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F Sasaki

Publications and source records attributed to F Sasaki.

At least 109 records · Page 6Linked to original sources
PubMed1995

[Lung injury and pulmonary vascular endothelial cell injury].

Pulmonary vascular endothelial cells are an important barrier that helps keep lung tissue intact. These cells are exposed to potentially injurious cells and to harmful mediators that are produced in or released into the blood. The endothelial cells may then be stimulated and injured. Stimulated and injured pulmonary vascular endothelial cells can themselves produce and release injury-promoting mediators. Using isolated perfused rat lungs and cultured human pulmonary endothelial cells, we assessed the effect of neutrophil-derived injurious mediators, leukotoxin, and neutrophil elastase on the pulmonary endothelium. Both mediators caused high-permeability pulmonary edema in the isolated lungs and caused dose-dependent and time-dependent damage in the cell cultures. Injury due to leukotoxin was suppressed in the presence of LNMMA or superoxide dismutase and injury due to neutrophil elastase was suppressed by neutrophil elastase inhibitors. These data indicate that these mediators cause lung injury via different mechanisms and that they may synergistically evoke clinical lung injury.

Acute Disease↗
PubMed1994

Immunohistochemical evidence of neurons with GHRH or LHRH in the arcuate nucleus of male mice and their possible role in the postnatal development of adenohypophysial cells.

BACKGROUND: The neonatal administration of monosodium L-glutamate (MSG) has been used in investigations of the possible role of the arcuate nucleus in neuroendocrine regulation during postnatal development. We used this method to examine whether the mouse arcuate contained cell bodies immunoreactive with antisera to growth hormone releasing hormone (GHRH) or luteinizing hormone releasing hormone (LHRH), and whether these hypothalamic peptides affect synthesis and secretion of growth hormone and gonadotropin and the testis. METHODS: The hypothalamus, pituitary, and testes of adult male mice treated with MSG during the neonatal period were fixed in Bouin's fluid or 10% neutral formalin. The hypothalamus was used in immune staining, the pituitary was used in both morphometry and immune staining, and the testis was stained with hematoxylin and eosin. RESULTS: Body weights in control and treated mice were not different. The treated mice had more subcutaneous adipose tissue and a shorter body than the control mice. The testes were heavier in the controls. Many perikarya immunoreactive with antisera to GHRH or LHRH were found in the arcuate nucleus in control mice, but few such perikarya were found in this nucleus in treated mice. The size of the anterior lobe and the number and size of GH cells, follicle stimulating hormone (FSH) cells, and prolactin (PRL) cells in treated mice were less than those of control mice. CONCLUSIONS: GHRH and LHRH neurons in the arcuate nucleus in male mice may cause body and testis weight to increase via GH and LH cells, respectively, in the adenohypophysis during postnatal development. There are some differences in the hypothalamo-pituitary-testis axis of mice and rats.

Adipose Tissue↗
PubMed1994

Adult precursor cells in the tail epidermis of Xenopus tadpoles.

Polyclonal antibodies were raised against Xenopus larva-specific 58 kDa keratin (PAK58) and adult-specific 63 kDa keratin (PAK63), in order to examine the origin of 63 kDa-keratin-producing cells in the tail skin. By immunofluorescent staining of the tail skin, the 58 kDa keratin was recognized in almost all of the larval epidermal cells, although a small number of PAK58-negative cells were detected at stage 64. In contrast, 63 kDa keratin was immunohistochemically recognized at stage 58, but the signal was very weak. The number of epidermal layers in the tail epidermis increased during a period from stage 58 to stage 64. At stage 64, a small number of PAK63-positive cells was clearly identified in the multilayered tail epidermis. Comparative analysis of successive sections showed that PAK63-positive cells are derived from a cell group differing from PAK58-positive cells. Immunohistochemical studies using cultured epidermal cells demonstrated that 58 kDa keratin is localized in the cytoskeletal bundles of skein cells, whereas 63 kDa keratin is produced not by skein cells but by basal cells and their descendants. These results suggest that basal cells are the adult precursor cells within the larval epidermis even in the tail area.

