Biomedical subjects

T Nakakuki

Publications and source records attributed to T Nakakuki.

At least 19 recordsLinked to original sources

PubMed2006

Inflammatory reaction following cataract surgery and implantation of acrylic intraocular lens in rabbits with endotoxin-induced uveitis.

PURPOSE: To investigate whether inflammatory responses are more severe in uveitic eyes than nonuveitic eyes when acrylic intraocular lens (IOL) is implanted after cataract surgery. METHODS: Clear lens removal (phacoemulsification and aspiration) was conducted and the hydrophobic acrylic IOL (AR40e, AMO) was implanted in adult albino rabbits. Just after the operation, rabbits were divided into two groups. One group (nine rabbits) received intravitreal injection of lipopolysaccharide (LPS, 200 ng/10 microl) into both eyes to induce endotoxin-induced uveitis (EIU) and the other group (nine rabbits) received intravitreal injection of phosphate-buffered saline (PBS, 10 microl) into both eyes as the control. Aqueous humour (AH) and IOLs were harvested 1, 3 , and 7 days after the intravitreal injection. The infiltrating cell number in AH was counted and the protein concentration of AH was measured. IOLs were evaluated morphologically. RESULTS: At 1 day after intravitreal injection, both the infiltrating cell number in AH and protein concentration of AH were significantly higher in the LPS-injected group than in the PBS-injected group. Similarly, more inflammatory cells attached to the surfaces of the IOLs in the LPS-injected group. However, 7 days later, inflammatory reactions subsided and no clear differences in any of the parameters examined were observed between the two groups. CONCLUSIONS: At 7 days after the operation, inflammatory reactions in eyes implanted with the hydrophobic acrylic IOLs were similar in uveitic eyes and nonuveitic eyes. The data suggest that the hydrophobic acrylic IOLs may be suitable for patients with uveitis.

Acrylic Resins↗

PubMed2005

Surgical treatment for bilateral carotid arterial stenosis.

Carotid endarterectomy (CEA) is a beneficial procedure for patients with high-grade carotid stenosis. However, patients with bilateral carotid stenosis have a higher surgical risk during CEA. Since the introduction of carotid stenting (CAS) may decrease some of the surgical complications of CEA, a combined treatment using CEA and CAS may be favorable for patients with bilateral carotid stenosis. We analyzed the safety and efficacy of this treatment strategy. Eighteen patients with bilateral carotid stenosis were treated from January 2000. Bilateral CEA was performed on the first two patients, CAS then CEA of contra-lateral symptomatic side in 13 patients, and bilateral CAS in three patients. There were no perioperative neurological complications or strokes during the follow-up period (mean 17 months). The combined treatment of CAS and CEA was a safe and effective strategy for bilateral carotid stenosis.

Aged↗

PubMed2005

Stenting for vertebrobasilar artery stenosis.

We report our experience with stenting for symptomatic vertebrobasilar artery stenosis. One hundred and sixteen patients with vertebrobasilar artery stenosis (101 vertebral ostial stenosis, 15 intracranial vertebrobasilar artery stenosis) were treated with stenting. Indication criteria of treatment were 1) symptomatic lesion, 2) angiographical stenosis more than 60%. Under local anesthesia, pre-dilatation was first performed, then stents were placed to the lesion. Successful dilatation was obtained in 115 cases. The stenosis rate reduced to 2% post-stenting in ostial lesions and 16% in intracranial lesions. Transient neurological complications developed in 2 patients. Follow-up angiographies more than 6 months after stenting were performed in 94 patients with ostial lesions and all patients with intracranial lesions. Of these, 8 patients (9.5%) with ostial lesions and 4 patients (27%) with intracranial lesions developed restenosis. All patients with restenosis were treated successfully with PTA (percutaneous transluminal angioplasty). During the follow-up period, 3 patients developed recurrence of VBI (vertebro-basilar insufficiency) symptoms due to restenosis. One patient developed brain stem infarction due to in-stent occlusion 8 months after stenting. Conclusion. Stenting for vertebrobasilar artery stenoses is feasible and safe. Prevention of restenosis, especially in intracranial arteries, is the next problem to be solved.

Aged↗

PubMed1997

[Localization of the pyramidal tract in the internal capsule: relationship between CT classification of thalamic hemorrhage and motor weakness].

To better understand the pyramidal tract of the internal capsule, we evaluated the relationship between the localization of thalamic hemorrhage and motor weakness. On an axial CT scan at the level of the pineal body, two lines were drawn as follows: line-a between the lateral edge of the anterior horn and the lateral edge of the trigone, line-b vertical to the sagittal line and passing the midpoint of the third ventricle. The location of the hematoma was classified into three types according to localization of the center of the hematoma and lateral extension beyond line-a as follows: type A (anterior), type P (posterior) and type PL (postero-lateral). Discrepancy of motor weakness between upper extremities and lower extremities was higher in patients with hematoma of type P and type PL (p < 0.05) than in those with hematoma of type A. Improvement of motor weakness on discharge was higher in patients with type P (p < 0.01) than in those with type A. We concluded that most of the pyramidal tract fibers were located in the third quarter of the posterior limb of the internal capsule but a small number of pyramidal tract fibers were located in the anterior two-thirds of it. A greater number of cortico-spinal fibers to the upper extremities than to the lower extremities occupy the third quarter of the posterior limb of the internal capsule.

