Biomedical subjects

Y Kodama

Publications and source records attributed to Y Kodama.

At least 181 records · Page 10Linked to original sources

PubMed1994

Novel antibiotics SF2738A, B and C, and their analogs produced by Streptomyces sp.

Three new antibiotics SF2738A, B and C, and their analogs were isolated from the culture broth of Streptomyces sp. The antibiotics are active against Gram-positive bacteria, Gram-negative bacteria and fungi, and exhibited cytotoxic activity against P388 murine leukemia cells with IC50 values of 0.08, 0.25 and 7.5 micrograms/ml, respectively. Their structures were determined by spectral analyses and chemical conversion. Especially, the structure of SF2738A was confirmed to be (E)-((4-methoxy-5-methylthio-2-(2-pyridyl)pyridin-6-yl)methylene)azan ol by X-ray crystallographic analysis.

Animals↗

PubMed1994

PF1018, a novel insecticidal compound produced by Humicola sp.

A new insecticidal compound PF1018 was isolated from the culture broth of Humicola sp. It exhibited insecticidal activity against a wide range of critical pest species. The structure of PF1018 was determined to be (7aS)-2-((2E)-1-hydroxy-3-((1S,3aR,4R,5R,7aR)-3a,4,5,7 a-tetrahydro-1,3,5,7- tetramethyl-5,1-((3S)-(Z)-2,3-dimethylpropeno)-1H-inden-4-yl )-2- propenylidene)pyrrolizidine-1,3-dione, by NMR spectral analyses coupled with X-ray crystallographic analysis and chemical degradation study.

Chromatography, High Pressure Liquid↗

PubMed1994

[A case of hemangioblastoma in the thalamus].

Supratentorial hemangioblastoma is encountered very rarely. About 80 cases in all have been reported. The authors present a case of supratentorial hemangioblastoma in the thalamus with gradually enlarging cysts. The patient was a 45-year-old man with complaints of left hemiparesis and headache. Computed tomographic scans of the brain showed a cystic mass with mural nodule in the right thalamus. Left vertebral angiography demonstrated a vascular tumor fed by a thalamogeniculate artery. A right temporo-parietal craniotomy was performed and the tumor was totally resected through the transcortical approach. The histological diagnosis was hemangioblastoma. Post-operative course was good except for a minor complication of the left lower quadrant homonymous hemianopsia and left hemiparesis which had disappeared at the time of discharge.

Hemangioblastoma↗

PubMed1994

In vivo binding characteristics of carbamazepine and carbamazepine 10, 11-epoxide to serum proteins in monotherapy adult patients.

The in vivo serum protein binding characteristics of carbamazepine and carbamazepine 10, 11-epoxide, which was the main metabolite of carbamazepine in plasma, were assessed in sera from 30 adult patients with epilepsy on carbamazepine monotherapy. The binding characteristics of each compound were analyzed according to the two-site binding model. Association constants to the high-affinity binding site on alpha 1-acid glycoprotein (AAG) were 0.053 l/mumol for carbamazepine and 0.013 l/mumol for carbamazepine 10, 11-epoxide. The maximum binding capacities for drug-AAG binding were 49.2 mumol/l for carbamazepine and 48.1 mumol/l for carbamazepine-10, 11-epoxide. The products of the association constant and binding capacity for the lower-affinity site (i.e., the linear component of albumin binding site) were 1.273 for carbamazepine and 0.525 for carbamazepine 10, 11-epoxide. Within the total concentration range of each compound investigated, the contribution of drug-AAG binding to the total serum binding was relatively larger than that of drug-albumin binding.

Adolescent↗

PubMed1994

[Two cases of traumatic intracerebral pneumocephalus].

Two cases of traumatic intracerebral pneumocephalus, a rare complication of head trauma, are presented. Case 1: A 14-year-old boy had a strong concussion in his forehead due to a motorbike accident. Slightly obtunded on admission showing GCS 10, he became conscious in several days. Head CT performed after 17 days showed a round air image in the right frontal lobe which kept increasing in size thereafter. Bilateral frontal craniotomy was performed 31 days after the injury. A craniodural defect with a herniated brain was found in the superior wall of the posterior ethmoid sinus and repaired. Case 2: A 55-year-old man received a left forehead concussion when his motorbike ran into a car from behind. Although he had been conscious ever since admission, head CT after 15 days showed a round air image in the left frontal lobe. MRI demonstrated the air to be located in the cerebral parenchyma distinctly and the brain to have herniated into the frontal sinus. As the air showed a tendency to increase in volume and mild psychic and memory disturbances appeared, bilateral frontal craniotomy was performed 34 days after the injury. A craniodural defect with a herniated brain was detected in the posterior wall of the frontal sinus and repaired. These two patients showed a small amount of cerebrospinal fluid (CSF) rhinorrhea before the operation. Following the surgical repair, no recurrence of pneumocephalus and CSF rhinorrhea has been seen in either case. Intracerebral pneumocephalus secondary to closed head trauma was thought to have been due to herniation of contused brain into a craniodural defect.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1994

[A case of brain abscess of the basal ganglia which resulted in disastrous outcome due to ventricular ruptures].

