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Biomedical subjects

K Kitajima

Publications and source records attributed to K Kitajima.

At least 235 records · Page 13Linked to original sources
PubMed1986

Multigranular exocytosis induced by phospholipase A2-activators, melittin and mastoparan, in rat anterior pituitary cells.

Effects of phospholipase A2-activators, melittin and mastoparan, on rat anterior pituitary cells were studied by use of the electron microscope. Rat anterior pituitaries were incubated in HEPES buffer containing 20 micrograms/ml of melittin or the same dose of mastoparan for 5 min, 10 min and 20 min. Features indicating discharge of granule contents by exocytosis were increased with time, and the simultaneous extrusion of a number of secretory granules, named "multigranular exocytosis", was often recognized in addition to single-granule exocytosis at 10 min and 20 min. Most membrane pits, where the multigranular exocytosis as well as the single-granule exocytosis occurred, were coated. Moreover, a large number of vesicles coated or non-coated were distributed near the trans side of the Golgi apparatus of melittin-treated or mastoparan-treated cells after 20 min. These vesicles might be related to membrane internalized from the excess surface membrane derived from the limiting membrane of exocytosed granules. These observations indicate that phospholipase A2-activators induce hormone release involving membrane fusion between limiting membranes of secretory granules, and between granule-limiting membrane and plasma membrane in rat anterior pituitary cells.

Animals↗
PubMed1986

A synthetic peptide vaccine involving the product of the pre-S(2) region of hepatitis B virus DNA: protective efficacy in chimpanzees.

The S gene encoding the major surface polypeptide of hepatitis B virus is preceded by the region pre-S(2) with a capacity to code for 55 amino acid residues. In the product of region pre-S(2), the sequence of 19 amino acid residues (amino acids 14-32 from the N terminus) representing an area of high local hydrophilicity is shared by viral strains of subtypes adr, ayw, and ayr; residue 22, phenylalanine, is replaced by leucine in a strain of the other subtype, adw. A synthetic peptide vaccine involving these 19 amino acid residues, when given to two chimpanzees, raised antibodies that bound to viral particles and protected the animals from challenge with 10(6) chimpanzee infectious doses of hepatitis B virus.

Animals↗
PubMed1986

Lack of detectable reverse transcriptase activity in human and chimpanzee sera with a high infectivity for non-A, non-B hepatitis.

A serum sample from a patient with hepatitis and samples from two experimentally infected chimpanzees, all with a high infectivity for non-A, non-B hepatitis, were tested for reverse transcriptase. Biopsy confirmed that the hepatocytes of the chimpanzees that received these sera contained the characteristic tubular structures associated with non-A, non-B hepatitis. None of these three sera revealed detectable enzyme activity. We have not been able to confirm the association of reverse transcriptase activity with non-A, non-B hepatitis reported recently.

Animals↗
PubMed1986

[A randomized control study of the antiemetic efficacy of betamethasone versus methylprednisolone].

A randomized control study of the antiemetic activity of betamethasone (B) vs. methylprednisolone (MP) was carried out. Fifty-six patients receiving CDDP (60 mg/m2-80 mg/m2) were entered. B (8 mg/body on day 1, 4 mg/body on days 2 and 3) was administered intravenously in 18 patients, and MP (1,000 mg/body on day 1, 500 mg/body on days 2 and 3) was administered intravenously in 19 patients. Severe vomiting occurred in 5 of the 19 (26.3%) with MP, 10 of the 18 (55.6%) with B, and 11 of 19 (57.9%) controls. Severe nausea occurred in 3 of the 19 (15.8%) with MP, 6 of the 18 (33.3%) with B, and 5 of the 19 (26.3%) controls. Methylprednisolone was thus considered effective (P less than 0.05) for CDDP-induced emesis.

Betamethasone↗
PubMed1985

Fine structural aspects of the shift of zonula occludens and cytoorganelles during the inversion of cell polarity in cultured porcine thyroid follicles.

