TRPC channels: interacting proteins

TRP channels, in particular the TRPC and TRPV subfamilies, have emerged as important constituents of the receptor-activated Ca2+ influx mechanism triggered by hormones, growth factors, and neurotransmitters through activation ofphospholipase C (PLC). Several TRPC channels are also activated by passive depletion of endoplasmic reticulum (ER) Ca2+. Although in several studies the native TRP channels faithfully reproduce the respective recombinant channels, more often the properties of Ca2+ entry and/or the store-operated current are strikingly different from that of the TRP channels expressed in the same cells. The present review aims to discuss this disparity in the context of interaction of TRPC channels with auxiliary proteins that may alter the permeation and regulation of TRPC channels.

Haplotype association of IL-8 gene with Behcet's disease

Interleukin-8 (IL-8), a CXC chemokine that recruits and activates inflammatory cells, plays a critical role in the pathogenesis of Behcet's disease (BD). To investigate the association of the genetic polymorphism of IL-8 and BD, we genotyped IL-8 -845 T/C, -738 T/A, -353 A/T, -251 A/T, +293 G/T, +678 T/C and receptors CXCR-1 +2607 G/C and CXCR-2 +785 C/T polymorphisms in 119 Korean patients with BD and 119 age- and sex-matched healthy blood donors. Then, single nucleotide polymorphisms (SNPs) and haplotypes were analyzed between patients and controls. There were no SNPs associated with BD. However, the frequency of haplotype TAT inferred from SNPs, IL-8 -353 A/T, -251 A/T and +678 T/C, was significantly higher in patients with BD than controls (5.9 vs 0.0%, P = 0.0001), as was haplotype ATC (6.7 vs 0.0%, P < 0.0001). The haplotype difference was still valid in human leukocyte antigen-B51-negative subjects. In conclusion, we found a significant difference in the distribution of IL-8 gene haplotypes between patients with BD and healthy controls. These results suggest that the genetic polymorphisms of proinflammatory chemokine IL-8 can contribute to the pathogenesis of BD.

Non-traumatic peroneal nerve palsy: MRI findings

AIM

To present magnetic resonance imaging (MRI) findings of non-traumatic peroneal nerve palsy and to evaluate the usefulness of MRI in patients with non-traumatic peroneal nerve palsy.

MATERIALS AND METHODS

In a retrospective study, 11 consecutive patients presenting with peroneal nerve palsy were included. MR images of the lower leg and electrophysiological examinations were also reviewed. The cause of peroneal nerve palsy was determined on the basis of MRI findings and was evaluated using electrophysiological data. Nine patients with causative lesions detected on MRI, underwent surgery.

RESULTS

Clinical examination and electromyography (EMG) disclosed 11 peroneal lesions. MRI and EMG revealed three types of signal intensity change, i.e. deep peroneal nerve palsy type, common peroneal nerve palsy type, and superficial peroneal nerve palsy type. The MRI and EMG findings were in agreement in seven (65%) of the 11 study patients. In nine patients the causative lesions were identified using MRI, including ganglion cyst (n=6), osteochondroma (n=1), synovial cyst (n=1), and aneurysm (n=1).

CONCLUSION

Ganglion cyst is the most common cause of non-traumatic peroneal nerve palsy. MRI offers a noninvasive method for obtaining useful information to assess, localize, and monitor peripheral peroneal nerve palsy.

Status analysis and strategic framework for sanitation management in Asia and Africa

Following rapid population increase and industrial development, the ever increasing environmental pollution and the associated sanitation-related problem are no longer regional or local but have become an issue requiring global-dimensional concern and the provision of problem-solving alternatives. Especially, since most problems result from inappropriate sewerage and the lack of sewage treatment system are in a serious state occurring in economically underdeveloped regions, and as such, their significance is enormous. The United Nations Environment Programme (UNEP) has been making efforts to establish the technology selection methodology applicable in developing countries, through the accurate status, investigation and analysis of the wastewater management state in Asian and African regions, and the sanitation management guideline utilisable by political leaders or decision-makers. As part of this effort, the Korea Institute of Water Environment (KIWE), together with the UNEP, selected China and Vietnam (in Asia) and Kenya and Ethiopia (in Africa) as subject countries to investigate and perform on-site sanitation management investigations and analysis in this research. Results obtained from the on-site investigation were analysed, and in order to be helpful in establishing a strategy for sanitation management in underdeveloped countries, the strategic framework (SF) has been made based on characterised results.

