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Biomedical subjects

T Sakai

Publications and source records attributed to T Sakai.

At least 595 records · Page 33Linked to original sources
PubMed1997

US-guided left-sided biliary drainage: nine-year experience.

PURPOSE: The feasibility and safety of left-sided biliary drainage with ultrasound (US) guidance were studied prospectively. MATERIALS AND METHODS: From July 1987 to July 1996, 208 consecutive patients underwent US-guided biliary drainage; all were evaluated for left-sided drainage. Drainage procedure was begun with puncture of the hepatic duct branch of the lateral segment of the left lobe when the branch was well visualized with US; otherwise, a right-sided approach was used. When the hepatic duct branch diameter was greater than 3 mm, puncture was performed with an 18-gauge needle; smaller branches were punctured with 21-gauge needles. RESULTS: In 147 (71%) patients, the left hepatic duct branch was well visualized with US, and the branch diameter was greater than 3 mm. In these patients, left-sided drainage with use of an 18-gauge needle was successful. In 26 (12%) patients, the left hepatic duct branch diameter was less than 3 mm, and drainage was initiated with a 21-gauge needle. In six (23%) of these 26 patients, left-sided drainage was unsuccessful, but five of these patients underwent successful US-guided drainage from the right hepatic duct branch. Two patients died of septic shock within 72 hours of completed drainage. Three patients experienced severe hemobilia. CONCLUSION: US-guided left-sided biliary drainage is a highly successful and safe method when the left hepatic duct branch diameter is greater than 3 mm.

Adolescent↗
PubMed1997

Interferon-gamma induces a decrease in the intracellular calcium pump in a human salivary gland cell line.

Interferon-gamma (IFN-gamma) +/- tumor necrosis factor-alpha (TNF-alpha) induces antiproliferation and intracellular Ca2+ store depletion in a human submandibular ductal cell line (HSG), which can be reversed on cytokine removal [A. J. Wu, G. C. Chen, B. J. Baum, and I. S. Ambudkar. Am. J. Physiol. 270 (Cell Physiol. 39): C514-C521, 1996]. Here we have examined a possible mechanism for the IFN-gamma-induced intracellular Ca2+ store depletion. There was a time-dependent decrease in thapsigargin-dependent internal Ca2+ release after exposure of the cells to the cytokines. The intracellular Ca2+ pump [sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA)] protein in lysates and membranes of cells treated with IFN-gamma +/- TNF-alpha, but not with TNF-alpha alone, showed a similar time-dependent decrease (examined using a SERCA2 antibody). Removal of the cytokines, which resulted in recovery of cell growth and refill of internal Ca2+ stores, also increased the level of SERCA protein. The decrease in SERCA is not a result of decreased cell proliferation, since thapsigargin, 2,5-di-(t-butyl)-1,4-hydroquinone, or serum-free growth conditions induced antiproliferative effects on HSG cells without any corresponding decrease in SERCA. We suggest that the IFN-gamma-induced decrease in the level of SERCA accounts for the depleted state of internal Ca2+ stores in cytokine-treated HSG cells. These data suggest a novel mechanism for the inhibition of HSG cell growth by IFN-gamma.

Calcium↗
PubMed1997

Analysis of urinary red blood cells of healthy individuals by an automated urinary flow cytometer.

A newly developed automated urinary flow cytometer allows clear discrimination of erythrocytes from other solid components of urine. In this study, the normal range of the urinary erythrocyte count and the source of urinary erythrocytes in healthy individuals were investigated using this analyzer. For the diagnosis of the source of the urinary erythrocytes, Kitasato University Kidney Center criteria for this analyzer were applied. The subjects were 133 regularly employed volunteers (age range 20-48 years, mean 30.5) who noted no urinary tract symptoms and showed normal blood pressure, consisting of 41 females not in their menstrual period (age range 20-39 years, mean 24.8) and 92 males (age range 20-48 years, mean 33.1). Mid-stream voided urine was collected from these subjects using urine sampling cups, immediately transferred to 50-ml sterilized Spitz tubes, and analyzed within 30 min using the automated urinary flow cytometer. Urinary erythrocytes were derived from glomeruli in all samples of healthy subjects. The urinary erythrocyte count showed a logarithmic normal distribution. Values 2 SD of the urinary erythrocyte count in healthy individuals or higher were regarded as abnormal, and hematuria was considered to be positive when 11.0/microliter or more erythrocytes were observed by this analyzer. The finding by this analyzer corresponded to the report of Birch et al.

Adult↗
PubMed1997

Two distinct epithelial responses may compensate for the ureteral obstruction in early and late phase of unilateral ureteral obstruction-treated rat: cellular proliferation in acute phase and osteopontin expression in chronic phase.

