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Biomedical subjects

T Tsuji

Publications and source records attributed to T Tsuji.

At least 793 records · Page 44Linked to original sources

Analysis of galactosyltransferase activity in rat gastric mucosa using crude mucosal homogenate.

Mucus glycoprotein is one of the major components of gastric mucus which plays an important role in mucosal defensive mechanisms as a mucus-bicarbonate barrier. Analysis of the mucus glycoprotein synthesis is a useful tool for evaluating gastric mucosal defensive factors. UDP-galactosyltransferase (UDP-Gal-T) is one of the regulating enzymes for the synthesis of the mucus glycoprotein. In the present paper, we studied assay methods for UDP-Gal-T activity in rat gastric mucosa using radiolabeled UDP-galactose and two different kinds of acceptor proteins, namely ovomucoid and asialomucin, and analyzed effects of antisecretory agents on the UDP-Gal-T activity. We used crude supernatants of homogenized scrapings of the fundic part of rat stomach as an enzyme preparation and determined optimal conditions. In each acceptor, Mn2+ and the non-ionic detergent Triton X-100 were required for the enzyme activity. With each acceptor molecule, the type of glycosidic linkages of galactose was beta-type linkage. With asialomucin as an acceptor, UDP-Gal-T activities of rat gastric mucosa decreased after intraperitoneal administration of antisecretory agents, while change of the enzyme activity was not observed with ovomucoid as an acceptor.

Animals↗

Sequence variations in the envelope protein of the hepatitis C virus: comparison with partial cDNA sequence of a new variant virus obtained by the polymerase chain reaction.

It has been reported that the envelope region located at the 3' portion of the structural protein coding region is one of the most variable regions at both nucleotide and amino acid sequence levels in the hepatitis C virus (HCV) genome. We cloned HCV cDNA fragments of an envelope protein coding region (HCVNK), which were derived from serum of a Japanese patient with hepatocellular carcinoma and were amplified by polymerase chain reaction. After determining the nucleotide sequence, deduced amino acid sequence of the envelope protein region was compared with those of six HCV strains already published (HCJ1, HCVUS, HCJ4, HCVJH, HCVJ and HCVBK). Homology analysis among the strains revealed that the seven strains were classified into two subtypes; a US subtype (HCJ1 and HCVUS) and a Japanese subtype (HCJ4, HCVJH, HCVJ, HCVBK and HCVNK), since percentage homologies between two subtypes (70.3-77.3%) were significantly lower than those within each subtype (83.9-93.5%). Detailed analysis of the amino acid sequences also indicates that the region at aa246-aa258, tentatively named intersubtype variable region-1, may distinguish the US subtype from the Japanese subtype.

Amino Acid Sequence↗

Immunohistochemical characterization of the lymphocyte and the immunoglobulin-containing cell in the epithelium and the lamina propria of normal human intestines.

In order to clarify difference of the mucosal immunity in various sites of normal large and small intestines, we studied the population of lymphocyte subsets and immunoglobulin (Ig)-containing cells in situ in biopsy specimens taken from various sites (ascending colon, sigmoid colon and rectum) of the large intestine and from the duodenum using an immunohistochemical method. Monoclonal antibodies against pan-T (Leu 1), cytotoxic/suppressor T (Leu2a), helper/inducer T (Leu3a), suppressor T (Leu15) and natural killer/K (Leu7) cells, and polyclonal antibodies to human IgG, IgA and IgM were used. In the duodenum, intraepithelial lymphocytes (IELs) were more prominent than in the large intestine. Immunoelectron microscopic observation revealed that some Leu2a+ IELs possessed pseudopods extending into intestinal epithelial cells, indicating that some IELs belong to the cytotoxic T cell subset. Leu7+ IELs were scarcely observed and Leu7+/Leu1+ ratio was higher in the large intestine than in the duodenum. Furthermore, the number of Leu7+ cells were more in the distal than the proximal colon. In the lamina propria Ig-containing cells tended to be fewer in the rectum than in the duodenum and the proximal colon. Our findings may suggest the variation of local immune responses and the difference of assigned immunological functions among the various sites of the intestines.

Adult↗

Association between high grade ventricular arrhythmia and extent of left ventricular hypertrophy in hypertrophic cardiomyopathy.

