[A case of portal hypertension due to arteriovenous fistula of the superior mesenteric vessels].
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Biomedical subjects
Publications and source records attributed to K Murase.
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The present study was designed to investigate a possibility of substitution of the venous blood radioactivity counts sampled 26 min post injection for the octanol-extracted arterial blood radioactivity counts obtained at 5 min after the injection of N-isopropyl-p-[123I]iodoamphetamine (123I-IMP). Furthermore, we investigated whether the integral of input function can be estimated from the venous blood radioactivity counts sampled 26 min post injection and the whole-brain time-activity curves early after 123I-IMP injection. There was a good correlation between the arterial blood radioactivity counts sampled 5 min post injection (y) and those obtained at 26 min (r = 0.902; n = 91; y = 2.348x - 867.063). There was also a good correlation between the arterial (x) and venous blood radioactivity counts (y) sampled 26 min post injection (r = 0.954; n = 14; y = 0.761x + 924.336). The venous blood radioactivity counts sampled at 26 min (x) correlated well with the octanol-extracted arterial blood radioactivity counts sampled at 5 min (y) (r = 0.964; n = 32; y = 0.173x - 21.598). There was a good correlation between the integrals of input function obtained from the regression equation obtained above and the whole-brain time-activity curves acquired during 7 min post injection (y) and those obtained by 5-min continuous arterial blood sampling (x) (r = 0.965; n = 41; y = 0.957x + 2665.208). These results indicate that this noninvasive and simple method can estimate the integral of input function for quantification of cerebral blood flow using 123I-IMP.
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Neuronal excitation evoked after dorsal-root (DR) stimulation in the spinal dorsal horn (DH) of rats was visualized with a high-resolution optical-imaging method, and the propagation mechanism was studied. Transverse slices of the spinal cord were obtained from 2-4 week-old rats and stained with the voltage-sensitive dye RH-482. Single-pulse stimulation to the primary-afferent A fibers in the DR attached to the slice evoked a weak, brief (<10 ms) excitatory optical response in the laminae I and III-V. When the stimulus intensity and duration were increased to activate both A and C fibers, an additional, much greater, and longer-lasting (>100 ms) excitatory response was generated in the laminae I-III, most intensely in the lamina II. A treatment with excitatory amino acid (EAA) antagonists, dl-2-amino-5-phosphonovaleric acid and 6-cyano-7-nitroquinoxaline-2, 3-dione, significantly reduced the amplitude and duration of the response in the lamina II. The optical response in the antagonists-containing solution was quite similar to that recorded in a Ca2+-free solution that blocked afferent synaptic transmission. The late component (>10 ms) was, however, slightly greater than that in the Ca2+-free solution. Treatment with the ATP-receptor antagonist, suramin, had a minimal effect on the response in the presence of EAA antagonists. These results suggested that the propagation of the DR-stimulus-elicited excitation was contributed largely by EAA receptors, but also by other receptors to a much lesser extent.
Tetanic stimulation of high-threshold primary afferent fibers in the dorsal root was found to elicit intrinsic optical signals (IOSs) in transverse slices of 11- to 20-day-old rat spinal cords. The IOS, lasting for 30 s or longer, was most prominent in the lamina II of the dorsal horn. Treatment with a Na+-K+-2Cl- co-transport blocker, furosemide, abolished the IOS, suggesting that the origin of the IOS is the cellular swelling due to an activity-dependent rise in extracellular K+. Substance P antagonist spantide, glutamate antagonists 2-amino-5-phosphonovaleric acid and 6-cyano-7-nitroquinoxaline-2,3-dione, and the mu-opioid agonist [d-Ala2,N-Me-Phe4,Gly5-ol]-enkephalin suppressed IOSs. Thus, IOSs represent at least in part the slow excitatory response that is known to be generated in dorsal horn neurons after tetanic activation of unmyelinated afferent fibers.
