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Biomedical subjects

S Kubo

Publications and source records attributed to S Kubo.

At least 199 records · Page 11Linked to original sources
PubMed1996

Difference in CDDP penetration into CSF between selective intraarterial chemotherapy in patients with malignant glioma and intravenous or intracarotid administration in patients with metastatic brain tumor.

Platinum (Pt) levels in plasma and cerebrospinal fluid (CSF) in patients with malignant glioma were determined after initiation of selective intraarterial chemotherapy with a combination of VP-16 (etoposide) and CDDP (cisplatin), and were compared with the CSF Pt levels in patients with metastatic brain tumors after intravenous or intracarotid administration of VP-16 and CDDP. CSF Pt levels were also compared for various administration routes, doses, CSF sampling routes and blood-CSF barriers in metastatic brain tumor. Changes in the blood-CSF barrier to CDDP during treatment in a patient with meningeal lymphoma and in a patient recovering from surgical removal of a metastatic brain tumor were also examined by periodic administration of CDDP. All CSF samples were taken through Ommaya reserviors placed in the anterior horn of the lateral ventricle or the postoperative cavity. The mean peak CSF/plasma total Pt ratio (T/T ratio) and the mean CSF total Pt/plasma ultrafiltrable Pt ratio (T/U ratio) were highest (15.0% and 24.4%, respectively) following selective intraarterial infusion of CDDP in patients with malignant glioma, followed by intravenous infusion in meningeal carcinomatosis (11.5% and 18.9%), intracarotid administration (5.4% and 8.7%) and intravenous infusion (60 mg/m2 2.5% and 100 mg/m2 2.9%; and 60 mg/m2 3.5% and 100 mg/m2 7.7%) in patients with the solid type of metastatic brain tumor. In CSF obtained from the postoperative cavity in cases of metastatic brain tumor, T/T and T/U ratios were extremely high (40.9% and 62.4%). However, the CSF Pt level even after selective intraarterial administration of CDDP in malignant glioma was 0.51-1.64 micrograms/ml total Pt and 0.43-1.08 micrograms/ml ultrafiltrable Pt. Even the CSF level obtained from the postoperative cavity was 1.0-4.7 micrograms/ml total Pt. These low levels of total and ultrafiltrable Pt are considered not to be cytotoxic to disseminated cells in the CSF space and to normal brain cells. As for changes in the blood-CSF barrier, repeated administration of CDDP showed that the rate of entry of Pt into the CSF decreased in parallel with improvements apparent on CT scans in the patient with meningeal lymphoma, and also showed that the blood-CSF barrier to Pt was gradually repaired after the metastatic brain tumor had been removed.

Antineoplastic Agents, Phytogenic↗
PubMed1996

Ventriculolumbar perfusion chemotherapy with methotrexate and cytosine arabinoside for meningeal carcinomatosis: a pilot study in 13 patients.

Thirteen patients with meningeal carcinomatosis were treated by ventriculolumbar perfusion using methotrexate (MTX) and cytosine arabinoside (Ara-C). MTX (10-30 mg) and Ara-C (40 mg) were infused at 8- to 12-hour intervals on six or nine occasions via an Ommaya reservoir placed in the lateral ventricle. Nine of thirteen patients had evaluable response (69% response rate with a mean survival of 8.8 months among responders) and ventriculolumbar perfusion therapy was effective in improving cerebral, cranial nerve, and spinal root signs and symptoms, especially sensorimotor disturbance in the lower limbs. Three of the six bedridden patients became ambulatory without assistance and two of the four patients who were walking with assistance became ambulatory without assistance. Urinary incontinence also markedly improved, except in one nonresponder. Lumbar cerebrospinal fluid parameters (cytological findings and tumor markers) also improved in association with the clinical improvement. Our pilot results were encouraging, especially the improvement of sensorimotor function in the lower limbs. However, the toxicity was unacceptable when compared with that of standard intrathecal chemotherapy. Thus, this therapy needs to be investigated further to establish the most appropriate drug doses and perfusate volume to reduce toxicity as well as determine its true efficacy in the treatment of meningeal carcinomatosis.

Adult↗
PubMed1996

Experimental infusion phlebitis: importance of titratable acidity on phlebitic potential of infusion solution.

