Biomedical subjects

T Hirai

Publications and source records attributed to T Hirai.

At least 55 records · Page 3Linked to original sources

PubMed2001

Use of a segment of transverse colon as a gastric substitute after total gastrectomy: an audit of 18 patients.

BACKGROUND: Various types of reconstruction have been employed in attempts to improve the quality of life after total gastrectomy. The use of a jejunal pouch has been the most common approach, and preservation of the duodenal passage has been recommended in several related studies. The aim of the present study was to investigate the benefit of the use of a segment of transverse colon as a gastric substitute. METHODS: Isoperistaltic interposition with a segment of transverse colon was performed after total gastrectomy in 18 patients with gastric malignancies. To clarify the benefits and disadvantages of this technique, a comparison was made between these patients and another 17 patients who underwent jejunal interposition without a pouch. The parameters to be compared included operation time, amount of blood loss, incidence of postoperative complications, and changes in body weight. RESULTS: Postoperative complications were more frequent in the patients reconstructed with the transverse colon, despite a lower incidence of extended lymphadenectomies in this group of patients. No advantage over those treated by the jejunal interposition, in terms of postoperative body weight, was evident during 2 years of follow-up. CONCLUSION: Although it may be too early to draw definite conclusions, there seems to be little benefit in the use of the transverse colon as a gastric substitute.

Carcinoma↗

PubMed2001

Expression of Cdx1 and Cdx2 mRNAs and relevance of this expression to differentiation in human gastrointestinal mucosa--with special emphasis on participation in intestinal metaplasia of the human stomach.

BACKGROUND: The caudal-type homeobox genes, Cdx1 and Cdx2, are candidates for directing intestinal development, differentiation, and maintenance of the intestinal phenotype. The aims of this study were: (1) to assess the normal tissue expression patterns of Cdx1 and Cdx2 in the human gastrointestinal tract and (2) to ascertain levels in intestinal metaplasia (IM) of the stomach associated with gastritis. METHODS: Fresh human tissues were collected by surgical resection from 39 patients after informed consent had been received. RNAs were extracted from 11 distinct sites in the gastrointestinal mucosa (gastric body, gastric antrum, duodenum, jejunum, ileum, cecum, ascending colon, transverse colon, descending colon, sigmoid colon, and rectum), and Northern hybridization was performed for Cdr1 and Cdx2 mRNAs. In addition, RNAs were also extracted from normal gastric mucosa, and gastric mucosa with mild to severe IM, confirmed histopathologically. Reverse-transcriptase polymerase chain reaction (RT-PCR) was then carried out for Cdx1 and Cdx2. RESULTS: The expression of Cdx1 mRNA increased gradually from the duodenum to the distal colon, with no expression detected in the stomach. Compared with the distribution of Cdx1 mRNA in the mouse gastrointestinal tract, the expression of Cdr1 mRNA in the human gastrointestinal tract showed greater predominance in the jejunum and ileum. The expression of Cdx2 mRNA increased gradually from the duodenum to the proximal colon and decreased from the ascending colon to the rectum. Compared with the expression pattern of Cdx2 mRNA in the mouse gastrointestinal tract, the expression of Cdx2 mRNA in the human gastrointestinal tract showed greater predominance in the ileum. By RT-PCR, both Cdx1 and Cdx2 mRNAs were detected in the mild and severe types of IM. However, neither of these mRNAs was identified in normal gastric mucosa without IM. CONCLUSIONS: Cdr1 and Cdx2 mRNAs are widely present in the human intestinal and colonic mucosae, but not in the gastric mucosa, suggesting that their expression may contribute to the intestinal phenotype. The high levels of these mRNAs in IM mucosa associated with chronic atrophic gastritis point to an association with this phenotypic shift in the gastric mucosa.

Adult↗

PubMed2001

Association of polymorphisms in the beta-2 and beta-3 adrenoceptor genes with risk of colorectal cancer in Japanese.

