Recent Progress in Diatom Biosilica: A Natural Nanoporous Silica Material as Sustained Release Carrier

A drug delivery system (DDS) is a useful technology that efficiently delivers a target drug to a patient's specific diseased tissue with minimal side effects. DDS is a convergence of several areas of study, comprising pharmacy, medicine, biotechnology, and chemistry fields. In the traditional pharmacological concept, developing drugs for disease treatment has been the primary research field of pharmacology. The significance of DDS in delivering drugs with optimal formulation to target areas to increase bioavailability and minimize side effects has been recently highlighted. In addition, since the burst release found in various DDS platforms can reduce drug delivery efficiency due to unpredictable drug loss, many recent DDS studies have focused on developing carriers with a sustained release. Among various drug carriers, mesoporous silica DDS (MS-DDS) is applied to various drug administration routes, based on its sustained releases, nanosized porous structures, and excellent solubility for poorly soluble drugs. However, the synthesized MS-DDS has caused complications such as toxicity in the body, long-term accumulation, and poor excretion ability owing to acid treatment-centered manufacturing methods. Therefore, biosilica obtained from diatoms, as a natural MS-DDS, has recently emerged as an alternative to synthesized MS-DDS. This natural silica carrier is an optimal DDS platform because culturing diatoms is easy, and the silica can be separated from diatoms using a simple treatment. In this review, we discuss the manufacturing methods and applications to various disease models based on the advantages of biosilica.

Initial phase establishment of an in vitro method for developmental neurotoxicity test using Ki-67 in human neural progenitor cells

Building a precise alternative neurotoxicological test is of great importance to respond to societal and ethical requirements. In this study, a new developmental neurotoxicity test (DNT) was established with the human neural progenitor cell line. ReNcell CX cells were exposed to neurotoxic chemicals (aphidicolin, hydroxyurea, cytosine arabinoside, 5-fluorouracil, and ochratoxin A) or non-neurotoxic chemicals (sodium gluconate, sodium bicarbonate, penicillin G, and saccharin). Propidium iodide (PI) was used to evaluate cell viability. BrdU and Ki-76 were employed to determine cell proliferation. Based on the cell viability and proliferation, mathematical models were built by linear discriminant analysis. Furthermore, the neurotoxic-considered chemicals inhibited cell cycle progression at the protein level, supporting the biomolecular rationale for the predictive model. Overall, these results show that the new test method can be used to determine the potential developmental neurotoxicants or new drug candidates.

Efficacy of detergent-based cleaning and wiping against SARS-CoV-2 on high-touch surfaces

Efficacy of cleaning methods against SARS-CoV-2 suspended in either 5% soil load (SARS-soil) or simulated saliva (SARS-SS) was evaluated immediately (hydrated virus, T0) or 2 hours post-contamination (dried virus, T2). Hard water dampened wiping (DW) of surfaces, resulted in 1.77-3.91 log reduction (T0) or 0.93-2.41 log reduction (T2). Incorporating surface pre-wetting by spraying with a detergent solution (D + DW) or hard water (W + DW) just prior to dampened wiping did not unilaterally increase efficacy against infectious SARS-CoV-2, however, the effect was nuanced with respect to surface, viral matrix, and time. Cleaning efficacy on porous surfaces (seat fabric, SF) was low. W + DW on stainless steel (SS) was as effective as D + DW for all conditions except SARS-soil at T2 on SS. DW was the only method that consistently resulted in > 3-log reduction of hydrated (T0) SARS-CoV-2 on SS and ABS plastic. These results suggest that wiping with a hard water dampened wipe can reduce infectious virus on hard non-porous surfaces. Pre-wetting surfaces with surfactants did not significantly increase efficacy for the conditions tested. Surface material, presence or absence of pre-wetting, and time post-contamination affect efficacy of cleaning methods.

New recorded diatoms in Holocene sediment cores from the Gonggeom-ji Wetland in Korea

The Gonggeom-ji reservoir is an agricultural one built for rice farming during the Proto-Three Kingdoms period and was designated as Gyeongsangbuk-do monument No. 121 because of its high historical value. The Nakdonggang National Institute of Biological Resources has been conducting paleontological and paleoenvironmental studies on major wetlands from Korea since 2016, as well as diatom, geological, and depth distribution analyses on the sedimentary soil of Gonggeom-ji. This study summarized the description and ecological characteristics of six newly recorded diatoms (Gomphonema lacusrankala, Pinnularia diandae, P. gibba var. hyaline, P. lacunarum, Sellaphora labda var. nipponica, Stauroneis angustilancea) found in samples collected through drilling in Gonggeom-ji in 2019.

Environmental factors affecting akinete germination and resting cell awakening of two cyanobacteria

Globally, cyanobacteria frequently cause blooms that outcompete other species in the waterbody, affecting the diversity, decreasing water exchange rates, and promoting eutrophication that leads to excessive algal growth. Here, Dolichospermum circinale (akinetes) and Microcystic aeruginosa (resting cells), were isolated from the sediment in the Uiam Dam in the North Han River and near Ugok Bridge in the Nakdong River, respectively. The morphology, germination process and rates, and growth was evaluated in different environmental conditions. D. cercinalis germination began on day two of culturing, with maximum cell growth observed on day ten. In contrast, M. aeruginosa exhibited daily increase in cell density and colony size, with notable density increase on day six. Next, different environmental conditions were assessed. Akinetes exhibited high germination rates at low light intensity (5-30 µmol/m²/s), whereas resting cells exhibited high growth rates at high light intensity (50-100 µmol/m²/s). Furthermore, both cell types exhibited optimum germination and growth in media containing N and P at 20-30° at a pH of 7-9. Our study reveals the optimum conditions for the germination and growth of cyanobacterial akinetes and resting cells isolated from river sediment, respectively, and will assist in predicting cyanobacterial blooms for appropriate management.

Flocculation kinetics and mechanisms of microalgae- and clay-containing suspensions in different microalgal growth phases

Interplays between microalgae and clay minerals enhance biologically mediated flocculation, thereby affecting the sedimentation and transportation of suspended particulate matter (SPM) in water and benthic environments. This interaction forms larger flocs with a higher settling velocity and enhances SPM sinking. The aim of this study was to investigate the flocculation kinetics of microalgae and clay in suspension and to elucidate the mechanisms associated with such interactions. Standard jar test experiments were conducted using various mixtures of kaolinite and microalgal samples from batch cultures (Chlorella vulgaris) to estimate biologically mediated flocculation kinetics. The organic matter (OM) composition secreted by the microalgae was characterized using a liquid chromatography - organic carbon detection system, and quantitative analysis of transparent exopolymer particles was conducted separately. A two-class flocculation kinetic model, based on the interaction between flocculi and flocs, was also adopted to quantitatively analyze the experimental data from flocculation. Results from the flocculation kinetic tests and OM analyses, in association with other data analyses (i.e., floc size distribution and flocculation kinetic model), showed that flocculation increased with OM concentration during the growth phase (10-20 d). However, on day 23 during the early stationary phase, flocculation kinetics started decreasing and substantially declined on day 30, even though the amount of OM (mainly biopolymers) continued to increase. Our results indicate that an adequate quantity of biopolymers produced by the microalgal cells in the growth phase enhanced floc-to-floc attachment and hence flocculation kinetics. In contrast, an excessive quantity of biopolymers and humic substances in the stationary phase enhanced the formation of polymeric backbone structures and flocculation via scavenging particles but simultaneously increased steric stabilization with the production of a large number of fragmented particles.

