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Biomedical subjects

H Itoh

Publications and source records attributed to H Itoh.

At least 415 records · Page 23Linked to original sources
PubMed1998

Expression of HNF-1 alpha and HNF-1 beta in various histological differentiations of hepatocellular carcinoma.

Hepatic nuclear factor 1 (HNF-1) regulates genes in a hepatocyte-specific manner. It has been previously reported that the ratio of HNF-1 alpha and HNF-1 beta mRNA is related to histological differentiation hepatocellular carcinoma (HCC). In this study, the expression levels of the HNF-1 alpha and HNF-1 beta proteins were analysed relatively and quantitatively in various histologically differentiated HCC and surrounding non-cancerous tissues, and HNF-1 alpha binding activity for the AT element of the B domain of the human alpha-fetoprotein enhancer was examined. Western blot analysis demonstrated that HNF-1 alpha protein was expressed at a higher level in well-differentiated HCC tissues than in the surrounding non-HCC tissues; on the other hand, the HNF-1 alpha protein was expressed at lower levels in moderately and poorly differentiated HCCs than in the surrounding non-HCC tissues. The levels of HNF-1 beta expression in well-differentiated and poorly differentiated HCCs were similar to and higher than those found in the respective surrounding non-cancerous portions. In binding assays, HNF-1 binding activity was high in well-differentiated HCC and lower in moderately and poorly differentiated HCCs. Most well-differentiated HCC cases showed immunohistochemical expression of HNF-1 alpha. These findings show that poor histological differentiation of HCC correlates with decreases in the level and activity of HNF-1 alpha proteins.

Blotting, Western↗
PubMed1998

Ocular hypotension induced by intravitreally injected C-type natriuretic peptide.

The purpose of the study is to determine if intravitreal injection of c-type natriuretic peptide (CNP) affects intraocular pressure (IOP), aqueous humor dynamics and guanosine 3',5'-cyclic monophosphate (cGMP) concentration in the aqueous humor of the rabbit eye. Also we investigated whether CNP-like immunoreactivities (CNP-LI) were present in porcine aqueous humor and whether CNP-LI were detected in rabbit and porcine ciliary body. The IOP was measured after intravitreal injection of 2 pmol approximately 20 nmol CNP into rabbit eyes. Aqueous humor dynamics (aqueous humor flow, outflow facility, and uveoscleral outflow) and cGMP concentration in the aqueous humor were determined at approximately 6 hr after CNP injection. The CNP concentration in aqueous was measured by radioimmunoassay in porcine eye, and CNP-LI were detected with a monoclonal antibody in porcine and rabbit eyes. Intravitreally injected CNP caused IOP reduction in a dose-dependent manner (P<0.0001) and the maximum effect was observed at 4 approximately 6 hr. CNP increased total outflow facility by approximately 35%, but did not affect aqueous humor flow or uveoscleral outflow. The cGMP concentration in the aqueous of CNP-treated eyes was about 4- to 14-fold higher than that in the contralateral untreated eyes. CNP concentration in aqueous was about 2-fold higher than that in plasma, and CNP-LI were found in non-pigmented epithelium of the ciliary body of both rabbit and porcine eyes. CNP may play an important role in the regulation of IOP.

Animals↗
PubMed1998

Possible role of platelet-activating factor in the in vivo expression of tissue factor in neutrophils.

BACKGROUND: Recently, we demonstrated that neutrophils express tissue factor (TF) in a model of acute obstructive cholangitis (AOC). However, the regulation of TF expression was not clear. In this study, we clarified the role of platelet-activating factor (PAF) in TF expression in neutrophils. MATERIALS AND METHODS: In a model of AOC, intravenous PAF antagonist, (SM-12502, 200 mg/kg) was administered 5 min before sepsis was induced. Normal saline was given as a control. Coagulation parameters and TF activity were monitored for 6 h. Thereafter, the liver was harvested for histological examination. RESULTS: The percentage of neutrophils which stained positive for TF was significantly reduced by SM-12502 (74.9 +/- 19.3% vs 96.3 +/- 2.8%) (P < 0.01). The number of leukocytes infiltrating the liver was also significantly reduced. Coagulation abnormalities, TF activity, and focal necrosis of the hepatocytes were reduced by SM-12502. CONCLUSIONS: SM-12502 inhibits TF expression in neutrophils which have infiltrated the liver sinusoids, reducing the subsequent infiltration of leukocytes. These results suggest that PAF plays an important role in the expression of TF in neutrophils in vivo.

