Source apportionment of fine carbonaceous particles by positive matrix factorization at Gosan background site in East Asia

Fine particle (aerodynamic diameter <2.5 microm) samples were collected during six intensive measurement periods from November 2001 to August 2003 at Gosan, Jeju Island, Korea, which is one of the representative background sites in East Asia. Chemical composition of these aerosol samples including major ion components, trace elements, organic and elemental carbon (OC and EC), and particulate polycyclic aromatic hydrocarbons (PAHs) were analyzed to study the impact of long-range transport of anthropogenic aerosol. Aerosol chemical composition data were then analyzed using the positive matrix factorization (PMF) technique in order to identify the possible sources and estimate their contribution to particulate matter mass. Fourteen sources were then resolved including soil dust, fresh sea salt, transformed natural source, ammonium sulfate, ammonium nitrate, secondary organic carbon, diesel vehicle, gasoline vehicle, fuel oil combustion, biomass burning, coal combustion, municipal incineration, metallurgical emission source, and volcanic emission. The PMF analysis results of source contributions showed that the natural sources including soil dust, fresh and aged sea salt, and volcanic emission contributed to about 20% of the measured PM(2.5) mass. Other primary anthropogenic sources such as diesel and gasoline vehicle, coal and fuel oil combustion, biomass burning, municipal incineration, metallurgical source contributed about 34% of PM(2.5) mass. Especially, the secondary aerosol mainly involved with sulfate, nitrate, ammonium, and organic carbon contributed to about 39% of the PM(2.5) mass.

Association between the Clara cell secretory protein (CC16) G38A polymorphism and the progression of IgA nephropathy

AIMS

Clara cell secretory protein (CC16) is a protein with anti-inflammatory and immunomodulatory properties. Moreover, both CC16 gene knockout and antisense-transgenic mouse models developed glomerulonephritis resembling IgA nephropathy (IgAN). In the present study, we evaluated the influence of the G38A polymorphism in the CC16 gene exon 1 on the development and progression of IgAN.

METHODS

Korean patients with biopsy-proven IgAN (n=267) with a minimal follow-up of 4 years (mean +/- SD 103.8 +/- 52.6 months) were recruited. Healthy normal subjects (n=315) were included as controls. The G38A polymorphism was determined using the polymerase chain reaction-restriction fragment length polymorphism method.

RESULTS

GG, GA and AA genotype frequencies were 36.3, 50.2 and 13.5% in IgAN patients, respectively, and 34.3, 50.2 and 15.5% in controls (chi2 = 0.596, p = 0.742). The G allele frequency was 0.614 in IgAN patients and 0.594 in controls (chi2 = 0.429, p = 0.512). Moreover, the GG genotype frequencies were 40.4% in patients showing stable disease course and 26.6% in those with progressive disease (chi2 = 4.029, p = 0.045). Patients with the GG genotype showed a better outcome by Kaplan-Meier analysis in terms of renal survival (p = 0.043). The CC16 polymorphism remained an independent risk factor for progression after multivariate analysis (Cox regression model, HR for CC16 AA genotype: 2.34, 95% CI 1.19-4.64, p = 0.014).

CONCLUSION

Our results suggest that CC 16 gene G38A polymorphism is not associated with the development of IgAN, but that it is an important marker of progression in IgAN.

Structure and in vitro cytocompatibility of the gastropod shell of Helix pomatia

Distinguishing features of biological constructions are high stability and adaptation to their environment. Beside biocompatibility, nontoxicity and degradability these characteristics are demanded for new biomaterials in the field of tissue engineering. This study investigated the chemical composition, the organization and the in vitro osteoconductive potential of the terrestrial gastropod shell (Helix pomatia) on CAL72 and human osteoblast-like cells. Chemical composition of the biomaterial was examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM) was performed to analyze the architecture of the snail shell and the morphology of the seeded cells. A double staining procedure (FDA/PI) and a proliferation test (EZ4U) assessed the viability of the cells. Microscopical images showed the multilayered architecture of the aragonite shell with hexagonal crystals on the inner side. The cells spread well on the biomaterial and the highest proliferation rate could be measured with CAL72 cells on the inner shell surface. The osteoconductive effects of this natural biomaterial could encourage further experiments in the field of tissue engineering.

