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H Sato

Publications and source records attributed to H Sato.

At least 307 records · Page 17Linked to original sources

Heterogeneity of growth potential of adult rat hepatocytes in vitro.

Nearly pure populations of small hepatocytes (SHs), parenchymal hepatocytes (PHs), and nonparenchymal cells (NPCs) were prepared from the adult rat, and cocultures of hepatocytes and NPCs were reconstituted from them first to obtain the direct evidence that NPCs promote the growth of hepatocytes and second to compare the growth potential between SHs and PHs. SHs and PHs underwent multiple divisions when cocultured with NPCs, whereas neither SHs nor PHs formed colonies at 10 days when cultured alone. Stellate cells in the NPCs were shown to be responsible for this growth promotion. SHs showed a higher growth capacity than PHs. To clearly show the relationship between the growth potential and the size of hepatocytes, SHs and PHs were further fractionated by a fluorescence-activated cell sorter, because the size distribution of SHs and PHs was half overlapped. SHs produced 2 cell populations, SH-R2 and SH-R3. The former showed a greater extent of granularity and autofluorescence than the latter. In contrast, PHs produced only 1 population (PH-R2), which corresponded to the SH-R2. The size of hepatocytes of SH-R3 was smaller (17.1 +/- 0.2 microm) than those of SH-R2 (22.6 +/- 0.5 microm) and PH-R2 (24.1 +/- 0.1 microm) and there was not a significant overlap in the size distribution between the 2 groups. The hepatocytes of SH-R3 were highly replicative and 4 or 5 times higher in their growth potential than those of SH-R2 and PH-R2. We concluded that the growth potential of hepatocytes is heterogeneous and is correlated with their size and the extent of their granularity and autofluorescence.

Animals↗

Convergence patterns of the posterior semicircular canal and utricular inputs in single vestibular neurons in cats.

The convergence of the posterior semicircular canal (PC) and utricular (UT) inputs in single vestibular nuclei neurons was studied intracellularly in decerebrate cats. A total of 160 vestibular neurons were orthodromically activated by selective stimulation of the PC and the UT nerve and classified according to whether or not they were antidromically activated from the spinal cord and oculomotor nuclei into vestibulospinal (VS), vestibulooculospinal (VOS), vestibuloocular (VO), and unidentified vestibular neurons. Fifty-three (33%) of 160 vestibular neurons received convergent inputs from both the PC and UT nerves. Seventy-nine (49%) vestibular neurons responded to PC inputs alone, and 28 (18%) neurons received inputs only from the UT nerve. Of 53 convergent neurons, 8 (15%) were monosynaptically excited from both nerves. Thirty-five (66%) received monosynaptic excitatory inputs from the PC nerve and polysynaptic excitatory or inhibitory inputs from the UT nerve, or vice versa. Approximately one-third of VS and VOS neurons received convergent inputs. A majority of the VS neurons descended to the spinal cord through the lateral vestibulospinal tract, while almost all the VOS neurons descended to the spinal cord through the medial vestibulospinal tract. The convergent neurons were found in all vestibular nuclei but more in the lateral nucleus and descending nucleus. The VS neurons were more numerous than VO neurons or VOS neurons.

Acceleration↗

Properties of utricular and saccular nerve-activated vestibulocerebellar neurons in cats.

Properties of otolith inputs to vestibulocerebellar neurons were investigated in 14 adult cats. In the vestibular nuclei, we recorded single-unit activities that responded orthodromically after stimulation of the utricular and/or saccular nerves and antidromically after stimulation of the cerebellum (uvula-nodulus and anterior vermis). Descending axonal projections to the spinal cord were also examined by antidromic stimulation of the caudal end of the C1 segment. Forty-seven otolith-activated neurons that projected to the uvula-nodulus were recorded. Thirteen (28%) of the 47 neurons received convergent inputs from the utriculus and sacculus. The remaining 34 (72%) vestibular neurons were non-convergent neurons: 18 (38%) received utricular input alone, and 16 (34%) received saccular input alone. Most (35/47) vestibulocerebellar neurons were located in the descending vestibular nucleus and only one of these projected to the spinal cord. Seven of the 47 vestibulocerebellar neurons were located in the lateral vestibular nucleus and most of these neurons projected to the spinal cord. The remaining neurons were located in group X (two neurons) and the superior vestibular nucleus (three neurons). In a different series of experiments, 37 otolith-activated vestibular neurons were tested to determine whether they projected to the uvula-nodulus and/or the anterior vermis. Nineteen of the 37 neurons projected to the anterior vermis, 13/37 projected to the uvula-nodulus, and 5/37 projected to both. The utricular and/or saccular nerve-activated vestibulocerebellar neurons projected to not only the uvulanodulus, but also to the anterior vermis. In summary, the results of this study showed that vestibular neurons receiving inputs from the utriculus and/or sacculus projected to the cerebellar cortex. This indirect otolith-cerebellar pathway terminated both in the anterior lobe and in the uvula/nodulus.

