Factors controlling accumulation and decomposition of organic carbon in humus horizons of Andosols

Andosols often accumulate soil organic matter (SOM) in large amounts. To investigate the factors controlling the stability and lability of organic carbon (OC) in humus horizons of Andosols, we selected 19 A horizon samples (surface and subsurface horizons) from the Field Station of Tohoku University including areas where benchmark soil profiles of non-allophanic Andosols are distributed. We determined the soil properties possibly controlling the OC accumulation, such as pH(H₂O), 1 M KCl-extractable aluminum (KCl-Al), pyrophosphate-extractable Al and iron (Al_p, Fe_p), acid oxalate-extractable silicon (Si_o), total OC, water-extractable OC, and humified OC. To evaluate the OC mineralization, we measured the soil respiration rates in a laboratory for non-treated, neutralized (CaCO₃, Ca(OH)₂ and NaOH), and nutrient applied (KH₂PO₄, (NH₄)₂SO₄) soil samples. Statistical analyses, including a path analysis, showed that the Al_p and pH(H₂O) values are directly related to the OC concentration (P?<?0.01 and P?<?0.05, respectively). There was a significant negative correlation (P?<?0.01) between the soil respiration rates of the non-treated samples and the ratios of the humified OC to total OC, showing that the humification of the SOM was definitely related to the OC stability. Effects of the chemical treatments to the soil respiration rates were greater in the surface horizon samples with an abundant labile OC than those in the subsurface samples. Neutralization affected the soil respiration rates more significantly than the nutrient application. Among the neutralization treatments, the liming materials more effectively increased the respiration rates. This was probably due to an increase in the lability of the humified OC by liming.     

Microorganisms in tile forest soils with different vegetation

Characteristic microfloras have been found to exist corresponding to the soil types. In cultivated soil, corynebacteria have been shown to be one of the dominant groups, and In grassland soil has been characterized by pseudomonads (1–3). In contrast, pine forest soil has been shown to contain Bacillus as a dominant genus (4).     

Significance of hydrous iron oxides in enhancing P sorption of soils with the addition of sodium hydrosulfite (Na2S2O4)

Phosphorus sorption (P_sor) of soils is affected by redox conditions. It has been shown that P_sor of lowland soils at a pH value of about 4.3 increases when a small amount of sodium hydrosulfite (Na₂S₂O₄) is added and decreases when an excess amount of (Na₂S₂O₄) is added to the mixture of a soil and P solution. Hydrous Fe-Al oxides, manganese dioxide (MnO₂) exchangeable Ca, models of reactive components with P in soils, were examined to identify the factors responsible for the increase of P_sor in lowland soils when a small amount of Na₂S₂O₄ was added. For clarifying the contribution of the hydrous Fe-Al oxides, goethite and 7 hydrous Fe-Al oxides (Fe/Al atomic ratio: 1/0, 5/1, 2/1, 1/1, 1/2, 1/5, and 0/1) were used. The P_sor of all these materials increased when they were treated with a small amount of Na₂S₂O₄ although the increase was the smallest for the hydrous Al oxide among the 7 oxides. Thus, the hydrous Fe oxides, and Al oxide to a smaller extent, play an important role in the increase in P_sor of the lowland soils treated with a small amount of Na₂S₂O₄ The P_sor of the hydrous Fe oxides was not appreciably affected by the addition of MnO₂. The increase in P_sor of the Ca-saturated Hachirogata soil was almost the same as that of the Nasaturated Hachirogata soil, indicating that exchangeable Ca did not affect appreciably the increase of P_sor in reduced soils at a pH value of about 4.3.     

Long‐term outcome in dogs undergoing mitral valve repair with suture annuloplasty and chordae tendinae replacement

Mitral valve repair under cardiopulmonary bypass was performed in three dogs with clinical signs associated with mitral regurgitation that were not controlled by medication. Mitral valve repair comprised circumferential annuloplasty and chordal replacement with expanded polytetrafluoroethylene. One dog died 2 years after surgery because of severe mitral regurgitation resulting from partial circumferential suture detachment. The others survived for over 5 years, but mild mitral valve stenosis persisted in one. The replaced chordae did not rupture in any dog. Mitral valve repair appears to be an effective treatment for mitral regurgitation in dogs. Chordal replacement with expanded polytetrafluoroethylene is a feasible technique, demonstrating long‐term durability in dogs. However, mitral annuloplasty techniques need improvement.     

Expression of Membrane Complement Regulatory Proteins Crry and CD55 in Normal Rats

Some anticancer therapeutic antibodies are designed to act through complement-dependent cytotoxicity (CDC). It has been reported that there are many membrane complement regulatory proteins (mCRPs) that inhibit CDC. In the present study, we examined the expression of two mCRPs, the complement receptor 1-related gene/protein Y (Crry) and the decay-accelerating factor CD55, in three normal rats by immunohistochemistry. Crry and CD55 were detected widely in rat organs and tissues. Crry was found mainly in the urinary, digestive, respiratory, immunohematopoietic, circulatory and neuroendocrine systems. CD55 was found in the urinary, digestive and neuroendocrine systems. However, the two molecules were expressed in separate cells within the same organ. These results suggest that the distribution of mCRPs is related to the strict regulation of CDC activation in these organs and tissues and that the two molecules have a nonoverlapping expression pattern, a fact indicating specific roles in CDC regulation.     

