Search PubMed⌕ Search

Biomedical subjects

K Araki

Publications and source records attributed to K Araki.

At least 217 records · Page 12Linked to original sources
PubMed1994

Comparison of kinetic properties between MSS4 and Rab3A GRF GDP/GTP exchange proteins.

The kinetic properties of MSS4 are studied in comparison with those of Rab3A GRF. MSS4 stimulates the dissociation of [3H]GDP from the lipid-modified and lipid-unmodified forms of Rab3A to the same extent, although Rab3A GRF is more effective on the lipid-modified form than on the lipid-unmodified form. Both MSS4 and Rab3A GRF are inactive on other Rab/Sec/Ypt family members including at least Rab2, Rab5, and Rab11. Rab GDI inhibits the MSS4 and Rab3A GRF effects on the lipid-modified form of Rab3A, but the doses of Rab GDI necessary for this inhibitory effect on Rab3A GRF are lower than those on MSS4. Moreover, Rab GDI slightly inhibits the Rab3A GRF effect on the lipid-unmodified form of Rab3A, but does not affect the MSS4 effect on the lipid-unmodified form of Rab3A. These results suggest that MSS4 and Rab3A GRF are different GDP/GTP exchange proteins for Rab3A.

GTP-Binding Proteins↗
PubMed1994

Cloning of thyroid hormone receptor genes expressed in metamorphosing flounder.

Two distinct cDNAs encoding thyroid hormone receptors (THRs) were cloned from a lambda gt10 library prepared from the whole bodies of metamorphosing flounder larvae (Paralichthys olivaceus). Deduced amino acid sequences of the two isolated cDNAs shared 96% and 92% homologies in their DNA- and hormone-binding domains, respectively. These were highly conserved when compared to THRs for other vertebrates: 88-96% in the DNA-binding domain and 84-94% in the hormone-binding domain. Other receptors in the nuclear receptor family showed lower homologies than those of THRs. Both THRs for the flounder had higher homologies with the alpha-type THRs of other vertebrates than with the beta-type. Thus, the two THRs for flounder were designated as fTHR alpha A and fTHR alpha B.

Amino Acid Sequence↗
PubMed1994

Spinal myoclonus resembling belly dance.

A 63-year-old man presented with an 11-month history of progressive myoclonus in the right abdominal wall. Administration of clonazepam reduced the frequency and amplitude. When the therapy was discontinued, the frequency and amplitude of the myoclonus increased, and synchronous and weak myoclonus also was observed in the left abdomen. The trunk was twisted just after the appearance of the abdominal myoclonus associated with myoclonic jerks spreading from the rostral to caudal paraspinal muscles. Later in the clinical course, the myoclonus became stimulus sensitive and was induced by tendon tap given anywhere on the body, with the latency ranging from 50 to 150 ms irrespective of the sites of tapping. Myoclonus seen in the abdominal wall was segmental and considered to be of spinal origin. The reflex myoclonus had a 150-ms refractory period. It can be postulated that increased excitability of anterior horn cells at a certain segment might make a spino-bulbo-spinal reflex manifest at the corresponding segment. This myoclonus is considered to be a new form of spinal reflex myoclonus, because the abdominal myoclonic jerk seems to trigger another myoclonic jerk involving the paraspinal muscles.

Abdominal Muscles↗
PubMed1994

Molecular cloning of a cDNA encoding the prepro-salmon gonadotropin-releasing hormone of the red seabream.

