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Biomedical subjects

F Goto

Publications and source records attributed to F Goto.

At least 109 records · Page 6Linked to original sources
PubMed1994

Ultrastructure of the main excretory duct epithelium of the female mouse submandibular gland with special reference to sexual dimorphism.

The fine structure of the main excretory duct epithelium (MEDE) of female mouse submandibular gland was investigated by scanning and transmission electron microscopy and the results compared with the previously established structure of male mouse MEDE. A comparative analysis of the subepithelial capillaries of both sexes was also performed. In this pseudostratified epithelium, principal cell-types were observed: types-I, -II, -III and basal cells. This differed significantly from male MEDE, where type-II and -III are absent and type-I cells are the most numerous. The latter cell-type had abundant mitochondria, a few lipid-containing granules, lysosomes in the infra-nuclear cytoplasm and well-developed basal infoldings. These cells were also characterized by abundant glycogen granules throughout the cytoplasm, many profiles of strands of smooth endoplasmic reticulum in the apical region, and lysosomes in the infranuclear region. Type-II cells were the second most numerous. Their most characteristic features were the presence of tubular vesicles which appeared to be invaginated from the plasma membrane, RER, SER, free ribosomes, a few peroxisomes with nucleoids, and primary lysosomes in extremely light cytoplasm. They had many mitochondria throughout the cytoplasm, except in the apical region, a few lipid-containing granules and no basal infoldings. Type-III cells were very few and were characterized by well developed basal infoldings, abundant free ribosomes, RER, SER, vesicles containing moderately dense material, and many lipid-containing granules. They also had many mitochondria throughout the cytoplasm, except apically. Basal cells had a large nucleus and the cytoplasm had few organelles.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Does interleukin-1 mediate tumour necrosis factor alpha-induced fever in rabbits?

We investigated the humoral mechanisms involved in tumour necrosis factor alpha (TNF alpha)-induced fever in rabbits. No change in lymphocyte-activating factor activity was detected in serum drawn during TNF alpha-induced fever. The pyrogenic activity of recombinant rabbit interleukin-1 beta (IL-1 beta) was entirely abolished by pre-incubation with anti-IL-1 beta antiserum from the goat. Fever induced by intravenous (i.v.) injection of IL-1 beta was significantly diminished by i.v. infusion of the antiserum. However, i.v. infusion of the antiserum for 1 h did not affect fever induced by i.v. injection of TNF alpha, when the antiserum infusion began either simultaneously with, or 2 h after, the injection of TNF alpha. Furthermore, intracerebroventricular injection of the anti-serum did not affect TNF alpha-induced fever. The intracerebroventricular administration of naloxone (an opioid receptor antagonist) significantly diminished TNF alpha-induced fever. The results suggest that IL-1, both in the blood circulation and in the brain, may not be involved in TNF alpha-induced fever. Similar to the contribution of eicosanoids, the opioid system in the brain seems somehow to contribute to the mechanism of the development of fever induced by TNF alpha in rabbits.

Animals↗
PubMed1994

Power spectral analysis of heart rate and blood pressure variability in lumbar epidural anaesthesia.

