Clinical characteristics and outcomes of Clostridioides difficile infection in the intensive care unit: a KASID multi-centre study

BACKGROUND

Despite the growing clinical and economic burden of Clostridioides difficile infection (CDI), data on CDI in the intensive care unit (ICU) in the Asia-Pacific region are lacking.

METHODS

This retrospective study analysed 191 patients who were treated with CDI in the ICUs of three hospitals in South Korea from January 2017 to May 2021. Backward-stepwise multiple logistic regression was used to identify factors influencing the treatment response and mortality.

RESULTS

Fifty-eight patients (30.4%) were considered immunocompromised. The mean Charlson comorbidity index was 5.65 ± 2.39 (10-year survival rate: 21%), the APACHE II score was 20.86 ± 7.78 (mortality rate: 40%), the ATLAS score was 5.45 ± 1.59 (cure rate: 75%), and the SOFA score was 7.97 ± 4.03 (mortality rate: 21.5%). Fifty-eight (30.4%) of the CDI cases were severe and 40 (20.9%) were fulminant. Oral vancomycin or oral metronidazole was the most frequently first-line treatments (N = 57; 32.6%). The 10-day response rate was 59.7% and the eight-week overall mortality rate was 41.4%. Fulminant CDI (OR 0.230; 95% CI 0.085-0.623) and each one-unit increment in the SOFA score (OR 0.848; 95% CI 0.759-0.947) were associated with treatment failure. High APACHE II (OR 0.355; 95% CI 0.143-0.880) and SOFA (OR 0.164; 95% CI 0.061-0.441) scores were associated with higher mortality.

CONCLUSIONS

High-risk patients in the ICU had a higher mortality rate and a lower cure rate of CDI. Further research is required to provide more accurate prediction scoring systems and better clinical outcomes.

Prognostic significance of bone marrow 2-[18F]-fluoro-2-deoxy-d-glucose uptake in diffuse large B-cell lymphoma: relation to iliac crest biopsy results

AIM

To investigate the prognostic significance of bone marrow (BM) 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (FDG) uptake in relation to posterior iliac crest BM biopsy (BMB) results in diffuse large B-cell lymphoma (DLBCL).

MATERIALS AND METHODS

Pretreatment integrated positron-emission tomography(PET)/computed tomography (CT) images of 512 DLBCL patients who underwent BMB and received rituximab combined with cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy were analysed retrospectively. BM uptake was assessed visually and by maximum standard uptake value (SUVmax). Associations with lymphoma-specific survival (LSS) were assessed using Kaplan-Meier and Cox regression analyses.

RESULTS

FDG(+) BM was observed in 64 cases (41 focal, 12 heterogeneous, 11 diffuse). This finding distinguished iliac crest involvement (positive in 59 and negative in 453) with 89.6% accuracy (459/512) and 93.6% specificity (424/453). In BMB(+) patients, BM-to-liver SUVmax ratio >1.8 concurred perfectly with FDG(+) BM. During 52 months of follow-up, there were 156 lymphoma-related deaths. In the entire population, multivariate analysis revealed high International Prognostic Index (IPI; p<0.001), old age (p=0.003), bulky disease (p=0.011), BMB(+) (p=0.028), and FDG(+) BM (p=0.019) as independent predictors of worse LSS. In the BMB(+) subgroup, high National Comprehensive Cancer Network-revised IPI (NCCN-IPI; p=0.029) and FDG(+) BM (p=0.008) were significant independent predictors. Among BMB(+) patients with low to low-intermediate NCCN-IPI, FDG(+) BM was associated with significantly worse 2-year LSS (33.3% versus 100%; p=0.017). The same was true among those with high-intermediate NCCN-IPI (34.7% versus 76.9%.; p=0.026).

CONCLUSION

Increased BM FDG in DLBCL is a predictor of worse LSS independent of BMB results and other prognostic variables including IPI/NCCN-IPI.

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.

Vesicular glutamate transporter-immunopositive axons that coexpress neuropeptides in the rat and human dental pulp

AIM

To examine the type of vesicular glutamate transporter (VGLUT)-immunopositive (+) axons that coexpress neuropeptides in the rat and human dental pulp, which may help understand peripheral mechanism of pulpal inflammatory pain in rats and humans.

METHODOLOGY

The trigeminal ganglia (TG) and the dental pulp of the maxillary molar teeth from three male Sprague-Dawley rats weighing 300-330 g and dental pulps of three healthy human (male) maxillary premolar teeth from three 16 to 28-year-old patients extracted for orthodontic treatment were used. The type of VGLUT + axons that coexpress substance P (SP)- and/or calcitonin gene-related peptide (CGRP) and parvalbumin in the rat TG and in the axons of the rat and the human dental pulp was examined by double fluorescence immunohistochemistry and quantitative analysis. Results were analyzed using one-way anova and the Kruskal-Wallis test.

RESULTS

SP and CGRP were expressed in many human VGLUT1 + pulpal axons but not in the rat VGLUT1 + TG neurons and pulpal axons (P < 0.05). SP and CGRP were expressed in a considerable number of human VGLUT2 + pulpal axons and also in many rat TG neurons and pulpal axons. The fraction of VGLUT1 + axons expressing parvalbumin was about three times higher in the rat than in the human dental pulp (P < 0.05).

CONCLUSIONS

These findings suggest that the types of VGLUT + axons, which release neuropeptides, may be different between the rat and the human dental pulp, raising a possibility that peripheral mechanism of pulpal inflammatory pain may be different between rats and humans.

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.