Complementary DNA fragments encoding the prepro-salmon gonadotropin-releasing hormone ([Trp7, Leu8]GnRH, sGnRH) of the red seabream Pagrus major were amplified from mRNA of the olfactory bulbs using a reverse transcriptase-polymerase chain reaction (RT-PCR), and the full-length cDNA was cloned from a cDNA library using the PCR-amplified cDNA as a probe. The cDNA consisted of 442 bp, including an open reading frame of 270 bp which encoded the prepro-sGnRH (90 amino acid residues). The prepro-sGnRH had the same architecture as that reported in other species. It was composed of a signal peptide, sGnRH and a GnRH-associated peptide (GAP), which was connected to sGnRH by a Gly-Lys-Arg sequence. The prepro-sGnRH of the red seabream had 90% amino acid identity to the prepro-sGnRH from an African cichlid Haplochromis burtoni which belongs to the same suborder as the red seabream; however, identity was lower to the prepro-sGnRH from Atlantic salmon Salmo salar (74%) and masu salmon Oncorhynchus masou (70%). The GnRH peptide itself and the Gly-Lys-Arg sequence in the prepro-GnRH are highly conserved among vertebrates. The red seabream GAP also shows significant amino acid identity to the GAPs of the African cichlid (89%), Atlantic salmon (74%), and masu salmon (67%), but exhibits no significant identity to chicken or mammalian GAP.

Amino Acid Sequence↗
PubMed1994

T cell cytotoxicity of autologous and allogeneic lymphocytes in a patient with Crohn's disease.

We report a 27-year-old male with Crohn's disease (CD) of the small and large intestine, whose peripheral blood lymphocytes (PBL) showed increased cell-mediated cytotoxicity (CTL). Autologous and allogeneic effector cells from PBL and intestinal lymph nodes (LN) were isolated on a Ficoll-Hypaque gradient. Colonic cells were prepared as the target and were incubated for 6h with effector cells, after being labeled with Na(2)51CrO4. The CTL activity [effector/target (E/T) ratio, 100:1] of PBL for autologous targets was increased by 38% compared with that in normal subjects (< 10%), while that shown by LN was not increased (14%). The CTL activity of allogeneic PBL prepared from three of four other CD patients was also increased. Anti-major histocompatibility (MHC) class I and II and CD4 and CD8 monoclonal antibodies (50 micrograms/ml) significantly inhibited CTL activity. Complement-mediated depletion of CD2+ cells significantly reduced CTL activity. These results suggest that MHC-restricted CTL may play a role in mucosal damage in some patients with Crohn's disease.

Adult↗
PubMed1994

Subcortical impairment in subclinical hepatic encephalopathy.

We have used short latency somatosensory evoked potential (SEP) in 108 patients with liver cirrhosis by viral hepatitis to evaluate hepatic encephalopathy. Short-latency SEPs were recorded by the MEM-4104 apparatus (Nihon Kohden Inc., Tokyo) in response to median nerve stimulation. For a precise analysis of the early components, we averaged 1000 responses during a 30-msec period. Early SEP components were prolonged in patients with decompensated, but not in those with compensated, cirrhosis. We also examined the relationship between consciousness level and interpeak latency (IPL) N13-N20 of SEP and between consciousness level and electroencephalograph in 51 patients among 108 patients with liver cirrhosis. The IPL N13-N20 was prolonged in the decompensated stage with normal consciousness, but EEG findings had not deteriorated in this stage. EEG grade became worse in the stage of abnormal consciousness. The prolongation of the IPL N13-N20 was attributed to the central conduction impairment. We postulate that subcortical impairment may occur in patients with subclinical hepatic encephalopathy. when the cortex is little affected.

Aged↗
PubMed1994

Histopathology of the lungs of rabbits experimentally infected with Dirofilaria immitis.

The lungs of rabbits experimentally infected with Dirofilaria immitis were examined histopathologically, to compare the changes with those seen in human pulmonary dirofilariasis. Eight rabbits were infected subcutaneously with two to eight immature worms to induce pulmonary dirofilariasis. Obstructive changes, similar to those reported in human pulmonary dirofilariasis, were observed in the blood vessels surrounding the worms. A form of arteritis, similar to occlusive arteritis, and periarteritis were also observed in the lungs of the rabbits. These results suggest that experimentally induced dirofilariasis in the rabbit is a useful animal model for human pulmonary dirofilariasis.

Animals↗
PubMed1994

Indirect longitudinal cytotoxicity of root canal sealers on L929 cells and human periodontal ligament fibroblasts.

