Search PubMed⌕ Search

Biomedical subjects

T Kusaka

Publications and source records attributed to T Kusaka.

At least 37 records · Page 2Linked to original sources
PubMed2000

Effects of bilirubin and its photoisomers on direct bilirubin measurement using bilirubin oxidase.

We examined the reactivity of human serum albumin-bound bilirubin and its photoisomers as substrates for a direct bilirubin assay using bilirubin oxidase. The reduction of (EZ)-cyclobilirubin reached 100% 5 min after addition of the enzyme at any pH tested (3.5-7.4) in 0.1 mol/L phosphate buffer, whereas the reduction of (ZE)-bilirubin or (ZZ)-bilirubin reached 100% only below pH 4.5 or 5.5, respectively. (ZZ)-Bilirubin and its photoisomers did not react in citrate-lactate buffer at pH 3.7. The circular dichroism spectrum of (ZZ)-bilirubin in this buffer did not show a positive Cotton effect. These results indicate that a three-dimensional structure surrounding the reaction site of bilirubin is important for the reactivity with bilirubin oxidase.

Bilirubin↗
PubMed2000

[Histopathological diagnosis in reflux esophagitis].

We reviewed the histopathological features for the diagnosis of reflux esophagitis and gastroesophageal reflux disease(GERD) including carcinogenesis of the esophagus. Histologically, the presence of capillary dilatation, elongation of papillary, hyperplasia of basal layer, inflammatory cells-infiltration, balloon cells in the epithelium, and ulceration were evaluated in GERD cases. Although, histopathological changes were not clear in endoscopic-negative GERD cases, immunohistochemical examination with cell cycle protein(PCNA, p21, and p27) revealed the same abnormalities with GERD cases. In Japan, the majority cases of GERD are evaluated in grade according to Los Angeles system, therefore the prevalence of Barrett's esophagus and cancer is very low. We hypothesize that esophageal squamous cell carcinoma arising from GERD different from Barrett's cancer sequence, and clinicopathological long-term follow up will be required to assess the carcinogenesis including gene analysis.

Barrett Esophagus↗
PubMed2000

Prevention of lymphocyst formation following systematic lymphadenectomy.

BACKGROUND: The occurrence of pelvic lymphocysts is an important complication following systematic lymphadenectomy for gynecological malignancies. We employed a procedure to prevent vaginal shortening following radical hysterectomy and we examined whether this procedure could be effective in preventing pelvic lymphocyst formation. METHODS: We studied the incidence of lymphocysts in 190 patients with 84 cervical cancers, 74 endometrial cancers and 32 ovarian cancers, using computed tomographic examination at 3 and 6 months subsequent to the surgery. The surgery included radical hysterectomy and a procedure to prevent vaginal shortening (101), modified radical hysterectomy (79) and simple hysterectomy (7), with systematic lymphadenectomy. RESULTS: There was a significant difference in the incidence of pelvic lymphocysts between cervical cancer (4.8%) and ovarian cancer (18.8%). The postoperative incidence of lymphocyst formation in patients undergoing radical hysterectomy with the procedure to prevent vaginal shortening (5.9%) was significantly lower than in those who underwent modified radical hysterectomy (15.2%). CONCLUSION: Our procedure to prevent vaginal shortening could be effective in preventing not only the shortening of the vagina but also the occurrence of pelvic lymphocysts in patients undergoing radical hysterectomy with systematic lymphadenectomy for gynecological malignancies.

Adolescent↗
PubMed2000

Relationship between cyclooxygenase-2 expression and K-ras gene mutation in colorectal adenomas.

BACKGROUND AND AIMS: Cyclooxygenase (COX)-2 has a trophic effect on gastrointestinal epithelial cells and is associated with the progression of colorectal adenomas. Mutation of the K-ras gene is also associated with the progression of colorectal adenomas and has recently been suggested to play an important role in the induction of COX-2. In the present study, we investigated the relationship between COX-2 expression and K-ras mutation in colorectal adenomas. METHODS: Twenty-nine colorectal adenomas were obtained from specimens resected by the use of surgery or endoscopic mucosal resection and analyzed clinicopathologically. Immunohistochemistry was performed to analyze COX-2 expression in the adenoma specimens. The K-ras codon 12 mutations were detected by using the polymerase chain reaction-restriction fragment length polymorphism method. RESULTS: An increase of COX-2-positive cells in adenoma was observed in 11 (37.9%) lesions, 10 (90.9%) of which had a K-ras gene mutation, suggesting a significant correlation between COX-2 expression and K-ras gene mutation in colorectal adenomas. Morphologically, COX-2-positive adenomas (13.8 +/- 2.6 mm) were significantly larger than COX-2-negative ones (5.8 +/- 0.9 mm). In addition, the increase of COX-2-positive cells in the lesion was observed more frequently in tubulovillous (63.6%) than in tubular (36.4%) adenoma. CONCLUSIONS: Cycloxygenase-2 expression in colorectal adenoma cells is strongly correlated with K-ras gene mutation, suggesting that COX-2 and mutated K-ras are connectively associated with the progression of colorectal adenoma.

