Biomedical subjects

S Ebihara

Publications and source records attributed to S Ebihara.

At least 91 records · Page 5Linked to original sources

PubMed1995

Pericranial muscle hardness in tension-type headache. A non-invasive measurement method and its clinical application.

Using a new method to measure the hardness of pericranial muscles, the role of muscle factors in tension-type headache was evaluated. In 223 normal healthy subjects, the hardness of trapezius muscles was 82 +/- 15 kPa/cm (mean +/- SD). The muscle hardness in women, 92 +/- 17 kPa/cm, was significantly greater than that in men, 74 +/- 14 kPa/cm (P < 0.01). Trapezius muscles were significantly harder than paraspinal posterior neck muscles measured at the level of the fifth cervical vertebra (71 +/- 13 kPa/cm; n = 26) but a significant correlation in muscle hardness did exist between these two muscle groups (r = 0.89, P < 0.001). Muscle hardness did not show a significant correlation with advancing age, blood pressure or subjective feeling of stiffness in the shoulder. A significant correlation was noted between the muscle hardness measured by the present method and the stiffness scores evaluated by manual palpation. In patients with tension-type headache (n = 60), the hardness of trapezius muscles, 114 +/- 24 kPa/cm (mean +/- SD), was significantly greater than that in normal subjects (P < 0.01). Twenty-six patients (43% of the total) showed significantly high values which exceeded the mean +/- 2 SD (113 kPa/cm) of the normal value, while the remaining patients (57%) constituted a high normal group. The hardness of posterior neck muscles measured in 27 patients (99 +/- 21 kPa/cm) was also significantly greater than that in normal subjects (P < 0.01). There was no significant difference in muscle hardness between episodic tension-type headache and chronic tension-type headache.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Effects of suprachiasmatic lesions on circadian rhythms of blood pressure, heart rate and locomotor activity in the rat.

To determine whether the circadian rhythms in blood pressure (BP), heart rate (HR) and locomotor activity are controlled by an internal biological clock located in the suprachiasmatic nucleus (SCN), we continuously measured these parameters in SCN-lesioned rats using a newly developed implantable radiotelemetry device and a computerized data collecting system. Although SCN-lesioned rats showed a weak but significant 24-h periodicity in BP and HR under light-dark (LD) cycles, BP, HR and locomotor activity became completely aperiodic under constant dark (DD) conditions. The amount of locomotor activity was significantly reduced in SCN-lesioned rats compared to that in intact rats. BP tended to be higher in SCN-lesioned rats, but the differences were significant only in the comparison of systolic blood pressure (SBP) under LD and DD (p < 0.05) and of mean blood pressure (MBP) under LD (p < 0.05). HR in SCN-lesioned rats was significantly lower under LD (p < 0.05), but not under DD. The standard deviation and the variation coefficient of MBP, as indices of short-term variability of this parameter, were significantly larger in SCN-lesioned rats than in intact rats, while those of HR and locomotor activity did not differ significantly between SCN-lesioned and intact rats. These results indicate that the SCN is important not only for generating circadian rhythms of BP, HR and locomotor activity, but also for buffering the short-term variability of BP in rats.

Animals↗

PubMed1995

[Changes in respiratory function before and after laryngectomy].

Many patients with head and neck cancer have a smoking history, and pulmonary complications frequently lead to post-operative death. Due to technical problems, spirometric pulmonary function tests are rarely performed in patients with laryngectomy. The purpose of this study is to evaluate respiratory function in patients with laryngectomy. We made a tracheal mask with a heat and moisture exchanging baseholder, and used it for spirometry. Eight patients with laryngectomy, including 5 with laryngeal cancer and 3 with hypopharyngeal cancer, were studied. Arterial blood gas analysis and pulmonary function measurements, such as VC, % VC, FEV1.0% and V25/height (V25/HT), were evaluated before and after laryngectomy. Statistical analysis of the data was performed with the Wilcoxon rank-sum test. The following results were obtained: 1) No statistically significant changes in arterial blood gases and FEV1.0% were found. 2) A statistically significant decrease in VC was found after total laryngectomy (p < 0.05). 3) A statistically significant decrease in V25/HT, which reflects small air way closure of the lung, was observed after total laryngectomy (p < 0.05). In all cases, the V25/HT value was below normal limits. We concluded that the decrease in VC was caused by a decrease in dead space in the upper airway, and that V25/HT may be a good parameter for evaluation of pulmonary function after laryngectomy.