Mycophenolic Acid Induces Islet Apoptosis by Regulating Mitogen-Activated Protein Kinase Activation

Mycophenolic acid (MPA), an inosine monophosphate dehydrogenase inhibitor, is widely used as an immunosuppressive drug after transplantations including those of pancreas islet cells. However, recent reports have indicated that MPA has apoptotic effects on islet cells in vitro. To study the effect of MPA on islet cells and determine its mechanism, we used an insulin secreting cell-line, HIT-T15. We examined mitogen-activated protein kinase (MAPK) activation after MPA treatment, and determining cell death levels using methylthiazdetetrazolium assays. The activations of extracellular signal-regulated protein kinase (ERK), c-jun N-terminal kinase (JNK), and p38 MAPK and caspase-3 cleavage were measured by Western blotting. MPA (1, 10, 30 micromol/L) increased cell death and caspase-3 cleavage within 24 hours. Exogenous 500 micromol/L guanosine reversed the MPA-induced islet cell death, but exogenous adenosine did not. MPA 10 micromol/L induced cell apoptosis and increased the activations of JNK, ERK, and p38 MAPK. Furthermore, exogenous guanosine, but not exogenous adenosine, reversed these effects induced by MPA. This study demonstrated that MPA may induce islet apoptosis in HIT-T15 cells by increasing activations of JNK, ERK, and p38 MAPK in a guanosine-dependent manner.

Measurement of atmospheric neutrino flux consistent with tau neutrino appearance

A search for the appearance of tau neutrinos from nu(mu) <--> nu(tau) oscillations in the atmospheric neutrinos has been performed using 1489.2 days of atmospheric neutrino data from the Super-Kamiokande-I experiment. A best fit tau neutrino appearance signal of 138+/-48(stat)-32(+15)(syst) events is obtained with an expectation of 78+/-26(syst). The hypothesis of no tau neutrino appearance is disfavored by 2.4 sigma.

Pretreatment with remifentanil to prevent withdrawal after rocuronium in children

BACKGROUND

Pain from rocuronium injection is a common side-effect reported to occur in 50-80% of the patients. This randomized, double-blind, placebo-controlled study was designed to evaluate the efficacy of pretreatment with i.v. remifentanil on prevention of withdrawal response during rocuronium injection in paediatric patients.

METHODS

After obtaining parental consents, 70 paediatric patients were randomly allocated into two groups to receive either i.v. remifentanil 1 mug kg(-1) (remifentanil group, n=35) or i.v. saline 5 ml (saline group, n=35). Anaesthesia was induced with thiopental sodium 2.5% (5 mg kg(-1)) and the test drug was injected over 30 s. One minute after the test drug injection, rocuronium 1% (0.6 mg kg(-1)) was injected over 5 s and the response was recorded. Mean arterial pressure (MAP) and heart rate were recorded on arrival in the operating theatre, before and 1 min after the tracheal intubation.

RESULTS

The overall incidence of withdrawal movements was significantly higher in the saline group (33 patients; 94%) than that in the remifentanil group (8 patients; 23%) (P<0.001). No patient in the remifentanil group showed generalized movement, whereas 51% of patients in the saline group did. Remifentanil prevented significant increase in MAP after intubation.

CONCLUSION

This study demonstrated that pretreatment with remifentanil 1 microg kg(-1) provided a safe and simple method for reducing the incidence of rocuronium-associated withdrawal movement with haemodynamic stability in children.

