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1.
J Small Anim Pract ; 64(4): 288-295, 2023 04.
Article in English | MEDLINE | ID: mdl-36444826

ABSTRACT

OBJECTIVES: To describe a standardised subserosal layer dissection technique and evaluate its outcomes in canine laparoscopic cholecystectomy. MATERIALS AND METHODS: Medical records of dogs undergoing laparoscopic cholecystectomy using the standardised subserosal layer dissection technique for the treatment of cholecystolithiasis, cholecystitis, and gall bladder mucocele at a single veterinary hospital from January 2015 to September 2021 were extracted. Operative time, subserosal layer dissection achievement rate, open conversion rate, and complication rate were evaluated. RESULTS: Thirty-four dogs were included. The most common preoperative diagnosis was cholecystolithiasis (n=29). Operative time was 190 minutes (range: 110 to 330 minutes). Subserosal layer dissection of more than 90% of the gall bladder bed was achieved in 27 (79%) dogs. Conversion to open surgery was required in three (8.8%) dogs. There were no cases of intraoperative bleeding, bile duct injury, or reoperation. CLINICAL SIGNIFICANCE: This study showed that laparoscopic cholecystectomy using the standardised subserosal layer dissection technique could be performed successfully in dogs. Future prospective clinical studies are needed to determine safety and effectiveness of this technique compared to standard techniques.


Subject(s)
Cholecystectomy, Laparoscopic , Cholecystolithiasis , Dog Diseases , Gallbladder Diseases , Dogs , Animals , Cholecystectomy, Laparoscopic/veterinary , Cholecystectomy, Laparoscopic/methods , Cholecystolithiasis/veterinary , Gallbladder Diseases/surgery , Gallbladder Diseases/veterinary , Prospective Studies , Dog Diseases/surgery
2.
Clin Nephrol ; 71(6): 703-7, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19473640

ABSTRACT

We herein report the case of a 12-year-old boy with dense deposit disease (DDD) evoked by streptococcal infection. He had been diagnosed to have asymptomatic hematuria syndrome at the age of 6 during school screening. At 12 years of age, he was found to have macrohematuria and overt proteinuria with hypocomplementemia 2 months after streptococcal pharyngitis. Renal biopsy showed endocapillary proliferative glomerulonephritis with double contours of the glomerular basement membrane. Hypocomplementemia and proteinuria were sustained for over 8 weeks. He was suspected to have dense deposit disease due to intramembranous deposits in the first and the second biopsies. 1 month after treatment with methylprednisolone pulse therapy, proteinuria decreased to a normal level. Microscopic hematuria disappeared 2 years later, but mild hypocomplementemia persisted for more than 7 years. Nephritis-associated plasmin receptor (NAPlr), a nephritic antigen for acute poststreptococcal glomerulonephritis, was found to be positive in the glomeruli for more than 8 weeks. DDD is suggested to be caused by dysgeneration of the alternative pathway due to C3NeF and impaired Factor H activity. A persistent deposition of NAPlr might be one of the factors which lead to complement dysgeneration. A close relationship was suggested to exist between the streptococcal infection and dense deposit disease in this case.


Subject(s)
Glomerulonephritis, Membranoproliferative/microbiology , Streptococcal Infections/complications , Antigens, Bacterial/ultrastructure , Child , Glomerulonephritis, Membranoproliferative/diagnosis , Glomerulonephritis, Membranoproliferative/drug therapy , Glomerulonephritis, Membranoproliferative/immunology , Glucocorticoids/administration & dosage , Hematuria/drug therapy , Hematuria/microbiology , Humans , Kidney/immunology , Kidney/pathology , Kidney/ultrastructure , Male , Methylprednisolone/administration & dosage , Proteinuria/drug therapy , Proteinuria/microbiology , Pulse Therapy, Drug , Receptors, Cell Surface/ultrastructure , Severity of Illness Index , Streptococcal Infections/diagnosis , Streptococcal Infections/immunology , Streptococcus pyogenes/immunology
3.
Methods Inf Med ; 47(3): 198-202, 2008.
Article in English | MEDLINE | ID: mdl-18473084

