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ABSTRACT: We investigated the influence of testicular and adrenal androgens on the presence of gap junctions between folliculo-stellate cells in the anterior pituitary glands of 60-day-old Wistar-Imamichi strain male rats. The animals were separated into six groups: Group A served as the controls and had free access to a normal diet and water, Group B was given a normal diet and 0.9% NaCl for their drinking water as the controls of adrenalectomized groups, Group C was castrated, Group D was adrenalectomized, Group E was both castrated and adrenalectomized, and Group F was also both castrated and adrenalectomized. In addition, the animals of Group F were administered a dose of testosterone that is known to produce high physiological levels of the hormones in plasma. Five rats from each group were sacrificed 1, 2, 3, 4, 5, 6, and 7 days after their respective operation, and the anterior pituitary glands were removed and prepared for observation by transmission electron microscopy. We quantified the number of follicles and gap junctions and calculated the rate of occurrence as the ratio of the number of gap junctions existing between folliculo-stellate cells per intersected follicle profile. Simultaneous removal of adrenal glands with castration resulted in a significantly decrease in the number of gap junctions, whereas the administration of testosterone to these rats compensated for this change. These observations indicate that the preservation of gap junctions between folliculo-stellate cells is mainly dependent on androgens from both the testes and adrenal glands in adult male rats. Microsc. Res. Tech., 2012. © 2012 Wiley Periodicals, Inc.
Microscopy Research and Technique 12/2012; 75(12):1632-8. · 1.79 Impact Factor
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ABSTRACT: In the transitional zone of the rat anterior pituitary, spontaneous and LHRH-induced Ca(2+) dynamics were visualized using fluo-4 fluorescence Ca(2+) imaging. A majority of cells exhibited spontaneous Ca(2+) transients, while small populations of cells remained quiescent. Approximately 70% of spontaneously active cells generated fast, oscillatory Ca(2+) transients that were inhibited by cyclopiazonic acid (10 μm) but not nicardipine (1 μm), suggesting that Ca(2+) handling by endoplasmic reticulum, but not Ca(2+) influx through voltage-dependent L-type Ca(2+) channels, plays a fundamental role in their generation. In the adult rat anterior pituitary, LHRH (100 μg/ml) caused a transient increase in the Ca(2+) level in a majority of preparations taken from the morning group rats killed between 0930 h and 1030 h. However, the second application of LHRH invariably failed to elevate Ca(2+) levels, suggesting that the long-lasting refractoriness to LHRH stimulation was developed upon the first challenge of LHRH. In contrast, LHRH had no effect in most preparations taken from the afternoon group rats euthanized between 1200 h and 1400 h. In the neonatal rat anterior pituitary, LHRH caused a suppression of spontaneous Ca(2+) transients. Strikingly, the second application of LHRH was capable of reproducing the suppression of Ca(2+) signals, indicating that the refractoriness to LHRH had not been established in neonatal rats. These results suggest that responsiveness to LHRH has a long-term refractoriness in adult rats, and that the physiological LHRH surge may be clocked in the morning. Moreover, LHRH-induced excitation and associated refractoriness appear to be incomplete in neonatal rats and may be acquired during development.
Endocrinology 11/2012; · 4.46 Impact Factor
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ABSTRACT: Residual subluxation of the hip is a major problem in pediatric orthopaedics. Corrective surgery by Salter innominate osteotomy is performed for residual subluxation before school age. Common indications for corrective surgery are determined based on the clinical condition, x-ray images, and arthrographic images. However, the surgical indications vary among institutions. Thus, further information that can predict acetabular growth with certainty is needed for precise decision- making. This study focused on signal intensity changes on magnetic resonance (MR) images within the weight-bearing portion of the acetabulum to determine whether these signal intensity changes could predict acetabular growth.
Thirty-six patients who showed residual subluxation after reduction of developmental dysplasia of the hip and whose MRIs were taken when they were around 3 years old were studied. Corrective surgery was performed in 14 patients, whereas the remaining 22 patients were followed conservatively. The presence of a high-signal intensity area (HSIA) within the weight-bearing portion of the acetabular cartilage on T2-weighted MR coronal section images was investigated, and the correlation between HSIA presence and acetabular growth was examined.
All patients who underwent corrective surgery showed an HSIA within the weight-bearing portion of the acetabular cartilage on T2-weighted MR images before surgery. After surgery, all patients showed HSIA disappearance or decrease. In patients who were followed conservatively, HSIA-positive patients had poor acetabular growth, whereas HSIA-negative patients had favorable acetabular growth.
HSIAs in the acetabular cartilage may be caused by an extraordinary stress load from the femoral head. The presence of HSIA on MRI may prevent acetabular growth. HSIA on MRI appears to be a significant decision-making tool for corrective surgery.
