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Biomedical subjects

S Ebihara

Publications and source records attributed to S Ebihara.

At least 145 records · Page 8Linked to original sources
PubMed1988

The phase-shifting effects of pentobarbital on the circadian rhythm of locomotor activity in the mouse: strain differences.

The phase response curves (PRCs) generated by pentobarbital injections (30 mg/kg) were obtained in SK and C57BL mice. Pentobarbital injections induced both advance and delay phase-shifts in the circadian rhythm of locomotor activity in SK mice but no phase-shifts were observed at any circadian time (CT) for pentobarbital injections in C57BL mice. The observation that a higher dose of pentobarbital (80 mg/kg) does not induce phase-shifting in C57BL mice has indicated that the differences in phase-shifting effects of pentobarbital are not quantitative but qualitative. These strains may be useful for studying the neurochemical regulation of the mammalian circadian rhythm.

Animals↗
PubMed1988

Loss of the circadian rhythms of locomotor activity, food intake, and plasma melatonin concentration induced by constant bright light in the pigeon (Columba livia).

Locomotor activity and feeding activity were measured together with circulating levels of melatonin in pigeons which were exposed to constant bright light (LLbright, 2000 lux) following light-dark (LD) cycles. Although all the pigeons showed daily rhythms of locomotor activity, feeding activity, and melatonin levels under LD cycles, they lost all the rhythms in prolonged LLbright. Acute exposure to bright light (2000 lux) during darkness reduced plasma melatonin levels. The half-time for the suppression in melatonin levels was about 30 min after short-term light exposure. These results support the hypothesis that melatonin may control the circadian rhythms of locomotor activity and feeding activity in the pigeon.

Animals↗
PubMed1988

The measurement and analysis of circadian locomotor activity and body temperature rhythms by a computer-based system.

A new computer-based system for collection and analysis of circadian body temperature and locomotor activity rhythms is described. This system makes possible the simultaneous measurements of body temperature and locomotor activity rhythms from 16 animals kept in separate cages. Several programs were developed for measurement and analysis of the data. This system is available not only in the study of circadian rhythms but also in other biological studies where long-term recordings of rest-activity cycles and body temperature are required.

Animals↗
PubMed1988

Different responses of the circadian system to GABA-active drugs in two strains of mice.

Recent work in our laboratory has shown that sodium pentobarbital injections can induce phase-dependent phase shifts of the circadian rhythm of locomotor activity with the maximum advance at circadian time (CT) 8 and the maximum delay at CT0 in SK/Nga mice but no phase shifts in C57BL/6 mice. In the present study, the possibility that the differences in the effects of pentobarbital on the circadian rhythm may be due to different contributions of the GABA-ergic system to circadian organization in the two strains was tested by comparing the responses of SK mice with those of C57BL mice to muscimol (2 mg/kg), a GABA receptor agonist, and triazolam (25 mg/kg), which is thought to act by potentiating the action of GABA. The hypothesis that pentobarbital-induced phase shifts of SK mice are mediated by the GABA receptor system was also tested by observing whether the phase-shifting effects of pentobarbital were blocked by bicuculline (0.5 mg/kg), a selective antagonist of GABA, injected 3 min prior to pentobarbital (30 mg/kg). The results indicated that muscimol induced phase advances at CT8 and phase delays at CT0, and triazolam induced phase advances at CT8 in SK mice. No phase shifts were induced by any treatment in C57BL mice. These results suggest that the role of GABA-ergic systems in circadian organization may be different in SK and C57BL mice. In addition, bicuculline could block the phase-shifting effects of pentobarbital in SK mice, suggesting that the GABA receptor system may mediate phase-shifting effects of pentobarbital in SK mice.

Animals↗
PubMed1988

[Quality of life in treated head and neck cancer patients].

Sixty-Seven patients with head and neck cancer have been studied with respect to their quality of life after their treatment. The Grogono Woodgate index was used to evaluate their quality of life, the quality of life of patients treated for laryngeal cancer was excellent, even if they underwent total laryngectomy. On the contrary, however, patients who had hypopharyngeal cancer and had undergone a pharyngolaryngoesophagectomy had the lowest indices. As for patients with an oral cancer, their indices were high if the cancer was being controlled by radiotherapy.

Activities of Daily Living↗
PubMed1988

[Prognostic factors of head and neck cancer].