ABSTRACT

OBJECTIVES: In a group home, caregivers should be aware of the inhabitant's real-time situation. The aim of our study is to facilitate the awareness of an inhabitant's situation by means of enhanced sound cues. METHODS: We propose an audio notification system that indicates the real-time situation of persons in a group home environment using sound cues instead of visual surveillance. The notification system comprises a prediction and a notification function. The prediction function estimates a person's real-time situation using a Bayesian network and sensed information; the notification function informs recipients of the predicted situation and the confidence level of the prediction by means of sound cues. We use natural sounds as sound cues. RESULTS: As a first step to examine our system in a group home, we conducted operation and performance tests of each unit under a simple test environment. The correct prediction of the subject's situation is approximately 90%; further, it is shown that the sound cues should be selected according to their environmental dependence. CONCLUSIONS: The results show that the method is useful for monitoring persons. As future study, we will conduct a field test on an implemented system and improve it for practical use in a group home.


Subject(s)
Auditory Perception/physiology , Caregivers/psychology , Computer Simulation , Cues , Group Homes , Monitoring, Physiologic/instrumentation , Social Support , Sound , Awareness , Bayes Theorem , Humans , Monitoring, Physiologic/methods , Sound Localization
4.
Circ Res ; 88(1): 30-6, 2001 Jan 19.
Article in English | MEDLINE | ID: mdl-11139470

ABSTRACT

Transforming growth factor (TGF)-beta plays a major role in the development of vascular diseases. Despite the pleiotropic effects of TGF-ss on vascular smooth muscle cells (VSMCs), only a few genes have been characterized as direct targets of TGF-beta in VSMCs. Cardiac ankyrin repeat protein (CARP) has been thought to be expressed exclusively in the heart. In the present study, we showed that CARP is expressed in the vasculature after balloon injury and in cultured VSMCs in response to TGF-beta. Analysis of a half-life of the cytoplasmic CARP mRNA levels and the transient transfection of the CARP promoter/luciferase gene indicates that the regulation of CARP expression is increased by TGF-beta at the transcriptional level. Transfection of expression vectors encoding Smads significantly activated the CARP promoter/luciferase activity. Deletion analysis and site-specific mutagenesis of the CARP promoter indicate that TGF-beta response element is localized to CAGA motif at -108 bp relative to the transcription start site. Electrophoretic mobility shift assays showed that the binding activity to the CAGA motif was increased in nuclear extracts of cultured VSMCs by TGF-beta. Cells transfected with adenovirus vector expressing CARP showed a significant decrease in DNA synthesis. Overexpression of CARP enhanced the TGF-beta-mediated inhibition of the DNA synthesis. These data indicate that CARP is a downstream target of TGF-beta/Smad signaling in VSMCs and suggest a role of CARP in mediation of the inhibitory effects of TGF-beta on the proliferation of VSMCs.


Subject(s)
DNA-Binding Proteins/physiology , Muscle, Smooth, Vascular/drug effects , Nuclear Proteins/genetics , Repressor Proteins/genetics , Signal Transduction , Trans-Activators/physiology , Transforming Growth Factor beta/pharmacology , 3T3 Cells , Animals , Base Sequence , Binding Sites , COS Cells , Cell Line , DNA/biosynthesis , DNA/drug effects , DNA/genetics , DNA-Binding Proteins/genetics , Dose-Response Relationship, Drug , Gene Expression Regulation/drug effects , Humans , Luciferases/genetics , Luciferases/metabolism , Mice , Molecular Sequence Data , Muscle Proteins , Muscle, Smooth, Vascular/cytology , Muscle, Smooth, Vascular/metabolism , Mutation , Promoter Regions, Genetic/genetics , RNA, Messenger/drug effects , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptors, Transforming Growth Factor beta/genetics , Receptors, Transforming Growth Factor beta/physiology , Recombinant Fusion Proteins/drug effects , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Response Elements , Reverse Transcriptase Polymerase Chain Reaction , Sequence Deletion , Smad6 Protein , Time Factors , Trans-Activators/genetics , Transcription, Genetic/drug effects , Transforming Growth Factor beta1 , Tumor Cells, Cultured
6.
Nat Commun ; 6: 10042, 2015 Dec 07.
Article in English | MEDLINE | ID: mdl-26640114

ABSTRACT

Strong spin-orbit coupling fosters exotic electronic states such as topological insulators and superconductors, but the combination of strong spin-orbit and strong electron-electron interactions is just beginning to be understood. Central to this emerging area are the 5d transition metal iridium oxides. Here, in the pyrochlore iridate Pr2Ir2O7, we identify a non-trivial state with a single-point Fermi node protected by cubic and time-reversal symmetries, using a combination of angle-resolved photoemission spectroscopy and first-principles calculations. Owing to its quadratic dispersion, the unique coincidence of four degenerate states at the Fermi energy, and strong Coulomb interactions, non-Fermi liquid behaviour is predicted, for which we observe some evidence. Our discovery implies that Pr2Ir2O7 is a parent state that can be manipulated to produce other strongly correlated topological phases, such as topological Mott insulator, Weyl semimetal, and quantum spin and anomalous Hall states.