The titratable acidity of infusion solutions has never been taken into account in infusion phlebitis. This study aims to clarify the importance of titratable acidity on the phlebitic potential of infusion solutions. Solutions with different titratable acidity (from 0.16 to 12 mEq/L) were infused into the ear veins of 6 rabbits for 6 h at 10 mL/kg/h, and the veins were later examined histopathologically. Even at pH 4.0, a commercial 10% glucose solution scarcely caused any changes because of its very low titratable acidity (0.16 mEq/L). A 10% glucose solution with its titratable acidity adjusted to 3 mEq/L (pH 4.3) with citrate and NaOH, however, caused phlebitic changes in all 6 rabbits, and adjusting the titratable acidity to 12 mEq/L (pH 4.4) increased the degree of phlebitis. On the other hand, a 10% glucose solution with a pH of 5.4 and a titratable acidity of 6 mEq/L caused slight phlebitic changes in half the rabbits. These results suggest that 1) the titratable acidity of infusion solutions is important to the phlebitic potential when the pH is low, 2) when the pHs are similar, the phlebitic potential of infusion solutions depend on the titratable acidity, and 3) the phlebitic potential of infusion solutions can not be estimated by pH or titratable acidity alone.

Journal Article↗
PubMed1996

Clinical usefulness of frequent short-time hemodiafiltration: trial for the effective removal of beta-2-microglobulin.

The aim of this study was to examine whether the frequent short-time hemodiafiltration (FSHDF) could remove beta2-microglobulin (beta2m), an amyloidogenic factor, more effectively compared with the conventional hemodiafiltration (CHDF). A uremic patient underwent FSHDF (each 90 min, 6 times/week) for 6 weeks after CHDF (each 4 h, 3 times/week) for 6 months. Pretherapeutic plasma concentrations of beta2m, small molecules, electrolytes and bicarbonate were measured every Monday for 4 weeks during CHDF and for 6 weeks during FSHDF. The body weight gain during these weeks was also determined. The time average concentrations in beta2m and blood urea nitrogen (TACbeta2m and TACBUN) were evaluated based on their concentrations in pre-, post- and intertherapeutic plasmas frequently collected for 1 week each during CHDF and FSHDF. The quantities of total protein, albumin and beta2m in the removed fluids for the same week were determined. The pretherapeutic concentration in beta2m was significantly lower (18.7 +/- 1.3 mg/l) during FSHDF than CHDF (32.4 +/- 2.8 mg/l). The TACbeta2m was decreased during FSHDF (from 23.5 to 13.7 mg/l), while the TACBUN did not change. The pretherapeutic bicarbonate concentration was higher and the gain of body weight per week was lower during FSHDF although the other parameters were not different. It is concluded that FSHDF therapy is more effective to decrease beta2m concentration and correct acidosis together with an adequate urea removal and clinical safety.

Amyloidosis↗
PubMed1996

Nested polymerase chain reaction for detection of low levels of enterotoxigenic Clostridium perfringens in animal feces and meat.

A rapid and sensitive method for detecting enterotoxigenic Clostridium perfringens in animal feces and meat is described. The method consists of a combination of nested polymerase chain reaction (PCR) with enrichment culture of the sample. In the PCR, two pairs of oligonucleotide primers homologous to the C. perfringens enterotoxin (CPE) gene were used: the first primer pair amplified a 425-bp fragment and the second one amplified a 199-bp fragment within the fragment amplified by the first PCR. When the specificity and sensitivity of nested PCR in the detection of the CPE gene of isolated C. perfringens were compared with those of the single PCR, the former amplified specifically the 199-bp fragment and the sensitivity was about 10(3)-fold higher that that of the latter. The nested PCR combined with enrichment culture was applied to detecting the CPE gene in samples inoculated artificially with enterotoxigenic C. perfringens. This method detected within 22-26 hr the CPE gene in samples of animal feces and meat inoculated with fewer than 10(1) CFU/g of enterotoxigenic C. perfringens. When the method was applied to detection of indigenous enterotoxigenic C. perfringens in cattle feces, pig feces, beef and pork, C. perfringens was found in one case (10%) of 10 cattle fecal samples, and the PCR-amplified product corresponded to the fragment of the CPE gene in restriction endonucleases digestion pattern.

Animals↗
PubMed1996

Purification and characterization of cell growth factor in bovine colostrum.

Bovine colostrum has growth factor activity for stimulating DNA synthesis in calf kidney epithelial cells (CKT-1), Madincanine kidney epithelial cells (MDCK) and rat L6 myoblasts (L6), of which the DNA stimulation level and the activity change with the time elapsed after the birth of a calf varied with their respective cells. The growth factor activity of colostrum for CKT-1 was stable regardless of the collection time of colostrum, and it was purified about 3,650-fold in an overall yield of 1.2% from colostrum obtained 30 min after the birth of a calf. The purified growth factor had a molecular weight (MW) of 5,000 and an isoelectric point of pH 9.7, and the amino acid composition was: Asx5, Thr2, Ser4, Glx14, Pro2, Gly4, Ala4, Val2, Ile, Leu2, Tyr, Phe, Lys, His and Arg. The stimulated DNA synthesis in CKT-1 and L6 by the addition of purified growth factor at a final concentration of 16ng/ml was as the same extent as calf serum at a final concentration of 1.52 mg/ml, and the relative activity for CKT-1 was even greater than that for L6.

