Reversible visceral ischemia detected by transesophageal echocardiography and near-infrared spectroscopy.
Explore the source record for details and available documents.
Aortic Dissection↗
Biomedical subjects
M Watari
Publications and source records attributed to M Watari.
Monitoring the melt-extrusion transesterification of ethylene-vinylacetate copolymer by self-modeling curve resolution analysis of on-line near-infrared spectra.
The transesterification of molten ethylene-vinylacetate (EVA) copolymers by octanol with sodium methoxide as catalyst in an extruder has been monitored by on-line near infrared (NIR) spectroscopy. A total of 60 NIR spectra were acquired for 37 min with the last spectrum recorded 31 min after the addition of octanol and catalyst was stopped. The experimental spectra show strong baseline fluctuations which are corrected for by multiplicative scatter correction (MSC). The chemometric methods of the orthogonal projection approach (OPA) and multivariate curve resolution (MCR) were used to resolve the spectra and to derive concentration profiles of the species. The detailed analysis reveals the absence of completely pure variables which leads to small errors in the calculation of pure spectra. The initial estimation of a concentration that is necessary as an input parameter for MCR also presents a non-trivial task. We obtained results that were not ideal but applicable for practical concentration control. They enable a fast monitoring of the process in real-time and resolve the spectra of the EVA copolymer and the ethylene-vinyl alcohol (EVAL) copolymer to be very close to the reference spectra. The chemometric methods used and the decomposed spectra are discussed in detail.
Journal Article↗
Cerebral tissue oxygen saturation during percutaneous cardiopulmonary support in a canine model of respiratory failure.
Percutaneous cardiopulmonary support (PCPS) has come to be applied for cardiopulmonary resuscitation and in the management of severe respiratory failure as well as severe heart failure. We investigated cerebral tissue oxygen saturation during PCPS in a canine model of respiratory failure using near-infrared spectroscopy. Animals were mechanically ventilated with 10% oxygen to make a respiratory failure model. Perfusion with PCPS was performed via the left femoral artery and switched to that via the right axillary artery. Cerebral tissue oxygen saturation was 54.2 +/- 3.4% during PCPS via the femoral artery and was 82.3 +/- 4.6% during PCPS via the axillary artery (p = 0.001). Hepatic tissue oxygen saturation was not significantly different. LV dP/dt max increased significantly after switching to the axillary blood supply (p = 0.001). Conventional PCPS may not have the capability of supporting cerebral circulation under severe respiratory failure without organic heart disease.
Analysis of Variance↗
Eccentric roller type total artificial heart creating interatrial shunt.
Creating an interatrial shunt to achieve left-right flow balance and modification of the blood chambers to improve the basic performance of the device were performed in developing an eccentric roller type total artificial heart (ERTAH). Smaller blood chambers reduce friction loss and increase durability and energy efficiency. We changed the left blood chamber volume of 60 ml to 40 ml and the right blood chamber volume of 53 ml to 35 ml compared with previous types. Designs of inlet and outlet ports were modified to prevent backflow. In the mock circulatory system, redesigning the blood chambers resulted in a 20% increase in energy efficiency, about a two-fold increase of cardiac output and improved durability compared to the previous type. In an animal experiment, the ERTAH operated at a driving rate of 160 rpm with a left flow rate of 6.0 L/min and a right flow rate of 5.4 L/min. Interatrial shunt flow rate was 250-400 ml/min.
Animals↗
Aortic arch branches are no longer a blind zone for transesophageal echocardiography: a new eye for aortic surgeons.
OBJECTIVES: Branch arteries of the aortic arch have been a blind zone for transesophageal echocardiography. Information regarding blood flow, which is important in both planned and emergency operations on the aorta, has therefore been limited. We have established a technique for visualizing these arteries in nearly all cases. METHODS: In 25 consecutive patients requiring either planned or emergency operations on the aorta, the branch arteries were visualized whenever cerebral malperfusion was suspected. Lateral flexion of the probe tip was used when the trachea interfered with visualization of the arteries. RESULTS: The left subclavian, left and right common carotid, right subclavian, innominate, and left and right vertebral arteries were visualized in 96% (24/25), 92% (23/25), 96% (24/25), 100% (25/25), 84% (21/25), 92% (22/24), and 88% (21/24), respectively. The origin of the innominate artery was visualized in 36% (9/25). In some cases, dissection extended into branch arteries during surgery or during conservative therapy. When the subclavian artery was clamped, retrograde flow was detected in the vertebral artery (steal flow). The cannula for selective cerebral perfusion occasionally was entered into the right common carotid or subclavian artery and obstructed the other branch with a balloon. CONCLUSIONS: The branch arteries of the aortic arch, including the vertebral artery, are no longer a blind zone for transesophageal echocardiography. The information obtained with our new transesophageal echocardiography technique is helpful for diagnosis, monitoring, and decision making during aortic surgery and in critical care medicine. Visualizing these vessels is worth the effort.
