Exposure to airborne particulate matter induces renal tubular cell injury in vitro: the role of vitamin D signaling and renin-angiotensin system

Background

Exposure to air pollution can interfere with the vitamin D endocrine system. This study investigated the effects of airborne particulate matter (PM) on renal tubular cell injury in vitro and explored the underlying mechanisms.

Methods

HK-2 human renal proximal tubule cells were treated with PM with or without 1,25(OH)₂D₃ analog, 19-Nor-1,25(OH)₂D₂ (paricalcitol, 10 nM) for 48 h. The dose- and time-dependent cytotoxicity of PM with or without paricalcitol was determined via cell counting kit-8 assay. Cellular oxidative stress was assessed using commercially available enzyme-linked immunosorbent assay kits. The protein expression of vitamin D receptor (VDR), cytochrome P450(CYP)27B1, CYP24A1, renin, angiotensin converting enzyme (ACE), angiotensin II type 1 receptor (AT1), nuclear factor erythroid 2-related factor 2 (Nrf2), nuclear factor-kB (NF-kB), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 was determined.

Results

PM exposure decreased HK-2 cell viability in a dose- and time-dependent manner. The activities of superoxide dismutase and malondialdehyde in HK-2 cells increased significantly in the group exposed to PM. PM exposure decreased VDR and Nrf2, while increasing CYP27B1, renin, ACE, AT1, NF-kB, TNF-α, and IL-6. The expression of VDR, CYP27B1, renin, ACE, AT1, and TNF-α was reversed by paricalcitol treatment. Paricalcitol also restored the cell viability of PM-exposed HK-2 cells.

Conclusion

Our findings indicate that exposure to PM induces renal proximal tubular cell injury, concomitant with alteration of vitamin D endocrine system and renin angiotensin system. Vitamin D could attenuate renal tubular cell damage following PM exposure by suppressing the renin-angiotensin system and by partially inhibiting the inflammatory response.

Prenylflavonoids isolated from Macaranga tanarius stimulate odontoblast differentiation of human dental pulp stem cells and tooth root formation via the mitogen-activated protein kinase and protein kinase B pathways

AIM

To identify odontogenesis-promoting compounds and examine the molecular mechanism underlying enhanced odontoblast differentiation and tooth formation.

METHODOLOGY

Five different nymphaeols, nymphaeol B (NB), isonymphaeol B (INB), nymphaeol A (NA), 3'-geranyl-naringenin (GN) and nymphaeol C (NC) were isolated from the fruit of Macaranga tanarius. The cytotoxic effect of nymphaeols on human DPSCs was observed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The effect of nymphaeols on odontoblast differentiation was analysed with Alizarin Red S staining and odontoblast marker expression was assessed using real-time polymerase chain reaction and Western blot analysis. The molecular mechanism was investigated with Western blot analysis. In order to examine the effect of INB on dentine formation in the developing tooth germ, INB-soaked beads were placed under the tooth bud explants in the collagen gel; thereafter, the tooth bud explant-bead complexes were implanted into the sub-renal capsules for 3 weeks. Tooth root formation was analysed using micro-computed tomography and histological analysis. Data are presented as mean ± standard error (SEM) values of three independent experiments, and results are compared using a two-tailed Student's t-test. The data were considered to have statistical significance when the P-value was less than 0.05.

RESULTS

Three of the compounds, NB, INB, and GN, did not exert a cytotoxic effect on human DPSCs. However, INB was most effective in promoting the deposition of calcium minerals in vitro (P < 0.001) and induced the expression of odontogenic marker genes (P < 0.05). Moreover, this compound strongly induced the phosphorylation of mitogen-activated protein (MAP) kinases and protein kinase B (AKT) (P < 0.05). The inhibition of p38 MAP, c-Jun N-terminal kinase (JNK), and AKT substantially suppressed the INB-induced odontoblast differentiation (P < 0.001). In addition, isonymphaeol B significantly induced the formation of dentine and elongation of the tooth root in vivo (P < 0.05).

CONCLUSIONS

Prenylflavonoids, including INB, exerted stimulatory effects on odontoblast differentiation and tooth root and dentine formation via the MAP kinase and AKT signalling pathways. These results suggest that nymphaeols could stimulate the repair processes for dentine defects or injuries.

Clinical Characteristics of Developmentally Delayed Children based on Interdisciplinary Evaluation

The aim of this study is to examine the clinical characteristics of children suspected to have neurodevelopmental disorders and to present features that could be helpful diagnostic clues at the clinical assessment stage. All children who visited the interdisciplinary clinic for developmental problems from May 2001 to December 2014 were eligible for this study. Medical records of the children were reviewed. A total of 1,877 children were enrolled in this study. Most children were classified into four major diagnostic groups: global developmental delay (GDD), autism spectrum disorder (ASD), developmental language disorder (DLD) and motor delay (MD). GDD was the most common (43.9%), and boys were significantly more predominant than girls in all groups. When evaluating the predictive power of numerous risk factors, the probability of GDD was lower than the probability of ASD among boys, while the probability of GDD increased as independent walking age increased. Compared with GDD and DLD, the probability of GDD was increased when there was neonatal history or when the independent walking age was late. Comparison of ASD and DLD showed that the probability of ASD decreased when a maternal history was present, whereas the probability of ASD increased with male gender. To conclude, the present study revealed the clinical features of children with various neurodevelopmental disorders. These results are expected to be helpful for more effectively flagging children with potential neurodevelopmental disorders in the clinical setting.

Endophytic and endolichenic fungal diversity in maritime Antarctica based on cultured material and their evolutionary position among Dikarya

Fungal endophytes comprise one of the most ubiquitous groups of plant symbionts. They live asymptomatically within vascular plants, bryophytes and also in close association with algal photobionts inside lichen thalli. While endophytic diversity in land plants has been well studied, their diversity in lichens and bryophytes are poorly understood. Here, we compare the endolichenic and endophytic fungal communities isolated from lichens and bryophytes in the Barton Peninsula, King George Island, Antarctica. A total of 93 fungal isolates were collected from lichens and bryophytes. In order to determine their identities and evolutionary relationships, DNA sequences of the nuclear internal transcribed spacer (ITS), nuclear ribosomal small subunit (nuSSU), nuclear large subunit (nuLSU), and mitochondrial SSU (mtSSU) rDNA were obtained and protein coding markers of the two largest subunit of RNA polymerase II (RPB1 and RPB2) were generated. Multilocus phylogenetic analyses revealed that most of the fungal isolates were distributed in the following six classes in the phylum Ascomycota: Dothideomycetes, Eurotiomycetes, Lecanoromycetes, Leotiomycetes, Pezizomycetes and Sordariomycetes. For the first time we report the presence of subphylum Mortierellomycotina that may belong to an undescribed order in endophytic fungi. Taken together, our results imply that lichens and bryophytes provide similar niches and harbour a selection of these fungi, indicating generalists within the framework of evolutionary adaptation.

Single-stage cell-based cartilage repair in a rabbit model: cell tracking and in vivo chondrogenesis of human umbilical cord blood-derived mesenchymal stem cells and hyaluronic acid hydrogel composite

OBJECTIVE

Human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) have gained popularity as a promising cell source for regenerative medicine, but limited in vivo studies have reported cartilage repair. In addition, the roles of MSCs in cartilage repair are not well-understood. The purpose of this study was to investigate the feasibility of transplanting hUCB-MSCs and hyaluronic acid (HA) hydrogel composite to repair articular cartilage defects in a rabbit model and determine whether the transplanted cells persisted or disappeared from the defect site.

DESIGN

Osteochondral defects were created in the trochlear grooves of the knees. The hUCB-MSCs and HA composite was transplanted into the defect of experimental knees. Control knees were transplanted by HA or left untreated. Animals were sacrificed at 8 and 16 weeks post-transplantation and additionally at 2 and 4 weeks to evaluate the fate of transplanted cells. The repair tissues were evaluated by gross, histological and immunohistochemical analysis.

RESULTS

Transplanting hUCB-MSCs and HA composite resulted in overall superior cartilage repair tissue with better quality than HA alone or no treatment. Cellular architecture and collagen arrangement at 16 weeks were similar to those of surrounding normal articular cartilage tissue. Histological scores also revealed that cartilage repair in experimental knees was better than that in control knees. Immunohistochemical analysis with anti-human nuclear antibody confirmed that the transplanted MSCs disappeared gradually over time.

