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Biomedical subjects

T Kodama

Publications and source records attributed to T Kodama.

At least 91 records · Page 5Linked to original sources
PubMed2001

Analyses of microbial community within a composter operated using household garbage with special reference to the addition of soybean oil.

A commercially available composter was operated using fixed composition of garbage with or without the addition of soybean oil. The composter was operated without adding seed microorganisms or bulking materials. Microflora within the composter were analyzed by denaturing gradient gel electrophoresis (DGGE) in the case of oil addition, or by 16/18 S rRNA gene sequencing of the isolated microorganisms in the case of no oil addition. The results showed that, irrespective of the addition of oil, the bacteria identified were all gram positive, and that lactobacilli seemed to be the key microorganisms. Based on the results, suitable microflora for use in a household composter are discussed.

Journal Article↗
PubMed2001

Promotive effect of auxins on UDP-glucose: flavonol glucosyltransferase activity in Vitis sp. cell cultures.

The addition of 2,4-dichlorophenoxyacetic acid (2, 4-D) to Vitis sp. cell cultures significantly enhanced the production of quercetin 3,7,4'-tri-O-glucoside, 3,7-di-O-glucoside and 3,4'-O-glucoside from quercetin. This enhancement of glucosylation by 2,4-D was also observed in cell cultures of other plant species. The activity of UDP-glucose: flavonol glucosyltransferase (UFGT) in cell-free extracts of Vitis sp. cell cultures increased approximately 10-fold, 48 h after the addition of 2,4-D to the culture medium. The UFGT activity increased linearly up to 15 h and showed a maximal response to the addition of 10-50 mg/l of 2,4-D at 48 h. The promotive effect of 2,4-D was inhibited by cycloheximide suggesting that de novo protein synthesis was involved in this phenomenon. Interestingly, similar promotive effects on the UFGT activity were observed for other phytohormones such as kinetin and several anti-auxins.

Journal Article↗
PubMed2001

Responses of transformed root culture of Atropa belladonna to salicylic acid stress.

The effect of salicylic acid (SA) on tropane alkaloid production and the responses to SA stress of transformed root cultures of Atropa belladonna (belladonna) were investigated. Treatment of A. belladonna transformed roots with 0.2 mM SA did not have any effect on tropane alkaloid production, but two compounds were produced in the medium. These were identified as the SA derivatives methylsalicylate and methyl-o-methoxybenzoate by high-resolution mass spectrometry and UV spectrometry. In contrast, treatment with 2 mM salicylic acid stimulated tropane alkaloid release from the transformed roots into the medium by up to 35% of the total alkaloids after 24 h, and the SA derivatives were not observed in the medium. These results revealed that transformed root of A. belladonna exhibits distinct by different responses to SA stress depending on the SA concentration.

Journal Article↗
PubMed2001

Evaluation of simultaneous excision of pancreatic cancer and the surrounding blood vessels.

Of the 139 patients who underwent excision for invasive cancer in the pancreatic duct at Kurume University Hospital between January 1965 and December 1998, the subjects were 38 patients in whom blood vessels around the cancer were simultaneously excised. The surgical methods were pancreatoduodenectomy (PD) in 31 patients, distal pancreatectomy (DP) in 5, and total pancreatectomy (TP) in 2. The excised blood vessels were the portal vein alone in 32 patients, the artery alone in 1, and both portal vein and artery in 5. Excision of the portal vein was performed by circumcision in 25 patients and by segmentectomy in 12. The range of circumcision was 1.0-7.0 cm (mean, 3.5 +/- 1.4 cm), and the blocking time of the portal vein was 8-36 min (mean, 19.5 +/- 8.8 min). Of the 25 patients who underwent circumcision, reconstruction was performed by end-to-end anastomosis in 23 and by transplantation of the autologous vein between the ends in 2. Of the 12 patients who underwent segmentectomy, direct suture was performed in 10, and transplantation of an autologous vein patch was performed in 2. Postoperative complications occurred in 14 of the 32 patients. In 5 of the 6 patients who underwent excision of the artery, reconstruction was performed by end-to-end anastomosis in 3 and by transplantation of the autologous vein between the ends in 2. Postoperative complications did not occur in the patient who had undergone excision of the artery alone, but 4 of the 5 patients who had undergone simultaneous excision of the portal vein and artery had postoperative complications, of whom 2 died during the period of hospitalization. Three patients with pv0, pv1 or pv2 survived for more than 3 years. Because some of the patients who had undergone excision of the portal vein alone survived for a long time and this method is relatively safe, this surgery can be generally applied, but simultaneous excision of the portal vein and artery should be carefully applied because the incidences of postoperative complications and death during the period of hospitalization are high. With the development of surgical techniques and postoperative control, simultaneous excision of pancreatic cancer and the surrounding blood vessels has become safe, but this method should only be applied to patients who have the potential to recover completely.