BACKGROUND: The adrenergic receptor system is involved in thermogenesis and in the activation of lipid mobilization in fat cells, and polymorphisms in the beta-2 and beta-3 adrenoceptor genes (BAR2 and BAR3) have been reported to be associated with obesity and insulin resistance. To examine links between polymorphisms in these genes and the risk of colorectal cancer in Japanese, we conducted the present hospital-based case-referent study. METHODS: Mutations of the BAR2 gene at codon 27 (Gln27Glu) and of the BAR3 gene at codon 64 (Trp64Arg) were examined in 131 patients with colorectal cancer (cases) and in 239 cancer-free referents. We also collected information on environmental factors, using a questionnaire approach. Odds ratios (ORs) were estimated with an unconditional logistic model, after adjustment for potential confounding factors. RESULTS: The proportional distribution of the mutations in BAR2 and BAR3 did not differ between cases and referents. Analysis of a subgroup with a higher body mass index showed that the Trp64Arg variant increased the OR (2.63; 95% confidence interval, 1.13-6.11) for colon cancer, but not for rectal cancer, compared with the Trp64 genotype. Altered ORs for colon and rectal cancers with the Gln27Glu variant were not observed in either the subgroup with the lower body mass index or the subgroup with the higher body mass index. CONCLUSION: These findings suggest that the BAR3 polymorphism may alter the susceptibility to colon cancer risk in obese subjects. To confirm this finding, a further study with a larger number of subjects is now required.

Adult↗

PubMed2001

Comparison between EPI and HASTE for ultra-fast MR imaging of the human brain.

Our purpose was to evaluate and compare the performance of ultra-fast single-shot T2-weighted sequences: echo-planar imaging (EPI) versus half-Fourier single-shot turbo spin-echo (HASTE) and to assess the usefulness of their combined reading. Comparative experiments on a phantom as well as a prospective clinical study in 47 patients were done. Axial images acquired with the following methods were compared: (a) HASTE; (b) segmented HASTE (s-HASTE); (c) single-shot spin-echo EPI (SE-EPI); and (d) gradient-echo EPI (GREEPI). Quantitative and qualitative criteria as well as lesion detectability were analyzed against the "gold standard" fast spin-echo (FSE) sequence. For contrast and contrast-to-noise ratio (CNR) between gray and white matter, GRE-EPI was best. The visibility of small markedly hyperintense lesion was best with HASTE and s-HASTE in the clinical study. Small hyperintense lesions were detected equally well with all four sequences, although all performed significantly worse than FSE. The two HASTE variants were better than the EPIs for the extraaxial lesions. The combination of the GRE-EPI and s-HASTE was judged best, and sometimes superior to the FSE image. HASTE or EPI alone cannot substitute for FSE in the screening evaluation of the brain. However, together, EPI and HASTE could provide comparable diagnostic information to that of FSE because their combination compensates for their individual limitations.

Adolescent↗

PubMed2001

Myocardial metabolism of 123I-BMIPP during low-flow ischaemia in an experimental model: comparison with myocardial blood flow and 18F-FDG.