Pioglitazone, a synthetic ligand for PPARγ, induces apoptosis in RB-deficient human colorectal cancer cells

No published data are available about the expression of peroxisome proliferator-activated receptor gamma (PPARgamma) and the role of PPARgamma in retinoblastoma protein (RB)-deficient human colorectal cancer (CRC) cells (SNU-C4 and SNU-C2A). Our aim was to investigate whether PPARgamma is expressed in SNU-C4 and SNU-C2A cells and to elucidate possible molecular mechanisms underlying the effect of pioglitazone, a synthetic ligand for PPARgamma, on cell growth in these cell lines. RT-PCR and Western blot analysis showed that both human CRC cell lines expressed PPARgamma mRNA and protein. Pioglitazone inhibited the cell growth of both cell lines through G2/M phase block and apoptosis. In addition, pioglitazone caused a down-regulation of the X chromosome-linked inhibitor of apoptosis (XIAP), Bcl-2, and cyclooxygenase-2 (COX-2) under conditions leading to PPARgamma down-regulation. These results suggest that pioglitazone may have therapeutic relevance or significance in the treatment of human CRC, and the down-regulation of XIAP, Bcl-2, and COX-2 may contribute to pioglitazone-induced apoptosis in these and other RB-deficient cell lines and tumors.

Biphasic changes of epithelial sodium channel abundance and trafficking in common bile duct ligation-induced liver cirrhosis

We hypothesize that dysregulation of the epithelial sodium channel (ENaC) may be responsible for the increased sodium retention in liver cirrhosis. Liver cirrhosis was induced by common bile duct ligation (CBDL). We examined the abundance of ENaC subunits and type 2 isoform of 11beta-hydroxysteroid dehydrogenase (11betaHSD2) in the kidney by immunoblotting and immunohistochemistry at 6 or 8 weeks after operation. At 6 weeks, cirrhotic rats had developed ascites and displayed a positive sodium balance. The urinary sodium excretion and fractional excretion of sodium were decreased, while plasma aldosterone was unchanged. The abundance of ENaC subunits was not changed in the cortex and outer stripe of the outer medulla (OSOM). In contrast, immunoperoxidase microscopy revealed an increased apical targeting of alpha-, beta- and gammaENaC in late distal convoluted tubule, connecting tubule and collecting duct. Moreover, 11betaHSD2 abundance was decreased in the cortex/OSOM and inner stripe of the outer medulla. At 8 weeks, urinary sodium excretion and fractional excretion of sodium were not changed, while the plasma aldosterone level was decreased. The expression of ENaC subunits was decreased in the cortex/OSOM. Immunoperoxidase microscopy confirmed decreased expression of ENaC subunits, whereas subcellular localization was not changed. These results suggest that increased apical targeting of ENaC subunits and diminished abundance of 11betaHSD2 may contribute to promote sodium retention in the sodium-retaining stage of liver cirrhosis (at 6 weeks). The subsequent decreased expression and reduced targeting of ENaC subunits may play a role in promoting sodium excretion in the later stage of liver cirrhosis (at 8 weeks).

Biological control agent of common scab disease by antagonistic strain Bacillus sp. sunhua

AIMS

To identify an antagonistic strain against Streptomyces scabiei and to characterize the antibiotic agent. The efficacy of the isolated strain in controlling common scab disease was also evaluated.

METHODS AND RESULTS

A bacterial strain antagonistic against S. scabiei was isolated from the soil of a potato-cultivating area. This bacterium was identified as a Bacillus species by 16S rRNA gene sequence analysis and was designated Bacillus sp. sunhua. Antibiotics produced by this strain were proven to be stable within a broad pH range and at high temperatures. The culture broth was extracted with ethyl acetate, and then the crude extract was applied to HPLC. Two compounds were isolated and identified as iturin A and macrolactin A by 1H-NMR, 13C-NMR, HMBC, HMQC and mass spectrometer. The culture broth of Bacillus sp. sunhua had a suppressive effect on common scab disease in a pot assay, decreasing the infection rate from 75 to 35%. This strain also suppressed Fusarium oxysporum, the pathogen of potato dry rot disease.

