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Biomedical subjects

S Honma

Publications and source records attributed to S Honma.

At least 91 records · Page 5Linked to original sources
PubMed1998

The human gemelli muscles and their nerve supplies.

The superior and inferior gemellus muscles were examined as to their forms and the patterns of nerve supply in 13 human cadavers (20 specimens). The superior gemellus muscle (Gs) was absent in 3 specimens, but showed no accessory slip or fusion with the internal obturator muscle (Oi). The nerve to the Gs originated from the nerve to the Oi (OiN) in 7, the nerve to the quadratus femoris muscle (QfN) in 4, or both in 6 specimens. The inferior gemellus muscle (Gi) was present in all, but fused with the Oi in 3 specimens. In one specimen, an accessory muscle bundle was observed between the Gi and Oi. The Gi always received branches from the QfN at its anterior surface, but received an additional nerve supply at its posterior surface from the OiN or the pudendal nerve in one specimen each, and the accessory bundle was supplied by a branch from the OiN at its posterior surface. In a well preserved specimen, a branch to the Gi from the QfN entered the Oi and communicated with the OiN after supplying and leaving the Gi. The frequency of the dual innervation of Gs by the OiN and QfN was 29.3%, but that of the Gi and Oi could not be determined, because of the occurrence of the fused part, the accessory bundle and nerve communication. There existed some gross anatomical differences between both gemelli muscles; they are considered to be parts of the internal obturator muscle in a broad sense.

Humans↗
PubMed1998

[Thymic anaplastic carcinoma successfully controlled by combination chemotherapy].

Thymic carcinomas are rare tumors for which the main treatments have been surgery, radiotherapy, or both. However, the role of chemotherapy is less well-defined. Here, we report a case of advanced thymic anaplastic carcinoma which was suspected to be the primary lesion, yet was successfully controlled despite brain metastases by EACUM combination chemotherapy consisting of cyclophosphamide, adriamycin, cisplatin, 5-FU, and methtrexate. Pathohistological findings on metastatic lesions of the right supracuravicular lymph nodes led to a diagnosis of anaplastic carcinoma. We could not give a diagnosis of thymic carcinoma because the biopsy specimen had not been taken from the thymus. There was no evidence of a primary neoplastic tumor other than thymoma. The patient was still alive 6 years and 9 months after the start of anticancer treatment and was working normally. The findings from this case should be of value to the establishment of effective combination chemotherapy regimens for advanced thymic carcinoma.

Adult↗
PubMed1997

Independence of feeding-associated circadian rhythm from light conditions and meal intervals in SCN lesioned rats.

Free-running period of the feeding-associated circadian rhythm was assessed in suprachiasmatic nucleus (SCN) lesioned rats under three different conditions using a feeding-fasting (FF) paradigm; restricted feeding (RF) with meal intervals of 24 h (T = 24 h) under 24 h light-dark cycle (LD), RF with T = 24 h under continuous dim light (dim LL), and RF with T = 25 h under dim LL. After the termination of RF, the rats were subjected to FF regimen five times repeatedly, in which food and water were available for 7 days, followed by total food deprivation for 3 days with free-access to water. Free-running period, which was measured with reference to the prefeeding activity peak during food deprivation, was very close to 24 h and was not different under three conditions. It is concluded that the feeding-associated circadian rhythm has a major period close to 24 h, which is not affected either by light conditions nor by meal intervals.

Animals↗
PubMed1997

Midday exposure to bright light changes the circadian organization of plasma melatonin rhythm in humans.

Effects of bright light exposure at midday were examined on plasma melatonin rhythm in humans under controlled living conditions. Bright light of 5000 1x was provided from the ceiling at midday (1100-1700 h) for 3 consecutive days and the circadian rhythm in plasma melatonin was determined from the fourth to fifth day. The control study was performed in the same subjects who spend four days under dim light conditions (less than 200 1x). The subjects were allowed to sleep from 2400 to 0800 h. The onset phase, but not the end phase, of plasma melatonin rhythm was significantly phase-advanced by bright light exposure. Furthermore, the area under the curve of nocturnal melatonin rise was significantly larger under bright light exposure than under dim light. These findings indicate that midday exposure to bright light for 3 consecutive days changes the circadian organization of plasma melatonin rhythm in humans.

Adult↗
PubMed1997

Free-running circadian rhythm of melatonin in a sighted man despite a 24-hour sleep pattern: a non-24-hour circadian syndrome.

