NOD1 and NOD2 mediate sensing of periodontal pathogens

In bacterial infection, Nucleotide-binding Oligomerization Domain (NOD) 1 and NOD2 induce innate immune responses by recognizing fragments of the bacterial component peptidoglycan (PGN). To determine the roles of these receptors in detection of periodontal pathogens, we stimulated human embryonic kidney cells expressing NOD1 or NOD2 with heat-killed Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum or their soluble PGNs (sPGNs). All bacteria and their sPGNs could stimulate activation of NF-kappaB. However, there were differences in NOD1- and NOD2-stimulatory activities among the species of bacteria. P. gingivalis showed weaker NOD1- and NOD2-stimulatory activities than did other bacteria. These differences in activities were confirmed by production of interleukin-8 from oral epithelial cells stimulated with sPGNs. These findings indicate that both NOD1 and NOD2 might be involved in the recognition of periodontal pathogens, and that the weak NOD-stimulatory property of P. gingivalis might be helpful for survival in the periodontal pocket.

Cyclosporin A and phenytoin modulate inflammatory responses

Gingival overgrowth is a common side-effect of administration of the immunosuppressant cyclosporin A and the anti-epileptic drug phenytoin. While cyclosporin-induced gingival overgrowth is often accompanied by gingival inflammation, phenytoin-induced gingival overgrowth usually forms fibrotic lesions. To determine whether these drugs alter the inflammatory responses of gingival fibroblasts, we investigated the effects of cyclosporin and phenytoin on Toll-like receptor (TLR)-mediated responses to microbial components. In Chinese hamster ovary reporter cell lines, cyclosporin alone triggered signaling, whereas phenytoin down-regulated signaling induced by the TLR2 or TLR4 ligand. In human gingival fibroblasts, cyclosporin alone did not induce evident inflammatory responses, but augmented the expression of CD54 and the production of interleukin (IL)-6 and IL-8 induced by TLR ligands, whereas phenytoin attenuated those responses. Cyclosporin also augmented CD54 expression in gingiva of mice injected with lipopolysaccharide. These results indicated that cyclosporin positively and phenytoin negatively modulated inflammatory responses of human gingival fibroblasts.

Green tea catechin inhibits lipopolysaccharide-induced bone resorption in vivo

BACKGROUND AND OBJECTIVE

Bone resorption is positively regulated by receptor activator of nuclear factor-kappaB ligand (RANKL). Pro-inflammatory cytokines, such as interleukin (IL)-1beta, promote RANKL expression by stromal cells and osteoblasts. Green tea catechin (GTC) has beneficial effects on human health and has been reported to inhibit osteoclast formation in an in vitro co-culture system. However, there has been no investigation of the effect of GTC on periodontal bone resorption in vivo. We therefore investigated whether GTC has an inhibitory effect on lipopolysaccharide (LPS)-induced bone resorption.

MATERIAL AND METHODS

Escherichia coli (E. coli) LPS or LPS with GTC was injected a total of 10 times, once every 48 h, into the gingivae of BALB/c mice. Another group of mice, housed with free access to water containing GTC throughout the experimental period, were also injected with LPS in a similar manner.

RESULTS

The alveolar bone resorption and IL-1beta expression induced by LPS in gingival tissue were significantly decreased by injection or oral administration of GTC. Furthermore, when GTC was added to the medium, decreased responses to LPS were observed in CD14-expressing Chinese hamster ovary (CHO) reporter cells, which express CD25 through LPS-induced nuclear factor-kappaB (NF-kappaB) activation. These findings demonstrated that GTC inhibits nuclear translocation of NF-kappaB activated by LPS. In addition, osteoclasts were generated from mouse bone marrow macrophages cultured in a medium containing RANKL and macrophage colony-stimulating factor with or without GTC. The number of osteoclasts was decreased in dose-dependent manner when GTC was added to the culture medium.

