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Biomedical subjects

K Uchiyama

Publications and source records attributed to K Uchiyama.

At least 91 records · Page 5Linked to original sources
PubMed1998

A case with subcapsular hematoma of the liver following laparoscopic cholecystectomy.

Laparoscopic cholecystectomy (LC) is a safe and less traumatic procedure for benign cholecystic disease. However there have been some complications peculiar to LC. Here we report a case with postoperative subcapsular hematoma of the liver after LC. A 78-year-old woman was admitted with acute cholecystitis due to cholecystolithiasis. She underwent LC and liver dysfunction was noted after the operation. Ultrasonography (US) and computed tomography (CT) showed subcapsular hematoma of the liver. It was supposed that it had happened to occur during the operation, but we could not make the cause clear. The patient was improved with only conservative therapy and discharged. It is important to handle the forceps carefully close to the liver in the laparoscopic surgery in order to prevent this complication. We report a case with subcapsular hematoma of the liver following LC with a review of the literature.

Aged↗
PubMed1998

Spigelian hernia: case report.

A spigelian hernia is an uncommon hernia of the anterior abdominal wall. We herein report a case of spigelian hernia, pre-operatively diagnosed as an incisional hernia. A 61-year-old woman had undergone an abdominal hysterectomy 14 years prior to her admission to our hospital complaining of a left lower abdominal mass with recurring pain. At the time of the operation the hernial orifice appeared not to be related to her previous surgical scar, but was located at the spigelian fascia below the level of the umbilicus. The hernial sac was dissected and the defect of the abdominal wall was closed. The diagnosis of a spigelian hernia can be difficult because of its nonspecific clinical findings and insidious nature. Diagnostic procedures and differential diagnosis are herein discussed with a review of the literature.

Diagnosis, Differential↗
PubMed1998

[Effect of the skull on brain perfusion SPECT imaging].

Because attenuation gradually decreases reconstructed counts from the periphery to the center portion of the object, the deep region far from the detector is not clearly observed if attenuation is not compensated. In brain perfusion SPECT, diagnosis is sometimes made using filtered back projection images without attenuation compensation (FBP). Brain perfusion SPECT has the unique characteristic that the radiopharmaceutical accumulates only within the brain and is never taken up by the surrounding skull. This study investigated the effect of skull on brain perfusion SPECT reconstructed with FBP. We theoretically derived the relation between the counts of brain and the linear attenuation coefficient of skull. It was found that the difference in reconstructed counts between the deep gray matter and peripheral gray matter decreased due to the existence of the skull. This result indicated that the deep gray matter was inclined to be visible if the FBP images were displayed according to relative counts normalized to the maximum count of each image. In order to confirm this, we made a numerical phantom with realistic human brain and skull contours on the basis of MR images from a normal volunteer. The linear attenuation coefficient of brain was assumed to be 0.15 cm-1, while that of skull was assumed to be 0.26 cm-1 (denoted as BONE+) or 0 cm-1 (BONE-). In accordance with the theoretical results, the deep gray matter of BONE+ images was more clearly observed than that of BONE- images, if these were displayed using the relative counts of each images. The physical phantom experiments also supported the theoretical and numerical phantom studies.

Cerebrovascular Circulation↗
PubMed1998

[Arterial infusion chemotherapy with SMANCS-Lipiodol for multiple hepatocellular carcinoma].

Fifty-five patients with hepatocellular carcinoma were treated with oily anticancer agent SMANCS dissolved in Lipiodol (SMANCS-LPD). The local response rate after the first arterial infusion in all patients was 39%, against 63% in 27 patients with Lipiodol accumulation occupying more than two thirds of tumor areas. The infusion therapy with SMANCS-LPD is adapted for a vascular-rich hepatocellular carcinoma. An infusion of 4 mg of SMANCS was ineffective for patients with tumors distributing in bilateral lobes of liver. Thus, an increase of infusion dosage or repeated infusions were recommended for such cases.

Aged↗
PubMed1998

[Breath-hold 3D MR urography with 2 ml Gd-DTPA injection].

Breath-hold gadolinium-enhanced 3D MR urography was performed in five healthy volunteers. Enhanced 3D fast gradient-echo with a spectral IR pulse sequence was used for depicting MR urography, which was obtained 5-10 minutes after the injection of 2 ml of gadopentate dimeglumine (0.013-0.02 mmol/kg). The urinary tract was depicted as a high-signal intensity area, and detectability of the non-dilated urinary tracts was superior to that of heavy T2-weighted images. At the same time, comparison between the urinary tract and vascular structure could be made using breath-hold contrast-enhanced 3D MR angiography with an additional Gd-DTPA injection.

