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T Kitamoto

Publications and source records attributed to T Kitamoto.

173 records · Page 10Linked to original sources
PubMed1986

Novel histochemical approaches to the prealbumin-related senile and familial forms of systemic amyloidosis.

The immunoperoxidase method, the autoclave method, and a newly developed alkaline-guanidine method were used to distinguish senile (SSA) and familial types (FAP) of prealbumin-related amyloidosis in formalin-fixed, paraffin-embedded tissue sections. Because all the amyloid deposits of SSA and FAP reacted positively with the antiprealbumin antiserum, a classification of the amyloid fibril proteins of FAP and SSA by immunohistochemistry, using polyclonal anti-prealbumin antisera, was not feasible. Both the senile and familial forms of amyloidosis showed unchanged Congophilia after prolonged autoclaving. In the alkaline-guanidine method, FAP amyloids were resistant to incubation for 2 hours. On the other hand, amyloid deposits of SSA lost the Congophilia and green birefringence with 2 hours' alkaline-guanidine treatment. Therefore, the autoclave method combined with the alkaline-guanidine method will considerably facilitate differentiation of SSA and FAP, without specific antisera.

Aged↗
PubMed1985

The quaternary structure and activity of newly purified fatty acid synthetase from the Harderian gland of guinea-pig.

Fatty acid synthetase was isolated from the Harderian gland of guinea-pig. The fatty acids synthesized by the purified enzyme were analyzed by mass fragmentography. The purified enzyme had an inherent capacity to utilize methylmalonyl-CoA and synthesize methyl-branched fatty acids. Physicochemical studies indicated that an active enzyme was a dimer, consisted of two subunits of Mr = 2.5 X 10(5). The negatively stained enzyme had an electron micrographic image of an ellipsoidal contour with a continuous middle cleft along the major axis. The major and minor axes were approximately equal to 220 and 150 A, respectively. In a dimer, the subunit had a rod-like structure about 220 A long and 50 A wide. The enzyme was inactivated and dissociated into subunits by incubation at 0 degree C. The inactivated enzyme was fully reactivated by raising the temperature of the solution. The relationship between the quaternary structure of the enzyme and the occurrence of enzymatic activity was studied by high-performance liquid chromatography. Neither active monomers nor inactive dimers were found in inactivation and reactivation processes. The initial velocity of reactivation was proportional to the enzyme concentration over a concentration range of 160-800 micrograms/ml, indicating that the rate-determining step in the reactivation reaction was unimolecular.

Amino Acids↗
PubMed1985

A new method to classify amyloid fibril proteins.

The permanganate method, the immunoperoxidase method, and a newly developed autoclave method were used to distinguish different types of amyloid fibril proteins in formalin-fixed, paraffin-embedded tissue sections. All tissues from permanganate-sensitive cases (AA type) lost the affinity of Congo red and green birefringence under polarized light after incubation with special autoclave treatment. AL type systemic amyloidosis and amyloid plaques of CJD and GSS were permanganate-resistant, but decreased markedly the affinity of Congo red after prolonged autoclaving. On the other hand, prealbumin type systemic amyloidosis and senile plaques of SDAT were resistant to both permanganate oxidation and prolonged autoclaving. Thus, amyloid plaques of CJD and GSS are identical to AL type in systemic amyloidosis, and senile plaques are similar to the prealbumin type. However, anti-prealbumin antiserum did not stain senile plaque amyloid. The anti-human P component stained positively systemic amyloids and cerebral amyloid plaques of SSE, but failed to stain senile plaques of SDAT. Therefore, the amyloid fibril protein of senile plaques is apparently different from other types of amyloid depositions. Amyloid plaques of SSE are different from senile plaques not only with regard to fibril proteins, but also to globular protein in the amyloid.

Adolescent↗
PubMed1983

Alpha-2-macroglobulin-like protease inhibitor from the egg white of cuban crocodile (Crocodylus rhombifer).

A high molecular weight protease inhibitor was purified from the egg white of Cuban crocodile (Crocodylus rhombifer). It inhibited the casein hydrolyzing activity of trypsin, subtilisin and papain. Its native molecular weight was 730,000 and it consisted of four subunits of equal molecular weight, each pair of which were disulfide bonded. The amino acid composition, circular dichroic spectrum and electron micrographs of this protein are also presented. Upon incubation with trypsin this protein yielded a fragment of Mr = 80,000, similar in size to the one known to originate from alpha 2-macroglobulin under the same conditions. The molecular parameters of this protein and the broad inhibitory activity towards thiol and serine proteases with different substrate specificities suggest that it is a protein closely related to alpha 2-macroglobulin in mammalian serum. From its native molecular weight and amino acid composition we believe that this protein is also a reptilian counterpart of the avian ovomacroglobulin described by Miller and Feeney (3).

Alligators and Crocodiles↗
PubMed1982

Hen egg white ovomacroglobulin has a protease inhibitory activity.

Hen egg white ovomacroglobulin purified by Miller and Feeney without reference to its activity was shown to have a protease inhibitory activity towards trypsin, papain, and thermolysin. It has four subunits of equal molecular weight (175,000 by SDS-PAGE) and each two of which are disulfide bonded. Upon incubation with trypsin it yields a fragment of Mr = 80,000 plus smaller ones. The subunit composition, amino acid composition and a newly found protease inhibitory activity place ovomacroglobulin as a closely related protein to human serum alpha 2-macroglobulin.

Amino Acids↗
PubMedDate not supplied

Thyrotropin releasing hormone (TRH)-induced release of 7B2 (neuroendocrine polypeptide) in vivo and in vitro using adenoma cells of a patient with acromegaly.

We demonstrated TRH-induced release of 7B2 (a neuroendocrine polypeptide) in vivo and in vitro (somatotroph adenoma cells) in a patient with acromegaly. The mean basal plasma 7B2 and growth hormone (GH) levels before operation were 142.8 +/- 3.2 ng/l and 52.4 +/- 1.6 micrograms/l (mean +/- SEM), respectively and these levels significantly rose after an i.v. administration of 500 micrograms of thyrotropin releasing hormone (TRH). After the transsphenoidal adenomectomy, the basal level of plasma GH was restored to the normal level and that of plasma 7B2 was slightly decreased. In addition, TRH-induced response of plasma 7B2 and GH disappeared post-operatively. In a primary culture of somatotroph adenoma cells obtained at surgery, TRH significantly induced secretions of both 7B2 and GH. Immunohistochemical studies showed the positive 7B2 and GH immunoreactivities in somatotroph adenoma cells. These findings strongly suggest that the somatotroph adenoma cells in this case produced and released 7B2 concomitant with GH.

Acromegaly↗
PubMedDate not supplied

Immunhistological evaluation of Creutzfeldt-Jakob disease with reference to the type PrPres deposition.

German patients suspected of having Creutzfeldt-Jakob disease (CJD) and related diseases were studied pathologically. The immunohistochemical findings after hydrolytic autoclaving pretreatment sensitively detected the synaptic-type deposition of the protease-resistant isoform of the prion protein (PrPres which thus served to establish the consensus diagnosis of CJD.

Aged↗