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Biomedical subjects

K Tabuchi

Publications and source records attributed to K Tabuchi.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Brown-Séquard syndrome and cervical CSF leakage due to a knife injury: a case report].

We report a case of Brown-Séquard syndrome and cervical CSF leakage caused by a knife injury. A 34-year-old man was involved in a fight and was stabbed on his occiput and back with a knife. Neurological examination on admission showed right hemiparesis, right hemihypesthesia and left hemihypalgesia, indicating Brown-Séquard syndrome. Furthermore, cerebrospinal fluid was leaking from the occipital stab wound. Head CT scan showed massive accumulation air in the subarachnoid space. Cervical MRI showed that the injury tract reached to the space between the occipital bone and the atlas. One week after admission, suboccipital craniectomy and duraplasty were performed because of continuous CSF leakage. Although, the CSF leakage recurred due to the wound infection, it disappeared naturally as the patient's general condition improved. Follow-up MRI studies demonstrated the cervical spinal lesion as hyperintensity on T2WI, which localized at the right side of the spinal cord. The patient's hemiparesis gradually improved and he underwent rehabilitation. Spinal cord injury due to a stab wound by a knife is rare in Japan. In this case, we suppose that the mechanism of spinal cord injury was due to direct injury by a knife avoiding the lateral corticospinal tract because his right hemiparesis obviously improved.

Adult↗
PubMed2000

Peroxiredoxin I expression in oral cancer: a potential new tumor marker.

This study investigates the applicability of the novel antioxidant protein, peroxiredoxin (Prx) I as a marker for tumor status in oral squamous cell carcinoma (SCC). Samples from 53 patients with SCC in the oral cavity were examined by immunohistochemistry. Correlations between the expression level of Prx I and proliferating cell nuclear antigen (PCNA), the clinical features of tumors, and their histopathological classifications were statistically analyzed. Cases exhibiting low Prx I expression level included significantly more with larger tumor mass cases (T-category, P=0.004), positive lymph node metastasis (N-category, P=0.015), advanced stage (P=0.002), and poorly differentiated cells (P=0.020). There was no significant difference between Prx I expression and the other indices.

Adult↗
PubMed2000

GAL4/UAS-WGA system as a powerful tool for tracing Drosophila transsynaptic neural pathways.

Visualization of specific transsynaptic neural pathways is an indispensable technique for understanding the relationship between structure and function in the nervous system. Here, we demonstrate the application of the wheat germ agglutinin (WGA) transgene technique for tracing transsynaptic neural pathways in Drosophila. The intracellular localization of WGA was examined by immunoelectron microscopy. WGA signals were detected in granule-like structures in both the outer photoreceptor cells expressing WGA and the second-order laminar neurons. Misexpression of tetanus toxin (TNT), which inactivates N-synaptobrevin, in the outer photoreceptor cells resulted in the elimination of on/off transients in electroretinogram (ERG) recordings and in a great reduction in WGA transfer into laminar neurons, suggesting that anterograde WGA transsynaptic transfer is dependent mainly on synaptic transmission. Retrograde WGA transfer was also detected upon its forced expression in muscle cells. WGA primarily expressed in muscle cells was taken up by motoneuron axons and transported to their cell bodies in the ventral nerve cord, suggesting that WGA can trace motoneuronal pathways in combination with the muscle-specific GAL4 driver. Thus, the GAL4/UAS-WGA system should facilitate the dissection of the Drosophila neural circuit formation and/or synaptic activity in various regions and at various developmental stages.

Animals↗
PubMed2000

A case report of FSH-producing nasal ectopic pituitary adenoma extending to the frontal cranial fossa.

We report the first case of an ectopic pituitary adenoma in the nasal cavity that produced follicle-stimulating hormone (FSH). A 60-year-old man complaining of left nasal bleeding had a polypoid tumor in the left nasal cavity. Findings of computed tomographic scanning and magnetic resonance imaging showed that the tumor originated from the olfactory cleft, occupied the nasal cavity, and extended to the frontal cranial fossa. Results of histologic examination suggested ectopic pituitary adenoma. Magnetic resonance imaging results showed the pituitary gland to be normal. Electron microscopy findings demonstrated a large number of secretory granules in the tumor cells that were positive for FSH on immunohistochemical analyses. Serum gonadotropin levels were normal, and no clinical signs of hypersecretory syndrome were noted. The above findings led us to establish the diagnosis of FSH-producing ectopic pituitary adenoma. The patient underwent craniofacial resection of the tumor followed by an uneventful recovery. The pathologic findings and clinical course of the case were comparable to those of FSH-producing adenomas arising from the pituitary gland.