Hepatic Artery↗
PubMed2001

Xanthogranulomatous cholecystitis.

Seven cases of xanthogranulomatous cholecystitis are presented, and their clinicopathological appearance is described. Three men and 4 women with xanthogranulomatous cholecystitis, aged 53-72 years old, were reviewed. Five patients had had previous attacks of acute cholecystitis lasting from 3 weeks to 6 months. Abdominal ultrasonography was performed in all patients, and computed tomography in 5 patients. Cholelithiasis and sludge were present in all patients. The gallbladder wall was thickened in all patients. On computed tomography, one patient showed no abnormal finding, and 4 patients had abnormal findings such as increased wall thickness and irregularity, and pericholecystic abnormalities. A diagnosis of gallbladder carcinoma was made preoperatively in 1 patient. During laparotomy, the gallbladders in all patients showed signs of chronic cholecystitis, and cholecystectomies were performed. Histological findings showed xanthogranulomatous cholecystitis, and 4 patients had stones in the gallbladder wall. Despite the characteristic histologic appearance of xanthogranulomatous cholecystitis, radiologic findings are nonspecific, varying from signs observed in other forms of cholecystitis to the appearance of a gallbladder neoplasm. We report here 7 cases of xanthogranulomatous cholecystitis and review the literature.

Aged↗
PubMed2001

A case of hepatocellular carcinoma rupturing after angiography.

We report a case of primary hepatocellular carcinoma (referred to as hepatocellular carcinoma below) apparently rupturing after angiography. The patient was a 62-year-old male who was admitted for the treatment of hepatocellular carcinoma. Ultrasonography (US) and computed tomography (CT) on admission showed a tumor occupying the entire left lobe of the liver and partly protruding outside the liver and a tumor embolus in the portal vein. We performed preoperative angiography, after which fever and abdominal discomfort appeared. Two days after the angiography, abdominal pain and a rapid increase in the size of the abdominal tumor were noted. US also revealed an unquestionable increase in the size of the tumor, leading to a diagnosis of intratumoral hemorrhage due to the rupture of hepatocellular carcinoma. Since child classification A, clinical stage I and ICG 11.7% indicated an adequate functional reserve of the liver, we performed an emergency operation. Laparotomy revealed that the tumor occupied almost the entire left lobe of the liver, partly protruded outside it, and was bleeding from part of its anterior surface. The volume of intra-abdominal hemorrhage was about 100 ml. A portal tumor embolus was present in the portal vein from the horizontal part to the trunk. We performed resection of the left and caudate lobes of the liver with removal of the portal tumor embolus. The resected specimens showed a hemorrhage in and around the tumor. We speculated that in a hepatocellular carcinoma that involves the surface of the liver and is complicated by tumor embolism of the portal vein, angiography could trigger the rupture of the carcinoma.

Angiography↗
PubMed2001

Carcinoma of the ampulla of Vater associated with other organ malignancies.