7.
Hypertension ; 27(1): 125-9, 1996 Jan.
Article in English | MEDLINE | ID: mdl-8591874

ABSTRACT

We investigated the relationship between changes in blood pressure and fat distribution after a 12-week low-calorie diet in 26 obese hypertensive women whose average age was 50 +/- 13 years, mean body mass index was 33.7 +/- 3.1 kg/m2, and mean blood pressure was 112 +/- 9 mm Hg. As an index of intra-abdominal fat accumulation, we used the ratio of the intra-abdominal visceral fat area to subcutaneous fat area, determined by a computed tomographic section at the level of the umbilicus. Subjects lost a mean of 9.4 +/- 4.1 kg on a 1200-kcal (5040-kJ) diet for 12 weeks. Their mean blood pressure fell from 112 +/- 9 to 101 +/- 12 mm Hg (P < .001). The ratio of the visceral to subcutaneous fat area was significantly reduced after weight reduction from 0.56 +/- 0.33 to 0.45 +/- 0.27 (P < .02). Fasting plasma glucose and plasma glucose area after a 75-g oral glucose tolerance test also were significantly reduced by weight reduction. The change in mean blood pressure after weight reduction was not correlated with the change in body weight or body mass index but was correlated with the reduction in visceral fat area or ratio of visceral fat to subcutaneous fat area. Changes in mean blood pressure also were correlated with changes in fasting plasma glucose levels and the plasma glucose area determined by 75-g oral glucose tolerance test. Results indicate that a decrease in intra-abdominal visceral fat, rather than simply of body weight, may reduce blood pressure in obese hypertensive subjects. The mechanism may involve an improvement in glucose tolerance caused by weight reduction.


Subject(s)
Adipose Tissue/diagnostic imaging , Blood Pressure , Hypertension/physiopathology , Obesity/diagnostic imaging , Abdomen , Adult , Aged , Diet, Reducing , Female , Humans , Hypertension/complications , Middle Aged , Obesity/complications , Obesity/diet therapy , Tomography, X-Ray Computed , Viscera
8.
Hypertension ; 16(5): 484-90, 1990 Nov.
Article in English | MEDLINE | ID: mdl-2228147

ABSTRACT

The relation between intra-abdominal visceral fat accumulation and blood pressure was investigated in 67 obese women (mean body mass index, 33.6 +/- 3.1; average age, 50 +/- 11 years). As an index of intra-abdominal fat accumulation, the ratio of the intra-abdominal visceral fat area to subcutaneous fat area was determined using a computed tomographic section at the level of the umbilicus. When the obese subjects were divided into a hypertensive group and a normotensive group, the ratio of the intra-abdominal visceral fat area to subcutaneous fat area in the hypertensive group was significantly higher (0.53 +/- 0.33 versus 0.29 +/- 0.12, p less than 0.01). Significant correlations between the ratio of intra-abdominal visceral fat area to subcutaneous fat area and systolic blood pressure (r = 0.62, p less than 0.001) and diastolic blood pressure (r = 0.53, p less than 0.001) also were found. However, no significant difference existed in either the body mass index or the waist-to-hip circumference ratio between the hypertensive and normotensive groups. Plasma renin activity, aldosterone, epinephrine, and norepinephrine levels were not significantly different between the two groups. Moreover, the correlation between the ratio of the intra-abdominal visceral fat area to subcutaneous fat area ratio and blood pressure was found independent of age and body mass index by multiple regression analyses. We conclude that intra-abdominal fat accumulation itself may play an important role in the pathogenesis of hypertension in obesity.