The purpose of this study was to evaluate autonomic nervous system activity during high and low lumbar epidural anaesthesia. Ten patients undergoing lower limb surgery with lumbar epidural anaesthesia (low epidural anaesthesia group; mean upper dermal block level, T10.7 +/- 1.1), and ten patients undergoing either abdominal total hysterectomy or inguinal hernia under lumbar epidural anaesthesia (high epidural anaesthesia group; mean upper dermal block level, T5.1 +/- 1.0). Ten healthy volunteers were used as the control group. The autonomic nervous system activity was measured by heart rate and blood pressure variability with power spectral analysis. For the analysis of heart rate variability, frequency components were divided into two factors, a low frequency component RR (LFCRR: 0.03 Hz-0.15 Hz) that mediated sympathetic and parasympathetic activity and a high frequency component RR (HFCRR: 0.15 Hz-0.4 Hz) that mediated parasympathetic activity. In the analysis of blood pressure variability, the frequency components were also divided into two factors; a low frequency component of systolic blood pressure and diastolic blood pressure (LFCSBP and LFCDBP: 0.03 Hz-0.15 Hz) that was mediated by peripheral sympathetic vasomotor activity and a higher frequency component of systolic blood pressure and diastolic blood pressure (HFCSBP and HFCDBP: 0.15 Hz-0.4 Hz) that was mediated by a mechanical consequence of respiration. There were no changes in heart rate variability during epidural anaesthesia. However, LFCSBP and LFCDBP decreased in high epidural anaesthesia (P < 0.01). On the contrary, LFCSBP increased in low epidural anaesthesia (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Dynamic changes in mRNA expression of neutrophils during the course of acute inflammation in rabbits.

To examine RNA/protein synthesis of neutrophils and related dynamic changes during the inflammatory process, we investigated mRNA expressions in neutrophils, by RNA blot hybridization analyses using 12 different rabbit gene probes. We first selected five candidate genes encoding inflammation-related proteins, i.e. tumor necrosis factor (TNF-alpha) IL-1 alpha, IL-1 beta, neutrophil activating peptide-1/IL-8 (NAP-1/IL-8) and monocyte chemoattractant protein (MCP)-1. We further selected several genes on basis of the results from gene subtraction between cDNA libraries from neutrophils at an early (5 h) and at a late (24 h) stage of casein-induced acute peritonitis in rabbits, i.e. immune activation gene-2 (Act-2), migration inhibitory factor-related protein-8 (MRP-8), MRP-14, gamma-actin, and formyl-methionyl-leucyl-phenylalanine receptor (fMLP-R), and ferritin light (L) chain. In addition to these genes we used ferritin heavy (H) chain gene, another component of the ferritin molecule. We examined mRNA expressions by cytoplasmic slot blot analysis of the above 12 genes in neutrophils obtained from blood and from various stages of casein-induced inflammation in rabbits. The observed patterns of mRNA expression kinetics were classified into three. Pattern 1: mRNAs of MRP-8, MRP-14, and gamma-actin were constitutively expressed in blood neutrophils, and increased rapidly after emigration into inflammatory sites. Pattern 2: mRNAs of IL-1 beta, NAP-1/IL-8, Act-2, and fMLP-R were undetectable in blood neutrophils, and were induced rapidly after the onset of inflammation. Pattern 3 mRNAs of ferritin L and H chain were induced slowly, and increased with progression of the inflammatory process.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Unilateral hypoglossal nerve paralysis following the use of the laryngeal mask airway.

We report a unilateral hypoglossal nerve paralysis following the use of a laryngeal mask airway in a 62-year-old woman with rheumatoid arthritis undergoing a shoulder joint replacement. Cervical epidural anaesthesia was combined with general anaesthesia using nitrous oxide administered via a laryngeal mask airway with the patient in the right lateral decubitus position. The next morning, the patient was noted to have a right hypoglossal nerve palsy. Compression of the nerve between the laryngeal mask airway cuff, distended with nitrous oxide, and the hyoid bone, was considered to be the cause of the nerve paralysis.

Constriction↗
PubMed1994

Effects of alpha-human natriuretic peptide on renal hemodynamics and diuresis in dogs and perfused rat kidneys.

