Biomedical subjects

K Onizuka

Publications and source records attributed to K Onizuka.

At least 37 records · Page 2Linked to original sources

PubMed1994

Neuronal damage following transient cerebral ischemia and its restoration by neural transplant.

The middle cerebral artery (mca) was intraluminally occluded for one hour prior to reperfusion in the rat. Neuronal damage as well as motor imbalance were assessed in both acute and chronic stages with or without neural transplant in the striatum. In acute stage, argyrophil III staining demonstrated "collapsed" dark neurons in the ipsilateral striatum, cortex, reticular thalamus, amygdala and sometimes in the hippocampus. They had shrunken somata and corkscrew-like dendrites. In accordance with the appearance of dark neurons, the immunoreactivity for calpain of endogenous inactive form decreased or disappeared in ischemic areas. In chronic stage, ischemic core area (striatum and cortex) got into porencephaly, and animals made rotations following methamphetamine injection. Neural transplant (fetal striatal cells) was made during 2 to 4 weeks after the ischemia. Once the transplant survived and grew in the striatum, the methamphetamine rotations were attenuated. Using mca ischemic model rats we report here pathophysiological processes that lead to neuronal damage and infarct. Neural transplants into these animals brought partial restoration in motor disturbance, offering a valuable information concerning therapeutic possibility.

Animals↗

PubMed1993

A multi-level description scheme of protein conformation.

We propose a novel description scheme of protein backbone conformation that can model the important factors of protein structure formation, such as global interaction and geometric constraints. This description scheme represents a protein conformation with several symbolic sequences of multiple levels of abstraction. Each symbol in the sequence denotes the class of abstracted topology of subconformation with the size specific to the level. Low level sequences of this description represent fine structures of high resolution, and high level sequences represent the abstracted topologies of large scale. The classification of protein backbone subconformations of various sizes is the most important base for this description scheme. This has never been tried so far due to the complexity in dealing with the number of degrees of freedom in subconformations. However, the proposed technique solved this problem by abstracting the topology of middle and large scale subconformations. This linear expansion technique extracts a fixed number of parameters as the expansion coefficients from the co-ordinate representation of subconformations. In this case, the simple reverse-transformation from the expansion coefficients reconstructs the three-dimensional topology of a subconformation. The analysis of the relation between primary structure of a region and the subconformation of that region at each level in this description helps to model both local and global interactions of protein structure formation. Further, the statistic analysis of overlapping patterns of two subconformations models the geometric constraints important for a structure prediction system in generating a conformation which is geometrically sound.

Amino Acid Sequence↗

PubMed1990

Unilateral VATER association.

We describe a case of unilateral "VATER association." In addition to the VATER manifestations, the patient had hemihypoplasia, unilateral congenital paralysis of a leg, and delayed ossification of the femoral head and carpal bones. All of the manifestations involved the left side of the body. The only drug exposure identified was a Chinese herbal medicine taken by the mother during early pregnancy.

Abnormalities, Multiple↗

PubMed1990

[Biosynthesis and significance of acute phase proteins].

Acute phase proteins (APP) increase by the chemical receptors of macrophage via stimulations of either Fc or complement or other chemical receptors. No differences of APP pattern were observed by the different stimulants, because the effects of stimulation are changed by many processing steps in the macrophage as well as in the liver cell thereafter. Whether the APP increase results in good prognosis for original sickness or not are examined by multiple regression analysis in 38 cases of maxillary and 51 cases of laryngeal cancer with the observation for over five years. Alpha 1X contributes positively with length of their life, whereas alpha 1AG and ceruloplasmin contribute negatively. We could say that not all components of APP increase are advantageous for the diseases.

Acute-Phase Proteins↗

PubMed1987