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Biomedical subjects

K Higuchi

Publications and source records attributed to K Higuchi.

At least 91 records · Page 5Linked to original sources
PubMed2000

Histological estimation of the efficacy of endoscopic laser coagulation therapy for diffuse antral vascular ectasia.

We present the case of a 72-year-old woman with successful control of repeated episodes of bleeding from diffuse antral vascular ectasia (DAVE) by laser coagulation therapy. In addition to DAVE, the patient also suffered from severe iron deficiency anaemia (due to recurrent bleeding), liver cirrhosis, and huge tumours of hepatocellular carcinoma (HCC). She was referred from another hospital after failure to stop her bleeding episodes. Endoscopic examination revealed diffuse speckled telangiectasia over most of the stomach (from antrum to the upper portion of the body) and large numbers of blood clots. The patient had received repeated blood transfusions, haemostatic drugs, and H2 receptor antagonists at the other hospital, without improvement of the repeated bleeding. She underwent three sessions of endoscopic laser coagulation therapy for the lesions at our hospital after the final diagnosis of DAVE had been made based on the characteristic histological findings of biopsied specimens. This treatment improved her general condition and stopped the bleeding from the gastrointestinal tract even without fasting. Unfortunately, however, her liver function gradually worsened due to HCC and previous massive bleeding, and she finally died of liver failure three months after the last laser session. Autopsied specimens obtained from the patient's stomach revealed that macroscopic diffuse speckled telangiectasia and microscopic typical vasodilatation in mucosal and submucosal layers of gastric tissue had disappeared in the treated areas but not all portions of the DAVE lesion. These histological findings for the treated areas, in addition to the clinical improvement of bleeding, suggest that endoscopic laser coagulation therapy may be useful and one of the first choices in treatment for DAVE.

Aged↗
PubMed2000

Marked enhancement by fish meal of Helicobacter pylori-induced gastritis in Mongolian gerbils.

In a search for dietary factors influencing Helicobacter pylori-induced gastritis, the effects of fish meal in the diet were examined in Mongolian gerbils. When a conventional diet containing 10% fish meal was given to Mongolian gerbils for 4 weeks after inoculation of H. pylori, edematous thickening with severe neutrophil and mononuclear cell infiltration in both the mucosa and submucosa was observed in the glandular stomach of 19 out of the 20 animals, and hemorrhagic spots were evident in 11 cases. These gastric lesions were enhanced by a 20% fish meal supplement, and edema and hemorrhage in the gastric mucosa were observed in 19 and 17 out of 20 animals, respectively. Although almost the same levels of viable bacteria were detected independent of the diet, edema and hemorrhage were seen in only 2 and 1 of 20 gerbils fed a diet containing 10% casein, instead of 10% fish meal, respectively. Neither edema nor hemorrhage was observed in 10% beef diet animals. These results suggest that fish meal contains factors which greatly enhance H. pylori-induced gastritis in Mongolian gerbils. Since the incidences of gastritis and gastric cancer are very high throughout the world, it is very important to identify these gastritis-enhancing factors.

Animals↗
PubMed2000

Parasporin, a human leukemic cell-recognizing parasporal protein of Bacillus thuringiensis.

An unusual property, human leukemic cell-recognizing activity, associated with parasporal inclusions of a noninsecticidal Bacillus thuringiensis soil isolate was investigated, and a protein (named parasporin in this study) responsible for the activity was cloned. The parasporin, encoded by a gene 2,169 bp long, was a polypeptide of 723 amino acid residues with a predicted molecular weight of 81, 045. The sequence of parasporin contained the five conserved blocks commonly found in B. thuringiensis Cry proteins; however, only very low homologies (<25%) between parasporin and the existing classes of Cry and Cyt proteins were detected. Parasporin exhibited cytocidal activity only when degraded by proteases into smaller molecules of 40 to 60 kDa. Trypsin and proteinase K activated parasporin, while chymotrypsin did not. The activated parasporin showed strong cytocidal activity against human leukemic T cells (MOLT-4) and human uterus cervix cancer cells (HeLa) but not against normal T cells.

Amino Acid Sequence↗
PubMed2000

Chromosomal and extrachromosomal synthesis of exfoliative toxin from Staphylococcus hyicus.