Hematological and Biochemical Reference Values for the Endangered Kiso Horse

To establish blood and biochemical references for the endangered Kiso horse, blood samples were collected from 111 adult Kiso horses, 74.5% of the existing breed. The samples were analyzed for 23 hematological and biochemical parameters to determine their means and standard deviations (SD). We compared the mean ± 2SD with the reference values cited in one of the most commonly used veterinary textbooks in Japan. The hematology of Kiso horses is characterized by lower erythrocyte count and hematocrit and hemoglobin levels. In addition, their serum biochemistry showed lower levels of aspartate transaminase, alkaline phosphatase, and γ-glutamyl transferase. Whether these propensities are attributed to breed-specific factors or are acquired factors remains unclear. Nevertheless, this study provides useful diagnostic indices for the endangered Kiso horse.     

The effects of the loop diuretics furosemide and torasemide on diuresis in dogs and cats

Torasemide is a new loop diuretic that combines the effects of furosemide and spironolactone. There are no reports on the effects of torasemide in cats and dogs. This study compared the diuretic effects of furosemide and torasemide in cats and dogs. Cats with pressure overload cardiac hypertrophy were given oral placebo, torasemide 0.3 mg/kg, or furosemide 1 mg/kg or 3 mg/kg. Control and mitral regurgitation dogs were given oral placebo, torasemide 0.2 mg/kg, and furosemide 2 mg/kg for 7 days. Urine samples were obtained at baseline and 1, 2, 3, 4, 5, 6, 8, 12, and 24 hr after each drug dose. Urine volume and urine Na(+) and K(+) were measured. Both furosemide and torasemide increased urine volume 1 hr after administration. Furosemide caused a dose-dependent increase in urine volume that peaked at 2-3 hr in cats and dogs. The diuretic effect of furosemide disappeared 6 hr after administration, while that of torasemide peaked 2-4 hr after administration and persisted for 12 hr in cats and dogs. In MR dogs, torasemide for 7 days significantly decreased urine potassium excretion. Plasma aldosterone increased with torasemide, whereas there was no change with furosemide. In conclusion, about 1/10 concentration of torasemide was as potent as furosemide and had a longer diuretic effect in cats and dogs. These data suggest that torasemide is useful for treating congestive heart failure or edema in cats and dogs.     

Effects of Lepidium meyenii Walp and Jatropha macrantha on blood levels of estradiol-17 beta, progesterone, testosterone and the rate of embryo implantation in mice

The effects of two Peruvian folk medicines, Lepidium meyenii Walp and Jatropha macrantha, on mouse sex steroid hormones and embryo implantation were investigated. Progesterone levels increased significantly in mice that received L. meyenii Walp, while testosterone levels increased significantly in mice that received L. meyenii Walp as well as in those that received both L. meyenii Walp and J. macrantha. However, there were no marked changes in blood levels of estradiol-17beta or the rate of embryo implantation.     

Analysis of genetic variations in the exon 27 region of the canine BRCA2 locus

Mammary tumors are the most common tumor type in women as well as in female dogs. The BRCA2 gene encodes a large nuclear protein that is involved in DNA repair, and mutations in the human BRCA2 confer an increased risk of female mammary tumors. The BRCA2 protein acts as a tumor suppressor, and inactivation of BRCA2 by loss of heterozygosity is implicated in mammary carcinogenesis. In this study, to establish an appropriate polymorphic marker for loss of heterozygosity analysis of the canine BRCA2, we analyzed the genomic sequences of the exon 27 regions of 30 mammary-tumor-bearing and 21 tumor-free dogs. In addition to 10204ins/delAAA, which is the only polymorphism previously identified for the canine BRCA2 locus, we discovered four novel single nucleotide polymorphisms. The analysis of these five polymorphisms revealed the presence of four allele types. Since 10204ins/delAAA was the most common of the five polymorphisms identified, we developed a PCR-based assay method to assay for this polymorphism. We believe that this method is valuable for loss of heterozygosity analysis of the canine BRCA2 gene in tumor pathogenesis.     

Primary and secondary structures of grammistins, peptide toxins isolated from the skin secretion of the soapfish Pogonoperca punctata

SUMMARY: Six peptides (grammistins Pp 1, 2a, 2b, 3, 4a and 4b) with both hemolytic and ichthyotoxic activities were isolated from the skin secretion of the soapfish Pogonoperca punctata by gel filtration and reverse-phase high performance liquid chromatography. They were completely sequenced and found to be simple peptides differing from the previous suggestion that they are peculiar peptides with tertiary amine or quaternary ammonium base moieties. Grammistins Pp 1, 2a and 2b were composed of 13 residues, Pp 3 of 25 residues and Pp 4a and 4b of 24 residues. While grammistins Pp 4a and 4b were identical and highly homologous with grammistin Gs 2 previously isolated from another soapfish Grammistes sexlineatus , the other grammistins did not have homologies with any proteinic or peptidic toxins known to date. Judging from circular dichroism data, helical wheel projections and hydrophobic moment plots, all the isolated grammistins are surface-seeking peptides with an abundance in amphiphilic α-helicity, similar to pardaxins from the skin secretion of two species of soles and melittin from bee venom as well as the G. sexlineatus grammistins.