Search PubMed⌕ Search

Biomedical subjects

H Hara

Publications and source records attributed to H Hara.

At least 73 records · Page 4Linked to original sources
PubMed2001

Implantation of rectal cancer cells in a fistula in ano: report of a case.

We report a case of implantation of tumor cells within a fistula in ano. A 36-year-old man with a 16-year history of an anal fistula underwent an operation for rectal carcinoma. Three weeks later, the anal fistula was resected. A histological examination of the specimen showed atypical cells; moreover, rectal carcinoma had proliferated in the granulation tissue lying underneath the intact squamous epithelium. Because there was no continuity to the rectal carcinoma or the anal glands, we diagnosed implantation of rectal cancer cells in a fistula in ano.

Adenocarcinoma↗
PubMed2001

Heparin-stimulated expression of extracellular-superoxide dismutase in human fibroblasts.

Extracellular-superoxide dismutase (EC-SOD) is the major SOD isozyme in the arterial wall and may be important for antioxidation capability of the vascular wall and normal vascular function. EC-SOD is expressed in various cell types in the vascular wall such as fibroblasts, smooth muscle cells and macrophages, and the synthesis of EC-SOD by human fibroblasts is known to be highly responsive to various inflammatory cytokines, although there is no response to oxidative stress. Heparin is a highly sulfated glycosaminoglycan with many functions such as antithrombotic, antilipemic and antiatherosclerotic effects. Another less well-known function of heparin is regulation of protein synthesis. In this study, we measured the induction of EC-SOD after treatment with heparin to understand the role of heparin in the antiatherosclerotic response of fibroblasts. Heparin induced EC-SOD expression at both the mRNA and protein levels. Heparin showed the greatest stimulatory effect and heparan sulfate showed moderate effects. The effect of chondroitin sulfate A was not clear. In contrast, desulfated heparin and chondroitin sulfate C did not increase EC-SOD expression. The stimulatory effect seemed to increase roughly with the degree of glycosaminoglycan sulfation. The enhanced expression of EC-SOD by heparin must contribute to the antiatherosclerotic effect of heparin.

Base Sequence↗
PubMed2001

Clinicopathologic significance of telomerase activity and hTERT mRNA expression in non-small cell lung cancer.

Telomerase has been reported to be a novel diagnostic marker for malignant diseases and has been recently proven to be composed of three main components, hTR (human telomerase RNA component), TP1 (telomerase-associated protein 1) and hTERT (human telomerase reverse transcriptase), the last of which plays a key role in telomerase activation. In the present study, quantitative levels of telomerase activity and hTERT gene mRNA (hTERT) expression were analyzed in cancerous and non-cancerous lung tissues of 62 lung cancer patients by telomeric repeat amplification protocol and reverse transcription-PCR, respectively. The telomerase expression levels of each group of tissue samples were compared with clinicopathologic variables. Telomerase activity and hTERT were detected in cancerous tissues (75.8 and 75.8%, respectively), while these parameters were not observed in any non-cancerous tissues. In quantitative assessment of telomerase expression, both telomerase activity and hTERT were significantly correlated with lymph node metastasis (N0 vs. N1+2, P<0.05). Telomerase activity also correlated with tumor cell differentiation and stage classification (P<0.05), but did not correlate with other clinicopathologic variables. The disease-free survival in patients with lung cancer demonstrated that patients with hTERT-positive tumor survived for a significantly shorter period than those with hTERT-negative tumor (P=0.0334). Since hTERT levels are correlated with N factor which represents the true aggressiveness of patients' disease concerning the evaluation of clinical outcome, hTERT was found to be one of the important markers revealing biological malignant potentials for lung cancer.

Adult↗
PubMed2001

Massive large bowel resection decreases bone strength and magnesium content but not calcium content of the femur in rats.

We examined the effects of massive large bowel resection (cecocolonectomy) on calcium and magnesium absorption and bone characteristics in rats. Male Sprague-Dawley rats were divided into two groups: sham-operated and cecocolonectomized rats. The rats were fed a sucrose-based diet containing casein at 250 g/kg diet for 10 d after a 9- to 10-d postoperative recovery period. Apparent magnesium absorption but not calcium absorption was lower in the resection group than in the sham group. There was a tendency of lower serum magnesium concentration (P = 0.070) but not calcium concentration (P = 0.418) in the resection group compared with the sham group. The maximum breaking force and magnesium content but not the calcium content of the femur were lower in the resection group than in the sham group. These results suggest that massive large bowel resection influences magnesium kinetics and decreases bone strength through reduction of the magnesium content of the femur in rats. Femoral breaking force was positively correlated (r = 0.617, P = 0.011) with only the magnesium content. We conclude that the changes in magnesium kinetics caused by cecocolonectomy could contribute to the fragility of bone.

