Biomedical subjects

H Irie

Publications and source records attributed to H Irie.

At least 19 recordsLinked to original sources

PubMed2000

MR cholangiopancreatographic differentiation of benign and malignant intraductal mucin-producing tumors of the pancreas.

OBJECTIVE: The purpose of this study was to establish MR cholangiopancreatographic criteria for discriminating benign from malignant intraductal mucin-producing tumors of the pancreas. MATERIALS AND METHODS: Thirty-one patients with 34 intraductal mucin-producing tumors underwent MR cholangiopancreatography. Tumors were classified as either main duct type (n = 10) or branch duct type (n = 24). In patients with the main duct type, the maximum diameter and the location of the main pancreatic duct, the extent of main pancreatic duct dilatation, and the presence of a filling defect were evaluated. For branch duct type, the location and maximum diameter of the cystic lesion, the presence of a filling defect, and the presence of associated main pancreatic duct dilatation were evaluated. RESULTS: In patients with the main duct type, the main pancreatic duct was significantly narrower when associated with benign rather than malignant tumors. All malignant tumors showed diffuse main pancreatic duct dilatation, whereas all benign tumors showed segmental dilatation. Among patients with branch duct type, the cyst was smaller when it was a benign rather than malignant tumor. All but one malignant tumor showed mild associated main pancreatic duct dilatation, whereas benign tumors were not associated with main pancreatic duct dilatation. Filling defects suggested malignancy, although half of the malignant tumors had no filling defects. CONCLUSION: In patients with intraductal mucin-producing tumors of the pancreas, filling defects are indicative of malignancy. Diffuse main pancreatic duct dilatation greater than 15 mm (main duct type), or any main pancreatic duct dilatation (branch duct type), is strongly associated with malignancy.

Adenocarcinoma↗

PubMed2000

[Role of apoptosis induced by acute herpes simplex virus].

Apoptosis is induced by acute herpes simplex viral infection in the adrenal cortex, myenteric plexus of the gut, ovary, and liver of mice. Viral replication is closely related to apoptosis. This apoptosis is increased in immunosuppressive regions like the adrenal cortex and liver of macrophag-depleted mice. However, the herpes simplex virus is known to possess US3 gene, which interferes with cell apoptosis. In the liver of macrophage-depleted mice infected with US3 gene-deficient mutant herpes, the apoptosis is confined to within the narrow limits of inflammatory cell infiltration, mainly of neutrophils, and it plays a part in the restriction of virus multiplication. Thus, a possibility exists that apoptosis works as a primitive immunity in herpes simplex virus infection.

Acute Disease↗

PubMed1999

MR detection of cytoplasmic fat in clear cell renal cell carcinoma utilizing chemical shift gradient-echo imaging.

We attempted to determine whether cytoplasmic fat in clear cell renal cell carcinoma (RCC) can be identified by chemical shift gradient-echo magnetic resonance imaging (CSI). CSI was performed for 22 clear cell RCCs and 30 other renal tumors (including 16 non-clear cell RCCs), all of which were surgically proven. Signal reduction in out-of-phase images of these tumors was retrospectively evaluated and compared. The signal loss ratio (SLR) was defined and calculated. Fat staining of specimens from 16 tumors was performed and correlated with SLR. SLR was significantly higher in clear cell RCCs than in non-clear cell RCCs (P < 0.001). There was a significant correlation between degree of fat staining positivity of the specimens and SLR (P < 0.01). When signal reduction in out-of-phase images suggested the diagnosis of clear cell RCC, correct diagnosis of this entity was made in resected renal tumors with sensitivity, specificity, and accuracy of 82%, 90%, and 87%, respectively. CSI can demonstrate cytoplasmic fat in clear cell RCCs, which helps to differentiate this entity from other RCCs.

Adenocarcinoma, Clear Cell↗

PubMed1999

Pseudolesions of the liver possibly caused by focal rib compression: analysis based on hemodynamic change.

OBJECTIVE: The purpose of this study is to show and analyze the CT appearance of pseudolesions of the liver caused by rib compression and to discuss the possible mechanism on the basis of findings of incremental dynamic CT, CT during arterial portography, and CT hepatic arteriography. CONCLUSION: Focal compression of the liver caused by curved ribs can cause transient focal diminishment of portal venous perfusion without significantly altering hepatic arterial perfusion. Such diminishment may be observed as low-density areas on the early phase of incremental dynamic CT.

Aged↗

PubMed1999

MR diagnosis of adenomyomatosis of the gallbladder and differentiation from gallbladder carcinoma: importance of showing Rokitansky-Aschoff sinuses.