The association between the extent of left ventricular (LV) hypertrophy and severity of ventricular or atrial arrhythmias are examined. Two-dimensional echocardiography and 24-h Holter electrocardiography monitoring were performed in 60 patients with hypertrophic cardiomyopathy (HCM). According to the distribution of the LV hypertrophy, the patients were divided into three groups: 1. Apical hypertrophy (APH), 2. Septal hypertrophy, and 3. Extensive hypertrophy. Ventricular arrhythmias were found in 82% of the patients and supraventricular arrhythmias were detected in 70% of the patients. Lown grade III and IV arrhythmias occurred significantly more frequently in patients with extensive than with septal hypertrophy. Lown grade III to IV arrhythmias did not occur in patients with APH. Present results show a significant association between the extent of LV hypertrophy and the severity of ventricular arrhythmias in HCM.

Adult↗

[Diffuse cerebrospinal gliomatosis. Case report].

A 65-year-old male was admitted with memory and gait disturbance. A computed tomography (CT) scan showed bilateral, diffuse, low-density areas with two round, slightly enhanced masses. T1-weighted magnetic resonance image revealed a low-intensity area in the left paraventricular region, which converted to increased signal intensity, extending to the right paraventricular region through the splenium, on T2-weighted images. The tumor was diagnosed as glioblastoma multiforme after needle biopsy and treated by irradiation and chemotherapy. Seven months after admission, a CT scan revealed subependymal infiltration of the tumor with spotty calcification. He died of respiratory complications 11 months after the onset of symptoms. The autopsy showed brain swelling with flattened gyri. Horizontal sections of the brain showed diffuse enlargement of the white matter and basal ganglia with scattered hemorrhage and necrosis. Microscopically, the lesion was far more extensive and diffuse than was suspected from gross examination. Wide glial tumor cell infiltration was observed in the cerebral hemispheres, basal ganglia, brainstem, cerebellum, and even the cervical spinal cord with minimum destruction of the pre-existing architecture. Calcification was found around the thrombosed vessels and necrotic lesions. The clinical diagnosis and histological features of gliomatosis cerebri are discussed with reference to reported cases.

Aged↗

Revascularization of the calcarine artery in moyamoya disease: OA-cortical PCA anastomosis--case report.

A 38-year-old male presented with moyamoya disease. Occlusion of the bilateral proximal posterior cerebral arteries (PCAs) resulted in homonymous 3/4 (right half and left lower quadrant) anopsia and various mental symptoms. To prevent impending cortical blindness, revascularization to the right PCA was performed by occipital artery (OA) to calcarine artery anastomosis. His neurological state was stabilized. OA-cortical PCA (calcarine artery) anastomosis is an alternative to omentum transplantation or occipital burr hole procedures for impending cortical blindness.

Adult↗

[Symposium: Current evaluation of diagnostic methods on viral hepatitis type C and consequent clinical features].

In this symposium, the speakers have discussed the progress of the current diagnostic methods available for the diagnosis of viral hepatitis type C, and the accuracy and reproducibility at hand now, or which should be attained in the near future. Since the first appearance of ELISA (Ortho) and RIA (Dainabot) kit, the screening of infected blood with HCV from donors has been very successful. Posttransfusion hepatitis following infected blood transfusion has clearly decreased. The carrier rate of HCV in the Ehime prefecture is reported to be 1.85% in males and 1.25% in females. Diagnostic methods of the second generation such as ELISA and RIBA using C200 and C22 (core) protein as antigens yield 92.6 to 100% positive results in a diagnosis of NANB hepatitis following anti-hemophilic sera injection or hemodialysis. Detection of HCV RNA by RT-PCR procedure promised accurate diagnosis. Using such diagnostic methods, the majority of the patients with NANB chronic hepatitis were diagnosed as having CH type C. IgM anti-C 100-3 antibody was not useful for early diagnosis of patients infected with HCV, but the titer was useful for determining the therapeutic response of patients on INF therapy. The route of infection was concluded to be mostly horizontal rather than vertical (maternal-child), though a few cases were present suggestive of maternal transmission. Interferon therapy against patients with CH type C was effective in CAH 2A, but only a poor response was observed in patients with CAH 2B.

