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1.
Endoscopy ; 43(1): 70-2, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21108178

ABSTRACT

Tocilizumab is a monoclonal antibody against human interleukin-6 receptor which blocks the binding of interleukin-6 to its receptor. Tocilizumab is effective for the treatment of inflammatory disorders including rheumatoid arthritis. We report a case of multiple ulcers in the small and large intestines, which occurred during tocilizumab therapy. A 57-year-old woman started to use tocilizumab for rheumatoid arthritis. Three months later, she complained of hematochezia. Double-balloon endoscopy revealed multiple small aphthoid ulcers in the small and large intestines. One month after the woman had recovered, she was given tocilizumab again. The woman had hematochezia and abdominal pain again 2 weeks later. Colonoscopy revealed multiple round, discrete punched-out ulcers in the terminal ileum, and vast deep ulcers from the cecum to the descending colon. Bioptic histopathology and cultivation showed non-specific findings. Six weeks after discontinuation of tocilizumab, ulcers in the small and large intestine dramatically improved, leaving ulcer scars. This disease course and the results of examination made us strongly suspect that tocilizumab induced multiple ulcers in the small and large intestines. Interleukin-6 is a pleiotropic cytokine and involved in intestinal mucosal wound healing as well as in inflammatory processes. It is possible that tocilizumab inhibited tissue repair of the intestine and caused intestinal ulcers.


Subject(s)
Antibodies, Monoclonal/adverse effects , Arthritis, Rheumatoid/drug therapy , Intestine, Large , Intestine, Small , Ulcer/chemically induced , Antibodies, Monoclonal, Humanized , Colonoscopy , Female , Humans , Interleukin-6/antagonists & inhibitors , Intestinal Diseases/chemically induced , Middle Aged
2.
Digestion ; 84(4): 261-8, 2011.
Article in English | MEDLINE | ID: mdl-21934307

ABSTRACT

BACKGROUND: This long-term 48-week study of acotiamide was carried out to investigate the efficacy, safety and administration pattern in patients with functional dyspepsia (FD). METHODS: This was a multicenter, open-label, single-arm, long-term phase III study in which patients with FD were given acotiamide, 100 mg t.i.d., for 48 weeks. The two major efficacy endpoints were global overall treatment efficacy (OTE) and the elimination rate of three cardinal symptoms (i.e. postprandial fullness, early satiation and upper abdominal bloating), which were evaluated weekly and daily by the patients, respectively. The long-term administration patterns were investigated by following the patients based on cessation and readministration criteria. RESULTS: Efficacy was analyzed in 405 patients. The OTE improvement rate was 26.1% at week 1 and increased with time. It was 60.6% at week 8 and subsequently maintained. Similarly, the symptom elimination rate increased up to week 8. Many patients who met the cessation criterion achieved remission of FD symptoms after experiencing dose interruption and readministration. The incidence rate of adverse drug reactions was 11.5% and most of the adverse drug reactions were mild in severity except increased ALT in 1 patient. CONCLUSION: FD symptoms were controlled by intermittent administration of acotiamide even in patients with relapsing FD.


Subject(s)
Benzamides/therapeutic use , Dyspepsia/drug therapy , Muscarinic Agonists/therapeutic use , Sensation/physiology , Thiazoles/therapeutic use , Abdominal Pain/etiology , Adult , Benzamides/pharmacology , Dyspepsia/complications , Dyspepsia/physiopathology , Female , Humans , Male , Middle Aged , Muscarinic Agonists/pharmacology , Postprandial Period , Satiation/drug effects , Satiation/physiology , Sensation/drug effects , Thiazoles/pharmacology , Time Factors , Treatment Outcome , Young Adult
3.
Endoscopy ; 41(2): 175-8, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19214900