Subject(s)
Abdomen/anatomy & histology , Adipose Tissue/anatomy & histology , Hypertension/etiology , Obesity/complications , Adult , Aged , Asian People , Female , Humans , Male , Menopause , Middle Aged , White People
9.
Atherosclerosis ; 73(2-3): 143-8, 1988 Oct.
Article in English | MEDLINE | ID: mdl-3190816

ABSTRACT

A novel system of low density lipoprotein (LDL) apheresis for familial hypercholesterolemia (FH) was developed, combining a centrifugal plasma separator (IBM-2997) with a new adsorption column specific to lipoproteins containing apolipoprotein B (apo-B), and its operation was compared to previous methods. The present system selectively removed LDL without the substantial reduction of high density lipoprotein that was seen with other methods using membrane filters. The capacity for LDL removal was slightly more reduced with the adsorption column than with the membrane filters when a single column was used. Since the ability to obtain plasma in the centrifugal system was much higher than in the system using membrane filters for plasma separation, efficient apheresis could be performed in a much shorter time, without making an arterio-venous shunt. Remixing of blood cells, such as platelets, with the separated plasma sometimes raises the pressure within the plasma component separator, but the problem could be avoided by withdrawing the buffy coat fraction, using the WBC pump of the IBM separator. In conclusion, the novel system, combining the centrifugal plasma separator with the adsorption column, has proved, in our hands, to be a more useful and more convenient method than those previously used for the treatment of severe FH.


Subject(s)
Hyperlipoproteinemia Type II/therapy , Lipoproteins, LDL , Plasmapheresis/instrumentation , Adsorption , Blood Proteins/analysis , Centrifugation , Cholesterol/blood , Cholesterol, HDL/blood , Filtration , Humans , Hyperlipoproteinemia Type II/blood , Plasmapheresis/methods , Triglycerides/blood
10.
Neuroscience ; 117(1): 55-61, 2003.
Article in English | MEDLINE | ID: mdl-12605892

ABSTRACT

The number of neurons in the brain is controlled by production of new neurons and neuronal death. Neural progenitor proliferation in the developing and adult brain plays a prominent role in the production of new neurons. Here, we examined the effects of lithium, a mood-stabilizing drug, on neuronal proliferation in rat primary neuronal cultures. The incorporation of 5-bromo-2'-deoxyuridine (BrdU) into replicating DNA was used to label proliferating cells. BrdU incorporation was detected by immunocytochemistry in cerebellar granule cells prepared from postnatal rats and cerebral cortical cultures prepared from embryonic rats. Quantification of BrdU incorporation into cultures was performed by counting BrdU-positive cells and BrdU-coupled enzyme-linked immunosorbent assay. Both methods revealed that lithium increased BrdU incorporation in cerebellar granule cells and cerebral cortical cultures. Most BrdU-positive cells colocalized with nestin, a neuroblast cell marker, in cerebral cortical cultures. Blockade of DNA replication by cytosine arabinoside almost completely abolished BrdU incorporation, suggesting that lithium-induced BrdU incorporation was mainly due to enhanced DNA replication. Glutamate, glucocorticoids and haloperidol were found to markedly reduce neural progenitor proliferation in cerebellar granule cells. The presence of lithium prevented the loss of proliferation induced by these agents. Lithium-induced neural progenitor proliferation in vitro suggests that similar effects might occur in vivo and this action could also be related to its clinical efficacy. Cultured brain neurons may provide a valuable model for studying the molecular mechanisms underlying lithium-induced up-regulation of neural proliferation.


Subject(s)
Cerebellum/drug effects , Cerebral Cortex/drug effects , Lithium/pharmacology , Neurons/drug effects , Stem Cells/drug effects , Animals , Cell Division/drug effects , Cell Division/physiology , Cells, Cultured , Cerebellum/cytology , Cerebellum/growth & development , Cerebral Cortex/cytology , Cerebral Cortex/growth & development , Dose-Response Relationship, Drug , Neurons/cytology , Rats , Stem Cells/cytology
11.
Neuroscience ; 114(4): 825-35, 2002.
Article in English | MEDLINE | ID: mdl-12379239