Determination of the optimal angle for needle insertion during caudal block in children using ultrasound imaging

Using ultrasound imaging, the optimal angle for needle insertion during caudal epidural injection in children was estimated. After general anaesthesia, ultrasonography was performed at the sacral hiatus in 130 children aged 2-84 months positioned in the lateral position. The median [range] values for the intercornual, caudal space depth and the distance from skin to the posterior sacral bony surface were 17.0 [9.6-24] mm, 3.5 [1-8] mm and 21.0 [10-39] mm, respectively. The optimal angle showed no significant correlation with age, weight, height or body surface area. The median [range] calculated optimal angle for the needle was 21.0 [10-38] degrees. We conclude that the needle should be inserted at about 20 degrees to the skin to avoid puncture of the bone and potential intra-osseous injection.

Laboratory-scale analysis of effect of plume spacing of air diffuser system on destratification efficiency

This paper presents a study conducted to develop guidelines for the design of an air bubble destratification system, with particular concern given to plume spacing. To investigate the effect of plume spacing on the destratification efficiency of the system, we first conducted a dimensional analysis that included major variables in bubble hydrodynamics. Then, we conducted laboratory experiments with various plume spacings and water depths under non-linear stratification conditions, and we evaluated the destratification efficiencies. Our results showed that the highest efficiency was obtained with a plume spacing of 0.75 times the water depth. Our study has shown that the overall efficiency of an air diffuser system can be increased by changing the spacing between diffusers and that plume spacing should be a major design parameter for future air diffuser systems.

Nodal staging in genitourinary cancers

In patients with genitourinary cancers nodal staging is an integral part of the pretreatment evaluation. The presence of nodal metastatic disease plays an important role in predicting prognosis and treatment planning. Although some nodal groups can be evaluated clinically, most patients undergo various imaging studies for nodal staging. Each modality has its own unique attributes and applications. This article reviews various imaging modalities, namely, contrast enhanced computerized tomography, magnetic resonance imaging (MRI), and positron emission tomography, used for nodal staging in patients with genitourinary cancers and highlights their strengths and weaknesses. Emerging novel techniques such as lymphotropic nanoparticle enhanced MRI are also highlighted.

The effect of epidural sufentanil in ropivacaine on urinary retention in patients undergoing gastrectomy

BACKGROUND

Although epidural opioids have excellent analgesic property, their side-effects limit its use in patient-controlled epidural analgesia (PCEA). This study was designed to compare side-effects of epidural sufentanil in ropivacaine with that of morphine in ropivacaine focusing on lower urinary tract function after major abdominal surgery.

METHODS

In total 60 patients undergoing gastrectomy were randomly allocated to receive either sufentanil in ropivacaine (Group S, n=30) or morphine in ropivacaine (Group M, n=30) for their PCEA. Epidural catheter was inserted between the 7th and 8th thoracic spine. Visual analogue pain score and side-effects such as nausea, vomiting, pruritus, hypotension and urinary retention were evaluated during postoperative days (PODs) 1 and 2 in the postanaesthetic care unit.

RESULTS

The incidence of serious to major micturition problem in Group S was lower than that in Group M (P<0.001). The incidence of pruritus, nausea and vomiting was also lower in Group S than in Group M on POD 1.

CONCLUSIONS

The lower incidence of major/serious micturition problem in patients receiving sufentanil in ropivacaine thoracic epidural analgesia suggests that continuation of urinary drainage may not be necessary from POD 1 onwards.

Chilaiditi syndrome caused by Fitz-Hugh-Curtis syndrome: multidetector CT findings

Chilaiditi syndrome is a condition in which the colon or small intestine is interposed temporarily or permanently between the liver and the diaphragm. Usually, it is an asymptomatic and incidental radiographic finding, but it may be a potential source of abdominal problems, ranging from intermittent mild abdominal pain to acute intestinal obstruction. We report multidetector computed tomographic findings of a case of Chilaiditi syndrome presenting as small bowel obstruction due to hepatodiaphragmatic interposition of the ileal loop, which was entrapped by adhesive bands caused by Fitz-Hugh-Curtis syndrome.