ABSTRACT

In recent years, primary gastrointestinal follicular lymphoma has been increasingly detected in the duodenum on esophagogastroduodenoscopy (EGD). Primary gastrointestinal follicular lymphomas are frequently distributed to multiple sites in the gastrointestinal tract. Therefore, investigation into the spread of follicular lymphomas in the small bowel is important in order to determine the most appropriate treatment strategy. The performance of double-balloon endoscopy (DBE) in the diagnosis of jejunoileal follicular lymphoma lesions has not been fully evaluated. We aimed to investigate the value of DBE in addition to computed tomography (CT) and (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG-PET) in the diagnosis of jejunoileal follicular lymphoma. DBE with biopsy was performed in seven patients with primary duodenal follicular lymphoma diagnosed by EGD, in order to investigate jejunoileal involvement. Jejunoileal follicular lymphoma lesions were detected by DBE in six out of the seven patients (three in the jejunum and three in the jejunum and ileum), whereas CT and (18)F-FDG-PET failed to detect the existence of these lesions. Endoscopic findings of the jejunoileal lesions revealed multiple white nodules and white villi, which were similar to those of duodenal lesions. DBE was more useful for the diagnosis of jejunoileal involvement in primary intestinal follicular lymphoma than CT and (18)F-FDG-PET. The use of DBE will become important for determining the most appropriate treatment for gastrointestinal follicular lymphoma.


Subject(s)
Catheterization/instrumentation , Endoscopy, Digestive System , Intestinal Neoplasms/diagnosis , Intestine, Small/pathology , Lymphoma, Follicular/diagnosis , Aged , Cohort Studies , Female , Humans , Intestinal Neoplasms/therapy , Lymphoma, Follicular/therapy , Male , Middle Aged , Predictive Value of Tests , Retrospective Studies , Treatment Outcome
4.
Gut ; 57(4): 475-81, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18198200

ABSTRACT

BACKGROUND/AIM: 5-Hydroxytryptamine (5-HT) released from enterochromaffin cells influences intestinal homeostasis by altering gut physiology and is implicated in the pathophysiology of various gut disorders. The mechanisms regulating 5-HT production in the gut remain unclear. This study investigated the T helper (Th) 1/Th2-based immunoregulation of enterochromaffin cell function and 5-HT production in a model of enteric infection. METHODS AND RESULTS: Trichuris muris-infected AKR (susceptible to infection and generates Th1 response), BALB/c (resistant to infection and generates Th2 response), Stat4-deficient (impaired in Th1 response) and Stat6-deficient (impaired in Th2 response) mice were investigated to assess enterochromaffin cells, 5-HT and cytokines. In association with the generation of a Th2 response we observed higher enterochromaffin cell numbers and 5-HT content in the colon of BALB/c mice compared with AKR mice. Numbers of enterochromaffin cells and amount of 5-HT were significantly lower in Stat6-deficient mice after infection compared with Stat4-deficient mice. In addition, enterochromaffin cell numbers and 5-HT content were significantly higher after reconstitution of severe combined immunodeficient mice with in-vitro polarised Th2 cells. CONCLUSION: The study demonstrated that enterochromaffin cell and 5-HT responses to the same infectious agent are influenced by Th1 or Th2 cytokine predominance and suggests that the immunological profile of the inflammatory response is important in the regulation of enterochromaffin cell biology in the gut. In addition to new data on enterochromaffin cell function in enteric infection and inflammation, this study provides important information on the immuno-endocrine axis in the gut, which may ultimately lead to improved strategies against gut disorders.


Subject(s)
Enterochromaffin Cells/pathology , Serotonin/metabolism , Th1 Cells/immunology , Th2 Cells/immunology , Trichuriasis/immunology , Animals , Cell Count , Cells, Cultured , Colon/metabolism , Colon/pathology , Disease Susceptibility , Enterochromaffin Cells/metabolism , Interferon-gamma/metabolism , Interleukin-4/metabolism , Male , Mice , Mice, Inbred Strains , Mice, SCID , Species Specificity , Trichuriasis/metabolism , Trichuriasis/pathology
5.
Cytotherapy ; 10(7): 698-710, 2008.
Article in English | MEDLINE | ID: mdl-18985477