Predictive value of plasma neutrophil gelatinase-associated lipocalin in acute charcoal-burning carbon monoxide poisoning

This study aimed to assess the feasibility of using the plasma neutrophil gelatinase-associated lipocalin (NGAL) level at the time of presentation in the emergency department (ED) to predict acute kidney injury (AKI) and the long-term neurological outcomes of acute charcoal-burning carbon monoxide (CO) poisoning. This retrospective study included 260 patients who suffered acute charcoal-burning CO poisoning. The median plasma NGAL concentration at the time of presentation in the ED after acute charcoal-burning CO poisoning was 78 (54–115) ng/ml. The NGAL level was an independent predictor of AKI development and could be used to stratify the severity of AKI. However, the area under the receiver operating characteristic curve (AUC) of the predictive model for AKI that included both the plasma NGAL level and clinical parameters was comparable to that of the predictive model including only the clinical parameters. The plasma NGAL level at the time of presentation in the ED was an independent factor predicting long-term neurological outcomes in patients who did not develop AKI. In these patients, the plasma NGAL level significantly improved the predictive accuracy of the model when used in combination with clinical parameters. In contrast, the plasma NGAL level was not associated with long-term neurological outcomes in patients who developed AKI. Measurement of the plasma NGAL level at the time ED presentation might improve the prediction of long-term neurological outcomes in patients who do not develop AKI after acute charcoal-burning CO poisoning. However, it might not offer additional benefit for AKI prediction compared to previously used markers.

Incidence of psoriasiform diseases secondary to tumour necrosis factor antagonists in patients with inflammatory bowel disease: a nationwide population-based cohort study

BACKGROUND

There are increasing reports of paradoxical psoriasiform diseases secondary to anti-tumour necrosis factor (TNF) agents.

AIMS

To determine the risks of paradoxical psoriasiform diseases secondary to anti-TNF agents in patients with inflammatory bowel disease (IBD).

METHODS

A nationwide population study was performed using the Korea National Health Insurance Claim Data. A total of 50 502 patients with IBD were identified between 2007 and 2016. We compared 5428 patients who were treated with any anti-TNF agent for more than 6 months (anti-TNF group) and 10 856 matched controls who had never taken anti-TNF agents (control group).

RESULTS

Incidence of psoriasis was significantly higher in the anti-TNF group (36.8 per 10 000 person-years) compared to the control group (14.5 per 10 000 person-years) (hazard ratio [HR] 2.357, 95% confidence interval [CI] 1.668-3.331). Palmoplantar pustulosis (HR 9.355, 95% CI 2.754-31.780) and psoriatic arthritis (HR 2.926, 95% CI 1.640-5.218) also showed higher risks in the anti-TNF group. In subgroup analyses, HRs for psoriasis by IBD subtype were 2.549 (95% CI 1.658-3.920) in Crohn's disease and 2.105 (95% CI 1.155-3.836) in ulcerative colitis. Interestingly, men and younger (10-39 years) patients have significantly higher risks of palmoplantar pustulosis (HR 19.682 [95% CI 3.867-100.169] and HR 14.318 [95% CI 2.915-70.315], respectively), whereas women and older (≥40 years) patients showed similar rates between the two groups.

CONCLUSIONS

The risks of psoriasiform diseases are increased by anti-TNF agents in patients with IBD. Among psoriasiform diseases, the risk of palmoplantar pustulosis shows the biggest increase particularly in male and younger patients.

Critical phenomena of a hybrid phase transition in cluster merging dynamics

Recently, a hybrid percolation transition (HPT) that exhibits both a discontinuous transition and critical behavior at the same transition point has been observed in diverse complex systems. While the HPT induced by avalanche dynamics has been studied extensively, the HPT induced by cluster merging dynamics (HPT-CMD) has received little attention. Here, we aim to develop a theoretical framework for the HPT-CMD. We find that two correlation-length exponents are necessary for characterizing the giant cluster and finite clusters separately. The conventional formula of the fractal dimension in terms of the critical exponents is not valid. Neither the giant nor finite clusters are fractals, but they have fractal boundaries. A finite-size scaling method for the HPT-CMD is also introduced.

Deficiency of aminopeptidase P1 causes behavioral hyperactivity, cognitive deficits, and hippocampal neurodegeneration

Metabolic diseases affect various organs including the brain. Accumulation or depletion of substrates frequently leads to brain injury and dysfunction. Deficiency of aminopeptidase P1, a cytosolic proline-specific peptidase encoded by the Xpnpep1 gene, causes an inborn error of metabolism (IEM) characterized by peptiduria in humans. We previously reported that knockout of aminopeptidase P1 in mice causes neurodevelopmental disorders and peptiduria. However, little is known about the pathophysiological role of aminopeptidase P1 in the brain. Here, we show that loss of aminopeptidase P1 causes behavioral and neurological deficits in mice. Mice deficient in aminopeptidase P1 (Xpnpep1^-/- ) display abnormally enhanced locomotor activities in both the home cage and open-field box. The aminopeptidase P1 deficiency in mice also resulted in severe impairments in novel-object recognition, the Morris water maze task, and contextual, but not cued, fear memory. These behavioral dysfunctions were accompanied by epileptiform electroencephalogram activity and neurodegeneration in the hippocampus. However, mice with a heterozygous mutation for aminopeptidase P1 (Xpnpep1^+/- ) exhibited normal behaviors and brain structure. These results suggest that loss of aminopeptidase P1 leads to behavioral, cognitive and neurological deficits. This study may provide insight into new pathogenic mechanisms for brain dysfunction related to IEMs.

Ossicular chain reconstruction improves bone conduction threshold in chronic otitis media

This study aimed to assess the elevation of bone conduction threshold in patients with chronic otitis media and to investigate the mechanism of this phenomenon. One hundred and six patients with unilateral chronic otitis media who had undergone a tympanomastoidectomy were reviewed retrospectively. The differences in the bone conduction thresholds between the diseased and normal sides were assessed and compared according to the duration of the disease and the presence of cholesteatoma. Post-operative changes in the bone conduction threshold were also assessed. The mean bone conduction thresholds were significantly elevated on the diseased side, ranging from 3.4 to 11.6 dB across frequencies, with a maximal elevation at 2000 Hz. The duration of disease and the presence of cholesteatoma did not affect the degree of the bone conduction elevation. After ossicular reconstruction, bone conduction thresholds improved significantly at all frequencies, with the greatest improvement being observed at 2000 Hz. These results suggest that the elevation in the bone conduction threshold in chronic otitis media is mainly caused by a change in the conductive mechanism in the middle ear.

