Biomedical subjects

T Ohshima

Publications and source records attributed to T Ohshima.

At least 19 recordsLinked to original sources

PubMed1996

Targeted disruption of the cyclin-dependent kinase 5 gene results in abnormal corticogenesis, neuronal pathology and perinatal death.

Although cyclin-dependent kinase 5 (Cdk5) is closely related to other cyclin-dependent kinases, its kinase activity is detected only in the postmitotic neurons. Cdk5 expression and kinase activity are correlated with the extent of differentiation of neuronal cells in developing brain. Cdk5 purified from nervous tissue phosphorylates neuronal cytoskeletal proteins including neurofilament proteins and microtubule-associated protein tau in vitro. These findings indicate that Cdk5 may have unique functions in neuronal cells, especially in the regulation of phosphorylation of cytoskeletal molecules. We report here generation of Cdk5(-/-) mice through gene targeting and their phenotypic analysis. Cdk5(-/-) mice exhibit unique lesions in the central nervous system associated with perinatal mortality. The brains of Cdk5(-/-) mice lack cortical laminar structure and cerebellar foliation. In addition, the large neurons in the brain stem and in the spinal cord show chromatolytic changes with accumulation of neurofilament immunoreactivity. These findings indicate that Cdk5 is an important molecule for brain development and neuronal differentiation and also suggest that Cdk5 may play critical roles in neuronal cytoskeleton structure and organization.

Animals↗

PubMed1996

Unexpected sudden death of a 12-year-old male with congenital single coronary artery.

A rare autopsy case of a 12-year-old male with a single coronary artery is reported in which he suddenly and unexpectedly died after a brief period of physical and mental excitation. The single coronary artery originated from the left aortic sinus, then branched out the left circumflex artery and afterwards descended as the left anterior descending artery, while the right coronary artery originated almost at a right angle from the left anterior descending artery. The entire heart as well as the cardiac conduction system depended exclusively on the single coronary artery for oxygenated blood supply, and the unbalanced blood distribution on his exertion probably led to sudden cardiac death. Moreover, in this case, both the deceased's mother (at the age of 20 years) and grandmother on the mother's side died suddenly, thus suggesting a possibility of maternal transmission of this congenital anomaly in his family.

Autopsy↗

PubMed1996

Molecular cloning and chromosomal mapping of the mouse gene encoding cyclin-dependent kinase 5 regulatory subunit p35.

A neural-specific activating subunit, p35, of cyclin-dependent kinase 5 (Cdk5) was recently reported to differ from other mammalian cyclins, suggesting a new type of regulatory subunit for Cdk activity. The mouse gene encoding p35, Cdk5r, was isolated from a mouse 129/SvJ genomic library, and the genomic structure of Cdk5r was characterized. The most notable features of Cdk5r are the absence of introns in the amino acid coding region and the high homology of amino acid sequence among species. The 5'-flanking region of Cdk5r contained no canonical TATA or CAAT box but had several putative promoter elements, including Sp1, AP2, MRE, and NGFIA. The mouse Cdk5r transcript was detected only in the brain by Northern blot analysis. Mouse Cdk5r was mapped to a position on mouse chromosome 11.

Amino Acid Sequence↗

PubMed1996

The dynamics of inflammatory cytokines in the healing process of mouse skin wound: a preliminary study for possible wound age determination.

The dynamics of inflammatory cytokines such as interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF alpha) during the healing process of mouse skin wounds were examined using the enzyme-linked immunosorbent assay and immunostaining. The applicability of this examination for wound age estimation is discussed from the perspective of forensic pathology. After wound induction, mice were sacrificed at intervals ranging from 0 to 240 h. The levels of TNF alpha and IL-1 beta began to elevate rapidly after wounding and reached a peak at 3 h. The IL-1 alpha level reached a peak at 6 h, and IL-6 peaked at 12 h. An infiltration of numerous leukocytes, indicating acute inflammation, was observed at 3 and 6 h, and the main source of the cytokines was immunohistochemically identified as neutrophils. These results indicate that TNF alpha and IL-1 beta play an important role in the commencement of inflammation. "Rebound" of cytokine levels, i.e. a re-increase, was observed at 72 h after wounding. Histological examination of the 72-h-old wound showed migration of fibroblasts and the formation of new granulation tissues, indicating the proliferative stage of the wound healing process. These experimental findings indicate that these cytokines have a close relationship to wound remodeling as well as to inflammation. From the viewpoint of forensic pathology, it is considered that inflammatory cytokines may become one of the markers for wound age estimation, but further studies are needed, especially those involving the investigation using human wound specimens with known time intervals after injury.