ABSTRACT

BACKGROUND: Ulcerative colitis (UC) is an intractable disease; therefore new therapies need to be developed. CD4(+) CD25(high) regulatory T cells (Treg) significantly ameliorate colitis in animal models. In active UC patients, although Treg are functionally preserved, their proportion in peripheral blood decreases. Thus Treg transfer therapy is expected to be efficacious for UC. During leukapheresis for UC, Treg are depleted, as well as colitogenic effector leukocytes. We therefore designed a leukapheresis/Treg transfer therapy in which Treg are isolated from leukapheresis products and transfused to patients, and studied large-scale germ-free methods of Treg preparation. METHODS: Using the CliniMACS cell selection system, we conducted Treg isolation experiments from leukapheresis products in which B and CD8(+) T cells were depleted, followed by positive selection of CD25(+) cells. In some experiments, isolated Treg or non-Treg were expanded with interleukin-2 (IL-2) +/- transforming growth factor (TGF)-beta1. Expression of a Treg-specific marker, FOXP3, and gut-homing receptors, and suppressor activity of isolated or cultured cells, were analyzed. RESULTS: CD4(+) CD25(high) T cells were collected and efficiently enriched with a good recovery rate. Isolated cells preferentially expressed FOXP3 and significantly suppressed T-cell proliferation in vitro. In addition, isolated Treg could be efficiently expanded, and Treg could be induced from non-Treg with TGF-beta1 in vitro. TGF-beta1 significantly up-regulated alphaEbeta7 and alpha4beta7 integrins. DISCUSSION: We have established a method of Treg isolation from leukapheresis products that can be used clinically; therefore, Treg transfer therapy is feasible in combination with leukapheresis for UC. Expansion or induction of Treg in vitro may be another approach to Treg-based immunotherapy.


Subject(s)
Cell Separation/methods , Colitis, Ulcerative/immunology , Leukapheresis/methods , T-Lymphocytes, Regulatory/immunology , Adolescent , Adult , Aged , CD4 Antigens/immunology , Cell Proliferation , Colitis, Ulcerative/therapy , Female , Forkhead Transcription Factors/immunology , Forkhead Transcription Factors/metabolism , Humans , Integrins/immunology , Integrins/metabolism , Interleukin-2 Receptor alpha Subunit/immunology , Male , Middle Aged , T-Lymphocytes, Regulatory/physiology , T-Lymphocytes, Regulatory/transplantation , Transforming Growth Factor beta1/immunology , Transforming Growth Factor beta1/metabolism
6.
Neurogastroenterol Motil ; 30(5): e13275, 2018 05.
Article in English | MEDLINE | ID: mdl-29278278

ABSTRACT

BACKGROUND: Clinical testing to determine a suitable dose of linaclotide for Japanese patients with irritable bowel syndrome with constipation (IBS-C) was needed. METHODS: This was a randomized, double-blind, placebo-controlled, dose-finding trial. Japanese patients with IBS-C diagnosed using Rome III criteria (n = 559, men/women: 49/510) were randomly assigned to 1 of 4 linaclotide doses (0.0625, 0.125, 0.25, or 0.5 mg) or placebo for the 12-week treatment period. The primary endpoint was responder rate of global assessment of relief of IBS symptoms during 12 weeks. The secondary endpoints included responder rates of complete spontaneous bowel movement (CSBM), SBM and abdominal pain/discomfort relief and others. KEY RESULTS: The primary endpoint was 23.2%, 36.2%, 38.7%, 34.8%, and 38.3% in placebo (n = 112), 0.0625 (n = 116), 0.125 (n = 111), 0.25 (n = 112), and 0.5 (n = 107) mg of linaclotide groups with the difference from the placebo group in each linaclotide group (13.0%, 15.5%, 11.6%, 15.1%, P > .05). Monthly responder rate of global assessment of relief of IBS symptoms at month 3 (48.6%), responder rate of CSBM during 12 weeks (45.8%), and responder rate of abdominal pain/discomfort relief during 12 weeks (32.7%) in the 0.5 mg were significantly higher than those in placebo group (29.5%, P < .01; 25.9%, P < .01; and 18.8%, P < .05 respectively). The most frequent adverse event in the linaclotide groups was diarrhea. CONCLUSIONS & INFERENCES: This study suggests that a linaclotide dose of 0.5 mg may be appropriate in Japanese patients with IBS-C.


