Core species and interactions prominent in fish-associated microbiome dynamics

魚の健康において鍵となる「コア微生物叢」 --ウナギ養殖水槽内の細菌叢動態--. 京都大学プレスリリース. 2023-03-30.[Background] In aquatic ecosystems, the health and performance of fish depend greatly on the dynamics of microbial community structure in the background environment. Nonetheless, finding microbes with profound impacts on fish’s performance out of thousands of candidate species remains a major challenge. [Methods] We examined whether time-series analyses of microbial population dynamics could illuminate core components and structure of fish-associated microbiomes in the background (environmental) water. By targeting eel-aquaculture-tank microbiomes as model systems, we reconstructed the population dynamics of the 9605 bacterial and 303 archaeal species/strains across 128 days. [Results] Due to the remarkable increase/decrease of constituent microbial population densities, the taxonomic compositions of the microbiome changed drastically through time. We then found that some specific microbial taxa showed a positive relationship with eels’ activity levels even after excluding confounding effects of environmental parameters (pH and dissolved oxygen level) on population dynamics. In particular, a vitamin-B12-producing bacteria, Cetobacterium somerae, consistently showed strong positive associations with eels’ activity levels across the replicate time series of the five aquaculture tanks analyzed. Network theoretical and metabolic modeling analyses further suggested that the highlighted bacterium and some other closely-associated bacteria formed “core microbiomes” with potentially positive impacts on eels. [Conclusions] Overall, these results suggest that the integration of microbiology, ecological theory, and network science allows us to explore core species and interactions embedded within complex dynamics of fish-associated microbiomes

Ovariectomy enhances renal cortical expression and function of cyclooxygenase-2

Ovariectomy enhances renal cortical expression and function of cyclooxygenase-2.BackgroundCyclooxygenase-2 (COX-2) inhibitors are used as analgesics in postmenopausal women, who develop edema and require a salt-restricted diet. This study was performed to determine the renal expression of COX-2 and on COX-2–dependent regulation of renal blood flow (RBF) in ovariectomized rats.MethodsSprague-Dawley rats were divided into 4 groups: sham-operated rats fed a normal-salt diet (Sh+NS) or a low-salt diet (Sh+LS), and bilaterally ovariectomized rats fed a normal-salt diet (Ox+NS) or a low-salt diet (Ox+LS) (N = 6 in each group). Estrogen replacement therapy was performed on other ovariectomized rats. A renal clearance study was performed in anesthetized animals.ResultsOvariectomy increased renal cortical COX-2 expression independently of dietary salt intake (Sh+NS <Ox+N; Sh+LS <Ox+LS). Inhibition of COX-2 by NS398 reduced the urinary excretion of 6-keto-prostaglandin F1α in all 4 groups, although the reduction was greater in the Ox+LS group than in the Ox+NS and Sh+LS groups, which in turn had a greater reduction than the Sh+NS group. RBF significantly decreased in every group except the Sh+NS group, but no effect on blood pressure, inulin clearance, or urinary sodium excretion was seen. The decrease in RBF was significantly greater in the Ox+LS group than in the Sh+LS and Ox+NS group. The decrease in RBF was dependent on cortical RBF in the Sh+LS and Ox+NS groups, and on both cortical and medullary RBF in the Ox+LS group. Estrogen replacement therapy reversed the ovariectomy-induced changes.ConclusionEstrogen-dependent COX-2 expression plays an important role in the RBF regulation in female rats

Survival rates of early-stage HCV-related liver cirrhosis patients without hepatocellular carcinoma are decreased by alcohol