OBJECTIVE: We evaluated the MR imaging features of adenomyomatosis of the gallbladder with particular emphasis on Rokitansky-Aschoff sinuses. MATERIALS AND METHODS: MR images of 17 patients with histologically proven adenomyomatosis were retrospectively reviewed. The presence of Rokitansky-Aschoff sinuses was evaluated and analyzed; four T2-weighted (fast spin-echo with a surface coil, with or without breath-holding, fast spin-echo with a phased-array coil with breath-holding, and half-Fourier rapid acquisition with relaxation enhancement with breath-holding) and two contrast-enhanced dynamic pulse sequences were studied. These six pulse sequences were separately rated on a 5-point scale by two radiologists for comparison. Interobserver differences were evaluated. Other MR findings were also analyzed. RESULTS: Among the six pulse sequences studied, three T2-weighted with breath-holding sequences were found to be superior to the other three sequences in showing Rokitansky-Aschoff sinuses. In particular, the half-Fourier rapid acquisition with relaxation enhancement was scored the highest by the two observers and received the highest kappa coefficient in our statistical analysis of the scoring. Diffuse-type adenomyomatosis typically showed early mucosal and subsequent serosal enhancement. Localized adenomyomatosis exhibited homogeneous enhancement, showing smooth continuity with the surrounding gallbladder epithelium. CONCLUSION: MR imaging may be able to provide important information in the diagnosis of adenomyomatosis.

Adenomyoma↗

PubMed1999

Vascular changes in hepatocellular carcinoma: correlation of radiologic and pathologic findings.

OBJECTIVE: Our objective was to analyze the hemodynamic properties and vascular supply changes in the carcinogenesis of hepatocellular carcinoma. MATERIALS AND METHODS: Ten nodules (nine patients) (one early, three early-advanced, and six advanced cases of hepatocellular carcinoma) less than 3 cm in diameter were selected from 45 patients (50 nodules) who underwent CT arteriography and CT during arterial portography. These images were correlated with histopathologic findings. Ratios of all microscopically counted (normal hepatic and abnormal) arteries, normal hepatic arteries, and portal veins in each nodule to those in the surrounding liver were calculated. RESULTS: Early hepatocellular carcinoma (one early case and early areas in three early-advanced cases) had low attenuation on CT arteriography and isoattenuation on CT during arterial portography. Advanced hepatocellular carcinoma (six advanced cases and advanced areas in three early-advanced cases) had high attenuation on CT arteriography and low attenuation on CT during arterial portography. In early hepatocellular carcinoma, the ratios of all arteries, normal hepatic arteries, and portal veins were 1.21 +/- 0.07, 0.60 +/- 0.07, and 0.73 +/- 0.06, respectively. In advanced hepatocellular carcinoma, the ratios were 2.66 +/- 0.26, 0.08 +/- 0.04, and 0.07 +/- 0.03, respectively. CONCLUSION: In early hepatocellular carcinoma, the combination of normal hepatic artery degeneration and preserved portal veins results in low attenuation on CT arteriography and isoattenuation on CT during arterial portography. In advanced hepatocellular carcinoma, the combination of neoplastic (abnormal) arterial development by angiogenesis and obliteration of portal veins results in high attenuation on CT arteriography and low attenuation on CT during arterial portography. These findings are a characteristic difference between early and advanced hepatocellular carcinoma.

Aged↗

PubMed1998

Systemic lupus erythematosus associated with primary large cell carcinoma of the lung.

The association between systemic lupus erythematosus (SLE) and malignancy has been controversial in the literature. We report a case of lung cancer in a 50-year-old woman with a 4-year history of SLE. She underwent surgery at a pathological stage of T2N2M0, but she eventually died of rapid recurrence of the cancer in the abdomen resulting in massive haemorrhage from the inferior vena cava (IVC). Immunological disorders related to SLE are thought to contribute to rapid progression of the malignancy.

Abdominal Neoplasms↗

PubMed1998

[Norwood procedure to hypoplastic left heart syndrome].