ABSTRACT

Monoamine oxidase type A and type B are major neurotransmitter-degrading enzymes in the CNS. The type A is present on mitochondrial outer membranes in the whole extent of noradrenergic and dopaminergic neurons, including their axon terminals. The type B is present in serotonergic neurons, but its subcellular localization has not been elucidated. In the present study, we used both a double-labeling immunofluorescence method and electron microscopic immunohistochemistry to examine the subcellular localization of monoamine oxidase type B in serotonergic neurons projecting from the dorsal raphe nucleus to the suprachiasmatic nucleus in the rat brain. In the dorsal raphe nucleus, serotonin-positive neuronal cell bodies were clustered, and virtually all of these cell bodies were also positive for monoamine oxidase type B. By contrast, serotonin-negative neuronal cell bodies were mostly free of this enzyme. Within the neuronal cell bodies and dendrites that were positive for monoamine oxidase type B, most mitochondria contained this enzyme on their outer membranes, but a substantial proportion of mitochondria lacked this enzyme. In the suprachiasmatic nucleus, serotonin-positive varicosities were concentrated, but none of these varicosities exhibited monoamine oxidase type B. In this nucleus, mitochondria were found in almost all serotonin-positive axon terminals, but monoamine oxidase type B was not observed in any axon terminal that contained mitochondria. Our results show that there are two kinds of mitochondria in serotonergic neuronal cell bodies and dendrites: one containing monoamine oxidase type B on their outer membranes, and the other lacking this enzyme. In addition, mitochondria in serotonergic axon terminals do not possess monoamine oxidase type B. It is suggested in serotonergic neurons that only mitochondria lacking monoamine oxidase type B are transported by axonal flow up to axon terminals. It is also probable that mitochondria containing monoamine oxidase type B are transported along the axons, but that this enzyme undergoes a change, for example, conformational change, decomposition or removal from the membranes.


Subject(s)
Mitochondria/enzymology , Monoamine Oxidase/analysis , Neurons/enzymology , Serotonin/physiology , Animals , Axonal Transport/physiology , Immunoenzyme Techniques , Male , Microscopy, Confocal , Microscopy, Electron , Monoamine Oxidase/metabolism , Neurons/ultrastructure , Raphe Nuclei/cytology , Rats , Rats, Sprague-Dawley , Suprachiasmatic Nucleus/cytology
12.
Neuroscience ; 81(4): 1183-91, 1997 Dec.
Article in English | MEDLINE | ID: mdl-9330376

ABSTRACT

The effects of trimethyltin on the hippocampus were investigated in terms of changes in histology, depth electroencephalography, learning acquisition and memory retention, choline acetyltransferase and neuropeptides, and seizure-induced c-fos messenger RNA expression. The results were as follows. (1) Morphologically, trimethyltin produced a progressive loss of hippocampal CA3 and CA4 pyramidal cells, starting from four days after peroral treatment with trimethyltin hydroxide (9 mg/kg), as described previously. (2) Neurophysiologically, the increased seizure susceptibility to pentylenetetrazol treatment reached a maximum at four days post-trimethyltin and then declined after five days post-trimethyltin. The maximal seizure susceptibility at four days post-trimethyltin was confirmed by the immediate and long-lasting appearance of spike discharge in the hippocampus. However, this was not verified by the expression of c-fos messenger RNA in the hippocampus, which was comparable between trimethyltin-treated and control rats. (3) Behaviorally, the time-courses of aggression and learning impairment were similar to that of the seizure susceptibility. (4) Neurochemically, trimethyltin treatment caused changes of neurochemical markers, which were manifested by the elevation of neuropeptide Y content in the entorhinal cortex, and of choline acetyltransferase in the hippocampal CA3 subfield. Trimethyltin may offer potential as a tool for investigations on the relationship between neuronal death in the hippocampus and the development of seizure susceptibility and learning impairment. Alterations in glucocorticoids, glutamate and neuropeptides may all contribute to the manifestation of the trimethyltin syndrome.


Subject(s)
Hippocampus/pathology , Learning/drug effects , Neurodegenerative Diseases/chemically induced , Neurodegenerative Diseases/pathology , Seizures/pathology , Trimethyltin Compounds/toxicity , Animals , Brain Chemistry/drug effects , Choline O-Acetyltransferase/metabolism , Corticotropin-Releasing Hormone/metabolism , Disease Models, Animal , Electroencephalography/drug effects , Hippocampus/enzymology , Immunohistochemistry , In Situ Hybridization , Male , Maze Learning/drug effects , Memory/drug effects , Neurodegenerative Diseases/enzymology , Neuropeptide Y/metabolism , Proto-Oncogene Proteins c-fos/biosynthesis , Rats , Rats, Sprague-Dawley , Seizures/chemically induced , Somatostatin/metabolism
13.
Am J Kidney Dis ; 38(4 Suppl 1): S129-33, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11576938