CONCLUSION

These results suggest that GTC suppresses LPS-induced bone resorption by inhibiting IL-1beta production or by directly inhibiting osteoclastogenesis.

The Role of Simulator Promis2 in Learning Laparoscopic Skill

Introduction: Laparoscopic surgery is unique and complex in nature, so the training is necessarybefore proceeding to operation room. Many computer aided simulators have been developed forthe purpose. Our objective is to assess the improvement of basic laparoscopic skills after training insimulator.Methods: The fi fth year medical students underwent training of three laparoscopic skills usingPromis2 simulator twice weekly for 4-6 weeks. The skills are laparoscopic orientation, target pointingand objects transferring. Time, path length of instruments and economy of movements were recorded.The comparisons were made for these parameters between session fi rst and the last using a Mann-Whitney U test.Results: Ten volunteers completed the exercises in less time (186.3±55.4 seconds) than the fi rstexercise (215.7±57.4 seconds) (P=0.0027). Both the right and left hand instrument path lengths werealso improved from 4425.8±1284.3 mm in the fi rst exercise to 3925.3±1313.6 mm in the last exercisein the left side (P=0.0219) and likewise from 4273.8±1859.4 mm to 3831.3±1717.4 mm in the right side(P=0.0027). Economy of the movement in the left handed instrument improved from 1114.4±453.5mm in the fi rst exercise to 966.8±411.1 mm in the last (P=0.0443) and in the right handed instrumentfrom 845±398.8 mm to 771.4±370.5 mm according to the software of Promis2 simulator (P >0.005).Conclusions: Training in Promis2 simulator improves the basic laparoscopic skills. The candidatesbecome consistently faster with shorter path lengths and had smoother instruments movements.They also became signifi cantly more consistent in their performance.Key Words: laparoscopy, promis2, simulator, training

The role of simulator Promis2 in learning laparoscopic skill

INTRODUCTION

Laparoscopic surgery is unique and complex in nature, so the training is necessary before proceeding to operation room. Many computer aided simulators have been developed for the purpose. Our objective is to assess the improvement of basic laparoscopic skills after training in simulator.

METHODS

The fifth year medical students underwent training of three laparoscopic skills using Promis2 simulator twice weekly for 4-6 weeks. The skills are laparoscopic orientation, target pointing and objects transferring. Time, path length of instruments and economy of movements were recorded. The comparisons were made for these parameters between session first and the last using a Mann-Whitney U test.

RESULTS

Ten volunteers completed the exercises in less time (186.3 +/- 55.4 seconds) than the first exercise (215.7 +/- 57.4 seconds) (P=0.0027). Both the right and left hand instrument path lengths were also improved from 4425.8 +/- 1284.3 mm in the first exercise to 3925.3 +/- 1313.6 mm in the last exercise in the left side (P=0.0219) and likewise from 4273.8 +/- 1859.4 mm to 3831.3 +/- 1717.4 mm in the right side (P=0.0027). Economy of the movement in the left handed instrument improved from 1114.4 +/- 453.5 mm in the first exercise to 966.8 +/- 411.1 mm in the last (P=0.0443) and in the right handed instrument from 845 +/- 398.8 mm to 771.4 +/- 370.5 mm according to the software of Promis2 simulator (P >0.005).

CONCLUSIONS

Training in Promis2 simulator improves the basic laparoscopic skills. The candidates become consistently faster with shorter path lengths and had smoother instruments movements. They also became significantly more consistent in their performance.

Evidence for association between a Toll-like receptor 4 gene polymorphism and moderate/severe periodontitis in the Japanese population

BACKGROUND AND OBJECTIVE

Chronic periodontitis is an inflammatory disease caused by bacteria in subgingival pockets. Because Toll-like receptor 2 and Toll-like receptor 4 have been shown to play an important role in the recognition of periodontal pathogens, we investigated the relevance of genetic variations in TLR2 and TLR4 to susceptibility to periodontitis.