Since March 1992, 25 neonates and small infants with HLHS have undergone a modified Norwood procedure. The mean age and weight at operation were 17 days (2 days-2 months) and 2.7 kg (1.6-3.3 kg). Isolated cerebral and/or myocardial perfusion (ICMP) with direct anastomosis of aorta and pulmonary artery was utilized since January 1995 to 16 patients. Under median sternotomy, PTFE graft (usually 3.0-3.5 mm) was anastomosed to the brachiocephalic artery and the arterial cannula was inserted to this PTFE graft. The left carotid and the left subclavian arteries were snared and a clamp was placed on the aortic arch just distal to the brachiocephalic artery. This allowed blood to enter the brain and the coronary arteries, keeping the brain perfused and the heart-beating. After reconstruction of distal aortic arch, a single dose of crystalloid cardioplesia was infused and the rest of the arch was reconstructed. There were 14 early deaths (56%) and 4 late deaths (16%). Bidirectional Glenn procedure was performed to 5 patients with 1 death. Three patients underwent modified Fontan procedure without mortality. Mean aortic cross clamp time was 24 min. and mean ICMP time was 32 min. There was no neurologic complications. In conclusion, isolated cerebral and/or myocardial perfusion may offer an advantage of protecting the brain and myocardium during arch in Norwood procedure.

Aorta↗

PubMed1998

Structures of spider toxins: hydroxyindole-3-acetylpolyamines and a new generalized structure of type-E compounds obtained from the venom of the Joro spider, Nephila clavata.

Facile structure determination of acylpolyamines, glutamatergic nerve blocker obtained from the venom of the Joro spider (Nephila clavata) was carried out with the use of micro-column LC/MS and high energy collision induced dissociation (CID) mass spectrometry. 6-hydroxyindole-3-acetyl was proposed previously as a putative partial structure, for the acyl moiety of hydroxyindole-type polyamines (NPTX-1 to -6). The NMR data obtained for NPTX-6, NPTX-687 and hydroxyindole-3-acetic acid which was released by acid hydrolysis of Nephila clavata crude venom extracts proved that the lipophilic head is the 4-hydroxyindole-3-acetic acid. Various hydroxyindole-3-acetyl polyamines were found in N. Clavata venom and characterized by mass spectrometry. As a result, type-E, a new class of generalized acylpolyamine structure was proposed in addition to the previously reported polyamine backbones type-A to -D.

Chromatography, Liquid↗

PubMed1998

Herpes simplex virus hepatitis in macrophage-depleted mice: the role of massive, apoptotic cell death in pathogenesis.

Infection with herpes simplex virus or hepatitis viruses can lead to fulminant hepatitis, but there is controversy about the underlying conditions needed for such disease. To investigate how the impairment of host defences might be involved, macrophages were depleted by administration of silica to mice before intravenous injection with herpes simplex virus type 1 (HSV-1). Such mice died rapidly and their livers were yellowish and shrunken (acute yellow atrophy), and occasionally grossly haemorrhagic. Small foci of apoptotic cells developed in the liver lobules; these rapidly became confluent and zonal over time. The overall lesion pattern was similar to massive hepatic necrosis, and there was extensive HSV replication in the liver lesions. In the liver, DNA fragmentation characteristic of apoptosis followed the time course of HSV-1 propagation. These findings suggest that one of the underlying conditions for fulminant viral hepatitis may be inadequate macrophage response, and that the massive hepatic damage, often defined as cell necrosis, may actually be apoptosis of liver cells subsequent to virus infection.

Alanine Transaminase↗

PubMed1998

Optimal MR cholangiopancreatographic sequence and its clinical application.

PURPOSE: To determine the appropriate acquisition parameters for magnetic resonance cholangiopancreatography (MRCP) with a half-Fourier rapid acquisition with relaxation enhancement (RARE) sequence; to determine the optimal MRCP technique by comparing half-Fourier RARE, steady-state free precession (SSFP) two-dimensional (2D) fast spin-echo (SE), and three-dimensional (3D) fast SE sequences; and to clarify the usefulness and limitations of MRCP in diagnosing pancreatic abnormalities. MATERIALS AND METHODS: Half-Fourier RARE MRCP images with varying parameters were compared by using a phantom. Duct conspicuity and contrast-to-noise ratios (C/Ns) were compared for the four MRCP techniques in a phantom and healthy volunteers. The optimal MRCP technique was used to study healthy volunteers and clinical cases. Receiver operating characteristic (ROC) curves were created for data analysis. RESULTS: A 5-mm-thick section without intersection gap was appropriate for half-Fourier RARE MRCP. Only half-Fourier RARE MRCP could depict a 1-mm duct. C/N was the highest with half-Fourier RARE, followed by 3D fast SE, 2D fast SE, and SSFP sequences. ROC curve analysis revealed no interobserver differences, and the area under the curve for detection of strictures of the main pancreatic duct was as high as 0.89. CONCLUSION: Half-Fourier RARE MRCP has the highest contrast and spatial resolution among the four techniques studied and may play an important role in diagnosing pancreatic abnormalities.