3T3 Cells↗
PubMed1996

Inhibition of chemiluminescence response of human polymorphonuclear leukocytes by three different stimulations in hyperosmotic condition comparable to the renal medulla.

Hyperosmolality in renal medulla inhibits functions of polymorphonuclear leukocyte (PMN) such as phagocytosis, intracellular killing, and superoxide generation. The main factors of hyperosmolality in the renal medulla are thought to be urea and NaCl. We studied the luminol-dependent chemiluminescence (CL) response of PMNs to three different stimulators: phorbol myristate acetate (PMA), formyl-methionyl-leucyl-phenylalanine (FMLP), and opsonized zymosan (OZ). When PMNs were incubated or preincubated with hyperosmotic urea or NaCl solutions, CL responses were significantly reduced following stimulation by each of PMA, FMLP, or OZ. Reduction of CL response was concentration and osmolality dependent in hyperosmotic urea and NaCl solution. These results suggest that respiratory burst and production of active oxygen species of PMNs through three different signal transduction pathways are inhibited in hyperosomotic conditions comparable to the renal medulla.

Cells, Cultured↗
PubMed1996

Glucose and xylitol tolerance tests for ketotic and healthy dairy cows.

Intravenous administration of 500 ml of 50% glucose solution to 10 nonketotic dairy cows increased the blood glucose and insulin concentrations 7-fold immediately following administration. Blood glucose and insulin concentrations of ketotic cows were about 6- and 3-fold higher, respectively, immediately following glucose administration. Administration of 1000 ml of 25% xylitol (xylo-pentane-1,2,3,4,5-pentol) in nonketotic cows increased blood glucose and insulin concentrations 2- and 9-fold, respectively. Ketotic cows treated with xylitol exhibited blood insulin concentration 12-fold higher following administration. This insulin increase might be explained by a decrease in insulin degradation because of the diffusion of xylitol, which is not dependent on insulin in peripheral tissues. For ketotic cows given xylitol, serum concentrations of free fatty acid decreased, and triglyceride concentrations and aspartic acid aminotransferase activity increased, but values were unchanged by xylitol administration to nonketotic cows. Thus, for ketotic cows, the responses of the blood glucose and insulin concentrations to xylitol administration were better than those responses to glucose administration. Improvements in clinical signs, i.e., disappearance of urinary ketone bodies and recovery to normal feed consumption, also suggested the usefulness of xylitol administration for the treatment of ketosis.

Animals↗
PubMed1996

[An autopsy case of the Reye's syndrome].

A case of sudden unexpected natural death in a 6-year-old girl was reported. She was found in dead with vomiting on her bed in the morning on 24. December. Autopsy did not reveal any injuries and abnormalities on her appearance. Small amount of light yellowish mucus in her nose, trachea and bronchus was found. Brain was slightly edematous (1395 g in weight). Liver was 750 g in weight and focal yellowish lesions were observed on its cut surfaces. Microscopically fatty degeneration (granulous fatty deposits) was observed in hepatocytes. Immunohistochemical staining of mitochondria in heart showed no staining microscopically, and degeneration and breakdown of mitochondria were found electromicroscopically. From the results of autopsy and histopathological findings, her cause of death was diagnosed as the Reye's syndrome.

Child↗
PubMed1996

Mechanism that regulates nitric oxide production by lipopolysaccharide-stimulated rat Kupffer cells.

Mechanism that regulates nitric oxide (NO) production by stimulated Kupffer cells was studied. Lipopolysaccharide (LPS) stimulated NO production by primary-cultured Kupffer cells in a time- and dose-dependent manner. Twenty-four h after incubation with 1 microgram/ml of LPS, the nitrite concentration in the culture medium increased from 2.87 +/- 1.4 to 73.6 +/- 6.9 nmol/ml. NO production started to increase around 6 h after adding LPS and reached a maximum within 24 h. NO production was inhibited by 0.3 mM of NG-monomethyl-L-arginine and was reversed by adding 3 mM of L-arginine. When incubated with 1 microgram/ml of LPS for 24 h, NO synthase activity in Kupffer cells increased from 0.164 +/- 0.035 to 3.16 +/- 0.11 nmol/min/mg protein. Dexamethasone and prednisolone significantly inhibited the induction of NO synthase and NO production in Kupffer cells. Expression of mRNA for inducible type of NO synthase (iNOS) started to increase around 4 h after adding LPS (1 microgram/ml) and reached a maximum by about 20 h. The enhanced expression of iNOS mRNA was also suppressed by 1 microM dexamethasone. On the other hand, calcium ionophore A23187 significantly enhanced the induction of NO synthase and iNOS mRNA expression in LPS-stimulated Kupffer cells. In addition, a tyrosine kinase inhibitor, genistein (100 microM), significantly inhibited NO production by LPS-stimulated Kupffer cells. Neither phorbol 12-myristate 13-acetate, dibutyryl cAMP, indomethacin nor a protein kinase C inhibitor H-7 affected NO production by Kupffer cells. These results suggested that iNOS mRNA expression, NO synthase activity and NO production increased in LPS-stimulated Kupffer cells by a glucocorticoid-inhibitable mechanism and that Ca2+ and tyrosine phosphorylation might play important roles in LPS-dependent induction of NO synthase.

