Biomedical subjects

K Naito

Publications and source records attributed to K Naito.

At least 19 recordsLinked to original sources

PubMed1992

Intranasal aerodynamic aspects in patients with nasal septal perforations.

In an attempt to determine the influence of septal perforations on nasal airflow, nasal resistances were measured with active posterior rhinomanometry and compared before and after closure of asymptomatic septal perforations in five patients. No significant differences were found in the nasal resistances before and after closure of perforations either on inspiration or expiration. All patients were also unaware of any perceptive changes in nasal patencies after closure of the perforations.

Aged↗

PubMed1992

Cloning and mapping of the CYS4 gene of Saccharomyces cerevisiae.

A DNA fragment containing the CYS4 gene of Saccharomyces cerevisiae was isolated from a genomic library. The cloned fragment hybridized to the transverse-alternating-field-electrophoresis band corresponding to chromosomes VII and XV. According to the 2 microns DNA chromosome-loss procedure, the cys2 and cys4 mutations, which are linked together and co-operatively confer cysteine dependence, were assigned to chromosome VII. By further mapping involving tetrad analysis, the cys2-cys4 pair was localized between SUP77 (SUP166) and ade3 on the right arm of chromosome VII.

Acetyltransferases↗

PubMed1992

Methotrexate, vinblastine, doxorubicin, and cisplatin for advanced urothelial cancer.

A series of 31 patients with advanced urothelial cancer were treated with combination chemotherapy consisting of 1-4 cycles of methotrexate, vinblastine, doxorubicin, and cisplatin (M-VAC). Of the 31 patients, 29 had measurable and evaluable lesions. A complete remission was achieved by 4 of these 29 patients (14%) for 1-46 months. A partial remission was observed in 14 of the 29 patients (48%) for 1-9 months. Whereas bony and hepatic metastatic lesions did not respond, some nodal (7/12), pulmonary (4/8), and pelvic lesions (2/3) as well as primary bladder tumors (4/6) and a tumor marker (1/2) responded. Complete tumor remission was observed in nodal (2/12) and pulmonary (1/8) metastatic lesions, in invasive lesions to the prostate and seminal vesicle (1/1), and in primary lesions in the bladder (2/6), ureter (1/1), and urethra (1/1). Two of three patients with non-transitional cell tumors attained a partial remission for 1-7 months. Complete remission of the pulmonary lesions was obtained in a case of squamous cell cancer of the bladder with pulmonary metastases. The toxicity of this regimen was generally tolerable and included moderate to severe myelosuppression, mild to moderate nausea and vomiting, renal toxicity, and mucositis. These results suggest that the M-VAC regimen holds promise for the treatment of advanced metastatic transitional cell cancer as well as non-transitional cell cancer of the urothelium.

Aged↗

PubMed1992

Combined Repeat Dose and Reproductive/Developmental Toxicity Screening Test (OECD): familiarization using cyclophosphamide.

A familiarization study was conducted on the "Combined Repeat Dose and Reproductive/Developmental Toxicity Screening Test (ReproTox)" proposed by the OECD. Cyclophosphamide (CP) at doses of 6.7, 4.5, 3, 2, and 0 mg/kg body wt was given daily by gavage to groups of 12 male and 12 female Sprague-Dawley rats. As a result, anemia and leukopenia were evident in treated males. The absolute and relative thymus and spleen weights were decreased in treated rats. Histopathologically, atrophy of the thymus, spleen, and bone marrow was observed. With respect to the reproductive/developmental toxicity, dose-dependent increases in postimplantation loss of fetuses and postnatal death were found in dams given CP. The body weight of pups treated with CP was significantly lowered in a dose-related manner. Thus the results demonstrated most of the known toxicological properties of CP, except the adverse effects on spermatogenesis and fertility. Therefore ReproTox can be considered as a useful screening test for assessing repeat dose and reproductive/developmental toxicity of existing chemicals of high production volume.

Animals↗

PubMed1992

Production of normal mice from oocytes fertilized and developed without zonae pellucidae.