Because of its location with respect to the biliary system, carcinoma of the ampulla of Vater is considered to manifest earlier in its course of development than carcinoma of the pancreas. The most common physical finding is jaundice, which occurs in 93-100% of cases [1,2]. This retrospective study describes the results of the treatment and prognosis for double primary cancers in which cancer of the ampulla of Vater was associated with malignancies in other organs in 5 patients who were diagnosed and treated at Kurume University Hospital. The patients included 5 men with an average age of 72.8 years. There were 3 synchronous double and 2 metachronous double cancer patients. Regarding prognoses of these patients, 1 patient with associated lung cancer died because of postoperative complications after pneumonectomy, 1 patient died due to carcinomatosa peritonei developing from the ampulla Vater carcinoma, and 1 patient died because of metastatic liver tumors from the ampullary carcinoma. In multiple cancers including ampulla Vater carcinoma, gastrointestinal cancers such as gastric or colon cancer occur frequently. Therefore, a careful gastrointestinal examination should be done preoperatively. We report our experience with 5 cases of ampullary carcinoma associated with malignancies in other organs and review the literature.

Aged↗
PubMed2001

Clinicopathological evaluation of surgical treatment for early gallbladder cancer.

We evaluated the therapeutic principles for early gallbladder cancer based on clinicopathological characteristics and outcomes in 27 patients encountered at the Kurume University Hospital between January, 1975 and December, 1999. Concerning the depth of wall penetration, 15 patients had mucosal cancers (m-cancers), and 12 patients muscularis propria cancers(mp-cancers). The gross patterns were lp (pedunculated) in 16 patients, ls (sessile) in 3 patients, IIa (flat elevated) in 4 patients, and IIb (flat) in 4 patients. The operative procedure used was cholecystectomy (C) in 12 patients, 4 of whom underwent lymph node dissection. Full-thickness cholecystectomy (FTC) was carried out in 3 patients, one of whom had lymph node dissection. Combination of C and gallbladder bed resection (GbBR) was performed in 7 patients, 6 of whom had lymph node dissection. Combination of C and bile duct resection (BDR), and lymph node dissection was performed in 1 patient. Combination of C and GbBR and BDR, and lymph node dissection was performed in 6 patients. All the patients who underwent lymph node dissection were negative for metastasis. Of the 27 patients, 2 underwent laparoscopic operation: one with m-cancer was 79 years old, and the other with mp-cancer 86 years old. In the m-cancers, no lymphatic, venous or perineural infiltration was observed. In contrast, in the mp-cancers, lymphatic and venous infiltration each were observed in 4 patients (33.3%), although no perineural infiltration was observed. A diagnosis of gallbladder cancer was made postoperatively in 6 patients, of whom 4 had the IIb pattern and all were complicated by gallstone, indicating the difficulty of diagnosing the IIb pattern. The 5-year survival rates for the m- and mp-cancers were as high as 90.9% and 80.8%, respectively. As a curative surgical technique for m- and mp-cancers, lymph node dissection should be performed in addition to FTC, GbBR, and BDR, in combination. When a postoperative histopathologic diagnosis of gallbladder cancer has been made, no second-look operation should be performed for m-cancers, but lymph node dissection of up to the second group should be performed for mp-cancers in a second-look operation.

Aged↗
PubMed2001

A new trend of breast cancer research in the genome era (Review).