Animals↗
PubMed1995

Effects of superoxide dismutase on nitric oxide production during reperfusion after focal cerebral ischemia is rats.

To assess the interaction of nitric oxide (NO) and superoxide during reperfusion after cerebral ischemia, we studied the dose effects of superoxide dismutase (SOD) on the levels of nitrosyl hemoglobin and plasma nitrite + nitrate which were increased at 30 min reperfusion after 2 h middle cerebral artery occlusion in rats. SOD was administered at 10 min before reperfusion. With 1, 5 and 10 mg/Kg of SOD, plasma nitrite + nitrate level was decreased by 25 mg/kg of SOD. The same amount of apo enzyme was without effect. These results suggest effect of superoxide in the NO level released during reperfusion after cerebral ischemia.

Animals↗
PubMed1995

Percutaneous transvenous mitral commissurotomy for mitral stenosis patients with markedly severe mitral valve deformity: immediate results and long-term clinical outcome.

In conclusion, to evaluate the efficacy and safety of PTMC for mitral stenosis patients with markedly severe valve deformity, we performed PTMC in 17 patients with severe mitral stenosis assessed by echocardiography (echo score > or = 12). This study demonstrates that PTMC can be performed safely and is clinically useful in treating the mitral stenosis patient with a markedly severe valve deformity.

Adult↗
PubMed1995

Cloning and sequencing of the gene coding for dextranase from Streptococcus salivarius.

We cloned and sequenced the dextranase (Dex) (1,6-alpha-glucanhydrolase; EC 3.2.1.11)-encoding gene from Streptococcus salivarius (Ss) strain M-33. Recombinant clones from an Ss genomic library specifying Dex activity were identified as colonies surrounded by transparent halos on blue dextran plates. One of the clones had a 4.3-kb KpnI fragment containing the gene coding for an 826-amino-acid polypeptide with a molecular mass of 87.9 kDa, which corresponds well to that of native Dex from the Ss culture supernatant. There was no sequence homology between the gene encoding Ss Dex and the gene encoding dextran glucosidase of S. mutans, or between their protein products.

Amino Acid Sequence↗
PubMed1995

[Lys(-2)-Arg(-1)]endothelin-1 solution structure by two-dimensional 1H-NMR: possible involvement of electrostatic interactions in native disulfide bridge formation and in biological activity decrease.

Addition of the Lys(-2)-Arg(-1) dipeptide, present in the precursor protein, to the N-terminus of endothelin-1 (ET-1), to form a 23-residue peptide (KR-ET-1) has been shown to greatly improve formation of native disulfide bridges and to dramatically decrease biological activity. Conformational analysis was carried out on this peptide. During protonation of the carboxyl groups, CD spectra showed a decrease in the helical contribution, and NMR spectra displayed strong chemical shift modifications, suggesting the importance of electrostatic interactions in the KR-ET-1 conformation. CD spectra and two-dimensional NMR experiments were performed to investigate the KR-ET-1 three-dimensional structure in water in the carboxylic acid and carboxylate states. Distance and angle constraints were used as input for distance geometry calculations. The KR-ET-1 carboxylic acid conformation was found to be very similar to ET-1, with a helix spanning residues 9-15 and an unconstrained C-terminal part. In contrast, in the carboxylate state, large changes in Arg(-1) and Phe14 chemical shifts and long-range NOEs were consistent with a conformation characterized by a helix extension to Leu17 and a stabilized C-terminal section folded back toward the N-terminus. In addition, thanks to NOEs with Cys11 and Phe14, the Arg(-1) side chain appeared well-defined. Simulated annealing and molecular dynamics calculations, supported an Arg(-1)-Glu10 salt bridge and an electrostatic network involving the charged groups of Trp21, Asp18, and Lys(-2). Moreover, stabilization of the KR-ET-1 C-terminal part is probably reinforced by hydrophobic interactions involving the Val12, Tyr13, Phe14, Leu17, Ile19, Ile20, and Trp21 side chains. In vitro, native disulfide bond formation improvement observed for KR-ET-1 could be ascribed to electrostatic interactions and more specifically to the Arg(-1)-Glu10 salt bridge. In vivo, similar interactions could play an important role in the native folding of the ET-1 precursor protein. On the other hand, modification in the environment and a reduced mobility of the KR-ET-1 Trp21 key residue, when compared to ET-1, could explain, at least in part, the strong decrease in biological activity.

Acetates↗