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Biomedical subjects

S Kida

Publications and source records attributed to S Kida.

70 records · Page 4Linked to original sources
PubMed1986

The origin of psammoma bodies in the human arachnoid villi.

The fine structure of the human arachnoid villi was studied to clarify the origin of psammoma bodies. Within the villous surface layer, collagen fibrils and fine granular material clustered forming microcores of variable caliber measuring up to 10 microns. An early stage of psammoma body formation was seen more frequently in these villous microcores than in the meningocytic whorls. The villous microcores contained a large number of membrane-free matrix granules as well as a small number of membrane-bound matrix vesicles and matrix minerals. The matrix granules were irregularly oval structures with electron-lucent halo, measuring 0.05-0.70 micron in diameter. Hydroxyapatite crystals were frequently precipitated within and around the matrix granules which aggregated with calcifying matrix vesicles and matrix minerals. Numerous calcifying matrix granules were present within and around enlarging psammoma bodies. The matrix granules may serve as the principal calcification nidi of psammoma bodies in the human arachnoid villi. The possible mechanisms of matrix granule biogenesis are extrusion of preformed arachnoid cell structures or secretion of fine granular material with its extracellular assemblage.

Adolescent↗
PubMed1986

Peritumoral oedema and lipid content.

The authors analyzed the water and lipid contents of oedematous tissues of white matter obtained during the operation, comparing with the absorption value in the CT scan. As the absorption value lowered its level, the water content increased, while the lipid decreased. However, after subtracting these two components, the content of protein also showed a significant decrement parallel to the absorption value despite the existence of extravasated protein. The decrement of lipid content was considered to be due to a dilution effect by an expanded volume of extravasated oedema fluid, as well as the decrease in protein, rather than the actual loss of tissue component; that is demyelination. It is the relative decrease in protein content which contributes to the low absorption value of oedematous tissue.

Adult↗
PubMed1986

Synthesis and antiviral activity of sulfonamidobenzophenone oximes and sulfonamidobenzamides.

To find antiviral agents, various sulfonamidobenzophenone oximes (II) were synthesized from the appropriate m-sulfonamidobenzophenones by hydroxylamine reaction. The reaction products were generally obtained as syn/anti mixtures which were separable by fractional crystallization. The anti isomer had more potent antipoliovirus activity than the syn isomer. Various sulfonamidobenzamides (III) which were structurally related to II were synthesized by the reactions of amino-substituted benzamides with sulfuryl chloride or amines with (aminosulfonyl)benzoyl chloride. Antiviral activity was examined by the plaque-inhibition test. Compounds 5, 36, and 69 exhibited strong antipicornavirus activity. The structure-activity relationships are discussed.

Animals↗
PubMed1984

Synthesis and neuroleptic activity of N-[(1-ethyl-2-pyrrolidinyl)methyl]-2-methoxy-5-sulfonamidobenzamide s.

A series of some novel N-[(1-ethyl-2-pyrrolidinyl)methyl]benzamides involving replacement of the sulfamoyl group in sulpiride with a sulfonamido group was synthesized and tested for dopamine receptor blockade. In comparison with sulpiride, several compounds were considerably more potent than sulpiride as dopamine receptor blockers. The structure-activity relationships are discussed.

Animals↗
PubMed1984

Synthesis and antiarrhythmic activity of new 1-[1-[2-[3-(alkylamino)-2-hydroxypropoxy]phenyl]vinyl]-1 H-imidazoles and related compounds.

Various 1-[1-[2-[3-(alkylamino)-2-hydroxypropoxy]phenyl]vinyl]-1 H-azoles were synthesized and investigated for beta-adrenoceptor-blocking and antiarrhythmic activities. Although no compounds showed more potent beta-blocking effects than propranolol in the isolated guinea pig right atria, many compounds exhibited significant antiarrhythmic effects against aconitine or ischemic arrhythmia in mice or dogs. 1-[2,5-Dichloro-6-[1-(1H-imidazol-1-yl)-ethenyl] phenoxy]-3-[(1-methylethyl)amino]-2-propanol hydrochloride (48) (711389-S) was selected as a candidate for clinical evaluation in man, since its antiarrhythmic effects were superior to those of quinidine, disopyramide, or propranolol. Asymmetric synthesis of (R)-(+)- and (S)-(-)-48 is described, and it is proven that there is no stereospecificity in the antiarrhythmic effect of 48.

Adrenergic beta-Antagonists↗
PubMed1976

Synthesis of hemopexin with and without hormonal supplementation in rat hepatocyte suspensions: comparison with that of albumin and of fibrinogen.

The rate of hemopexin synthesis in adult rat hepatocyte suspension (0.17 +/- 0.019 (6)) (mean +/- SEM (n) mg/g hepatocytes per hour) was found to be linear for 48 h. By contrast, the rate of synthesis of albumin and fibrinogen was close to linear for only 12 h after which it continued at a diminished rate. Supplementation of the incubation medium with insulin, cortisol, glucagon, triiodothyronine, and growth hormone affected no significant increase in the synthesis rate of hemopexin but by contrast did do so in that of albumin (22%) and of fibrinogen (123%) (although not to the point of causing these last to become linear). The pattern of hemopexin synthesis and its response to hormones is clearly different from that observed with other plasma proteins studied in this hepatocyte system. Hempoexin synthesis appeared to be at its maximum and to be independent of hormone supplementation, and it was continuing linearly at a time when the synthesis of other plasma proteins was falling.

Albumins↗
PubMed1975

Relationship of the biosynthesis of alpha-fetoprotein, albumin, hemopexin, and haptoglobin to the growth state of fetal rat hepatocyte cultures.

