Biomedical subjects

T Uozumi

Publications and source records attributed to T Uozumi.

At least 37 records · Page 2Linked to original sources

PubMed1999

Telomerase activity in central nervous system malignant lymphoma.

BACKGROUND: Primary central nervous system malignant lymphoma (PCNSL) has been regarded as a rare neoplasm. Recently, however, its incidence has been rapidly increasing. Despite active clinical trials, its clinical and biologic features remain unknown and there has been no effective treatment or prognostic factor. The current study attempted to elucidate telomerase activity and expression of the telomere-related RNA of PCNSL as novel prognostic factors. METHODS: The subjects were 12 patients with histologically diagnosed PCNSL. All patients were treated with chemoradiotherapy consisting of whole-brain radiation, vincristine, etoposide, and prednisolone. Telomerase activity in the resected tumor was analyzed both qualitatively and quantitatively using the TRAP (telomeric amplification assay protocol)/TRAP-HPA (hybridization protection assay) method. The expression of telomere-related RNA (hTERT, hTERC, and TEP1) was analyzed by reverse transcriptase-polymerase chain reaction. RESULTS: Telomerase activity was detected in 10 of 12 patients with PCNSL, with an average activity of 148.9 relative light units. The average telomere length was 5.55 kb. The expression of hTERT correlated with telomerase activity, and there was a statistically significant correlation between telomerase activity and both the duration of survival and the interval to tumor progression. CONCLUSIONS: Telomerase activity and the expression of hTERT may be novel prognostic factors in patients with PCNSL.

Adult↗

PubMed1999

A cytotoxic ribonuclease targeting specific transfer RNA anticodons.

The carboxyl-terminal domain of colicin E5 was shown to inhibit protein synthesis of Escherichia coli. Its target, as revealed through in vivo and in vitro experiments, was not ribosomes as in the case of E3, but the transfer RNAs (tRNAs) for Tyr, His, Asn, and Asp, which contain a modified base, queuine, at the wobble position of each anticodon. The E5 carboxyl-terminal domain hydrolyzed these tRNAs just on the 3' side of this nucleotide. Tight correlation was observed between the toxicity of E5 and the cleavage of intracellular tRNAs of this group, implying that these tRNAs are the primary targets of colicin E5.

Anticodon↗

PubMed1999

Comparison of gene structures and enzymatic properties between two endoglucanases from Humicola grisea.

We have cloned two endoglucanase genes (egl3 and egl4) from a thermophilic fungus, Humicola grisea. The coding region of the egl3 gene was interrupted by an intron of 56-bp, and the deduced amino acid sequence of the egl3 gene was 305 amino acids in length and showed 98.4% identity with Humicola insolens EGV. The coding region of the egl4 gene was also interrupted by an intron of 173-bp, which contains 34 TTC repeated sequence units, and the deduced amino acid sequence of the egl4 gene was 227 amino acids in length and showed 61.5% identity with H. grisea EGL3. The typical hinge and the cellulose-binding domain were observed in the C-terminal region of EGL3, but they were not observed in EGL4. In the 5' upstream region of both genes, there were a TATA box or its similar sequence, CAAT motifs, and 6-bp sites which are identical or similar to the consensus sequence for binding a catabolite repressor CREA in Aspergillus nidulans. The egl3 and the egl4 genes were expressed in Aspergillus oryzae, and the translation products were purified. The fusion protein, EGL4CBD, which consists of a catalytic domain of EGL4 and the C-terminal region of EGL3, was also constructed and produced by A. oryzae, and purified. These enzymes showed relatively high activity toward carboxymethyl cellulose (CMC) and could not hydrolyze p-nitrophenyl-beta-D-glucoside and p-nitrophenyl-beta-D-cellobioside. The positive effect of substituting the C-terminal region of EGL4 with that of EGL3 was observed in the hydrolysis of CMC.

Amino Acid Sequence↗

PubMed1999

Brain metastasis of Merkel cell carcinoma. Case report and review of the literature.

Merkel cell carcinoma (MCC) is a rare primary cutaneous neuroendocrine tumor that is locally aggressive and has potential for metastatic spread. However, brain metastases are rare, and therapy for such tumors has never reported. The authors present a 48-year-old woman with MCC of the left elbow and a right cerebellar metastasis. After the right cerebellar mass was totally resected, radiation treatment and chemotherapy were performed. Eight cases of brain metastasis have been reported in the literature, but only 5 have been presented in sufficient detail for analysis. Therapy for brain metastases has always been palliative whole-brain irradiation and chemotherapy except for our patient, who underwent total removal of the tumor and survived for 11 months without neurological deficit. Except in the case of 1 with a particularly radiosensitive MCC, the patients with brain metastases died within 9 months after detection of the brain lesions. If possible, aggressive excision of brain metastases as well as of the primary lesion should be done.

