Therapeutic drug monitoring of mirtazapine in a routine outpatient setting in Asian psychiatric patients

INTRODUCTION

Mirtazapine is an antidepressant that acts by enhancing serotonergic and noradrenergic neurotransmission. This study aimed to evaluate mirtazapine pharmacokinetic data from Korean psychiatric patients and to identify the potential factors affecting its steady-state concentration.

METHODS

A total of 337 samples of steady-state mirtazapine concentrations from 188 adult psychiatric outpatients were retrospectively evaluated. Serum mirtazapine concentrations were measured by high-performance liquid chromatography-tandem mass spectrometry.

RESULTS

Median mirtazapine concentration was 43.6 μg/L (164.37 nmol) at a daily dosage range of 7.5-60 mg. At the steady state, mirtazapine dose had a positive correlation with the drug concentration. Mean concentration-to-dose (C/D) ratio was 1.48 μg/L/mg/day (5.58 nmol/mg/day), which was higher than that in a previous study in Caucasian subjects. Age and paroxetine co-medication were positively associated with C/D ratio. Initial mirtazapine concentration and C/D ratio did not show an association with responsiveness in depressive patients.

DISCUSSION

This study presented the therapeutic drug monitoring data for mirtazapine and pharmacokinetic variations of mirtazapine in an Asian population. A further study could be helpful for clinical decision making based on the characteristics of patients.

Randomised clinical trial: the effects of Helicobacter pylori eradication on glandular atrophy and intestinal metaplasia after subtotal gastrectomy for gastric cancer

BACKGROUND

Helicobacter pylori eradication is recommended for early gastric cancer (GC) patients after resection.

AIM

To evaluate whether H. pylori eradication improves glandular atrophy and intestinal metaplasia (IM) in GC patients undergoing subtotal gastrectomy.

METHODS

This randomised, double-blind trial was performed in tertiary care setting. Distal GC patients with H. pylori infection were randomised to receive proton pump inhibitor-based triple therapy or placebo. The histology was evaluated using the updated Sydney system before and at 36 months after surgery. The endpoints were the comparison of atrophy and IM score changes between the allocated groups and according to final H. pylori status.

RESULTS

Overall, 190 patients were randomised to the treatment and placebo groups. For lesser curvature of the corpus, mean atrophy and IM scores did not differ between the treatment and placebo groups. However, the H. pylori-eradicated patients had significantly lower mean scores than the H. pylori-persistent patients regarding atrophy (0.55 ± 0.95 vs. 1.05 ± 1.10 respectively; P = 0.0046) and IM (0.66 ± 0.99 vs. 1.05 ± 1.16 respectively; P = 0.0284). The percentage change from baseline was more marked in the H. pylori-negative than in the H. pylori-positive groups (-58.6% vs. -11.0% for atrophy and -60.5% vs. -35.6% for IM respectively). For greater curvature, mean atrophy score was lower in the H. pylori-negative group than in the H. pylori-positive group (0.14 ± 0.50 vs. 0.41 ± 0.75 respectively; P = 0.0281). The percentage change was -36.4% vs. 86.3%.

CONCLUSION

Helicobacter pylori eradication in GC patients is beneficial, as reflected by lower scores of atrophy and IM at 36 months after subtotal gastrectomy. (ClinicalTrials.gov number, NCT01002443).

Epidemiology of the Foot-and-Mouth Disease Serotype O Epidemic of November 2010 to April 2011 in the Republic Of Korea

The largest epidemic of foot-and-mouth disease (FMD) in Korea since the first record in 1911 occurred between November 2010 and April 2011. The outbreak was confirmed in 153 farms, and more than three million animals were destroyed. This study presents the temporal and spatial distribution patterns, epidemiological investigation and the control measures for the 2010/2011 epidemic in Korea. The index case of this 2010/2011 FMD epidemic was reported in a pig-farming complex with five piggeries in Andong, GyeongBuk Province, on 28 November 2010, and the outbreak lasted 145 days. The largest number of new detection of the infected farms per day was recorded in mid-January. Epidemiological investigation revealed that the FMD virus had spread from farm to farm through routine movements associated with animal husbandry operations. In contrast to FMD epidemics in other countries in which movement of the infected animals largely contributed to the spread of the disease, human behaviours were major factors in the spread of the FMD virus in the Korean epidemic. The 2010/2011 epidemic was first confirmed in a local small and medium city where share of smallholder producers is higher than that of other provinces. Although Korea had a well-developed emergent response system with the experience of controlling infection and re-obtaining FMD-free status after the previous epidemics, Korea was prompted to revise their contingency plan by tailoring it to its unique livestock environment. Practical contingency plans tailored to Korea for control of FMD can be fully effective when farmers, livestock-related agencies, veterinary service providers and the general public work together.