AFP and albumin are produced by arginine-synthesizing fetal rat hepatocytes in vitro. AFP and hemopexin production are coupled to hepatocellular proliferation, whereas albumin and haptoglobin production are not. During the cell cycle, AFP is synthesized prior to S and released prior to M. AFP may play a role in regulation of hepatocellular growth through estradiol binding and modulation of the intracellular concentration of lipoprotein (VLDL).

Albumins↗
PubMed1974

Complementation in vitro between mutationally altered beta2 subunits of Escherichia coli tryptophan synthetase.

Cross-reacting beta(2) subunits (CRMs) were purified from eight trpB missense mutants to test for complementation in vitro after urea dissociation and reaggregation. One CRM (B290, demonstrating "repairability," i.e., the appearance of enzymatic activity on combination with alpha subunits) was clearly positive with four others, all "non-repairable" CRMs resulting from mutations at three different but neighboring sites. One complementing pair, B290-B248, was studied in more detail and found, upon mixing purified proteins, to give complementation in the absence of denaturants. Complementation activity was low in each case. To study the mechanism of the modest increases in activity, we used a reduced beta(2) subunit as an artificial CRM to form hybrids where both the amount of activity due to complementation and the amount of hybrid could be measured. (In a reduced beta(2) subunit, the two pyridoxal phosphate cofactors have been chemically reduced by sodium borohydride and are covalently attached to lysine residues. This abolishes activity in the tryptophan synthetic reaction and causes the protein to migrate much faster than normal in acrylamide gel electrophoresis.) Reduced beta(2) subunit formed hybrid dimers with the non-repairable CRMs B244 and B248 at pH 6.0, but no enzymatic activity appeared. On the other hand, when reduced beta(2) subunit was mixed with B290 CRM at pH 6.0 to 6.6, an activity increase was seen that was proportional to the amount of hybrid. We conclude that hybrid formation is essential for complementation and that the mechanism of complementation in this system is the correction of a repairable active site on the B290 beta chain by a conformational change occuring when hybrid dimer is formed. This type of complementation must be restricted to a small class of CRMs having a conformationally deformed active site. From the amount of hybrid present and the increase in activity, a specific activity of 50 U/mg was calculated for the hybrid containing reduced and B290 beta chains. This value is slightly less than but close to the activity of the hybrid formed between reduced and normal beta chains, shown earlier to have half the specific activity of the normal dimer.

Cell-Free System↗
PubMedDate not supplied

Percutaneous transluminal angioplasty and stent placement for subclavian and brachiocephalic artery stenosis in aortitis syndrome.

A 43-year-old man with progressive right common carotid, subclavian artery, and brachiocephalic artery stenoses due to aortitis syndrome is presented. The patient's right common carotid artery had been treated by percutaneous transluminal angioplasty (PTA) four times previously, but it was finally occluded. The right subclavian artery was treated by PTA once, which resulted in restenosis. The stenosis extended to the brachiocephalic artery. For this patient, PTA followed by stent placement was performed for the right subclavian and brachiocephalic artery stenosis. Because arterial stenosis is progressive in cases of aortitis syndrome, simple PTA alone does not appear to be sufficient for treatment. We suggest that PTA followed by stent placement may be an alternative treatment for recurrent stenosis in aortitis syndrome.

Adult↗
PubMedDate not supplied

Endovascular embolization of unruptured vertebral dissection using Guglielmi electrolytically detachable coils: case report.

We present a patient with unruptured vertebral dissection whose angiograph showed further enlargement of the aneurysm, after a transient reduction in the size of the fusiform dilatation. Tolerance of parent artery occlusion was first confirmed by a balloon occlusion test. Both proximal and distal portions of the vertebral artery, including the dissected site, were occluded using Guglielmi electrolytically detachable coils; there were no complications. No new symptoms occurred during a 9-month follow-up period. For cases presenting with angiographic aneurysmal enlargement, embolization of the lesion using electrolytically detachable coils may be effective.

Aortic Dissection↗
PubMedDate not supplied

Surgical pathology of spinal schwannoma: has the nerve of its origin been preserved or already degenerated during tumor growth?

OBJECTIVE: This study was aimed to understand ultrastructural pathology of nerves of tumor origin of spinal schwannomas, which has not been reported so far, in order to understand the mechanism of the postoperative functional restoration after the nerve transection. METHODS: From 13 patients who underwent sacrifice of an affected nerve root at total removal of spinal schwannomas (C2 conus), the proximal (spinal cord side, n = 12) and distal (dorsal root ganglion side, n = 10) stumps of the nerves of the tumor origin were collected and examined by light and electron microscope, followed by morphometric analysis (n = 9). RESULTS: Almost all of affected nerves at both proximal and distal to the lesion were composed of well-preserved myelin sheath and axons with mild disturbance of endo- and perineurial structures at light microscopic level except one case, which showed severe fibrosis. Electron-microscopically, regenerated axons with thin myelin were found in part in the proximal and distal nerves with few macrophages in three cases. The area of nerves (mm2), density of myelinated axons (axons/mm2) and total number of myelinated axons in the proximal stump (0.552 +/- 0.430, 10,400 +/- 5,240 and 5,480 +/- 4,790) was approximately 70%, 80% and 60%, respectively, of those in the distal stump (0.765 +/- 0.333, 12,400 +/- 5,180 and 9,970 +/- 8,630). CONCLUSIONS: This data combined with no permanent deficits after nerve transection suggest that the nerves of tumor origin are in the processes of slowly progressed deterioration with repeated degeneration and regeneration/remyelination, and the postoperative rapid recovery from the transient neurological deficit may be explained by functional compensation by the adjacent non-affected nerves with slow tumor growth.

Adult↗