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Biomedical subjects

M Kitajima

Publications and source records attributed to M Kitajima.

At least 379 records · Page 21Linked to original sources
PubMed1990

Structural analysis of multiple bovine P-450(11 beta) genes and their promoter activities.

A bovine genomic library was constructed using a cosmid vector, pHC79, and bovine DNA partially digested by EcoRI. Bovine P-450(11 beta) cDNA, pcP-450(11 beta)-2 [Morohashi et al. (1987) J. Biochem. 102,559-568], was used as a probe for screening the genomic library. Ten clones carrying P-450(11 beta) genomic DNA were isolated from 8 x 10(4) colonies and classified into five groups (CB11 beta-1, CB11 beta-3, CB11 beta-7, CB11 beta-20, and CB11 beta-21) according to differences in the restriction endonuclease sites. Nucleotide sequences of amino acid coding regions of the five clones were determined by the dideoxy sequencing method using synthetic nucleotides corresponding to various parts of the cDNA as primers. The nucleotide sequences revealed that three clones, CB11 beta-1, CB11 beta-3, and CB11 beta-21, were pseudogenes. Amino acid sequences coded by the other two clones, CB11 beta-7 and CB11 beta-20, were identical with that coded by a previously described cDNA, pcP-450(11 beta)-3 [Kirita et al. (1988) J. Biochem. 104, 683-686]. The promoter regions of the five clones were introduced in front of chloramphenicol acetyltransferase (CAT) gene of pSV00CAT and used to examine P-450(11 beta) gene regulation in cultured cells. The five recombinant plasmids showed cAMP-responsive CAT activities in Y-1 cells, a cell strain derived from adrenal tumor. The induction rates of the recombinant plasmids carrying the promoters of normal genes, CB11 beta-7 and -20, were larger than those of pseudogenes, CB11 beta-1, -3, and -21. CAT activities expressed by the promoter regions of the normal genes in the presence or absence of cAMP in Y-1 cells were almost equal to that by the promoter region of human P-450(SCC) gene. Though the promoter of the P-450(SCC) gene also showed cAMP-responsive CAT activity in I-10 cells, a cell strain derived from Leyding cell tumor, P-450(11 beta) gene promoter did not express the activity in I-10 cells.

Amino Acid Sequence↗
PubMed1990

Alternation of gastric mucosal glycoprotein (lectin-binding pattern) in gastric mucosa in stress. A light and electron microscopic study.

Gastric mucosal cells of the rat glandular stomach were studied by light and electron microscopic procedures by use of lectins in the development of acute gastric mucosal lesions. Effects of the H2-receptor antagonist sofalcone (2'carboxymethoxy-4,4'-bis 3-methyl-2) and truncal vagotomy with pyloroplasty on lectin binding sites and distribution were also investigated. Biotinylated lectins in combination with ABC (avidin-biotinyl peroxidase complex) method were used for light and horseradish peroxidase (HRP)-labeled lectins for electron microscopic studies. Gastric mucosal cells showed the specific binding pattern for each lectin by light microscopy. Especially, binding sites and distribution of peanut agglutinin (PNA) were characteristic after induction of stress, truncal vagotomy, and administration of each drug. Staining and distribution increased in the gastric mucosa upward and downward after that. In electron microscopic studies, PNA strongly stained the membranes of the intracellular secretory canaliculi of a parietal cell. These results suggested that alternation of binding sites and distribution was regulated by change of gastric mucosal blood flow and of acidity in the parietal cells. Therefore, increase of glycoconjugate distribution is supposed to be a possibility of cytoprotective effect for a change of environment in the parietal cells.

Animals↗
PubMed1990

The role of endogenous free radical scavengers on tissue recovery in the experimental ulcer model.