Subject(s)
Abdominal Pain/drug therapy , Constipation/drug therapy , Gastrointestinal Agents/administration & dosage , Guanylyl Cyclase C Agonists/administration & dosage , Irritable Bowel Syndrome/drug therapy , Peptides/administration & dosage , Adult , Defecation/drug effects , Dose-Response Relationship, Drug , Double-Blind Method , Female , Gastrointestinal Agents/therapeutic use , Guanylyl Cyclase C Agonists/therapeutic use , Humans , Japan , Male , Middle Aged , Peptides/therapeutic use , Treatment Outcome
7.
Article in English | MEDLINE | ID: mdl-28205278

ABSTRACT

BACKGROUND: Previous studies showed that 5 µg of ramosetron, a serotonin (5-hydroxytryptamine: 5-HT)-3 receptor antagonist, is only effective in male patients with irritable bowel syndrome (IBS) with diarrhea (IBS-D). We hypothesized that either dose 1.25, 2.5, or 5 µg of ramosetron would be effective in female patients with IBS-D. METHODS: This randomized, double-blind, placebo-controlled, phase II dose-finding exploratory trial included 409 female outpatients with IBS-D treated in Japan. They were administered oral placebo (n=102), or 1.25 µg (n=104), 2.5 µg (n=104), or 5 µg (n=99) of ramosetron once daily for 12 weeks after a 1-week baseline period. The primary endpoint was monthly responder rates of global improvement of IBS symptoms in the first month. Secondary endpoints included global improvement in the other months, abdominal pain/discomfort, weekly mean changes in the Bristol Stool Form Scale (BSFS), and IBS-QOL. KEY RESULTS: Middle dose (2.5 µg) of ramosetron significantly improved abdominal pain/discomfort at second month (62.5%, P=.002), third month (60.6%, P=.005), and the last evaluation point (63.5%, P=.002) and weekly BSFS (P<.05) except at Week 8, 11, and 12 than placebo. IBS-QOL did not change. Ramosetron induced more constipation than placebo. CONCLUSIONS & INFERENCES: The trial suggested that 2.5 µg of ramosetron is the most effective and least harmful option for treating female patients with IBS-D (Clinicaltrials.gov ID: NCT01274000).


Subject(s)
Benzimidazoles/administration & dosage , Diarrhea/drug therapy , Irritable Bowel Syndrome/drug therapy , Serotonin Antagonists/administration & dosage , Abdominal Pain/drug therapy , Adult , Diarrhea/complications , Double-Blind Method , Female , Humans , Irritable Bowel Syndrome/complications , Middle Aged , Treatment Outcome
8.
Neuropharmacology ; 37(2): 159-68, 1998.
Article in English | MEDLINE | ID: mdl-9680240

ABSTRACT

We studied the effect of YM-39558, orotic acid ethylester, in a focal cerebral ischemia model in anesthetized cats. YM-39558 has good permeability across the blood brain barrier, and in the brain is hydrolyzed to orotic acid, the main active substance. Cats were subjected to permanent occlusion of the middle cerebral artery (MCA) for 6 h, then killed and examined histologically. Treatment with YM-39558 (intravenous infusion of 11.8 mg (10 mg as orotic acid)/6 ml per kg per h) starting 15 min after MCA occlusion markedly reduced the volume of ischemic damage (from 2450 +/- 82 mm3 of the cerebral hemisphere in the saline-treated cats to 1644 +/- 123 mm3 in the YM-39558-treated cats, P < 0.01). In contrast, YM-39558 (2.26 and 1.18 mg/0.8 ml per kg per h) showed no significant protective effect on ischemic damage. No significant differences were observed between saline- and YM-39558-treated cats concerning physiological variables including brain temperature. This evidence for the neuroprotective efficacy of YM-39558 in gyrencephalic species suggests its therapeutic potential in the treatment of stroke in humans.


