T Yamahira

Gifu University Hospital, Gihu, Gifu, Japan

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Publications (51)30.95 Total impact

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    ABSTRACT: The ultrastructure of the parathyroid glands of adult Japanese lizards (Takydromus tachydromoides) in the spring and summer season was examined. The parenchyma of the gland consists of chief cells arranged in cords or solid masses. Many chief cells contain numerous free ribosomes and mitochondria, well-developed Golgi complexes, a few lysosome-like bodies, some multivesicular bodies and relatively numerous lipid droplets. The endoplasmic reticulum is mainly smooth-surfaced. Cisternae of the rough endoplasmic reticulum are distributed randomly in the cytoplasm. Small coated vesicles of 700-800 Å in diameter are found occasionally in the cytoplasm, especially in the Golgi region. The chief cells contain occasional secretory granules of 150-300 nm in diameter that are distributed randomly in the cytoplasm and lie close to the plasma membrane. Electron dense material similar to the contents of the secretory granules is observed in the enlarged intercellular space. These findings suggest that the secretory granules may be discharged into the intercellular space by an eruptocrine type of secretion. Coated vesicles (invaginations) connected to the plasma membrane and smooth vesicles arranged in a row near the plasma membrane are observed. It is suggested that such coated vesicles may take up extracellular proteins. The accumulation of microfilaments is sometimes recognized. Morphological evidence of synthetic and secretory activities in the chief cells suggests active parathyroid function in the Japanese lizard during the spring and summer season.
    Journal of Morphology 02/2005; 161(2):145 - 155. · 1.60 Impact Factor
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    ABSTRACT: We studied the ultrastructure of the parathyroid gland of young golden hamsters after short-term treatment with ethanol (1.5 g/kg bw or 6.0 g/kg bw). We did not find any ultrastructural changes of the parathyroid gland after administration of 1.5 g/kg ethanol. In the hamsters, 3 hours after administration of 6.0 g/kg ethanol, the mean serum calcium concentration was significantly low as compared to that of the control animals. In the parathyroid gland 1 hour after administration of 6.0 g/kg ethanol, the Golgi complexes associated with a few prosecretory granules and the volume density occupied by the Golgi complexes decreased compared with that of the control animals. In the parathyroid glands 3 hours after administration of 6.0 g/kg ethanol, the Golgi complexes decreased as compared with those of the control animals, while the large vacuolar bodies increased. These findings suggest that the cellular activity of the parathyroid gland is suppressed after short-term treatment with ethanol. Intracellular lumen was found in the parathyroid chief cells 3 hours after administration of 6.0 g/kg ethanol, and the significance of this structure is discussed.
    Histology and histopathology 11/1998; 13(4):973-9. · 2.28 Impact Factor
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    ABSTRACT: Although there have been many reports regarding the structure of the parathyroid glands of various terrestrial mammals, little is known about the parathyroid glands of marine mammals including Cetacea. The morphology of the parathyroid glands of three Risso's dolphins,Grampus griseus(about 3 m in length and 300 kg in weight), and three bottlenose dolphins,Tursiops truncatus(about 3 m in length and 300 kg in weight), was examined macroscopically and microscopically. The dolphins examined in the present study had two or four parathyroid glands that varied in size and location on the thyroid gland. Each parathyroid gland was encapsulated by fibrous tissue on the dorsal surface of the thyroid gland, and was divided into several lobules by interlobular connective tissue which contained numerous capillaries. The parenchymal cells consisted of pale staining chief cells. Each cell was polygonal and about 15 μm in diameter, and had one round or oval nucleus. Oxyphil cells were not found. Considering their greater body size, the parathyroid glands were rather small. By electron microscopic observation, the parathyroid gland of the bottlenose dolphin had sparse granular endoplasmic reticulum, poorly developed Golgi complexes, and abundant secretory granules in the cytoplasm of the chief cells. These results support a possibility that the activity of the parathyroid gland is suppressed to adapt to a sea habitat.
    General and Comparative Endocrinology 04/1998; · 2.82 Impact Factor
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    ABSTRACT: To investigate the morphological changes of the parathyroid gland of the immobilized hamsters, we studied the ultrastructure of the parathyroid gland of golden hamsters kept in special small cage (Ballman cage II). All hamsters of the control group were kept in one ordinary cage. Each hamster of the isolated group was kept in ordinary cage individually. Each hamster of the immobilized group was kept in Ballman cage II individually. All hamsters were kept for 5 days. On the first and fifth day of the experiment, bone mineral content (BMC) and bone mineral density (BMD) of whole body were measured by dual energy X-ray absorptiometry (DXA). In the control and isolated groups, BMD of the fifth day was significantly increased as compared to that of the first day. In the immobilized group BMC and body weight were significantly decreased. There was no significant difference among 3 groups concerning the mean serum calcium level. Volume density of the cell organelles and inclusions was estimated and compared among 3 groups. Volume density of the lysosomes and large vacuolar bodies of the isolated and immobilized groups was significantly higher than that of the control group. Much more lipid droplets were observed in the immobilized group than the control and isolated groups. No particular differences were observed as to the Golgi complex in the isolated and the immobilized groups compared to the control group. These findings suggest that the cellular activity of the parathyroid gland is suppressed with immobilization.
