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Biomedical subjects

N Hosomi

Publications and source records attributed to N Hosomi.

At least 19 recordsLinked to original sources
PubMed1998

Interferon therapy in LKM-1 positive patients with chronic hepatitis C: follow-up by a quantitative radioligand assay for CYP2D6 antibody detection.

BACKGROUND/AIMS: Liver/kidney microsomal type 1 (LKM-1) antibodies described by indirect immunofluorescence using frozen sections of kidney, stomach and rat liver define a group of patients with type 2 autoimmune hepatitis. Sera react with a non-glycosylated 50-kD protein of the endoplasmic reticulum, which was recently identified as cytochrome P4502D6 (CYP2D6). LKM-1 antibodies may also be associated with hepatitis C virus infection (HCV+/LKM-1+). For this subset of patients, the choice of steroids or interferon alpha therapy may be difficult because of the association of hepatitis C virus infection and autoimmune manifestations. Recently we developed a quantitative immunoprecipitation radioligand assay using 35S-methionine-labeled CYP2D6 protein produced by in vitro transcription and translation reaction. This method detects antibodies against linear and conformational epitopes in both AIH-2 and HCV+/LKM-1+ patients. The aim of this study was to analyze the time-course of HCV+/LKM-1+ patients, applying our radioligand assay over a long follow-up. METHODS: We studied five patients who were positive for CYP2D6 antibodies from among 235 chronic hepatitis C virus hepatitis patients (2.1%) treated with interferon alpha for a minimal follow-up of 2 years. We analyzed LKM-1 antibody titer sequentially by radioligand assay, HCV RNA titer and alanine aminotransferase activity in these patients. RESULTS: We found no aggravation of liver disease in this group of patients. Three of these patients showed a sustained biochemical and virological response after interferon. Two others responded partially to interferon therapy. Alanine aminotransferase levels and HCV-RNA decreased during interferon therapy in responder patients. CYP2D6 antibodies did not change in three responder patients during follow-up. One responder patient decreased CYP2D6 antibody level by radioligand assay, but indirect immunofluorescence titers showed a similar pattern. One partial responder patient decreased CYP2D6 antibody level but was negative by indirect immunofluorescence. CONCLUSIONS: Our results show that patients with hepatitis C virus who are positive for CYP2D6 antibodies may be treated with interferon, and respond in the same way as CYP2D6 antibody negative patients. Radioligand assay could be helpful for monitoring HCV+/LKM-1+ patients receiving interferon therapy.

Adult↗
PubMed1998

Spiral CT during pharmacoangiography with angiotensin II in patients with pancreatic disease. Technique and diagnostic efficacy.

PURPOSE: To compare the diagnostic efficacy of pancreatic pharmacoangiographic CT using angiotensin II with conventional angiographic CT. MATERIAL AND METHODS: Eighteen patients with space-occupying pancreatic disease were examined in this study. Pharmacoangiographic CT was performed with a 1-3 micrograms/6-ml solution of angiotensin II injected through a catheter into the celiac artery during spiral CT. RESULTS: In 17 of the 18 (94%) patients, the area of pancreatic parenchymal enhancement was the same or larger at pharmacoangiographic CT than at conventional angiographic CT. The attenuation value of the pancreatic parenchyma was significantly increased at pharmacoangiographic CT (p = 0.0010). Although the attenuation value of tumors was also increased on images obtained after the injection of angiotensin II, the tumor-to-pancreas contrast was significantly greater at pharmacoangiographic CT (p = 0.0479). The mean differences in attenuation between tumor and pancreas at angiographic CT with and without angiotensin II were respectively 182 HU and 115 HU. CONCLUSION: Pharmacoangiographic CT with angiotensin II proved superior to conventional angiographic CT in the diagnosis of pancreatic disease. We therefore recommend it as a supplementary technique at the angiographic examination of patients with suspected pancreatic tumor.

Adult↗
PubMed1998

[A measure to continue intra-arterial infusion chemotherapy long-term for locally advanced pancreatic cancer].