Animals↗

Sacculo-ocular reflex connectivity in cats.

The otolith system contributes to the vestibulo-ocular reflexes (VOR) when the head moves linearly in the horizontal plane or tilts relative to gravity. The saccules are thought to detect predominantly accelerations along the gravity vector. Otolith-induced vertical eye movements following vertical linear accelerations are attributed to the saccules. However, information on the neural circuits of the sacculo-ocular system is limited, and the effects of saccular inputs on extraocular motoneurons remain unclear. In the present study, synaptic responses to saccular-nerve stimulation were recorded intracellularly from identified motoneurons of all twelve extraocular muscles. Experiments were successfully performed in eleven cats. Individual motoneurons of the twelve extraocular muscles--the bilateral superior recti (SR), inferior recti (IR), superior obliques (SO), inferior obliques (IO), lateral recti (LR), and medial recti (MR) were identified antidromically following bipolar stimulation of their respective nerves. The saccular nerve was selectively stimulated by a pair of tungsten electrodes after removing the utricular nerve and the ampullary nerves of the semicircular canals. Stimulus intensities were determined from the stimulus-response curves of vestibular N1 field potentials in order to avoid current spread. Intracellular recordings were performed from 129 extraocular motoneurons. The majority of the neurons showed no response to saccular-nerve stimulation. In 17 (30%) of 56 extraocular motoneurons related to vertical eye movements (bilateral SR and IR), depolarizing and/or hyperpolarizing postsynaptic potentials (PSPs) were observed in response to saccular-nerve stimulation. The latencies of PSPs ranged from 2.3 to 8.9 ms, indicating that the extraocular motoneurons received neither monosynaptic nor disynaptic inputs from saccular afferents. The majority of the latencies of the depolarization, including depolarization-hyperpolarization, were in the range of 2.3-3.3 ms. Latencies of hyperpolarizations were typically longer than those of depolarizations. Only one contralateral SO motoneuron of 43 recorded oblique extraocular motoneurons (bilateral SO and IO) showed a depolarization-hyperpolarization in response to saccular-nerve stimulation at a latency of 2.5 ms. None of 30 recorded horizontal extraocular motoneurons (bilateral LR and MR) responded to stimulation of the saccular nerve. The neural linkage in the sacculo-ocular system is relatively weak in comparison to the utriculo-ocular and sacculo-collic systems, suggesting that the role of the sacculo-ocular system in stabilizing eye position may be reduced when compared with utriculo-ocular and semi-circular canal-ocular reflexes.

Animals↗

Convergence of posterior semicircular canal and saccular inputs in single vestibular nuclei neurons in cats.

Convergence between posterior canal (PC) and saccular (SAC) inputs in single vestibular nuclei neurons was investigated in decerebrated cats. Postsynaptic potentials were recorded intracellularly after selective stimulation of the SAC and PC nerves. Stimulation of either the SAC or PC nerve orthodromically activated 143 vestibular nuclei neurons. Of these, 61 (43%) were antidromically activated by stimulation of the C1-C2 junction, 14 (10%) were antidromically activated by stimulation of the oculomotor or trochlear nucleus, and 14 (10%) were antidromically activated by stimulation of both the oculomotor or trochlear nucleus and the spinal cord. Fifty-four (38%) neurons were not activated by stimulation of either or both. We named these neurons vestibulospinal (VS), vestibulo-ocular (VO), vestibulooculo-spinal (VOS) and vestibular (V) neurons, respectively. Both PC and SAC inputs converged in 47 vestibular nuclei neurons (26 VS, 2 VO, 6 VOS and 13 V neurons). Of these, 19 received monosynaptic excitatory inputs from both nerves. This input pattern was frequently seen in VS neurons. Approximately half of the convergent VS neurons descended to the spinal cord through the lateral vestibulospinal tract. The remaining half and all the convergent VOS neurons descended to the spinal cord through the medial vestibulospinal tract. Most of the convergent neurons were located in the lateral nucleus or descending nucleus.

