Search PubMed⌕ Search

Biomedical subjects

K Kihara

Publications and source records attributed to K Kihara.

At least 127 records · Page 7Linked to original sources
PubMed1992

Intravesical combination chemotherapy with mitomycin C and doxorubicin for superficial bladder cancer: a randomized trial of maintenance versus no maintenance following a complete response.

Between November 1986 and April 1989, 101 patients with superficial bladder cancer were treated with intravesical instillations of mitomycin C on day 1 and doxorubicin on day 2 of each week for 5 consecutive weeks. Of 61 complete responders, 23 patients with carcinoma in situ and 28 with papillary cancer were randomly assigned to a non-maintenance group or to a group receiving maintenance therapy consisting of monthly instillations of the same drugs for 12 months. The 2-year non-recurrence rate calculated for patients with carcinoma in situ was significantly better in the maintenance group than in the non-maintenance group. A similar tendency was observed for patients with papillary cancer, although the difference was not significant. Side effects were considerable, with moderate to severe bladder irritation occurring in approximately half of the patients. In addition to our previous findings, the present results indicate that this intravesical combination chemotherapy is effective in eliminating superficial bladder cancers and that since the effect is not durable, even in complete responders, maintenance therapy is necessary to reduce subsequent tumor recurrence.

Administration, Intravesical↗
PubMed1992

Therapeutic effect of oral dipyridamole on myocardial perfusion and cardiac performance in patients with hypertrophic cardiomyopathy.

Recent studies have indicated that myocardial ischemia could occur and could play an important role in the pathophysiology of patients with hypertrophic cardiomyopathy (HCM). We therefore investigated whether or not dipyridamole--a selective coronary vasodilating agent--could favorably modify myocardial perfusion and the clinical manifestations in 20 patients with HCM (19 nonobstructive and one mildly obstructive) with an average age of 50 years. Oral dipyridamole, 150 mg/day for 2 weeks, prevented reversible perfusion defects initially observed in six patients on baseline exercise thallium-201 (201TI) scintigraphy and significantly increased the 201TI clearance (40 +/- 13% to 44 +/- 12%), while one patient developed new reversible perfusion defects. There were significant increases in echocardiographic fractional shortening and treadmill exercise time and reductions in cardiac size and supraventricular arrhythmias with dipyridamole therapy. These observations suggest that coronary vasodilation with dipyridamole may improve myocardial perfusion and cardiac function in patients with HCM.

Administration, Oral↗
PubMed1992

A mechanism of retrograde ejaculation after bilateral hypogastric nerve transections in the dog.

To pursue the mechanism of retrograde ejaculation after bilateral hypogastric nerve transections, the disability of the lumbosacral sympathetic trunk and the spermatic nerve to compensate bladder neck closure was investigated while both act as compensatory pathways for seminal emission. Five mongrel dogs were used for each experiment. By manual penis-stimulation, all dogs showed only retrograde ejaculation one month and six months after transection of bilateral hypogastric nerves. Bladder neck closure did not occur by electrical stimulation of either the lumbosacral sympathetic trunk or the spermatic nerve before and one month after transection of bilateral hypogastric nerves in all dogs examined and persistent relaxation of bladder neck was observed one and six months after transection of bilateral hypogastric nerves. The present results and our previous data indicate that retrograde ejaculation after bilateral hypogastric nerve transections is attributable to the absence of effective compensatory sympathetic pathways for bladder neck closure under the recovery of seminal emission by compensatory pathways.

Animals↗
PubMed1992

Ability of each lumbar splanchnic nerve and disability of thoracic ones to generate seminal emission in the dog.

Control of seminal emission by canine thoracolumbar splanchnic nerves which constitute the caudal mesenteric plexus (inferior mesenteric and superior hypogastric plexuses in human) was investigated. Electrical stimulation of a splanchnic nerve group which branched from sympathetic trunks at thoracic and L1 ganglia and descended on the ventral wall of the aorta between bilateral spermatic arteries via the intermesenteric plexus did not cause seminal emission in all 13 dogs examined. In contrast, electrical stimulation of the other splanchnic nerve group which branched from lumbar sympathetic trunks at ganglia L1-L5 and descended behind bilateral spermatic arteries induced seminal emission regardless of branching levels or sides. The results indicate that efferent signals via the intermesenteric plexus do not generate seminal emission, while those via each lumbar splanchnic nerve have ability to generate seminal emission in the dog.

Animals↗
PubMed1992

Relationship between the effects on bacterial activity of selected disinfectants and the hydrophobic characters of dibasic acid diesters.