Risk stratification of coronary artery disease may provide a basis for selection of treatment to prevent myocardial events and to assist functional recovery. Iodine-123 (rho-iodophenyl)-3-R,S-methylpentadecanoic acid (123I-BMIPP) is a radioiodinated fatty acid analogue for single-photon emission tomographic (SPET) imaging, and several reports have demonstrated that the abnormal uptake of 123I-BMIPP is associated with wall motion abnormality and severe coronary artery stenosis. Clarification of the contribution of fatty acids to myocardial metabolism would be highly valuable in recognising this critical condition. In this study, we investigated the myocardial uptake of 123I-BMIPP under low-flow ischaemia, and compared it with the uptake of fluorine-18 fluorodeoxyglucose (18F-FDG). Using open chest dogs, the flow of the left anterior descending coronary artery was controlled using a pneumatic occluder in order to maintain a 30%-40% reduction of Doppler flow. 123I-BMIPP and 18F-FDG were injected into the left atrium after 90 min of ischaemia (protocols 1 and 3). Canine hearts were excised after 120 min of ischaemia for the measurement of radioactivity. In protocol 2, 123I-BMIPP alone was injected and hearts were excised 8 min after the injection. A time-course biopsy study was also performed at the same time (protocol 3). Wall thickening was evaluated using a wall tracker module. The uptake of 18F-FDG increased significantly in the ischaemic region (232%+/-135% vs non-ischaemic, P<0.05 in protocol 1) even on mild reduction of myocardial blood flow (MBF). The increased uptake of 18F-FDG did not correlate well with the severity of MBF. On the other hand, 123I-BMIPP uptake decreased gradually (78.9%+/-23.6%, P<0.05 in protocol 1, and 85.9%+/-24.3% in protocol 2) in the ischaemic region, specifically in the endocardium (64.0%+/-28.9%, P<0.05 in protocol 1, and 75.1%+/-28.8%, P<0.05 in protocol 2), and correlated strongly with MBF (r=0.93 in protocol 1 and r=0.97 in protocol 2) as a logarithmic function. This indicated that the abnormal uptake of 123I-BMIPP was associated not only with wall motion abnormality but also with the severity of MBF. In the biopsy study (protocol 3), the radioactivity of either 123I-BMIPP or 18F-FDG correlated well with the MBF at the time of tracer injection and was similar to post-mortem analysis. It is concluded that 18F-FDG is a valid tool for identifying ischaemic myocardium even in its earliest stages. On the other hand, 123I-BMIPP might be used to detect moderately to severely ischaemic myocardium such as hibernation, suggesting the potential value of 123I-BMIPP in the risk stratification of patients with severe coronary artery disease who require revascularisation without delay.

Animals↗

PubMed2001

Lymph node metastasis in cancer of the middle-third stomach: criteria for treatment with a pylorus-preserving gastrectomy.

A retrospective study was conducted to establish the criteria for performing a pylorus-preserving gastrectomy. This study was performed on 491 patients who had cancer of the middle-third stomach and had been curatively treated with a distal gastrectomy. The incidence of node metastasis for each lymph node station (the group of regional lymph nodes which have been anatomically defined and classified by the Japanese Classification of Gastric Carcinoma) was evaluated with reference to the depth of invasion, tumor size, and circumferential location, to show any significant correlations with an increase in tumor diameter or in the depth of tumor invasion. The benefits of resecting each station was then evaluated based on the incidence of metastasis to each station and the rate of long-term survivors among those with metastasis to each station. The benefit was substantial for the lymph nodes along the lesser curvature, along the right gastroepiploic artery, and at the base of the left gastric artery, while the advantages were almost negligible for the suprapyloric nodes and right paracardial nodes. In conclusion, carcinoma that fulfills either of the following conditions may thus be indicated to undergo a pylorus-preserving gastrectomy: (i) restricted to a depth of m or sml, (ii) a depth of sm2 or mp with a diameter of less than 2cm, (ii) a depth of sm2 or mp and located in the greater curvature.

Adult↗

PubMed2001

Effects of deep inspiration on bronchoconstriction in the rat.

It is important to understand the mechanisms by which a deep inspiration (DI) affects bronchoconstriction in rodents so that their relevance as animal models of asthma can be assessed. We investigated the effect of DI on respiratory input impedance after methacholine inhalation in four groups of rats: a control group, a group receiving DI prior to challenge, and two groups receiving different degrees of DI after challenge. We measured respiratory input impedance for 15 min following a challenge. This provided time-courses approximating the resistance of the conducting airways and the impedance of the respiratory tissues. We found no significant difference in the peak changes in airway resistance comparing the control group and any of the DI groups following challenge. However, the peak increase in tissue impedance was reduced in the group receiving the largest DI after challenge. Our results thus suggest that the DIs that we administered were neither bronchodilatory nor bronchoprotective, but that they were able to reduce the amount of airway closure occurring following bronchoconstriction.

Animals↗

PubMed2001

Fish gonadotropin and thyrotropin receptors: the evolution of glycoprotein hormone receptors in vertebrates.