Animals↗

PubMed1996

Acid alpha-glucosidase deficiency: identification and expression of a missense mutation (S529V) in a Japanese adult phenotype.

We report a missense mutation in an adult Japanese patient with acid alpha-glucosidase (GAA) deficiency. A TC to GT transition at nucleotides 1585-1586, was identified. This transition resulted in an amino acid substitution of Ser-529 to Val (S529V) in exon 11. We also have demonstrated that the S529V mutation abolishes the catalytic activity of the enzyme. Our data suggest that this mutation is the cause of the clinical manifestation known as adult-onset GAA deficiency. The missense mutation described here is a new mutation, and the first identified in Japanese patients with GAA deficiency.

Adult↗

PubMed1996

Hydrocarbon chain distribution of ether phospholipids of the ascidian Halocynthia roretzi and the sea urchin Strongylocentrotus intermedius.

The contents and compositions of the 1-O-alk-1'-enyl-2-acyl, 1-O-alkyl-2-acyl, and 1,2-diacyl glycerophospholipids in the muscle and viscera of the ascidian Halocynthia roretzi, and of the gonad of the sea urchin Strongylocentrotus intermedius, which are eaten to some extent in Alaska and in Asia, were analyzed by gas-liquid chromatography. 1-O-Alk-1'-enyl-2-acyl glycerophospholipids were found in all of the samples, accounting for 64.4-69.0% of the ethanolamine glycerophospholipid (EPL). By contrast, the levels of the 1-O-Alk-1'-enyl-2-acyl choline glycerophospholipids (CPL) were low (3.1-5.7%). CPL was rich in the 1-O-alkyl-2-acyl subclass amounting to 12.5-23.9% in the ascidian sample. The level of CPL in the sea urchin gonad was extremely high, amounting to 46.1%. The most prominent alkyl chains in the sn-1 position of CPL from the ascidian muscle were 16:0 (44.6%), 18:1 (26.5%), and 18:0 (10.7%), and of CPL from the sea urchin gonad were 18:0 (36.2%), 16:0 (33.0%), and 18:1 (17.8%). Unusually high levels of odd-numbered alkyl chains, e.g., 19:0 and anteiso 17:0, were detected in the CPL of all samples. The prominent alkenyl chains of EPL were 18:0 (69.4%), 16:0 (10.0%), and 18:1 (8.54%) (not counting the vinyl double bond) for the sea urchin gonad. Relatively high levels of 20:1 alkenyl chains were also present. The glycerol sn-2 positions contained high proportions of polyunsaturated fatty acids. Thus, 20:5n-3 (43.6%) and 22:6n-3 (20.1%) were most abundant in the alkylacyl CPL from the ascidian muscle and 20:5n-3 (54.9%) and 20:4n-6 (30.1%) in alkylacyl CPL from the sea urchin gonad. Despite a possible interconversion of the alkyl and alkenyl chains of each class of the ether phospholipids, they showed few features in common.

Animals↗

PubMed1996

Determination of hydroperoxides and structures by high-performance liquid chromatography with post-column detection with diphenyl-1-pyrenylphosphine.

A high-performance liquid chromatographic method, using post-column detection with diphenyl-1-pyrenylphosphine (DPPP), was developed for the quantitative and qualitative determination of isomeric lipid hydroperoxides (OOH). The OOH eluted from a normal-phase column were passed through a photodiode array detector and then mixed with DPPP solution in a reaction coil heated at 80 degrees C. DPPP oxide formed by the reaction with OOH was determined by monitoring the fluorescence intensity at 380 nm and excitation at 352 nm. The conjugated diene OOH (13-cis,trans- and 9-cis,trans-OOH) and nonconjugated OOH (12-cis-trans-and 10-cis,trans-OOH) from photosensitized oxidation of methyl linoleate were determined in a molar ratio of 31:29:19:21, respectively. However, only the two conjugated hydroperoxides were detected by ultraviolet absorption at 234 nm. Further applications were carried out for the determination of OOH of methyl oleate and methyl linolenate. This method proved to be useful for the determination of the OOH containing both conjugated and nonconjugated diene structures.