CONCLUSIONS

Bacillus sp. sunhua was shown to inhibit S. scabiei effectively.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report demonstrating that macrolactin A and iturin A inhibit S. scabiei. This study demonstrated the possibility of controlling potato scab disease using Bacillus sp. sunhua.

Seasonal variation of chemical composition in fine particles at Gosan, Korea

PM2.5 aerosol samples were collected at Gosan in Jeju Island during six intensive measurement periods between November 2001 and August 2003. In order to investigate the chemical composition of fine particles, major ion components, trace elements, and elemental and organic carbon were analyzed. Quite different seasonal characteristic in the chemical composition of fine particles was observed. The concentration of most secondary aerosol components showed a summer minimum and a winter maximum with higher correlation between them at Gosan. This fact clearly reveals the possibility of long-range transport of such pollutants in winter. On the other hand, OC and EC had the highest concentration and good correlation with ion components, such as K+, Ca2+ in fall. It means that biomass burning could significantly influence the ambient fine carbonaceous particulate in fall, which was primarily long-range transported.

Association of C-509T and T869C polymorphisms of transforming growth factor-beta1 gene with susceptibility to and progression of IgA nephropathy

AIMS

Transforming growth factor (TGF)-beta1 is a cytokine with both beneficial anti-inflammatory effects and detrimental profibrotic activity in the pathophysiology and progression of glomerulonephritides. The transcriptional activity of the gene for TGF-beta1 and the plasma levels of TGF-beta1 protein are associated with C-509T polymorphism at the promoter region, and with T869C (Leu 10Pro) polymorphism at codon 10, of the TGF-beta1 gene.

METHODS

Using PCR-RFLP and the amplification refractory mutation system PCR, we investigated the C-509T and T869C polymorphisms, respectively, to elucidate whether allele frequency differences exist between IgA nephropathy (IgAN) patients who were followed up for at least 3 years (n = 108) and a normal population (n = 55). We also determined the correlations between the TGF-beta1 polymorphisms and the progression of IgAN.

RESULTS

In C-509T polymorphism, there were significant differences in genotype frequency between IgAN patients and normal controls (CC: CT: TT, 20:29:33 vs. 11:31:13, chi2 = 6.299, p = 0.043). In Kaplan-Meier survival analysis, the patients with TT genotype showed a poorer renal survival than those with CC + CT genotypes (p = 0.042). In T869C polymorphism, there were also significant differences in genotype frequency between IgAN patients and normal controls (TT : TC : CC, 4 : 79 : 25 vs. 0 : 52 : 2, chi2 = 12.552, p = 0.002). The initial serum creatinine (Scr) level was higher in the patients with CC genotype than in those with TT + TC genotypes. In Kaplan-Meier survival analysis, the patients with CC genotype showed a poorer renal survival than those with TT + TC genotypes, but not to a statistically significant extent (p = 0.076). In the combined survival analyses, the high TGF-beta1 producer group showed a poor renal survival rate (p = 0.014).

CONCLUSION

Compared to normal population, the frequencies of genotypes producing high TGF-beta1 protein were higher in IgAN patients. Moreover, patients with genotypes producing high TGF-beta1 plasma levels showed a poor renal survival rate.

Incidence and risk factors of renal dysfunction after liver transplantation in Korea

Renal dysfunction, one of the most common complications after liver transplantation, influences patient outcomes. Little is known, however, about it in Korea. The aims of this study were to determine the incidence and to identify the risk factors for renal dysfunction after liver transplantation. Sixty-two patients who survived over 6 months after transplantation were enrolled. Renal function was classified by creatinine clearance (Ccr, mL/min), which was estimated using the Cockcroft-Gault formula. Twenty-seven patients (44%) showed mild renal dysfunction (60 < or = Ccr < 90), and 27 patients (44%), moderate dysfunction (30 < or = Ccr < 60). The others were found to have normal function (Ccr > or = 90). None displayed severe dysfunction (Ccr < 30). Compared to a control group (Ccr > or = 60), the renal dysfunction group showed lower preoperative Ccr (91 +/- 28.6, 63 +/- 21.9, respectively, P < .01) and lower Ccr at 3 months after transplantation (72 +/- 17.1, 49 +/- 14.6, respectively, P < .05). Age, sex, immunosuppressive drug usage, serum tacrolimus levels, and the frequency of postoperative acute renal failure did not affect the postoperative renal dysfunction. Twenty-six patients received mycophenolate mofetil while reducing the dose of calcineurin inhibitors because of compromised renal function. With mycophenolate mofetil treatment, the renal function seemed to improve, although the difference was not statistically significant (P = .057). These data demonstrate that renal dysfunction is common after liver transplantation and that preoperative renal function is the important factor predicting postoperative renal dysfunction.