The role of lipid peroxidation and endogenous oxygen-derived free radical scavengers on ischemia-reperfusion injury and tissue recovery in rat ulcer model corresponding to the gastric histopathology was investigated. Male Wistar rats weighting 200-250 g were heparinized before occlusion of the celiac axis for 1.5 h. Endogenous CuZn-superoxide dismutase (SOD), Mn-SOD, glutathione peroxidase, fumarase, cytochrome c oxidase, and thiobarbituric acid-reactive compounds as lipid peroxidation products were measured in the gastric tissue at 3 h, and 1, 2, 4, and 7 days after release and in the controls (no occlusion). At 3 h after release, erosion of the gastric mucosa was observed, and gastric ulcers beyond the muscularis mucosae were present in the gastric body 2 days later. Seven days after release, gastric ulcers had disappeared. Activity levels for all five enzymes (CuZn-SOD, Mn-SOD, glutathione peroxidase, fumarase, and cytochrome c oxidase) were low for days 1-4 after release and did not return to control levels by the seventh day. It was observed that the ulcer formation, as evidenced by the histopathology, was significantly related to the levels of endogenous CuZn-SOD, Mn-SOD, glutathione peroxidase, fumarase, and cytochrome c oxidase activities. Thiobarbituric acid-reactive compounds were also low through the entire course of ulcer formation. The study concludes that decreases in the levels of these oxygen-derived free radical scavengers may result in the formation of gastric ulcers; however, endogenous free-radical scavengers may not correspond with tissue recovery. Lipid peroxidation may not be related to ulcer formation.

Animals↗
PubMed1990

[Alteration of the gastric mucosal glycoprotein in stress].

Many studies have postulated the role of gastric acid and mucosal microcirculation in the development of gastric ulcer. We considered that gastric mucosal glycoprotein played one of the most important roles as the defensive factors of te gastric mucosa. The purpose of this study is to investigate te location and distribution of glycoprotein in the gastric mucosa in normal and stressful condition. Male Wistar rats, weighing 250 g were used as the experimental animals. Alternation and distribution of glycoprotein in the gastric mucosa were studied by light and electron microscopic examination employing HRP-labeled lectin such as PNA, DBA, ConA, RCA, SBA, WGA and UEA-1 as a parameter before and after the development of stress ulcer. Around Thirty percent scalding burn of the rat body surface area was created. At 2, 5 and 24 hours after burn induction, the gastric mucosa was examined. PNA-binding sites which were primarily localized to the generative cell zone in the control rat appeared to extend from the upper layer to the intermediate or the basal layer of the gastric mucosa in accordance with the development of stress ulcer after burn. Most of the binding sites was detected in the parietal cells particularly along microvilli in the intracellular secretory canaliculi. The tubulovesicular system in the parietal cells became stainable with PNA in the stress-loaded rats. Alternation and binding pattern of lectin, especially of PNA may indicate the local response of the parietal cells of the gastric mucosa against the stress.

Animals↗
PubMed1989

Gastric microcirculatory change and development of acute gastric mucosal lesions (stress ulcer).

Concerning the pathogenesis of acute gastric mucosal lesions, gastric microcirculatory change has drawn attention as an important factor. In view of this fact, gastric mucosal blood flow and microvascular structure were investigated in normal and in burn stressed rats. Moreover, alterations in acid and pepsin activities in by morphological and biochemical procedures in order to evaluate the relationship between defensive and aggressive factors of the gastric mucosa. Gastric mucosal blood flow decreased significantly in early period after induction of stress (p less than 0.01). The incidence of ulceration showed a correlative relation with the decrease of mucosal blood flow. Reduction of blood flow in burn was due to opening of arteriovenular shunt and it appeared that this was responsible for mucosal ischemia and congestion. Following the decrease of blood flow, acid output was lower in stress than that in control. Finally, the results of these studies demonstrated the importance of defensive factors. The reduction of mucosal blood flow resulted in the sequence of events that led to formation of acute gastric mucosal lesion.

Acute Disease↗
PubMed1989

[Metastatic liver cancer from the stomach successfully treated by combined immunochemotherapy and transarterial embolization].

