Biomedical subjects
Publications and source records attributed to N Maeda.
A method to determine risk factors for particular outcomes using trained multilayer neural networks is proposed. The basic idea is to measure the partial differentials of the output with respect to input variables of the network. Differentiable activation functions and continuity of input variables is assumed.
The aggregation kinetics of erythrocytes is studied by using laser light scattering. Laser light is passed through a well mixed sample of blood and the forward-scattered light intensity is recorded continuously. During the process of aggregation and sedimentation under a gravitational field, erythrocytes are subjected to different orientations. The events of a single cell's movement, formation of aggregates and their sedimentation produce a variation in scattered-light intensity. The mean intensity variation that bears this information is effectively employed to arrive at the kinetics of single cells, one-dimensional aggregates and three-dimensional aggregates during sedimentation. In addition to this, the time intervals of different phases of aggregation and sedimentation are also measured. All these parameters are obtained for erythrocytes suspended in native plasma. Then, the results are compared with erythrocytes suspended in dextran (Dx) 70 and Dx 500.
Rheological characteristics of red cells in two patients with refractory anemia (with single chromosomal abnormality of 20q- or 13q-, respectively) were investigated with the hematological and biochemical properties. (1) Whole blood viscosity was remarkably increased, and the red cell deformability was greatly impaired (the impairments were prominent in patient with 20q-). (2) The hematocrit of both patients was about half of the normal value. Remarkable anisocytosis with elliptocytes and poikilocytes was observed in the patient with 20q-, but the anisocytosis was not so prominent in the patient with 13q-. (3) 2,3-diphosphoglycerate content in red cells was markedly increased in both patients, but adenylate content was not. (4) The red cells were slightly resistant to osmotic hemolysis, but they were not heat-labile. (5) Structural abnormality of spectrin was suggested from the impaired dimer-dimer association in red cell membrane and from the different susceptibility of spectrin to tryptic digestion. In conclusion, the rheological impairments and the abnormal shape of red cells in refractory anemia probably originated from the structural abnormality of cytoskeletal proteins in membrane, and the functional and structural abnormality may be different among patients.
Anomalous junction of the pancreaticobiliary duct (AJPBD) is a congenital anomaly associated with gallbladder carcinoma. Especially patients with noncystic dilatation and without dilatation of the biliary tract are at risk of gallbladder carcinoma. A 56-year-old woman with advanced gallbladder cancer associated with AJPBD but without dilatation of the biliary tract was treated at our hospital. Although histologically cancer cells remained in the layer of the proprial mucosa, extensive metastases to lymph nodes including the paraaorta and peripancreas were detected. According to the TNM classification this case was of Stage IVB. The cancer consisted of medullary round cells, and was diagnosed as undifferentiated carcinoma. After surgery poor prognosis was expected, but three years have elapsed with no recurrence. The case is of interest because of two points of discrepancy: the primary cancer did not show deep invasion but demonstrated extensive lymph node metastases; the cancer was histologically malignant but prognosis was relatively good.
This study compared the antibacterial activities of three dentin primers and investigated a newly designed experimental system using a bovine tooth model method for evaluating antibacterial activity by comparing this method with a conventional disk diffusion method. The antibacterial activities of SA primer in Clearfil Liner Bond, LB primer in Clearfil Liner Bond II, and ED primer in Panavia 21 were evaluated using the conventional disk diffusion method. The 50 microliters aliquot of each primer was applied to three sterilized paper disks, then placed onto Tryptic Soy agar plates already inoculated with Streptococcus mutans. After anaerobic incubation for 48 hours, the diffusion of antibacterial components was determined using the inhibition zone produced around the paper disk. The diameter of the inhibition zones was measured and the average calculated. Standardized cavities (diameter 5.0 mm, depth 3.0 mm) were prepared on the labial surfaces of bovine teeth and inoculated with S mutans (10(6) CFU/microliter) following sterilization by 60Co gamma rays (50 KGy). The teeth were divided into four groups: SA primer, LB primer, ED primer, and a control group. Except for the control teeth, the cavity preparations were treated with the respective dentin primers, and then firmly sealed with a temporary sealing material. The teeth were placed in bottles containing melted Tryptic Soy agar. Five ml of Tryptic Soy broth was then added to the surface of the hardened Tryptic Soy agar. After 1 week's incubation of the teeth in the bottles at 37 degrees C, the number of bacteria remaining in each cavity was counted, except for eight specimens, which were used for SEM observation. The ED primer showed the widest inhibition zone in the disk diffusion test, which was significantly different from the other primers. Using the bovine tooth model, all dentin primers showed antibacterial activity, with significant differences found among the four groups. The results indicated that ED primer had the strongest antibacterial effect among the three primers.