Improvement of cadmium ion removal by base treatment of juniper fiber

Juniper is a small-diameter underutilized lignocellulosic material. We evaluated the efficacy of base-treated juniper fiber (BTJF) for cadmium (Cd2+) sorption and the viability of juniper fiber as a sorbent for removing Cd2+ from water. Fourier transform infrared spectroscopy analysis indicated that carboxylate ion is a major functional group responsible for Cd2+ sorption. The apparent ideal sodium hydroxide concentration for base treatment is approximately 0.5M. A batch sorption isotherm test showed that equilibrium sorption data were better represented by the Langmuir model than the Freundlich model. After base treatment, the maximum Cd2+ sorption loading, Qmax, was greatly improved (9.18-29.54 mg/g), despite a decrease in specific surface area. A pseudo-second-order kinetic model fitted well for the sorption of Cd2+ onto BTJF. Initial metal ion concentration and treatment alkalinity were found to be major parameters influencing the kinetics of the sorption reaction. As a result of its strong ability to bind cadmium and its faster kinetics in low concentration, BTJF could be an inexpensive and efficient sorbent for removing heavy metals from stormwater runoff.

Characteristics of ion components and trace elements of fine particles at Gosan, Korea in spring time from 2001 to 2002

Size-segregated measurements of the composition of an aerosol are used to determine the transport of natural and anthropogenic aerosols to the Gosan site in springtime from 2001 to 2002. Although the transport of Asian dust is a well-known phenomenon in springtime, this study shows that not only is soil dust transported into Gosan each spring but so are anthropogenic aerosols, including sulfur, enriched trace metals such as Pb, Zn, Ni, K, S. This study also combines the size- and time-resolved aerosol composition measurements with isentropic, backward air-mass trajectories in order to identify some potential source regions of the anthropogenic aerosols. Finally, four types of transport episodes were identified: (1) anthropogenic pollutants, (2) dust storm mixed with the anthropogenic aerosols, (3) typical dust storms, (4) some sea salt with clean air mass. Overall, in addition to typical soil dust, a large amount of anthropogenic aerosols, whether mixed with the soil dust or not, are transported to Gosan each spring.

Removal of phosphorus from water using lignocellulosic material modified with iron species from acid mine drainage

Lignocellulosic biosorbents, including juniper fiber, show promise as sorbents for removing pollutants from wastewater run-off because of their low cost. In this study, juniper fiber modified with iron species from acid mine drainage (AMD) was tested for its capacity to remove phosphorus from water compared to unmodified juniper fiber. In batch tests, the maximum adsorbate loading (Qmax) of phosphorus onto the modified adsorbent was 1.83 mg g(-1) at pH 4.0, obtained by fitting the isotherm results to the Langmuir isotherm model. This value is similar to the sorption capacity of other conventional adsorbents such as goethite, which implies that the modified lignocellulosic material would be effective as a sorbent for removing phosphorus from water. In the kinetic test, the pseudo-second order kinetic model fitted well the sorption of phosphorus onto the modified filter medium, showing the kinetic constant (k) of 8.09 x 10(-2) g(mg min)(-1) at initial phosphorus concentration of 10 mg l(-1).

Effects of hippocampal cholinergic deafferentation on learning strategy selection in a visible platform version of the water maze

Recent evidence has suggested that the relative levels of acetylcholine (ACh) between brain structures may be an important factor in the choice of behavioral strategy in settings in which either hippocampal or dorsal striatal brain systems can be employed both effectively and independently (McIntyre and Gold. 1999. Soc Neurosci Abs 25:1388). The current investigation used the neurotoxin 192 IgG-saporin to deplete the hippocampus of ACh selectively, while leaving ACh in other brain regions, including dorsal striatum, intact. Rats were then trained on a version of the Morris water maze, in which behavioral strategies attributed to the hippocampus and dorsal striatum are placed in direct competition. It was predicted that rats with hippocampal ACh depletion would display a cue bias. Contrary to this prediction, depleting hippocampal ACh did not bias against and, in fact, promoted use of a hippocampal place strategy in this task, as indicated by choice in competition tests and performance on hidden platform training trials. These data add to a growing literature demonstrating that the septohippocampal cholinergic system is not required for accurate spatial learning and suggest a complex role for basal forebrain projections in processing information about the spatial environment.