A multivariate analysis of survival in 403 cases of head and neck cancer was carried out. Primary sites of the 403 cases were, oral cavity, larynx, hypopharynx, mesopharynx, epiharynx and maxillary sinus. The purpose of the analysis was to determine patient and tumor factors that influence survival. The patient factor observed to influence survival was patient age (p = 0.0009), however, patient gender was not significantly related to survival. Tumor factors were evaluated by T, N classification, histological type and the location of primary site. Although location of primary site was not related to survival, primary site (T) and lymph node (N) classification did influence survival rate (T; p = 0.0001, N; p = 0.0000). A significant correlation was also recognized between histological type and prognosis (p = 0.0189).

Adenocarcinoma↗
PubMed1987

Pineal indole metabolism in the mouse.

The activity of two pineal enzymes serotonin N-acetyltransferase (SNAT) and hydroxyindole-O-methyltransferase, (HIOMT) and the pineal content of serotonin (5-HT) and N-acetylserotonin (NAS) were measured in several strains of mice (Mus domesticus) in order to compare melatonin synthetic pathways among them. Of the strains we examined, C57BL/6J, AKR/J, BALB/c, NZB/BLNJ and wild mice, only wild mice synthesize pineal melatonin. Wild mice had high activity of both SNAT and HIOMT; NZB had SNAT activity but did not have HIOMT; the three other strains had neither SNAT nor HIOMT; the activity of SNAT in wild mice showed a clear daily rhythm but HIOMT activity did not show any significant daily changes. The pineal content of 5-HT in wild and NZB mice was higher during the day than during the night, however in C57BL and AKR, 5-HT levels were higher during the night than during the day. As expected NAS was found in wild and NZB mice.

Acetylserotonin O-Methyltransferase↗
PubMed1987

Oral and pharyngeal reconstruction using the free forearm flap.

Recent progress in myocutaneous and free flaps has facilitated the primary closure of various complex defects resulting from ablative surgery of head and neck cancers. The musculocutaneous flap (such as the pectoralis major flap or the latissimus dorsi flap) has in particular proved its greater versatility. The forearm free flap for intraoral defects can provide thin and pliable skin and has great potential in the reconstruction of oropharyngeal defects. Between November 1982 and August 1985, we achieved 74 free forearm flap transfers for patients with head and neck cancers. Herein we present several clinical applications of the free forearm flap and discuss its advantages and disadvantages, especially hand morbidity after flap elevation.

Adult↗
PubMed1987

Hamartoma of the parotid gland: a case report with immunohistochemical and electron microscopic study.

A case of a solid parotid tumour in a 16-year-old boy is presented. Histologically, the tumour demonstrated some peculiar findings. An acinar pattern was predominant although every component seen in the normal salivary gland was present, namely, serous and mucous gland acini, ducts, myoepithelial cells, adipose and lymphoid tissue. Large eosinophilic granules were abundant in the large acinar cell cytoplasm. Immunohistochemically, the tumour demonstrated the proteins which are present in the normal parotid gland, for example, amylase, lactoferrin and lysozyme. Electron microscopic features were quite similar to those of normal parotid tissue except for accumulation of a large number of cytoplasmic granules in the acinar cells. There has been no previous report of a tumour with the same features as seen in this case. Our pathological diagnosis is hamartoma, although the possibility of hyperplasia or neoplasia can not be excluded.

Adolescent↗
PubMed1987

The phase relationship between the circadian rhythms of locomotor activity and circulating melatonin in the pigeon (Columba livia).

The phase relationship between the circadian rhythms of locomotor activity and circulating melatonin levels under LD 12:12 and constant dim light conditions (LLdim) was examined in pigeons. Our new radioimmunoassay technique had sufficient sensitivity to detect the concentration of melatonin from a small quantity of plasma, which enabled us to measure locomotor activity simultaneously with circulating melatonin rhythms from each individual pigeon. The relationship of phase between the two circadian rhythms in LLdim was the same as in LD. The rhythms of locomotor activity and melatonin levels free-run but maintain the relation of 180 degrees out of phase in LLdim. These results do not contradict the hypothesis that melatonin may entrain the circadian rhythm of locomotor activity in the pigeon.

Animals↗
PubMed1987

Primary esophageal reconstruction after resection of the cancer in the hypopharynx or cervical esophagus: comparison of free forearm skin tube flap, free jejunal transplantation and pull-through esophagectomy.

