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Biomedical subjects

S Yamada

Publications and source records attributed to S Yamada.

At least 937 records · Page 52Linked to original sources
PubMed1994

[Clinical investigation of clean intermittent catheterization].

We evaluated 120 patients with neurogenic bladder treated by clean intermittent self catheterization (CIC) in our department. These cases were divided into 2 groups: early treatment cases in which CIC started within 1 year after onset of dysuria, and late treatment cases in which CIC started after more than 1 year. Urinary tract infections (UTI) were recognized in 35% of the early treatment cases and 80% of the late treatment cases in the subsequent period. Pyelonephritis was experienced in 4% of the early treatment cases and 12% of the late treatment cases. Antibiotics therapy was considered unnecessary for asymptomatic UTIs. After CIC treatment, hydronephrosis detected by intravenous pyelography (IVP) and ultrasonography was improved in 18 of the 20 cases, and no cases showed deteriorated renal function. In the cases with neurogenic bladder after radical operations of the uterus or rectum, 45% of the early treatment cases have become free from CIC within 3 months postoperatively, and 84% eventually became free. Most of the late treatment cases have been continuing CIC. We considered that CIC was unnecessary when the residual urine was less than 100ml based on the periodical urinalysis and observation of renal function.

Adolescent↗
PubMed1994

Active and passive mechanisms of [fluorine-18] fluorodeoxyglucose uptake by proliferating and prenecrotic cancer cells in vivo: a microautoradiographic study.

UNLABELLED: In this study, [18F]FDG uptake mechanisms were investigated in neoplastic cells during cell proliferation and cell death. METHODS: Detailed analysis was performed on mouse tumor models of different growth rates using [18F]FDG, [6-13H]thymidine [3H]Thd (a precursor of DNA synthesis) and [125I]bovine serum albumin ([125I]BSA) (a marker of diffusion) with autoradiographic and histopathologic techniques and electron microscopy. RESULTS: The three compounds, [18F]FDG, [3H]Thd and [125I]BSA, showed different heterogeneous patterns of distribution within tumor tissue sections in neoplastic and non-neoplastic cellular elements. The uptake of [18F]FDG by prenecrotic (or necrobiotic) tumor cells surrounding focal necrotic cell debris was 1.5 to 2.3 times higher than that of viable tumor cells. Prenecrotic cells did not retain trapped [18F]FDG; therefore, the uptake was considered to be nonmetabolic. Inconspicuous cell membrane, vesicular cytoplasmic organelles and condensed nuclear chromatin were remarkable findings in the prenecrotic cells. A comparison of viable tumor cells in tumors undergoing different growth rates showed that the ratio of [18F]FDG uptake was similar to that of [3H]Thd uptake in each S-phase cell. Fluorine-18-FDG showed a cell cycle dependency, with a higher uptake observed in cells in G0/G1 and G2 phases of the cell cycle compared with the S and M phases. CONCLUSION: A passive mechanism of [18F]FDG uptake may exist in the necrobiotic/prenecrotic or hypoxic/anoxic cells in tumors. However, the discordance of [18F]FDG and [3H]Thd uptake may be the result of the different cell cycle dependency of tracer uptake in the same tumor.

Animals↗
PubMed1994

[A clinical study of so-called rare pulmonary tumors].

Six so-called rare pulmonary tumors, resected at the hospital are reported. Histologically there were pulmonary blastoma, pulmonary adenocarcinoma of fetal lung type, alveolar soft part sarcoma, oncocytic carcinoid tumor, hemangioendothelioma, and leiomyoma in each one case. The represented about 1.5% of all resected lung tumors. The age of these patients ranged from 28 to 67 years old, and all were females. Two patients experienced hemosuputum, but the others have no clinical symptoms. All the patients showed relatively well circumscribed mass shadows on chest X-ray films, but none could have accurate diagnosis by preoperative examinations. One patient with alveolar soft part sarcoma died of brain metastasis 18 months after the resection, however, the other 5 patients remained well from 2 year 7 months to 11 years after the surgery.

Adenocarcinoma↗
PubMed1994

[Basic and clinical studies on cefditoren pivoxil in pediatric field].