Carcinoma, Merkel Cell↗

PubMed1999

A phase II study of KRN8602(MX2), a novel morpholino anthracycline derivative, in patients with recurrent malignant glioma.

KRN8602(MX2) is a newly developed morpholino-anthracycline that has been found to cross the blood-brain barrier and be distributed in brain tissue after intravenous administration and to be effective against human glioma cells and the intracerebrally transplanted tumors in vivo. In order to confirm these promising preclinical observations clinically, we performed a phase II trial of KRN8602 in patients with recurrent malignant glioma. The 44 patients enrolled received at least 2 cycles of KRN8602 35 mg/m2/day at 3-4 week intervals by intravenous bolus. Of the 44 patients, 37 could be evaluated for response, and 39 for toxicity. One patient with anaplastic astrocytoma had a complete response (1/37, 3%), and 2 patients with anaplastic astrocytoma and 1 with brain stem glioma had a partial response (3/37, 8%). The overall response rate was 11% (4/37). All patients who responded had received prior chemotherapy that included nitrosoureas. No response was observed in the patients with glioblastoma. Myelosuppression was moderately severe, with 72% of patients developing grade 3 or 4 leukopenia. Severe nausea/vomiting was observed in 31% of the patients. No severe cardiotoxicity was observed. The results indicate that KRN8602 has modest activity against recurrent malignant glioma with relatively severe, but manageable toxicity. It seems to be worthwhile to further assess the efficacy and toxicity of KRN8602 against malignant glioma, which is generally less sensitive to chemotherapy.

Adult↗

PubMed1999

Molecular cloning and expression of the novel fungal beta-glucosidase genes from Humicola grisea and Trichoderma reesei.

A novel fungal beta-glucosidase gene (bgl4) and its homologue (bgl2) were cloned from the cellulolytic fungi Humicola grisea and Trichoderma reesei, respectively. The deduced amino acid sequences of H. grisea BGL4 and T. reesei BGL2 comprise 476 and 466 amino acids, respectively, and share 73.1% identity. These beta-glucosidases show significant homology to plant beta-glucosidases belonging to the beta-glucosidase A (BGA) family. Both genes were expressed in Aspergillus oryzae, and the recombinant beta-glucosidases were purified. Recombinant H. grisea BGL4 is a thermostable enzyme compared with recombinant T. reesei BGL2. In addition to beta-glucosidase activity, recombinant H. grisea BGL4 showed a significant level of beta-galactosidase activity, while recombinant T. reesei BGL2 showed weak beta-galactosidase activity. Cellulose saccharification by Trichoderma cellulases was improved by the addition of recombinant H. grisea BGL4.

Amino Acid Sequence↗

PubMed1999

Isolation and characterization of the actin gene from the cellulolytic fungus Humicola grisea and analysis of transcription levels of actin and cellulase genes.

An actin gene was isolated from the cellulolytic fungus Humicola grisea. The gene structure, which has 5 introns in the coding region, is similar to those of the so far cloned fungal actin genes. But there are some differences in intron sizes and codon usage. Transcription levels of actin and cellulase genes were also investigated.

5' Untranslated Regions↗

PubMed1999

Transcriptional regulation of the Bacillus ohbensis cyclodextrin glucanotransferase gene in B. subtilis.

The expression of the cyclodextrin glucanotransferase (CGTase) gene (cgt) of Bacillus ohbensis, when introduced into an alpha-amylase-defective strain of B. subtilis on a multicopy plasmid, pHY300PLK, was induced in the presence of starch and was subject to catabolite repression by glucose as well as in the original strain, B. ohbensis. We constructed a cgt'::'lacZ translational fusion to study the expression in B. subtilis, and this construct was confirmed to be subject to both starch induction and catabolite repression. In order to define the region involved in the regulation of the cgt gene, a series of cgt'::'lacZ gene with various lengths of deletion in the promoter region was constructed on pHY300PLK. DNA regions responsible for starch induction and catabolite repression by glucose could be separated in the deletion experiment. Primer extension analysis showed that the catabolite repression was controlled at the initiation of transcription, while the starch induction is likely to be controlled by a transcriptional termination-antitermination mechanism.

5' Untranslated Regions↗

PubMed1999

The relationship between magnetic resonance imaging findings and clinical manifestations of hypothalamic hamartoma.

