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Biomedical subjects

T Naito

Publications and source records attributed to T Naito.

At least 73 records · Page 4Linked to original sources
PubMed1999

Effects of cholestyramine on hepatic cholesterol 7alpha-hydroxylase and serum 7alpha-hydroxycholesterol in the hamster.

Cholestyramine increases activities of hepatic cholesterol 7alpha-hydroxylase and serum levels of 7alpha-hydroxycholesterol. To examine if serum 7alpha-hydroxycholesterol levels parallel with enzyme activity, 0, 0.5, 1, 2, 4, and 10% of cholestyramine was administered to female golden Syrian hamsters for 28 d in the dose-dependent study, and 2% cholestyramine for 0, 1, 3, 7, 14, 21, and 28 d in the time-dependent study. In the dose-dependent study, hepatic and serum cholesterol levels were significantly decreased dose-dependently when more than 0.5% of cholestyramine was fed for 28 d. Cholestyramine increased the cholesterol 7alpha-hydroxylase activity in a dose-dependent manner, while the serum 7alpha-hydroxycholesterol level was essentially unchanged. No correlation was found between the serum level and the hepatic enzyme activity. In the time-dependent study, hepatic and serum cholesterol levels markedly decreased when 2% cholestyramine was fed for longer than 3 d. The serum triglyceride level increased significantly for the first 7 d and then decreased. Cholesterol 7alpha-hydroxylase activity increased significantly as early as day 1, reached maximum activity level on day 7, and then kept the significantly high values until day 28. The serum 7alpha-hydroxycholesterol level significantly increased for the first 7 d and decreased to the pretreatment level thereafter. 7Alpha-hydroxycholesterol levels significantly correlated with serum cholesterol and triglyceride levels. We conclude that the serum 7alpha-hydroxycholesterol level does not always reflect the activity of hepatic cholesterol 7alpha-hydroxylase, when cholesterol metabolism is severely disturbed by cholestyramine.

Animals↗
PubMed1999

Cell-dependent replication potentials of HIV-1 gag mutants.

An infectious molecular clone of human immunodeficiency virus type 1 (HIV-1), designated pNLaiKH, which is tropic for both lymphocytic and monocytic cells, was constructed. To study the early function of HIV-1 Gag proteins in two types of cells, the mutations known to give host cell-dependent early defects were introduced into pNLaiKH, and the replication potentials and defective replication sites in the cells of the resultant mutants were monitored. All mutants grew in some lymphocytic cells, but not at all in monocytic cells. A nucleocapsid mutant was found to be defective at an early replication phase in all the cell lines to various extent, as expected. In contrast, a matrix mutant and a capsid mutant displayed a replication defect in a producer-cell-dependent manner. These results demonstrated that complex interactions of cell factors and Gag proteins are involved in an early process of HIV-1 replication.

Cell Line↗
PubMed1999

A sudden death case of laryngocele accompanied by infarction of the dorso-lateral portion of the medulla oblongata.

A 70-year-old man, who had a laryngeal tumor discovered by otolaryngological examination during admission for suspicion of facial nerve paralysis was found dead in his bed on the seventh hospital day. Clinical doctors aspirated a large amount of mucous sputum from his larynx during their attempt at resuscitation. Although the direct cause of death was clinically unknown, an autopsy revealed an internal type laryngocele, a type of laryngeal cyst, in the right larynx and infarction of the left dorso-lateral portion of the medulla oblongata. Suffocation resulted from mucous sputum filling his larynx, which had been narrowed by a laryngocele from the right, in an unfortunate association with movement disturbance of the left larynx caused by the infarction of the left dorso-lateral portion of the medulla oblongata. We assumed this to be the direct cause of death, because the heart and lungs showed no remarkable changes that could be ascribed to it. This case offers important suggestions concerning the risks of suffocation due to laryngeal cysts, especially in patients with complications.

Journal Article↗
PubMed1999

Life-long dietary restriction modulates the expression of collagens and collagen-binding heat shock protein 47 in aged Fischer 344 rat kidney.

