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K Sano

Publications and source records attributed to K Sano.

At least 379 records · Page 21Linked to original sources
PubMed1993

Protocadherins: a large family of cadherin-related molecules in central nervous system.

Using the polymerase chain reaction, we have isolated numerous rat and human cDNAs of which the deduced amino acid sequences are highly homologous to the sequences of the extracellular domain of cadherins. The entire putative coding sequences for two human proteins defined by two of these cDNAs have been determined. The overall structure of these molecules is very similar to that of classic cadherins, but they have some unique features. The extracellular domains are composed of six or seven subdomains that are very similar to those of cadherins, but have characteristic properties. The cytoplasmic domains, on the other hand, have no significant homology with those of classic cadherins. Since various cDNAs with almost identical features were obtained also from Xenopus, Drosophila and Caenorhabditis elegans, it appears that similar molecules are expressed in a variety of organisms. We have tentatively named these proteins protocadherins. They are highly expressed in brain and their expression appears to be developmentally regulated. The proteins expressed from the two full-length cDNAs in L cells were approximately 170 or 150 kDa in size, and were localized mainly at cell-cell contact sites. Moreover, the transfectants showed cell adhesion activity.

Amino Acid Sequence↗
PubMed1993

Negative selection of thymus-dependent CD4+8+ intestinal intraepithelial lymphocytes by internal superantigens.

CD4 and CD8 double-positive (DP) T cells were transiently found in the Peyer's patch of mice 2 to 3 weeks after birth and preceded the appearance of DP intestinal intraepithelial lymphocytes (iIEL). DP iIEL were detected in euthymic-specific pathogen-free mice, but not in athymic and germ-free mice. The pattern of V beta genes expressed on these DP iIEL was similar to that of CD4 single-positive peripheral T cells, which reflected the negative selection by internal superantigens, M1s, and I-E. CD8 SP T cells did not receive such a strict negative selection with these antigens. DP iIEL expressed a high density of T cell receptor alpha beta and CD3 and responded to immobilized anti-CD3 to undergo blastogenesis and de novo IL2 receptor expression. These results indicate that DP iIEL are mature thymus-dependent T cells immigrated to intraepithelial space via the Peyer's patch in response to intestinal antigenic stimulation.

Animals↗
PubMed1993

Cytotoxic activity of rev protein of human immunodeficiency virus type 1 by nucleolar dysfunction.

The rev protein (Rev) of the human immunodeficiency virus type 1 (HIV-1) is known as a post-transcriptional regulator of viral gene expression. It is located in the cell nucleolus. Transiently expressed Rev caused nucleolar ballooning and deformity with aberrant accumulation of rRNAs, and de novo synthesis of rRNAs decreased dramatically in these cells. However, similarly expressed rex protein (Rex) of the human T-cell leukemia virus type I, which is a functional homologue to Rev, did not affect nucleolar structure and function. Rev expression resulted in cell death with nucleolar destruction in an inducible cell line. Analysis of Rev mutants revealed that both the nucleolar targeting signal of Rev and the multimerization domain are prerequisites to the nucleolar disintegration by Rev. Human T-cells acutely infected with HIV-1 contained nucleoli which were deformed and filled with Rev, but chronically infected cells had intact nucleoli. Involvement of Rev in cytopathic effects in HIV-1 infection is discussed.

Base Sequence↗
PubMed1993

Brain stem haemorrhage during transsphenoidal surgery. Possible risk of the manoeuvre of increasing the endexpiratory pressure in a case of pituitary adenoma associated with dural arteriovenous malformation. Case report.

The authors report a case of pituitary adenoma associated with dural arteriovenous malformation (AVM), which caused brain stem haemorrhage during transsphenoidal surgery. The manoeuvre of increasing the endexpiratory pressure in order to push the suprasellar component of the adenoma down to the sella turcica could be the reason of this bleeding. The authors therefore recommend that in cases of such a combination any manoeuvres which are likely to increase the intracranial venous pressure or otherwise affect the intracranial pressure, are avoided. The dural AVM spontaneously regressed after haemorrhage.

