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Biomedical subjects

T Nishimura

Publications and source records attributed to T Nishimura.

At least 19 recordsLinked to original sources
PubMed2006

A simplified method for continuous hepatic arterial port-catheter system placement not requiring catheter end-hole occlusion.

PURPOSE: To evaluate the efficacy of hepatic port-catheter system placement without distal catheter tip occlusion or gastroduodenal artery embolization distal to the catheter tip. MATERIAL AND METHODS: A port-catheter system was percutaneously implanted in 29 patients (16 men, 13 women; mean age 65.6 years) with unresectable liver cancer. Persistent blood flow through the end hole of the catheter was verified immediately and 1-10 days after catheter placement. RESULTS: In all cases, percutaneous port-catheter placement was successfully performed. In seven of 29 (24.1%) patients, flow through the end hole of the catheter was verified immediately after the procedure. However, no flow was seen 1-10 days after the procedure. CONCLUSION: It is not necessary to occlude the end hole of the catheter tip and embolize the gastroduodenal artery beyond the catheter tip when placing a port-catheter system for repeated hepatic arterial infusion chemotherapy.

Aged↗
PubMed2006

Spontaneous regression of gastric varices after iatrogenic injury to a gastrorenal shunt.

We present a patient with gastric varices complicating portal hypertension caused by liver cirrhosis related to hepatitis C virus. The patient underwent balloon-occluded retrograde transvenous obliteration. The gastric varices almost completely disappeared, without any sclerotic agent being used, after iatrogenic injury of the gastrorenal shunt at the time of the interventional procedure.

Balloon Occlusion↗
PubMed2006

Percutaneous transluminal angioplasty for hepatic arterial occlusion following hepatic arterial infusion chemotherapy.

We report a case in which hepatic arterial occlusion developed during repeated hepatic arterial infusion chemotherapy through an implanted port-catheter system for advanced malignant hepatic neoplasia. After successful recanalization of the hepatic artery by using percutaneous transluminal angioplasty, another port-catheter system was placed percutaneously by interventional radiology techniques, allowing the continuation of hepatic arterial infusion chemotherapy.

Angiography↗
PubMed2006

Duration of pneumothorax as a complication of CT-guided lung biopsy.

The purpose of this study was to determine management guidelines for biopsy-induced pneumothorax with the assistance of manual aspiration, mainly based on the duration of complicated pneumothorax. Data from 388 consecutive percutaneous needle lung biopsies were examined. Patients with pneumothorax on postbiopsy chest CT images underwent percutaneous manual aspiration with an 18-G i.v. catheter. Frequency and management of biopsy-induced pneumothorax and period to its disappearance were reviewed. Postbiopsy pneumothorax occurred in 133 of 388 (34.3%) procedures. Manual aspiration in 72 of these 133 patients was carried out immediately after biopsy. The pneumothorax had resolved completely on follow-up chest radiographs without chest tube placement in 121 of the 133 pneumothoraces (91.0%). In cases requiring chest tube, the mean period from biopsy until resolution of the pneumothorax was 6.0 +/- 5.3 days, but was only 2.4 +/- 2.9 days when chest tube placement was not needed. Specifically, time until recovery was short both in those not requiring manual aspiration (2.1 +/- 3.4 days) and in those with a pneumothorax that disappeared completely or almost completely after manual aspiration (1.9 +/- 2.0 days). The almost equally short recovery periods in patients not requiring manual aspiration and those requiring immediate manual aspiration indicates the value of rapid management.

Adolescent↗
PubMed2006

Non-cavernomatous superior mesenteric thrombosis successfully recanalized with interventional radiological procedures carried out with a combination transmesenteric and transjugular approaches.

This is the study of a 52-year-old man with oesophageal, rectal and anal varices caused by portal hypertension with complete obstruction of the superior mesenteric vein. Treatment by two sessions of interventional radiological procedures was successful. The first was a catheter-directed thrombolysis using the transmesenteric approach. The second was percutaneous transluminal angioplasty and stent implantation for the obstructed segment of the superior mesenteric vein and the creation of a transjugular intrahepatic portosystemic shunt. In the second session, devices were advanced over a guidewire inserted from the right jugular vein and pulled out of the ileocolic vein using the pull-through technique.

Angioplasty, Balloon↗
PubMed2006

Prophylactic implantation of inferior vena cava filter during interventional radiological treatment for deep venous thrombosis of the lower extremity.