In order to clarify cellular responses in dilated renal tubules in the acute and chronic phase of ureteral obstruction, we investigated the expression of proliferating cell nuclear antigen and osteopontin (OPN) in unilateral ureteral obstruction (UUO)-treated rat kidneys. The results showed that renal epithelial cells proliferate in association with tubular dilatation to compensate for the ureteral obstruction in the acute phase of UUO while the proliferative activity decreases in the chronic phase. In the chronic phase, however, the expression of OPN was up-regulated in various tubules but not associated with the tubular dilatation. Taken together with its chemoattractant activity for macrophage, OPN may be involved in the interstitial fibrosis as another compensatory mechanism in the chronic phase of ureteral obstruction. Therefore, these results suggest that two distinct epithelial responses may compensate for the ureteral obstruction in the acute and chronic phase of UUO-treated rat, respectively.

Acute Disease↗
PubMed1997

Converting enzyme inhibitor improves forearm reactive hyperemia in essential hypertension.

Endothelial function is known to be impaired in essential hypertensive patients. In this study, we examined whether antihypertensive drugs improve forearm vasodilatory response to reactive hyperemia in 26 patients with essential hypertension (62 +/- 2 years) without diabetes mellitus, hyperlipidemia, coronary heart disease, or cerebrovascular disease. Antihypertensive drugs were never given or were discontinued for at least 4 weeks before the study. Patients were treated with monotherapy of either temocapril (2 or 4 mg, n = 15) or amlodipine (2.5 or 5 mg, n = 11) for 6 months. Forearm blood flow was measured by strain-gauge plethysmography. Vasodilator response to the release of upper arm compression at 300 mm Hg for 5 minutes and to sublingual administration of nitroglycerin (0.3 mg) were assessed. Changes of forearm blood flow response to reactive hyperemia were significantly less in hypertensive patients (99 +/- 18%) than in age-matched normotensive control subjects (150 +/- 22%, P < .01, n = 39). Blood pressure (mm Hg) was similarly decreased by the treatment with temocapril (160 +/- 4/94 +/- 2 to 139 +/- 3/83 +/- 3, P < .001) or amlodipine (165 +/- 5/94 +/- 3 to 141 +/- 4/82 +/- 3, P < .001). Response to nitroglycerin was not changed by either drug. Forearm vasodilatory response to reactive hyperemia was improved by temocapril (102 +/- 20% to 168 +/- 25%, P < .01) but not by amlodipine (97 +/- 16% to 114 +/- 14%, NS). These results indicate that the treatment with the angiotensin-converting enzyme inhibitor temocapril improved forearm vasodilatory response to reactive hyperemia, suggesting its beneficial effect on endothelial function.

Aged↗
PubMed1997

Simultaneous or delayed administration of hepatocyte growth factor equally represses the fibrotic changes in murine lung injury induced by bleomycin. A morphologic study.

Hepatocyte growth factor (HGF) is a humoral mediator of epithelial-mesenchymal interactions, acting on a variety of epithelial cells as mitogen, motogen, and morphogen. Exogenous HGF acts as a hepatotrophic factor and a renotrophic factor during experimental injury. To investigate whether HGF has a pulmotrophic function, human recombinant HGF was administered to C57BL/6 mice with severe lung injury by bleomycin (BLM). Low dose simultaneous and continuous administration of HGF (50 micrograms/mouse/7 d) with BLM (100 mg/mouse/7 d) repressed fibrotic morphological changes at 2 and 4 wk. Ashcroft score showed a significant difference in lung fibrosis with and without HGF at 4 wk (3.7 +/- 0.4 versus 4.9 +/- 0.3, p < 0.05). Furthermore, either simultaneous or delayed administration of high dose HGF (280 micrograms/mouse/14 d) equally repressed fibrotic changes by BLM when examined at 4 wk (Ashcroft score: 2.6 +/- 0.4 and 2.4 +/- 0.2 versus 4.1 +/- 0.2, p < 0.01). Hydroxyproline content in the lungs was significantly lower in mice with either simultaneous or delayed administration of high dose HGF as compared to those administered BLM alone (121.8 +/- 8.1% and 113.2 +/- 6.2% versus 162.7 +/- 4.6%, p < 0.001). These findings indicate that exogenous HGF acts as a pulmotrophic factor in vivo and prevents the progression of BLM-induced lung injury when administered in either a simultaneous or delayed fashion. HGF may be a potent candidate to prevent or treat lung fibrosis.