Glial cell line-derived neurotrophic factor contributes to delayed inflammatory hyperalgesia in adjuvant rat pain model

Neurotrophic factors, such as nerve growth factor and brain-derived neurotrophic factor, are members of the structurally related neurotrophin family that play important roles in pain modulation. Although there are also indications for the involvement of glial cell line-derived neurotrophic factor (GDNF), it is unclear whether and how GDNF is involved in inflammatory pain. In the present study, we studied the expression pattern of GDNF in dorsal root ganglia (DRG) and spinal cord, using confocal microscopy. We demonstrate that GDNF is well associated with nonpeptidergic pain pathway and that GDNF could possibly be anterogradely transported from DRG neurons to superficial spinal cord dorsal horn. We also studied the dynamic changes of GDNF expression in rats during chronic inflammation using injection of complete Freund's adjuvant as a model of chronic pain. We found that GDNF was down-regulated in both dorsal root ganglia and spinal cords 2 weeks after arthritis induction. To assess the impact of this down-regulation on pain transmission, we used a function-blocking antibody against GDNF delivered intrathecally in the same chronic-pain animal models. Injection of this antibody to GDNF produced no immediate effect, but decreased the delayed, bilateral hyperalgesia induced from a unilateral injection of complete Freund's adjuvant. The effect of this antibody coincided with the down-regulation of GDNF immunoreactivity in response to inflammation, suggesting that GDNF supports biochemical changes that contribute to hyperalgesia.

No association of the TGF-beta1 gene polymorphisms with the renal progression in autosomal dominant polycystic kidney disease (ADPKD) patients

BACKGROUND

Two genetic loci, PKD I and PKD2, have been identified as being responsible for ADPKD, and PKD1 is known to be associated with a poor prognosis. However, the presence of an intrafamilial study clinical diversity suggests that there are disease-modifying loci. Because the mechanism ofthe renal failure in ADPKD includes a cystic growth and tubulointerstitial atrophy and fibrosis, we studied the associations between 2 polymorphisms in the TGF-beta1 gene, which are known to be associated with chronic tubulointerstitial inflammation, and ADPKD progression in Korean patients.

PATIENTS AND METHODS

One hundred and twenty-five individuals who had ADPKD and 47 normal control subjects were genotyped by PCR-RFLP, the T869C (Leu10Pro) variant of TGF-beta gene leader sequence was discriminated with MspA1I and the G915C (Arg25Pro) variants with Bg1I. Statistical significances were determined using the Chi-square test.

RESULTS

The distribution of the alleles for the TGF beta1 Leu10Pro polymorphism in ADPKD was: T 54%, C 46%, which was similar to the Korean (56: 44, p = 0.887) and Western controls (65: 35). In addition, no differences were found between the ESRD and the non-ESRD groups (p = 0.888) or the early hypertension and the normotension groups (p = 0.249). The distribution of alleles for the TGF beta1 Arg25Pro polymorphism showed only the GG type which was different from the Western population controls (G:C = 90:10, p = 0.000).

CONCLUSIONS

Our results suggest that the polymorphism at Arg25Pro of TGF-beta1 in the Korean population has an allele distribution different from that ofthe Western population and that the polymorphism at Leu10Pro of TGF-beta1 has no association with the renal progression in Korean ADPKD patients.

