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Biomedical subjects

Y Kawata

Publications and source records attributed to Y Kawata.

At least 145 records · Page 8Linked to original sources
PubMed1988

Low molecular weight RNA of Drosophila cells which is induced by heat shock--II. Structural properties.

Heat shock-induced small cytoplasmic RNA (HSI scRNA) from Drosophila culture cell was larger in size after dimethylchloroacetal treatment than in 7 M urea. Judging from its thermal denaturation profile and the nuclease S1 digestion experiment it was supposed that HSI scRNA is double-stranded. Nucleotide sequence analysis of the scRNA also suggested that it is double-stranded RNA with the blunt-ends.

Animals↗
PubMed1987

Unfolding and refolding of a type kappa immunoglobulin light chain and its variable and constant fragments.

By limited proteolysis of a type kappa immunoglobulin light chain (Oku) with clostripain, both the VL and CL fragments were obtained with a high yield. The unfolding and refolding by guanidine hydrochloride of light chain Oku and its VL and CL fragments were studied at pH 7.5 and 25 degrees C with circular dichroism and tryptophyl fluorescence. The concentration of guanidine hydrochloride at the midpoint of the unfolding curve was 1.2 M for the VL fragment and 0.9 M for the CL fragment. As in the case of the CL fragment of light chain Nag (type lambda) [Goto, Y., & Hamaguchi, K. (1982) J. Mol. Biol. 156, 891-910], the unfolding and refolding kinetics of the CL fragment could be explained in principle on the basis of the three-species mechanism U1 in equilibrium U2 in equilibrium N, where N is native protein and U1 and U2 are the slow-folding and fast-folding species, respectively, of unfolded protein. The unfolding and refolding kinetics of the VL(Oku) fragment were described by a single exponential term. Double-jump experiments, however, showed that two forms of the unfolding molecule exist. The equilibrium and kinetics of unfolding of light chain Oku were explained by the sum of those of the VL and CL fragments. On the other hand, the refolding kinetics of light chain Oku were greatly different from the sum of those of the VL and CL fragments.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1987

Conformation of the constant fragment of the immunoglobulin light chain: effect of cleavage of the polypeptide chain and the disulfide bond.

In order to understand the conformations and stabilities of the immunoglobulin domains, a derivative of the type-lambda constant fragment in which the peptide bond Arg190-Ser191 is cleaved and a derivative of the type-kappa constant fragment in which the peptide bond Arg142-Glu143 is cleaved were prepared by limited proteolysis with the proteinase from mouse submaxillary gland, endoproteinase Arg-C [EC 3.4.21.40]. The cleaved peptide bond of each derivative is located in the loop formed by the intrachain disulfide bond and the two peptides formed are linked by the disulfide bond. The two nicked CL fragments did not assume any ordered conformation. On the other hand, a derivative in which the intrachain disulfide bond is reduced had a conformation very similar to that of the intact CL fragment, although the stability was considerably low. Since the entropy of the nicked fragment should be nearly the same as that of the reduced CL fragment in the unfolded state, a destabilizing effect of cleavage of the polypeptide bond in the folded state in addition to the entropic effect in the unfolded state seems necessary to account for the conformations of the nicked CL fragments.

Ammonium Sulfate↗
PubMed1986

[Clinical study of chemotherapy (PPM therapy) with cisplatin, peplomycin and mitomycin C in squamous cell lung cancer].

The effect of PPM therapy, consisting of cisplatin, peplomycin and mitomycin C, was evaluated in 15 cases of squamous cell lung cancer. Ten partial responses were achieved in primary cases and the response rate was 66.7%. Nephrotoxicity was well controlled with a continuous infused drip and FOM. The nausea and vomiting were reasonably well controlled with methylprednisolone and metoclopramide. Severe interstitial pneumonitis occurred in 5 cases (33.3%). PPM therapy is considered to be a very useful combination chemotherapy for squamous cell lung cancer but careful attention must be paid to pulmonary toxicity.

Aged↗
PubMed1985

Exposed tyrosine residues of lambda cro repressor protein evidenced by nitration and photo CIDNP experiments.