Subject(s)
Brain Ischemia/drug therapy , Brain/drug effects , Neuroprotective Agents/therapeutic use , Pyrimidines/therapeutic use , Animals , Blood Pressure/drug effects , Body Temperature/drug effects , Brain/pathology , Brain/physiology , Brain Ischemia/pathology , Carbon Dioxide/blood , Cats , Electroencephalography/drug effects , Hydrogen-Ion Concentration , Male , Oxygen/blood
9.
Neuroreport ; 8(3): 607-10, 1997 Feb 10.
Article in English | MEDLINE | ID: mdl-9106732

ABSTRACT

We studied the effects of orotic acid, a precursor of pyrimidine nucleotide, on delayed neuronal death of hippocampal CA1 neurones induced by global cerebral ischaemia in Mongolian gerbils. Neuronal damage was significantly reduced in animals treated with orotic acid 2 h before ischaemia at doses of 100, 200 or 300 mg kg-1, i.p. A dose of 300 mg kg-1 given 24 h after ischaemia also suppressed CA1 neuronal damage, but had no effect when given at 48 or 72 h. These results demonstrate a protective effect of orotic acid on ischaemic neuronal damage with a wide therapeutic time window.


Subject(s)
Hippocampus/pathology , Ischemic Attack, Transient/drug therapy , Ischemic Attack, Transient/pathology , Neurons/pathology , Orotic Acid/therapeutic use , Animals , Gerbillinae , Hippocampus/drug effects , Male , Nerve Degeneration , Neurons/drug effects , Pyramidal Cells/drug effects , Pyramidal Cells/pathology , Time Factors
10.
Neurosci Lett ; 219(2): 119-22, 1996 Nov 22.
Article in English | MEDLINE | ID: mdl-8971794

ABSTRACT

We recently reported that the density of mRNA for the dopamine D4 receptor was extremely low in human cerebral cortex but unexpectedly higher in the corpus callosum and spinal cord both of which contain substantial white-matter area. Under low stringency conditions, Northern blot analysis using the D4 probe detected cross-hybridized mRNAs having a similar distributional profile to the D4 mRNA in human brain regions, suggesting the mRNA distributional profile is not peculiar to the D4 receptor. Homology screening revealed one of the mRNAs to be an orphan seven-transmembrane receptor, APJ, abundantly expressed in the corpus callosum and spinal cord. In porcine spinal cord the APJ mRNA was detected at a higher level in white-matter rather than in gray-matter area. These data suggest that a group of seven-transmembrane receptors, including the D4 and APJ receptor, is preferentially expressed in the white-matter area probably in non-neuronal glial cells.


Subject(s)
Brain/metabolism , RNA, Messenger/metabolism , Receptors, Dopamine D2/genetics , Receptors, Dopamine D2/metabolism , Receptors, G-Protein-Coupled , Animals , Apelin Receptors , Blotting, Northern , Humans , Spinal Cord/metabolism , Swine , Tissue Distribution
11.
Life Sci ; 55(16): 1293-9, 1994.
Article in English | MEDLINE | ID: mdl-7934631