It has been shown that the expression of HSP47 and collagens is substantially increased in the sclerotic/fibrotic process in various organs, including kidney. However, the factors regulating the increased expression of HSP47 are not yet clear. In this study, we examined the effect of dietary restriction for the expression of collagens and collagen-binding HSP47 in the kidneys of 6- and 24-month-old male Fischer 344 (F 344) rats fed ad libitum or 30% diet-restricted. No significant histological alteration was found in the kidneys of 6-month-old fed or diet-restricted rats. Kidneys obtained from 24-month-old freely fed rats showed glomerulosclerosis with marked tubulointerstitial damage including interstitial fibrosis, while in the kidneys of 24-month-old diet-restricted rats, renal damage was remarkably less than those noted in 24-month-old freely fed rat kidneys. Immunohistochemical analysis showed an increased accumulation of type I, type III and type IV collagens in areas of glomerulosclerosis and interstitial fibrosis in old rat kidneys. Dietary restriction significantly reduces renal accumulation of collagens in old age. Aging enhanced expression of HSP47 in 24-month-old freely fed rat kidneys whereas dietary restriction suppressed its expression in 24-month-old diet-restricted rat kidneys. Also, phenotypic alterations of mesangial cells and interstitial cells (immunopositive for alpha-smooth muscle actin), glomerular epithelial cells (immunopositive for desmin) and tubular epithelial cells (immunopositive for vimentin) were seen in 24-month-old freely fed rat kidneys and found to express HSP47. Dietary restriction significantly diminished phenotypically altered renal cells in 24-month-old rat kidneys. Our results suggest that increased expression of HSP47 is associated with age-related renal damage and that diet-restricted alteration of its expression is associated with the modulation of age-associated renal sclerosis/fibrosis.

Actins↗
PubMed1999

Fas on renal parenchymal cells does not promote autoimmune nephritis in MRL mice.

BACKGROUND: Although Fas on pancreatic islets promotes autoimmune diabetes in mice, the role of Fas expression on kidney parenchymal cells during autoimmune disease is unknown. METHODS: To determine whether Fas on renal parenchymal cells promotes autoimmune renal destruction, we compared apoptosis and pathology in Fas-intact and Fas-deficient kidneys in an autoimmune milieu. For this purpose, we transplanted single, normal kidneys from MRL-++ (Fas-intact) mice (3 months of age) into age-matched, congenic MRL-Faslpr (Fas-deficient) recipients after removal of nephritic kidneys. These Fas-intact kidneys were compared with Fas-deficient nephritic kidneys. RESULTS: There is a progressive increase of FasL on kidney-infiltrating cells and Fas and FasL on renal parenchymal cells in MRL-++ kidneys during engraftment (0, 2, 4-6, and 8 weeks). By comparison, we detected an increase in FasL in MRL-Faslpr kidneys (3 to 5 months of age), whereas Fas was not detectable. The engagement of T cells bearing FasL with Fas expressing tubular epithelial cells (TECs) induced TEC apoptosis in vitro. However, apoptosis and pathology were similar in kidneys (MRL-++, 8 weeks postengraftment vs. MRL-Faslpr, 5 months) with equivalent amounts of FasL-infiltrating cells or FasL TECs, regardless of Fas on renal parenchymal cells. CONCLUSION: The expression of Fas on renal parenchymal cells does not increase apoptosis or promote renal disease in MRL-++ mice. We speculate that the autoimmune milieu evokes mechanisms that mask, counter, or pre-empt Fas-FasL-initiated apoptosis in MRL kidneys.

Animals↗
PubMed1999

Genetic control of telomere integrity in Schizosaccharomyces pombe: rad3(+) and tel1(+) are parts of two regulatory networks independent of the downstream protein kinases chk1(+) and cds1(+).

The Schizosaccharomyces pombe checkpoint gene named rad3(+) encodes an ATM-homologous protein kinase that shares a highly conserved motif with proteins involved in DNA metabolism. Previous studies have shown that Rad3 fulfills its function via the regulation of the Chk1 and Cds1 protein kinases. Here we describe a novel role for Rad3 in the control of telomere integrity. Mutations in the rad3(+) gene alleviated telomeric silencing and produced shortened lengths in the telomere repeat tracts. Genetic analysis revealed that the other checkpoint rad mutations rad1, rad17, and rad26 belong to the same phenotypic class with rad3 with regard to control of the telomere length. Of these mutations, rad3 and rad26 have a drastic effect on telomere shortening. tel1(+), another ATM homologue in S. pombe, carries out its telomere maintenance function in parallel with the checkpoint rad genes. Furthermore, either a single or double disruption of cds1(+) and chk1(+) caused no obvious changes in the telomeric DNA structure. Our results demonstrate a novel role of the S. pombe ATM homologues that is independent of chk1(+) and cds1(+).

Adenosine Triphosphatases↗
PubMed1999

Cholesterol hydroperoxides in erythrocyte membranes of alcoholic patients.