The purpose of this study was to evaluate the filtering effect of the Gunther tulip retrievable vena cava filter (GTF) during treatment of deep venous thrombosis (DVT) in the lower extremity using various interventional radiological procedures. Subjects of the study were all 17 consecutive patients (8 women, 9 men; age range 18-87 years; mean age 55.9 years) with symptomatic lower limb DVT referred for interventional radiological treatment between February 2001 and September 2004. In all of these patients, the GTF was implanted during interventional radiological treatment. Trapped thrombus in the filter was evaluated with venocavography performed repeatedly during the treatment for DVT. Implantation of a total of 29 GTFs was successfully performed in the 17 patients. In 10 (58.8%), more than 2 filters were subsequently implanted to prolong implantation time. Also in 10 patients, the DVT resolved after therapy and retrieval of the final GTF was successful with one exception. Worsening of or new formation of pulmonary embolism was avoided in all patients. In 8 (47.1%) of the 17 patients, a trapped thrombus in the GTF was observed during treatment for DVT. In six patients the trapped thrombus was large, filling more than half the height of the filter. In conclusion, we found that the GTF is effective in filtering the relieved thrombus from DVT in the lower extremity and in protecting against movement of the thrombus to the pulmonary artery during therapies with interventional radiological procedures.

Adolescent↗
PubMed2005

Monoclonal antibody A7-superparamagnetic iron oxide as contrast agent of MR imaging of rectal carcinoma.

Superparamagnetic iron oxide (SPIO)-based colloid has been used clinically as a tissue-specific magnetic resonance contrast agent. We coupled monoclonal antibody A7 (Mab A7), which reacts specifically with human colorectal carcinoma, to Ferumoxides (SPIO) and examined the accumulation of this conjugate in xenografted tumours in nude mice. We examined in vitro immunoreactivity of Mab A7 coupled to Ferumoxides and its in vivo distribution in nude mice with human colorectal carcinoma. Magnetic resonance imaging of tumour-bearing nude mice was performed 72 h after injection of A7-Ferumoxides. A7-Ferumoxides retained binding activities that were nearly identical to intact Mab A7. More of the radiolabelled A7-Ferumoxides accumulated in the tumour than normal mouse IgG-Ferumoxides from 12 h onwards after injection (P<0.05). Both A7-Ferumoxides and normal mouse IgG-Ferumoxides disappeared from blood linearly over time. The accumulation levels in normal tissue decreased linearly over time but were lower than levels in tumours from 6 h. In magnetic resonance T2-weighted imaging of the tumour-bearing nude mice, signal intensity was reduced at the margin of the tumour by injection of A7-Ferumoxides. Mab A7 coupled to Ferumoxides is potentially suitable as a magnetic resonance contrast agent for detecting local recurrence of rectal carcinoma.

Animals↗
PubMed2005

Etiologic agents of acute gastroenteritis among Japanese infants and children: virus diversity and genetic analysis of sapovirus.

A total of 371 fecal specimens from infants and children with acute gastroenteritis in Maizuru, Tokyo and Osaka, Japan from July 2002 to June 2003 were tested for the presence of diarrheal viruses by reverse transcription-polymerase chain reaction (RT-PCR), reverse passive hemagglutination (PRHA), RNA-polyacrylamide gel electrophoresis (PAGE), latex agglutination and sequence analysis methods. Among diarrheal viruses detected, group A rotavirus was the most prevalent (42.2%) followed by norovirus (28.9%), group C rotavirus (8.4%), sapovirus (6.7%), adenovirus (5.3%) and astrovirus (0.9%), respectively. There was the high rate (7.6%) of viral mixed infections. Sapovirus was classified into 6 genotypes (GI/1, GI/4, GI/5, GI/6 and GII/1 and one novel tentatively called GII/5). It is noteworthy that genogroup II sapovirus can be classified into 5 genotypes. Our findings confirmed the presence of many diarrheal viruses co-circulating among Japanese infants and children and showed the great genetic diversity among sapoviruses.

Acute Disease↗
PubMed2005

MR tractography for the evaluation of functional recovery from lenticulostriate infarcts.

OBJECTIVE: To evaluate the anatomic and clinical relationship between the lenticulostriate artery (LSA) territory and the corticospinal tract (CST) in patients with acute infarcts in this territory using MR tractography. METHODS: Thirteen consecutive patients who presented with acute infarcts in the LSA territory and who also had undergone an MRI study within 3 days after symptom onset were studied. Visualization of the CST was achieved by postprocessing the acquired diffusion tensor imaging data. To classify lesion location, the LSA territory was divided into four subsegments, the boundaries of which were drawn by axial and coronal planes crossing through the foramen of Monro. Infarct volume and extent of CST involvement were measured and compared with neurologic findings. RESULTS: All of the infarcts were located in the posterior segment. All of the depicted CSTs crossed the LSA territory only at the posterosuperior quadrant. The extent of CST involvement within the infarcts was correlated with the severity of the patient's motor deficit (p < 0.01) and with the clinical outcome (p < 0.05). CONCLUSIONS: The corticospinal tracts (CSTs) crossed the lenticulostriate artery territory exclusively at the posterosuperior quadrant, and the degree of CST involvement within the infarcts was directly related to stroke severity and functional recovery.

