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Biomedical subjects

Tatsuo Kumazaki

Publications and source records attributed to Tatsuo Kumazaki.

At least 19 recordsLinked to original sources
PubMed2006

Liver microcirculation after hepatic artery embolization with degradable starch microspheres in vivo.

AIM: To observe the dynamic changes of liver microcirculation in vivo after arterial embolization with degradable starch microspheres (DSM). METHODS: DSM were injected into the proper hepatic artery through a silastic tube inserted retrogradely in gastroduodenal artery (GDA) of SD rats. Fluorescent microscopy was used to evaluate the dynamic changes of blood flow through the terminal portal venules (TPVs), sinusoids and terminal hepatic venules (THVs). The movements of DSM debris were also recorded. Six hours after injection of DSM, percentages of THVs with completely stagnant blood flow were recorded. RESULTS: Two phases of blood flow change were recorded. In phase one: after intra-arterial injection of DSM, slow or stagnant blood flow was immediately recorded in TPVs, sinusoids and THVs. This change was reversible, and blood flow resumed completely. In phase two: after phase one, blood flow in TPVs changed again and three patterns of blood flow were recorded. Six hours after DSM injection, 36.9% +/- 9.2% of THVs were found with completely stagnant blood flow. CONCLUSION: DSM can stop the microcirculatory blood flow in some areas of liver parenchyma. Liver parenchyma supplied by arteries with larger A-P shunt is considered at a higher risk of total microcirculatory blood stagnation after injection of DSM through hepatic artery.

Animals↗
PubMed2006

Differences in null points between the left and right ventricles in contrast-enhanced inversion recovery MR imaging in patients with cardiac diseases.

Delayed contrast-enhanced inversion recovery (IR) gradient-echo MR imaging has been applied to several cardiac diseases, including myocarditis, sarcoidosis, hypertrophic cardiomyopathy, and myocardial damages induced by medical procedures. Although a preliminary study has indicated the usefulness of this imaging for the detection of right ventricular (RV) myocardial damage associated with arrhythmogenic right ventricular cardiomyopathy, the null points of the RV myocardium have not been assessed on contrast-enhanced IR MR imaging. In this study, the null points of the RV and left ventricular (LV) myocardia were evaluated using an IR fast multi-shot echo-planar imaging (Look-Locker sequence) in 26 patients with various cardiac diseases. In nine of the 26 patients, the null points of the RV myocardium were shorter than those of the LV myocardium in the Look-Locker sequence. The RV myocardial signals were significantly higher than the LV myocardial signals in delayed contrast-enhanced MR images. Thus, more attention should be paid to evaluation of the late enhancement of the RV myocardium, and delayed contrast-enhanced MR imaging with a shorter inversion time may be required in some cases.

Adult↗
PubMed2006

Minimally invasive diagnosis of persistent sciatic artery by multidetector-row computed tomographic angiography.

Persistent sciatic artery is a rare but potentially significant vascular anomaly that is associated with a high incidence of aneurysm formation and limb-threatening ischemic complications. The diagnosis of persistent sciatic artery has usually been made by conventional angiography. We report a case of occluded and patent persistent sciatic arteries in which multidetector-row computed tomographic angiography allowed a definitive diagnosis of this rare vascular condition.

Aged↗
PubMed2006

Clinical applications of ECG-gated myocardial perfusion SPECT.

Erectrocardiogram (ECG)-gated myocardial perfusion single photon emission computed tomography (SPECT) can be used to assess myocardial perfusion and left ventricular function simultaneously. Various clinical applications of gated SPECT and their usefulness have been reported. The functional variables that can be determined with gated SPECT have been limited to systolic indices. Therefore, we evaluated left ventricular diastolic function with gated SPECT using data obtained from various frames per cardiac cycle and found that date generated from 32-frames are suitable for clinical use. Serial assessment of left ventricular function was also performed during bicycle exercise and dobutamine stress by means of gated SPECT using short-time data collection. These techniques, therefore, have the potential to provide useful information for evaluating myocardial conditions, such as hibernation and residual ischemia in infarct areas. Recently, we have developed a new technique for three-dimensional registration of CT coronary angiography (CTCA) and ECG-gated myocardial perfusion SPECT. This technique of registration may assist the integration of information from gated SPECT and CTCA and may have clinical application for the diagnosis of ischemic heart disease. These various applications would contribute to the development of nuclear cardiology.