Hepacivirus↗

Intrafamilial transmission of hepatitis C.

To identify intrafamilial transmission of hepatitis C virus, we tested for antibodies to hepatitis C virus (anti-HCV) in serum samples of 160 family members (12 parents, 17 siblings, 73 children, and 58 spouses) of 76 index patients with chronic hepatitis C. Anti-HCV was detected in 14 of 160 family members (8.75%). This positive rate was significantly higher than the anti-HCV-positive rate in age-matched volunteer blood donors in our district (8.75% vs. 1.42%; P less than 0.01). Among 14 members, 5 had normal liver function tests and 9 had hepatitis C. In 4 of 73 children, anti-HCV was detected (5.48% vs. 0.55%; P less than 0.01). In the two children, transmission from mother to child in their childhood was suspected, and in the other children, transmission was from father to child. Furthermore, 7 of 58 spouses (12.1%) had anti-HCV (12.1% vs. 2.13%; P less than 0.01). These results suggest that intrafamilial transmission, especially horizontal infection may play an important role in the spread of hepatitis C.

Adult↗

Encapsulated multicellular spheroids of rat hepatocytes produce albumin and urea in a spouted bed circulating culture system.

Multicellular spheroids are spherical cell-aggregates that retain tridimensional architecture and tissue-specific functions. For use of multicellular spheroids of hepatocytes in a bioreactor for hybrid artificial liver support, we studied the effect of encapsulation and circulating culture on their integrity and tissue-specific functions. Multicellular spheroids of rat hepatocytes were encapsulated into microdroplets of calcium alginate gel and were used as a bioreactor in medium circulating in a spouted bed chamber. Approximately 10% of the hepatocytes of an adult rat were entrapped in a bioreactor chamber, connected to a gas exchanger and a medium reservoir. The total bed volume of the system was 250 ml. The pH and DO2 of the hormonally defined circulating medium was maintained constantly. Albumin and urea were produced in a linear fashion for 64 h at the rates of 0.02 micrograms/microgram cell protein/day and 0.15-0.2 ng/micrograms cell protein/day, respectively. Viability and structural stability of the spheroids were well preserved after the culture period. These results indicate that these encapsulated multicellular hepatocyte spheroids will provide a useful bioreactor for the continuous production of albumin, in vitro and also a prototype hybrid artificial liver support.

Albumins↗

[Effects of denopamine on hemodynamics and blood gases in secondary pulmonary hypertension].

The acute hemodynamic and blood gas changes caused by denopamine (2 micrograms/kg/min, d.i.) were investigated in 13 patients with chronic respiratory failure and secondary pulmonary hypertension. Denopamine significantly reduced mean pulmonary arterial pressure from 25 +/- 7 to 23 +/- 7 mmHg (p less than 0.05), and pulmonary vascular resistance from 314 +/- 166 to 276 +/- 168 dyne/sec/cm-5 (p less than 0.05), while mean systemic arterial pressure and systemic vascular resistance showed no significant change. Pulmonary-systemic vascular resistance ratio was reduced significantly from 0.22 +/- 0.09 to 0.18 +/- 0.09 (p less than 0.05). These findings suggest that denopamine has more marked effects on the pulmonary artery than on systemic arteries. Arterial oxygen tension (PaO2) increased significantly from 59.0 +/- 8.1 to 62.5 +/- 10.5 Torr (p less than 0.01), and arterial carbon dioxide tension (PaCO2) decreased significantly from 49.1 +/- 6.8 to 44.6 +/- 7.0 Torr (p less than 0.01) by denopamine. Mixed venous oxygen tension (PvO2), which is an indicator of tissue oxygenation, increased significantly from 33.3 +/- 3.5 to 34.4 +/- 3.3 Torr (p less than 0.05). We conclude that denopamine is thought to be useful for the improvement of hemodynamics and tissue oxygenation in patients with secondary pulmonary hypertension. However, further long-term studies are necessary to establish its therapeutic efficacy.

Adult↗

Surgical indication and significance of portal vein resection in biliary and pancreatic cancer.