For locally advanced non-resectable cancer of the pancreas, we have routinely performed intra-arterial chemotherapy: Each catheter is placed in the splenic artery and gastroduodenal artery during laparotomy, and a mixture of Methotrexate and Angiotensin-II is infused within 30 minutes. This treatment is repeated weekly at our outpatient clinic as long as possible. However, obstruction of the catheter or corresponding artery is the major cause of interruption of treatment. The present paper reports a case in which intra-arterial chemotherapy was possible by repeated catheterization for the catheter obstruction. A 54-year-old woman with non-resectable pancreatic cancer underwent catheter placement during laparotomy, but they became occluded one month later. Another catheter was placed into the common hepatic artery by the Seldinger method. After this catheter was occluded again, another catheter was placed into the inferior pancreaticoduodenal artery via the superior mesenteric artery by the Seldinger method. By repeating this catheter placement, we succeeded in continuing the intra-arterial chemotherapy, and the patient has remained alive (30 postoperative months) without losing her quality of life.

Angiotensin II↗
PubMed1998

Pancreatic invasion as the prognostic indicator of duodenal adenocarcinoma treated by pancreatoduodenectomy plus extended lymphadenectomy.

UNLABELLED: Pancreatoduodenectomy has become the standard procedure in resection of the duodenal adenocarcinoma, and some adjuvant therapies can be added to obtain further improvement in postoperative outcome. However, for patient selection, it is necessary to have a predictive indicator showing, if possible before laparotomy, which instances are noncurable by surgery alone or need adjuvant therapies. METHODS: A retrospective analysis was made for 24 consecutive patients whose duodenal adenocarcinoma were treated by pancreatoduodenectomy plus a wide range of lymphadenectomies without any adjuvant therapies at Osaka Medical Center for Cancer and Cardiovascular Diseases. Patient survival rates were related to macroscopic and microscopic findings and to findings obtained by preoperative imaging techniques. RESULTS: The overall survival rate was 69% at 3 years and 57% at 5 years; locoregional recurrence was the primary cause of death. Although the 5-year survival rate was 44% in patients with nodal involvement and 76% in those without, this difference did not reach statistical significance (P = .079). Instead, invasion into the pancreatic parenchyma at a macroscopic level was the most significant prognostic factor; the 5-year survival rate was 78% in the 16 patients without and 16% in the 8 patients with pancreatic invasion (P = .0047). Invasion into the pancreas correlated well with the angiographic findings; the 5-year survival rate was 25% in patients whose angiograms delineated the pancreatic invasion and 83% in patients whose angiograms did not (P = .0084). CONCLUSION: When duodenal adenocarcinoma was treated by pancreatoduodenectomy plus a wide range of lymphadenectomy, pancreatic invasion at a macroscopic level was most associated with patient survival. Pancreatic invasion was well delineated by the preoperative angiogram, which would be helpful in patient selection.

Adenocarcinoma↗
PubMed1997

[Unruptured intracranial aneurysms: evaluation with high-resolution MR angiography with magnetization transfer contrast (MTC) and tilted optimized nonsaturating excitation (TONE)].

Forty-one patients with suspected intracranial aneurysms were evaluated by conventional three-dimensional (3D) time-of-flight (TOF) MR angiography (MRA) or high-resolution 3D TOF MRA with magnetization transfer contrast (MTC) and tilted optimized nonsaturating excitation (TONE). Correlative study was done with conventional angiography in all patients. 3D TOF MRA detected 30 of 36 aneurysms depicted at conventional angiography. The overall rate of sensitivity for the detection of aneurysms was 83%. Unruptured aneurysms were unlikely to occur in the anterior communicating artery (3%), but were frequently found at the bifurcation of the middle cerebral artery (33%). Conventional MRA showed 7 of 9 aneurysms demonstrated at catheter angiography. The rate of sensitivity of conventional MRA for aneurysms smaller than 5 mm and greater than or equal to 5 mm were 0% and 100%, respectively. High resolution MRA with MTC and TONE demonstrated 23 of 27 aneurysms detected by catheter angiography. Sensitivities of high resolution MRA with MTC and TONE for aneurysms smaller than 5 mm and greater than or equal to 5 mm were 71% and 100%, respectively. Our results indicate that high-resolution 3D TOF MRA with MTC and TONE can provide precise, accurate depiction of intracranial aneurysms larger than or equal to 5 mm.

