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Biomedical subjects

T Uozumi

Publications and source records attributed to T Uozumi.

At least 73 records · Page 4Linked to original sources
PubMed1996

Analysis of Cre1 binding sites in the Trichoderma reesei cbh1 upstream region.

A 1.5-kb XbaI-SacII fragment containing the upstream region of the Trichoderma reesei cellobiohydrolase I gene (cbh1) has been sequenced. The 1.5-kb fragment contains eight 6-bp sites having an identical or similar sequence to the consensus sequence for binding a catabolite repressor, Aspergillus nidulans CreA. Results of binding assays with the maltose-binding protein::Cre1(10-131) fusion protein (Cre1 is a catabolite repressor of T. reesei) and the cbh1 upstream region revealed that a 504-bp XbaI-NspV fragment (nucleotide position -1496 to -993) bearing three 6-bp sites, A1, A2, and A3, and a 356-bp NspV-MunI fragment (nucleotide position -994 to -639) bearing three 6-bp sites, B1, B2, and B3, were shifted in the electrophoretic mobility shift assay. DNase I footprinting experiments showed that the 6-bp sites A2, B1, B2, and B3 were protected from DNase I digestion.

Base Sequence↗
PubMed1996

Cloning, sequencing, and expression of the cellulase genes of Humicola grisea var. thermoidea.

We have cloned an endoglucanase (EGI) gene and a cellobiohydrolase (CBHI) gene of Humicola grisea var. thermoidea using a portion of the Trichoderma reesei endoglucanase I gene as a probe, and determined their nucleotide sequences. The deduced amino acid sequence of EGI was 435 amino acids in length and the coding region was interrupted by an intron. The EGI lacks a hinge region and a cellulose-binding domain. The deduced amino acid sequence of CBHI was identical to the H. grisea CBHI previously reported, with the exception of three amino acids. The H. grisea EGI and CBHI show 39.8% and 37.7% identity with T. reesei EGI, respectively. In addition to TATA box and CAAT motifs, putative CREA binding sites were observed in the 5' upstream regions of both genes. The cloned cellulase genes were expressed in Aspergillus oryzae and the gene products were purified. The optimal temperatures of CBHI and EGI were 60 degrees C and 55-60 degrees C, respectively. The optimal pHs of these enzymes were 5.0. CBHI and EGI had distinct substrate specificities: CBHI showed high activity toward Avicel, whereas EGI showed high activity toward carboxymethyl cellulose (CMC).

Amino Acid Sequence↗
PubMed1996

Cloning, sequencing and transcriptional regulation of the draT and draG genes of Azospirillum lipoferum FS.

From Azospirillum lipoferum (Al) FS, a nitrogen-fixing bacterium isolated from the rhizosphere of rice, we cloned and sequenced draT, encoding dinitrogenase reductase ADP-ribosyltransferase, and draG, encoding dinitrogenase reductase-activating glycohydrolase. The nucleotide sequences of draTG showed extensive similarity to the same genes from Azospirillum brasilense, Rhodospirillum rubrum and Rhodobacter capsulatus, and they are assumed to be co-transcribed as a single operon. When this draTG operon was introduced into Klebsiella oxytoca, this organism acquired the ability to respond to extracellular NH(+4) ions with reversible inhibition of nitrogenase activity, similar to that seen in Al FS. We constructed a plasmid containing a draT::lacZ gene fusion and found that beta-galactosidase activity was detected under microaerobic conditions, regardless of NH(+4) concentration, but not under aerobic conditions. This indicates that the transcription of draTG responds to the level of oxygen, but not to that of NH(+4) ions.

ADP Ribose Transferases↗
PubMed1996

Diagnosis of carotid-cavernous fistulas with magnetic resonance angiography--demonstrating the draining veins utilizing 3-D time-of-flight and 3-D phase-contrast techniques.

This study assessed the ability to diagnose carotid-cavernous fistulas (CCFs) non-invasively using magnetic resonance angiography (MRA). Both three-dimensional time-of-flight (3-D TOF) MRA and three-dimensional phase-contrast (3-D PC) MRA were compared with conventional cerebral angiography in nine patients with CCFs. CCFs were grouped according to Barrow's classification. In all cases, 3-D TOF MRA revealed an inferior petrosal sinus as a draining vein. 3-D PC MRA demonstrated a dilated and tortuous superior ophthalmic vein (SOV) and reflux of the SOV in seven patients. In conclusion, CCFs can be diagnosed with MRA alone by demonstrating the drainging veins.