Adenoma↗
PubMed2000

Down's syndrome with myelodysplastic syndrome showing t(7;11)(p13;p14).

We report a boy with Down's syndrome (DS) who developed myelodysplastic syndrome (MDS) after spontaneous remission of transient myeloproliferative disorder (TMD) at birth. Chromosomal analysis of the blasts in the MDS phase demonstrated t(7;11)(p13;p14) which had not been detected in the TMD phase. NUP98-HOXA9 chimera mRNA, which is known to be involved in t(7;11)(p15;p15) translocation in acute myeloid leukemia (AML), was not detected by reverse transcriptase-polymerase chain reaction, and NUP98 rearrangement was not detected by Southern blot analysis of the blasts in the MDS phase. Reciprocal translocation is very rare in AML/MDS in DS, and the t(7;11)(p13;p14) found in our patient was different from the recurrent translocation t(7;11)(p15;p15) previously reported.

Blotting, Southern↗
PubMed2000

Hypermethylation of p16 and p15 genes and RB protein expression in acute leukemia.

Both p16 and p15, encoded by genes located on chromosome 9p21, are inhibitors of cyclin-dependent kinases 4/6 (CDK4/6) and upstream regulators of RB function, and set up the RB/p16 tumor suppressive pathway, which is abrogated frequently in human neoplasms, either through inactivation of the RB or p16 tumor-suppressor protein, or alteration of the cyclin D1 or CDK4 oncoproteins. In hematological malignancies, deletion of p16/p15 locus has been shown to be highly specific to lymphoid malignancies, and more particularly to T-cell acute lymphoblastic leukemia (T-ALL). However, in the other subsets of ALL, deletions of p16 and p15 are relatively rare events. To investigate whether these genes are inactivated by methylation of the 5' CpG islands, we examined 35 leukemia cell lines and 29 childhood acute myeloid leukemia (AML) patients by Southern blot, polymerase chain reaction (PCR) and Western blot analyses. We found methylation of p16 in 12 (50%) of 24 ALL cell lines, 5 (50%) of 10 AML cell lines without homozygous deletion of p16, and 11 (38%) of 29 AML patients. Those leukemia cell lines subjected to p16 methylation were found to have lost p16 protein expression. The p15 gene was methylated in 10 (34%) of 29 ALL cell lines, 6 (60%) of 10 AML cell lines without homozygous deletion of p15, and 15 (52%) of 29 AML patients. These results revealed the frequent methylation of p16 and p15 genes in B-ALL and AML despite a low frequency of p16 and p15 deletions and mutations in these leukemias. In the study for expression of RB protein, we found no expression of RB in 4 of 16 leukemia cell lines. Inactivation of the p16 gene was found in all the cell lines with expression of RB. Neither amplification nor rearrangement of cyclin D1 gene was found in any cell lines. These results suggest that inactivation of p16 and p15 genes is one of the most common genetic events in acute leukemia, and plays an important role for the RB/p16 pathway in the pathogenesis of acute leukemia.

Acute Disease↗
PubMed2000

Hydroxyl radical formation in the perilymph of asphyxic guinea pig.

To elucidate the role of hydroxyl radical (.OH) species in the generation mechanism of the cochlear pathology induced by transient asphyxia and subsequent re-ventilation, the concentrations of 2,3-hydroxybenzoic acid (DHBA) and 2,5-DHBA, major products arising from the attack of .OH upon salicylate, were measured in the perilymph of the guinea pig by the high performance liquid chromatography-electrochemical/UV method. The mean value of 2, 3-DHBA concentration in the perilymph significantly increased from the pre-asphyxic level (6.4 microM) to 7.6 microM and 8.8 microM during asphyxia of 3 min duration and at 5 min after the onset of re-ventilation, respectively. The 2,5-DHBA concentration was 7.9 microM before asphyxia, and also significantly increased to 11.5 microM and 16.2 microM during and after asphyxia, respectively. These results strongly indicated that .OH was generated in the perilymph of the asphyxic and re-ventilated guinea pig cochlea, and the significance of this increased .OH in generating anoxia and re-perfusion injury is discussed with respect to iron and oxygen-derived free radicals.