Cefditoren pivoxil (CDTR-PI, ME1207) granules, a new oral cephem, was given to pediatric patients with infectious diseases to evaluate antibacterial activities against clinical isolates, pharmacokinetics, clinical efficacy and safety, and the following results were obtained. 1. In sensitivity test, 30 strains were used comprised of 5 species, isolated from the patients before administered with CDTR-PI. Against Staphylococcus aureus, MICs of 7 agents, cefditoren (CDTR), cefaclor, cefixime, cefteram, cefotiam, cefpodoxime and methicillin, were determined. Against other 4 species, MICs of the above 6 agents excluding methicillin were determined. Among Gram-positive cocci tested, the MICs of CDTR were 0.78 to 100 micrograms/ml or higher against S. aureus (16 strains), < or = 0.025 microgram/ml against Streptococcus pyogenes (5 strains), and 0.10 or 0.39 microgram/ml against Streptococcus pneumoniae (2 strains). These values were equal to or lower than those of conventional cephems and of methicillin. Among Gram-negative rods tested, the MICs of CDTR were < or = 0.025 microgram/ml against Haemophilus influenzae (3 strains), and 0.10 or 0.20 microgram/ml against Escherichia coli (4 strains). Also, these values were equal to or lower than those of conventional cephems. 2. When CDTR-PI granules was orally administered in a single dose of 3.0 mg/kg to 1 patient and that of 6.0 mg/kg to 2 patients 30 minutes after meal, plasma CDTR concentrations reached their maxima 4 hours after administration in the former patient and 1 or 2 hours after administration in the latter 2 patients, and the peak plasma concentrations were 1.91, 3.46 and 4.82 micrograms/ml with half-lives of 1.01, 0.81 and 0.88 hours and AUCs of 8.62, 9.89 and 13.52 micrograms.hr/ml, respectively. Dose-dependency was observed for the peak plasma concentrations and AUCs also tended to depend on dose excepting for the AUC in one 6.0 mg/kg patient. 3. The urinary concentrations in the above patients reached their peaks at 4 to 6 hours after administration in one 3.0 mg/kg patient and at 4 to 6 hours and 2 to 4 hours after administration in two 6.0 mg/kg patients, and the corresponding values were 126.0, 195.0 and 234.0 micrograms/ml, respectively. Recovery rates in the first 8 hours after administration were 18.2, 24.6 and 21.3%, respectively. 4. Of 53 patients with 13 diseases, CDTR-PI was clinically judged "excellent" in 32 (60.4%) and "good" in 21 (39.6%), showing excellent efficacy. 5. Bacteriologically, excellent results were obtained, i.e., 29 (96.7%) of 30 strains from 5 species were eradicated. 6. Side effects were observed in none of the 54 patients treated.(ABSTRACT TRUNCATED AT 400 WORDS)

Bacteria↗
PubMed1994

Microautoradiographic study for the differentiation of intratumoral macrophages, granulation tissues and cancer cells by the dynamics of fluorine-18-fluorodeoxyglucose uptake.

UNLABELLED: A substantial amount of macrophage infiltration occurs in both human and animal tumors. We previously showed that 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) uptake was higher in tumor-associated macrophages and young granulation tissues than in tumor cells. Differentiation of intratumoral non-neoplastic cells from neoplastic cells is important not only for the reduction of false-positives in FDG-PET tumor studies but also for patient management. METHODS: A time-course study was performed using micro- and macro-autoradiography and tissue distribution in C3H/He mice bearing transplanted syngeneic FM3A mammary carcinoma and MH134 hepatoma was evaluated to analyze the intratumoral cellular dynamics of [18F]FDG and 2-deoxy-D-[3H]glucose in vivo. RESULTS: The volume-doubling time in vivo was 1.3 days for MH134 and 4.9 days for FM3A, and the survival time of the host was 32.1 and 40.3 days, respectively. The peak uptake of both tracers in the tumor was 60 min after intravenous injection. The uptake by MH134 was 1.7-2.1 times higher than that by FM3A. The intracellular concentration as determined by counting the silver grains on micro-autoradiographic sections showed that the uptake by macrophages and focal small necrotic areas in both tumors was faster than the blood clearance until 15 min after tracer injection. CONCLUSION: Thus, non-neoplastic cellular elements can be differentiated from viable neoplastic cells by means of the dynamic analysis of [18F]FDG uptake.