CONCLUSION

Transplanting hUCB-MSCs and HA composite promote cartilage repair and interactions between hUCB-MSCs and host cells initiated by paracrine action may play an important role in cartilage repair.

Epileptiform abnormalities predict delayed cerebral ischemia in subarachnoid hemorrhage

OBJECTIVE

To identify whether abnormal neural activity, in the form of epileptiform discharges and rhythmic or periodic activity, which we term here ictal-interictal continuum abnormalities (IICAs), are associated with delayed cerebral ischemia (DCI).

METHODS

Retrospective analysis of continuous electroencephalography (cEEG) reports and medical records from 124 patients with moderate to severe grade subarachnoid hemorrhage (SAH). We identified daily occurrence of seizures and IICAs. Using survival analysis methods, we estimated the cumulative probability of IICA onset time for patients with and without delayed cerebral ischemia (DCI).

RESULTS

Our data suggest the presence of IICAs indeed increases the risk of developing DCI, especially when they begin several days after the onset of SAH. We found that all IICA types except generalized rhythmic delta activity occur more commonly in patients who develop DCI. In particular, IICAs that begin later in hospitalization correlate with increased risk of DCI.

CONCLUSIONS

IICAs represent a new marker for identifying early patients at increased risk for DCI. Moreover, IICAs might contribute mechanistically to DCI and therefore represent a new potential target for intervention to prevent secondary cerebral injury following SAH.

SIGNIFICANCE

These findings imply that IICAs may be a novel marker for predicting those at higher risk for DCI development.

Potentially modifiable risk factors for atrial fibrillation following lung resection surgery: a retrospective cohort study

Atrial fibrillation is the most frequent arrhythmia after thoracic surgery and is associated with increased hospital costs, morbidity and mortality. In this study, we aimed to identify potentially modifiable risk factors for postoperative atrial fibrillation following lung resection surgery and to suggest possible measures to reduce risk. We retrospectively reviewed the medical records of 4731 patients who underwent lobectomy or more major lung resection over a 6-year period. Patients who developed atrial fibrillation postoperatively and required treatment were included in the postoperative atrial fibrillation group, while the remaining patients were assigned to the non-postoperative atrial fibrillation group. Risk factors for postoperative atrial fibrillation were analysed by multivariate analysis and propensity score matching. Overall, 12% of patients developed postoperative atrial fibrillation. Potentially modifiable risk factors for postoperative atrial fibrillation were excessive alcohol consumption (odds ratio (OR) = 1.48, 95% CI 1.08-2.02, p = 0.0140), red cell transfusion (2.70(2.13-3.43), p < 0.0001), use of inotropes (1.81(1.42-2.31), p < 0.0001) and open (vs. thoracoscopic) surgery (1.59(1.23-2.05), p < 0.0001). Compared with inotrope use, vasopressor administration was not related to postoperative atrial fibrillation. Use of steroids or thoracic epidural anaesthesia did not reduce the incidence of postoperative atrial fibrillation. We conclude that high alcohol consumption, red cell transfusion, use of inotropes and open surgery are potentially modifiable risk factors for postoperative atrial fibrillation. Pre-operative alcohol consumption needs to be addressed. Avoiding red cell transfusion and performing lung resection via video-assisted thoracoscopic surgery may reduce the incidence of postoperative atrial fibrillation and the administration of vasopressors rather than inotropes is preferred.

Formation of dimethyldithioarsinic acid in a simulated landfill leachate in relation to hydrosulfide concentration

Dimethyldithioarsinic acid (DMDTA(V)), present in such intense sources as municipal landfill leachate, has drawn a great deal of attention due to its abundant occurrence and different aspect of toxicity. The hydrosulfide (HS(-)) concentration in leachate was studied as a major variable affecting the formation of DMDTA(V). To this end, the HPLC-ICPMS system equipped with the reversed-phase C18 column was used to determine DMDTA(V). Simulated landfill leachates (SLLs) were prepared to cover a mature landfill condition with the addition of sodium sulfate and sulfide at varying concentrations in the presence of dimethylarsinic acid (DMA(V)). The concentration of sodium sulfide added in the SLLs generally exhibited a strong positive correlation with the concentration of DMDTA(V). As such, the formation of DMDTA(V) in the SLLs is demonstrated to be controlled by the interactive relationship between DMA(V) and the HS(-).

Effectiveness of activated carbon disk for the analysis of iodine in water samples using wavelength dispersive X-ray fluorescence spectrometry

A novel approach using wavelength dispersive X-ray fluorescence (WDXRF) spectrometry combined with an activated carbon (AC) disk was developed for the determination of total iodine concentrations in water samples. Dissolved iodine species (i.e., I(-) and IO3(-)) in water samples were preconcentrated on the AC disk and directly analyzed by WDXRF spectrometry. The adsorption behavior of I(-) and IO3(-) on the AC disk was assessed at varying pH levels (4, 6, and 8). The AC disks completely retained the I(-) and IO3(-) for all the pH levels tested. The calibration curve obtained from the iodine concentrations (i.e., 0, 20, 200, and 400 μg) of AC disks and the measured X-ray intensity from the WDXRF analysis showed a good linearity (R(2)=0.9960), with a relatively low limit of detection (0.575 μg). The durability of the AC disk for repeatable measurements was also assessed to validate the sustainability of the proposed method and consequently the measured X-ray intensity for the AC disks was constant until 8d of analysis time. The accuracy of the proposed AC-WDXRF method was confirmed by measuring iodine concentration spiked in drinking water using inductively coupled plasma-mass spectrometry (ICP-MS). The proposed method is simple, rapid, efficient, and environmental friendly for iodine analysis in water samples. As a precursor of disinfection by products (DBPs), it is important to determine the total iodine concentrations in raw water.

Malva verticillata seed extracts upregulate the Wnt pathway in human dermal papilla cells

OBJECTIVE

Mesenchymal-epithelial interactions are important in controlling hair growth and the hair cycle. The β-catenin pathway of dermal papilla cells (DPCs) plays a pivotal role in morphogenesis and normal regeneration of hair follicles. Deletion of β-catenin in the dermal papilla reduces proliferation of the hair follicle progenitor cells that generate the hair shaft and induces an early onset of the catagen phase. In this study, a modulator of the Wnt/β-catenin activity was studied in oriental herb extracts on cultured human DPCs.

METHODS

The effect of Malva verticillata (M. verticillata) seeds on human DPCs was investigated by a Wnt/β-catenin reporter activity assay system (β-catenin-TCF/LEF reporter gene) and cell proliferation analysis. The synthesis of the factors related to hair growth and cycling was measured at both the mRNA and the protein level by semi-quantitative PCR and Western blot analysis, respectively.

RESULTS

An extract from M. verticillata seeds increased Wnt reporter activity in a concentration-dependent manner and also led to increased β-catenin levels in cultured human DPCs. Myristoleic acid, identified as an effective compound of M. verticillata seeds, stimulated the proliferation of DPCs in a dose-dependent manner and increased transcription levels of the downstream targets: IGF-1, KGF, VEGF and HGF. Myristoleic acid also enhanced the phosphorylation of MAPKs (Akt and p38).

CONCLUSION

Overall, the data suggest that this extract of M. verticillata seeds could be a good candidate for treating hair loss by modulating the Wnt/β-catenin pathway in DPCs.

Neural stem cell transplantation at critical period improves learning and memory through restoring synaptic impairment in Alzheimer's disease mouse model

Alzheimer's disease (AD) is characterized by neuronal loss in several regions of the brain. Recent studies have suggested that stem cell transplantation could serve as a potential therapeutic strategy to halt or ameliorate the inexorable disease progression. However, the optimal stage of the disease for stem cell transplantation to have a therapeutic effect has yet to be determined. Here, we demonstrated that transplantation of neural stem cells into 12-month-old Tg2576 brains markedly improved both cognitive impairments and neuropathological features by reducing β-amyloid processing and upregulating clearance of β-amyloid, secretion of anti-inflammatory cytokines, endogenous neurogenesis, as well as synapse formation. In contrast, the stem cell transplantation did not recover cognitive dysfunction and β-amyloid neuropathology in Tg2576 mice aged 15 months when the memory loss is manifest. Overall, this study underscores that stem cell therapy at optimal time frame is crucial to obtain maximal therapeutic effects that can restore functional deficits or stop the progression of AD.

