoma

AIM

Through analysis and summarization of clinicopathological features, immunohistochemical expression, pathological diagnostic criteria, prognostic and other factors in patients suffering from bladder neuroendocrine carcinoma (BNEC), a better understanding of BNEC could be achieved to provide solid evidence for clinicopathology and prognosis.

MATERIALS AND METHODS

The clinicopathological data of 39 cases of BNEC with up to 5-year follow-up data (median follow-up=650 days) were analyzed retrospectively based on immunohistochemical staining. Survival analyses were carried out using the Kaplan-Meier method and tested with the log-rank method. Multivariate Cox regression analysis was adopted to screen independent risk factors affecting patients' survival. In these 39 cases of BNEC, there were 26 cases of male patients, 13 female, with the proportion of male to female being 2:1. The ages of onset ranged from 44 to 86, with the median age being 62 and the average age 61.97 years, respectively. Histologically, referring to the WHO standard of neuroendocrine lung tumor classification, there were 7 cases of typical carcinoid tumors, 8 atypical carcinoid, 12 small-cell carcinomas and 12 large-cell carcinomas. In these cases there were 11 cases of featured urothelium carcinomas and 9 cases of adenocarcinomas.

RESULTS

Immunohistochemical staining showed that, in these 39 cases of BNEC, the positive expression for the neuroendocrinic markers, including neural cell adhesion molecule 56 (CD56), synaptophysin (Syn), chromogranin A (CgA), neuron-specific enolase (NSE), thyroid transcription factor-1 (TTF-1), cytokeratin (CK) and cytokeratin 7 (CK7), accounted for 39/39, 27/39, 18/39, 39/39, 19/39, 10/39 and 8/39, respectively. In contrast, cytokeratin 20 (CK20), protein 63 (P63), human melanoma black 45 (HMB45), S-lfln protein 100 (S-100) and leukocyte common antigen (LCA) were all negatively expressed. During the follow-up period, 12 patients died. The 1-, 3- and 5-year overall survival (OS) rates were 76.92%, 74.36% and 69.23%.

CONCLUSION

BNEC is one of the most malignant tumors with severe invasiveness and poor prognosis. Immunohistochemistry revealed that CD56, Syn, CgA, NSE, TTF-1, CK, CK7, CK20, P63, HMB45, S-100 protein and LCA immune markers play important roles in diagnosis and differentiation. Many factors, including the patient's age, size and shape of the tumor, operative method, perineuronal invasion, vascular invasion, distant organ metastasis and pathological type, show great difference in influencing OS time of patients, among which the size of the tumor, no invasion, vascular invasion and distant organ metastasis are independent risk factors affecting prognosis (survival time). Radical cystectomy is the prior alternative to treat this tumor.

[Clinical analysis of 21 cases with short fetal femur in the third trimester]

Objective: To analyze the clinical features and to explore the etiology of short fetal femur during the third trimester. Methods: From January 2010 to June 2016, 21 singleton pregnancies with short fetal femur detected by ultrasonography during the third trimester were referred to the Chinese PLA General Hospital. Clinical data were collected, karyotype or single nucleotide polymorphism microarray was carried out to detect chromosomal abnormalities, and FGFR3 c.1138G>A mutation detection was carried out to detect achondroplasia (ACH) via invasive procedure, respectively. The deviation of femur length from the mean value of the gestational age in ultrasonography was expressed as the Z-score. The difference between ACH and isolated short femur (ISF, in the absence of associated structure abnormality or genetic abnormality) was then explored. Results: In the 21 fetuses, 11 had abnormal genetic test results(52%, 11/21), including 9 cases of ACH, 1 case of Ellis-van Creveld Syndrome and 1 case of Pallister-Killian syndrome. In the 10 ISF fetuses (48%, 10/21), 3 cases were fetal growth restriction, 1 was normal small for gestational age infant and 6 cases were unexplained. The median Z-scores for 9 cases of ACH and 10 cases of ISF in the third trimester were -5.04, -3.20, respectively. The short femur in ACH was more severe than in ISF (P=0.005) in the third trimester. Conclusions: The etiology of short fetal femur is complicated, including skeletal dysplasia, chromosomal abnormality, fetal growth restriction, as well as normal variants during fetal development. Genetic test should be considered during the antenatal consultation.

Nickel oxide nanoparticles induced pulmonary fibrosis via TGF-β1 activation in rats

Nano nickel oxide (NiO), widely used in industry, has recently been discovered to have pulmonary toxicity. However, no subchronic exposure studies about nano NiO-induced pulmonary fibrosis have been reported. The objective of this study was to investigate pulmonary fibrosis induced by nano NiO and its potential mechanism in rats. Male Wistar rats ( n = 40, 200–240 g) were randomized into control group, nano NiO groups (0.015, 0.06, and 0.24 mg/kg), and micro NiO group (0.024 mg/kg). All rats were killed to collect lung tissue after intratracheal instillation of NiO particles twice a week for 6 weeks. To identify pulmonary fibrosis, Masson trichrome staining, hydroxyproline content, and collagen protein expression were performed. The results showed widespread lung fibrotic injury in histological examination and increased content of hydroxyproline, collagen types I and III in rat lung tissue exposed to nano NiO. To explore the potential pulmonary fibrosis mechanism, transforming growth factor beta 1 (TGF- β1) content was measured by enzyme-linked immunosorbent assay, and the messenger RNA expression of key indicators was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The TGF- β1 content was increased in nano NiO exposure groups, as well as the upregulated gene expression of TGF- β1, Smad2, Smad4, matrix metalloproteinase, and tissue inhibitor of metalloproteinase. The findings indicated that nano NiO could induce pulmonary fibrosis, which may be related to TGF- β1 activation.

Associations between markers of colorectal cancer stem cells, mutation, microRNA and the clinical features of ulcerative colitis

AIM

Several factors have been implicated in the pathogenesis of colorectal cancer (CRC) associated with ulcerative colitis (UC). We investigated markers of cancer cell pluripotency, including CD44 and CD166, microRNA-21 (miR-21) and microRNA-215 (miR-215), and APC, K-ras and DCC mutations in biopsy specimens from patients with UC to evaluate any correlations with clinical risk factors.

METHOD

We observed 18 patients with UC and collected two biopsy specimens from each patient at diagnosis and at a follow-up end-point. We examined the expression of CD44, CD166, miR-21 and miR-215, and APC, K-ras and DCC mutations. We compared these markers at the two time points and assessed their associations with clinical characteristics, including the duration of colitis, histological alterations and the age of the patient at the onset of UC.

RESULTS

Most (16/18) patients had alleviation of mucosal inflammation or remained stable during follow-up; one patient developed dysplasia and one had severe aggravation of the lesion during follow-up. Enhanced expression of CD44, CD166 and miR-21 with miR-215 was found in the specimens obtained at follow-up, despite alleviation of mucosal lesions. Coherence of cancer stem cell markers and miRNAs was seen in patients who had significant worsening of inflammation, dysplasia and a long duration of colitis. APC mutation occurred in only one patient; this patient had the longest duration of UC (23 years).

CONCLUSION

Enhanced markers of CRC in follow-up colonic mucosal samples support the conclusion that the duration of UC plays the most important role in UC-related carcinogenesis.

