Takashi Matsunaga

Expression of the estrogen receptor in human thyroid neoplasms

The expression and quantitation of the estrogen receptor (ER) in human thyroid tumors were examined by biochemical, immunohistochemical, and reverse transcriptase-polymerase chain reaction (RT-PCR) techniques. For this study, neoplasms, adenomatous goiters and adjacent normal thyroid tissues were obtained from 35 patients which included 10 cases of papillary carcinomas, 17 cases of adenomas and 8 cases of adenomatous goiters. Regardless of the histopathological subtype, ER was detected in 19% (5/27) of the neoplastic tissues with the mean value of ER content of 5.0 +/- 1.3 fmol/mg protein and the mean Kd value of 0.38 +/- 0.28 nM. ER was also detected, but at a lower concentration (2.8 +/- 1.6 fmol/mg protein), in the surrounding normal tissues. There was no significant difference between the neoplasms and adenomatous goiters with respect to the incidence of ER positivity and ER content. Furthermore, ER-positive specimens, as determined by both biochemical and immunohistochemical techniques, also showed the expression of ER mRNA detected by RT-PCR method. These results demonstrate that both ER mRNA as well as ER protein are expressed in thyroid neoplasms. This suggests the possibility that estrogen may affect the tumorigenesis or the progression of some thyroid neoplasms.

Immunohistochemical analysis of estrogen receptors in 313 paraffin section cases of human thyroid tissue

Three hundred and thirteen cases of human thyroid tissues, comprising 39 nodular goiters from 34 females and 5 males, 130 adenomas from 93 females and 37 males, and 144 carcinomas from 99 females and 45 males were used for the present immunohistochemical assessment of estrogen receptor (ER) expression. Thirty-three cases of follicular carcinoma, 115 cases of papillary carcinoma and 6 cases of anaplastic carcinoma were included in the malignant tumor group. Incidences of ER-positive cases were 23/39 (58.9%) for nodular goiter, 44/130 (33.8%) for adenoma and 26/144 (18.0%) for cancer. In the individual carcinoma categories, 7/23 (30.4%) follicular, 19/115 (16.5%) papillary and 0/6 (0%) anaplastic lesions were judged as positive cases. Thus, the incidence of ER-positive cases tended to decrease with the degree of malignancy; this trend being similar in both sexes. Moreover, the average ages of ER-positive cases were lower than those of ER-negative cases for all types of thyroid carcinoma except the follicular variety in males. It was thus suggested that ER expression may be related to prognosis and tumor growth at early stage. Since the incidence of ER does not significantly differ between females and males, the observed sex differences regarding thyroid tumor incidence may reflect the higher estrogen serum content in females.

Rapid and transient up-regulation of Na+/myo-inositol cotransporter transcription in the brain of acute hypernatremic rats

The osmoregulatory system is well developed in the brain. Osmolytes contribute to maintenance of cell volume and cellular functions without changing intracellular ionic composition. Myo-inositol is regarded as one of the major osmolytes in the brain. In the present study, we investigated the changes in expressions of sodium myo-inositol cotransporter (SMIT) mRNA in the brain of acute hypernatremic rats by in-situ hybridization and Northern blot methods. Under moderate acute hypernatremic conditions, SMIT mRNA level increased markedly at 1 h and returned to almost control levels at 3 h, in accordance with plasma Na+ concentrations. Especially, distinct increases in SMIT mRNA expression were observed in the granule cells and glial cells in the cerebellum. These findings indicate that SMIT plays an important role in osmoregulation, especially in the early stages of acute hypernatremia in the brain.

Role of Glucocorticoid in Vestibular Compensation in Relation to Activation of Vestibular Nucleus Neurons

It is still not established whether or not glucocorticoids are effective in the treatment of vestibular disorders such as dizziness and imbalance, although these drugs in combination with several others are used to treat dizziness and imbalance in some diseases. This study was undertaken to investigate the effects of a glucocorticoid, dexamethasone, on vestibular disorder following unilateral labyrinthectomy in pigmented rabbits. Neuronal activities of the medial vestibular nucleus (MVN) in alpha-chloralose-anesthetized cats were also investigated. Systemic injection of dexamethasone decreased the frequency of nystagmus and head deviation dose-dependently following hemilabyrinthectomy, and the rate of decrease was faster than that obtained by saline. In contrast, RU38486 (a glucocorticoid receptor antagonist) delayed the reduction of nystagmus and head deviation. Micro-iontophoretic application of dexamethasone rapidly enhanced the spontaneous firing of MVN neurons in a dose-dependent manner. These increases were blocked by RU38486, but not by GDEE (a glutamate receptor antagonist) or Co2+ (a Ca2+ channel blocker). These results suggest that dexamethasone directly activates the MVN neurons, thereby accelerating vestibular compensation.

Tornwaldt's disease.