Adult↗
PubMed1998

[MR cholangiopancreatography of pancreas divism and anomalous arrangement of the pancreaticobiliary ducts].

The purpose of this study was to evaluate the usefulness of MR cholangiopancreatography (MRCP) for pancreas divism and anomalous arrangement of pancreaticobiliary ducts (APBD). In 214 patients, MRCP was performed. In 204 patients (94%), pancreaticobiliary ductal junction could be recognized. Pancreas divism was observed in 13 of 204 patients (6%), and APBD was observed in 10 of 204 patients (5%). Dynamic MRCP after secretin stimulation was useful for diagnosing pancreas divism and APBD.

Bile Ducts↗
PubMed1998

[MR cholangiopancreatography of Mirizzi syndrome and Lemmel syndrome].

The purpose of this study is to evaluate the usefulness of MR cholangiopancreatography (MRCP) in diagnosing Mirizzi syndrome and Lemmel syndrome. MRCP could show compressed common hepatic duct by enlarged gallbladder in Mirizzi syndrome. Periampulary duodenal diverticulum and compressed lower bile duct can be recognized clearly by MRCP after secretin stimulation. So MRCP should apply for diagnosing of Mirizzi syndrome or Lemmel syndrome.

Aged↗
PubMed1998

[Combined scatter and attenuation correction for 201Tl myocardial perfusion SPECT using OS-EM algorithm].

There are two possible ways to obtain scatter-corrected images with the ML-EM (maximum likelihood expectation maximization) algorithm: one is the subtraction of scatter estimate si from projection data pi, and then (pi-si) is used for scatter-corrected projection data (denoted as SC(T)); the other method is the addition of scatter estimate si to the projections calculated from the reconstructed image without performing data subtraction (SC(E)). This paper investigated these two ML-EM algorithms of combined scatter and attenuation correction on 201Tl myocardial perfusion SPECT imaging. Scatter windows were placed one full width at half maximum (FWHM) below and above the photopeak centerline. The scatter fraction in the primary peak was estimated using trapezoidal approximation by the triple energy window method. Phantom and clinical images were reconstructed using 6 iterations of ordered subsets EM algorithm (OS-EM). A cylindrical phantom with a cold-rod insert and a heart/thorax phantom with liver insert were used to evaluate scatter and the attenuation compensation technique. A cylindrical phantom filled with uniform 201Tl solution was used to evaluate statistical noise. The percent root-mean-square uncertainty (%RMSU) was used as a quantitative measure of noise amplification. %RMSU showed that the SC(E) method amplified noise less in comparison with the SC(T) method, however, no significant difference in image quality was observed between the two methods. In conclusion, both the SC(T) and SC(E) methods provided significant and similar improvement in the removal of scatter in 201Tl myocardial perfusion SPECT imaging.

Absorption↗
PubMed1997

Duodenal obstruction by gallstone: case report of Bouveret's syndrome.

Bouveret's syndrome involves gastric outlet obstruction by gallstone. Herein we describe an unusual case of duodenal bulb obstruction by gallstone. An 80-year-old woman was hospitalized with a fifteen-day history of vomiting. Computed tomography (CT) showed pneumobilia and a round calcified mass in the second portion of the duodenum. Upper gastrointestinal tract series demonstrated the same sized oval radiolucency between the bulbus and the second portion of the duodenum. Endoscopic examination revealed a round black mass in the second portion of the duodenum, totally occupying the lumen. Endoscopic removal and destruction of the gallstone was attempted using a dye-laser, but the stone was too hard to crush. Eventually surgical enterolithotomy was successfully performed without cholecystectomy or closure of the fistula. Improved preoperative systemic management and prompt examination allowed earlier surgical intervention and reduced the morbidity. Surgical approach whether fistula closure should be performed remains controversial.

Aged↗
PubMed1997

Effect of troglitazone on blood insulin levels after pancreas transplantation with systemic venous drainage in rats.