Although alcohol abuse is the most common cause of liver cirrhosis in the United States, the enhancing effects of alcohol on the long-term prognosis of hepatitis C virus (HCV) related liver cirrhosis has not been clarified. To investigate how alcohol abuse influences the prognosis of hepatitis virus related liver cirrhosis, we studied 716 Japanese patients. Cumulative survival and hepatocellular carcinoma (HCC) development rates were analyzed in alcohol abusive, cirrhotic patients with or without hepatitis virus infection. Patients who abused alcohol were younger (p<0.0001) than HCV infected, non-abusive patients. The overall survival rate among patients with alcoholic cirrhosis (Al group), HCV related cirrhosis (HCV group), and HCV infected + alcoholic cirrhosis (HCV + Al group), showed no significant differences, although the 10-year cumulative survival rate of Al group was the highest of the three groups. The HCC development rate of Al group was the lowest. In addition, alcohol abuse decreased the survival rates of HCV group in the early stage with no HCC (p = 0.0028). In conclusion, alcohol abuse might affect the progression of liver damage in HCV infected patients with liver cirrhosis in the early stage, although the influence of alcohol abuse on the long term prognosis seems to be rather small

Nutrient concentraｔions of precipitation, throughfall, soil water, groundwater, hyporheic water and stream water in a konara oak (Quercus serrata) forest

中国山地中央部に位置する鳥取大学・蒜山の森のコナラ林流域において, 降水, 林内雨, 土壌水, 地下水, 河床間隙水, 及び河川水の濃度分布を調べた. 2010年4月から2012年8月までの間に, 月に1～5回の頻度でこれらの水を採取し, 窒素とリンの濃度を分析した. 中央値に着目すると, 溶存態窒素の濃度は, 降水(0.39～0.59mg/l)よりも林内雨(0.60～0.67mg/l)はわずかに高く, 土壌水(1.92～2.93mg/l)はさらに高かったのに対し, 地下水(0.13～0.07mg/l), 河床間隙水(0.23～0.31mg/l), 及び河川水(0.20mg/l)は低かった. 溶存態リンの濃度は, 降水(0.003～0.004mg/l)よりも林内雨(0.015～0.039mg/l)で顕著に高かったのに対し, 土壌水(0.002mg/l), 地下水(0.001～0.002mg/l), 河床間隙水(0.001mg/l), 及び河川水(0.002mg/l)で低かった. 懸濁態の濃度については, 窒素もリンも林内雨で高く, 河川水で低かった. 全窒素と全リンについては, いずれも降水(全窒素:0.47～1.08, 全リン:0.007～0.019mg/l)よりも河川水(全窒素:0.27, 全リン:0.006mg/l)の方が低かった. これらの結果は, 当該地域の物質循環や水環境の研究にとって重要なバックグランドデータとなりうる

Older boys benefit from higher initial prednisolone therapy for nephrotic syndrome

Older boys benefit from higher initial prednisolone therapy for nephrotic syndrome.BackgroundA long course of the initial prednisolone therapy has been shown to be more effective than standard-course therapy in reducing relapse rates in children with idiopathic nephrotic syndrome, but it is commonly accompanied by corticosteroid toxicities. There has been no study on prednisolone dosage for the effective treatment of nephrotic syndrome.MethodsSixty-eight children (42 boys and 26 girls) with an initial attack of nephrotic syndrome were randomly allocated into two different long-course treatment groups. Patients in Group 1 received a daily prednisolone dose of 60 mg/m2 for six weeks, followed by an alternate-day dose of 40 mg/m2 for six weeks. Patients in Group 2 had a daily dose of 40 mg/m2 instead of 60 mg/m2.ResultsFour children in each group did not respond within six weeks. Group 1 was associated with a significantly earlier response but more frequent corticosteroid toxicities than Group 2. Boys in Group 1 had a higher rate of sustained remission than boys in Group 2 (P = 0.0073), especially boys four years old or more (P = 0.0027), but girls did not show a significant difference (P = 0.863). Boys four years old or more in Group 1 had a course of frequent relapsing less often than those in Group 2 (2 of 13 vs. 6 of 8, P = 0.0075).ConclusionThese findings indicate that efficient prednisolone doses may vary between sexes and ages, and that a higher initial prednisolone therapy may be of greater benefit to older boys

Mechanical Properties and Histological Evaluation of Bone Grafting Materials Containing Different Ratios of Calcium Phosphate Cement and Porous β-tricalcium Phosphate Granules

Article信州医学雑誌 66(2): 139-150(2018)journal articl