Animals↗
PubMed1994

Body-specific proliferation of adult precursor cells in Xenopus larval epidermis.

Cell proliferation was examined in the back and tail epidermis of larval Xenopus laevis using bromodeoxyuridine (BrdU). The BrdU labeling index of the back epidermis increased temporally at stage 59, followed by a rapid decrease to the same level as at stage 51. epidermis produced a new epidermal layer composed of basal cells. In vitro analysis showed that tri-iodothyronine (T3) promotes cell proliferation of basal cells but suppresses that of skein cells. Immunohistochemical studies showed that the newly formed basal cell layer functions as adult precursor cells which produce the adult epidermal cells. In contrast to the back epidermis, the labeling index of the tail epidermis decreased from stage 57. However, when the tail skin was transplanted to the back area, cell proliferation in the tail epidermis increased to the same level as that of the normal back epidermis. Cell proliferation of the back epidermis was not suppressed by transplanting the skin to the tail area. These results suggest that some promoting factors are produced in the body region and regulate the number of adult precursor cells, which determine the developmental fate of the larval skin.

Animals↗
PubMed1994

Liver resection in children, using a water-jet.

The water-jet method has been used during hepatic resection in children. The instrument cuts the hepatic tissue by means of a high-pressure fine water-jet, while the exposed intrahepatic vessels are spared injury. Physiological saline was used for the jet water, and pressure of 12 to 15 kilograms of force per square centimeter (kgf/cm2) through a 0.15-mm-diameter nozzle was found to be optimal for cutting the liver parenchyma. The authors evaluated the usefulness of the water-jet dissector (n = 8) during bisegmentectomy or trisegmentectomy in comparison to the Cavitron Ultrasonic Surgical Aspirator (CUSA) (n = 5). The mean operation time was 4.08 +/- 0.87 hours for the water-jet group and 5.08 +/- 1.33 hours for the CUSA group. The mean blood loss was 602 +/- 659 mL for the water-jet group and 1,036 +/- 521 mL for the CUSA group. Although there were no significant differences with respect to operation time, blood loss, or postoperative complications, the liver parenchyma was dissected more easily using the water-jet. The authors believe that the mechanical simplicity and safety of the water-jet method will lead to its more widespread use in liver resection in children.

Blood Loss, Surgical↗
PubMed1994

Congenital biliary dilatation with pancreatico-biliary maljunction: a comparative study between children and adults.

A comparative study of congenital biliary dilatation with pancreatico-biliary maljunction in 15 children and 16 adults was undertaken. Cystic and fusiform dilatation of the common bile duct was seen in 9 and 6 cases respectively in the child group, with 8 and 8 cases respectively in the adult group. Cholangiographically, neither the length of the common channel nor the type of pancreatico-ductal union varied significantly between groups. Furthermore the incidence of higher amylase levels of bile showed no apparent variance from group to group. This was also true when looking histologically at the number and distribution of periductal glands surrounding the intra-hepatic bile duct. Therefore, we concluded that there was no essential etiological difference between the two groups.

Adult↗
PubMed1994

The presence of low molecular weight germinative substances in Bacillus cereus T spore extract.

An extract from intact spores of Bacillus cereus T having a germination-inducing activity was studied. Two distinct germinative principles were found through dialysis of the extract. One was diffusible through the dialysis membrane and the other was non-diffusible. The activity of the former fraction was inhibited by the addition of 1 mM glycoletherdiamine-N,N,N',N'-tetraacetic acid (GEDTA), whereas the latter fraction was inactive unless GEDTA was added to the assay system. The diffusible principle maintained the major portion of the activity found in the crude spore extract. By means of high-performance liquid chromatography (HPLC) using a gel permeation chromatography column, 9 fractions were obtained from the deproteinized diffusible fraction. Of those fractions, two fractions (No. 1 and No. 8) were responsible for the germination-inducing activity, but no reconstituted activity was observed unless both fractions No. 1 and No. 8 were added to the assay system. Amino acid analysis of fraction No. 1 revealed that the fraction was rich in free amino acids, especially in alanine. On the other hand, by the use of reverse-phase HPLC and fast atom bombardment mass spectrometry, it was concluded that the effective substance in fraction No. 8 was inosine. Based on these findings, it was suggested that the active substances in fraction No. 1 might be a free amino acid such as L-alanine and/or Ca2+ and a Ca(2+)-binding substance.