Adult↗

PubMed1995

Enzymatic synthesis of novel fructosyl and oligofructosyl trehaloses by Aspergillus sydowi beta-fructofuranosidase.

An intracellular beta-D-fructofuranosidase produced by Aspergillus sydowi IAM 2544 was purified by Q-Sepharose and Alkyl-Sepharose chromatographies. The molecular mass was 50 kDa by SDS-PAGE analysis. The optimum pH and temperature of sucrose hydrolyzing activity of the enzyme were 5.5 and 75 degrees C, respectively, but those of fructosyl transferase activity were 5.2 and 55 degrees C, respectively. The enzyme efficiently transferred the fructose residue of sucrose as a donor to trehalose as an acceptor. And the amount of fructosyl and oligofructosyl trehaloses produced was changed by the molar ratio of trehalose as an acceptor to sucrose as a donor used. The most efficient production of the transferred products was achieved at the reaction conditions in the range of molar ratios of 1:1 to 3:1 (trehalose:sucrose). The chemical structures of these new kinds of resulting series of fructosyl and oligofructosyl trehaloses produced were identified as O-beta-D-Fru-(2-->6)-alpha-D-Glc-(1-->1)-alpha-D-glucopyranoside, O-beta-D-Fru-(2-->6)-alpha-D-Glc-(1-->1)-alpha-D-glucopyranoside, and O-beta-D-Fru-(2-->1)-O-beta-D-Fru-(2-->1)-O-beta-D-Fru-(2-->6)-alpha-D-G lc- (1-->1)-alpha-D-glucopyranoside. These results indicate that beta-fructofuranosidase from Aspergillus sydowi specifically transferred the fructose residue of sucrose to the C6-OH position of the glucose residue of trehalose at the early stage of the reaction, following the elongation of the fructose residue by the transfructosylation of the enzyme to form oligofructosyl trehalose of a longer fructose chain.

Aspergillus↗

PubMed1991

Usefulness of the pulse oximeter as a respiratory monitor during intravenous sedation.

During intravenous sedation, the pulse oximeter was applied as a respiratory monitor to 17 patients (Physical status classification of the American Society of Anesthesiologists, Class I-II) who were to have oral surgical operations, and the changes in arterial saturation of oxygen (SaO2) was observed consecutively. SaO2 dropped after administration of sedative agents in each case; there was some individual variation. Respiratory depression during sedation was evaluated from arterial blood gas analysis. The reduction in SaO2 caused by surgical manipulations was also noted. Furthermore, arterial partial pressures of oxygen (PaO2) and saturation calculated from PaO2 (SAT) measured from blood gas analysis were compared with SaO2 measured by the pulse oximeter. Both PaO2 and SAT correlated well with SaO2. The differences between SAT and SaO2 exceeded the range of error (+/- 2%) in many cases after the administration of sedative agents. These results suggest that the pulse oximeter is useful as a respiratory monitor during oral surgery. However, the pulse oximeter gives incorrect SaO2 readings in the presence of abnormal hemoglobin due to medication with nitrites or smoking habit.

Anesthesia, Dental↗

PubMed1990

Enzymatic synthesis of p-nitrophenyl alpha-maltoheptaoside by transglycosylation of maltohexaose-forming amylase.

An extracellular maltohexaose-forming amylase [EC 3.2.1.98] from Klebsiella pneumoniae mutant is a normal hydrolytic enzyme that hydrolyzes short-chain amylose (DP = 23) to give about 40% maltohexaose. Transglycosylation from maltoheptaose to the 4-position of p-nitrophenyl alpha-glucoside was efficiently induced through the use of maltohexaose-forming amylase in an aqueous methanol solution. The enzyme specifically produced p-nitrophenyl alpha-maltoheptaoside (13% of the p-nitrophenyl alpha-glucoside) from maltoheptaose as a donor and p-nitrophenyl alpha-glucoside as an acceptor. The yield of p-nitrophenyl alpha-maltoheptaoside depended on the concentration of methanol solvent, the pH, and temperature. Furthermore, the use of the aqueous methanol system in the reaction not only improved the solubility of p-nitrophenyl alpha-glucoside but also greatly increased the formation of p-nitrophenyl alpha-maltoheptaoside, which is a useful substrate for assay of human amylase in serum and urine.

Chromogenic Compounds↗

PubMed1982