Evidence for the existence of two molecular species of exfoliative toxin (ET) synthesized by Staphylococcus hyicus (SHET) under chromosomal and plasmid control is presented. Serological evidence that these molecular species of toxins are distinct from each other is given. The molecular weights of SHET from plasmidless strain P-1 (SHETA) and from plasmid-carrying strains P-10 and P-23 (SHETB) were almost equal. Both of the serotypes of SHET exhibited exfoliation in 1-day-old chickens. The plasmid-cured (P(-)) substrains (P-23C1 and P-23C2) of S. hyicus P-23 did not cause exfoliation in 1-day-old chickens, whereas P(-) substrains (P-10C1 and P-10C2) of strain P-10 caused exfoliation, but they decreased their exfoliative activity. These findings suggest that SHETB was synthesized along with SHETA by strain P-10, whereas the P-23 strain synthesized SHETB alone. The plasmid-carrying strain (P-23) as well as the plasmidless strain (P-1) exhibited the typical clinical signs of exudative epidermitis in pigs. However, plasmid-cured (P(-)) substrains of P-23 (P23C1 and P23C2) did not exhibit the typical clinical signs of exudative epidermitis. These findings suggest that SHETA is synthesized under chromosomal control and SHETB is synthesized under plasmid control and that SHET-producing strains can be divided into three groups: SHETA-producing strains, SHETB-producing strains, and strains producing both toxins.

Animals↗
PubMed2000

Pentoxifylline accelerates gastric ulcer healing in rats: roles of tumor necrosis factor alpha and neutrophils during the early phase of ulcer healing.

BACKGROUND/AIMS: Pentoxifylline has many anti-inflammatory properties including inhibition of production of tumor necrosis factor alpha (TNF-alpha). Although pentoxifylline prevents several types of gastric mucosal injury, the effect of this drug on ulcer healing is unknown. In this study, we examined the effect of pentoxifylline on healing of acetic acid induced gastric ulcers in rats. METHODS: Rats with gastric ulcer received an intraperitoneal injection of 10 mg/kg pentoxifylline once daily for 14 days or for only the first 7 days or the last 7 days of the 14-day treatment period. Some rats were given antirat neutrophil antiserum intraperitoneally every other day. Ulcer size, myeloperoxidase activity, and concentration and location of TNF-alpha in ulcer tissue were assessed. RESULTS: Administration of pentoxifylline for 14 days or for the first 7 days, but not for the last 7 days, of the 14-day treatment period accelerated ulcer healing. TNF-alpha was detected mainly in monocytes/macrophages and in some neutrophils at ulcer bases and margins. Pentoxifylline markedly decreased the concentration of TNF-alpha as well as the myeloperoxidase activity in ulcer tissue on days 2 and 4. Antirat neutrophil antiserum inhibited neutrophil infiltration into ulcer tissue and accelerated ulcer healing. CONCLUSION: Pentoxifylline accelerates healing of acetic acid induced gastric ulcer in rats. This effect may be due in part to reduction of neutrophil infiltration and inhibition of production of TNF-alpha by inflammatory cells. Early-phase inhibition of inflammatory response may accelerate ulcer healing.

Acetic Acid↗
PubMed2000

[Development and evaluation of a local area network system to make drug information paper for inpatient--adaptation to characteristics of diseases, and expansibility to other hospitals and the Internet].

We developed and evaluated a local area network system to make drug information papers. Because pharmacists should explain drug information both orally and using papers to patients in response to their understanding and characteristics of their diseases. The merit of this system is as follows: pharmacists can use it without any education for its operation; most data can be inputted by selection from the lists and automatic reference; the data are adjustable for individuals; different contents are available for different wards; multiple users can access the same data file. Input data in this system are available for making explanation papers on the medical examination of outpatients, and making a plan for pharmaceutical care and guidance services. This system is also available in other hospitals, and on the internet. First, we surveyed the time required for preparing drug information papers. Making a hand written paper for typical patient takes 395 sec. for manuscript, 160 sec. with the system using text data only, and 178 sec. with the system using text and picture data. Next, we surveyed 27 patients' views on the addition of drug pictures to drug information papers, and with the result that 19 patients thought it very good. Last, we surveyed 13 ward pharmacists about their usage of this system. We found that 8 pharmacists used frequently this system, and 3 pharmacists used the same file in the same hours at the maximum.