Residual Antimicrobial Coating Efficacy Against SARS-CoV-2

AIMS

This study evaluated the residual efficacy of commercially available antimicrobial coatings or films against SARS-CoV-2 on nonporous surfaces.

METHOD AND RESULTS

Products were applied to stainless steel or ABS plastic coupons and dried overnight. Coupons were inoculated with SARS-CoV-2 in the presence of 5% soil load. Recovered infectious SARS-CoV-2 was quantified by TCID50 assay. Tested product efficacies ranged from <1.0 to >3.0 log₁₀ reduction at a 2-hour contact time. The log₁₀ reduction in recovered infectious SARS-CoV-2 ranged from 0.44 to 3 log₁₀ reduction on stainless steel and 0.25 to >1.67 log₁₀ on ABS plastic. The most effective products tested contained varying concentrations (0.5 to 1.3%) of the same active ingredient: 3- (trihydroxysilyl) propyldimethyloctadecyl ammonium chloride. Products formulated with other quaternary ammonium compounds were less effective against SARS-CoV-2 in this test.

CONCLUSIONS

The residual antimicrobial products tested showed varied effectiveness against SARS-CoV-2 as a function of product tested. Several products were identified as efficacious against SARS-CoV-2 on both stainless steel and ABS plastic surfaces under the conditions evaluated. Differences in observed efficacy may be due to variation in active ingredient formulation; efficacy is, therefore, difficult to predict based upon listed active ingredient and its concentration.

SIGNIFICANCE AND IMPACT

This study highlights formulation-specific efficacy of several products against SARS-CoV-2 and may inform future development of residual antiviral products for use on nonporous surfaces. The identification of antimicrobial coatings or films showing promise to inactivate SARS-CoV-2 suggests that these products may be worth future testing and consideration.

Coagulopathy after snake envenomation in South Korea

OBJECTIVE

This retrospective study investigated the nature and severity of venom-induced consumption coagulopathy (VICC) and determined the clotting factors involved in VICC in patients after envenomation by South Korea's snakes. Additionally, we studied the effectiveness of antivenom for the treatment of VICC after envenomation.

METHODS

Included patients were divided into three groups according to the severity of VICC (no VICC, partial VICC, and complete VICC). Data, including changes in coagulation parameters during hospitalization and clotting factors at presentation, were collected and analyzed.

RESULTS

One hundred nineteen patients who presented at our emergency department within 3 h after snake envenomation were included. VICC developed in 34 patients (27 patients with partial VICC and 7 patients with complete VICC). Two of 34 patients with VICC required blood transfusions. Five patients with complete VICC had an undetectable fibrinogen concentration at presentation. Three patients with complete VICC had an unmeasurable INR and aPTT within 24 h. The median times of the most extreme values were 10 h for INR, 12 h for aPTT, and 16 h for fibrinogen after presentation in the VICC group. The D-dimer concentration peaked at a median of 63.5 h after presentation. The activities of factors II and X were significantly reduced in the complete VICC group (factor II: 88 (84-99.3)% in the non-VICC group vs. 69 (49.5-83.5)% in the complete VICC group; factor X:94 (83-102) in the non-VICC group vs. 70 (66.5-79.8)% in the complete VICC group), while there was no difference in factor V activity at presentation. The time from bite to first antivenom administration did not correlate with the time course and most extreme concentrations for fibrinogen and D-dimer within the VICC groups.

DISCUSSION AND CONCLUSION

VICC occurs in approximately one-quarter of snakebite patients in South Korea; however, VICC itself does not appear to lead to clinical deterioration. Fibrinogen is an early diagnostic maker for complete VICC. Clotting factors II and X are involved in VICC. Future investigations should explore the mechanism of VICC from Korean snakebites and the effect of antivenom on VICC.

Asynchronous multi-decadal time-scale series of biotic and abiotic responses to precipitation during the last 1300 years

East Asian summer monsoon (EASM)-driven rapid hydroclimatic variation is a crucial factor with major socioeconomic impacts. Nevertheless, decadal- to centennial-scale EASM variability over the last two millennia is still poorly understood. Pollen-based quantitative annual precipitation (PqPann) and annual precipitation reconstructed by artificial neural networks (ANNs) for the period 650-1940 CE were reconstructed from a paleo-reservoir in South Korea. ANNs reconstruction was performed to compensate for a hiatus section. On a decadal timescale, 10 high-precipitation periods were identified, and PqPann and ANNs reconstructions were comparable to local instrumental rainfall and historic drought records. Biotic lags to rapid climatic changes ranging from 25 to 100 years were recognized by asynchronous pollen and speleothem responses to precipitation. We suggest that PqPann-based decadal- to centennial-scale climatic change reconstruction should take biotic lags into account, although the lags can be ignored on the millennial scale. The position of the EASM rainband influenced rainfall magnitude.

The concordance rate of non-chromosomal congenital malformations in twins based on zygosity: a retrospective cohort study

OBJECTIVE

To examine the concordance rate of non-chromosomal congenital malformations in twin pairs based on zygosity.

DESIGN

Retrospective cohort study.

SETTING

A tertiary hospital in Korea.

POPULATION

Twin pairs born at Seoul National University Hospital between 2001 and 2019.

METHODS

Congenital malformations were diagnosed by postnatal workups of neonates or autopsy in cases of stillborn infants. Zygosity was confirmed by sex, chorionicity and DNA analysis.

MAIN OUTCOME MEASURES

Concordance rate of congenital malformations in twin pairs based on zygosity.

RESULTS

In total, 3386 twin pairs were included. The risk of a congenital malformation in the index twin increased significantly if the co-twin had the congenital malformation, and the concordance rate was higher in monozygotic (MZ) than in dizygotic (DZ) twins (37.04 versus 16.77, P < 0.001). An increased risk of a congenital malformation in the presence of the same congenital malformation in the co-twin was observed only for malformations of the nervous system, eye/ear/face/neck, circulatory system, cleft lip/palate, genital organs, urinary system and musculoskeletal system. Significantly higher concordance rates in MZ than in DZ twin pairs were observed only for the nervous system (40.00 versus 0.00, P < 0.001), circulatory system (32.97 versus 19.74, P = 0.021), cleft lip/palate (44.44 versus 0.00, P = 0.017) and urinary system (22.22 versus 0.00, P = 0.004), whereas significant differences were not found for the genital organs or musculoskeletal system.