The genetics of an early Neolithic pastoralist from the Zagros, Iran

The agricultural transition profoundly changed human societies. We sequenced and analysed the first genome (1.39x) of an early Neolithic woman from Ganj Dareh, in the Zagros Mountains of Iran, a site with early evidence for an economy based on goat herding, ca. 10,000 BP. We show that Western Iran was inhabited by a population genetically most similar to hunter-gatherers from the Caucasus, but distinct from the Neolithic Anatolian people who later brought food production into Europe. The inhabitants of Ganj Dareh made little direct genetic contribution to modern European populations, suggesting those of the Central Zagros were somewhat isolated from other populations of the Fertile Crescent. Runs of homozygosity are of a similar length to those from Neolithic farmers, and shorter than those of Caucasus and Western Hunter-Gatherers, suggesting that the inhabitants of Ganj Dareh did not undergo the large population bottleneck suffered by their northern neighbours. While some degree of cultural diffusion between Anatolia, Western Iran and other neighbouring regions is possible, the genetic dissimilarity between early Anatolian farmers and the inhabitants of Ganj Dareh supports a model in which Neolithic societies in these areas were distinct.

Genuine non-self-averaging and ultraslow convergence in gelation

In irreversible aggregation processes droplets or polymers of microscopic size successively coalesce until a large cluster of macroscopic scale forms. This gelation transition is widely believed to be self-averaging, meaning that the order parameter (the relative size of the largest connected cluster) attains well-defined values upon ensemble averaging with no sample-to-sample fluctuations in the thermodynamic limit. Here, we report on anomalous gelation transition types. Depending on the growth rate of the largest clusters, the gelation transition can show very diverse patterns as a function of the control parameter, which includes multiple stochastic discontinuous transitions, genuine non-self-averaging and ultraslow convergence of the transition point. Our framework may be helpful in understanding and controlling gelation.

Effect of the gel elasticity of model skin matrices on the distance/depth-dependent transmission of vibration energy supplied from a cosmetic vibrator

OBJECTIVE

The purpose of this study was to determine how the energies supplied from a cosmetic vibrator are deeply or far transferred into organs and tissues, and how these depths or distances are influenced by tissue elasticity.

METHODS

External vibration energy was applied to model skin surfaces through a facial cleansing vibrator, and we measured a distance- and depth-dependent energy that was transferred to model skin matrices. As model skin matrices, we synthesized hard and soft poly(dimethylsiloxane) (PDMS) gels, as well as hydrogels with a modulus of 2.63 MPa, 0.33 MPa and 21 kPa, respectively, mostly representing those of skin and other organs. The transfer of vibration energy was measured either by increasing the separation distances or by increasing the depth from the vibrator.

RESULTS

The energies were transmitted deeper into the hard PDMS than into the soft PDMS and hydrogel matrices. This finding implies that the vibration forces influence a larger area of the gel matrices when the gels are more elastic (or rigid). There were no appreciable differences between the soft PDMS and hydrogel matrices. However, the absorbed energies were more concentrated in the area closest to the vibrator with decreasing elasticity of the matrix. Softer materials absorbed most of the supplied energy around the point of the vibrator. In contrast, harder materials scattered the external energy over a broad area.

CONCLUSIONS

The current results are the first report in estimating how the external energy is deeply or distantly transferred into a model skins depending on the elastic moduli of the models skins. In doing so, the results would be potentially useful in predicting the health of cells, tissues and organs exposed to various stimuli.

Universality in boundary domain growth by sudden bridging

We report on universality in boundary domain growth in cluster aggregation in the limit of maximum concentration. Maximal concentration means that the diffusivity of the clusters is effectively zero and, instead, clusters merge successively in a percolation process, which leads to a sudden growth of the boundary domains. For two-dimensional square lattices of linear dimension L, independent of the models studied here, we find that the maximum of the boundary interface width, the susceptibility χ, exhibits the scaling χ ~ L^γ with the universal exponent γ = 1. The rapid growth of the boundary domain at the percolation threshold, which is guaranteed to occur for almost any cluster percolation process, underlies the the universal scaling of χ.

Hybrid Percolation Transition in Cluster Merging Processes: Continuously Varying Exponents

Consider growing a network, in which every new connection is made between two disconnected nodes. At least one node is chosen randomly from a subset consisting of g fraction of the entire population in the smallest clusters. Here we show that this simple strategy for improving connection exhibits a more unusual phase transition, namely a hybrid percolation transition exhibiting the properties of both first-order and second-order phase transitions. The cluster size distribution of finite clusters at a transition point exhibits power-law behavior with a continuously varying exponent τ in the range 2<τ(g)≤2.5. This pattern reveals a necessary condition for a hybrid transition in cluster aggregation processes, which is comparable to the power-law behavior of the avalanche size distribution arising in models with link-deleting processes in interdependent networks.

Two Types of Discontinuous Percolation Transitions in Cluster Merging Processes

Percolation is a paradigmatic model in disordered systems and has been applied to various natural phenomena. The percolation transition is known as one of the most robust continuous transitions. However, recent extensive studies have revealed that a few models exhibit a discontinuous percolation transition (DPT) in cluster merging processes. Unlike the case of continuous transitions, understanding the nature of discontinuous phase transitions requires a detailed study of the system at hand, which has not been undertaken yet for DPTs. Here we examine the cluster size distribution immediately before an abrupt increase in the order parameter of DPT models and find that DPTs induced by cluster merging kinetics can be classified into two types. Moreover, the type of DPT can be determined by the key characteristic of whether the cluster kinetic rule is homogeneous with respect to the cluster sizes. We also establish the necessary conditions for each type of DPT, which can be used effectively when the discontinuity of the order parameter is ambiguous, as in the explosive percolation model.