Aged↗
PubMed2000

Decrease of nitric oxide end-products during coronary circulation reflects elevated basal coronary artery tone in patients with vasospastic angina.

The aim of this study was to investigate the role of nitric oxide (NO) in the coronary circulation and its relation to basal coronary artery tone in patients with vasospastic angina (VSA). We evaluated the level of nitric oxide end-products (NOx; nitrite + nitrate) in coronary circulation blood using an HPLC-Griess system for nine patients with VSA and nine control patients. All of the patients with VSA experienced focal spasm in the proximal to middle segments of the left anterior descending coronary artery (LAD) in response to intracoronary injection of ergonovine maleate. The luminal diameter of the coronary artery was measured in each patient by quantitative coronary arteriography. Blood samples for NOx measurement were obtained from the coronary sinus (NOxV) and the ostium of the left coronary artery (NOxA). The NOx difference, calculated from the coronary venous-arterial difference in NOx, was close to zero for the control patients whereas it was clearly negative for the patients with VSA. In addition, the NOx difference in the patients with VSA showed a negative correlation with basal coronary artery tone (r = -0.91, p < 0.01) and a positive correlation with the dose of ergonovine required for spasm provocation (r = 0.77, p < 0.05). These results indicate that increased basal coronary artery tone and higher susceptibility to ergonovine in patients with VSA would be a consequence of coronary endothelial dysfunction as is indicated by NOx.

Adult↗
PubMed2000

Scanning electron microscopic studies of the vascular smooth muscle cells and pericytes in the rat heart.

The cytoarchitecture of smooth muscle cells and pericytes in the rat cardiac vessels was studied by scanning electron microscopy after the removal of connective tissue matrices using a modified KOH-collagenase digestion method. The initial stem of the coronary arteries had groups of smooth muscle cells which ran in various directions on the outermost layer of the media. Although smooth muscle cells in coronary arteries of more than 100 microm in the outer diameter were arranged in a rough circle around the vessel axis, oblique and/or longitudinal muscle bundles were often present in the medio-adventitial border of the vessels. The presence of irregularly oriented muscular bundles is probably connected with resistance against the stretching force induced by the beating of the heart. As the vessel size decreased toward the periphery, almost all of the smooth muscle cells became spindle-shaped with several tiny processes and ran circularly or helicaly to the vessel axis. In the precapillary arterioles (6-12 microm), smooth muscle cells acquired various cytoplasmic processes which helicaly surrounded endothelial cells. Unmyelinated nerves were often associated with arterioles. Blood capillaries were morphologically divided into three segments: arterial capillaries which had pericytes with wide and circularly oriented processes, true capillaries whose pericytes extended long and thin primary processes bilaterally along the vessel axis, and venous capillaries surrounded irregularly and loosely by wide pericytic processes. The stellate pericytes in the postcapillary venules (10-30 microm) gradually changed into flat tape-like smooth muscle cells, which ran circularly in the collecting venules and veins (30-200 microm). The large collecting veins were finally overwhelmed by superficial thin layer of the myocardium, their own smooth muscle cells being very sparse. This suggests that large veins have poor ability to contract by themselves but are influenced by the surrounding myocardial cells.

Animals↗
PubMed2000

Phenotypical and morphological analyses of intraepithelial and lamina propria lymphocytes in normal and regenerating gastric mucosa of rats in comparison with those in intestinal mucosa.

While the intestine has abundant intraepithelial lymphocytes (IELs) including extrathymically differentiated T-cell populations and natural killer (NK) cells, the stomach contains only a few IELs. To elucidate whether the gastric epithelium is capable of inducing predominant lymphocyte lodging and subsequent differentiation within, we counted the number of IELs and lamina propria lymphocytes (LPLs) and calculated the percentage of IELs to total lymphocytes for each alpha-beta T cell, gamma-delta T cell, CD4+ cell, CD8+ cell and NK cell in normal and regenerating gastric mucosa as well as the intestinal mucosa of the rat. In the normal rat pylorus, a few alpha-beta T cells but no gamma-delta T cells were found in the epithelium and lamina propria. In regenerating gastric mucosa, all subsets of LPLs increased in number to a degree comparable to those in intestinal mucosa, whereas every IEL subset, though slightly increased, was much smaller in number than in the intestinal mucosa, consequently giving lower percentages of IELs. Electron microscopic observations revealed that all IELs in regenerating gastric mucosa were agranular, while 55% of intestinal IELs were large granular lymphocytes positively stained for an NK-cell, alpha-beta-cell or gamma-delta T-cell marker. The present results indicate that, unlike the intestinal epithelium, the gastric epithelium does not induce the preferential localization of T cells/NK cells and T-cell differentiation into granular lymphocytes in the epithelium even under conditions of prominent LPL infiltration.