Adult↗
PubMed1996

Effects of pravastatin sodium and simvastatin on plasma fibrinogen level and blood rheology in type II hyperlipoproteinemia.

Elevated plasma fibrinogen level is known to progress atherosclerosis and to be one of the risk factors for the occurrence of cardiovascular diseases. The objective of this study is to evaluate the changes in plasma fibrinogen level and blood rheology in patients with type II hyperlipoproteinemia before and after random administrations of HMG-CoA (3-hydroxy-e-methylglutaryl-cocarboxylase-A) reductase inhibitors, pravastatin sodium and simvastatin, and compare with results in normal subjects. Of a total of 28 patients with type II primary hyperlipoproteinemia with > 230 mg/dl fasting total plasma cholesterol, 16 patients (mean, 59.7 years old) were administered 10-15 mg/day of pravastatin sodium for an average of 10.2 weeks, and 12 patients (mean, 62.0 years old) were administered 5-10 mg/day of simvastatin for an average of 13.9 weeks. Patients were evaluated before and after drug administration and results were compared with those of 16 normal subjects of similar age (mean, 56.9 years old). Blood viscosities were measured using a cone-plate viscometer (Biorheolizer, BRL-1000, Japan). The following were measured before and after drug administration: whole blood viscosity at shear rates of 75-375 s-1, corrected blood viscosity at low (112.5 s-1) and high (225.0 s-1) shear rates for the standard hematocrit of 45%, plasma viscosity, hematocrit, total protein, serum albumin, and plasma fibrinogen. Total cholesterol level was significantly decreased (from 270 to 225, mg/dl, mean values; P < 0.0007) an average of 10.2 weeks after start of pravastatin sodium administration. In addition to the reductions of whole blood viscosity, at every shear rate examined, corrected blood viscosity, and plasma viscosity, plasma fibrinogen levels were significantly decreased (from 354 to 309 mg/dl, mean values; P < 0.0007) after start of pravastatin sodium administration. Fibrinogen level and blood rheology were not significantly changed after start of simvastatin administration despite similar significant reductions in total cholesterol level (from 260 to 207 mg/dl, mean values; P < 0.0001) to those in the case of pravastatin sodium. From the results, we conclude that administration of pravastatin sodium, but not simvastatin, reduced the plasma fibrinogen level and blood viscosities to normal levels in type II hyperlipoproteinemic patients while both drugs reduced total cholesterol level. The hydrophilicity and a small binding capacity with plasma protein of pravastatin sodium may be responsible in part for the beneficial hemorheologic effects observed in the patients with type II hyperlipoproteinemia. Further investigations should be conducted to confirm the findings observed.

Acyl Coenzyme A↗
PubMed1996

Nimodipine improves brain energy metabolism and blood rheology during ischemia and reperfusion in the gerbil brain.

Whether nimodipine improves cerebral blood flow (CBF) and metabolism in cerebral ischemia remains a controversial issue. We investigated the effect of nimodipine on CBF, brain energy metabolism, using a laser-Doppler flowmeter and in vivo 31phosphorus nuclear magnetic resonance (31P NMR) spectroscopy, and blood rheology during forebrain ischemia and reperfusion in gerbils. Eighty-three adult gerbils received nimodipine (1 micrograms/kg/min), or an equal volume of the vehicle, or saline, over 60 min prior to a transient forebrain ischemia for 60 min. We measured sequential changes in phosphocreatine (PCr) / inorganic phosphate (Pi) ratio, beta-ATP/Pi ratio, and intracellular pH (pHi) during ischemia and reperfusion by 31P NMR spectroscopy, and the measurement of whole blood viscosity (WBV) at 60 min after reperfusion. CBF was measured continuously throughout the study by a laser-Doppler flowmeter. During forebrain ischemia, PCr/Pi and beta-ATP/Pi ratios were higher significantly in the nimodipine-treated group (p < 0.05 and 0.01) than in the vehicle- or saline-treated groups. During reperfusion, PCr/Pi and beta-ATP/Pi ratios recovered significantly only in the nimodipine-treated group (p < 0.05 and 0.01). The WBV at high shear rate (562.5 s-1) lowered significantly in the nimodipine-treated group (p < 0.05) compared with the vehicle- or saline-treated group. CBF was higher significantly only during administration of nimodipine in the nimodipine-treated group (p < 0.01) than other groups. Nimodipine improved brain energy metabolism and blood rheology during forebrain ischemia and reperfusion in the gerbil brain.