BACKGROUND: Although coronary artery lesions are critical complications of Kawasaki disease, their long-term outcome is still unclear. It is sometimes difficult to monitor progressive changes from aneurysms to stenotic lesions because coronary angiography (CAG) cannot be repeated very often, especially in infants. Our prospective study was designed to evaluate the prognostic value of dipyridamole-thallium single-photon-emission CT (SPECT) in the long-term follow-up of patients with Kawasaki disease. METHODS AND RESULTS: Of 459 consecutive patients with Kawasaki disease, coronary aneurysms were detected in 90 cases by echocardiography during the acute stage. After paired studies of selective CAG and SPECT were conducted, all patients were followed up and monitored for the occurrence of any cardiac events for > or =8 years. During the follow-up interval, there were 15 cardiac events (1 death, 5 infarctions, 2 coronary artery bypass graft operations, and 7 occurrences of unstable angina). Of patients who had some event, thallium redistribution was found on SPECT in 14 (93%, P<0.001). Of the various clinical and scintigraphic image variables, the presence of thallium redistribution was the best multivariate independent predictor of a late cardiac event (chi2=57.8, P<0.0001). The number of aneurysms detected on CAG added minimal statistical improvement to the model (chi2=1.9, P=0.0009). CONCLUSIONS: Dipyridamole-thallium SPECT is safely performed and is useful and important for risk stratification in the long-term follow-up of patients with Kawasaki disease.
Individuals with a predominance of small low-density lipoprotein (LDL) particles appear to be at increased risk for coronary artery disease. The purpose of this study was to determine whether the LDL particle size was modulated in response to a 75-g oral glucose load. Overall, there were no significant changes in the LDL particle size after glucose load. However, the difference in LDL particle size (deltaLDL size) between the fasting and 2-h post-load states was inversely correlated with the fasting LDL particle size. Also, deltaLDL size was positively correlated with BMI and the post-load glucose levels. Forward stepwise regression analysis revealed three parameters as independent factors capable of modulating LDL particle size: BMI, fasting insulin, and post-load glucose levels. After adjustment for BMI and glucose levels, the levels of fasting and 2-h post-load insulin remain independent determinants of deltaLDL size. These results suggest that plasma insulin levels during glucose load modulate LDL particle size.
This study was performed to evaluate the usefulness of spectral analysis (SA) applied to dynamic single photon emission computed tomography studies with N-isopropyl-p-(123I)iodoamphetamine (IMP). The unidirectional clearance of IMP from the blood to the brain tissue (K1) obtained by SA (y (ml/g/min)) agreed well with that obtained from a two-compartment model using the nonlinear least-squares (NLSQ) method (x (ml/g/min)) (y = 0.994x + 0.003, r = 0.999, standard error of the estimate (SEE) = 0.005 ml/g/min). The rate constant for back diffusion of IMP from the brain tissue to the blood (k2) obtained by SA (y (min(-1))) also agreed well with that obtained by the NLSQ method (x (min(-1))) (y = 0.985x + 0.000, r = 0.948, SEE = 0.001 min(-1)). The brain vascular volume (V0) obtained by SA (y (ml/g)) correlated well with that obtained by the NLSQ method (x (ml/g)) (y = 1.138x + 0.000, r = 0.867, SEE = 0.012 ml/g). These results indicate that SA is applicable and useful for quantification of the kinetic parameters of IMP in the human brain, and can be an alternative approach to compartment analysis.
In order to evaluate the relationship between tumour necrosis factor-alpha (TNF-alpha) level in muscle and metabolic abnormalities in obesity and diabetes mellitus, pioglitazone, a novel insulin-sensitizing agent, was administered to Wistar fatty rats and time-dependent changes in muscle TNF-alpha content and plasma indicators of diabetes and obesity were measured. Wistar fatty rats were hyperglycaemic, hyperlipidaemic and hyperinsulinaemic, and their plasma and muscle TNF-alpha levels were two or more times higher than those in normal lean rats at 16 weeks of age. When pioglitazone was administered to fatty rats at a dose of 3 mg kg(-1) day(-1), the plasma triglyceride level and TNF-alpha levels in plasma and muscle decreased time-dependently, and reached the levels of lean rats within 4 days. Plasma glucose and insulin levels also decreased time-dependently with pioglitazone, but on day 4, these levels were still much higher than the levels in lean rats. Neutral sphingomyelinase (SMase) activity in muscle of fatty rats was two times higher than that in lean rats and was lowered to the level of that in lean rats by 4 days' pioglitazone administration. The plasma leptin level in fatty rats was 8 times higher than that in lean rats, but pioglitazone did not affect the level during the 4-day administration period. These results suggest that an increase in TNF-alpha production and subsequent activation of SMase in muscle leads to metabolic abnormalities in obesity and diabetes and that antidiabetic activity of pioglitazone is deeply associated with the suppression of TNF-alpha production.