ABSTRACT

Atrial natriuretic peptide (ANP) relaxes the vascular smooth muscle via particulate guanylate cyclase. Smooth muscle cells isolated from the caecal circular muscle layer of the guinea pig were used to examine the direct inhibitory effect of ANP on those cells. The role of adenylate cyclase, particulate guanylate cyclase, and soluble guanylate cyclase in the direct inhibitory effect of ANP on contraction of this muscle cell induced by carbachol was investigated. ANP inhibited the contractile response produced by 10(6)M carbachol in a concentration-dependent manner, with an IC50 value of 8nM. An inhibitor of adenylate cyclase (2',5'-dideoxyadenosine) and two inhibitors of particulate guanylate cyclase (HS-142-1, and PMA) had no significant effect on the relaxation produced by ANP. In contrast, an inhibitor of soluble guanylate cyclase (LY83583) significantly and completely inhibited the relaxation produced by ANP. This is the first report demonstrating the direct inhibitory action of ANP on the isolated caecal smooth muscle cells via soluble guanylate cyclase, which differs from the intracellular mechanism responsible for the relaxation of vascular smooth muscle produced by ANP.


Subject(s)
Atrial Natriuretic Factor/pharmacology , Cecum/drug effects , Guanylate Cyclase/metabolism , Muscle Relaxation/drug effects , Muscle, Smooth/drug effects , Aminoquinolines/pharmacology , Animals , Carbachol/pharmacology , Cecum/cytology , Cecum/physiology , Dideoxyadenosine/pharmacology , Guanylate Cyclase/drug effects , Guinea Pigs , Male , Muscle, Smooth/cytology , Muscle, Smooth/physiology , Solubility , Tetradecanoylphorbol Acetate/pharmacology
12.
Life Sci ; 58(24): 2243-9, 1996.
Article in English | MEDLINE | ID: mdl-8649211

ABSTRACT

Smooth muscle cells isolated separately from the caecal circular smooth muscle layer of the guinea pig were used to investigate whether corticotropin releasing hormone (CRH) can inhibit directly the contraction produced by cholecystokinin octapeptide (CCK-8). In addition, the role of adenylate cyclase and guanylate cyclase in the direct inhibitory effect of CRH was examined. CRH inhibited the contractile response produced by 10(-9)M CCK-8 in a concentration-dependent manner, with an IC50 value of 0.16nM. An inhibitor of particulate guanylate cyclase and an inhibitor of soluble guanylate cyclase had no significant effect of the relaxation produced by CRH. In contrast, an inhibitor of adenylate cyclase and an inhibitor of cAMP-dependent protein kinase significantly inhibited the relaxation produced by CRH. This is the first report demonstrating the direct inhibitory action of CRH on the isolated caecal smooth muscle cells via adenylate cyclase system.


Subject(s)
Adenylyl Cyclase Inhibitors , Cecum/drug effects , Corticotropin-Releasing Hormone/pharmacology , Muscle, Smooth/drug effects , Aminoquinolines/pharmacology , Animals , Cecum/enzymology , Cecum/physiology , Enzyme Inhibitors/pharmacology , Guanylate Cyclase/antagonists & inhibitors , Guinea Pigs , In Vitro Techniques , Muscle Relaxation/drug effects , Muscle, Smooth/enzymology , Muscle, Smooth/physiology , Sincalide/antagonists & inhibitors , Sincalide/pharmacology , Tetradecanoylphorbol Acetate/pharmacology
14.
ASAIO J ; 41(1): 84-8, 1995.
Article in English | MEDLINE | ID: mdl-7727827

ABSTRACT

To analyze the hemodynamic parameters during prosthetic circulation as an entity, non linear mathematical techniques were used. To compare natural and prosthetic circulation, two pneumatically actuated ventricular assist devices were implanted as biventricular bypasses in chronic animal experiments using adult goats to consitute the biventricular bypass complete prosthetic circulation model with ventricular fibrillation. After implantation, these goats were placed in a cage and extubated after waking. All hemodynamic parameters with the natural circulation without biventricular bypass pumping, and the artificial circulation with biventricular bypass pumping under ventricular fibrillation were recorded under awake conditions. By the use of a non linear mathematical technique, the arterial blood pressure waveform was embedded into a four dimensional phase space and projected into three dimensional phase space. The Lyapunov numeric method is used as an adjunct to the graphic analysis of the state space. A phase portrait of the attractor showed a high dimension complex structure, with three dimensional solid torus suggesting deterministic chaos during natural circulation. However, a simple attractor, such as a limit cycle attractor, was observed during artificial circulation. Positive Lyapunov exponents during artificial circulation suggest the lower dimensional chaotic system. Thus, hemodynamic parameters during prosthetic circulation must be carefully controlled when unexpected stimuli are fed from outside.


