富栄養海域における新生沈殿物量とその性状からみたリンの動態

湖沼に比べて海域でのリン沈積速度の実測例は多くない。浅海の海水・底土間のリン循環を検討するため,潜水作業を要しない沈降物捕集装置(Fig.1)を考案し,瀬戸内海備後灘で1975年4月～1977年1月の約2年間にわたって沈積速度(1日1cm2当りの乾重量(DW)および粒子態リン(PP)の沈降量)を測定した。捕集された沈降物の性状(リン含有率, chl.a含有率など)を同時に採取した海水中懸濁物(セストン)および底土最表層部の性状と比較し,また水中懸濁量と沈積量とを比較して,リンの動態を考察した。 1. 特別に高い捕集値を除くと,沈降量の平均は,DWでは,水深の浅い岸寄りのSt.2で0.98,沖側のSt.BG-1で0.42㎎/cm2/dayとなった。PPではそれぞれ0.64,0.33μg/cm2/dayであった(Table2)。 2. 季節別にみると,沈降量は概ね5～10月の高水温期に大きく,11～4月の低水温期に小さい。両期におけるDWの平均沈降量はSt.2で1.26および0.60㎎/cm2/day, St.BG-1で0.83および0.11㎎/cm2/dayで,低水温期のSt.BG-1で特に低かった。これらは,水柱中での粒子態有機物生産や,流入陸水が搬入する陸源の土粒子量などの季節変化を反映したものと考えられた(Table2)。 3. 水中懸濁物のリン含有率(乾重比)に比べ,沈降物のそれは格段に低いことが特微であり,平均で,0.21%対0.072%であった。従って,水中懸濁物は,沈降物(いわゆる新生堆積物)として捕集されるまでの過程で,7割近いリンを溶存態として海水中に放出していたことになる(Fig.3)。 4. 底土最表層部の試料は,5～65日間の沈降量に相当する厚さを採取して用いたが,そのリン含有率は沈降物と差がなく,両者のリン含有率の季節変化もほぼ一致した(Fig.2, Table3)。一方,chl.a含有率は底土最表層よりも沈降物で高かった(Fig.3)。 5. 水柱中の懸濁量に対する1日間沈降量の割合は,平均で,リンの場合7.3(St.2)および25%(St.BG-1)であった。DWの場合には地点間の差が大きく,25.1(St.2)および6.3%(St.BG-1)であり,St.2ではDW沈降量が懸濁物に対して顕著に高い割合を示した(Table2)。 6. 水中懸濁物のリン含有率の鉛直的変化,沈降物のリン・chl.a含有率,捕集物の予備的検鏡結果などから,PPの沈積には,デトリタス状物質の凝集大型化および動物プランクトン等による糞塊生成作用が重要な役割りを果すと推測された。 7. 水柱中の懸濁物が新生堆積物となるまでに海水中に放出するリン量(即ち沈降過程における粒子態リンから溶存態リンへの移行量)を上記の3と5の結果から計算し,St.2で0.43～5.3,St.BG-1で0.07～0.3μgP/ cm2/dayの値を得た(Fig.4)。 8. 上記1の平均値にもとずき,一定の仮定を設けて堆積速度を厚さで試算したところ,St.2で10.6mm/yr, St.BG-1で4.6mm/yrとなった。実際には,捕集器中への再懸濁物の混入,堆積後の溶出を多少とも見込む必要があるので長期的に見た底土の堆積速度はこれをやや下まわると推定される。Precipitation rates of particulate matter, as expressed in terms of dry weight and particulate phosphrus, were measured on 11 occasions at each of Sts. 2 and BG-1 in the central part of the Seto Inland Sea (water depths ea. 7 and 24 m, and 2 and 10 km from shore, respectively) during April 1975 - January 1977 with a sedimentation trap that does not require diving operations (collecting area 107.5 cm2; exposure period 1 or 2 days). On the overall average, 0.98 and 0.42 mg of dry matter and 0.64 and 0.33µg of P were found to precipitate onto each cm2 of collecting area per day at the respective stations. The foregoing daily precipitation corresponded on the average to 25.1 and 6.3% in terms of dry weight (7.3 and 2.5% in terms of particulate phosphorus) of the seston crop simultaneously present in the overlying water column at the respective stations. P content of the precipitates collected in the trap averaged 0.072%, or only 1/3 of the average P content of the seston. The loose uppermost layer of muddy sediment showed the P content similar to, and the chlorophyll a content lower than the precipitates in the trap. It was preliminarily estimated that the bottom sediment augments in thickness by 10.6 and 4.6 mm per year at the respective stations. Geographical and seasonal variation in the precipitation rates and the possibility of resuspended sediment particles to be collected in the trap were discussed.This study was supported partly by the Grant in Aid for Fundamental Scientific Research of the Ministry of Education and partly by the Research Fund on the Ecosystem under contract with the Fisheries Agency, Ministry of Agriculture and Forestry

