Search PubMed⌕ Search

Biomedical subjects

I Sato

Publications and source records attributed to I Sato.

At least 235 records · Page 13Linked to original sources
PubMed1994

Transcription of the MRP RNA gene in frog stage I oocytes requires a novel cis-element.

The RNA component of the mitochondrial RNA processing (MRP) enzyme is related to both replication of mitochondrial DNA and processing of 5.8S rRNA, which are accelerated in the frog earliest stage (stage I) of frog oocytes. Microinjection of the deleted genes into the stage I oocytes showed positive cis-elements in the upstream region of the gene. The specific binding of protein(s) to this region was detected in cell extracts from stage I oocytes and liver but not in extracts of stage II-IV oocytes and the concentration of this protein was 40 times higher in the extract of stage I oocytes than that in liver.

Animals↗
PubMed1994

Macrophage colony-stimulating factor enhances platelet recovery following cisplatin/carboplatin chemotherapy in ovarian cancer.

To assess the effects of macrophage colony-stimulating factor (M-CSF) on platelet recovery in patients given chemotherapy for advanced and recurrent ovarian cancer, we selected 29 cases treated with carboplatin (280 mg/m2, Day 1) and cisplatin (70 mg/m2, Day 2). We evaluated the response and the platelet recovery effects of M-CSF, which was infused intravenously for 7 consecutive days after the second and fourth courses of chemotherapy. For the 54 courses of M-CSF infusion, the platelet nadir averaged 12.8 +/- 6.3 x 10(4)/microliters, with 9% of the courses designated Grade 3 or 4 on the toxicity scale, according to World Health Organization recommendations, both of which were significantly different from the M-CSF noninfused control courses (P < 0.05). The number of periods in which platelets were below 7.5 x 10(4)/microliters was significantly less in the courses of M-CSF infusion (P < 0.01). Response to treatment was pathologic complete in 23% and partial in 41%, for a total response of 64%. Cisplatin combined with carboplatin was effective in treating patients with advanced and recurrent ovarian cancer. M-CSF infusion may enhance the recovery from the thrombocytopenia that accompanies such chemotherapy.

Adult↗
PubMed1994

Direct lymphatic drainage from the esophagus into the thoracic duct.

The lymphatic vessels from around the esophagus which drain into the thoracic duct were identified macroscopically and histologically in 106 cadavers. Direct lymphatic drainage to the duct was macroscopically demonstrated by 84 vessels in 46 cases (43.4%). In 23 cases (19.8%), large collecting vessels arose from the thoracic esophagus and opened directly into the duct. In most of these cases (15/23) these lymphatic connections were found at the levels of the 1st-3rd or 6th-8th thoracic vertebrae. Histologic study revealed that two vessels originated from the fine lymphatic plexus in the esophageal adventita, which showed monocytic infiltration. In 11 of the 23 cases, an intercalated node was found along the thoracic duct. The results suggest that lymph drains rapidly into the systemic circulation via the thoracic duct. In view of the clinical applications in esophageal carcinoma, previous accounts of the extramural esophageal lymphatics concerned in direct drainage are discussed.

Aged↗
PubMed1994

Morphology and analysis of the development of the human temporomandibular joint and masticatory muscle.

The calcification levels of the mandible and the temporal bone of human fetuses, which ranged from 12 to 32 weeks of gestation, were systematically investigated with a soft X-ray analyzer linked to an image analyzer. The profile of the condylar process (head) revealed high levels of calcification, in contrast to that in the mandibular fossa of the temporal bone. The basal portion of the condylar process and the mandibular notch exhibited moderate calcification from 12 weeks of gestation. The weight and the cross-sectional areas of the muscle and the muscle fibers in masticatory muscles (masseter, temporal, medial, and lateral pterygoid muscles) are all increased gradually during development from 12 to 32 weeks of gestation. These changes in calcification and in cross-sectional area of muscle suggest that muscle development may be related to bone calcification during formation of the mandible.