Animals↗
PubMed1997

Hepatocyte growth factor in bronchoalveolar lavage fluids and cells in patients with inflammatory chest diseases of the lower respiratory tract: detection by RIA and in situ hybridization.

Pulmonary fibrosis is a chronic inflammatory disorder characterized by diffuse fibrous remodeling of alveolar spaces. Although much interest is focused on mechanisms of the inflammatory process in pulmonary fibrosis, little is known about the repair and regenerative process. Hepatocyte growth factor (HGF), originally discovered as a mitogen for hepatocyte regeneration, is now recognized as a multifunctional mesenchymal factor for epithelial regeneration, including the regeneration of alveolar type II epithelial cells. Involvement of HGF and its receptor (c-met) is evident in animal models of acute lung injury produced by hydrochloride inhalation. We studied the role of HGF in patients with idiopathic pulmonary fibrosis (IPF) (25 cases), lung fibrosis associated with rheumatoid arthritis (22 cases), and sarcoidosis (39 cases). Immunohistochemical evaluation demonstrated that hyperplastic alveolar type II epithelial cells, as well as alveolar macrophages, were strongly stained with anti-HGF antibody in tissues of patients with IPF. The concentration of HGF in bronchoalveolar lavage fluid (BALF) was significantly higher than in normal controls (0.23 +/- 0.09 pg/microg) in patients with IPF (0.77 +/- 0.88 pg of HGF/microg of albumin, P < 0.001), lung fibrosis associated with rheumatoid arthritis (0.50 +/- 0.64 pg/microg, P < 0.01), and sarcoidosis (0.41 +/- 0.61 pg/microg, P < 0.05). In situ hybridization revealed mRNA for HGF in alveolar macrophages (especially small monocytelike macrophages). These results indicate that the increase in HGF concentration in patients' peripheral air spaces is due to augmented HGF production by alveolar epithelial cells and alveolar macrophages. HGF, through a paracrine mechanism, may play an important role in the repair and healing of the inflammatory lung damage in pulmonary fibrosis.

Adult↗
PubMed1997

Cis-acting region associated with lung cell-specific expression of the secretory leukoprotease inhibitor gene.

Secretory leukoprotease inhibitor (SLPI) is a serine protease inhibitor, produced locally in respiratory and genital glands, but not in the liver. In the present study the promoter region of this gene was analyzed to better understand the molecular mechanisms involved in transcriptional regulation. DNase-I hypersensitive sites were detected within 1 kbp upstream of exon I in chromatin structures of type II pneumocyte cell line A549 and utero-cervical cell line HeLa, both of which express SLPI mRNA transcripts. The function of the SLPI promoter encompassing these DNase-I hypersensitive sites has been studied by deletion analysis with the luciferase gene as a transient expression vector. In this analysis, we found three transcription control regions that function in A549 cells but not in nonlung cell lines, such as HeLa and hepatoma Hep G2. Among three cis-regulatory regions, a proximal 41-bp region (-132 to -92 bp relative to the transcription start site) is responsible for the most striking magnitude of transcriptional activity. This region corresponds to the transcriptional activating sequence detected in another lung cell line, HS-24, indicating that this 41-bp sequence is required for lung cell-specific expression. An electrophoretic mobility shift assay demonstrated that this 41-bp promoter region contains an 11-bp recognition sequence for two nuclear binding proteins, one of which is abundant in lung cell lines, and the other in nonlung cell lines. These results suggest that the ratio of these two nuclear binding proteins confers the cell type specificity on the expression pattern of the SLPI gene.

Adenocarcinoma↗
PubMed1997

Involvement of RBP-J in biological functions of mouse Notch1 and its derivatives.

Notch is involved in the cell fate determination of many cell lineages. The intracellular region (RAMIC) of Notch1 transactivates genes by interaction with a DNA binding protein RBP-J. We have compared the activities of mouse RAMIC and its derivatives in transactivation and differentiation suppression of myogenic precursor cells. RAMIC comprises two separate domains, IC for transactivation and RAM for RBP-J binding. Although the physical interaction of IC with RBP-J was much weaker than with RAM, transactivation activity of IC was shown to involve RBP-J by using an RBP-J null mutant cell line. IC showed differentiation suppression activity that was generally comparable to its transactivation activity. The RBP-J-VP16 fusion protein, which has strong transactivation activity, also suppressed myogenesis of C2C12. The RAM domain, which has no other activities than binding to RBP-J, synergistically stimulated transactivation activity of IC to the level of RAMIC. The RAM domain was proposed to compete with a putative co-repressor for binding to RBP-J because the RAM domain can also stimulate the activity of RBP-J-VP16. These results taken together, indicate that differentiation suppression of myogenic precursor cells by Notch signalling is due to transactivation of genes carrying RBP-J binding motifs.