    Okajimas Folia Anatomica Japonica 04/1998; 74(6):259-69.
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    ABSTRACT: Several previous studies have indicated that ingestion of ethanol can induce hypocalcemia or osteoporosis. However, few data are available concerning the effects of ethanol on the parathyroid gland. To clarify the mechanism of ethanol-induced hypocalcemia, we studied the ultrastructure to the parathyroid gland in golden hamsters after shortterm treatment with ethanol. Ethanol was administered by gavage via an intragastric tube at 6g/kg of 50% ethanol in distilled water. The mean serum calcium concentration was significantly low at 3 and 5h after administration. The Golgi complexes of the parathyroid chief cells significantly decreased 1 and 3h after administration. The lipid droplets and the large vacuolar bodies significantly increased 5h after administration. These findings suggest that the cellular activity of the parathyroid gland is suppressed after shortterm treatment with ethanol.
    Medical Electron Microscopy 01/1997; 30(3):148-153.
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    ABSTRACT: The effects of streptozotocin treatment on parathyroid water-clear cells in golden hamsters were investigated. In the cytoplasm of the water-clear cells, lipid droplets were increased as compared to that of the control animals. This finding suggests that treatment of streptozotocin affects functional activity in the parathyroid water-clear cells of the golden hamsters.
    Okajimas Folia Anatomica Japonica 06/1996; 73(1):7-13.
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    ABSTRACT: The ultrastructure of the parathyroid glands in golden hamsters after administration of progesterone was investigated. In the parathyroid glands of the female hamsters after administration of progesterone, the mean serum calcium concentration was significantly higher when compared to that of the control hamsters. In the male experimental hamsters, the percentage area occupied by Golgi complexes and lipid droplets was significantly increased when compared to that of the control hamsters, respectively. In the female hamsters after administration of progesterone, the percentage area occupied by large vacuolar bodies was significantly decreased when compared to that of the control hamsters. In the male and female experimental hamsters, the mean number of secretory granules per 100 microns2 of cytoplasm showed a significant increase compared with that of the male and female control hamsters, respectively. These findings suggest that the secretory activity of the parathyroid glands may be stimulated in response to hypocalcemia induced by progesterone.
    Histology and histopathology 11/1995; 10(4):907-11. · 2.28 Impact Factor
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    ABSTRACT: The effects of different ages on large vacuolar bodies in the parathyroid glands of golden hamsters after administration of prostaglandin E2 (PGE2) were investigated. In the parathyroid glands of the young and senile animals 15 min and the senile animals 60 min after administration of PGE2, the mean serum calcium concentration was significantly higher when compared to that of the young and senile control animals, respectively. In the experimental adult animals 60 min after administration of PGE2, the serum calcium concentration was seen to increase. In the parathyroid glands of the young animals 15 min and the adult and senile animals 60 min after administration of PGE2, the percent area occupied by large vacuolar bodies was significantly increased when compared to that of the young, adult and senile control animals, respectively. These findings suggest that the percent area occupied by large vacuolar bodies is increased in response to hypercalcemia induced by PGE2. It is thought that in the parathyroid glands suppressed by hypercalcemia there is a relationship between the percent area occupied by large vacuolar bodies and aging.
    Histology and histopathology 05/1994; 9(2):269-73. · 2.28 Impact Factor
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    ABSTRACT: The ultrastructure of the parathyroid glands of magnesium-treated golden hamsters exposed to a 5 gravity environment was studied. In the parathyroid glands of the magnesium-treated animals exposed to a hypergravity environment, the Golgi complexes and cisternae of the granular endoplasmic reticulum were increased as compared to those of the magnesium-treated animals and decreased as compared to those of animals exposed to a hypergravity environment, but were almost the same as those of the control animals. In the control and experimental animals, the chief cells were rich in free ribosomes and mitochondria. In addition, numerous secretory granules were situated close to the plasma membrane in the magnesium-treated animals exposed to a hypergravity environment. These observations suggest that the synthesis of parathyroid hormone may be stimulated in the parathyroid glands of magnesium-treated hamsters exposed to hypergravity environment.
    Okajimas Folia Anatomica Japonica 01/1994; 70(5):209-17.
