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T Nagata

Publications and source records attributed to T Nagata.

728 records · Page 41Linked to original sources
PubMedDate not supplied

Determination of ampicillin residues in fish tissues by liquid chromatography.

A liquid chromatographic (LC) method is described for determination of ampicillin residues in fish tissues. The drug is extracted from tissues with methanol, and the extract is evaporated to dryness. This residue is cleaned up by Florisil cartridge chromatography. LC analysis is carried out on a Nucleosil C18 column, and ampicillin is quantitated by ultraviolet detection at 222 nm. Recoveries of ampicillin added to tissues at levels of 0.2 and 0.1 ppm were 73.2 and 61.5%, respectively. The detection limit was 3 ng for ampicillin standard, and 0.03 ppm in tissues.

Ampicillin↗
PubMedDate not supplied

Liquid chromatographic determination of spiramycin residues in chicken tissues.

A liquid chromatographic (LC) method is described for determination of spiramycin residues in chicken muscles. The drug is extracted from muscles with acetonitrile, the extract is concentrated to 3-4 mL and rinsed with n-hexane followed by ethyl ether, and the drug is extracted with chloroform. LC analysis is carried out on a Zorbax BP-C8 column, and spiramycin is detected spectrophotometrically at 231 nm. Recoveries of spiramycin added to chicken muscles at 0.2 and 0.1 ppm were 93.9 and 89.0%, respectively. The detection limit was 5 ng for spiramycin standard, and 0.05 ppm in chicken muscles.

Animals↗
PubMedDate not supplied

Liquid chromatographic determination of amprolium in chicken tissues, using post-column reaction and fluorometric detection.

A method is presented for determination of amprolium residues in chicken muscles by a liquid chromatographic post-column reaction system. The drug is extracted from muscles with methanol, and the extract is concentrated to 3-4 mL. This aqueous solution is rinsed with n-hexane and cleaned up by alumina column chromatography. The drug is separated from the interferences on a LiChrosorb RP-8 column, reacted with ferricyanide in alkaline solution, and quantitated by fluorometric detection at 367 nm (excitation) and 470 nm (emission). Recoveries of amprolium added to chicken muscles at levels of 0.1 and 0.2 ppm were 74.9 and 80.9%, respectively. The detection limit was 1 ng for amprolium standard and 0.01 ppm in chicken muscles.

Amprolium↗
PubMedDate not supplied

Sensitive determination of ethopabate residues in chicken tissues by liquid chromatography with fluorometric detection.

A liquid chromatographic (LC) method is described for determination of ethopabate residues in chicken tissues. The drug is extracted from tissues with acetonitrile, and the extract is concentrated to 2-3 mL. This aqueous solution is rinsed with ethyl acetate and cleaned up by Florisil column chromatography. LC analysis is carried out on a Zorbax ODS column, and ethopabate is quantitated by using a fluorometric detector set at 306 nm (excitation) and 350 nm (emission). Recoveries of ethopabate added to chicken tissues at levels of 0.01 and 0.05 ppm were 87.8 and 92.7%, respectively. The detection limit was 100 pg for ethopabate standard, and 0.5 ppb in chicken tissues.

Aminobenzoates↗
PubMedDate not supplied

Predictive factors for efficacy of interferon therapy in chronic hepatitis type C.

BACKGROUND/AIMS: It has recently become possible to quantify HCV-RNA in serum and to analyze the HCV-RNA genotype. In this study, we investigated the relationship among the response to interferon therapy, the HCV-RNA concentration, genotype and histological findings of the liver. PATIENTS AND METHODS: Sixty-three patients with chronic hepatitis type C received interferon alfa therapy for 24 weeks. The HCV-RNA concentration in serum was measured semiquantitatively with reverse transcript semi-nested polymerase chain reaction and classified as negative to +3. HCV-RNA genotype was analyzed using a mixture of four type specific primers. RESULTS: HCV-RNA concentration was significantly higher in patients with genotype II and CAH2B than genotype III, CPH and CAH2A (p < 0.05). At 24 weeks after the end of interferon therapy, HCV-RNA in serum disappeared in 24 of 63 patients (38%). Strong resistance to the therapy was noted in patients with both genotype II and a high concentration of HCV-RNA in serum (the efficacy was only 7%). Therapy efficacy decreased with the severity of liver histological findings, reaching only 20% in those with CAH2B. CONCLUSION: Both the concentration and genotype of HCV-RNA seem to be important factors in determining the efficacy of interferon therapy.

Adult↗
PubMedDate not supplied

Development of mouse submandibular gland studied by field emission scanning electron microscopy.

The ultrastructural organization of mouse submandibular gland from 15 days gestation to 180 days of age was studied by field emission scanning electron microscopy. At 15 days of gestation several groups of acini, intercalated and striated ducts were present. They consisted of numerous pyramidal and/or polyhedral cells with spherical or elongated nuclei and short microvilli. At 3 days after birth different shapes of acinar structures covered by a network of fine collagen bundles were observed. The acinar portions corresponded to the terminal tubules and showed the acinar cells containing immature secretory granules. Fractured specimens of ducts revealed a flat surface with large central nuclei. At 14 days after birth acinar terminal portions possessed a round shape; branches of either intercalated and striated ducts were also observed. Gap junctions and interdigitations were numerous at the base of acinar cells. At 30 days after birth the acinar terminal portions and striated ducts revealed a large number of secretory granules. Acinar cells showed a pyramidal shape and basal nuclei. Freeze-cracked surfaces of the striated ductal cells evidenced also a pyramidal shape. Secretory granules ranged from 0.3 to 1.2 microns in size and were clearly observed by infoldings of the basement membranes. At 90 days after birth the ultrastructural features were more differentiated when compared with the previous ages. The freeze-cracked specimens showed very numerous secretory granules in all acinar and striated ductal cells. The granules occupied almost all the apical region of the cells. The outer surface of the basement membrane of acinar and myoepithelial cells was constituted by a spongy-like material covered by fine collagen fibrils. At 180 days after birth numerous secretory granules were seen either in acinar and ductal cells. A morphofunctional polarization of the cell was finally clearly observed in that the cytoplasmic organelles were concentrated in the basal portion whereas the secretory granules were located in the apical region of the cells.

Animals↗