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Biomedical subjects

S Tanaka

Publications and source records attributed to S Tanaka.

At least 127 records · Page 7Linked to original sources
PubMed2003

Mouse mammary epithelial histamine system.

Histamine is suggested to play a role in mammary gland growth regulation, differentiation and functioning during pregnancy and lactation. Two pools of histamine are thought to be involved in these processes: mastocyte- and epithelial cell related histamine. In the present study we focused on epithelial cells. Immunohistochemistry has shown that the epithelial cells positive for histamine and L-histidine decarboxylase (HDC), the primary enzyme regulating histamine biosynthesis, were mainly found in cells forming alveolar structures in the mammary gland. Cultured primary mouse mammary epithelial cells (MMEC) expressed strong HDC immunoreactivity, especially dividing cells and non-differentiated ones. Histidine decarboxylase activity undergoes significant changes during pregnancy and lactation. Pregnancy associated intensive growth of the mammary gland coincided with an increase and the first days of lactation with a decrease of HDC protein expression. Binding studies with mammary tissue membranes and epithelial cell membranes revealed the presence of H1 and H3 but not H2 receptors. Summarizing, our data have shown that mammary epithelial cells are capable of synthesizing and excreting histamine and they bear histamine receptors. These findings further substantiate the role of histamine in mammary gland physiology.

Animals↗
PubMed2003

[Surgical treatment to an old patient with right coronary artery aneurysm; report of a case].

The patient was 75-year-old woman. The patient was referred to our hospital for operation due to a developing right coronary artery aneurysm. The coronary artery angiography showed that the aneurysm was 3 cm in diameter which had not existed two years previously, and with a 75% distal stenosis. The operation was made during cardiac arrest. A sapheous vein graft was used to bypass to the distal artery first. Then the aneurysm was resected, and both proximal and distal arteries were ligated. The pacemaker was implanted on the third postoperative day for sick sinus syndrome, the patient got a better recovery. Surgical treatment should be recommended to coronary artery aneurysm, and sapheous vein was a good selection for bypass graft when the diameter of native artery was relatively large.

Aged↗
PubMed2003

Realistic Virtual Endoscopy of the ventricle system and haptic-based surgical simulator of hydrocefalus treatment.

New methods and software tools for automatic extraction of the ventricle system from magnetic resonance imagery (MRI) data, ventricle part classification, and realistic texturing are proposed to support Virtual Endoscopy (VE). Volume- and surface-based medical atlases are intensively used as templates in the methods. The processed ventricle-related surfaces are then utilized in a haptic-based system, which provides a surgeon with several basic functions simulating "virtual treatment" of hydrocephalus.

Cerebral Ventricles↗
PubMed2002

Vortex imaging in the pi band of magnesium diboride.

We report scanning tunneling spectroscopy imaging of the vortex lattice in single crystalline MgB2. By tunneling parallel to the c axis, a single superconducting gap (Delta=2.2 meV) associated with the pi band is observed. The vortices in the pi band have a large core size compared to estimates based on H(c2) and show an absence of localized states in the core. Furthermore, superconductivity between the vortices is rapidly suppressed by an applied field. These results suggest that superconductivity in the pi band is, at least partially, induced by the intrinsically superconducting sigma band.

Journal Article↗
PubMed2002

Laparoscopic hepatectomy and dissection of lymph nodes for intrahepatic cholangiocarcinoma. Case report.

Usually intrahepatic cholangiocarcinoma has a poor prognosis, especially when it occurs with lymph node metastasis. As a treatment for intrahepatic cholangiocarcinoma, dissection of lymph nodes alone does not seem to offer any significant advantages. The laparoscopic hepatectomy procedure, however, is a minimally invasive liver surgery. We recently had the case of a patient who underwent successful laparoscopic hepatectomy and dissection of lymph nodes for intrahepatic cholangiocarcinoma in the left lateral segment of the liver. The patient had intrahepatic cholangiocarcinoma with distant lymph node metastasis around the common hepatic artery determined to stage IVb according to TNM classification. The operation time was 335 min, and the total blood loss was only 225 ml. A left lateral hepatectomy and complete lymph node dissection around the hepatoduodenal ligament and celiac trunk was performed. In this case, a laparoscopic procedure enabled the patient to have an early discharge, and there was no recurrence for 14 months. Another advantage for this patient was that the hospital stay lasted only 10 days. As compared with conventional surgery, laparoscopic surgery reduces blood loss and shortens the hospital stay. In conclusion, laparoscopic surgery for intrahepatic cholangiocarcinoma is a good treatment for advanced intrahepatic cholangiocarcinoma because it allows a positive early postoperative outcome and possibly a better result over the long term.

