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Biomedical subjects

T Kodama

Publications and source records attributed to T Kodama.

At least 559 records · Page 31Linked to original sources
PubMed1993

[A pilot study of induction chemotherapy with cisplatin, mitomycin C and vindesine for stage III N2 non-small cell lung cancer].

PURPOSE: The postoperative survival of patients with preoperatively identified stage III N2 non-small cell cancer (NSCLC) is poor. A pilot study of induction chemotherapy consisting of cisplatin, mitomycin C and vindesine (CMV) was undertaken in an attempt to improve the curative potential of surgery in this group of patients. PATIENTS AND METHODS: Thirty-two patients with stage III N2a NSCLC received two cycles of CMV, (80 mg/m2 cisplatin i.v. on day 1, 8 mg/m2 mitomycin C i.v. on day 1, and 3 mg/m2 vindesine i.v. on day 1 and 8, every 4 weeks) preoperatively. The responding patients received a further two courses of CMV after surgery. RESULTS: The response rate was 63% (20 PR). All patients underwent operation including radical mediastinal node dissection. Twenty-six resections were curative and six were absolute non-curative. The toxicity was generally mild, but there were two hospital deaths, due to bronchopleural fistula and postoperative pneumonia. Sixteen patients have shown recurrent disease up to now. When the recurrence patterns were classified by clinical response, 11 responding patients were disease-free (9-84 months), but all non-responding patients had recurrent diseases. The median survival of curatively resected patients with pathological N2 was 39 months with a 5-year survival of 29%. CONCLUSIONS: This induction chemotherapy was well tolerated and revealed a high response rate. The current survival is obviously improved compared with the historical control, indicating that subsequent phase III clinical trials are urgently needed.

Adult↗
PubMed1993

Susceptibility of methicillin-resistant Staphylococcus aureus clinical isolates to various antimicrobial agents. III. Novel, inducible resistance to macrolide-lincosamide-streptogramin B (MLS) antibiotics.

Resistance patterns against 25 antimicrobial agents consisting of beta-lactams, aminoglycosides, tetracyclines, fluoroquinolones, macrolides and etc. were examined for 69 strains of methicillin-resistant Staphylococcus aureus (MRSA) isolated at Hiroshima University Hospital from July 1991 to April 1992. Regarding overall resistance (the percentage of highly and moderately resistant strains), the following antimicrobial agents were no more effective chemotherapeutics for MRSA infections (%resistance): methicillin (100), flomoxef (100), kanamycin (100), tobramycin (100), amikacin (100), isepamicin (100), gentamicin (78), dibekacin (100), ofloxacin (99), levofloxacin (99), temafloxacin (99), erythromycin (100), clarithromycin (100), tetracycline (93), minocycline (93) and fosfomycin (100). Further spread of arbekacin-resistant strain, which was isolated in April 1991, into a clinical environment could not be recognized during the period covered in the present study. All the MRSA strains were resistant either constitutively (26 strains) or inducibly (43 strains) to macrolide-lincosamide-streptogramin B (MLS) antibiotics. When expression is constitutive, the strains are resistant to all MLS antibiotics. In contrast, 16-membered macrolide (i.e., jasamycin), lincomycin and mikamycin B escape resistance in the strains with a typical inducible resistance overcome in the presence of 14-membered macrolides by a translational attenuation mechanism. Three of 4 beta-lactamase-positive strains, however, can not be classified in these two resistance groups, being exclusively resistant to mikamycin B. The strains grown in the presence of any inducing MLS antibiotic became susceptible to mikamycin B even in the inducer-free culture.

Anti-Bacterial Agents↗
PubMed1993

Effects of long-term, low-fat diet on plasma apo E in familial LCAT deficiency.

To study the metabolic abnormalities in familial lecithin-cholesterol acyltransferase (LCAT) deficiency, the effects of a long-term, low-fat diet and LCAT replacement therapy on plasma lipids and apolipoproteins were investigated in a patient with LCAT deficiency. The patient had elevated triglycerides (TG, 543.7 mg/dl) and phospholipids (PL, 350.3 mg/dl) and normal total cholesterol (TC, 206.9 mg/dl). Change to a low-fat diet reduced TC and TG by 20% and 75%, respectively. These reductions occurred mainly in the d < 1.006 fraction. At baseline, the patient had normal apolipoprotein B (apo B), low apolipoprotein A-I (apoA-I) and apolipoprotein A-II (apoA-II) and elevated apolipoprotein E (apo E). Long-term treatment with a low-fat diet increased plasma apoA-I and decreased apo E. However, urinary protein excretion did not change throughout the observed period. LCAT replacement with fresh frozen plasma (FFP) after the low-fat diet further reduced plasma apo E to the normal range. These results indicate that the elevated plasma apo E in LCAT deficiency was related not only to the lack of LCAT in the plasma, but also to fat intake. A low-fat diet may be effective in correcting lipid abnormalities. Moreover, plasma apo E may be a good indicator of the efficacy of diet therapy.