Sixty-six patients with carcinoma of the hypopharynx or cervical esophagus received esophageal extraction and primary reconstruction. The methods of reconstruction were free forearm skin tube grafting, free jejunal transplantation and immediate pharyngo-gastrostomy after pull-through esophagectomy. Considering the postoperative complications of each method, free forearm skin tube transplantation is the safest, but it can only be used for a short defect of the esophagus. With pull-through esophagectomy, we are able to extract the whole esophagus and have no fear of leaving any remaining cancer in the thoracic esophagus, but the operative burden and the rate at which complications occur are higher. Free jejunal transplantation can be used for a short or long defect of the cervical esophagus with small operative burden. Among three methods of reconstruction, free jejunal transplantation is recommended for primary reconstruction of the cervical esophagus.

Esophageal Neoplasms↗
PubMed1987

Acoustic screening for laryngeal cancer.

An acoustic screening method for indicating the possible presence of laryngeal cancer was investigated. Three acoustic parameters, comprising perturbations in pitch-period and peak-amplitude sequences, and vocal noise, were measured from a sustained vowel, e, spoken by the subjects taking part in the investigation. Experiments to discriminate between normal and cancer groups were performed with voice samples taken from 64 normal control subjects and 57 patients with laryngeal cancer. Experiments were also carried out to test the perceptual significance of the three parameters. From the results, we have been able to conclude that their combined use will enable us to build an acoustic screening system for laryngeal cancer.

Aged↗
PubMed1986

Genetic control of melatonin synthesis in the pineal gland of the mouse.

Pineal melatonin may play an important role in regulation of vertebrate circadian rhythms and in human affective disorders. In some mammals, such as hamsters and sheep, melatonin is involved in photoperiodic time measurement and in control of reproduction. Although wild mice (Mus domesticus) and some wild-derived inbred strains of mice have melatonin in their pineal glands, several inbred strains of laboratory mice (for example, C57BL/6J) were found not to have detectable melatonin in their pineal glands. Genetic analysis suggests that melatonin deficiency in C57BL/6J mice results from mutations in two independently segregating, autosomal recessive genes. Synthesis of melatonin from serotonin in the pineal gland requires the enzymes N-acetyltransferase (NAT) and hydroxyindole-O-methyltransferase (HIOMT). Pineal glands from C57BL/6J mice have neither NAT nor HIOMT activity. These results suggest that the two genes involved in melatonin deficiency are responsible for the absence of normal NAT and HIOMT enzyme activity.

Animals↗
PubMed1986

Reconstruction of the oral commissure.

A technical refinement for oral commissure reconstruction is presented. The oral commissure has an important role in oral sphincteric function. We use a combination of local skin flaps for soft tissue reconstruction and a pedicled tongue flap for intraoral lining, with satisfactory results. A case involving a large mucosal ulcer around the oral commissure, in which the excisional defect was repaired by this method, is presented.

Female↗
PubMed1986

Normalized noise energy as an acoustic measure to evaluate pathologic voice.

In order to evaluate noise components included in pathologic voice signals, a novel acoustic measure, normalized noise energy (NNE), is proposed and its effectiveness for the detection of laryngeal pathologies is investigated with 250 vowel samples spoken by 64 control (normal) subjects and 186 patients with various laryngeal diseases. The NNE is automatically computed from the voice signals using an adaptive comb filtering method performed in the frequency domain. Experiments with the voice samples show that the NNE is especially effective for detecting glottic cancer, recurrent nerve paralysis, and vocal cord nodules. Specifically, when glottic cancer is represented in terms of the T classification adopted by the UICC (Union Internationale Contre le Cancer), glottic T2-T4 cancer can be perfectly discriminated from normal samples, but 22.6% of patients with glottic T1 cancer are incorrectly classified as normal, with an error rate of 9.4% for normal subjects.

Glottis↗
PubMed1986

Histologic factors influencing prognosis of adenoid cystic carcinoma of the head and neck.

Histologic specimens from 61 cases of adenoid cystic carcinoma of the head and neck were reviewed in order to determine prognostic factors of this peculiar neoplasm. After the tumor was reviewed and classified according to several criteria, follow-up information, which was available in 54 cases, was analyzed and compared with each histological subgroup. As for the histologic pattern, the prognosis of adenoid cystic carcinoma with a solid pattern was worse than that without a solid pattern in respect of 5- and 10-year survival rates. However, there was no difference in 15-year survival between the two groups. Tumors with severe cell atypia showed more malignant behavior than those with moderate or mild atypia (p less than 0.001). Increased mitotic activity of more than two cells in mitosis per high power field was also found to be a sign of poor prognosis (p less than 0.001). Presence of perineural invasion was not correlated with the final outcome of the disease. Cell atypia and mitotic activity as well as the histologic pattern should be evaluated for assessing the degree of malignancy of adenoid cystic carcinoma.

Adolescent↗