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Biomedical subjects

Y Takagi

Publications and source records attributed to Y Takagi.

At least 109 records · Page 6Linked to original sources

Centrosomal kinases, HsAIRK1 and HsAIRK3, are overexpressed in primary colorectal cancers.

Members of the recently identified family of Homo sapiens Aurora / Ipl1-related kinases (HsAIRKs), homologous to chromosome segregation kinases, fly Aurora and yeast Ipl1, are highly expressed during M phase, and have been suggested to regulate centrosome function, chromosome segregation, and cytokinesis. In the present study, immunohistochemical analyses were performed of HsAIRK1 and HsAIRK3 expression in 78 primary colorectal cancers and 36 colorectal adenomas as well as 15 normal colorectal specimens. In normal colon mucosa, some crypt cells showed weak positive staining in 10 and 12 out of 15 cases for HsAIRK1 and HsAIRK3, respectively, the remaining cases being negative. Elevated expression of HsAIRK1 was observed in 53 (67.9%) of the colorectal cancers, and of HsAIRK3 in 40 (51.3%). Furthermore, colorectal adenomas showed high expression of HsAIRK1 and HsAIRK3 in 11 (30.6%) and 7 (19.4%) cases, respectively, thus being intermediate between colorectal cancers and normal colorectal mucosa. Interestingly, HsAIRK1 overexpression was significantly associated with pT (primary tumor invasion) and p53 accumulation in colorectal cancers. There was no significant correlation between proliferating cell nuclear antigen-labeling index (PCNA-LI) and the levels of these proteins. The results suggest that overexpression of HsAIRK1 and HsAIRK3 might be involved in tumorigenesis and / or progression of colorectal cancers.

Adenoma↗

Dynamic aspects of the structured cell population in a swarming colony of Proteus mirabilis.

Proteus mirabilis forms a concentric-ring colony by undergoing periodic swarming. A colony in the process of such synchronized expansion was examined for its internal population structure. In alternating phases, i.e., swarming (active migration) and consolidation (growth without colony perimeter expansion), phase-specific distribution of cells differing in length, in situ mobility, and migration ability on an agar medium were recognized. In the consolidation phase, the distribution of mobile cells was restricted to the inner part of a new ring and a previous terrace. Cells composing the outer part of the ring were immobile in spite of their ordinary swimming ability in a viscous solution. A sectorial cell population having such an internal structure was replica printed on fresh agar medium. After printing, a transplant which was in the swarming phase continued its ongoing swarming while a transplanted consolidation front continued its scheduled consolidation. This shows that cessation of migration during the consolidation phase was not due to substances present in the underlying agar medium. The ongoing swarming schedule was modifiable by separative cutting of the swarming front or disruption of the ring pattern by random mixing of the pattern-forming cell population. The structured cell population seemed to play a role in characteristic colony growth. However, separation of a narrow consolidation front from a backward area did not induce disturbance in the ongoing swarming schedule. Thus, cells at the frontal part of consolidation area were independent of the internal cell population and destined to exert consolidation and swarming with the ongoing ordinary schedule.

Culture Media↗

Alterations of the PPP2R1B gene located at 11q23 in human colorectal cancers.

BACKGROUND/AIMS: In 1998 the PPP2R1B gene encoding the A subunit of the serine/threonine protein phosphatase was identified as a putative tumour suppressor gene in lung and colon cancer in the chromosome region 11q22-24. The aim of the present study was to determine the type of alterations in primary rectal cancers as well as colon cancers and the correlation between these alterations and clinicopathological data. METHODS: Mutation analyses of the PPP2R1B gene sequence encoding the binding sites of the catalytic C subunit (Huntington elongation A subunit TOR (HEAT) repeats 11-15) and partial binding sites of the regulatory B subunit were carried out on cDNA samples from 30 primary colorectal cancer specimens and corresponding normal tissues using a combination of the polymerase chain reaction and subsequent direct DNA sequencing. RESULTS: Five missense mutations producing amino acid substitutions were detected in the four colon cancer cases (13.3%; four of 30 colorectal cancers): (15)glycine (GGT) to alanine (GCT) and (499)leucine (TTA) to isoleucine (ATA) in the same case, and (498)valine (GTG) to glutamic acid (GAG), (500)valine (GTA) to glycine (GGA), and (365)serine (TCT) to proline (CCT). Of these five mutations, three (60%) were located in HEAT repeat 13 and four (80%) showed T to other nucleotide substitutions. In addition, a normal polymorphism, (478)leucine, was found. No correlation was found between these mutations and clinicopathological data. CONCLUSION: Our results suggest that the PPP2R1B gene is one of the true targets at 11q23, and its inactivation is involved in the development of all types of colorectal cancers.