MATERIAL AND METHODS

A total of 97 patients with chronic periodontitis and 100 control subjects were examined for mutations in TLR2 and TLR4. Case-control analysis was performed using individual single nucleotide polymorphisms detected during the mutation search.

RESULTS

The missense mutations reported previously in TLR2 (677 Arg>Trp and 753 Arg>Gln) and in TLR4 (299 Asp>Gly and 399 Thr>Ile) were not detected in 97 of the Japanese patients with chronic periodontitis or in 100 of the Japanese control subjects. Nine single nucleotide polymorphisms were identified in exons of TLR2 and TLR4. The case-control analysis revealed that the frequency of the C/C genotype at base-pair position +3725 in TLR4 was significantly higher in both the moderate and the severe periodontitis patient group than in the control group.

CONCLUSION

A genetic variation of TLR4 might be associated with moderate and severe periodontitis in the Japanese population.

Amelioration of human lupus-like phenotypes in MRL/lpr mice by overexpression of interleukin 27 receptor alpha (WSX-1)

Objective:

In the present work, we investigate the role of interleukin (IL)27/IL27 receptor α (Rα) (WSX-1) in the development of autoimmune disorders in the MRL/lpr mouse, which is considered as an experimental model of systemic lupus erythaematosus (SLE) in humans.

Methods:

We generated two strains of WSX-1 transgenic mice in the MRL/lpr background with different expression levels of WSX-1, and investigated the effect of WSX-1 overexpression on survival, glomerulonephritis and immunological properties.

Results:

In comparison with wild type (WT) MRL/lpr and transgenic (Tg) low (TgL) mice, Tg high (TgH) mice exhibited a prolonged lifespan and no apparent development of autoimmune nephritis. Production of anti-dsDNA antibody and total IgG and IgG2a were significantly lower in TgH mice than those of TgL and WT mice. The expressed amounts of interferon (IFN)γ and IL4 mRNA by CD4⁺ T cells from Tg mice decreased in a dose-dependent fashion. CD4⁺ splenic lymphocytes in TgH mice were more subject to the IL27-mediated suppression of cytokine production. In vitro stimulation of CD4⁺ T cells by IL27 resulted in over phosphorylation of STAT3 in TgH cells than in WT cells.

Conclusion:

WSX-1 overexpression in the MRL/lpr background rendered the autoimmune prone mice protected from the development of autoimmune diseases. Our results suggest that IL27 signalling may be a therapeutic target against autoimmune diseases, including human SLE.

Protein intake of more than 0.5 g/kg BW/day is not effective in suppressing the progression of chronic renal failure

BACKGROUND

Although it is well-known that the restriction of protein intake in chronic renal failure (CRF) is effective in slowing the progressive loss of renal function, recent randomized controlled trials have not consistently shown a beneficial effect on CRF. There is controversy regarding the amount of protein intake that results in this effect. In this study, various amounts of protein intake were compared in CRF patients due to chronic glomerulonephritis (CGN) in order to explore effective restriction of dietary protein.

METHODS

CGN patients (121 in total) with a serum creatinine level of 6 mg/dl were studied. They were subdivided into six groups depending on their protein intake: 0.3 g/kg BW/day (0.3 g), 0.4, 0.5, 0.6, 0.7, and > or =0.8 g (control group C). Deterioration of renal function was evaluated by the mean rate of decline in creatinine clearance, and the amount of protein intake was estimated on the basis of the urea nitrogen appearance rate in a 24-hour urine sample.

RESULTS

There was no significant difference in the suppression of the progression of renal dysfunction in the 0.6- and 0.7-g groups. However, significant suppression was observed in the 0.5-, 0.4-, and 0.3-g groups in comparison with those that received more than 0.6 g (p < 0.05). The renal survival rate in the groups that received less than 0.5 g was higher than that in the groups that received more than 0.6 g (p < 0.05). Malnutrition was not observed in all patients studied.

CONCLUSION

We found that a protein intake of more than 0.5 g/kg BW/day is not effective in suppressing further deterioration of renal function in CRF resulting from CGN.