Adult↗
PubMed1996

Matrix metalloproteinase-9 secretion by human pituitary adenomas detected by cell immunoblot analysis.

Twenty-two pituitary adenomas were examined on the secretion of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) using a cell immunoblot assay, and discussed regarding an association between cavernous sinus invasion and the secretion of these proteins. The cell immunoblot assay, a kind of immunoblot procedure, is able to detect proteins at the single cell level and to detect the incidence of tumour cells secreting the target proteins in the total tumour cell population. The incidence of tumour cells secreting MMP-9 was significantly higher in invasive adenomas than in noninvasive ones. On the other hand, TIMP-1 secretion was not detected in any adenomas in this study. This result suggested that MMP-9 secretion, and especially the number of MMP-9-secreting cells, may be associated with cavernous sinus invasion of pituitary adenomas.

Adenoma↗
PubMed1996

Type IV collagenase activity and cavernous sinus invasion in human pituitary adenomas.

Pituitary adenomas are regarded generally as benign tumours, but some of them can invade the cavernous sinus. On the other hand, matrix metalloproteinase-9 (MMP-9), which is a type IV collagenase, recently has been found to be expressed in matastases and to be related to the invasiveness of various malignant tumours including brain tumours. In order to investigate some characteristic features of pituitary adenomas which invade the cavernous sinus, we examined immunohistological studies for MMP-9 in seven pituitary adenomas for type IV collagen in a dura mater and assayed for type IV collagenase activity in seven adenomas using type IV collagen labelled with fluorescein isothiocyaniate (FITC). We found immunopositive adenoma cells for MMP-9 in all invasive adenoma and immunopositive spindle like cells for type IV collagen in the dura mater. All three invasive adenomas had high levels of type IV collagenase activity (0.57-0.72 U/ml), but the four adenomas which did not invade the cavernous sinus had low levels of type IV collagenase activity (0.0-0.10 U/ml). These results suggest that the level of type IV collagenase activity in a pituitary adenoma may be related to its ability to invade the cavernous sinus.

Adenoma↗
PubMed1996

Isolation and characterization of the nuclease O gene (nucO) from Aspergillus oryzae.

Nuclease O in the mycelia of Aspergillus oryzae has been purified 55-fold by successive steps of chromatography from the filtrate of the autolyzate. The molecular mass of nuclease O was 32 kDa, as estimated by SDS polyacrylamide-gel electrophoresis. The nuclease O gene (nucO) encoding this enzyme was cloned and sequenced. The open reading frame is interrupted by four introns with conserved splice sites and contains 328 amino-acid residues of the mature enzyme. A. nidulans transformants obtained by introduction of the cloned nucO gene produced 2.5-times as much nuclease O as the wild-type strain, showing that the cloned DNA fragment encodes nuclease O.

Amino Acid Sequence↗
PubMed1996

Endoscopic resection of intraventricular ependymal cyst presenting with psychosis.

BACKGROUND: Intracranial ependymal cysts are rare lesions generally located in the cerebral parenchyma, juxtraventricular region, or subarachnoid space; but no case of a purely intraventricular ependymal cyst has been reported. CASE REPORT: A case of intraventricular ependymal cyst presenting with symptoms of psychosis is reported. The patient's symptoms resolved almost completely following endoscopic resection of the cyst. The embryologic basis of the development of an ependymal cyst inside the ventricle and its histologic characteristics are discussed. Possible mechanism of psychosis in this case is also discussed. CONCLUSION: Minimally invasive techniques, as in this case, may be useful in refractory psychotic cases with cystic lesions.

Adult↗
PubMed1996

New approach for the treatment of medulloblastoma by transfection with glial fibrillary acidic protein gene.