Adult↗

PubMed1998

Autoimmune pancreatitis: CT and MR characteristics.

OBJECTIVE: Our goal was to elucidate the CT and MR imaging characteristics in patients with autoimmune pancreatitis, which is a reversible chronic pancreatitis with an autoimmune cause. CONCLUSION: On CT and MR imaging, a capsulelike rim, which is thought to correspond to an inflammatory process involving peripancreatic tissues, appears to be a characteristic finding of autoimmune pancreatitis. Also, diffuse pancreatic enlargement along with hypointensity on T1-weighted MR images and delayed enhancement on dynamic CT and MR studies are other features of this disorder.

Aged↗

PubMed1998

Value of MR cholangiopancreatography in evaluating choledochal cysts.

OBJECTIVE: The aim of this retrospective study was to clarify whether MR cholangiopancreatography (MRCP) is a suitable replacement for ERCP in evaluation of the choledochal cyst. MATERIALS AND METHODS: Sixteen patients (six adult and 10 pediatric) with choledochal cysts underwent MRCP using a half-Fourier acquisition single-shot turbo spin-echo sequence. Extent of the cyst, defects within the biliary tree, and presence or absence of the anomalous junction of the pancreaticobiliary duct were evaluated. Findings were compared with those of ERCP. RESULTS: MRCP better defined the proximal biliary tree than did ERCP in two patients. Defects within the biliary tree were diagnosed correctly on MRCP in eight patients; however, two defects within the distal common bile duct were missed in pediatric patients. The presence of the anomalous junction of the pancreaticobiliary duct was revealed accurately by MRCP in all adult patients but was revealed accurately in only four of the 10 pediatric patients. CONCLUSION: MRCP appears to offer diagnostic information that is equivalent to that of ERCP for assessment of choledochal cysts in adults. In pediatric patients, MRCP should not replace ERCP; however, MRCP can play an important role as a noninvasive examination and should be considered a first-choice imaging technique for evaluation of choledochal cysts.

Adult↗

PubMed1998

Role of virus-induced apoptosis in a host defense mechanism against virus infection.

Many animal viruses are known to induce apoptosis in infected cells. This virus-induced apoptosis has been often described as a mechanism of host defense against virus infection, based on the finding that mutants of an insect virus with the ability to induce extensive apoptosis in some cells cannot grow in the same cells. In animal virus infection, we have shown that (1) viruses can somehow overcome this defense mechanism and that (2) virus multiplication in the apoptotic cells is not as completely suppressed as in the insect virus infection. These results suggest that, in the case of animal viruses, the virus-induced apoptosis does not play the same role in the host defense system as in insect cells. However, by examining the virus infection under the conditions comparable to the infection in vivo, we demonstrated the defensive role of apoptosis in animal virus infection.

Animals↗

PubMed1997

Indications and problems of coronary artery bypass grafting without cardiopulmonary bypass.

As an alternative method of myocardial protection and to obviate the inherent risks of cardiopulmonary bypass (CPB), we have been performing coronary artery bypass grafting (CABG) without CPB in carefully selected patients. Since the first such operation was successfully performed in January 1995 on a patient with angina pectoris and lung cancer, four other patients have subsequently undergone this technique. This series of 5 patients, being 1 man and 4 women ranging in age from 68 to 80 years, is presented in this report. The reasons for the selection of this procedure were concomitant diseases including lung cancer, a calcified aorta, and myocardial infarction. The mean time of ischemia for each anastomosis was 15.3 +/- 5.3 min, and the maximum cardiac muscle creatine phosphokinase (CPK-MB) was less than 14 unit/l postoperatively. None of the patients required ventilatory support for longer than 24 h postoperatively, and oral intake was started within 24 h after extubation in all patients. Postoperative angiography confirmed graft patency and none of the patients developed any ischemic symptoms. All the patients were discharged between 1 and 2 months postoperatively. Thus, the off-pump technique is useful when concomitant diseases are present and will become an alternative method of treatment for coronary artery disease in selected patients.

Aged↗

PubMed1997

Factors affecting hypertrophic scar development in median sternotomy incisions for congenital cardiac surgery.