Ecklonia cava promotes hair growth

BACKGROUND

Previous studies have reported the protective effects on skin elasticity of the edible marine seaweed Ecklonia cava, which acts through regulation of both antioxidative and anti-inflammatory responses.

AIM

We evaluated the effect of E. cava and one of its components, dioxinodehydroeckol, on hair-shaft growth in cultured human hair follicles and on hair growth in mice.

METHODS

The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was used to check cell viability of human dermal papilla cells (DPCs) and outer root sheath (ORS) cells after treatment with E. cava and its metabolite, dioxinodehydroeckol. Hair-shaft growth was measured using the in vitro hair-follicle organ-culture system, in the presence or absence of E. cava and dioxinodehydroeckol. Anagen induction activity was examined by topical application of E. cava to the dorsal skin of C57BL/6 mice. Insulin-like growth factor (IGF)-1 expression was measured by reverse transcriptase PCR and ELISA.

RESULTS

The proliferation activity was found to be highest for the ethyl acetate-soluble fraction of E. cava (EAFE) in DPCs and in ORS cells. Treatment with EAFE resulted in elongation of the hair shaft in cultured human hair follicles, and promoted transition of the hair cycle from the telogen to the anagen phase in the dorsal skin of C57BL/6 mice. In addition, EAFE induced an increase in IGF-1 expression in DPCs. Dioxinodehydroeckol, a component of E. cava, induced elongation of the hair shaft, an increase in proliferation of DPCs and ORS cells, and an increase in expression of IGF-1 in DPCs.

CONCLUSIONS

These results suggest that E. cava containing dioxinodehydroeckol promotes hair growth through stimulation of DPCs and ORS cells.

A simplified analysis of dimethylarsinic acid by wavelength dispersive X-ray fluorescence spectrometry combined with a strong cation exchange disk

Dimethylarsinic acid (DMA(V)) was pre-concentrated from water samples using a strong cation exchange (SCX) disk functionalized with sulfonic groups, before being analyzed by wavelength dispersive X-ray fluorescence spectrometry (WDXRF). The adsorption of DMA(V) occurred preferentially on the surface of the SCX disk, regardless of pH levels, probably due to interactions with the sulfonic functional groups. However, no other arsenic species, such as arsenate (iAs(V)), arsenite (iAs(III)), and monomethylarsonic acid (MMA(V)), were retained. The SCX-WDXRF method produced a strongly linear calibration curve (R(2)=0.9996) with its limit of detection at 0.218 μgL(-1) when a one-liter water sample was used for pre-concentration. The As intensity of the system was sensitive to the Pb content retained on the SCX disk owing to the proximity of the As-Kα and Pb-Lα lines. To compensate for this interference, a correction factor was developed by considering the calibration slope ratio between the X-ray intensity measured at a Bragg angle of 48.781° and the Pb content of the SCX disks. The results of spike tests for iAs(V), iAs(III), MMA(V), and DMA(V) with and without the addition of Pb in synthetic landfill leachate exhibited reasonable recoveries (i.e., 98-105%) after the spectral adjustment for the Pb interference.

A comparison of the BURP and conventional and modified jaw thrust manoeuvres for orotracheal intubation using the Clarus Video System

We evaluated the effects of three airway manipulation manoeuvres: (a) conventional (single-handed chin lift); (b) backward, upward and right-sided pressure (BURP) manoeuvre; and (c) modified jaw thrust manoeuvre (two-handed aided by an assistant) on laryngeal view and intubation time using the Clarus Video System in 215 patients undergoing general anaesthesia with orotracheal intubation. In the first part of this study, the laryngeal view was recorded as a modified Cormack-Lehane grade with each manoeuvre. In the second part, intubation was performed using the assigned airway manipulation. The primary outcome was the time to intubation, and the secondary outcomes were the modified Cormack-Lehane grade, the number of attempts and the overall success rate. There were significant differences in modified Cormack-Lehane grade between the three airway manipulations (p < 0.0001). Post-hoc analysis indicated that the modified jaw thrust improved the laryngeal view compared with the conventional (p < 0.0001) and the BURP manoeuvres (p < 0.0001). The BURP worsened the laryngeal view compared with the conventional manoeuvre (p = 0.0132). The time to intubation in the modified jaw thrust group was shorter than with the conventional manoeuvre (p = 0.0004) and the BURP group (p < 0.0001). We conclude that the modified jaw thrust is the most effective manoeuvre at improving the laryngeal view and shortening intubation time with the Clarus Video System.

The effects of prolonged inspiratory time during one-lung ventilation: a randomised controlled trial

We evaluated the effects of a prolonged inspiratory time on gas exchange in subjects undergoing one-lung ventilation for thoracic surgery. One hundred patients were randomly assigned to Group I:E = 1:2 or Group I:E = 1:1. Arterial blood gas analysis and respiratory mechanics measurements were performed 10 min after anaesthesia induction, 30 and 60 min after initiation of one-lung ventilation, and 15 min after restoration of conventional two-lung ventilation. The mean (SD) ratio of the partial pressure of arterial oxygen to fraction of inspired oxygen after 60 min of one-lung ventilation was significantly lower in Group I:E = 1:2 compared with Group I:E = 1:1 (27.7 (13.2) kPa vs 35.2 (22.1) kPa, respectively, p = 0.043). Mean (SD) physiological dead space-to-tidal volume ratio after 60 min of one-lung ventilation was significantly higher in Group I:E = 1:2 compared with Group I:E = 1:1 (0.46 (0.04) vs 0.43 (0.04), respectively, p = 0.008). Median (IQR [range]) peak inspiratory pressure was higher in Group I:E = 1:2 compared with Group I:E = 1:1 after 60 min of one-lung ventilation (23 (22-25 [18-29]) cmH2O vs 20 (18-21 [16-27]) cmH2O, respectively, p < 0.001) and median (IQR [range]) mean airway pressure was lower in Group I:E = 1:2 compared with Group I:E = 1:1 (10 (8-11 [5-15]) cmH2O vs 11 (10-13 [5-16]) cmH2O, respectively, p < 0.001). We conclude that, compared with an I:E ratio of 1:2, an I:E ratio of 1:1 resulted in a modest improvement in oxygenation and decreased shunt fraction during one-lung ventilation.

Efficacy and safety of the dipeptidyl peptidase-4 inhibitor gemigliptin compared with sitagliptin added to ongoing metformin therapy in patients with type 2 diabetes inadequately controlled with metformin alone

AIMS

This study was designed to assess the efficacy and safety of a dipeptidyl peptidase-4 inhibitor, gemigliptin versus sitagliptin added to metformin in patients with type 2 diabetes.

METHODS

We conducted a double-blind, randomized, active-controlled trial in 425 Asian patients with inadequately controlled type 2 diabetes being treated with metformin alone. Eligible patients were randomized into three groups: 50 mg gemigliptin qd, 25 mg gemigliptin bid or sitagliptin 100 mg qd added to ongoing metformin treatment for 24 weeks. Haemoglobin A1c (HbA1c) and fasting plasma glucose (FPG) were measured periodically, and oral glucose tolerance tests were performed at baseline and 24 weeks after starting the treatment regimen.

RESULTS

Twenty-four weeks later, adding gemigliptin (50 mg/day) to ongoing metformin therapy significantly improved glycaemic control. Reduction in HbA1c caused by 50 mg gemigliptin qd (-0.77% ± 0.8) was non-inferior to that caused by 100 mg sitagliptin qd (-0.8% ± 0.85). Proportion of patients achieving HbA1c <7% while taking 25 mg gemigliptin bid (50%) or 50 mg gemigliptin qd (54.07%) was comparable to the results with 100 mg sitagliptin qd (48.87%). There were significant decreases in FPG, postprandial glucose and AUC0-2 h glucose, as well as increases in GLP-1 and β cell sensitivity to glucose (supported by homeostasis model assessment of β-cell function, postprandial 2-h c-peptide and insulinogenic index) in patients receiving gemigliptin treatment with their metformin therapy. There was no increased risk of adverse effects with this dose of gemigliptin compared with sitagliptin 100 mg qd.

CONCLUSIONS

Addition of gemigliptin 50 mg daily to metformin was shown to be efficacious, well tolerated and non-inferior to sitagliptin in patients with type 2 diabetes mellitus.