Glial fibrillary acidic protein (GFAP) is one of the intermediate filaments found in mature normal astrocytes and differentiated glioma cells. It seems to be able to stabilize the cytoskeleton of the astrocyte and may play a role in maintaining astrocyte cell shape, in association with other cytoskeletal components such as microfilaments and microtubles. However, its tissue-specificity remains unclear. To clarify the effect of GFAP expression in brain tumour cells, transfer of the GFAP gene into the human medulloblastoma cell line, DAOY-1 (which does not express GFAP) was carried out using liposomes. Upon transfection, we observed the alterations in the characteristics of GFAP transfected cells. Cell growth, morphology and sensitivity to anticancer drugs were compared between GFAP gene transfected DAOY-1 and control DAOY-1 cells. Growth inhibition and increase of sensitivity to anticancer drugs were observed with GFAP expression in GFAP gene-transfected DAOY-1 cells. However, no morphological changes were noted.

Brain Neoplasms↗
PubMed1996

Experimental studies of the antitumor effect of TNP-470 on malignant brain tumors. Antitumor effect of TNP-470 on a human medulloblastoma xenograft line.

It has been shown that angiogenesis plays an important role in pathological conditions including the growth of solid tumors. Furthermore, it is thought that anti-angiogenic agents might be clinically useful for therapy of these diseases. TNP-470 (TNP), a synthetic analog of fumagillin isolated from Aspergillus fumigatus, was used as an anti-angiogenic agent in this study in a nude mouse model with a subcutaneously implanted fragment of medulloblastoma. After treatment with this agent for 4 weeks, the inhibition rates of tumor growth were as follows: 15.9% in the group given 1 mg/kg, 16.9% with 10 mg/kg, 29.6% with 30 mg/kg, 49.9% with 50 mg/kg and 65.7% with 100 mg/kg. TNP inhibited the growth of brain tumor dose-dependently and induced various ischemic changes within the tumor tissue. Therefore, TNP may be effective for the treatment of malignant brain tumors such as medulloblastoma.

Animals↗
PubMed1996

Ipsilateral hemiplegia caused by right internal capsule and thalamic hemorrhage: demonstration of predominant ipsilateral innervation of motor and sensory systems by MRI, MEP, and SEP.

A patient with a right internal capsule and thalamic hemorrhage showed ipsilateral hemiplegia. MRI at 10 months after the cerebral hemorrhage demonstrated Wallerian degeneration, which could be traced to the ipsilateral anterior funiculus at the cervical level. The findings of motor evoked potentials and somatosensory evoked potentials indicate a predominantly ipsilateral innervation of motor and sensory systems in this particular patient.

Cerebral Hemorrhage↗
PubMed1996

Cloning of a gene encoding a putative carbon catabolite repressor from Trichoderma reesei.

We report the cloning and sequencing of a Trichoderma reesei genomic DNA clone that encodes a protein similar to the Aspergillus CREA, a carbon catabolite repressor. The deduced amino acid sequence predicts a zinc finger protein of 402 amino acids in length. The overall amino acid sequence of the T. reesei CREA shows about 52% similarity with Aspergillus CREAs.

Amino Acid Sequence↗
PubMed1996

Effect of surgery on gonadal function of premenopausal women with pituitary adenomas other than prolactinomas.

The effects of surgery on pituitary-gonadal function were investigated in women with pituitary adenomas other than prolactinomas. The subjects were 46 women of premenopausal age with a pituitary adenoma. Twenty tumors were GH producing, 19 were nonfunctioning, and 7 were adrenocorticotropin producing adenomas. The surgery was performed mainly via the transsphenoidal route, with the aim of eradicating the tumor and preserving pituitary function. The menstrual cycle was preserved postoperatively in 9 out of 10 (90%) patients with regular preoperative menstruation. Menstrual disturbance was seen in 36 (78.3%) cases preoperatively. The causative factors for menstrual disturbance were gonadotropin impairment and hyperprolactinemia in GH producing and nonfunctioning adenoma. Excessive hormonal secretion itself is a major causative factor for menstrual disturbance in GH and ACTH producing adenoma. Regular menstruation was restored following surgery in 20 out of 36 (55.6%) patients with menstrual problems. The predicting factors for postoperative recovery of menstruation are: size of adenoma less than 40 mm, period of amenorrhea less than 5 years, and preoperatively preserved gonadotropin secretion. In addition, preoperative hyperprolactinemia was also a predicting factor in women with nonfunctioning adenoma. Thus, even in patients with pituitary adenomas other than prolactinoma, the restoration of menstruation is highly achievable when surgery is performed with attention to preserving pituitary function.