Animals↗
PubMed1998

Rabbit models of bucket-handle-like meniscal tear.

After radial tears were artificially created in the periphery of the middle third of the lateral menisci in Japanese white male rabbits, the menisci were sampled postoperatively at 2, 4, 6, 12 and 24 weeks. We noted that radial tears often progressed to longitudinal tears, and the length of longitudinal tears increased with time. On the other hand, the areas in which radial tears had been artificially created were filled with granulation-like tissue. Radial tears thus created may lead to bucket-handle-like tears of the menisci.

Animals↗
PubMed1998

Evaluation of functional deficits determined by four different hop tests in patients with anterior cruciate ligament deficiency.

The purpose of this study was to analyze the validity of the newly designed functional ability test (FAT) for the normal population and patients with deficiency of the anterior cruciate ligament (ACL). The FAT consists of four tests: the figure-of-eight hop, the up-down hop, the side hop, and the single hop. Sixty control subjects and 50 patients with unilateral ACL deficiency were tested. In the control group, the values measured were significantly different between males and females in all of the tests. On the other hand, when left/right difference values were compared, no significant difference was found between males and females in any of the tests. More than 95% of control group exhibited symmetrical function in each part of the FAT, whereas in the ACL-deficient group, the percentage of patients who showed abnormal symmetry was 68% in the figure-of-eight hop, 58% in the up-down hop, 44% in the side hop, and 42% in the single hop. The percentage of ACL-deficient patients with functional asymmetry in at least one of the four tests was 82%. The FAT was found to be useful in evaluating lower limb function in ACL-deficient patients.

Adolescent↗
PubMed1998

Effects of hyaluronic acid on meniscal injury in rabbits.

Using a model of meniscal injury in rabbit, the effects of hyaluronic acid (HA) injection into the joint on the rate of filling area and the cell shape in the defects were studied. After a cylindrical defect was made in the anterior horn of the lateral meniscus, HA was injected into the joint once a week. At 1 and 6 weeks after the beginning of the weekly injections, the meniscus was compared with a control, which was injected with phosphate buffer instead of HA. The healing in the defect progressed with time. HA administration caused a significant increase in the rate of filling area in the defect. The cell population in the repair tissue changed from fibroblast-like cells to chondrocyte-like cells with the progress of repair. At 6 weeks, the ratio of chondrocyte-like cells to all cells in the repair tissue of the HA-treated meniscus was higher than that of control. These data indicate that HA increases the healing rate of meniscal injury.

Animals↗
PubMed1998

Developmental expression of the tight junction protein, occludin, in the gastrointestinal tract of the chick embryo.

The developmental expression of occludin was studied biochemically in whole chick embryos to determine when intercellular tight junctions develop. Occludin mRNA was first detected after 3 days of incubation by the reverse transcriptase-polymerase chain reaction. On northern blot analysis, although occludin mRNA was not discernible in 3-day-old embryos, weak but clear expression was noted on day 4 of incubation and increased dramatically in 5-day-old embryos. Occludin was not detectable on days 3 or 4 of incubation by western blot analysis, and was first detected in 5-day-old embryos. In addition, the expression of occludin was examined immunohistochemically in the gastrointestinal tract of 3- to 21-day-old embryos. Immunoreactivity for occludin was not expressed on day 3 of incubation. On day 4 of incubation, weak immunoreactivity was demonstrated in the gastrointestinal tract, and gradually became stronger with development. By day 11 of incubation, a positive immunoreaction was obtained only on the apical surfaces of the epithelial cells, i.e., at the junctional complexes, while weak immunoreactivity was diffusely distributed throughout the epithelial cells. The possible roles of occludin in the developing gastrointestinal tract are discussed.

Animals↗
PubMed1998

Differential expression of SHP2, a protein-tyrosine phosphatase with SRC homology-2 domains, in various types of renal tumour.

