Effects of antibiotics on the in vitro ERG of the albino rabbit

This study describes the effects of penicillin G (PC-G) potassium, PC-G sodium, cloxacillin sodium (MCIPC), disodium sulbenicillin (SBPC), cefazolin sodium (CEZ) and cefsulodin sodium (CFS) on the in-vitro electroretinogram (ERG) of the albino rabbit.The b-wave and oscillatory potentials (OPs) were unchanged by 0.1 mM PC-G potassium or PC-G sodium. The OPs were slightly suppressed by 0.3 mM of either drug. While the a- and b-waves were not deteriorated, the OPs were greatly suppressed by 1.0 mM concentration. The effect of PC-G on the ERG was characterized by a selective suppression of the OPs. The b-wave and OPs were not suppressed by 0.03 mM MCIPC. They were slightly suppressed by 0.05 mM MCIPC. The a-wave, b-wave and OPs were not deteriorated by 1.0 mM SBPC. The b-wave and OPs were suppressed by 3.0 mM or 6.0 mM SBPC respectively. These changes appeared to be dose-dependent. Since the b-wave and OPs were concomitantly suppressed by both MCIPC and SBPC, these antibiotics, unlike PC-G, did not selectively suppress the OPs. The b-wave and OPs were unchanged by 0.1 mM CEZ or CFS. The OPs were slightly suppressed by 0.3mM CEZ or CFS. CEZ or CFS of 1.0 mM did not deteriorate the a- and b-waves, but selectively suppressed the OPs. The effects of CEZ and CFS on the ERG were characterized by a selective suppression of the OPs. The above-described changes in the ERG were reversible.     

Nontoxic concentration of antibiotics for intravitreal use — evaluated by human in-vitro ERG

The effects of penicillin G (PC-G) sodium, procaine PC-G, cloxacillin sodium (MCIPC), disodium sulbenicillin (SBPC), cefazolin sodium (CEZ), gentamicin sulfate (GM) and fosfomycin sodium (FOM) on the electroretinogram (ERG) of the human in-vitro eye-cup were studied. The oscillatory potentials (OPs) were selectively and greatly suppressed by 1.0mM PC-G sodium. The OPs and c-wave were suppressed by 0.85mM procaine PC-G. The b-wave and OPs were slightly suppressed by 1.0mM MCIPC. The a-wave, b-wave, OPs and c-wave were not deteriorated by 1.0mM SBPC. The OPs appeared to be selectively suppressed by 1.0mM CEZ. The b-wave was suppressed and the peak latencies of the OPs were delayed by 184g/ml (approximately 0.4mM) GM. The amplitudes of the a-wave and c-wave were slightly enhanced and their peak latencies were slightly delayed by 184g/ml GM. The a-wave, b-wave, OPs and c-wave were not deteriorated by 1.0mM FOM. The results of the present study on the human retina were comparable to those on the albino rabbit retina in our previous studies.     

The genetic contribution of HLA‐DRB5*01:01 to systemic lupus erythematosus in Thailand

Human leucocyte antigen (HLA) study in patients with systemic lupus erythematosus (SLE) has been investigated in various countries, but the results are still inconclusive. This study was performed to investigate the association between HLA‐DR and SLE in patients in northern Thailand. HLA‐DR subtyping was performed in 70 patients with SLE and 99 normal healthy controls living in northern Thailand using the INNO‐LiPA HLA‐DR Decoder kit (Innogenetics) and MICRO SSP HLA DNA Typing kit (One Lambda) for reconfirmation. The allele frequency (AF) of DRB5*01:01 in SLE was significantly higher than in the controls [25.7% vs. 14.6%, P = 0.012, Pc = 0.048, OR = 2.02 (95%CI = 1.17–3.48)]. The AF of DRB1*15:01 and DRB1*16:02 showed a nonsignificant tendency to be higher in SLE (10.7% vs. 8.1%, and 17.9% vs. 11.1%). Interestingly, the DRB5*01:01 allele linked to DRB1*16:02 in 47.2% of SLE and 37.9% of controls, and the prevalence of the DRB1*16:02‐DRB5*01:01 haplotype was higher in the patients with SLE [12.1% vs. 5.6%, P = 0.044, OR = 2.35 (95%CI = 1.06–5.19)]. The DRB1*16:02 linked to DRB5*02:02 and *02:03 in 18.2% and 31.8% of controls, respectively, and linked to DRB5*02:03 in 32.0% of SLE patients. The frequency of DRB1*03:01 and *15:02 alleles was not increased in Thai SLE. There was no significant association between DRB5*01:01 and any auto‐antibodies or clinical manifestations of SLE. DRB5*01:01 is associated with Thai SLE, and the association is stronger than that of DRB1*15:01. The genetic contribution of DRB5*01:01 is due partially to the linkage disequilibrium between DRB1*16:02 and DRB5*01:01 in the northern Thai population.     

Nontoxic concentration of kanamycin and gentamicin for intravitreal use — evaluated by in vitro ERG

The effects of kanamycin (KM) and gentamicin (GM) on the in-vitro electroretinogram of the albino rabbit were studied. The b-wave and oscillatory potentials (OPs) were unchanged by 0.1 mM KM. The photopic b-wave and OPs were slightly suppressed by 0.4 mM. The b-wave and OPs were not deteriorated by 23 µg/ml (approximately 0.05 mM) GM. The photopic b-wave and OPs were slightly suppressed by 46 µg/ml (approximately 0.1 mM) GM. The minimum concentration affecting the ERG was tentatively defined as the mean of the minimum concentration needed to change the ERG and the maximum concentration which induced no discernible changes in the ERG. The minimum concentration of KM and GM affecting the ERG were 0.25mM (approximately 150 g/ml) and 35 g/ml (approximately 0.075 mM) respectively. The minimum concentration of KM affecting the ERG was higher than its minimum inhibitory concentration against Staphylococcus aureus and Streptococcus pneumoniae. The minimum concentration of GM affecting the ERG was higher than its mimimum inhibitory concentration against Staphylococcus aureus, Streptococcus pneumoniae and Pseudomonas aeruginosa.     

