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Biomedical subjects

K Tago

Publications and source records attributed to K Tago.

At least 19 recordsLinked to original sources
PubMed1991

[Intravesical instillation of bacillus Calmette-Guerin for superficial bladder carcinoma: study on significance of additional maintenance instillations of bacillus Calmette-Guerin].

The efficacy of maintenance bacillus Calmette-Guerin (BCG) instillations for superficial bladder tumors was studied by prospective randomized trial. From June 1985 to October 1988, 42 newly diagnosed patients with superficial bladder carcinoma (pTa or pT1) were treated by transurethral tumor resection and subsequent five daily instillations of mitomycin C. Then they were divided into non-maintenance group (22 patients) and maintenance group (20 patients) by randomization. The patients received six weekly instillations of 80 mg of BCG. Tokyo strain (Japan BCG manufacturing Co., Tokyo, Japan), suspended in 40 ml of physiological saline, and the patients in the maintenance group received four additional instillations of BCG every three months. We could not complete the six-week course of BCG instillations in three patients due to adverse effects (two in non-maintenance group and one in maintenance group) and we lost six patients from follow-up within one year (one in non-maintenance group and five in maintenance group). The mean follow-up period of the remaining 33 patients was 28.1 months. Of these 33 patients, six patients had been found to have recurrent tumors, and the over-all three-year non-recurrence rate was 82%. Before employing BCG, when we used only mitomycin C after TUR-Bt, the three year non-recurrence rate was 58%. This indicates prophylactic effect of BCG instillations. The stage of the initial tumor of the six recurrent cases were all pT1b. The non-recurrence rate of the patients with pT1b tumor was significantly lower than that of the patients with pTa and pT1a tumor. However, multiplicity and grade of tumors did not affect the non-recurrence rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Intravesical↗
PubMed1990

Early site of lymphatic involvement from right renal cell carcinoma: CT demonstration and method of lymphadenectomy.

The value of lymphadenectomy in the treatment of renal cell carcinoma remains controversial. The precise location of nodal metastasis and method of lymphadenectomy had seldom been mentioned. We report 2 patients with right renal cell carcinoma who had regional lymph node involvement without blood-borne metastasis. The involved lymph nodes were demonstrated by CT scan just behind the inferior vena cava at the level of renal hilus. These nodes seemed to be the first sites of nodal involvement from the right renal cell carcinoma. Elevation of the inferior vena cava by dividing its small branches, including a few lumbar veins, was necessary for complete removal of these nodes en bloc with the right kidney.

Aged↗
PubMed1990

[Glomerular function and renal functional reserve].

Protein intake has been shown to raise glomerular filtration rate (GFR). The difference between peak and baseline GFR following acute protein load indicates renal functional reserve (RFR). In this paper, we review 1) normal glomerular function and its regulating factors, 2) the concept of RFR and the mechanism by which the acute protein load induces hyperfiltration response in healthy subjects and 3) the RFR in patients with renal disease.

Glomerular Filtration Rate↗
PubMed1989

Construction of less neurovirulent polioviruses by introducing deletions into the 5' noncoding sequence of the genome.

Viral attenuation may be due to lowered efficiency of certain steps essential for viral multiplication. For the construction of less neurovirulent strains of poliovirus in vitro, we introduced deletions into the 5' noncoding sequence (742 nucleotides long) of the genomes of the Mahoney and Sabin 1 strains of poliovirus type 1 by using infectious cDNA clones of the virus strains. Plaque sizes shown by deletion mutants were used as a marker for rate of viral proliferation. Deletion mutants of both the strains thus constructed lacked a genome region of nucleotide positions 564 to 726. The sizes of plaques displayed by these deletion mutants were smaller than those by the respective parental viruses, although a phenotype referring to reproductive capacity at different temperatures (rct) of viruses was not affected by introduction of the deletion. Monkey neurovirulence tests were performed on the deletion mutants. The results clearly indicated that the deletion mutants had much less neurovirulence than with the corresponding parent viruses. Production of infectious particles and virus-specific protein synthesis in cells infected with the deletion mutants started later than in those infected with the parental viruses. The rate at which cytopathic effect progressed was also slower in cells infected with the mutants. Phenotypic stability of the deletion mutant for small-plaque phenotype and temperature sensitivity was investigated after passaging the mutant at an elevated temperature of 37.5 degrees C. Our data strongly suggested that the less neurovirulent phenotype introduced by the deletion is very stable during passaging of the virus.