Animals↗
PubMed2000

The contribution of phospholipase A2 to the cochlear dysfunction induced by transient ischemia.

The objective of the present study was to examine whether mepacrine, a commonly used phospholipase A2 inhibitor, decreases ischemic damage to the cochlea. Transient ischemia of the cochlea was induced in albino guinea pigs for 15, 30 or 60 min by pressing the labyrinthine artery at the porus acusticus internus. The animals were intraperitoneally given mepacrine or physiological saline solution (PSS) 20 min prior to ischemia. Although mepacrine failed to alleviate the post-ischemic threshold shift of compound action potential (CAP) in case of 60 min ischemia, a statistically significant reduction in the CAP threshold shift was observed in the mepacrine-treated animals after 15 and 30 min ischemia. However, there was no statistically significant difference in the post-ischemic threshold shift of cochlear microphonic between the mepacrine-given and the PSS-given animals. Furthermore, mepacrine partially alleviated ischemia-induced swelling of radial afferent dendrites of primary auditory neurons. These results suggest that excessive activation of phospholipase A2 plays an injury-producing role at least by enhancing excitotoxicity in ischemia-reperfusion injury of the cochlea.

Action Potentials↗
PubMed2000

Effect of calmodulin antagonists on the compound action potential of the cochlea.

This study aimed to evaluate the effect of calmodulin antagonists on the threshold of the compound action potential (CAP) and the functional recovery of the cochlea after transient ischemia. When trifluoperazine and W-7 were administered to albino guinea pigs with perilymphatic perfusion, these drugs did not significantly affect the CAP thresholds. Transient cochlear ischemia of 30-min duration was obtained via a skull base approach. Although trifluoperazine significantly ameliorated the post-ischemic CAP threshold shifts 4 h after the onset of reperfusion, 1 to 50 microM W-7 did not affect the CAP threshold shifts. These results suggest that the action antagonizing calmodulin has no effect on the CAP threshold, while the role that calmodulin plays in cochlear ischemia-reperfusion injury still remains unclear.

Action Potentials↗
PubMed2000

c-Abl expression in oral squamous cell carcinomas.

c-Abl is proto-oncogene product. c-Abl has roles in signal transduction, cell cycle regulation, and inhibition of apoptosis. There are many reports about c-Abl function in hematopoietic cells, but few are concerned with solid tumors. In the present study, biopsy specimens from 44 patients with oral squamous cell carcinomas were subjected to immunohistochemistry, and the expression levels of c-Abl were correlated with clinicopathological features. Statistical analyses revealed that c-Abl expression was significantly associated with T-category (p = 0.011), sex (p = 0.014), and differentiation (p = 0.007), but no significant difference was observed with N-category, age, primary tumor region, or the other histological gradings. The low c-Abl expression group included more T4, male, and poorly differentiated cases. There was a trend towards longer tendency survival in the high expression group, but the difference was not significant. We conclude that c-Abl is a good candidate for a tumor-expansion marker.

Adult↗
PubMed2000

Levels of beta-human chorionic gonadotropin in cerebrospinal fluid of patients with malignant germ cell tumor can be used to detect early recurrence and monitor the response to treatment.