Mitofusins deficiency elicits mitochondrial metabolic reprogramming to pluripotency

Cell reprogramming technology has allowed the in vitro control of cell fate transition, thus allowing for the generation of highly desired cell types to recapitulate in vivo developmental processes and architectures. However, the precise molecular mechanisms underlying the reprogramming process remain to be defined. Here, we show that depleting p53 and p21, which are barriers to reprogramming, yields a high reprogramming efficiency. Deletion of these factors results in a distinct mitochondrial background with low expression of oxidative phosphorylation subunits and mitochondrial fusion proteins, including mitofusin 1 and 2 (Mfn1/2). Importantly, Mfn1/2 depletion reciprocally inhibits the p53-p21 pathway and promotes both the conversion of somatic cells to a pluripotent state and the maintenance of pluripotency. Mfn1/2 depletion facilitates the glycolytic metabolic transition through the activation of the Ras-Raf and hypoxia-inducible factor 1α (HIF1α) signaling at an early stage of reprogramming. HIF1α is required for increased glycolysis and reprogramming by Mfn1/2 depletion. Taken together, these results demonstrate that Mfn1/2 constitutes a new barrier to reprogramming, and that Mfn1/2 ablation facilitates the induction of pluripotency through the restructuring of mitochondrial dynamics and bioenergetics.

Diagnosis of bovine tuberculosis using a metal oxide-based electronic nose

Electronic noses (e-noses) have been used for environmental monitoring, standardization of medicinal flavourings, food safety tests and diagnosis of infectious diseases based on the statistical analysis of volatile organic compounds (VOCs). Bovine tuberculosis (bTB) is officially diagnosed using the intradermal skin test (IST), which is time-consuming and labour-intensive. Therefore, a more convenient and rapid test with greater sensitivity would be advantageous as prescreening test. In this study, we used a metal oxide sensor (MOS) type e-nose to analyse VOCs in a bTB-infected (n = 11) and bTB-free (n = 10) sera, from cattle whose health status was confirmed using the IST, and pathological and bacteriological examinations. The differences in VOCs from bTB-infected and bTB-free sera detected by the e-nose were statistically analysed using principal components and discriminant factor analyses. bTB-infected and bTB-free sera could be discriminated by MOS type e-nose, and analysing time per sample was only 20 min. VOC analysis using a MOS e-nose was a rapid and automated prescreening method to diagnose bTB, and can be used to select bTB-suspect cattle for IST confirmation. Further studies are required to estimate test sensitivity and specificity. Significance and impact of the study: Bovine tuberculosis (bTB) in cattle is diagnosed using the intradermal skin test (IST); however, this method is very time-consuming and labour-intensive. We analysed volatile organic compounds that are obtained from serum using a metal oxide sensor type of electronic nose to discriminate between TB-infected and TB-free sera. This simple and automated technique will be useful to prescreen bTB-suspects and reduce the time and labour required to perform the IST.

Crossover behavior of conductivity in a discontinuous percolation model

When conducting bonds are occupied randomly in a two-dimensional square lattice, the conductivity of the system increases continuously as the density of those conducting bonds exceeds the percolation threshold. Such a behavior is well known in percolation theory; however, the conductivity behavior has not been studied yet when the percolation transition is discontinuous. Here we investigate the conductivity behavior through a discontinuous percolation model evolving under a suppressive external bias. Using effective medium theory, we analytically calculate the conductivity behavior as a function of the density of conducting bonds. The conductivity function exhibits a crossover behavior from a drastically to a smoothly increasing function beyond the percolation threshold in the thermodynamic limit. The analytic expression fits well our simulation data.

Peripheral G protein-coupled inwardly rectifying potassium channels are involved in δ-opioid receptor-mediated anti-hyperalgesia in rat masseter muscle

BACKGROUND

Although the efficacy of peripherally administered opioid has been demonstrated in preclinical and clinical studies, the underlying mechanisms of its anti-hyperalgesic effects are poorly understood. G protein-coupled inwardly rectifying potassium (GIRK) channels are linked to opioid receptors in the brain. However, the role of peripheral GIRK channels in analgesia induced by peripherally administered opioid, especially in trigeminal system, is not clear.

METHODS

Expression of GIRK subunits in rat trigeminal ganglia (TG) was examined with reverse transcription-polymerase chain reaction, Western blot and immunohistochemistry. Chemical profiles of GIRK-expressing neurons in TG were further characterized. Behavioural and Fos experiments were performed to examine the functional involvement of GIRK channels in δ-opioid receptor (DOR)-mediated anti-hyperalgesia under an acute myositis condition.

RESULTS

TG expressed mRNA and proteins for GIRK1 and GIRK2 subunits. Majority of GIRK1- and GIRK2-expressing neurons were non-peptidergic afferents. Inhibition of peripheral GIRK using Tertiapin-Q (TPQ) attenuated antinociceptive effects of peripherally administered DOR agonist, [D-Pen(2), D-Pen(6) ]-enkephalin (DPDPE), on mechanical hypersensitivity in masseter muscle. Furthermore, TPQ attenuated the suppressive effects of peripheral DPDPE on neuronal activation in the subnucleus caudalis of the trigeminal nucleus (Vc) following masseteric injection of capsaicin.

CONCLUSIONS

Our data indicate that peripheral DOR agonist-induced suppression of mechanical hypersensitivity in the masseter muscle involves the activity of peripheral GIRK channels. These results could provide a rationale for developing a novel therapeutic approach using peripheral GIRK channel openers to mimic or supplement the effects of peripheral opioid agonist.