Animals↗
PubMed1994

Effect of initial therapy on dynamics of immunogloblin G levels to some periodontopathic bacteria in serum and gingival crevicular fluid.

Using enzyme-linked immunosorbent assay, the IgG antibody levels to specific gram-negative periodontopathic bacteria in serum of 21 adult periodontitis patients and the gingival crevicular fluid (GCF) from 42 sites with destructive lesions and 21 healthy sites were evaluated before and after initial preparation. Porphyromonas gingivalis, Bacteroides forsythus, Prevotella intermedia, Prevotella nigrescens, Campylobacter rectus, Treponema denticola and Actinobacillus actinomycetemcomitans in subgingival plaque samples from the patients were examined by indirect immunofluorescence microscopy. Subgingival plaque, GCF, and serum samples were taken at baseline and three weeks after initial preparation. For 14 patients, changes in clinical parameters due to the initial preparation were correlated with reduction of periodontopathogens and to IgG antibody levels in GCF and serum against them. P. gingivalis, T. denticola and C. rectus were found to be predominant in destructive sites. No significant differences were found in GCF IgG antibody levels between destructive and healthy sites. In destructive sites, the prevalence of P. gingivalis and C. rectus was significantly correlated with elevated IgG antibody against these microorganisms in GCF. The initial preparation resulted in significant reduction of serum IgG antibody levels against all microorganisms tested. No decrease in GCF IgG antibody was observed, but levels to P. gingivalis and C. rectus were significantly increased (p<0.05). The assessment of GCF IgG antibodies to specific periodontopathic bacteria may be of considerable value in reflecting the conditions of periodontitis.

Adult↗
PubMed1993

Characterization of slow postsynaptic K+ current of Aplysia LUQ neurons in culture.

We have characterized the slow inhibitory synaptic connection between an left upper quadrant (LUQ) neuron and neuron L10, L12 or L13 in culture. A slow postsynaptic outward current in the LUQ neuron was elicited by repetitive firing of the co-cultured cholinergic neuron L10 as well as neuron L12 or L13 which were not cholinergic but FMRFamide synthesizing neurons. This outward current was due to an increase in K+ conductance and was relatively insensitive to external application of tetraethylammonium and 4-aminopyridine. We also investigated the effects of injection of a guanosine 5'-triphosphate (GTP) analogue into the LUQ neuron and extracellular application of serotonin and an adenosine 3',5'-cyclic monophosphate (cAMP) analogue on the current. In all the investigated properties, no significant difference was found among neuron L10, L12 and L13 as a presynaptic neuron. The slow postsynaptic current appeared to be virtually identical to the FMRFamide or acetylcholine (ACh)-induced K+ current reported in vivo, which resembled the 'S' current in Aplysia sensory neurons. We performed experiments to see the effect of phenyltrimethylammonium, an ACh antagonist, on the postsynaptic, ACh-, and FMRFamide-induced currents, clearly indicating that the neurotransmitter used in the cultured synapses was not ACh.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1993

Molecular cloning of fish Pit-1 cDNA and its functional binding to promoter of gene expressed in the pituitary.

Pit-1 is a pituitary-specific transcription factor responsible for activating growth hormone (GH) and prolactin genes. Here, we describe the isolation of a rainbow trout cDNA clone that contains the entire Pit-1 coding region. The deduced amino acid sequence contains 358 residues, encoding a 39-kDa protein. Comparison of the protein sequences of the rainbow trout and rat Pit-1 shows that the 160 residue POU domain at the C terminus is highly conserved (86% identical). However, homology is much weaker in the N-terminal region (56% identical), and the rainbow trout Pit-1 contains segments of 29 and 33 amino acids that are not present in rat Pit-1. The protein produced by expression of rainbow trout Pit-1 cDNA in Escherichia coli binds specifically to at least four sites in the rainbow trout GH gene promoter. Moreover, we demonstrate that the promoter region of salmon somatolactin gene, which belongs to the GH prolactin gene family and is also expressed specifically in the pituitary, has at least five rainbow trout Pit-1 binding sites. The consensus sequence of these binding sites closely matches the 9-base pair motif, (T/A)(T/A)TATNCAT, recognized by rat Pit-1. Rainbow trout Pit-1 specifically activates rainbow trout GH promoter fusion gene expression, confirming the ability of Pit-1 to bind in a transcriptionally active conformation in GH gene promoter.