Effect of gene polymorphims on the warfarin treatment at initial stage

The adverse reactions of warfarin that were found mainly occurred in the first month. This study was carried out to observe the effect of gene polymorphisms on the warfarin therapy at the initial stage. Four-hundred and sixty Chinese patients began warfarin treatment with daily 2.5 mg after heart valve replacement operations were enrolled. The daily international normalized ratio (INR) for anticoagulation were recorded till the seventh day. Blood samples were collected and used to detect genotypes for VKORC1 rs7294, CYP2C9 rs1057910, CYP4F2 rs2108622 and ORM1 rs17650. INR and their changes were compared among genotypes. INR was partially correlated with the VKORC1 rs7294, CYP2C9 rs1057910, CYP4F2 rs2108622 and ORM1 rs17650 polymorphisms from the third, fourth and sixth day on, respectively. VKORC1 rs7294 and CYP4F2 rs2108622 carriers responded lower than the wild genotype, whereas CYP2C9 rs1057910 and ORM1 rs17650 carriers responded higher, respectively. Fifty percent of AA/*1*3/CC/*S*S patients and 16% of AA/*1*1/CC/*S*S patients were over anticoagulation treated with INR >4.0 at the third day. Ninety percent of VKORC1 rs7294 carrier patients have INR <1.63, a mark of the 25% of lower responders of the wild genotype. Our study provided another kind of evidence that VKORC1 rs7294, CYP2C9 rs1057910, CYP4F2 rs2108622 and ORM1 rs17650 affected the action of warfarin in different styles. Patients with AA/*1*1/CC/*S*S, AA/*1*3/CC/*S*S should use a less initial dosage to avoid over anticoagulation, and patients with VKORC1 rs7294 should use larger initial dose to proof an effective therapy.

The influence of cytidine deaminase -33delC polymorphism on treatment outcome with high-dose cytarabine in Chinese patients with relapsed acute myeloid leukaemia

WHAT IS KNOWN AND OBJECTIVE

Identification of biomarkers that could predict high-dose cytarabine (Ara-C) efficacy and toxicity is a key issue in individualized therapy. The aim of our study was to evaluate the influence of cytidine deaminase (CDA) single nucleotide polymorphisms (SNPs) -451G>A (rs532545), 435C>T (rs1048977) and -33delC (rs3215400) on treatment outcome in patients with relapsed acute myeloid leukaemia (AML) after high-dose Ara-C chemotherapy.

METHODS

In total, 173 patients with relapsed AML, treated with high-dose Ara-C chemotherapy, were genotyped for three polymorphisms in CDA gene using the allele-specific matrix-assisted laser desorption/ionization time-of-flight mass spectrometry assays. Binary logistic regression was used to evaluate the influence of selected polymorphisms on tumour response and occurrence of treatment-related toxicity.

RESULTS AND DISCUSSION

The CC genotype at -33delC, a promoter polymorphism, increased the odds of overall response rate (odds ratio [OR] = 5·125; 95% confidence intervals (CI) = 2·446-10·74; P = 0·0008) and grade ≥3 infection toxicity incidence rate (OR = 3·572; 95% CI = 1·68-7·594; P = 0·003). In multivariable analysis, this polymorphism was a potential independent prognostic marker for the risk of overall response (P = 0·011), but not grade ≥3 infection toxicity incidence rate (P = 0·49). Two other polymorphisms, -451G>A and 435C>T, did not influence treatment outcome, including overall response rate, infection toxicity and nausea/vomiting, in patients with relapsed AML (P > 0·05).

WHAT IS NEW AND CONCLUSION

The findings suggest that CDA -33delC variant might be a potential marker for predicting treatment outcome in Chinese patients with relapsed AML given high-dose cytarabine chemotherapy.

Reduced expression levels of let-7c in human breast cancer patients

Circulating microRNAs (miRNAs) are important in the diagnosis of a number of diseases, since serum or plasma miRNAs are more stable compared with miRNA isolated from blood samples. The aim of the present study was to investigate the association between the expression levels of serum let-7c miRNA and the clinical diagnosis of breast cancer (BC). The circulating let-7c levels of 90 BC patients and 64 healthy controls were determined by performing a reverse transcription-quantitative polymerase chain reaction assay. The results demonstrated that let-7c expression was downregulated in the BC tissues compared with the paracarcinoma control tissues. In addition, the let-7c expression in the serum of BC patients was significantly lower compared with the healthy controls (P<0.01). Using a cutoff value of 0.374×10³ copies/ml, the serum expression levels of let-7c exhibited 87.5% sensitivity and 78.9% specificity for distinguishing BC patients from healthy controls (area under the receiver operating characteristic curve, 0.848; 95% confidence interval, 0.785-0.911). Furthermore, the results demonstrated that the serum expression levels of let-7c were significantly higher in premenopausal compared with postmenopausal patients (P<0.05), supporting the hypothesis that postmenopausal status may affect the serum expression levels of let-7c. However, no statistically significant differences were detected in the serum levels of let-7c between ER (or PR)-positive and -negative patients. Therefore, the current study hypothesized that serum let-7c may be used as a novel and valuable biomarker for the diagnosis of BC.

Higher expression of circulating miR-182 as a novel biomarker for breast cancer

MicroRNAs (miRNAs), present in the serum in a stable and reproducible manner, may be used as biomarkers for various diseases. Few studies have previously investigated circulating miRNAs in the peripheral blood of breast cancer (BC) patients. To identify the role of serum miR-182 levels in BC, the present study detected miR-182 levels in the serum of 46 BC patients and 58 controls, by quantitative PCR. The results showed that the serum miR-182 levels in BC patients were significantly higher compared with the serum of healthy controls (P<0.01). The miR-182 was also overexpressed in the BC tissues compared with the para-carcinoma tissues. Furthermore, the serum levels of miR-182 in the estrogen receptor (ER)-positive patients were considerably lower compared with those in the ER-negative patients. The serum levels of miR-182 in the progesterone receptor (PR)-positive patients were also found to be lower compared with those in the PR-negative patients. The current study highlights results consistent with miR-182 as a novel and valuable biomarker for the diagnosis of BC.

[The analysis of Leber's hereditary optic neuropathy associated with mitochondrial tRNAAla C5601T mutation in seven Han Chinese families]

We reported here the clinical, genetic, and molecular characterization of Leber's hereditary optic neuropathy (LHON) with C5601T mutation in seven Chinese families. The ophthalmologic examinations of seven Chinese families who were clinically diagnosed LHON were conducted. Strikingly, these families exhibited very low penetrance of visual impairment, and the penetrance was 9.5%, 14.3%, 4.5%, 8.3%, 10.0%, 22.2% and 25.0%. Meanwhile, entire mitochondrial genome of seven probands was amplified by PCR using 24 pairs of oligonucleotide primers with overlapping fragments. Molecular analysis of mitochondrial DNA (mtDNA) in these pedigrees revealed the absence of three common LHON associated G11778A, G3460A and T14484C mutations but the presence of homoplastic LHON associated tRNAAla C5601T mutation in probands and other matrilineal relatives. These mtDNA polymorphism sites belongs to the Asian haplogroups G2, G2a1, G2a1, G2, G2b, G2a1 and G2. By analyzing mitochondrial genome, seven LHON families all carry the C5601T mutation. The C5601T mutation occurs at the highly conserved nucleotide (conventional position 59) of tRNAAla, thereby contributing to the structural formation and stabilization of functional tRNAs and leading to mitochondrial dysfunction involved in visual impairment. The incomplete penetrance of visual loss in these seven Chinese pedigrees strongly indicates that the tRNAAla C5601T mutation was itself insufficient to produce a clinical phenotype. The lack of functional mtDNA variants in these pedigrees ruled out the role of mitochondrial background in the phenotypic expression of visual loss. Therefore, nuclear backgrounds and environmental factors seem to be modifying factors for the phenotypic manifestation of the tRNAAla C5601T mutation in the seven Chinese families.

