Biomedical subjects

K Araki

Publications and source records attributed to K Araki.

At least 163 records · Page 9Linked to original sources

PubMed1997

[A case of successful surgical treatment for active endocarditis 2 days after the onset of cerebral infarction].

We performed double valve replacement for a patient with active endocarditis 2 days after the onset of cerebral infarction because of intractable cardiac failure. The use of heparin and the hypotension brought by cardiopulmonary bypass can lead exacerbation of the cerebral symptoms after open heart surgery which is performed during acute phase of cerebral infarction. Perfusion pressure was maintained over 70 mmHg during cardiopulmonary bypass and activated clotting time was kept about 400 seconds to prevent aggravation of cerebral complications in this case. The patients recovered from surgery uneventfully. We described a case who was received double valve replacement 2 days after the onset of cerebral infarction successfully.

Aortic Valve↗

PubMed1997

Persistent sciatic artery aneurysm with ruptured internal iliac artery aneurysm.

A case of aneurysm of persistent sciatic artery with ruptured aneurysm of the internal iliac artery is reported. A 62-year-old man was admitted to our hospital in emergency because of abdominal severe pain. Abdominal CT and angiography showed aneurysm of the infrarenal aortic aorta and left internal iliac artery and left persistent sciatic artery. The persistent sciatic artery aneurysm was coursed down the left thigh. Left superficial femoral artery was supplying blood to the popliteal artery as normal connection. Emergency operation was performed. The left internal iliac aneurysm was ruptured to a retroperitoneal space. The aneurysm was replaced by a Y-shaped dacron double velour graft from the infrarenal abdominal aorta to right common iliac and left external iliac arteries, which was followed by a ligation at the origin of left persistent sciatic aneurysm. The pulsation of the left lower extremity was good and additional bypass procedure to the popliteal artery was not performed. The post-operative course of the patient was excellent and post-operative angiography showed normal anatomy of the left lower extremity. Optimal management of ruptured abdominal aneurysm thus requires not only an emergency operation but detailed observation of preoperative CT and angiography in order to scrutinize the associated vascular anomalies.

Aneurysm↗

PubMed1997

The role of E-selectin for neutrophil activation and tumor metastasis in vivo.

The selectin class of adhesion molecules plays a critical role in facilitating leukocyte adhesion to and subsequent transmigration of endothelium. On this basis, selectins have been suggested to promote metastasis of certain types of tumors, although direct evidence is lacking. To explore this hypothesis two sets of transgenic mice were developed, one TgNES, which constitutively expresses cell surface E-selectin in all tissues, the other TgNEsol, which expresses truncated, soluble E-selectin in the liver. Both transgenic mice showed apparently normal phenotype. However in TgNES mice, but not in TgNEsol mice, the number of neutrophil decreased to 50% compared with that in their negative littermate. And also these neutrophils were markedly activated. On the other hand, B16 F10 melanoma cells were stably transfected with alpha 1-3/4 fucosyltransferase-specific cDNA (B16F10 ft), allowing them to express E-selectin ligands. Normal mice injected with B16F10 ft developed lung tumors exclusively. In contrast, TgNES mice developed massive, infiltrating liver tumors. TgNEsol mice also developed liver tumors that grow more slowly. These observations suggest the important role of E-selectin for neutrophil activation and tumor metastasis in vivo.

Actins↗

PubMed1997

[A case of cavernous dural arteriovenous fistula resulting in intracerebral extravasation during transvenous embolization].

Cortical venous drainage has been described as one of the major risk factors for dural arteriovenous fistula, which may induce venous hypertension leading to venous ischemia or intracerebral hemorrhage. However, it is rather rare to observe cortical venous drainage manifesting in this way in the cavernous sinus region. We report a case of a 55-year-old gentleman with a right cavernous dural arteriovenous fistula, presenting with conjunctival chemosis, exophthalmus and ocular hypertension on the affected side. Magnetic resonance imaging showed a small intracerebral hemorrhage in the right frontal lobe. Cerebral angiography revealed a dural arteriovenous fistula in the right cavernous sinus draining into the right olfactory vein via the uncal vein, as well as into the superior and inferior ophthalmic veins. This unusual cortical venous reflux was thought to be consistent with the intracerebral hemorrhage found on the magnetic resonance imaging. The patient underwent transvenous embolization for the dural arteriovenous fistula using an inferior petrosal catheterization into the uncal vein was difficult, and the cortical venous reflux through the vein seemed to be slight. However, extravasation of the contrast material occurred in the right frontal lobe after obliteration of the ophthalmic veins during the procedure. The cause of the extravasation was suspected to be the same olfactory vein that had been involved in the previous intracerebral hemorrhage. The obliteration of the dural fistula was continued rapidly, and the fistula disappeared after the embolization. Neurologically, the patient had no noticeable troubles, except for a mild headache. The pretreatment symptoms were alleviated within several days, and the patient was discharged in a week. We emphasize the following points from this rare case in order to facilitate a safer procedure during transvenous embolization for cavernous dural arteriovenous fistula. It is important to obliterate the cortical venous drainage as early as possible, even if the reflux is small or the catheterization is difficult. Repeated, careful sinography is useful for the evaluation of the drainage pattern at certain stages during the transvenous embolization procedure.