Subject(s)
Coronary Circulation/physiology , Heart, Artificial/standards , Heart-Assist Devices/standards , Hemodynamics/physiology , Animals , Blood Pressure/physiology , Disease Models, Animal , Goats , Heart, Artificial/trends , Heart-Assist Devices/trends , Nonlinear Dynamics , Ventricular Fibrillation/physiopathology , Ventricular Fibrillation/therapy
15.
Int J Artif Organs ; 18(4): 190-6, 1995 Apr.
Article in English | MEDLINE | ID: mdl-8530198

ABSTRACT

In order to analyze the hemodynamic parameters in prosthetic circulation as an entity and not as decomposed parts, non linear mathematical analyzing techniques, including the fractal dimension analyzing theory, were utilized. Two pneumatically actuated ventricular assist devices were implanted, as biventricular bypasses (BVB), in chronic animal experiments, using four healthy adult goats. For the comparison between the natural and prosthetic circulation in the same animals, the BVB type complete prosthetic circulation model with ventricular fibrillation, was adopted. All hemodynamic parameters with natural and prosthetic circulation were recorded under awake conditions, and calculated with a personal computer system. Using the non-linear mathematical technique, the arterial blood pressure waveform was embedded into the return map as the beat-to-beat time series data and fractal dimension analysis were performed to analyze the reconstructed attractor. By the use of the Box counting method, fractal dimension analysis of the hemodynamics was performed. Return map of the hemodynamics during natural and artificial circulation showed fractal characteristics, and fractal dimension analysis of the arterial blood pressure revealed the fact that lower dimensional fractal dynamics were evident during prosthetic circulation. Fractal time series data is suggested to have robustness and error resistance, thus our results suggest that the circulatory regulatory system with an artificial heart may have these desired characteristics.


Subject(s)
Coronary Circulation/physiology , Fractals , Heart, Artificial , Heart-Assist Devices , Hemodynamics/physiology , Animals , Goats , Heart Bypass, Left
16.
Int J Artif Organs ; 18(1): 17-21, 1995 Jan.
Article in English | MEDLINE | ID: mdl-7607752

ABSTRACT

In order to analyze hemodynamic parameters during left ventricular assistance as an entity and not as decomposed parts, non-linear mathematical techniques were utilized. Pneumatically actuated ventricular assist systems (VAS) were implanted as left heart bypasses in acute animal experiments, using healthy adult mongrel dogs. By the use of the non-linear mathematical technique, the arterial blood pressure waveform (AP) was embedded into the four-dimensional phase space and projected into the three-dimensional phase space. The Lyapunov numerical method was used as an adjunct to the graphical analysis of the state space. The phase portrait of the attractor showed a complex structure; a three dimensional solid torus with a screw type structure as a part, suggesting deterministic chaos in the AP without left ventricular assistance. Positive lyapunov exponents confirmed the existence of chaos. During counterpulsation mode left ventricular assistance, the phase portrait of the attractor showed a more complex structure, and positive Lyapunov exponents suggested a greater dimensional deterministic chaos. However, non-structured patterns were seen in the phase space during internal mode VAS driving, suggesting the possibility of dissipative dynamics in the four dimensional phase space. These results suggest that the cardiovascular system with counterpulsation mode VAS driving is in a homeochaotic state, which is thought to be a flexible and intelligent control system. And there is greater dimensional complex dynamics in the circulatory regulatory system with VAD during internal mode assistance.