Adenoma↗
PubMed1999

Isolation, identification and determination of a magenta subsidiary colour in food blue no. 1 (brilliant blue FCF).

A magenta subsidiary colour was isolated from commercial Food Blue No. 1 (B-1; Brilliant Blue FCF). The absorption maximum for this subsidiary colour at 580 nm is outside of the range of 614-628 nm found for other subsidiary colours and m,m-B-1. On the basis of MS and NMR analyses, the structure of the subsidiary colour was elucidated as the disodium salt of 2-[[4-[N-ethyl-N-(3-sulphophenylmethyl)amino]phenyl][4-oxo- 2,5-cyclohexadienylidene]methyl]benzenesulphonic acid. HPLC analyses revealed that 24 batches of commercial Food Blue No. 1 (three manufacturers) contain 0.1-0.8% (average: 0.5%) of the magenta subsidiary colour.

Benzenesulfonates↗
PubMed1998

Functional magnetic resonance imaging during recognition of written words: Chinese characters for concrete objects versus abstract concepts.

An attempt was made to apply functional magnetic resonance imaging (fMRI) to reveal cortical areas activated upon presentation of two groups of Chinese characters in six normal right-handed, male, Japanese subjects. Presentation of the characters representing 'abstract concepts' activated the bilateral occipital region without a significant difference between the bilateral occipital and temporal regions. Presentation of the characters representing 'concrete objects' resulted in significantly stronger activation in the left occipital and temporal regions. These results suggest that recognition of concrete characters involves a stronger initial process in the left occipital temporal cortices than recognition of abstract characters.

Adult↗
PubMed1998

Functional magnetic resonance imaging during recognition of written words: Chinese characters for concrete objects versus abstract concepts.

An attempt was made to apply functional magnetic resonance imaging (fMRI) to reveal cortical areas activated upon presentation of two groups of Chinese characters in six normal right-handed, male, Japanese subjects. Presentation of the characters representing 'abstract concepts' activated the bilateral occipital region without a significant difference between the bilateral occipital and temporal regions. Presentation of the characters representing 'concrete objects' resulted in significantly stronger activation in the left occipital and temporal regions. These results suggest that recognition of concrete characters involves a stronger initial process in the left occipital temporal cortices than recognition of abstract characters.

Adult↗
PubMed1998

Activation of non-primary motor areas during a complex finger movement task revealed by functional magnetic resonance imaging.

We examined the brain activation induced by a complex finger movement task using functional magnetic resonance imaging (fMRI) with echo planar imaging (EPI). Imaging planes were set up for the observation of non-primary motor areas. Among five normal males examined, four subjects naive to the task showed activations in contralateral primary and supplementary motor areas and the ipsilateral superior anterior part of the cerebellar hemisphere. Also, the bilateral premotor areas and the contralateral ventrolateral nucleus of thalamus were occasionally activated. No changes were observed in the putamen and globus pallidus. The subject accustomed to the task showed activation in the narrow areas of the contralateral primary motor and supplementary motor and premotor areas but not in the cerebellum. These results suggest that fMRI has nearly the same degree of detectability to that of positron emission tomography (PET) in regard to motor functions.

Adult↗
PubMed1995

Effect of calcium antagonist, nicardipine, on cerebral blood flow in postasphyxial newborn piglets.

An experiment was carried out in nine piglets within 24 h after birth (control group: four, nicardipine group: five) for the purpose of evaluating the effects of a calcium antagonist, nicardipine, on cerebral blood flow changes induced by asphyxia neonatorum. Under respiratory control with a mechanical ventilator, the animals were exposed to hypoxia. The inspiratory oxygen level was lowered at 15 min intervals from 0.08 to 0.06 and then to 0.05. When bradycardia (heart rate; 60/min or less) was observed, 100% oxygen, adrenaline, and sodium bicarbonate were administered for resuscitation. Nicardipine was administered at a dosage of 10 micrograms/kg via bolus injection 30 min after the resuscitation. It was administered thereafter at a rate of 10 micrograms/kg per h. The cerebral blood flow was measured using a laser Doppler velocimeter. The cerebral blood flow, electroencephalograph (EEG), blood pressure, and heart rate were continuously measured for 120 min after the resuscitation. In the control group, the mean arterial pressure 35 min after the resuscitation was 60 mmHg or more. However, the cerebral blood flow was lower than the prehypoxia value in the animals with a mean arterial pressure of 75 mmHg or less. In the nicardipine group, the mean arterial pressure was lower, but the cerebral blood flow was higher than the prehypoxia value and cerebral ischemia was not induced. The mean arterial pressure 120 min after the resuscitation was 72.0 +/- 8.2 mmHg in the control group, while it was 56.7 +/- 7.5 mmHg in the nicardipine group. It was significantly lower in the latter.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Characterization of the DNA-binding state of the rat uterine estrogen receptor by UV cross-linking.