Journal of pediatric orthopedics 06/2011; 31(4):381-7. · 1.23 Impact Factor
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ABSTRACT: : Stroke patients experience postural instability that can impede functional improvements in their gait. However, the precise functions of the dominant and non-dominant hemispheres in controlling static standing posture and weight-bearing remain unclear.
: To investigate differences in balancing ability between right-handed patients with right and left hemispheric lesions.
: Weight shifting was quantitatively evaluated to determine the ability of patients to control their balance in a static posture and during conscious weight shifting onto the paretic or non-paretic leg. Participants were enrolled from a consecutive series of stroke patients attending a rehabilitation program (n=49; 31 male, 18 female; mean age 69.3+/-9.4 years). Age-matched normal controls were recruited as volunteers (n=12; 4 male, 8 female; mean age 67.9+/-4.9 years).
: Patients with cortical lesions in the right hemisphere were able to shift less weight onto the non-paretic leg than patients with cortical lesions in the left hemisphere (p<0.05). There were no correlations between the existence of unilateral spatial neglect and the percentage of weight shifted onto the non-paretic leg, static standing posture (r=0.27, p=0.40) or dynamic standing posture (r=-0.37, p=0.24). In contrast, there was a significant correlation between the percentage of weight consciously shifted onto the non-paretic leg and the existence of anosognosia (r=0.74, p=0.006), but not between static standing posture and anosognosia (r=-0.15, p=0.63).
: Patients with right cortical hemispheric lesions were able to shift less body weight onto their non-paretic leg. These patients should be encouraged to practice shifting their weight towards their non-paretic leg to improve their balance.
Clinical neurology and neurosurgery 03/2010; 112(5):406-12. · 1.30 Impact Factor
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ABSTRACT: Since [Westlud, K.N., Chils, G.V., 1982. Localization of serotonin fibers in the rat adenohypophysis. Endocrinology 111, 1761-1763] initially identified the serotonin nerve fibers in the anterior pituitary gland, attention has been paid to the rostral zone of the anterior lobe into which nerve fibers enter and subsequently spread to deeper regions of the lobe. The rostral zone is the trifurcated junction of the partes tuberalis, intermedia and distalis, and has the important role(s) for hormone secretion via the "transitional zone" [Sato, G, Shirasawa, N, Sakuma, E, Sato, Y, Asai, Y, Wada, I, Horiuchi, O, Sakamoto, A, Herbert, DC, Soji, T, 2005a. Intercellular communications within the rat anterior pituitary. XI: An immunohistochemical study of distributions of S-100 positive cells in the anterior pituitary of the rat. Tissue and Cell 37, 269-280.]. The objective of this study was to focus on the ultrastructure of this "zone." All of the animals studied were fixed by perfusion with glutaraldehyde via the left ventricle of the heart and examined by electron microscopy. In the "transitional zone," a cluster of neuronal elements was observed between the folliculo-stellate cell-rich area and the anterior lobe. This cluster consisted of myelinated fibers, unmyelinated fibers, neuroendocrine fibers, large cells, and supporting cells. The large cells were perikarya of neurons which made a "ganglion-like" structure with associated satellite cells. Agranular, folliculo-stellate cells were intermingled among the elements. This is the first report that neuronal elements form clusters in the "transitional zone." A relationship of the unmyelinated and neuroendocrine fibers in the basal layer and in the "transitional zone" is discussed.
Tissue and Cell 07/2008; 40(3):157-66. · 1.04 Impact Factor
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Hiroshi Kojima,
Eisuke Sakuma,
Yoshio Mabuchi,
Jun Mizutani,
Osamu Horiuchi, Ikuo Wada,
Mitsuya Horiba,
Yutaka Yamashita,
Damon C Herbert,
Tsuyoshi Soji,
Takanobu Otsuka
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ABSTRACT: Although exercise is believed to reduce the risk of rupture of the myotendinous junction, exercise-induced structural changes in this region have not been studied. We examined exercise-induced ultrastructural changes in the myotendinous junction of the lower legs in rats.
Ten adult male LETO rats were used. Five rats were randomly placed in the Exercise group; the remaining five were used as controls and placed in the non-Exercise group. Running exercise was performed every day for 4 weeks. The tibialis anterior and gastrocnemius muscles were then removed from both legs from each animal in the two groups. The specimens were subsequently examined by transmission electron microscopy (TEM). Numerous finger-like processes were observed at the myotendinous junction. The changes in frequency of branching of the finger-like process (the number of times one finger-like process branched) and the direction of the processes (the angle of the major axis of a finger-like process to the longitudinal direction of the muscle fiber) were studied. To evaluate the two indicators above, each 10 fingerlike process was randomly and separately selected from the tibialis anterior and gastrocnemius muscles of rats, providing 50 finger-like processes of both muscles for evaluation per group.