Apart from insulinomas, pancreatic tumors are rarely complicated by hypoglycemia and some may produce insulin-like growth factor II (IGF-II). To our knowledge, IGF-II-producing pancreatic tumors associated with hypoglycemia have not been reported previously. We describe what we believe to be the first case of "big" IGF-II-producing pancreatic acinar cell carcinoma. A 68-year-old man presented with a history of recurrent hypoglycemia. Abdominal computed tomography scan and magnetic resonance imaging showed a mass, approximately 5 cm in diameter, in the tail of the pancreas and two low-density areas in the liver. Low serum glucose was associated with low insulin levels and high levels of hormones (i.e., glucagon and IGF-II) that are functionally opposite to insulin. Although serum IGF-II level was within the normal range, most IGF-II was of the high molecular weight form, as determined by Western immunoblot analysis. Based on these findings, a diagnosis of hypoglycemia induced by IGF-II-producing pancreatic tumor was made. Surgery was not possible because of the patient's poor general condition. The patient ultimately died as a result of malignant cachexia. At autopsy, a yellowish-white tumor was found in the tail of the pancreas, and a histopathologic diagnosis of acinar cell carcinoma was made. Immunohistologically, the tumor cells contained IGF-II in an irregular staining pattern, suggesting that the hypoglycemia was caused by a pancreatic tumor producing "big" IGF-II.
Ceramides and 1,2-diacylglycerol have been demonstrated in intracellular signaling pathways. A method of simultaneous mass determination of ceramides and 1,2-diacylglycerol in tissues was developed using the latroscan which combines thin layer chromatography and flame ionization detection (TLC/FID) techniques. Because of relatively low amounts of these components in tissues, the fraction of nonpolar lipids, which included ceramides and glycerides, was eluted with chloroform/acetone mixture (3:1, vol/vol) through a silicic acid column to eliminate the polar phospholipids. Development of Chromarods was carried out using three solvent systems in a four-step development technique. The relationship of the peak area ratio to weight ratio compared with cholesteryl acetate added as an internal standard was linear. The amount of ceramides increased with incubation of rat heart homogenate and human erythrocyte membranes in the presence of sphingomyelinase (E.C. 3.1.4.12). The latroscan TLC/FID system provided a quick and reliable assessment of ceramides and 1,2-diacylglycerol.
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The aim of this study was to develop a simplified method for quantitative analysis of liver scintigraphy with 99Tc(m)-diethylenetriamine pentaacetic acid-galactosyl-human serum albumin (GSA) using spectral analysis. Dynamic liver scintigraphy using GSA was performed in three normal volunteers and 19 patients with chronic liver disease. Dynamic data were obtained with a gamma camera for 30 min after the injection of approximately 185 MBq GSA. The rate constant for the liver uptake of GSA from the blood (Ku, min(-1)), total excretion rate (Ke, min(-1)) and non-specific volume of distribution (Vh) were obtained by spectral analysis. Vh was defined as the volume in the liver region of interest (ROI) occupied by GSA which was in equilibrium with that in the blood. It should be noted that Vh had no units, since the counts in both the liver and heart ROIs were normalized by scan length to obtain counts pixel(-1) min(-). For comparison, compartmental analysis was also performed. A receptor index (LHL15) was calculated by dividing the radioactivity of the liver ROI by that of the liver plus heart ROIs 15 min post-injection. The Ku values obtained by spectral analysis (y) agreed well with those obtained by compartmental analysis (x) (y = 0.953x - 0.013, r = 0.992, S.E.E. = 0.016 min(-1)). The Ke and Vh values obtained by spectral analysis (y) correlated significantly with those obtained by compartmental analysis (x) (y = 1.149x - 0.016, r = 0.826, S.E.E. = 0.017 min(-1) for Ke; y = 1.191x + 0.044, r = 0.975, S.E.E. = 0.021 for Vh). The Ku values obtained by spectral analysis decreased as the severity of liver disease progressed, and were non-linearly related to the LHL15 values, suggesting that Ku is more sensitive to liver damage than LHL15, especially in the early stages of liver damage. These results suggest that spectral analysis applied to dynamic liver scintigraphy with GSA provides a simple, non-invasive and useful tool for the quantitative evaluation of liver function.