Development and comparison of a new personalized warfarin stable dose prediction algorithm in Chinese patients undergoing heart valve replacement

BACKGROUND

Pharmacogenetics-based algorithms would be especially desirable for patients undergoing heart valve replacement (HVR), who are particularly sensitive to warfarin during the initial treatment phase following surgery. We aimed to derive a warfarin dosing algorithm from data of Chinese patients undergoing HVR, and to compare it with previously published dosing algorithms as applied to our HVR patients.

METHODS

641 Chinese HVR patients on stable maintenance dose of warfarin were enrolled from a single clinic site. Data of 321 patients were used to derive a warfarin dosing algorithm using stepwise multiple linear regression analysis. Previously published algorithms were selected from Pubmed database for comparison. The performance of all the algorithms was characterized according to mean absolute error (MAE) and percentage of predicted doses falling within +/- 20% of clinically observed doses (percentage of ideal prediction) in the other 320 patients.

RESULTS

The newly developed algorithm included eight factors: VKORC1-1639G > A, CYP2C9*3, BSA, age, number of increasing INR drugs, smoking habit, preoperative stroke history and hypertension. Our algorithm accounted for 56.4% of variations in the inter-patient warfarin stable doses. All the algorithms showed better performance in a medium-dose (1.88-4.38 mg/day) and high-dose (> or = 4.38 mg/day) groupings than in a low-dose (< or = 1.88 mg/day) grouping. Compared with the 14 previously published algorithms, our algorithm had the lowest MAE (-0.07 mg/day) and the highest percentage of ideal prediction (62.8%) in the total validation cohort.

CONCLUSIONS

Our warfarin dosing algorithm is potentially useful for patients whose population profiles are similar to those of our patients.

Clinical features of primary biliary cirrhosis: An analysis of 114 cases

AIM: To summarize the clinical characteristics of primary biliary cirrhosis (PBC) and to explore the clinical significance of serum anti-mitochondrial antibodies (AMAs) in the diagnosis and assessment of severity of PBC.

METHODS: A retrospective analysis of clinical manifestations, serum biochemical parameters, serum antibodies and pathological features was performed in 114 patients with PBC. M2 antibody-positive patients (105 cases) were divided into four groups: those positive for only M2 (61 cases), for both M2 and M9 (9 cases), for both M2 and M4 (25 cases), and for M2, M4, and M9 (10 cases). Serological markers and complications were compared among the four groups.

RESULTS: Main clinical manifestations of PBC include fatigue, jaundice, and skin itching. The levels of alkalinity phosphatase (ALP), γ-glutamyl transpeptidase (GGT), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin (TBIL) increased to varying degrees. Serum AMA and M2 antibodies had a very high specificity and sensitivity in diagnosing PBC. Compared to the M2-positive group, the levels of ALP and IgM in M2-M4-positive group were higher (P = 0.010, 0.014, P < 0.05). Compared to the M2-M9-positive group, the levels of AST, TBIL, and IgG in the M2-M4-M9 positive group were higher (P = 0.039, 0.016, 0.039, P < 0.05). Compared to the M2-positive group, the level of TBIL in the M2-M4-M9 positive group was higher (P = 0.023, P < 0.05). Compared to the M2-M9 positive group, the level of IgG in the M2-positive group was higher (P = 0.031, P < 0.05). Thus, serum M4 and M9 levels have clinical significance in the diagnosis of PBC.

CONCLUSION: Understanding the clinical characteristics of PBC can help improve the diagnosis, treatment, and prognosis of this disease.

Significance of BISAP combined with coagulation parameters in predicting the severity of acute pancreatitis

AIM: To explore the significance of BISAP (bedside index for severity in AP) combined with coagulation parameters in predicting the severity of acute pancreatitis (AP).

METHODS: One hundred and sixty-six patients with AP who were admitted to Shengjing Hospital of China Medical University from 2008 to 2012 were included in this study. The BISAP and APACHE-Ⅱ scores were calculated using data from the first 24 h from admission and the Ranson's score using data from the first 48 h. CTSI was calculated in patients who underwent CECT within 72 h from onset. The activated partial thromboplastic time (APTT), prothrombin time (PT), D-dimer, fibrinogen (FIB) and platelet (PLT) were measured within the first 24 h from admission. The area under the receiver operating characteristic (ROC) curve (AUC) was calculated to explore the significance of BISAP combined with coagulation parameters in predicting the severity of AP.

RESULTS: Multivariate Logistic regression analysis showed that D-dimer was an independent predictor of the severity of AP. Increased BISAP score is associated with an increased risk of severe AP (SAP). Taking 2 as the cutoff value for SAP, we obtained the maximum Youden index. The AUC for BISAP in predicting SAP was 0.836 (95%CI: 0.776-0.896), and the BISAP score performed similar to the three "traditional" scoring systems. BISAP score combined with D-dimer (BISAP^+D) could improve the predictive validity.

CONCLUSION: BISAP score is an accurate means for predicting the severity of AP, and BISAP^+D score may enhance the accuracy of early prediction of SAP.

Cognitively directed spatial selection in the frontal eye field in anticipation of visual stimuli to be discriminated

Single neuron activity was recorded in the frontal eye field (FEF) of monkeys trained to perform a difficult luminance discrimination task. The appearance of a cue stimulus informed the monkeys of the locations of two gray luminance stimuli that would appear within 500-1500ms. The monkeys were rewarded for making a saccade to the brighter of the two luminance stimuli, or if they were the same luminance, for making a saccade to the cue stimulus. Sixty percent (51/85) of FEF neurons exhibited elevated activity when the cue informed the monkeys that one of the luminance stimuli would appear in their response field (RF). This spatially selective anticipatory activity occurred without any visual stimulus appearing in their RF and was not related to saccade choice or latency. The responses of 27 of the anticipatory neurons (32% of the total sample) were also incompatible with the hypothesis that the activity represents saccade probability because they did not exhibit elevated activity for the cue stimulus which was the most probable saccade target. Behaviorally, monkeys exhibited improved perception at locations informed by cue than at unpredictable locations. These results provide physiological evidence that FEF serves an important role in endogenous spatial attention in addition to its well-known role in saccade production.