OBJECT: Hypothalamic hamartoma is generally diagnosed based on its magnetic resonance (MR) imaging characteristics and the patient's clinical symptoms, but the relationship between the neuroradiological findings and clinical presentation has never been fully investigated. In this retrospective study the authors sought to determine this relationship. METHODS: The authors classified 11 cases of hypothalamic hamartoma into two categories based on the MR findings. Seven cases were the "parahypothalamic type," in which the hamartoma is only attached to the floor of the third ventricle or suspended from the floor by a peduncle. Four cases were the "intrahypothalamic type," in which the hamartoma involved or was enveloped by the hypothalamus and the tumor distorted the third ventricle. Six patients with the parahypothalamic type exhibited precocious puberty, which was controlled by a luteinizing hormone-releasing hormone analog, and one patient was asymptomatic. No seizures or mental retardation were observed in this group. All patients with the intrahypothalamic type had medically intractable seizures, and precocious puberty was seen in one. Severe mental retardation and behavioral disorders including aggressiveness were seen in two patients. The seizures were controlled in only one patient, in whom stereotactically targeted irradiation of the lesion was performed. This topology/symptom relationship was reconfirmed in a review of 61 reported cases of hamartoma, in which the MR findings were clearly described. The parahypothalamic type is generally associated with precocious puberty but is unaccompanied by seizures or developmental delay, whereas the intrahypothalamic type is generally associated with seizures. Two thirds of patients with the latter experience developmental delays, and half also exhibit precocious puberty. CONCLUSIONS: Classification of hypothalamic hamartomas into these two categories based on MR findings resulted in a clear correlation between symptoms and the subsequent clinical course.

Adolescent↗

PubMed1999

[A case of cerebral juvenile pilocytic astrocytoma: observation of the development of the tumor].

A case with cerebral juvenile pilocytic astrocytoma (JPA) was reported. The patient was 33-month-old boy, who developed headache and loss of activity on December, 1994. Although he was indicated macrocephaly at the age of just 1 year, CT scan showed no abnormality at that time. On admission, MRI revealed multiple large cysts with an enhanced mural nodule in the left frontal lobe. The tumor was totally removed, and histologically diagnosed as JPA, because of alternating two types of structures of loose knit tissue composed of satellite astrocytes and compact tissue consisting of highly fibrillate cells. MIB-1 percent positivity was almost negative. We summarized and discussed the clinicopathological and proliferating characteristics of the cerebral JPA. These considerations suggested that the tumor already existed at the age of 1 year and developed during these 20 months, according to the theory that the growth rate of JPAs is programmed to slow down as the patient grows.

Astrocytoma↗

PubMed1999

[The accuracy and reverse effects of thallium myocardial SPECT using adenosine triphosphate loading in the diagnosis of coronary artery disease: comparison with other loading methods semiquantitatively].

The adverse effects and diagnostic accuracy of thallium-201 myocardial SPECT after intravenous infusion of adenosine triphosphate (ATP) were studied and compared with SPECT examinations with other type of loading. The subjects of the study were 147 patients with or without coronary artery disease, who underwent some type of loading SPECT and coronary arteriography (CAG) within 30 days. Myocardial ischemia was evaluated qualitatively in SPECT and was compared with CAG for the diagnostic accuracy of coronary artery disease. The degree of myocardial uptake defect was also calculated semiquantitatively using visual scoring method and compared with coronary artery severity score. The adverse effects occurred in 46.7% of ATP loading SPECT which was more frequent than DIP loading SPECT, but all of them were transient and mild. As for the diagnostic ability, the ATP loading SPECT was as effective as other type of loading in qualitative interpretation, and the perfusion defect scores showed a good correlation with coronary artery stenosis grade. The myocardial SPECT using ATP is safe and useful for the diagnosis of coronary artery disease especially in patients who cannot exercise.

Adenosine Triphosphate↗

PubMed1998

Overproduction of recombinant Trichoderma reesei cellulases by Aspergillus oryzae and their enzymatic properties.

We have established an expression system of Trichoderma reesei cellulase genes using Aspergillus oryzae as a host. In this system, the expression of T. reesei cellulase genes were regulated under the control of A. oryzae Taka-amylase promoter and the cellulase genes were highly expressed when maltose was used as a main carbon source for inducer. The production of recombinant cellulases by A. oryzae transformants reached a maximum after 3-4 days of cultivation. In some cases, proteolysis of recombinant cellulases was observed in the late stage of cultivation. The recombinant cellulases were purified and characterized. The apparent molecular weights of recombinant cellulases were more or less larger than those of native enzymes. The optimal temperatures and pHs of recombinant cellulases were 50-70 degrees C and 4-5, respectively. Among the recombinant cellulases, endoglucanase I showed broad substrate specificities and high activity when compared with the other cellulases investigated here.