Improved search for nu(mu) --> nu(e) oscillation in a long-baseline accelerator experiment

We performed an improved search for nu(mu) --> nu(e) oscillation with the KEK to Kamioka (K2K) long-baseline neutrino oscillation experiment, using the full data sample of 9.2 x 10(19) protons on target. No evidence for a nu(e) appearance signal was found, and we set bounds on the nu(mu) --> nu(e) oscillation parameters. At Deltam(2)=2.8 x 10(-3) eV(2), the best-fit value of the K2Knu(mu) disappearance analysis, we set an upper limit of sin(2)2theta(mue) < 0.13 at a 90% confidence level.

Genetic variation at the perilipin locus is associated with changes in serum free fatty acids and abdominal fat following mild weight loss

OBJECTIVE

Perilipin (PLIN) is a class of protein-coating lipid droplets in adipocytes. We aimed to examine the association between common single-nucleotide polymorphisms (SNPs) at PLIN locus with circulating free fatty acid (FFA) and abdominal fat distribution in response to weight loss.

METHODS

Non-diabetic/overweight-obese Koreans (n=177) participated in a 12-week calorie restriction (-300kcal/day) program. Seven SNPs (6209T>C, 10076C>G, 10171A>T, 11482G>A, 13042A>G, 13048C>T and 14995A>T), abdominal fat areas (visceral/subcutaneous fat areas at 1st lumbar and 4th lumbar levels), serum lipids, glucose, insulin, FFA, oxidized low-density lipoprotein (LDL) and urinary 8-epi-prostaglandin F(2alpha) (PGF(2alpha)) were examined.

RESULTS

Single-nucleotide polymorphisms 10076C>G/10171A>T showed the strongest positive linkage disequilibrium (LD) (D'=0.923, R (2)=0.839, P<0.001) and SNPs11482G>A/14995A>T showed moderate positive LD (D'=0.824, R (2)=0.578, P<0.001). Calorie restriction induced 4.6% weight loss with significant abdominal fat reduction. In response to weight loss, subjects with nCA/nCA haplotypes at SNPs 10076C>G/10171A>T showed greater reduction in FFA levels than those with CA/CA haplotype (CA/CA: C/C at SNP 10076 and A/A at SNP 10171, nCA: non-CA haplotype carrier). On the other hand, subjects with nGA/nGA haplotype at SNPs 11482G>A/14995A>T had increased FFA levels with a rapid loss in abdominal fat, whereas GA/GA haplotype carriers had reduction in FFA levels. These results still remained significant after adjusting for age, gender and BMI. Prostaglandin F(2alpha) and oxidized LDL were also more reduced in GA/GA haplotype carriers than in nGA haplotype carriers. This effect remained significant after adjusting for baseline level, age, gender and BMI. Paradoxically, nGA haplotype carriers had increased levels of urinary PGF(2alpha) after weight reduction.

CONCLUSION

Fasting plasma FFA changes following a modest weight loss in overweight-obese subjects are influenced by the genetic variability at the PLIN locus. Furthermore, circulating FFA changes rather than body fat itself may determine changes in lipid peroxides such as urinary PGF(2alpha) and oxidized LDL.