Arteriovenous Fistula↗

PubMed1997

Genetic variation in the VP7 gene of human rotavirus serotype 3 (G3 type) isolated in China and Japan.

Sequence analysis of the VP7 gene was performed on twenty-one human isolates of serotype 3 related-rotavirus in China and Japan. The five Chinese isolates were found to be not similar to the 16 Japanese isolates and to SA11 (simian rotavirus). The Chinese isolates, especially CHW2 and CH-32, were different from the major serotype 3 human isolates. AU-1 and 02/92 which previously showed a wider spacing between RNA segments 10 and 11 by RNA polyacrylamide gel electrophoretic analysis, were more closely related to each other and could be differentiated from the other Chinese and Japanese isolates. For these reasons, serotype 3 viruses were considered to be intraserotypically more heterologous than serotype 1, 2 and 4 viruses.

Amino Acid Sequence↗

PubMed1997

[A case report of choroid plexus carcinoma].

Choroid plexus carcinoma (CPC) is a rare tumor with poor prognosis, whose optimal treatment has not yet been established. We report a case of a one-year-old infant who has been treated with successive combined therapy. The therapy involved two operations for partial removal, interrupted radiotherapy up to 12Gy, 2 cycles of salvage chemotherapy, followed by an operation for total removal, and then a further 3 cycles of chemotherapy. CT scan after the preoperative salvage chemotherapy showed remarkable shrinkage of the residual tumor, which made operative procedure easier. The patient was disease-free for ten months after the last operation. Patients with combined preoperative chemotherapy and total resection seem to enjoy prolonged progression-free survival, so preoperative chemotherapy for choroid plexus carcinoma seems to be of benefit, despite the fact that its optimal recipe has not yet been established.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1996

Comparison of mutagenic activity of bile between Chilean and Japanese female patients having cholelithiasis.

The mutagenic activity of bile was compared between Chilean and Japanese female patients having cholelithiasis by the Ames assay using Salmonella typhimurium tester strain TA98 in the presence of S9 mix with blue rayon adsorption technique. A reason for conducting the present investigation is that Chile and Japan have the highest mortality rates for the gallbladder cancer (GBC) in the world. Of 24 bile samples collected in Chile, 20 (83.3%) samples showed mutagenicity. In the case of Japanese bile, 21 (80.8%) of 26 and 5 (19.2%) of 26 cases were mutagenic in samples from high- and low-risk areas for GBC, respectively. Therefore, both the Chilean and the Japanese samples collected in high-risk areas showed higher mutagenic rates than the Japanese ones in a low-risk area, with a statistical significance (p < 0.001), chi-square test). The average number of revertant colonies were 128 +/- 92 (mean +/- SD), 62 +/- 14 and 66 +/- 13, respectively, when the blue rayon extracts of 200 microliters bile were applied to the Ames test. Thus, Chilean bile had a tendency to show a higher mutagenic activity than Japanese.

Adult↗

PubMed1996

E-selectin binding promotes neutrophil activation in vivo in E-selectin transgenic mice.

E-selectin is a membrane protein expressed by endothelial cells activated by cytokines released during the inflammatory process; it plays an important role in neutrophil emigration into inflamed tissues. To further explore in vivo the function of E-selectin, we have generated transgenic mouse line expressing E-selectin under the control of a chicken beta-actin promoter. In these mice, the number of blood neutrophils was reduced, without any other obvious phenotype or tissue damage. These neutrophils, however, displayed two significant changes: first, an alteration in the levels of expression of two membrane receptors involved in neutrophil adhesion to endothelial cells, namely a marked increased in the Mac-1 antigen (CD11b/CD18) and a decrease in the Mel-14 antigen (L-selectin); second, an increased oxidative activity when compared to blood neutrophils of non-transgenic mice, as shown by their capacity to oxidize 2',7'-dichlorofluorescein (DCFH) into a fluorescent compound. These observations indicate that the binding of E-selection with neutrophils bearing its ligands promotes neutrophil activation in vivo.

