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Biomedical subjects

T Nose

Publications and source records attributed to T Nose.

At least 199 records · Page 11Linked to original sources
PubMed1995

Clinical application of diffusion-weighted magnetic resonance imaging to intracranial disorders.

Diffusion-weighted magnetic resonance imaging was performed to determine the changes in water diffusion and to investigate the detectability of diffusion anisotropy in patients with intracranial disorders. Diffusion maps of the apparent diffusion coefficient (ADC) were created of 19 patients with cerebral infarction, five with intracerebral hematoma, four with glioma, four with meningioma, four with hydrocephalus, and five with subdural hematoma. ADC was increased in chronic cerebral infarction and glioma, and decreased in acute cerebral infarction, meningioma, and the marginal area of glioma compared with the ADC of the normal gray matter. There was a significant difference in ADC between the marginal and internal areas of glioma. Increased ADC may be due to increased vasogenic edema in infarction and a lack of significant restriction of diffusion within glioma. Decreased ADC can be attributed to restricted diffusion caused by cytotoxic edema in infarction and the underlying histological pattern of densely packed tumor cells in glioma. Diffusion anisotropy of the internal capsule was less detectable in pathological than normal hemispheres. Diffusion anisotropy was less detectable in patients with hydrocephalus and subdural hematoma. Intracranial lesions were thought to have influenced the compression of the brain structures and cells, resulting in decreased diffusion. The measurement of ADC by diffusion-weighted magnetic resonance imaging has the potential for greater understanding of the biophysical changes in various intracranial disorders, including correct diagnosis of cerebral infraction, and histological diagnosis of brain tumor.

Adolescent↗
PubMed1995

Epidural hematoma associated with cephalohematoma in a neonate--case report.

A female neonate presented with cephalohematoma over the temporoparietal region on the right side. Computed tomography (CT) revealed the presence of an underlying epidural hematoma (EDH) and associated skull fracture with communication between the hematomas. Aspiration of the cephalohematoma was followed by reduction in the size of the EDH. CT revealed cure without the need for an operative procedure. Aspiration is indicated for neonatal EDH with mild symptoms and liquefied cephalohematoma.

Brain↗
PubMed1995

Non-radioactive mismatch analysis to detect small mutations in human hypoxanthine-guanine phosphoribosyl transferase cDNA.

We have combined a cDNA-driven PCR technique and a non-radioactive chemical-cleavage mismatch method, followed by a direct sequencing for detecting small mutations in the human hypoxanthine-guanine phosphoribosyl transferase (HPRT) gene. HPRT cDNA was synthesized by RT-PCR from 1,000 wild-type or HPRT(-) mutant cells. Wild-type cDNA was hybridized with mutant cDNA to form heteroduplexes. The resultant mismatched bases were modified and cleaved by base-specific chemicals, followed by analysis by denaturing polyacrylamide gel electrophoresis. Cleaved fragments were detected without using radioactive materials. Finally, direct sequencing of the PCR products was performed with a focus on a small limited region indicated by the mismatch analysis (focused sequencing). In this study, three small mutations in exon-3 of HPRT cDNA were detected and characterized completely with this system. As compared with the radioactive method, this system was shown to be very simple and efficient.

Base Sequence↗
PubMed1995

[Transient cerebellar mutism after removal of a posterior fossa tumor in two cases].

We have reported the cases of two young patients who presented transient mutism in the course of recovery from removal of a cerebellar medulloblastoma. Although cerebellar symptoms were observed immediately after surgery, neither consciousness disturbance nor sensory aphasia was observed when the patients were mutic. From the analysis of serial magnetic resonance imaging (MRI). Gd-enhanced regions were noticed in the dentate nucleus and the cerebellar peduncle when mutism appeared, and they disappeared when mutism was gone. Although the mechanism of this interesting symptom is not clear, these MRI findings may indicate that focal ischemia or edema associated with surgical procedure may play a role in the appearance of this symptom.

Adolescent↗
PubMed1995

[Low incidence of point mutation of N-ras oncogene in human gliomas].

We examined the incidence of point mutations in codon 12 and 61 of N-ras gene in human gliomas using PCR with mismatched primers. This method detects point mutations. PCR with mismatched primers induced restriction sites in normal DNA but not in mutational DNA. Genomic DNAs were extracted from paraffin-embedded tissues and were amplified with nested PCR. Among 17 cases, point mutation has not been able to be found so far, when examined in codon 12 of N-ras gene and among 10 cases in codon 61 of N-ras gene. It can thus be said that point mutational activation of N-ras oncogene is an uncommon event in human gliomas.

