Biomedical subjects
Publications and source records attributed to M Kanai.
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In 17 consecutive patients who underwent major hepatic resection, 9 of whom with combined resection of the gastrointestinal tract or the pancreatic head (or both), postoperative hepatic blood flow was investigated. In this study, the patients were classified into two groups according to their postoperative serum total bilirubin level: Group A comprised 7 patients with the level higher than 7 mg/dl for more than 1 week postoperatively, and group B comprised 10 patients who did not meet this criterion. For 2 weeks after surgery, the portal blood flow velocity, the hepatic artery resistive index (RI) calculated from the changes in Doppler frequency shifts, and the hepatic venous blood flow velocity were measured intermittently using color Doppler ultrasonography. Liver volume was assessed by computed tomography to provide the restoration. Significant differences in portal blood flow velocity and hepatic artery RI were noted between the two groups from the third postoperative day. In group A the portal blood flow velocity decreased below the preoperative value, and the hepatic artery RI increased above 0.75. In contrast, group B showed high portal blood flow velocity and low hepatic artery RI. In both groups the RI correlated significantly with the total bilirubin level (r = 0.74; p < 0.0001), and the growth rate of the remnant liver was proportional to the mean postoperative portal blood flow velocity (r = 0.70; p = 0.016). We concluded that measurement of the portal blood flow velocity and hepatic artery RI can be useful for predicting postoperative liver dysfunction and liver regeneration after major hepatic resection.
The most important role in a radiologist's work is communicating his findings to the attending physician. This is difficult when the radiologic examinations are performed with portable X-ray units because the attending physician wishes to read the images as soon as possible. To resolve this problem, we have developed an independent double reading system. The hardware consists of a magnetic card reader, a display station, a personal computer and a mouse, all linked with the digital image database and a communication network between HIS and RIS. We also present the software of this system and evaluate the results of the implementation to establish the accuracy of the technique. It was concluded that this system could expand the contribution of the radiologist to portable radiographic examinations and to improve the quality of the RIS database.
Decreased levels of cerebrospinal fluid (CSF) Abeta42 is a diagnostic marker of Alzheimer's disease. To clarify the biological basis of this marker, the physiological alterations of CSF Abeta40 and Abeta42 by aging were studied. CSF samples from 92 normal subjects between 8 and 89 years old were measured using a specific ELISA for Abeta40 and Abeta42(43). High concentrations of Abeta40 and Abeta42(43) in the young group, under 29 years old, changed to be at low concentrations in the adult group between 30 and 59 years old. Subsequently, the levels increased again with age. Third order regression analysis showed a significant correlation between the levels of Abeta40 and age (Y = - 169 X(3) + 3.1X(2)- 0.02X + 4135; P < 0.034) and between the levels of Abeta42(43) and age (Y = - 46 X(3) + 0.9 X(2)- 0.005X + 992; P < 0.005). The levels of CSF Abeta40 and Abeta42(43) were physiologically regulated to show a U-shaped natural course in normal aging. These findings suggested that the physiological increase of Abeta42(43) over 59 years of age is selectively inhibited in Alzheimer's disease.
Carboxyl-terminal fragments of beta amyloid precursor protein (betaAPP) were expressed in mice under the transcriptional control of an ubiquitous promoter system, based upon a chicken beta-actin (betaA) promoter combined with cytomegalovirus (CMV) enhancer to obtain a systemic overproduction of amyloid beta protein (Abeta). Three transgene constructs were designed to encode signal peptide and carboxyl-terminal 99 amino acid residues to betaAPP (NOR-beta), methionine and C-terminal 103 amino acid residues of betaAPP (deltaNOR-beta), and methionine and C-terminal 103 amino acid residues with KM-NL substitution of betaAPP (deltaNL-beta). Although the transcriptional mRNA level and post-translational protein level from transgenes showed the same expression pattern, both the expression of Abeta and distribution of Abeta deposits were completely different among these strains. In NOR-beta mice, considerable amounts of Abeta were detected in plasma and Abeta deposits were observed in the pancreas. Brain Abeta deposits and small amounts of plasma Abeta were recognized in deltaNL-beta. These findings indicate that tissue specific processing and transgene constructs are major factors to determine the distribution of Abeta deposits.