The cytotoxicity of two root canal sealers was evaluated in vitro. The powder components of both sealers, mainly zinc, were the same. The liquid for one sealer, Canals, was clove oil (included eugenol in more than 80%) and other materials. For the other, Canals-N, the liquid was composed of higher fatty acids and glycol. The experiments included two cell lines, heteroploid L929 mouse fibroblasts and diploid human periodontal ligament fibroblasts. Cytotoxicity was assessed using the radiochromium release method with 4-h exposure time. The assay involved using insert chambers in multiwell arrays to produce indirect contact of materials with the cell monolayer at a controlled distance of approximately 1 mm. This model also allowed for the longitudinal study of the same material sample to assess time-dependent changes in toxicity. Freshly mixed Canals was highly toxic (p < 0.01) to both cell lines. On and after 24 h of setting no toxicity was detected. At no time could cytotoxicity be observed when experimenting with Canals-N. These results indicate that both materials have a low content of water diffusible toxic components. Substituting eugenol can further decrease the toxicity of the sealer.

Animals↗
PubMed1994

A flow visualization study of the NCVC centrifugal blood pump.

A compact centrifugal pump, NCVC-1, has an open-type impeller with 6 curved vanes, and it is characterized by no shaft and no seal. A tunnel is placed in the center of the impeller-rotor assembly to irrigate the back space behind the rotor. To evaluate the flow, we performed 3 visualization methods: tracer, oil film, and injection streak line method. The flow, observed by the tracer method in NCVC-1, indicated little turbulence along vanes. A volute chamber proved effective to reduce vortex formation in the outlet. Oil film pattern revealed no flow separation on vanes at 5 L/min. Washout flow behind the rotor is essential to prevent thrombus formation and was shown as inward spiral flow without any stagnation. These data suggested that a combination of visualization techniques was useful to analyze various flow conditions, and the NCVC-1 has excellent flow characteristics with little turbulence and little flow stagnation, which must be beneficial to low hemolysis and high antithrombogenicity.

Heart-Assist Devices↗
PubMed1994

[An outbreak of enteric adenovirus type 41 endemic in Fjieda, Japan].

To determine the incidence of enteric adenovirus, 447 stool specimens were collected between January 1991 to October 1992 from children with gastroenteritis at a clinic in Fujieda, Japan. Each specimen was tested for adenovirus group antigen and for specific enteric adenovirus types 40 and 41 (Ad40/41) by using monoclonal antibody enzyme immunoassays. Adenovirus was found in 10.7% (48 of 447) cases and 77.1% (37 of 48) of them were Ad40/41. There were two peaks of adenovirus infection May and November 1991. The virus was isolated with 293 cells from 48 of adenovirus positive specimens, and then was typed according to the SmaI cleavage pattern of the viral DNA and by neutralization with specific antisera. Ad41 was predominantly isolated in 64.6% (31 of 48), and Ad40 was in 10.4% (5 of 48). The remaining virus isolates were typed as Ad1, 2, 5, and 6. Ad41 was founded in 89.3% (25 of 28) from October 1991 to March 1992. Though Sma I and Hind III cleavage identified six Ad41 variants in the period, the variants identified from October 1991 to March 1992 were only two. The results indicated two variants of Ad41 strains caused an outbreak during the end of 1991 to early 1992 in Fujieda.

Adenovirus Infections, Human↗
PubMed1994

[Detection of group C rotavirus in the day care center].

Group C rotavirus was detected in stools of four patients from February to April, 1993. Of these patients, three were infants who were attendants of the day care center of the hospital. Although the route of viral infection has not been determined, the virus might have been spread within the center. Because the clinical symptoms of acute gastroenteritis caused by group C rotavirus were vomiting, serious anorexia and subsequent difficulty of oral intake of food, patients often required fluid administration therapy at the outpatient clinic. The symptoms continued 1 to 2 days. Diarrhea occurred 1.7 times daily for 1.2 days. Watery stool was found in 3 cases of patients, but no whitish stool was discovered. Vomiting developed 2.2 times daily for 1.2 days. These symptoms were less severe than those of gastroenteritis by group A rotaviral infection. The electrophoretic RNA pattern of group C rotavirus detected in the four cases were the same. However it was different from that of the virus strains previously isolated.