Chromatography, High Pressure Liquid↗

PubMed1996

Contribution of lysosomes to the subcellular distribution of basic drugs in the rat liver.

PURPOSE: We examined the subcellular distribution of the basic drugs, chlorpromazine (CPZ), imipramine (IMP) and biperiden (BP), in rat liver, and evaluated the contribution of lysosome (Lys) to their intracellular distribution in comparison with that of mitochondria (Mit). METHODS: In an in vivo distribution, the concentrations of CPZ, IMP and BP in the liver subcellular fractions were determined. In an in vitro study, uptake of [3H]IMP into Lys and Mit fractions was determined in the presence or absence of several agents. RESULTS: The distribution of these drugs 10 min after administration was quite similar. However, the relative specific contents (the drug concentration per protein of each fraction divided by that of the total homogenate) in Lys were 7.3, 9.6 and 4.2, respectively for CPZ, IMP and BP, whereas those in the other organella were only 0.4 approximately 1.7. In an in vitro uptake study, the dose response of IMP uptake into Lys was biphasic, while that into Mit fractions was monophasic. The binding of IMP to the high affinity sites of Lys was pH dependent and disappeared in 50 mM NH4Cl or 50 microM CPZ, both of which increased the intralysosomal pH, the low affinity sites were not affected by these drugs. CONCLUSIONS: The results indicated that Lys has the highest affinity for the basic drugs in the liver and that its contribution to their subcellular distribution depends on the intralysosomal pH, which is also affected by these drugs. The importance of these effects may become significant in combination therapy using various basic drugs.

Animals↗

PubMed1996

Molecular cloning of the mouse apolipoprotein D gene and its upregulated expression in Niemann-Pick disease type C mouse model.

Apolipoprotein D (ApoD) is a member of the lipocalin superfamily. The primary structure and diverse expression of ApoD suggest that this protein is a multiligand, multifunctional glycoprotein. Here we report the structure of the mouse ApoD gene, which is composed of six exons spanning approximately 20 kb in length. All the exon-intron splice junctions follow the consensus GT/AG sequence. The 5'-flanking region of the mouse ApoD gene contains several putative regulatory elements, including FSE-2, GRE, SDR, MRE, IL-6RE, and TATA box. Northern blot analysis revealed that ApoD was highly expressed in the brain and adipose tissue in mouse. Lower levels of expression were observed in the heart, lung, thymus, testis, and salivary glands. In situ hybridization for the brain showed that ApoD mRNA was mainly localized in the subarachnoid space including the pia. In the Niemann-Pick disease type C mouse model, ApoD expression was upregulated in many organs such as brain, adipose tissue, heart, and thymus, presumably due to enhanced ApoD synthesis in perivascular fibroblasts.

Animals↗

PubMed1996

Saturable function of P-glycoprotein as a drug-efflux pump in multidrug-resistant tumour cells.

P-glycoprotein acts as an active drug-efflux pump in multidrug-resistant tumour cells. We studied the capacity of P-glycoprotein to extrude drugs from the cells. For nanomolar concentrations of vinblastine P388/ADR cells, which overexpress P-glycoprotein in the plasma membrane, accumulated vinblastine, at 37 degrees C for 30 min, to a much lower extent than the sensitive cells (P388/S), while in the micromolar range the cellular concentration was similar for both types of cells. When cells were incubated with a low (10 nM) or high concentration (1 microM) of vinblastine while energy deprived, the vinblastine concentration increased only in the resistant cells incubated with the low concentration of vinblastine, and this increased level was lowered to the level under the normal conditions by addition of glucose. In contrast, the cellular concentrations in other cases were increased to the normal level by glucose. After cells were loaded with the low concentration of vinblastine, the cellular vinblastine was extruded more rapidly from the resistant cells than from the sensitive cells. The courses of vinblastine efflux from the cells loaded with the high concentration of vinblastine were similar in both types of cells. NA-382, a reported P-glycoprotein inhibitor, effectively increased the intracellular vinblastine and inhibited the drug efflux only from multidrug-resistant cells, P388/ADR and AH66 cells, which were incubated with the low concentration of vinblastine. Cellular uptake of NA-382 was also less in P388/ADR cells than in P388/S cells in culture with 10 nM but not 1 microM of the agent, and this low level was reversed to the level in the sensitive cells by 10 microM vinblastine. These results indicate that P-glycoprotein as a drug-efflux pump works effectively under low extracellular concentrations of substrates, but does not under the high concentrations.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1996

