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Biomedical subjects

K Tago

Publications and source records attributed to K Tago.

72 records · Page 4Linked to original sources
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

4-Aminobutyraldehyde dehydrogenase activity in rat brain.

An enzyme with NAD+-dependent 4-aminobutyraldehyde dehydrogenase activity was purified about 360-fold from rat brain extract. AMP-Sepharose chromatography was effective in separating the enzyme from other NAD+-dependent aldehyde dehydrogenases included in the extract. The KmS for the substrates NAD+ and 4-aminobutyraldehyde were 4.8 x 10(-4) and 8.3 x 10(-5) M, respectively. The pH optimum for the enzyme was about 8.0. The ratio of activities toward 4-aminobutyraldehyde, propionaldehyde, succinate semialdehyde, and benzaldehyde was 1.00:0.17:0.24:0.09:0.03 when the activity toward 4-aminobutyraldehyde was set equal to 1.00. The enzyme activity in subcellular fractions of rat brain was localized in cytosol.

Aldehyde Oxidoreductases↗
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↗