Aged↗
PubMed1994

HELLP syndrome: CT evaluation.

Patients with the HELLP syndrome (hemolysis, elevated liver enzymes, and low platelet count) require careful observation and expedient delivery. However, those who develop this syndrome peripartum do not always fulfill its diagnostic criteria before labor begins. We investigated the potential usefulness of liver and spleen CT evaluation in identifying such patients. Seven patients with this syndrome were studied by CT scanning on postpartum days 0-3 and again 3-4 weeks after delivery. Although 3 patients with severe thrombocytopenia had a reduced liver-spleen CT number ratio (< 1.1) and subsequent normalization, the remaining 4 with less severe thrombocytopenia demonstrated no CT changes. Thus, antepartum evaluation of liver and spleen by CT may not be sensitive enough to detect patients who develop HELLP syndrome during the peripartum period. Serial examination of platelet counts may be more useful than CT in detecting patients at risk for this peripartum syndrome.

Adult↗
PubMed1994

Complementary improvement of the method for determining cholinergic activities in the small intestine and its application to experiments in vivo.

The concentration of acetylcholine (ACh) in rat jejunum that had been homogenized with an ultra-high-speed homogenizer (Biotron) was significantly higher than that in jejunum homogenized with a glass homogenizer. Rats were injected once or repeatedly for 10 days with a muscarinic agonist, pilocarpine (1 mg/kg), or a muscarinic antagonist, scopolamine (5 mg/kg). Animals were killed 20 min or 24 hr after single or consecutive injections, respectively, for determinations of cholinergic activities in the jejunum. Single treatment: Pilocarpine did not cause significant changes in the level of ACh, the activity of acetylcholinesterase (AChE), the binding of [3H]quinuclidinyl benzilate (QNB) or the contractile responses to ACh. Scopolamine reduced the level of ACh and binding of [3H]QNB without inducing significant changes in the activity of AChE and the contractile response. Consecutive treatment: Pilocarpine reduced the binding of [3H]QNB by changing the value of Bmax and reduced the contractile response without affecting the level of ACh or the activity of AChE. Scopolamine increased the binding of [3H]QNB without any effects on the level of ACh, the activity of AChE or the contractile response. In summary, it is possible to determine the level of ACh in a tissue as hard as intestine by homogenization with a Biotron and to assess the cholinergic situation in the intestine of animals that have been poisoned with various agents by estimating cholinergic activities.

Acetylcholine↗
PubMed1994

Differentiation of histochemical properties of masticatory muscles in Bovidae and Cervidae (Artiodactyla).

We analyzed the masticatory muscles (masseter, temporal, medial pterygoid and lateral pterygoid muscles) of Bovidae and Cervidae (Artiodactyla) for the histochemical characteristics of their fiber types. Analysis of muscle fiber types in the present study was based on the staining reaction for SDH, Sudan black B, alpha-GPDH, and myosin-ATPase after alkaline preincubations. Histochemical properties were found to contribute to masticatory function, including a slow-twitch fatigue resistant activity derived from the high percentage of red fibers, in spite of the differences in the distributions of fiber types in three portions (superficial, medial and profound portions) of each masticatory muscle. These results indicate a correlation between the histochemical profiles of individual masticatory muscles in these species and their functions during jaw movements.

Animals↗
PubMed1994

The superior alveolar nerves: their topographical relationship and distribution to the maxillary sinus in human adults.