Mouse oocytes, freed from zonae pellucidae, were inseminated and cultured in vitro. When inseminated with a modest concentration of spermatozoa (approximately 5/microliter), 79% of 151 oocytes were fertilized normally, of which the majority developed into blastocysts. When 177 blastocysts were transferred to 12 pseudopregnant foster mothers, 10 (83%) of the mothers became pregnant and 37 live pups were obtained. Although the overall rate of development of zona-free embryos was slightly inferior to that of zona-intact (control) embryos, these results nevertheless indicate that the oocyte and embryo are potentially capable of normal fertilization and development in the total absence of the native zona pellucida. Since the acrosome reaction is essential for successful sperm-oocyte fusion, zona-free oocytes must have been fertilized by spermatozoa which had undergone the reaction either in the medium or on the surface of the oocyte plasma membrane. Such acrosome reactions, which are not mediated by the native zona pellucida, can be called 'unphysiological' or 'spurious' but the spermatozoa with such reactions were certainly functional, as they produced healthy offspring.

Animals↗

PubMed1992

Maturation, fertilization, and development of dog oocytes in vitro.

Preovulatory oocytes were collected from ovaries of beagle bitches that had received superovulatory treatment. They were cultured in a modified Krebs-Ringer bicarbonate solution containing 10% fetal calf serum and 30 mg/L gentamicin sulfate for up to 72 h. About 32% of oocytes reached metaphase II by 72 h of culture. When these in vitro-matured oocytes were inseminated with ejaculated beagle spermatozoa that had been preincubated for 4 h, sperm penetration of the zona pellucida started about 1 h after insemination, and both male and female pronuclei were seen in the ooplasm at 8 h after insemination. At 18-20 h after insemination, oocytes were transferred to Whitten's medium and cultured for 76-78 h. The first cleavage was observed at 48 h after insemination, and 15 of 45 oocytes developed to the 2-8-cell stage. These results demonstrate that in vitro-matured canine oocytes can be fertilized and develop to the 8-cell stage in vitro.

Animals↗

PubMed1992

Comparison of histone H1 kinase activity during meiotic maturation between two types of porcine oocytes matured in different media in vitro.

Histone H1 kinase (H1K) activity was assayed during meiotic maturation in porcine oocytes matured in a modified Krebs-Ringer bicarbonate solution (KRB) or in porcine follicular fluid (pFF) in vitro. Oocytes matured in KRB displayed lower male pronucleus formation ability, delayed first polar body emission, and a higher spontaneous activation rate than oocytes matured in pFF. In oocytes matured in pFF, H1K activity was low at the germinal vesicle stage and increased about 8-fold at first and second metaphases, with a transient depression at first anaphase and telophase. The H1K activity at second metaphase in oocytes matured in KRB was significantly lower than that in oocytes matured in pFF. These results suggest that the maturation medium used influences the fluctuation pattern of H1K activity and the biological characteristics of porcine oocytes cultured in vitro.

Animals↗

PubMed1992

Effect of a partial deletion of Y chromosome on in vitro fertilizing ability of mouse spermatozoa.

The effect of a partial deletion of Y chromosome on sperm fertilizing ability was investigated through an in vitro fertilization technique. Epididymal spermatozoa of a congenic line, B10.BR-Ydel, which is characterized by a high incidence of abnormal spermatozoa, revealed a significantly lower in vitro fertilization rate (22%) than that (79%) of its control strain (B10.BR/SgSn), which has a normal-sized Y chromosome. Incidence of capacitated spermatozoa as determined by chlortetracycline fluorescence assay was significantly lower in B10.BR-Ydel than in B10.BR/SgSn spermatozoa. The fertilization rate was significantly improved when B10.BR-Ydel spermatozoa were separated from the supernatant of sperm suspension by Percoll gradient centrifugation. A reconstitution experiment revealed that the B10.BR-Ydel spermatozoa were more sensitive to the inhibitory effect of the supernatant than B10.BR/SgSn spermatozoa. Spermatozoa from F1 (C57BL/6N male x B10.BR-Ydel female) males showed higher fertilization rates than those from F1 (B10.BR.Ydel male x C57BL/6N female) males. These observations suggest that not only the morphology but also the fertilizing ability of spermatozoa is directly related to partial deletion of Y chromosome.