Immunohistochemical analyses on serum proteins in nephrons of protein-overload mice by "in vivo cryotechnique"

Immunohistochemical analyses on local distributions of serum proteins in living mouse kidneys are usually difficult to examine with conventional preparation methods. By using our "in vivo cryotechnique" combined with freeze-substitution, we have checked immunolocalizations of the serum proteins in nephrons of bovine serum albumin (BSA)-overload mice, and compared them with those obtained by the conventional preparation methods. In two days of daily BSA-injected mice, the immunolocalization of BSA could be observed in Bowman's space and urinary tubules with their overt proteinuria, where another endogenous mouse albumin was similarly immunolocalized. The leakage of BSA and mouse albumin in Bowman's space and their reabsorption into proximal tubules were detected in 55% of nephrons, where no leakage of immunoglobulin G1 (IgG1) was detected. However, the leakage of IgG1, in addition to BSA and mouse albumin, was detected in the other nephrons. By carefully examining immunolocalizations of BSA and IgG1, they were obviously different from those obtained by the conventional preparation methods without normal blood circulation into the kidneys. The immunolocalizations of both BSA and mouse serum proteins could be directly analyzed with the "in vivo cryotechnique", suggesting that functional damage to glomerular filtration barriers are different at early stages of the BSA-overload mouse model, depending on each nephron of living mice.

Loss of SOCS3 in the liver promotes fibrosis by enhancing STAT3-mediated TGF-beta1 production

Recently, DNA methylation and reduced expression of the suppressor of the cytokine signaling-3 (SOCS3) gene in human hepatocellular carcinoma (HCC) patients have been reported. However, the roles of SOCS3 in HCC development in vivo have not been clarified. Using RT-PCR analysis and Western blotting, we confirmed that SOCS3 expression was reduced in HCC patients. However, reduced expression of SOCS3 occurred not only in HCC but also in nontumor regions, and this reduction was stronger as the fibrosis grade increased. Furthermore, SOCS3 levels were inversely correlated with signal transducers and activators of transcription-3 (STAT3) activation as well as transforming growth factor (TGF)-beta1 levels in the non-HCC region. To define the molecular consequences of SOCS3 silencing/STAT3 hyperactivation and liver fibrosis, we examined liver-specific SOCS3-deficient mice. We demonstrated that SOCS3 deletion in the liver resulted in hyperactivation of STAT3 and promoted ConA- and chemical-induced liver fibrosis. The expression of TGF-beta1, a mediator of fibrosis, was enhanced by SOCS3 gene deletion, but suppressed by the overexpression of a dominant-negative STAT3 or SOCS3 both in vivo and in vitro. These data suggest that TGF-beta1 is a target gene of STAT3 and could be one of the mechanisms for enhanced fibrosis in SOCS3-deficient mice. Thus, our present study provides a novel role of SOCS3 and STAT3 in HCC development: in addition to the previously characterized oncogenic potentials, STAT3 enhances hepatic fibrosis through the upregulation of TGF-beta1 expression, and SOCS3 prevents this process.

Spreds, inhibitors of the Ras/ERK signal transduction, are dysregulated in human hepatocellular carcinoma and linked to the malignant phenotype of tumors

Aberrant activation of the Ras/Raf-1/extracellular-regulated kinase (ERK) pathway has been shown to be involved in the progression of human hepatocellular carcinoma (HCC). However, the mechanism of dysregulation of ERK activation is poorly understood. Recently, we identified Sprouty-related protein with Ena/vasodilator-stimulated phosphoprotein homology-1 domain (Spred) as a physiological inhibitor of the Ras/Raf-1/ERK pathway. In this study, we found that the expression levels of Spred-1 and -2 in human HCC tissue were frequently decreased, comparing with those in adjacent non-tumorous tissue. Moreover, Spred expression levels in HCC tissue were inversely correlated with the incidence of tumor invasion and metastasis. Forced expression of Spred-1 inhibited HCC cell proliferation in vitro and in vivo, which was associated with reduced ERK activation. Spred-1 overexpression also reduced the secretion of matrix metalloproteinase-9 (MMP-9) and MMP-2, which play important roles in tumor invasion and metastasis. In addition, Spred-1 inhibited growth factor-mediated HCC cell motility. These data indicate that the reduction of Spred expression in HCC is one of the causes of the acquisition of malignant features. Thus, Spred could be not only a novel prognostic factor but also a new therapeutic target for human HCC.