Apolipoproteins E↗
PubMed1993

[Detection of Helicobacter pylori by polymerase chain reaction].

The application of PCR method to the detection of H. pylori is reviewed. In most of the assays reported to date, primer pairs based on the sequences of urease and 16S rRNA genes have been chosen. Clinical samples tested have ranged widely from gastric biopsy specimens to gastric aspirates, feces, dental plaques, saliva, etc. As few as one organism can be detected by the most sensitive assay. The reports suggest that PCR assay is suited for laboratory diagnosis of the organism as well as epidemiologic studies. A future problem is to search the target sequences which are more specific to H. pylori and more informative for researching pathogenesis of gastrointestinal disorders associated with H. pylori infection.

Helicobacter pylori↗
PubMed1993

[Cell proliferation and maturation of ectopic submucosal glands of the stomach].

Stomachs with multiple submucosal glands keep our attention because of their high risk for having gastric carcinomas, but little is known about the relationship between submucosal glands and occurring cancers. So we investigated the structure of submucosal glands including location of proliferating cells. We labeled proliferating cells of three stomachs with cancerous lesions by circulating artificial blood through the isolated organs with bromodeoxyuridine (BrdU). Serial sections of submucosal glands were stained with hematoxylin eosin, periodic acid Schiff, Alcian blue, high iron diamine-Alcian blue, concanavalin A paradox, galactose oxidase Schiff as well as anti-BrdU immunohistochemically. Results showed that most of submucosal glands were composed of functionally matured cells and these cells made regular structure just like those of mucosal layer. Labeling index of BrdU of these submucosal glands were low (0.2%-0.7%). Two atypical glands were seen, and labeling index were 2.6% and 22.2% respectively. In conclusion, submucosal glands of the stomachs were thought to be made by moving proliferating cells from mucosal layer to submucosal layer. So we saw these submucosal glands paracancerous lesions rather than precancerous ones. But we couldn't deny the possibility to occur cancerous lesions from atypical glands in submucosal glands.

Aged↗
PubMed1993

[Risk factors and therapeutic methods for sternal wound infection following cardiac surgery].

In a study of 1040 patients undergoing cardiac surgery at The Osaka Medical College Hospital from 1984 through 1991, we analyzed the correlation between a variety of preoperative and operative parameters and the risk of postoperative sternal wound infection, as well as the efficacy of various therapeutic method for this condition. Sternal infection or mediastinitis developed after cardiac surgery in 31 patients (3.0%). As the risk factors for wound infections, age, diabetes mellitus, reexploration, duration of cardiopulmonary bypass and use of bilateral internal thoracic artery grafting were listed. Application of pectoral muscle flaps significantly led to shorten a duration between diagnosis of infection and hospital discharge, and increased survival rate, than the other treating methods such as debridement or irrigation. We conclude that bilateral internal thoracic artery grafts should not be used in the cases with diabetes, and closure with pectoral muscle flaps is effective for sternal infection and mediastinitis.

Coronary Artery Bypass↗
PubMed1993

[Structural and function of the human macrophage scavenger receptor].

Macrophage scavenger receptors (MSR) mediate the binding, internalization and processing of the wide range of negatively charged macromolecules. Functional receptors are trimers of two C-terminally different subunit containing 6 functional domains; cytoplasmic, transmembrane, spacer, alpha-helical coiled-coil, collagen-like, type specific domain. The C-terminal region of the collagen-like domain is essential for the ligand recognition of MSR. Human MSR gene consists of 11 exons, and two types of mRNAs are generated by alternative splicing from exon 8 to either exon 9 (type II) or to exons 10 and 11 (type I). Exon 1 encodes the 5' untranslated resion followed by a 12 kb intron which separates the transcription initiation site and the translation initiation site. Exon 2 encodes a cytoplasmic domain; Exon 3, a transmembrane domain; Exons 4 and 5, an alpha-helical coiled-coil; and exon 6 to 8, a collagen-like domain. The MSR gene consists of a mosaic of exons which encode the functional domains. The arrangement of exons helped determine the fine structural characteristics of functional domains.

Arteriosclerosis↗
PubMed1993

[Macrophage scavenger receptors and the maintenance of blood vessels].