Mitogen-activated protein kinase (MAP kinase) plays a central role in the signal transduction for diverse cellular responses, such as proliferation, differentiation, stress response and cell death, via activation after binding of growth factors to the respective receptors on the cell membrane. In the human placental tissues, however, little is known about the expression and activation of the classical MAP kinases, extracellular signal-regulated kinase1/2 (ERK1/2). We therefore examined the expression of ERK1/2 in the human chorionic and placental tissues between 5 and 41 weeks of gestation, using Western blotting, immunohistochemistry and in situ hybridization. To explore the activation of ERK1/2 protein, we used an antibody that reacts with both phosphorylated and non-phosphorylated ERK1/2 (total ERK1/2), as well as antibodies that react only with phosphorylated ERK1/2. The expression pattern of phosphorylated ERK1/2 in the trophoblasts was compared with that of various growth factor receptors, such as c-met, IGF-1R, flt-1, EGFR, PDGFR, Bek, and flg. Total ERK1/2 was immunolocalized in the villous cytotrophoblasts (CTs), but not in the syncytiotrophoblasts (STs), throughout pregnancy. In situ hybridization also showed the localization of ERK1 mRNA in the villous CTs. Interestingly, however, phosphorylated ERK1/2 was immunolocalized in the villous CTs only up to 12 weeks of gestation. Western blot also showed the stronger bands of phosphorylated ERK1/2 in the tissues of the first trimester. Among the growth factor receptors, c-met was strongly expressed in the villous CTs during the first trimester, and resembled the expression pattern of phosphorylated ERK1/2. These findings suggest that the MAP kinase pathway is activated in the villous CTs during the first trimester in the human placenta.
The pathophysiology of altitude-related disorders in untrained trekkers has not been clarified. In the present study, the effects of workload on cardiovascular parameters and regional cerebral oxygenation were studied in untrained trekkers at altitudes of 2700 m and 3700 m above sea level. We studied 6 males and 4 females at each altitude, and their average ages were 31.3+/-7.1 y at 2700 m and 31.2+/-6.8 y at 3700 m, respectively. The resting values of heart rate and mean blood pressure were not significantly different at 2700 m and 3700 m than at sea level. However, increases in these values after exercise were more prominent at high altitudes (heart rate increase = 51.6% at 2700 m and 70.4% at 3700 m; mean blood pressure increase: 19.0% at 2700 m and 17.2% at 3700 m). In addition, post-exercise blood lactate concentration was significantly higher at 3700 m than at sea level or at 2700 m (i.e., 7.6 mM at 3700 m, 3.8 mM at 2700 m, and 4.17 mM at 0 m, respectively). Exercise induced an acute reduction in the arterial oxygen saturation value (SpO2) at 2700 m and 3700 m (i.e., 11.2% reduction at 2700 m and 9.4% at 3700 m), whereas no changes were observed at sea level. The resting values of regional oxygen saturation (rSO2)--measured by a near infra-red spectrophotometer at sea level, 2700 m, and 3700 m-were nearly identical. Exercise at sea level did not reduce this value. In contrast, we observed a decrease in rSO2 after subjects exercised at 2700 m and 3700 m (i.e., 26.9% at 2700 m and 48.1% at 3700 m, respectively). The rSO2 measured 2 min and 3 min after exercise at 3700 m was significantly higher than the preexercise value. From these observations, we concluded that alterations in cardiovascular parameters were apparent only after an exercise load occurred at approximately 3000 m altitude. Acute reduction in cerebral regional oxygen saturation might be a primary cause of headache and acute mountain sickness among unacclimatized trekkers.
BACKGROUND/AIMS: To clarify a correlation between serum alkaline phosphatase (ALP) levels and liver function and regeneration after major hepatectomy. METHODOLOGY: Post-operative changes in serum ALP levels were retrospectively examined in 91 non-cirrhotic patients with biliary tract carcinoma who underwent right hepatic lobectomy or more extensive liver resection. In addition, changes in liver volume after resection were assessed in 31 patients who underwent computed tomography before surgery and within 1 month after resection. RESULTS: Serum ALP levels reached its nadir on post-operative day 1, followed by a gradual increase until post-operative day 28. In patients with post-hepatectomy liver failure (n = 32), serum ALP levels were significantly lower on days 1, 7, 10, 14, 21, and 28 after resection than in those without such failure (n = 59). Unexpectedly, the volumetric study of the liver showed no significant difference between the two groups in the remnant liver volume after resection. CONCLUSIONS: Serum ALP levels can function as an indicator of liver function after hepatectomy, but not reflect morphological regeneration of the liver. Thus, increased ALP levels after hepatectomy may not reflect the cellular proliferation process itself.