Amino Acid Sequence↗
PubMed1993

Preventive effect of gomisin A, a lignan component of shizandra fruits, on acetaminophen-induced hepatotoxicity in rats.

The preventive effect of gomisin A, a lignan component of shizandra fruits, on acetaminophen-induced hepatotoxicity in rats was examined by histological and biochemical analysis. Acetaminophen at a dose of 750 mg/kg was administered to male Wistar rats with or without pretreatment with 50 mg/kg of gomisin A. Gomisin A inhibited not only the elevation of serum aminotransferase activity and hepatic lipoperoxides content, characteristic of acetaminophen administration, but also the appearance of histological changes such as degeneration and necrosis of hepatocytes. However, gomisin A did not affect the decrease in liver glutathione content. These results suggest that gomisin A protects the liver from injury after administration of acetaminophen through the suppression of lipid peroxidation.

Acetaminophen↗
PubMed1993

Preparation and characterization of S-[2-carboxy-1-(1H-imidazol-4-yl)ethyl]glutathione and its derivatives as proposed precursors of S-[2-carboxy-1-(1H-imidazol-4-yl)ethyl]cysteine, a compound found in human urine.

Formation of 3-[(carboxymethyl)thio]-3-(1H-imidazol-4-yl)propanoic acid (I) and S-[2-carboxy-1-(1H-imidazol-4-yl)ethyl]cysteine (II), compounds found in human urine, has been demonstrated by enzymatic degradation of S-[2-carboxy-1-(1H-imidazol-4-yl)ethyl]glutathione (III). Compound (III) was chemically synthesized in 72% yield by incubating the reaction mixture of trans-urocanic acid and 3-fold excess GSH at 65 degrees C for 1 wk, which was accompanied by formation of N-(S-[2-carboxy-1-(1H-imidazol-4-yl)ethyl]cysteinyl)glycine (IV) in 15% yield. S-[2-Carboxy-1-(1H-imidazol-4-yl)ethyl]-N-gamma-glutamylcysteine (V) was produced by partial hydrolysis of compound (III) in HCl. The synthesized compounds were characterized mainly by fast-atom bombardment mass spectrometry and high-voltage paper electrophoresis as well as chemical degradation. Incubation of compound (III) with rat kidney homogenate in a Tris buffer (pH 8), formed compound (II) in 80% yield possibly via compound (IV). Yield of compound (II) was increased by adding glycylglycine to the reaction mixture. However, little degradation of compound (III) occurred in the use of rat liver, brain, heart or spleen homogenate as the enzyme source. Compound (II) was further metabolized to compound (I) by incubation with rat kidney homogenate in a phosphate buffer of pH 7.4. From these results, we suggest that the urinary compounds are products of enzymatic degradation of compound (III) and that GSH may participate in the metabolism of urocanic acid, the first catabolite of L-histidine.

Animals↗
PubMed1993

[Radiation therapy for superficial type esophageal carcinoma].

During the period from 1984 through 1991, fifteen patients with superficial esophageal carcinoma were treated with radiation therapy. The clinical stage of these patients was I in 13 cases and IV in two cases. We analyzed the treatment results of 13 patients with stage I disease. Seven patients were treated with external irradiation only and six patients with external irradiation plus high dose rate intracavitary irradiation. The survival rates at one, two and five years were 73.3%, 73.3% and 30.6%, respectively. The relapse-free survival rates at one, two and five years were 76.9%, 76.9% and 76.9%, respectively. Combination chemotherapy and combined therapy with intracavitary irradiation did not improve the local control rate or survival. At present, six patients have already died. The cause of death was uncontrolled primary lesion in one, radiation-induced esophageal ulcer in one, other causes in three and unknown cause in one patient. Local control was achieved in 84.6%(11/13). Radiation therapy for superficial esophageal carcinoma seems as effective as surgical therapy and may become a curative alternative.