Recent molecular cloning of cDNAs for Macrophage Scavenger Receptors (MSR) reveal several unexpected features of these receptors. These MSRs mediate wide range of ligands, especially negatively charged macromolecules. Expression of MSRs are highly specific to macrophages. The intracellular pathways for endocytosis and recycling of MSRs are efficient only in macrophages. Immunocytochemical study of MSRs show that all of the tissue macrophages, including brain scavenger cells (FGP cells) are MSR positive. Under some pathological conditions, such as atherosclerotic lesions, macrophages infiltrating into these lesions, which are derived from monocytes, are also positive for MSR. Macrophages expressing MSR are thought to play an important role in the clearance and maintenance of blood vessels. Brain scavenger cells may play a role in the maintenance of small blood vessels in the brain.

Animals↗
PubMed1993

[Analysis of proliferative activity in gastric biopsy specimens by combined BrdU and DNA polymerase alpha immunohistochemistry].

To evaluate correctly the proliferative activity of tumor cells, it is necessary to clarify not only S-phase fraction but also the growth fraction of tumor tissues. We used combined BrdU and DNA polymerase alpha (pol-alpha) immunohistochemistry to gastric biopsy specimens, and analyzed the proliferation of the neoplastic lesions of various degrees of malignancy. The results were as follows: The distribution of pol-alpha positive cells were almost the same as that of BrdU positive cells, but the percentage of pol-alpha positive cells was higher than that of BrdU positive cells irrespective of the mucosal specimens. In the adenomas, both BrdU and pol-alpha positive cells distributed generally superficially in the mucosal layer. In the well differentiated adenocarcinomas, both BrdU and pol-alpha positive cells distributed diffusely in the deeper layer of the mucosa. The ratio of the number of BrdU positive cells to that of pol-alpha positive cells, which means the S-phase fraction in the growth fraction, was higher in the tumor and that higher in the well differentiated adenocarcinomas than that of the adenomas. In conclusion, the combined BrdU and pol-alpha immunohistochemistry in gastric biopsy specimens are useful to evaluate the degree of malignancy.

Adenocarcinoma↗
PubMed1993

[Structure and function of the scavenger receptor].

The macrophage scavenger receptors are consisted of six domains: cytoplasmic, membrane-spanning, spacer, alpha-helical coiled-coil, collagen-like and a type-specific C-terminal. The collagen-like domain is revealed to have important role for ligand binding. The receptor gene is located on human chromosome 8. The human scavenger gene spans approximately 80 kb and is composed of 11 exons. Two types of scavenger receptor mRNA were shown to result from alternative splicing of exon 9 for type II or 10 and 11 for type I to the common exon 1-8. The scavenger receptor proteins were detected in macrophages of various organs and tissues such as Kupffer cells, alveolar macrophages, macrophages in the spleen and lymph nodes and perivascular macrophages in the brain. In the atheromatous plaques, scavenger receptors may participate progression of foam cells. Elimination and detoxication of endotoxin by macrophage scavenger receptor may suggest the defending function against a wide variety of pathogenic agents.

Amino Acid Sequence↗
PubMed1993

Cytotoxicity of unstimulated and thrombin-activated platelets to human tumour cells.

Platelet cytotoxicity was examined in vitro using various tumour cell lines as target cells. Thrombin-activated platelets as well as unstimulated platelets exerted a cytotoxic effect on some tumour cell lines including K562, KU812, LU99A and KG1, but other tumour cell lines including U937, MIA PaCa-2 and MOLT-4 were completely insensitive to this effect. Electron microscopic examinations showed that unstimulated platelets adhered to target K562 cells but thrombin-activated platelets did not. Morphological changes of K562 cells induced by unstimulated and thrombin-activated platelets were indistinguishable. When platelets and K562 cells were co-cultured in the same vessel but were prevented from coming into direct cell-to-cell contact by means of a membrane barrier, cytotoxicity of unstimulated platelets was completely blocked but that of thrombin-activated platelets was still detectable. However, no cytotoxic activity to K562 cells was detected in the supernatants obtained after stimulation of platelets with either target cells or thrombin for 4 hr. Extracellular Ca2+ ion was not required for the platelet-mediated cytotoxicity. Esterase inhibitors SBTI and TPCK had no effect on the formation of platelet-target cell adhesion but inhibited the cytotoxicity of unstimulated platelets. In contrast, the inhibitors had no effect on the cytotoxic activity of thrombin-activated platelets. These results suggest that direct contact between platelets and target cells is essential for unstimulated platelets but not for thrombin-activated platelets to exert cytotoxicity and that some esterases play a role in the cytotoxic process of unstimulated platelets. They also provide evidence that some cytotoxic effectors are soluble and easily inactivated factors liberated by activated platelets. Our findings indicate that platelets may be one of the cytotoxic effector cells against certain neoplasia.