SHP2, a widely distributed protein-tyrosine phosphatase with src homology-2 (SH2) domains, is highly expressed in the brain and may play a role in synaptic communications or cellular proliferation. In this study, we examined SHP2 protein expression in 110 renal cell tumours of various histological subtypes, including clear, granular, papillary, chromophobe, collecting duct, and sarcomatoid-type renal cell carcinoma (RCC), and oncocytoma. SHP2 was expressed predominantly in normal distal tubules and collecting ducts, and positivity in various types of renal tumours was as follows: clear cell RCC, 0% (0/77 cases); granular, 7.7% (1/13); papillary, 50% (3/6); sarcomatoid, 0% (0/1); chromophobe, 85.7% (6/7); collecting duct carcinoma, 0% (0/2); oncocytoma, 100% (4/4). Clear and granular-type RCCs showed a very low but positive expression of SHP2. Chromophobe RCC and oncocytoma showed the highest rates and strongest intensities of SHP2 protein on immunostaining. SHP2 may serve as a powerful marker in detecting rare tumours. Estimates of its expression may be useful in histological diagnosis.

Adenoma, Oxyphilic↗
PubMed1998

Expression of type IV collagen in the developing human kidney.

The distribution of alpha1-6 chains of type IV collagen (alpha1-6(IV)) in human fetal kidneys was examined by indirect immunofluorescence. By 11 weeks of gestation, alpha1, 2, 3, 4, and 6(IV) were already present, but alpha5(IV) appeared relatively late, at 21 weeks. Alpha1(IV) and alpha2(IV) were present in all basement membranes, alpha3(IV) and alpha4(IV) were restricted to the glomerular basement membrane and parts of the tubular basement membrane. Alpha5(IV) was distributed in the glomerular basement membrane, Bowman's capsule, and parts of the tubular basement membrane. Alpha6(IV) was present in the Bowman's capsule, parts of the tubular basement membrane, and occurred in parts of the glomerular basement membrane at the early capillary loop stage, but disappeared during the later capillary loop stage.

Amino Acid Sequence↗
PubMed1998

Formation of giant liposomes promoted by divalent cations: critical role of electrostatic repulsion.

Spontaneous formation of giant unilamellar liposomes in a gentle hydration process, as well as the adhesion energy between liposomal membranes, has been found to be dependent on the concentration of divalent alkali cations, Ca2+ or Mg2+, in the medium. With electrically neutral phosphatidylcholine (PC), Ca2+ or Mg2+ at 1-30 mM greatly promoted liposome formation compared to low yields in nonelectrolyte or potassium chloride solutions. When negatively charged phosphatidylglycerol (PG) was mixed at 10%, the yield was high in nonelectrolytes but liposomes did not form at 3-10 mM CaCl2. In the adhesion test with micropipette manipulation, liposomal membranes adhered to each other only in a certain range of CaCl2 concentrations, which agreed with the range where liposome did not form. The adhesion range shifted to higher Ca2+ concentrations as the amount of PG was increased. These results indicate that the divalent cations bind to and add positive charges to the lipids, and that membranes are separated and stabilized in the form of unilamellar liposomes when net charges on the membranes produce large enough electrostatic repulsion. Under the assumption that the maximum of adhesion energy within an adhesive range corresponds to exact charge neutralization by added Ca2+, association constants of PC and PG for Ca2+ were estimated at 7.3 M(-1) and 86 M(-1), respectively, in good agreement with literature values.

Calcium↗
PubMed1998

Effects of periodontal support and fixed splinting on load transfer by removable partial dentures.

STATEMENT OF PROBLEM: Periodontally compromised abutment teeth complicate the design of bilateral distal extension removable partial dentures. PURPOSE: This study investigated the stress induced in the remaining oral structures by a bilateral distal extension I-bar-retained RPD with periodontally involved abutments in a photoelastic simulation model. MATERIAL AND METHODS: Composite photoelastic models were used as a simulation model in determining the stress generating characteristics of I-bar RPDs with varying degrees of periodontal involvement of the distal abutments. Effects of fixed splinting were considered. RESULTS AND CONCLUSIONS: Under the same load conditions, the highest stresses developed in the model with the largest osseous defect. Increasing the number of splinted teeth did not provide a proportional decrease in maximum stress levels. The more severe the osseous defect, the greater assistance was provided by splinting to periodontally sound teeth. This simulation study suggests that routine cross-arch splinting may not be appropriate.

Acrylic Resins↗
PubMed1998

Effects of endurance physical training on hydroxyl radical generation in rat tissues.