In terms of the frequency of branching of the fingerlike processes, the mean values obtained in the non-Exercise group were 0.04 and 0.18 times, respectively, in the tibialis anterior and gastrocnemius muscles and were 0.38 and 1.16 times, respectively, in these two muscles in the Exercise group. Regarding the direction of the finger-like processes, the values were 4.1 degrees and 3.6 degrees, respectively in the non-Exercise group and 10.4 degrees and 14.5 degrees , respectively in the Exercise group. The differences between the two animal groups were significant.
Morphological changes in the myotendinous junction occurred as an adaptation to tension increased by exercise.
Journal of Orthopaedic Science 06/2008; 13(3):233-9. · 0.84 Impact Factor
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ABSTRACT: Full-scale three-dimensional (3D) models offer a useful tool in preoperative planning, allowing full-scale stereoscopic recognition from any direction and distance with tactile feedback. Although skills and implants have progressed with various innovations, rheumatoid cervical spine surgery remains challenging. No previous studies have documented the usefulness of full-scale 3D models in this complicated situation. The present study assessed the utility of full-scale 3D models in rheumatoid cervical spine surgery. Polyurethane or plaster 3D models of 15 full-sized occipitocervical or upper cervical spines were fabricated using rapid prototyping (stereolithography) techniques from 1-mm slices of individual CT data. A comfortable alignment for patients was reproduced from CT data obtained with the patient in a comfortable occipitocervical position. Usefulness of these models was analyzed. Using models as a template, appropriate shape of the plate-rod construct could be created in advance. No troublesome Halo-vests were needed for preoperative adjustment of occipitocervical angle. No patients complained of dysphasia following surgery. Screw entry points and trajectories were simultaneously determined with full-scale dimensions and perspective, proving particularly valuable in cases involving high-riding vertebral artery. Full-scale stereoscopic recognition has never been achieved with any existing imaging modalities. Full-scale 3D models thus appear useful and applicable to all complicated spinal surgeries. The combination of computer-assisted navigation systems and full-scale 3D models appears likely to provide much better surgical results.
European Spine Journal 06/2008; 17(5):644-9. · 1.97 Impact Factor
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ABSTRACT: Legg-Calvé-Perthes disease (LCPD) is a relatively common disease in pediatric hip disorder. Now the disease is categorized into osteochondrosis. This disease was firstly reported by Legg A.T. (USA) , Calvé J. (France) , and Perthes G.C. (Germany) in 1910. Since then its pathophysiology, clinical and imaging findings, and natural history have been researched, but the true etiology remains unknown, and effective treatment methods for some types of this disease are not constituted. In this issue, its pathophysiology, clinical symptoms, peculiar features of the imaging modalities, and currently acceptable treatments were addressed.
Clinical calcium 03/2008; 18(2):239-48.
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ABSTRACT: Although numerous investigators in 1970s to 1980s have reported the distribution of LH-RH nerve fibers in the median eminence, a few LH-RH fibers have been shown to be present in the pars tuberalis. The significance of the finding remains to be elucidated, and there are few studies on the distribution of LH-RH neurons in the pars tuberalis, especially in the dorsal pars tuberalis (DPT). Adult male Wistar-Imamichi rats were separated into two groups: one for electron microscopy and the other for immunohistochemistry to observe LH-RH and neurofilaments. Pituitary glands attached to the brain were fixed by perfusion, and the sections were prepared parallel to the sagittal plane. The typical glandular structure of the pars tuberalis was evident beneath the bottom floor of the third ventricle, and the thick glandular structure was present in the foremost region. Closer to the anterior lobe, the glandular structure changed to be a thin layer, and it was again observed at the posterior portion. Then the pituitary stalk was surrounded with the dorsal, lateral, and ventral pars tuberalis. LH-RH and neurofilaments fibers were noted in the bottom floor, and some of them vertically descended to the gland. Adjacent to the glandular folliculostellate cells in the pars tuberalis, Herring bodies with numerous dense granules invading into the gland were present between the pituitary stalk and DPT. It was postulated that the "message" carried by LH-RH might have been transmitted to the cells in the DPT to aid in the modulation of LH release.