Adult↗

Primary small cell neuroendocrine carcinoma of the vagina. Marked effect of combination chemotherapy: a case report.

Primary small cell neuroendocrine carcinoma of the vagina is extremely rare and very aggressive. Nineteen patients with this cancer have been reported in the English-language literature to date. We report a 51-year-old woman with this cancer. Punch biopsy specimens of the vaginal tumor were studied. Electron microscopy demonstrated neuroendocrine granules in the cytoplasm. Tumor cells were strongly stained for cytokeratin, neuron-specific enolase, chromogranin A and serotonin. These findings were consistent with small cell neuroendocrine carcinoma. The patient was treated with combination chemotherapy. The cancer mass completely disappeared after five cycles of the therapy. The patient is still alive without metastasis 41 months after diagnosis. This is the first report of such a remarkable effect of combination chemotherapy on small cell neuroendocrine carcinoma of the vagina.

Antineoplastic Combined Chemotherapy Protocols↗

Giant noninflammatory and nonatherosclerotic coronary arterial aneurysm in the left main trunk assessed by intravascular ultrasound imaging--a case report.

A case of a giant noninflammatory and nonatherosclerotic coronary arterial aneurysm in the left main trunk of a 69-year-old female is reported. Preoperative intravascular ultrasound (IVUS) images were helpful for visualizing the morphologic and histologic features of the coronary aneurysm. They were also useful for determining the etiologic background and surgical procedure.

Aged↗

The non-collagenous dentin matrix proteins are involved in dentinogenesis imperfecta type II (DGI-II).

Dentinogenesis Imperfecta type II (DGI-II) is a localized form of mesodermal dysplasia of the dentin affecting both the primary and permanent dentitions. This is an autosomal-dominant disease in which there is a disorder in dentin mineralization. Several studies have localized DGI-II to human chromosome 4 in the region 4q 12-21. Many ECM genes-such as OPN, DMP1, DMP2, DMP3 (DSPP), and BSP-have been mapped to the same locus. Biochemical studies indicated that dentin phosphophoryn (DMP2) might be a candidate gene in DGI-II. In this study, we have used histological and RFLP analyses of tissues from a DGI-II-affected patient, as compared with two normal controls, to determine if DMP1, 2, or 3 was linked to DGI-II. The histology of the affected tooth was very different in the DGI-II patient as compared with the normals. In particular, the dentinal tubules in the DGI-II patient were very irregular, which could be the result of perturbations in the process of dentin formation. Patient and control DNA samples were digested with EcoRI or PstI and Southern-hybridized with the DMP1, DMP2, and DMP3 cDNAs. Few differences in the restriction pattern were observed between affected and normal samples for DMP1 and DMP3-3' region (phosphophoryn-like sequences) probes. On the other hand, DMP2 showed a dramatic shift in the restriction pattern in DGI-II. This study suggests that the different restriction enzyme digestion profiles of the DNA from the DGI-II patient, as probed by DMP2, might be related to the defective mineralization of dentin in DGI-II.

Chromosomes, Human, Pair 4↗

Behavioural thermoregulation of chum salmon during homing migration in coastal waters.

Homing Pacific salmon are suggested to utilise directional cues in shallow water while migrating in coastal waters. Since salmonids are typical cold-water fish, they may have to cope with warm surface water while gathering directional information. We studied behavioural thermoregulation of 31 free-ranging chum salmon Oncorhynchus keta using micro data loggers off the Sanriku coast from early October to December. The surface water temperature was approximately 20 degrees C in early October and decreased to approximately 12 degrees C in December. The seasonal change of water temperature transformed the behaviour of salmon markedly from deep diving to shallow swimming. In October, salmon frequently dived to depths exceeding 100 m. Duration of deep dives tended to be prolonged as the thermal difference between sea surface and bottom water increased. The results indicated that salmon sought the coolest thermal refuge that they could exploit by vertical movement. Thermal refuge could be a way for salmon to minimise metabolic energy cost; however, salmon repeatedly returned to the surface water column. We found a positive correlation between surface swimming of salmon and the presence of cool covering water, which could contain river waters. This suggests that salmon tend to be risk-prone when subjected to a high concentration of directional cues. Salmon in December spent most of their time in shallow water. These findings suggest that salmon adjusted their behavioural strategy with the hydrographic structure of the sea in order to achieve a balance between acquiring directional cues and behavioural thermoregulation.