Association of CYP3A4*18B polymorphisms with the pharmacokinetics of cyclosporine in healthy subjects

The aim of this study is to evaluate the association of the CYP3A4*18B genotype with the cyclosporine metabolism in healthy subjects. We employed PCR-RFLP assays for analysis of the CYP3A4*18B genotype. Each of 26 subjects, comprising 12 CYP3A4*1/*1, 12 CYP3A4*1/*18B and 2 CYP3A4*18B/*18B, was given a single oral dose of cyclosporine (4 mgkg(-1)). The plasma concentrations of cyclosporine were measured for up to 24 h post dose by high-performance liquid chromatography-electrospray mass spectrometry. We found that the mean Cmax (95% confidence intervals) of cyclosporine were 2237 (2905, 1859) (*1/*1), 2247 (2916, 1869) (*1/*18B), and 905 (1192, 506) ng ml(-1) (*18B/*18B)(p = 0.037) and the mean AUCO-4 were 5026 (6181, 4372) (*1/*1), 4434 (5481, 3841) (*1/*18B) and 2561 (3155, 1736) ng ml(-1) h (*18B/*18B) (p=0.021). The CL in the *18B/*18B group was significantly higher than in the *1/*1 group. However, Tmax exhibited no difference among the three genotypes. *18B/*18B group showed 50% reduction in concentration at 2 h post dose compared with *1/*18B (p = 0.062) or *1/*1 (p = 0.047), but no statistical significance was detected between*1/*1 and *1/*18B groups (p > 0.05). The data suggest that the CYP3A4*18B genotype affects cyclosporine pharmacokinetics probably resulting from a higher enzymatic activity of this mutation in healthy subjects.

Preparation and electrocatalytic properties of Pt–SiO2 nanocatalysts for ethanol electrooxidation

Due to their high stability in general acidic solutions, SiO(2) nanoparticles were selected as the second catalyst for ethanol oxidation in sulfuric acid aqueous solution. Pt-SiO(2) nanocatalysts were prepared in this paper. The micrography and elemental composition of Pt-SiO(2) nanoparticles were characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy, respectively. The electrocatalytic properties of Pt-SiO(2) nanocatalysts for ethanol oxidation were investigated by cyclic voltammetry. Under the same Pt loading mass and experimental conditions for ethanol oxidation, Pt-SiO(2) nanocatalysts show higher activity than PtRu/C (E-Tek), Pt/C (E-Tek), and Pt catalysts. Additionally, Pt-SiO(2) nanocatalysts possess good anti-poisoning ability. The results indicate that Pt-SiO(2) nanocatalysts may have good potential applications in direct ethanol fuel cells.

Pharmacokinetics and bioavailability of florfenicol following intravenous, intramuscular and oral administrations in rabbits

This study examined the disposition kinetics and bioavailability of florfenicol after intravenous (i.v.), intramuscular (i.m.) and oral administration to rabbits at a dose of 30 mg/kg BW. Serial blood samples were collected through an indwelling catheter intermittently for 24 h for various routes. Plasma antibacterial concentrations were determined using a microbiological assay method with Bacillus subtilis ATCC 6633 as a reference organism. Plasma concentration-time data generated in the present study were analysed by non-compartmental methods based on statistical moment theory. Following i.v. administration, the overall elimination half-life (t1/2beta) was 1.54 h, mean residence time (MRT) was 1.69 h, mean volume of distribution at steady-state (Vdss) was 0.57 L/kg, and total body clearance (Cltot) was 0.34 L/kg/h. After i.m. and oral dosing, the terminal part of the curve should correspond to the absorption phase, instead of to the elimination phase, with terminal half-lives of 3.01 and 2.57 h, respectively. The mean absorption time (MAT) was 2.65 h for i.m. and 2.01 h for oral administration. Elimination rate constants differed with i.v., i.m. and oral administrations, suggesting a flip-flop situation. The observed mean peak plasma concentrations (Cmax obs) were 21.65 and 15.14 microg/ml achieved at a post-injection time (Tmax obs) of 0.5 h following i.m. and oral dosing, respectively. The absolute systemic availabilities were 88.25% and 50.79%, respectively, and the extent of plasma protein binding percent was 11.65%.

Regularity of distribution of immunoreactive pulmonary surfactant protein A in rat tissues

Existing data has shown that SP-A-like protein or mRNA is widely distributed in lamellar bodies such as tissues and mucosal surfaces. Using immunohistochemistry method with a polyclonal antibody against human SP-A, in this study we investigated distribution of immunoreactive pulmonary surfactant protein A (IR-SP-A) in a number of rat tissues. The SP-A-like immunoreactivity was found in alveolar, parenchyma, pleura of lung; myelin sheath of brain; epithelia of Bowman's capsule, glomerulus and renal tubules of kidney; epithelia of colon, stomach, duct of salivary gland, pharynx; and blood vessel wall and connective tissue of extracellular matrix. The positive signal was blocked by pre-absorbed SP-A antigen from recombinant or bronchoalveolar lavage (BAL). SP-A has long been considered as an important frontier host defense molecule which participates in immune and inflammatory regulation of lung. With every inhalation, small particles, viruses, bacteria, and antigens from environment are continuously deposited onto the vast pulmonary epithelial surface. While a proper host defense is required to protect the lung, an over-exuberant response can disrupt the appropriate balance between pro- and anti-inflammatory. Traditional Chinese medicine believes that body is an open system relevant to the external environment. The physical, chemical and biological environmental factors constantly affect the open system, and the body properly reacts to maintain homeostasis of body machinery. The Chinese traditional medicine scholars have thus hypothesized that 'Qi' (meaning air) is the communication way between the body and external environment. What is 'Qi'? The results from our study suggest that IR-SP-A is a candidate of 'Qi'. It is compatible with the sites, theoretically containing collagenous and lectin domain molecules, also compatible with the primary injury sites of some autoimmune diseases. SP-A may be as one of 'Qi' molecules mentioned in traditional Chinese medicine that trigger some of autoimmune diseases.

Foveal versus full-field visual stabilization strategies for translational and rotational head movements

Because we view the world from a constantly shifting platform when our head and body move in space, vestibular and visuomotor reflexes are critical to maintain visual acuity. In contrast to the phylogenetically old rotational vestibulo-ocular reflex (RVOR), it has been proposed that the translational vestibulo-ocular reflex (TVOR) represents a newly developed vestibular-driven mechanism that is important for foveal vision and stereopsis. To investigate the hypothesis that the function of the TVOR is indeed related to foveal (as opposed to full-field) image stabilization, we compared the three-dimensional ocular kinematics during lateral translation and rotational movements with those during pursuit of a small moving target in four rhesus monkeys. Specifically, we tested whether TVOR rotation axes tilt with eye position as in visually driven systems such as pursuit, or whether they stay relatively fixed in the head as in the RVOR. We found a significant dependence of three-dimensional eye velocity on eye position that was independent of viewing distance and viewing conditions (full-field, single target, or complete darkness). The slopes for this eye-position dependence averaged 0.7 +/- 0.07 for the TVOR, compared with 0.6 +/- 0.07 for visually guided pursuit eye movements and 0.18 +/- 0.09 for the RVOR. Because the torsional tilt versus vertical gaze slopes during translation were slightly higher than those during pursuit, three-dimensional eye movements during translation could partly reflect a compromise between the two different solutions for foveal gaze control, that of Listing's law and minimum velocity strategies. These results with respect to three-dimensional kinematics provide additional support for a functional difference in the two vestibular-driven mechanisms for visual stability during rotations and translations and establish clearly the functional goal of the TVOR as that for foveal visual acuity.