Alanine↗
PubMed1994

Characterization and localization of mouse hypothalamic growth hormone-releasing factor and effect of gold thioglucose-induced hypothalamic lesions.

Hypothalamic growth hormone-releasing factor (GRF) in higher mammals, including human GRF, is a 44 amino acid residue peptide and is highly homologous in structure. By contrast, mouse GRF (mGRF) recently deduced by cDNA cloning consists of only 42 residues and shows relatively low homology to the GRFs of higher mammals and the same rodent species, rat. To characterize and localize the predicted mature mGRF peptide in the hypothalamus, we have generated its antiserum and developed a homologous radioimmunoassay. Immunoreactive mGRF in the acid hypothalamic extract was eluted as a single peak at a position identical to that of synthetic peptide on both gel filtration chromatography and reverse-phase high-performance liquid chromatography (HPLC). Secretion of immunoreactive mGRF from incubated hypothalami increased several fold in response to 50 mM K+, and this rise was abolished in the absence of medium Ca2+. Only a single peak of immunoreactive mGRF that coeluted with synthetic replicate was observed after the K(+)-stimulated medium was extracted on Bond Elut C18 cartridges and applied on reverse-phase HPLC. Immunohistochemistry identified many mGRF-positive cell bodies in the arcuate nucleus and dense bundles of immunoreactive fibers in the median eminence. Treatment of mice with gold thioglucose (GTG), a chemical agent known to cause hypothalamic lesions, markedly depleted both content and in vitro secretion of immunoreactive mGRF. The decline in mGRF secretion was greater in GTG obese than in nonobese mice, whereas somatostatin secretion was not affected by GTG treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Murine granulated metrial gland cell population in beige (bg/bg) and SCID (scid/scid) genotypes.

Morphology of granulated metrial gland (GMG) cell, a uterine natural killer (NK) cell, was reported to be normal in pregnant uteri of NK cell-deficient mice and T-cell- and B-cell-deficient mice, but little is known about the number of GMG cells. To determine whether the number of GMG cells is influenced by such mutations, their number in the bg mice (genotype C57BL/6J-bg/bg) and SCID mice (genotype C.B-17/Icr-scid/scid) was compared to that of control mice on day 12 of gestation. GMG cells in these mutant mice were normal in number. Thus, the present results support the previous reports that GMG cells can differentiate normally in bg mice and that the GMG cell differentiation is not affected by functional T- nor B-cells.

Animals↗
PubMed1994

Bronchial hyperresponsiveness to acetylcholine in patients with vasospastic angina pectoris.

STUDY OBJECTIVE: To investigate the similarity between coronary vasospasm and bronchial spasm. DESIGN: Nonrandomized, case-control study. SETTING: Referral-based clinics for cardiac and pulmonary disease at one secondary care center. PATIENTS: Seventeen patients with vasospastic angina pectoris (VSAP) and 14 patients with chest pain syndrome (CPS). INTERVENTIONS: Medications prohibited: those with known effects on bronchial responsiveness. MEASUREMENT: Induction of coronary vasospasm: ergonovine maleate (10, 20, 40 micrograms) injection into coronary arteries during coronary angiography. Bronchial responsiveness to acetylcholine (ACh): acetylcholine chloride (0.08 to 20 mg/ml) inhalation and calculation of the provocative concentration of ACh (PC20-ACh) that revealed 20 percent fall in FEV1. RESULTS: The median value for PC20-ACh in patients with VSAP, 7.80 mg/ml, was significantly lower than that in patients with CPS, > 20.0 mg/ml (p < 0.01 by Mann-Whitney U test). The PC20-ACh in patients with VSAP, however, was correlated neither with the responsive threshold of ergonovine maleate, which induced coronary vasospasm, nor with the duration from the latest angina attack. CONCLUSION: These results suggest that bronchial responsiveness was increased in most patients with VSAP, but not with CPS. We therefore speculate that patients with VSAP may also have hypercontractibility to ACh of noncoronary systemic smooth muscles.