Animals↗

Effect of murine kidney extracts on the proliferation of hematopoietic progenitor cells in human umbilical cord blood.

We examined the effect of murine kidney extract (MKE) on the clonal growth of highly purified CD34+ hematopoietic progenitor cells from human umbilical cord blood. MKE did not affect the total number of colonies of erythroid burst-forming units (BFU-E), granulocyte-macrophage colony-forming units (CFU-GM) or granulocyte-erythroid-macrophage-megakaryocyte colony-forming units (CFU-Mix/CFU-GEMM) in a methylcellulose culture with exogenous recombinant human granulocyte colony-stimulating factor, granulocytemacrophage colony-stimulating factor, interleukin-3, stem cell factor and erythropoietin. MKE significantly increased the proportion of BFU-E- or CFU-Mix-derived colonies, and suppressed the formation CFU-GM-derived colonies depending on the MKE dose. However, because of an increase in small megakaryocyte colonies derived from mature CFU-Meg MKE increased by approximately 40% the growth of megakaryocyte colony-forming units (CFU-Meg) in plasma clot culture stimulated by recombinant human thrombopoietin. Also MKE promoted an increase in hyperploid megakaryocytes, suggesting that the active factor(s) in MKE acts on the mature CFU-Meg and promotes the maturation of megakaryocytes. Gel-filtration high performance liquid chromatography of MKE showed that the promoting factor(s) in MKE was approximately 45 kDa. These results indicate that the factor(s) detected in MKE influence human hematopoiesis in vitro, especially thrombopoiesis.

Animals↗

Effect of ejaculation intervals on semen quality in cats.

The relationship between ejaculation intervals and semen quality in 4 male cats aged 3-5 years was investigated in this study. Semen was collected 10 times at intervals of every day, every other day, and every three days using an artificial vagina. Semen was collected consecutively twice on the day of semen collection, and the semen quality was examined. In semen collected every day, the number of sperm in the first collection decreased, and the frequency of immature sperm rapidly increased after the 4th day. In semen collected every other day and every three days, although the semen volume markedly varied among the animals on both first and second collections, the volume remained stable for each animal, the number of sperm was similar in the first and second collections, but was clearly larger in the first collection (p<0.01). Sperm motility and abnormality were stable among the various intervals and between the first and second collections in each animal.

Animals↗

Artificial intravaginal insemination using fresh semen in cats.

To clarify the sperm count required for fertilization by artificial intravaginal insemination (AIVI), twenty-nine female cats were examined. Six male cats aged 2-12 years with normal semen quality, copulation capability, and fertility were used. In AIVI, animals received administration of 250 iu hCG once or 100 iu twice on days 2-4 of estrus to induce ovulation, and were inseminated 15, 20, or 30 hr after the initial hCG administration. The success of ovulation was judged by elevation of the peripheral progesterone level after hCG administration. AIVI was investigated at three sperm counts, 20 x 10(6) (Experiment 1), 40 x 10(6) (Experiment 2), and 80 x 10(6) (Experiment 3), with semen collected by the artificial vagina method. Semen was infused in the vagina under general anesthesia by advancing a 9 cm-long nylon probe with 1.5 mm diameter connected to a 1 ml syringe in the vagina for 3-4 cm. Ovulation was induced in 43 of 45 animals (95.6%). One of 16 animals was fertilized (conception rate: 6.6%) by AIVI in Experiment 1. In Experiments 2 and 3, conception was obtained in six of 18 animals (33.3%) and seven of nine animals (77.8%), respectively, and the mean numbers of kits were 4.0 +/- 0.4 and 3.3 +/- 0.5, respectively, and the mean numbers of kits were 4.0 +/- 0.4 (SE) and 3.3 +/- 0.5, respectively, showing no significant difference. There were no differences in the time of insemination after hCG administration and the conception rate among these groups. Our findings showed that the number of sperm required for fertilization by AIVI of fresh semen in cats was 80 x 10(6).

Animals↗

Unilateral intrauterine horn insemination of fresh semen in cats.