Animals↗
PubMed1996

Kinetic characterization of antibody-catalyzed insertion of a metal ion into porphyrin.

The insertion of a copper (II) ion into mesoporphyrin by a monoclonal catalytic antibody has been investigated kinetically by measuring the increase in Soret absorbance due to the production of copper (II)-mesoporphyrin. The initial rate of the reaction showed saturation kinetics as a function of the mesoporphyrin concentration, while it increased linearly with an increase in the copper (II) concentration. Based on observations, a scheme for the reaction was proposed: mesoporphyrin binds to the antibody to form a complex, and copper (II) binds to the complex to yield copper (II)-mesoporphyrin. Kinetic parameters for the respective steps were estimated, and the thermodynamic parameters were calculated. The binding of mesoporphyrin to the antibody was endothermic and entropically driven. This implies that hydrophobic interactions are an important factor in the binding. Free energy profiles for the antibody-catalyzed and uncatalyzed reactions were drawn by use of the obtained thermodynamic parameter values. The results demonstrate that the rate acceleration by, the antibody is ascribable to transition-state stabilization, and suggest that the structure of mesoporphyrin in the complex is more distorted than that of free mesoporphyrin.

Animals↗
PubMed1996

Duration threshold of induced hypertension on cerebral blood flow, energy metabolism, and edema after transient forebrain ischemia in gerbils.

We have investigated whether there is a duration threshold for the effects of phenylephrine-induced hypertension on CBF, brain energy metabolism, and cerebral parenchymal specific gravity (SG) following transient forebrain ischemia in gerbils. Sixty gerbils were randomly assigned to one of the four treatment groups: one control group and three groups subjected to an increase of 25 mm Hg in MABP induced by treatment, 30 min after reperfusion, with phenylephrine for 15 min, 30 min, or 60 min. The local CBF was measured continuously, and the SG was evaluated 120 min after reperfusion. Sequential changes in brain energy metabolism, as shown by the ratio of phosphocreatine to inorganic phosphate (Pi), the beta-ATP/Pi ratio, and intracellular pH, were also measured. The 15-min induced hypertension regimen was most suited to the recovery of brain energy metabolism, which was associated with an increase in local CBF and a decrease in cerebral edema. These results demonstrate that a suitable duration can be chosen to optimize the beneficial effects of phenylephrine-induced hypertension on ischemic brain injury following transient forebrain ischemia.

Animals↗
PubMed1996

[Hepatic resection with "wrapping therapy" for advanced hepatocellular carcinoma uncontrolled by arterial embolization].

We report a 70-year-old male patient who had successful hepatic resection with "Wrapping therapy" for advanced hepatocellular carcinoma (HCC) uncontrolled by arterial embolization. His laboratory tests were as follows: Alb: 4.7 (g/dl), T. Bil:0.9 (mg/dl), ICG R15:26.8 (%), PT: > 100%, AFP:33 (ng/ml), HCV-Ab:(-), HBs-Ag:(-). Hepatic angiogram showed a 20 cm sized tumor in the left lobe and many large and small tumors in the right lobe. He received chemoembolization (TAE) five times during seven months. At the time of the fifth hepatic angiogram, TAE was assessed as ineffective because of the resulting collateral feeding arteries. Thus, he underwent left lobectomy, partial resection of the right lobe, and partial "Wrapping therapy" for the regions including foci supplied with parasitic branch. Afterwards, he had TAE two times. One year and five months after the procedure, he is still alive without signs of recurrence.

Aged↗
PubMed1996

[Double lumen--coaxial catheter system for combined CT during arterial portography and CT hepatic angiography].