Motor scaling by viewing distance of early visual motion signals during smooth pursuit

The geometry of gaze stabilization during head translation requires eye movements to scale proportionally to the inverse of target distance. Such a scaling has indeed been demonstrated to exist for the translational vestibuloocular reflex (TVOR), as well as optic flow-selective translational visuomotor reflexes (e.g., ocular following, OFR). The similarities in this scaling by a neural estimate of target distance for both the TVOR and the OFR have been interpreted to suggest that the two reflexes share common premotor processing. Because the neural substrates of OFR are partly shared by those for the generation of pursuit eye movements, we wanted to know if the site of gain modulation for TVOR and OFR is also part of a major pathway for pursuit. Thus, in the present studies, we investigated in rhesus monkeys whether initial eye velocity and acceleration during the open-loop portion of step ramp pursuit scales with target distance. Specifically, with visual motion identical on the retina during tracking at different distances (12, 24, and 60 cm), we compared the first 80 ms of horizontal pursuit. We report that initial eye velocity and acceleration exhibits either no or a very small dependence on vergence angle that is at least an order of magnitude less than the corresponding dependence of the TVOR and OFR. The results suggest that the neural substrates for motor scaling by target distance remain largely distinct from the main pathway for pursuit.

Assessment of cytochrome P450 activity by a five-drug cocktail approach

OBJECTIVES

Our goal was to establish and validate a modified cocktail approach including probe drugs caffeine, chlorzoxazone, mephenytoin, metoprolol, and midazolam for simultaneous phenotyping of CYP1A2, CYP2E1, CYP2C19, CYP2D6, and CYP3A.

METHODS

The study was conducted in 14 healthy, nonsmoking male volunteers with a cocktail of 5 drugs consisting of 100 mg caffeine, 200 mg chlorzoxazone, 100 mg mephenytoin, 100 mg metoprolol, and 7.5 mg midazolam in a randomized manner with a 7 x 7 Latin square design. Plasma was obtained at 1, 4, and 6 hours, and urine was collected from 0 to 8 hours after oral drug administration.

RESULTS

The phenotypic indexes determined for caffeine, chlorzoxazone, mephenytoin, metoprolol, and midazolam were not significantly different when the drugs were given in different combinations. There were no metabolic interactions or analytic interference of these probe drugs.

CONCLUSIONS

This cocktail approach can simultaneously provide independent in vivo phenotypic measures for the cytochrome P450 (CYP) enzymes CYP1A2, CYP2E1, CYP2C19, CYP2D6, and CYP3A.

CYP2C19 genotype determines enzyme activity and inducibility of S-mephenytoin hydroxylase

BACKGROUND

The association between decreased drug clearance and decreased activity of cytochrome P4502C19 (CYP2C19), the inherited nature of the deficiency, and its frequency and clinical importance were evaluated extensively in the past over one decade. There is an interethnic difference in the frequency of poor metabolizers and mutant alleles of CYP2C19 among Chinese nationalities. Different frequency of mutations that code for CYP2C19 results in interethnic differences in distribution of the polymorphic trait for this enzyme. CYP2C19 genotype is a major determined factor for metabolisms of S-mephenytoin (S-MP), diazepam, and omeprazole (OP). The formations of their metabolites, 4'-hydroxymephenytoin (4'-OH-MP), demethyldiazepam, and 5-hydroxyomeprazole (5-OH-OP) are CYP2C19 genotype dependent. The inducibility of CYP2C19 activity is also related to CYP2C19 genotype.

CONCLUSIONS

The availability of phenotyping and genotyping methods should help identify the adverse reaction and toxicity of drugs that metabolized by CYP2C19 and determine the doses of these drugs according to individual CYP2C19 genotype.

Effect of asymmetric dimethylarginine on osteoblastic differentiation

BACKGROUND

Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide synthase (NOS) that accumulates in renal insufficiency and may be a uremic toxin. To determine whether ADMA inhibits bone metabolism, we investigated the in vitro effect of ADMA on osteoblastic differentiation in mouse bone marrow-derived mesenchymal stem cells (BMSCs).

METHODS

The effect of ADMA on nitric oxide (NO) production was determined by measuring the stable end product of NO, nitrite, in the culture medium using commercial NO kit. The temporal sequence of osteoblastic differentiation in BMSCs was assessed in the presence and absence of ADMA by measuring alkaline phosphatase (ALP) activity, mineralization, and osteoblast gene expression at 0, 4, 8, 12 days of culture.

RESULTS

ADMA (5, 50, 500 micromol. L-1) resulted in a dose-dependent decrease in nitrite formation in conditioned media of BMCS cultures, consistent with inhibition of NOS. ADMA treatment was associated with reduced ALP activity, calcium deposition and osteoblast-related gene expression in BMSCs cultures. Concurrent treatment with l-arginine (3600 micromol. L-1) reversed the ADMA (500 micromol. L-1)-mediated decrease in NO production, restored the differentiation potential of BMSCs, and significantly attenuated the down-regulation of Cbfa1 and osteocalcin gene expression by ADMA.

CONCLUSIONS

ADMA inhibition of the NO-NOS pathway in BMSCs impairs osteoblastic differentiation of mouse BMSC cultures. These studies further support a role of NO in the local regulation of bone metabolism and the possibility that ADMA may act as uremic toxin on bone through its effect to inhibit NO actions in osteoblasts.

Pharmacokinetics of sertraline in relation to genetic polymorphism of CYP2C19

OBJECTIVE

Our objective was to evaluate the relationship between the disposition of sertraline and the presence of the CYP2C19 gene and to define the contribution of cytochrome P450 2C19 (CYP2C19) to sertraline N-demethylation.

METHODS

A single oral 100-mg dose of sertraline was administered to 6 subjects who were extensive metabolizers and 6 subjects who were poor metabolizers recruited from 77 healthy Chinese volunteers whose genotypes were predetermined by polymerase chain reaction-based amplification, followed by restriction fragment length polymorphism analysis. Phenotypes were determined by use of the omeprazole metabolic rate. The plasma concentrations of sertraline and desmethylsertraline were determined by gas chromatography with electron-capture detection.

RESULTS

Six poor metabolizers with m1 mutation had area under the plasma concentration versus time curve (AUC(0-infinity)) values (983.6 +/- 199.3 microg x h/L versus 697.6 +/- 133.0 microg x h/L; P <.05) and terminal elimination half-life values of sertraline (35.5 +/- 5.6 hours versus 23.5 +/- 4.4 hours; P <.01) that were significantly higher than the values in 6 extensive metabolizers who were either homozygous or heterozygous for CYP2C19*1. The oral clearance of sertraline in poor metabolizers (105.3 +/- 19.4 L/h) was significantly lower than that of extensive metabolizers (148.4 +/- 28.6 L/h). The area under the concentration-time curve from 0 to 144 hours and the maximum plasma concentration of desmethylsertraline in poor metabolizers were significantly lower than the values of extensive metabolizers (627.6 +/- 203.8 microg x h/L versus 972.1 +/- 270.3 microg x h/L; P <.05; and 23.6 +/- 6.5 nmol/L versus 32.4 +/- 8.2 nmol/L; P <.01; respectively).