CONCLUSIONS

Monozygotic twins had higher concordance rates than DZ twins only in specific organ systems. It may be speculated that nervous system, circulatory system, cleft lip/palate and urinary system are primarily genetically affected.

TWEETABLE ABSTRACT

Monozygotic twins had higher concordance rates than dizygotic twins only in specific organ systems.

The effect of myocardial injury on the clinical course of snake envenomation in South Korea

CONTENT

This study investigated the incidence, progression and clinical course of myocardial injury-related snake envenomation in South Korea. In addition, this study evaluated whether antivenom guidelines are appropriate to control envenomation in patients with myocardial injury.

METHODS

The study included 198 patients who received antivenom after a snakebite, and they were divided into two groups according to evidence of myocardial injury (defined as elevated troponin I or ischemic change on electrocardiogram) at presentation. Data including serial troponin I, echocardiogram/coronary angiogram findings, the clinical course, and treatment were collected and analyzed.

RESULTS

The incidence of myocardial injury at presentation was 15.2%. The troponin I level was 0.11 (0.07-0.56) ng/ml at presentation and tended to decrease over 24 h. Echocardiograms revealed neither regional wall motion abnormalities nor left ventricular dysfunction in 15 of 17 patients, while two patients showed signs of coronary artery stenosis on echocardiograms and coronary angiograms. However, compared with patients without myocardial injury, patients with myocardial injury had a higher frequency of systemic envenomation complications, including bleeding, respiratory failure, hypotension, acute kidney injury, thrombocytopenia and venom-induced consumption coagulopathy (VICC). The patients with myocardial injury at presentation needed significantly more frequent and larger doses of antivenom than indicated by the initial severity of envenomation. Multivariate analysis showed that myocardial injury was associated with the need for additional antivenom administration after initial administration.

DISCUSSION AND CONCLUSION

Myocardial injury is not uncommon after snake envenomation in Korea. Although myocardial injury itself seems to be benign, the clinical course of patients with myocardial injury is complicated, and myocardial injury is associated with the need for additional antivenom administration. The optimal use of antivenom to control envenomation in patents with myocardial injury after snake envenomation in South Korea should be established.

Second-phase validation study of an alternative developmental toxicity test using mouse embryonic stem cell-derived embryoid bodies

The embryoid body test (EBT) is a developmental toxicity test method that measures the size of embryoid bodies (EBs) and the viability of mouse embryonic stem cells (mESCs) and fibroblasts (3T3 cells). The previous pre-validation study confirmed the high accuracy (above 80%) of EBT using 26 coded test chemicals. This second-phase validation study assessed the inter-laboratory reproducibility (5 chemicals in common) and predictive capacity (10 chemicals in each laboratory) test using the coded test chemicals at three laboratories. For the prediction model, the accuracy is increased when more data is accumulated. Therefore, we updated the prediction model and analyzed the results of the second year with the newly created-prediction model. Statistical analysis of the inter-laboratory reproducibility test results indicated that accuracy, sensitivity, and specificity were 87%, 78%, and 100%, respectively. The results of the statistical analysis of the predictive capacity test showed an accuracy of 80%, sensitivity of 78%, and specificity of 81%. In conclusion, the EBT can accurately classify various embryotoxicants within a short period and with relatively little effort. Therefore, EBT can be used as a good way to test developmental toxicity.

The impact of hyperthermia after acute carbon monoxide poisoning on neurological sequelae

This study investigated whether hyperthermia within the first 24 h after presentation was associated with long-term neurological outcomes after acute carbon monoxide (CO) poisoning. This retrospective study included 200 patients with acute severe CO poisoning. Hyperthermia (≥ 37.5°C) developed during the first 24 h after presentation in 55 (27.5%) patients, and poor long-term neurological sequelae assessed at 23 months after acute CO poisoning developed in 19.5% of the patients. The incidence of poor long-term neurological outcomes was significantly higher in the hyperthermia group than in the normothermia group. Patients with poor long-term neurological outcomes had higher maximum temperatures than patients with good outcomes. No significant difference was found in the time of hyperthermia onset within the first day according to the neurological outcomes. Hyperthermia (adjusted odds ratio (aOR) 5.009 (95% confidence interval (CI) 1.556-16.126)) and maximum temperature (aOR 2.581 (95% CI 1.098-6.063)) within the first 24 h after presentation to the emergency department were independently associated with poor long-term neurological outcomes. Body temperature measurements, which are easily and noninvasively recorded at the bedside in any facility, help to predict the risk for poor long-term neurological outcomes. This study carefully emphasizes fastidious control of pyrexia, particularly during the early period after acute CO poisoning.

Serum neuron-specific enolase levels at presentation and long-term neurological sequelae after acute charcoal burning-induced carbon monoxide poisoning

OBJECTIVE

This study aimed to investigate whether clinical parameters and serum neuron-specific enolase (NSE) levels measured at emergency department (ED) presentation help stratify the risk of acute or delayed persistent severe neurological sequelae after acute carbon monoxide (CO) poisoning induced by charcoal burning.

METHODS

This retrospective study included 236 patients who suffered from CO poisoning. Demographic information, serum NSE levels measured in the ED, treatment, clinical course, and long-term neurological outcomes were recorded.

RESULTS

The median serum NSE level at presentation was 15.5 (10.9-22.7) ng/mL. No differences were observed in the duration of CO exposure; the initial Glasgow Coma Scale (GCS) score; the levels of arterial HCO₃^-, white blood cells (WBCs), C-reactive protein (CRP) or troponin I; or the frequency of abnormal diffusion-weighted imaging finding at presentation among the groups with different serum NSE levels at presentation. The incidences of acute and delayed persistent neurologic sequelae assessed at 22.3 months after acute charcoal CO poisoning were 5.1% and 8.5%, respectively. No difference in the NSE level was observed between patients stratified according to long-term neurological status. According to the multinomial logistic regression analysis, age, serum CRP levels and the initial GCS score were risk factors for the two types of persistent severe neurological sequelae, whereas troponin I levels were associated only with the acute persistent severe neurological sequelae. However, the adjusted NSE level was not a risk factor for any persistent neurological sequelae.

CONCLUSIONS

Serum NSE levels at presentation were not correlated with the risk of acute or delayed persistent neurological sequelae. Further studies with blood sampling at optimal time points and serial measurements should be conducted. Age, initial GCS score, and CRP levels may be risk factors for persistent severe neurological sequelae.

In-hospital outcomes and delayed neurologic sequelae of seizure-related endosulfan poisoning

PURPOSE

This study investigated the predictive factors for progression from seizure-related endosulfan poisoning to status epilepticus (SE) and refractory SE (RSE). This study also investigated delayed neurologic sequelae in seizure-related endosulfan poisoning.

METHODS

This retrospective, observational case series consisted of 73 patients who developed at least one seizure after endosulfan ingestion.