Base Sequence↗
PubMed1995

[Planning for brachytherapy using a 3D-simulation model].

A 3D-simulation model made with a milling system was applied to HDR-brachytherapy. The 3D-simulation model is used to simulate the 3D-structure of the lesion and the surrounding organs before the actual catheterization for brachytherapy. The first case was recurrent prostatic cancer in a 61-year-old man. The other case was lymph node recurrence of a 71-year-old woman's upper gum cancer. In both cases, the 3D-simulation model was very useful to simulate the 3D-conformation, to plan the treatment process and to avoid the risk accompanying treatment.

Aged↗
PubMed1995

[High dose rate fractionated interstitial radiotherapy for vulvar cancer using traction technique].

A 73-year-old woman with vulvar cancer T2NO was treated with high dose rate fractionated interstitial radiotherapy after 30 Gy of external radiotherapy. Sufficient space to insert 12 needles was made by pulling the vulva out perpendicular to the perineal skin. Four surgical threads were introduced between the vulva and the underlying pubic bones. A pair of custom-made templates were attached sandwiching the vulva pulled out with the threads. Using traction technique 12 stainless needles were easily inserted and replaced by plastic tubes. Forty Gy/10 fractions/six days was delivered, and the tumor has been controlled clinically and histologically so far.

Aged↗
PubMed1995

Overall time in telecobalt therapy for T1 glottic carcinoma treated with 2 Gy per day.

BACKGROUND/AIM: We already reported the tumor response during radiotherapy as a prognostic factor for T1 glottic carcinoma. In these reports, we did not evaluate the overall treatment time. There were many reports of correlation between local control and overall treatment time of radiation for head and neck cancer. Our aim was to evaluate the overall treatment time as a prognostic factor of the local control for T1 glottic carcinoma or not. PATIENTS AND METHODS: From 1967 through 1985, 295 patients of T1 glottic carcinoma were treated with telecobalt therapy at the Department of Radiology, Osaka University Medical School. Of 295 patients, 219 patients treated with 2 Gy per day were evaluated. The median of total doses was 60 Gy (42 to 72 Gy). Overall treatment times of patients with tumor clearance at 40 Gy were significantly shorter than those with tumor persistence at 40 Gy. RESULTS: According to the univariate analysis, there were no statistically significant factors for local control except tumor response during treatment. Of 124 patients treated with a total dose of 60 Gy and the overall treatment time of 40 to 46 days, local control rates of patients treated with the overall treatment time of 40 to 42 days and 43 to 46 days were 88% and 78%, respectively (p = 0.3072). For 91 patients with tumor clearance at 40 Gy, local control rates of patients treated with the overall treatment time of 40 to 42 days and 43 to 46 days were 96% and 82%, respectively (p = 0.1645). Corresponding figures for 31 patients with tumor persistence at 40 Gy were 63% and 65%, respectively (p = 0.4227). CONCLUSION: We compare the treatment results of patients treated with the same total dose and the same tumor response during radiotherapy. We concluded that the overall treatment time was not a prognostic factor for T1 glottic tumor treated with overall time of 40 to 46 days.

Carcinoma↗
PubMed1995

Human thrombin receptors are insensitive to thrombin-like snake venom enzymes.

Thrombin-like snake venoms enzymes, flavoxobin, and okinaxobin I isolated from Trimeresurus flavoviridis and Trimeresurus okinavensis, respectively, were examined in SH-EP cells and evaluated whether or not they can activate human thrombin receptors. Flavoxobin was almost completely inactive in both assays for phosphoinositide turnover and DNA synthesis. In contrast, okinaxobin I stimulated phosphoinositide turnover in a dose dependent manner, but considerably weakly. The EC50 value was about 100 nM, which was 4,000 times larger than that of alpha-thrombin. This stimulation was not inhibited by hirudin, an effective inhibitor of alpha-thrombin. Okinaxobin I also induced a very weak stimulation of DNA synthesis. These results suggest that thrombin-like snake venom enzymes interact with human thrombin receptors in inefficient ways. Weak interactions of the enzymes with thrombin receptor and inhibitor were ascribed to the incomplete formation of a lysine-cation cluster necessary for electrostatic molecular recognition.

Amino Acid Sequence↗
PubMed1995

Nuclear characterization and G2M ploidy in human brain tumors using semiautomated image analysis.