It is well known that the defect in bone resorption in osteopetrotic (op/op) mice brings about deformation of the cranium and failure of tooth eruption. However, the influences on longitudinal growth of the craniofacial skeleton have not been elucidated. This study was thus conducted to examine craniofacial morphology and longitudinal changes in the op/op mice by means of morphometric analysis with lateral cephalograms. Lateral cephalograms, taken every 10 days from 10- to 90-day-old mice, were analyzed on a personal computer for 11 measurement items. For the nasal bone region, the most prominent differences were found between the op/op and normal mice. The anterior cranial base and occipital bone height presented almost equivalent growth changes in both the op/op and normal mice. The size of mandible, meanwhile, was significantly smaller in the op/op mice than in the normal controls. The gonial angle was also significantly larger in the op/op mice than in the normal mice throughout the experimental period. Thus, substantial differences in craniofacial growth were demonstrated in various areas of the craniofacial complex, which are assumed essentially due to the lack of osteoclastic bone resorption during growing period. Since the difference became more prominent in the anatomic regions relevant to the masticatory functions, it would be a reasonable assumption that reduced masticatory function is also a key determinant for the less-developed craniofacial skeleton in the op/op mouse.
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The prognosis of primary liver cancer, especially cholangiocarcinoma, is extremely poor. A long term, 12 years survivor of intrahepatic cholangiocarcinoma arising in a local dilatation of the intrahepatic bile duct is presented. A 40-year-old male patient was presented with recurrent upper abdominal pain, fever, and jaundice. Computed tomography revealed a localized duct dilatation, and ultrasound clearly demonstrated a tumor mass arising within the bile duct. At surgery in March, 1982, the tumor mass was resected and histologically confirmed as a well differentiated papillary adenocarcinoma arising. In March, 1994, the patient is alive and cancer-free, 12 years after surgical resection. To our knowledge, there has been no report on a patient surviving more than 10 years after initial treatment. This case suggests that a localized cystic dilatation of the intrahepatic-bile duct on imaging modalities may harbor a bile duct carcinoma, and this in turn may contribute to early diagnosis of carcinomas and improved long term survival.
OBJECTIVE: Bromhexine has been reported to alleviate the xerostomia and xerophthalmia associated with secondary Sjögren's syndrome. The aim of this study was to determine if it might prove useful in the treatment of Sjögren's syndrome-like disease of the NOD mouse model for autoimmune sialoadenitis. METHODS: Groups of mice were divided into sets receiving 60 mg/kg bromhexine in drinking water and control pair-fed animals. The efficacy of drug treatment was assessed by weekly measurement of stimulated saliva volumes, protein concentration, and amylase activity. At termination (20 weeks) submandibular and lacrimal glands were removed to assess the levels of lymphocytic infiltration by histological evaluation under light microscopy. RESULTS: Control and bromhexine-treated groups of mice showed no difference in the loss or rate of reduction in stimulated saliva flow over the 12 weeks of treatment. No differences were noted in the protein concentration and amylase loss with increasing age of the animals. Similar temporal changes in total protein profiles and aberrant expression of the 20 kDa parotid secretory protein isoform were observed by SDS-polyacrylamide gel profiles and Western bolt analysis. Histological evaluation of exocrine gland sections failed to detect any reduction in focal lymphocyte infiltration. CONCLUSION: Bromhexine therapy did not alter the development or severity of Sjögren's syndrome-like disease in the NOD mouse model for autoimmune sialoadenitis.