Adult↗
PubMed2005

Altered expression of GABA(A) and GABA(B) receptor subunit mRNAs in the hippocampus after kindling and electrically induced status epilepticus.

Epilepsy may result from altered transmission of the principal inhibitory transmitter GABA in the brain. Using in situ hybridization in two animal models of epileptogenesis, we investigated changes in the expression of nine major GABA(A) receptor subunits (alpha1, alpha2, alpha4, alpha5, beta1-beta3, gamma2 and delta) and of the GABA(B) receptor species GABA(B)R1a, GABA(B)R1b and GABA(B)R2 in 1) hippocampal kindling and 2) epilepsy following electrically-induced status epilepticus (SE). Hippocampal kindling triggers a decrease in seizure threshold without producing spontaneous seizures and hippocampal damage, whereas the SE model is characterized by spontaneous seizures and hippocampal damage. Changes in the expression of GABA(A) and GABA(B) receptor mRNAs were observed in both models, and compared with those seen in other models and in human temporal lobe epilepsy. The most prominent changes were a relatively fast (24 h after kindling and electrically-induced SE) and lasting (7 and 30 days after termination of kindling and SE, respectively) reduction of GABA(A) receptor subunit delta mRNA levels (by 43-78%) in dentate granule cells, accompanied by increases in mRNA levels of all three beta-subunits (by 8-79%) and subunit gamma2 (by 11-43%). Levels of the minor subunit alpha4 were increased by up to 60% in dentate granule cells in both animal models, whereas those of subunit alpha5 were decreased 24 h and 30 days after SE, but not after kindling. In cornu ammonis 3 pyramidal cells, downregulation of subunits alpha2, alpha4, alpha5, and beta1-3 was observed in the ventral hippocampus and of alpha2, alpha5, beta3 and gamma2 in its dorsal extension 24 h after SE. Similar but less pronounced changes were seen in sector cornu ammonis 1. Persistent decreases in subunit alpha2, alpha4 and beta2 transcript levels were presumably related to SE-induced cell loss. GABA(B) receptor expression was characterized by increases in GABA(B)R2 mRNA levels at all intervals after kindling and SE. The observed changes suggest substantial and cell specific rearrangement of GABA receptors. Lasting downregulation of subunits delta and alpha5 in granule cells and transient decreases in subunit alpha2 and beta1-3 mRNA levels in cornu ammonis 3 pyramidal cells are suggestive of impaired GABA(A) receptor-mediated inhibition. Persistent upregulation of subunits beta1-3 and gamma2 of the GABA(A) receptor and of GABA(B)R2 mRNA in granule cells, however, may result in activation of compensatory anticonvulsant mechanisms.

Animals↗
PubMed2005

Fluids containing a highly branched cyclic dextrin influence the gastric emptying rate.

The rates of gastric emptying for highly branched cyclic dextrin (HBCD) and other carbohydrate (CHO) solutions were examined using ultrasonograph techniques. Ten healthy volunteers ingested water, physiological saline, or solutions containing various CHO, such as HBCD, glucose, maltose, sucrose, and commercially available dextrin. After a subject drank one of the solutions, the relaxed cross-sectional area of the pylorus antrum was measured at rest by real-time ultrasonography. The time required for gastric emptying was correlated with the relaxed cross-sectional area of the pylorus antrum. Among all of the solutions tested, physiological saline was transferred fastest from the stomach to the small intestine. For solutions of the same CHO, 5 % solution was transferred faster than 10 % solution. For CHO solutions other than HBCD, a low osmotic pressure was associated with rapid transfer from the stomach. The gastric emptying time (GET) of HBCD solution increased with an increase in its concentration. A shorter GET was observed for the CHO solutions at 59 to 160 mOsm regardless of their concentration. A sports drink based on 10 % HBCD adjusted to 150 mOsm by the addition of various minerals, vitamins, and organic acids was evacuated significantly (p < 0.05) faster than a 10 % HBCD solution or a sports drink based on 10 % commercially available dextrin (DE16), which has a higher osmotic pressure (269 mOsm). Our results suggest that a shorter GET could be achieved with CHO solutions with osmotic pressures of 59 - 160 mOsm. Therefore, a sports drink based on 10 % HBCD adjusted to 150 mOsm by the addition of minerals, vitamins, and organic acids could supply adequate quantities of CHO, fluid, and minerals simultaneously in a short time, without increasing GET.