Porcine thyroid follicles, when isolated by enzymatic digestion and suspended in Eagle's MEM containing 10% fetal calf serum, undergo inversion of cellular polarity. After isolation, the strands for the tight junctions (zonulae occludentes) between follicle cells begin to move towards the side of the medium and gather at this side of the lateral plasma membrane during 24 h of incubation. Around this time, microvilli of many follicular cells protrude into the culture-medium. The elements of the Golgi apparatus are located at the luminal as well as the culture-medium side of the cytoplasm, and also at the lateral side of the nucleus after 24 h of suspension culture, and by 94 h of incubation almost all elements of this organelle, as well as lysosomes and the central cilium have migrated to the side of the medium. The migration of the zonulae occludentes is considered to be the initial change in the reversal of the polarity of this cell.

Animals↗
PubMed1984

Transformation of ATLA-negative leukocytes by blood components from anti-ATLA-positive donors in vitro.

Anti-ATLA-positive blood components transformed healthy human leukocytes in vitro. Blood components examined were packed red cells, whole blood, platelet concentrate and fresh frozen plasma. Leukocytes present in anti-ATLA-positive blood components such as packed red cells, whole blood and platelet concentrate easily transformed anti-ATLA-negative leukocytes. Co-culture in fresh frozen plasma, however, did not transform recipient leukocytes, and leukocytes of anti-ATLA-positive recipients proved refractory to transformation. The transformed cells were morphologically lymphoid, grew in suspension, and possessed normal recipient karyotypes except in the case of three platelet concentrates. A high proportion of all the transformed populations formed E-rosettes with neuraminidase-treated sheep erythrocytes. The cytoplasm of over 90% of each recipient was stained brilliantly with antibodies against ATLV-determined antigens. Electron microscopy of these transformed cells revealed many C-type virus particles in the extracellular space. Blood components, such as packed red cells, whole blood and platelet concentrate, containing leukocytes from anti-ATLA-positive donors, should be used cautiously to prevent the transmission on ATLV to anti-ATLA-negative recipients.

Adult↗
PubMed1984

Novel oligosaccharide chains on polysialoglycoproteins isolated from rainbow trout eggs. A unique carbohydrate sequence with a sialidase-resistant sialyl group, DGa1NAc beta 1 leads to 4(NeuGc2 leads to 3)DGa1NAc.

A series of novel carbohydrate chains all possessing a hitherto unknown trisaccharide unit, Ga1NAc beta 1 leads to 4-(NeuGc2 leads to 3)Ga1NAc beta 1 leads to, have been isolated from trout egg polysialoglycoproteins, a new class of glycoproteins, on alkali-borohydride treatment. On the basis of chemical (methylation, Smith degradation, and hydrazinolysis-nitrous deamination) and direct-probe mass spectrometric methods. deamination) and direct-probe mass spectrometric methods, the structures of a series of the first major type of oligosaccharide alditols having a sialidase-resistant N-glycolyneuraminic acid residue in each molecule were determined. The structures thus determined are novel and all possess a unique carbohydrate sequence (sialidase-resistant unsubstituted sialyl group italicized): Ga1NAc beta 1 leads to 4(NeuGc2 leads to 3)Ga1NAc beta 1 leads to 3Gal beta 1 leads to-4Gal beta 1 leads to 3[(leads to 8NeuGc alpha 2)n leads to 6]Ga1NAcol (n = 0 through 3).

Animals↗
PubMed1984

Fish egg polysialoglycoproteins: circular dichroism and proton nuclear magnetic resonance studies of novel oligosaccharide units containing one sialidase-resistant N-glycolylneuraminic acid residue in each molecule.