Identification of marine bacteria affecting lithium adsorbents in seawater

Lithium manganese oxide-based adsorbents have been developed for the recovery of lithium from seawater. To maximize the recovery efficiency, it is important to prevent microfouling of lithium adsorbents by marine bacteria. To identify the marine bacteria that cause biofouling against the lithium adsorbents, lithium adsorbents were installed into a non-coated frame or a frame coated with an antifouling agent soaked in seawater. Microorganisms from the surface of lithium adsorbents were collected for 30 days at 10-day intervals, cultured in marine broth, isolated, and identified by 16S rDNA sequencing. Pseudoalteromonas and Vibrio were constituted to 35.6 and 28.8 % of total isolates, respectively, and were predominant in the non-coated frame, whereas Vibrio was poorly isolated (2.3 %) from the antifouling agent-coated frame. In this study, antifouling strategy for maximum lithium recovery efficiency in the marine area takes account of Pseudoalteromonas and Vibrio.

A multicentre, multinational, randomized, placebo-controlled, double-blind, phase 3 trial to evaluate the efficacy and safety of gemigliptin (LC15-0444) in patients with type 2 diabetes

AIM

This study was designed to assess the efficacy and safety of the dipeptidyl peptidase IV inhibitor gemigliptin (LC15-0444) 50 mg versus placebo in patients with type 2 diabetes.

METHODS

We conducted a 24-week, randomized, double-blind, placebo-controlled phase III trial in 182 patients (74 from Korea and 108 from India) with type 2 diabetes. After an initial 2 weeks of a diet and exercise programme followed by 2 weeks of a single-blind placebo run-in period, eligible patients were randomized to gemigliptin 50 mg or placebo, receiving the assigned treatment for 24 weeks. HbA1c and fasting plasma glucose (FPG) were measured periodically, and oral glucose tolerance test was performed at baseline and weeks 12 and 24.

RESULTS

At week 24, gemigliptin treatment led to significant reductions in HbA1c measurements compared to placebo (adjust mean after subtracting the placebo effect size: -0.71%, 95% confidence interval: -1.04 to -0.37%). A significantly greater proportion of patients achieved an HbA1c <7% with gemigliptin than with placebo. The placebo-subtracted FPG change from baseline at week 24 was -19.80 mg/dl. The overall incidence rates for adverse events were similar in the gemigliptin and placebo groups.

CONCLUSIONS

This study showed the efficacy and safety of gemigliptin 50 mg administered once daily as a monotherapy for type 2 diabetes patients.

Activation of de novo GSH synthesis pathway in mouse spleen after long term low-dose γ-ray irradiation

Glutathione (GSH) is an important cellular antioxidant and has a critical role in maintaining the balance of cellular redox. In this study, we investigated the GSH biosynthesis genes involved in the elevation of endogenous GSH levels using an irradiation system with an irradiation dose rate of 1.78 mGy/h, which was about 40,000 times less than the dose rates used in other studies. The results showed that GSH levels were significantly increased in the low-dose (0.02 and 0.2 Gy) irradiated group compared to those in the non-irradiated group, but enzymatic antioxidants such as superoxide dismutase and catalase were not induced at any doses tested. The elevation in GSH was accompanied by elevated expression of glutamate-cysteine ligase modifier subunit, but no changes were observed in the expression of glutamate-cysteine ligase catalytic subunit and thioredoxin in de novo GSH synthesis. In the case of genes involved in the GSH regeneration cycle, the expression of glutathione reductase was not changed after irradiation, whereas glutathione peroxidase was only increased in the 0.2 Gy irradiated group. Collectively, our results suggest that the de novo pathway, rather than the regeneration cycle, may be mainly switched on in response to stimulation with long-term low-dose radiation in the spleen.

Effect of radiation therapy on survival in surgically resected retroperitoneal sarcoma: a propensity score-adjusted SEER analysis

BACKGROUND

Currently no prospective randomized trial has measured the efficacy of radiation therapy for resected retroperitoneal sarcomas (RPS). Our objective was to determine the effect of radiation therapy on disease-specific and overall survival between propensity score-matched surgically resected RPS patients using the Surveillance, Epidemiology, and End Results (SEER) database.

PATIENTS AND METHODS

The study population consisted of patients with histologically confirmed RPS who underwent surgical resection between 1988 and 2006. Exclusion criteria included multiple malignancies, distant metastasis, and unknown grade or stage. Cox modeling was used to determine covariate associations with disease-specific survival. Propensity score methods were used to perform survival analysis in patients who received radiation matched with patients who underwent surgery alone.

RESULTS

Prior to matching, there were 762 patients (558 surgery only, 204 surgery with radiation). Factors independently associated with radiation therapy were age (P = 0.037), geographic region (P = 0.041), grade (P = 0.047), stage (P = 0.003), and surgery type (P = 0.01). Cox modeling demonstrated that age, sex, grade, and stage were independently associated with survival. Propensity scoring (309 matched pairs) and survival analysis using Kaplan-Meier methods demonstrated no difference between propensity score-matched patients receiving radiation therapy and those who did not (P = 0.35).

CONCLUSION

At present, SEER patients with surgically resected RPS who received radiation therapy did not demonstrate survival benefit.

A case of bilateral ovarian synchronous tumors (left ovarian serous papillary adenocarcinoma and right ovarian malignant mixed Müllerian tumor)

Synchronous bilateral ovarian cancer is extremely rare and there is no established guideline for management. A case of a 58-year-old multiparous woman with bilateral ovarian synchronous malignant tumors is presented. The clinical consideration and treatment of related cases are discussed.

A multicenter, randomized, placebo-controlled, double-blind phase II trial evaluating the optimal dose, efficacy and safety of LC 15-0444 in patients with type 2 diabetes

AIM

The objective of this study was to evaluate the optimal dose, efficacy and safety of a novel dipeptidyl peptidase-4 (DPP-IV) inhibitor, LC15-0444, in Korean subjects with type 2 diabetes mellitus treated by diet and exercise.

METHODS

This study was a double-blind, randomized, multicenter and parallel-group, dose-range finding study. We enrolled 145 patients (91 men and 54 women) with a median age of 53 years and a median body mass index of 25.1 kg/m(2) . The median baseline fasting plasma glucose (FPG) was 8.1 mmol/l, the median HbA1c was 7.9% and the median time since the diagnosis of diabetes was 3 years. After 2 weeks of an exercise/diet programme followed by 2 weeks of a placebo period, the subjects were randomized to one of the four following groups for a 12-week active treatment period: placebo and 50, 100 or 200 mg of LC15-0444.

RESULTS

All three doses of LC15-0444 significantly reduced the HbA1c from baseline compared to the placebo group (-0.06 vs. -0.98, -0.74 and -0.78% in the placebo and 50, 100 and 200 mg groups, respectively), without a significant difference between the doses. Subjects with a higher baseline HbA1c (≥8.5%) had a greater reduction in HbA1c. Insulin secretory function, as assessed using homeostasis model assessment-beta cell, C-peptide and the insulinogenic index, improved significantly with LC15-0444 treatment. Insulin sensitivity, as assessed using homeostasis model assessment-insulin resistance, also improved significantly after 12 weeks of treatment. The 50 and 200 mg groups had significantly reduced total cholesterol and low-density lipoprotein cholesterol levels at 12 weeks compared to the placebo group. No dosage of LC15-0444 affected weight or waist circumference. The incidences of adverse events were similar in all study subjects.

CONCLUSIONS

LC15-0444 monotherapy (50 mg for 12 weeks) improved the HbA1c, FPG level, oral glucose tolerance test results, β-cell function and insulin sensitivity measures, and was well tolerated in Korean subjects with type 2 diabetes.

Superoxide is a potential culprit of caspase-3 dependent endothelial cell death induced by lysophosphatidylcholine

Oxidative stress in the vascular wall has intimately been implicated in the apoptosis of human umbilical vein endothelial cells (HUVECs) by lysophosphatidylcholine (LPC). However, the major type of reactive oxygen species (ROS) in this apoptotic signaling pathway remains to be clarified. In this study, we report that superoxide mediate LPC-induced caspase-3 dependent apoptosis in cultured HUVECs. The stimulation of HUVECs with LPC evoked apoptosis and ROS generation, and inhibited nitric oxide (NO) production in a dose-dependent manner. The classical caspase-3 dependent apoptosis was determined after 16 hours treatment by Western blotting using an antibody against cleaved caspase-3. The caspase-3 activation induced by LPC was prominently inhibited by antioxidants or NO donors and enhanced by NO inhibitors. Especially, LPC-induced caspase-3 activation was inhibited by superoxide dismutase (SOD) and enhanced by ammonium tetrathiomolybdate, SOD inhibitor. Additionally, xanthine/xanthine oxidase mixture increased the caspase-3 activation but catalase failed to reduce this superoxide-induced caspase-3 activation. These findings indicate that the superoxide generation caused by LPC activates the caspase-3 which results in HUVECs death. This study reveals some evidences linking superoxide with caspase-3 activation and provides a new dimension to superoxide-mediated caspase-3 activation in developing the endothelial dysfunction and atherosclerosis.