Animals↗
PubMed1989

Determinants in the 5' noncoding region of poliovirus Sabin 1 RNA that influence the attenuation phenotype.

A number of recombinants between the virulent Mahoney and attenuated Sabin strains of type 1 poliovirus were constructed by using infectious cDNA clones of the two strains. To identify a strong neurovirulence determinant(s) residing in the genome region upstream of nucleotide position 1122, these recombinant viruses were subjected to biological tests, including monkey neurovirulence tests. The results of the monkey neurovirulence tests suggested the important contribution of an adenine residue (Mahoney type) at position 480 to the expression of the neurovirulence phenotype of type 1 poliovirus. This nucleotide, however, had only a minor effect, if any, on viral temperature sensitivity. Monkey neurovirulence tests on the recombinant virus whose genome had a guanine residue (Sabin type) at position 480 and variants generated from this recombinant virus in the central nervous system of monkeys strongly suggested that only one nucleotide change, from adenine to guanine, was not sufficient for full expression of the attenuation phenotype encoded by this genome region. These results suggest that the expression of the attenuation phenotype depends on the highly ordered structure formed in the 5' noncoding sequence and that the formation of such a structure is possibly influenced by the nucleotide at position 480. Furthermore, in vitro biological tests performed on viruses recovered from the central nervous system of monkeys injected with a temperature-sensitive recombinant virus showing the small-plaque and d phenotypes revealed that most of the recovered viruses had even higher temperature sensitivities and that all of the recovered viruses that had acquired the large-plaque phenotype had lost the d phenotype to some extent. These results indicate that there may be an unknown selection pressure(s) in the central nervous system and that common determinants might be involved in the expression of the small-plaque and d phenotypes.

Animals↗
PubMed1988

A recombinant virus between the Sabin 1 and Sabin 3 vaccine strains of poliovirus as a possible candidate for a new type 3 poliovirus live vaccine strain.

Biological tests including the monkey neurovirulence test performed on recombinants between the virulent Mahoney and attenuated Sabin 1 strains of type 1 poliovirus indicated that the genome region encoding mainly the viral capsid proteins had little correlation with the neurovirulence or attenuation phenotype of the virus. The results suggested that new vaccine strains of type 2 and type 3 polioviruses may be constructed in vitro by replacing the sequence encoding the antigenic determinants in viral capsid proteins of the Sabin 1 genome by the corresponding sequences of the type 2 and type 3 genome, respectively. Accordingly, we constructed recombinants between the Sabin 1 and Sabin 3 strains of poliovirus in which genome sequences of the Sabin 1 strain encoding most or all capsid proteins were replaced by the corresponding genome sequences of the Sabin 3 strain. One of the recombinant viruses thus constructed was fully viable and showed antigenicity and immunogenicity identical to those of type 3 poliovirus. The monkey neurovirulence tests and in vitro phenotypic marker tests (temperature sensitivity of growth, sodium bicarbonate concentration dependency of growth under agar overlay, and size of plaque) were performed on the recombinant virus. The stability of the virus in regard to the temperature sensitivity phenotype was also tested. The results suggested that the recombinant virus is a possible candidate for a new type 3 poliovirus vaccine strain.

Animals↗
PubMed1988

Serum and renal tissue concentrations of cefotaxime in urinary tract obstruction in rabbits.

Serum cefotaxime and desacetylcefotaxime concentrations and their tissue concentrations in the kidney were determined at 30 minutes after cefotaxime (80 mg/kg) bolus intravenous infusion in rabbits when the urinary tract was obstructed. Serum concentration was highest in bilateral ureteral obstruction (BUO) animals (142.1 +/- 25.4 mg/L), followed in order by unilateral ureteral obstruction (UUO) animals (92.6 +/- 10.4 mg/L) and sham-operated animals (50.4 +/- 9.9 mg/L). Both serum cefotaxime and desacetylcefotaxime concentrations were highly correlated with serum creatinine levels. Conversely, the renal tissue/serum concentration ratio of cefotaxime and its metabolite was lowest in BUO animals, which was in accordance with physiological evidence that renal blood flow was reduced in BUO. Indomethacin pretreatment exaggerated cefotaxime and desacetylcefotaxime accumulation in the obstructed kidney of the UUO model, indicating that this drug inhibits renal elimination of cefotaxime when urinary tract obstruction exists.

Animals↗
PubMed1987

Ex vivo comparison of radiological and histological evaluation of early metastatic lesions of pelvic lymph nodes from carcinoma of the bladder or prostate.