Adenoma↗
PubMed1993

Serum depletion increases the neurofilament protein mRNA levels in a neuroblastoma cell line, GOTO.

A human neuroblastoma cell line, GOTO, extends neurite-like processes upon withdrawal of serum from culture medium. This morphological change was accompanied by a 5-fold increase in the neurofilament (NF)-L and a 10-fold increase in the NF-M mRNA levels after 24 h. The addition of a protein kinase inhibitor, H-7 (1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride) also induced the extension of neurite-like processes; however, it did not increase the NF mRNA levels. Thrombin inhibited the extension of neurite-like processes in serum-free culture without affecting the increase in the NF mRNA levels. There was no difference in the number of cells progressing through the S phase between serum-containing and -free cultures at 24 h. This indicates that the increase in the NF mRNA levels upon withdrawal of serum was not preceded by the growth arrest. Treatment with actinomycin D and cycloheximide inhibited the increase in the NF mRNA levels. The half life of the NF gene transcripts was prolonged in the serum-free condition. These results indicate that the serum depletion-induced increase in the NF-L and -M mRNA levels was regulated by both transcriptional and post-transcriptional mechanisms, and the increase in the expression of the NF genes was not simply mediated by growth arrest but controlled by unknown regulator proteins.

Cell Division↗
PubMed1993

Short-term changes in lipid and protein metabolism in liver transplants from living-related donors.

The effects of liver transplantation involving living-related donors were investigated in 20 pediatric cases in terms of protein and lipid metabolism using the extent of cholesterol esterification and the levels of total cholesterol, lecithine-cholesterol acyltransferase, apolipoprotein A-I, cholinesterase, and rapid turnover proteins as parameters. Cholesterol esterification increased from preoperative values of 39% +/- 4% to 67% +/- 1% (mean +/- SEM, n = 17) at 3 weeks after liver transplantation in successful cases but decreased from the preoperative value of 45% +/- 10% to 26% +/- 6% (n = 3) at 3 weeks in unsuccessful cases. Cholinesterase, transferrin, and prealbumin levels remained low after 3 weeks even in successful cases. Patients who had partial liver transplantations from living-related donors showed rapid recovery of cholesterol esterification. However, patients with graft livers required an extensive period before normalization of protein metabolism occurred, indicating the necessity for long-term follow-up of recipient development.

Adolescent↗
PubMed1993

Effects of photodynamic therapy in the normal mouse tongue.

The effects of photodynamic therapy (PDT) on the normal mouse tongue were investigated. After using various doses (2.5, 10, and 20 mg/kg body wt) of the photosensitizing drug hematoporphyrin oligomers and 90 or 180 J/cm2 red light (630-nm) emitted from a pulsed neodymium:yttrium-aluminum-garnet dye laser was used to activate it 3 or 24 hours later. It was found that the 20-mg/kg dose elicited a severe response that included extensive vesicular and edema formation. A less severe response was observed with 10 mg/kg of the drug and low-power light (5 mJ/cm2/pulse) periodically delivered (1 hour interval between two 30-minute photoradiations). Such a regimen, however, produced more damage when compared with the higher power (15 mJ/cm2), continuous light delivery counterpart. Healing, except for the protocol with only a 3-hour drug-light interval, was attained by 5 days post-PDT as indicated by regeneration with histologically normal tissues and quantitatively a return to untreated, control values for cross-sectional areas and number of blood vessels. Bromodeoxyuridine immunohistochemistry disclosed an immediate increase in the labeling indices, ie, the percentage of S phase cycling cells, indicating stimulated cell proliferation secondary to repair and fast repopulation of the epithelium. Under the commonly used protocols, PDT was provided safely to the mouse tongue. The regimen of low drug dose and low power of light periodically delivered appears to be the most acceptable method. These parameter-dependent results may partly form the basis for the judicious application of PDT to the oral cavity.