Acetylcholine↗
PubMed1994

Comparison of endothelium-dependent and -independent tension oscillation in aortae of stroke-prone spontaneously hypertensive rats and Wistar Kyoto rats.

Differences in noradrenaline-induced tension oscillations between aortae from stroke-prone spontaneously hypertensive rats (SHRSP) and normotensive control Wistar Kyoto rats (WKY) were studied. Endothelium-intact and -removed ring preparations were made from thoracic aorta of SHRSP and WKY, and isometric contraction was observed. Endothelium-intact preparations from WKY showed tension oscillations in response to high concentration of noradrenaline at significantly higher ratio, while only a few endothelium-removed preparation showed tension oscillations in response to low concentration of the drug. Fifteen out of 41 endothelium-removed preparations from SHRSP showed tension oscillations in response to low concentration of noradrenaline but no preparation showed oscillations in response to high concentration of the drug. Seven and 14 out of 42 endothelium-intact preparations from SHRSP showed oscillatory response to low and high concentration of the drug, respectively. Acetylcholine-induced relaxation and tension oscillations, both of which being significantly less in the preparation from SHRSP. Both the endothelium-independent tension oscillations and endothelium-dependent tension oscillations were abolished by removal of extracellular Ca or by verapamil. It is suggested that aortic smooth muscle of SHRSP possesses the property which produced tension oscillations, while the tension oscillations of WKY aorta is endothelium-dependent. The opening of voltage-dependent Ca++ channel of smooth muscle cell membrane which generates rhythmic contraction is increased in the aorta of SHRSP, while the release of endothelium-derived factors which induces rhythmic activities of smooth muscle cell is decreased.

Animals↗
PubMed1994

[Preoperative and postoperative variations of human hepatocyte growth factor (hHGF) in hepatectomized patients].

We clinically analyzed significance of serum human hepatocyte growth factor (hHGF) concentrations (ng/ml) before and after hepatectomies. We examined 39 hepatectomized patients (Group H) and 8 non-hepatectomized patients as control (Group C). In group H, hHGF levels elevated significantly on postoperative 1st, 3rd, 5th, and 7th days (0.59 +/- 0.24, 0.47 +/- 0.23, 0.38 +/- 0.16, 0.38-0.14, respectively) compared with the preoperative value (0.27 +/- 0.11). On the 3rd day hHGF levels in Group H (0.45 +/- 0.22) were significantly higher than those in Group C (0.30 +/- 0.06). Nineteen cases of 2-segmentectomy and 8 cases of partial resection showed significantly higher hHGF levels on the 3rd day than those in Group C. In 12 patients with liver cirrhosis, hHGF levels were significantly higher on the 5th and 21st days than those in 27 patients without cirrhosis. Three patients with hepatic failure showed significantly higher hHGF levels correlated conversely with preoperative serum albumin and hHGF levels on the 1st day after operation significantly correlated with operative time, blood loss during the operation. It was suggested that serum hHGF level correlated with hepatic functional reserve. We concluded that serial measurement of hHGF was useful for evaluation of postoperative damage of hepatic functions, and prolonged high hHGF levels might suggest hepatic failure.

Adult↗
PubMed1994

[Effects of inhaled furosemide after indomethacin premedication on bronchial hyperresponsiveness in patients with chronic congestive heart failure].