The high sensitivity of CT during arterial portography (CTAP) for hepatic lesions is accompanied with a lack of specificity for diagnosis. Combined CTAP and CT hepatic angiograpy (CTHA) had been proved to improves lesion detection and heightens confidence in interpreting perfusion abnormalities. We describe a new double lumen - coaxial catheter system for performing combined CTAP and CTHA without the need for repeated transfer of the patient or bilateral arterial punctures. This technique was employed in eight patients with liver neoplasms. In all eight patients, CTAP and CTA images were obtained successfully. We concluded that this method was useful for the evaluation of liver tumors.

Catheterization↗
PubMed1996

[Usefulness of spiral CT in the detection of hypovascular, well-differentiated hepatocellular carcinoma].

Whole liver scanning during artery-dominant phase using spiral CT was performed in 14 patients with 17 histologically proven well-differentiated HCCs, which were not depicted by hepatic digital subtraction angiography but by CT during arterial portography. The density of HCC relative to the liver was evaluated with conventional precontrast CT, spiral CT, and following conventional CT during the equilibrium phase. Comparison between spiral CT and magnetic resonance (MR) imaging of dynamic contrast studies was also investigated. Four tumors of 17 HCCs (24%) were shown as a high-density area by the artery-dominant phase using spiral CT. Consequently, the total sensitivity of these three kinds of CT techniques was elevated to 82%. The sensitivity of dynamic MR imaging was slightly greater than that of spiral CT. However, spiral CT sometimes made the diagnosis more conspicuous by it's good spatial resolution. Our results indicate that spiral CT has a potential benefit in the detection of hypovascular well-differentiated HCC, and MR imaging and spiral CT may be complement each other.

Aged↗
PubMed1995

Cerebellar diaschisis in pontine infarctions: a report of five cases.

We evaluate regional cerebral and cerebellar perfusion to prove the occurrence and follow the persistence of crossed cerebellar diaschisis in infratentorial pontine infarction. Six consecutive patients exhibiting mild hemiparetic symptoms or a heavy feeling in the head (mean age 65 years; four women, two men) and diagnosed as having pontine infarction by magnetic resonance imaging were subjected to evaluation. Lesions due to infarction were located at the upper basis pontis in five patients and the upper tegmentum pontis in one, and medially at the paramedian portion in four and laterally in two. Regional cerebral and cerebellar perfusion was evaluated semiquantitatively by iodine-123 N-isopropyl-p-iodoamphetamine (IMP) single-photon emission tomography (SPET); this was done during the acute stage in five cases (mean time after onset: 0.7 months) and during the chronic stage in three (mean time after onset: 14.8 months). Four patients had two examinations during their clinical courses. For semiquantitative evaluation of perfusion, an asymmetry index was calculated for each region of interest, set symmetrically in regions of the cerebral cortex and cerebellum in both hemispheres. Significant asymmetry (P < 0.01) in cerebellar perfusion, which was reduced in the contralateral (n = 4) or ipsilateral (n = 1) cerebellar hemisphere, was demonstrated semiquantitatively in four cases during the acute stage and in one during the chronic stage, as compared with normal controls (n = 5, mean age 61 years). This asymmetry continued to the chronic stage (6.5 and 33.0 months) in two cases, while no patient showed any significant asymmetries in cerebral perfusion in any region of interest in either SPET study.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

[Evaluation of multislice dynamic MR imaging of the whole liver].

In 47 patients with liver cirrhosis, we performed dynamic MRI with a multisection FLASH technique that enabled us to obtain 13 T 1-weighted images of the entire liver within a single breath hold. Computed tomographic arterial portography (CTAP), US, CT, angiography (AOG) and MRI (spin echo [SE] and dynamic MRI) were performed in all 47 patients. Except for cyst, hemangioma and metastatic tumor, 104 focal nodules less than 3 cm in diameter were detected. These 104 focal lesions were divided into three groups according to the pattern of CTAP: 69 portal supply negative, 11 portal supply decreased, and 24 portal supply normal. In the portal supply negative group, 63 lesions (91%) were detected by dynamic MRI, which was superior to other modalities (US 77%, CT 41%, AOG 70%, MRI-SE 61%). The superiority of dynamic MRI resulted from its excellent ability to detect liver lesions less than 1 cm in diameter. We confirmed histologically that dynamic MRI had almost the same ability to detect hepatocellular carcinoma (HCC) as CTAP. Dynamic MRI should be clinically useful as a noninvasive examination for the detection of HCC.