Aged↗

PubMed1995

[Fourteen cases of malignant melanoma of the nasal cavity].

Fourteen cases of malignant melanoma of the nasal cavity were treated in our department during 31 years from 1962 to 1993. Ten were males and 4 were females. The ages ranged from 48 to 92 years old, with an average of 64.6 years. The chief complaints were epistaxis in 10 cases, nasal obstruction in 7, nasal cavity tumor in 1, and dull headache in 1. Histologically, 3 cases were amelanotic type, 3 oligomelanotic and 8 melanotic. The cellular types were classified as follows: 5 spindle and 9 large epitheloid cell types. Palliative treatment was performed in 1 patient, and 13 patients were treated radically. Local recurrences were seen in 8 patients, 9 regions; 3 near the posterior margin, 1 near the upper margin, 1 cheek, 2 ethmoid sinus, 1 maxillary sinus, and 1 uncertain. The cumulative survival rate among the 14 patients was 54.2% after 2 years and 31.0% after 5 years. One patient had local recurrence 13 years after surgical treatment.

Aged↗

PubMed1995

Malignant tumors of the nasal cavity: review of a 60-case series.

Sixty cases of primary malignant tumor of the nasal cavity treated in our hospital between 1962 and 1993 were reviewed. Males were affected 2.8 times more frequently than females. The age at the first consultation ranged from 11 to 92 years, with a mean of 55.1 years. The peak distribution was seen in the 6th decade. Twenty-six cases were epithelial malignancies (squamous cell carcinoma 15; adenocarcinoma 3; adenoid cystic carcinoma 3; undifferentiated carcinoma 3; mucoepidermoid carcinoma 1; malignant mixed tumor 1), while 34 cases were non-epithelial malignancies (malignant melanoma 14; malignant lymphoma 14; plasmacytoma 3; olfactory neuroblastoma 2; rhabdomyosarcoma 1). The most common symptom on presentation was nasal obstruction (66.7%), followed by epistaxis (55.0%). The first recurrence was local in 19 patients, whereas cervical lymph node metastasis occurred in three patients, bone metastasis in two, intraperitoneal metastasis in two, and brain metastasis in one. The overall five-year cumulative survival rate was 48.0%. The five-year survival rates for squamous cell carcinoma, malignant melanoma, and malignant lymphoma were 57.0%, 31.0%, and 40.0%, respectively.

Adolescent↗

PubMed1995

Radiotherapy for laryngeal cancer in patients under 50 years old.

Fifty-nine cases of laryngeal cancer treated by radiotherapy at the National Cancer Center Hospital between 1962 and 1990 were analyzed retrospectively. All the patients were less than 50 years old. The median total dose of the radiation delivered to the primary tumor site was 70 Gy. The overall 5-yr survival rate and 5-yr local control rate were 88% and 72%, respectively. Five (8.5%) of the 59 patients developed late recurrence more than five yr after initial treatment, but subsequent salvage operations were successful for disease control; three patients had T1 glottic cancer, one had T2-3 glottic cancer and one had T3N1 supraglottic cancer. Since the local control rate and the 5-yr survival rate after radiotherapy are satisfactory, radiotherapy, which allows both functional and esthetic conservation, has an important role in the treatment of laryngeal cancer in adults under 50 yr of age.

Adult↗

PubMed1994

Mediastinal tracheostomy during esophagectomy for cervicothoracic esophageal carcinoma invading the proximal trachea.

A total of 16 patients with carcinoma in the cervicothoracic esophagus underwent pharyngolaryngoesophagectomy with construction of a mediastinal tracheostoma. Among them, seven patients underwent transhiatal esophagectomy without thoracotomy, four proximal esophagectomy by cervicotomy and sternal split, and five cervical and thoracic esophagectomy and lymphadenectomy by cervicotomy and right thoracotomy. Free jejunal transfer was performed to reconstruct the esophagus in five patients, and the stomachs were used in ten. One patient died of pneumonia 27 days after surgery, and two of arterial blowout. Plastic and reconstructive surgery techniques were introduced to protect large vessels and cover the wound. The postoperative 30-day mortality was 6.3% and the total operative mortality was 18.8%. Median survival was 327 days. Mediastinal tracheostomy is safely applicable today for patients with esophageal carcinoma invading the proximal trachea, allowing them to achieve safe respiration and to enjoy meals.