We studied the effects of inhaled furosemide (40 mg) on bronchial responsiveness to acetylcholine (ACh) in patients with chronic congestive heart failure who had been premedicated with indomethacin (75 mg/day) for five days. The measurement of bronchial responsiveness was performed by inhaling doses of ACh and calculating the provocative concentration of ACh needed to cause a 20% fall in FEV1.0 (PC20-ACh). Inhaled furosemide (N = 11) had no effect on resting pulmonary function but did cause a significant increase in the median value of PC20-ACh, from 7.58 to 11.9 mg/ml (p < 0.01). Irrespective of premedication with indomethacin, inhaled furosemide reduces bronchial hyperresponsiveness to ACh in patients with chronic congestive heart failure. Therefore, we speculate that the mechanism of bronchial hyperresponsiveness noticed in our patients is not related to prostaglandins such as PGE2 or PGI2.

Administration, Inhalation↗
PubMed1993

[CT appearance of thorotrast-related and non-thorotrast-related peripheral cholangiocarcinoma].

To assess the differences in CT findings among patients with peripheral cholangiocarcinoma with and without a history of Thorotrast administration, CT studies from 13 Thorotrast patients and eight non-Thorotrast patients were reviewed. Diagnostic and prognostic differences were evaluated between the two groups. Despite periodic imaging surveillance, eight of the 13 (62%) lesions discovered by CT were larger than 6 cm. The prognosis for Thorotrast patients was unfavourable due to difficulties in early detection and complications from associated hepatic fibrosis. The main problem with early detection was that a background of uneven Thorotrast deposits visualized in the liver disguised the tumor as Thorotrast granulations. Although non-Thorotrast patients were not monitored regularly, they had a better chance of undergoing curative resection for the following three reasons: 1) it was easy to detect the tumor (detection rate, 100%); 2) this group rarely had associated liver cirrhosis in noncancerous areas, and 3) non-Thorotrast patients were younger than Thorotrast patients. Early detection of cancer by CA19-9 assay and imaging in asymptomatic subjects without any history of liver disease could be important steps toward the early and radical resection of cancer to achieve a better prognosis.

Adenoma, Bile Duct↗
PubMed1993

Anomalous excretion of bile and pancreatic juice in a patient with choledochal cyst.

The authors report the findings of endoscopic retrograde cholangiopancreatography in a 1-year-old girl with choledochal cyst; contrast dye injected through the common channel was excreted solely through the duct of Santorini. The obstruction to the bile and pancreatic juice caused by marked bending of the common channel was responsible for the abnormal drainage of bile and pancreatic juice.

Bile↗
PubMed1993

The effect of tube feeding on postprandial gastroesophageal reflux.

Distal esophageal pH in supine position was monitored for 6 hours in 13 asymptomatic infants. During this period the patients received 15 to 20 mL/kg of 5% glucose solution twice every 3 hours. Each meal was fed orally or through a pH sensor tube. When the patient was fed through a tube, the meal was introduced into the stomach or into the distal esophagus. The extent of reflux during 2 hours after feeding was compared between oral and tube feeding. Comparing oral and intragastric tube feeding, intragastric tube feeding showed significantly fewer reflux events, a smaller percentage of time in the esophageal pH below 4, and a shorter duration of the longest single reflux event. Comparing oral and intraesophageal tube feeding, intraesophageal tube feeding showed the same pattern. The data indicated that tube feeding significantly diminishes the postprandial reflux.

Enteral Nutrition↗
PubMed1993

Secretion of chondroitin sulfate from embryonic epidermal cells in Xenopus laevis.

We examined proteoglycans (PGs) in amphibian epidermal cells by immunofluorescence microscopy. Immunoelectron microscopy with pre- and post-embedding methods, combined with HRP- or gold-conjugated secondary antibody, revealed ultrastructural localization of glycosaminoglycans (GAGs). Embryonic epidermis secretion granules in Xenopus laevis contained chondroitin 6-sulfate and unsulfated chondroitin. Immature secretion granules were also labeled with anti-chondroitin 6-sulfate and anti-chondroitin. A step-wise digestion experiment on chondroitinase ABC revealed that fine filaments in the secretion granules were chondroitin sulfate chains. Inhibition experiments with brefeldin A revealed that the life of a secretion granule was 5-10 hr, suggesting that GAG secretion from embryonic epidermis is routed through a regulated pathway.

Animals↗