Content study of N-nitroso impurities in 5 types of β-blockers / 中国药房

OBJECTIVE To determine the contents of N-nitroso impurities in raw materials/formulations of propranolol， metoprolol， atenolol， esmolol and bisoprolol， and clarify the attention threshold. METHODS Ultra-high performance liquid chromatography-quadrupole/electrostatic field orbitrap high-resolution mass spectrometry（UPLC-Q/Orbitrap HRMS）was adopted. An ACE Excel 3 C18-AR column was used for the separation and a mixture of 0.2% formic acid solution with 0.01 mol/L ammonium acetate and methanol was employed as the mobile phase by gradient elution， at a flow rate of 0.60 mL/min. The column temperature was set at 40 ℃ ， and the sample size was 5 μL. The heated electrospray ionization source was employed in the positive full mass spectra-selected ion monitoring mode. The contents of N-nitroso impurities in raw materials/formulations of 15 batches of β-blockers from 10 manufacturers were determined by this method. Discovery Studio software was applied to predict the toxicity of the impurities and estimate the attention threshold. RESULTS Among 5 kinds of β-blockers， the linear ranges of N-nitroso propranolol， N-nitroso metoprolol， N-nitroso atenolol， N-nitroso esmolol and N-nitroso bisoprolol were 1.01-503.38， 1.02-508.38， 0.97-483.63， 1.11-554.27 and 1.05-523.92 ng/mL， respectively （r＞0.999）. The limits of quantitation were 1.04， 0.25， 0.05， 0.55 and 1.05 ng/mL， and the limits of detection were 0.52， 0.08， 0.02， 0.17 and 0.52 ng/mL， respectively. RSDs of precision， reproducibility， recovery， stability and durability tests were all lower than 7.5% （n＝6 or n＝5）. Among the 15 batches of samples， except for 1 batch， N-nitroso propranolol （1.07-8.91 ng/mg）， N-nitroso metoprolol （1.43-3.37 ng/mg）， N-nitroso atenolol （1.33 ng/mg）， N-nitroso esmolol （0.19 ng/mg） and N-nitroso bisoprolol （1.27 ng/mg） were detected in all other batches. According to predictions， the above 5 impurities had varying degrees of reproductive toxicity， mutagenicity and carcinogenicity， with attention thresholds of 1.0， 0.4， 4.3， 0.2 and 46.7 ng/mg， respectively. CONCLUSIONS The established method is simple， rapid， sensitive and specific， the estimated attention thresholds are clear， which can be used for the control of N-nitroso impurities in various β-blockers.

The Role of Intestinal Microbiota and Mast Cell in a Rat Model of Visceral Hypersensitivity

Background/Aims@#To explore the role of intestinal flora and mast cells in visceral hypersensitivity (VH). @*Methods@#The experimental animals were divided into 4 groups: control group, VH group, VH + VSL#3 group, and VH + ketotifen group. Stool samples were collected from each group (n = 3) for a further analysis using 16S ribosomal DNA gene sequence. Visceral sensitivity was evaluated by abdominal withdrawal reflex (AWR) score. Colon tissues of rats were obtained from each group. Mast cells were detected by toluidine blue staining. The degranulation of mast cells was assessed by transmission electron microscopy. @*Results@#VH rat model could successfully be induced by acetic acid enema combined with partial limb restraint method. Compared with rats in the control group, AWR score, number of mast cells, and degranulation of mast cells were increased in the VH rats, which could be reduced by administration of ketotifen or probiotic VSL#3. Clostridium sensu stricto 1 abundance was higher in the VH group compared to the control group, which could be restored by application of probiotic VSL#3. @*Conclusions@#Probiotic VSL#3 decreases visceral sensitivity in VH rats. The mechanism may be related to mast cell and intestinal flora. Change of Clostridium sensu stricto 1 abundance may be a basis for VH observed in irritable bowel syndrome and may be prevented by specific probiotic administration.

Clinical Significance of Detection by Fluorescence in Situ Hybridization for Bladder Cancer / 中国肿瘤临床

Objective: To analyze chromosome aberrations in bladder transitional cell carcinoma with exfoliated cells, and to evaluate the clinical value of fluorescence in situ hybridization (FISH) in bladder cancer. Methods: FISH was performed using centromeric probes of 3, 7, 17 and locus probe of p16 to examine chromosome aberrations of exfoliated cells of 56 bladder cancer patients and 20 healthy controls to analyze the correlation of chromosome aberration with the pathological features of bladder cancer. The urine cytology of the 56 bladder cancer patients was performed. Results: The rates of aneuploidy of chromosomes 3, 7, and 17 were 58.9%, 39.3%, 58.9% and 75.0% for aberration of p16 in exfoliated cells from the 56 bladder cancer patients. All of the aberrations had no correlation with tumor stage (P>0.05). The aberrations of chromosomes 3, 7, and 17 were significantly correlated with pathological grade (P<0.05). The sensitivity of the 4 chromosome probes for detecting bladder cancer was 80.4%. The detection rate of FISH was obviously higher than that of udne cytology. Conclusion: Chromosome aberration is correlated with the growth of bladder cancer. The detection of FISH has significance for early di-agnosis, prognosis evaluation, and recurrence monitoring of bladder cancer.

Appreciation of school deworming program by parents in Ha Giang Province (Vietnam).

School-based deworming programs are one of the most cost-effective public health strategies to reach children with anthelminthics and health education. However, despite their low cost and high health impact, they are not implemented on a large scale. The present survey investigated a school-based deworming program in Ha Giang Province, Vietnam, to assess the community perception and support towards these programs. Information from 81 households, 88 primary school students, 25 teachers and 9 people in charge of commune health stations was collected by structured questionnaires. The survey displayed complete satisfaction and a high level of support within all 4 questioned groups. In addition 96.1% of all parents noticed an improvement in their children's health. The great appreciation of the deworming program by the community is an additional argument to convince decision makers to implement and scale up these programs. Even teachers that did not receive any specific training were able to distribute the drug successfully following the page of written instructions accompanying the drug.

Evaluation of coverage of deworming interventions in Vietnam.

In 2004-2005, the school deworming program in Vietnam targeted 2,400,000 school-children in 25 provinces. A questionnaire survey of a random sample of schools throughout the country was organized to validate the teacher feedback, assess the real coverage of the program and estimate the occurrence of side-effects. A total of 91 schools in four different provinces were visited few days after drug distribution. A total of 2,323 children and 80 teachers were questioned. The total cost of the monitoring has been estimated at US dollar 7,000 (less than 10% of the deworming program). The survey demonstrated a coverage of 95% for school-children and of 86.3% for teachers (on average a coverage 2% lower than the one reported by the teachers through forms on the day of drug administration). Approximately 0.4% of those interviewed reported side-effects after deworming, while the occurrence of side effects through routine reports was 0.15%. In both cases, the side effects were described as mild forms of nausea, abdominal pain, or headaches that did no required pharmacological treatment. The survey confirmed the positive results of routine reporting; we consider the survey a cost-effective activity to maintain the control activities under monitoring.