The leech excitatory peptide, a member of the GGNG peptide family: isolation and comparison with the earthworm GGNG peptides

AbstractA member of the GGNG peptide family was isolated from Hirudo nipponia (leech). GGNG peptides had only been isolated previously from earthworms. The C-terminus structure of the leech peptide, LEP (leech excitatory peptide), was –Gly–Gly–Asn–amide, while that of the earthworm peptides, EEP (earthworm excitatory peptide), was –Gly–Gly–Asn–Gly. LEP exerted 1000-fold more potent activities on leech gut than did EEP-2. On the other hand, EEP-2 was 1000-fold more potent than LEP on the crop-gizzard of the earthworm. Analog peptides of LEP and EEP-2 were synthesized, and the myoactive potency of each analog on the leech and earthworm tissues was compared

(-)-Epigallocatechin Gallate Reduces Platelet-Derived Growth Factor-BB-Stimulated Interleukin-6 Synthesis in Osteoblasts: Suppression of SAPK/JNK

We previously showed that the mitogen-activated protein (MAP) kinase superfamily, p44/p42 MAP kinase, p38 MAP kinase, and stress-activated protein kinase (SAPK)/c-Jun N-terminal (JNK), positively plays a part in the platelet-derived growth factor-BB- (PDGF-BB-) stimulated synthesis of interleukin-6 (IL-6), a potent bone resorptive agent, in osteoblast-like MC3T3-E1 cells while Akt and p70 S6 kinase negatively regulates the synthesis. In the present study, we investigated whether (-)-epigallocatechin gallate (EGCG), one of the major green tea flavonoids, affects the synthesis of IL-6 in these cells and the mechanism. EGCG significantly reduced the IL-6 synthesis and IL-6 mRNA expression stimulated by PDGF-BB, EGCG reduced the PDGF-BB-stimulated IL-6 synthesis also in primary-cultured osteoblasts. EGCG had no effect on the levels of osteocalcin and osteoprotegerin in MC3T3-E1 cells. The PDGF-BB-induced autophosphorylation of PDGF receptor β was not suppressed by EGCG. The PDGF-BB-induced phosphorylation of p44/p42 MAP kinase and p38 MAP kinase was not affected by EGCG. On the other hand, EGCG markedly suppressed the PDGF-BB-induced phosphorylation of SAPK/JNK. Finally, the PDGF-BB-induced phosphorylation of Akt and p70 S6 kinase was not affected by EGCG. These results strongly suggest that EGCG inhibits the PDGF-BB-stimulated synthesis of IL-6 via suppression of SAPK/JNK pathway in osteoblasts

Investigation of the Therapeutic Effect of Tobramycin in Mice with Experimental Pneumonia in One-shot Versus Divided-dose Schedules

