Chemical Studies on the Stability of Soil Aggregates : Change in Permeability of Soil Aggregate Column Induced bu Percolating with Neutral and Alkaline Solution

既報の結果に基づいて推論した粒団生成に関与する成分が, 果して土粒子の耐水性連結にいかなる役割を演じているかを明らかにする研究の一環として, 静置状態で土壌粒団に中性ならびにアルカリ性の溶液を透過させて土壌から特定の成分の離脱を試み, その場合に起こる粒団の崩壊と土壌の持つ透液性の変移をしらべた。1. 主として水溶性と置換性の成分を土壌から溶脱する機能のある0.05N塩化ナトリウム溶液を土壌粒団に透過させると土壌粒団の崩壊ならびに透液性の低下は極めて少なかった。したがって, 置換性塩基類は粒団の安定性に対し大きな役割を果していないことが明らかになった。2. アルカリ性の腐植抽出剤である0.5%水酸化ナトリウム溶液を土壌粒団に透過させると, 粒団の崩壊が著しく, それに応じて土壌の持つ透液性も低下した。しかし, 土壌からの腐植の離脱量と透液性の低下との間に認められた相関は高くないので粒団の安定性は腐植の単独作用によって律せられるものでないことがわかった。この際同時にアルミニウムがかなり多量に離脱され, これが粒団の安定性に関与することが類推された。3. 中性の腐植抽出剤である0.1Mピロ燐酸ナトリウム溶液を土壌粒団に透過させると, 土壌の種類によってその程度はかなり異なるが概して粒団崩壊と透液比の低下は大きかった。ところが, 土壌から離脱した腐植量と透液比の低下との間には相関が見出せなかった。ピロ燐酸ナトリウム溶液は土壌から腐植と同時に鉄, アルミニウム, カルシウムなどの無機成分を溶脱し, これらの正電荷を抑えて土粒の分散を促がす機能が高いから, この場合の粒団の崩壊はとくに同時に離脱する鉄やアルミニウムによるところが大きいと考えられる。 / With the object to determine the kinds of binding materials in soil aggregates and the part played by each of them, experiments were made on the effect of percolation with neutral or alkaline solution on the aggregate stability. The results obtained are as follows : 1) Aggregates were not greatly affected by the treatment with 0.05N sodium chloride solution. Hence, the part played by exchangeable bases appeared not large in the stabilization of aggregates. 2) When 0.5% sodium hydroxide solution was passed through the column to remove humus from aggregates, the permeability was remarkably lowered. But since the amount of humus removed was not so closely related to the degree of lowering in permeability, the aggregate stability did not seem attributable to the function of humus alone. It was suggested that aluminum removed from aggregates in a large amount in addition to humus participates in their stability. 3) When treated with 0.1M sodium pyrophosphate solution, neutral reagent for humus extraction, the aggregates were markedly broken down and their permeability was greatly lowered, though not without some differences in the extent of effect among the kinds of soil. On the other hand, no distinct correlation was found between the amount of humus removed and the degree of lowering in permeability ratio (the ratio of the permeability at any given time after treatment, Pt, to the initial permeability, Pi). In this case, inorganic components such as aluminum and iron, which were removed by sodium pyrophosphate solution in addition to humus, were considered to be intimately concerned with the result. 4) From these results, it may be indicated that the part played by the combined action of humus and aluminum or iron is important for the stability of soil aggregates

The ladies trial: laparoscopic peritoneal lavage or resection for purulent peritonitisA and Hartmann's procedure or resection with primary anastomosis for purulent or faecal peritonitisB in perforated diverticulitis (NTR2037)

Background: Recently, excellent results are reported on laparoscopic lavage in patients with purulent perforated diverticulitis as an alternative for sigmoidectomy and ostomy. The objective of this study is to determine whether LaparOscopic LAvage and drainage is a safe and effective treatment for patients with purulent peritonitis (LOLA-arm) and to determine the optimal resectional strategy in patients with a purulent or faecal peritonitis (DIVA-arm: perforated DIVerticulitis: sigmoidresection with or without Anastomosis). Methods/Design: In this multicentre randomised trial all patients with perforated diverticulitis are included. Upon laparoscopy, patients with purulent peritonitis are treated with laparoscopic lavage and drainage, Hartmann's procedure or sigmoidectomy with primary anastomosis in a ratio of 2:1:1 (LOLA-arm). Patients with faecal peritonitis will be randomised 1:1 between Hartmann's procedure and resection with primary anastomosis (DIVA-arm). The primary combined endpoint of the LOLA-arm is major morbidity and mortality. A sample size of 132:66:66 patients will be able to detect a difference in the primary endpoint from 25% in resectional groups compared to 10% in the laparoscopic lavage group (two sided alpha = 5%, power = 90%). Endpoint of the DIVA-arm is stoma free survival one year after initial surgery. In this arm 212 patients are needed to significantly demonstrate a difference of 30% (log rank test two sided alpha = 5% and powe