Association study of polymorphisms in SOCS family genes with type 1 diabetes mellitus

Suppressors of cytokine signalling (SOCS) proteins play important roles in the negative regulation of cytokine signal. We first searched for polymorphisms in SOCS-1, SOCS-3 and SOCS-5 genes, and examined the association of the polymorphisms with type 1 diabetes (T1D). As a result, we did not find any significant associations between SOCS genes and T1D.

[Nephrotic syndrome after extended thymectomy for thymoma with myasthenia gravis; report of a case]

A 35-year-old man visited our hospital complaining of blepharoptosis and fatigability of the left arm. Under a diagnosis of myasthenia gravis (Osserman Ila), ambenonium was administered and improvements were noted. At 40-year-old, the patient underwent extended thymectomy due to the development of thymoma, which invaded the lung and pericardium (Masaoka stage Ill). Then ADOC therapy (doxorubicin hydrochloride+cisplatin+vincristine sulfate+cyclophosphamide) was initiated. At 47-year-old, we found recurrence of disseminated thymoma in thoracic cavity. Because of multiple metastatic lesions, radiotherapy in combination with chemotherapy was chosen and these lesions were reduced in size. Facial and foot edema developed at 50-year-old. Chest X-ray revealed bilateral pleural effusion. He was diagnosed as minimal change nephrotic syndrome and steroid therapy was started. The changes in cellular immunity due to thymoma is considered to be causative in the development of nephrotic syndrome. We report the clinical course of our case and discuss with reference to the literature.

The characteristics of karyotype and telomeric satellite DNA sequences in the cricket, Gryllus bimaculatus (Orthoptera, Gryllidae)

The chromosomes derived from the Japanese population of Gryllus bimaculatus were characterized by C-banding and Ag-NOR staining. The chromosome number, 2n = 28 + XX (female)/XO (male), corresponded with that of other populations of G. bimaculatus, but the chromosome configuration in idiograms varied between the populations. NORs were carried on one pair of autosomes and appeared polymorphous. The positive C-bands located at the centromere of all chromosomes and the distal regions of many chromosome pairs, and the size and the distribution pattern of the distal C-heterochromatin showed differences among the chromosomes. In addition, this paper reports on the characteristics of HindIII satellite DNA isolated from the genome of G. bimaculatus. The HindIII repetitive fragments were about 0.54 kb long, and localized at the distal C-bands of the autosomes and the interstitial C-bands of the X chromosome. Molecular analysis showed two distinct satellite DNA sequences, named the GBH535 and GBH542 families, with high AT contents of about 67 and 66%, respectively. The two repetitive families seem to be derived from a common ancestral sequence, and both families possessed the same 13-bp palindrome sequence. The results of Southern blot hybridization suggest that the sequence of the GBH535 family is conserved in the genomic DNAs of Gryllus species, whereas the GBH542 family is a species-specific sequence.

Glycogen depletion in intrafusal fibres in rats during short-duration high-intensity treadmill running

AIM

The recruitment patterns of the intrafusal and extrafusal fibres in the soleus (SOL) and extensor digitorum longus (EDL) muscles of rats were investigated during brief-intensity exercise by assaying their glycogen content histochemically.