BACKGROUND: Tumor marker-producing germ cell tumors of the central nervous system are malignant and require radiation and/or chemotherapy. Although serum beta-human chorionic gonadotropin (hCG) has been used to monitor the course of treatment, the levels of beta-hCG in the cerebrospinal fluid (CSF) have not been measured routinely in the clinic. To determine whether they can be used to evaluate parameters of tumor status, such as progression or response to therapy, levels of beta-hCG in the serum and CSF of patients with germ cell tumors were studied. METHODS: Fifty-four paired samples of CSF and serum were taken from seven patients with germ cell tumor and their beta-hCG levels were measured. Beta-hCG was negative in both serum and CSF in 11 instances and the levels in the other 43 paired samples were analyzed for any correlation or relationship to therapy. They were also compared with the clinical courses. RESULTS: The mean CSF beta-hCG level was 11.5 mIU/ml, which was significantly higher than the level in serum (3.5, p = 0.002). In all the paired samples except for one time point, the level in CSF was higher than that in serum. Out of 43 instances where the beta-hCG level in CSF was elevated, the level in serum was elevated in only 16 (37.2%). Among cases of recurrent malignant germ cell tumor, there were nine instances of recurrence or progression despite therapy. In all five instances where beta-hCG CSF levels were measured, the levels were elevated prior to any increase or detectability of the serum values. CONCLUSION: It seems likely that the level of beta-hCG in CSF is a good marker for monitoring tumor recurrence or evaluation of treatment results.

Adolescent↗
PubMed2000

Induction of apoptosis in glioma cells by recombinant human Fas ligand.

OBJECTIVE: Fas ligand (FasL) belongs to the tumor necrosis factor family and has the ability to induce apoptosis in susceptible target cells by binding to its receptor, Fas. It has been demonstrated recently that the FasL/Fas system plays a pivotal role in the cytocidal activity of T lymphocytes in the immune system. FasL may act as a cytotoxic effector molecule to Fas-expressing malignant tumor cells. We reported previously that Fas is commonly expressed in human brain tumor cells. In this study, we examine the possible application of FasL to therapy for malignant brain tumors. METHODS: To develop an expression system yielding large amounts of FasL, we constructed a baculovirus vector containing complementary deoxyribonucleic acid of human FasL under the control of a polyhedrin promoter. We produced human FasL in Spodoptera frugiperda (Sf9) insect cells infected by the recombinant baculovirus carrying FasL complementary deoxyribonucleic acid and studied the cytocidal activity of FasL against the T98G human glioblastoma cell line. RESULTS: FasL expression in Sf9 cells was confirmed immunocytochemically with rabbit antibody raised against the cytoplasmic domain of human FasL. The FasL released into the supernatant of cultured Sf9 cells was also verified by Western blotting, and it specifically induced apoptosis in T98G cells. The induced apoptosis by recombinant human FasL was confirmed by annexin V-fluorescein isothiocyanate staining. CONCLUSION: The present results suggest that the induction of apoptosis by the Fas/FasL system could be a new strategy for the treatment of malignant brain tumors, which are resistant to conventional therapies.

Animals↗
PubMed2000

[Drug sensitivity, conjugative R plasmids and plasmid profiles of Salmonella isolated from humans with infectious enteritis].

Using 92 Salmonella strains isolated from patients suspected of having infectious diseases of the intestinal tract who visited 13 hospitals in Japan during the six years between 1991 and 1996, we investigated the drug susceptibility, prevalence of conjugative R plasmid, and the plasmid profiles. 1) Of the bacterial isolates tested, 52.2% showed drug-resistance. Regarding the drug-resistance patterns, 70.8% of the isolates were resistant to a single drug, while 29.2% were multi drug-resistant. 2) Dividing the resistance patterns by the serotypes, among Salmonella Enteritidis isolates, single-drug resistance to SM was the most frequent, being detected in 27 isolates. Single-drug resistance to NA and two-drug resistance to SM/TC were the second-most frequent, each being detected in isolates. Among Salmonella Hadar isolates, four isolates showed two-drug resistance to SM/TC, and one isolate showed single-drug resistance to TC. Among Salmonella Typhimurium isolates, one isolate each showed three-drug resistance to ABPC/CER/KM and KM/TC/CP. Among Salmonella Agona isolates, one isolate each showed two-drug resistance to SM/TC and single-drug resistance to SM. Among Salmonella Derby isolates, two isolates showed single-drug resistance to SM. 3) The prevalence of conjugative R plasmid was investigated in 48 drug-resistant isolates, and six isolates (12.5%) contained the plasmid. 4) The prevalence of the plasmid was investigated in 29 drug-resistant S. Enteritidis isolates, and 22 isolates (75.9%) contained the plasmid. These isolated were classified by the plasmid profiles into types H1 to H7. 5) Regarding the plasmid profiles of the S. Enteritidis isolates, a position corresponding to 60 Kbp was the most frequently detected in 90.5%.