We measured the plasma levels of tobramycin administered by different methods and evaluated the therapeutic effects of tobramycin in mice with experimental pneumonia in various methods and dose schedules. (1) Mice were dosed with tobramycin intramuscular, intravenous oneshot injection and drip infusion, and intramuscular injection in divided doses at intervals of 15 minutes. The plasma concentration of the drug was determined at timed intervals after administration in each instance. Intramuscular and one-shot intravenous injections resulted in substantially parallel time courses of plasma concentration and plasma concentration with drip infusion was similar to that after divided intramuscular injection. (2) A therapeutic experiment was conducted in mice with Klebsiella pneumoniae pneumonia using one-shot and divided intramuscular injection methods of tobramycin. The one-shot injection group showed a satisfactory result at the dose level of 2 mg/kg, but the injection in four divided doses yielded better results at 1 mg/kg. Therefore, in cases where high doses are not feasible or are undesirable, the time of contact of the bacteria and the drug should be prolonged, rather than trying to increase the peak plasma concentration of the drug

Visceral fat obesity is the key risk factor for the development of reflux erosive esophagitis in 40–69-years subjects

[Background] Visceral fat obesity can be defined quantitatively by abdominal computed tomography, however, the usefulness of measuring visceral fat area to assess the etiology of gastrointestinal reflux disease has not been fully elucidated. [Methods] A total of 433 healthy subjects aged 40–69 years (234 men, 199 women) were included in the study. The relationship between obesity-related factors (total fat area, visceral fat area, subcutaneous fat area, waist circumference, and body mass index) and the incidence of reflux erosive esophagitis was investigated. Lifestyle factors and stomach conditions relevant to the onset of erosive esophagitis were also analyzed. [Results] The prevalence of reflux erosive esophagitis was 27.2% (118/433; 106 men, 12 women). Visceral fat area was higher in subjects with erosive esophagitis than in those without (116.6 cm2 vs. 64.9 cm2, respectively). The incidence of erosive esophagitis was higher in subjects with visceral fat obesity (visceral fat area ≥ 100 cm2) than in those without (61.2% vs. 12.8%, respectively). Visceral fat obesity had the highest odds ratio (OR) among obesity-related factors. Multivariate analysis showed that visceral fat area was associated with the incidence of erosive esophagitis (OR = 2.18), indicating that it is an independent risk factor for erosive esophagitis. In addition, daily alcohol intake (OR = 1.54), gastric atrophy open type (OR = 0.29), and never-smoking history (OR = 0.49) were also independently associated with the development of erosive esophagitis. [Conclusions] Visceral fat obesity is the key risk factor for the development of reflux erosive esophagitis in subjects aged 40–69 years

Prolonged recurrence-free survival following OK432-stimulated dendritic cell transfer into hepatocellular carcinoma during transarterial embolization

金沢大学医薬保健研究域医学系Despite curative locoregional treatments for hepatocellular carcinoma (HCC), tumour recurrence rates remain high. The current study was designed to assess the safety and bioactivity of infusion of dendritic cells (DCs) stimulated with OK432, a streptococcus-derived anti-cancer immunotherapeutic agent, into tumour tissues following transcatheter hepatic arterial embolization (TAE) treatment in patients with HCC. DCs were derived from peripheral blood monocytes of patients with hepatitis C virus-related cirrhosis and HCC in the presence of interleukin (IL)-4 and granulocyte-macrophage colony-stimulating factor and stimulated with 0.1 KE/ml OK432 for 2 days. Thirteen patients were administered with 5 × 106 of DCs through arterial catheter during the procedures of TAE treatment on day 7. The immunomodulatory effects and clinical responses were evaluated in comparison with a group of 22 historical controls treated with TAE but without DC transfer. OK432 stimulation of immature DCs promoted their maturation towards cells with activated phenotypes, high expression of a homing receptor, fairly well-preserved phagocytic capacity, greatly enhanced cytokine production and effective tumoricidal activity. Administration of OK432-stimulated DCs to patients was found to be feasible and safe. Kaplan-Meier analysis revealed prolonged recurrence-free survival of patients treated in this manner compared with the historical controls (P = 0.046, log-rank test). The bioactivity of the transferred DCs was reflected in higher serum concentrations of the cytokines IL-9, IL-15 and tumour necrosis factor-α and the chemokines CCL4 and CCL11. Collectively, this study suggests that a DC-based, active immunotherapeutic strategy in combination with locoregional treatments exerts beneficial anti-tumour effects against liver cancer. © 2010 The Authors. Clinical and Experimental Immunology © 2010 British Society for Immunology