Aspergillus oryzae↗

PubMed1998

Demonstration of the optic pathway in sellar/juxtasellar tumours with visual disturbance on MR imaging.

OBJECTIVE: To prospectively compare the demonstration of the intracranial optic pathway in patients with sellar/juxtasellar tumours and with clinical evidence of visual disturbance using either spoiled gradient recalled acquisition in steady state (SPGR) or conventional spin echo (CSE) T1-weighted imaging. MATERIALS AND METHODS: We studied 108 patients with sellar/juxtasellar tumours presenting visual disturbance. Visualization of the optic pathway (nerves, chiasm, tracts) was compared between CSE T1-weighted coronal image and SPGR coronal image. In 18 patients, SPGR imaging was performed before and after administration of Gd-DTPA and visualization of the optic pathway was compared. RESULTS: On CSE T1-weighted coronal images of 108 patients with visual disturbance, the rates for visualization of the optic nerves, chiasms and tracts were 50%, 77.8% and 89.8% respectively. In contrast, on SPGR coronal image the rates were 80.6%, 96.3% and 92.6% respectively. The rates of visualization of the optic pathway were greater in non-enhanced that in those with enhancement. The rates of visualization in patients with recurrent tumours were less than those in patients with primary tumours. The rate of visualization of optic nerves in patients with meningioma was less than in patients with pituitary adenoma, craniopharyngioma or Rathke cleft cyst. CONCLUSION: The rate of visualization of optic pathway structures on SPGR imaging (without enhancement) is greater than that on CSE T1-weighted imaging. It is important to understand the accurate position of the optic pathways with using new MR modality especially in surgical planning for lesions around the sella turcica.

Adolescent↗

PubMed1998

Sympathetic skin responses recorded from non-palmar and non-plantar skin sites: their role in the evaluation of thermal sweating.

OBJECTIVE: To characterize the sympathetic skin responses (SSRs) recorded from non-palmar and non-plantar (non-Pa/P1) skin sites and to evaluate their clinical usefulness. METHODS: SSRs were recorded from 6 non-Pa/P1 sites as well as palmar and plantar (Pa/P1) sites using magnetic neck stimulation in 33 normal subjects, 17 neurological patients with dysautonomia and one patient with lumbar sympathectomy. A conventional thermoregulatory sweat test (TST) was also carried out in 3 patients. RESULTS: Clear and reproducible SSRs were obtained from all recording sites in all of the normal subjects when the skin temperatures of the subjects were maintained above 34 degrees C and the subjects drank 100-200 ml of hot water. The distribution of absent SSRs was closely correlated with that of anhidrosis or a sweating delay shown by the TST in the patients. Nine of the 17 neurological patients (53%) showed normal responses at Pa/P1 sites, and abnormal responses at non-Pa/P1 sites. CONCLUSIONS: Recording SSRs from multiple skin sites including non-Pa/P1 sites after magnetic stimulation is more sensitive in detecting sudomotor dysfunction than is the conventional method of recording SSRs from only Pa/P1 sites. In addition, this new method is very useful for the objective clinical evaluation of thermal sweating.

Adrenoleukodystrophy↗

PubMed1998

Age-dependent changes in physiological threshold asymmetries for the motor evoked potential and silent period following transcranial magnetic stimulation.

OBJECTIVE: To study the effect of age on the physiological threshold asymmetries for the motor evoked potential (MEP) and silent period (SP) following transcranial magnetic stimulation. METHODS: We studied 63 right-handed subjects and 13 young left-handed subjects (19-39 years). The right-handers were classified into three age groups; 22 young (20-38 years), 20 middle-aged (40-58 years) and 21 old (61-82 years) subjects. We measured the MEP thresholds at rest and during voluntary contraction (VC), and the SP thresholds from the right and left abductor pollicis brevis (APB) muscles. We also measured the side to side differences of the F wave persistency and the F wave/M wave amplitude ratio from the same muscles. RESULTS: Among young subjects, all of the MEP and SP thresholds for the right APB were significantly lower than those for the left APB in the right-handers, and the reverse was true in the left-handers. The results in the middle-aged right-handers were similar to those in the young right-handers, but in the old right-handers, none of the thresholds were different between the two sides. We did not find any asymmetries of the F wave in the subjects of any age group. CONCLUSION: We speculate that the age-dependent threshold asymmetries are preferentially related to functional asymmetries at the cortical level.