A case of deep-seated brain abscess that ruptured twice into the ventricle and resulted in death is presented. A 45-year-old man had experienced pyrexia and headache for 3 days before admission. On admission he was somnolent (GCS: 13) but there were no abnormal neurological findings except nuchal rigidity and Kernig's sign. Computed tomography (CT) scan showed a ring enhanced mass near the left caudate head and dilated ventricles. In comparison with CT performed at the former hospital it was diagnosed that a rupture into the ventricle of the brain abscess had occurred. Ventricular drainage was performed at once and white purulent cerebrospinal fluid was obtained. Thereafter, he was treated with some antibiotics and his conditions seemed to stabilize for a while. Serial CT images demonstrated that the size of the abscess seemed to be enlarging. Just when we planned to undertake stereotactic aspiration, the second ventricular rupture occurred and he died. According to this case, it is suggested that once a deep-seated brain abscess near the ventricular system is suspected, it should be aspirated by means of CT-guided stereotactic surgery immediately.

Basal Ganglia Diseases↗

PubMed1994

Pregnancy complicated by liver dysfunction: possible pathogenesis of vasospasm.

BACKGROUND: Acute fatty liver of pregnancy, the syndrome of hemolysis, elevated liver enzymes, and low platelet count (HELLP), and severe preeclampsia form a disease spectrum. We report a case that showed a vasospastic phenomenon supported angiographically and hematologically. CASE: A 31-year-old Japanese woman presented at 37 weeks gestation with a 1-week history of nausea, vomiting and general fatigue. She underwent cesarean delivery for fetal distress. Liver dysfunction and disseminated intravascular coagulopathy were detected. The celiac angiogram showed vascular narrowing and irregularity of the vascular wall. Serum endothelin and the ratio of thromboxane B2 to 6-keto-prostaglandin F1 alpha were increased at the same time. The patient experienced rapid resolution of symptoms and laboratory abnormalities in the immediate postoperative period. CONCLUSION: A pregnancy complicated by liver dysfunction showed a vasospastic phenomenon, which may suggest the presence of a vasospastic syndrome.

Adult↗

PubMed1993

Frequent occurrence of in vivo clonal expansion of CD4- CD8- T cells bearing T cell receptor alpha beta chains in adult humans.

We have previously reported 2 cases of healthy men showing in vivo monoclonal expansion of mature CD4- CD8- alpha beta T cells. In the present study, an additional 3 adults were found to exhibit such an expansion, among a total 464 adult donors studied. These 5 individuals were otherwise physiologically normal, with no history of severe illness and autoimmune disease at the time of examination. To investigate the mechanisms of the clonal expansion, further characterization of the clonal cells was attempted. No apparent preference for usage of the T cell receptor beta chain variable region was observed in the clonal T cells. These clonal T cells showed lectin-dependent or redirected antibody-dependent cell-mediated cytotoxicities, whereas they could not lyse autologous lymphoblastoid cell lines. Failure of Fas antigen expression was not observed for any of these clones. These results suggest that clonal expansion of CD4- CD8- alpha beta T cells frequently occurs in the periphery without any T cell abnormalities.

Adult↗

PubMed1993

In vivo determinations of carbamazepine and carbamazepine-10, 11-epoxide binding parameters to serum proteins in monotherapy patients.

The in vivo serum protein binding parameters of carbamazepine (CBZ) and carbamazepine-10, 11-epoxide (CBZ-E), which was the main metabolite of CBZ in plasma, were determined in sera from 27 patients on CBZ monotherapy. Based on the results by recent studies, the authors assumed that CBZ and CBZ-E binding to serum proteins were composed of specific binding sites on alpha 1-acid glycoprotein (AAG) and albumin. Therefore, the authors determined the binding parameters of each compound by specific binding equation for two proteins. Association constants for drug-AAG binding were .071 L/mumol for CBZ and .016 L/mumol for CBZ-E. Conversely, those for drug-albumin binding were .00052 L/mumol for CBZ and .00072 L/mumol for CBZ-E. Within the investigated total concentration ranges in each compound, the AAG binding contributes largely to the drug-serum protein interactions. Furthermore, our results indicate that the albumin binding contributes to the nonsaturable serum protein binding of these compounds in the therapeutic range.