A 53-year-old-man, who suffered from advanced gastric carcinoma with liver metastasis (P0H3S2N1; stage IV) underwent simple gastrectomy. After the operation, the patient was treated by chemotherapy (1/2 MFC, M: mitomycin C, F: FT-207, C: Cylocide) combined with immunotherapy (PSK, lentinan) and intraarterial injection (mitomycin C & Lipiodol). Liver metastases disappeared soon after the combined therapy, and these findings were confirmed by CT and US. Moreover, the serum level of CEA and CA 19-9 also decreased from 160 ng/ml and 51 U/ml to the normal level. The duration of the complete disappearance of the liver metastasis was not so long, but quality of life was well maintained for 2 and one half years. This case suggested that combined therapy may well be effective for advanced gastric cancer with liver metastases.

Adenocarcinoma↗
PubMed1988

Impairment of gastric microcirculation in stress.

Gastric mucosal blood flow and microvascular patterns were studied in normal and stressed rats. In addition, various regulating factors of gastric mucosal blood flow, such as autonomic nervous system and biogenic amines, were investigated by histochemical procedures. Gastric mucosal blood flow was determined by the hydrogen gas clearance method as well as the hydrogen gas electrolytic method, and the microvascular structure was observed by the infusion method with two-colored silicon rubber. The gastric mucosal blood flow decreased significantly in the early period after induction of burn stress. The incidence of acute gastric mucosal lesions had a highly correlative relation with the decrease in mucosal blood flow. Reduction of mucosal blood flow was consequently due to opening of an arteriovenous shunt and hyperpermeability of true capillaries. This hemodynamic change, regulated by biogenic amines and autonomic nerves, was followed by ischemia and congestion of the gastric mucosa. The results of these studies demonstrated the importance of defensive factors; that reduction of mucosal blood flow resulted in the sequence of events that led to formation of acute gastric mucosal lesions.

Animals↗
PubMed1988

Improvement of in vivo stability of alginate-polylysine capsules.

Dextran (MW 70,000) and rat islets were encapsulated in alginate-polylysine membrane. The capsules were further coated with tolylene 2,4-diisocyanate. Both of positive and negative charges were detected on the surface of alginate-polylysine capsules, which were absent after coating the capsules with tolylene 2,4-diisocyanate. In the peritoneal cavity, alginate-polylysine capsules were entrapped by the peritoneum, and 89% of dextran was leaked out of the capsules. Alginate-polylysine capsules coated with tolylene 2,4-diisocyanate were present freely in the peritoneal cavity and no leakage of dextran from the capsules were detected. Insulin release from the encapsulated islets was almost the same in both of tolylene 2,4-diisocyanate-coated and uncoated capsules. This study demonstrates that in vivo stability of capsules is dependent on the charge on the surface and can be improved by coating with tolylene 2,4-diisocyanate.

Alginates↗
PubMed1987

[The effect of tegafur suppository and glutathione in patients with gastric and colonic cancer with special reference to the histopathological anticancer effect].

The purpose of these studies is to evaluate the anticancerous effects of tegafur suppository and Glutathione (GSH) as enhanced drug and compare the difference of the histopathological effects and tissue concentration of 5-FU and FT-207 in gastric and colon cancer. Thirty three patients with gastric cancer and 17 with colon cancer were treated by tegafur suppository at a dose of 1,500 mg/day and GSH, 1,200 mg/day intravenously. These patients were clinically divided into two groups, one of which was treated with tegafur suppository (Group A) and another administered with suppository and GSH (Group B). Five-fluorouracil was measured by GC-MF method and FT-207 was also done by HPLC method. After surgery, relationship between tissue concentration of 5-FU and histopathological effects were investigated. In gastric cancer, 5-FU concentration in cancer tissue was significantly kept high level in cancer tissue in patients treated with tegafur and GSH (Group B). However, there was no same results in colon cancer. These results seemed to be the difference of organ specificity. According to histopathological studies, well differentiated adenocarcinoma including papillary carcinoma were markedly effective compared to poorly differentiated adenocarcinoma in both cancer. This difference of anticancerous effect was supposed to be microangiographically different of microvascular architecture and quantity of anticancerous agents in tumor.

Colonic Neoplasms↗
PubMed1986

[A long-term survivor of primary hepatoma--a case suggesting the superiority of a multi-drug (OK-432, SPG, PSK) over mono-drug immunotherapy].