We have cloned and characterized, for the first time in fish, two different gonadotropin receptors (GTHR) and a single thyrotropin receptor (TSHR) from amago salmon (Oncorhynchus rhodurus) and Nile tilapia (Oreochromis niloticus). Phylogenetic analyses and intron/exon structure suggest that the two GTHRs in fish are comparable to tetrapod follicle stimulating hormone and luteinizing hormone receptors. Temporal and spatial expression patterns, examined by Northern blot analysis and in situ hybridization, paralleled those seen in mammals and birds. Consequently, genetic and functional divergence of two GTHRs and TSHR probably occurred before the teleost and tetrapod split.

Animals↗

PubMed2001

Mechanism of the inhibitory effect of histamine on amygdaloid-kindled seizures in rats.

PURPOSE: The mechanism of the inhibitory effect of histamine on amygdaloid-kindled seizures was investigated in rats. METHODS: Under pentobarbital anesthesia, rats were fixed to a stereotaxic apparatus, and bipolar electrodes were implanted into the right amygdala. A guide cannula made of stainless steel tubing was implanted into the right lateral ventricle. Electrodes were connected to a miniature receptacle, which was embedded in the skull with dental cement. EEG was recorded with an electroencephalograph; stimulation of the amygdala was applied bipolarly every day by a constant-current stimulator and continued until a generalized convulsion was obtained. RESULTS: Intracerebroventricular (i.c.v.) injection of histamine at doses of 2-10 microg resulted in a dose-related inhibition of amygdaloid-kindled seizures. I.c.v. injection of calcium chloride at doses of 10-50 microg and A23187 at doses of 2-10 microg also caused dose-dependent inhibition of amygdaloid-kindled seizures. Calcium chloride at a dose of 10 microg, which showed no significant effect on amygdaloid-kindled seizures when used alone, significantly potentiated the effect of histamine. Similar findings were observed with A23187 at a dose of 2 microg. In addition, EGTA and EGTA/AM antagonized the inhibition of kindled seizures induced by histamine. Moreover, the inhibition of kindled seizures induced by histamine was antagonized by KN62. However, calphostin C did not antagonize the inhibitory effect of histamine. CONCLUSIONS: These results indicated that histamine-induced inhibition of amygdaloid-kindled seizures may be closely associated with a calcium calmodulin-dependent protein kinase II activation pathway.

Amygdala↗

PubMed2001

Enhanced external counterpulsation improved myocardial perfusion and coronary flow reserve in patients with chronic stable angina; evaluation by(13)N-ammonia positron emission tomography.

AIMS: The mechanism by which enhanced external counterpulsation therapy exerts its beneficial effects on chronic and symptomatic stable angina is largely unknown. To clarify the mechanism of action of enhanced external counterpulsation, we used(13)N-ammonia positron emission tomography to evaluate myocardial perfusion. METHODS AND RESULTS: This was not a randomized controlled study. Eleven patients (eight male, age: 61.6+/-9.7) with angina pectoris underwent enhanced external counterpulsation therapy for 35 1 h sessions. They underwent a treadmill exercise test and(13)N-ammonia positron emission tomography, both at rest and with dipyridamole, before and after enhanced external counterpulsation therapy. Neurohumoral factors and nitric oxide were also evaluated. Myocardial perfusion increased at rest after therapy (0.69+/-0.27 to 0.85+/-0.47 ml x min(-1) x g(-1), P<0.05). In ischaemic regions, particularly the anterior region, myocardial perfusion at rest and with dipyridamole and coronary flow reserve improved significantly after therapy (at rest: 0.71+/-0.26 to 0.86+/-0.31;P<0.05, with dipyridamole: 1.26+/-0.65 to 1.84+/-0.94;P<0.02, coronary flow reserve: 1.75+/-0.24 to 2.08+/-0.28;P<0.04). Exercise time was prolonged and the time to 1-mm ST depression improved markedly (P<0.01). After therapy, nitric oxide levels increased (P<0.02) and neurohumoral factors decreased. CONCLUSIONS: Enhanced external counterpulsation therapy improved myocardial perfusion at rest and with dipyridamole and was associated with an increased exercise tolerance with(13)N-ammonia positron emission tomography and increased nitric oxide levels. These results suggest that one of the enhanced external counterpulsation mechanisms is development and recruitment of collateral vessels.