ABSTRACT

To elucidate brain oxygen metabolism in uremic patients, regional cerebral blood flow (rCBF), oxygen extraction (rOEF), and oxygen metabolism (rCMRO(2)) were measured by positron emission tomography (PET) in 10 hemodialysis (HD) patients and 13 predialysis patients with chronic renal failure (CRF). Data were compared with 20 nonuremic patients (controls) without neurological abnormalities, congestive heart failure, history of cerebrovascular accident, diabetes mellitus, or symptomatic brain lesion on magnetic resonance imaging. In the hemisphere, rCMRO(2) in both HD (1.82 +/- 0.10 mL/min/100 g) and CRF patients (1.95 +/- 0.09 mL/min/100 g) showed significantly lower values compared with controls (2.23 +/- 0.05 mL/min/100 g; P < 0.01). Hemispheric rCBF in HD (35.6 +/- 2.1 mL/100 g/min) and CRF patients (36.1 +/- 2.1 mL/100 g/min) was not different from controls (31.8 +/- 1.4 mL/100 g/min). Hemispheric rOEF in CRF patients (45.7% +/- 1.6%) was significantly greater than that in controls (40.5% +/- 1.2%; P < 0.02), but rOEF in HD patients (43.7% +/- 1.9%) did not increase significantly. These tendencies were similar in all regions of interest, especially cerebral cortices. All PET parameters in frontal cortices tended to show the lowest values in patients with renal failure. For all HD patients, rCBF in both the frontal cortex and white matter correlated inversely with HD therapy duration (P < 0.05). In conclusion, brain oxygen metabolism is depressed in patients with renal failure on or before the start of HD therapy. The cause for depressed brain oxygen metabolism is considered to be either dysregulation of cerebral circulation or lower brain cell activity.


Subject(s)
Brain/metabolism , Kidney Failure, Chronic/complications , Oxygen/metabolism , Brain/diagnostic imaging , Cerebrovascular Circulation , Cognition Disorders/etiology , Cognition Disorders/metabolism , Female , Humans , Kidney Failure, Chronic/metabolism , Kidney Failure, Chronic/therapy , Male , Middle Aged , Renal Dialysis , Tomography, Emission-Computed
14.
Brain Res Mol Brain Res ; 38(1): 85-90, 1996 May.
Article in English | MEDLINE | ID: mdl-8737671

ABSTRACT

In situ hybridization histochemistry was used to evaluate the expression of the immediate-early gene c-fos following the induction of audiogenic seizures in adult rats with transient neonatal hypothyroidism. The rats treated with 0.02% propylthiouracil (PTU) through mother's milk during days 0-19 after delivery showed a high incidence of seizures to auditory stimulation at the age of 4 months. The significant induction of c-fos mRNA by audiogenic seizures is prominent in several brain areas including central gray, peripeduncular nucleus, inferior colliculus, septal nucleus, bed nucleus of stria terminalis, and dorsomedial hypothalamus. However, the expression of c-fos mRNA was comparable in neocortex, dorsal hippocampus and medial geniculate body between control rats and PTU-treated, seizure-induced rats. These results confirm the previous report on the c-fos expression following audiogenic seizure sensitized during development by a loud noise [20]. The present results indicate that the neonatal PTU treatment may provide a useful tool for studying the mechanism underlying the seizure susceptibility and development after maturation.


Subject(s)
Hypothyroidism/metabolism , Nerve Tissue Proteins/genetics , Proto-Oncogene Proteins c-fos/genetics , RNA, Messenger/biosynthesis , Seizures/metabolism , Acoustic Stimulation , Animals , Animals, Newborn , Male , Propylthiouracil , Rats , Rats, Sprague-Dawley , Seizures/chemically induced
15.
Am J Hypertens ; 3(2): 140-7, 1990 Feb.
Article in English | MEDLINE | ID: mdl-2137703