Aged↗
PubMed1993

Structural studies on the bacterial lyase-resistant tetrasaccharides derived from the antithrombin III-binding site of porcine intestinal heparin.

Three discrete tetrasaccharide structures which are resistant to Flavobacterium heparinase and heparitinases I and II were isolated from porcine intestinal heparin after exhaustive digestion with a mixture of all the above enzymes, and the tri-, tetra-, and penta-sulfated structures were determined by negative ion mode fast atom bombardment mass spectrometry and 500-MHz 1H NMR analysis as delta 4,5GlcA beta 1-4GlcNAc (6-sulfate)alpha 1-4GlcA beta 1-4GlcN(N,3-disulfate), delta 4,5 GlcA beta 1-4GlcNAc(6-sulfate)alpha 1-4GlcA beta 1-4GlcN (N,3,6-trisulfate), and delta 4,5GlcA beta 1-4GlcN (N,6-disulfate)alpha 1-4GlcA beta 1-4GlcN(N,3,6-trisulfate). The three components share the 3-O-sulfated reducing GlcN and the 6-O-sulfated internal GlcN, indicating that they are structural variants derived from the nonreducing portion of the minimal pentasaccharide sequence required for binding to antithrombin III. Isolation of the pentasulfated component has never been reported. Their unexpected resistance to heparitinases I and II indicates that 3-O-sulfation of the reducing GlcN contributes to the resistant nature of these tetrasaccharides to the enzymes. The present study demonstrates that the nonreducing trisaccharide portion of the structural variants of the antithrombin III-binding pentasaccharide sequence can be isolated in tetrasaccharides resistant to heparinase/heparitinases I and II, while the rest of the repeating region is degraded into disaccharide units. The lyase treatment is applicable to evaluation of heparin/heparan sulfate preparations in terms of the presence or absence of the specific structure containing the 3-O-sulfated GlcN representing biosynthetic precursors, intermediates or final products of the binding site.

Animals↗
PubMed1993

Chronic treatment with haloperidol modifies the sensitivity of autoreceptors that modulate dopamine release in rat striatum.

The effects of apomorphine or sulpiride on electrically evoked dopamine release from striatal slices of rats pretreated with haloperidol were investigated. Chronic haloperidol treatment (1 mg/kg per day for 21 days) significantly reduced electrically evoked dopamine release from striatal slices until 72 h after the last injection. The apomorphine-induced reduction and the sulpiride-induced increase in evoked dopamine release were significantly enhanced by the chronic treatment with haloperidol at 72 h after the last injection. The enhancement of the sulpiride-induced increase in evoked dopamine release was inversely correlated with the dopamine release evoked by the first stimulation in striatal slices from haloperidol-treated (r = -0.85, n = 12, P < 0.01) but not from saline-treated rats. These results suggest that an increase in the sensitivity of dopamine autoreceptors due to chronic treatment with haloperidol could partially account for the reduction in dopamine release from striatal slices of rats.

Animals↗
PubMed1993

Changes of serum 7S fragment of type IV collagen and N-terminal propeptide of type III procollagen after transcatheter arterial embolization as a model of acute liver injury.

To evaluate the mechanism of increased serum concentrations of the N-terminal propeptide of type III procollagen and the 7S fragment of type IV collagen in acute liver injury, we serially measured serum levels of these substances after transcatheter arterial embolization in patients with hepatocellular carcinoma. The results demonstrated marked increases in serum levels of the 7S fragment of type IV collagen in accordance with increased serum levels of transaminase after transcatheter arterial embolization. In contrast, a transient decrease in serum levels of the N-terminal propeptide of type III procollagen was found after transcatheter arterial embolization and transcatheter arterial infusion, although no significant changes in serum levels of the N-terminal propeptide and 7S fragment were seen after hepatic arteriography alone. The absolute change in serum levels of the 7S fragment after treatment showed positive correlation with serum transaminase levels and negative correlation with the decrease in serum levels of alpha-fetoprotein, although serum levels of N-terminal peptide did not demonstrate such a correlation. The results suggest that in acute liver injury induced by transcatheter arterial embolization, at least in part, increased in serum levels of the 7S fragment of type IV collagen reflect accelerated liberation of type IV collagen from the destroyed surrounding nontumorous tissues and that decreased serum N-terminal propeptide of type III procollagen reflects diminished synthesis of type III collagen caused by anticancer drugs.