Animals↗

Saccular and utricular inputs to single vestibular neurons in cats.

Saccular and utricular organs are essential for postural stability and gaze control. Although saccular and utricular inputs are known to terminate on vestibular neurons, few previous studies have precisely elucidated the origin of these inputs. We investigated the saccular and utricular inputs to single vestibular neurons in whole vestibular nuclei of decerebrated cats. Postsynaptic potentials were recorded from vestibular neurons after electrical stimulation of the saccular and utricular nerves. Ascending and descending axonal projections were examined by stimulating the oculomotor/trochlear nuclei and the cervical segment of the spinal cord, respectively. After each experiment, locations of recorded neurons were identified. The recorded neurons (140) were classified into vestibulo-spinal (79), vestibulo-oculo-spinal (9), and vestibulo-ocular (3) neurons based on antidromic responses; 49 other vestibular neurons were unidentified. The majority of recorded neurons were mainly located in the lateral vestibular nucleus. Most of the otolith-activated vestibular nuclei neurons seemed to participate in vestibulospinal reflexes. Of the total 140 neurons recorded, approximately one third (51) received saccular and utricular inputs (convergent neurons). The properties of these 51 convergent neurons were further investigated. Most (33/51) received excitatory postsynaptic potentials (EPSPs) after saccular and utricular nerve stimulation. These results implied that most of the convergent neurons in this study additively coded mixed information for vertical and horizontal linear acceleration. Based on the latencies of convergent neurons, we found that an early integration process for vertical and horizontal linear acceleration existed at the second-order level.

Acceleration↗

Predictive risk factors for delayed extubation in patients undergoing coronary artery bypass grafting.

Prolonged mechanical ventilation increases hospitalization costs, airway and lung trauma, and stress. The objective of this study was to elucidate patient characteristics and operative variables that predict delayed extubation in patients undergoing coronary artery bypass grafting (CABG). The records of 167 patients who underwent CABG between 1994 and 1998 were examined retrospectively. The patients were divided into early and delayed extubation groups. Putative factors affecting the duration of intubation were included in a univariate analysis using the t-test and chi-squared test. A logistic regression model was then developed to determine the factors associated with delayed extubation. Forty-four percent of the patients needed prolonged mechanical ventilation (more than 24h). Univariate predictors of delayed extubation (P < 0.05) were emergency surgery, preoperative use of an intra-aortic balloon pump (IABP), the duration of anesthesia, surgery, cardiopulmonary bypass and aortic cross-clamping, the total volume of fentanyl. lowest rectal temperature, glucose level, perioperative transfusion, bleeding, perioperative heart failure, perioperative insertion of IABP, postoperative transfusion, cardiac index, inspired oxygen fraction (FiO2), arterial oxygen tension (PaO2), the PaO2/FiO2 ratio, and the volume of catecholamine. In the delayed extubation group, the intensive care unit stay was significantly longer (P < 0.001) and re-exploration was required more frequently (P = 0.004). Excellent prediction was provided by a model consisting of six variables: age, duration of surgery, perioperative heart failure, glucose level, postoperative transfusion, and the PaO2/FiO2 ratio. These results suggest that decreasing the cardiopulmonary bypass time, maintaining a low glucose level during cardiopulmonary bypass, and ensuring adequate perioperative hemostasis may help to avoid pulmonary dysfunction and delayed extubation. Moreover, the PaO2/FiO2 ratio may be a useful predictor of delayed extubation in patients undergoing CABG.