To study the limitations of lymphangiography in the detection of early lymphatic spread of pelvic malignancies, we evaluated 587 lymph nodes from 23 patients with stages pN0 to 2 carcinoma of the bladder or prostate. Pelvic lymphadenectomy was performed 5 to 10 days after bipedal lymphangiography. Excised lymph nodes were separated one by one and an x-ray of each node was taken (lymphnodegram). The individual lymphnodegram was compared to the histological findings. Interpretations of lymphnodegrams from all 17 nodes with metastases were positive in 5, suspicious in 1, negative in 9 and radiolucent in 2. False negative judgments occurred chiefly because metastatic foci were microscopic. Two lymph nodes without metastasis were interpreted as positive for disease because of fat replacement of the nodes. These results indicated that lymphangiography is not suitable for the detection of early lymphatic metastases of carcinoma of the bladder or prostate.

Humans↗
PubMed1986

Regulation of chloride self exchange by cAMP in cortical collecting tubule.

The hormonal control of Cl transport was examined in rabbit cortical collecting tubules using the lumen-to-bath 36Cl tracer rate coefficient (KCl, nm/s). Tracer movement via Cl-HCO3 exchange was minimized by using HCO3-CO2-free solutions. The electrical driving force was minimized by treating with amiloride. Under these conditions, net Cl transport was zero, yet there was a large KCl that fell 88% on removing bath (trans) Cl. These results are consistent with the mechanism of tracer flux being predominantly Cl self exchange. KCl fell spontaneously with time in vitro; after this decline KCl could be stimulated with 8-bromo-cAMP. cAMP present from the onset of perfusion prevented the time-dependent fall in KCl. When tracer movement was restricted to diffusion by eliminating Cl self exchange (0 Cl bath), cAMP had no effect on KCl. Although both isoproterenol and vasopressin are known to stimulate adenylate cyclase in this epithelium, only isoproterenol mimicked the cAMP effect on KCl. The isoproterenol effect was blocked by either propranolol or prostaglandin E2. Lumen addition of the disulfonic stilbene DIDS had no effect on KCl. Lumen addition of furosemide or trichloromethiazide had minimal or no effect. Taken together, these results indicate that Cl self exchange is regulated by beta-adrenergic agents acting via cAMP. The lack of an effect of vasopressin suggests cellular heterogeneity in this response to cAMP.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1986

Stimulation of chloride transport by HCO3-CO2 in rabbit cortical collecting tubule.

We examined both the role of HCO3-CO2 in Cl transport as well as the effect of in vivo acid-base status on Cl transport by the rabbit cortical collecting tubule. The lumen-to-bath 36Cl tracer flux, expressed as the rate coefficient KCl, was measured in either HEPES-buffered (CO2-free) or HCO3-CO2-containing solutions. Amiloride was added to the perfusate to minimize the transepithelial voltage and thus the electrical driving force for Cl diffusion. Because KCl fell spontaneously with time in HCO3-CO2 solutions in the absence but not the presence of cAMP, we used cAMP throughout to avoid time-dependent changes. Acute in vitro removal of bath HCO3-CO2 reduced KCl. Acetazolamide addition in HEPES-buffered solutions also lowered KCl; KCl could be restored to control values by adding exogenous HCO3-CO2 in the presence of acetazolamide. In vivo acid-base effects on Cl transport were determined by dissecting tubules from either NaHCO3-loaded or NH4Cl-loaded rabbits. Tubules from HCO3-loaded rabbits had higher rates of Cl self exchange. Acute in vitro addition of bath HCO3-CO2 increased KCl and did so to a greater degree in tubules from HCO3-loaded rabbits. Most of this effect of HCO3-CO2 addition on KCl could not be accounted for by Cl-HCO3 exchange; rather, it appeared due to stimulation of Cl self exchange. The data are consistent with 36Cl transport occurring via Cl-HCO3 exchange as well as Cl self exchange. Both processes are acutely stimulated by HCO3 and/or Co2, and both are chronically regulated by in vivo acid-base status.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1986

Effects of inhibitors of Cl conductance on Cl self-exchange in rabbit cortical collecting tubule.