We prepared test solutions which contained 80% (v/v) ethanol and 0.2% (w/v) chlorhexidine (CH) or benzalkonium chloride (BC) with or without a dibasic acid diester. After complete evaporation of the ethanol from the solution on filter paper, an overnight broth culture (Staphylococcus aureus) was repeatedly inoculated onto the filter paper, and viable bacterial counts were measured at 5 min after the last inoculation. By comparison with viable counts for CH or BC alone, we estimated the potentiating effects of dibasic acid diester on the bactericidal activity of CH or BC, and confirmed that this activity of the two disinfectants was potentiated in the presence of certain compounds in the homologs of di-n-butyl esters of aliphatic dibasic acid, and di-alkyl esters of adipic and phthalic acid. Diisobutyl adipate, one of the most effective diesters, substantially enhanced the bactericidal activities of benzethonium chloride, cetyl pyridinium chloride and didecyl dimethyl ammonium chloride, as well as CH and BC, but not those of polyhexamethylene biguanide or alkyldiaminoethyl glycinate. The potentiating effects of dibasic acid diesters observed for both CH and BC seemed to be affected by the hydrophobic character of these diesters themselves and are also expressed well by a particular quadratic equation as a function of these characters: namely, capacity factors, as determined by high-performance liquid chromatography.

Chemical Phenomena↗
PubMed1992

Beneficial antiarrhythmic effect of beta-blockade in patients with dilated cardiomyopathy.

Antiarrhythmic effects of beta-blockade (BB) in patients with dilated cardiomyopathy were compared with those of various antiarrhythmic agents using ambulatory Holter monitoring. The BB therapy effectively suppressed ventricular extrasystoles (VEs) in 85% of patients, as evidenced by improvement in Lown's grade or a reduction in the number of the highest grade VEs greater than 50%. In contrast, conventional antiarrhythmic agents, except flecainaid and amiodarone, were poorly effective in suppressing VEs. BB therapy gradually increased left ventricular fractional shortening (16 +/- 6% to 22 +/- 12%) and improved 12-month survival rates as compared with those receiving conventional therapy (93 vs 69%). This antiarrhythmic potency seemed to be an additional therapeutic efficacy of BB in the management of patients with dilated cardiomyopathy, which frequently associated with serious VEs.

Adrenergic beta-Antagonists↗
PubMed1992

Dissociation of magnitude of relaxation from cyclic AMP levels in rabbit urinary bladder smooth muscles.

The effects of forskolin and isoproterenol on contractile force and cyclic AMP levels were compared in smooth muscle strips from rabbit urinary bladder dome. Both of forskolin and isoproterenol produced the time- and the dose-dependent relaxation and the time- and the dose-dependent increases in cAMP levels. The relaxant response to forskolin caused more slowly than that to isoproterenol. The two agents caused almost the same relaxant responses at same concentration. However, cAMP levels induced by forskolin was much more than those induced by isoproterenol. These results that amounts of cAMP in urinary bladder don't correlate with the relaxation responses in urinary bladder smooth muscle strips suggest that some forms of functional compartmentalization of cAMP may exist in the urinary bladder.

Animals↗
PubMed1992

[Adjuvant chemotherapy for invasive bladder cancer. Multicenter study].

During 2 years and 10 months from November 1985 to September 1988, 50 patients with invasive bladder cancer (pT2-4, pN0-2, M0) were treated with total cystectomy followed by adjuvant combination chemotherapy including cis-platinum. In addition, so-called immunopotentiator (OK-432) and Kanpo (Juzentaihoto: TJ-48) were given to the patients in a random fashion to evaluate whether or not these agents had any significant effect on patients' prognosis. The 3- and 5-year survival rates for 48 evaluable patients were 71% and 67%, respectively. Histologic grade of primary tumors and number of cycles of adjuvant chemotherapy administered had a significant correlation to patients' survival: patients with grade 2 anaplasia had a better 3- and 5-year survival rates than those with grade 3 anaplasia, and patients receiving 3 or more cycles of chemotherapy had a better 3-year survival rate than those with 2 or less cycles. pT and pN categories also affected patients' survival, though not statistically significant. Administration of OK-432 or TJ-48 and pre-operative treatment such as irradiation and intra-arterial chemotherapy had no favourable effects on the survival. Side effects of the adjuvant chemotherapy were minimal to moderate and more than 70% of the patients tolerated at least 3 cycles of chemotherapy. It is likely that adjuvant chemotherapy, when given in a post-operative setting, should be repeated at least 3 cycles or more.

Adult↗
PubMed1992

[Clinical study on myocardial imaging with beta-methyl-p-(123I)-iodophenyl-pentadecanoic acid in patients with mitochondrial myopathy].