Aged↗

PubMed1994

Electron-microscopic investigations of vasoactive intestinal peptide (VIP)-like immunoreactive terminal formations in the lateral septum of the pigeon.

Vasoactive intestinal peptide (VIP)-like immunoreactive terminal fields were examined in the lateral septum of the pigeon by means of immunocytochemistry. According to light-microscopic observations, these projections originated from VIP-like immunoreactive cerebrospinal fluid (CSF)-contacting neurons, which are located in the ependymal layer of the lateral septum and form a part of the lateral septal organ. The processes of these cells gave rise to dense terminal-like structures in the lateral septum. Pre-embedding immuno-electron microscopy revealed that VIP-like immunoreactive axon terminals had synaptoid contacts with perikarya of small VIP-immunonegative neurons of the lateral septum, which were characterized by an invaginated nucleus, numerous mitochondria, a well-developed Golgi apparatus, endoplasmic reticulum and a small number of dense-core vesicles (about 100 nm in diameter). VIP-like immunoreactive axons were also seen in contact with immunonegative dendrites in the lateral septum. In both axosomatic and axodendritic connections, VIP-like immunoreactive presynaptic terminals contained large dense-core vesicles, clusters of small vesicles and mitochondria. These findings suggest that VIP-immunoreactive neurons of the lateral septal organ project to small, presumably peptidergic nerve cells of the lateral septum and that the VIP-like neuropeptide serves as a neuromodulator (-transmitter) in this area.

Animals↗

PubMed1994

Application of in vivo microdialysis to pineal research in birds: measurement of circadian rhythms of melatonin.

Circadian rhythms of pineal melatonin release were measured in free-moving pigeons, Japanese quails, and chickens under light-dark cycles followed by constant dim light. Although melatonin levels differed among individual birds, circadian rhythms of melatonin were observed in all of them. Using this technique, we could examine phase shifts of melatonin rhythms and suppression of melatonin release by photic stimulation in pigeons. We could also examine effects of norepinephrine infusion on melatonin release. These results indicate that microdialysis is useful for the study of pineal melatonin rhythms in birds.

Animals↗

PubMed1994

The locus controlling pineal serotonin N-acetyltransferase activity (Nat-2) is located on mouse chromosome 11.

Melatonin is synthesized from serotonin by the enzymes serotonin N-acetyltransferase (SNAT) and hydroxyindole-O-methyl-transferase (HIOMT). We have previously reported that C57BL/6 mice do not have SNAT activity because of a mutation in an autosomal gene which is responsible for the absence of normal SNAT activity. In the present study, we have tried to map the loci of Nat-2 (the locus controlling SNAT activity) on chromosomes using a set of the BxH recombinant inbred strains which were derived from an initial cross between C3H/He with SNAT and C57BL/6 without the enzyme. Based on strain distribution patterns (SDPs), a close linkage on chromosome 11 was found between Nat-2, Es-3 (esterase-3), Glk (the locus controlling galactokinase activity) and Myla (myosin alkali light chains expressed in cardiac atrial muscle). The linkage between Nat-2 and Es-3 was confirmed by a conventional linkage test and the recombination frequency between these loci was estimated to be 16.1 +/- 3.6% (mean +/- S.E.M.).

Acetylserotonin O-Methyltransferase↗

PubMed1994

An inferior rectus abdominis bridge flap for revascularization of an ischemic tongue.

Ablative surgery to completely eradicate cancer may injure or necessitate ligation of major vessels. Unplanned necrosis of intact adjacent tissues and/or organs may result due to insufficient blood supply. We report a case in which a free inferior rectus abdominis musculocutaneous flap was successfully used as a bridge flap. Reconstruction of a soft tissue defect as well as revascularization of an ischemic organ (the tongue) was simultaneously achieved with a single flap transfer. To the best of our knowledge, this is the first report of a free inferior rectus abdominis musculocutaneous flap used successfully as a bridge flap.

Adult↗

PubMed1994

Versatility of a free inferior rectus abdominis flap for head and neck reconstruction: analysis of 200 cases.