Adenoma↗
PubMed1996

Effects of surgery on testosterone secretion in male patients with pituitary adenomas.

The purpose of this study was to assess the effect of surgery on gonadal function in 42 male patients with pituitary adenomas Gonadal functions were evaluated by measuring total serum testosterone concentrations pre- and postoperatively. The subjects of the study were 20 patients with GH secreting adenoma, 7 patients with prolactinoma and 15 patients with nonfunctioning (NF) adenoma. Their ages ranged from 18 to 60 years (mean +/- SEM, 41 +/- 1.9). The serum testosterone concentration was low at less than 300 ng/dl preoperatively in 14 of 20 patients (70%) with GH producing adenoma, 6 of 7 patients (86%) with prolactinoma, and 7 of 15 patients (47%) with NF adenoma. Postoperatively, the total serum testosterone concentration was normalized in 9 of 14 patients (64%) with GH producing adenoma, one of 6 patients (17%) with prolactinoma, and 5 of 7 patients (71%) with NF adenoma. The normalization of serum GH and prolactin concentrations is indispensable for the restoration of gonadal function. It is very important to preserve the normal preoperative gonadotropin secretion by means of gentle surgery.

Adenoma↗
PubMed1996

[Indication of early surgery in elderly patients with ruptured intracranial aneurysms--the comparison between surgical and conservative therapy].

The purpose of this study was to investigate the indication of direct early surgery for elderly cases aged over 70 years with ruptured intracranial aneurysms. The result of early surgical treatment in 39 elderly cases was analyzed and was compared with that of conservative treatment in 39 elderly patients. According to the multiple logistic analysis, surgery was only significant factor influenced the outcome, however, Hunt & Kosnik grade (HKG), activity of daily life (ADL) before subarachnoid hemorrhage (SAH) and past history were related to the outcome. The outcome in the direct early surgical group statistically correlated (p < 0.05) with preoperative HKG, although the outcome in the conservative group did not correlate with HKG. The outcome in conservative group was miserable because of rerupture or poor preoperative neurological grade. The indication of direct early surgery for elderly cases with ruptured intracranial aneurysms should be considered as follows, HKG 1 to 3, ADL before SAH 1, no or minor past history and age under 84 since most elderly patient was 84 in our series. Direct early surgery in elderly patients seems to improve the outcome under these indications.

Activities of Daily Living↗
PubMed1996

Mesenchymal chondrosarcoma in anterior skull base: case report.

We report the case of a 16-year-old boy who presented with mesenchymal chondrosarcoma involving the ethmoid sinus, right orbit, nasal cavity, and anterior cranial fossa. The tumor was totally resected by craniofacial surgery; the patient's postoperative course was uneventful. Microscopically, the tumor was composed of highly cellular undifferentiated small cells, alternating with zones of cartilaginous tissues. Mesenchymal chondrosarcoma is a rare, aggressive variant of chondrosarcoma, which might be encountered more frequently due to the advances in neuroimaging and surgical procedures.

Adolescent↗
PubMed1995

[Treatment of hypothalamic-pituitary tumors--experiences at Hiroshima University School of Medicine].

Hypothalamic-pituitary tumors are unique tumors which are present with various disorders of the cerebrum, cranial nerve, and endocrine system, and which critically ruin the patients' quality of life. However, during the past two decades, hypothalamic-pituitary tumor treatment has developed dramatically. The curative method of the pituitary adenoma had not yet been introduced in the mid-1970s, but was accomplished several years after and spread rapidly through out the world. The main contributors which led to this development were the introduction of micro-neurosurgery (including transsphenoidal surgery), the development of new imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI), and the introduction of newer, more effective medicine. Other kinds of hypothalamic-pituitary tumor are also being cured by function-oriented surgery, drugs, and radiation therapy, which give the long-term useful life to patients. Regrettably, there are some malignant tumors which still resist to any multidisciplinary remedy. Efforts to prolong the useful lives of patients with malignant hypothalamic-pituitary tumors and also to improve the quality of life of patients with benign tumors should be continued. The most important point in managing hypothalamic pituitary tumors is to focus on "patient-oriented treatment" tailoring treatment to individual symptoms and needs.

Adenoma↗