The sperm count required were investigated to obtain a conception rate of 80% by unilateral intrauterine insemination (UIUI) of fresh semen in cats. The conception rates obtained by insemination before and after ovulation were also examined. Thirty-six female cats aged 1-7 years were used in the experiments, and the number of experimental cases was 44. Seven male cats aged 2-12 years from which semen could be collected by the artificial vagina method were used. In artificial insemination, 100 iu x 2 or 250 iu of hCG was administered on days 2-4 of estrus, and sperm were introduced into the uterine horn with a greater number of ovulations (or mature follicles) 15, 20 and 30 hr after hCG administration by laparotomy. The inseminated sperm counts were 2 x 10(6) (Exp. 1). 4 x 10(6) (Exp. 2), and 8 x 10(6) (Exp. 3). As a result, ovulation was induced in 42 of 44 cases (induction rate: 95.5%) regardless of the dosage of hCG. Conception was obtained by UIUI in two of 16 animals (conception rate: 12.5%) in the Exp. 1, five of 16 animals (31.3%) in Exp. 2, and eight of 10 animals (80.0%) in Exp. 3. Regarding the relationship between the ovulation state at insemination and conception, the conception rate obtained by insemination before ovulation was clearly higher than that obtained by insemination after ovulation (p<0.05). Regarding the number of kits compared to the number of ovulations on the inseminated side, the percentages of cases in which the number of kits exceeded the number of ovulations on the inseminated side were similar in all groups inseminated with a different number of sperm. It is therefore necessary to investigate conception rates obtained by bilateral insemination to increase the fertility rate. Based on the above findings, it was shown that the sperm count required for fertilization by UIUI is 8 x 10(6).

Animals↗

Unilateral intrauterine horn insemination of frozen semen in cats.

Frozen feline semen was prepared using two types of extenders, egg yolk Tris-fructose citric acid (EYT-FC) and egg yolk sodium citrate solution (EYC), and the semen qualities after thawing and the conception rates obtained by unilateral intrauterine horn insemination (UIUI) were investigated. Cats used in the experiment were six males and 11 females aged 2-12 years (the number of experimental cases was 17). For preparation of frozen semen, semen collected by the artificial vagina method was adjusted to I x 10(8) sperm/m/ and 7% glycerol, put in 250 microl straws, and then frozen using a cell freezer. The mean sperm motility after thawing was 30.0+/-9.7 (SE) % in the semen prepared with EYT-FC and 30.0+/-3.3% in the semen prepared with EYC. Four of seven animals were fertilized by UIUI using two straws in both extenders, and the conception rate was 57.1%. The mean ratios of number of kits to the number of ovulations in the inseminated side were 61.1+/-24.5% and 30.5+/-3.4% for EYT-FC and EYC, respectively, showing that the ratio tended to be higher in the semen prepared with EYT-FC. The above findings, comparing the two extenders for preparation of frozen feline semen, showed that EYT-FC is slightly superior to EYC. To increase conception and fertility rates, it may be important to increase the sperm count for insemination and to inseminate both uterine horns.

Animals↗

Radiation sensitivity of megakaryocyte colony-forming cells in human placental and umbilical cord blood.

The in vitro radiation sensitivity of CFU-Meg isolated from human placental and umbilical cord blood was evaluated in plasma clot cultures stimulated by recombinant human cytokines, including thrombopoietin, the FLT3 ligand (FLT3LG), interleukin-3, interleukin-11 and stem cell factor. The CD34(+) cells were irradiated with X rays at a dose rate of 73 cGy/ min. The megakaryocyte colonies were identified by using an FITC-conjugated antibody to glycoprotein IIbIIIa and were classified into two groups based on colony size: large colonies (immature CFU-Meg) and small colonies (mature CFU-Meg). Treatment with thrombopoietin alone or in combination with FLT3LG and/or interleukin-11 gave exponential radiation survival curves (D(0) for immature CFU-Meg = 56-77 cGy, D(0) for mature CFU-Meg = 86 cGy-1.12 Gy), while marked shoulders were observed on the survival curves for colonies supported by the combination of thrombopoietin, interleukin-3 and stem cell factor (D(0) for immature CFU-Meg = 89- 98 cGy; D(0) for mature CFU-Meg = 1. 25-1.31 Gy). Our results showed that the immature CFU-Meg were more radiosensitive than the mature CFU-Meg and that the combination of cytokines, including thrombopoietin, interleukin-3 and stem cell factor, affected the radiation sensitivity of CFU-Meg to the same extent as with thrombopoietin alone or in combination with FLT3LG and/or interleukin-11.