Between 1984 and 1991, 200 inferior rectus abdominis muscle and musculocutaneous free flap transfers were performed for reconstruction of defects or deformities resulting from removal of cancer in the head and neck region. Primary reconstruction was performed in 190 of 200 cases (95 percent), and secondary reconstruction in 10 cases (5 percent). The most common indication was tongue cancer in 78 patients, followed by cancer of the oropharynx. Total flap necrosis occurred in 10 cases (5 percent) and partial necrosis in two cases (1 percent). Donor-site morbidity was minimal. One of the distinct advantages of this flap is that the volume of the muscle and/or the fatty tissue attached to a given skin paddle can be readily adjusted to suit individual requirements. This flap has proven particularly useful for complex or large tissue defects in the head and neck region.

Adolescent↗

PubMed1994

Suramin and reactive blue 2 are antagonists for a newly identified purinoceptor on rat megakaryocyte.

1. The effects of purinoceptor antagonists on ATP-induced oscillatory K(+)-currents in rat isolated megakaryocytes were investigated. 2. Both reactive blue-2 (RB-2), a selective antagonist of the P2Y purinoceptor, purinoceptor, at concentrations of 0.3-10 microM and suramin, a non-selective P2 purinoceptor antagonist, at 1-30 microM blocked the ATP-induced oscillation in a concentration-dependent manner. 3. RB-2 and suramin also blocked the ADP-induced K(+)-current oscillation at the same concentration range as in the case of ATP. However, both suramin and RB-2 had no effect on thrombin- and inositol 1,4,5-trisphosphate (IP3)-induced K+ current oscillation, indicating that they act as specific purinoceptor antagonists. 4. Thus, the purinoceptors on megakaryocytes show the properties of the P2 subtype according to their blockade by antagonists.

Adenosine Diphosphate↗

PubMed1994

Circadian and estrous cycle-dependent variations in blood pressure and heart rate in female rats.

To determine whether cardiovascular functions are controlled by the endogenous circadian system and whether they change with the estrous cycle in female rats, we measured mean arterial pressure (MAP), heart rate (HR), and spontaneous activity (ACT) of female rats using an implantable radiotelemetry device and a computerized data-collecting system. Under a 12:12-h light-dark (LD) cycle, these parameters exhibited daily rhythms that were entrained to the photic cycle. The patterns of the daily rhythms varied with estrous cycles, and variations were particularly marked in the proestrous stage. During the dark period of this stage, ACT levels were significantly higher, but HR was significantly lower than in other stages. Although the peak MAP occurred within 2 h after the onset of the dark phase in three of the estrous stages, it occurred around midnight in the proestrous stage. Such estrous cycle-dependent variations were eliminated by ovariectomy. The implantation of 17 beta-estradiol produced a gradual increase in MAP and an abrupt decrease in HR. During constant darkness, all three parameters were free running, maintaining the same internal phase relationships with each other as during LD cycles. These results indicate that daily variations in these parameters were controlled by the endogenous circadian oscillating system, that they vary with the estrous cycle in female rats, and that estrogen may be responsible for these estrous cycle-dependent variations.

Analysis of Variance↗

PubMed1994

Gramicidin perforated patch-clamp technique reveals glycine-gated outward chloride current in dissociated nucleus solitarii neurons of the rat.

1. The inhibitory response of exogenously applied glycine was investigated in freshly dissociated rat nucleus tractus solitarii neurons under whole cell configuration using new perforated patch-clamp technique termed "gramicidin perforated patch technique," which maintains intact intracellular Cl- concentrations. 2. Using the gramicidin perforated patch technique, at a holding potential (VH) of -45 mV, glycine induced outward currents in a concentration-dependent manner with a EC50 of 4.0 x 10(-5) M and at a Hill coefficient of 1.5. In contrast, using the nystatin perforated patch technique, glycine induced inward currents at the same VH in a concentration-dependent manner with an EC50 of 4.9 x 10(-5) M and at a Hill coefficient of 1.2. 3. The glycine-induced outward currents were blocked by strychnine in a concentration dependent manner with an IC50 of 2.2 x 10(-8) M. The blockade was competitive. 4. The current-voltage relationship for the 10(-5) M glycine response showed a clear outward rectification. 5. Ten-fold change of extracellular Cl- with a large impermeable anion resulted in a 65 mV shift of the reversal potential of glycine-induced currents (EGly), indicating that the membrane behaves like a Cl- electrode in the presence of glycine. 6. The intracellular Cl- activity calculated from the EGly ranged from 7.3 to 18.2 mM, with a mean value of 13.3 mM. 7. The values of EGly in the individual neurons were significantly negative to the resting membrane potentials, suggesting the existence of active transport of Cl-.