Subject(s)
Blood Pressure/physiology , Heart-Assist Devices/adverse effects , Animals , Cardiac Output/physiology , Dogs , Electrocardiography , Female , Heart Bypass, Left , Male , Models, Biological , Nonlinear Dynamics
17.
Int J Artif Organs ; 15(10): 606-10, 1992 Oct.
Article in English | MEDLINE | ID: mdl-1428209

ABSTRACT

A sympathetic neurogram is potentially useful for the development of a real time total artificial heart (TAH) control system. We used sympathetic tone and hemodynamic derivatives to estimate the following cardiac output in acute animal experiments using adult mongrel dogs. Moving averages of the mean left atrial pressure and mean aortic pressure were used as parameters of the preload and afterload, respectively. Renal sympathetic nerve activity (RSNA) was employed as a parameter of sympathetic tone. Equations for the following cardiac output were calculated using multiple linear regression analysis of the time series data. A significant correlation was observed between the estimated and following measured cardiac output. These results suggest the potential usefulness of the sympathetic neurogram for the real time TAH automatic control system.


Subject(s)
Cardiac Output , Heart, Artificial , Heart/innervation , Hemodynamics , Sympathetic Nervous System/physiology , Animals , Blood Pressure , Dogs , Electrocardiography , Female , Kidney/innervation , Male , Pulmonary Circulation
18.
Int J Artif Organs ; 15(1): 49-54, 1992 Jan.
Article in English | MEDLINE | ID: mdl-1551728

ABSTRACT

Circulatory maintenance with a left ventricular assist device (LVAD) alone during cardiac arrest until heart transplantation has been evaluated. To assess the effect on the autonomic nervous system, the sympathetic neurogram was analyzed by power spectrum and coherence function. LVAD were inserted between the left atrium and the descending aorta in seven adult mongrel dogs and ventricular fibrillation was induced electrically. Renal sympathetic nerve activity (RSNA) was detected by bipolar electrodes attached to the left renal sympathetic nerve. Values of squared coherence between the arterial pulse wave and RSNA were calculated. Under the condition of circulatory maintenance with only LVAD, coherence at the cardiac rhythm frequency was decreased, and coherence at the LVAD pumping rhythm frequency was increased. These results indicate that the arterial pulse wave observed during maintenance of the circulation with only LVAD contributed to the sympathetic neurogram.


Subject(s)
Heart-Assist Devices , Heart/physiology , Hemodynamics/physiology , Kidney/innervation , Sympathetic Nervous System/physiology , Animals , Dogs , Female , Male , Myocardial Contraction/physiology , Pressoreceptors/physiology , Reflex/physiology , Ventricular Fibrillation/physiopathology
19.
Fukuoka Igaku Zasshi ; 83(9): 352-6, 1992 Sep.
Article in Japanese | MEDLINE | ID: mdl-1427559

ABSTRACT

Case 1. A 39-yr-old male was presented with anemia. Initial blood examination showed remarkable iron deficiency anemia. Small bowel X-ray and abdominal CT examination revealed a dilated tract at the end of the ileum. Surgical operation was done. The surgical specimen showed side to side anastomosis which was reconstructed at the operation for rt. inguinal herniation 46 days after his birth. The oral side of the tract was remarkably dilated. Case 2. A 50-yr-old male was presented with dizziness. He had anemia and clubbed fingers. A small bowel X-ray examination was done and it showed side to side anastomosis in the middle of the small intestine. Surgical operation was performed. The surgical specimen showed side to side anastomosis about 2 m 20 cm from the Treitz' ligament, which was reconstructed during the operation for ileus when he was 10 years old. The blind portion was remarkably dilated. In both case, the anemia was improved after the operation.


Subject(s)
Anemia/etiology , Blind Loop Syndrome/complications , Adult , Anastomosis, Surgical , Blind Loop Syndrome/diagnostic imaging , Blind Loop Syndrome/surgery , Humans , Intestine, Small/surgery , Male , Middle Aged , Tomography, X-Ray Computed
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