Aged↗

Effects of occupational metallic mercury vapour exposure on suppressor-inducer (CD4+CD45RA+) T lymphocytes and CD57+CD16+ natural killer cells.

OBJECTIVES: To examine the effects of metallic mercury vapour on the cellular and humoral immune system. METHODS: We measured T lymphocyte and natural killer (NK) cell subpopulations, B lymphocytes, and serum immunoglobulins (i.e. IgG, IgA and IgM) together with total T (CD3 +) lymphocytes and total lymphocytes in blood samples from 20 male, fluorescent-lamp makers (mercury workers) and the same number of gender-, age- and smoking-matched controls. Urinary concentrations of inorganic mercury (UHg) in the 20 workers ranged from 1.8 to 163.5 (mean 44.8) microg/l. They had been exposed to mercury vapour for 4 to 62 (mean 31) months. RESULTS: Numbers of CD4+CD45RA+ (suppressor-inducer) T lymphocytes and total CD4+ T lymphocytes in the mercury workers were significantly smaller than those in the controls (paired-sample t-test, P < 0.01). The number of CD57+CD16+ NK cells was inversely correlated with UHg. CONCLUSION: It is suggested that numbers of CD4+CD45RA+ T lymphocytes and CD57+CD16+ NK cells are inversely affected by exposure to metallic mercury vapour in workers, with an average urinary inorganic mercury concentration of 45 microg/l being found.

Adult↗

Pigmented ameloblastic fibrodentinoma: a novel melanin-pigmented intraosseous odontogenic lesion.

This paper reports about an ameloblastic fibrodentinoma with macroscopically visible pigmentation, resulting in the clinical appearance of a melanotic lesion in a 21-year-old Japanese male. In addition to the characteristic histopathologic features of ameloblastic fibrodentinoma, various-formed and -sized cells, which were considered to be melanophages containing numerous aggregates of melanin pigment in their cytoplasm, were densely distributed throughout the mesenchymal component. In addition, melanin pigment was deposited in dentin. Some of the pigmented cells showed dendritic form and were regarded as melanocytes. Furthermore, pigmented cells were frequently distributed in the epithelial component, and melanin pigment was seen in some epithelial cells. Perusal of the English language literature revealed 30 cases of pigmented odontogenic tumors: 18 were calcifying odontogenic cysts, three were ameloblastic fibro-odontomas, three were adenomatoid odontogenic tumors, two were odontomas, one was an ameloblastic fibroma and one was an odontogenic fibroma. However, all of these reported lesions did not show macroscopically visible pigmentation. The possible histogenesis of melanocytes in the odontogenic lesions is discussed, although no firm conclusion could be drawn.

Adult↗

Survival of destrobilated adults of Taenia crassiceps in T-cell-depleted Mongolian gerbils.

In Mongolian gerbils (Meriones unguiculatus), prednisolone treatment induces the survival of strobilated Taenia crassiceps to sexual maturity followed by fecal release of gravid proglottides. The mechanism underlying the effects of prednisolone has not been elucidated in this taeniid/rodent model. Using a novel murine monoclonal antibody specific to a cell-surface determinant of gerbil T-cells (HUSM-M.g.15 of IgG2b isotype) for in vivo depletion of the cells, we examined the T-cell dependence of the following two phenomena: (1) elimination of strobilated T. crassiceps from the intestine of naive gerbils, and (2) depressed egg formation by the cestode in prednisolone-treated gerbils. In T-cell-depleted gerbils, only destrobilated adults were recovered from the intestine, although the recovery rate was comparable with that observed in prednisolone-treated animals. Egg formation by the cestode in T-cell-depleted, prednisone-treated gerbils did not differ from that seen in gerbils treated with prednisolone alone. We conclude that one of main effects of prednisolone can be ascribed to the suppression of T-cell functions that work to eliminate strobilated T. crassiceps from gerbils.

Animals↗

Identification of 187 single nucleotide polymorphisms (SNPs) among 41 candidate genes for ischemic heart disease in the Japanese population.