Adult↗

PubMed2001

Ossification of the posterior longitudinal ligament and ligamentum flavum: imaging features.

Ossifications of the posterior longitudinal ligament and ligamentum flavum are both special subcategories of degenerative diseases responsible for compression of the spinal cord. Ossification of the ligaments is well demonstrated by plain radiography and computed tomography. Magnetic resonance imaging noninvasively provides useful information about the degree and extent of spinal cord compression as well as the character of the ossification. T2-weighted sequences are most effective to evaluate both spinal cord compression due to the ossification and abnormal signal intensity of the spinal cord.

Adult↗

PubMed2001

Potential use of beards for single-follicle micrografts: convenient follicle-harvesting technique using an injection needle.

The authors developed a convenient hair-harvesting procedure using a disposable 18-gauge injection needle, which is common in every clinical scene. The needle was used as a skin puncher to harvest single follicles. The harvested micrografts were transplanted without trimming any of the adjacent tissue around the follicle. Clinical applications for the reconstruction of eyebrows in cases of anhydrotic ectodermal dysplasia and facial scars are demonstrated. Each patient showed a favorable result, and there was no scar formation at the donor site. This procedure makes hair harvesting smooth, speedy, and less traumatic. Beards as well as occipital hairs can be used as donors for single-follicle micrografts with this method in male patients.

Adult↗

PubMed2001

Effects of nitric oxide synthase inhibition on vascular conductance during high speed treadmill exercise in rats.

To determine the functional role of nitric oxide (NO) in regulating vascular conductance during high intensity dynamic exercise in skeletal muscles composed of all major fibre types, female Wistar rats (277 +/- 4 g; n = 7) were run on a motor-driven treadmill at a speed and gradient (60 m min(-1), 10 % gradient) established to yield maximal oxygen uptake (V(O2,max)). Vascular conductance (ml min(-1) (100 g)(-1) mmHg(-1)), defined as blood flow normalised to mean arterial pressure (MAP), was determined using radiolabelled microspheres during exercise before and after NO synthase (NOS) inhibition with N (G)-nitro-L-arginine methyl ester (L-NAME; 10 mg kg(-1), I.A.). The administration of L-NAME increased MAP from pre-L-NAME baseline values, demonstrating that NOS activity is reduced. The administration of L-NAME also reduced vascular conductance in 20 of the 28 individual hindlimb muscles or muscle parts examined during high speed treadmill exercise. These reductions in vascular conductance correlated linearly with the estimated sum of the percentage of slow twitch oxidative (SO) and fast twitch oxidative glycolytic (FOG) types of fibres in each muscle (Deltaconductance = -0.0082(%SO + %FOG) - 0.0105; r = 0.66; P < 0.001). However, if the reduction in vascular conductance found in the individual hindquarter muscles or muscle parts was expressed as a percentage decrease from the pre-L-NAME value (%Delta = (pre-L-NAME conductance - post-L-NAME conductance)/ pre-L-NAME conductance x 100), then the reduction in vascular conductance was similar in all muscles examined (average %Delta = -23 +/- 2 %). These results suggest that NO contributes substantially to the regulation of vascular conductance within and among muscles of the rat hindquarter during high intensity exercise. When expressed in absolute terms, the results suggest that the contribution of NO to the regulation of vascular conductance during high intensity exercise is greater in muscles that possess a high oxidative capacity. In contrast, if results are expressed in relative terms, then the contribution of NO to the regulation of vascular conductance during high intensity exercise is similar across the different locomotor muscles located in the rat hindlimb and independent of the fibre type composition.