The decipherment of the human genome, as accomplished recently in USA and in Europe, now enables us to search for the cause of a disease at the levels of the whole spectrum of gene expressions (mRNAs) of the human genome. A set of investigations came to the world in AD 2000 to show that: a) A total of 50 genes of the estrogen receptor positive (ER+) human breast cancer cell line MCF-7 in their gene expressions were found to undergo stimulation from a physiological concentration of 17beta-estradiol. b) Comparison of estrogen-responsiveness among a number of estrogen-responsive genes, among cancer cell lines of both the breast and endometrium with and without active ER, and among cell lines of normal tissues revealed that association between the presence of active ER and estrogen-responsive genes is quantitative rather than qualitative including some exceptions, and that none of the estrogen-responsive genes tested was classified as of breast cancer specific. For this review, we collected information from our and other laboratories to investigate problems that remain to be disputed. Five items of discussion are given as follows: a) The dose of a steroid used for the production of an experimental tumor was fixed not to a physiological concentration but to a pharmacological concentration. In the case of estradiol, the latter was higher than the former by over 3 orders. The mitotic activity of MCF-7 underwent stimulation from the former but distinct suppression from the latter. b) A massive dose of a single steroid, when given at a good time of the host age, could produce a tumor of any kind. The timing of treatment rather than the nature of a steroid was found critical. c) Experience with the morphological development of Drosophila suggests the possibility that deficiency rather than amplification of gene expression in the infant age of Drosophila is responsible for the induction of morphological changes in an adult fly. Likewise, deficiencies of some escort steroids rather than overflow of estradiol may have more chance of occurrence in the genesis of spontaneous breast cancer, as suggested by many researchers including us. The plasma concentration of estradiol was found to be normal in patients with cancers of both the breast and endometrium. Future studies of breast cancer as well as other cancers should be directed to the multisteroidal carcinogenesis hypothesis rather than the monosteroidal carcinogenesis hypothesis. d) The necessity of recruiting an appropriate case-control data set and the difficulty of data interpretation were emphasized in the search for good biomarkers of breast cancer. e) Case-control studies of tamoxifen use was found useful for the prevention and clinical control of breast cancer of non-hereditary type but not for the breast cancer of hereditary type. Both decreased risk of breast cancer and increased risk of endometrial cancer were detected in the same population of tamoxifen use. The observed dualism of both human breast cancer and tamoxifen action can be taken as evidence to support the multi-steroidal carcinogenesis hypothesis rather than the mono-steroidal carcinogenesis hypothesis.

Animals↗
PubMed2001

Macrophage scavenger receptor (SR-A I/II) deficiency reduced diet-induced atherosclerosis in C57BL/6J mice.

The effects of SR-A I/II deficiency and a synthetic anti-oxidant BO-653 on a diet-induced atherosclerosis in C57BL/6J, an inbred strain known to be susceptible to diet-induced atherosclerotic lesion formation, were examined. Quantitative analysis of the extent of atherosclerotic lesions in the mice fed the high-fat diet revealed that the atherosclerotic lesion area in SR-A I/II mutants was significantly reduced by 70% compared to wild type mice. A similar level of lesion reduction (75%) was found in wild type mice fed the high-fat diet supplemented with 0.6% BO-653 compared to those without BO-653. Thus, for C57BL/6J in the setting of prolonged exposure to a high-fat diet, defect of SR-A I/II expression is significantly protective against the development of atherosclerosis, as is the synthetic anti-oxidant BO-653. These results indicate that SR-A I/II has a crucial role in atherosclerotic lesion formation with uptake of oxidized-LDL in this mouse model.

Animals↗
PubMed2001

Diabetes-induced disruption of gap junction pathways within the retinal microvasculature.

PURPOSE: Microvascular damage caused by diabetes is a leading cause of visual loss. Identifying events early in the course of diabetic retinopathy may help in understanding and, perhaps, preventing this disorder. The hypothesis that cell-to-cell communication within the retinal microvasculature may be affected soon after the onset of diabetes was tested. METHODS: Streptozotocin was used to induce diabetes in rats. To assess cell-to-cell coupling the gap junction-permeant tracer, Neurobiotin, was delivered via patch pipettes into pericytes located on microvessels freshly isolated from the retinas of diabetic and control animals. Subsequently, immunohistochemical methods revealed the extent of the intercellular spread of the tracer. Electrophysiological methods were also used to detect intercellular communication. RESULTS: In retinal microvessels of control rats, Neurobiotin spread hundreds of micrometers from the tracer-loaded pericytes. However, within days after the onset of diabetes, this cell-to-cell coupling was dramatically reduced. In contrast, microvessels of insulin-treated diabetic rats showed no significant loss of intercellular communication. Consistent with protein kinase C (PKC) playing a role in the diabetes-induced inhibition of gap junction pathways, exposure of microvessels to a PKC activator (phorbol myristate acetate) markedly reduced tracer coupling. CONCLUSIONS: Within retinal microvessels there is extensive cell-to-cell coupling, which is markedly reduced soon after the onset of streptozotocin-induced diabetes. The closure of gap junction pathways disrupts the multicellular organization of retinal microvessels and may contribute to vascular dysfunction.