Animals↗

PubMed1992

Cloning and characterization of the CYS3 (CYI1) gene of Saccharomyces cerevisiae.

A DNA fragment containing the Saccharomyces cerevisiae CYS3 (CYI1) gene was cloned. The clone had a single open reading frame of 1,182 bp (394 amino acid residues). By comparison of the deduced amino acid sequence with the N-terminal amino acid sequence of cystathionine gamma-lyase, CYS3 (CYI1) was concluded to be the structural gene for this enzyme. In addition, the deduced sequence showed homology with the following enzymes: rat cystathionine gamma-lyase (41%), Escherichia coli cystathionine gamma-synthase (36%), and cystathionine beta-lyase (25%). The N-terminal half of it was homologous (39%) with the N-terminal half of S. cerevisiae O-acetylserine and O-acetylhomoserine sulfhydrylase. The cloned CYS3 (CYI1) gene marginally complemented the E. coli metB mutation (cystathionine gamma-synthase deficiency) and conferred cystathionine gamma-synthase activity as well as cystathionine gamma-lyase activity to E. coli; cystathionine gamma-synthase activity was detected when O-succinylhomoserine but not O-acetylhomoserine was used as substrate. We therefore conclude that S. cerevisiae cystathionine gamma-lyase and E. coli cystathionine gamma-synthase are homologous in both structure and in vitro function and propose that their different in vivo functions are due to the unavailability of O-succinylhomoserine in S. cerevisiae and the scarceness of cystathionine in E. coli.

Amino Acid Sequence↗

PubMed1992

Hyperbaric oxygen therapy for control of intractable cyclophosphamide-induced hemorrhagic cystitis.

We report a case of intractable hemorrhagic cystitis due to cyclophosphamide therapy for Wegener's granulomatosis. Conservative treatment, including bladder irrigation with physiological saline and instillation of prostaglandin F2 alpha, failed to totally control hemorrhage. We then used hyperbaric oxygen at an absolute pressure of 2 atm, 5 days a week for 8 consecutive weeks. The bleeding ceased completely by the end of treatment and the patient remained free of hematuria thereafter. No side effect was noted during the course of therapy. In future, this form of therapy can offer a safe alternative in the treatment of cyclophosphamide-induced hemorrhagic cystitis.

Cyclophosphamide↗

PubMed1992

The microvasculature of the human bone marrow correlated with the distribution of hematopoietic cells. A computer-assisted three-dimensional reconstruction study.

Surgical specimens of ordinary bone marrow from eight patients were submitted to computer-assisted three-dimensional reconstruction from resin-embedded, semi-thin serial sections. This was undertaken with the aim of contributing to a better understanding of hematopoietic microenvironment by establishing the basic architecture of the bone marrow, particularly the microvasculature and its relation to the hematopoietic cell series. The basic vascular structure was found to consist of mutually intertwining sinuses and hematopoietic cords (or compartments), the latter with an arteriole running along the axis. This allowed to define the unitary structure of the bone marrow as a hematopoietic cord with a central arteriole and surrounded by sinuses. Here granulopoietic cells were distributed mostly along the wall of the central arteriole. Erythropoietic cells, located mainly around the sinus wall, proved to be forming a continuous network of cord instead of separate "islands" as usually assumed, justifying a designation of "erythroblastic cords". Megakaryocytes were positioned in close vicinity to the sinus wall. These findings appear not only to be helpful in analyzing factors involved in the in vivo hematopoiesis of man, but also to visualize the importance of structural studies of bone marrow.

Adult↗

PubMed1992

Determination of diborane by adsorption sampling using modified silica gel and the chromotropic acid-HPLC method.