SP600125 suppresses Cdk1 and induces endoreplication directly from G2 phase, independent of JNK inhibition

Cell cycle controls ensure that DNA replication (S phase) follows mitosis resulting in two precise copies of the genome. A failure of the control mechanisms can result in multiple rounds of DNA replication without cell division. In endoreplication, cells with replicated genomes bypass mitosis, then replicate their DNA again, resulting in polyploidy. Endoreplication from G2 phase lacks all hallmarks of mitosis. Using synchronized cells, we show that the c-Jun N-terminal kinase (JNK) inhibitor, SP600125, prevents the entry of cells into mitosis and leads to endoreplication of DNA from G2 phase. We show that cells proceed from G2 phase to replicate their DNA in the absence of mitosis. This effect of SP600125 is independent of its suppression of JNK activity. Instead, the inhibitory effect of SP600125 on mitotic entry predominantly occurs upstream of Aurora A kinase and Polo-like kinase 1, resulting in a failure to remove the inhibitory phosphorylation of Cdk1. Importantly, our results directly show that the inhibition of Cdk1 activity and the persistence of Cdk2 activity in G2 cells induces endoreplication without mitosis. Furthermore, endoreplication from G2 phase is independent of p53 control.

Comparison of desaturation and resaturation response times between transmission and reflectance pulse oximeters

BACKGROUND

In general, there is a response time between actual arterial hypoxemia and its detection by pulse oximeters. We compared the desaturation and resaturation response times between two types of pulse oximeters, transmission and reflectance pulse oximeters, to find out which oximeter has a more rapid response time.

METHODS

Thirty-three ASA 1 or 2 patients were enrolled in this study. A transmission pulse oximeter was placed on the index finger and a reflectance pulse oximeter was placed on the forehead and monitored simultaneously. After the induction of general anesthesia without pre-oxygenation, we waited until the oxygen saturation value of any of two pulse oximeters declined to 90%, and then mask ventilation was started with 100% oxygen. Oxygen saturation was recorded at an interval of 2 s during this time.

RESULTS

The desaturation response time of SpO(2) to 95% after apnea was 82.0 s (interquartile range: 67.0-98.5 s) vs. 94.0 s (interquartile range: 84.0-106.5 s) (P<0.001) and SpO(2) to 90% was 94.0 s (interquartile range: 75.5-109.5 s) vs. 100.0 s (interquartile range: 84.5-114.5 s) (P<0.001) in the reflectance and transmission oximeters, respectively. The resaturation response time from mask ventilation to 100% SpO(2) was 23.2+/-5.6 vs. 28.9+/-7.6 s (P<0.001) in the reflectance and transmission oximeters, respectively.

CONCLUSION

In clinical situations in which rapid changes in oxygen saturation are expected, we recommend the forehead reflectance pulse oximeter because it responds more quickly in detecting oxygen desaturation and resaturation compared with the transmission pulse oximeter.

Does propofol and alfentanil-induced sedation cause periodic apnoea in chronic renal failure patients?

AIMS

There is evidence suggesting that the respiratory response to sedation is different in patients with sleep apnoea, which is common in patients with chronic renal failure (CRF). This study examined the respiratory response of sedation with propofol and alfentanil, whose pharmacokinetics are not affected by the renal function, in CRF patients.

METHODS

Chronic renal failure patients who underwent arteriovenous-fistular surgery (CRF group) and patients who underwent chemoport insertion (control group) were enrolled in this study. Sedation was induced by infusing propofol 1.5 micro/ml and alfentanil 0.2 micro/kg/min continuously in both groups. In the desaturation study, the respiratory rate and peripheral oxygen saturation in room air were checked. In the apnoea-hypopnoea study, the patient's sedation (Observer's Assessment of Alertness/Sedation) score, apnoea-hypopnoea index (AHI) was recorded using a portable ventilation effort recorder (microMesam) while applying 5 l/min of oxygen through a facial mask.

RESULTS

The desaturation event was more common (21.5/h vs. 2/h, p = 0.001) in the CRF patients. Apnoea and hypopnoea (AHI: 13.0 vs. 1.6, p = 0.012, per cent of patients with an AHI > 5: 53.3% vs. 7.1%, p = 0.014) occurred more frequently in the CRF patients but the sedation score was not different.

CONCLUSION

Chronic renal failure patients have a higher risk of developing apnoea and hypopnoea during sedation, which highlights the need for careful monitoring and management in these patients.

Stimulation of large-conductance Ca2+-activated K+ channels by the Na+/Ca2+ exchanger inhibitor dichlorobenzamil in cultured human umbilical vein endothelial cells and mouse aortic smooth muscle cells

We investigated the effects of the selective inhibitor of Na(+)/Ca(2+) exchanger (NCX), 2',4'- and 3',4'-dichlorobenzamil (DCB), on large-conductance Ca(2+)-activated K(+) (BK(Ca)) channels in cultured human umbilical vein endothelial cells (HUVECs) and fresh isolated mouse aortic smooth muscle cells (MASMCs) using the patch clamp techniques. Both kinds of DCB reversibly activated BK(Ca) currents in whole-cell clamped HUVECs or MASMCs. The EC(50) of 2',4'-DCB for BK(Ca) current activation in HUVECs was 2.64 +/- 0.10 muM. In inside-out and outside-out patches, 2',4'-DCB remarkably increased BK(Ca) channels activity. 2',4'-DCB increased open frequency, but had no significant effect on mean open time. In inside-out patches, 2',4'-DCB shifted the relationship curve between [Ca(2+)](i) and open probability (NP(o)) to the left; the [Ca(2+)](i) required to evoke half-maximal activation changed from 1087.45 +/- 142.91 nM to 500.24 +/- 66.83 nM by 10 muM 2',4'-DCB. In addition, 2',4'-DCB shifted the relationship curve between membrane potential and NP(o) to the left; the membrane potential to evoke half-maximal activation changed from 81.1 +/- 2.4 to 64.7 +/- 3.1 mV by 10 muM 2',4'-DCB. 3',4'-DCB also increased BK(Ca) channels activity. There was no significant difference in the effect of DCB on BK(Ca) channels between both excised patches. These results suggested that 2',4'- and 3',4'-DCB activate BK(Ca) channels activity in HUVECs and MASMCs by increasing the sensitivity of BK(Ca) channels to cytosolic free Ca(2+) and membrane potential. Our report would provide a consideration if they are used as NCX blocker in vascular endothelial cells or smooth muscle cells.

Characteristics of atmospheric hydrogen peroxide variations in Seoul megacity during 2002-2004

Atmospheric hydrogen peroxides (H(2)O(2)) and methyl hydroperoxide (CH(3)OOH) were measured in Seoul, the capital of South Korea. Experiments were performed for several days almost every month from January 2002 to April 2004. Gaseous hydroperoxide was collected in aqueous solution and determined by HPLC-fluorescence method. In general, the higher levels of H(2)O(2) were found in warm and humid air with high ozone concentrations, but lower concentrations of SO(2), NO(2), CO and PM(10). For two-year measurements, seasonal factor was the most dominant and the concentrations of H(2)O(2) were highest in summer, for which the median, mean, and upper 90% values were 0.53 ppbv, 0.81 ppbv, and 1.61 ppbv, respectively. In highly polluted metropolitan Seoul, the photochemical activity controlling H(2)O(2) variations was seemingly more sensitive to meteorological conditions than the level of chemical pollutants. It was mainly due to high emissions of pollutants, particularly NOx, which was demonstrated by the occasional occurrence of CH(3)OOH.