BACKGROUND: Even after successful operations on children, unattractive postoperative scars are often distressing to patients and their parents. There are no reports about the factors affecting keloid or hypertrophic scar (HS) development after congenital cardiac surgery. STUDY DESIGN: Postoperative scars were studied in 75 patients 3 months after congenital cardiac surgery by median skin incision. The mean age of the 51 males and 24 females was 2.7 +/- 2.3 years (range, 2 days-12 years). The scars were evaluated according to degree of redness, expressed as redness score, and skin blood flow, as measured by laser Doppler imaging. Skin blood flow ratio was calculated as blood flow at the scar divided by blood flow below the navel. After surgery, 40 patients received 5 mg/kg/day of tranilast, which inhibits the collagen synthesis of keloid fibroblasts. RESULTS: None of the 75 patients had keloid formation and 21 (28%) developed HS after operation. Mean age of patients with HS (HS (+) group) was 4.4 +/- 3.3 years and that of patients with no HS development (HS (-) group) was 1.5 +/- 1.9 years (p < 0.01). There were no significant differences between these two groups in gender or in pre- or postoperative cyanosis. Hypertrophic scar (+) patients exhibited significantly higher skin blood flow ratios than HS (-) patients (2.7 +/- 1.3 versus 1.4 +/- 0.6; p < 0.001). Hypertrophic scar was seen in 11 of 40 tranilast administered patients (28%) and in 10 of 34 patients not receiving tranilast (29%) (NS). Hypertrophic scar was less apparent in the patients who received tranilast versus those who did not; redness scores were 29.5 +/- 16.5 and 51.6 +/- 14.9, respectively (p < 0.01). CONCLUSIONS: These data suggest that age and skin blood flow ratio were the factors affecting HS development. Postoperative use of tranilast did not affect the frequency of HS development but did reduce its redness.

Age Factors↗

PubMed1997

Small hepatocellular carcinoma on magnetic resonance imaging. Relation of signal intensity to angiographic and clinicopathologic findings.

RATIONALE AND OBJECTIVES: The authors discuss the clinicopathologic features and angiographic vascularity of various signal intensity patterns on magnetic resonance (MR) imaging of small hepatocellular carcinomas (HCCs). METHODS: Magnetic resonance images of 88 resected HCCs (< or = 3 cm) were obtained using T1- and T2-weighted spin-echo images and T1-weighted images after gadolinium (Gd)-DTPA administration. Images were compared with angiographic and histopathologic findings. RESULTS: Forty HCCs (45%) were depicted on T1-weighted images, 51 (58%) on T2-weighted images, and 41 (49%) on T1-weighted images after Gd-DTPA administration. Overall, 64 (76%) were found on at least one image. On T1-weighted images, hyperintense HCCs histologically showed fatty metamorphosis and portal tracts within the tumor. On T2-weighted images, HCC hyperintensity correlated with expansive growth, peliotic change, and hypervascularity. By contrast, HCCs that were undetected or hypointense on T2-weighted images were well differentiated with replacing growth and portal tracts. On T1-weighted images after Gd-DTPA, hyperintense HCCs had peliotic change; undetected HCCs were well differentiated and hypovascular. CONCLUSIONS: Histologic grade, vascularity, portal tracts and peliotic change correlate with MR signal intensity. For hyperintense HCCs on T1-weighted images and hypo- or isointense HCCs on T2-weighted images, treatment methods must be assigned with the consideration that HCCs may be receiving transsinusoidal and portal blood supplies.

Adult↗

PubMed1997

New evaluation method for postoperative scar redness.

Even after successful operations, ugly postoperative skin scars are often distressing to patients and their parents. To judge the success of surgical methods and postoperative treatment, postoperative scars should be evaluated using a quantitative system. Height and width are easily measured, but scar redness is not. We have developed a simple and effective method for evaluating scar redness. According to the color definitions employed in computer graphics, each color can be expressed as RGB (red, green or blue) coordinates (r, g, b): 0 < or = r, g, b < or = 10. The degree of scar redness is defined by the following formula: redness score (RS) = (r1 - r0)2 + (g1 - g0)2 + (b1 - b0)2. Here, (r1, g1, b1) = coordinates of the scar color and (r0, g0, b0) = coordinates of the surrounding skin color. RS was evaluated in 59 children (35 males, 24 females; ages 1 month to 12 years old) who had scar redness after congenital cardiac surgery. For each patient, scar color and surrounding skin color was identified on the color sample table. Scar redness was also evaluated by the conventional grading method: 1 = mild, 2 = moderate and 3 = severe. The RS of the colored scars ranged from 4 to 100 (38 +/- 27). By the conventional grading method, 44 scars were grade 1, 15 grade 2 and none grade 3. RS was significantly higher among grade 2 than grade 1 patients, 52 +/- 25 and 33 +/- 27, respectively (P < 0.05). Given its subjectivity, the conventional grading method yields variable data surrounding skin color, moreover, is not considered. Our new evaluation method using RS effectively and accurately defines scar and skin colors, and allows quantitative studies of these factors.

Child↗