Imipramine Is an Orally Active Drug against Both Antimony Sensitive and Resistant Leishmania donovani Clinical Isolates in Experimental Infection

Background: In an endeavor to find an orally active and affordable antileishmanial drug, we tested the efficacy of a cationic amphiphilic drug, imipramine, commonly used for the treatment of depression in humans. The only available orally active antileishmanial drug is miltefosine with long half life and teratogenic potential limits patient compliance. Thus there is a genuine need for an orally active antileishmanial drug. Previously it was shown that imipramine, a tricyclic antidepressant alters the protonmotive force in promastigotes, but its in vivo efficacy was not reported. Methodology/Principal Findings: Here we show that the drug is highly active against antimony sensitive and resistant Leishmania donovani in both promastigotes and intracellular amastigotes and in LD infected hamster model. The drug wasfound to decrease the mitochondrial transmembrane potential of Leishmania donovani (LD) promastigotes and purified amastigotes after 8 h of treatment, whereas miltefosine effected only a marginal change even after 24 h. The drug restores defective antigen presenting ability of the parasitized macrophages. The status of the host protective factors TNF a, IFN c and iNOS activity increased with the concomitant decrease in IL 10 and TGF b level in imipramine treated infected hamsters and evolution of matured sterile hepatic granuloma. The 10-day therapeutic window as a monotherapy, showing about 90% clearance of organ parasites in infected hamsters regardless of their SSG sensitivity. Conclusions: This study showed that imipramine possibly qualifies for a new use of an old drug and can be used as an effective orally active drug for the treatment of Kala-azar

Comparative localization of inositol 1,4,5-trisphosphate and ryanodine receptors in intestinal smooth muscle: an analytical subfractionation study.

[3H]Ins(1,4,5)P3- and [3H]ryanodine-binding sites were characterized in membrane fractions from guinea-pig intestinal smooth muscle (longitudinal layer) and their subcellular localization was investigated by analytical cell-fractionation techniques. Fractions collected at low centrifugal fields (N and M fractions) contained predominantly low-affinity [3H]Ins(1,4,5)P3-binding sites (KD 80 nM), whereas microsomal (P) fractions contained only high-affinity binding sites (KD 5 nM). Total sedimentable high-affinity binding sites of [3H]Ins(1,4,5)P3 were 9-10-fold more numerous than those of [3H]ryanodine. Both high-affinity binding sites were purified in microsomal fractions, and their sub-microsomal distribution patterns after isopycnic density-gradient centrifugation were similar to those of presumed endoplasmic reticulum (ER) constituents, indicating that Ins(1,4,5)P3 and ryanodine receptors were localized primarily in ER and probably associated with rough as well as smooth ER. However, the stoichiometric ratio of Ins(1,4,5)P3 to ryanodine receptors was distinctly higher in high-density RNA-rich subfractions than in low-density RNA-poor subfractions, suggesting that Ins(1,4,5)P3 receptors were somewhat concentrated in the ribosome-coated portions of ER. The low overall stoichiometric ratio of ryanodine to Ins(1,4,5)P3 receptors in intestinal smooth muscle (1:9-10) might explain, at least partly, the existence of a Ca(2+)-storage compartment devoid of ryanodine-sensitive Ca2+ channels, but equipped with Ins(1,4,5)P3-sensitive channels, in saponin-permeabilized smooth-muscle cells [Iino, Kobayashi and Endo (1988) Biochem. Biophys. Res. Commun. 152, 417-422]

Subcellular localization of [3H]-nitrendipine binding sites in guinea-pig ileal smooth muscle.

The binding of [3H]-nitrendipine was studied in microsomal fractions isolated from guinea-pig ileal smooth muscle. Only one class of specific binding sites was detected, with a KD of 0.4 nM. For various dihydropyridine derivatives, including the stereoisomers of nimodipine and the 'Ca agonist' Bay K 8644, the potency for inhibition of [3H]-nitrendipine binding correlated well with the reported pharmacological potency in smooth muscle preparations. To establish the subcellular localization of [3H]-nitrendipine binding sites, untreated and digitonin-treated microsomal fractions were subfractionated by isopycnic density gradient centrifugation. The density distribution of [3H]-nitrendipine binding was markedly shifted by digitonin towards higher densities, as were the distributions of 5'-nucleotidase and [3H]-ouabain binding, whereas the distributions of NADPH:cytochrome c reductase and NADH:cytochrome c reductase were hardly modified by digitonin. It is concluded that most, if not all, [3H]-nitrendipine binding sites in guinea-pig ileal smooth muscle are present in the plasma membrane, in agreement with the postulated mode of action of dihydropyridines as inhibitors of plasmalemmal Ca channels

Influence of zero tillage on carabidae populations

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