RESULTS

The progression rates from seizure-related endosulfan poisoning to SE and from SE-related endosulfan poisoning to RSE were 78.1% and 54.4%, respectively. The SE and RSE fatality rates were 19.2% and 41.9%, respectively. No patients reported the development of delayed neurological sequelae at least six months after discharge. Glasgow coma scale (GCS) score were identified as an independent factor for progression from seizure-related endosulfan poisoning to SE and from SE-related endosulfan poisoning to RSE. Lorazepam administration was independently associated with preventing progression from SE-related endosulfan poisoning to RSE.

CONCLUSION

Seizure-related endosulfan poisoning had higher progression rates to SE and RSE and higher fatality rates than other drug-induced seizures. However, delayed neurologic sequelae after discharge were not demonstrated. Due to the high progression rates from seizure-related endosulfan poisoning to SE and RSE and the absence of an established treatment for SE-related endosulfan poisoning, physicians should aggressively treat patients who experience a seizure after endosulfan poisoning and who present with decreased GCS score. Lorazepam should be considered a first-line anti-epileptic drug for controlling seizures in patients with endosulfan poisoning.

Randomized clinical trial of preoperative skin antisepsis with chlorhexidine gluconate or povidone–iodine

Background

Skin antiseptic agents are used to prevent surgical-site infection (SSI); few trials have reported the superiority of any specific agent in clean-contaminated abdominal surgery. This RCT was designed to compare the effectiveness of chlorhexidine gluconate and povidone–iodine.

Methods

Consecutive patients who underwent clean-contaminated upper gastrointestinal or hepatobiliary–pancreatic open surgery between 2011 and 2014 were assigned randomly to either chlorhexidine gluconate or povidone–iodine. The primary endpoint was the occurrence of SSI within 30 days of surgery. Secondary endpoints included causative organisms and risk factors for SSI.

Results

A total of 534 patients were randomized; 31 (5·8 per cent) developed an SSI. There was no difference in the overall SSI rate in the chlorhexidine gluconate and povidone–iodine groups: 15 of 267 (5·6 per cent) and 16 of 267 (6·0 per cent) respectively (P = 0·853). The most common causative organism was Enterococcus faecalis. In subgroup analysis, biliary–pancreatic surgery had a higher SSI rate (26 of 127, 20·5 per cent) than upper gastrointestinal (2 of 204, 1·0 per cent) and hepatic (3 of 203, 1·5 per cent) resection. Both age (60 years and over) and type of incision were associated with the risk of SSI.

Conclusion

No difference was detected between chlorhexidine gluconate and povidone–iodine antiseptics for prevention of SSI. Registration number: NCT01495117 (http://www.clinicaltrials.gov).

Sex Difference in Chronic Obstructive Lung Disease. Does it Matter? A Concise Review

Chronic obstructive lung disease (COPD) primarily affects men; however, its epidemiology has been changing because more women have become smokers. Recently, investigators found that although women and men were exposed to the same amount of smoke fume, women tended to have more severe disease and higher mortality rate. They also complain of more dyspnoea and may experience more severe exacerbations than men. This led to the question of whether sex has an impact on COPD course and whether women have a higher susceptibility to smoke fumes than men. That may be explained by multiple complex factors highlighting the relationship between sex, epidemiology, method of diagnostics and the clinical course of the disease. In this review, sex differences in epidemiology, clinical presentation, exacerbation, co-morbidities and treatment are covered.

Impact of Intra-Abdominal Adhesion on Living Donor Right Hepatectomy

The impact of intra-abdominal adhesion (IAA) on living donor right hepatectomy (LDRH) remains to be clarified. The purpose of this study was to compare both the donor and recipient outcomes of right lobe living donor liver transplantation according to IAA detected intraoperatively. LDRH donors were identified through a prospectively maintained database at the authors' institution between March 2008 and February 2014. IAA was graded according to Beck et al (Dis Colon Rectum 2000; 43: 1749-1753). LDRH donors with IAA (group A) were matched 1:3 to those without IAA (group B) based on age, gender, and BMI. Perioperative data, complications by the Clavien classification, and the outcomes with at least 12 months follow-up were compared. Thirty-two (7.6%) of a total of 420 LDRH donors had IAA around the liver. Nineteen donors had previous abdominal surgery. LDRH was successfully completed under upper midline laparotomy in all donors. Compared with group B, group A had a longer operative time (270 vs. 172 min; p < 0.001), a higher wound complication rate (28.1% vs. 4.2%; p = 0.009), and a longer postoperative stay (10 vs. 7 days; p = 0.009). All donors recovered completely to their previous activities. The 1-year graft and recipient survivals of recipients were comparable between two groups. These findings support the feasibility and safety of LDRH in patients with IAA.

Randomised clinical trial: vercirnon, an oral CCR9 antagonist, vs. placebo as induction therapy in active Crohn's disease

BACKGROUND

Many patients with active Crohn's disease do not adequately respond to therapies, highlighting the need for new treatments.

AIMS

To conduct a randomised, double-blind, placebo-controlled phase 3 study to assess the efficacy and safety of vercirnon, an oral inhibitor of CC chemokine receptor-9, for the treatment of patients with moderately-to-severely active Crohn's disease.

METHODS

Patients with a Crohn's Disease Activity Index (CDAI) of 220-450, plus evidence of active disease (endoscopically confirmed or elevation of both C-reactive protein and faecal calprotectin), who had failed corticosteroid or immunosuppressant therapy were enrolled. Patients were equally randomised to receive placebo, vercirnon 500 mg once daily or vercirnon 500 mg twice daily. The primary endpoint was clinical response, defined as a 100-point decrease in CDAI from baseline to week 12.

RESULTS

Six hundred and eight patients were randomised. Patient characteristics and baseline demographics were similar among the groups. The proportions of patients achieving a clinical response were 25.1%, 27.6% and 27.2% for placebo, once daily and twice daily respectively; treatment differences were not significant (2.5%; 95% confidence interval, CI -6.1% to 11.0%, P = 0.546 for once daily vs. placebo, and 2.1%; 95% CI -6.5% to 10.7%, P = 0.648 for twice daily vs. placebo). Adverse events were reported in 69.8%, 73.3% and 78.1% with serious adverse events in 8.9%, 5.9%, and 6.0% of patients in the placebo, once-daily and twice-daily groups, respectively.

CONCLUSIONS

We did not demonstrate efficacy of vercirnon as an induction therapy in patients with moderately-to-severely active Crohn's disease; its effect in maintenance therapy was not addressed.

Clinical and demographic characteristics predictive of treatment outcomes for certolizumab pegol in moderate to severe Crohn's disease: analyses from the 7-year PRECiSE 3 study

BACKGROUND

Clinical factors were previously identified as predictors of short-term treatment efficacy in Crohn's disease (CD). The PRECiSE 3 (P3) 7-year trial provides an opportunity to study predictors of short- and long-term clinical remission among CD patients treated with certolizumab pegol (CZP).