Coronary Angiography↗
PubMed2006

Evaluation of no-reflow phenomenon using 201TlCl/123I-BMIPP dual-isotope myocardial SPECT.

OBJECTIVES: We assessed the usefulness of (201)thallous chloride (TlCl)/(123)I-beta-methyl iodophenyl pentadecanoic acid (BMIPP) dual-isotope single-photon emission computed tomography (SPECT) to identify the "no-reflow phenomenon," defined as inadequate myocardial perfusion through a given segment of the coronary circulation without angiographic evidence of mechanical vessel obstruction. METHODS: (201)TlCl/(123)I-BMIPP SPECT was performed in 73 patients within approximately 1 week of initial acute myocardial infarction (AMI) after percutaneous coronary intervention (PCI). We divided the left ventricular myocardium into 17 segments on each SPECT image and scored tracer accumulation in each segment with a five-point scoring system according to the American Heart Association criteria. Total severity scores were calculated by summing the scores for all 17 segments. The mismatch ratio between myocardial perfusion and metabolism was derived from the (201)TlCl and (123)I-BMIPP total severity scores: mismatch ratio=((123)I-BMIPP total severity score -(201)TlCl total severity score)/(123)I-BMIPP total severity score. Patients were classified according to Thrombolysis in Myocardial Infarction (TIMI) flow grade as having TIMI reflow grade 0-I (TIMI 0-I reflow group; n=11), II (TIMI II reflow group; n=17) and III (TIMI III reflow group; n=45). The TIMI III reflow group was subdivided into two groups with (201)TlCl total severity scores of < or =13 (TIMI III (A) reflow group; n=36) and > or =14 (TIMI III (B) reflow group; n=9), respectively. RESULTS: The mismatch ratios in the TIMI II (0.4 +/- 0.3) and TIMI III (0.4 +/- 0.2) reflow groups were significantly higher than that in the TIMI 0-1 reflow group (0.1 +/- 0.1, p<0.05). Although coronary angiography revealed TIMI III flow after reperfusion, the mismatch ratios in the TIMI III (B) reflow group (0.2 +/- 0.1) and in the TIMI 0-I reflow group (0.1 +/- 0.1) were significantly lower than that in the TIMI III (A) reflow group (0.4 +/- 0.2, p<0.01), reflecting noneffective recanalization (so called no-reflow phenomenon). CONCLUSION: (201)TlCl/(123)I-BMIPP dual-isotope myocardial SPECT reveals the biochemical degree of the no-reflow phenomenon, whereas coronary angiography shows recanalized vascular flow only. Dual-isotope myocardial SPECT might be useful for evaluating reperfusion therapy.

Adult↗
PubMed2005

Reduction of drug leakage by negative-balance isolated pelvic perfusion: correlation between leakage and in-out flow rate in a pig model.

PURPOSE: Isolated pelvic perfusion (IPP) therapy exposes target tissues to high doses of anticancer drugs with low systemic concentrations, but the major drawback is drug leakage into the systemic circulation, which often thwarts the increased drug concentration. In this study, the efficacy of altering the in-out flow rate during IPP in order to decrease the leakage was assessed in adult pigs. METHODS: The abdominal aorta and the infrarenal vena cava were occluded with two balloon catheters, blood in the extracorporeal circuit was circulated with twin rotary pumps, and the IPP was performed with platinum. Three sets of in-out flow rates were used, and the degree of drug leakage into the systemic circulation was evaluated. The volume of blood withdrawn was equal to the volume returned (300 ml/min; group A), 5% higher (group B), or 10% higher (group C). The platinum concentrations in the pelvic circulation, systemic circulation, and urine were measured and compared. RESULTS: The average and maximum plasma platinum concentrations in the pelvic circulation did not significantly differ among the three groups. The plasma platinum concentrations in the systemic venous circulation of the three groups significantly (P<0.01) decreased as the volume withdrawn during IPP increased. The percentage of platinum eliminated in the urine during IPP was significantly (P<0.01) lower in group B and C than in group A. CONCLUSIONS: Setting the volume withdrawn higher than the volume returned decreased leakage into the systemic circulation under isolated pelvic perfusion.