Animals↗

PubMed2001

Maximum stenosis of extracranial internal carotid artery: effect of luminal morphology on stenosis measurement by using CT angiography and conventional DSA.

PURPOSE: To assess the luminal morphology of the extracranial internal carotid artery at three-dimensional (3D) computed tomographic (CT) angiography and how this factor affects measurement of maximum carotid arterial stenoses at conventional intraarterial digital subtraction angiography (DSA). MATERIALS AND METHODS: Prospectively, conventional intraarterial DSA and 3D CT angiography were performed in 42 carotid arteries in 21 patients with suspected carotid artery disease. The longest axis length-perpendicular axis length (L/P) ratios of the arterial lumen on the cross-sectional images at the most stenotic area and distal nonstenotic area were analyzed by acquiring multiplanar reconstruction (MPR) images at 3D CT angiography. The maximum stenosis was measured at each modality with North American Symptomatic Carotid Endarterectomy Trial criteria. RESULTS: The L/P ratios in the most stenotic areas ranged from 1.0 to 3.2 (mean, 1.5 +/- 0.5 [SD]). The mean difference in maximum percentage of stenosis between the two modalities for L/P ratios of 2.0 or greater was significantly greater than that for L/P ratios of less than 1.5 (P < .05). Three carotid arteries with 70%-99% stenosis, with grades determined only with 3D CT angiography, had L/P ratios of 2.0 or greater. CONCLUSION: On MPR images at 3D CT angiography, the lumen of extracranial internal carotid artery stenosis showed a wide range of shapes. When a carotid artery has a high L/P ratio, the luminal morphology of the carotid artery stenosis may affect the assessment of maximum stenosis of the internal carotid artery at conventional DSA.

Aged↗

PubMed2001

Preoperative evaluation of intracranial aneurysms: usefulness of intraarterial 3D CT angiography and conventional angiography with a combined unit--initial experience.

PURPOSE: To assess the usefulness of intraarterial computed tomographic (CT) angiography in conjunction with digital subtraction angiography (DSA) by using a combined CT and angiographic unit in the preoperative evaluation of intracranial aneurysms. MATERIALS AND METHODS: Prospectively, 22 patients with or without subarachnoid hemorrhage underwent CT angiography in conjunction with DSA. Two radiologists independently evaluated DSA and CT angiographic images. Referring neurosurgeons were questioned as to how the additional information provided by CT angiography changed patient treatment. RESULTS: Intraarterial CT angiography was superior to DSA for use in aneurysm detection in three (12%) of 26 aneurysms and for delineation of aneurysm shape, neck, and location in more than half. In 14 (64%) of 22 patients, CT angiography demonstrated 18 additional findings: a very small aneurysm (n = 2), aneurysm shape and neck (n = 6), relationship of the aneurysm to adjacent arteries or bone structure (n = 8), and branches deriving from the aneurysm (n = 2). In four (27%) of 15 patients who underwent surgery or embolization, additional information obtained at CT angiography affected the treatment. CT angiography failed to clearly demonstrate an aneurysm adjacent to bone structures and small perforators, which were derived from the parent artery. CONCLUSION: Intraarterial CT angiography is useful for preoperative evaluation of intracranial aneurysms as a supplement to DSA.

Adult↗

PubMed2001

Endothelial nitric oxide synthase intron 4 polymorphism influences the progression of renal disease.