Electrical and optical properties of indium zinc oxide (IZO) thin films by continuous composition spread

Indium zinc oxide (IZO) films were deposited on glass substrate at room temperature using off-axis RF sputtering-continuous composition spread (CCS) system. The full range composition of IZO films were controlled by the deposition rate and thickness profiles of In2O3 and ZnO target. The structural, electrical and optical properties of IZO thin films were measured as functions of position. IZO thin film had the lowest resistivity and highest carrier concentration at the position of 15 mm (5.02 x 10(-4) omega cm, 3.9 x 10(20)/cm3). And IZO thin film had high transmittance in visible region at measured all positions. This study has investigated to explore the new composition of IZO films using CCS system.

Avoiding a spanning cluster in percolation models

When dynamics in a system proceeds under suppressive external bias, the system can undergo an abrupt phase transition, as can happen when an epidemic spreads. Recently, an explosive percolation (EP) model was introduced to understand such phenomena. The order of the EP transition has not been clarified in a unified framework covering low-dimensional systems and the mean-field limit. We introduce a stochastic model in which a rule for dynamics is designed to avoid the formation of a spanning cluster through competitive selection in Euclidean space. We use heuristic arguments to show that in the thermodynamic limit and depending on a control parameter, the EP transition can be either continuous or discontinuous if d < d(c) and is always continuous if d ≥ d(c), where d(c) is the spatial dimension and d is the upper critical dimension.

The impact of total antioxidant capacity on pulmonary function in asthma patients

BACKGROUND

Oxidative stress, mediated by an imbalance between oxidants and antioxidants, contributes significantly to the pathogenesis of asthma.

OBJECTIVE

To evaluate the impact of serum total antioxidant capacity (TAC) on the pulmonary function of Korean asthma patients.

METHOD

A total of 104 adult asthma patients enrolled from the COREA (Cohort for Reality and Evolution of Adult Asthma in Korea) programme participated in the study. Baseline clinical parameters at enrolment, and the results of pulmonary function tests at baseline and 1 and 2 years after enrolment were collected. TAC at baseline was measured using a Trolox-equivalent antioxidant capacity assay. Patients were divided into two groups based on TAC levels, and various clinical parameters were compared.

RESULT

Serum TAC levels correlated with forced expiratory volume in 1 second (FEV(1)) at baseline (r = 0.22, P = 0.03). The group with higher baseline TAC levels maintained greater mean FEV(1) both 1 and 2 years after enrolment, even after adjusting for sex, age, height, weight, body mass index and smoking status.

CONCLUSION

These results suggest an important link between serum TAC levels and pulmonary function, indicating that higher TAC levels may be a biomarker for favourable prognosis in asthma patients.

The optimization of ELISA for methamphetamine determination: the effect of immunogen, tracer and antibody purification method on the sensitivity

To obtain more sensitive immunoassay for methamphetamine (MA) determination, the optimum condition of enzyme-linked immunosorbent assay (ELISA) was investigated in regard to immunogens, antibody purification methods and coating tracers. Activated MA, N-(4-aminobutyl)methamphetamine (4-ABMA), was conjugated with bovine serum albumin (BSA) or keyhole limpet hemocyanin (KLH) and used as immunogen. The antibodies were purified by protein G chromatography or various immunoaffinity chromatography-linked MA-protein ligands, such as MA-BSA, MA-KLH or MA-ovalbumin (OVA). Each purified antibody was characterized by means of sensitivity and cross-reactivity using the three MA-protein coating tracers, MA-BSA, MA-KLH and MA-OVA. The best sensitivity of each antibody was acquired with the MA-OVA tracer although the tracer concentration and the antibody titer level at optimum condition were varied. The antibody with high titer level did not always yield good sensitivity. At optimum condition, immunoaffinity chromatography-purified antibodies were better for sensitivity and for specificity than protein G-purified antibodies. The cross-reactivity of the purified antibodies seemed to be affected by immunogen structure and showed somewhat different patterns according to the immunoaffinity ligand utilized. These data show that the antibody purification method as well as choice of coating tracer and immunogen is essential for the sensitivity and specificity of EIA; the optimum condition for assay should be discovered using various methods and combinations.

Countering the livestock-targeted bioterrorism threat and responding with an animal health safeguarding system

Attacks against livestock and poultry using biological agents constitute a subtype of agroterrorism. These attacks are defined as the intentional introduction of an animal infectious disease to strike fear in people, damage a nation's economy and/or threaten social stability. Livestock bioterrorism is considered attractive to terrorists because biological agents for use against livestock or poultry are more readily available and difficult to monitor than biological agents for use against humans. In addition, an attack on animal husbandry can have enormous economic consequences, even without human casualties. Animal husbandry is vulnerable to livestock-targeted bioterrorism because it is nearly impossible to secure all livestock animals, and compared with humans, livestock are less well-guarded targets. Furthermore, anti-livestock biological weapons are relatively easy to employ, and a significant effect can be produced with only a small amount of infectious material. The livestock sector is presently very vulnerable to bioterrorism as a result of large-scale husbandry methods and weaknesses in the systems used to detect disease outbreaks, which could aggravate the consequences of livestock-targeted bioterrorism. Thus, terrorism against livestock and poultry cannot be thought of as either a 'low-probability' or 'low-consequence' incident. This review provides an overview of methods to prevent livestock-targeted bioterrorism and respond to terrorism involving the deliberate introduction of a pathogen-targeting livestock and poultry.

Lessons from two cases of anaphylaxis to proton pump inhibitors

WHAT IS KNOWN AND OBJECTIVE

Proton pump inhibitors (PPIs), which are widely used for the treatment of peptic ulcers and gastroesophageal diseases, reduce both basal and stimulated gastric acid secretion by inhibiting the parietal cell enzyme H(+)-K(+)-adenosine triphosphatase. There have been several reports of hypersensitivity reactions to PPIs but anaphylaxis is very rare. We report on two cases of anaphylaxis to PPIs.