We performed pancreatoduodenectomy for 5 patients with gastric cancer, and here we present 2 who have survived for more than 10 years. Patient one had a large antral tumor tightly adherent to the head of the pancreas. Pancreatoduodenectomy with lymph node dissection was performed. Pathologic examination of the resected specimen revealed that the tumor was a well differentiated adenocarcinoma invading the duodenum, but not the pancreas. Patient two had an infrapyloric lymph node metastasis invading not only the pancreatic head, but also the duodenocolic ligament and the transverse mesocolon. Pancreatoduodenectomy and right hemicolectomy with lymph node dissection were performed. Pathological examination of the resected specimen revealed grade III lymph node metastasis, and invasion of the pancreas by the metastatic infrapyloric lymph node. These results indicate that complete resection of tumor by pancreatoduodenectomy may result in a long survival not only for the patients in whom pancreatic invasion and/or lymph node metastasis is limited, but also for some patients with tumor invading the pancreatic parenchyma and/or of grade III lymph node metastasis.
A 70 year-old female, who presented with jaundice and abdominal pain, was found to have an advanced gallbladder cancer involving the liver parenchyma, duodenum, and transverse colon. This was complicated by a bilio-biliary fistula between the gallbladder and both the right and left hepatic ducts. After obtaining an accurate pre-operative diagnosis, the patient underwent hepatopancreatoduodenectomy (HPD) with lymph node dissection around the hepatic pedicle, celiac trunk, aorta, and inferior vena cava. Histologic examination revealed adenosquamous carcinoma. This rare variant accounts for 3.5% of gallbladder cancers, and is associated with a worse prognosis than adenocarcinoma. The patient is in good condition without any signs of recurrence 42 months after the HPD. In this case report, we discuss the histological type and internal biliary fistula with regard to the literature, and the usefulness of an aggressive surgical procedure such as HPD with extended lymph node dissection which can improve survival and quality of life in selected patients.
BACKGROUND AND OBJECTIVE: We investigated the effect of photodynamic therapy (PDT) using topically administered ATX-S10(Na) on corneal neovascularization (CoNV). MATERIAL AND METHODS: Rabbit eyes with induced CoNV were treated with ATX-S10(Na) eye drops (10 mg/mL) every 5 minutes, 5 to 25 times. Five to ninety minutes after topical administration, the CoNV were irradiated with a diode laser using a wavelength of 670 nm. RESULTS: The CoNV were occluded fluorescein angiographically in 7 of 16 treated eyes. The eyes having occluded, CoNV were irradiated using fluence of 510-1019 J/cm2 within 20 minutes of eye-drop administration. However, the effect was more variable than what we found using systemic administration in our previous investigation. CONCLUSIONS: Experimental CoNV was occluded by photodynamic therapy using topically administered ATX-S100(Na), suggesting this modality as a possible treatment for CoNV avoids the side effects found with systemic administration of the dye. Further efforts to improve the eye drops in terms of pH and osmotic pressure are needed to achieve increased dye accumulation.
We report two different types of portal vein obstruction after liver resection: portal vein thrombosis due to steal phenomenon via a splenorenal shunt, and kinking of the skeletonized left portal vein after right hepatic lobectomy with caudate lobectomy. The two cases of portal vein obstruction were asymptomatic without any suggestive laboratory findings. Only routine Doppler ultrasonography detected portal vein obstruction which was successfully treated by emergency operation.