Association of abdominal fat distribution and cardiometabolic risk factors among obese Korean adolescents

The association between abdominal fat distribution and cardiometabolic risk factors using direct measures of abdominal fat in adolescents has not been extensively researched. This study was designed to investigate the association between visceral and subcutaneous fat and cardiometabolic risk factors, in obese Korean adolescents. The study enrolled 175 adolescents (72 boys, 103 girls), from ages nine to 19 years, who were referred to the Obesity Clinic of Asan Medical Center. Body mass index (BMI) and waist circumference (WC) were measured for each study participant. Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) areas were calculated by computed tomography. Blood pressure, fasting plasma glucose, total cholesterol, triglycerides, HDL cholesterol, insulin and homeostasis model assessment (HOMA) score were measured. Systolic blood pressure, HDL cholesterol, fasting insulin and the HOMA score were significantly correlated with BMI, WC, VAT and SAT. In addition, VAT was significantly correlated with diastolic blood pressure and triglyceride levels. On multiple regression analysis, VAT was independently correlated with blood pressure, triglycerides, HDL cholesterol, fasting insulin and the HOMA score, while SAT was independently correlated with systolic blood pressure, fasting insulin and the HOMA score. This study determined that cardiovascular risk factors are closely associated with VAT, while insulin resistance is closely associated with both VAT and SAT among obese Korean adolescents.

The effect of beta-cyclodextrin complexation on the bioavailability and hepatotoxicity of clotrimazole

Clotrimazole, a poorly water-soluble antimycotic agent, is a promising therapeutic agent for various diseases including cancer and sickle cell anemia. The oral bioavailability and hepatic toxicity of clotrimazole were compared with its beta-cyclodextrin inclusion form which was prepared by the spray-drying method. The inclusion complex gave significantly higher initial plasma concentrations, Cmax and AUC than did clotrimazole alone, indicating that the drug from the inclusion compound could be more easily absorbed in rats. Furthermore, mice treated with the inclusion compound showed significantly higher GOT/GPT values compared to clotrimazole alone. The inclusion compound also induced hypertrophy of hepatic cells by fat accumulation and disappearance of hepatic sinusoids, indications of pathological changes of liver, suggesting that the inclusion compound could induce more severe tissue damage in the liver than clotrimazole alone. Thus, hepatotoxicity of clotrimazole seems to be correlated with the enhanced oral bioavailability by inclusion complexation. Our results suggest that, in the development of a novel oral product, appearance or enhancement of hepatic toxicity must be considered along with oral bioavailability.

Differential modulation of myosin heavy chain phenotype in an inactive extensor and flexor muscle of adult rats

The effects of chronic neuromuscular inactivity on the phenotype and size of muscle fibres in a fast ankle extensor (medial gastrocnemius, MG) and a fast ankle flexor (tibialis anterior, TA) muscle of the rat hindlimb were determined. Inactivity was produced by spinal cord isolation (SI), i.e. complete spinal cord transections at a mid-thoracic and high sacral level and bilateral deafferentation between the transection sites. After 90 days of SI, the MG and TA muscle weights were 53 and 45% lower than in age-matched controls. Overall mean fibre sizes in the deep (close to the bone) and superficial (away from the bone) regions were approximately 60 and 65% smaller in the MG and approximately 40 and 50% smaller in the TA of SI than control rats, respectively. The myosin heavy chain (MHC) composition shifted towards the faster isoforms after SI: the MG showed an increase in both types IIx (20%) and IIb (23%), whereas the TA showed a marked increase in type IIx (94%) and a decrease in type IIb (18%) MHC. Both muscles in SI rats showed no type IIa and only one MG muscle had approximately 5% type I MHC. These results show that prolonged inactivity has a stronger effect on a fast extensor compared with a fast flexor in the rat hindlimb. The larger decrease in mass and fibre size in the MG than the TA most probably reflects the larger impact of chronic inactivity on the normally more highly recruited extensor than flexor muscle. The primary shift to type IIb MHC in the MG and type IIx MHC in the TA indicate a different default mode for an inactive extensor vs. flexor muscle, and may reflect differing activity-independent neural influences, i.e. neurotrophic factors, on muscle fibre phenotype in extensors vs. flexors.

Evaluation of the Cobra perilaryngeal airway (CPLA) as an airway conduit

BACKGROUND AND OBJECTIVE

The effectiveness of the Cobra perilaryngeal airway as a routine airway device and as a conduit for tracheal intubation has not been prospectively studied to date. This study aimed to evaluate the Cobra perilaryngeal airway for its potential role in an emergency airway rescue, by analysing its use as a bridge to blind or fibre-optic-guided intubation.

METHODS

In 49 patients, the procedure was carried out as follows: fibre-optic view through the Cobra perilaryngeal airway was assessed after the insertion of the Cobra perilaryngeal airway, then blind intubation through the Cobra perilaryngeal airway was attempted. After evaluating the success of blind intubation, fibre-optic-guided intubation was performed through the Cobra perilaryngeal airway. The endotracheal tube was removed after evaluating the success of fibre-optic-guided intubation, and then conventional laryngoscopy was carried out to evaluate the Cormack & Lehane grade and airway trauma.

RESULTS

In all, 95.9% (47/49) of patients had adequate ventilation using the Cobra perilaryngeal airway; the success rates for the blind and fibre-optic-guided intubation were 36.2% and 83.0%, respectively. The patients were divided into two groups according to the fibre-optic view. Group 1 included patients with an obstructed view by an anterior grill of the Cobra perilaryngeal airway head, and a view of the anterior epiglottis (downfolded epiglottis) with or without a visible larynx (16/47, 34.0%). Group 2 included the remaining patients (31/47, 66.0%). The success rates of the blind and fibre-optic intubations were different between the two groups (blind intubation: 12.5% vs. 48.4%, fibre-optic intubation: 62.5% vs. 93.6%, P 0.05). 42.6% of patients had blood staining after removing the device and complications such as trauma and oedema were confirmed under direct laryngoscopy.

CONCLUSION

This study suggests that the Cobra perilaryngeal airway could be a useful airway device as a vehicle for fibre-optic-guided intubation; however, it needs caution against airway trauma.

Effects of sevoflurane on the cAMP-induced short-circuit current in mouse tracheal epithelium and recombinant Cl- (CFTR) and K+ (KCNQ1) channels

BACKGROUND

An optimal level of airway surface liquid is essential for mucociliary clearance in lungs. The cAMP-activated cystic fibrosis transmembrane conductance regulator (CFTR) and KCNQ1 channels in tracheal epithelium play key roles in luminal and basolateral membranes, respectively. The aim of this study was to examine the effects of sevoflurane on cAMP-induced chloride secretion by the mouse tracheal epithelium and the modulation of recombinant CFTR and KCNQ1 channels.

METHODS

The equivalent short-circuit current (Isc) of the mouse tracheal epithelium was measured using a flow-type Ussing chamber technique. Inhibition of Na+ absorption was achieved through the luminal application of amiloride. cAMP-dependent Cl- secretion was evoked by forskolin and isobutylmethylxanthine (Fsk/IBMX) applied to the basolateral side. The effect of sevoflurane on CFTR and KCNQ1 channels was assessed using a whole-cell patch clamp in human embryonic kidney 293T cells expressing CFTR and KCNQ1 channels.

RESULTS

Fsk/IBMX induced a sustained Isc that was suppressed by the application of sevoflurane [decreased by 49 (4.5)% at 190 microM]. The Fsk/IBMX-induced Isc was also blocked by basolateral application of chromanol 293B, a blocker of the KCNQ1 K+ channel. In KCNQ1-expressing cells, sevoflurane 190 microM reduced the outward currents to 59 (4.9)% at 80 mV. The CFTR current was not affected by sevoflurane (approximately 360 microM).

CONCLUSIONS

These results suggest that the inhibition of KCNQ1 underlies sevoflurane-induced decrease in airway secretion.

Influence of the baricity of a local anaesthetic agent on sedation with propofol during spinal anaesthesia

BACKGROUND

This study examined the effect of different levels of spinal anaesthesia, induced by solutions of different baricity but containing the same amount of local anaesthetic agent, on the requirement for sedation with propofol.

METHODS

Thirty-six patients undergoing varicose vein surgery under spinal anaesthesia were randomly allocated to receive tetracaine 15 mg in 3 ml of either glucose 5% (hyperbaric) or CSF (isobaric). I.V. propofol was started 5 min after the intrathecal injection and was titrated to maintain a bispectral index (BIS) score of 65-75. The propofol requirements to maintain this range in the two groups were compared every 5 min.

RESULTS

The propofol requirement was always lower in the hyperbaric group, with the differences becoming statistically significant 20 min after the intrathecal injection. Total consumption of propofol over the 55 min of the study was also less in the hyperbaric group.