CONCLUSIONS

The polymorphic CYP2C19 appears to be a major enzyme involved in the N-demethylation of sertraline, and both extensive and poor metabolizers had marked differences in the disposition of sertraline.

Effect of the CYP2C19 oxidation polymorphism on fluoxetine metabolism in Chinese healthy subjects

AIMS

The study was designed to investigate whether genetically determined CYP2C19 activity affects the metabolism of fluoxetine in healthy subjects.

METHODS

A single oral dose of fluoxetine (40 mg) was administrated successively to 14 healthy young men with high (extensive metabolizers, n=8) and low (poor metabolizers, n = 6) CYP2C19 activity. Blood samples were collected for 5-7 half-lives and fluoxetine, and norfluoxetine were determined by reversed-phase high performance liquid chromatography.

RESULTS

Poor metabolizers (PMs) showed a mean 46% increase in fluoxetine peak plasma concentrations (Cmax, P < 0.001), 128% increase in area under the concentration vs time curve (AUC(0, infinity), P < 0.001), 113% increase in terminal elimination half-life (t(1/2)) (P < 0.001), and 55% decrease in CLo (P < 0.001) compared with extensive metabolizers (EMs). Mean +/- (s.d) norfluoxetine AUC(0, 192 h) was significantly lower in PMs than that in EMs (1343 +/- 277 vs 2935 +/- 311, P < 0.001). Mean fluoxetine Cmax and AUC(0, infinity) in wild-type homozygotes (CYP2C19*1/CYP2C19*1) were significantly lower than that in PMs (22.4 +/- 3.9 vs 36.7 +/- 8.9, P < 0.001; 732 +/- 42 vs 2152 +/- 492, P < 0.001, respectively). Mean oral clearance in individuals with the wild type homozygous genotype was significantly higher than that in heterozygotes and that in PMs (54.7 +/- 3.4 vs 36.0 +/- 8.7, P < 0.01; 54.7 +/- 3.4 vs 20.6 +/- 6.2, P < 0.001, respectively). Mean norfluoxetine AUC(0, 192 h) in PMs was significantly lower than that in wild type homozygotes (1343 +/- 277 vs 3163 +/- 121, P < 0.05) and that in heterozygotes (1343 +/- 277 vs 2706 +/- 273, P < 0.001), respectively.

CONCLUSIONS

The results indicated that CYP2C19 appears to play a major role in the metabolism of fluoxetine, and in particular its N-demethylation among Chinese healthy subjects.

Single plasma sampling to predict oral clearance of CYP3A probe midazolam

AIM

To find out a single plasma sampling to estimate oral clearance of midazolam (MDZ) and CYP3A activity, and explore the pharmacokinetics of midazolam hydroxylation in Chinese subjects.

METHODS

The pharmacokinetics of midazolam was assessed in ten healthy male individuals after an oral dose of 7.5 mg midazolam.

RESULTS

A significant correlation (r = 0.7, P < 0.05, n = 10) was found between plasma MDZ clearance and the plasma ratio of 1'-hydroxymidazolam to midazolam, which was assessed at 1 h after MDZ intake in the volunteers. Pharmacokinetics parameters of midazolam were as follows: Cmax (191 +/- 17) nmol/L, tmax (1.01 +/- 0.14) h, t(1/2) (3.2 +/- 0.4) h, AUC(0-infinity) (681 +/- 43) nmol.h.L-1), Cl(oral) (0.54 +/- 0.04) L.h-1.kg-1, Ke (0.2415 +/- 0.0021) h-1, Kalpha (0.82 +/- 0.18) h-1.

CONCLUSION

Single plasma sampling of 1 h after 7.5 mg oral MDZ intake can be used to predict the oral clearance of midazolam.

Plasma caffeine metabolite ratio (17X/137X) in vivo associated with G-2964A and C734A polymorphisms of human CYP1A2

Either G-2964 or A734 in the human CYP1A2 gene was confirmed to be associated with high inducible enzyme activity in smokers, but not in nonsmokers. In this study, for the first time, we observed an association between phenotypes and genotypes of CYP1A2 with respect to the two genetic polymorphisms in 163 healthy Chinese volunteers living in Qidong. The ratio of plasma 17X/137X at 6 h after oral administration of 300 mg caffeine was employed in CYP1A2 phenotyping analysis, while genotyping analysis was carried out by polymerase chain reaction-restriction fragment length polymorphism. The allele frequencies of A at -2964 and A at 734 in 139 non-smoking subjects were 0.25 and 0.67, respectively. The A/A-2964C/C734, G/A-2964C/C734 or A/A-2964C/A734 genotype that was thought to have lower inducibility/activity of CYP1A2 than the other genotypes did not exist in the tested Chinese subjects. The ratio of 17X/137X was 0.46 +/- 0.26 in G/G-2964A/A734 genotypes (n = 22) and 0.36 +/- 0.19 in non-G/G-2964A/A734 (n = 117). In addition, there was significant difference between them (P = 0.036). A similar result was also achieved in 24 smokers. Since Qidong is a special region with particularly high incidence of hepatocellular carcinoma in China, the association of phenotypes with genotypes of CYP1A2 in the Qidong population might result from some inducible environmental factors such as those of cigarettes in smokers.

Transcranial electrical motor evoked potential monitoring for brain tumor resection

OBJECTIVE

This study was designed to examine whether transcranial electrical motor evoked potential (MEP) monitoring is safe, feasible, and valuable for brain tumor surgery.

METHODS

Fifty consecutive patients undergoing brain tumor resection were studied, using nitrous oxide/propofol anesthesia. MEPs were continuously recorded throughout surgery, using a Sentinel 4 evoked potential system (Axon Systems, Inc., Hauppauge, NY). The MEPs were elicited by transcranial electrical stimulation (train of 5; stimulation rate, 0.5-2 Hz; square wave pulse with a time constant of 0.5 ms; stimulation intensity, 40-160 mA) through spiral electrodes placed over the primary motor cortex and were recorded by needle electrodes inserted into the contralateral orbicularis oris, biceps, abductor pollicis brevis, and anterior tibialis muscles. When MEP amplitudes decreased by more than 50%, MEP stimulation was repeated, with increased stimulation intensity, and MEP changes were reported to the surgeon. The motor function of each patient was examined before and after surgery, using a reproducible scale. The relationship between MEP amplitude decreases and worsening motor status was analyzed using linear regression.

RESULTS

Preoperative neurological examinations revealed mild to moderate motor deficits (2/5 to 4/5) for 38% of patients (19 of 50 patients). Most of the patients (96%) exhibited recordable baseline MEPs. Persistent MEP decreases of more than 50% were noted for eight patients (16%) (11 muscles). The MEPs were completely abolished in two patients (three muscles). The degree of postoperative worsening of motor status was correlated with the degree of intraoperative MEP amplitude reduction (r = -0.864; P < 0.001).