AIM

To identify factors that influence long-term remission of CD with CZP treatment.

METHODS

Patients who had completed placebo-controlled studies (PRECiSE 1/PRECiSE 2, P1/P2) enrolled in P3 and received open-label CZP 400 mg every 4 weeks up to 7 years. Baseline predictors included, but were not limited to, smoking status, disease duration, prior inflammatory bowel disease (IBD) surgery, Harvey-Bradshaw Index (HBI), albumin, haematocrit and CZP exposure; association with time to initial remission (HBI ≤4) was tested for patients who received CZP in P1/P2; time to loss of remission/frequency of maintenance of remission was also tested. Univariate analyses and multivariate Cox or logistic regression models were used.

RESULTS

Predictors for initial remission (N = 377) included age, haematocrit, prior IBD surgery and entry HBI (P < 0.05 for all). Predictors for loss of remission (N = 437) included HBI, serum albumin concentration, haematocrit, smoking status and exposure. Predictors of maintenance of remission (N = 437) included haematocrit, IBD surgery, HBI, disease duration, serum albumin concentration and exposure. Significant predictors were confirmed with stepwise multivariate regression models.

CONCLUSIONS

These analyses identified several influential parameters for short-and long-term remission of Crohn's disease with certolizumab pegol treatment. The data yield valuable hypotheses regarding factors that influence certolizumab pegol treatment. More investigation is needed. (ClinicalTrials.gov identifier NCT00552058).

Successful living donor liver transplantation between septuagenarians

We report a case of a 76-year-old female who underwent living donor right hepatectomy for her 75-year-old husband with recurrent hepatocellular carcinoma. With her voluntary decision, full medical and psychiatric assessment was performed. The operative time was 130 min in the donor and 399 min in the recipient. Both the donor and recipient had an uneventful recovery and were discharged on days 7 and 10, respectively with normal liver function. The couple has had no complication so far and is currently doing well in good health 26 months after living donor liver transplantation.

Long-term safety and efficacy of certolizumab pegol in the treatment of Crohn's disease: 7-year results from the PRECiSE 3 study

BACKGROUND

The efficacy and safety of certolizumab pegol (CZP) in moderate-to-severe Crohn's disease were demonstrated in two 26-week double-blind studies (PRECiSE 1 & 2).

AIM

To report the safety and efficacy outcomes of long-term, CZP therapy from PRECiSE 3, in which patients received treatment up to 7 years treatment.

METHODS

Patients completing PRECiSE 1 or 2 were eligible to enter PRECiSE 3 in which they received CZP 400 mg, open-label, every 4 weeks (without additional induction therapy) for up to 7 years, for up to 91 doses from study start. Safety (adverse events, including infections and malignancies) and efficacy (Harvey-Bradshaw Index, faecal calprotectin, C-reactive protein) were prospectively monitored. Remission was analysed using observed cases, last observation carried forward imputation and nonresponder imputation.

RESULTS

A total of 595 patients entered the study; 117 (20%) completed 7 years. Discontinuation rates were 29.2%, 13.6%, 16.1%, 7.9%, 5.0%, 4.5% and 3.9% (years 1-7 respectively). During 1920 patient-years of exposure to CZP, no new safety signals were observed. Incidence rates (new cases/100 patient-years) for serious infections and malignant neoplasms were 4.37 and 1.06 respectively. No lymphoproliferative malignancies were reported. Clinical remission rates were ≥68% at each year (observed cases); rates by last observation carried forward and nonresponder imputation were 58% and 45% at year 1, 56% and 26% at year 3 and 55% and 13% at year 7 respectively.

CONCLUSION

Certolizumab pegol was well tolerated in the long-term treatment of Crohn's disease, with sustained remission in some patients continuing in the study for up to 7 years. ClinicalTrials.gov identifier NCT00552058.

Effects of Dietary Fat Types on Growth Performance, Pork Quality, and Gene Expression in Growing-finishing Pigs

This study was performed to determine the effects of dietary fat sources, i.e., beef tallow, soybean oil, olive oil and coconut oil (each 3% in feed), on the growth performance, meat quality and gene expression in growing-finishing pigs. A total of 72 crossbred pigs (Landrace×Large White×Duroc) were used at 71±1 kg body weight (about 130 d of age) in 24 pens (320×150 cm) in a confined pig house (three pigs per pen) with six replicate pens per treatment. The growing diet was given for periods of 14±3 d and the finishing diet was given for periods of 28±3 d. The fat type had no significant effect either on growth performance or on chemical composition or on meat quality in growing-finishing pigs. Dietary fat type affected fatty acid composition, with higher levels of unsaturated fatty acids (UFAs) and monounsaturated fatty acids (MUFAs) in the olive oil group. Microarray analysis in the Longissimus dorsi identified 6 genes, related to insulin signaling pathway, that were differentially expressed among the different feed groups. Real time-PCR was conducted on the six genes in the longissimus dorsi muscle (LM). In particular, the genes encoding the protein kinase, cAMP-dependent, regulatory, type II, alpha (PRKAR2A) and the catalytic subunit of protein phosphatase 1, beta isoform (PPP1CB) showed the highest expression level in the olive oil group (respectively, p<0.05, p<0.001). The results of this study indicate that the type of dietary fat affects fatty acid composition and insulin signaling-related gene expression in the LM of pigs.

Clinical outcomes and risk factors of hepatitis B virus recurrence in patients who received prophylaxis with entecavir and hepatitis B immunoglobulin following liver transplantation

INTRODUCTION

Although entecavir (ETV) and hepatitis B immunoglobulin (HBIG) have widely been used for prophylaxis of hepatitis B virus (HBV) recurrence following liver transplantation (OLT), there have been few studies about clinical outcomes and risk factors of HBV recurrence.

MATERIALS AND METHODS

This study retrospectively assessed clinical outcomes and identified risk factors of post-transplant HBV recurrence in 154 patients who received prophylaxis with both ETV and HBIG after OLT.

RESULTS

The median follow-up duration was 28.0 months (range, 1.0-57.8). Post-transplant HBV recurrence occurred in 5 patients (3.2%) without any ETV-resistant mutants. The overall rates of HBV recurrence at 1, 2, and 4 years were 0.6%, 1.6%, and 6.2%, respectively. We found that recurrent hepatocellular carcinoma (HCC) was an independent risk factor of HBV recurrence (hazard ratio = 13.5, 95% confidence interval, 2.4-74.4; P = .006).

CONCLUSIONS

Prophylaxis with a combination of ETV and HBIG resulted in a low HBV recurrence rate following OLT without any emergence of ETV-resistant mutants. Recurrent HCC was an independent risk factor of HBV recurrence in patients who received prophylaxis with both ETV and HBIG for prophylaxis following OLT.