Adolescent↗

PubMed1993

Effect of unbound clearance on binding parameters of valproic acid to serum proteins.

Nine healthy subjects received 400 mg sodium valproate orally in the fasting state. Binding parameters of valproic acid to serum proteins were determined by Scatchard analysis for individual series of valproic acid data. Total and unbound (intrinsic) clearances (CLt and CLu) were calculated by dividing the dose by the appropriate area under the serum drug concentration-time curve. Unbound clearance correlated positively with the product of association constant (Ka) and concentration of free protein ((P)) (P < .05). Conversely, no significant correlation was found between CLt and binding parameters. The average unbound concentration correlated negatively with both CLu and ka(P) values. The result indicates an effect of CLu on Ka(P) value of valproic acid.

Administration, Oral↗

PubMed1993

The effect of a prostaglandin I2 analogue (OP-41483) on energy metabolism in liver preservation and its relation to lipid peroxidative reperfusion injury in rats.

The effect of the stable prostacyclin (PGI2) analogue OP-41483 (OP) on liver preservation was investigated in the rat liver transplant model. In a 1-week survival study, 33 orthotopic liver transplants were performed using Wistar rats. In group A, untreated livers were stored with modified UW (mUW) solution at 4 degrees C. In group B, livers from OP-pretreated donors (2 micrograms/kg, i.v.) were stored with mUW solution containing OP (1 microgram/ml) at 4 degrees C. After 24 h storage, the donor grafts in each group were transplanted to untreated recipients. OP treatment (group B) significantly improved 1-week survival (62.5%, 10/16, P < 0.01 versus group A; 11.8%, 2/17). For the measurement of adenine nucleotides and lipid peroxidation (malondialdehyde, MDA) in liver tissue before preservation, after preservation, and 3 h after transplantation, 20 rat livers in groups A and B were studied. In both groups, the levels of adenosine triphosphate (ATP) declined 6 h after cold preservation, but this degradation of ATP was significantly halted at the level of adenosine monophosphate (AMP) in the OP-treated livers after 24 h of storage. However, OP treatment showed no significant difference in the degree of ATP recovery after transplantation. On the other hand, OP treatment resulted in suppression of the increase in MDA levels and histological amelioration of microcirculatory disturbance 3 h after transplantation. Our data suggested that the combined use of the stable PGI2 analog (OP-41483) and UW solution is beneficial in liver preservation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenine Nucleotides↗

PubMed1993

Effect of side-stream cigarette smoke on the hepatic cytochrome P450.

The effect of inhalation of side-stream cigarette smoke on the hepatic microsomal cytochrome P450 was investigated Rats were placed in a chamber of 0.1 m3 in volume, in which cigarettes were burned at the rate of 1, 3, or 5 cigarettes per h, 8 h/day for 5 days. Cytochrome P450 and NADPH-cytochrome c reductase showed no significant changes; however, cytochrome b5 increased significantly. On the other hand, the activity of aryl hydrocarbon hydroxylase (AHH) decreased in the rats treated with a high concentration of cigarette smoke. In order to study the changes of isoforms of cytochrome P450, western blot analyses were performed. The inductions of three kinds of isoforms, cytochromes P450IA1, IA2, and IIB1, were demonstrated immunochemically. However, there were disagreements between the results of the western blot analyses and the measurements of total cytochrome P450 content and AHH activity.

Animals↗

PubMed1993

Personal exposure to nitrogen dioxide from indoor heaters and cooking stoves.

The personal exposure to NO2 generated from various heaters and cooking stoves were studied, using 85 university students. The students attached NO2 filter badges to their chests or collars and wrote down the period of time for heating and cooking for 1 week. Types of heaters and smoking habits were described through a questionnaire. The urinary hydroxyproline/creatinine ratio (HOP/C) was examined as a biomarker for health effects. The outdoor NO2 concentration during the study period was 13.5-13.7 micrograms/m3. Smoking and the usage of electric heaters did not affect the exposure to NO2. Exposure increased according to the length of time kerosene heaters or oil fan heaters were used. The NO2 concentration during the heating by a kerosene heater and an oil fan heater was calculated to be 219 and 474 micrograms/m3, respectively. The correlation between the period of cooking and personal exposure was also observed. The NO2 levels during cooking were calculated to be 290 micrograms/m3. Using these calculated values of NO2 concentration, it is possible to presume the personal exposure levels from the length of time heaters and cooking stoves are used even if the subjects do not attach the filter badges. Neither smoking nor exposure to NO2 were associated with the increase of urinary HOP/C.

Adult↗

PubMed1993

In vivo binding characteristics of carbamazepine and carbamazepine-10,11-epoxide to serum proteins in paediatric patients with epilepsy.