Adult↗
PubMed1993

Prognostic value of the number of metastatic lymph nodes in gastric cancer with radical surgery.

To evaluate the effectiveness of extended lymph node dissection in gastric cancer, the relationship between the number of lymph nodes with metastasis and the long-term outcome was studied retrospectively in 761 patients who underwent curative resection with extensive lymph node dissection. The cumulative 5-year survival rate was 85.8% in patients without lymph node metastasis, 60.2% in those with 1-4 lymph nodes, 35.6% with 5-10 nodes, and 12.3% with 11 or more nodes involved. Concerning N2 or N3 patients in whom metastatic lymph nodes would have remained without extensive dissection, the 5-year survival rate was 70.5% in those with 1-4 lymph nodes involved and 44.0% with 5 or more lymph nodes involved when no serosal invasion was observed. It was 38.5% with 1-4 lymph nodes and 5% with 5 or more lymph nodes involved when serosal invasion was observed. These results suggest that extensive lymph node dissection is effective in gastric cancer patients without serosal invasion and, when only a few lymph nodes are involved, also in those with serosal invasion. However, it is not considered to be effective in patients with serosal invasion and metastasis to many lymph nodes. Combination therapies are thought to be required in such patients.

Adult↗
PubMed1993

Role of 2,3,5-trichlorophenyl methyl sulfone, a metabolite of 1,2,4-trichlorobenzene, in the induction of hepatic microsomal drug-metabolizing enzymes by 1,2,4-trichlorobenzene in rats.

2,3,5- and 2,4,5-trichlorophenyl methyl sulfides, 2,3,5- and 2,4,5-trichlorophenyl methyl sulfoxides, and 2,3,5- and 2,4,5-trichlorophenyl methyl sulfones (TCPSO2Mes) were detected in the urine of rats dosed with 1,2,4-trichlorobenzene (TCB). After the administration of 1,2,4-TCB to rats, swift decreases in concentrations of 1,2,4-TCB in blood, liver, kidneys, and adipose tissue were observed. On the other hand, 2,3,5-TCPSO2Me appeared in blood, liver, kidneys, and adipose tissue and remained detectable in the blood and the three tissues until 120 hr. The increases in the activities of aminopyrine N-demethylase and aniline hydroxylase and the contents of cytochromes P450 and b5 in hepatic microsomes produced by 1,2,4-TCB occurred after increases in the hepatic concentration of 2,3,5-TCSO2Me. 2,3,5- and 2,4,5-TCPSO2Me increased the above four parameters in rat liver microsomes. The inducing intensity of 2,3,5-TCPSO2Me was much higher than that of 2,4,5-TCPSO2Me. 2,3,5-TCPSO2Me was considered to be a potent inducer and to play a principal role in the induction by 1,2,4-TCB. When 1,2,4-TCB was injected ip into bile duct-cannulated rats, little 2,3,5-TCPSO2Me was detected in blood, liver, kidneys, and adipose tissue. In the antibiotic-pretreated rats dosed with 1,2,4-TCB, 2,3,5-TCPSO2Me concentrations in the blood and the three tissues markedly decreased. These findings suggest that the formation of methylsulfonyl metabolites from 1,2,4-TCB depends largely upon the metabolism of some precursor(s) excreted in the bile by intestinal microflora. The increasing effects of 1,2,4-TCB administration on the activities of aminopyrine- and aniline-metabolizing enzymes and the contents of cytochromes P450 and b5 in hepatic microsomes were not observed in the bile duct-cannulated rats. These findings provide evidence that the induction of drug-metabolizing enzymes by 1,2,4-TCB is not due to the action of 1,2,4-TCB itself but is due to its methylsulfonyl metabolite, 2,3,5-TCPSO2Me.

Animals↗