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Biomedical subjects

T Takagi

Publications and source records attributed to T Takagi.

At least 91 records · Page 5Linked to original sources
PubMed2001

Folding units in calcium vector protein of amphioxus: Structural and functional properties of its amino- and carboxy-terminal halves.

Muscle of amphioxus contains large amounts of a four EF-hand Ca2+-binding protein, CaVP, and its target, CaVPT. To study the domain structure of CaVP and assess the structurally important determinants for its interaction with CaVPT, we expressed CaVP and its amino (N-CaVP) and carboxy-terminal halves (C-CaVP). The interactive properties of recombinant and wild-type CaVP are very similar, despite three post-translational modifications in the wild-type protein. N-CaVP does not bind Ca2+, shows a well-formed hydrophobic core, and melts at 44 degrees C. C-CaVP binds two Ca2+ with intrinsic dissociation constants of 0.22 and 140 microM (i.e., very similar to the entire CaVP). The metal-free domain in CaVP and C-CaVP shows no distinct melting transition, whereas its 1Ca2+ and 2Ca2+) forms melt in the 111 degrees -123 degrees C range, suggesting that C-CaVP and the carboxy- domain of CaVP are natively unfolded in the metal-free state and progressively gain structure upon binding of 1Ca2+ and 2Ca2+. Thermal denaturation studies provide evidence for interdomain interaction: the apo, 1Ca2+ and 2Ca2+ states of the carboxy-domain destabilize to different degrees the amino-domain. Only C-CaVP forms a Ca2+-dependent 1:1 complex with CaVPT. Our results suggest that the carboxy-terminal domain of CaVP interacts with CaVPT and that the amino-terminal lobe modulates this interaction.

Amino Acid Sequence↗
PubMed2001

Plantar verrucous carcinoma: report of a case treated with Boyd amputation followed by reconstruction with a free forearm flap.

Verrucous carcinoma is a relatively rare, well-differentiated, squamous cell carcinoma. Although it is slow-growing and mimics benign skin lesions, it can cause extensive local destruction that necessitates amputation. It is often underdiagnosed as a benign tumor in its early course. We report a case of extensive verrucous carcinoma on a recalcitrant ulcer and a severe long-standing scar around it on the sole of the right forefoot, which had been treated as a benign tumor for more than two years. We treated it successfully with amputation of the foot and were able to spare the heel by using a free innervated forearm flap to cover the defect at the stump. The present case should remind clinicians that a verrucous lesion developing on a refractory ulcer may be a complex malignant neoplasm; an accurate diagnosis is difficult without a combination of clinical features and pathological findings from an adequately deep specimen.

Amputation, Surgical↗
PubMed2001

Mouse chromosome 19 and distal rat chromosome 1: a chromosome segment conserved in evolution.

Through a combination of radiation hybrid mapping and studies by FISH and zoo-FISH we have made a comparative investigation of the distal portion of rat chromosome 1 (RNO1) and the entire mouse chromosome 19 (MMU19). It was found that homologous segments of RNO1 and MMU19 are similar in banding morphology and in length as determined by several different methods, and that the gene order of the 46 genes studied appears to be conserved across the homologous segments in the two species. High-resolution zoo-FISH techniques showed that MMU19 probes highlight only a continuous segment on RNO1 (1q43-qter), with no detectable signals on other rat chromosomes. We conclude that these data suggest the evolutionary conservation of a chromosomal segment from a common rodent ancestor. This segment now constitutes the entire MMU19 and a large segment distally on RNO1q in the mouse and rat, respectively.

Animals↗
PubMed2001

[A case of sepsis by Neisseria meningitidis beginning with pneumonia during a trip abroad].

A 62-year-male presented a high fever and a dry cough during a trip to Australia. He was admitted to a hospital as soon as be returned to Japan. The next day after returning to Japan, he was transferred to our hospital with septic shock and loss of consciousness. Neisseria meningitidis was cultured from his blood. N. meningitidis is rare in Japan. However its seems common, in some foreign countries. With these findings, it can be postulated that N. meningitidis might be one of the etiological agents of the imported infectious disease.

Humans↗
PubMed2001

Effect of the molar ratio of branched-chain to aromatic amino acids on growth and albumin mRNA expression of human liver cancer cell lines in a serum-free medium.