The superior alveolar nerves in human adults were investigated macroscopically using whole-mount silver impregnation, paying special attention to their topographical relationship and distribution to the mucous membrane of the maxillary sinus. In addition, the fiber composition of the alveolar nerves was analysed in order to estimate their contribution to teeth innervation. The posterior superior alveolar nerve (PSAN) ran through canaliculi in the lateral wall of the sinus (23 of 37 cases, 62.2%) or under the mucous membrane of the sinus (14 of 37 cases, 37.8%). Moreover, the PSAN gave off many fine twigs to make complex plexus under the mucous membrane of the sinus before joining the superior dental plexus. The plexus of the maxillary sinus was separated from the superior dental plexus by the bony wall of the sinus. After the above gross observations, the perimeter compositions of myelinated fibers of the plexus, PSAN and the anterior alveolar nerve were analysed in the same specimen. The plexus was composed of myelinated fibers of less than 27 microns in circumference perimeter (mean: 14.3 microns) and numerous unmyelinated fibers. The fiber composition suggested that few fibers in the plexus of the maxillary sinus contribute to the formation of the superior dental plexus. The superior dental plexus, innervating the upper teeth, was located in the thick alveolar process of the maxilla, and not on the maxillary sinus wall. The clinical importance of these results was discussed in relation to nerve injury during antrostomy of the maxillary sinus.

Aged↗
PubMed1994

Venous drainage of the thoracic esophagus toward the pulmonary vein.

Venous drainage of the thoracic esophagus toward the pulmonary vein (PV) was investigated in 52 human specimens in which the veins around the esophagus were clearly observed owing to venous blood retention after injection of 10 L of formol solution into the femoral artery. Below the level of the tracheal bifurcation, 43 cases (right, 21; left, 22) of venous drainage toward the PV were observed in 29 of the 52 specimens examined (55.8%). The direct drainage to the PV was observed mainly on the left side (19 of the 22 cases). In contrast, drainage via the bronchial vein toward the PV existed mainly on the right side (18 of the 21 cases). These drainage routes merged into the tributaries of the inferior PV, such as the inferior or superior basal vein. The draining veins often communicated with the azygos vein system on the right side (10 of the 21 cases). The veins passed through the pulmonary ligament, and also often along the vagus nerve or the bronchial artery. No venous valves were found during the course of direct drainage from the esophagus to the PV. Venous drainage toward the PV was considered to be one of the main drainage routes from the thoracic esophagus.

Aged↗
PubMed1994

[Alteration in production of vasomediators associated with in vitro aging in cultured human umbilical vein endothelial cells].

Differences in the secretion of some vascular regulators, endothelin-1 (ET-1), prostacylin (PGI2), thromboxane A2 (TXA2) and nitric oxide (NO) associated with in vitro aging, were investigated in cultured endothelial cells isolated from normal human umbilical veins (HUVECs). HUVECs from different population doubling levels (PDLs) were cultured in a medium MCDB-104 supplemented with FBS and ECGF. Cell saturation density of HUVECs decreased by 5-fold between PDL 7 and 67. PGI2 secretion per cell increased by 6-fold, and TXA2 secretion per cell increased by 18-fold between PDL 7 and 67. The ratio of PGI2 to TXA2 secretion decreased 3-fold between PDL 7 and 40 and remained at the lower level between PDL 40 and 67. The secretion of ET-1 by HUVECs at a young stage of growth (PDL 7) increased linearly with time between 0 and 36 hours of incubation. ET-1 secretion per cell increased between PDL 7 and 67 by 5-fold after 4-hr incubation and by 3-fold after 9-hr incubation. The release of NO was assayed by a newly established, highly sensitive assay system monitoring guanosine 3':5'-cyclic monophosphate (cGMP) formation in a pig kidney epithelial cell line cocultured with HUVECs. The cGMP formation by NO released from HUVECs decreased 3.3-fold between PDL 8 and 50. These results suggest that the vaso-constrictive activity of endothelial cells increases during in vitro aging which may reflect the increased vascular disorders in the aged people.

Aging↗
PubMed1994

Enzyme-cytochemistry of human chorion laeve at term: enzyme localization on the chorionic trophoblast.