Sleep and plasma melatonin rhythms were measured longitudinally in a sighted young man (21 years old) under a day-right environment. At each measurement, the responsiveness of the melatonin rhythm to a single light pulse was examined in addition to the 24-hour profile. In experiment 1, the timing of sleep was decided by the subject himself. Although most sleep episodes were observed between 21:02 h and 10:55 h, the plasma melatonin rhythm free-ran for a period of 24.18 h. In experiment 2, the sleep-wake schedule of the subject was strictly fixed. The subject was instructed to go do bed at 24:00 h and wake up, at the latest, before 8:00 h for 40 days. The melatonin rhythm, however, continued to free-run for a period of 24.12 h. Nocturnal melatonin level could not be suppressed by a 3-hour light pulse of 500 lx, but was suppressed by a pulse of 1000 lx. It is concluded that internal desynchronization occurred in this particular sighted subject where the sleep-wake rhythm was entrained by the 24-hour day-night environment, whereas the plasma melatonin rhythm free ran, and that a forced sleep schedule did not act as a strong zeitgeber.

Adult↗
PubMed1997

A sighted man with non-24-hour sleep-wake syndrome shows damped plasma melatonin rhythm.

Twenty-four-hour profiles of plasma melatonin, cortisol and rectal temperature were measured longitudinally in a sighted man who has been suffering from sleep disorders for more than 10 years. The sleep-wake rhythm of this subject free-ran, despite his routine life, and occasionally showed a sign of internal desynchronization, where sleep was lengthened up to 30 h. These states were classified into the non-24-hour sleep-wake syndrome. Plasma melatonin concentrations in the subjective night remained at a low level and showed a damped circadian rhythm. At the same time, robust circadian rhythms were detected in plasma cortisol and rectal temperature, indicating that the circadian pacemaker was intact. The causal relationship between the damping of nocturnal melatonin rise and a failure of entrainment of the sleep-wake cycle is discussed.

Adult↗
PubMed1997

Daily melatonin intake resets circadian rhythms of a sighted man with non-24-hour sleep-wake syndrome who lacks the nocturnal melatonin rise.

Effects of daily melatonin intake on the circadian rhythms of sleep and wakefulness, rectal temperature and plasma cortisol were examined in a sighted man who had suffered from the non-24-hour sleep-wake syndrome. The subject lacked the nocturnal melatonin rise in plasma, but showed robust circadian rhythms in rectal temperature and plasma cortisol. The sleep-wake rhythm free-ran with a period longer than 24 hours. Daily melatonin intake at 21:00 h concentrated sleep episodes in the nocturnal period (24:00-8:00 h), and increased the length of the episodes. A single oral dose (3 mg) of melatonin increased plasma melatonin levels to about 1300 pg/mL within one hour and remained at pharmacological levels for approximately 6 hours. The trough of rectal temperature and the circadian rise of plasma cortisol were fixed to the early morning. A higher dose of melatonin (6 mg) did not improve the general feature. After the cessation of melatonin intake, the sleep-wake rhythm began to free-run together with the circadian rhythms in rectal temperature and plasma cortisol. It is concluded that daily intake of melatonin at early night time resets the circadian rhythms in a sighted man who lacked the nocturnal melatonin rise and showed free-running circadian rhythms in routine life.

Administration, Oral↗
PubMed1997

Expression and degradation of rat androgen receptor following castration, testosterone replacement and antiandrogens administration: analysis by Western blot and immunohistochemistry.

To elucidate the autoregulation of androgen receptor (AR) by androgen and antiandrogen, Western blot analysis and immunohistochemical study were performed. Castration reduced the immunodetected AR content, and nuclear staining was lost without cytoplasmic staining. Testosterone (T) supplement restored AR content. Quick response of AR content restoring following single administration of T was observed 48 hours after castration. The recovery of AR content detected by Western blot under each condition was accompanied by recovery of the reduced unclear staining intensities in the epithelia. Neither steroidal nor non-steroidal antiandrogens, chlormadinone acetate and flutamide, altered the AR content in normal rat ventral prostate 5, 12, 24 or 48 hours after single administration. Furthermore, neither of the drugs at various doses altered AR levels 12 hours after single administration. In summary, the rat AR is upregulated by androgen. Single administration of antiandrogens have no effect on immunodetected AR content.

Administration, Oral↗
PubMed1997

[Clinical evaluation of 2-mg granisetron tablet for nausea and vomiting induced by anticancer drugs including cisplatin].