Three novel mutations of the PKD1 gene in Korean patients with autosomal dominant polycystic kidney disease

Mutations at the PKD1 locus account for 85% of cases of the common genetic disorder called autosomal dominant polycystic kidney disease (ADPKD). Screening for mutations of the PKD1 gene is complicated by the genomic structure of the 5'-duplicated region encoding 75% of the gene. To date, more than 90 mutations of the PKD1 gene have been reported in the European and American populations, and relatively little information is available concerning the pattern of mutations present in the Asian populations. We looked for mutations of the PKD1 gene in 51 unrelated Korean ADPKD patients, using polymerase chain reaction (PCR) with primer pairs located in the 3' single-copy region of the PKD1 gene and by single-strand conformation polymorphism (SSCP) analysis. We found three novel mutations, a G to A substitution at nucleotide 11012 (G3601S), a C to A substitution at nucleotide 11312 (Q3701X), and a C to T substitution at nucleotide 12971 (P4254S), and a single polymorphism involving a G to C substitution at nucleotide 11470 (L3753L). These mutations were not found in control individuals, and no other mutations in the 3' single-copy region of the PKD1 gene of patients with these mutations were observed. In particular, P4254S segregated with the disease phenotype. The clinical data of affected individuals from this study, and of previously reported Korean PKD1 mutations, showed that patients with frameshift or nonsense mutations were more prone to develop end-stage renal failure than those with missense mutations. Our findings indicate that many different PKD1 mutations are likely to be responsible for ADPKD in the Korean population, as in the Western population.

D609-sensitive tyrosine phosphorylation is involved in Fas-mediated phospholipase D activation

Both Fas and PMA can activate phospholipase D via activation of protein kinase Cbeta in A20 cells. Phospholipase D activity was increased 4 fold in the presence of Fas and 2.5 fold in the presence of PMA. The possible involvement of tyrosine phosphorylation in Fas-induced activation of phospholipase D was investigated. In five minute after Fas cross-linking, there was a prominent increase in tyrosine phosphorylated proteins, and it was completely inhibited by D609, a specific inhibitor of phosphatidylcholine-specific phospholipase C (PC-PLC). A tyrosine kinase inhibitor, genistein, can partially inhibit Fas-induced phospholipase D activation. There were no effects of genistein on Fas-induced activation of PC-PLC and protein kinase C. These results strongly indicate that tyrosine phosphorylation may in part account for the increase in phospholipase D activity by Fas cross-linking and D609 can block not only PC-PLC activity but also tyrosine phosphorylation involved in Fas-induced phospholipase D activation.

Multimerization of phosphorylated and non-phosphorylated ArcA is necessary for the response regulator function of the Arc two-component signal transduction system

To adapt to anaerobic conditions, Escherichia coli operates the Arc two-component signal transduction system, consisting of a sensor kinase, ArcB, and a response regulator, ArcA. ArcA is converted to the active form, phosphorylated ArcA (ArcA-P), by ArcB-mediated phosphorylation. The active ArcA-P binds to the promoter regions of target genes, thereby regulating their transcriptional activities. The phosphoryl group of ArcA-P is unstable with a half-life of 30 min. However, we were able to inhibit the dephosphorylation for more than 12 h by the addition of EDTA; this allowed us to characterize ArcA-P. Gel-filtration and glycerol sedimentation experiments demonstrated that ArcA exists as a homo-dimer. ArcA phosphorylated by either ArcB or carbamyl phosphate multimerizes to form a tetramer of dimers; this multimer binds to the ArcA DNA binding site. Isoelectric focusing gel electrophoresis and nitrocellulose-filter binding analyses indicated that the ArcA multimer is composed of both ArcA-P and ArcA in a ratio, 1:1. The ArcA(D54E) mutant protein was unable to be phosphorylated by ArcB. This defect resulted in the inability of ArcA(D54E) to form a multimer or to bind to the ArcA DNA binding site. These results indicate that phosphorylation of ArcA induces multimerization prior to DNA binding, and the multimerization is a prerequisite for binding. Our results suggest a novel model that phosphorylation of ArcA by ArcB regulates multimerization of ArcA, which in turn functions as a response regulator.