Animals↗
PubMed2001

Interleukin-8-positive neutrophils in psoriasis.

We performed an immunohistochemical study to try to determine the cellular source of interleukin-8 (IL-8) in psoriatic skin lesions. IL-8 was positively stained in the vast majority of neutrophils but not in the mononuclear cells, macrophages, or keratinocytes. IL-8-positive neutrophils were seen both in Munro's microabcesses in cases of psoriasis vulgaris and in a small spongiform pustule and much larger macropustules of Kogoj in cases of pustular psoriasis. Some IL-8-positive neutrophils were observed in the upper dermis of pustular psoriasis. The staining was considered to be specific because it could be completely blocked by preabsorption with recombinant IL-8. In addition, stimulation of human neutrophils with lipopolysaccharide (LPS) or tumor necrosis factor-alpha (TNF-alpha) for 18 h induced IL-8 production in vitro. In our study, IL-8 was expressed in the neutrophils of psoriasis, suggesting that neutrophils are one of the sources of IL-8 in psoriasis. The expression of IL-8 and the influx of neutrophils led us to speculate that the IL-8 autocrine and/or paracrine system functions in the formation of the microabcesses and pustules in proriasis.

Humans↗
PubMed2001

Non-essential amino acids play an important role in adaptation of the rat exocrine pancreas to high nitrogen feeding.

We have previously demonstrated that feeding a diet with a high amino acid (60% AA diet) content, as a mixture simulating casein, induced pancreatic growth and pancreatic protease production in rats. In the present study, we examined the effects of an increasing dietary content of essential amino acids (EAA, x1 - x3 in exp. 1 and x1 - x3.3 in exp. 2) and non-essential amino acids (NEAA, x1 - x3 in exp. 1 and x1 - x5.2 in exp. 2) on pancreatic growth, amylase and protease adaptation using casein-type amino acid mixtures (exp. 1, basal diet; 20% AA diet) and egg white-type amino acid mixtures (exp. 2, basal diet; 12% AA diet). Pancreatic growth and trypsin activity were induced as the dietary content of NEAA was increased in experiments 1 and 2. Amylase activity in the pancreas was also induced as the dietary content of NEAA was increased, even with the decrease in dietary carbohydrate in experiment 2. The values of all pancreatic variables decreased with the increase in dietary EAA (x2 and x3) without an increase in NEAA. The changes in the pancreas were coincident with increases in plasma arginine and lysine concentrations and a decrease in the plasma alanine concentration. In rats fed a 60% AA diet (EAA and NEAA x3), in the case of which the EAA content was balanced with the NEAA content, pancreatic growth and protease production increased and reached maximum levels as the plasma amino acid concentrations decreased, except for alanine. These results show that NEAA, not EAA, are associated with induction of pancreatic growth and protease production upon feeding a diet with a high AA content, and that some metabolites may be involved in the induction process. The suppression of pancreatic growth and protease production in rats fed the high EAA diets without balanced NEAA may be associated with impairment of amino acid metabolism rather than the increments in the concentration of one or more essential amino acids. Our results also suggest that there is an unknown mechanism or unknown factors involved in regulating pancreatic amylase.

Journal Article↗
PubMed2001

Endoscopic management of a traumatic disruption of the bulbous urethra using a thin trocar puncture.

A case is reported in which complete disruption of the bulbous urethra resulted in a straddled-type injury, which was managed by endoscopic realignment with a thin trocar needle. The endoscopic urethroplasty consisted of: (i) direct observation of the proximal end of the obliterated urethra by an antegrade flexible cystoscope; (ii) adjustment of the direction of trocar penetration under fluoroscopy and direct vision; (iii) confirmation of the exact trocar position and penetration by antegrade flexible cystoscope; and (iv) placement of the guidewire following the trocar penetration as guidance for urethrotomy. A Foley catheter was left in place for 6 weeks. To date, no further endoscopic revision has been required. Although long-term follow up and more experience are required, this technique is reported because it appears to be safe, reproducible, simple and minimally invasive.

