Phosphorylation of ovalbumin by dry-heating in the presence of pyrophosphate: effect on protein structure and some properties

Ovalbumin (OVA) was phosphorylated by dry-heating in the presence of pyrophosphate at pH 4.0 and 85 degrees C for 1 and 5 days, and the physicochemical and structural properties of phosphorylated OVA were investigated. The phosphorus content of OVA increased to 1.01% by phosphorylation, and the electrophoretic mobility of PP-OVA also increased. Although the solubility of dry-heated OVA decreased, the decrease was slightly depressed by phosphorylation. The circular dichroism spectra showed that the change of the secondary structure in the OVA molecule, as measured by alpha-helix content, was mild by phosphorylation. The exchange reaction between the sulfhydryl and disulfide groups was enhanced and the surface hydrophobicity of OVA increased by phosphorylation. The tryptophan fluorescence intensity of OVA decreased by phosphorylation, suggesting that the conformational change occurred in the OVA molecule by phosphorylation. Although the differential scanning calorimetry thermograms of OVA showed a lowering of the denaturation temperature from 78.3 to 70.1 degrees C by phosphorylation, the stability of OVA against heat-induced insolubility at pH 7.0 was improved. The results indicated molten (partially unfolded) conformations of OVA formed by dry-heating in the presence of pyrophosphate.     

Determination of inorganic tin in biological samples by hydride generation-atomic absorption spectrometry after silica gel cleanup

A method is described for the determination of inorganic tin in biological samples by hydride generation-atomic absorption spectrometry (HG-AAS). A sample is extracted with ethyl acetate after addition of HCl and NaCl. The concentrated extract is passed through a silica gel column. The column is washed with ethanol, water, and 0.2N HCl successively, and then inorganic tin is eluted with 2N HCl and measured by HG-AAS. Recoveries from fish muscle spiked with 0.1 micrograms/g Sn4+ are 78.9 +/- 4.2% (average +/- standard deviation, n = 5). The detection limit is 0.01 micrograms/g as Sn.     

The effect of magmatic activity on hydrothermal venting along the superfast-spreading East pacific rise

A survey of hydrothermal activity along the superfast-spreading (approximately 150 millimeters per year) East Pacific Rise shows that hydrothermal plumes overlay approximately 60 percent of the ridge crest between 13 degrees 50' and 18 degrees 40'S, a plume abundance nearly twice that known from any other rige portion of comparable length. Plumes were most abundant where the axial cross section is inflated and an axial magma chamber is present. Plumes with high ratios of volatile ((3)He, CH(4), and H(2)S) to nonvolatile (Mn and Fe) species marked where hydrothermal circulation has been perturbed by recent magmatic activity. The high proportion of volatile-rich plumes observed implies that such episodes are more frequent here than on slower spreading ridges.     

Comparison of two alkaline treatments in the extraction of organic compounds associated with water repellency in soil under Pinus taeda

Isopropanol:NH₃ and Methanol:KOH (saponification) alkaline treatments are usually applied in the study of soil organic matter. The first is used in studies of soil water repellency, and the latter in the extraction of ester-bound lipids from soil. In this study, isopropanol:NH₃ and methanol:KOH treatments were applied separately in a solvent extracted repellent soil, in order to compare their efficiency in the extraction of water repellent compounds. The soil sample was taken from a site under a 16 year old Pinus taeda stand. The amount and class of organic compounds released by each treatment were compared using gas chromatography-mass spectrometry (GC-MS). Both treatments resulted in wettable soil after alkaline extraction. In general, alkaline treatments yielded extracts with the same class of organic compounds. Alkanoic acids, α,ω-alkanedioic acids, hydroxyalkanoic acids, aromatic compounds, and alkanols were identified, indicating the preservation of suberin and cutin biopolyester in the soil. Large differences were observed in the amounts of ω-hydroxyalkanoic acids, as well as in the quantity and distribution of dihydroxyalkanoic and trihydroxyalkanoic acids. In contrast to methanol:KOH, isopropanol:NH₃ was not efficient in the extraction of whole aliphatic biopolyesters, mainly pine cutin-related products. Methanol:KOH was more effective in hydrolysis. The presence of biopolyesters in water repellent soil under the P. taeda stand seems to play an important role in water repellency.     

IMAGING DIAGNOSIS—ECTOPIC SPLEEN MIMICKING HEPATIC TUMOR WITH INTRA‐ABDOMINAL METASTASES INVESTIGATED VIA TRIPLE‐PHASE HELICAL COMPUTED TOMOGRAPHY IN A DOG

A 10‐year‐old castrated male miniature dachshund was presented with an abdominal mass. The dog had a history of splenectomy. Triple‐phase helical computed tomography was utilized, revealing a hepatic mass and multiple intra‐abdominal solid masses. In triple‐phase helical computed tomography the images, hepatic mass and two of four intra‐abdominal masses were heterogenous in all phases. Therefore, we diagnosed a malignant hepatic tumor and presumed intra‐abdominal metastases. The masses were surgically removed and were histologically composed of normal spleen tissues, findings which were consistent with ectopic spleen.