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Biomedical subjects

Yutaka Tajima

Publications and source records attributed to Yutaka Tajima.

15 recordsLinked to original sources
PubMed2006

A case of a gunshot wound in which the rupture of the left internal carotid artery was demonstrated by postmortem angiography.

A 54-year-old man was shot into the face by a robber while sleeping in bed. Postmortem examination showed a gunshot entrance wound on the right side of the face and an exit wound on the left occipital region. Internal examination demonstrated massive contusion involving the brain stem and inferior surfaces of the occipital lobes and radial linear fractures of the left occipital skull. Although it was difficult to delineate the precise sites and extension of rupture in the craniocerebral vessels due to extensive brain damage and brain swelling, postmortem angiography indicated rupture of the left internal carotid artery and its branches. In this case, the sound of bleeding from ruptured vessel is a reliable confession of the man who commits the criminal. Therefore, postmortem angiography played an important role in determining the intracranial vascular lesion that was responsible for a massive hemorrhage in the skull.

Angiography↗
PubMed2006

Characterization of human deoxyribonuclease I gene (DNASE1) promoters reveals the utilization of two transcription-starting exons and the involvement of Sp1 in its transcriptional regulation.

Levels of deoxyribonuclease I (DNase I) activity in vivo have been shown to be altered by physiological and/or pathological processes. However, no information is available on the regulation of DNase I gene (DNASE1) expression in vivo or in vitro. We first mapped the transcription start sites of DNASE1 in human pancreas and in the DNase I-producing human pancreatic cancer cell line QGP-1, and revealed a novel site approximately 12 kb upstream of exon 1, which was previously believed to be the single transcription-starting exon. This initiation site marks an alternative starting exon, designated 1a. Exons 1 and 1a were used simultaneously as transcription-starting exons in pancreas and QGP-1 cells. Promoter assay, EMSA and chromatin immunoprecipitation analysis with QGP-1 cells showed the promoter region of exon 1a in which the Sp1 transcription factor is specifically involved in promoter activity. This is the first to be identified as a transcription factor responsible for gene expression of vertebrate DNase I genes. Furthermore, RT-PCR analysis indicated alternative splicing of human DNASE1 pre-mRNA in pancreas and QGP-1 cells. Only two transcripts among eight alternative splicing products identified can be translated to produce intact DNase I protein. These results suggest that human DNASE1 expression is regulated through the use of alternative promoter and alternative splicing.

Alternative Splicing↗
PubMed2005

Polyoxotungstates reduce the beta-lactam resistance of methicillin-resistant Staphylococcus aureus.

Bacterial strains isolated from clinical specimens have become more and more resistant to many anti-microbials. This is because we have consumed large amounts of strong antimicrobials over long periods of time and thus bacterial cells are able to survive by altering the target(s) of antimicrobial agents. A good example of this phenomenon is methicillin-resistant Staphylococcus aureus (MRSA). One of the cell wall-synthesizing enzymes (known as PBP2') of this pathogen has low affinity to beta-lactams, and therefore the bacterial cells continue to grow even under high concentrations of the agents. However, this drug resistance does not seem to be total. They seem to have some weak spots and several substances are known to sensitize strains of MRSA to beta-lactams. This review discusses the ability of polyoxotungstates (POTs) to sensitize MRSA to beta-lactams by reducing the expression of PBP2'. It is also possible that the sensitization is a type of stress response of MRSA to POTs. This idea may provide a hint for the development of a new antimicrobial agent.

Anti-Bacterial Agents↗
PubMed2005

[Neuroendoscopic placement of the reservoir in an elderly patient with recurrenced craniopharyngioma: case report].

We report a case of recurrent craniopharyngioma in the third ventricle with obstructive hydrocephalus, which was successfully treated by placement of the Ommaya reservoir by neuroendoscopic procedure. A 72-year-old male with disorientation and gait disturbance was admitted to our hospital. He had been suffering chronic heart failure and arrhythmia due to mitral valve insufficiency, and panhypopituitarism after the first craniotomy for craniopharyngioma. MRI demonstrated obstructive hydrocephalus at the foramen of Monro by the cystic tumor. Cyst decompression and placement of Ommaya reservoir were successfully performed in local anesthesia. Postoperatively, his disorientation and gait disturbance were improvement, and no chemical meningitis developed. Neuroendoscopic management for cystic craniopharyngioma with obstructive hydrocephalus was effective procedure for elderly patient with systemic risk factor.