Extrahepatic portal obstruction is one of the causes of portal hypertension, in which well-developed hepatopetal pathways are commonly recognized. Herein an extremely rare case of extrahepatic portal obstruction without hepatopetal pathway, probably caused by arterioportal fistula, is reported. The patient was a normally matured 16-year-old girl admitted for further evaluation of jaundice, presenting with the clinical manifestations of the portal hypertension associated with hypersplenism and portosystemic venous shunt. Celiac angiography clearly demonstrated an intrahepatic arterial aneurysm fed by the right hepatic artery shunting to the superior mesenteric vein, and portography disclosed complete obstruction of the portal trunk with conspicuous hepatofugal pathway but no hepatopetal collateral veins. The exact mechanism of this phenomenon is not known and whether the extrahepatic portal obstruction was primary or secondary is still obscure. However, this is the first case report in the world literature describing extrahepatic portal obstruction with absence of hepatopetal pathway.
BACKGROUND/AIMS: Liver weight at autopsy in patients with hepatocellular carcinoma (HCC) has been found to differ by geographic region. The clinicopathological characteristics of HCC in relation to liver weight at autopsy have not been reported for Japanese cases. METHODOLOGY: From 1980 to 1992, a total of 107 consecutive HCC autopsy cases were studied. Seven cases were excluded (5 surgically resected cases and 2 cases of occult-type HCC (Berman) which were diagnosed at autopsy for the first time). The 100 cases of HCC were divided into 4 groups according to liver weight at autopsy: less than 999 g (group A, n = 15, 15%); 1000-1999 g (group B, n = 50, 50%); 2,000-2,999 g (group C, n = 20, 20%); and more than 3,000 g (group D, n = 15, 15%). Various clinical and pathological findings, including age, sex, hepatitis B surface antigen (HBsAg) status, history of blood transfusions, treatment, cause of death, underlying liver disease, survival after diagnosis, tumor size, macroscopic findings, microscopic findings, splenic weight and liver weight were studied. RESULTS: Significant differences between groups were found in sex (p < 0.01), underlying liver disease (p < 0.001), tumor size (p < 0.0001), microscopic findings (p < 0.001) and survival (p < 0.01). The lowest liver weight group (group A) had a significantly longer mean survival rate than the other three groups (p < 0.001). CONCLUSIONS: These results showed that 15% of HCC occurred in large size livers (more than 3,000 g), 15% occurred in small size livers (less than 999 g) and 70% occurred in livers between 1,000 g and 2,999 g, and that tumor size (p < 0.0001) and microscopic findings (p < 0.001) were the major determinants of liver weight in HCC patients. The total liver volume reflected by liver weight in HCC cases may be valuable for the assessment of the clinicopathological features of HCC and its prognosis.
Agenesis or hypoplasia of the hepatic lobe and floating gallbladder are both rare. We report an extremely rare case of hypoplasia of the left hepatic lobe accompanied by floating gallbladder. The patient was a 71-year-old woman, with no past history of related symptoms, who was admitted for further evaluation of postprandial epigastralgia, nausea, and diarrhea. Laboratory data on admission showed chronic liver disease with positive anti-hepatitis C virus antibody. Abdominal ultrasonography and computed tomography revealed the absence of the left hepatic lobe and displacement of the gallbladder to the left. On endoscopic retrograde cholangiography, the cystic duct originated from the right side of the bile duct, but the gallbladder was displaced to the left. Poor yolk-induced gallbladder contraction suggested the existence of hypotonic biliary dyskinesia. Angiography demonstrated no middle or left hepatic arteries, indicating congenital hypoplasia of the left hepatic lobe. Open cholecystectomy was carried out, and a diagnosis of hypoplasia of the left hepatic lobe accompanied by floating gallbladder and chronic hepatitis was confirmed. We believe that this is the first reported case of a hypoplasia of the left hepatic lobe coexisting with floating gallbladder.