We used image analysis to study nuclear morphometry and DNA content in relation to time to tumor progression in a series of 88 patients with brain tumors. Clinical follow-up was obtained for 73 patients. The patients with diploid tumors had a longer time to tumor progression than those with triploid, tetraploid, or hypertetraploid tumors. Mean SG2M-DNA indices (DIs) increased significantly with a increase in mean DIs in all tumors. The mean DIs appeared to be dependent on the number of SG2M phase cells. We conclude that tumors with hypertetraploid in G2M ploidy are highly malignant. Those tumor cells have a large nuclear size, much deformity in nuclear shape, and great proliferative potential. The G2M-tetraploid tumors showed a shorter time to tumor progression when the number of SG2M fractions was large. In contrast, the G2M-hypotetraploid tumors showed a longer time to tumor progression in comparison with other tetraploid and hypertetraploid tumors, but the difference was not significant.

Aneuploidy↗
PubMed1994

Differential roles of two consecutive phenylalanine residues in thrombin receptor-tethered ligand peptides (SFFLRNP) in thrombin receptor activation.

A synthetic heptapeptide H-Ser-Phe-Phe-Leu-Arg-Asn-Pro-NH2, which corresponds to the ligand peptide latent in rodent thrombin receptors, was able to activate the thrombin receptor with no thrombin. In order to evaluate the structural requisites of two consecutive phenylalanines, three sets of analogs with substitutions at position either 2 or 3 were synthesized and examined for their stimulatory activity in phosphoinositide turnover in SH-EP epithelial-like cells. The replacement of Phe-2 by Ala completely eliminated the activity, while that of Phe-3 retained about 50% activity with a full stimulation. The Phe/Leu substitution resulted in a large increase (37-fold) in EC50 value for Phe-2, but in insignificant change for Phe-3. Substitution of para-fluorophenylalanine ((p-F)Phe) for Phe-2 enhanced strongly (4-fold) the activity, in contrast to a reduction by the Phe-3/(p-F)Phe substitution. Elimination of either Phe-2 or Phe-3 resulted in a complete loss of activity. These results indicated that Phe-2 and Phe-3 play different roles in the receptor activation. A highly specific aromatic phi-phi interaction was suggested between Phe-2-phenyl and thrombin receptor binding site, while Phe-3 appeared to be important for retaining a bioactive conformation.

Amino Acid Sequence↗
PubMed1994

Role of Src homology 3 domains in assembly and activation of the phagocyte NADPH oxidase.

The phagocyte NADPH oxidase, dormant in resting cells, is activated during phagocytosis to produce superoxide, a precursor of microbicidal oxidants. The activated oxidase is a complex of membrane-integrated cytochrome b558, composed of 91-kDa (gp91phox) and 22-kDa (p22phox) subunits, and two cytosolic factors (p47phox and p67phox), each containing two Src homology 3 (SH3) domains. Here we show that the region of the tandem SH3 domains of p47phox (p47-SH3) expressed as a glutathione S-transferase fusion protein inhibits the superoxide production in a cell-free system, indicating involvement of the domains in the activation. Furthermore, we find that arachidonic acid and sodium dodecyl sulfate, activators of the oxidase in vitro, cause exposure of p47-SH3, which has probably been masked by the C-terminal region of this protein in a resting state. The unmasking of p47-SH3 appears to play a crucial role in the assembly of the oxidase components, because p47-SH3 binds to both p22phox and p67phox but fails to interact with a mutant p22phox carrying a Pro-156-->Gln substitution in a proline-rich region, which has been found in a patient with chronic granulomatous disease. Based on the observations, we propose a signal-transducing mechanism whereby normally inaccessible SH3 domains become exposed upon activation to interact with their target proteins.

Amino Acid Sequence↗
PubMed1994

Hairpin loop and second kringle domain are essential sites for heparin binding and biological activity of hepatocyte growth factor.

Hepatocyte growth factor (HGF) has a strong affinity for heparin. About one fourth of HGF secreted from MRC-5 human embryonic lung fibroblast cells was found to be associated with heparin and heparan sulfate proteoglycan on the cell surface and extracellular matrix. To identify heparin-binding sites within the HGF molecule, we constructed variously deleted mutant HGFs and examined their binding ability to an immobilized heparin column. Native HGF and mutant HGFs, including d-K1 (deletion of the first kringle domain), d-K3 (deletion of the third kringle domain), d-K4 (deletion of the fourth kringle domain), d-beta (deletion of beta-chain), and HK1K2 (consisting of the N-terminal hairpin loop and the first two kringle domains), tightly bound to a heparin column, but d-H (deletion of the N-terminal hairpin loop) and d-K2 (deletion of the second kringle domain) markedly decreased binding ability to the column. These observations suggest that the N-terminal hairpin loop and the second kringle domain are essential for the heparin-binding of HGF. The finding that HK1K2 competed the binding of 125I-HGF to immobilized heparin provided additional evidence that the N-terminal half of HGF alpha-chain is the principal heparin-binding site. The hairpin loop in HGF possesses a cluster of basic amino acid residues and a highly positive net charge, when compared with hairpin loop structures in the other proteins, plasminogen and HGF-like protein. The second kringle domain in HGF has the basic amino acid cluster in the central region. Thus, it is likely that the basic clusters in these domains cooperatively contribute to the binding of HGF to the anionic heparin or heparan sulfate molecule.