Animals↗
PubMed1993

Absorption of recombinant human granulocyte colony-stimulating factor (rhG-CSF) from rat nasal mucosa.

Nasal absorption of recombinant human granulocyte colony-stimulating factor (rhG-CSF) was examined in the rat. The relative bioavailability of rhG-CSF for subcutaneous administration was approximately 2%, as evaluated from the immunologically active rhG-CSF concentration in rat plasma and the area under the curve (AUC) of the plasma rhG-CSF concentration versus time for 8 hr. Pharmacological availability relative to subcutaneous administration was determined from the increase in total blood leukocyte numbers. The pharmacological availability was 5-10%, determined from the AUC for the increased ratio of total leukocyte numbers versus time for 48 hr; it was slightly dependent on the pH and the osmotic pressure of the dosing solution. Accordingly, the plasma concentration of rhG-CSF did not always reflect its pharmacological effects. Relative bioavailability and pharmacological availability were increased about 23 times and 3 times, respectively, by polyoxyethylene 9-lauryl ether (Laureth-9), but no increase in availability occurred with sodium glycocholate. The increase in total leukocyte numbers was maintained during multiple rhG-CSF dosing, and the addition of Laureth-9 further increased the pharmacological effects of this agent. This study indicates that nasal administration of rhG-CSF is an effective parenteral administration route.

Absorption↗
PubMed1993

Lipid metabolism after liver transplantation from a living related donor.

1. The recovery of lipid metabolism was investigated in paediatric patients treated for terminal liver disease by liver transplantation from living related donors. 2. The cholesterol ester ratio (esterified cholesterol/total cholesterol) and the total cholesterol/phospholipid ratio increased from preoperative values of 0.35 +/- 0.04 and 0.59 +/- 0.03 to 0.65 +/- 0.01 and 0.68 +/- 0.01 at 3 weeks after liver transplantation in successful cases (means +/- SEM, n = 26), respectively, whereas these two parameters decreased in failed cases (n = 4). 3. Biochemical analysis indicated that weekly recoveries in the cholesterol ester ratio and the total cholesterol/phospholipid ratio are characteristic of successful liver transplantation with a graft from a living related donor.

Adolescent↗
PubMed1993

A carcinoid tumor of the rectum removed by strip biopsy.

In a 29-year-old male complaining of constipation, total colonoscopy revealed a 5 mm yellowish submucosal tumor at a distance of 6 cm from the anal ring. The histologic diagnosis of specimens obtained by biopsy was rectal carcinoid tumor and transanal ultrasonography revealed the tumor localization within the submucosal layer in the rectum. A strip biopsy was performed. Histopathological examination confirmed the diagnosis and ascertained complete excision. Rectal carcinoid tumors should be removed completely and strip biopsy may be a suitable procedure for removal of rectal submucosal tumors less than 10 mm in diameter.

Adult↗
PubMed1993

Surgical techniques and innovations in living related liver transplantation.