Myocardial imaging with beta-methyl-p-(123I)-iodophenyl-pentadecanoic acid (123I-BMIPP), a new radiopharmaceutical designed to evaluate myocardial fatty acid metabolism, was performed in 7 patients with mitochondrial myopathy to detect their myocardial damages in comparison with 201Tl myocardial imaging. These patients were divided into 4 chronic progressive external ophthalmoplegia (CPEO) cases, 2 mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) cases and 1 myoclonus epilepsy with ragged-red fibers (MERRF). In visual assessment, we observed more myocardial segments with decreased uptake of 123I-BMIPP compared to 201Tl in MELAS cases than in CPEO cases. The mean myocardial uptake of 123I-BMIPP was higher than that of 201Tl in CPEO cases. On the other hand, in MELAS and MERRF cases, the mean myocardial uptake of 123I-BMIPP was lower than that of 201Tl. Abnormal findings suggesting myocardial damages were observed in echocardiogram and/or in electrocardiogram in MELAS and MERRF cases, while no such abnormal findings were observed in CPEO cases. Along with the previously reported experimental result that the impairment of rat myocardial mitochondria decreased myocardial uptake of 125I-BMIPP, these results suggest that 123I-BMIPP may be useful to detect myocardial damages in patients with mitochondrial myopathy.

Adolescent↗
PubMed1991

Positive and negative elements upstream of the meiosis-specific glucoamylase gene in Saccharomyces cerevisiae.

The SGA1 gene encoding glucoamylase is specifically expressed late in meiotic development of the yeast Saccharomyces cerevisiae. We found that accumulation of both enzyme activity and transcripts was regulated negatively by both nutritional signals and a haploid-specific negative regulator gene of meiosis. RME1, and positively by the inducer genes for meiosis, IME1 and IME2. To study the role of sequences upstream of the SGA1 gene in its expression and regulation, we generated internal deletions in the 5' non-coding region of the gene and chimeric genes with portions of the upstream sequence inserted into a reporter gene. By analyzing the expression of these genes, we have identified both a 19 bp upstream activation sequence (UAS) and a 49 bp negatively regulating element (NRE). The UAS activated transcription with no requirement for heterozygosity at the mating-type locus, but this activation was still under negative control by nutrients. The NRE showed no UAS-like activity but conferred IME2-dependent (or meiosis-specific) expression on a heterologous promoter. These results suggest that meiosis-specific expression of the SGA1 gene is established by a regulatory hierarchy including positive and negative factors, the actions of which are mediated through the two separate upstream regulatory elements, UAS and NRE, respectively. Also, that two independently acting cascades exist for the regulation of SGA1 expression: one transduces both the mating-type and nutritional signals and includes the IME2 product, which acts to relieve the repression through NRE; and another transduces only the nutritional signal independently of the above pathway and inhibits positive factors acting on UAS.

Autoradiography↗
PubMed1991

Lumbosacral sympathetic trunk as a compensatory pathway for seminal emission after bilateral hypogastric nerve transections in the dog.

Seminal emission after transection of canine bilateral hypogastric nerves was investigated. Stimulation of severed hypogastric nerves caused full volume seminal emission (greater than four drops) in all six dogs examined. In contrast, stimulation of sympathetic trunks of other six dogs at the level of caudal mesenteric artery caused no emission in three dogs and a limited volume of seminal emission (less than one drop) by pressing the ampulla in the remaining. When hypogastric nerves were transected one month prior to the experiment, however, stimulation of sympathetic trunks in the same manner caused full volume of seminal emission in all six dogs. Distal dissection of sympathetic trunks demonstrated nerve fibers to the seminal tract via the pelvic splanchnic nerves. The results indicate that the seminal tract receives at least two sympathetic pathways; one from hypogastric nerves and the other from lumbosacral sympathetic trunks, and that the latter compensatorily generates seminal emission after hypogastric nerve transection.

Animals↗
PubMed1991

Seminal emission by electrical stimulation of the spermatic nerve and epididymis.

The spermatic nerve and epididymis were stimulated electrically in dogs to elucidate the possibility of artificial seminal emission after bilateral transection of the hypogastric nerves and sympathetic trunks. Before transection, electrical stimulation of a distal end of the severed spermatic nerve caused a trace amount of emission in two dogs and no emission in the remaining four. In contrast, 1 month after the transection, stimulation of a distal end of the severed spermatic nerve caused seminal emission in all six dogs examined, with full seminal volume in four dogs and partial volume in the remaining two. Anatomically, sympathetic nerves originating from the upper portion of the lumbar sympathetic ganglia descended along the spermatic arteries to the testes as spermatic nerves. The present results indicate that spermatic nerves have the potential to generate seminal emission as a compensatory pathway after bilateral transection of the hypogastric nerves. Both direct and percutaneous electrical stimulation of epididymal tails resulted in a full volume of seminal emission in all dogs with transection of both hypogastric nerves and lumbosacral sympathetic trunks as well as in unoperated controls, while high voltage (8 V vs 40-80 V) was required to cause seminal emission by electrical stimulation on the skin surface. Direct stimulation of epididymal tails in men undergoing orchidectomy as treatment for prostatic carcinoma or during biopsy of the contralateral testis in a patient with a testicular tumour, resulted in seminal emission in all five epididymides examined either from the end of the severed vas deferens or in the posterior urethra if the vas deferens was not severed.

Animals↗