Search PubMed⌕ Search

Biomedical subjects

T Koide

Publications and source records attributed to T Koide.

At least 181 records · Page 10Linked to original sources
PubMed1993

Congenital subclavian steal syndrome with anomaly of the aortic arch.

A case of congenital subclavian steal syndrome associated with an anomalous right-sided aorta is reported. A 41-year-old man complaining of vertigo and a loss of consciousness was admitted. Physical examination revealed a blood pressure differential between the arms that was 20 mm Hg less in the left. Aortography showed a right aortic arch from which arose the right subclavian and both common carotid arteries. The left subclavian artery did not opacify. Right vertebral angiography showed retrograde filling of the left vertebral. A left carotid-subclavian bypass was performed. Postoperatively, the patient is symptom free with equalized blood pressure.

Abnormalities, Multiple↗
PubMed1993

Functional roles of cyclic guanosine 3',5'-monophosphate analogue in cerebral vasodilation.

1. Vasodilating effects of cyclic nucleotides in cerebral vasculature were examined using membrane permeable cyclic nucleotide analogues, 8-bromoguanosine 3',5'-cyclic monophosphate (8-Br-cGMP) and 8-bromoadenosine 3',5'-cyclic monophosphate (8-Br-cAMP). 2. In isolated canine basilar artery (CBA), 8-Br-cGMP but not 8-Br-cAMP, significantly inhibited Ca(2+)-induced and agonist [serotonin(5-HT), prostaglandin(PG)F2 alpha or endothelin]-induced contraction, in a concentration-dependent manner. 3. When Ca2+ was depleted from intracellular store sites by pretreatment with A23187, 8-Br-cGMP but not 8-Br-cAMP strongly attenuated contractions induced by Ca(2+)-influx. 4. Neither 8-Br-cGMP nor 8-Br-cAMP modified contraction induced by caffeine which elicits Ca2+ release from intracellular Ca2+ store. 5. 8-Br-cGMP lowered the high K(+)-induced sustained [Ca2+]i elevation. 6. These results suggest that, at least in CBA, cGMP exerts its inhibitory effect on the contraction induced by influx of Ca2+, by reducing the level of [Ca2+]i and reducing [Ca2+]i sensitivity of the contractile machinery.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1993

Relationship between development of diarrhea and the concentration of SN-38, an active metabolite of CPT-11, in the intestine and the blood plasma of athymic mice following intraperitoneal administration of CPT-11.

Severe diarrhea occurred during daily intraperitoneal administration of 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxycamptothecin (CPT-11) at a dose of 50 mg/kg in athymic mouse. Serial determination of CPT-11 and 7-ethyl-10-hydroxycamptothecin (SN-38), with the use of an on-line solid extraction HPLC system, demonstrated that much higher levels of the compounds are retained in the intestine and the blood plasma after five consecutive daily injections than after a single injection. Histologic examination of the gastrointestinal tract showed hemorrhagic colitis on day 7 and later after five consecutive daily injections of CPT-11. The direct cause of diarrhea associated with CPT-11 administration is considered to be enterocolitis caused by high levels of SN-38 and/or CPT-11 retained for a long period in the intestine.

Animals↗
PubMed1993

Influence of ionic strength on crystal adsorption and inhibitory activity of macromolecules.

We investigated the influence of ionic strength on both the binding ability of macromolecules onto calcium oxalate crystals and the inhibitory activity of macromolecules related to calcium oxalate crystal growth and aggregation in vitro. The amount of heparin sodium salt adsorbed onto calcium oxalate crystals was studied in both a seed and a non-seed crystal system at various ionic strengths with the aid of radiolabelled heparin. In both adsorption models, adsorption of heparin was greater in the buffered solutions of lower ionic strength, and significantly so in the range of physiological ionic strength. The inhibitory activity of heparin in the non-seed crystal system, which was determined using a Coulter Multisizer, increased as the adsorbed dose increased. The naturally existing urinary macromolecules showed a similar change in their inhibitory activity on calcium oxalate crystal growth and/or aggregation in accordance with changes in ionic strength. These results indicate that macromolecular inhibitory activity seems to be enhanced in urine of lower ionic strength as a result of an increased adsorption of macromolecules on the surface of calcium oxalate crystals.

Adsorption↗
PubMed1993

Investigation of the dimethylsulfoxide-trifluoroacetic acid oxidation system for the synthesis of cystine-containing peptides.

Disulfide bonds of peptides were effectively established between S-protected cysteine residues as well as free cysteine residues by the action of dimethylsulfoxide in trifluoroacetic acid. Oxytocin and alpha-human calcitonin gene-related peptide were synthesized using this oxidation system. The feasibility of this method for the formation of two disulfide bridges of apamin was also examined.

Amino Acid Sequence↗
PubMed1993

Syntheses and biological activities of selenium analogs of alpha-rat atrial natriuretic peptide.

alpha-Rat atrial natriuretic peptide (7--28) (rANP (7--28)) and a series of its analogs in which half cystine residue(s) were substituted with half selenocystine residue(s) were synthesized by using the Fmoc-based solid-phase method followed by cyclization by means of dimethylsulfoxide (DMSO)-trifluoroacetic acid (TFA) oxidation. These analogs possess comparable activities in both receptor binding and cGMP accumulation in rat vascular smooth muscle cells to those of rAMP (7--28).