Effects of alpha-human atrial natriuretic polypeptide (alpha-hANP) on renal function were studied in anesthetized dogs and isolated perfused rat kidneys. Two doses of alpha-hANP were used to determine whether renal hemodynamics or tubular reabsorption is tha major factor in the diuretic action of alpha hANP. The excretion rates of sodium (Na) and inorganic phosphate (PO4) were evaluated to determine the site of diuretic action in the renal tubule. In dogs that received the smaller dose of alpha-hANP (5 ng.kg-1.min-1) infused into the renal arteries without changes in systemic or renal hemodynamics, urine volume (UV) and urinary Na excretion (UNaV) increased significantly. Fractional excretion of Na (FENa) was increased, while fractional excretion of PO4 (FEpo4) was unchanged, following the infusion of alpha-hANP. The calculated fractional Na reabsorption in the distal tubule (DTRNa) during the infusion of alpha-hANP was significantly suppressed. In dogs that received the a larger dose of alpha-hANP (50 ng.kg-1.min-1), the glomerular filtration rate (GFR), UV, and FENa were increased and DTRNa was decreased. In isolated rat kidneys perfused at a constant pressure, a lower concentration of alpha-hANP (0.5 ng.ml-1) in the perfusate caused diuresis and increased Na and PO4 excretion without any renal hemodynamic alterations. A higher concentration of alpha-hANP (5 ng.ml-1) increased GFR, Na and PO4 excretion. Since PO4 reabsorption is believed to occur primarily in the renal proximal tubule, these findings suggest that the diuretic action of alpha-hANP in smaller doses in induced by direct action on renal distal nephron.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

[Alteration of lipid peroxidation and the activity of peroxide metabolism enzymes in the liver, kidney and lung following the administration of paraquat in mice].

The sequential changes of the activity of peroxide metabolism enzymes and thiobarbituric acid reaction substance (TBARS) as an indicator of lipid peroxide concentration were observed to analyze the mechanisms of tissue injury due to the administration of paraquat in DDY mice. Each six mice were decapitated at 3, 6, 9, 12, 15, 18, 21 or 24 hours following the intraperitoneal administration of paraquat 60 mg.kg-1, and the liver, kidney and lung were removed and homogenized to quantify lipid peroxide concentration and the activity of peroxide metabolism enzymes. In the liver and kidney, TBARS increased gradually and reached the maximum level at 9 hours after the administration of paraquat in the liver and at 12 hours in the kidney. Significant increases in superoxide dismutase (SOD), glutathione peroxidase and catalase (CAT) activities were observed at 15 or 18 hours after the injection of paraquat. In the lung, lipid peroxide concentration decreased significantly and the activities of SOD and CAT increased at 15 hours after injection of paraquat. TBARS in serum started to increase at 9 hours after the administration of paraquat and reached the maximum level at 15 hours. These findings indicate that the induction of peroxide metabolism enzymes followed the increase of TBARS which was induced by paraquat in the liver and kidney. However, the enzyme induction was produced by paraquat without the increase of TBARS in the lung. Active oxygen radicals play an important role in the toxic action of paraquat and might produce the induction of peroxide metabolism enzymes following the administration of paraquat.

Animals↗
PubMed1993

Time course in thoracic epidural pressure measurement.

The purpose of this study was to measure thoracic epidural pressure at the time of insertion of an epidural needle. The pressure was measured using a closed pressure measurement system after insertion of a Tuohy needle at the T7-8 intervertebral level. This system is unique because it has a pressure transducer equipped with a device which regulates flow through the transducer and prevents the heparinized saline in the system from being evacuated into the epidural space due to sudden pressure change. As reported previously, high negative epidural pressures, up to -60 mmHg, were observed at the moment of epidural puncture. However, the pressure became positive in about 30 sec in 12 of the 13 patients, and stabilized at +3.7 +/- 3.2 mmHg (mean +/- SD) within 90 sec. Similar results were observed when the procedure was repeated within a few minutes to the same patients. This suggests that negative epidural pressures at the moment of epidural puncture are artifacts induced by tenting of the dural membrane. Subsequent adaptation of the surrounding tissue results in restoration of the normal positive epidural pressure.

Adaptation, Physiological↗
PubMed1993

[Effects of epidural analgesia combined with general anesthesia on hemodynamics during neck surgery].