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    ABSTRACT: Isolated parathyroid glands from adult female golden hamsters were incubated on a black Millipore filter in an incubation vessel containing Ham's F-12 medium, with or without melatonin at final concentration of 10(-5) M for 1 hour. In the parathyroid glands used for in vitro treatments with melatonin, the Golgi complexes associated with a few prosecretory granules and cisternae of the rough endoplasmic reticulum showed a significant decrease, and lipid droplets and lysosomes appeared to be increased compared with those of the control parathyroid glands. These changes are considered to be induced by suppression of the synthesis of parathyroid hormone in parathyroid glands incubated in a vessel containing medium with melatonin.
    Histology and histopathology 11/1992; 7(4):715-8. · 2.28 Impact Factor
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    ABSTRACT: The present report is concerned with two cases of the horseshoe kidney. During the dissecting practice at Gifu University School of Medicine in 1991, the case 1 was found in a female Japanese cadaver of 84 years old and the case 2 in a female Japanese cadaver of 84 years old and the case 2 in a female Japanese cadaver of 85 years old. 1) In both cases, the two kidneys were united at their lower ends across the midline of the body. The part of fusion called the isthmus consisted of renal tissues. 2) In both the cases 1 and 2, the hilus of each kidney opened anteriorly, and the ureters passed in front of the isthmus and entered the urinary bladder normally. The location of each kidney was lower than that of the normal kidney. 3) Surplus arteries arising from the abdominal aorta were observed in the cases 1 and 2. In the case 1, one surplus artery entered the left kidney and the isthmus. In the case 2, five surplus arteries were observed; two arteries entered the right kidney, one the left kidney and two the isthmus. 4) The incidence of the horseshoe kidney during the dissecting practice at Gifu University School of Medicine from 1971 to 1991 was 0.33% (three out of 908 bodies). 5) In both the cases 1 and 2, no malformation was observed in other organs.
    Kaibogaku Zasshi 07/1992; 67(3):226-9.
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    ABSTRACT: Changes of the water-clear cells of the parathyroid glands in adult and senile golden hamsters 2 and 5 days after starvation were investigated. The ultrastructure of the water-clear cells of the parathyroid glands in the starved adult and senile animals almost resembled that of the control adult and senile animals. However, lipid droplets were very numerous in the water-clear cells in the adult and senile animals after starvation. It is considered that starvation affects functional activity in the water-clear cells of the parathyroid gland.
    Okajimas Folia Anatomica Japonica 04/1992; 68(6):365-75.
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    ABSTRACT: The effects of different ages on large vacuolar bodies in the parathyroid glands of golden hamsters after short-term treatment with calcium were investigated. In the parathyroid glands of the young and adult animals 15 min and the senile animals 15 and 60 min after administration of calcium, the percent area occupied by large vacuolar bodies was significantly increased as compared to that of the young, adult and senile control animals, respectively. These findings suggest that the percent area occupied by large vacuolar bodies is increased in response to acute hypercalcemia. It is thought that in the parathyroid glands suppressed by hypercalcemia there is a relationship between the percent area occupied by large vacuolar bodies and aging.
    Acta Anatomica 02/1992; 143(3):223-30.
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    ABSTRACT: The ultrastructure of the parathyroid glands of fetal and pregnant golden hamsters exposed to 5-gravity environment was studied. In the centrifuged fetal animals the Golgi complexes associated with some prosecretory granules were significantly increased compared with those of the control fetal animals, and several secretory granules were located in a peripheral position just beneath the plasma membrane. In the centrifuged pregnant animals the Golgi complexes associated with numerous prosecretory granules were significantly increased, cisternae of the granular endoplasmic reticulum appeared to be increased compared with those of the control pregnant animals, many secretory granules were located in the peripheral cytoplasm and several granules were situated close to the plasma membrane. These findings suggest that in the parathyroid glands of the fetal golden hamsters as well as the pregnant animals the synthesis and release of parathyroid hormone may be stimulated in response to a hypergravity environment.
    Acta Anatomica 02/1992; 145(2):112-8.
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    ABSTRACT: The ultrastructure of the parathyroid glands of phosphate-treated golden hamsters exposed to a 5-G environment was studied. In the phosphate-treated animals exposed to a hypergravity environment, the Golgi complexes associated with numerous prosecretory granules, and the enlarged intercellular spaces containing floccular or finely particulate material showed a significant increase compared to those of the control, centrifuged, and phosphate-treated groups, and the cisternae of the granular endoplasmic reticulum showed a significant increase compared to those of the control and phosphate-treated groups. In addition, numerous secretory granules were situated close to the plasma membrane of chief cells in the phosphate-treated animals exposed to a hypergravity environment. These findings suggest that the synthesis, and to a greater extent the release of secretory granules may be markedly stimulated, in the parathyroid glands of phosphate-treated animals exposed to a hypergravity environment.
