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Biomedical subjects

H Nishiguchi

Publications and source records attributed to H Nishiguchi.

At least 19 recordsLinked to original sources
PubMed2004

Transplantation of cultured salivary gland cells into an atrophic salivary gland.

Patients with dry mouth have been treated with salivary substitutes and/or medications such as pilocarpine or cevimeline hydrochloride. These treatments temporarily relieve their symptoms and induce salivation from residual tissue. However, no treatment is available for the purpose of regenerating an atrophic gland. In this study, the feasibility of a cell transplantation therapy for the atrophic submandibular glands was investigated in rats. Further, the potential of cell differentiation into a useful phenotype was assessed by immunohistochemistry together with cell tracking with the fluorescent dye PKH 26. Rat submandibular glands were excised, and the salivary gland epithelial cells were cultured for 3 weeks with 3T3 cells as a feeder layer. Ductal ligation of the submandibular gland was employed to generate an atrophic gland. One week after the operation, the ligation was removed, and the cultured cells labeled with PKH 26 were injected into the atrophic submandibular glands. As a control, the cultured cells were also injected into normal submandibular glands. Two weeks after cell transplantation, the transplanted cells were detectable in both the experimental and control groups. The cells were clustered in the connective tissue between the lobules. Four weeks after transplantation, the labeled cells were detectable in the experimental group but not in the control group. In the atrophic glands, the scattered transplanted cells were observed over a broad area of the gland but localized mainly around the acini and ductal region. Immunostaining results showed a possible involvement of the transplanted cells in ductal regeneration, while neither myoepithelial nor acinar differentiations were observed within the 4 weeks since transplantation. This study demonstrated that cell transplantation to the salivary gland is feasible, and that the transplanted cells were selectively attracted to and remained in the damaged area without affecting normal tissue.

3T3 Cells↗
PubMed2001

Nonstoichiometric La(2 - x)GeO(5 - delta) monoclinic oxide as a new fast oxide ion conductor.

Oxide ion conductivity in La(2)GeO(5)-based oxide was investigated and it was found that La-deficient La(2)GeO(5) exhibits oxide ion conductivity over a wide range of oxygen partial pressure. The crystal structure of La(2)GeO(5) was estimated to be monoclinic with P2(1)/c space group. Conductivity increased with increasing the amount of La deficiency and the maximum value was attained at x = 0.39 in La(2 - x)GeO(5 - delta). The oxide ion transport number in La(2)GeO(5)-based oxide was estimated to be unity by the electromotive force measurement in H(2)-O(2) and N(2)-O(2) gas concentration cells. At a temperature higher than 1000 K, the oxide ion conductivity of La(1.61)GeO(5 - delta) was almost the same as that of La(0.9)Sr(0.1)Ga(0.8)Mg(0.2)O(3 - delta) or Ce(0.85)Gd(0.15)O(2 - delta), which are well-known fast oxide ion conductors. On the other hand, a change in the activation energy for oxide ion conductivity was observed at 973 K, and at intermediate temperature, the oxide ion conductivity of La(1.61)GeO(5 - delta) became much smaller than that of these well-known fast oxide ion conductors. The change in the activation energy of the oxide ion conductivity seems to be caused by a change in the local oxygen vacancy structure. However, doping a small amount of Sr for La in La(2)GeO(5) was effective to stabilize the high-temperature crystal structure to low temperature. Consequently, doping a small amount of Sr increases the oxide ion conductivity of La(2)GeO(5)-based oxide at low temperature.

Journal Article↗
PubMed2000

Structure, expression, and chromosome mapping of LATS2, a mammalian homologue of the Drosophila tumor suppressor gene lats/warts.

We have cloned and characterized LATS2, a novel mammalian homologue of the Drosophila tumor suppressor gene lats/warts. Northern blot analysis showed ubiquitous expression of mouse LATS2 (MmLATS2) mRNA, whereas expression of human LATS2 (HsLATS2) mRNA was enhanced in skeletal muscle and heart. Immunoblotting analysis of fractionated cell lysates showed HsLats2 to be a nuclear protein. We mapped the MmLATS2 gene to mouse chromosome 14 by interspecific backcross analysis. We also mapped the HsLATS2 gene (by fluorescence in situ hybridization) to the 13q11-q12 region, in which a loss of heterozygosity has been frequently observed in many primary cancers and to which the tumor suppressor genes RB and BRCA2 have also been mapped.

Amino Acid Sequence↗
PubMed1997

Changes in intracellular Ca2+ concentration produced by the alteration of intracellular pH in rat parotid acinar cells.