Angiography↗
PubMed2005

Urinary excretion of vasoactive factors following contrast media exposure in humans.

BACKGROUND: Radiographic contrast media (CM) induce renal vasoconstriction and may initiate induced nephropathy. Endothelin (ET), a vasoconstrictor, and nitric oxide (NO), a vasodilator, which are synthesized in the kidney by the vascular endothelium as well as by tubular epithelial and glomerular mesangial cells, are key modulators of renal circulation after CM administration. Intravascular CM, in addition, induces pronounced diuresis and natriuresis. The aim of the present study was to evaluate and compare changes in endogenous vasoactive mediators and contrast-induced natriuresis after CM administration. METHODS: Diagnostic angiographic procedures were performed in 14 patients (9 males and 5 females) using the non-ionic CM Iopamidol. Before and immediately after angiography, venous blood and urine samples were obtained. The urinary excretion of ET-1 and nitrates/nitrites (NOx), and the fractional excretion of sodium (FENa) were measured and analyzed. RESULTS: The urinary excretion of both ET-1 and NOx increased significantly (p < 0.05) after angiography, and urinary ET-1 and NOx excretion was correlated with an increase in FENa (p < 0.05). CONCLUSION: Exposure to CM in humans is associated with an increase in urinary ET and NOx. The excretion of sodium following CM administration is associated with an increase in urinary ET and NOx. ET and NO might be important in the renal change in humans after CM administration.

Aged↗
PubMed2005

Three-dimensional registration of myocardial perfusion SPECT and CT coronary angiography.

OBJECTIVE: In this study, we describe a new technique for three-dimensional registration of CT coronary angiography (CTCA) and gated myocardial perfusion SPECT. METHODS: Twelve patients with known or suspected CAD who underwent CTCA and gated SPECT were enrolled retrospectively. Coronary arteries and their branches were traced using CTCA data manually and reconstructed in three-dimensions. Gated SPECT data were registered and mapped to a left ventricle binary model extracted from CTCA data using manual, rigid and nonrigid registration methods. RESULTS: Three-dimensional reconstruction and volume visualization of both modalities were successfully achieved for all patients. All 3 registration methods gave better quality based on visual inspection, and nonrigid registration gave significantly better results than the other registration methods (p < 0.05). The cost function for three-dimensional registration using nonrigid registration (235.3 +/- 13.9) was significantly better than those of manual and rigid registration (218.5 +/- 15.3 and 223.7 +/- 17.0, respectively). Inter-observer reproducibility error was within acceptable limits for all methods, and there were no significant difference among the methods. CONCLUSION: This technique of image registration may assist the integration of information from gated SPECT and CTCA, and may have clinical application for the diagnosis of ischemic heart disease.

Aged↗
PubMed2005

Assessment of contractile response to dobutamine stress by means of ECG-gated myocardial SPECT: comparison with myocardial perfusion and fatty acid metabolism.

UNLABELLED: The present study assessed left ventricular performance during dobutamine stress measured using gated SPECT, and compared the results to myocardial perfusion and fatty acid metabolism. METHODS: Thirty-six patients with myocardial infarction given (99m)Tc-sestamibi or (99m)Tc-tetrofosmin were examined by gated SPECT at rest and during dobutamine stress (4-20 microg x kg(-1) x min(-1)). After acquiring data at the highest dose, 201TlCl was injected and dual-isotope SPECT was performed to assess myocardial ischemia. Thirty of 36 patients also underwent myocardial SPECT with 123I-BMIPP. Regional wall motion changes during dobutamine infusion were determined from the gated SPECT data and classified as: (1) Improvement, (2) Worsening, (3) No change, and (4) Biphasic response. For myocardial segments of each infarct area, stress 201Tl, rest (99m)Tc and (123)I-BMIPP uptakes were graded on a five-point scoring system of defects from 0 (normal) to 4 (grossly defective). RESULTS: Rest 99mTc defect score index (DSI) in No change area was significantly higher than that in Biphasic area. The ADSI (stress 201Tl - rest (99m)Tc) in Biphasic area was significantly higher than those in Improvement and No change areas. The deltaDSI (BMIPP - (99m)Tc) in Worsening area tended to be higher than that in No Change area. CONCLUSIONS: Regional contractile response to dobutamine stress analyzed by gated SPECT showed that the response in-myocardial infarct areas could be classified by rest and stress myocardial perfusion and BMIPP accumulation.