    Acta Anatomica 02/1992; 144(2):184-8.
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    ABSTRACT: Effects of 5-gravity environment on the ultrastructure of the parathyroid glands of norepinephrine-treated golden hamsters were studied. In the centrifuged animals treated with norepinephrine, the volume density occupied by the Golgi complexes associated with numerous prosecretory granules was significantly increased compared with that of the control, centrifuged and norepinephrine-treated animals, as well as the volume density occupied by the cisternae of the granular endoplasmic reticulum compared with that of the control and centrifuged animals. In addition, in the centrifuged animals treated with norepinephrine, numerous secretory granules were situated close to the plasma membrane. It is suggested that the synthesis and release of secretory granules may be markedly stimulated in the parathyroid glands of the norepinephrine-treated golden hamsters subjected to a hypergravity environment.
    Acta Anatomica 02/1992; 145(4):349-53.
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    ABSTRACT: The authors studied the mode of branching of the celiac trunk in 184 Japanese cadavers during dissecting practice at Gifu University from 1985 to 1988. The findings were as follows; 1) One hundred and sixty-six of the 184 cases belonged to Type I of Adachi's classification of variation in the arrangement of the branches of the celiac trunk. One hundred and twenty-nine cases belonged to Group 1, one case to Group 2, 10 cases to Group 3, 9 cases to Group 4, one case to Group 6, 2 cases to Group 7, 8 cases to Group 8 and 4 cases to Group 11. Two cases did not belong to any group. One of them had an anastomosis between the hepatic artery and the superior mesenteric artery. The other one had the middle colic artery arising from the hepatic artery. 2) Seven cases belonged to Type II, Group 12. 3) Two cases belonged to Type III. One belonged to Group 18. The other one had an accessory right hepatic artery arising from the superior mesenteric artery. 4) One case belonged to Type IV, Group 20. 5) Three cases belonged to Type V, Group 23. 6) Two cases belonged to Type VI. One case had a gastrolienal trunk and an accessory right hepatic artery arising from the superior mesenteric artery. The other one had a gastrolienal trunk and an accessory right hepatic artery arising from the gastrolienal trunk. 7) Of the 184 cases, three could not be classified according to Adachi. Two cases had a gastrolienal trunk and the hepatic artery arising from the abdominal aorta. One case had a lienomesenteric trunk and a gastrohepatic trunk.
    Kaibogaku Zasshi 11/1991; 66(5):452-61.
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    ABSTRACT: The ultrastructure of the parathyroid glands of hypophysectomized golden hamsters was studied. In the parathyroid glands of hypophysectomized animals the Golgi complexes and secretory granules were significantly decreased and large vacuolar bodies were significantly increased compared with those of the control animals. In addition, the chief cells contained a few prosecretory granules in the Golgi areas and a few secretory granules were present in the peripheral cytoplasm. These results suggest that the synthesis and release of parathyroid hormone may be suppressed in the parathyroid glands of the hypophysectomized animals.
    Histology and histopathology 11/1991; 6(4):453-8. · 2.28 Impact Factor
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    ABSTRACT: During the dissecting practice of students at Gifu University School of Medicine in 1989, a rare developmental anomaly showing the sciatic artery was found in the left lower limb of a cadaver of 88-year-old Japanese female. The left sciatic artery (5 mm in diameter) arose from the internal iliac artery and appeared at the buttock between the piriformis and superior gemellus muscles through foramen infrapiriforme. The femoral artery (6 mm in diameter) of the left lower limb was normal in distribution and belonged to the type III by Adachi's classification (1928). The terminal vessel of the femoral artery was joined to the sciatic artery at the popliteal fossa.
    Kaibogaku Zasshi 03/1991; 66(1):27-30.
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    ABSTRACT: Ultrastructural changes of the parathyroid glands of melatonin-treated golden hamsters were studied. Many chief cells in the parathyroid glands after 1 hour of administration of melatonin contained poorly-developed Golgi complexes associated with a few prosecretory granules and numerous lipid droplets as compared with those of the control animals. The morphology of the parathyroid glands after 5 hours of administration resembled that of the control animals. Many chief cells in the parathyroid glands after 24 hours of administration had well-developed Golgi complexes and cisternae of the granular endoplasmic reticulum, numerous prosecretory granules, a few lipid droplets and many secretory granules in the peripheral cytoplasm as compared with those of the control animals. The ultrastructure of the parathyroid glands after 48 hours of administration was almost similar to that of the control animals. It is considered that melatonin affects the secretory activity of the parathyroid gland.
    Histology and histopathology 02/1991; 6(1):1-7. · 2.28 Impact Factor