Bile Duct Neoplasms↗
PubMed2002

Molecular and cellular characterization of a water-channel protein, AQP-h3, specifically expressed in the frog ventral skin.

Two cDNAs encoding frog aquaporin (AQP) were cloned from a cDNA library constructed for the ventral skin of the tree frog, Hyla japonica and sequenced. One AQP (Hyla AQP-h1) consisted of 271 amino-acid residues with high homology to toad AQP-t1, Rana CHIP28 (AQP1), and rat AQP1. The other AQP (AQP-h3) consisted of 271 amino-acid residues with higher homology to mammalian AQP2 than to mammalian AQP3. The predicted amino-acid sequence contained the conserved two NPA motifs found in all MIP family members and the putative six transmembrane domains. The sequence also confers mercurial sensitivity, which is common to all the AQPs except AQP0, AQP4 and AQP7. Potential N-glycosylation sites were present at Asn-44 in AQP-h1, and at Asn-124 and Asn-125 in AQP-h3. In addition, AQP-h3 had a putative phosphorylation site by protein kinase A at Ser-255, which is identical to mammalian AQP2. In swelling assays using Xenopus oocytes, AQP-h1 facilitates water permeability, whereas AQP-h3 displayed weak water permeability. Searching for the expression of these two AQP mRNAs revealed that AQP-h1 was expressed in most tissues, whereas AQP-h3 was observed only in the ventral skin. An antibody (ST-141) against the C-terminal peptide of the AQP-h3 protein recognized a 29.0 kDa-protein with a molecular mass close to that of the Hyla AQP-h3 protein and immunostained predominantly in the abdominal pelvic skin. In pelvic skin, the label for AQP-h3 was more intense in the upper layer of the stratum granulosum and was localized to both the apical and basolateral plasma membranes of the principal cells. These findings suggest that Hyla AQP-h3 plays a pivotal role in constitutively absorbing water from ventral pelvic skin.

Animals↗
PubMed2002

Laparoscopy-assisted hepatectomy using the Endoclose: a case report.

Hemostasis of a resected stump of liver is extremely difficult in laparoscopic hepatectomy. Although Pringle's maneuver, which is a total clamping of the hepatoduodenal ligament, is a useful technique, it is often difficult in laparoscopic circumstances. Moreover, total inflow occlusion leads to postoperative liver damage. Therefore, the local bleeding method is ideal. The Endoclose, a device for port site closure, is formed from an outer sheath and an inner needle with a notch to load the suture. The Endoclose is loaded with a suture and passed through the liver. The suture is left under the liver, and the device is removed. Next, the suture carrier is passed through the liver at an appropriate distance, and the suture is regrasped by this suture carrier and brought out of the liver. Herein we report a case in which a new bleeding control method using Endoclose was introduced for laparoscopy-assisted hepatectomy.

Aged↗
PubMed2002

Ultrafast optical switching from an ionic to a neutral state in tetrathiafulvalene-p-chloranil (TTF-CA) observed in femtosecond reflection spectroscopy.

Ultrafast optical switching from an ionic ( I) to a neutral ( N) state in TTF-CA was observed in femtosecond reflection spectroscopy. Charge transfer excitation in the I phase produces N donor ( D0) acceptor ( A0) strings within 2 ps. These initial N states decay with a lifetime of 300 ps at 4 K, but rather multiply leading to macroscopic I-N conversion within 20 ps at 77 K just below the N-I transition temperature T(NI). Near T(NI), we also found the evidence for the coherent motion of the macroscopic N-I domain boundary with a period of 85 ps.

Journal Article↗
PubMed2002

Unconstrained and non-invasive measurement of heart-beat and respiration periods using a phonocardiographic sensor.