Coronary Vessels↗
PubMed2005

Characteristic localisation of denatured high-density lipoprotein (HDL) at the periphery of a lipid core in human atherosclerotic lesions.

AIMS: High-density lipoprotein (HDL) has been reported to efflux cholesterol (Chl) from the cell membrane, and the physiological balance between the influx and efflux of Chl is important in the formation of atherosclerotic lesions. METHODS: In order to clarify these mechanisms in atherosclerotic lesions, the ratios of areas of apoprotein A-I (apo A-I)-positive areas were determined using a fluorescence polarisation microscope coupled to a spectrometer. RESULTS: According to the staining patterns of apo A-I, atherosclerotic lesions are classified into three types, namely, focal dense area (FA), diffuse dense area (DA) and shading area (SA). In FA, protein was prominent and lipid was minimal in the intercellular space of degenerated cells in the thickened intima. In DA, the protein and lipid were co-localised. In SA, at the periphery of lipid core, more lipids were present than protein. In the developed lesions, FA and SA were statistically bigger than those in the early lesions. CONCLUSIONS: These results suggest that an effective micro-solubilisation mechanism in FA may result in a low lipid content. Moreover, accumulated HDL may alter the relationship between various lipid vesicles and crystals in the extracellular matrix, and be an additional factor for the fragility of atheromatous plaques at the periphery of the lipid core.

Adult↗
PubMed2005

Long-term results of partial splenic artery embolization as supplemental treatment for portal-systemic encephalopathy.

OBJECTIVES: To present long-term results of angiographic partial splenic artery embolization (PSE) as a supplemental treatment of portal-systemic encephalopathy. METHODS: Twenty-five patients with portal-systemic encephalopathy were divided into two groups: 14 patients underwent transportal obliteration and/or balloon-occluded retrograde transvenous obliteration (BRTO) of portal-systemic shunts (PSS), followed by PSE (PSE(+) group), and 11 patients underwent only transportal obliteration and/or BRTO of PSS (PSE(-) group). RESULTS: Portal venous pressures pretreatment was similar to posttreatment in the PSE(+) group, but lower than posttreatment in the PSE(-) group. Serum ammonia levels were higher at pretreatment than at 1 wk posttreatment in both groups, but the levels in the two groups were similar at pretreatment, 1 wk, 3 months, 3 yr, 4 yr, and 5 yr posttreatment. However, serum ammonia levels were lower in the PSE(+) group than in the PSE(-) group 6 months, 9 months, 1 yr, and 2 yr posttreatment. Grades of encephalopathy were higher at pretreatment than at 1 wk posttreatment in both groups, but the levels in the two groups were similar at pretreatment, 1 wk, 2 yr, 3 yr, 4 yr, and 5 yr posttreatment. However, grades of encephalopathy were lower in the PSE(+) group than in the PSE(-) group 3 months, 6 months, 9 months, and 1 yr posttreatment. CONCLUSIONS: Obliteration of PSS followed by PSE benefit patients with portal-systemic encephalopathy.

Adult↗
PubMed2005

Calcifications in mucinous and serous cystic ovarian tumors.

Mucinous cystic ovarian tumors sometimes contain calcifications, but the frequency and significance of such calcifications in diagnostic radiology are not well understood. We therefore retrospectively investigated the radiological and histopathological evidence of calcifications in 44 cases of ovarian mucinous cystic tumors (22 benign, 13 borderline, and 9 malignant) and 21 cases of ovarian serous cystic tumors (6 benign and 15 malignant) in which a non-contrast CT scan was performed. The shape and distribution of the calcifications in the mass lesion were assessed both radiologically and histopathologically. Calcifications were noted in 34.1% of mucinous cystic tumors on CT scans and 56.8% in histopathological studies, and they were found in two locations, intramural and intra-cystic, according to the histopathological findings. Intramural calcifications were frequent in benign tumors, and intra-cystic calcifications were frequent in proliferating tumors. Calcifications (psammoma bodies) were noted in 4.7% of serous cystic tumors on CT scans and 14.3% in histopathological studies. CT was not sufficiently sensitive in the detection of intra-cystic calcification in mucinous tumors and psammoma bodies in serous tumors. However, the presence of intramural calcifications may be a good indicator of mucinous tumors. Understanding the frequency and morphology of the calcifications in these neoplasms is one of the keys to making a correct diagnosis.