Cystoscopy↗
PubMed2001

Ingestion of insoluble dietary fibre increased zinc and iron absorption and restored growth rate and zinc absorption suppressed by dietary phytate in rats.

We examined the effects of ingestion of five types of insoluble fibre on growth and Zn absorption in rats fed a marginally Zn-deficient diet (6.75 mg (0.103 mmol) Zn/kg diet) with or without added sodium phytate (12.6 mmol/kg diet). The types of insoluble fibre tested were corn husks, watermelon skin, yam-bean root (Pachyrhizus erosus) and pineapple core, and cellulose was used as a control (100 g/kg diet). Body-weight gain in the cellulose groups was suppressed by 57 % by feeding phytate. Body-weight gain in phytate-fed rats was 80 % greater in the watermelon skin fibre and yam-bean root fibre group than that in the cellulose group. Zn absorption ratio in the cellulose groups was lowered by 46 and 70 % in the first (days 7-10) and second (days 16-19) measurement periods with feeding phytate. In the rats fed the phytate-containing diets, Zn absorption ratio in the watermelon skin, yam-bean root and pineapple core fibre groups was 140, 80 and 54 % higher respectively than that in the cellulose group, in the second period. Fe absorption was not suppressed by phytate, however, feeding of these three types of fibre promoted Fe absorption in rats fed phytate-free diets. The concentration of soluble Zn in the caecal contents in the watermelon skin fibre or yam-bean root fibre groups was identical to that in the control group in spite of a higher short-chain fatty acid concentration and lower pH in the caecum. These findings indicate that ingestion of these types of insoluble fibre recovered the growth and Zn absorption suppressed by feeding a high level of phytate, and factors other than caecal fermentation may also be involved in this effect of insoluble fibre.

Animals↗
PubMed2001

Effects of lomerizine, a novel Ca2+ channel blocker, on the normal and endothelin-1-disturbed circulation in the optic nerve head of rabbits.

We examined the effects of lomerizine, a new diphenylmethylpiperazine Ca2+ channel blocker, on the normal circulation in the optic nerve head and long posterior ciliary artery, and on endothelin-1-induced hypoperfusion in the optic nerve head in anesthetized rabbits using a hydrogen gas clearance method and laser Doppler flowmetry. These effects were compared with those of nilvadipine and pranidipine. Lomerizine (0.1 and 0.3 mg/kg, i.v.) significantly increased tissue blood flow in the optic nerve head and the putative blood flow in the long posterior ciliary artery with smaller reduction of blood pressure (0.3 mg/kg, i.v.) and without change in heart rate. On the other hand, nilvadipine (0.003 and 0.01 mg/kg, i.v.) and pranidipine (0.003 and 0.01 mg/kg, iv.) each significantly increased blood flow and lowered blood pressure. Moreover, lomerizine (0.1 and 0.3 mg/kg, i.v.) and nilvadipine (0.01 mg/kg, i.v.), when administered 5 min before an endothelin-1 injection (10(-6) M, 100 microl), inhibited the hypoperfusion in the optic nerve head. These results suggest that lomerizine improves the ocular circulation with minimal cardiovascular side effects. Therefore, lomerizine may have clinical potential for the treatment of eye diseases associated with local circulatory disturbances, such as normal-tension glaucoma.

Animals↗
PubMed2001

Various indigestible saccharides enhance net calcium transport from the epithelium of the small and large intestine of rats in vitro.

An Ussing chamber technique was used to determine the effects of six indigestible saccharides on net Ca absorption from the luminal side to the basolateral side of isolated preparations of rat jejunal, ileal, cecal and colonic epithelium in vitro. The concentrations of Ca in the Tris buffer solution on the serosal side and on the mucosal side were 1.25 and 10 mmol/L, respectively. After a 30-min incubation, the Ca concentration in the serosal medium was determined and the net transepithelial Ca transport was calculated. The addition of 0.1-200 mmol/L maltitol, difructose anhydride (DFA)III, DFAIV, raffinose, fructooligosaccharide (FOS) or polydextrose (PD) to the mucosal medium increased the net Ca absorption dose-dependently in the jejunum, ileum, cecum and colon preparations. The threshold concentration required to enhance Ca transport and the extent of enhancement of Ca transport differed among the saccharides tested and among the portions of the intestine examined. Among the saccharides tested, DFA IV had the strongest effect on Ca absorption in the jejunum and cecum. We conclude that indigestible carbohydrates directly affect the epithelial tissue and promote Ca absorption in both the small and large intestine in vitro.