To investigate whether common variants in the human genetic background are associated with pathogenesis of ischemic heart diseases, we systematically surveyed 41 possible candidate genes for single-nucleotide polymorphisms (SNPs) by directly sequencing 96 independent alleles at each locus, derived from 48 unrelated Japanese patients with myocardial infarction, including 25.8 kb 5' flanking regions, 56.8 kb exonic and 35.4 kb intronic sequences, and 1.8 kb 3' flanking regions. In this genomic DNA of nearly 120 kb, we identified 187 SNPs: 55 in 5' flanking regions, seven in 5' untranslated regions (UTRs), 52 in coding elements, 64 in introns, eight in 3' UTRs, and one in a 3' flanking region. Among the 52 coding SNPs, 26 were non-synonymous changes. Allelic frequencies of some of the polymorphisms were significantly different from those reported in European populations. For example, the Q506R substitution in the coagulation factor V gene, the so-called "Leiden mutation", has a reported frequency of 2.3% in Europeans, but we detected the Leiden mutation in none of the Japanese genomes that we investigated. The allelic frequencies of the -33A>G SNP in the thrombomodulin gene were also very different; this allele occurred at a 12% frequency in the Japanese patients that we examined, although it had been detected in none of 82 Caucasians reported previously. These data support the hypothesis that some SNPs are specific to particular ethnic groups.

3' Untranslated Regions↗

Unanswered and uncounted items of the illness behavior questionnaire count: a comparison between patients who answered all the items in the questionnaire and those who left one or more items unanswered in a pain management program.

PURPOSE: This study aimed to understand the significance of unanswered and uncounted items on the illness behavior questionnaire (IBQ) in the setting of the Mayo Clinic pain management program for patients with chronic pain. METHODS: Three hundred and seventy-eight patients who completed the questionnaire were studied. The data included (1) age, (2) IQs, (3) IBQ score profiles, (4) litigation status, (5) admission status (inpatient vs outpatient), and (6) dismissal status ("graduates" vs "dropouts"). RESULTS: Comparison between patients who answered all the items (n = 272) and those who left one or more items unanswered (n = 106) showed a significant difference in the completion rate of the Wechsler Adult Intelligence Scale ( P < 0.05), Scale 5 (affective disturbance) score (P < 0.05), and the rate of dropout from the program (P < 0.05). Also, those who dropped out of the pain management program had a significantly lower score on Scale 5 (P < 0.001) and a significantly greater number of unanswered items that were not counted toward the scale score (P < 0.05). CONCLUSION: Unanswered and uncounted items of the IBQ seem to count toward a better understanding of patients' pain behavior.

Journal Article↗

Hemoperitoneum secondary to exophytic leiomyoma: report of a case.

We report herein the case of a 63-year-old male with hemoperitoneum secondary to exogastric leiomyoma. The patient had been receiving anticoagulation therapy for a cerebral embolism and complained of sudden, severe abdominal pain. A sonogram and computed tomography scan showed an exogastric mass and massive ascites. A peritoneal puncture proved the presence of an intraperitoneal hemorrhage. An emergency laparotomy revealed a pedunculated bleeding tumor, thus confirming the preoperative diagnosis of a ruptured exogastric tumor. A microscopic analysis of the excised tumor demonstrated gastric leiomyoma. Other authors have reported hemoperitoneum secondary to gastric myogenic tumors, but no cases of leiomyomas could be found in the literature.

Biopsy, Needle↗

Multiplex PCR amplification of TH01, D9S304, and D3S1744 loci.

A multiplex typing method of the tetrameric short tandem repeat (STR) loci TH11, D9S304, and D3S1744 was developed. The allelic ladder included alleles 6-11 (80-100bp) and 9.3 (95bp) for TH01, alleles 6-15 (125-161 bp) for D9S304, and alleles 13-22 (174-210bp) for D3S1744. The observed heterozygosity of D9S304 was 0.851. The combined discrimination power of the three loci was 0.991.

Base Sequence↗

Beneficial effect of prodromal angina pectoris is lost in elderly patients with acute myocardial infarction.