Carcinoma, Hepatocellular↗
PubMed1994

Pleural invasion by peripheral bronchogenic carcinoma: assessment with three-dimensional helical CT.

PURPOSE: To evaluate the potential role of three-dimensional (3D) computed tomography (CT) in assessment of pleural invasion by peripheral bronchogenic carcinoma. MATERIALS AND METHODS: Twenty-four-second helical CT scans were obtained during a single breath hold in 42 consecutive patients with peripheral bronchogenic carcinoma. Conventional two-dimensional (2D) images and 3D reconstruction images were reviewed independently by three blinded observers, who reached a decision by consensus. All patients underwent surgical resection of the tumor, and CT findings were correlated with the findings in pathologic specimens. RESULTS: Twelve patients had visceral pleural invasion, five had parietal pleural invasion, and 25 had no evidence of pleural invasion. Visceral pleural invasion was identified on 2D CT images in two patients and on 3D reconstructions in 11. Parietal pleural invasion was identified on 2D CT images in two patients and on 3D reconstructions in three. CONCLUSION: 3D reconstruction imaging is superior to conventional 2D CT in assessment of pleural invasion by peripheral bronchogenic carcinoma.

Carcinoma, Bronchogenic↗
PubMed1993

[Differentiation of bronchogenic carcinoma from benign nodule by MR imaging: quantitative evaluation].

To distinguish benign from malignant nodules with MR imaging, 39 pulmonary nodules (23 bronchogenic carcinomas, nine tuberculomas and seven other benign lesions) were studied. MR equipment of 1.5 Tesla was used, and relative signal intensities of pulmonary nodules on T 2- and T 1-weighted images before and after administration of gadopentate dimeglumine were evaluated. On T 2-weighted images, the relative signal intensity of bronchogenic carcinomas to subcutaneous fat was 5.48 +/- 1.69, that of tuberculomas was -2.56 +/- 2.22 and that of other benign lesions was -0.88 +/- 3.37; the difference between tuberculomas and bronchogenic carcinomas was statistically significant (p < 0.05). On T 1-weighted images before and after administration of gadopentate dimeglumine, the relative signal enhancement of bronchogenic carcinomas was 17.6 +/- 2.0, that of other benign lesions was 20.0 +/- 5.2 and that of tuberculomas was -0.0074 +/- 0.763; the difference between tuberculomas and bronchogenic carcinomas as well as benign nodules was statistically significant (p < 0.001). The relative signal intensity on T 2-weighted images and the ratio of signal enhancement to noise could differentiate tuberculomas from bronchogenic carcinomas and other benign lesions. However, bronchogenic carcinomas and other benign lesions could not be differentiated by MR imaging.

Aged↗
PubMed1993

Bladder tumors: staging with gadolinium-enhanced oblique MR imaging.

To clarify the importance of imaging plane in evaluation of invasion by tumor into muscle, 50 patients with bladder tumors underwent examination with magnetic resonance (MR) imaging performed with an oblique plane and the early phase of contrast enhancement. After the ideal oblique plane was selected, an oblique T2-weighted image was obtained. Gadopentetate dimeglumine was then administered, and an oblique T1-weighted image was obtained. The staging based on oblique T2-weighted and oblique contrast material-enhanced T1-weighted MR images was then correlated with histopathologic staging. The respective accuracies of oblique contrast-enhanced T1-weighted and oblique T2-weighted images were 78% and 60% for overall staging (P < .05), 90% and 74% for differentiation between (a) stage T1 and lower-stage tumors and (b) stage T2 and higher-stage tumors (P < .05), and 92% and 88% for differentiation between (a) stage T2 and lower-stage tumors and (b) stage T3a and higher-stage tumors (P > .05). Oblique MR imaging performed in conjunction with the early phase of contrast enhancement showed significantly high staging accuracy, especially in differentiation between superficial tumors and tumors with superficial muscle invasion.

Adult↗