Animals↗
PubMed2000

[Case report of a patient with invading bladder cancer and lymph node swelling which decreased following 5'-DFUR treatment].

We report a 75-year-old man with invading bladder cancer and enlarged lymph nodes, which decreased following 5'-DFUR treatment. A postoperative abdominal CT showed lymph node swelling around the great vessels. The patient refused aggressive chemotherapy, so he was given a 5-FU derivative, 5'-DFUR, 800 mg/day orally. The enlarged lymph node had decreased in size by the 22nd day after the treatment, and the patient has maintained a near CR.

Aged↗
PubMed2000

[Infratemporal fossa approach for mid-skull base lesion: its usefulness, surgical anatomy, and intraoperative device].

The usefulness of the infratemporal fossa type C approach is reported through a presentation of a case of clival chordoma, which was successfully treated by this approach. Although it is complicated and includes some demerits, this approach gives a shorter and wider access to mid-skull base pathology than other approaches. Among the demerits, deformity of the temporal region caused by extensive drilling of the bone could be minimized by cosmetic mastoidectomy, which was first applied during this approach by the authors. The surgical anatomy for this approach is demonstrated using a cadaver specimen.

Adult↗
PubMed2000

Helicobacter pylori: criminal or innocent bystander?

Most patients with peptic ulcer disease are infected with Helicobacter pylori. However, the infection may not be always causative for the disease. The prevalence of H. pylori infection is about 50% in general. Therefore, half of the patients with peptic ulcer could be infected with this microorganism just by chance. In such cases, H. pylori may do nothing for the ulcer, although it causes chronic active gastritis. This could be the reason for the existence of both H. pylori-positive nonrecurring ulcers and ulcers that recur even after cure of H. pylori infection. H. pylori-positive non-recurring ulcers should be included in non-H. pylori ulcer disease in addition to H. pylori-negative ulcers. NSAIDs are the major cause of H. pylori-negative ulcers, especially H. pylori-negative gastric ulcers. However, more than 10% of ulcers recurred even after cure of H. pylori infection in nonusers of NSAIDs in a 7-year follow-up study. In the same study, 46% of ulcers did not recur in patients in whom eradication of H. pylori failed. There are few (<5%) H. pylori-negative ulcers; about 10% of ulcers recur after cure of H. pylori infection, and about 40% of H. pylori-positive ulcers do not recur. These are all non-H. pylori ulcers, and they represent 30% of all ulcers, which is the general prevalence rate for nonulcer subjects. Therefore, H. pylori may be an innocent bystander in approximately one third of all ulcer patients.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2000

Comparison of nasal and oral tolerance for the prevention of collagen induced murine arthritis.

OBJECTIVE: Administration of bovine type II collagen (CII) or of its peptide either orally or nasally has been reported to suppress the development of collagen induced arthritis (CIA) in mice and rats. We examined the inhibitory effects of CII delivered by each route on CIA in DBA/1J mice to determine which route was superior. METHODS: Male mice were injected twice with CII in Freund's complete adjuvant to induce CIA. Before induction of CIA, 1, 10, or 40 microg of CII were administered nasally 15 times and 10, 100, 500, or 1000 microg of CII were given 10 times orally. The development of arthritis, arthritis score, CII-specific delayed-type hypersensitivity (DTH) response, and CII-specific antibody levels were examined. RESULTS: Nasal administration of 10 microg of CII 15 times had the most prominent suppressive effects, reducing disease incidence by 50% and inhibiting both CII-specific IgG antibody and DTH responses. Of all the mice undergoing oral administration, those receiving 500 microg of CII 10 times showed the greatest suppressive potential. However, the treatment only delayed disease onset for roughly 3 weeks, lowering CII-specific IgG antibody levels but failing to suppress DTH responses. CONCLUSION: Nasal administration of CII reduced CIA development and inhibited CII-specific T cell and antibody responses to a greater degree than did oral administration.