Aged↗
PubMed2004

[Arylsulfatase].

Explore the source record for details and available documents.

Arylsulfatases↗
PubMed2003

The effects of tungstophosphate and tungstosilicate on various stress promoters transformed in Escherichia coli.

Although tungsten is an important material in some industrial and chemical processes, the biological and biochemical effects, including the toxicity, of tungsten compounds are not known well. In this study, a reporter gene assay using special strains of Escherichia coli was performed to investigate the mode of action of two polyoxotungstates, i.e. undecatungstophosphate (PW(11)) and undecatungstosilicate (SiW(11)). When the bacterial cells were cultured with PW(11), osmY (a stress promoter gene sensitive to osmotic signals) was induced to some extent, while other stress promoters were expressed only slightly. SiW(11) gave similar results, but clpB (an analogue of human heat shock protein) was more strongly induced. It is possible that PW(11) and SiW(11) can produce an osmotic signal at lower concentrations without increasing ionic strength. Since the constituents of PW(11)/SiW(11) (i.e. HPO(4)(2-), SiO(3)(2-), WO(4)(2-)) showed almost no effect, a chemical feature unique to PW(11)/SiW(11) and originating from neither of their constituents, i.e. a polyanionic characteristic, may play an important role in their biological effects.

Escherichia coli↗
PubMed2003

Effects of tungstosilicate on strains of methicillin-resistant Staphylococcus aureus with unique resistant mechanisms.

In a previous study, it was found that polyoxotungstates such as undecatungstosilicate (SiW11) greatly sensitized strains of methicillin-resistant Staphylococcus aureus (MRSA) to beta-lactams. In this report, the effects of SiW11 on several MRSA strains with unique resistant mechanisms were studied. SiW11 was still effective to MRSA mutants with higher beta-lactam resistance due to reduced cell-lytic activity. Since the antimicrobial effect of TOC-39 (a cephem antibiotic with strong affinity to penicillin-binding protein (PBP) 2') was not strongly enhanced in any case, it was confirmed that the sensitizing effect of SiW11 is due to reduced expression of PBP2'. However, the sensitizing effect of SiW11 was relatively weak in MRSA strains with lowered susceptibility to glycopeptide antibiotics. A certain resistant mechanism other than the mecA-PBP2' system worked in such a strain. Interestingly, an MRSA mutant with the Eagle-type resistance was dramatically sensitized. This result suggests that SiW11 has another site of action besides reducing the expression of PBP2'.

Anti-Bacterial Agents↗
PubMed2003

[A hypothesis about anti-DNA antibody].

"Anti-DNA antibody" is the antibody which can bind DNA molecules. It is well accepted that this antibody, especially in anti-double strand DNA antibody, has a high disease specificity for SLE. Usually, the antibody is detected by using DNA molecule as a binding target in the clinical laboratory test performed in vitro. However, it is quite unknown what the antibody is actually attacking in vivo. This review will introduce many findings known to date and try to solve the mystery of anti-DNA antibody with a hypothesis that the antibody nonspecifically crossreacts to negatively charged substances(e.g., polysaccharides) in vivo. Probably, a type of charge interaction is dominantly involved in this binding.

Autoantibodies↗
PubMed2002

[Unexpected drug-interaction].

The case of a male patient suffering from chronic normal pressure hydrocephalus is outlined. Antidepressant and pravastatin were administered because of the patient's abulia and hypercholesterolemia, but neuroleptic malignant syndrome-like conditions developed. All physicians should suppose the occurrence of such an "unexpected drug-interaction" in any case. The author considered that a good sense of careful discernment and rapid reference system of medical information are "essential tools" for clinical management.

Aged↗
PubMed2002

[Undecatungstophosphate sensitized strains of methicillin-resistant Staphylococcus aureus to beta-lactams].

Previously, a factor (Factor T) was found in aged mixtures of tungstate and phosphate, which greatly sensitizes strains of methicillin-resistant Staphylococcus aureus to beta-lactams. Factor T was purified and identified as undecatungstophosphate([PW11O39]7-). Undecatungstosilicate([SiW11O39]8-), a compound closely related to undecatungstophosphate, showed a similar enhancing effect. Chemically, these compounds are classified as "polyoxotungstates", and it is expected that these tungsten compounds will be useful as a "tool" in laboratory tests: i.e., in screening media for highly resistant MRSA strains. They may be also useful to investigate the resistant mechanism of the bacterial cells.

Anti-Bacterial Agents↗