ABSTRACT

To study the effects of atrial natriuretic peptide (ANP) on body fluid volume regulation, we estimated the changes in intra- and extravascular fluid volume by measuring hematocrit (Hct), plasma protein concentration and water balance, and the changes in intra- and extracellular fluid volume by the electrical impedance method during intravenous infusion of ANP. We did two studies, as follows: ANP was infused into 18 patients with essential hypertension, 29 with renal parenchymal hypertension and 15 normotensives at 0.025 microgram/kg/min for 40 min. Both hypertensive groups showed greater natriuretic responses to ANP than normotensives. ANP infusion into essential hypertensive patients increased the urinary excretion of water by 125%, Na by 205%, Hct by 4.2% and plasma total protein (TP) by 5.2% (each P less than .001). In 9 patients (1 with renal hypertension and 8 normotensives) who did not show a natriuretic response (-2.1%), the infusion of ANP also significantly increased Hct (3.8%) and plasma TP (3.1%, each P less than .01). The electrical impedance method was applied to 12 subjects to simultaneously detect the intracellular (Ri) and extracellular resistivities (Re), of which reciprocals reflect the fluid volume in the extra- and intracellular spaces, respectively. ANP infusion increased Re in all subjects (3.96 +/- 0.16 [SE] v 4.03 +/- 0.16 omega.m, P less than .05), but decreased Ri in 7. Changes in urinary Na excretion correlated positively with those in both Re (r = 0.62, P less than .05) and Ri (r = 0.75, P less than .01).(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Atrial Natriuretic Factor/pharmacology , Body Fluids/drug effects , Adult , Blood Pressure/drug effects , Blood Proteins/metabolism , Body Fluids/metabolism , Electrodiagnosis/methods , Extracellular Space/drug effects , Extracellular Space/metabolism , Hematocrit , Humans , Hypertension/metabolism , Hypertension/physiopathology , Hypertension, Renal/metabolism , Hypertension, Renal/physiopathology , Intracellular Fluid/drug effects , Intracellular Fluid/metabolism , Middle Aged , Natriuresis/drug effects , Plasma Volume/drug effects
16.
Ann N Y Acad Sci ; 873: 245-61, 1999 Apr 20.
Article in English | MEDLINE | ID: mdl-10372174

ABSTRACT

The effects of flow on the changes of electrical resistivity and light-scattering characteristics of blood are experimentally and theoretically discussed. Studies indicate that most erythrocytes deform and orient themselves in the flow direction when blood flows in a conduit. Such oriented blood shows anisotropic properties. Anisotropic electrical resistivity of flowing blood is measured in three rectangular directions with a measurement cell of coaxial cylindrical type. From these experimental results, the orientation and deformation of erythrocytes are discussed. The orientation ratio and the deformation are calculated using a simplified spheroidal model of an erythrocyte. Calculated results show that the fractions of erythrocytes with their short axis parallel to each direction and the equivalent axis ratio for a simplified spheroidal model change with the shear rate of flow.


Subject(s)
Blood Physiological Phenomena , Erythrocytes/cytology , Blood Flow Velocity , Cell Size , Electric Impedance , Erythrocytes/physiology , Hematocrit , Humans , Models, Biological , Scattering, Radiation
17.
Ann N Y Acad Sci ; 873: 77-88, 1999 Apr 20.
Article in English | MEDLINE | ID: mdl-10372153

ABSTRACT

Erythrocyte orientation and deformation cause differences in impedance between flowing and resting blood. Through theoretical calculation and experimental measurements, we studied the effects of these factors on blood impedance. The size and shape of the erythrocyte and the conductivity of the interior medium of the erythrocyte change when the osmotic pressure of plasma is changed. From experimental results, we obtained the following: when the size of the erythrocyte becomes larger than the normal size due to the osmotic pressure change, the beta dispersion frequency decreases and the intra- and extracellular fluid resistance increase. These experimental results corroborate that the change of tissue impedance like muscle impedance during hemodialysis is caused by the change of the fluid distribution and the change of ionic concentration of the electrolyte in tissues during hemodialysis. Also, we could estimate the relative change value of the intra- and extracellular fluid volume by the impedance method, if there were no ionic concentration change in the electrolyte. It would be very difficult to estimate the absolute change value of them because a shadow effect due to the cells depends greatly upon the shape and size of the cells and the cell concentration.