Supplementation of branched-chain amino acids (BCAAs) is often used for the treatment of hepatic encephalopathy and low albuminemia in Japan. In this scenario, although many cases are complicated with hepatocellular carcinoma in chronic viral infection, the effect of BCAA levels on hepatocellular carcinoma cells remains unclear. We investigated the effect of the molar ratios of BCAAs to aromatic amino acids (AAAs) on the growth and albumin mRNA expression of cultured human liver cancer cell lines, HCC-M, HCC-T, PLC/PRF/5, and Hep G2. To exclude the effect of fetal serum in culture media on modification of the growth and albumin transcription of cell lines, we used a synthetic serum-free medium. We found that an increase in the molar ratio of BCAAs to AAAs reduced the growth of Hep G2 cells, and it increased albumin mRNA expression in this cell line at a molar ratio of 0.1-10. These results suggest that the molar ratio of BCAAs to AAAs affect the growth and mRNA expression of some liver cancer cells, and supplementation of BCAAs may at least be beneficial to patients with cirrhosis, even complicated with liver cancer.

Albumins↗
PubMed2001

Time course of reoxygenation in experimental murine tumors after carbon-beam and X-ray irradiation.

We compared the tumor reoxygenation patterns in three different murine tumor cell lines after X-irradiation with those after carbon-beam irradiation using a heavy-ion medical accelerator (HIMAC) system. The tumors of the cell lines SCCVII, SCCVII-variant-1 and EMT6 on the hind legs of mice received local priming irradiation with a carbon-beam (8 Gy, 73 keV/microm in LET, 290 MeV/u, 6 cm SOBP) or X-rays (13 Gy, 250 kVp). After various intervals, the mice were given whole-body test irradiation (16 Gy. 250 kVp X-ray) either in air or after they were killed. The hypoxic fractions were estimated as the proportions of the surviving fractions of the tumors in killed mice to those in air-breathing mice. In the SCCVII tumors, the hypoxic fractions at 0.5 h were 50% and 21% (p < 0.05) after the priming X-irradiation and carbon-beam irradiation, respectively. In the SCCVII-variant-1 tumors, the hypoxic fractions were 85% and 82% at 0.5 h, 84% and 20% at 12 h (p < 0.01), and 21% and 31% at 24 h after X-ray and after carbon-beam irradiation, respectively. In the EMT6 tumors, the reoxygenation patterns after X-irradiation and carbon-beam irradiation were quite similar. We concluded that the reoxygenation pattern differed among the three tumor cell lines, and that reoxygenation tended to occur more rapidly after carbon-beam irradiation than after X-irradiation for SCCVII and SCCVII-variant-1 tumors.

Animals↗
PubMed2001

Bacillus cereus brain abscesses occurring in a severely neutropenic patient: successful treatment with antimicrobial agents, granulocyte colony-stimulating factor and surgical drainage.

Multiple brain and liver abscesses developed immediately after Bacillus cereus bacteremia in a neutropenic patient with acute lymphoblastic leukemia. After even 8 weeks of antimicrobial chemotherapy together with administration of granulocyte colony-stimulating factor, every infectious process disappeared but the patient's headache has still persisted. Because the wall of one brain abscess became thin and was in danger of rupturing into the ventricle, surgical drainage was performed, resulting in disappearance of headache and resolution of brain abscess. The present case indicates that a combined medical and surgical approach is mandatory to treat patients with brain abscesses.

Aged↗
PubMed2001

Reduced-dose chop therapy for elderly patients with non-Hodgkin's lymphoma.

While CHOP therapy is effective for malignant lymphoma, the optimum schedule for elderly patients remains controversial. The present study investigated the usefulness of reduced-dose CHOP therapy for elderly patients. Previously untreated patients aged 65 years or older with intermediate to high-grade non-Hodgkin's lymphoma were given up to 6 courses of reduced-dose CHOP therapy at 3-week intervals. Group A patients were given (5/6) of the standard dose and Group B received 7/12 of the standard dose. Filgrastim was administered when the white blood cell count fell below 2,000/microL. Fifty-seven patients were evaluable and the scheduled therapy was completed in 37. For patients aged from 65 to 79 years and for patients older than 80 years, the complete response rate was 79.5% and 46.2%, overall 3-year survival was 58.2% and 30.4%, and event-free 3-year survival was 49.3% and 44.4%, respectively. Major toxicities (> or = grade 3) included leukopenia in 42 patients and documented infection in 7 patients. Grade 3 cardiac plus renal failure, grade 3 peritonitis due to small bowel perforation, and grade 3 liver dysfunction occurred in 1 patient each. One patient died of toxicity (grade 4 hematological toxicity and pneumonia). In conclusion, it seems that in the elderly patients with non-Hodgkin's lymphoma, response to reduced-dose ((5/6) dose) CHOP therapy is comparable to that for standard CHOP in younger adults, mainly because of improved dose-intensity.