The Anatomical Record Advances in Integrative Anatomy and Evolutionary Biology 12/2007; 290(11):1388-98. · 1.47 Impact Factor
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Yumi Sato,
Hikaru Hashitani,
Nobuyuki Shirasawa,
Eisuke Sakuma,
Akira Naito,
Hikaru Suzuki,
Yuji Asai,
Goro Sato, Ikuo Wada,
Damon C Herbert,
Tsuyoshi Soji
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ABSTRACT: Since Farquhar [1957. "Corticotrophs" of the rat adenohypophysis as revealed by electron microscopy. Anat. Rec. 127, 291] was the first to report the presence of agranular folliculo-stellate cells as corticotrophs in the anterior pituitary gland, there were no reports about electro-physiological characteristics of the folliculo-stellate cells because of its no hormonal activity and the chaotic distribution of the parenchyma cells. Male Wistar rats, aged 7 weeks with weighing 250--300 g, were separated into two groups. One group was used for immunohistochemical and light microscopical studies to detect S-100 protein and connexin 43. The other group was used for the electro-physiological study and then for the electron microscopical study to know the fine structural character of folliculo-stellate cells after the electro-physiological experiment. Clusters of S-100 protein cells (agranulated folliculo-stellate cells) and numerous connexin 43 positive sites on S-100 protein cells were clear in the "transitional zone" at which the pituitary tissue made the transition from the pars tuberalis to the proximal part of the anterior lobe. Penetration of electrodes to the cells distributed in the transitional zone showed stable membrane potential ranged between--27 and--67mV with no spontaneous activity. Random penetration of electrode showed that larger populations of cell ( approximately 80%) had membrane potentials with -55.6+/-5.1 mV, and less than 20% of cells had the resting membrane potential with -36.0+/-4.4 mV. There were two types of cell couplings; one major group for the recordings from cells with similar deep resting membrane potentials and the other for the recordings from cells with different resting membrane potentials. The former indicated that two cells were electrically coupled while the latter no electrical couples were observed. Carbenoxolone depolarized the membrane by 12.3+/-5.5 mV and reduced the amplitude of electrotonic potentials, and the response recovered by removal of carbenoxolone by the superfusate. The transitional zones of the pituitary glands examined the electrical coupling were observed by an electron microscopy. Almost cytological profiles were observed as intact. The results clearly indicated that the folliculo-stellate cell system deeply participated in the regulation of the anterior pituitary parallel with the portal vessel system, which was the main regulatory system for pituitary hormone secretion.
Tissue and Cell 09/2005; 37(4):281-91. · 1.04 Impact Factor
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ABSTRACT: The distribution of the S-100 protein cell (folliculo-stellate cell) is very important to our understanding of the regulation of the anterior pituitary. In this study, 10 intact 60-day-old male Wistar-Imamichi rats, were separated equally into two groups. One was used for immunohistochemical study, and the other for electron microscopic analysis. Immunostained pituitary sections with S-100 protein antibody were photographed using a CCD camera equipped with a computer. The S-100 protein cells were then measured using NIH image software, and the three-dimensional distribution of the cells was analyzed. The distribution of the cells observed in each serial section showed that S-100 protein cells were dense at the basal zone of the gland and at the "transitional zone" where the pars tuberalis adjoined the anterior and intermediate lobes, where they represented over 50% of the total cell population. They then decreased in number with distance from this region to mid-way towards the sagittal axis before increasing again in the tail of the gland. The population of cells also decreased with increasing distance from the "transitional zone" to the wing and with distance from the basal zone. Portal vessels entered the anterior lobe through the "transitional zone" as thick capillaries, ran through the basal surface and penetrated into the central area of the anterior lobe. In all planes, S-100 protein cells encircled the capillaries. Ultrastructural observations confirmed the light microscopic findings indicating that clusters of agranular cells were densely located at the "transitional zone" and in the pars tuberalis. The distribution pattern of the folliculo-stellate cells and the capillaries showed good agreement and the spatial relationship between these two is detailed so as to better understand hypophyseal histophysiology.
Tissue and Cell 09/2005; 37(4):269-80. · 1.04 Impact Factor
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ABSTRACT: We report three patients with sporadic merosin-positive congenital muscular dystrophy (CMD) with torticollis and/or developmental dislocation of the hip in early childhood. Diagnosis of merosin-positive CMD was based on their clinical and dystrophic muscle biopsy findings. At the age 13 months, patient 1 was found to have developmental dislocation of both hips, which was surgically treated at 5 years. Patient 2 had severe torticollis and contracture of both hip joints which had been present since the neonatal period, and underwent repair of the torticollis at 2 years. Patient 3 was found to have developmental dislocation of the left hip at one month of age. Although she had generalized muscle hypotonia she learned to walk at 23 months. She had no facial muscle involvement nor contracture of joints, but had hyperlaxity of distal joints. Her muscle biopsy showed complete collagen VI deficiency immunohistochemically. In contrast to merosin-deficient CMD, merosin-positive CMD appears to be a group of heterogeneous diseases. Since collagen VI was reported to be defective in Ullrich's disease, patient 3 may be diagnosed as having Ullrich's disease but had no typical clinical characteristics of the disease. Further study is needed to identify the pathogenetic mechanism of congenital muscular dystrophy with early joint abnormalities to determine whether there is a primary abnormality of the connective tissue including collagen VI.
No to hattatsu. Brain and development 04/2003; 35(2):159-64.