Hypothalamic-pituitary-adrenal axis function and corticosterone receptor expression in behaviourally characterized young and aged Long-Evans rats

In the current investigation, hypothalamic-pituitary-adrenal (HPA) axis function was examined in young and aged male Long-Evans rats that were initially assessed on a version of the Morris water maze sensitive to cognitive impairment during ageing. In behaviourally characterized rats, a 1-h restraint stress paradigm revealed that plasma corticosterone concentrations in aged cognitively impaired rats took significantly longer to return to baseline following the stressor than did those in young or aged cognitively unimpaired rats. No differences in basal or peak plasma corticosterone concentrations, however, were observed between young or aged rats, irrespective of cognitive status. Using ribonuclease protection assays and in situ hybridization, we evaluated mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) mRNA abundance in young and aged rats characterized on the spatial task. Abundance of MR mRNA was decreased as a function of age in stratum granulosum but not hippocampus proper, and the decrease in MR mRNA was largely unrelated to cognitive status. However, GR mRNA was significantly reduced in several hippocampal subfields (i.e. stratum granulosum and temporal hippocampus proper) and other related cortical structures (medial prefrontal and olfactory regions) of aged cognitively impaired rats compared to either young or aged cognitively unimpaired cohorts, and was significantly correlated with spatial learning ability among the aged rats in each of these brain regions. In agreement with previous stereological data from this ageing model, no changes were detected in neuron density in the hippocampus of the rats used in the in situ hybridization analysis. These data are the first to describe a coordinated decrease in GR mRNA in a functional brain system including hippocampus and related cortical areas that occurs in tandem with impairments of the HPA response to stress and cognitive decline in ageing.

Adenovirus-mediated GDNF protects cultured motoneurons from glutamate injury

The protective effects of adenovirus-mediated glia cell line-derived neurotrophic factor (GDNF) gene transaction was investigated on cultured motoneurons. First, the dose- and time-response relationship of glutamate neurotoxicity was determined on spinal motoneuron cultures. Then, the effect of the gdnf recombinant adenovirus (AdCMVgdnf) was tested in this cellular model. AdCMVgdnf at 20 MOI (multiplicity of infection) was found to significantly reduce the cell loss of motoneurons, as compared to AdCMVgdnf at 20 MOI, the recombinant adenovirus containing the marker gene lacZ. Furthermore, the adenovirus was proved to mediate erogenous gene expression using X-Gal staining and a semi-quantitative RT-PCR method. These results suggested a therapeutic potential of adenovirus vector-mediated gdnf gene therapy in human motoneuron diseases.

Changes in brain content of nociceptin/orphanin FQ and endomorphin 2 in a rat model of neuropathic pain

Orphanin FQ (OFQ) and endomorphins (EM) are newly characterized members of opioid peptide family. OFQ has been shown to antagonize morphine analgesia at supraspinal level, whereas endomorphins are highly selective endogenous ligands for mu receptor, showing analgesic effect at both spinal and supraspinal level. OFQ and EM-2 (EM2) immunoreactivity (ir) was measured by radioimmunoassay in nociception-related brain areas of rats subjected to L5/L6 spinal nerve ligation, using sham operated rats as control. It was found that: (1) the content of EM2-ir of spinal nerve ligated rats showed a significant increase (778%) in periaqueductal gray (PAG), and a significant decrease (43%) in striatum, compared with the control group. (2) a significant increase of the content of OFQ-ir was found in amygdala (+841%) and PAG (+459%), respectively in spinal nerve ligated rats. High pressure liquid chromatography showed that the EM2-ir and OFQ-ir were both heterogeneous with the major part eluting at the position of EM2 and OFQ standard, respectively. These results suggest that spinal nerve ligation induces significant changes in the content of EM2-ir and OFQ-ir in some discrete brain areas, which may play a role in nociceptive modulation.

A novel method for convenient assessment of arthritic pain in voluntarily walking rats

Quantification of arthritic pain can be very useful in elucidating the mechanisms of arthritis and in assessing the effect of anti-arthritic medication or treatment. Here we report a novel method that allows convenient measurements of the severity of arthritic pain in voluntarily walking rats. We constructed a device to measure the weight load on each leg while the animal was walking through a path, the bottom of which was equipped with strain gauge weight sensors. Using this device, we measured the weight load on the right hind leg before and after induction of arthritis by carrageenan injection into the knee joint cavity of this leg. The carrageenan injection resulted in a significant reduction of weight load on the affected leg; the load decreased to the minimum level at 4 h after the injection and gradually returned to the pre-injection level by the fifth day. Intraperitoneal administration of morphine at 5.5 h after carrageenan injection could reverse the weight load change. These results suggest that our new device is an effective tool for convenient measurements of arthritic pain in dynamic conditions like walking.