Fate and transport of radiocesium, radiostrontium and radiocobalt on urban building materials

Kinetics of (137)Cs, (60)Co and (85)Sr sorption on powdered building materials in aqueous suspensions at 20 °C for interaction times of 1, 7, 14 and 28 days were studied. The (137)Cs distribution coefficient (Kd) values for all building materials except limestone practically did not change during 28 days of sorption. The Kd ((85)Sr) was several orders of magnitude lower than for (60)Co. The highest values were observed for asphalt and granite. An effective method to study the radionuclide distribution in depth of building materials using layer-by-layer sanding was developed. Using the developed method, the (137)Cs, (60)Co and (85)Sr distribution with depth of selected building materials at different air humidity, time and temperature was studied. Relative humidity (RH) was found to influence significantly the (85)Sr depth distribution in the case of granite (unlike (137)Cs and (60)Co). While (85)Sr penetrated to 0.5 mm in depth of granite at RH 30%, at RH 87% the depth of (85)Sr penetration to granite reached up to 7 mm.

Clinical characteristics of patients with tuberculosis-destroyed lung

SETTING

Multicentre study.

OBJECTIVE

To define the clinical characteristics of patients with tuberculosis (TB) destroyed lung due to past TB.

DESIGN

We reviewed patients with TB-destroyed lung between May 2005 and June 2011.

RESULTS

A total of 595 patients from 21 hospitals were enrolled. The mean age was 65.63 ± 0.47 (mean ± standard error); 60.5% were male. The mean number of lobes involved was 2.59 ± 0.05. Pleural thickening was observed in 54.1% of the patients. Mean forced vital capacity (FVC), forced expiratory volume in 1 s (FEV(1)), FEV(1)/FVC, bronchodilator response and number of exacerbations per year were respectively 2.06 ± 0.03 l (61.26% ± 0.79), 1.16 ± 0.02 l (49.05% ± 0.84), 58.03% ± 0.70, 5.70% ± 0.34, and 0.40 ± 0.04. The number of lobes involved was significantly correlated with FVC and FEV(1), and with the number of exacerbations per year. Use of long-acting muscarinic antagonists or long-acting beta-2 agonists plus inhaled corticosteroids resulted in bronchodilatory effects. Multivariable regression analysis showed that age, initial FEV(1) (%) and number of exacerbations during follow-up were independent factors affecting change in FEV(1).

CONCLUSION

Decreased lung function with exacerbation, and progressive decline of FEV(1) were observed in patients with TB-destroyed lung.

GenoType® MTBDRplus assay detection of drug-resistant tuberculosis in routine practice in Korea

SETTING

Korea is an intermediate-burden country with high rates of tuberculosis (TB) drug resistance.

OBJECTIVE

To evaluate the performance of the GenoType® MTBDRplus (MTBDR) assay in diagnosing drug-resistant TB in routine practice in Korea.

DESIGN

The MTBDR assay was performed on 428 samples, and the results were retrospectively compared with the results of conventional drug susceptibility testing (DST). The interval between treatment and diagnosis of drug resistance was also compared.

RESULTS

The sensitivity, specificity and positive and negative predictive values of the MTBDR assay were respectively 96.6%, 98.9%, 93.4% and 99.5% for the detection of rifampicin (RMP) resistance; 93.8%, 98.3%, 92.7% and 98.6% for isoniazid (INH) resistance; and 91.1%, 99.2%, 99.4% and 98.7% for multidrug-resistant TB (MDR-TB). The median interval between the start of anti-tuberculosis chemotherapy and the reporting of results was 88.9 days for conventional DST and 19.8 days for MTBDR using clinical specimens.

CONCLUSION

The specificity of the MTBDR assay in detecting MDR-TB was very high, although the sensitivity in detecting INH resistance and MDR-TB was not optimal (<95%). Although the turnaround time in detecting drug resistance was dramatically reduced with MTBDR compared to conventional DST, more effort is needed to shorten the turnaround time.

Lymph node ratio is an independent prognostic factor in patients with rectal cancer treated with preoperative chemoradiotherapy and curative resection

PURPOSE

To evaluate the prognostic effect of lymph node ratio (LNR) in patients with locally advanced rectal cancer who were treated with curative resection after preoperative chemoradiotherapy (CRT).

METHODS

Between October 2001 and December 2007, 519 patients who had undergone curative resection of primary rectal cancer after preoperative CRT were enrolled. Of these, 154 patients were positive for lymph node (LN) metastasis and were divided into three groups according to the LNR (≤ 0.15 [n=80], 0.16-0.3 [n=44], >0.3 [n=30]) to evaluate the prognostic effect on overall survival (OS) and disease-free survival (DFS).

RESULTS

LNR (≤ 0.15, 0.16-0.3, and >0.3) was significantly associated with 5-year OS (90.3%, 75.1%, and 45.1%; p<0.001) and DFS (66.7%, 55.8%, and 21.9%; p<0.001) rates. In a multivariate analysis, LNR (≤ 0.15, 0.16-0.3, and >0.3) was a significant independent prognostic factor for OS (hazard ratios [HRs], 1, 3.609, and 8.197; p<0.001) and DFS (HRs, 1, 1.699, and 3.960; p<0.001). LNR had a prognostic impact on OS and DFS in patients with <12 harvested LNs, as well as in those with ≥ 12 harvested LNs (p<0.05).

CONCLUSION

LNR was a significant independent prognostic predictor for OS and DFS in patients with locally advanced rectal cancer who were treated with curative resection after preoperative CRT.

Increased striatal dopamine transporter density in moderately severe old restless legs syndrome patients

BACKGROUND AND PURPOSE

Dopamine dysregulation in restless legs syndrome (RLS) may be varied by the severity of RLS, which could contribute to the conflicting results from previous functional neuroimaging studies on the central dopaminergic neurotransmission of RLS. The aim of this study was to observe whether reduced striatal dopaminergic neurotransmission is associated with moderate to moderately severe RLS.

METHODS

Thirteen elderly patients with RLS and 12 normal elderly controls were enrolled in the study. All the subjects were dopaminergic-drug naïve and twelve patients with RLS had the severity of moderate to moderately severe degree based on the International Restless Legs Syndrome Study Group (IRLSSG) Severity Scale. We compared dopamine transporter density (DAT) availability and D2 receptor density in the striatum between patients with RLS and controls using [(123)I]2β-carbomethoxy-3β-(4-iodophenyl)tropane single-photon emission computed tomography (SPECT) and [(123)I]iodobenzamide SPECT.

RESULTS

Dopamine transporter density of patients with RLS was increased in the caudate (P = 0.037), posterior putamen (P = 0.041), and entire striatum (P = 0.046) compared with that of normal controls. DAT density was higher in the anterior putamen of patients with RLS than controls, although statistically not significant (P = 0.079). There was no difference in the D2 receptor density between patients with RLS and normal controls in the whole striatum or any of subregions.

CONCLUSIONS

Dysregulation rather than simple upregulation or downregulation of central dopaminergic neurotransmission may underlie the pathogenesis of RLS, and decreased dopaminergic neurotransmission may cause moderate to moderately severe RLS in the elderly.