Animals↗
PubMed1997

Single and repeated intravenous toxicity studies of pamiteplase (genetical recombination) in rats and monkeys.

Single and repeated intravenous toxicity studies of Pamiteplase (genetical recombination) YM866, a novel recombinant human tissue-type plasminogen activator, were conducted. No animal died from toxic effects of YM866 after single administration to F344 rats, squirrel monkeys and cynomolgus monkeys. Male and female F344 rats were given YM866 intravenously for 4 weeks at doses of 0 (vehicle), 0.1, 0.3 and 1 mg/kg/day. An increase in platelet count, slight decreases in hemoglobin and hematocrit, increases in plasma phospholipids, total cholesterol and total protein, and liver weight were observed at 1.0 mg/kg. Histopathology revealed no changes in any organ except for hemorrhage at the injection sites. These changes recovered after 4 weeks of withdrawal. Male and female squirrel monkeys were given YM866 intravenously for 4 weeks at doses of 0 (saline), 0 (vehicle), 0.1, 0.3 and 1 mg/kg/day. Prolongation of coagulation time at the injection site was observed at 0.3 mg/kg or more. Subcutaneous hemorrhage and a transient decrease in locomotor activity were observed at 1 mg/kg. Prolongation of coagulation time at the injection site was considered to be related to the pharmacological action of YM866. The results show that the approximate single lethal dose of YM866 is more than 60 mg/kg in rats, and more than 10 mg/kg in squirrel monkeys and cynomolgus monkeys. The no-toxic-effect level of YM866 after repeated administration for 4 weeks in rats and squirrel monkeys is considered to be 0.3 mg/kg.

Animals↗
PubMed1997

Three cases of renal angiomyolipoma.

We report three non-typical cases of renal angiomyolipoma including clinical features, imaging examinations (with ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI) and angiography) and histological findings. Microaneurysms observed by angiography were common to the three cases and were considered to be an important finding in the diagnosis of renal angiomyolipoma. Moreover, the short tau inversion recovery (STIR) method of MRI, which suppresses photon signals of fat, was considered to be useful for the diagnosis. Case 1 was accompanied by spontaneous rupture, Case 2 was difficult to diagnose because of little fat tissue and Case 3 revealed a very small tumor.

Adolescent↗
PubMed1997

Optical mapping of conduction patterns of normal and tachycardia-like excitations in the rat atrium.

Multiple-site optical recording of transmembrane voltage activity (MSORTV), using a voltage-sensitive dye and a 12 x 12-element photodiode array, was employed to monitor action potentials in the rat atrium. Atrial preparations including the sinus node area, caval area, and atrial septum were dissected from adult rat hearts and stained with a voltage-sensitive merocyanine-rhodanine dye (NK2761). For suppression of optical artefacts due to contractile movements, a bathing medium containing 2,3-butanedione monoxime (BDM: 10-20 mM) was used. The spread of spontaneous excitation from the pacemaker was assessed optically by timing the initiation of the action potential-related extrinsic absorption changes. The optical signals were recorded from more than 300 contiguous loci in the atrium by sliding the photodiode array over the image of the preparation; in this way, the intra-atrial conduction pattern of spontaneous excitation was mapped. The obtained maps revealed a non-radial spread of excitatory waves originating in the pacemaking area over the atrium. Furthermore, we also mapped the conduction pattern of long-lasting tachycardia-like excitation evoked by a short train of electrical stimulation (5-10 Hz, 1-2s) applied with a bipolar electrode. These maps suggest that excitatory waves are propagated in a circular pathway which often surrounds the ostium of the superior or inferior vena cava. Various patterns for the pathway were also demonstrated optically.

Action Potentials↗
PubMed1997

Infected subdural effusion associated with resolving subdural hematoma--case report.

A 70-year-old male presented with rapid neurological deterioration and fever 3 months after suffering a closed head trauma. He underwent craniotomy for possible subdural empyema based on computed tomography and clinical findings. Dural incision revealed an outer membrane typical of chronic subdural hematoma which covered a clear, yellowish fluid containing Campylobacter fetus. Histological examination confirmed the capsule of the hematoma, with a necrotic focus infiltrated by neutrophils. Administration of intravenous imipenem and topical tobramycin and cefalothin achieved total resolution of his neurological deficits. Development of the infected subdural effusion was probably secondary to bacterial infection in the pre-existing chronic subdural hematoma in the resolving stage. The presence of the hematoma capsule always carries the risk of development of an infectious focus.

Aged↗
PubMed1997

Giant unruptured aneurysm of the vertebral artery presenting with rapidly progressing bulbar compression--case report.