The effects of intracellular pH (pH(i)) on intracellular Ca2+ concentration ([Ca2+]i) vary in different cells, and mechanisms underlying these effects are still not clear. In the experiments reported here, the effects of changes in pH(i) produced by ammonium chloride and butyric acid were studied in enzymatically dispersed acinar cells of rat parotid glands. The changes in pH(i) and [Ca2+]i were estimated using the fluorescent dyes biscarboxyethyl-5,6-carboxyfluorescein (BCECF) and fura-2, respectively. pH(i) was altered using NH4Cl, butyric acid, or propionic acid while keeping the external pH constant at 7.4. NH4Cl (20 mM) applied for 4-5 min increased pH(i) from 7.18 to 7.79 (a decrease of proton concentration, [H+]i, from 66 to 16 nM) and produced a transient [Ca2+]i increase followed by a small sustained decrease. On the other hand, butyric acid (20 mM) decreased pH(i) from 7.16 to 6.81 (an increase of [H+]i from 69 to 155 nM) and produced a small sustained increase in [Ca2+]i. Washing out the butyric acid 4 min after application induced the recovery of pH(i) from 6.93 to 7.43 (a decrease of [H+]i from 118 to 37 nM) and a further transient increase in [Ca2+]i. The removal of external Ca2+ had little effect on changes in pH(i) produced by NH4Cl or butyric acid, but markedly reduced both the sustained and transient components of [Ca2+]i response. Cyclopiazonic acid (0.3 microM), an inhibitor of Ca2+ pump in intracellular stores, abolished the transient [Ca2+]i increase produced by the application of NH4Cl or withdrawal of butyric acid. These results suggest that a decrease in [H+]i, not the absolute level of [H+]i may release Ca2+ from intracellular stores.

Animals↗
PubMed1996

Effect of 'bakumondo-to', a Chinese-Japanese herbal medicine, on cultured and dispersed salivary gland cells.

'Bakumondo-to', a Chinese-Japanese herbal medicine, has been used for patients with xerostomia in Japan. Although the efficacy of this medicine for xerostomia has been reported, the pharmacological basis was only partially understood. The aim of this study was to clarify the direct effect of Bakumondo-to on salivary gland cells using isolated and cultured cells. In the physiological experiment using the fluorescent dye fura-2, Bakumondo-to showed no direct effect on isolated parotid gland cells. On the other hand, Bakumondo-to, when applied to cultured salivary gland cells, showed enhancement effects on cell proliferation. After inspection by transmission electron microscopy, we concluded that Bakumondo-to did not show an increase in the number of secretion granules but did increase the mean size of secretion granules in parotid gland cells. These mechanisms, together with other in vivo effecters, may contribute to clinical efficacy.

Bromodeoxyuridine↗
PubMed1993

[Characteristic features of the atrophic border of gastric ulcers in elderly].

We studied the characteristic features of gastric ulcers in 50 elderly cases (over 60 years old) concerning 2 points. Initially, we compared the clinical features of the elderly patients with those of the non-elderly (under 60 years old) patients. Secondly, we compared the endoscopic appearance of the atrophic border of elderly patients with that of elderly persons without gastric ulcer, using the Takemoto and Kimura's classification of endoscopic atrophic borders. The results were that elderly patients with gastric ulcer had few symptoms. The symptoms associated with bleeding, however, were recognized. Many of them had some complications. There was no difference in the healing rate at 8 weeks from the beginning of the treatment by histamine H2-receptor blocker (H2 blocker) between the elderly and non-elderly with gastric ulcer. Concerning the endoscopic atrophic border of the elderly persons without ulcers, the number of the open type cases was significantly greater than that of the closed type. On the contrary, in elderly persons with gastric ulcer, the number of the closed type was significantly greater than that of the open type, especially the number of C-2 type was the greatest. The healing rate of the elderly with closed type border was higher than that of elderly cases with open type border in 4 and 8 weeks from the beginning of the treatment.

Aged↗
PubMed1989

[Development of a J-shaped sheath and its usefulness for angiography].

We developed a new sheath for selective trans-brachial and trans-femoral arteriography. This sheath has a J-shaped tip and can be inserted by the conventional Seldinger method using a linear dilator. This sheath was particularly useful for abdominal angiography via the brachial artery and pelvic arteriography via the femoral artery.

Angiography↗
PubMed1989

[CT findings of primary and secondary malignant lymphoma of the brain].

Eleven patients with primary brain lymphoma and three patients with secondary brain lymphoma were analysed in detail on the results from the CT studies. Almost all the lesions were found in the basal ganglia and periventricular regions. Leptomeningeal lesion was noted only in one case in the three cases with secondary lesions while no such lesions were revealed in the cases with primary lesions. On the contrast studies while almost all the lesions showed homogenous contrast enhancement, the central low density areas in the lesions were seen in the two lesions in the 28 primary lesions (7.1%) and in the one lesion in the 5 secondary lesions (20%). The leptomeningeal spread of the lesion and the more frequent central low density area in the lesion are considered to be the differential points of the secondary brain lymphoma from the primary brain lymphoma.

Aged↗
PubMed1989

[Tuberculous abdominal mass: a case report].

A 64-year-old women was admitted for the examination of the abdominal mass (5 X 4.5 cm) at porta hepatis with acoustic shadow on ultrasonogram. CT demonstrated peripheral calcification of the mass compressing the portal vein. Left gastric lymph nodes were enlarged and showed ring like enhancement. Those were revealed tuberculous granulomas by the exploratory laparatomy.

Abdomen↗