Adult↗
Echocardiography-assisted surgery in transaortic endovascular stent grafting: role of transesophageal echocardiography.
OBJECTIVE: Transesophageal echocardiography was applied to visualizing endovascular procedures during transaortic stent grafting for aneurysm and dissection at the distal arch, and the use of transesophageal echocardiography was evaluated. METHODS: The 16 consecutive patients (13 with aneurysms and 3 with dissections) were examined. Transesophageal echocardiography was used for (1) determining graft size, (2) guiding placement of the catheter in the descending aorta at an appropriate position without intimal damage, (3) guiding graft tailoring with a balloon catheter, and (4) examining the results after the procedures. RESULTS: Visualization was disturbed in one patient who had undergone a previous operation. The graft size was appropriate, except in one patient as a result of underestimation. Transesophageal echocardiography was helpful for navigating the graft placement and tailoring without intimal damage. We tried to keep a distance from the diaphragm of 9 cm and an attachment portion of 4 cm. In one patient the graft was placed too distally (7 cm from the diaphragm) to cover the thick atheromatous plaque with the graft. The patient had paraplegia. Transesophageal echocardiographic assessment of endoleak and thromboexclusion was identical to that of postoperative computed tomography or angiography, with a sensitivity of 100% (1/1) and a specificity of 100% (13/13). Leakage at the proximal suture and graft kinking were found in 3 patients. Successful thromboexclusion by transesophageal echocardiographic assessment (13 patients) was predictive of subsequent regression of aneurysm and dissection in the midterm follow-up period: there was complete and partial regression in 5 and 8 patients, respectively. CONCLUSION: Transesophageal echocardiography enables echocardiography-assisted operations with secure step-by-step endoluminal procedures and immediate intraoperative assessment, which is predictive of the postoperative results.
Adult↗
Newly designed eccentric roller type total artificial heart.
We have produced an eccentric roller type total artificial heart (ERTAH). As the first step in the development of this ERTAH, we conducted simulations such as a numerical simulation, a mock test, and an acute animal experiment using DeBakey roller pumps to analyze the left-right balance during its operation. The next step was redesigning the blood chambers to improve energy efficiency and implanting the ERTAH with an interatrial shunt into an animal for evaluation of the in vivo performance of the device. In the simulations, shunt flow through the bronchial arteries was approximately 500-600 ml/min, and the interatrial resistance was varied from 2.9-7.7 mmHg.min/liter. Redesigning the blood chambers resulted in the mock test in a 20% increase in energy efficiency, about a two-fold increase in cardiac output and improved durability compared to the previous type in the mock test. In the animal experiment the ERTAH operated with a left flow rate of 6.0 liters/min and a right flow rate of 5.4 liters/min. The interatrial shunt flow rate was 250-400 ml/min. Creating an interatrial shunt is a useful method for balancing the blood flow between the left and right heart of the ERTAH. A decrease in friction resistance and the prevention of backward flow resulted in an increase in energy efficiency, cardiac output, and improved durability, in spite of downsizing the blood chambers.
Animals↗
[Community-acquired pneumococcal pneumonia: a comparative study of bacteremic and nonbacteremic patients].