CASE SUMMARY

Our two interesting and instructive cases of anaphylaxis to PPIs relate to the orally disintegrating form of lansoprazole and omeprazole. The first patient had taken esomeprazole 20 mg/day for 1 month without any side effects before experiencing anaphylaxis to lansoprazole. To our knowledge, this is the first report of anaphylaxis to the orally disintegrating form of lansoprazole. In the second case, the patient was misdiagnosed with penicillin allergy which she suffered from earlier.

WHAT IS NEW AND CONCLUSION

Physicians need to be more aware of the possibility of hypersensitivity to PPIs.

yaInChI: modified InChI string scheme for line notation of chemical structures

A modified InChI (International Chemical Identifier) string scheme, yaInChI (yet another InChI), is suggested as a method for including the structural information of a given molecule, making it straightforward and more easily readable. The yaInChI theme is applicable for checking the structural identity with higher sensitivity and generating three-dimensional (3-D) structures from the one-dimensional (1-D) string with less ambiguity than the general InChI method. The modifications to yaInChI provide non-rotatable single bonds, stereochemistry of organometallic compounds, allene and cumulene, and parity of atoms with a lone pair. Additionally, yaInChI better preserves the original information of the given input file (SDF) using the protonation information, hydrogen count +1, and original bond type, which are not considered or restrictively considered in InChI and SMILES. When yaInChI is used to perform a duplication check on a 3D chemical structure database, Ligand.Info, it shows more discriminating power than InChI. The structural information provided by yaInChI is in a compact format, making it a promising solution for handling large chemical structure databases.

Suppression effect on explosive percolation

Percolation transitions (PTs) of networks, leading to the formation of a macroscopic cluster, are conventionally considered to be continuous transitions. However, a modified version of the classical random graph model was introduced in which the growth of clusters was suppressed, and a PT occurs explosively at a delayed transition point. Whether the explosive PT is indeed discontinuous or continuous becomes controversial. Here, we show that the behavior of the explosive PT depends on detailed dynamic rules. Thus, when dynamic rules are designed to suppress the growth of all clusters, the discontinuity of the order parameter tends to a finite value as the system size increases, indicating that the explosive PT could be discontinuous.

Immunophilin dysfunction and neuropathology

In case of nervous damages, like nervous system trauma or various neurodegenerative diseases such as dementia or Parkinson, several treatments are available to restore neurological function. In spite of these treatments, results are often insufficient or not satisfactory in many neurologic diseases, especially for central nervous system (CNS) lesions. To minimize neurological dysfunction, it is critical to reduce neuronal death, avoiding loss of the synaptic connections, and securing viable neurons to extend axons. Unfortunately, there are no effective strategies to fulfill these basic needs except for some cases of peripheral neural damage up to now. Rescue of damaged neurons, stimulation of neurogenesis and transplantation of nervous tissue are strategies proposed to prevent neurodegenerative disorders. A number of studies have recently reported successful axon regeneration and neurological recovery by using immunosuppressants, such as FK506. Immunosuppressants act as excellent agents for enhancing the rate and extent of axon regeneration and neurological recovery. FK506 and other neuroimmunophilin ligands (NILs) might reverse neuronal degeneration. In several animal models mimicking Parkinson's disease, dementia and surgical damage, NILs induces resprouting, by acting as neurotrophic agents and preventing nerve damage, although more studies are necessary to identify new NILs with neuroprotective action, but lacking the side immunological effects observed in the ligands analyzed to date. This review explores the new clinical role of immunosuppressants in the treatment of nerve surgery of autologous, allografts or xenografts. Results of studies regarding immunosuppressant treatment of nervous system trauma and neurodegenerative diseases, like neurogenic erectile dysfunction, will be here considered.

Reliability and validity of the St George's Respiratory Questionnaire for asthma

BACKGROUND

The St George's Respiratory Questionnaire (SGRQ) is a self-administered questionnaire that has been used to evaluate the health-related quality of life of patients with chronic respiratory diseases.

OBJECTIVE

To assess the validity and reliability of the SGRQ for a large population with asthma.

DESIGN

We used the previously developed Korean version of the SGRQ (SGRQ-K) to assess 676 asthma patients enrolled from the Cohort for Reality and Evolution of Adult Asthma in Korea study. Cronbach's α was used to assess test reliability and Pearson's correlation coefficient was used to assess the correlation between SGRQ scores and various clinical factors.

RESULTS

The total SGRQ-K score had acceptable reliability (Cronbach's α = 0.92). The total SGRQ-K score was significantly correlated with symptom duration (r = 0.157, P < 0.001), pulmonary function (% FEV(1) of predicted r = -0.314, P < 0.001; % FVC of predicted r = -0.224, P < 0.001; FEV(1)/FVC r = -0.224, P < 0.001), asthma severity (r = 0.278, P < 0.001) and history of asthma exacerbation.

CONCLUSION

With the exception of the SGRQ-K symptoms, SGRQ-K is a reliable and valid test for evaluation of the quality of life of patients with asthma. Scores were well correlated with duration of symptoms, lung function and previous history of asthma exacerbation.

Discontinuous percolation transitions in real physical systems

We study discontinuous percolation transitions (PTs) in the diffusion-limited cluster aggregation model of the sol-gel transition as an example of real physical systems, in which the number of aggregation events is regarded as the number of bonds occupied in the system. When particles are Brownian, in which cluster velocity depends on cluster size as v(s)~s(η) with η=-0.5, a larger cluster has less probability to collide with other clusters because of its smaller mobility. Thus, the cluster is effectively more suppressed in growth of its size. Then the giant cluster size increases drastically by merging those suppressed clusters near the percolation threshold, exhibiting a discontinuous PT. We also study the tricritical behavior by controlling the parameter η, and the tricritical point is determined by introducing an asymmetric Smoluchowski equation.