Actins↗

PubMed1996

An intensive chemotherapy of adult T-cell leukemia/lymphoma: CHOP followed by etoposide, vindesine, ranimustine, and mitoxantrone with granulocyte colony-stimulating factor support.

SUMMARY: An intensive combination chemotherapy regimen supported by granulocyte colony-stimulating factor (G-CSF) was evaluated in adult T-cell leukemia/lymphoma (ATLL) patients in a multiinstitutional, cooperative study. Vincristine 1 mg/m2 i.v. day 1, Adriamycin 40 mg/m2 i.v. day 1, cyclophosphamide 400 mg/m2 i.v. day 1, prednisolone 40 mg/m2 i.v. days 1 to 3 and 8 to 10, etoposide 35 mg/m2 i.v. days 1 to 8, vindesine 2 mg/m2 i.v. day 8, ranimustine 50 mg/m2 i.v. day 8, mitoxantrone 7 mg/m2 i.v. day 8, and G-CSF 50 mg/m2 s.c. days 9 to 21 were given for 2 to 4 courses every 3 weeks to 83 patients with ATLL. Complete remission (CR) and partial remission (PR) were achieved in 35.8 and 38.3 percent, respectively, of 81 evaluable patients. The median survival of all patients was 8.5 months, with a predicted 3-year survival of 13.5 percent by the Kaplan-Meier method. The median duration of response was 7.6 months (range 0.2-42.7), and 13 patients were alive. Their median survival time was 29.1 months (range 19.2-44.7). In 67.6 percent of courses, white blood cell (WBC) nadirs were < 1.0 x 10(9)/L. Days required for the recovery of WBC from the nadir to > 1.0 x 10(9)/L were <5 days in 71.4 percent of the treatment courses. The G-CSF supported an intensified chemotherapy regimen for ATLL and yielded better response rate and longer survival compared to previous reports in Japan. Because duration of remission is still short, further studies of postremission therapy or other strategies are warranted.

Adult↗

PubMed1996

Redirection of tumor metastasis by expression of E-selectin in vivo.

The selectin class of adhesion molecules plays a critical role in facilitating leukocyte adhesion to and subsequent transmigration of endothelium. On this basis, selectins have been suggested to promote tumor cell attachment to endothelium, thereby facilitating metastasis of certain types of tumors, although direct evidence for such a role is lacking. To explore this hypothesis, two sets of transgenic mice were developed: TgnES, which constitutively expresses cell surface E-selectin in all tissues, under the control of the beta-actin promoter; and TgnEsol, which expresses truncated, soluble E-selectin in the liver, under the control of the alpha 1 antitrypsin promoter. B16F10 melanoma cells were stably transfected with alpha(1,3/1,4) fucosyltransferase-specific cDNA (B16F10ft), allowing them to express E-selectin ligands or with hygromycin resistance selection vector only B16F10hygro). Normal mice injected with B16F10ft and B16F10hygro and transgenic mice injected with B16F10hygro developed lung tumors exclusively. In contrast, TgnES mice injected with B16F10ft cells developed massive infiltrating liver tumors. B16F10ft cells injected into TgnEsol mice also formed liver tumors, but these grew more slowly, with a well-delineated, noninfiltrating distinct histologic pattern. These observations provide direct evidence that expression of E-selectin can redirect metastasis of tumor cells expressing appropriate ligands in vivo.

Animals↗

PubMed1996

Two families of murine carbohydrate ligands for E-selectin.

In search of endogenous oligosaccharide ligands for the endothelial adhesion molecule E-selectin in mouse, glycolipids from tissues and the neutrophilic cell line 32D c13 were tested for E-selectin binding. Kidneys of BALB/c and NMRI mice (but not CBA) and the 32D c13 cells were found to contain minor glycolipid populations that support strongly the binding of murine E-selectin. By chromatogram binding experiments and in situ liquid secondary ion mass spectrometry (LSIMS) with neoglycolipids derived from their endoglycoceramidase-released oligosaccharides, in conjunction with compositional and linkage analyses, one of the glycolipid ligands in kidney was identified as the Le(x)-active extended globo-glycolipid: [formula: see text] Neoglycolipids enriched for the ligand structures were obtained from oligosaccharides released by endo-beta-galactosidase from the 32D c13 cells. By TLC-LSIMS and antibody binding, the main E-selectin binding determinant on these was identified as sialyl-Le(a).

Animals↗

PubMed1996

Prevention of murine lupus by an I-E alpha chain transgene: protective role of I-E alpha chain-derived peptides with a high affinity to I-Ab molecules.