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BACKGROUND/AIMS: We conducted the present study in order to clarify the clinicopathologic features of primary cholesterol hepatolithiasis and compare them with those in primary calcium bilirubinate hepatolithiasis. MATERIALS AND METHODS: We reviewed the clinicopathologic features of 24 patients with primary cholesterol hepatolithiasis. The clinical symptoms were mild, and the median duration of symptoms was 5 years. RESULTS: In 22 patients complete stone clearance was obtained using percutaneous cholangioscopic lithotomy, partial hepatectomy, or their combination. The patients showed excellent clinical outcome (median follow-up period, 6 years) despite the absence of bilioenteric drainage. Stones have recurred in 4 patients, who remain asymptomatic. The histopathologic findings in 7 hepatectomized patients were compared with those in 7 patents with calcium bilirubinate hepatolithiasis. The inflammatory changes around the stone-containing duct, i.e., wall thickening, fibrosis, sludge formation, and glandular hyperplasia, were significantly milder in the cholesterol hepatolithiasis patients (p < 0.01 or p < 0.05). CONCLUSIONS: These clinical and histopathologic findings indicate that primary cholesterol hepatolithiasis should be regarded as a different clinical entity from calcium bilirubinate hepatolithiasis which has a close relationship with bile stasis and bacterial infection as etiological factors.
Cholangitis is a risk factor for posthepatectomy liver failure and therefore should be treated aggressively by urgent biliary drainage before definitive liver surgery for bile duct carcinoma. We present a case of bile duct carcinoma of the hepatic hilus with segmental cholangitis. The patient was a 38-year-old man. Percutaneous transhepatic biliary drainage (PTBD) was performed in the left anterior, right anterior, and right posterior segmental ducts to alleviate jaundice and to evaluate the biliary system. One month after PTBD, the patient developed high fever with leukocytosis, suggesting the onset of segmental cholangitis. An urgent repeat PTBD was carried out at the caudate and left medial segmental bile ducts. The bile juice was purulent, and the tube cholangiogram revealed miliary abscesses. After PTBD, cholangitis was subsided, and extended left hepatic lobectomy with caudate lobectomy was performed. The postoperative recovery was uneventful and the patient has been well for 13 months. We conclude that the onset of fever in patients with hilar bile duct cancer, PTBD catheters, and undrained biliary segments suggests the presence of segmental cholangitis.
We describe a case of biliary cystadenocarcinoma of the liver in a 72 year-old woman presented to our hospital with abdominal fullness. Laboratory data showed an elevation of alkaline phosphatase and a decreased excretion of Indocyanine green (ICG). CT revealed a cystic tumor with papillary projections, measuring 13A approximately 15cm, in the left medial segment of the liver (S4). Percutaneous transhepatic cholangioscopy (PTCS) disclosed the tumor in the dorsal subsegmental duct of S4 and the cholangioscopic biopsy from the tumor revealed papillary adenocarcinoma. PTCS showed the left lateral posterior segmental bile duct (B2) joined the common tract of the left medial (B4) and left lateral anterior (B3) segmental bile duct, and the tumor involved B4 and B3 but not the common tract of B4 and B3. A radical surgery, which included segment 4 and 3 resection with preservation of the left hepatic duct and the segment 2 was performed. The histopathological examination revealed that the tumor did not involve the liver parenchyma and had no lymph node metastasis. Postoperative course was unremarkable and the patient at present time, 4 years after the operation, is doing well. This case report discusses the importance of preoperative evaluation by PTCS for a rational surgical procedure.
We present a case report of metastatic seeding at the percutaneous transhepatic biliary drainage tract in a 68 year-old man who previously underwent pancreatoduodenectomy with bile duct resection for distal bile ductal carcinoma. Three years and 5 months after the initial operation, dilation of the left lateral segmental bile ducts was detected by abdominal ultrasonography. Percutaneous transhepatic cholangiography disclosed a stricture at the confluence of the ventral and dorsal branches of the left lateral anterior segmental duct. This region corresponded to the punctured point of the previous percutaneous transhepatic biliary drainage. Implantation of the bile duct carcinoma at the percutaneous transhepatic biliary drainage sinus tract was diagnosed, and the recurrent tumor was successfully resected by an extended left hepatic lobectomy with a total caudate lobectomy. Currently, 8 years and 3 months after the second surgery, the patient is in good health without any signs of tumor recurrence. This case report discusses the entity of metastatic seeding, a rare but serious complication of percutaneous transhepatic biliary drainage. An aggressive surgical approach is important for recurrent biliary tract malignancies.