Animals↗

PubMed1994

Differences in circadian photosensitivity between retinally degenerate CBA/J mice (rd/rd) and normal CBA/N mice (+/+).

Using the magnitude of phase shift of circadian locomotor rhythms induced by a single pulse of white fluorescent light, we compared the sensitivity of the circadian system to light in retinally degenerate mice and in normal mice. In the first experiment, phase response curves (PRCs) for 10-lux white light were generated in CBA/J mice with retinal degeneration (rd/rd) and CBA/N mice with normal retinas (+/+). Although large phase delays early in the subjective night and small phase advances in the late subjective night were observed in CBA/N mice, CBA/J mice showed only small phase delays early in the subjective night. In the second experiment, we found that the magnitude of phase shifts at circadian time (CT) 16 for delays and CT 24 for advances in CBA/J mice became larger with increasing light intensity, and that CBA/J mice could show the same amount of phase shift as CBA/N mice when higher intensities were used. These findings indicate that the differences in the shapes of PRCs are not due to differences in the nature of the oscillating system, but to differences in circadian photosensitivity between these strains. Because the genetic background for the rd loci was not completely identical in the CBA/N and CBA/J mice, it was possible that genes other than the rd gene might have caused different photosensitivity in these mice. Therefore, in the last experiment, we studied the circadian photosensitivity in F1 hybrids between CBA/N and CBA/J mice and in the backcross progeny with different genotypes (+/rd and rd/rd) obtained from the crossing between F1 hybrids between CBA/N and CBA/J mice and in the backcross progeny with different genotypes (+/rd and rd/rd) obtained from the crossing between F1 and CBA/J mice. In these mice with heterogeneous genetic backgrounds as well, mice with retinal degeneration were always less sensitive to light, suggesting that reduced circadian photosensitivity is caused by retinal degeneration. These results are discussed in relation to recent findings in retinally degenerate C57BL mice, which have been found to have normal circadian sensitivity to light.

Animals↗

PubMed1994

Effects of unilateral phrenic nerve denervation on diaphragm contractility in rat.

We examined the early effects of phrenic nerve denervation on the diaphragm muscle 1, 3, 7 and 14 days after unilateral denervation in rats. In the denervated hemidiaphragms, force frequency curves at 3, 7 and 14 days decreased significantly by 51%, 50% and 38% respectively of the peak tension of the force frequency curves of the diaphragms of rats with sham operation. Twitch tensions increased significantly at 14 days, and contraction times and half relaxation times slowed significantly at 3, 7 and 14 days. The tensions of denervated diaphragms at 5 min during the fatigue runs was significantly increased at 14 days. As determined by histological staining, the mean cross sectional area of fast-twitch fibers (type II) decreased significantly from 2,742 (sham) to 1,599 microns (14 days), but that of the slow-twitch fibers (type I) did not change significantly during the same period. These findings suggest that, during the first two weeks of denervation, fast twitch fibers (type II) atrophy more rapidly than slow twitch fatigue resistant fibers (type I), as confirmed by the contractile properties and histological findings.

Adenosine Triphosphatases↗

PubMed1994

Estrous-related variations of blood pressure and heart rate in female rats.

In female rats, several biological variables change with a 4 or 5 day estrous cycle. To clarify whether blood pressure and heart rate show estrous-related changes, we measured three variables, i.e. mean arterial pressure (MAP), heart rate (HR) and spontaneous activity (ACT), using an implantable radiotelemetry transmitter and a computerized data collecting system non-invasively and chronically for more than 2 months. Under a 12-12 light-dark cycle, the three variables revealed clear daily variations and modulations by the estrous cycle which were most pronounced in the proestrous night. During the proestrous night, ACT showed a remarkable increase and a peak in the first half of the night, whereas MAP showed a gradual increase and a peak around midnight, and HR remained low without forming a peak. All modulations by the estrous cycle disappeared following bilateral ovariectomy. It is concluded that daily variations of blood pressure and heart rate are modulated according to the estrous cycle.

Animals↗