Actuarial Analysis↗
PubMed2001

Chemotherapy with irinotecan (CPT-11), a topoisomerase-I inhibitor, for refractory and relapsed non-Hodgkin's lymphoma.

Irinotecan hydrochloride (CPT-11), a DNA topoisomerase-I inhibitor, is now widely used in the treatment of various solid tumors, including colorectal, gastric, breast, lung, and ovarian cancer. Despite the good response shown in the late phase-II study, CPT-11 was not often employed in the treatment of malignant lymphoma, mainly because of severe leukopenia and diarrhea caused by the recommended schedule: 40 mg/m2 of CPT-11 on days 1 to 3, 8 to 10, 15 to 17, then discontinued for at least 2 weeks. In clinical use, administration of CPT-11 had to be ceased on days 15 to 17 in almost all cases, and on days 8 to 10 in a considerable number of patients. Subsequently, a lower dose schedule (less than 40 mg/m2) was developed. Our phase II trial employing a reduced dose of CPT-11 on days 1 and 2, plus ADM on day 3 with 3-week interval in patients with refractory and relapsed NHL showed a fairly good response of relapsed B-cell lymphoma and a substantial response of T-cell lymphoma with acceptable toxicity. The combination of a topoisomerase-I inhibitor (CPT-11) and a topoisomerase-II inhibitor is an interesting concept for the treatment of NHL. Another phase II trial in combination with CPT-11 and other anti-cancer drugs, particularly cisplatin or topoisomerase-II inhibitors, is warranted. A superior salvage chemotherapy regimen could be found in the future by investigating combinations of low-dose CPT-11 and cisplatin or topoisomerase-II inhibitors.

Antineoplastic Agents, Phytogenic↗
PubMed2001

Recurrence of a neurenteric cyst with malignant transformation in the foramen magnum after total resection. Case report.

A 53-year-old man presented with recurrence of a neurenteric cyst with malignant transformation in the foramen magnum 3.5 years after total resection of the original tumor had been reported. For 2 years following the initial surgery, the patient had been in good condition, but then underwent ventriculoperitoneal shunt placement for intracranial hypertension. At the time there was no evidence of recurrence of the tumor on magnetic resonance (MR) images. One and one-half years later, he presented with headache and anorexia. A massive recurrent tumor was identified on MR images. The tumor was severely adhesive to the brainstem, cranial nerves, and vessels, allowing only partial resection. Histological examination of tumor specimens obtained during the first and second craniotomies indicated a malignant change from a typical neurenteric cyst with a one-layer epithelium in the first specimen to an adenocarcinoma with papillary proliferation in the second. The results of various immunohistochemical studies of the first specimen were typical of those of a neurenteric cyst. The second specimen displayed stronger staining of carbohydrate 19-9 and carcinoembryonic antigens than the initial specimen. The percentage of Ki-67 antigen (MIB-1)-positive cells increased from 0% in the first specimen to 6.7% in the second. To the authors' knowledge this is the first case in which malignant transformation has been demonstrated after total resection of a neurenteric cyst in the foramen magnum.

Adenocarcinoma, Papillary↗
PubMed2001

Usefulness of endoscopic ultrasonographic analysis of variceal hemodynamics for the treatment of esophageal varices.