CONCLUSION

The known difference in level of spinal anaesthetic block induced by solutions of different baricity, but the same dose of local anaesthetic, was associated with different requirements for propofol sedation as determined by BIS assessment.

Expression and role of interleukin-6 in distraction osteogenesis

Distraction osteogenesis is a special form of bone healing in which well-controlled distraction stresses and consequent tensile strains within callus tissue induce very efficient new bone formation. Proinflammatory cytokines are involved during the early phase of fracture healing and callus remodeling. Temporal expression patterns of proinflammatory cytokines were assessed in Sprague-Dawley rat tibial models of distraction osteogenesis and acute lengthening, and only interleukin-6 (IL-6) was found to be specifically induced during the distraction phase. IL-6 immunoreactivity was detected not only in hemopoietic cells and osteoblasts but also in the spindle-shaped cells of the fibrous interzone, where most of the tensile strains are concentrated. In vitro study revealed that IL-6 did not affect the proliferation of C3H10T1/2 cells, mouse bone marrow stromal cells (MSCs), or MC3T3-E1 cells; but its blocking antibody reduced the proliferation of C3H10T1/2 cells and MSCs. The mRNA expression of COL1A1 and osteopontin were not changed by IL-6 or its blocking antibody, but the alkaline phosphatase activities of MC3T3-E1 cells were increased by IL-6 and decreased by its blocking antibody. These findings indicate that IL-6 is a proinflammatory cytokine that responds to tensile strain during distraction osteogenesis. IL-6 negatively affects the proliferation of primitive mesenchymal cells, whereas the differentiation of more mature osteoblastic lineage cells is enhanced by IL-6 in vitro. IL-6 appears to be one of the cytokines involved in the complex network of signal cascades evoked during distraction osteogenesis and may differentially affect immature and mature osteoblastic lineage cells.

The prevalence and risk factors associated with isolated untreated systolic hypertension in Korea: the Korean National Health and Nutrition Survey 2001

Although isolated systolic hypertension (ISH) increases the risk of coronary heart disease and stroke, more than any other hypertension subtype, the prevalence and risk factors associated with ISH in the Korean population are not known. The 2001 Korean National Health and Nutrition Survey was a cross-sectional and nationally representative survey conducted in 2001. The prevalence of ISH by age and body mass index (BMI) was examined in 6601 Korean adults over 20 years of age. After adjusting for age, 4.32+/-0.32% of Korean adults had ISH, 5.28+/-0.37% had isolated diastolic hypertension and 5.82+/-0.36% had systolic/diastolic hypertension. The overall prevalence of ISH was found to increase directly with advancing age and increasing BMI. Although the ISH was found to be more common in men overall (4.81+/-0.50% in men, 4.12+/-0.37% in women), it was more common in women over 70 years of age. Independent variables associated with risk for ISH included advanced age, BMI, triglyceride (TG) levels, monthly income and alcohol intake. However, gender, fasting blood glucose, total cholesterol and high-density lipoprotein cholesterol levels, residential area, education level and smoking were found not to be significantly associated with ISH risk. The findings of the present study demonstrate that the prevalence of untreated ISH in Korea was lower than in Western countries. Age, BMI, TG levels, monthly income and alcohol intake were associated with ISH.

Activation of NF-κB by HDAC inhibitor apicidin through Sp1-dependent de novo protein synthesis: its implication for resistance to apoptosis

Histone deacetylase (HDAC) inhibitors are promising anti-cancer drugs, but these exert differential responses depending on the cell types. Here, we demonstrate a new mechanism for activation of nuclear factor-kappaB (NF-kappaB) by HDAC inhibitor apicidin and the role of NF-kappaB signaling pathway for mediating differential cellular responses, especially, apoptosis. Treatment of HeLa cells with apicidin increases transcriptional activity of NF-kappaB and its target gene IL-8 and cIAP-1 induction, which involves the activation of IKK-IkappaBalpha signaling pathway through Sp1-dependent de novo protein synthesis. In parallel, apicidin treatment leads to histone hyperacetylation in the IL-8 promoter region independent of NF-kappaB signaling pathway, which is not sufficient for full transcription of IL-8 gene. This NF-kappaB activation contributes to resistance of HeLa cells to apoptotic potential of apicidin. Collectively, our results suggest that activation of NF-kappaB signaling cascade functions as a critical modulator to determine cell fate on apoptosis in response to HDAC inhibitors.

Magnetic resonance imaging with true fast imaging with steady-state precession and half-Fourier acquisition single-shot turbo spin-echo sequences in cases of suspected placenta accreta

PURPOSE

To present the magnetic resonance imaging (MRI) findings of placenta accreta in suspected cases of placenta accreta with true fast imaging with steady-state precession (True FISP) and half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences.

MATERIAL AND METHODS

Five patients underwent MRI with HASTE (n = 5) and/or True FISP (n = 4) sequences for suspected placenta accreta. Retrospective review of MRI was performed to define the location and extent of the implantation abnormality.

RESULTS

The uteroplacental interface was visualized as three layers; inner low signal intensity layer, middle high signal intensity layer of myometrium, and outer low signal intensity layer of uterine serosa. Three cases were diagnosed with placenta accreta on MRI and focal non-visualization of the inner layer was demonstrated.

CONCLUSION

The finding of focal non-visualization of the inner layer between the placenta and myometrium by MRI with True FISP and HASTE sequences was the diagnostic finding for placenta accreta.

Cadaveric renal transplantation in hepatitis B antigen–positive recipients using hepatitis B antigen–positive donor organs with lamivudine treatment

Although renal transplantation has been regarded as the best renal replacement therapy in end-stage renal disease patients, there have never been enough organ donors. Therefore, hepatitis B surface antigen (HBsAg)-negative patients are often given priority over HBsAg-positive patients. We performed cadaveric renal transplantation in six HBsAg-positive recipients given HBsAg-positive donor organs who were on lamivudine treatment. Donors were found to have normal renal function by serum and urine laboratory tests. All recipients underwent liver biopsies before transplantation; those with liver cirrhosis were excluded. All recipients were treated with 100 mg lamivudine once daily because of positive titers of hepatitis B viral (HBV) DNA (three patients), and increased levels of alanine aminotransferase (ALT) (three patients). During the follow-up period, one patient died from hepatic failure at 50 months after transplantation without deterioration of graft function. The remaining five patients showed sustained normal ALT levels. Decreases in HBV DNA titer were observed among patients who were positive before transplantation, but did not reverse to negative. Acute rejection developed in two patients: one was treated successfully with steroid pulse therapy, and the other had two bouts of acute rejection within a 33-month interval. The first was successfully treated with steroid pulse therapy, but the second failed. The four remaining patients have maintained normal renal function for a considerable time. HBsAg-positive donor organs must be used carefully in renal transplantation of HBsAg-positive recipients.

Simple bone cyst occurring in calvarium

A 60 year-old female presented with a non-specific headache that she had experienced for 4 years. A simple skull X-ray indicated a well-defined, lobulated and radiolucent lesion with a thin sclerotic rim involving the parietal bone (Fig. 1A). Computed tomography revealed a hypodense lesion. Magnetic resonance imaging showed a 2 cm-sized cystic lesion in the diploic space with both tabular involvement. This lesion was not enhanced by contrast agent. It was well defined and the periosteum was intact. The cyst paralleled the CSF in signal intensity on all pulse sequences. No fluid levels were detected (Fig. 1B, C, D). After the scalp was incised, a semi-translucent and light yellow- to white-coloured bony lesion was easily identified. The outer bony cortex of this lesion was slightly elevated, and the consistency was same as that of the normal skull. A craniectomy was performed and the cystic skull lesion was removed. The inner surface of this cystic lesion was intact but appeared irregular. The cystic cavity was empty and the dura did not appear to be involved. Histologically, it was a simple cystic cavity without lining epithelium, and the surrounding bony structures were normal (Fig. 1E, F). It was diagnosed as a simple bone cyst (SBC). The postoperative course was uneventful.