METHODS

Six adult male rats were assigned to each of four groups that ran up a 6 degrees incline on a motor-driven treadmill, at 40 m min(-1) for either 0.5, 1, 2, or 4 min. Six adult male rats in the control group did not run. Extrafusal and intrafusal fibres were classified by myosin ATPase staining. Optical densities for glycogen content were evaluated in serial periodic acid Schiff (PAS) stained-sections from the B and C regions of intrafusal fibres.

RESULTS

The glycogen content of type IIA fibres in the SOL and EDL muscles decreased significantly in the early phase of exercise whereas the glycogen content of type I fibres in these muscles decreased later than that of type IIA fibres. The glycogen content of bag2 fibres decreased after 1 min of exercise in the SOL muscle and after 2 min of exercise in the EDL muscle. On the other hand, the glycogen content of bag1 and chain fibres decreased significantly after 2 min in the SOL muscle but not in the EDL muscle.

CONCLUSION

The results suggest that during brief-intensity exercise, as the glycogen content of type IIA fibres is reduced earlier than that of type I fibres, bag2 fibres are most important early in this type of exercise.

Suppressor of cytokine signalling 1 in lymphocytes regulates the development of intestinal inflammation in mice

BACKGROUND AND AIMS

Imbalance between pro- and anti-inflammatory cytokines produced by intestinal T cells induces inflammatory bowel diseases (IBD). However, the importance of regulation of cytokine signalling in IBD has not been fully clarified. We have demonstrated that suppressor of cytokine signalling 1 (SOCS1) is expressed in inflamed tissues in an experimental colitis model. In the present study, we investigated the role of SOCS1 in colitis models to clarify the mechanism of IBD development.

METHODS

Intestinal T cells in transgenic mice expressing high levels of SOCS1 in lymphocytes (SOCS1Tg mice) were characterised by flow cytometric analysis and cytokine production from intestinal T cells was determined by ELISA. 2,4,6-Trinitrobenzene sulphonic acid (TNBS) induced colitis was induced in SOCS1Tg mice and severity was compared with control littermates by measurement of survival rates. Intracellular signalling was assessed by western blotting analysis.

RESULTS

SOCS1Tg mice developed colitis spontaneously with age. Young SOCS1Tg mice less than 15 weeks of age, before the onset of colitis, were susceptible to TNBS induced colitis. Intestinal T cells of SOCS1Tg mice showed increased interferon gamma and tumour necrosis factor alpha production and decreased transforming growth factor beta production. Expression of cytotoxic T lymphocyte associated antigen 4 (CTLA-4), a negative regulator of T cell activation, in SOCS1Tg mice was severely impaired at the protein level although mRNA levels of CTLA-4 in SOCS1Tg mice were comparable with those in control mice.

CONCLUSIONS

Our data suggest that SOCS1 plays an important role in the regulation of colitis by controlling intestinal T cell activation mediated through CTLA-4 expression.

Molecular cytogenetic characterization and chromosomal distribution of the satellite DNA in the genome of Oxya hyla intricata (Orthoptera: Catantopidae)

The genomic DNA of the grasshopper (Oxya hyla intricata) was subjected to electrophoresis after digestion with HaeIII, and the result showed two bands of highly repetitive DNA, approximately 200 and 400 bp in length. The 200-bp HaeIII-digested fragment was cloned and characterized by sequencing and fluorescence in situ hybridization (FISH). The results showed the presence of two distinct satellite DNA (stDNA) families: one consisting of a 169-bp repeated element having an A+T content of 60.9% and the other consisting of a 204-bp repeated element having an A+T content of 53.9%. No significant homology between the two stDNA families was observed. FISH showed that the chromosomal locations of these families are different from each other. The 169-bp element was located in the C-band-positive regions of the short arms of most of the chromosomes, whereas the 204-bp element was located in the centromeric regions of three chromosome pairs. These results imply that the origins of these two DNA families are different. The results of zoo-blot hybridization to the genomic DNA from four Oxya species, O. hyla intricata, O. japonica japonica, O. chinensis formosana, and O. yezoensis, suggest that the two stDNA families found in the present study are species-specific for O. hyla intricata.