Physical exercise is known to increase oxygen consumption to compensate for enhanced ATP consumption and thus to induce oxidative stress in tissues. Our previous data indicate that training significantly increased the hydroxyl radical level in rat tissues after physical exercise, but reduced the basal level in aged rats. This result suggests the paradoxical effect of physical training, which may be to increase or scavenge reactive oxygen species (ROS) generated by physical exercise. In this paper, the effects of training on the levels of hydroxyl radicals and the anti-oxidative glutathione system, were examined in rats. After 3 weeks' training, rats were sacrificed at rest or after treadmill running, and the levels of hydroxyl radicals trapped with salicylic acid, reduced (GSH); and oxidized glutathione (GSSG) in tissues were quantified by high-performance liquid chromatography-electrochemical detection (HPLC-ECD). Endurance training reduced the basal level of hydroxyl radicals significantly in plasma and soleus muscle. In liver and brain a similar tendency was observed, but the difference was not statistically significant. In liver the basal level of GSH increased significantly after training. Slower training with longer duration reduced the basal levels of hydroxyl radical in plasma more markedly than more intense training. These results suggest that endurance exercise can increase the anti-oxidative capacity in rats.

Animals↗
PubMed1998

The significance of the Trp 64 Arg mutation of the beta3-adrenergic receptor gene in impaired glucose tolerance, non-insulin-dependent diabetes mellitus, and insulin resistance in Japanese subjects.

It has been reported that the Trp 64 Arg mutation of the human beta3-adrenergic receptor (beta3-AR) gene is related to an earlier age of onset of non-insulin-dependent diabetes mellitus (NIDDM) and features of insulin resistance and weight gain in morbidly obese patients. However, such findings have not been consistent in varying ethnic populations. In the present study, we investigated the frequency of the Trp 64 Arg mutation of the human beta3-AR gene in Japanese control subjects (n = 253) and in NIDDM (n = 314) and impaired glucose tolerance (IGT) patients (n = 100). We compared the frequency of the mutation with the body-mass index (BMI) in these groups and with the metabolic clearance rate (MCR) of glucose in the NIDDM patients. A Trp 64 Arg mutation was observed in 36.7%, 31.6%, and 37.0% of the control, NIDDM, and IGT subjects, respectively. The frequency of the homozygotes for the mutation was 4.3%, 4.8%, and 3.0%, respectively. Neither the genotype frequency (Trp/Arg, Arg/Arg) nor the frequency of the mutated allele was significantly different among the three groups. The BMI of the subjects with the mutation was not significantly higher than that of the subjects without the mutation in each group. Furthermore, the allele frequency (A) was not different among the subjects with different BMIs (BMI < 22.0, 22.0 < or = BMI < or = 26.4, BMI > 26.4) in each group. In a separate group of NIDDM patients, the MCR of the subjects with intermediate BMIs (22.0 < or = BMI < or = 26.4) with the mutation tended to be lower than that of those without the mutation. In addition, the MCR of the subjects with the mutation in this group was significantly lower compared with that of those with a BMI less than 22. These results indicate that the Trp 64 Arg mutation of the beta3-AR gene may not contribute to the development of NIDDM or be a determinant of obesity in the Japanese population. However, the mutation may contribute to insulin resistance in NIDDM patients with an intermediate BMI.

Adult↗
PubMed1998

Florid reactive follicular hyperplasia in elderly patients. A clinicopathological study of 23 cases.

Florid reactive follicular hyperplasia (FRFH) of the enlarged lymph node in elderly patients requiring biopsy is a relatively uncommon phenomenon as compared with younger age groups. We experienced 23 patients, aged 60 years or more, from whom the biopsied lymph node specimens histologically showed inappropriate FRFH for their age, in the period between 1982 and 1996. These cases were morphologically subdivided into three groups, FRFH with interfollicular plasmacytosis, that with progressive transformation of germinal center, and FRFH without additional specific findings. FRFH with interfollicular plasmacytosis were observed in 11 cases, all of whom were accompanied with several immunological abnormalities (six with rheumatoid arthritis, three with multicentric Castleman's disease and one each with myoepithelial sialoadenitis and autoimmune hemolytic anemia). Three men with uncertain etiology exhibited an unusual histology of progressive transformed germinal centers which were clinically characterized by a bulky neck mass. Among the nine cases with nonspecific FRFH, only four had a specific etiology (one each with adult onset Still's disease, chronic sinusitis, Epstein-Barr virus infection and infectious lateral cervical cyst), while the other five with unknown etiology showed abnormal laboratory findings suggestive of an abnormal humoral immune response, i.e. hypergammaglobulinemia and seropositivities for some autoantibodies. None of our patients developed malignant lymphoma during the follow-up period. Of note, 16 (70%) of the 23 cases were found to be associated with various types of imbalances of the immune system, some of which appeared to be currently ill-defined as clinicopathological entities that were simply categorized as autoimmune disease.