BACKGROUND/AIM: Nitric oxide is a potent regulator of intrarenal hemodynamics and may influence the renal function. We investigated whether polymorphism of intron 4 of the endothelial constitutive nitric oxide synthase (ecNOS) gene is related to the progression of chronic renal failure. METHODS: Polymorphism of ecNOS intron 4 was studied in 1,005 hemodialysis patients (710 with nondiabetic nephropathy and 295 with diabetic nephropathy) and was compared with the findings in 189 healthy subjects. ecNOS genotypes were determined by the polymerase chain reaction, followed by agarose gel electrophoresis. RESULTS: The frequencies of ecNOS4a/a, ecNOS4a/b, and ecNOS4b/b genotypes were, respectively, 0% (0/189), 13.8% (26/189), and 86.2% (163/189) in the control group; 1.7% (12/710), 22.1% (157/710), and 76.2% (541/710) in the nondiabetic nephropathy group, and 1.0% (3/295), 22.7% (67/295), and 76.3% (225/295) in the diabetic nephropathy group. The frequency of ecNOS4a (ecNOSa/a and ecNOSa/b) was significantly higher in both the nondiabetic group and in the diabetic group than in the controls (p = 0.0025 and p = 0.0438, respectively). CONCLUSION: There was a significantly higher frequency of the a allele of intron 4 in both nondiabetic and diabetic hemodialysis patients, so the polymorphism of intron 4 of the ecNOS gene may have a wide influence on the progression of renal disease.

Adult↗

PubMed2001

Relation of fibrillatory wave amplitude with hemostatic abnormality and left atrial appendage dysfunction in patients with chronic nonrheumatic atrial fibrillation.

Large left atrium (LA) and LA appendage (LAA) dysfunction are known to relate to cardiogenic thromboembolism, so the present study investigated the relation of the atrial fibrillatory wave (F wave) amplitude to hemostatic markers and LAA function. Transthoracic and transesophageal echocardiographic studies were performed in 82 consecutive patients with chronic, nonrheumatic atrial fibrillation (AF). Patients were divided into 2 groups according to F wave amplitude in lead V1 on the 12-lead ECG: coarse AF (the greatest amplitude of F wave > or =1 mm, n=44) and fine AF (<1 mm, n=38). Plasma levels of thrombin-antithrombin III complex, D-dimer, platelet factor 4 and beta-thromboglobulin were determined. Compared with patients with coarse AF, those with fine AF had lower LAA peak flow velocity (p<0.05) and higher prevalence of embolic cerebral infarction (50% vs 27%, p<0.05). Platelet activity did not differ between the 2 groups; however, plasma levels of thrombin-antithrombin III complex and D-dimer were significantly higher in patients with fine AF than in those with coarse AF (p<0.05). Multiple logistic regression analysis showed that fine AF was independently associated with cerebral embolism. Therefore, the presence of fine F wave in V1 would be a useful marker of LAA dysfunction and hypercoagulability, and indicate a risk for cerebral embolism in patients with chronic, nonrheumatic AF.

Aged↗

PubMed2001

Effects of exercise training on myocardial fatty acid metabolism in rats with depressed cardiac function induced by transient ischemia.

The effects of exercise training on metabolic and functional recovery after myocardial transient ischemia were investigated in a rat model. Male Wistar Kyoto rats were subjected either to a 30-min left coronary artery occlusion followed by reperfusion or to a sham operation. At 4 weeks after operation, the rats were randomly assigned either to sedentary conditions or to exercise training for 6 weeks. In the ischemic rats, pinhole SPECT (single photon emission computed tomography) imaging with thallium-201 (201Tl) and 123I-(rho-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) showed a reduction of both myocardial perfusion and fatty acid metabolism in the risk zone of the left ventricle (LV). The LV was dilated and the ejection fraction was decreased after ischemic injury. The severity score showed a significant decrease on both 201Tl and BMIPP (201Tl, from 19.9+/-2.7 to 17.0+/-2.2, p<0.05; BMIPP, from 21.5+/-2.4 to 18.6+/-1.9, p<0.05) after exercise training in the ischemic trained rats, but did not change significantly in their sedentary counterparts. Plasma levels of free fatty acids normalized in the ischemic trained rats, but elevated in the ischemic sedentary rats (0.53+/-0.05 vs 0.73+/-0.06 mmol/L, p<0.05). Furthermore, the trained rats had a significant increase in LV stroke volume (0.25+/-0.02 vs 0.21+/-0.01 ml/beat, p<0.05) and adaptive cardiac hypertrophy. These findings demonstrate that adaptive improvements in myocardial perfusion, fatty-acid metabolism and LV function were induced by exercise training after transient ischemia.

Animals↗