Adult↗

PubMed1998

Isolation of the gene and characterization of the enzymatic properties of a major exoglucanase of humicola grisea without a cellulose-binding domain.

An exoglucanase gene was cloned from a cellulolytic fungus, Humicola grisea. DNA sequencing of this gene, designated as exo1, revealed that it contained four introns in the coding region. The deduced amino acid sequence of EXO1 was 451 amino acids in length and showed 57.7% identity with that of H. grisea cellobiohydrolase 1 (CBH1), but lacked the typical domain structures of a cellulose-binding domain and a hinge region. Transcriptional analysis of the exo1 and cbh1 genes showed that the expression of these genes was induced by Avicel, and repressed in the presence of glucose. The exo1 gene was expressed in Aspergillus oryzae, and the recombinant EXO1 protein was purified. EXO1 and CBH1 produced by A. oryzae showed relatively higher activity toward Avicel, but showed much lower activity toward carboxymethyl cellulose (CMC) and p-nitrophenyl-beta-D-cellobioside (PNPC), than H. grisea endoglucanase 1 (EGL1). The addition of a cellulose-binding domain and a hinge region to EXO1 caused decreases in its enzymatic activities as well as the deletion of the cellulose-binding domain from CBH1. EXO1 showed relatively weak or no synergistic activity toward Avicel with H. grisea endoglucanases, but showed a significant level of apparent synergism with H. grisea CBH1 and Trichoderma reesei EGLI. CBH1 showed a significant level of apparent endo-exo synergism with H. grisea and T. reesei endoglucanases. H. grisea has at least two different types of major exoglucanase components and shows strong cellulolytic activity through synergism with cellulase components including EXO1 and CBH1.

Amino Acid Sequence↗

PubMed1998

Trans-sellar color Doppler ultrasonography during transsphenoidal surgery.

OBJECTIVE: To improve the safety and efficacy of transsphenoidal pituitary adenoma surgery, we investigated transsphenoidal intraoperative color Doppler ultrasonography using a biplane transducer system. METHODS: We studied 23 patients with pituitary adenomas (18 patients with macroadenomas and 5 patients with microadenomas) who underwent transsphenoidal surgery. The Hitachi EUB555 color Doppler ultrasound system (Hitachi Medical, Tokyo, Japan) was used with a pediatric biplane transesophageal echo cardiography probe (EUP-ES533, 7.5 MHz, biplane phased array sector probe, 9.8-mm tip). The probe was inserted into the saline-filled sphenoid sinus after the sellar floor was opened. Intra- and suprasellar images were obtained just before dural incision and after the tumor removal was thought to have been accomplished. RESULTS: In all patients, the tumor was depicted as a slightly hyperechoic mass, as compared with the cerebrum. Using color Doppler imaging, major cerebral arteries were depicted clearly in 74% of patients. The pituitary glands, pituitary stalks, and optic chiasms were observed in patients with small adenomas, but not when large adenomas were present. Cavernous sinus invasion, concomitant aneurysm, and residual tumor were clearly visualized. In patients with large adenomas, the end point of surgery was decided when there was an ultrasonographically demonstrated collapsed tumor capsule, subcapsular total vacancy, and reappearance of the optic chiasm. CONCLUSION: Trans-sellar color Doppler ultrasonography seems to be a useful intraoperative guiding system that may improve the safety and efficacy of transsphenoidal surgery.

Adenoma↗

PubMed1998

Isolation of the creA gene from the cellulolytic fungus Humicola grisea and analysis of CreA binding sites upstream from the cellulase genes.

A carbon catabolite repressor gene, creA, was isolated from the cellulolytic fungus Humicola grisea by using a portion of the Trichoderma reesei cre1 gene as a probe. The deduced amino acid sequence predicts a zinc finger protein of 419 amino acids in length, and its zinc finger regions show high similarity with those of Aspergillus CreAs, T. reesei Cre1, and Saccharomyces cerevisiae MIG1. Northern blot analysis showed that the H. grisea creA gene was highly transcribed when the mycelia were grown on glucose-containing media, but the transcription of the H. grisea endoglucanase 1 gene (egl1) and the exoglucanase 1 gene (exo1) were repressed under these conditions. Results of binding assays with the maltose-binding protein::CreA(1-166) fusion protein and the egl1 and the exo1 upstream regions showed that some 6-bp sites having an identical or similar sequence to the consensus sequence for CreA binding were protected from DNase I digestion.

Amino Acid Sequence↗