With the rapid growth in the number of elderly people in the population, interest in health monitoring is increasing. Therefore the development of an unconstrained and non-invasive vital signs measurement system could be important for monitoring health status at home or in hospitals or nursing facilities. A simple system is proposed for measuring heart-beat and respiration periods for home healthcare. This was achieved with a phonocardiographic (PCG) sensor set on a water-mat or air-mat. The PCG sensor was an acceleration sensor that extracted the vibration of the mat caused by heart-beat and respiration. By calculating an autocorrelation function of the fully rectified sensor output or by local pattern matching between the rectified output and a reference signal (pre-memorised for each subject), the system measured the average and instantaneous periods of both heart-beat and respiration. Results showed that these periods were measured to a similar level of accuracy as for the electrocardiogram and thermistor respiration pickup. The comparative accuracies were within the following ranges: average heartbeat 0.19% to 0.67%, instantaneous heartbeat 0.53% to 1.15%, average respiration 0.51% to 2.17%, and instantaneous respiration 2.51% to 5.20%.

Adult↗
PubMed2002

Long-term outcome of intracranial germinoma with hCG elevation in cerebrospinal fluid but not in serum.

OBJECTIVE: Pure germinomas have a good prognosis compared to those with syncytiotrophoblastic giant cells (STGCs), which show elevated human chorionic gonadotropin or human chorionic gonadotropin-beta (hCG/hCG-beta) levels and relapse frequently. However, the long-term outcome of patients with germinoma and detectable hCG/hCG-beta in cerebrospinal fluid (CSF) but not in serum is unclear. MATERIALS AND METHODS: The outcome of patients with pure germinomas (no increase in hCG/hCG-beta in serum or CSF, 13 cases; group A), germinomas with STGC (increased hCG/hCG-beta in serum, 13 cases; group B) and germinomas with increased hCG/hCG-beta only in CSF (6 cases; group C) was analyzed. RESULTS: All three groups received similar radiotherapy. Groups A and C each showed a 10-year survival rate of 100%, while this was only 69.2% in group B. The 10-year relapse-free survival rates were 92.3%, 69.2% and 83.3% (groups A, B and C, respectively). Groups A and C each had one case of tumor relapse, but there was no recurrence simply by the application of radiotherapy. On the other hand, in group B, tumor relapse was seen in 4/13 (30.8%) cases. Three of them showed relapse within the region of the initial radiation exposure and died despite all available treatment. CONCLUSION: Patients with an increased hCG/hCG-beta level in CSF may be considered to be similar to pure germinomas and should be treated and followed-up carefully.

Adolescent↗
PubMed2002

Corazonin reduces the spinning rate in the silkworm, Bombyx mori.

The insect neuropeptide, [Arg(7)]-corazonin was injected into larvae of the silkworm, Bombyx mori to investigate its influence on development and behavior. A single injection of 50 pmol of corazonin into the fourth and fifth instar larvae induced prolongation of the spinning period in all experimental groups except for those injected on day 10 of the fifth instar. The injection also caused a prolongation of the pupal period in some experimental groups, while it had no effect on the timing of larval ecdysis and the length of feeding period of the fifth instar. The spinning period was significantly prolonged even at a low dose of 1 pmol. Both the spinning rate and the rate of increase in hemolymph ecdysteroid level during the spinning stage were reduced by injection of corazonin. However, corazonin injection during days 5-7 of the fifth instar reduced the spinning rate without influencing the ecdysteroid level until the end of day 8, thereafter the rate of increase in hemolymph ecdysteroid level was slower in the corazonin-injected larvae than in the control larvae. Therefore, the suppressed ecdysteroid level observed in the corazonin-injected larvae appears to be a result rather than a cause of the reduced spinning rate. This study is the first published report for the corazonin effect on the behavior in insects.

Journal Article↗
PubMed2002

A comparison of phase-related shifts in behavior and morphometrics of an albino strain, deficient in [His(7)]-corazonin, and a normally colored Locusta migratoria strain.