A method for determining atmospheric diborane in concentrations higher than 1/10 of TLV, i.e., 0.01 ppm, has been developed using the adsorption sampling method. Silica gel impregnated with potassium permanganate, synthetic resin activated carbon impregnated with or without mercury(II) chloride and activated carbon impregnated with chromate salt showed adsorption capacities larger than 18 l of 3 ppm diborane test gas when the test gas was drawn at 300 ml/min. Complete desorption of the adsorbed diborane was possible only from silica gel impregnated with potassium permanganate into a hydroxylamine hydrochloride solution. As methods for determining the desorbed boron, both the chromotropic acid-HPLC method and ICP-AES were applied. The former was more sensitive, but the latter was less influenced by coexistent substances. The most sensitive and reproducible procedure for diborane determination was as follows: diborane is collected with silica gel impregnated with potassium permanganate (0.05% (w/w)) and desorbed into hydroxylamine hydrochloride solution (400 micrograms/ml) followed by the determination of boron by the chromotropic acid-HPLC method. When diborane in 3 l of 0.1 ppm test gas was collected, the desorption efficiency was 105.3% with an RSD of 13.5%. The limit of quantitation of this method was 0.0026 ppm in 3 l air. Much lower concentrations can be determined by sampling larger amounts of air.

Adsorption↗

PubMed1992

[Spontaneous cerebrospinal fluid otorrhea in a normal inner ear. A case report].

A 49-year-old male with spontaneous cerebrospinal fluid (CSF) otorrhea, an extremely rare condition, is presented as the third reported case in Japan. The patient visited us complaining of sudden hearing loss and fullness of the ear on the left side. A tegmen defect of the posterior cranial fossa and CSF leakage from the fistula into the mastoid air cells, but a normal inner ear, were found by means of metrizamide CT. The fistula was surgically occluded with fascia temporalis and an artificial bone with fibrin glue. The CSF otorrhea from the tegmen defect was successfully stopped by this procedure and no recurrence has been observed. We discuss this extremely rare disease in this paper.

Cerebrospinal Fluid Otorrhea↗

PubMed1992

Aortic valve replacement for Takayasu's arteritis.

We report 12 cases of aortic valve replacement performed for Takayasu's arteritis and discuss the genesis of aortic regurgitation and the clinical outcome after aortic valve replacement. This group of twelve patients who underwent aortic valve replacement between April 1982 and March 1990 included four male and eight female patients, aged 24 to 67 years (mean age 48 years). Preoperative angiography showed systemic multiple stenoocclusive or aneurysmal dilated vascular lesions in addition to aortic regurgitation. The multiple lesions included a lesion in the aortic arch branch in nine (75%), in the pulmonary artery in seven (58%), an aneurysmal dilation in the ascending aorta of more than 6 cm in four (33%), a coronary lesion in four (33%), a thoracic aortic lesion in six (50%), and a lesion in the abdominal aorta and its visceral branch in six (50%). Simple aortic valve replacement alone was performed in two patients and in combination with another operation in ten patients, with aortic root reconstruction in two, ascending aortic plication in three, coronary artery bypass grafting in two, aortic arch branch bypass grafting in one, aortic arch branch bypass grafting and coronary ostium endarterectomy in one, and mitral valve replacement and ascending aortic plication in one. There was no operative death, and only one patient died later, 18 months after the operation, because of secondary amyloidosis. The postoperative recovery of the clinical status and cardiac function was good. Intraoperative observations suggested that aortic valve regurgitation may be caused by an extension of aortitis, although histopathologic examinations of the valve showed nonspecific findings. One of the characteristic problems in Takayasu's arteritis is the necessity for prednisolone administration in some patients preoperatively or postoperatively, or both. We conclude that aortic valve replacement for patients with Takayasu's arteritis is an effective and safe treatment. Our data related to the genesis of aortic regurgitation in Takayasu's arteritis remain insufficient to draw conclusions, and further analysis is planned.