CONCLUSION

Persistent intraoperative MEP reductions of more than 50% were associated with postoperative motor deficits. The degree of MEP amplitude reduction was correlated with postoperative worsening of motor status. Transcranial electrical MEP monitoring is feasible, safe, and valuable for brain tumor surgery.

Determination of estradiol metabolites in human liver microsome by high performance liquid chromatography-electrochemistry detector

AIM

To constitute a method to determine the estradiol metabolites in human liver microsome in low concentration of estradiol.

METHODS

Use high performance liquid chromatography after solvent extraction, evaporation, and reconstitution to separate the metabolites and use a electrochemistry detector to detect the metabolites.

RESULTS

With a mobile phase of acetic acid buffer-acetonitrile (50:50, v/v, pH 4.5) at flow rate of 1.0 mL/min and a potential of +0.7 V vs Ag/AgCl, all six composition were well separated and satisfactorily detected. There are E3, 16alpha-OHE1, 2-OHE2, E1, and two unidentified composition. The minimum detectable amount is about 100 p g on column. This method is sensitive enough to detect E1 in a substrate concentration of 1 micromol/L.

CONCLUSION

The method can be used to study the metabolism mechanism of estradiol in liver microsome.

Arg389Gly beta 1-adrenoceptor polymorphism varies in frequency among different ethnic groups but does not alter response in vivo

There are marked interethnic differences in beta 1-adrenoceptor-mediated responsiveness, with sensitivity decreased in African-Americans and increased in Chinese compared with Caucasians. Therefore, the frequency of a common naturally occurring polymorphism of the human beta 1-adrenoceptor gene (Arg389Gly), which has functional importance in vitro, was determined in 194 African-Americans, 316 Caucasian-Americans, 221 Hispanic-Americans and 142 Chinese. African-Americans were found to have a significantly lower frequency of the Arg389 allele than the other three ethnic groups (all P < 0.01). In the populations studied, the order of the distribution of the Arg389 allele was: Chinese (74%) > Caucasians (72%) > Hispanics (67%) > African-Americans (58%). To determine the functional significance of the Arg389Gly beta 1-adrenoceptor polymorphism, in-vivo heart rate responses to exercise were compared in healthy subjects homozygous for the Arg (n = 9) and Gly (n = 8) alleles. Heart rate response to exercise was not affected by genotype (P = 0.4). Although ethnic differences in the frequency of the beta 1-adrenoceptor Arg389Gly polymorphism exist, the polymorphism does not appear to have functional significance in healthy subjects and therefore may not contribute to ethnic differences in response to drugs acting through the beta 1-adrenoceptor.

Interindividual variations in levels and activities of cytochrome P-450 in liver microsomes of Chinese subjects

AIM

To compare the level and/or activity of several important cytochrome P-450 (CYP) enzymes in liver microsomes prepared from different Chinese subjects.

METHODS

Individual CYP contents, including CYP1A2, CYP2C9, and CYP3A4, in liver microsomes of 17 Han, 17 Zhuang, and 8 Miao subjects were determined by using Western blot analysis and densitometric scanning. The substrates for measuring the activity of individual CYP in vitro included phenacetin, tolbutamide, debrisoquine, and omeprazole.

RESULTS

There was a large interindividual variability in the content and activity of CYP1A2, 2C9 and 3A4. And the activity of CYP2D6 also varied greatly between individual samples. CYP3A4 (32 %) is the most abundant CYP in Chinese liver microsomes, and the levels of CYP2C9 (19 %) and CYP1A2 (16 %) were also considerable. No clear ethnic, sex- and age-related differences in individual CYP content and catalytic activity were detected in 42 Chinese liver samples, except that there were somewhat ethnic and sex-related differences in the content and activity of CYP1A2. Good correlation between enzyme protein content and activity was found for CYP1A2, 2C9 and 3A4.

CONCLUSION

Our results may provide useful information for the study of drug metabolism by liver microsomes in Chinese.

Role of cytochrome P450 in estradiol metabolism in vitro

AIM

Catechol estrogens and 16alpha-hydroxy estrogen are important metabolites that cause carcinogenesis. This study was aimed to stud y the role of cytochrome P450 in estradiol metabolism.

METHODS

The estradiol metabolites were determined with HPLC-ECD. Correlation of estradiol metabolites production between cytochrome P450 activity, the inhibitory effect of specific inhibitors and enzyme catalyzing kinetics were studied in cDNA-expressed P450 or human liver microsomes.

RESULT

CYP1A2, CYP3A4, and CYP2C9 catalyze the estradiol 2-hydroxylation. CYP2C9, CYP2C19, and CYP2C8 have high activity in catalyzing 17beta-hydroxy dehydrogenation in cDNA expressed P450, but CYP1A2 is the most important enzyme in catalyzing estradiol 2-hydroxylation. Using furafyllin and troleandomycin to inhibit CYP1A2 and CYP3A4 in liver microsomes, it was found that the 2-hydroxylation had been inhibited about the same amount. This result suggests that in human liver microsomes CYP1A2 and CYP3A4 play an important role in 2-hydroxy estradiol formation. At low substrate concentration, 17beta -hydroxy dehydrogenation dominated the estradiol metabolism, but at high substrate concentration, 2-hydroxylation exceeded 17beta-hydroxy dehydrogenation to become the important mechanism.

CONCLUSION

CYP1A2 and CYP3A4 are two important enzymes catalyzing the main estradiol 2-hydroxylation metabolism pathway at high substrate concentrations. 17beta-hydroxy dehydrogenation is the main metabolism pathway at low concentrations, and CYP2C9, CYP2C19, and CYP2C8 may have high catalyzing activity.

Effects of CYP2C19 genotype and CYP2C9 on fluoxetine N-demethylation in human liver microsomes

AIM

The present study was designed to define the kinetic behavior of fluoxetine N-demethylation in human liver microsomes and to identify the isoforms of cytochrome P-450 (CYP) involved in this metabolic pathway.

METHODS

The kinetics of Ne formation of norfluoxetine was determined in human liver microsomes from six genotyped CYP2C19 extensive metabolizers (EM). The correlation studies between the fluoxetine N-demethylase activity and various CYP enzyme activities were performed. Selective inhibitors or chemical probes of various cytochrome P-450 isoforms were also employed.

RESULTS

The kinetics of norfluoxetine formation in all liver microsomes were fitted by a single-enzyme Michaelis-Menten equation (mean Km=32 micromol/L+/-7 micromol/L). Significant correlations were found between N-demethylation of fluoxetine at both 25 micromol/L and 100 micromol/L and 3-hydroxylation of tolbutamide at 250 micromol/L (r1=0.821, P1=0.001; r2=0.668, P2=0.013), respectively, and S-mephenytoin 4'-hydroxylase activity (r=0.717, P=0.006) at high substrate concentration of 100 micromol/L. S-mephenytoin (SMP) (a CYP2C19 substrate) at high concentration and sulfaphenazole (SUL) (a selective inhibitor of CYP2C9) substantially inhibited norfluoxetine formation. The reaction was minimally inhibited by coincubation with chemical probe, inhibitor of CYP3A4 (triacetyloleandomycin, TAO). The inhibition of fluoxetine N-demethylation at high substrate concentration (100 micromol/L) was greater in PM livers than in EM livers (73 % vs 45 %, P < 0.01) when the microsomes were precoincubated with SUL plus TAO.