Anti-Bacterial Agents↗
PubMed2000

Effect of 7-nitroindazole upon cochlear dysfunction induced by transient local anoxia.

The purpose of the present study was to further elucidate how nitric oxide (NO) is involved in cochlear anoxia-reperfusion injury. Transient local anoxia of the cochlea was induced in albino guinea pigs for 15, 30, or 60 minutes by transiently compressing the labyrinthine artery through a skull base approach. 7-Nitroindazole (7NI), a relatively selective neuronal nitric oxide synthase (nNOS) inhibitor. was intraperitoneally administered to the guinea pigs 30 minutes before the onset of local anoxia. The compound action potential (CAP) thresholds were measured before the administration of 7NI and 4 hours after the onset of reperfusion. A statistically significant reduction in the postanoxic CAP threshold shift from the preadministration value was observed in the 7NI-administered animals as compared with the control animals after 15- and 30-minute periods of anoxia. These results confirm the involvement of NO and nNOS in the cochlear injury induced by transient local anoxia.

Action Potentials↗
PubMed2000

An evaluation of neurobehavioural problems as perceived by family members and levels of family stress 1-3 years following traumatic brain injury in Japan.

OBJECTIVE: To ascertain the proportion of patients with traumatic brain injury (TBI) admitted to a Japanese district hospital and to evaluate the levels of stress and anxiety in fami ies living with those TBI patients. DESIGN: A retrospective study of patients admitted to hospital from April 1995 to March 1997 and a questionnaire study of family members of survivors. SETTING AND SUBJECTS: All patients referred or transferred to the Emergency Department at the Saga Medical School Hospital, Japan with a primary diagnosis of TBI were studied. Family members living with TBI patients were sent questionnaires. MAIN OUTCOME MEASURES: The Barthel Index, the Patient Competency Rating Scale, the modified Caregiver Strain Index and the Hospital Anxiety and Depression Scale. RESULTS: There were 34 patients who required hospitalization for care relating to TBI. Of these, nine family members took part in the questionnaire study. Three carers reported fairly high levels of stress and another three carers were considered to be at risk of anxiety and depression. There was a tendency for family members who reported that patients had difficulties in performing behavioural tasks to have higher levels of stress themselves. CONCLUSION: These preliminary results showed that family members experienced certain levels of stress and were also at risk of anxiety and depression. The impact of TBI on families as well as patients should receive more attention.

Adolescent↗
PubMed2000

[Management strategy for patients with coronary artery disease associated with valve disease].

BACKGROUND: The indication of combined operation of coronary artery bypass (CAB) and valve surgery is controversial. METHODS: Between April 1992 and January 2000, 13 patients underwent a combined operation with CAB and valve replacement, and 4 patients (2 were overlapped) who had had a previous CAB underwent a reoperative valve replacement. RESULTS: One patient who underwent AVR and reCAB 11 years after the initial CAB died. Another patient with preoperative MRSA pneumonia and received MVR and CAB died 4 months after surgery with MRSA sepsis. However, others showed an excellent post-operative course. The causes of necessitating the reoperation were: unawareness of aortic stenosis at the initial emergency CAB in 1 patient, progression of aortic stenosis in 1 patient, progression of aortic regurgitation in 1 patient, and progression of mitral regurgitation in 1 patient. CONCLUSION: The results of the combined CAB and valve replacement operation were acceptable. Patients with mild-moderate valve disease should be considered as candidates for valve surgery at the time of CAB.

Aged↗
PubMed2000

Detection and investigation of Campylobacter jejuni by polymerase chain reaction-restriction fragment length polymorphism analysis.

A molecular typing approach for Campylobacter jejuni with restriction fragment length polymorphism (RFLP) analysis of the flagellin gene flaA in C. jejuni, was generated and studied. Using polymerase chain reaction (PCR)-RFLP with the restriction endonuclease Mbo I, it was demonstrated that C. jejuni could be divided into four types. Genotypic analysis of C. jejuni by PCR-RFLP is a valuable technique for epidemiological typing.

Animals↗