Administration, Oral↗
PubMed2005

Movement of the side hole occurring in a port-catheter system percutaneously implanted for hepatic arterial infusion chemotherapy.

The authors report a case in which catheter-related difficulties occurred with a port-catheter system implanted to perform repeated hepatic arterial infusion chemotherapy for advanced hepatocellular carcinomas. The port-catheter system had been percutaneously implanted with the catheter tip fixation method, and a side hole had been created in the indwelling catheter for placement in the common hepatic artery. Four months after port-catheter placement, however, the indwelling catheter became bent at the location of the side hole in the proper hepatic artery. Subsequently, the side hole moved into the left hepatic artery, resulting in a lack of distribution of chemotherapeutic agents to the tumours in the segments of the liver supplied by the right hepatic artery. This situation was easily corrected with a simple interventional radiological method so that hepatic arterial infusion chemotherapy could be resumed with sufficient distribution over the entire liver. To our knowledge, such a problem involving a port-catheter system implanted with the catheter tip fixation method and its management thereafter has not been reported in the published literature.

Aged↗
PubMed2005

Spontaneous healing of chyle leakage after lymphangiography.

We report a 34-year-old man with the complication of chylous ascites after retroperitoneal lymphadenectomy that was refractory to various conservative therapies. Because surgical treatment for chylous ascites was considered, lymphangiography was performed to identify the area of leakage of chyle, after which the chylous ascites spontaneously healed.

Adult↗
PubMed2004

Temperature-induced gelation of concentrated silicon carbide suspensions.

Due to the steric barrier provided by the adsorption of the dispersant hypermer KD1 (a polyester/polyamine condensation polymer), stable and low-viscosity suspensions of SiC, Y(2)O(3), and Al(2)O(3) powder mixtures could be prepared in methyl ethyl ketone (MEK)/ethanol (E) solvent with solids loading as high as 60 vol%. The solvency of the dispersant in MEK/E decreased dramatically on cooling. Steady shear viscosity and oscillatory measurements were performed as a function of temperature for suspensions with different solids loading. The viscosity and elastic modulus of suspension increased with decreasing temperature and became more sensitive with the increase of solids loading. The suspensions with solids loading higher than 40 vol% could be solidified with decreasing temperature, but gelation temperature and gelation stiffness decreased with decreasing solids loading. The 60 vol% solid-loaded suspension was a stable and free-flowing fluid at 20 degrees C and gradually transformed to a very highly viscous and elastic system upon cooling to about 13 degrees C. Complete solidification occurred when the temperature was decreased to 5 degrees C. The gelation mechanism was mainly based on the collapse of the adsorbed layer as the temperature decreases, which induced incipient flocculation and formed a stiff network. The gelled body was further strengthened by separation of the dispersant from the suspension.

Carbon Compounds, Inorganic↗
PubMed2004

Posterior cingulate metabolic changes in frontotemporal lobar degeneration detected by magnetic resonance spectroscopy.

Differences in prognosis and symptomatic treatment have highlighted the importance of the differential diagnosis of frontotemporal lobar degeneration (FTLD) and other dementias, but the variable clinical features make diagnosis difficult. We studied metabolic changes using multivoxel proton magnetic resonance spectroscopy (MRS) in regions of FTLD, including the posterior cingulate gyrus, which is also the area most affected by Alzheimer's disease (AD) in the early stages. We examined six patients with FTLD, six with presumed AD, and five healthy volunteers using repetition and echo times of 2000 and 135 ms. We analysed peak ratios of choline (Cho), creatine (Cr), and N-acetylaspartate (NAA) from frontal and temporoparietal regions, basal ganglia, and posterior cingulate gyrus in both hemispheres. A decreased NAA/Cr ratio was observed in the posterior cingulate gyri in presumed AD (right: 1.56+/-0.44, P =0.011; left: 1.46+/-0.25, P =0.008) and FTD (right: 1.47+/-0.40, P =0.005; left: 1.36+/-0.32, P =0.002). No statistically significant changes in Cho/Cr were identified in the posterior cingulate gyri in presumed AD or FTLD, and no differences were observed in peak ratios in other regions. Decreased NAA may reflect neuronal activity in the posterior cingulate gyrus, and this study may contribute to insights into the pathophysiology of FTLD.

Adult↗