Evidence for the presence of 5alpha-hydroperoxycholest-6-en-3beta-ol (cholesterol 5alpha-hydroperoxide, Ch 5alpha-OOH) and 7alpha- and 7beta-hydroperoxycholest-5-en-3beta-ols (cholesterol 7-hydroperoxides: Ch 7alpha-OOH and Ch 7beta-OOH, respectively) in human erythrocyte membrane was found. Blood samples were collected from alcoholic patients and healthy volunteers (controls), and their cholesterol hydroperoxides were analyzed by high-performance liquid chromatography postcolumn chemiluminescence and roughly identified by liquid chromatography-mass spectrometry. Ch 7alpha-OOH and Ch 7beta-OOH were present in each sample, being significantly higher in alcoholic samples than in control samples. Ch 5alpha-OOH was present in some alcoholic samples, but not in the control ones. The accumulation of cholesterol hydroperoxides suggests enhanced lipid peroxidation by active oxygen species and/or a reduced elimination system for lipid peroxide in alcoholic patients.

Adult↗
PubMed1999

[A case of endophthalmitis and abscesses in the liver and the lung caused by Klebsiella pneumoniae].

[Case report] A 65-year-old male war admitted to a local hospital because of fever. He was treated with piperacillin and clindamycin without noticeable effect. He began to complain of loss of vision on the third hospital day and culture of the blood specimen yielded Klebsiella pneumoniae. He was diagnosed as endophthalmitis and referred to our hospital for further examination. The hematological laboratory test showed leukocytosis (12,700/microliter) and increased CRP (20.4 mg/dl). A computed tomographic (CT) scan of the thorax revealed multiple lung abscesses. An abdominal ultrasonographic scan and a CT scan of the abdomen revealed multiple liver abscesses. We drained the abscess in the liver and Klebsiella pneumoniae was detected from the sample of aspirated fluid and his sputum. Meropenem was administered intravenously. Fever started to improve on the tenth hospital day and the size of both liver and lung abscesses were reduced. He has lost vision of his right eye. He was discharged after sixty days. He did not have any immunosuppressive underlying disease including HIV infection and diabetes mellitus which cause these lesions.

Aged↗
PubMed1999

The utility of endoscopic ultrasonography and endoscopy in the endoscopic mucosal resection of early gastric cancer.

OBJECTIVE: To clarify the usefulness of endoscopic ultrasonography (EUS) and endoscopy in the endoscopic mucosal resection (EMR) of early gastric cancer. Patients/Methods-EMR was performed in 61 patients with early gastric cancer over the past five years. The accuracy of the assessment of the depth of cancerous invasion was studied in 49 patients who had EUS before EMR. Forty eight patients were treated with endoscopy alone; in these patients, EUS and endoscopic findings correlated with the clinical course. RESULTS: Forty six patients showed no changes in the submucosal layer or deeper structures on EUS. Pathologically these included 37 patients with mucosal cancer and nine with submucosal cancer showing very slight submucosal infiltration. Three patients showed diffuse low echo changes in the submucosal layer on EUS; pathologically, these included two with submucosal cancer and one with mucosal cancer with a peptic ulcer scar within the tumour focus. Of 48 patients receiving endoscopic treatment alone, 45 showed no tumour recurrence or evidence of metastases on EUS and endoscopy. Three cases of recurrence were observed. Two of these patients had a surgical gastrectomy, and one was re-treated endoscopically. In the former cases, the surgical results correlated well with assessment by EUS and endoscopy. In addition, the latter patient who was re-treated endoscopically after evaluation with EUS and endoscopy has so far had no recurrence. CONCLUSION: The combined use of EUS and endoscopy is effective in diagnosing the depth of cancerous invasion in patients undergoing EMR as well as in clarifying changes both within and between anatomic levels during follow up.

Aged↗
PubMed1999

Synthesis and antifungal activities of (2R,3R)-2-aryl-1-azolyl-3-(substituted amino)-2-butanol derivatives as topical antifungal agents.

2-Aryl-1-azolyl-3-(substituted amino)-2-butanol derivatives I were prepared by ring-opening reaction of epoxides II with excess amine, and their antifungal activities were evaluated as topical agents. Azolyl-cyclic amine derivatives with a methylene group showed extremely strong activity with a broad spectrum in vitro. In general, anti-Trichophyton mentagrophytes activities of most of the topical antifungal agents are substantially reduced by addition of keratin (a major constituent of the keratinized tissue). However, the triazole derivative (2R,3R)-2-(2,4-difluorophenyl)-3-(4-methylenepiperidino)-1-(1H-1,2 ,4- triazol-1-yl)-2-butanol ((-)-40, KP-103) showed very little deactivation by addition of keratin. This biological characteristic of triazole derivative (-)-40 resulted in excellent therapeutic efficacy on dermatophytosis superior to that of the corresponding imidazole derivative ((-)-41).