Is the chorion laeve merely a remnant of the chorion frondosum in placental development? Or is it metabolically active, having something to do with maternofetal interactions? In order to answer these questions at least in part, we determined the ultracytochemical localizations of some important enzymes such as nonspecific phosphatase (alkaline phosphatase), specific phosphatase (Ca(++)-ATPase and 5'-nucleotidase) and adenylate cyclase in the human chorion laeve at term. Strong activities of these enzymes were localized by ultracytochemistry on the plasma membrane of the trophoblast in the chorion laeve. These enzyme activities were confirmed by a series of cytochemical-control experiments, i.e., substrate-free control, heat-stability control, and inhibition control by inhibitors of alkaline phosphatase. These observations indicate that the chorionic trophoblast is probably metabolically active and that it might play an important role in the physiology of the fetal membrane.

5'-Nucleotidase↗
PubMed1994

[Effect of isoflurane on spinal dorsal horn WDR neuronal activity in cats].

The effects of isoflurane (0.5% and 1.5%) on the spinal dorsal horn wide dynamic range (WDR) neuronal activity were studied in either spinal cord intact or spinal cord-transected cats. Extracellular activity was recorded in the dorsal horn from single WDR neurons responding to noxious and non-noxious stimuli applied to the cutaneous receptive fields on the left hind foot pads of intact or decerebrate, spinal cord transected (L1-2) cats. When bradykinin (BK) 10 micrograms was injected into the femoral artery ipsilateral to the recording site as the noxious test stimulus in the spinal cat, all of 17 WDR neurons gave excitatory responses which were not depressed by 0.5% isoflurane but were depressed significantly by 1.5%. On the other hand, when the injection of BK 10 micrograms into the femoral artery ipsilateral to the recording site was used in the intact cat, 13 of 24 WDR neurons (54%) gave excitatory responses, which were significantly depressed by 0.5% and 1.5% isoflurane, and 11 of 24 WDR neurons (46%) gave inhibitory responses, which were significantly depressed by 0.5% and 1.5% isoflurane. We have found that isoflurane reduces the excitation as well as the inhibition of dorsal horn WDR neuronal activity induced by BK injection.

Action Potentials↗
PubMed1994

[Anesthetic management for cesarean section in patients with maternal myotonic dystrophy].

Myotonic dystrophy involves not only voluntary muscles of extremities, pharyngeal muscle and respiratory muscle but also smooth muscle in the gastrointestinal tract. This muscle involvement can cause difficulty in excreting sputa, delayed emptying time of stomach and regurgitation of gastric content, all of which can lead to disastrous complications of anesthetic management. Pregnancy is rare because of ovarian atrophy. We report two cases of cesarean section for patients with myotonic dystrophy. In one case, the newborn baby had dyspnea due to congenital myotonic dystrophy, and in another case, patient experienced postoperative pneumonia. Our cases and other reports suggest that spinal or epidural anesthesia is safely applied for a cesarean section of a patient with myotonic dystrophy.

Adult↗
PubMed1994

[A new operative technique for pulmonary artery banding: adjustment of pulmonary artery bands by mitral valve flow velocity].

We developed a new technique to adjust the pulmonary artery band at surgery by monitoring the mitral valve flow velocity, which is indirectly indicative of the pulmonary flow. We employed this technique for 10 consecutive patients aged from 5 days to 5 months (mean, 1 months) weighing from 2.7 to 4.4 kg (mean, 3.3 kg). Underlying disease was aortic coarctation or interrupted+ventricular septal defect in 7 patients, single ventricule in 1 patients and miscellaneous defects in 2 patients. The pulmonary artery was exposed through a left lateral thoracotomy and a 3 mm wide Teflon tape was placed around the main pulmonary artery. The transducer of the Doppler echocardiography was placed along the left sternal border. The band was tightened gradually until the maximum velocity of the mitral valve flow decreased to around 70% of the previous level. During banding procedure, arterial oxygen saturation, heart rate and left ventricular contractility were monitored continuously. If bradycardia, unacceptable hypoxemia or ventricular dysfunction occurred, the band was released. The mitral valve flow velocity decreased rapidly by just a little additional tightness of the band between the range of 50% to 80% of the previous level. This technique enabled a very fine adjustment (less than 0.5 mm plication) and postoperative management has become very easy. Although there is a limitation of this technique that monitoring of the mitral valve flow velocity cannot be applied to the patients with significant interatrial shunt or mitral regurgitation, we conclude that this technique is simple and useful to obtain the optimum constriction of the pulmonary artery with excessive pulmonary blood flow.