Subject(s)
Blood Physiological Phenomena , Body Fluids/physiology , Renal Dialysis , Anisotropy , Cell Size , Electric Impedance , Erythrocytes/physiology , Hematocrit , Humans , Models, Biological , Sodium Chloride/pharmacology
18.
Hypertens Res ; 24(6): 705-9, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11768731

ABSTRACT

Targeted disruption of the klotho gene induces multiple phenotypes characteristic of human aging, including arteriosclerosis, pulmonary emphysema and osteoporosis. Moreover, we previously observed that insufficient klotho expression in mice leads to endothelial dysfunction. In the present study, we used Otsuka Long-Evans Tokushima Fatty (OLETF) rats, which exhibit hypertension, obesity, severe hyperglycemia and hypertriglyceridemia, and are thus considered an animal model of atherogenic disease, to test the effects of oral administration of troglitazone (200 mg/kg) on renal klotho mRNA expression and endothelial function. Systolic blood pressure, body weight, plasma glucose and triglyceride levels were all significantly higher in 30-week-old OLETF rats than in controls (LETO; Long-Evans Tokushima Otsuka) (p<0.05, n=7). In addition, endothelium-dependent relaxation of the aorta in response to 10(-5) M acetylcholine was significantly attenuated in OLETF rats (p<0.05, n=7), as was renal expression of klotho mRNA. Administration of troglitazone for 10 weeks significantly reduced systolic blood pressure, plasma glucose and triglyceride levels in OLETF rats, while augmenting endothelium-dependent aortic relaxation and renal klotho mRNA expression. These findings suggest that troglitazone protects the vascular endothelium against damage caused by the presence of multiple atherogenic factors.


Subject(s)
Chromans/pharmacology , Endothelium, Vascular/drug effects , Kidney/metabolism , Membrane Proteins/genetics , Obesity/physiopathology , RNA, Messenger/metabolism , Rats, Inbred OLETF/physiology , Thiazoles/pharmacology , Thiazolidinediones , Vasodilator Agents/pharmacology , Animals , Arteriosclerosis/etiology , Endothelium, Vascular/physiopathology , Glucuronidase , Hypertension/genetics , Klotho Proteins , Male , Metabolic Diseases/genetics , Rats , Risk Factors , Troglitazone
19.
Brain Res ; 581(1): 161-4, 1992 May 22.
Article in English | MEDLINE | ID: mdl-1498667

ABSTRACT

The anticonvulsant effect of 1-naphthylacetyl spermine, an analogue of Joro spider toxin (JSTX), was studied against seizures induced by quisqualate (QUIS), a non-NMDA agonist, as assessed electrophysiologically and behaviorally in freely moving rats. Electrodes were implanted into right dorsal hippocampus and an injection cannula for drugs into right ventricle. The pretreatment with JSTX analogue significantly inhibited both of QUIS-induced hippocampal discharges (80-11%) and generalized tonic clonic seizures (100-33%) in a dose-dependent manner, whereas JSTX had no effect on seizures induced by quinolinate, a NMDA agonist. The paper provides the first direct evidence that the JSTX analogue exerts a potent and selective suppression of hippocampal epileptic discharges mediated by non-N-methyl-D-aspartate (non-NMDA) receptors.


Subject(s)
Epilepsy/prevention & control , Hippocampus/drug effects , Quisqualic Acid/antagonists & inhibitors , Spermine/analogs & derivatives , Animals , Electroencephalography/drug effects , Epilepsy/chemically induced , Male , Rats , Rats, Inbred Strains , Spermine/pharmacology
20.
Brain Res ; 706(1): 173-6, 1996 Jan 08.
Article in English | MEDLINE | ID: mdl-8720508

ABSTRACT

The anticonvulsant effect of 1-naphthylacetyl spermine (1-NA-Spm), an analogue of Joro spider toxin, against amygdaloid kindled seizures was studied in rats. 1-NA-Spm (10, 20 and 40 micrograms/rat) dose-dependently improved kindled seizures and shortened the afterdischarge duration 30 min after the administration. The anticonvulsant effect was observed even one day after the drug, and then gradually disappeared within 4 days. The present findings demonstrate that 1-NA-Spm acts as a potent and long-acting anticonvulsant against amygdaloid kindled seizures, and also suggest, together with the previous findings, that the calcium-permeable AMPA receptors, which are selectively antagonized by 1-NA-Spm, play a critical role in the seizure generation mechanism of amygdaloid kindling.


Subject(s)
Amygdala/physiology , Anticoagulants/pharmacology , Kindling, Neurologic , Seizures/drug therapy , Spermine/analogs & derivatives , Animals , Dose-Response Relationship, Drug , Electric Stimulation , Electroencephalography/drug effects , Excitatory Amino Acid Antagonists/pharmacology , Male , Neurotoxins , Quinoxalines/pharmacology , Rats , Rats, Wistar , Receptors, AMPA/antagonists & inhibitors , Seizures/etiology , Spermine/pharmacology , Spider Venoms
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