Administration, Intranasal↗
PubMed2000

Cytoprotective effect of rabeprazole against ethanol-induced gastric mucosal damage: possible involvement of nitric oxide.

The cytoprotective effect of rabeprazole, a new proton pump inhibitor, against ethanol-induced gastric mucosal damage was investigated in rats. Rats received intraperitoneal injections of rabeprazole once only or once daily for 3 days. Subsequently, the rats were given 1 ml of absolute ethanol by oral intubation. Some rats given rabeprazole were treated with N-omega-nitro-L-arginine methyl ester (L-NAME) or indomethacin. Repeated administration of rabeprazole significantly inhibited ethanol-induced gastric mucosal damage, although single administration of this drug did not. Pretreatment with L-NAME abolished the cytoprotective effect of rabeprazole. This inhibitory effect of L-NAME was reversed by L-arginine but not by D-arginine. Pretreatment with indomethacin did not influence the cytoprotective effect of rabeprazole. These results suggest that repeated intraperitoneal administration of rabeprazole has a cytoprotective effect against ethanol-induced gastric mucosal damage and that this effect may be mediated via nitric oxide but not via prostaglandins.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2000

[Small cell carcinoma of the urinary bladder: a case report].

A 64-year-old man presented with asymptomatic gross hematuria. Cystoscopy revealed a non-papillary broad-based tumor on the posterior wall of the bladder. He had no evidence of metastases. Urine cytology showed a cluster of molded tumor cells with naked hyperchromatic nuclei, which indicated small cell carcinoma. He received preoperative irradiation to the bladder and underwent partial cystectomy. Pathological examination of the specimen showed small cell carcinoma at the stage of pT2. Two years after the operation, he had no evidence of recurrence.

Carcinoma, Small Cell↗
PubMed2000

[Study of the two-step tuberculin tests and gamma-interferon assays in elderly persons].

Recently, an outbreak of lung tuberculosis among elderly residents happened in the home for aged, and it has become a social problem. To analyze the problem of tuberculosis in the elderly persons, we performed two-step tuberculin tests at two weeks interval and gamma-interferon assays for diagnosis of human tuberculosis to residents in the home for aged. 45 males (age; 77.3 +/- 8.9 SD) and 118 females (age; 81.9 +/- 8.6 SD) elderly persons (> or = 60) were examined. Standard dose of PPD was injected intracutaneously, and read at 48 hours. Erythema of 10 mm diameter or more was considered positive. The results were as follows. (1) The percentages of positive reactors in the 1st (T1) and the 2nd (T2) tuberculin tests were 50.3% and 68.1%, respectively. (2) The diameters of erythema and percentage of positive reactors (T1) did not very with age, but the size of erythema increased from 13.5 mm (T1) to 21.2 mm (T2) among those below 80 years, and from 13.0 mm (T1) to 16.4 mm (T2) among those 80 years or higher (p < 0.01). (3) The percentage of positive reactors (T1) varied by sex, namely males react stronger than females. (4) A dose of interferon-gamma released specifically in response to PPD stimulation of whole blood cultures showed no close relation with the diameters of erythema. In conclusion, tuberculin reactivity waned among elderly persons, and the fact suggests that they would have lower resistance against new infections, and as a result, they might have higher risk of developing tuberculosis. Elderly residents should be performed two-step tuberculin tests at the time of their entrance to the home for aged, and negative reactors should carefully be followed up.

Aged↗
PubMed2000

Characterization of the anti-cancer-cell parasporal proteins of a Bacillus thuringiensis isolate.

An unusual activity, associated with non-insecticidal and non-haemolytic parasporal inclusion proteins of a Bacillus thuringiensis soil isolate, designated 89-T-26-17, was characterized. The parasporal inclusion of this isolate was bipyramidal, rounded at both ends, containing proteins of 180, 150, 120, 100, and 88 kDa. No homologies with the Cry and Cyt proteins of B. thuringiensis were detected based on N-terminal sequences. Proteolytic processing of the inclusion proteins by proteinase K, trypsin, and chymotrypsin produced a major protein of 64 kDa exhibiting cytocidal activity against human leukaemic T cells and uterus cervix cancer (HeLa) cells. The protease-activated proteins showed no cytotoxicity to normal T cells.

Amino Acid Sequence↗