The expression of a transgene encoding the I-E alpha chain prevents a lupus-like autoimmune syndrome in BXSB mice. However, it had not been elucidated whether the E alpha d transgene-mediated protective effect results from I-E expression or from the generation of I-E alpha chain-derived peptides (E alpha peptide) displaying high affinity for the I-Ab molecule. To address this question, two different BXSB lines expressing the transgene at low or high levels were crossed with lupus-prone MRL mice; this resulted in three types of (MRL x BXSB)F1 mice, differing in the expression levels of I-E molecules and of E alpha peptides presented by I-Ab molecules. Comparative analysis of these three (MRL x BXSB)F1 mice as well as several BXSB transgenic lines showed that the E alpha d transgene-mediated protection paralleled the expression levels of E alpha peptide presented by I-Ab molecules, but not of I-E molecules on B cells. In addition, use of transgenic and nontransgenic double bone marrow chimeras showed a selective activation of nontransgenic B cells during I-Ab-restricted T cell-dependent immune responses, while both transgenic and nontransgenic B cells were comparably activated during T cell-independent responses. These results favor a model of autoimmunity prevention based on competition for antigen presentation, in which excessive generation of E alpha peptides prevents, because of their high affinity to the I-A molecules, activation of potential autoreactive T and B cells.

Amino Acid Sequence↗

PubMed1996

Diagnostic value of magnetic resonance imaging for malignant tumors in the oral and maxillofacial region.

The purpose of this study was to clarify the diagnostic value of magnetic resonance imaging for malignant tumors in the oral and maxillofacial region. Computed tomography and magnetic resonance images of 25 patients with malignant tumors of the oral and maxillofacial region were evaluated. Computed tomography scans were performed with intravenous contrast enhancement. A 0.2-Tesla (Hitachi Medical Corp., Tokyo, Japan) permanent magnetic resonance unit was used to obtain T1-, T2-, and proton-density-weighted images with spin-echo pulse sequences. Gadolinium-diethylene-triamine-pentaacetic acid was administered in 11 cases. Severe artifacts influencing image interpretation were observed in 10 (40%) cases on computed tomography but only in 5 (20%) cases on magnetic resonance imaging. There was no difference in the detectability of bone invasion between images from the two systems. Contrast enhancement with gadolinium-diethylene-triamine-pentaacetic acid provided additional useful information in only 3 of 11 cases compared with nonenhanced magnetic resonance images. Malignant tumors showed a higher signal intensity than that of muscle on T2-weighted images in all cases and on proton-density-weighted images in 23 (92%) cases. On T1-weighted images, an intermediate signal intensity similar to that of muscle was seen in 16 (64%) cases and a hyperintense signal in 9 (36%) cases. There was poor correlation between signal intensity and pathologic diagnosis of the tumors. These results suggest that in cases with severe artifacts that disturb the interpretation of the images on computed tomography, magnetic resonance examinations are preferable for defining the exact extent of the primary lesion.

Adult↗

PubMed1996

Comparison of mucosal microvasculature between the proximal and distal human colon.

The microcirculation of the human colon with special reference to the differences in microvascular architecture between the proximal and distal colon was studied by scanning electron microscopy with vascular corrosion casting technique. The subsurface capillary networks of the ascending colon were honeycomb-like and multi-layered, with an average number of capillary layers per capillary loop of 3.28 +/- 1.10 (mean +/- SD). Whereas, those of the sigmoid colon were almost single-layered, and the average number of capillary layers was 1.19 +/- 0.39. In the cross-section of vascular casts of both parts of the colon, the ascending capillaries originating from the submucosal arterioles ascended into the mucosal layer and joined into the subsurface capillary networks, which drained into the collecting venules near the surface. The mean diameter of the collecting venules of the ascending and the sigmoid colon was 29.3 +/- 6.41 microns and 19.48 +/- 2.23 microns, respectively. From these findings, it is speculated that the multi-layered capillary networks of the proximal colon are closely related to the greater water absorption and electrolyte transport activities compared to those of the distal colon.

Aged↗

PubMed1996

Meiotic abnormalities of c-mos knockout mouse oocytes: activation after first meiosis or entrance into third meiotic metaphase.