Long-term efficacy of entecavir therapy in chronic hepatitis B patients with antiviral resistance to lamivudine and adefovir

No studies have reported the long-term effects of entecavir switching in patients with multidrug resistance who developed resistance after lamivudine/adefovir sequential therapy. We evaluated the efficacy of 96 weeks of entecavir therapy in patients with resistance to lamivudine/adefovir sequential therapy. In total, 33 patients with chronic hepatitis B virus (HBV) infection with evidence of active viral replication (HBV DNA levels ≥ 10(5) copies/mL) or a history of treatment failure to lamivudine/adefovir sequential therapy between April 2007 and July 2009 were treated with entecavir (1.0 mg daily) for at least 48 weeks. The rates of alanine transaminase (ALT) normalization and HBV DNA negativity were 66.7% (14/21) and 24.2% (8/33) at 48 weeks, respectively. The initial HBV DNA level was the only factor that was inversely associated with serum HBV DNA negativity after 48 weeks of entecavir therapy (P < 0.023). At 96 weeks, the rates of ALT normalization and HBV DNA negativity were 77.8% (7/9) and 16.7% (3/18), respectively. Viral breakthrough occurred in 21.2% (7/33) and 78.9% (15/19) of patients at 48 and 96 weeks, respectively. Patients who achieved a HBV DNA level of <4 log(10) copies/mL at 48 weeks maintained a similar HBV DNA level and a normal ALT level until 96 weeks. Entecavir monotherapy for 96 weeks was not efficacious for patients with lamivudine/adefovir-resistant HBV. The initial HBV DNA level was the only predictive factor for antiviral efficacy. However, patients who achieved a HBV DNA level of <4 log(10) copies/mL with a normal ALT level at 48 weeks should maintain, rather than stop, entecavir therapy.

Genetic polymorphism in exon 2 of cathepsin D is not associated with vascular dementia

BACKGROUND

Cathepsin D, the most abundant lysosomal and endosomal aspartyl protease, shows beta and gamma secretase activity in vitro by cleaving the amyloid precursor protein (APP) into amyloid beta protein (Aβ). Polymorphism at position 224, C224T, on exon 2 of cathepsin D gene (CTSD) has been associated with an increased risk for Alzheimer's disease (AD) by some investigators, but there have been contrary findings by others. However, an association between CTSD polymorphism and vascular dementia (VaD) has not been reported thus far.

OBJECTIVE

To investigate whether a polymorphism at CTSD C224T is associated with VaD in the Korean population.

METHODS

We compared the genotype and allele frequencies at this polymorphism site in clinically assessed 162 VaD patients with those in 197 healthy Koreans.

RESULTS AND CONCLUSION

The major genotype frequency at CTSD C224T in normal controls was higher in the Asian population than in various European populations. Our study does not show a significant difference in genotype (P=0.3071) and allele (P=0.2291) frequencies of CTSD C224T between VaD and normal controls. This was the first genetic association study of CTSD in a VaD population.

Accessory polar renal artery encountered in transperitoneal systemic laparoscopic paraaortic lymphadenectomy

OBJECTIVE

To increase vigilance among gynecological surgeons for the presence of accessory polar renal artery (APRA) encountered with transperitoneal systemic laparoscopic paraaortic lymphadenectomy (LPAL).

METHODS

A retrospective review was conducted on 156 women who underwent LPAL for various gynecologic malignancies between November 2003 and December 2009.

RESULTS

The median age, parity, body mass index, and number of previous abdominal surgeries, respectively, of the women were 52 years (range, 23-82 years), two (range, 0-7), 24.1 kg/m2 (range, 17.4-35.0 kg/m2), and 0 (range, 0-3). During the study period, we found four women with APRA. There were three cases of right lower APRAs arising from the abdominal aorta, caudal to the inferior mesenteric artery (IMA), terminating at the parenchyma of the lower pole of the right kidney. In the other case, the APRA arose from the abdominal aorta superior to the IMA. There were no vascular complications, such as transection or ligation of the APRA.

CONCLUSION

It is important for the gynecological oncologic surgeon to have knowledge of retroperitoneal vascular anatomy, experience in laparoscopic surgery, and an accurate surgical technique to avoid vascular injury during LPAL.

Finite-size scaling theory for explosive percolation transitions

The finite-size scaling (FSS) theory for continuous phase transitions has been useful in determining the critical behavior from the size-dependent behaviors of thermodynamic quantities. When the phase transition is discontinuous, however, FSS approach has not been well established yet. Here, we develop a FSS theory for the explosive percolation transition arising in the Erdős and Rényi model under the Achlioptas process. A scaling function is derived based on the observed fact that the derivative of the curve of the order parameter at the critical point t(c) diverges with system size in a power-law manner, which is different from the conventional one based on the divergence of the correlation length at t(c). We show that the susceptibility is also described in the same scaling form. Numerical simulation data for different system sizes are well collapsed on the respective scaling functions.

Cluster aggregation model for discontinuous percolation transitions

The evolution of the Erdos-Rényi (ER) network by adding edges is a basis model for irreversible kinetic aggregation phenomena. Such ER processes can be described by a rate equation for the evolution of the cluster-size distribution with the connection kernel Kij approximately ij , where ij is the product of the sizes of two merging clusters. Here we study that when the giant cluster is discouraged to develop by a sublinear kernel Kij approximately (ij)omega with 0<or=omega<1/2 , the percolation transition (PT) is discontinuous. Such discontinuous PT can occur even when the ER dynamics evolves from proper initial conditions. The obtained evolutionary properties of the simple model sheds light on the origin of the discontinuous PT in other nonequilibrium kinetic systems.