Tornwaldts disease was first described by Tornwaldt as one of the causes of epipharyngitis, and is an inflammation or abscess of the embryonic remnant cyst of the pharyngeal bursa appearing at the posterior median wall of the nasopharynx. Although many cases are symptom-free, symptoms can often be caused by nasal tamponade, trauma, adenotomy, or other mechanical stimuli. Only a few cases have been reported in Japan between 1929 and 1992. At about the 10th week of embryonic development, the pouch, which forms by adhesion of the pharyngeal ectoderm to the notochord at the most cranial end of the notochord, becomes closed at the orifice (cystic type), or crusts adhere to the orifice without closing (crust type). Symptoms are those of upper respiratory tract infection with obstinate occipital pain, purulent choanal discharge, nasal obstruction, halitosis, feeling of ear fullness, clearing of the throat, etc. Posterior rhinoscopy, simple lateral view X-ray tomography, nasopharyngeal fiberoscopy, CT scan and MRI are useful in showing adhesion to the cervical vertebrae. While complete extirpation via a transpalatal approach is desirable, incision or excision of the cyst can also be performed.

The Effect of Vasopressin upon the Cochlear Potentials in the Guinea Pig

The change in the EP, CM, SP and AP during perilymphatic perfusion of vasopressin (antidiuretic hormone) was examined in the guinea pig. The EP was recorded with a microelectrode through the spiral ligament of the second turn. The CM, SP and AP were measured with the differential electrodes in the basal turn. The perfusion of vasopressin at concentration of more than 10(-5)M produced a reversible decrease in the EP. The extent of the EP decline was dependent upon the concentration of vasopressin. Abolition of the effect of vasopressin upon the EP by the resumption of respiration after transient asphyxia was observed. During the perfusion of vasopressin, the CM and AP decreased, while the negative component of the SP increased. The mechanism causing the effect of vasopressin upon the cochlear potentials is discussed.

Glutamate as a primary afferent neurotransmitter in the medial vestibular nucleus as detected by in vivo microdialysis

An in vivo microdialysis study using alpha-chloralose-anesthetized cats was performed to elucidate whether glutamate is actually released from the vestibular nerve terminals in the medial vestibular nucleus (MVN) with electrical stimulation of the vestibular nerve. When repetitive stimuli composed of rectangular pulses (200 micros in duration, 0.5 mA, and 0.1-50 Hz) were applied to the vestibular nerve for 10 min, a significant frequency-dependent increase in the release of glutamate was observed in the MVN. However, the levels of other amino acids such as aspartate, glycine and GABA remained unaltered with the stimuli. These findings indicate that glutamate is the primary afferent neurotransmitter from the vestibular nerve to the MVN neurons.

The Effect of Stress Application on Vestibular Compensation

It is still unknown how stress, which is known to delay recovery from vestibular symptoms in patients with vertigo, influences recovery from vertigo. We therefore investigated the effect of stress on vestibular compensation following unilateral labyrinthectomy (UL) as a model of recovery from vertigo. In addition, we examined the effect of trilostane (4

Prednisolone excitation of medial vestibular nucleus neurons in cats

An electrophysiological study was performed to determine whether prednisolone hydrochloride directly influenced neuronal activities of the medial vestibular nucleus (MVN) in α-chloralose-anesthetized cats. Single neuronal activities of MVN were recorded extracellularly with a glass-insulated silver wire microelectrode attached along a seven-barreled micropipette. Each barrel was filled with prednisolone, glutamate, glutamic acid diethylester (GDEE) or COCl2. Except for prednisolone, which was administered both intravenously and microiontophoretically, other chemicals were applied microiontophoretically to the immediate vicinity of the target neurons. These MVN neurons were classified as type I and 11 neurons according to their responses to horizontal and sinusoidal rotations. Intravenous prednisolone (up to 5 mg/kg) enhanced spontaneous and rotation-induced neuronal firings of both type I and II neurons in a dose-dependent manner. In a similar tendency, microiontophoretically applied prednisolone (50–200 nA) dose-dependently increased spontaneous and rotation-induced firings of both type I and II neurons. Microiontophoretic GDEE, a non-selective glutamate receptor antagonist, inhibited glutamate- and rotation-induced neuronal discharges without affecting prednisolone-induced increases in neuronal responses of MVN. In addition, iontophoretically applied CoCl2, a Ca2+ channel blocker, did not affect prednisolone-, glutamate- and rotation-induced neuronal firings of MVN. These results suggest that prednisolone induces excitation of type I and II neurons, probably by acting directly on the membrane of MVN neurons. Thus, glucocorticoids such as prednisolone may be effective for the treatment of vertigo resulting from hypofunction of vestibular nucleus neurons.

Ultrastructural Study of Mitochondria in Oncocytes

A number of mitochondria in oncocytes show pleomorphism by conventional electron microscopy. In an investigation of their stereostructure, specimens were obtained from 11 patients with Warthins tumor, parts of which were used in the preparation of serial thin sections. It was revealed that cup-shaped and concentric ring forms of mitochondria resulted from invagination and that aberrant cristae such as the sheaflike and vesicular types were both derived from laminated cristae with vesicular structure.