In Xenopus oocytes, Mos activates the mitogen-activated protein kinase (MAPK) signal transduction cascade and regulates meiosis. In mammalian oocytes, however, the functions of Mos are still unclear. In the present study, we used c-mos knockout mouse oocytes and examined the roles of Mos in mouse oocyte maturation and fertilization, including whether Mos controls MAPK and maturation promoting factor (MPF) activity. The kinetics of germinal vesicle breakdown (GVBD) and the first polar body emission were similar in wild-type, heterozygous mutant, and homozygous mutant mice. Activities of MPF were also not significantly different among the three genotypes until the first polar body emission. In contrast, MAPK activity in c-mos knockout oocytes did not significantly fluctuate throughout maturation, and the oocytes had abnormal diffused spindles and loosely condensed chromosomes, although a clear increase in MAPK activities was observed after GVBD in wild-type and heterozygous mutant oocytes that had normal spindles and chromosomes. After the first polar body emission, 38% of c-mos knockout oocytes formed a pronucleus instead of undergoing second meiosis, indicating the crucial role of Mos in MPF reactivation after first meiosis. When oocytes that reached second metaphase were fertilized or stimulated by ethanol, many c-mos knockout oocytes emitted a second polar body and progressed into third meiotic metaphase instead of interphase, although all fertilized or activated oocytes in the heterozygote progressed to interphase, indicating that Mos deletion leads to compensatory factors that might not be degraded after fertilization or parthenogenetic activation. These results suggest that Mos is located upstream of MAPK in mouse oocytes as in Xenopus oocytes but is independent of MPF activity, and that Mos/MAPK is not necessary go GVBD and first polar body emission. Our results also suggest that Mos plays a crucial role in normal spindle and chromosome morphology and the reactivation of MPF after first meiosis.

Animals↗

PubMed1996

Supramolecular cationic tetraruthenated porphyrin induces single-strand breaks and 8-oxo-7,8-dihydro-2'-deoxyguanosine formation in DNA in the presence of light.

The aim of this investigation is the evaluation of DNA interaction of with tetraruthenated porphyrin (TRP) and of DNA damage in the presence of light. Direct-fluorescence and electronic absorption measurements after incubation of DNA with TRP indicate strong binding between pBR322 DNA or calf thymus DNA with the modified porphyrin. Exposure of pBR322 DNA to TRP (up to 3 microM) and light leads to single-strand break formation as determined by the conversion of the supercoiled form (form I) of the plasmid into the nicked circular form (form II). Oxidative DNA base damage was evaluated by the detection of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) after irradiation of calf thymus DNA in the presence of the TRP. The data demonstrated a dose and time dependence with each type of DNA damage. These data indicate (1) a specificity of the binding mode and (2) type I and II photoinduced mechanisms leading to strand scission activity and 8-oxodGuo formation. Accordingly, singlet molecular oxygen formation, after TRP excitation, was confirmed by near-infrared emission. From these investigations a potential application of TRP in photodynamic therapy is proposed.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed1996

[Epidemiology of rotavirus infection in five different locations in the Asian area].

Between 1991 and 1994, serotypes and electropherotypes were determined for clinical specimens of group A human rotavirus (HRV) rotavirus collected from five different locations in the Asia, Saitama, Shizuoka, Taichung, Hong Kong, and Beijing. HRVs were detected through the year in Taichung and Hong Kong. The peaks of each rotavirus season were in January in Hong Kong, in March in Taichung, and in February and March in Saitama and Shizouka. We set one study year as that from July to next June. Serotype G1 was the most prevalent strain in the five different settings. Most of serotype G3 strains were identified in the study year 1991. Serotype G2 was the most predominant in Shizuoka and Taichung in the year 1993. Electropherotypes indicated the possible G types except in six cases of an unusual variant type whereas the serotype was G2 and the electropherotype was the "long" type. Five of the 502 cases and three of the 622 cases were identified as group C HRV by PAGE in Saitama and Shizouka respectively. In 216 samples in Taichung, no group C HRV strain was detected.

Asia↗

PubMed1996

[A case of schistosomiasis suspected by circumoval precipitin test and diagnosed by rectal biopsy].

A forty-year-old female from Brazil was admitted to Teikyo Hospital because of easy fatigability, fullness of the abdomen and left hyochondralgia. She was anxious about Schistosoma mansoni infection, because three of her relatives died of the infection. Physical examinations revealed a tenderness at the left hypochondrium. Laboratory data showed no abnormal finding. No egg of S. mansoni was found in the stool. A circumoval precipitin test (COPT) with the serum showed a deposite around the egg. Enzyme-linked immunosorbent assay (ELISA) revealed the presence of antibody against S. mansoni in the serum. A colonoscopy showed no abnormal finding macroscopically. The rectal biopsy showed the existence of mild procitis. The diagnosis was made by finding the characteristic lateral-spined eggs in the biopsy specimens from the rectum. Treatment of 3 g of prazicantel per day for three days was started. She complained of mild nausea at the first dosing. A month later, another three-day-treatment was given. In the case where there are no eggs found in the stool, COPT and ELISA are usefull in detecting the disease, and colonoscopy is recommended in diagnosing the disease.

Adult↗