We have developed a new method to replace the conventional method of quantitatively measuring cerebral blood flow (CBF), in which octanol-extracted radioactivity counts are measured in continuous arterial blood samples. With the new method, the whole-brain time-activity curves early after the intravenous injection of N-isopropyl-p-[123I]iodoamphetamine were first obtained by the least-squares curve-fitting method. The equation thus obtained was differentiated and the radioactivity counts were corrected by the 5-min octanol-extracted radioactivity counts of the arterial blood sample obtained at a single time point. In the present study, the value obtained by integrating the equation from 0 to 5 min, which was obtained by curve-fitting, was compared with the octanol-extracted radioactivity counts obtained by 5-min continuous arterial blood sampling in 160 patients with cerebrovascular disorders. The results showed good agreement between the values obtained by the two procedures (y = 1.049x - 1522.4; r = 0.987). Using the CBF obtained by the 5-min continuous arterial blood sampling as the standard, the errors using the present integral values of the input function were 7.1 +/- 4.9%. Measurements of the integral of the input function by the present one-point arterial blood sampling method has the potential for use in the routine measurement of CBF, because it is less invasive and more convenient than the conventional method, and it is unaffected by cardiopulmonary disease or smoking.
We describe a young Japanese woman who was diagnosed with Crohn's disease affecting the ileum, transverse colon, and rectum, as confirmed by barium studies, colonoscopy, and histopathological examination. Her father and sister also had Crohn's disease. After a 4-yr course of sulfasalazine and elemental diet therapy, she was readmitted for perianal abscess associated with the presence of pancytopenia, microhematuria with granular cast, hypocomplementemia, and high titers of autoimmune antibodies (anti-ANA and anti-dsDNA antibodies). Based on these features, a diagnosis of systemic lupus erythematosus (SLE) was made. Despite the rarity of such combination (Crohn's disease with SLE), patients with Crohn's disease who develop such clinical findings might need evaluation for SLE.
OBJECTIVE: The purpose of this study was to quantify the heterogeneous distribution of a carbon particle radioaerosol in the lungs of patients with pulmonary emphysema using single-photon emission computed tomography (SPECT) and fractal analysis. SUBJECTS AND METHODS: Ventilation SPECT was performed on 19 patients with pulmonary emphysema, seven patients with suspected pulmonary emphysema, and 14 healthy volunteers. We delineated the lungs using five cutoff levels (15%, 20%, 25%, 30%, and 35% of the maximal pixel radioactivity) and measured the total number of pixels in the areas surrounded by the contours obtained with each cutoff level. We calculated fractal dimensions from the relationship between the total number of pixels and cutoff levels transformed into logarithms. RESULTS: The fractal dimensions increased with the severity of pulmonary emphysema. The fractal dimensions for patients with pulmonary emphysema, patients with suspected pulmonary emphysema, and healthy volunteers were 2.03+/-0.61 (mean +/- SD), 0.77+/-0.09, and 0.59+/-0.06, respectively. A significant difference (p < .0005) in the fractal dimension was found when any of these three groups was compared with any other group of subjects. CONCLUSION: Three-dimensional quantitative evaluation of the emphysematous lung was possible using SPECT and fractal analysis. Our results suggest that fractal analysis can quantify the heterogeneity of the distribution of a carbon particle radioaerosol in the lung. Fractal analysis appears to be applicable for routine clinical use because it is simple and the fractal dimensions can be obtained easily without using special software.
Cerebral blood flow (CBF) has been measured using a microsphere model with octanol-extracted radioactivity counts (integral value of input function). We developed a new method estimating the integral value of input function. First, we fitted the whole brain time-activity curves early after intravenous injection of N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) by the least-squares method. Second, we differentiated this equation. Third, we calibrated it using octanol-extracted radioactivity counts of the arterial blood sampled at 5 min. Finally, we integrated it. A significant correlation was found between the integral values obtained using a new method and those obtained using the continuous arterial blood sampling data (y = 1.048x-1206, r = 0.984). The errors between the CBF values obtained using a new method and those obtained using the 5-min continuous arterial blood sampling was 6.88 +/- 4.78%. Measurement of integral values of the input function using a new method with one-point arterial blood sampling is less invasive and convenient, and is not influenced by cardiopulmonary disease or smoking. Therefore, it would be useful for the routine measurement of CBF.
We developed a new microsphere method using 123I-IMP in which arterial blood is collected at one time point early after 123I-IMP injection instead of conventional continuous arterial blood sampling, and the input count is estimated using a whole brain time-activity curve until that time point. The differential curve dCb(t)/dt of the brain time-activity curve Cb(t) early after 123I-IMP injection (when the microsphere model is established) approximates the arterial time-activity curve Ca(t) as an input function. The input count as the integral value of Ca(t) at 0-5 min was estimated using the 50 min whole brain activity Cb(5 min) and the differential value dCb(5 min/dt and the 5-min octanol-extracted count of arterial samples obtained at one time point Ca(5 min). The input counts calculated by this method were very closely correlated with measurement values obtained by continuous arterial sampling. This method is more convenient and less invasive than the continuous arterial sampling method.