Predictive factors for gastroduodenal toxicity based on endoscopy following radiotherapy in patients with hepatocellular carcinoma

PURPOSE

The aim of this work was to determine predictive factors for gastroduodenal (GD) toxicity in hepatocellular carcinoma (HCC) patients who were treated with radiotherapy (RT).

PATIENTS AND METHODS

A total of 90 HCC patients who underwent esophagogastroduodenoscopy (EGD) before and after RT were enrolled. RT was delivered as 30-50 Gy (median 37.5 Gy) in 2-5 Gy (median 3.5 Gy) per fraction. All endoscopic findings were reviewed and GD toxicities related to RT were graded by the Common Toxicity Criteria for Adverse Events, version 3.0. The predictive factors for the ≥ grade 2 GD toxicity were investigated.

RESULTS

Endoscopic findings showed erosive gastritis in 14 patients (16 %), gastric ulcers in 8 patients (9 %), erosive duodenitis in 15 patients (17 %), and duodenal ulcers in 14 patients (16 %). Grade 2 toxicity developed in 19 patients (21 %) and grade 3 toxicity developed in 8 patients (9 %). V25 for stomach and V35 for duodenum (volume receiving a RT dose of more than x Gy) were the most predictive factors for ≥ grade 2 toxicity. The gastric toxicity rate at 6 months was 2.9 % for V25 ≤ 6.3 % and 57.1 % for V25 > 6.3 %. The duodenal toxicity rate at 6 months was 9.4 % for V35 ≤ 5.4 % and 45.9 % for V35 > 5.4 %. By multivariate analysis including the clinical factors, V25 for stomach and V35 for duodenum were the significant factors.

CONCLUSION

EGD revealed that GD toxicity is common following RT for HCC. V25 for the stomach and V35 for the duodenum were the significant factors to predict ≥ grade 2 GD toxicity.

The embryo lethality of Escherichia coli isolates and its relationship to the presence of virulence-associated genes

The aims of this study were to determine if the chicken embryo lethality assay and the presence of 9 virulence-associated genes of Escherichia coli were correlated and to discover which virulence genes contributed most to embryo lethality. We examined 58 E. coli strains isolated from visceral organs of chickens with colibacillosis for the presence of 9 virulence genes (fimC, tsh, fyuA, irp2, iucD, cvi/cva, iss, astA, and vat) by PCR. The gene FimC (type I fimbriae) was detected with the highest prevalence in 93.1% of the isolates, followed by iucD (67.24%), iss (58.62%), tsh (34.48%), cvi/cva (34.48%), fyuA (32.76%), astA (31.0%), irp2 (27.59%), and vat (17.24%). The embryo mortality ranged from 5 to 100%; however, most of the isolates were moderately or highly virulent. High positive correlations were observed between the presence of virulence genes and chicken embryo lethality. In addition, presence of the iucD (aerobactin) gene was the trait that best contributed to embryo mortality by using the multivariate model. These results suggest that expression frequency of these 9 virulence genes is associated with embryo mortality, and the gene that best predicted embryo mortality was iucD.

Clinical manifestations of foot-and-mouth disease during the 2010/2011 epidemic in the Republic of Korea

We reviewed the clinical signs of the foot-and-mouth disease (FMD) incidences in the Republic of Korea occurring from November 2010 to April 2011. Profuse salivation, vesiculation, lameness or ataxia, and ulceration were the most commonly observed clinical signs of FMD among the infected animals, irrespective of the species. The clinical signs of FMD manifested more clearly in the dairy cattle and pigs compared to the beef cattle, deer and goats on infected farms. About 54% of the infected dairy farms reported vesicles on the teats as the primary clinical sign, while vesiculation on the nose, including the snout and muzzle, was the major lesion observed in infected beef cattle and pig farms. The teat and feet were the second most frequently vesiculated body parts on infected pigs. Although the average age of the first-to-appear clinical lesion in the animals in the beef and dairy cattle farms subjected to vaccination was higher than that observed in the animals in the farms not subjected to vaccination, a reverse pattern was observed in the pig farms. In this study, the clinical signs of FMD were described on the basis of the subjective observations by the farm workers. The present results highlight the clinical signs expected on specific body parts of different types of susceptible animals, and therefore, they may be useful for generating public awareness, particularly among farm workers, as well as for early detection of future FMD outbreaks.