Electroneutral vs. conductive pathways of Cl transport were examined by measuring transepithelial conductance (GT) and the lumen-to-bath 36Cl rate coefficient (KCl). Experimental conditions minimized both Cl-HCO3 exchange [HCO3/CO2-free, N-2-hydroxyethylpiperazine-N'-2-ethane-sulfonic acid (HEPES)-buffered solutions] and the electrical driving force for paracellular Cl diffusion (amiloride in the perfusate, transepithelial voltage near zero). Two agents known to inhibit Cl conductances in other epithelia, anthracene-9-carboxylate (9AC, 1 mM) and diphenylamine carboxylate (DPC, 0.1-0.5 mM) reversibly reduced GT and KCl when added to the bath. Both reduced KCl to values consistent with paracellular diffusion. Bath DPC had no effect on GT in the presence of 4 mM lumen Ba2+, suggesting that the DPC-sensitive conductance is in series with an apical K conductance, i.e., resides on the basolateral membrane. Lumen DPC also reduced GT and KCl, but was less potent than bath DPC. Because the lumen DPC effect on GT was also blocked by lumen Ba2+, lumen DPC probably inhibits a basolateral Cl conductance. K removal and ouabain (0.5 mM) had no effect on KCl, suggesting that Cl tracer movement is not predominantly through the principal cell. We assume that these agents are inhibiting Cl conductive pathways and propose a model in which transcellular Cl movement through the intercalated cell occurs via an apical electroneutral entry step in series with a basolateral conductive pathway.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1984

Unilateral and segmental medullary sponge kidney: renal function and calcium excretion.

The renal acidification defect and renal hypercalciuria have been reported in patients with pan-renal and bilateral medullary sponge kidney. However, little is known about patients with unilateral or segmentally affected medullary sponge kidney. We report 2 cases of partially affected medullary sponge kidney with normal acidification ability and normal urinary calcium excretion, although the ability to concentrate urine was diminished. These findings suggest that in patients with partially affected medullary sponge kidney nephrolithiasis is not the consequence of renal hypercalciuria induced by systemic acidosis but is owing to the urinary stasis caused by cystic dilatation of the terminal collecting duct.

Adult↗
PubMed1984

Medullary sponge kidney and renal acidification defect.

Medullary sponge kidney ( MSK ) is one of the entities which comprises a subclass of renal cystic disorders. While the clinical signs, symptoms, and radiological findings have been well documented in the past, the literature concerning renal function in these patients is relatively sparse. Thus, the purpose of the present studies was to examine the renal function in 11 patients with MSK and compare them to seven healthy volunteers and ten control patients with bilateral renal stones. Patients with MSK had normal GFR, RPF, and capacity to dilute urine; however, their urine concentrating ability was diminished. Urine pH in MSK patients was higher than in control patients with NH4Cl administration, while titratable acid excretion was lower than normal. Steady-state plasma bicarbonate concentration was lower in MSK patients than in controls but arterial pH was within normal limits. These studies suggest that MSK patients have defects in urinary acidification and concentration mechanism which may, in part, be the result of functional abnormality of the terminal collecting ducts.

Acid-Base Equilibrium↗
PubMed1982

Anterior decompression for myelopathy resulting from ossification of the posterior longitudinal ligament.

In this series, 15 patients with ossification of the posterior longitudinal ligament underwent anterior decompression to relieve moderate or severe myelopathy, which in 11 included urinary disturbance. The operation consisted of partial resection of the vertebrae, release of the ossified plaque from the surrounding tissue and the insertion of an iliac bone graft. The extent of ossification was confirmed by computerised tomography before and after operation. The plaque was completely detached and moved forward in half of the patients, but only partially moved in the remainder. Symptoms improved considerably. Urinary disturbance disappeared in all patients, but sensory disturbance was left in most. Two patients had prolonged symptoms which were not relieved despite the complete release of the ossified defect.

Adult↗
PubMed1976

Antiviral antibiotic S15-1. Taxonomy of the producing strain and study of conditions for production of the antibiotic.

Strain S15-1 which produces antiviral antibiotic S15-1 belonging to the streptothricin group of antibiotics was isolated from a soil sample. Cell analysis, colony morphology, the absence of sporangia-like vesicles, the formation of spores in chains of the Rectus Flexibilis type, and the ability to produce melanoid pigment, indicate that this strain belongs to the genus Streptomyces Waksman and Henrici. A comparison of the characteristics of strain S15-1 with related Streptomyces show that it should be identified as Streptomyces purpeofuscus Yamaguchi and Saburi. The investigation of cultural conditions show that soluble starch and meat extract are the most suitable carbon and organic nitrogen sources for the production of antibiotic S15-1. Strain S15-1 grew poorly on media with no organic nitrogen sources, and did not produce the antibiotic. Antiviral antibiotic S15-1 is accumulated at the highest level after 3 or 4 days growth of the producing organism.

Anti-Bacterial Agents↗