[Renal cell carcinoma with solitary asynchronous adrenal metastasis].

We report 3 cases of renal cell carcinoma (RCC) with solitary asynchronous adrenal metastasis. Case 1; A 43-year-old female was diagnosed with ipsilateral adrenal metastasis 10 years after nephrectomy of RCC (T2, N0, M0). She is alive with no evidence of disease five years after adrenalectomy. Case 2; A 53-year-old female had contralateral adrenal metastasis 10 years after nephrectomy (T3, N0, M0). She died with distant metastasis fourteen months post-operatively. Case 3; A 56-year-old man was diagnosed with contralateral adrenal metastasis 3 years after nephrectomy (T3, N0, M0). He is alive with no evidence of disease twenty months postoperatively. Two of our three cases are alive and tumor-free. However, adrenal metastasis was found in case 1 and case 2, even though more than ten years had passed after nephrectomy. Therefore we should observe the patients periodically after radical nephrectomy for a long time.

Adrenal Gland Neoplasms↗

PubMed1996

Use of REMEDi HS in emergency toxicology for a rapid estimate of drug concentrations in urine, serum, and gastric samples.

The REMEDi HS is a broad spectrum drug identification system, designed for emergency toxicology screening and forensic applications. The total analysis time is about 20 min. The current library has 555 drugs and metabolites. The system has a software routine that uses an internal standard (IS) to perform quantitative analysis for target compounds when calibrators are available; further, response factors (RF) are supplied for a rapid estimate of drug concentrations when calibrators are unavailable. In the present study, The concentrations of six drugs (bromisovalum, ephedrine, hydroxyzine, diphenhydramine, ranitidine, and lidocaine) and a metabolite of lidocaine (glycinexylidide) were determined using both methods. The slopes of the regression lines between the rapid estimate method and the IS method were generally within 20% of unity, in agreement with the manufacturer's claim. Semiquantitative estimates based on RF also showed good agreement with results obtained using multipoint calibration. These estimates were sufficient for clinical differentiation of routine and toxic levels. Our study demonstrated that the REMEDi HS is particularly useful for a rapid estimate of drug concentrations in the samples from emergency cases when calibrators are not readily available. Our study also showed that this system can be used for the therapeutic monitoring of ranitidine, bromisovalum, lidocaine, and diphenhydrmine.

Blood↗

PubMed1996

[Death due to cold of a 63-year-old male associated with hepatocellular carcinoma--bibliographic consideration on alcohol metabolism of the patients with liver dysfunction].

In the early morning of late December, a 63-year-old man was found dead in front of his apartment house. At medico-legal autopsy, subcutaneous hemorrhages of the occipital region and linear fractures of the occipital bone was observed, but there was no cerebral contusion leading him to death. Many white tumors, ranging from 0.5 to 2.0 cm in diameter, were observed in the liver. On sections of the liver, hepatic parenchyma was found entirely occupied by the tumors, which were histopathologically diagnosed as moderately- or well-differentiated hepatocellular carcinoma. Alcohol concentrations of the mixed intracardiac blood and the urine were determined to be 1.9 and 3.6 mg/ml, respectively. Through the police investigation, it became clarified that the male had been sleeping in front of his apartment house about at 10:30 p.m. on the day before he was found dead. The cause of his death was, therefore, considered due to cold, and the authors gave a bibliographic consideration on blood and urine alcohol concentrations and alcohol metabolism of a patient with liver dysfunction due to hepatocellular carcinoma.