We analyzed the clinical and laboratory features of 37 adult patients with community-acquired pneumococcal pneumonia requiring hospitalization. Blood culture was positive in 11, and negative in 26. The average age of the 37 patients was 70.2 years, and 28 were male. Compared with the patients with negative blood culture, the patients with positive blood culture were more likely to have liver cirrhosis, less sputum production, lower body temperature, and higher respiratory rate on physical examination. In the laboratory data on admission, the values for serum total protein, albumin, and glucose were significantly lower in the patients with positive blood culture. Thirty-two percent of the pneumococcal isolates were resistant to penicillin G (MIC > or = 0.12 microgram/ml). There was no difference in the frequency of drug-resistant pneumococci in the two groups. The use of mechanical ventilation was more frequent in the patients with positive blood culture than in the patients with negative blood culture (27.3% vs 3.8%). Moreover, mortality was higher (27.3% vs 7.7%) and the duration of hospitalization was longer in the bacteremic group. However, from a univariate analytical perspective, these differences were not significant. We concluded that blood culture can be a highly valuable diagnostic aid and useful for the prognostic evaluation of patients with community-acquired pneumonia requiring hospitalization.
Adult↗
[Mortality and prognostic factors in patients with community-acquired pneumonia: an analysis of 231 cases].
We prospectively analyzed the mortality and prognostic factors in 231 patients with community-acquired pneumonia. The patients were enrolled between May 1996 and April 1998. The average patient age was 67.6 +/- 17.5 years, and 68% were male. The mean hospital length of stay was 21.9 +/- 21.7 days. The mortality was 6.5% at the 30th day, 13.9% at hospital discharge, and 19.9% at 1 year later. Stepwise logistic regression analysis showed that liver cirrhosis, diastolic hypotension (< 60 mmHg), hypoxemia (< 50 Torr) were significantly correlated with death at the 30th day, and that alcoholism, malignancy, diastolic hypotension, hypoxemia, hypoalbuminemia (< 3.0 g/dl), and increased creatinine (> 1.2 mg/dl) were significantly correlated with discharge mortality. Furthermore, the prognostic factors at 1 year later were the same as those at hospital discharge, with the exception of alcoholism, which was replaced by ischemic heart disease in the 1-year mortality. We conclude that liver cirrhosis, diastolic hypotension, and hypoxemia are very important prognostic factors during the acute stage of pneumonia, and that alcoholism, malignancy, hypoalbuminemia and renal complications are significantly correlated with hospital death and 1-year mortality.
Adolescent↗
Ruptured sinus valsalva with infectious endocarditis: a technique of defect closure with an autologous-xenologous pericardial sandwich patch.
We report a case of ventricular septal defect with acquired rupture of sinus Valsalva induced by infectious endocarditis. After irrigati on of all infectious tissues, the defect was closed twice using two different patches. One was an autologous pericardial patch from the right ventricle and the other was a composite patch made of an autologous pericardium and axenologous pericardium from the left ventricle. As a result, the xenologous pericardium was sandwiched between autologous pericardiums. We thought that this "sandwiched patch" would compensate for the shortcomings of each type of pericardium and resist left ventricular pressure and infection. Despite the development of antibiotic therapy, infectious endocardit is (IE) is still one of the most difficult disease to cure. In the case of a rupture of sinus Valsalva, because of the rapid spread of infection into any of the cardiac chambers, surgical intervention is necessary. In this report, we describe a case treated successfully.
Adult↗
Mutations in the leucine zipper motif and sterol-sensing domain inactivate the Niemann-Pick C1 glycoprotein.
Niemann-Pick type C (NPC) disease, characterized by accumulation of low density lipoprotein-derived free cholesterol in lysosomes, is caused by mutations in the NPC1 gene. We examined the ability of wild-type NPC1 and NPC1 mutants to correct the NPC sterol trafficking defect and their subcellular localization in CT60 cells. Cells transfected with wild-type NPC1 expressed 170- and 190-kDa proteins. Tunicamycin treatment resulted in a 140-kDa protein, the deduced size of NPC1, suggesting that NPC1 is N-glycosylated. Mutation of all four asparagines in potential N-terminal N-glycosylation sites to glutamines resulted in a 20-kDa reduction of the expressed protein. Proteins with a single N-glycosylation site mutation localized to late endosome/lysosomal compartments, as did wild-type NPC1, and each corrected the cholesterol trafficking defect. However, mutation of all four potential N-glycosylation sites reduced ability to correct the NPC phenotype commensurate with reduced expression of the protein. Mutations in the putative sterol-sensing domain resulted in inactive proteins targeted to lysosomal membranes encircling cholesterol-laden cores. N-terminal leucine zipper motif mutants could not correct the NPC defect, although they accumulated in lysosomal membranes. We conclude that NPC1 is a glycoprotein that must have an intact sterol-sensing domain and leucine zipper motif for cholesterol-mobilizing activity.