Long-core units having the common sequence Ga1NAc beta 1 leads to 4(NeuGc2 leads to 3)Ga1NAc beta 1 leads to 3Gal beta 1 leads to 4Ga1 beta 1 leads to 3Ga1NAc are one of the major constituents of rainbow trout egg polysialoglycoproteins. The existing ambiguity regarding the anomeric configuration of the sialidase-resistant unsubstituted sialyl group present in this novel type of oligosaccharide chains has been resolved by a circular dichroism difference spectral method. The fact that the negative band originating from the carbohydrate n leads to pi transition for this sialyl group was observed offers conclusive proof of the alpha-anomeric configuration. Next particularly interesting is the fact that the chemical shifts of the sialidase-resistant sialyl H-3eq and H-3ax protons were respectively found at relatively higher and lower magnetic field than for the corresponding protons of other sialyl groups. A consideration of molecular models shows that the observed anomalies are all in the directions compatible with expectations on the basis of the magnetic anisotropy effect due to the carboxylate group and steric compression effects by van der Walls interactions between groups that are sterically compressed. In addition to the observed resistance to bacterial sialidases of this sialyl group, it did not behave even as a competitive inhibitor of the sialidase, Arthrobacter ureafaciens, indicating that inaccessibility of this unique sialyl group toward the enzyme. Finally, the analysis of the proton nuclear magnetic resonances of sialidase-sensitive mono- and oligosialyl groups present in the long-core units was based on comparisons of diagnostically important regions in the spectra of homologous oligosaccharides of N-glycolylneuraminic acid.

Animals↗
PubMed1984

Chromosome abnormalities of leukemia cells in adult patients with T-cell leukemia.

Chromosomes of 30 patients with adult T-cell leukemia were analyzed. Chromosome abnormalities were found in all the patients examined. The modal chromosome number of abnormal cells was hypodiploid in 2 patients, diploid in 14, and hyperdiploid in 9. The remaining 5 patients had bimodal chromosome numbers (diploid and hyperdiploid modes). Although all the patients showed various numerical or structural chromosome abnormalities, they also had common chromosome abnormalities. Aberrations of chromosome 1 were noted in 20 of the 30 patients, aberrations of chromosome 3 were seen in 20, trisomy 6 or 6q- was found in 17, aberrations of chromosome 10 were noted in 16, aberrations of the long arm of chromosome 14 were seen in 9, and trisomy 18 was seen in 7. There was no particular relationship between the difference in clinical symptoms and disparity in chromosome abnormalities.

Adult↗
PubMed1984

Beta-propiolactone for the inactivation of non-A/non-B type 1 hepatitis virus capable of inducing cytoplasmic tubular ultrastructures in chimpanzees.

Non-A/Non-B type 1 hepatitis virus may be recognized because it induces characteristic tubular ultrastructures in the hepatocyte cytoplasm of chimpanzees. 3 chimps received 0.1 ml of a chimp serum containing more than 100 chimp infecting units of non-A/non-B type 1 hepatitis virus after it had been treated with beta-propiolactone with or without combined ultraviolet irradiation. All of the chimps escaped infection throughout the observation period of 23 weeks. The treatment of the serum with beta-propiolactone at the mildest condition employed (0.05%, 4 degrees C, 20 min) was still effective in inactivating the virus. The susceptibility of the chimps was ascertained by the subsequent challenge with 0.1 ml of the untreated serum which invariably induced non-A/non-B type 1 hepatitis in them. On the basis of these results, beta-propiolactone was extremely efficacious for the cold sterilization of non-A/non-B type 1 hepatitis virus.

Animals↗
PubMed1984

Tumor-forming acute myeloid leukemia with facial paralysis.

A 55-year-old male with acute myeloid leukemia, which had been well controlled for 2 years, developed a sudden onset of facial palsy. Otologic examinations proved the right mastoid bone to be infiltrated by leukemic cells, which formed a nonchloroma to occlude the right external auditory canal. The precise site for the right facial paralysis by tumor formation was found in the intrastapedial region of peripheral portion of the right facial nerve. Regarding the tumor formation in myeloid leukemia, its frequency (particularly among Japanese subjects), complications (particularly in otologic field), possible pathogeneses, and treatments were discussed.

Audiometry↗