The authors successfully performed a series of 33 living related liver transplantations (LRLT) on children (15 males and 18 females, ranging from 7 months to 15 years of age) from June 1990 to May 1992, with the informed consent of their parents and the approval of the Ethics Committee of Kyoto University. Before operation, six of the children required intensive care, another 14 were hospitalized, and 13 were homebound. Donors (12 paternal and 21 maternal) were selected solely from the parents of the recipients on the basis of ABO blood group and graft/recipient size matching determined by computed tomography scanning. Procurement of graft was performed using ultrasonic aspirator and bipolar electrocautery without blood vessel clamping and without graft manipulation. All donors subsequently had normal liver function and returned to normal life. The left lateral segment (16 cases), left lobe (16 cases), or right lobe (one case) were used as grafts. The partial liver graft was transplanted into the recipient who underwent total hepatectomy with preservation of the inferior vena cava using a vascular side clamp. Twenty-seven of 33 recipients are alive and well with the original graft and have normal liver function. The patient survival rate was 89% (24/27) in elective cases and 50% (3/6) in emergent cases. The other six recipients had functioning grafts but died of extrahepatic complications. Complications of the graft were minimal in all cases. Hepatic vein stenosis, which occurred three times in two cases, was successfully treated by balloon dilatation. In cases with sclerotic portal vein, the authors anastomosed the portal vein of the graft to the confluence of the splenic vein and the superior mesenteric vein without a vascular graft, after experiencing a case of vascular graft thrombosis. After hepatic artery thrombosis occurred in one of the initial seven recipients whose arterial anastomosis was done with surgical loupe, microsurgery was introduced for hepatic artery reconstruction. There has been no occurrence of thrombosis since then. The current results with LRLT suggested that the meticulous management of surgical factors at each stage of the LRLT procedure is crucial for successful outcome. Living related liver transplantation is a promising option for resolving the graft shortage in pediatric liver transplantation and may be regarded as an independent modality to supplement cadaver donation.

Adolescent↗
PubMed1993

Experience with FK506 in living-related liver transplantation.

The new immunosuppressive agent FK506 was used with steroids to treat 22 pediatric patients who received living-related partial liver transplantation. Seventeen recipients survived and 5 died between one and 16 months after transplantation. Three of the 5 patients who died had required intensive care preoperatively. Autopsy findings showed no evidence of rejection. There was no episode of rejection that required retransplantation in any of the patients. Liver allograft dysfunction, which was suspected to be a rejection response, was encountered in 2 recipients with ABO-nonidentical but compatible grafts. However, their clinical and biochemical findings were ameliorated upon steroid pulse therapy or upon augmented FK506 administration without additional potent immunosuppressive agents. Steroid treatment has been discontinued in all surviving patients at 1-9 months after transplantation. Infectious complications encountered in 9 patients included 2 bacterial, 5 viral, and 2 fungal infections. One recipient died of fungal pneumonia. Abnormal increase of serum creatinine level was confined to the complicated patients. Hypertension was a temporary adverse reaction in the early postoperative period, and only one patient needed an antihypertensive drug at 2 months after transplantation. Acute pancreatitis with hyperamylasemia was observed in one patient who was treated successfully with reduction of FK506 administration. Tremor was observed in 8 patients, itching in 4, insomnia in 2, and vomiting in one. Hirsutism, gingival hypertrophy, and lymphoma were not observed. FK506 was highly effective in living-related partial liver transplantation not only in terms of immunosuppressive potential but also because it produced fewer adverse effects.

Adolescent↗
PubMed1993

[A stick type filter unit for prevention of biohazard in a research laboratory].

It is important to prevent unexpected laboratory infections in a biosafety area. It is recommended that extreme caution should be used when handling needles and syringes to avoid autoinoculation, and that needles and syringes should be used only when there is no alternative. To remove cells and cell debris, a disk-type microfilter unit, which is recommended using a needle, has been used for filtrating supernatant from HIV-1-infected cell cultures. We compared a stick-type microfilter unit, which can be used without a needle, with a disk-type one for their safety and recovery of human immunodeficiency virus particle after filtration. To confirm the right of our comparison, we observed the filter electron microscopically for the virus particles and virus suspensions were carried out and discussed. In conclusion, the stick-type filter should be improved, since the filter unit is inferior to the disk-type filter unit in purification of the virus, but for the safety is superior to the disk-type.

Acquired Immunodeficiency Syndrome↗
PubMed1993

[Non-radioisotopic reverse transcriptase assay using biotin-11-deoxyuridine-triphosphate and a primer-immobilized microtiter plate: application for detection and identification of isolated retroviruses from HIV-1-seropositive hemophiliac patients].