Amino Acid Sequence↗
PubMed1994

MRI contrast enhancement by Gd-DTPA-monoclonal antibody in 9L glioma rats.

To achieve a tissue-specific enhancement in diagnosis of brain tumor, a magnetic resonance imaging (MRI) study was performed using conjugate of Gd-DTPA and monoclonal antibody (MoAb) against 9L glioma cells. Fisher 344 strain rats were used for this study. MoAb against 9L glioma cells was conjugated with Gd-DTPA according to the method of Hnatowich et al. (1983) and used for the MRI study. The gadolinium (Gd) concentration in the Gd-MoAb injected to the rats was 0.01-0.03 mmol/kg. The enhancement effect increased gradually and persisted for 24 hours after the injection. This was longer than Gd-DTPA, which showed a peak of enhancement effect within 30 minutes after injection and was washed out within 120 min. This result was compatible with scintigraphy studies using 125I labeled anti 9L monoclonal antibody, in which the accumulation of the 125I antibody increased at 24, 48 and 72 hours after the injection. By using tumor-specific contrast agents such as Gd-MoAb, it may be possible to differentiate among tumor, perifocal edema and radiation injury.

Animals↗
PubMed1994

Purification and characterization of a coagulant enzyme, okinaxobin II, from Trimeresurus okinavensis (himehabu snake) venom which release fibrinopeptides A and B.

A coagulant enzyme, okinaxobin I, which was purified from Trimeresurus okinavenis (himehabu snake) venom, released specifically fibrinopeptide B from fibrinogen to form fibrin clots. In the present study, its isozyme denoted as okinaxobin II has been purified to homogeneity from the same venom by chromatographies on Sephadex G-100, CM-Toyopearl 650M, and FPLC Mono-Q columns. Differently from okinaxobin I, okinaxobin II specifically cleaved fibrinopeptides A and B from fibrinogen similarly as found for alpha-thrombin. The enzyme acted on fibrinogen with specific activity of 42 NIH units/mg at optimum pH of 8.0. Okinaxobin II was a monomeric glycoprotein with a mol. wt of 37,500 on SDS-PAGE, which was reduced to 29,500 after treatment with N-glycanase. Okinaxobin II was much more basic (pI = 8.1) than okinaxobin I (pI = 5.4). The N-terminal sequence was highly similar to those of okinaxobin I and some other snake venom coagulant enzymes such as flavoxobin (Trimeresurus flavoviridis), batroxobin (Bothrops atrox and Bothrops moojeni), and catroxobin (Crotalus atrox). Okinaxobin II hydrolyzed tosyl-L-arginine methyl ester and benzoyl-L-arginine p-nitroanilide. The esterase activity was strongly inhibited by diisopropylfluorophosphate and to a lesser extent by tosyl-L-lysine chloromethyl ketone, indicating that the enzyme is a serine protease like alpha-thrombin. In terms of amino acid composition, okinaxobin II was similar to okinaxobin I and dissimilar to alpha-thrombin.

Amino Acid Sequence↗
PubMed1994

A case-control study of ulcerative colitis in Japan.

To determine whether risk factors of ulcerative colitis among Japanese are the same as those observed in other countries, we conducted a case-control study in Japan in 1988-90. Patients selected for the study were receiving financial aid for treatment of the disease; an equal number of population-based controls matched by age and sex were selected. Smoking decreased the risk of the disease (odds ratio = 0.30; 95% confidence interval, 0.16-0.56), and stopping smoking increased the risk (odds ratio compared with those who had never smoked = 1.44; 95% confidence interval, 0.73-2.85). In those who drank alcoholic beverages > or = 5 days a week, disease development was less likely than in others (odds ratio = 0.49; 95% confidence interval, 0.30-0.81). In addition, difficulties in human relations at work, a family history of asthma, a medical history of surgical procedures, and personality traits such as nervousness, anxiety, and obsessive behavior were also considered risk factors. Although some findings are similar to those in former studies, a few findings are different: surgical procedures, occupational status, and a family history of the disease. To clarify whether the differences are consistent will require other case-control studies.

Adult↗