Amino Acid Sequence↗
PubMed1993

Synthetic study on selenocystine-containing peptides.

N-9-Fluorenylmethoxycarbonyl-Se-4-methoxybenzylselenocysteine++ + [Fmoc-Sec(MBzl)-OH] was synthesized from selenocystine and successfully applied to Fmoc-based solid-phase peptide synthesis. The stability and the deprotection conditions of the Se-MBzl group were examined. The diselenide bond of a peptide was directly and effectively established between Sec(MBzl) residues by treatment with iodine or the dimethyl sulfoxide-trifluoroacetic acid system. Reduction kinetics of diselenide and disulfide in model peptides by reduced glutathione were also studied comparatively.

Amino Acid Sequence↗
PubMed1993

Adhesiveness of glass ionomer cement containing tannin-fluoride preparation (HY agent) to dentin--an evaluation of adding various ratios of HY agent and combination with application diammine silver fluoride.

We bonded a glass ionomer cement (GIC) containing various amounts of incorporated tannin-fluoride preparation (HY agent) to bovine dentin and investigated the effect of the ratio of incorporated preparations and the changes in bond strength over time. HY agent was incorporated into the powder at 0% (HY0), 1.5% (HY1.5), 5.0% (HY5), and 10.0% (HY10) by weight. The shear bond strength and percent of the cohesive failure were measured. Similar tests were performed on samples where diammine silver fluoride was applied to the dentin prior to placing the cement. It was found that the bond strength on the first day was increased by incorporating 1.5% of the HY agent in the GIC. The combined use of diammine silver fluoride increased the bond strength of the GIC.

Adhesiveness↗
PubMed1993

[The effect of long-term alkali therapy for recurrent calcium stone patients with distal renal tubular acidosis].

Alkali therapy is widely accepted as a treatment for recurrent calcium stone patients with distal renal tubular acidosis (dRTA). Nine patients, five with complete and four with incomplete type of dRTA, were treated with alkali agents for more than three years; an average period of 10.8 years. In five patients, new stone formation and stone growth were completely prevented by this treatment. Among the four failed cases, three did not take enough alkali agents (in spite of our medication), and the other had recurrent urinary tract infection resulting in infectious stone formation. In conclusion, the long-term efficacy of alkali therapy for prevention of recurrent stone formation with dRTA is confirmed when the patient takes enough alkali agents and the urinary tract infection is well controlled.

Acidosis, Renal Tubular↗
PubMed1993

[Transurethral endoureteropyelotomy].

Transurethral endoureteropyelotomy was performed in a total of 37 patients with primary ureteropelvic junction obstruction or various ureteral strictures. Thirty-one (84%) of the 37 evaluable patients showed a radiographical improvement of hydronephrosis with a mean follow-up period of 15.8 +/- 10.5 months (range: 3-40). The clinical success rates were as follows: primary ureteropelvic junction obstruction, 11/12 92%); upper ureteral stricture, 6/7 (86%); lower ureteral stricture, 14/18 (78%). This endourological procedure required a mean operation time of 38.0 +/- 27.7 minutes and hospital stay of 7.3 +/- 4.9 days. No major complication has been identified. This retrograde procedure has a straight access to the strictured segment of ureteropelvic junction. It is safe and less invasive to the renal parenchym as it does not require percutaneous nephrostomy. Therefore, it might be clinically useful for the treatment of primary ureteropelvic junction obstruction and other ureteral strictures.

Adolescent↗
PubMed1993

Obturation of dentinal tubules with tannin-fluoride preparation (HY agent) incorporated into glass ionomer cement.

The degree of obturation of dentinal tubules as well as the dentinal uptake of F, Zn and Sr was investigated after placement of glass ionomer cement (GIC) containing variable proportions of the tannin-fluoride preparation, HY agent, into freshly prepared cavities. It was found that when HY agent was incorporated into the cement powder, there was both increase in electrical resistance in the dentinal floor of the GIC-restored cavity in addition to inhibition of dye penetration. Further, these changes were directly proportional to the concentration of HY agent. Electron probe microanalysis of the principal constituents of HY agent (F, Zn and Sr) revealed that the penetration depth for F and Zn was also directly proportional to the relative amount of incorporated HY agent, whereas Sr could not be detected regardless of HY concentration. Results clearly demonstrated that the higher the concentration of HY agent incorporated into GIC, the greater the degree of dentinal tubular obturation.

Animals↗
PubMed1993

Hyperparathyroidism--comparison of flash imaging with spin echo MR imaging.