BACKGROUND: Troglitazone is a new oral antidiabetic agent and has been reported to reduce insulin resistance and improve peripheral hyperinsulinemia in patients with noninsulin-dependent diabetes mellitus. To examine the effect of troglitazone on insulin regulation after pancreas transplantation with systemic venous drainage, we measured peripheral glucose and insulin levels and performed an intravenous glucose tolerance test. METHODS: We divided the rats into four groups: diabetic rats with a pancreas graft and administration of troglitazone at 40 mg/day orally (group P+T, n=4), rats with a pancreas graft only (group P, n=4), age-matched normal rats (group N, n=5), and diabetic rats (group DM, n=4). RESULTS: Fasting insulin levels in group P were relatively higher than those in group N, whereas the values in group P+T were normalized. In the intravenous glucose tolerance test, troglitazone clearly regulates sigma immunoreactive insulin levels of pancreas transplanted rats (P vs. P+T: 244+/-23 vs. 145+/-14 microU/ml, P<0.05). CONCLUSION: Hyperinsulinemia induced by systemic venous drainage, which may progress atherosclerosis, can be controlled with troglitazone treatment.

Animals↗
PubMed1997

Versatility of the free anterolateral thigh flap for reconstruction of head and neck defects.

OBJECTIVE: The anterolateral thigh flap has many advantages in head and neck reconstruction. However, it has not yet come into widespread use because of the anatomic variations of its perforators. Herein, we describe a safe operative technique related to the patterns of the perforators and discuss its wide versatility. SETTING: A national cancer center hospital. PATIENTS: Thirty-eight anterolateral thigh flaps were transferred. Confirmation and dissection of the flap pedicle were simultaneously performed with tumor resection. The design and elevation of the flap were carried out immediately after the tumor resection was completed. RESULTS: From the study of the anatomic variations of the perforators, septocutaneous patterns were recognized in 10 cases (26.3%) and musculocutaneous patterns in 28 cases (73.7%). All flaps were easily and safely elevated with our techniques. Thirty-six flaps survived. Partial necrosis was noted owing to excessive thinning procedure in one patient and total necrosis was noted owing to venous thrombosis at the anastomosis part in another patient. CONCLUSIONS: We found that the anterolateral thigh flap has numerous advantages. It is possible to perform the flap elevation and the tumor resection simultaneously. The flap is generally thin and is suitable for reconstruction of intraoral defects. Combined flaps with neighboring tissues and other, distant flaps can be used. Furthermore, since our technique minimizes the problems of confirmation and dissection of the perforators, we conclude that this flap can be successfully used to repair a variety of large defects of the head and neck.

Adult↗
PubMed1997

Primary aortoduodenal fistula caused by duodenal tuberculosis without an abdominal aortic aneurysm: report of a case.

A 66-year-old man died of massive gastrointestinal hemorrhage caused by a fistula between the third portion of the duodenum and the abdominal aorta. An autopsy revealed that duodenal tuberculosis had resulted in the development of a fistula into the aorta with no pathological changes, and no active pulmonary tuberculosis was found. Duodenal tuberculosis and primary aortoduodenal fistula (ADF) without an aneurysm are both extremely rare. Thus, we report herein a unique case of primary aortoduodenal fistula without an abdominal aortic aneurysm, but associated with duodenal tuberculosis, and review the current literature.

Aged↗
PubMed1997

Precision of the gallbladder ejection fraction obtained with Tc-99m-pyridoxyl-5-methyl-tryptophan (99mTc-PMT) hepatobiliary scintigraphy as compared with the contraction ratio in three-dimensional computed tomography.

UNLABELLED: The gallbladder ejection fraction (GBEF) obtained with Tc-99m-pyridoxyl-5-methyl-tryptophan (99mTc-PMT) hepatobiliary scintigraphy has been used as a parameter of gallbladder function. To determine the accuracy of GBEF, the relationship with the contraction ratio of the gallbladder (GBCR) obtained with three-dimensional helical computed tomography (3D-CT) was studied. PATIENTS AND METHODS: A normal volunteer, 8 patients suffering from cholecystolithiasis and a patient with gallbladder dyskinesia were examined. The percent initial dose (%ID) for the gallbladder and GBEF with hepatobiliary scintigraphy were used to compare the volume of the gallbladder and GBCR which was measured by 3D-CT. RESULTS: The %ID of the gallbladder was correlated with the volume of the gallbladder by 3D-CT (Y = 1.000X - 1.818, r = 0.928). GBEF was correlated well with GBCR by 3D-CT (Y = 0.916X + 6.296, r = 0.975). CONCLUSIONS: The %ID of the gallbladder obtained with hepatobiliary scintigraphy may be a good indicator of the volume of the gallbladder. The accuracy of GBEF was confirmed by comparison with 3D-CT examination. GBEF is considered a useful parameter of pathophysiological gallbladder function.