BACKGROUND: Prodromal angina pectoris occurring shortly before the onset of acute myocardial infarction is associated with a favorable outcome by the mechanism of ischemic preconditioning. Recent experiments have reported that the beneficial effect of ischemic preconditioning are reversed in the aged heart. METHODS: We studied 990 patients who underwent coronary angiography within 12 hours after the onset of acute myocardial infarction. Patients were divided into 2 groups: those aged <70 years (nonelderly patients, n = 722) and those aged >/=70 years (elderly patients, n = 268). Prodromal angina in the 24 hours before infarction was found in 190 of 722 nonelderly patients and in 66 of 268 elderly patients (26% vs 25%, P =.61). RESULTS: In nonelderly patients, prodromal angina was associated with lower peak creatine kinase levels (2438 +/- 1939 IU/L vs 2837 +/- 2341 IU/L, P =.04), lower in-hospital mortality rates (3.7% vs 8.8%, P =.02), and better 5-year survival rates (P =. 007). On the contrary, in elderly patients there was no significant difference in peak creatine kinase levels (2427 +/- 2142 IU/L vs 2256 +/- 1551 IU/L, P =.51), in-hospital mortality rate (21.2% vs 17. 4%, P =.49), and 5-year survival rates (P =.47). A multivariate analysis showed that prodromal angina in the 24 hours before infarction was associated with 5-year survival rate in nonelderly patients (odds ratio 0.49, P =.009) but not in elderly patients (odds ratio l.12, P =.65). CONCLUSIONS: In nonelderly patients, prodromal angina in the 24 hours before infarction was associated with a smaller infarct size and better short- and long-term survival, suggesting a relation to ischemic preconditioning. However, such a beneficial effect was not observed in elderly patients.

Adult↗

Enzyme-linked immunosorbent assay for anti-tropomyosin antibodies and its clinical application to various heart diseases.

Tropomyosin is one of the key proteins for muscle contraction. We developed an enzyme-linked immunosorbent assay for antibodies to porcine muscle tropomyosin and measured serum anti-tropomyosin antibodies in patients with heart diseases and in normal controls. The mean values of absorbance in the ELISA assay of patients with ischemic heart disease (n=36, P<0.001), dilated cardiomyopathy (n=28, P<0.005), valvular heart disease (n=27, P<0.05), and collagen disease (n=38, P<0.05) were significantly higher than those of normal controls (n=53), but the value in patients with hypertrophic cardiomyopathy (n=19) was not significantly different from that of normal controls. When the cut-off value was fixed at the mean+2 SD of absorbance in normal controls, positive reactions were found in 19.4%, 7.1%, 18.5% and 15.8% of patients with ischemic heart disease, dilated cardiomyopathy, valvular heart disease, and collagen disease, respectively. An inhibition study revealed that anti-tropomyosin antibodies were different from anti-myosin antibodies, but there was a partial cross-reactivity between the two. Thus, there was a weak correlation of the titers of the two types of antibody within the group of heart diseases. These data indicate that measurement of anti-tropomyosin antibodies by ELISA is helpful for detecting autoimmune abnormalities in various heart diseases.

Adult↗

Expression of matrix metalloproteinase-2 (MMP-2) and of membrane-type-1-matrix metalloproteinase (MT1-MMP) in transitional cell carcinoma of the upper urinary tract.

Tumor cell invasion and metastasis are biologically dependent on the proteolytic destruction of surrounding matrix components. Matrix metalloproteinase-2 (MMP-2) is able to cleave type IV collagen, and membrane-type-1-matrix metalloproteinase (MT1-MMP) induces activation of proMMP-2. We investigated the expression of MMP-2 and MT1-MMP using in situ hybridization and immunohistochemistry in 102 cases of transitional cell carcinoma of the upper urinary tract (TCC-UUT). A positive expression of each metalloproteinase was recognized in all samples and was apparent within the cytoplasm of tumor epithelial cells and/or stromal cells situated at the interface between tumor and stroma. Our analysis of clinicopathologic findings showed a relationship between MMP-2 and MT1-MMP expression and stage. The correlation between the MMP-2 protein staining score for tumor epithelial cells and overall survival rate reached significance in the univariate analysis. However, only stage was associated with disease-free and overall survivals in the multivariate analysis. In conclusion, the detection of MMP-2 and MT1-MMP would appear to be of limited value in informing the prognosis of TCC-UUT.

Adult↗