The studied patient (70 years old, male) had primary hepatoma with rupture of the liver. We resected his left lobe partially and were able to save him. Since a residual tumor was found after surgery, we injected a total of 30 mg of MMC into the SCA 3 times. Under continuous administration of OK-432, the patient survived for 3 years and 6 months in remission. Because the tumor grew gradually, we started a multi-drug immunotherapy (OK-432 5 KE/2 W/intradermal, PSK/3.0 g/day/P.O., SPG/20 mg/2 W/I. M.) which we have advocated. In 6 months the tumor regressed to 1/3 of its original size. The patient is currently in good condition 4 years and 7 months after the operation. This case demonstrated the superiority of multi-drug immunotherapy over single-drug immunotherapy.

Aged↗
PubMed1984

[Study of lincomycin concentrations in hepatocystic duct].

Penetration of lincomycin (LCM) in choledochal and cholecystic bile as well as in the gallbladder tissue and liver tissue was investigated together with bacteria detectable in the bile in order to evaluate basically usefulness of this antibiotic in the treatment of infections of the hepatocystic duct. Intravenous drip infusion of LCM 1.5 g (in 500 ml of 5% glucose solution) over 1.5--2 hours resulted in mean drug concentrations of 33.9 and 10.1 micrograms/ml in serum at 2 and 4 hours post start of infusion respectively; 215.5 micrograms/ml in choledochal bile at 3 hours 15 minutes; 252.7 micrograms/ml in cholecystic bile at 3 hours 36 minutes; 28.1 micrograms/g in gallbladder tissue at 2 hours 55 minutes; and 15.4 micrograms/g in liver tissue at 4 hours. A cross-over study of LCM and cefazolin (CEZ) in 2 cases where T-tubes were employed demonstrated evidently higher biliary levels of LCM than CEZ. Bacteriological examination showed that Hafnia alvei plus Streptococcus faecalis were presented in choledochal bile from just 1 of 4 cases while in cholecystic bile from 9 of 15 cases were detected 22 strains of organisms including Klebsiella pneumoniae (7 strains), Bacteroides fragilis (5), Escherichia coli (2), Citrobacter freundii (2) and Serratia marcescens (2). A total of 7 strains of anaerobes including B. fragilis was isolated. The above concentrations of LCM in the bile, gallbladder tissue and liver tissue sufficiently covered the MIC90 of this antibiotic determined by us in 1980 for major species of anaerobes including clinical isolates of B. fragilis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1982

[Evaluation of pre-operative chemotherapy using FT-207 suppositories combined with glutathione--with special reference to histopathological antitumor effect].

Thirty patients with gastric cancer were clinically studied by rectal administration of FT-207 suppository at a dose of 1500mg per day as a preoperative adjuvant chemotherapy. Eighteen of thirty patients were divided into two groups, 13 patients of which were only administrated with tegafur (FT-207) suppository (Group A) and 5 patients were administrated with glutathione (GSH) at a dose of 1200mg daily with FT-207 suppository (Group B): The tissue concentration of FT-207 and 5-FU in normal and cancer tissues was measured following the resection of the stomach. In addition, we studied anticancer effect of FT-207 suppository on the basis of our original pathological criteria. Experimental results revealed that 5-FU concentration in serum was reached to maximum at 3 to 4 hours following administration in both groups. The serum concentration in most cases of the former group was decreased to the lower level of the effective concentration for 8 hours, however the latter could be kept the effective concentration for more than 10 hours. The correlation between the tissue concentration and total dose was analyzed. 5-FU concentration, which was active substance of FT-207, in cancer tissue was higher than in normal one, especially in Borrmann II type cancer, but the difference of concentration was not found between group A and B. The correlation between total dose and anticancer effect was also analyzed. Histopathological effect in group A showed a mild change, such as necrosis of cancer nest. On the other hand, group B revealed a markedly effective change like scarring formation. As the result, administration of FT-207 suppository with GSH was clinically and histopathologically effective procedure as preoperative adjuvant chemotherapy.

Antineoplastic Agents↗