MR images of the neck were prospectively studied in 19 patients with hyperparathyroidism. Fast low angle shot (FLASH) sequence was performed in addition to T1- and T2-weighted spin echo (SE) sequences. FLASH images were obtained with 320/12/20 degrees (TR/TE/flip angle) using presaturation technique. TE of 12 ms was chosen to eliminate high signal of fat tissue. In the evaluation of detectability, a combination of T1-weighted SE and FLASH images (T1WI + FLASH) was compared with a combination of T1- and T2-weighted SE images (T1WI + T2WI). MR imaging correctly depicted 20 of 30 abnormal glands on both T1WI + FLASH and T1WI + T2WI. FLASH imaging effectively eliminated high signal of fat tissue. Nineteen abnormal glands demonstrated higher signal than surrounding tissues on FLASH images, whereas 12 glands were high-intense on T2-weighted SE images. We conclude that FLASH imaging provides improved tissue contrast and anatomic delineation and, thus, may replace T2-weighted SE imaging in the neck.

Adenoma↗
PubMed1993

[Efficacy of 48-hour infusion of 5-fluorouracil for gall bladder cancer].

Usefulness of an adjuvant chemotherapy for 23 patients who had undergone "non-curative" resection for adenocarcinomas of the gallbladder was investigated. Patients were divided into two groups: Group A (16 patients) was given MF (mitomycin C 6 mg/m2, 5-fluorouracil 250 mg/body) by injection on the 2nd and 9th postoperative day and received orally Tegafur 600 mg/day and PSK 3 g/day. Group B(7 patients) was treated weekly with a 48-hour infusion of 5-FU (1,000 mg/m2/24 hours), for 6 weeks and leucovorin (30 mg/body) was given for 2 hours prior to 5-FU infusion. The results were evaluated by the Kaplan-Meier method. Response rate of anti-tumor was 0% in Group A and 14.3% in Group B, including: PR, 1 and NC, 6 cases. The 50% survival time was 230 days in group A and 471 days in group B (p = 0.0008). The results suggest that treatment with 5-FU and LV is effective for gallbladder cancer.

Adenocarcinoma↗
PubMed1993

[Cardiac hemangioma of the interventricular septum and right ventricle: a case report].

A 52-year-old man who had been pointed out cardiac tumor on echocardiography, CT, MRI and coronary angiography was admitted to our hospital. He was asymptomatic. The surgical excision of the tumor was performed under extracorporal circulation and the postoperative period was free of event. It was not certain whether it originated from interventricular septum or right ventricle. The histology was mixed hemangioma composed of capillary and cavernous type.

Heart Neoplasms↗
PubMed1993

[A midbrain arteriovenous malformation at quadrigeminal plate completely obliterated by embolization].

An eighteen year-old boy presented sudden loss of consciousness and tetraparesis. Radiological examinations revealed a ruptured midbrain arteriovenous malformation (AVM) at the right quadrigeminal plate. The patient recovered from symptoms by conservative treatment over 6 months with residual right hemisensory disturbance and mild diplopia during bilateral horizontal gaze. One year later, he was admitted to our institute for radical treatment of the AVM. On the angiography, the AVM was fed by two branches of the right long circumferential artery and a left paramedian penetrating artery of the posterior cerebral artery (PCA), and drained into the straight sinus via a dilated quadrigeminal vein. After much discussion on several strategies, endovascular surgery was chosen as a radical treatment. In the initial session, a medial branch of the right long circumferential artery was catheterized with Tracker-18, and embolized with 1.0 ml of ethylene vinyl alcohol copolymer (EVAL) without any deficits after negative provocative tests using Amytal and Xylocaine. Then, a lateral branch of the same artery was embolized with 0.8 ml of EVAL in the same way without any deficits. In the second session, catheterization into the left paramedian artery was difficult because of its small diameter and steep branching angle, and only a 3 mm hooked tip of Tracker-18 could be canulated into the feeding pedicle. Left oculomotor palsy was induced by provocative Xylocaine test. However, angiographic cure of the AVM was expected to be made possible by the occlusion of this pedicle, and the procedure was continued due to the request of the patient and his family.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

[Urolithiasis].

Explore the source record for details and available documents.

Adolescent↗
PubMed1993

[Fibromuscular dysplasia with an internal carotid artery web on the angiograms].

A 58-year-old woman experienced a transient right-sided hemianopsia. She also had difficulty finding words and trouble naming parts of objects. On admission, three days later, there were no signs of residual neurological deficit. Laboratory studies showed findings of neither diabetes mellitus, hypertension nor cardiac disease. Her serum cholesterol level was normal. No bruit was heard over the head and neck. Preoperative angiograms showed a discrete web (septum) at the left internal carotid origin (Fig. 2). 123I-IMP SPECT revealed a decreased areas of perfusion mainly in the left middle cerebral artery distribution (Fig. 3A). A reconstructive operation was performed. A firm discrete nonatherosclerotic ridge (septum) protruding into the vessel lumen was resected. Microscopic examination of the surgical specimen demonstrated intimal fibroplasia, a rare subtype of fibromuscular dysplasia (FMD). Postoperatively, hypoperfused areas in SPECT were improved (Fig. 3B). The patient has been free of symptoms to the present time (for about one year). In addition to the rarity of the lesion, the available data suggest that web-like subtype of FMD is apt to be associated with an increase in the risk of hemodynamic compromise and thromboembolism. Surgical therapy is recommended, especially for symptomatic patients.

Carotid Artery, Internal↗