Aortic Valve↗

PubMed1992

Tumor-specific chemoimmunotherapy of murine fibrosarcoma using tumor-specific transplantation antigen, cyclophosphamide, and interleukin-2.

The anti-tumor effect of active specific chemoimmunotherapy, using butanol-extracted tumor-specific transplantation antigen (TSTA), cyclophosphamide (CY), and continuous intrasplenic infusion of interleukin-2 (IS-IL-2), was assessed in a C3H/HeJ murine methylcholanthrene (MCA)-induced fibrosarcoma model. Sole administration of TSTA induced tumor-specific, suppressor T cells in the spleens of mice bearing 3-day established tumors. Concomitant low-dose (20 mg/kg) CY treatment not only inhibited TSTA-mediated suppressor cell induction, but also evoked splenic lymphocytes of tumor-bearing mice to display tumor-specific cytotoxic activity. High-dose (200 mg/kg) CY abrogated the immunotherapeutic benefit. The immune effectors generated by TSTA plus CY bear the Thy 1, L3T4, Lyt 2 phenotype. Continuous IS-IL-2 infusion in combination with TSTA and CY induced tumor-specific Lyt 2+ cytolytic T cells, as well as the activation of L3T4+ cytostatic T cells. Thus, a triple regimen using TSTA, CY, and IS-IL-2 appears to augment CTL induction in tumor-bearing hosts undergoing stimulation of helper elements by TSTA and inhibition of suppressor cells by CY.

Animals↗

PubMed1992

[A case of retroperitoneal Castleman's disease associated with bladder tumor and a review of 59 cases in Japan].

We present a case of retroperitoneal Castleman's disease associated with bladder tumor. The patient was a 62-year-old man, who underwent partial cystectomy under a diagnosis of bladder tumor in 1989. Subsequently, recurrent bladder tumor was detected and he consulted the outpatient clinic at our University Hospital in November, 1990, at which time computerized tomography (CT) revealed a retroperitoneal tumor. From February, 1991 four courses of combined chemotherapy (methotrexate, vinblastine, pirarubicin, cisplatin) were administered for the tumor. The tumor reduction rate after the chemotherapy was 60% on CT, and retroperitoneal lymph node dissection and left nephroureterectomy were performed in July, 1991. Histological examination revealed Castleman's disease, hyaline-vascular type. Fifty-nine reported cases of retroperitoneal Castleman's disease in Japan are reviewed.

Castleman Disease↗

PubMed1992

[Multiorgan failure following intravesical bacillus Calmette-Guerin administration: a case report].

We describe a case of multiorgan failure after intravesical bacillus Carmette-Guern (BCG) immunotherapy for bladder cancer. A 58-year-old man with superficial transitional cell carcinoma of the bladder was initially treated by transurethral resection and intravenous chemotherapy, and then administered 11 sessions of BCG intravesically. He was administered BCG intravesically after cystoscopic examination. The next day he complained of nausea and malaise. He became hypotensive. The symptom progressed with multiorgan failure, disseminated intravascular coagulation and respiratory failure. The patient gradually improved with administration of antibiotics and corticosteroid, and hemodialysis, without antituberculous antibiotics. Intravesical instillation of BCG should not be carried out immediately after cystoscopic examination.

Administration, Intravesical↗

PubMed1992

[Flow cytometric bromodeoxyuridine (BrdU)/DNA analysis using fresh solid tumors and its clinical significance].

It is very important to determine the biological characteristics of individual cancers, not only in order to evaluate malignant potentials but also to decide on the most effective anticancer therapy. A method which combines BrdU labeling and flow cytometric bromodeoxyuridine (BrdU)/DNA analysis makes it possible to plot the DNA synthetic rate of cells against their DNA content. Hence, this method yields more useful information than the previous method of flow cytometric DNA analysis. When this method is performed correctly, it can be also applied to fresh solid tumors. In this paper, we will describe the results of our preliminary investigation and discuss its clinical significance.

Animals↗