Amino Acid Substitution↗
Effect of lomerizine, a new Ca(2+)channel blocker, on the microcirculation in the optic nerve head in conscious rabbits: a study using a laser speckle technique.
We examined the effect of a new Ca(2+)channel blocker, lomerizine (KB-2796), and compared it with that of nilvadipine, on the optic nerve head circulation in conscious rabbits using a laser speckle method. Lomerizine (0.03, 0.1 and 0.3 mg kg(-1), i.v.) and nilvadipine (0.003, 0.01 and 0.03 mg kg(-1), i.v.) each significantly increased the normalized blur values (an index of tissue blood velocity) in the optic nerve head in a dose-dependent manner. Neither lomerizine nor nilvadipine caused a significant change in intraocular pressure. Lomerizine produced no significant change in mean arterial blood pressure, although at 0.3 mg kg(-1), i. v. heart rate was significantly increased 5 min after its administration. In contrast, nilvadipine significantly decreased mean arterial blood pressure at 5 to 15 min after its administration and increased heart rate at 5-30 min after its administration (both effects being dose-dependent). Our results indicate that while lomerizine, like nilvadipine, increased tissue blood velocity in the optic nerve head, it did not affect mean arterial blood pressure at the doses that affected optic nerve head circulation, unlike nilvadipine. The plasma concentration of lomerizine (free base) obtained from rabbits at 15 min after administration at a dose of 0. 03 mg kg(-1)i.v., when time there was a significant increase in tissue blood velocity in the optic nerve head, was very similar to plasma concentration with healthy subjects receiving lomerizine at 10 mg (5 mgx2) day(-1), p.o., a dose that achieved a significant reduction in the frequency and mean duration of headache attacks but did not affect the blood pressure or heart rate. These results suggest that lomerizine may be clinically effective in favorably affecting the optic nerve circulation without producing systemic effects such as the hypotension seen during treatment with other Ca(2+)channel blockers.
Animals↗
Pro-inflammatory cytokines induce expression of matrix-metabolizing enzymes in human cervical smooth muscle cells.
The process of cervical ripening has been likened to an inflammatory reaction associated with the catabolism of cervical extracellular matrix by enzymes released from infiltrating leukocytes. We hypothesized that smooth muscle cells in the cervix also participate in this process and that pro-inflammatory cytokines act on cervical smooth muscle cells (CSMC) to provoke the expression of matrix-degrading enzymes. We treated primary cultures of human CSMC with tumor necrosis factor-alpha (TNF-alpha) and examined expression of the elastinolytic enzyme, cathepsin S, the collagen metabolizing matrix metalloproteinases (MMP)-1, -3, -9, and the tissue inhibitor of metalloproteinase (TIMP)-1 and -2. A time course analysis revealed that 10 ng/ml of TNF-alpha induced cathepsin S, MMP-1, -3, and -9 mRNA expression with the maximal response observed after 24-48 hours. TNF-alpha induced cathepsin S, MMP-1, -3, and -9 mRNA expression in a dose-dependent manner: the maximal effect was observed at a concentration of 10 ng/ml, with appreciable increases observed at concentrations of 0.1 to 1.0 ng/ml. In contrast, TIMP-1 and -2 mRNAs were not significantly increased by TNF-alpha treatment. Interleukin-1beta produced a pattern of gene expression in the CSMC similar to that observed following TNF-alpha treatment. Western blot analysis and zymography confirmed the induction of proMMP-1, -3, and -9 in response to TNF-alpha, but MMP-2 immunoreactivity and zymographic activity were unaffected. TNF-alpha increased secretion of procathepsin S, but did not affect TIMP-1 and reduced TIMP-2 production. We conclude that CSMC are targets of pro-inflammatory cytokines, which induce a repertoire of enzymes capable of degrading the cervical extracellular matrix. The induction of these enzymes may facilitate the normal ripening of the cervix at term and participate in the premature cervical changes associated with preterm labor.
Blotting, Western↗
Endovascular stent-grafting via the aortic arch for chronic aortic dissection combined with coronary artery bypass grafting.
Explore the source record for details and available documents.
Aged↗
Flow balance between the left and right cardiac output of an eccentric roller type total artificial heart.