Blood Platelets↗
PubMed1993

Central retinal vein occlusion in two patients with immunoglobulin G multiple myeloma associated with blood hyperviscosity.

A 69-year-old man (Patient 1) complained of anorexia, lumbago, and seeing floaters OS. The results of laboratory tests showed immunoglobulin (Ig) G lambda-type multiple myeloma associated with blood hyperviscosity. Retinal hemorrhages OD and central retinal vein occlusion OS were found. A 71-year-old woman (Patient 2) with IgG kappa-type multiple myeloma had blood hyperviscosity. Retinal microaneurysms OD and central retinal vein occlusion OS were found. We believe that our patients represent rare cases of IgG multiple myeloma associated with blood hyperviscosity and central retinal vein occlusion.

Aged↗
PubMed1992

Expression of scavenger receptors on renal cell carcinoma cells in vitro.

Messenger RNAs and proteins of scavenger receptor thought to be macrophage specific protein were expressed in renal cell carcinoma (RCC) cells in vitro. Acetyl LDL was taken up into RCC cells and promoted the production of interleukin-6 (IL-6), an in vitro autocrine growth factor to proliferate the cells. These results suggested that RCC cells might have a scavenger pathway which has not yet been demonstrated except for macrophages.

Blotting, Northern↗
PubMed1992

Novel linear and branched polyamines in the extremely thermophilic eubacteria Thermoleophilum, Bacillus and Hydrogenobacter.

Novel tertiary branched tetra-amines, quaternary branched penta-amines, linear penta-amines and linear hexa-amines were distributed as the major polyamines in six obligately extremely thermophilic eubacteria belonging to Thermoleophilum, Bacillus or Hydrogenobacter. The major polyamine of Thermoleophilum album and Thermoleophilum minutum was identified as a quaternary branched penta-amine, 4,4-bis(3-aminopropyl)-1,8-diamino-4-azaoctane (NH2[CH2]3N+([CH2]3NH2)2[CH2]4NH2) by h.p.l.c., t.l.c. and g.c.-m.s. Hydrogenobacter thermophilus and Hydrogenobacter halophilus contained another quaternary branched penta-amine, 4,4-bis(3-aminopropyl)-1,7-diamino-4-azaheptane (NH2[CH2]3N([CH2]3NH2)2[CH2]3NH2) as the major polyamine, and tertiary branched tetra-amines (4-(3-aminopropyl)-1,7-diamino-4-azaheptane (NH2[CH2]3N([CH2]3NH2)[CH2]3NH2), 4-(3-aminopropyl)-1,8-diamino-4-azaoctane (NH2[CH2]3N([CH2]3NH2)[CH2]4NH2)) and 4,4-bis(3-aminopropyl)-1,8-diamino-4-azaoctane were confirmed as minor components. Bacillus schlegelii contained a branched tetra-amine, 4-(3-aminopropyl)-1,8-diamino-4-azaoctane, a branched penta-amine, 4,4-bis(3-aminopropyl)-1,8-diamino-4-azaoctane, a linear penta-amine, 1,16-diamino-4,8,13-triazahexadecane (NH2[CH2]3NH[CH2]3NH[CH2]4NH[CH2]3NH2) and linear hexa-amine(s), 1,20-diamino-4,8,12,17-tetra-azaeicosane (NH2[CH2]3NH[CH2]3NH[CH2]3NH[CH2]4NH[CH2]3NH2 ) and/or 1,20-diamino-4,8,13,17-tetra-azaeicosane (NH2[CH2]3NH[CH2]3NH[CH2]4NH[CH2]3NH[CH2]3NH2 ).

Bacillus↗
PubMed1992

Enhancement of acetylcholine release during REM sleep in the caudomedial medulla as measured by in vivo microdialysis.

Previous studies in our laboratory have found that muscle atonia could be triggered by two distinct areas of the medial medulla, a caudal region, corresponding to the nucleus paramedianus (NPM) and a rostral region, corresponding to the nucleus magnocellularis (NMC). The former region is responsive to acetylcholine (ACh) and the latter region is responsive to glutamate. In this study we have measured the endogenous ACh release across the sleep-wake cycle in these two areas with the microdialysis technique in unanesthetized, freely moving cats. We found that ACh release in NPM was state-dependent and was about 30% higher (P less than 0.001) during rapid eye movement (REM) sleep than during slow-wave sleep and wakefulness. However, ACh release in NMC was not selectively elevated in REM sleep. The enhancement of ACh release in NPM during REM sleep supports our hypothesis that ACh release onto cholinoceptive neurons in this area mediates the muscle atonia of REM sleep.

Acetylcholine↗