Chronic obstructive lung disease-related health care utilisation in Korean adults with obstructive lung disease

OBJECTIVES

The numbers of nationwide epidemiological surveys about chronic obstructive pulmonary disease (COPD) prevalence and prospective cohort studies for health care utilisation are limited. We investigated COPD-related health care utilisation in adults with obstructive lung disease in the second Korean National Health and Nutritional Survey (KNHANES II) in 2001 using Korean national medical insurance claim data.

METHODS

Among people aged >40 years, obstructive lung disease (OLD) is defined according to Global Initiative for Chronic Obstructive Lung Disease criteria. Data from a total of 1942 subjects were linked with Korean national medical insurance claims data, and we investigated their COPD-related out-patient visits from 2002 to 2005.

RESULTS

Among the 1942 subjects, 256 (13.2%) had airflow obstruction. COPD-related out-patient visits were reported for 8.2% of patients without airway obstruction, 18.1% of those with mild airway obstruction, and 33.9% of those with moderate to very severe airway obstruction. Multivariate analysis revealed that previous COPD diagnosis by a physician (OR 2.54; P = 0.02) and lower socio-economic status (OR 0.45; P = 0.02) were independent predictors of COPD-related out-patient visits in subjects with OLD.

CONCLUSIONS

Of the subjects with airway obstruction, those with poor financial status utilised COPD-related health care services less frequently, and those previously diagnosed as having COPD by a physician utilised the services more frequently.

Relative bioavailability of two 5-mg montelukast sodium chewable tablets: a single dose, randomized, open-label, 2-period crossover comparison in healthy korean adult male volunteers

Montelukast sodium, cysteinyl leukotriene receptor 1 specific antagonist, has been marketed in Korea for the treatment of bronchial asthma and allergic rhinitis. The aim of this study was to compare the pharmacokinetics and relative bioavailability of a test and reference formulation of montelukast 5-mg chewable tablets in healthy Korean male volunteers to meet KFDA regulatory criteria for marketing of the new generic formulation. This study was designed as a single-dose, 2-treatment, and 2-period crossover trial with 32 healthy volunteers. Each subject was randomly assigned to receive the test (Dong-Kook Montelukast Sodium Chewable Tablet 5 mg®) or reference (Singulair Chewable Tablet 5 mg®) formulation. The tablet was chewed 20 times, and then swallowed with 240 mL of water. Plasma concentrations of montelukast up to 24 h after the dose were determined using a validated UPLC-MS/MS method, and the bioequivalence between the 2 formulations was assessed by statistical analysis of mean ratios of log-transformed AUC0-24 h and Cmax. No period or sequence effects were detected. The AUC0-24 h was 1 835 ng·h/mL for the test formulation, and 1 930 ng·h/mL for the reference formulation. The respective values of AUC0-∞ were 1 917 and 2 015 ng·h/mL. The Cmax of the test and reference products (247 and 283 ng/mL, respectively) reached at 2.25 and 2.72 h, respectively. Then, they gradually decreased with the mean terminal t1/2 of 5.25 and 5.30 h for the test and reference products, respectively. The 90% CIs for the ratio of log-transformed AUC0-24 h and Cmax for the test and reference formulations were 0.92-0.99 and 0.83-0.91, respectively. No adverse events were reported in this study. This single dose study found that the test and reference products met the regulatory criteria for bioequivalence in these fasting healthy Korean male volunteers.

Co-morbid diabetes in patients with Crohn's disease predicts a greater need for surgical intervention

BACKGROUND

The prevalence of diabetes is increasing rapidly. Given its pro-inflammatory nature, comorbid diabetes may affect the course of Crohn's disease (CD).

AIM

To determine whether comorbid diabetes influences the natural history of CD.

METHODS

We compared a cohort with CD and comorbid diabetes to a nondiabetic control population and calculated the period prevalence of surgical intervention over a 5-year period. Unadjusted and adjusted odds-ratios were calculated regarding the need for surgical intervention using univariate and multivariate logistic regression.

RESULTS

A total of 240 patients were identified, 16 of whom were diabetics (6.7%). The period prevalence of CD-specific surgery in the diabetic cases was 75.0% and in the nondiabetic controls, 31.7%. The diabetic patients were more obese than the controls (44% vs. 10%; P < 0.0001) and older than the controls (47.4 years vs. 38.6; P < 0.01). There was no difference in the frequency of biologic therapy use, immunomodulator use, smoking, perianal disease, ileal involvement or corticosteroid use between the diabetics and controls. Univariate analysis revealed that diabetes (OR 6.46 [95% CI 2.01-20.8]), smoking (OR 2.46 [95% CI 1.24-4.90]), ileal disease (OR 2.21 [95% CI 1.15-4.24]) and obesity (OR 2.22 [95% CI 1.04-4.77]) were risk factors for needing surgery. After adjustment for covariates, the OR for surgical intervention in diabetics was 5.4 (95% CI 1.65-17.64).

CONCLUSION

Co-morbid diabetes in patients with Crohn's disease predicts a greater need for surgical intervention.

Studies on nanosized iron based modified catalyst for Fischer-Tropsch synthesis application

To improve catalytic performance iron based catalyst, the effects of some metal promoters, especially potassium, copper and other transition metal oxides as well as different supports have been reported. A series of Fe/K/Cu catalysts promoted with magnesium and ceria by precipitation method, followed by impregnation method; keeping Cu and K content same. The catalysts were characterized by XRD, N2 physisorption, TPR and TEM techniques. From XRD, the presence of hematite (Fe2O3) phase was detected in all precipitated iron catalysts and CFe2.5 phase in all used catalysts. TPR results showed that addition of Mg facilitated the reduction of Fe2O3 and decrease in reduction temperature. The catalytic performance was investigated in a fixed-bed reactor at 250 degrees C, 2 MPa pressure and H2/CO molar ratio of 2. Concentration of Mg was found to affect the CO conversion and product distribution. It was found that precipitated iron catalyst Fe/Mg/Cu/K with Mg/Fe ratio of 0.1 showed highest conversion (60.6%) and C5(+) selectivity (92.4%) among all catalysts tested.

Non-tuberculous mycobacterial diseases presenting as solitary pulmonary nodules

SETTING

South Korea, 2005-2007.

BACKGROUND

Non-tuberculous mycobacterial diseases presenting as solitary pulmonary nodules (NTM-SPN) are rare and may be misdiagnosed as tuberculoma.

DESIGN

Eleven NTM-SPN patients were enrolled retrospectively and compared with two groups each of 33 patients with upper lobe cavitary (UC) and nodular bronchiectatic (NB) type NTM diseases, respectively.