Alcohol Drinking↗

PubMed1996

A case of death due to outbreak of fire during thinner abuse.

A 22-year-old male, who could not escape from a residential fire, was found dead at the scene, although the other three persons who had been in the same room escaped safely. At the medico-legal autopsy, the burned body presented the second degree level of body destruction (T. Nagano. Jpn J Legal Med., 1982) and the pugilistic attitude caused by fire. Soot was observed not only in the trachea but also in the bronchi or even the alveoli. Forensic toxicological analyses were performed using the intratracheal gas, left and right ventricular blood, urine, stomach contents, cerebrum, cerebellum, left and right lungs, liver, spleen, kidney, skeletal muscle and adipose tissue. The carboxyhemoglobin concentration was 61.4% in the left ventricular blood and 59.5% in the right ventricular blood. Ethanol and toluene were qualitatively detected in the intratracheal gas by gas chromatography-mass spectrometry. The ethanol and toluene concentration was 0.48 mg/g and 20.4 microgram/g, respectively, in the blood, and 0.40 mg/g and 28.7 microgram/g, respectively, in the cerebrum. Moreover, the urinary hippuric acid concentration was 1.76 mg/ml. The ethanol concentrations were not at the toxic level, while the toluene concentrations in the blood and cerebrum were almost at the lethal level. However, since the preservation of the capacity for vital reactions was apparent at the autopsy in the form of soot in the air passages and the formation of CO-Hb in the blood, it was surmised that the victim was still alive when the fire broke out, but subject to severe disturbance of the central nervous system function. The cause of death in the present case was diagnosed as death due to fire.

Adult↗

PubMed1996

[Direct detection of human cytomegalovirus in urine specimens from bone marrow transplant patients by polymerase chain reaction].

Human cytomegalovirus (HCMV) infection is a major causative life-threatening agent that results in opportunistic infections in bone marrow transplant patients. Since antiviral therapy is available for severe HCMV infections, methods to rapidly identify infected patients are needed so that therapy can be promptly instituted. In this study, we used direct method to detect HCMV in urine specimens by nested polymerase chain reaction (nested-PCR) to monitor urinary excretion of HCMV in patients undergoing bone marrow transplantation. The viral DNA was amplified directly from preheated urine without further treatment prior to amplification. Five microliter of urine proved to give the most efficient amplification. The detection limit of the PCR assay for detection of HCMV was 10 copies/microl. The positive rate of the PCR assay and the tissue culture method for detection of HCMV were 15 of 61 (24.6%) and 4 of 61 (6.6%), respectively. Sensitivity and specificity of the PCR assay were 100% and 81% respectively. Based on these data, urinary excretion of HCMV in 21 patients undergoing bone marrow transplantation were monitored weekly by the PCR assay. As a result, in addition to a higher sensitivity, the PCR assay allowed to identify HCMV infection 3.1 (1 approximately 5) weeks earlier than culture method or antibody elevation. Repeated monitoring of virus excretion by this rapid and simple method was useful to promptly detect HCMV infection, allowing proper institution of antiviral drug therapy in patients undergoing bone marrow transplantation.

Adolescent↗

PubMed1995

Experimental studies on postmortem diffusion of ethanol-d6 using rats.