Aortic Coarctation↗
PubMed1994

Adjustment of pulmonary artery banding by mitral valve flow velocity.

In order to determine the tightness of the pulmonary artery band, Doppler echocardiography is used to assess mitral valve flow velocity, which is an indirect indicator of pulmonary blood flow. The band is tightened until the velocity decreases to 70% of the original maximal level. Additional adjustment of the constriction is then made to obtain reasonable arterial oxygen saturation, heart rate and ventricular contractility. Using this method, 12 consecutive patients underwent pulmonary artery banding with satisfactory results. This technique is simple but useful in obtaining optimum constriction of the pulmonary artery in congenital heart disease with excessive pulmonary blood flow.

Aorta, Thoracic↗
PubMed1994

Enzyme-cytochemistry of human chorion laeve at term: enzyme localization on the chorionic trophoblast.

Is the chorion laeve merely a remnant of the chorion frondosum in placental development? Or is it metabolically active, having something to do with maternofetal interactions? In order to answer these questions at least in part, we determined the ultracytochemical localizations of some important enzymes such as nonspecific phosphatase (alkaline phosphatase), specific phosphatase (Ca(++)-ATPase and 5'-nucleotidase) and adenylate cyclase in the human chorion laeve at term. Strong activities of these enzymes were localized by ultracytochemistry on the plasma membrane of the trophoblast in the chorion laeve. These enzyme activities were confirmed by a series of cytochemical-control experiments, i.e., substrate-free control, heat-stability control, and inhibition control by inhibitors of alkaline phosphatase. These observations indicate that the chorionic trophoblast is probably metabolically active and that it might play an important role in the physiology of the fetal membrane.

Alkaline Phosphatase↗
PubMed1993

Augmentation of endothelin-1, prostacyclin and thromboxane A2 secretion associated with in vitro ageing in cultured human umbilical vein endothelial cells.

Differences in the secretion of the vascular regulators endothelin-1 (ET-1, prostacyclin (PGI2) and thromboxane A2 (TXA2) associated with ageing were investigated in cultured endothelial cells isolated from normal human umbilical veins (HUVECS). HUVECS at different population doubling levels (PDLs) were cultured in medium MCDB-104 supplemented with FBS and ECGF. Cell saturation density was determined by a Coulter counter, and concentrations of ET-1, PGI2 and TXA2 in the media were determined by radioimmunoassay. The cellular and nuclear size of HUVECS increased with advancing age, and the dividing ability decreased. Cell saturation density of HUVECS decreased 5-fold between PDLs 7 and 67 (P < 0.01). The secretion of ET-1 by HUVECS at a young stage of growth (PDL 7.6) increased linearly between 0 and 36 h of incubation (P < 0.01). ET-1 secretion increased approximately 3-fold between PDLs and 67 (P < 0.01). PGI2 secretion increased 6-fold between PDLs 7 and 67 (P < 0.01), and TXA2 secretion increased 18-fold between PDLs 7 and 67 (P < 0.01). The ratio of PGI2 to TXA2 secretion decreased 3-fold between PDLs 7 and 40 (P < 0.01), and remained at the lower ratio between PDLs 40 and 67. This data indicates that the anti-thrombotic or anti-vasoconstrictive role of endothelial cells may decrease during in vitro ageing.

Aging↗