Correction to: Differences in gut microbiota associated with age,sex, and stool consistency in healthy Japanese subjects

Journal of Gastroenterology - The authors would like to correct the errors in the publication of the original article. The correction details are given below for your reading.     

Anti-tumor-promoting activities of agaro-oligosaccharides on two-stage mouse skin carcinogenesis

We have previously reported that agaro-oligosaccharides (AGOs) suppressed the elevated levels of nitric oxide (NO), prostaglandin E?(PGE?), and pro-inflammatory cytokines in activated monocytes/macrophages, via heme oxygenase-1 induction. In this report, we initially demonstrated that AGOs intake inhibited NO production in activated peritoneal macrophages. Then, we tested for the ability of AGOs to prevent tumor promotion on the two-stage mouse skin carcinogenesis model. As a result, AGOs feeding led to delayed tumor appearance and decreased tumor number. It is known that PGE? is one of key players in carcinogenesis. Thus, we confirmed that PGE? production was suppressed by AGOs intake in TPA-induced ear edema model. We also demonstrated that cyclooxygenase-2 and microsomal PGE synthase-1, rate-limiting enzymes in PGE? production, were down-regulated by AGOs in human monocytes. Consequently, AGOs are expected to prevent tumor promotion by inhibiting PGE? elevation in chronic inflammation site.     

Oligosaccharides from agar inhibit murine intestinal inflammation through the induction of heme oxygenase-1 expression

Background

Agarose is hydrolyzed easily to yield oligosaccharides, designated as agaro-oligosaccharides (AGOs). Recently, it has been demonstrated that AGOs induce heme oxygenase-1 (HO-1) expression in macrophages and that they might lead to anti-inflammatory property. Nevertheless, the molecular mechanism of AGO-mediated HO-1 induction remains unknown, as does AGOs’ ability to elicit anti-inflammatory activity in vivo. This study was undertaken to uncover the mechanism of AGO-mediated HO-1 induction and to investigate the therapeutic effect of AGOs on intestinal inflammation.

Methods

Mice were treated with 2,4,6-trinitrobenzene sulfonic acid (TNBS) to induce colitis. The respective degrees of mucosal injury of mice that had received AGO and control mice were compared. We investigated HO-1 expression using Western blotting, quantitative real-time PCR (qRT-PCR), and immunohistochemistry. The expression of tumor necrosis factor-α (TNF-α) was measured using qRT-PCR and enzyme-linked immunosorbent assay.

Results

AGO administration induced HO-1 expression in colonic mucosa. The induction was observed mainly in F4/80 positive macrophages. Increased colonic damage and myeloperoxidase activity after TNBS treatment were inhibited by AGO administration. TNBS treatment induced TNF-α expression, and AGO administration suppressed induction. However, HO inhibitor canceled AGO-mediated amelioration of colitis. In RAW264 cells, AGOs enhanced HO-1 expression time-dependently and concentration-dependently and suppressed lipopolysaccharide-induced TNF-α expression. Furthermore, agarotetraose-mediated HO-1 induction required NF-E2-related factor 2 function and phosphorylation of c-jun N-terminal kinase.

Conclusions

We infer that AGO administration inhibits TNBS-induced colitis in mice through HO-1 induction in macrophages. Consequently, oral administration of AGOs might be an important therapeutic strategy for inflammatory bowel disease.     

Association of HLA-DRB1*15:02 and DRB5*01:02 allele with the susceptibility to systemic sclerosis in Thai patients

A genetic study, particularly in HLA-DRs, has never been performed in Thai patients with systemic sclerosis (SSc). This study was performed to investigate the association between the HLA-DR series in Thai SSc patients. HLA-DR subtypes were determined in 50 Thai SSc patients and 99 healthy controls (HCs). All SSc patients met the ACR classification criteria for SSc. HLA-DR typing was performed using INNO-LiPA HLA-DRB Decoder kits (INNOGENETICS) and reconfirmed using MICRO SSP HLA DNA Typing kits (ONE LAMBDA). The allele frequency (AF) of HLA-DR*15, compared with HC, was significantly higher in all SSc patients (41.0 vs 21.7 %, Pc = 0.0083) and SSc patients with anti-Scl70 antibody positive (anti-Scl70+) (47.1 %, Pc = 0.0018). Among the HLA-DR*15 alleles, the AF of the DRB1*15:02 was increased significantly in all SSc patients (29.0 vs 12.6 %, Pc = 0.0219) and SSc patients with anti-Scl70+ (32.4 vs 12.6 %, Pc = 0.0196). The AF of the HLA-DRB5*01:02 allele was also increased in all SSc patients (27.0 vs 12.6 %, Pc = 0.0166) and in SSc patients with anti-Scl70+ (29.4 %, Pc = 0.0124). The AF of the DR*04 was significantly lower in the SSc patients (1.0 vs 9.6 %, Pc = 0.0399). However, the AF of the DRB1*15:02 and DRB5*01:02 was not different among SSc patients with or without clinical manifestations (pulmonary fibrosis, digital pitting scar, sclerodactyly, myositis, and sicca symptoms). In addition, there was no significant association between clinical manifestations among individuals who carried HLA-DRB1*15:02 or DRB5*01:02. HLA-DRB1*15:02 and DRB5*01:02 alleles were significantly elevated in Thai SSc patients, especially in those with anti-Scl70+. The HLA-DRB1*04 was a protective allele against Thai SSc patients.