Tumor and vascular resection was carried out in 27 patients with biliary and pancreatic cancer. Vascular resection included resection and reconstruction of the both the portal vein and hepatic artery in two of the patients. Portal vein resection only was carried out in 23 patients, and resection of the side wall and plasty of the portal vein was carried out in the other two patients. The technical limit of portal vein resection without graft was 4 cm in the hepatic hilus and 7 cm after total pancreatectomy or pancreatoduodenectomy without grafts. On temporary occlusion of the portal vein between resection and reconstruction, simple occlusion was sufficient if it occurred within 30 minutes. In occlusion of more than 30 minutes, simultaneous occlusion of the superior mesenteric artery is better to prevent congestion of the intestine. If occlusion of more than 60 minutes is anticipated, a bypass between the superior mesenteric vein and the femoral vein with Anthron tube is recommended. The postoperative course was uneventful in 20 of the 27 patients. Two patients died within 1 month after surgery. The mortality rate for this aggressive surgery was 8.4%. Minor complications such as hydrothorax, small bile leakage, and localized abscess were observed but soon subsided in five patients. Fourteen of 27 patients survived or are alive after more than 1 year, and 9 of 14 patients survived or are alive after 2 years. Forty-seven percent of the patients who had no lymph node metastasis or peritumor lymph node metastasis without cancerous invasion of the portal vein intima survived more than 2 years. The longest length of survival of a patient with nonfunctioning islet cell carcinoma of the pancreatic head was 5 years 9 months. The longest surviving patient with ductal cell carcinoma of the pancreas is still living after 4 years. This approach is recommended in certain patients with vascular involvement but without lymph node metastasis or those patients with only peritumor lymph node involvement. Frozen section of mesenteric and paraaortic nodes should be standard practice before this aggressive resection.

Adult↗

[Changes in cell kinetics of rat lens epithelial cells with aging].

Whole-mount preparations of developing rat lens epithelium were made and 3H-thymidine autoradiography was performed on them. The distribution of 3H-thymidine-labeled (DNA-synthesizing) epithelial cells was examined by the above combined methods. Labeled cells were evenly distributed in the epithelial cell layer (not the definitely germinal zone) until 1 week after birth. In 3- or 7-week-old rat lens, labeled cells were mainly distributed in the germinal zone, and the number of labeled cells localized in the anterior subcapsular epithelial cell layer decreased according to age of the rat. The 24-week-old rat showed localization of labeled cells at the germinal zone, which seemed to be similar to the human adult lens.

Aging↗

[Acute and chronic effects of vasodilators in a case of chronic recurrent pulmonary embolism].

A 65-year-old man was admitted to our hospital because of shortness of breath on exertion. As the results of examinations including pulmonary angiography, pulmonary perfusion scan and pulmonary ventilation scan, we diagnosed the case as chronic recurrent pulmonary embolism. Although the patient received thrombolytic therapy by a tissue plasminogen activator (t-PA), there was no noticeable improvement. However, oxygen and vasodilator therapy had marked effective on the hemodynamics. In chronic pulmonary embolism, vasodilators are generally not considered to be effective for improvement of hemodynamics. However, if the acute effects of vasodilators were confirmed, we should try to administer them while paying attention to possible adverse effects.

Aged↗

A single amino acid substitution in the A subunit of Escherichia coli enterotoxin results in a loss of its toxic activity.

A plasmid encoding a mutant gene of heat-labile enterotoxin (LT), produced by enterotoxigenic Escherichia coli, was induced by treatment of plasmid EWD 299 with hydroxylamine. A mutant strain of E. coli HB 101 carrying the mutant plasmid pTUH 6A produced a low toxic LT analogue (mutant LT), which was cross-reactive with anti-LT antibody. The mutant LT activity was less than 0.15 and 0.006% of the normal LT in the rabbit ileal loop test and in the rabbit skin permeability test, respectively. The amino acid composition of the mutant LT-B subunit was the same as that of the normal B subunit. Though the A2 fragment of the mutant LT was identical to normal LT by DNA analysis, the A1 fragment of the mutant LT differed from the normal A1 fragment in one amino acid at position 112; namely it had lysine instead of glutamic acid from the N terminus. These data suggest that glutamic acid at position 112 from the N terminus of the A1 fragment is important for the A subunit to express its biological activity.

Amino Acid Sequence↗