The in vivo serum protein binding characteristics of carbamazepine (CBZ) and carbamazepine-10,11-epoxide (CBZ-E) were assessed in sera from 23 paediatric patients on CBZ monotherapy. We assumed that CBZ and CBZ-E binding to serum proteins comprised specific binding sites on alpha 1-acid glycoprotein (AAG) and non-specific binding sites on serum albumin. Therefore, the binding characteristics of each compound were analysed according to specific and nonspecific binding equations. Association constants for drug-AAG binding were 0.096 l.mumol-1 for CBZ and 0.023 l.mumol-1 for CBZ-E. Within the concentration ranges investigated the specific binding of each compound contributes to the drug-serum protein interactions. Age did not show a significant correlation with the serum unbound fraction of each compound.

Adolescent↗

PubMed1993

Biological monitoring of toluene and DNA polymorphism in humans.

The effects of genetic polymorphism in aldehyde dehydrogenase 2 (ALDH2) on alcohol intakes and toluene metabolism were studied in workers who handle toluene. The genotypes of ALDH2 were divided into three groups, which were the homozygous genotype of normal ALDH2 (NN), the homozygous genotype of an inactive one (DD) and the heterozygous genotype of normal and inactive ones (ND), using the polymerase chain reaction (PCR) method in a solution containing ddGTP. The alcohol intake of the DD group was very small. On the other hand, the alcohol intake of NN group was higher than that of DD group. That of ND group was about half way between those of NN group and DD group. The alteration of toluene metabolism by the polymorphism of ALDH2 was not clear because the exposure levels of the workers to toluene were low.

Adult↗

PubMed1993

Effect of antianginal agents on the relationship between rate-pressure product and myocardial oxygen uptake.

To evaluate the effects of antianginal agents on the correlation between rate-pressure product and myocardial oxygen uptake, multistage supine leg exercise tests were performed by 21 patients with stable effort-induced angina pectoris before and after administration of antianginal drugs (a calcium channel blocker of the dihydropyridine class [10 mg of nisoldipine orally] in 11 patients and a beta-blocker [0.2 mg/kg of propranolol intravenously] in 10 patients). The rate-pressure product was closely correlated with myocardial oxygen uptake before and after administration of each drug. However, the slope of the regression line of rate-pressure product (X) and myocardial oxygen uptake (Y) became significantly steeper after the calcium channel blocker administration, and the Y-intercept was significantly increased by administration of the beta-blocker. Myocardial oxygen uptake was increased after administration of the calcium channel blocker and the beta-blocker compared with control values at corresponding rate-pressure product. These observations should be considered when the rate-pressure product is used to predict myocardial oxygen uptake in patients with angina pectoris who are receiving antianginal drugs.

Adult↗

PubMed1993

Passive protection against bovine rotavirus-induced diarrhea in murine model by specific immunoglobulins from chicken egg yolk.

Chicken egg yolk immunoglobulins (yIg) specific against bovine rotavirus (BRV) serotypes 6 (strain Shimane) and 10 (strain KK-3) were used for oral passive immunization of suckling mice against experimental BRV challenge. The protective capacity of the antibody preparation was tested using different concentrations of yIg against a challenge dose of 10(7.5) TCID50 for Shimane and 10(7.0) TCID50 for KK-3 strain. There was a significant homotypic (P < 0.05) and heterotypic (P < 0.01) protection using 160 anti-Shimane or 160 anti-KK-3 neutralizing antibody titer (NAT) compared to control mice given yIg derived from eggs of mock-immunized (control) hens. The titer of infectious BRV recovered from intestinal tissue or luminal chyme decreased with increasing homotypic yIg NAT. A decrease in degree and duration of BRV antigen localization in the villus epithelial lining was observed in mice treated with homotypic yIg at optimum dose for prevention of diarrhea. The NAT in sera of challenged mice increased with decreasing NAT in the yIg given before challenge suggesting that protection was dose-dependent. The present findings indicate that a passive protection could be achieved by the use of yIg against BRV-induced diarrhea in this murine model.

Animals↗

PubMed1993

Frequency of reciprocal translocations and dicentrics induced in human blood lymphocytes by X-irradiation as determined by fluorescence in situ hybridization.

This study was designed to test the scoring efficiency of reciprocal translocations and dicentrics induced by X-irradiation in vitro using the fluorescence in situ hybridization (FISH) technique. An excess was found in the frequencies of reciprocal translocations relative to those of dicentrics by measurement with FISH at the first cell division after irradiation (translocation:dicentric approximately 60:40). However, when the same metaphases were also evaluated sequentially by a conventional staining method, the ratio of about 50:50 was restored. This was due in part to misclassification of certain dicentrics as reciprocal translocations by the FISH technique.

Adult↗