A 65-year-old male with a giant aneurysm of the vertebral artery, which had caused minimal neurological deficits for a few years, suffered rapid onset of respiratory disturbance followed by coma. Serial neuroimaging studies showed the thrombosed aneurysm continued to enlarge, resulting in increasing compression of the brainstem. Intraoperative observation and histological examination revealed that the aneurysm was composed of totally organized thrombus. Total extirpation of the giant aneurysm resulted in the patient regaining spontaneous respiration and clear consciousness, suggesting that growth of this aneurysm is due to increases in the size and number of the intrathrombotic capillary channels.

Aged↗
PubMed1997

[Sjögren's syndrome with presenting as aseptic meningoencephaloradiculopathy in an elderly woman].

A 76-year-old woman was found to have acute aseptic meningoencephalitis with meningial irritation, disturbance of consciousness, elevation of cell counts in cerebrospinal fluid, and swelling of a right temporal-lobe lesion on a CT scan of the head. Muscle weakness in the lower extremities and urinary dysfunction developed and progressed gradually. The protein content of cerebrospinal fluid was high, and the distal latencies of F waves were prolonged, which suggested that the inflammation extended to the nerve roots. Sjögren's syndrome was diagnosed on the basis of atrophy of the labial salivary glands; invasions of lymphocytes and plasma cells to the intercellular space; and elevation of the titers of serum antinuclear antibody, anti-SS-A antibody, and anti-SS-B antibody. The patient had no xerosis. Aseptic meningoencephalitis was the first manifestation of Sjögren's syndrome. In recent years, several cases in which Sjögren's syndrome was associated with aseptic meningitis have been reported. However, we know of no previous report of such a case in a patient of this age. Aseptic meningoencephalitis can be the first manifestation of Sjögren's syndrome.

Acute Disease↗
PubMed1997

Effect of polydextrose on absorption of triglyceride and cholesterol in mesenteric lymph-fistula rats.

In most experimental designs, the inhibitory effect of water-soluble dietary fibers on lipid absorption is evaluated by the decrease in plasma lipid concentration or the increase in fecal lipid output. The aim of this study was to evaluate the acute effect of a water-soluble polysaccharide, polydextrose, on lipid transport to the mesenteric lymph using lymph-fistula rats. The mesenteric lymph duct of rats was cannulated, and an infusion tube was introduced into the duodenum. After recovery, a lipid emulsion containing radioactive triolein and cholesteryl oleate was infused into the duodenum for 8 hr. The tested group was infused with the lipid emulsion containing 5% or 10% polydextrose as dietary fiber. Samples from the lymph-fistula were collected, and the luminal contents and mucosa were collected at the end of infusion. Lymph flow in the mesenteric lymph decreased in the polydextrose group after the infusion. The amounts of both triglyceride and cholesterol remaining in the lumen were greater in the polydextrose group, due to decreased transport of lipid into the lymph. These effects were dose dependent in the 5% and 10% polydextrose groups. The results of this study indicate that polydextrose retarded the transport of triolein and cholesterol into the mesenteric lymph.

Animals↗
PubMed1997

A genomic study on the cultivable and nerve invading Mycobacterium HI-75 after the recovery 3 months of the inoculation to nude mice.

The sequence of the polymerase chain reaction (PCR) product of 16S ribosomal RNA (16S rRNA) of the leproma-derived and cultivable Mycobacterium HI-75 (M. HI-75) which was obtained from the infected regions of inoculated mice, was examined and compared with that of the cultured bacteria by the direct sequencing techniques. The sequence was completely consistent with the cultured bacilli in the comparable 837 bases of 16S rRNA. The mycobacterium examined in this study was originally isolated as M. leprae (ML) by Skinsnes, et al. in 1975 from leproma of a lepromatous type Hansen's disease patient and therefore named as Mycobacterium leprae HI-75 by them, and was maintained from 1984 using either Ogawa's or Sauton's media in the beginning and Ogawa's medium enriched with glucronic acid and N-acetyl-D-glucosamine recently. Sasaki and Hamit reported the nerve invasion and the growth of the inoculated bacilli either to the nude mice or the I131 treated immunocompromised Swiss mice. We previously reported that cultured HI-75 was most similar to M. scrofulaceum by the direct sequencing of the gene of 16S rRNA. The 16S rRNA obtained from the mouse tissue in the present study indicated that M. HI-75 would be a variant of M. scrofulaceum possessing an ability to invade into peripheral nerve. The results suggest that the HI-75 strain claims a nature as a pathogen to develop a leproma-like lesion.

Animals↗