We have made an eccentric roller type total artificial heart (ERTAH). The ERTAH is a positive-displacement device comparable to a DeBakey roller pump. Its left and right outputs are determined by the size of its blood chambers, and the ratio of its left and right output is almost constant. We focused on an interatrial shunt to achieve left-right balance. We have conducted numerical simulation, a mock test, and an acute animal experiment to analyze left-right heart balance during ERTAH operation. Numerical simulation was performed under conditions in which the flow of the left artificial heart was fixed at 6 L/min, the flow of the right artificial heart was varied from 4.8 to 6 L/min, and the interatrial resistance was also varied. The relationship between the interatrial shunt flow rate and the output of the left and right artificial hearts was balanced when the flow of the right artificial heart was at 5.45 L/min. In a mock test, 2 DeBakey roller pumps were connected to the left and right sides of a Donovan mock circulatory system, and an interatrial shunt was created between the inlet ports of the left and right roller pumps. The interatrial resistance of the mock system was varied from 7.7, to 4.3, and to 2.9 mm Hg x min/L when the inner diameter of the interatrial shunt was 6, 8, and 10 mm, respectively. As in the mock test, 2 roller pumps were used to bypass the right and left hearts of a goat weighing 60 kg. The flow rate of the left heart was almost constant (4.7 L/min). The flow of the right heart was approximately 4.1 L/min when the interatrial shunt flow rate was zero. A leading consideration was that the left to left shunt through the bronchial arteries in this goat was approximately 0.6 L/min. In developing the ERTAH, we considered that creating an interatrial shunt between the inlet ports of the ERTAH as well as making a difference between the chamber volumes might be effective in balancing the left-right sides of the artificial heart.
Animals↗
Possibility of focal activation around the left upper pulmonary vein during chronic atrial fibrillation with mitral valve disease.
Focal regular activations were sometimes observed during chronic atrial fibrillation (AF) associated with mitral valve disease. We present a 58 year-old male diagnosed with mitral valvular stenosis and regurgitation with chronic atrial fibrillation. Intraoperative mapping of both atria was performed during mitral valvular surgery. Regular and repetitive activations around the left superior pulmonary vein were observed, in contrast to irregular and chaotic activations of the right atrium. This regular activation was supposed to be the focus of chronic AF. Surgical ablation of the posterior left atrium was successfully performed and eliminated the chronic AF, concomitant with mitral valve replacement.
Atrial Fibrillation↗
[Comparative study of clinical features of typical and atypical pneumonias].
We prospectively analyzed the clinical and laboratory features of 74 patients with community-acquired pneumonia who required hospitalization between May 1996 and October 1997. Typical pathogens were identified in 47, and atypical pathogens in 27. The average age was higher in patients affected by typical pathogens (73.9 years), than in patients affected by atypical pathogens (50.9 years). Univariable analysis found that atypical pneumonias were more frequent in healthy patients than typical pneumonias. Moreover, the presence of relatives with symptoms of airway infection, headache, and earache was more common among the patients with atypical pneumonias, while leukocytosis and elevated C-reactive protein levels were more frequent among patients with typical pneumonias. Typical pathogens accounted for up to 79.6% of the cases of pneumonia with in older patients (aged 60 years or more), whereas atypical pathogens accounted for up to 80% of the cases of pneumonia in younger patients (aged under 60 years). This difference was statistically significant. Of all 74 patients, 39 (52.7%) were afflicted by severe community-acquired pneumonia, as categorized by American Thoracic Society guidelines. The most common pathogen among these patients was Streptococcus pneumoniae. Legionella was one of the top four. Selection of the initial antimicrobial treatment is an important clinical decision that should be made on the basis of clinical features at admission, age, and severity of the patient's illness.
Adolescent↗
Endovascular stent-grafting via the aortic arch for distal arch aneurysm: An alternative of endovascular stent-grafting in a complicated case.
A 67-year-old man with severe discomfort was diagnosed with a rupture of the thoraco-abdominal aneurysm, a distal arch aneurysm and triple coronary artery disease. After emergency surgery for a thoracoabdominal aneurysm, a scheduled surgery for coronary artery bypass grafting and endoluminal stent-grafting for the distal arch aneurysm was performed simultaneously. A stent-graft was introduced into the descending aorta via a small incision on the arch aorta. Open endovascular stent-grafting via the arch aorta is an alternative for repairing a distal arch aneurysm with coronary artery bypass grafting.
Aged↗