Determination of biodegradation potential by two culture-independent methods in PAH-contaminated soils

Biodegradation potentials of polycyclic aromatic hydrocarbons (PAHs) were determined with soil samples collected from various depths of a PAH-contaminated site and of a site nearby where PAHs were not found. Putative dioxygenase genes were amplified by a primer set specific for initial dioxygenases and identified by web-based database homology search. They were further categorized into several groups of which four dioxygenases were selected as probes for DNA hybridization. The hybridization signals according to the presence of putative dioxygenases were positively related to the extent of PAH contamination. However, the signal intensities varied depending on the probes hybridized and moreover were not consistent with PAH biodegradation activities determined by CO2 evolution. Despite widely accepted advantages of molecular biodegradation assessment, our data clearly present the variations of assessment results depending on the genetic information used and suggest that the methodology may tend to underestimate the real biodegradation capacity of a site probably due to the limited dioxygenase database available at the moment. Therefore, the molecular assessment of biodegradation potential should involve a very careful primer and probe design and an extensive microbiological examination of a site of interest to accurately delineate the biodegradation potential of the site.

Weight loss effect on inflammation and LDL oxidation in metabolically healthy but obese (MHO) individuals: low inflammation and LDL oxidation in MHO women

OBJECTIVE

Recently, a subtype of obesity characterized as a metabolically healthy but obese (MHO) individual has been identified. However, limited data are available on these MHO individuals' metabolic and inflammatory profiles, and the effect of weight loss on these profiles. We investigated metabolic and inflammatory markers in MHO women to determine the effects of a 12-week weight loss on those markers.

SUBJECTS

One hundred and twenty-nine overweight-obese Korean women participated for 12 weeks in a clinical intervention study involving a 300 kcal/day intake reduction. The subjects were divided into two groups: MHO and metabolically abnormal obese (MAO) individuals.

METHODS

Computed tomography was performed. C-reactive protein (CRP), interkeukin-6 (IL-6) and oxidized low-density lipoprotein (LDL), as well as blood lipids, glucose and insulin concentrations were determined at baseline and after weight loss.

RESULTS

At baseline, plasma CRP (P<0.001), IL-6 (P<0.05) and oxidized LDL (P<0.001) levels were significantly lower in the MHO group than in the MAO group. Visceral fat at L1 (P<0.005) and visceral fat at L4 (P<0.001) were significantly lower in the MHO group than in the MAO group. The treatment induced weight loss averaging 3.11% of initial body weight, and the degree of weight loss between the two groups was similar. Visceral fat at L1 and L4 was reduced from its initial values by 3.2 and 5.4%, respectively, after weight loss. The levels of CRP (P<0.05) and oxidized LDL (P<0.01) were significantly reduced in the MAO group after the 12-week weight loss, whereas these effects were not seen in the MHO group.

CONCLUSIONS

Our results showed that MHO individuals exhibited lower visceral fat accumulation and more favorable metabolic and inflammatory states than MAO individuals. After a 12-week weight loss program, significant reductions in blood lipids, CRP and oxidized LDL levels were observed in MAO individuals. However, there was no measurable effect of weight loss on lipid profiles and inflammation in MHO individuals, indicating differing effects of weight loss on these markers between MAO and MHO groups.

AtBAG6, a novel calmodulin-binding protein, induces programmed cell death in yeast and plants

Calmodulin (CaM) influences many cellular processes by interacting with various proteins. Here, we isolated AtBAG6, an Arabidopsis CaM-binding protein that contains a central BCL-2-associated athanogene (BAG) domain. In yeast and plants, overexpression of AtBAG6 induced cell death phenotypes consistent with programmed cell death (PCD). Recombinant AtBAG6 had higher affinity for CaM in the absence of free Ca2 + than in its presence. An IQ motif (IQXXXRGXXXR, where X denotes any amino-acid) was required for Ca2 +-independent CaM complex formation and single amino-acid changes within this motif abrogated both AtBAG6-activated CaM-binding and cell death in yeast and plants. A 134-amino-acid stretch, encompassing both the IQ motif and BAG domain, was sufficient to induce cell death. Agents generating oxygen radicals, which are known to be involved in plant PCD, specifically induced the AtBAG6 transcript. Collectively, these results suggest that AtBAG6 is a stress-upregulated CaM-binding protein involved in plant PCD.