Antigens, CD34↗

MR imaging of the salivary glands in sicca syndrome: comparison of lipid profiles and imaging in patients with hyperlipidemia and patients with Sjögren's syndrome.

OBJECTIVE: We correlated abnormalities on MR imaging with the plasma lipid profiles of patients with hyperlipidemia and symptoms of sicca syndrome. SUBJECTS AND METHODS: MR imaging features of the salivary glands, salivary function, immunologic abnormalities, and plasma lipid profiles were analyzed in 24 patients with hyperlipidemia and symptoms of sicca syndrome and compared with those of 50 patients with Sjögren's syndrome. RESULTS: Swelling of the parotid gland, impaired salivary flow, or both were observed in 20 (83%) of 24 patients with hyperlipidemia and symptoms of sicca syndrome. MR imaging findings included an enlarged parotid gland replaced with extensive lipid infiltration, whereas sialography of the parotid gland revealed normal findings. Immunologic studies and analyses of the labial glands of the mouth revealed distinctive features in patients with Sjögren's syndrome. Importantly, elevated levels of plasma triglyceride correlated with parotid gland swelling, and increased cholesterol levels significantly affected salivary flow. CONCLUSION: Our findings suggest a distinct entity of sicca syndrome in patients with hyperlipidemia compared with patients with Sjögren's syndrome. Characteristic MR imaging findings of salivary glands in patients with hyperlipidemia included extensive lipid infiltration and gland enlargement.

Adolescent↗

[A newly developed method for taking pictures of tooth crown cracks for clinical records].

It is very important to examine fine cracks on the crown surface of traumatized tooth in the dental clinic because the presence of these cracks may cause discomfort or hypersensitivity of the tooth. By the emission of routinely used light, it is difficult to illuminate cracks, and the usual intraoral photography using strobe light emission is not useful to make records of cracks in most cases. In the present study, a method for taking pictures to record tooth crown cracks was newly developed using LED as a light source, and applied to patients with traumatized teeth in the dental clinic. The results were as follows: 1. Cracks on the tooth surface could be confirmed with the LEDs of all the colors used in this study. However, the blue LED enabled cracks in the incisal edge part to be more easily confirmed, and the white LED enabled cracks in the cervical part to be more easily confirmed. 2. Cracks of multiple modalities on the tooth surface was illuminated more often when the LED light was emitted at 45 degrees to the axis of the tooth than 90 degrees. 3. The light exposure field became wider by the use of the LED of diameter 5 mm than that of diameter 3 mm. However, the LED of diameter 3 mm was more favorable than that of diameter 5 mm for the observation of the cracks because the former could more easily change the direction of light emission.

Child↗

[Hepatitis B virus gene mutations in the sera of three patients with coexisting hepatitis B surface antigen and anti-surface antibody].

We analyzed gene mutations in the Hepatitis B virus of three virus carriers with coexisting Hepatitis B surface(HBs) antigen and anti-HBs antibody. Viral DNAs were extracted from sera and the pre-S, S and X(including core promoter and pre-core region) regions were amplified by PCR, and sequenced. Case 1 and Case 2 were positive for HBe antigen, while Case 3 was negative. All three cases were positive for HBe antibody and HBV DNA. In the S gene region, various point mutations were detected in all three cases. Mutations were clustered in the first hydrophilic loop region(codon 47-46) essential for the secretion of surface antigen. A few mutations were detected in 'a' loop(codon 124-147) of the S gene. None of the cases had an amino acid substitution of codon 145 of the S gene that is reported to be responsible for weak recognition by the HBs antibody. These data suggest the existence of hyper-variable sequence in S region, or otherwise result of low-fidelity of Taq DNA polymerase-reaction. Case 1 possessed a point mutation, T to C at nucleotide position 1753, in the region overlapping the coding region of the X gene and the CCAAT/enhancer binding protein(C/EBP) binding region within the core promoter region. Case 2 possessed both a large deletion(129 bp) in the pre-S1 and in-frame deletions of 15 and 27 bp in the pre-S2 region. Case 3 had an in-frame deletion of 30 bp in the pre-S2 region, and a point mutation in precore region. The point mutation, G to A at a nucleotide position 1986, converts Trp(TGG) to a stop codon TAG, and may contribute the fulminant hepatitis. These results suggest that the mutations in the pre-S, the core promoter, or the X gene may imply coexistence of the HBs antigen and antibody after seroconversion, while the point mutations in the S region are not likely to be responsible for the HBV escape mutant.

Adult↗