Animals↗
PubMed1999

Periodontal and computer tomography scanning evaluation of endosseous implants in conjunction with sinus lift procedure. A 6-case series.

The aim of the present study was to evaluate endosseous implants in conjunction with the sinus lift procedure using periodontal parameters and computed tomography (CT) scanning. In 6 patients, 8 sinus lift procedures were performed to the atrophic posterior maxilla. Fourteen endosseous implants were placed. The condition of the peri-implant mucosa was assessed postoperatively at an average of 31 months using periodontal parameters such as plaque index, probing depth, clinical attachment level, and bleeding on probing. All the implants were maintained in a clinically healthy condition throughout the observation period. CT images revealed the difference in the morphology of the sinus floor between the locations of the block-shaped bone and the small pieces of bone which were both grafted. The results indicated that endosseous implants in conjunction with the sinus lift procedure could be maintained by monitoring the periodontal parameters.

Adult↗
PubMed1999

Hyperimmunoglobulin E syndrome associated with nephrotic syndrome.

A 21-year-old man was admitted to Kure National Hospital with nephrotic syndrome in September 1996. He had suffered from an intractable pruritic skin rash and recurrent subcutaneous abscesses caused by the hyperimmunoglobulin E syndrome since the age of 18 months. Renal biopsy gave a diagnosis of membranoproliferative glomerulonephritis. Steroid therapy decreased urinary protein loss and hypoproteinemia, and his pruritic skin rash was improved. Patients with hyperimmunoglobulin E syndrome have a defective immune response, especially to Staphylococcus aureus infection. Continuous antigen stimulation may have caused this patient's renal histological damage as in immune complex glomerulonephritis.

Adult↗
PubMed1999

Circulating levels of beta-chemokines in systemic lupus erythematosus.

OBJECTIVE: Recent evidence suggests the role of beta-chemokines and their receptors in human immunodeficiency virus infection. We examined the serum levels of beta-chemokines in patients with systemic lupus erythematosus (SLE). METHODS: The serum levels of beta-chemokines, macrophage inflammatory protein-1alpha (MIP-1alpha), MIP-1beta, RANTES, and monocyte chemoattractant protein-1 (MCP-1) in patients with SLE were determined by ELISA. RESULTS: There were significant differences between the patients with SLE and healthy controls in the serum concentrations of RANTES (p < 0.001) and MCP-1 (p < 0.01), but not MIP-1alpha (p = 0.07) and MIP-1beta (p = 0.68). A decrease of RANTES and an increase of MCP-1 was observed with the progression of disease activity in the patients with SLE. CONCLUSION: Changes in the serum levels of RANTES and MCP-1 may indicate an interaction between SLE disease activity and the production of beta-chemokines.

Adolescent↗
PubMed1999

[Induction of genes into the rabbit eye by iontophoresis].

PURPOSE: After inducing 6-carboxyfluorescein (6-FAM)-labeled phosphorothioate oligonucleotides (S-ODNs) noninvasively into albino rabbit eyes by iontophoresis, we assessed the transfer of S-ODNs into the ocular tissues, their stability, and the possible presence of injury to the ocular tissues. METHODS: The iontophoresis group consisted of 12 eyes of 6 rabbits and the control group consisted of 4 eyes of 2 rabbits given eye drops containing S-ODNs. Aqueous humor and vitreous humor were collected after iontophoresis, subjected to electrophoresis with a fluorescent DNA sequencer and analyzed by the Gene Scan program. Frozen sections at 10 microns were prepared for observations under a fluorescent microscope. A plasmid 4.7 kbp in size that expresses green fluorescent protein (GFP) was induced into 18 eyes of 9 rabbits by the same procedure. RESULTS: In the iontophoresis group, S-ODNs were detected in the anterior chamber 5 minutes after electrophoresis and in the vitreous 10 minutes after. These S-ODNs maintained the same length as at the initial synthesis. S-ODNs could also be detected in the posterior retina 20 minutes after electrophoresis. No evidence of degeneration or inflammation due to the above procedure was found in the ocular tissues. Fluorescence showing GFP gene expressions were found in the cornea, the anterior chamber angle, and the ciliary subepithelial tissues. CONCLUSIONS: These findings show that iontophoresis is an effective method to induce gene into rabbit eyes.

Animals↗