Mitochondrial DNA content is decreased in autosomal dominant optic atrophy

BACKGROUND

Autosomal dominant optic atrophy (ADOA) is the commonest form of inherited optic neuropathy. Mutations in the OPA1 gene encoding a dynamin-related mitochondrial protein underlie ADOA and may perturb the biogenesis and maintenance of mitochondria.

OBJECTIVE

To investigate the mutation spectrum of the OPA1 gene and assess alterations in mitochondrial content caused by OPA1 mutations.

METHODS

Sixteen Korean patients with clinically suspected ADOA were studied. The mutation spectrum of the OPA1 gene was analyzed by PCR single-strand conformation polymorphism and sequencing, and mitochondrial DNA (mtDNA) content was quantified by real-time PCR.

RESULTS

Eight different mutations were found, including five novel mutations. Quantitative real-time PCR analysis showed excellent linearity and precision for the determination of mtDNA copy numbers. The number of mtDNA copies per cell in patients with OPA1 gene mutations (ages 7 to 40) was significantly lower than those in all normal control subjects (p = 0.037), particularly lower than in normal control subjects ages 10 to 39 (p = 0.022).

CONCLUSION

The mutation spectrum of the OPA1 gene disclosed marked genetic heterogeneity and the mitochondrial DNA content was found to be lower in autosomal dominant optic neuropathy, which provides direct evidence for a pathogenetic role of mutations of the OPA1 gene.

Surgical treatment for congenital arteriovenous malformation: 10 years' experience

OBJECTIVES

We report our 10 years experience of the surgical treatment of congenital arteriovenous malformation (AVM).

METHODS

We retrospectively reviewed the medical records of 145 patients with AVM who visited Samsung Medical Center in Korea from 1994 to 2003. Among the 145 patients, 21 patients were operated on. Preoperative embolo/sclerotherapy was done in 20 out of the 21 patients.

RESULTS

The surgically treated AVMs were 13 cases of head and neck lesions, four cases of upper extremity lesions, one case each of back lesion, uterus lesion, lower extremity lesion and multiple site lesions. There were 10 patients with the extratruncular infiltrating type, nine patients with the extratruncular limited type, one patient with a truncular superficial AV fistula and one patient with a mixed type. Fourteen cases were operated on for cosmetic reasons and since they had localized lesions, and five cases were operated on for tissue necrosis. Fourteen cases were cured by a single operation, yet seven cases needed several sessions of operation to cure the AVM or to promote wound healing after surgery.

CONCLUSION

The surgical treatment of AVM is a challenging issue for vascular surgeons. To minimise the complications related to surgery, a multidisciplinary team approach should be considered.

Effect of leptin on insulin resistance of muscle – direct or indirect?

We examined the effect of leptin on the insulin resistance in skeletal muscles by measuring glucose transport. Male Wistar rats were fed rat chow or high-fat diets for 30 days. Before sacrifice, rats fed high-fat diet were subcutaneously injected with leptin (1 mg/kg b.w.) for 3 days. The glucose transport in epitrochlearis and soleus muscles did not differ in the experimental groups under basal conditions, however these values decreased significantly in the rats fed high-fat diet under insulin stimulation (p<0.01). Leptin treatment recovered the decreased glucose transport in epitrochlearis (p<0.05) and soleus muscles (p=0.08). Triglyceride concentrations in soleus muscles were increased significantly in the rats fed high-fat diet as compared to rats fed chow diet (p<0.01), and were decreased significantly by leptin treatment (p<0.01). The glucose transport was measured under basal conditions and after 60 microU/ml of insulin treatment with or without 50 ng/ml of leptin. Leptin had no direct stimulatory effect on glucose transport under both basal and insulin-stimulated conditions in vitro. These results demonstrate that leptin injection to rats fed high-fat diet recovered impaired insulin responsiveness of skeletal muscles and muscle triglyceride concentrations. However, there was no direct stimulatory effect of leptin on insulin sensitivity of skeletal muscles in vitro.