Animals↗
PubMed2001

Effect of cytosine protonation and cation on thermodynamic properties of parallel DNA triplex family.

The conformational and thermodynamic properties of three modified parallel triplexes, which have the same base composition but differ in the orientation of the Hoogsteen third strand with respect to the core duplex, were comparatively discussed. The results show that the intermolecular triplex is unstable relatively to the intramolecular triplex and the thermodynamic properties are slightly dependent on the 3' or/and 5' junctions. Furthermore, mono- and divalent cations compete each other in stabilizing the triple helix structure and a higher concentration of the monovalent cation would shield the effect of divalent cations on the triplex stability.

Base Sequence↗
PubMed2001

Caspase-independent cell death and mitochondrial disruptions observed in the Apaf1-deficient cells.

Apaf1 is a critical molecule in the mitochondria-dependent apoptotic pathway. Here we show that Apaf1-deficient embryonic fibroblasts died at a later phase of apoptotic induction, although these cells were resistant to various apoptotic stimulants at an early phase. Neither caspase 3 activation nor nuclear condensation was observed during this cell death of Apaf1-deficient cells. Electron microscopic examination revealed that death in response to apoptotic stimulation resembled necrosis in that nuclei were round and swollen with low electron density. Necrosis-like cell death was also observed in wild-type cells treated with z-VAD-fmk. Mitochondria were not only morphologically abnormal but functionally affected, since mitochondrial transmembrane potential (DeltaPsim) was lost even in cells with intact plasma membrane integrity. These mitochondrial alterations were also observed in the wild-type cells dying of apoptosis. Combined, these data suggest that cells without caspase activation, such as Apaf1-deficient cells or cells treated with caspase inhibitors, die of necrosis-like cell death with mitochondrial damage in response to "apoptotic stimulation."

Amino Acid Chloromethyl Ketones↗
PubMed2001

Dietary protein peptic hydrolysates stimulate cholecystokinin release via direct sensing by rat intestinal mucosal cells.

We previously demonstrated that a peptic hydrolysate of guanidinated casein strongly stimulates exocrine pancreatic secretion in chronic bile-pancreatic juice-diverted rats and cholecystokinin (CCK) release from dispersed rat intestinal mucosal cells. These results reveal that the chemically modified protein hydrolysate stimulates CCK secretion and increases pancreatic secretion by a luminal trypsin-independent direct action on the small intestine. In the present study, we examined the direct effect of peptic hydrolysates of naturally occurring dietary proteins, casein, soybean protein isolate (SPI), egg white, and wheat gluten on CCK release under in vitro trypsin-independent conditions. All protein hydrolysates significantly stimulated CCK release from dispersed rat intestinal mucosal cells. Among the hydrolysates treated, SPI hydrolysate was the most effective in stimulating CCK release. The potential of SPI hydrolysate to stimulate CCK release was increased by long-term peptic digestion. However, an SPI-like amino acid mixture did not effect CCK release. In conclusion, peptic hydrolysates of commonly ingested dietary proteins stimulate CCK release via trypsin-independent direct sensing by intestinal mucosal cells.

Animals↗
PubMed2001

Heparin-Affinity of human extracellular-superoxide dismutase in the brain.

Extracellular-superoxide dismutase (EC-SOD) is one of the three SOD isozymes in humans and has affinity for heparin-like sulfated glycosaminoglycans in the extracellular matrix. The C-terminal portion of EC-SOD is responsible for the heparin-affinity of this enzyme, but this portion should be a target of proteinases. Recently, Oury et al. reported that EC-SOD is localized within the cytoplasm of neuronal cells, while this enzyme is found in the extracellular matrix in most other tissues. It has been speculated that the heparin-binding domain of EC-SOD in the brain is sensitive to proteolysis, which may result in a loss of extracellular immunoreactivity. This study was performed to investigate the heparin-affinity of EC-SOD in the human brain. We found that human EC-SOD in brain tissue has high heparin-affinity similar to that in the umbilical cord. Moreover, heparin-affinity of EC-SOD in brain homogenate was not decreased by incubation at 37 degrees C for 72 h. The proteolytic activity in brain homogenate might be less than that in umbilical cord homogenates. The intracellular localization of EC-SOD could contribute to its slow clearance from the brain and maintenance of its physiological functions in the brain.