In an investigation of postmortem ethanol diffusion deuterium-labeled ethanol-d6 was instilled by peroral gavage immediately after death by CO into the stomach of rat carcasses which were subsequently kept for 12-72 h at 5 or 30 degrees C. The heart blood, abdominal fluid and several tissues were collected and analyzed by head space gas chromatography-mass spectrometry. Rat carcasses showed no macroscopic changes until at least 72 h at 5 degrees C, and 12 h at 30 degrees C. At 30 degrees C, slight macroscopic change was observed after 24 h, moderate change after 48 h and marked change after 72 h. In the abdomen ethanol-d6 diffused gradually into neighboring organs (hepatic left lobe, left kidney and spleen) at 5 degrees C, with ethanol-d6 reaching a peak concentration of 0.75-2.38 mg/g at 24 h. At 30 degrees C, ethanol-d6 was also detected in neighboring organs and reached a peak concentration of 1.06-2.61 mg/g at 12 h. Thereafter, the ethanol-d6 concentration in the liver, kidney and spleen decreased, with concentrations ranging from 0.30 to 0.61 mg/g at 30 degrees C and 0.05 to 1.47 mg/g at 5 degrees C at 48 h. In the femoral skeletal muscle, ethanol-d6 was not detected until 24 h or more storage at 30 degrees C and never detected at 5 degrees C. In the brain and the organs in the thoracic cavity ethanol-d6 was detected after 12 h or more at 5 or 30 degrees C. Comparison of these results of direct peroral gastric instillation with those when ethanol-d6 was injected into the stomach through a laparotomy incision suggest that the brain and thoracic cavity changes were a result of diffusion from the mouth and esophagus. After 24 h at 30 degrees C, the postmortem ethanol production (0.33-0.85 mg/g) was comparable to those in previous reports. These results indicate that the assessment of ethanol concentration in the heart blood and organs in autopsy cases must be carefully conducted in comparison with the alcohol content of the stomach.

Animals↗

PubMed1995

Postmortem degradation of administered ethanol-d6 and production of endogenous ethanol: experimental studies using rats and rabbits.

Deuterium-labeled ethanol-d6 was employed to study the metabolism and postmortem change of ethanol in putrefied organ tissues. First, 4 ml/kg body weight of 25% (w/v) solution of ethanol-d6 was administered orally to each of 15 rats. The heart blood and organs were collected 15-90 min after the administration and the ethanol-d6 was analyzed by head space gas chromatography/mass spectrometry. The ethanol-d6 concentration in the organ tissues reached its maximum at 15 min after the administration and then gradually declined, showing the same pattern as human ethanol metabolism. Ethanol-d6 (3 ml of the same solution/kg body weight) was injected into the vein of a rabbit's ear (total of 12 rabbits). The rabbit was killed with carbon monoxide 30 min after the administration and the carcass was allowed to stand for 1-4 days at 30 degrees C in a moist chamber. The concentration of ethanol-d6 decreased moderately. Postmortem ethanol and 1-propanol concentrations, in contrast, showed marked increases 2.5 days and more after sacrifice in line with the degree of putrefaction of each organ tissue including skeletal muscle. This suggests the postmortem activation of micro-organism activity. These results indicate that ethanol concentrations in cadaver tissues must be carefully assessed with due consideration of postmortem degradation and production.

1-Propanol↗

PubMed1995

Structural organization and expression of the mouse gene encoding alpha-galactosidase A.

alpha-Galactosidase A (alpha-D-galactoside galactohydrolase, EC 3.2.1.22; alpha GalA) is a lysosomal enzyme that hydrolyses the alpha-D-galactosyl residues from glycosphingolipids. Fabry disease, an inhibited X-linked recessive human metabolic disorder, results from a mutation in the alpha GalA gene at Xq22. As a prerequisite for generating a mouse model of Fabry disease by gene targeting, we have isolated and characterized the mouse alpha GalA gene and cDNA. A cloned mouse alpha GalA cDNA encoded a putative precursor protein of 419 amino acids (aa), including a 31-aa signal peptide (SP). The deduced aa sequence showed high homology (79%) with the human alpha GalA protein. Nucleotide sequence analysis of genomic clones revealed that the overall structure and organization of the gene was very similar to that of human alpha GalA. All exon-intron splice junctions conformed to the GT/AG consensus sequence. Comparison of genomic and cDNA sequences revealed the occurrence of two putative polyadenylation signals whose alternative use results in the two mouse alpha GalA transcripts of 1.4 and 3.6 kb. The 5'-flanking region of mouse alpha GalA had no typical TATA box. Several putative promoter-associated elements including Sp1, AP1 and a potential cAMP-responsive element (CRE) were identified. Northern blot analysis revealed the widespread tissue distribution of mouse alpha GalA transcripts. Lower expression levels, however, were observed in some tissues, implying tissue-specific differences in alpha GalA promoter function.

Amino Acid Sequence↗