The correlation of between the endoscopic findings of esophageal varices and endoscopic ultrasound findings of the collaterals outside the esophageal wall in patients with portal hypertension remains unclear. We investigated the relationship between esophageal varices and the collaterals by endoscopy and endoscopic ultrasound. Moreover, we investigated the correlation between the collaterals around the esophagus and recurrence of esophageal varices in patients with portal hypertension who had undergone endoscopic injection sclerotherapy. The collaterals were divided into two groups: 1; those with peri-esophageal collateral veins (peri-ECVs) adjacent to the muscularis externa of the esophagus, and 2; those with para-esophageal collateral veins (para-ECVs) distal to the esophageal wall without contact with the muscularis externa. Peri- and para-ECVs were scored as mild or severe according to the stage of development. According to endoscopy, the varix form was significantly larger in severe peri-ECVs group than in mild peri-ECVs group. In contrast, the varix form did not differ significantly between the mild and severe para-ECVs group. The prevalence of perforating veins increased according to the varix form. With regard to variceal recurrence, in patients with variceal recurrences, EUS findings included a significantly higher incidence of severe-type peri-ECVs, a significantly larger number of perforating veins, and a significantly larger diameter of perforating veins compared with patients without recurrence. Moreover, when EUS found the abnormalities when no endoscopic recurrence was found, the results were the almost same as the findings when EUS was performed at the same time when endoscopic recurrence was found. In conclusion, the presence of severe peri-ECVs and large perforating veins in the esophageal wall strongly correlates with occurrence and recurrence of esophageal varices in patients with portal hypertension. An understanding of these EUS abnormalities on the basis of hemodynamics around the esophagus is thought to be important for management of esophageal varices in patients with portal hypertension.

Collateral Circulation↗
PubMed2001

[Pressure wire guide provisional coronary stent implantation].

OBJECTIVES: Whether coronary artery lesion successfully dilated by balloon angioplasty should be stented or not is unclear. The purpose of this study is to evaluate the provisional stent implantation method assessing residual ischemia by pressure wire. METHODS: Thirty-one patients with de-novo lesions suitable for stenting were enrolled in a pressure wire guided provisional stent study. The pressure wire was used to assess the fractional flow reserve(FFR) before and after balloon angioplasty. When the FFR after angioplasty was less than 0.75, stent implantation was planned. Patients with lesions consisting of an intermediate stenosis proximal to the target lesion, chronic total occlusion, bypass graft and left main lesion were excluded from the study. Stent implantation was permitted even if the FFR was more than 0.75 when the operator thought stenting was necessary. Medical treatment was given with aspirin 162 mg/day, cilostazol 200 mg/day for 6 months and additional ticlopidine 200 mg/day for a month after stenting the lesion. RESULTS: Target vessel was the left anterior descending coronary artery in 19 lesions, the right coronary artery in 3, and the circumflex coronary artery in 9. Stent implantation was performed in seven (23%) of 31 lesions and the other 24(77%) lesions were treated with only balloon angioplasty. The FFR before intervention was 0.58 +/- 0.16, and improved to 0.87 +/- 0.07 (p < 0.0001). Percentage diameter stenosis before intervention was 70.7 +/- 12.6% and improved to 20.1 +/- 13.3% (p < 0.0001) after intervention. There was no major cardiac event (death, coronary artery bypass grafting, myocardial infarction, stent thrombosis). Six months follow-up angiography was performed in 27 patients (87%). Angiographic restenosis (percentage diameter stenosis > or = 50%) was found in four patients (15%). A new lesion was found in two patients. Target vessel revascularization was performed in six patients (21%). CONCLUSIONS: Lesions successfully dilated by balloon angioplasty with FFR > or = 0.75 do not require stenting.

Angioplasty, Balloon, Coronary↗
PubMed2001

Algae-removal performance of a fluidized-bed biofilm reactor system for lake water treatment.

The algae removal efficiency of a pilot plant--based on a fluidized-bed biofilm reactor system for treating--was investigated. This system does not require back-washing because the fluidized-bed suffers no clogging. Moreover, the system uses dissolved oxygen in the influent water for aerobic biological treatment without the need for additional aeration equipment. This, it is an easy-maintenance, low-energy system for purifying eutrophic lake water. The system was operated continuously at a flow rate of 1500 m3/d for nine months at Tsuchiura Port in Lake Kasumigaura. And concentrations of chlorophyll-a and dissolved oxygen in both the influent and effluent water were continuously monitored. In summer (August to September) when water bloom occurred, the average efficiency of chlorophyll-a removal was 64% at an average influent chlorophyll-a concentration of 137.8 micrograms/L. Over the entire experimental period of nine months, the average daily amount of removed chlorophyll-a was 40.3 g/d at an average influent chlorophyll-a concentration of 89.5 micrograms/L. By analyzing the relationship between the amount of removed chlorophyll-a and the consumption of dissolved oxygen, it was estimated that almost all of the algae trapped in the reactor was biologically degraded.