Acute Disease↗
PubMed1994

rac p21 is involved in insulin-induced membrane ruffling and rho p21 is involved in hepatocyte growth factor- and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced membrane ruffling in KB cells.

Insulin and hepatocyte growth factor (HGF) induced morphologically different membrane rufflings in KB cells. Insulin-induced membrane ruffling was inhibited by microinjection of rho GDI, an inhibitory GDP/GTP exchange regulator for both rho p21 and rac p21 small GTP-binding proteins, but not inhibited by microinjection of botulinum exoenzyme C3, known to selectively ADP-ribosylate rho p21 and to impair its function. This rho GDI action was prevented by comicroinjection with guanosine 5'-(3-O-thio)triphosphate (GTP gamma S)-bound rac1 p21. In contrast, HGF-induced membrane ruffling was inhibited by microinjection of rho GDI or C3. This rho GDI action was prevented by comicroinjection with GTP gamma S-bound rhoA p21, and this C3 action was prevented by comicroinjection with GTP gamma S-bound rhoAIle-41 p21, which is resistant to C3. Microinjection of either GTP gamma S-bound rac1 p21 or rhoA p21 alone induced membrane ruffling in the absence of the growth factors. The rac1 p21-induced membrane ruffling was morphologically similar to the insulin-induced kind, whereas rhoA p21-induced ruffling was apparently different from both the insulin- and HGF-induced kinds. Membrane ruffling was also induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), a protein kinase C-activating phorbol ester, but not by Ca2+ ionophore or microinjection of a dominant active Ki-ras p21 mutant (Ki-rasVal-12 p21). The phorbol ester-induced membrane ruffling was morphologically similar to the rhoA p21-induced kind and inhibited by microinjection of rho GDI or C3. These results indicate that rac p21 and rho GDI are involved in insulin-induced membrane ruffling and that rho p21 and rho GDI are involved in HGF- and phorbol ester-induced membrane rufflings.

ADP Ribose Transferases↗
PubMed1994

Multiple cranial neuritis associated with large granular lymphocytosis.

A patient with a unique form of large granular lymphocytosis and multiple cranial neuritis is reported. The patient presented with facial weakness, diplopia and dysarthria. An increase in large granular lymphocytes (LGLs) was seen in blood (1.8 x 10(9)/l), CSF (237/microliters) and bone marrow (20% in a normocellular bone marrow). The phenotype of the LGLs in CSF, blood and bone marrow was CD2+ CD3+ CD4+ CD8- CD16- CD56- and CD57-. The unique features of this case include the CD4+ phenotype, the relative abundance of CSF LGL and the clinical presentation.

Antigens, CD↗
PubMed1994

Studies on the quantitative computed tomography of normal parotid and submandibular salivary glands.

A better understanding of computed tomographic (CT) numbers of normal salivary glands might help make CT diagnosis more accurate. The CT numbers of the parotid and submandibular salivary glands were measured using both non-enhanced and enhanced CT images by setting a circular region of interest (ROI). The normal range of CT numbers, the difference between the CT numbers of right and left glands, and the correlation with age were all investigated. There was a close correlation between the CT numbers of right and left glands. No significant difference was seen between the average of right and left CT numbers in both glands, on either non-enhanced or enhanced CT images. The difference between right and left numbers on enhanced CT were larger than those on non-enhanced CT. A significant difference was seen between the CT numbers of the parotid and submandibular glands. A sex difference was seen on both non-enhanced and enhanced CT images in the parotid gland, while it was only seen on enhanced CT in the submandibular gland. The range as well as the mean of CT numbers in all cases of enhanced CT were larger than those of non-enhanced CT. CT numbers of the parotid glands tended to decrease proportionally with age, up to the age of 40 years; over the age of 40, no relationship could be detected. In the submandibular gland, the difference in the correlation coefficient was not significant between the two age groups. Further investigation into the factors affecting the CT numbers of normal glands is required before they can be used for diagnostic purposes.

Adolescent↗
PubMed1994

Clinical utility of insulin-like growth factor binding protein-3 in the evaluation and treatment of short children with suspected growth hormone deficiency.