Contrast-enhanced computed tomography angiography and volume-rendered imaging for evaluation of cellophane banding in a dog with extrahepatic portosystemic shunt

A 4-year-old, 1.8 kg, male, castrated Maltese was presented for evaluation of urolithiasis. Urinary calculi were composed of ammonium biurate. Preprandial and postprandial bile acids were 44.2 and 187.3 μmol/ , respectively (reference ranges 0–10 and 0–20 μmol/ , respectively). Single-phase contrast-enhanced computed tomography angiography (CTA) with volume-rendered imaging (VRI) was obtained. VRI revealed a portocaval shunt originating just cranial to a tributary of the gastroduodenal vein and draining into the caudal vena cava at the level of the epiploic foramen. CTA revealed a 3.66 mm-diameter shunt measured at the level of the termination of the shunt and a 3.79 mm-diameter portal vein measured at the level between the origin of the shunt and the porta of the liver. Surgery was performed using cellophane banding without attenuation. Follow-up single-phase CTA with VRI was obtained 10 weeks after surgery. VRI revealed no evidence of portosystemic communication on the level of a cellophane band and caudal to the cellophane band. CTA demonstrated an increased portal vein diameter (3.79–5.27 mm) measured at the level between the origin of the shunt and the porta of the liver. Preprandial and postprandial bile acids were 25 and 12.5 μmol/ , respectively (aforementioned respective reference ranges), 3 months post-surgery. No problems were evident at 6 months.

A Systematic Study of the Structural and Luminescence Properties of P-Type Porous Silicon

The structural and luminescence properties of (001) p-type porous silicon samples (p∼0.1-0.2 Ω•cm) fabricated electrochemically under various conditions were investigated using high resolution double and triple axis diffraction and photoluminescence spectroscopy. We show the sensitivity of the structure of the porous silicon to the current density in the range of 10-50 mA/cm2, HF acid concentration in the range of 15% - 30%, and the evolution of the structure with time. We have found a systematic dependence of the amount of strain in the porous silicon layer (PSL) on the current density. The effect of the HF concentration is such that at 25% and 30% HF, PSLs are formed which are crystalline and strained, but at a lower HF concentration (15%), strained layers are not formed. The perpendicular strain in the layer increases linearly with storage time but the in-plane lattice constant of the porous silicon remains matched to the substrate. Further, we utilized x-ray reciprocal space maps to observe that, with storage time, there is an increase in the diffuse scattering from the PSL due to an increase in the range of tilts in the layer. Room temperature photoluminescence emission was observed for all 15% and 25% HF samples, but not for all 30% HF samples. Higher peak luminescence energy was obtained with lower HF concentration. Finally, we note the relationship between the strain in the PSL and the luminescence properties.

Non-Linear Optical Polymers for Active Optical Devices

Second order non-linear optical (NLO) polymers have been the focus of intense research effort in recent years [1]. This effort is justified by the potential value of these materials in a range of attractive optical signal processing applications with lower device costs and enhanced device performance.

Material Requirements for a Boron Phosphide Thermal Neutron Counter

Electrical characterization (current versus voltage and capacitance versus voltage) of nonstoichiometric amorphous boron phosphide Schottky diodes for neutron detection is presented. These results are incorporated in a Monte Carlo model of detector response to determine material requirements for a boron phosphide neutron counter.

Comparison Between Cadmium Zinc Telluride Crystals Grown in Russia and in the Ukraine

A comparative analysis of different Cd1−xZnxTe (CZT) crystals grown by a vertical high pressure Bridgman (VHPB) method is reported. The results of several analytical techniques, such as triple axis x-ray diffraction (TAD), rocking curves, low temperature photoluminescence (PL), scanning electron microscopy (SEM), and proton induced x-ray emission (PIXE) are discussed. Segregated carbon inclusions were identified by SEM and energy dispersive x-ray fluorescence (EDXRF), and the results are interpreted in terms of constitutional supercooling of the solidifying CZT melt. The carbon inclusions significantly decrease the resistivity, and in some cases, the noise is too large for the fabrication of radiation detectors. Combining these results with other measurements reported by our research team [1], we identify correlations between the growth and the defects identified in these CZT crystals.

Survival rate of H5N1 highly pathogenic avian influenza viruses at different temperatures

The survival rate of Korean H5N1 highly pathogenic avian influenza (HPAI) viruses was investigated at different temperatures under the laboratory conditions. The estimated survival days for a starting viral concentration of 10(6.5) 50% egg infectious dose/0.1 mL were 930, 1,042, and 3,213 d at 4 degrees C; 226, 232, and 293 d at 20 degrees C; and 51, 55, and 58 d at 30 degrees C for A/chicken/Korea/ES/03, A/chicken/Korea/IS/06, and A/chicken/Korea/Gimje/08 (Gimje/08) viruses, respectively. The stability of the Gimje/08 virus was statistically significant compared with the other 2 viruses except for the data between Gimje/08 and A/chicken/Korea/IS/06 virus at 30 degrees C. This result indicated that the survival rate of 3 Korean HPAI viruses is different at various temperatures, which might have partially influenced the large scale of HPAI outbreak in Korea in 2008.