The albino Okinawa strain of Locusta migratoria is deficient in the neurohormone [His(7)]-corazonin. This peptide induces darkening of the cuticle, one of the typical features of gregarious locusts. As part of a broader study on the possible role of [His(7)]-corazonin in phase transition, we explored whether corazonin-deficiency might be associated with differences in behavior and morphometrics between albino and normal phenotypes of L. migratoria. Using a modification of the logistic-regression assay of behavioral phase state previously derived for Schistocerca gregaria, we found that there were strain dependent behavioral differences between crowd-reared nymphs of the albino Okinawa and the normally colored African strain, with no evidence of the albino strain being obligatorily solitarious. However, upon isolation, a shift towards more solitarious behavior occurs in both strains, even more profoundly in the Okinawa albinos. A shift could also be recorded in morphometrics. The conclusion is that the albino strain, although showing some solitarious features even when crowd-reared, is not, as has been suggested, obligatory solitarious and, as a consequence, the complete absence of corazonin is not sufficient to bring about the solitarious state.

Journal Article↗
PubMed2002

Effects of [His(7)]-corazonin on the phase state of isolated-reared (solitarious) desert locusts, Schistocerca gregaria.

[His(7)]-corazonin is a neuropeptide produced in the pars lateralis of the brain. It is stored in the corpora cardiaca and probably released from there. The only well-documented effect in locusts is increased melanization of the cuticle. We investigated whether this hormone might also be causally related to changes in behavior and morphometrics that, like melanization, occur during crowding-induced gregarization. Solitary fourth-instar nymphs of Schistocerca gregaria (Forsk.) were injected thrice with 1 nmol [His(7)]-corazonin. After molting to the 5th stadium their behavioral phase state was measured in an arena assay and analyzed using multiple logistic regression analysis. The hormone was found not to induce behavioral phase changes. Upon reaching adulthood, morphometrics shifts occurred towards values typical for crowd-reared and regregarized animals. Our results thus indicate that [His(7)]-corazonin is not involved in behavioral gregarization but may participate in morphometrical phase change.

Journal Article↗
PubMed2002

Vascular endothelial growth factor-C expression predicts lymph node metastasis of human gastric carcinomas invading the submucosa.

We examined the relationship between vascular endothelial growth factor (VEGF)-C expression and lymph node metastases in gastric carcinomas invading the submucosa. Of the six human gastric carcinoma cell lines, two constitutively expressed VEGF-C mRNA. In three of 12 gastric biopsy specimens (25%), VEGF-C mRNA was detected in tumour tissues, but not in corresponding normal mucosa by reverse transcriptase-polymerase chain reaction (RT-PCR). Of the 139 resected gastric carcinomas, 44 (32%) showed intense cytoplasmic VEGF-C immunoreactivity in many cancer cells at the invading edge. VEGF-C immunoreactivity was associated with greater depth of tumour invasion, lymphatic invasion and lymph node metastases. In addition, vessel count was also significantly higher in the VEGF-C immunoreactive tumours than in other tumours. These results suggest that VEGF-C may be involved in the progression of human gastric carcinoma, particularly via lymphangiogenesis. VEGF-C expression at the invading edge of a gastric carcinoma may be a sensitive marker for metastasis to the lymph nodes.

Blotting, Northern↗
PubMed2002

Human papillomavirus type 38 infection in oral squamous cell carcinomas.

In this study, 53 paraffin-embedded oral squamous cell carcinoma (OSCC) biopsy specimens were used. Human papillomavirus type 38 (HPV-38) infection was demonstrated in OSCCs using the PCR technique, DNA sequencing analysis, in situ hybridization, and immunohistochemical techniques. Additionally, the correlation between HPV-38 infection and expressions of proliferating cell nuclear antigens (PCNA) or p53 protein was analyzed immunohistochemically. Using consensus primers for the L1 region (L1-PCR), we identified 35 of 53 specimens (66%) as positive for HPV-38 DNA. Furthermore, specimens from patients over 60 years of age revealed a lower prevalence for the HPV-38 (56.7%) than did those below that age (78.3%). Immunohistochemically, positive stainings for PCNA and p53 protein were more frequently detected in HPV-38 positive OSCCs than HPV negative ones. These results indicate that HPV-38 positive OSCCs were higher in proliferative cellular activity than HPV negative ones. Moreover, the findings suggest that HPV-38 infection may cause malignant transformation of the oral mucosal epithelium.

Adult↗