We have shown previously that serum insulin-like growth factor binding protein-3 (IGFBP-3) levels have good predictive value for complete, but not partial, growth hormone deficiency (GHD). In this study, we compare IGFBP-3 levels in short children previously divided into groups on the basis of their post-stimulation GH levels. Complete GHD (N = 59) included those children with peak post-stimulation GH < 5 micrograms/l. The partial GHD group (N = 49) had post-stimulation GH peaks of > 5 micrograms/l but < 10 micrograms/l. The normal children with short stature (N = 103) had post-stimulation GH peaks > 10 micrograms/l. Partial GHD and normal children with short stature also were divided into either low IGF-I or normal IGF-I subgroups. The clinical sensitivity of IGFBP-3 for complete GHD was 92%, whereas its sensitivity for partial GHD was 39%. For partial GHD, among those with low IGF-I (N = 19) 68% were also low for IGFBP-3, while 80% of those with normal IGF-I (N = 30) were also normal for IGFBP-3. The clinical specificity of IGFBP-3 for normal children with short stature was 69%. For these groups, among those with low IGF-I (N = 22) 73% also were low for IGFBP-3, while 80% of those with normal IGF-I (N = 81) also were normal for IGFBP-3. In addition, we tested whether IGFBP-3 can predict the response to GH treatment in prepubertal children by comparing pretreatment IGFBP-3 with the height gain achieved by 1 year of GH treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Epithelial wound healing in the denervated cornea.

We studied the epithelial healing of denervated corneas in New Zealand albino rabbits with their left trigeminal ganglia surgically amputated. On the 14th day after amputation, the corneas were keratectomized (in 8.5 mm diameter) and documentation of the healing process began. We calculated the epithelial healing rate using simple regression analysis. We observed a mean healing rate of 0.463 +/- 0.059 mm2/hr (mean +/- SE) in the denervated corneas, compared to 0.609 +/- 0.031 mm2/hr in the control corneas; a statistically significant difference of P < 0.001. We performed scanning electron microscopic observation (SEM) at three points; before keratectomy, 48 hrs after keratectomy, and 14 days after keratectomy. SEM observation revealed that, in contrast to the control corneas, the surface of the epithelial cells in denervated corneas appeared rough with numerous exfoliating cells observed. This indicates that the epithelial cells might attach only weakly to the floor in denervated corneas. Transmission electron microscopic observation (TEM) performed at 48 hrs and 14 days after keratectomy also supports this finding. For example, the intercellular space is widened and fewer desmosomes are observed in denervated corneas. Using immunohistochemistry, the surface of the wound bed was covered with fibronectin in a similar fashion to the control. In the late stage, the denervated corneas demonstrated spontaneous epithelial breakdown with 83% of them having persistent epithelial defects. Epithelial healing in the control corneas displayed no abnormal signs. On the 14th day after keratectomy, these eyes were enucleated for immunohistochemistry using bromodeoxyuridine (Brd U) to observe dividing cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

[Immortalization of rat corneal epithelial cells by SV40-adenovirus recombinant vector].

Using a SV40-adenovirus recombinant vector, we have successfully established a rat corneal epithelial cell line (RatCE) and studied its biological characteristics. RatCE continued to grow for more than 400 generations. It proliferated centrifugally in the early phase of the culture (1-3 days in culture) and had a cobblestone-like appearance in confluency. Desmosomes and microvilli were clearly seen under a transmission electron microscope. RatCE could be stored in liquid nitrogen and its biological characteristics were: doubling time, 18.3 hrs, colony forming ability, 36%, and growth ability in soft agar, 2%. When the insoluble extract from RatCE was electrophoresed, insoluble proteins were seen at 36 kD, 40 kD, 44 kD, 48 kD, 56 kD, and 64 kD. Anti-64 kD cytokeratin antibody strongly reacted with numerous filaments in the cytoplasm of RatCE. Hence, RatCE possessed 64 kD corneal specific keratin. A large amount of fibronectin was also assessed at focal contact by immunohistochemistry. Thus, RatCE retains several kinds of epithelial characteristics, is derived from one clone, and is immortalized. RatCE will be a useful tool in studies of the corneal epithelium.

Animals↗