Biofilms↗
PubMed2001

Chemical oxidation of organic matter in secondary-treated municipal wastewater by using methods involving ozone, ultraviolet radiation and TiO2 catalyst.

The efficiencies of chemical oxidation of organic matter in genuine secondary-treated municipal wastewater by using O3, O3/UV, O3/TiO2, UV/TiO2 and O3/UV/TiO2 methods were compared experimentally. Effects of carbonates on these efficiencies were also investigated. Elimination of carbonates from the water increased TOC reduction efficiency of all the methods. The effect of the carbonates on the O3 method was less significant than that on the other methods. The O3/UV method was the most effective for reducing TOC under both carbonate-present and decarbonated conditions. The catalytic ozone process (O3/TiO2) showed a tendency to increase the ozonation efficiency at the beginning of the reaction under the decarbonated condition, but the addition of the TiO2 catalyst inhibited the ozonation under the carbonate-present condition. The photocatalytic oxidation process (UV/TiO2) did not reduce TOC as much as the other methods, but it could reduce TOC over a long time. And the O3/UV/TiO2 method did not show a synergistic effect of ozonation and photocatalytic oxidation. Furthermore, zonation prior to coagulation increased TOC reduction efficiency of coagulation, but this effect was also affected by the carbonates in water.

Carbonates↗
PubMed2001

[Significance of nucleic acid extraction for the performance of COBAS AMPLICOR Mycobacterium-PCR assay].

On an AMPLICOR-PCR assay for the diagnosis of mycobacterial infections, it has been found that approximately 10% of the routinely performed assays appear as indefinable cases with internal control (IC)-negative, which is caused by contaminant PCR-inhibitory substances in the extracted nucleic sample. To decrease the number of indefinable cases, we studied the IC performance of four nucleic acid extraction methods in one manual method(A) and three commercial kits(B, C and D). Thirty samples from 10 kinds of specimens without mycobacterial infections were subjected to the four nucleic extraction methods and the nucleic extracts were compared on PCR-inhibitory. The frequency of IC-negative samples was different among the four methods and the rates were 33.3%(n = 10) in A, 30.0%(n = 9) in B, 16.7%(n = 5) in C and 6.7%(n = 2) in D. In the PCR-inhibitory experiments using serially diluted IC-negative samples, the recovery of IC positivity was also different according to the method used. Although the IC-negative nucleic samples by D method easily became IC-positive at the 1/5 range of dilution, some of the IC-negative nucleic samples by A, B or C method were still IC-negative in the 1/10 range. These results indicate that the occurrence rate of indefinable cases with IC-negative is markedly different in the nucleic extraction method, suggesting that utilizing a suitable nucleic acid extraction method is important when using the diagnostic AMPLICOR-PCR assay.

DNA, Bacterial↗
PubMed2001

Arthroscopic synovectomy for rheumatoid arthritis using a holmium:YAG laser.

OBJECTIVE: To determine the usefulness of the holmium:YAG laser system in arthroscopic synovectomy (ASSX) for treating rheumatoid arthritis (RA). METHODS: ASSX was performed on 15 knees (one Larsen Grade 1, 7 Grade 2, 7 Grade 3) and 8 ankles (6 Grade 2, 2 Grade 3) of 17 female patients with RA. The average age at ASSX was 50.6 years (25-70). The average followup period was 24.4 months (10-47). RESULTS: Seven out of 8 knees with grade 1 or 2 had reduced pain and swelling, as well as decreased average serum levels of C-reactive protein (CRP) (from 3.6+/-1.1 to 1.4+/-0.3 mg/dl). However, 4 out of 7 knees with grade 3 showed recurrence of pain and swelling along with persistent average serum level of CRP (from 4.3+/-1.0 to 3.8+/-1.0 mg/dl). All 8 ankles with Grade 2 or Grade 3 experienced reduced pain and swelling, while the average serum CRP levels did not change (from 3.2+/-0.9 to 2.9+/-1.0 mg/dl). CONCLUSION: The Holmium:YAG laser was useful in ASSX for treating RA knees and ankles.

Adult↗