Characterization of the DNA-binding state of the rat uterine estrogen receptor was examined by UV cross-linking using [32P]5-bromo-2'-deoxyuridine-substituted 25-base pair synthetic oligonucleotide containing a Xenopus vitellogenin A2 estrogen response element (BrdUVRE). After UV irradiation of the receptor-BrdUVRE complexes, they were analyzed by SDS-polyacrylamide gel electrophoresis. In the nuclear estradiol-, ICI164, 384- and 4-hydroxytamoxifen-receptor complexes, the bands corresponding to the mobility of the receptor homodimer were observed. In a molybdate stabilized soluble receptor, we observed the bands with the slower mobility than the receptor homodimers.

Animals↗
PubMed1993

[Cerebrospinal fluid fistula following an operation of mediastinal schwannoma: a case report].

A 33-year-old man was operated for the mediastinal schwannoma. During the operation, the 9 th intercostal nerve was avulsed and revealed liquorrhea. Lyodura and fibrin glue was applied for sealing the site of dural defect. But post-operative course was not successful. So, we used the external cerebrospinal fluid drainage system. After this procedure, thoracic fluid from the chest tube was reduced and we could remove the chest tube in the 20th post operative day. This case indicates that in case of thoracotomy, it is difficult to expect easy closure of cerebrospinal fluid fistula under conservative therapy. Therefore it was considered that specific repair during the operation and spinal drainage in the post-operative early phase should be performed.

Adult↗
PubMed1992

Liquid chromatography-mass spectrometry of hydroxy and non-hydroxy fatty acids as amide derivatives.

A useful method for analyzing fatty acids by liquid chromatography-mass spectrometry with an atmospheric-pressure chemical-ionization interface system has been developed. The sensitivity of six kinds of palmitamide derivatives monitored by a single ion of [M+H]+ was, in decreasing order: N-n-propylamide greater than anilide greater than N,N-diethylamide, amide greater than N,N-diphenylamide greater than N-1-naphthylamide. Individual fatty acids were identified from a mixture of amide derivatives of authentic fatty acids from C16:0 to C30:0 on a mass chromatogram. This method was used to detect both hydroxy and non-hydroxy fatty acids. Many kinds of fatty acid, including hydroxy fatty acids of the rat brain, were detected in a single run.

Animals↗
PubMed1992

[A cardiodynamic study on cardio-assistive effect of the assist device: evaluation on left ventricular dehematizing system].

Of late years, assist artificial heart device has been more and more investigated with subsequent reports being made of its clinical application. Dehematization of left ventricular assist device (LVAD) is divided into two systems, i.e., left atrial dehematization and left ventricular dehematization according to the location of the canula's tip. At present in our country, the former system is being adopted for the majority of LVADs and is generally regarded as preferably acceptable. However, because of low survival rate of LVAD in spite of its comparatively good rate of break-away, not a few cases appear to exist beyond the limit of the former system's effects. Then, compared with the left atrial dehematizing system, LVAD according to the left ventricular dehematizing system was examined for its cardio-assistive effect both blood circulatorily and cardiodynamically. A pneumatically-driven diaphragm type pump was implanted between the left ventricular apex and the descending aorta of a dog and was driven by ECG-synchronous counterpulsation method with heart rate versus pump beating number ratios of 1:1, 2:1 and 4:1 and fixed beating number method with beating number of 60 and 80 beats/min (bpm). In order to measure the left ventricular diameter and myocardial length, 7 pairs of ultrasonic sonomicrometers were embedded intra-left ventriculomurally. Ischemia was prepared by ligating the left anterior descending coronary artery (LAD). Bulk mechanical work and regional mechanical work were calculated from these dimensions and the left ventricular pressure. The following results were obtained: 1) In all driving modes but that of 4:1, compared with non-driven pumping, heart rate, peak left ventricular pressure, mean left atrial pressure and total peripheral resistance showed low values, and mean aortic pressure and total blood flow showed high values. Moreover, in the above driving modes, total bypass was obtained. 2) In the above driving modes, bulk and regional mechanical works were practically null with a de-loading effect of 100% or so being obtained. 3) Compared with the left atrial dehematizing system, peak left ventricular pressure showed remarkably low value with increases in mean aortic pressure and total blood flow, and with remarkable decreases in bulk and regional mechanical works. 4) In driving modes of 2:1, 1:1, I60 and I80, little difference in the effect according to the driving mode was noted.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1992

[A case of middle lobar bulla associated with severe bronchial asthma].

We experienced a case of middle lobar bulla associated with severe bronchial asthma. Bulla occurs favoritely at apical area and S6, and middle lobar bulla which is very rare has been reported to cause higher ventilatory disorder compared with superior lobar bulla, when it becomes giant. The pathogenesis of the present middle lobar bulla remains unknown, but steroid administration to bronchial asthma may possibly have influenced pleura and/or lung parenchyma. We would like to make its further observation, paying attention to its possible recurrence and its occurrence at other sites.

Adult↗