Adult↗
PubMed2005

Recent advances in interventional radiology for acute massive pulmonary thromboembolism.

Acute massive pulmonary thromboembolism is life-threatening and requires vigorous treatment. Anticoagulation is the most traditional treatment for pulmonary thromboembolism, but may not be sufficient for massive thromboemboli. Systemic thrombolytic therapy and surgical thrombectomy are the traditional therapeutic options in this situation. Catheter-directed thrombolysis, percutaneous embolectomy and, more recently, percutaneous thrombus fragmentation techniques using specialized devices are now available to treat the most severe cases of massive pulmonary thromboembolism. The success of these techniques depends on a thorough understanding of the mechanism of action of each of the devices and familiarity with the relevant catheterization techniques. We present a review of currently available equipment and techniques, and describe our work with hybrid treatment using a combination of mechanical fragmentation, localized fibrinolysis and clot aspiration.

Acute Disease↗
PubMed2005

[Clinical study of porous gelatin sphere (YM 670) in transcatheter arterial embolization].

A clinical study on the use of porous gelatin particles(sterile gelatin embolization material, YM 670, Gelpart) in transcatheter arterial embolization (TAE) was performed in patients with hepatocellular carcinoma, and the efficacy (embolization,anti-tumor effect, recanalization and operationality) and safety (tolerability) were studied. An additive agent comprising porous gelatin particles and low osmolarity contrast media was administered peripherally through a catheter into the hepatic artery proper of 63 patients with hepatocellular carcinoma. Good hepatic arterial embolization was confirmed in all cases (embolization: 100%), and a tumor necrosis effect was obtained in most cases (35/62 patients, 56.5%). Moreover, operationality was assessed as "highly easy to use" or "easy to use" in all cases. Frequencies of adverse events in which a relationship to TAE was not excluded and abnormalities of clinical laboratory data were high at 71.4% and 9 8.4%, respectively. The most common adverse reactions were pyrexia, abdominal pain, queasiness and blood pressure increase;abnormalities in clinical laboratory data included hepatic function with increased AST (GOT), increased ALT (GPT), decreased cholinesterase, increased LDH and increased total bilirubin. These adverse reactions and abnormalities in clinical laboratory data, however, were transient and attributed to the TAE procedure itself, and no adverse reactions related to YM 670 as an embolic material were observed. In addition, with regard to tolerability (safety), the treatment was assessed as suitable for use in all the present cases.

Adult↗
PubMed2005

A case of dermoid cyst of the ovary with malignant transformation complicated with small intestinal fistula formation.

A 54-year-old woman complained of abdominal pain and watery diarrhea that had begun two days before admission. Physical examination revealed abdominal distention and tenderness throughout the abdomen, but there was no muscle guarding or rebound tenderness. The leukocyte count was 27.0 x 10(3)/microl, and CRP was 28.5 mg/dl. A plain film of the abdomen revealed the shadow of a huge gas-containing mass with an air-fluid level and a dilated small intestine with air-fluid level. CT showed a huge gas-containing cystic mass with fatty component and solid structure. Omental thickening was also noted. Emergency surgery was performed, and an enlarged left ovary that was adherent to the small intestine was removed. Microscopic examination revealed a squamous cell carcinoma in the dermoid cyst wall. The carcinoma had directly invaded the small intestine and a fistula between the cyst and the intestine was noted. Thickened omentum showed granulomatous inflammation in the fatty tissue, but no metastases were detected. The histopathological diagnosis was dermoid cyst with malignant transformation and invasion of the small intestine. Chemotherapy was performed, but the patient died of progression of peritoneal metastases 10 months after the operation.

Carcinoma, Squamous Cell↗