CONCLUSION

Cytochrome P-450 CYP2C9 is likely to be a major CYP isoform catalyzing fluoxetine N-demethylation in human liver microsomes at a substrate concentration close to the therapeutic level, while polymorphic CYP2C19 may play a more important role in this metabolic pathway at high substrate concentration.

5-hydroxylation of omeprazole by human liver microsomal fractions from Chinese populations related to CYP2C19 gene dose and individual ethnicity

It has been previously reported that omeprazole (OP) oxidation is mediated by CYP2C19 and CYP3A4 in human livers. In this study, we assessed their relative contributions with human liver microsomal fractions from Chinese populations that were genotyped by CYP2C19 and recruited from two ethnic groups, Han and Zhuang. The kinetics of 5-hydroxyomeprazole (5-OH-OP) formation was best described by the two-enzyme and single-enzyme Michaelis-Menten equations for liver microsomes from CYP2C19 extensive (EMs) and poor metabolizers, respectively. At a low substrate concentration that may be encountered in vivo, the monoclonal antibody to CYP2C8/9/19 strongly inhibited 5-OH-OP formation in EM microsomes, whereas troleandomycin (TAO) eliminated most of the formation at a high substrate concentration. In poor metabolizer microsomes, either TAO or anti-CYP3A4 could alone abolish 5-OH-OP formation. Furthermore, there were differences between homozygous and heterozygous EMs in the percentage of inhibition by TAO and the antibodies. At the low substrate concentration, OP 5-hydroxyaltion was correlated well with S-mephenytoin 4'-hydroxylation and CYP2C19 contents in liver microsomes of 34 Chinese individuals. Moreover, in these individuals, obviously genetic and somewhat ethnic differences in OP 5-hydroxylation were observed between different CYP2C19 genotypes (wt/wt > wt/m1 > m1/m1) and between Han and Zhuang (Han > Zhuang), respectively. The results indicate that CYP2C19 is a high-affinity enzyme for OP 5-hydroxylation by liver microsomes from Chinese individuals and that its contribution is CYP2C19 gene dependent and ethnically related. Similar studies indicate that OP sulfoxidation is mediated mainly by CYP3A4 and independent of CYP2C19 genotype status.

Determination of fluoxetine and its metabolite norfluoxetine in human liver microsomes by reversed-phase HPLC in vitro

AIM

A high-performance liquid chromatography (HPLC) method was developed for the determination of fluoxetine (FLU) and its metabolite norfluoxetine (N-FLU) in human liver microsomes in vitro.

METHODS

An incubation buffer containing human liver microsomes, NADPH-generating system, and FLU, after termination of enzyme reaction and addition of nortriptyline (NOR) as internal standard (IS), was extracted with n-hexane/acetonitrile, and separated on a reversed-phase ODS column. Detection was achieved at 226 nm by ultraviolet detector (UV).

RESULTS

The limit of detection was 5 micrograms/L for both FLU and N-FLU. No potential interference was found. The method provides recoveries of up to 94%-104% and acceptable coefficients of variation were found for both within-run (< 7.8%) and day to day (< 9.1%) assays.

CONCLUSION

This method is rapid, sensitive, and simple for studying the metabolism of FLU and N-FLU.

G-2964A and C734A genetic polymorphisms of CYP1A2 in Chinese population

AIM

To observe the G-2964A and C734A genetic polymorphisms of human CYP1A2 in Chinese population.

METHODS

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was employed in genotyping analysis.

RESULTS

The allele frequencies of A-2964 were 0.25 and 0.22 in Qidong and Changsha populations, respectively. The incidences of A734 were 0.68 in Qidong population and 0.66 in Changsha population. No more than two low-inducibility/activity alleles were presented in one person.

CONCLUSION

The distribution of the G-2964A and C734A genetic polymorphisms did not show significant difference between Chinese and Japanese populations. The incidence of C734A in Chinese was also similar to that in Caucasian population.

Ethnic differences in drug metabolism

Ethnic differences in drug metabolism are well documented for a number of drugs. The molecular mechanisms responsible for ethnic differences in drug metabolism have been partly clarified because of the advances in molecular biology in recent years. Gene dosage determines the drug metabolism as demonstrated for S-mephenytoin and diazepam metabolism. Genotype analysis indicates a different frequency for the mutant alleles in different ethnic populations, which results in variations in the frequency of subjects who are homozygous for the mutant allele among the extensive metabolizers in different ethnic populations. Ethnic differences in drug metabolism may result from differences in distribution of a polymorphic trait and mutations which code for enzymes with abnormal activity which occur with altered frequency in different ethnic groups.

Probing CYP2C19 and CYP3A4 activities in Chinese liver microsomes by quantification of 5-hydroxyomeprazole and omeprazole sulphone

AIM

To develop an analytical method for simultaneous quantification of 5-hydroxyomeprazole (5-OH-OP) and omeprazole sulfone (OPS), and explore whether omeprazole (OP) is an appropriate phenotypic probe for CYP2C19 and CYP3A4 in Chinese liver microsomes.

METHODS

OP metabolism in vitro was conducted in Chinese liver microsomes, and the major metabolites 5-OH-OP and OPS were determined using high pressure liquid chromatography (HPLC). Monoclonal antibodies anti-CYP2C8/9/19 and anti-CYP3A4 were employed to conduct inhibition experiments. The protein contents of CYP2C19 and CYP3A4 were quantified using Western blot analysis and densitometric scanning.

RESULTS

5-OH-OP and OPS gave a baseline resolution in the HPLC analysis. The detection limits for both compounds were 0.01 nmol and the recovery (98%-102%) had good precision with relative standard deviation of < 9.5%. Both anti-CYP2C8/9/19 and anti-CYP3A4 had a significant inhibitory effect (P < 0.05) on the 5-OH-OP formation in a substrate concentration-dependent manner, and anti-CYP3A4 alone could almost abolish the formation of OPS (> 87%). At a substrate concentration of 2 mumol/L OP, good correlations were found between OP 5-hydroxylation and S-mephenytoin 4'-hydroxylation activities (r = 0.72, P < 0.01), OP 5-hydroxylation activities and CYP2C19 contents (r = 0.82, P < 0.01), and OP sulfoxidation activities and CYP3A4 contents (r = 0.78, P < 0.01) in Chinese liver microsomes.

CONCLUSION

OP metabolism is mediated mainly by CYP2C19 and CYP3A4, and OP can be used to probe CYP2C19 and CYP3A4 activities in Chinese liver microsomes at appropriate substrate concentrations with the HPLC method presently developed.

Polymorphism of CYP450 and cancer susceptibility

CYP450s form a superfamily involved in the metabolism of many endogenous and exogenous substrates. In this review, the substrates, probe drugs, genetic polymorphisms, and associated cancers of CYP1A1, CYP1A2, CYP2C19, CYP2D6, CYP2E1, and CYP3A4 are summarized.