The tyrosine residues of lambda cro repressor were partially nitrated with tetranitromethane under mild conditions. After digestion by Achromobacter protease I, the extent of nitration was determined by HPLC and amino acid analysis. Tyr 26 was most easily nitrated and Tyr 51 followed it. Tyr 10 was resistant to nitration. By comparison of the proton magnetic resonance spectrum of the partially nitrated cro protein with the above result, the aromatic proton resonances of the tyrosine side chains could be assigned to individual tyrosine residues. The extent of nitration is parallel to the accessibility to a flavin dye as measured by photo CIDNP (chemically induced dynamic nuclear polarization).

Amino Acids↗
PubMed1985

Computed tomography of cerebral infarction along the distribution of the basal perforating arteries. Part I: Striate arterial group.

Computed tomographic (CT) manifestations of cerebral infarction along the distribution of the basal perforating arteries were reviewed in correlation with cerebral angiography. Infarcts in the territories of perforators were demonstrated individually based on knowledge of their three-dimensional distribution as demonstrated by microangiography of cadavers. In Part I of the study, the areas supplied by the medial (MSA) and lateral striate arteries (LSA) were examined. Infarction along the branches of the MSA usually involved the antero-inferior portion of the corpus striatum, immediately posterolateral to the most inferior part of the frontal horn of the lateral ventricle. Infarcts along the branches of the LSA abutted the territory of the MSA posteriorly and superiorly and involved the posterolateral region of the corpus striatum. Clinical and neuroradiological correlations are discussed.

Cadaver↗
PubMed1985

Computed tomography of cerebral infarction along the distribution of the basal perforating arteries. Part II: Thalamic arterial group.

Computed tomographic (CT) manifestations of cerebral infarction along the distribution of the basal perforating arteries were reviewed and correlated with cerebral angiography. Infarcts in the territories of perforators were demonstrated individually based on knowledge of their three-dimensional distribution as shown by microangiography of cadavers. In Part II of the study, the posterior areas supplied by the thalamic arteries were examined. Infarcts in the area supplied by the thalamotuberal arteries involved the anterior pole of the thalamus; those in the area of the thalamoperforate arteries involved the medial portion of the thalamus, along the lateral wall of the third ventricle; those in the area of the thalamogeniculate arteries involved the posterolateral portion of the thalamus; and those in the area of the choroidal arteries of the lateral ventricle involved the most posterolateral and dorsolateral portions of the thalamus. Clinical and neuroradiological correlations are discussed.

Arteries↗
PubMed1985

[Squamous cell carcinoma of the frontal sinus caused osteomyelitis of the frontal bone].

A case of the squamous cell carcinoma of the frontal sinus complicated with osteomyelitis of the frontal bone was reported. A 47-year-old male was admitted to Asahikawa Medical College Hospital because of a bulging of forehead and remittent fever of a six-month history and general convulsive seizures on the day before admission. On physical examination, a bulging of forehead with redness, tenderness and fluctuation was noted. Sense of smell diminished bilaterally. Oto-laryngological examination disclosed paranasal sinusitis. Skull X-P and CT scan suggested osteomyelitis of the frontal bone secondary to frontal sinusitis. However, a frontal sinus tumor with osteomyelitis was also possible. Operation was performed and a granulomatous mass attached to the dura with thick epidural abscess was noted. The mass and affected bone edge were removed. Pathological examination of the specimens disclosed findings of squamous cell carcinoma and osteomyelitis. Recurrence of the tumor rapidly occurred and reoperation was performed a month after the first operation. Postoperative irradiation and chemotherapy with pepleomycin were done but failed to control the growth and recurrence occurred immediately. The tumor penetrated the skin of the forehead and the patient died of cachexy 7 months after the first surgery. Osteomyelitis usually occurred in the metaphysis of long tubular bone and rarely in short bone or flat bone such as a skull. This is attributed to the difference of distribution of the bone marrow vessels. Embolization and subsequent growth of bacteria in the blood flow is less liable to occur in short bone and flat bone.(ABSTRACT TRUNCATED AT 250 WORDS)

Carcinoma, Squamous Cell↗