The aim of the present study was to investigate the effect of epidural analgesia combined with general anesthesia on hemodynamics. Thirty patients undergoing surgery for the treatment of cancer of the neck were studied. The patients were divided into two groups of those who received epidural analgesia combined with general anesthesia group (Group 1) and those with general anesthesia alone (Group 2). Blood pressure was not different between the groups. But heart rate and rate pressure products in Group 1 were significantly lower than those of Group 2. CVP in Group 1 increased significantly to 10.1 +/- 2.9 mmHg during surgery from 6.8 +/- 1.8 mmHg at the beginning of the surgery. There was no difference in intraoperative blood loss and the amount of fluid infused between the two groups. These results suggest that epidural anesthesia combined with general anesthesia is effective to stabilize hemodynamics during cervical surgery, but we have to be careful about using local anesthetics during long cervical procedures, because it increases CVP which might result from the depression of cardiac function.

Aged↗
PubMed1993

Synergistic effects of vascular endothelial growth factor and basic fibroblast growth factor on the proliferation and cord formation of bovine capillary endothelial cells within collagen gels.

BACKGROUND: Angiogenesis occurs within the interstitial matrix. We therefore cultured endothelial cells within collagen gels rather than on the surface of culture dishes. We measured the effect of a human glioblastoma-derived factor, and the combined effect of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), on both the proliferative and morphologic changes exhibited by endothelial cells. EXPERIMENTAL DESIGN: Bovine capillary endothelial (BCE) cells were cultured in a gel of type I collagen. Effects of growth factors were evaluated by the cell recovery from the gel and the morphologic changes of cells. The glioblastoma-derived factor was characterized by column chromatography, immunoblotting, and immunoadsorption with an anti-VEGF antibody. RESULTS: After 4 days of culture in the collagen gel with 10% calf serum Dulbecco's minimum essential medium, most of the BCE cells died. Addition of glioblastoma-conditioned medium resulted in a change in morphology from a round shape to an elongated spindle shape; moreover, the number of BCE cells was enhanced. The major activity in the conditioned medium was VEGF. In the 3-dimensional gel, we found a higher activity associated with VEGF, compared with bFGF when the growth factors were added 24 hours after seeding. In this assay, the response to bFGF diminished within 24 hours, but that to VEGF continued for 48 hours. When the two factors were added to the culture simultaneously, the cell number was greater than the sum of those stimulated with either growth factor alone. In the presence of both bFGF and VEGF, cord-like structures became prominent in the BCE cell cultures. CONCLUSIONS: A human glioblastoma cell line produced VEGF, which enhanced the proliferation of BCE cells and induced an elongated shape in collagen gels. VEGF and bFGF increased the rate of proliferation and the number of cord-like structures in a synergistic manner.

Animals↗
PubMed1993

[The sprotte needle decreases the incidence of postspinal headache].

Postspinal headache (PSH) is the most frequent complication of spinal anesthesia. The factors responsible for the development of PSH include needle size, shape of the needle tip, patient's age, sex, infusion volume and period of resting. The purpose of this study is to compare the incidence of PSH between two different types of needle, Sprotte needle and Quincke needle. The Sprotte needle is characterized by a round profiled tip equipped with a lateral orifice. Our investigation by questionnaires revealed that the incidences of PSH after using either 22G Sprotte needle or 21-25G Quincke needle were 0% and 38.8%, respectively. We conclude that the Sprotte needle decrease the incidence of PSH.

Adult↗
PubMed1993

[Effect of anesthetic methods on hemodynamics and metabolic changes caused by hepatic ischemia and reperfusion in pigs].