Non-radioisotopic reverse transcriptase assay (Non-RTA) was successfully applied for detection and identification of the retroviruses isolated from peripheral mononuclear cells from eight HIV-1-seropositive hemophiliac patients. Of 40 samples, 36 (90%) were consistent in detection between Non-RI and RI RTA. Four samples which showed RT activities slightly above the cutoff level of RI RTA were not detected by Non-RI RTA. Non-specific RT-inhibitors in the culture supernatant decreased the sensitivity of Non-RI RTA more significantly than that of RI RTA. It was demonstrated that higher concentrations (> 20%) of fetal calf serum in RPMI-1640 culture medium inhibited the hybridization of poly rA template with immobilized primer, resulting in reducing the sensitivity of Non-RI RTA. Then we identified the isolated retroviruses using specific RT-inhibiting (RTI) antibodies against HIV-1 and HIV-2. HIV-1 RTI antibody specifically inhibited RTs of isolated retroviruses and HIV-1 strain, LAV-1, but not HIV-2 and Rous-associated virus 2 (RVA-2) RT. Conversely, HIV-2 RTI antibody specifically inhibited HIV-2 RT, but not HIV-1 and RAV-2 RT. These findings agreed with previously reported results showing the type-specificity of HIV-1 and -2 RTI antibodies, and suggest the possibility that isolated retroviruses could be identified by these antibodies.

Biotin↗
PubMed1993

Human neuroblastoma cells express alpha and beta platelet-derived growth factor receptors coupling with neurotrophic and chemotactic signaling.

Both platelet-derived growth factor (PDGF) A- and B-chains are expressed in mammalian neurons, but their precise roles still remain to be clarified. In the present studies, we examined the expression of two PDGF receptor genes in human tumor cell lines derived from neural crest. The expression of alpha and/or beta PDGF receptors was detected in a wide variety of neural crest-derived human tumor cell lines such as neuroblastoma, primitive neuroectodermal tumor, and Ewing's sarcoma by RNA blot analysis, and confirmed by immunoblot analysis. We have also demonstrated that PDGF receptors on the human neuroblastoma cell lines were biologically functional. Accordingly, chemotactic and mitogenic activities were induced by either PDGF-AA or PDGF-BB in serum-free medium. PDGF isoforms as well as nerve growth factor induced morphological changes showing neuronal cell maturation. Moreover, PDGF coordinately increased the levels of the transcript of the midsize neurofilament gene. The neuroblastoma cell lines also expressed the transcripts of PDGF A- and B-chains. These findings suggest that PDGF isoforms are involved not only in the promotion of the neuroblastoma cell growth, but also in neuronal cell migration, growth, and differentiation in human brain development.

Amino Acid Sequence↗
PubMed1993

Coexistence of renin and cathepsin B in secretory granules of granular duct cells in male mouse submandibular gland.

Cathepsin B, a representative lysosomal cysteine proteinase, has been demonstrated to coexist with renin in secretary granules of rat pituitary LH/FSH cells and renal juxtaglomerular cells. We investigated immunocytochemically the localization of cathepsins B, H, and L in the submandibular gland of male mice, in which active renin is also produced. By light microscopy, granular immunodeposits for cathepsin B were detected in epithelial cells of the gland, particularly in granular duct cells and interstitial cells. Immunoreactivity for cathepsins H and L was mainly found in interstitial cells, although that for cathepsin H was weakly seen in acinar cells. By electron microscopy, immunogold particles indicating cathepsin B intensely labeled small granules near the Golgi complex of granular duct cells and weakly labeled large secretory granules, whereas those showing renin labeled both granules. Double immunostaining co-localized immunogold particles showing renin and cathepsin B in small perinuclear granules near the Golgi complex. Some immunopositive granules seemed to be closely associated with the Golgi elements. These results indicate that the co-localization of renin and cathepsin B is also seen in secretory granules of granular duct cells in the mouse submandibular gland, as seen in rat juxtaglomerular and LH/FSH cells. This suggests that cathepsin B is one of the possible candidates for the renin-processing enzyme.

Animals↗