Adult↗
PubMed2001

Characterization of binding between the rat small intestinal brush-border membrane and dietary proteins in the sensory mechanism of luminal dietary proteins.

Dietary proteins are recognized by the gastrointestinal tract to display physiological functions, however, the sensory mechanism of the intestinal mucosa is not known. We examined binding properties between the rat small intestinal brush-border membrane (BBM) and proteins by using a surface plasmon resonance biosensor. BBM and solubilized BBM prepared from the rat jejunum bound to casein immobilized on the sensor surface, but not to bovine serum albumin. The ileal BBM showed less binding to casein than the jejunal BBM. Solubilized BBM binding to immobilized alpha-casein was slightly inhibited by aminopeptidase inhibitors, but still more inhibited by addition of casein with the inhibitors. Guanidinated casein inhibited the solubilized BBM binding to alpha-casein more strongly than casein (casein sodium and alpha-casein) inhibited. Trypsinization of solubilized BBM abolished its binding activity to alpha-casein. These results indicate that some membrane protein, but not aminopeptidases, contained in BBM interacts with dietary proteins, and that guanidinated casein has a higher affinity for BBM than intact casein. These binding intensities for proteins were closely correlated to physiological responsiveness, and are possibly involved in a sensory system for dietary protein in the intestine.

Aminopeptidases↗
PubMed2001

Improving effect of feeding with a phosphorylated guar gum hydrolysate on calcium absorption impaired by ovariectomy in rats.

We have previously reported that a phosphorylated guar gum hydrolysate (P-GGH) promoted calcium absorption and the accumulation of bone calcium in rats. We now investigate the effect of P-GGH (50 g/kg of diet) on the intestinal calcium absorption and bones of ovariectomized (OVX) rats in comparison with sham-operated rats over a six-week ingestion period. The apparent calcium absorption was decreased by aging and ovariectomy in the rats fed on the control and GGH diets (50 g/kg of diet), but not in the rats fed on the P-GGH diet. The absorption was higher in the P-GGH group than in the GGH and control diet groups in the fourth and sixth weeks after feeding the test diets to OVX rats. Femoral calcium and strength were decreased by OVX in the rats fed on the control and GGH diets, but not in the rats fed on the P-GGH diet. The values of these parameters were higher in the P-GGH group than in either the control or GGH group of OVX rats. The amount of soluble calcium in the ileal contents was higher in the P-GGH group than in the control and GGH groups. These results indicate that P-GGH may be useful for preventing the reduction of intestinal calcium absorption and bone in the condition of estrogen deficiency.

Absorption↗
PubMed2001

Effects of vitamin E and sesamin on hypertension and cerebral thrombogenesis in stroke-prone spontaneously hypertensive rats.

The preventive effects of sesamin, a lignan from sesame oil, and vitamin E on hypertension and thrombosis were examined using stroke-prone spontaneously hypertensive rats (SHRSP). At 5 weeks of age the animals were separated into four groups: (i) a control group; (ii) a vitamin E group, which was given a 1,000 mg alpha-tocopherol/kg diet; (iii) a sesamin group, given a 1,000 mg sesamin/kg diet; and (iv) a vitamin E plus sesamin group, given a 1,000 mg alpha-tocopherol plus 1,000 mg sesamin/kg diet for 5 weeks from 5 to 10 weeks of age. Resting blood pressure was measured by the tail-cuff method once weekly. A closed cranial window was created and platelet-rich thrombi were induced in vivo using a helium-neon laser technique. The number of laser pulses required for formation of an occlusive thrombus was used as an index of thrombotic tendency. In control rats, systolic blood pressure and the amount of urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) became significantly elevated with age. However, the elevation in blood pressure and 8-OHdG were significantly suppressed in rats administrated vitamin E, sesamin, or vitamin E plus sesamin. At 10 weeks, the number of laser pulses required to induce an occlusive thrombus in arterioles of the control group was significantly lower than in the other groups (p<0.05). These results indicate that chronic ingestion of vitamin E and sesamin attenuated each of elevation in blood pressure, oxidative stress and thrombotic tendency, suggesting that these treatments might be beneficial in the prevention of hypertension and stroke.

8-Hydroxy-2'-Deoxyguanosine↗