Cleavage of purified neuronal clathrin assembly protein (CALM) by caspase 3 and calpain

The most efficient means of protein internalization from the membrane are through clathrin-coated pits, which concentrate protein interactions with the clathrin-associated assembly protein complex AP-2 and internalization signals in the cytoplasmic domain of transmembrane proteins. Binding of clathrin assembly protein to clathrin triskelia induces their assembly into clathrin-coated vesicles (CCVs). Due to a difficulty of isolating clathrin molecules from their complex or assembly state in the cells, most of the studies were carried out with recombinant clathrin proteins, which may present different conformation and structural variation. In this study, we have developed an efficient method of isolating the native clathrin assembly protein lymphoid myeloid (CALM) from the bovine brain that is enriched with clathrin and clathrin associated proteins and characterized by their sensitivity to proteases and it's ability to form CCV. The purified CALM has molecular weight of approximately 100,000 dalton on SDS-PAGE, which is consistent with the result of in vitro translation. The purified CALM protein could promote the assembly of clathrin triskelia into clathrin cage, and cleaved CALM proteolysed by caspase 3 and calpain could not promote them. In this respect, our data support a model in which CALM functions like AP180 as a monomeric clathrin assembly protein and might take part in apoptotic process in neuronal cells.

Role of reactive oxygen species in apoptosis induced by N-ethylmaleimide in HepG2 human hepatoblastoma cells

We have previously reported that N-ethylmaleimide induces apoptosis through activation of K(+), Cl(-)-cotransport in HepG2 human hepatoblastoma cells. In this study, we investigated the role for reactive oxygen species as a mediator of the apoptosis induced by N-ethylmaleimide. N-ethylmaleimide induced a significant elevation of intracellular level of reactive oxygen species. Treatment with antioxidants (N-acetyl cysteine, N,N'-diphenyl-p-phenylenediamine) which markedly suppressed generation of reactive oxygen species, significantly inhibited the N-ethylmaleimide-induced activation of K(+), Cl(-)-cotransport and apoptosis. Inhibitors of NADPH oxidase (diphenylene iodonium, apocynin, D-(+)-neopterine) also significantly blunted the generation of reactive oxygen species, activation of K(+), Cl(-)-cotransport and apoptosis induced by N-ethylmaleimide. These results suggest that reactive oxygen species generated through activation of NADPH oxidase may play a role in the N-ethylmaleimide-induced stimulation of K(+), Cl(-)-cotransport and apoptosis in HepG2 cells.

The role of cholecystokinin in conditional compensatory responding and morphine tolerance in rats

As elaborated in the conditioning analysis of tolerance, cues present at the time of drug administration become associated with the drug effect. A particularly salient cue that may become associated with the drug effect is the pharmacological drug-onset cue inherent to drug administration. Drug-associated cues contribute to tolerance by eliciting a conditional compensatory response that attenuates the drug effect. For example, the early drug effect, having been paired with the subsequent larger drug effect, may elicit the release of antiopioid peptides that counter opioid effects. The role of a putative antiopioid peptide, cholecystokinin-8 (CCK), in the associative mechanisms of opiate tolerance was evaluated. The results of these experiments suggest that a CCK2 receptor antagonist attenuates both the expression of opiate tolerance and the conditional compensatory response hypothesized to mediate such tolerance.

The flow rate of the elastomeric balloon infusor is influenced by the internal pressure of the infusor

The purpose of this study was to evaluate the flow rate of elastomeric balloon infusor composed of rubber or silicone materials. Two models were studied: the Baxter Twoday Infusor and Advance Silicone Infusor. Each infusion device has a preset flow rate of 2 mL/hr. Fifteen units of each device were filled with 100 mL of normal saline. The flow rate was measured gravimetically using an electronic balance. The internal pressure of the balloon infusor was measured with a Digital pressure meter via the pressure transducer. The monitored internal pressure of the two kinds of infusor was not maintained uniformly during the entire delivery period, which was divided into 3 phases: the phase of decreasing, maintained, and increasing pressure during the delivery of drug. Both devices initially infused at a relatively high rate, followed by a somewhat steady flow rate. The flow rate distinctly increased in the small residual volume. The flow rate of the balloon infusor used in this study was not sustained uniformly during the entire delivery period and was in proportion to the internal pressure of the infusor regardless of the materials.

Diarylheptanoids with free radical scavenging and hepatoprotective activity in vitro from Curcuma longa

Assay-guided fractionation of the EtOAc soluble fraction of the rhizomes of Curcuma longa furnished three DPPH free radical scavenging diarylheptanoids, curcumin (1), demethoxycurcumin (2), and bisdemethoxycurcumin (3). Compounds 1-3 showed the DPPH radical scavenging effects with IC(50) values of 2.8, 39.2, 308.7 microM, respectively. L-Ascorbic acid and resveratrol as positive controls exhibited IC(50) values of 22.5 and 25.0 microM, respectively. Compounds 1-3 showed significant hepatoprotective effects on tacrine-induced cytotoxicity in human liver-derived Hep G2 cells. The EC(50) values of 1-3 are 86.9, 70.7, and 50.2 microM, respectively. Silybin (EC(50) = 69.0 microM) and silychristin (EC(50) = 82.7 microM) were used as positive controls.

Hypermethylation of tumor-related genes in genitourinary cancer cell lines

Hypermethylation of CpG island is a common mechanism for the inactivation of tumor-related genes. In the present study, we analyzed 13 genitourinary cancer cell lines for aberrant DNA methylation of 5 tumor-related genes using methylation- specific polymerase chain reaction (MSP). GSTP1 was methylated in 5 (38.5%), E-cadherin in 1 (8%), VHL in 1 (8%), and MGMT and hMLH1 in none (0%). Six out of thirteen genitourinary cancer cell lines had methylation of at least one of five genes; 5 had one gene methylated, and, 1 had two genes methylated. Methylation of these 5 genes was not detected in any of the bladder cancer cell lines. GSTP1 was methylated in all of the 3 prostate cancer cell lines. We conclude that aberrant hypermethylation may be an important mechanism for the inactivation of cancer-related genes in kidney and prostate cancer cell lines.

In vitro effects of hydroxybenzaldehydes from Gastrodia elata and their analogues on GABAergic neurotransmission, and a structure-activity correlation

The present study was designed to characterize the modulatory effects of the constituents of Gastrodia elata and their analogues on the GABAergic neurotransmission. 4-Hydroxybenzaldehyde (1) and 4-hydroxy-3-methoxybenzaldehyde (4) inhibited potently the activity of GABA transaminase (IC(50) = 4.1 and 5.4 microg/ml, respectively), while the activity of another constituent, 4-hydroxybenzyl alcohol (2), was very weak. Further investigation with 10 analogues revealed a structure-activity correlation, suggesting that the aldehyde group and the hydroxy group at C-4 are necessary for the inhibitory effect on the enzyme activity. Some potent enzyme inhibitors were examined for the effect on the radioligands to the GABA(A) receptor complexes of rat cerebral cortices. Among them, the component 4 dose-dependently increased (20 - 30 %) the binding of [(3)H]flunitrazepam in the presence of GABA.

Rapid and reversible changes in dendrite morphology and synaptic efficacy following NMDA receptor activation: implication for a cellular defense against excitotoxicity

Postsynaptic neuronal dendrites undergo functional and morphological changes in response to pathologically excessive synaptic activation. Although rapid formation of segmental focal swelling (varicosity) is the most prominent hallmark in such excitotoxic injury, little is known about the pathophysiological function of these structural alterations. We used cultured rat hippocampal slices to evaluate the relationship between the formation of varicosities and subsequent neuronal death. Substantial numbers of segmental dendritic varicosities were observed all over the hippocampus within 5 minutes of exposure to 30 μM NMDA, although neuronal death was detected only in the CA1 region 24 hours after NMDA exposure. Sublethal NMDA concentrations (1-10 μM) induced reversible focal swelling in all hippocampal subregions. NMDA-induced neuronal death was prevented either by NMDA receptor antagonists or by the use of Ca2+-free medium, whereas varicosity formation was virtually independent of Ca2+ influx. Rather, the Ca2+-free conditions per se produced dendritic focal swelling. Also, NMDA-induced varicosity formation was dependent on extracellular Na+ concentration. Thus, we believe that varicosity formation is not causally related to neuronal injury and that the two phenomena are separable and involve distinct mechanisms. Interestingly, dendrite swelling was accompanied by AMPA receptor internalization and a rapid, long-lasting depression in synaptic transmission. Moreover, low Na+ conditions or treatment with ethacrynic acid or proteinase inhibitors, which effectively prevent varicosity formation, aggravated NMDA-induced excitotoxicity, and eliminated the regional specificity of the toxicity. Therefore, the pathological changes in dendrite morphology and function may be associated with an early, self-protective response against excitotoxicity.