Animals↗
PubMed2001

PDGF-induced coupling of function with metabolism in microvascular pericytes of the retina.

PURPOSE: The aim of this study was to test the hypothesis that platelet-derived growth factor (PDGF)-BB regulates the physiology of retinal pericytes, which are contractile cells located on the abluminal surface of capillaries. The expression of PDGF-BB and its cognate receptor in retinal vessels suggests a vasoactive function. However, although endothelium-derived PDGF-BB appears vital for the development of pericyte-containing microvessels, its role in the mature vasculature remains uncertain. METHODS: Based on the premise that ion channels mediate the responses of pericytes to vasoactive signals, the perforated-patch configuration of the patch-clamp technique was used to determine the effect of PDGF-BB on the ionic currents and membrane potential of pericytes located on microvessels freshly isolated from the adult rat retina. Changes in pericyte calcium levels were monitored with the calcium indicator fluo-4. Differential interference contrast optics and image analysis software aided in assessing the effects of PDGF-BB on the lumens of isolated pericyte-containing microvessels. In some experiments, blockers of adenosine triphosphate (ATP) synthesis created chemical ischemia. RESULTS: Electrophysiological recordings from pericytes showed that PDGF-BB can activate nonspecific cation channels, chloride channels, and ATP-sensitive potassium channels. The metabolic status of an isolated capillary determined which of these ion channels were activated by PDGF-BB and thereby whether the membrane potential decreased or increased, the cell calcium rose or fell, and the vessel lumen constricted or dilated. CONCLUSIONS: The ability of PDGF-BB to be a vasoconstrictor when energy supplies are ample and to be a vasodilator under ischemic conditions may provide an efficient mechanism to link capillary function to local metabolic needs.

Aniline Compounds↗
PubMed2001

Clinical significance of antibiotic therapy in guided tissue regeneration with a resorbable membrane.

This study was designed to evaluate the clinical significance of antibiotic therapy combined with guided tissue regeneration (GTR) therapy with a collagen membrane. The subjects were 20 adults diagnosed with periodontitis (20 intrabony periodontal defects). Ten patients were treated with GTR alone (control group) and the other 10 patients were treated with a combination of GTR and antibiotics (antibiotic group). In the antibiotic group, minocycline ointment was applied locally before GTR therapy, and doxycycline and amoxyline were systemically administered after GTR therapy. Clinical manifestations, the presence or absence of exposed membrane, and microbiological findings were assessed 1 month before, immediately after, and 2 weeks, 6 weeks, and 3 months after GTR therapy. The results showed no significant differences in reduction of probing depth, probing attachment gain (PAG), or the ratio of PAG to intraoperative depth of the intrabony defect (vertical relative attachment gain) between the antibiotic group and the control group before and 3 months after GTR therapy. A DNA probe test and specific enzymatic activity test revealed no significant differences in the improvement and the rate of bacterial negativity before, and 6 weeks and 3 months after, GTR therapy. These findings indicate that antibiotic therapy is not clinically beneficial when combined with GTR therapy with a collagen membrane.

Absorbable Implants↗
PubMed2001

[A case of Mycobacterium intracellulare infection complicated by immotile cilia syndrome].

A 25-year-old woman with a history of immotile cilia syndrome (ICS) was admitted to our hospital with dyspnea. Chest roentgenography revealed dense infiltrates in both lower lung fields in addition to bronchiectasis and small nodular opacities, which had been observed previously. Transbronchial lung biopsy demonstrated evidence of non-caseating epithelioid cell granuloma. Sputum specimens were examined, and isolates were identified as Mycobacterium intracellulare. The patient was given antituberculous therapy and clarithromycin, which induced clinical improvement. It is well known that bronchial mucociliary transport is severely impaired in patients with ICS. However, to our knowledge, cases of M. intracellulare infection complicated by ICS have not been reported in Japan. We must pay close attention to the concurrence of these diseases.

Adult↗