RESULTS

The patients' median age was 52 years. Compared with UC-type disease, NTM-SPN patients showed female (n = 9) and never smoker (n = 8) predominance and fewer comorbidities (n = 0; P < 0.05 for each). Mycobacterium avium (n = 9) was predominant in NTM-SPN patients, followed by M. intracellulare (n = 2), whereas M. intracellulare was most frequently isolated from patients with both UC- and NB-type NTM (P < 0.05). The nodules were a median of 2.3 cm in diameter (range 1.6-6.3 cm) and were distributed evenly in all lobes. In all patients, percutaneous needle aspiration/biopsy was performed with a median 71 days of diagnostic delay. Ten patients successfully completed treatment, and one showed spontaneous reduction of nodule size without treatment. Reverse blot hybridisation assays of six DNA samples identified four subjects with M.avium-intracellulare complex (MAC), in line with conventional test data.

CONCLUSION

NTM-SPN was caused exclusively by MAC. Although clinical outcome was favourable, confirmatory diagnosis was delayed. Molecular methods are needed for early diagnosis of NTM-SPN.

Characterization of filamentous bacteriophage PE226 infecting Ralstonia solanacearum strains

AIMS

The aim of this study was to isolate and characterize new bacteriophages that infect a wide range of plant pathogenic Ralstonia solanacearum strains.

METHODS AND RESULTS

Fifteen bacteriophages were isolated from pepper, tomato and tobacco plant rhizospheres infected with R. solanacearum. A host specificity analysis of the isolated phages using nine strains of R. solanacearum indicated great phage diversity in a single soil. Two phages, PE226 and TM227, showed clear plaques on all nine bacterial hosts tested and were virtually identical in morphology and genome. PE226, an Inovirus, is a long, flexible, filamentous phage carrying a circular (+) sense single-strand DNA genome of 5475 nucleotides. DNA sequences of PE226 exhibited nine open reading frames (ORF) that were not highly similar to those of other phages infecting R. solanacearum. The genome organization of PE226 was partially similar to that of p12J of Ralstonia pickettii. One ORF of PE226 showed identity to the zot gene encoding zonula occludens toxin of Vibrio cholera. Orf7 of PE226 was also present in the genome of R. solanacearum strain SL341. However, SL341, a highly virulent strain in tomato, was still sensitive to phage PE226.

CONCLUSIONS

A new, flexible, filamentous phage PE226 infected wide range of R. solanacearum strains and carried unique circular single-strand DNA genome with an ORF encoding Zot-like protein.

SIGNIFICANCE AND IMPACT OF THE STUDY

PE226 may be a new type of temperate phage, based on its lytic nature on a wide range of hosts and the presence of a zot homologue in a host bacterial genome.

Association of the G-protein and α2-adrenergic receptor gene and plasma norepinephrine level with clonidine improvement of the effects of diuretics in patients with cirrhosis with refractory ascites: a randomised clinical trial

OBJECTIVE

Clonidine is an α(2)-adrenoceptor agonist which, by coupling with G-protein, has been proposed as an alternative treatment for refractory ascites of patients with cirrhosis for several years. Genetic polymorphisms of β-adrenoceptor and angiotensin II type 1 receptor blockers have been reported to affect drug response in patients with cirrhosis. This study evaluated the clonidine-diuretic response rate, favourable predictors and genetic components of the clonidine-diuretic response in patients with cirrhosis with refractory ascites.

METHODS

270 patients with cirrhosis with refractory ascites were randomised equally into two treatment groups to receive diuretics alone or the clonidine-diuretics association. The primary end point was clonidine-diuretic response rate. Secondary end points were mean daily dose of diuretics, times of paracentesis, ascites-related readmission and 1-year survival rate.

RESULTS

Good clonidine responders had better natriuresis and diuresis as well as a significant decrease in abdominal circumference, plasma renin, aldosterone and norepinephrine levels. The overall clonidine-diuretics response rate was 55-60%. In patients with cirrhosis, the prevalence of ARDA(2)C WD/DD and GNB3 CT/TT genotypes was 71% and 77%, respectively. Among the responders, 71% of patients with cirrhosis had the ARDA(2)C WD/DD genotype and 67% has the GNB3 CT/TT genotype. Besides higher baseline norepinephrine levels, the presence of both ARDA(2)C WD/DD and GNB3 CT/TT genotypes showed a positive predictive value of 82% and a negative predictive value of 79% for good clonidine response.

CONCLUSIONS

These results suggest that neurohormonal and genetic testing may be used as predictive factors for the additive effects of clonidine on the diuresis and natriuresis effects of diuretics in patients with cirrhosis with refractory ascites.

Nano-sized cobalt based Fischer-Tropsch catalysts for gas-to-liquid process applications

Nano-sized cobalt supported catalysts were prepared for Fischer-Tropsch synthesis in gas-to-liquid (GTL) process. The dependence of crystallite size and reducibility of Co3O4 on the supports were investigated with FTS activity. XRD peaks revealed nano crystallites (< 5.47 nm) of Co3O4 crystallites. TEM showed round shaped particles with size less than 5 nm. Support with higher acidity decreased crystallite size of Co3O4. XRD data of used catalysts showed Co3O4 crystallites smaller than 3.5 nm which do not reduce easily to Co(0) state. The crystallite size of Co3O4 plays a role in its reduction to Co(0). TPR results showed that the reduction temperature shifts to higher temperature due to metal-support interaction. The variation in the activity of the catalysts depends on the support which in turn affects the crystallite size, dispersion, reducibility and activity of Co species in Fischer-Tropsch Synthesis (FTS). In this study, Co/Al2O3 showed higher CO conversion than the other catalysts. However, the C5+ production was in order Co/SiO2 (78.1%) > Co/Al2O3 (70.0%) > Co/R_TiO2 (61%) > Co/A_TiO2 (57.5%).

Changes in the organ procurement system in South Korea: effects on brain-dead donor numbers

In Korea, the Organ Transplantation Act came into effect in 2000, establishing the Korean Network for Organ Sharing (KONOS) with centralized authority for organ procurement as well as for approval of donors and recipients to ensure fair organ allocation. However, the number of brain-dead donors decreased sharply, and the organ allocation system proved inefficient. The government revised the Organ Transplantation Act in August 2002, introducing an incentive system. If a transplantation hospital formed a Committee for Brain Death Evaluation and a Hospital Organ Procurement Organization, it could receive a kidney from a brain dead-donor as an incentive to foster organ procurement regardless of the KONOS wait list. The government also launched a pilot brain-dead donor registry program to strengthen Hospital Organ Procurement Organization activity. If local hospitals collaborated with specialized hospitals in organ procurement, local hospitals obtained financial incentives. But because the organ shortage problem has not been resolved, the government has proposed four initiatives: first, broadening the incentive system, which makes it possible to give each specialized hospital a choice of one of eight organs from each donor as an incentive; second, development of an Independent Organ Procurement Organization; third introduction of an opt-out system; and last, improvement of the Committee for Brain Death Evaluation system. It is uncertain which initiatives will be adopted, but changes in organ procurement systems are nonetheless considered a key to solve the organ shortage problem in Korea.