The effects of halothane, isoflurane and epidural anesthesia combined with isoflurane on hemodynamic and metabolic changes caused by hepatic ischemia and reperfusion were studied in 16 pigs. Hepatic arterial and portal venous blood flows were measured electromagnetically. Lactate pyruvate ratio (L/P) and arterial ketone body ratio (AKBR) were calculated as markers of hepatic aerobic metabolism. Total hepatic blood flow (THBF), cardiac output (CO) and THBF/CO showed no significant differences among three anesthetic methods in ischemic and reperfusion period. In the group with epidural anesthesia combined with isoflurane, L/P was significantly lower and AKBR was significantly higher compared with the data obtained in ischemic period. However, hepatic metabolism was severely disturbed after the reperfusion of the liver in all three groups. Especially, halothane group showed the most remarkable decrease in AKBR. In summary, epidural anesthesia will be useful for aerobic hepatic metabolism because of inhibition of the release of endogenous cathecolamines, but hepatic metabolism will not be maintained following hepatic ischemia and reperfusion.

Anesthesia↗
PubMed1993

[Resistance to anticoagulant activity of heparin in a patient for cardiac surgery].

Resistance to anticoagulant activity of heparin was observed in a patient for cardiac surgery. The activated coagulation time (ACT) was maintained over 300 seconds with additional doses of heparin which mounted to the total of 29 ml in 3 hours during cardiopulmonary bypass. Although antithrombin-III activity was not measured in this case, the heparin resistance might have been caused by the decrease in the activity of antithrombin-III which might have resulted from the preoperative malnutrition, infection of urinary tract and/or institution of intraaortic balloon pumping (IABP).

Cardiac Surgical Procedures↗
PubMed1992

Treatment of intraoperative hypertension with enflurane, nicardipine, or human atrial natriuretic peptide: haemodynamic and renal effects.

The purpose of this study was to assess the effects of the calcium entry blocker nicardipine and alpha human atrial natriuretic peptide (hANP) on antihypertensive and diuretic activity in hypertensive surgical patients. The site of the diuretic actions of these drugs along the nephron were also investigated by measuring the excretion rate of inorganic phosphate (PO4). Hypertension during gastrectomy was treated by increasing the concentration of enflurane, by nicardipine infusion (0.5-2.0 micrograms.kg-1 x min-1), or by hANP infusion (0.05-0.2 microgram.kg-1 x min-1) under general anaesthesia. Enflurane, nicardipine and hANP all decreased arterial pressure to the same extent. Urine flow, Na and PO4 excretion increased following the administration of nicardipine or hANP. Fractional distal reabsorption of sodium was suppressed from 89.7 +/- 2.8% to 82.1 +/- 5.0% by the hANP, but not by the nicardipine infusion. Creatinine clearance was increased by hANP infusion, but did not change in the nicardipine group. It is concluded that nicardipine and hANP can be used safely for the treatment of hypertension during surgery. Both drugs induced phosphaturic diuresis, but the site of action of the two drugs on the nephron may be different. Phosphate reabsorption is considered to occur largely in the renal proximal tubule, so that its appearance in the urine in increased quantities without the change of renal circulation in the nicardipine group suggests a proximal tubular action of this drug. However, the site of action of hANP in the kidney was not determined because GFR increased and distal sodium reabsorption was suppressed due to the drug infusion.

Absorption↗
PubMed1992

Calcium entry blocker nicardipine inhibits sodium and inorganic phosphate reabsorption independent of renal circulation in dogs.

The effects of nicardipine on renal function were studied in anesthetized dogs. The changes in the tubular sodium (Na) and inorganic phosphate (PO(4)) reabsorption caused by the drug infusion into the renal artery without altered systemic and real circulation were especially evaluated. In dogs receiving a smaller dose of nicardipine (5 ng.kg(-1).min(-1)) into the left renal artery the blood pressure and renal circulation did not change, but urine volume and urinary Na and PO(4) excretion increased significantly. In dogs receiving a larger dose of nicardipine (50 ng.kg(-1).min(-1)) into the renal artery, renal plasma flow, urine volume and urinary Na and PO(4) excretion increased significantly, but creatinine clearance did not. The fractional distal Na reabsorption did not change with nicardipine infusion in either group. PO(4) reabsorption is considered to occur mainly in the proximal renal tubule, so its appearance in urine in increased quantities without the changes of systemic and renal circulation suggests proximal activity of the drug.

Journal Article↗