Aged↗
PubMed1998

Occurrence of monocytoid B-cells in reactive lymph node lesions.

Benign monocytoid B-cells are a peculiar subset of B-cells. They are closely related to marginal zone B-lymphocytes, show cytological diversity and may be recognized in a variety of reactive lymph node conditions. To analyze the incidence, cytological spectrum and phenotypic features of benign monocytoid B-cells, we investigated a series of 301 consecutively biopsied and unselected cases of reactive lymph node change from 1988 and 1995. A monocytoid B-cell reaction was identified in 46 (15%) cases and could be cytologically subclassified into two groups: 31 (67%) cases with common-type cells and 15 (33%) cases with large, transformed cells, according to the description by Plank et al. [19]. These reactions were regularly associated with follicular hyperplasia (95%) and were part of an epithelioid cell response in 24 cases (50%). Immunohistologically, both types of benign monocytoid B-cells were negative for bcl-2 protein expression, which was in contrast to the bcl-2 positive reaction in marginal zone B-lymphocytes and their neoplastic counterpart in monocytoid B-cell lymphoma. An association of Epstein-Barr virus (EBV) with monocytoid B-cells was investigated by in situ-hybridization. EBV genomes were detected in five (15%) of 31 cases tested. In each of these five cases, positive cells were represented in both high and low numbers. The morphologic features of the EBV-positive cells were not consistent with monocytoid B-cells, but rather with medium-sized to large lymphoid cells. It appeared that the occurrence of monocytoid B-cell reaction in reactive lymph node lesions was not related to EBV infection in the majority of cases.

Adolescent↗
PubMed1998

Imprint cytology of large B-cell lymphoma with high content of epithelioid cells. A report of two cases.

An association of epithelioid cell reaction in follicular center cell lymphomas seems to be a rare phenomenon. The cytological features of this type of B-cell lymphoma from two patients are presented. In both cases, immunohistochemistry applied to paraffin sections revealed reactivity of tumor cells for CD10, 20 and 79a. The first patient, a 77-year-old male, presented with bilateral inguinal bulky masses. The second patient, a 76-year-old female, revealed left supraclavicular bulky masses. Imprint cytological specimens of these two cases showed large lymphoid cells interspersed with epithelioid histiocytes, which were present in small aggregated clusters or in isolated forms. Most tumor cells showed centroblastic morphology, whereas the minority of them looked like immunoblasts. Occasionally, a monotonous proliferation of these large atypical blastic cells was also detected. On the other hand, in some parts of the imprint specimens, numerous epithelioid cells obscured the underlining tumor cells. Reactive cells other than epithelioid cells were not prominent. These cytologic features closely resembled the histologic patterns of this rare follicular center cell lymphoma. Careful examination of the cytological specimens is needed to detect the monotonous proliferation of tumor cells to establish the diagnosis of malignant lymphoma.

Aged↗
PubMed1998

CT features of retroperitoneal neurilemmoma.

PURPOSE: The aim of this study was to characterize the CT features of retroperitoneal neurilemmoma. METHODS: The CT findings were reviewed in seven patients with retroperitoneal neurilemmoma. RESULTS: All of the tumours were well-demarcated round or oval masses. In five cases, heterogeneous contrast enhancement was noted after contrast medium administration. Areas of minimal enhancement reflected diffuse edema in one tumour. Areas without definite enhancement represented prominent cyst formation in three tumours. There were three cases with tumour calcification (two with punctate calcification and one with mottled calcification). CONCLUSION: CT findings may suggest the diagnosis of retroperitoneal neurilemmoma preoperatively.

Adult↗