Non-synonymous single-nucleotide polymorphisms associated with blood pressure and hypertension

In this study, we determined the association of 1180 non-synonymous single-nucleotide polymorphisms (SNPs) with systolic blood pressure (SBP) and hypertensive status. A total of 8842 subjects were taken from two community-based cohorts--Ansung (n=4183) and Ansan (n=4659), South Korea--which had been established for genome-wide association studies (GWAS). Five SNPs (rs16835244, rs2286672, rs6265, rs17237198 and rs7312017) were significantly associated (P-values: 0.003-0.0001, not corrected for genome-wide significance) with SBP in both cohorts. Of these SNPs, rs16835244 and rs2286672 correlated with risk for hypertension. The rs16835244 SNP replaces Ala288 in arginine decarboxylase (ADC) with serine, and rs2286672 replaces Arg172 in phospholipase D2 (PLD2) with cysteine. A comparison of peptide sequences between vertebrate homologues revealed that the SNPs identified occur at conserved amino-acid residues. In silico analysis of the protein structure showed that the substitution of a polar residue, serine, for a non-polar alanine at amino-acid residue 288 affects a conformational change in ADC, and that Arg172 in PLD2 resides in the PX domain, which is important for membrane trafficking. These results provide insights into the function of these non-synonymous SNPs in the development of hypertension. The study investigating non-synonymous SNPs from GWAS not only by statistical association analysis but also by biological relevance through the protein structure might be a good approach for identifying genetic risk factors for hypertension, in addition to discovering causative variations.

Design and construction of a compact microwave proton source for a proton linac

A 100 MeV, 20 mA proton linear accelerator is being developed by the Proton Engineering Frontier Project at the Korea Atomic Energy Research Institute. 20 MeV acceleration system using radio frequency quadrupole and drift tube linac was already developed and has been tested. To operate this acceleration system with a long time, more reliable proton source is needed. A compact microwave proton source was proposed and has been designed and constructed as a prototype ion source for the 100 MeV proton linear accelerator. The design of microwave power injection system is based on the microwave proton injector at LANL and CEA. The wave power from a 2.45 GHz, 2 kW magnetron source is introduced into a compact plasma chamber with 7 cm diameter and 5 cm length through a standard tapered, double-ridged waveguide (WRD250) and a quartz window. The microwave power supply is installed on high voltage platform. Axial magnetic fields up to 1 kG can be provided with a water-cooled solenoid coil. A single-hole three electrode extraction system is designed for an extraction current up to 30 mA at a 50 kV extraction voltage. The design and initial operations of the proton source are presented.

Patterns of hearing loss after microvascular decompression for hemifacial spasm

BACKGROUND

The purpose of this study was to analyse audiological data after microvascular decompression (MVD) for hemifacial spasm (HFS), and to compare the data with hearing before surgery.

METHODS

Auditory functions were studied before and after surgery in 698 patients who underwent an MVD of the intracranial portion of the facial nerve for HFS. The results were expressed as the average of pure tone audiometry (PTA) and speech discrimination score (SDS).

RESULTS

668 patients (95.7%) had no hearing loss immediately after surgery (group 1). 17 patients (2.4%) had a postoperative decrease in PTA exceeding 15 dB and a decrease in SDS which was proportional to the postoperative PTA thresholds (group 2). Eight patients (1.2%) had poor SDS that appeared to be out of proportion to the degree of hearing loss depicted by the postoperative PTA thresholds, suggesting retrocochlear or cochlear nerve pathology (group 3). Five patients (0.7%) had total deafness after surgery (group 4). In group 2, 12 patients (70.6%) returned to their preoperative hearing capacity. However, among the eight patients in group 3 and five in group 4, only two (25%) and none (0%) have returned to their preoperative hearing status, respectively.

CONCLUSION

In this large study, permanent hearing loss occurred in 16 patients (2.2%). Patients with a mild hearing loss with a good SDS (cochlear type) demonstrated much better prognosis than those with poor SDS (retrocochlear type) or total deafness. In addition, total deafness after surgery had no chance of recovery to preoperative hearing capacity.

Percolation transitions in scale-free networks under the Achlioptas process

It has been recently shown that the percolation transition is discontinuous in Erdos-Rényi networks and square lattices in two dimensions under the Achlioptas process (AP). Here, we show that when the structure is highly heterogeneous as in scale-free networks, a discontinuous transition does not always occur: a continuous transition is also possible depending on the degree distribution of the scale-free network. This originates from the competition between the AP that discourages the formation of a giant component and the existence of hubs that encourages it. We also estimate the value of the characteristic degree exponent that separates the two transition types.

HLA-DRB1*0908, a new allele was identified by sequence-based typing in a Korean individual

A new human leukocyte antigen DRB1*0908 differs from GTC to AGC in DRB1*090102 at codon 57 with a coding change, valine to serine.

A case of ricin poisoning following ingestion of Korean castor bean

Ricin is a member of a group of protein toxins whose cytosolic target is the 28S rRNA of the 60S ribosomal subunit. It was recently introduced as a weapon of terrorism in some countries. There is little evidence about the mechanism, diagnosis and treatment of ricin poisoning. The case history is reported of a patient with ricin poisoning who presented with nausea and vomiting following ingestion of Korean castor bean.

VDUP1 potentiates Ras-mediated angiogenesis via ROS production in endothelial cells

Vitamin D3 up-regulated protein 1 (VDUP1) is a tumor suppressor of which expression is reduced in a variety of cancer cells, and enforced expression inhibits the tumor cell proliferation. It inhibits the activity of thioredoxin, thus contributing cellular ROS generation. Since ROS is a critical factor for angiogenesis, we investigated the role of VDUP1 in angiogenesis and endothelial proliferation. The expression of VDUP1 was upregulated by overexpression of an oncogene, Ras. Enforced expression of VDUP1 increases ROS production and proliferation of Ras-overexpressing endothelial cells. Overexpression of VDUP1 increases the resistance to the anchorage-dependent cell death and tube formation of the Ras-overexpressing endothelial cell. In addition, the removal of ROS by ROS scavenger attenuates the effect of VDUP1 on tube formation. These results suggest that VDUP1 is involved in Ras-mediated angiogenesis via ROS generation in endothelial cells.