Adult↗
PubMed1997

Capillary electrochromatographic separation of amino acid enantiomers using on-column prepared molecularly imprinted polymer.

The use of molecularly imprinted polymer polymerized in capillary for the separation of amino acid enantiomers by electrochromatography is described. The substrate-selective polymers were prepared by using L-phenylalanine anilide as print molecule and methacrylic acid and/or 2-vinylpyridine as the functional monomers, which is believed to interact both ionically and through hydrogen bonding with the print molecule. Several aspects of the polymer preparation were investigated, including the treatment of the inside surface of the capillary, the composition of the polymers and the running conditions of the capillary electrochromatography. Such separation was highly specific and depended on the presence of both the print molecule and the functional monomer in the polymerization mixture. This preliminary report demonstrates a novel and simple method for the development of the capillary electrochromatographic separation of amino acid enantiomers using molecularly imprinted polymer.

Amino Acids↗
PubMed1997

Polygalacturonase isolated from the culture of the psychrophilic fungus Sclerotinia borealis.

A polygalacturonase was isolated from the culture medium of Sclerotinia borealis, a psychrophilic fungus that grows on lawn and wheat seedling under the snow in winter and induces the snow mold disease. Pectic acid was a better substrate of this enzyme than pectin when the activity was determined by measuring the reducing sugar produced. However, when the activity was measured by viscosity change, the viscosity of pectin decreased more rapidly than that of pectic acid. The results of viscosity change apparently indicate that the polygalacturonase catalyzes pectin hydrolysis as an endo-type enzyme. Highly methyl-esterified pectin was a poor substrate, as determined by measurements of reducing sugar production and viscosity change. It is suggested from the results that the methoxy group of pectin affects the polygalacturonase reaction. A reaction mechanism was proposed for the polygalacturonase reaction. Molecular mass of this enzyme was 40 kDa and its isoelectric point was pH 7.5. Optimum pH of the enzyme reaction was 4.5 and its optimum temperature was 40-50 degrees C. Thirty percent of the maximum activity was observed at 5 degrees C, but it was only slightly active above 60 degrees C. The activity was preserved for more than 2 years at 5 degrees C and pH 4.5, but it was lost when kept at room temperature overnight or heated at 50 degrees C for 30 min. The amino acid sequence of the N-terminal region of the psychrophilic polygalacturonase of Sclerotinia borealis is compared with those of polygalacturonases of mesophilic fungi. The function of this enzyme against the target plants is discussed with reference to the reaction of polygalacturonases of mesophilic fungi.

Amino Acid Sequence↗
PubMed1997

Inhibition by hop bract polyphenols of cellular adherence and water-insoluble glucan synthesis of mutans streptococci.

The inhibitory effect of hop bract polyphenols (HBP) on cariogenic streptococci was investigated. It was found that the high molecular weight polyphenol (estimated about 36,000-40,000) inhibited the cellular adherence of Streptococcus mutans MT8148 (serotype C) and Streptococcus sobrinus ATCC 33478 (serotype g) at much small concentrations than the polyphenols extracted from oolong tea or green tea leaves. Furthermore, HBP also inhibited the action of glucosyltransferase, which was involved in the water-insoluble glucan synthesis, but did not suppress the growth and the acid production of the bacteria. These results suggest that HBP would be a candidate to act against dental caries caused by Mutans Streptococci.

Bacterial Adhesion↗
PubMed1997

[Examination of scanning technique for lung cancer screening with helical CT].

As a new application of helical CT scanning we evaluated the parameters for lung cancer screening with an extremely low doses and large helical pitch. On the phantom studies, the image quality obtained with the low dose parameter was not inferior to that of the usual screening technique but artifacts were increased with the large helical pitch. A scanning technique using 120 kv, 40-60mA, 10mmth, 20mm/ sec, and a reconstruction pitch of 2 was used for lung cancer screening (screening parameters) (50 cases), and comparison was made between the detectability of the screening parameters and the routine parameters (120 kv, 200mA, 10mmth, 10-13mm/sec, and a reconstruction pitch of 1-1.3). Detectability with the screening parameters was as follows: nodular lesions (< 5mm in size: 76%. 5-10mm: 90-93% 10mm < 100%), linear lesions: 94-95%, infiltrations: 93-100%. There were no false negative lesions, when the reconstruction pitch of the screening parameters was changed from 1 to 0.25. In conclusion, reconstruction pitch had the most influence on lesion detectability.

Adult↗