The antiemetic effects on nausea and vomiting induced by anticancer drugs and safety of a 2-mg granisetron tablet were studied in cancer patients, particularly in the field of gynecology, who had been treated with anticancer drugs including cisplatin (CDDP) at 50 mg/m2 or more. The 1-mg granisetron tablet is already commercially available and used widely in clinical practice by oral administration of two tablets per dosage. In this investigation, the clinical efficacy, safety and usefulness of a 2-mg tablet, which can be taken more easily, were studied. The 2-mg granisetron tablet was judged to be "remarkably effective" or "effective" for nausea and vomiting in 22 (66.7%) of 33 patients. For safety, neither adverse experiences nor abnormal laboratory values were judged to be of clinical significance. The 2-mg granisetron tablet was considered "extremely useful" or "useful" in 22 (66.7%) of 33 patients. The above results confirmed the excellent antiemetic effect on nausea and vomiting induced by anticancer drugs including CDDP and the high degree of safety of a 2-mg granisetron tablet.

Adult↗
PubMed1996

Vitamin B12 enhances the phase-response of circadian melatonin rhythm to a single bright light exposure in humans.

Eight young males were subjected to a single blind cross-over test to see the effects of vitamin B12 (methylcobalamin; VB12) on the phase-response of the circadian melatonin rhythm to a single bright light exposure. VB12 (0.5 mg/day) or vehicle was injected intravenously at 1230 h for 11 days, which was followed by oral administration (2 mg x 3/day) for 7 days. A serial blood sampling was performed under dim light condition (less than 200 lx) and plasma melatonin rhythm was determined before and after a single bright light exposure (2500 lx for 3 h) at 0700 h. The melatonin rhythm before the light exposure showed a smaller amplitude in the VB12 trial than in the placebo. The light exposure phase-advanced the melatonin rhythm significantly in the VB12 trail, but not in the placebo. These findings indicate that VB12 enhances the light-induced phase-shift in the human circadian rhythm.

Adult↗
PubMed1996

Persistence of circadian oscillation while locomotor activity and plasma melatonin levels became aperiodic under prolonged continuous light in the rat.

In order to examine the mechanism for a loss of circadian rhythms in several functions under prolonged continuous light (LL), rats were blinded following LL over 5 months, and the mode of reappearance of circadian rhythms were analyzed in locomotor activity and plasma melatonin levels. Locomotor activity and plasma melatonin levels in individual rats became aperiodic after the exposure to LL. On the day of blinding, plasma melatonin levels showed circadian rhythms having a peak coincided with the activity time of locomotor rhythm which was restored after blinding. The time of melatonin peak was not related to the time of blinding (onset of darkness) nor to the initial time of blood sampling. Circadian rhythm in plasma melatonin levels reappeared faster than those in locomotor activity. The findings suggest that aperiodism developed in these functions under prolonged LL is not due to disruption of the circadian oscillation but to uncoupling of overt functions from the circadian pacemaker.

Animals↗
PubMed1996

Substance P receptor regulates the photic induction of Fos-like protein in the suprachiasmatic nucleus of Syrian hamsters.

Substance P (SP) is a candidate neurotransmitter or neuromodulator for conveying light information from the retina to the hypothalamic suprachiasmatic nucleus (SCN) where a circadian oscillator(s) is located in mammals. Immediate early gene c-fos has been demonstrated to be induced in the SCN with a brief light exposure at the subjective night, and suggested to play an important role in the photic entrainment of the oscillator. To clarify the possibility of an involvement of the SP receptor in the photic-induction of c-fos in the SCN, we examined effects of a SP receptor antagonist, spantide, on the light-induced Fos-like protein immunoreactivity (Fos-lir) in the SCN of Syrian hamster. The light-induced Fos-lir was inhibited with the pretreatment of spantide in a dose-related manner and in an anatomically distinctive way. The higher dose of spantide (8 nmol) blocked light-induced Fos-lir substantially in the rostral and central areas of the SCN, and in the dorsal portion of the caudal SCN. However, it blocked Fos-lir only slightly in the ventral portion of the caudal SCN. These results suggest that the SP is involved in conveying light information to induce Fos protein in the hamster SCN, and that different neurotransmitter systems are involved in the light-induced Fos-lir in the different portions of hamster SCN.

Animals↗
PubMed1996

Methamphetamine stimulates the release of neuropeptide Y and noradrenaline from the paraventricular nucleus in rats.

Effects of methamphetamine (MAP) on the extracellular neuropeptide Y (NPY) and noradrenaline (NA) levels were examined in the vicinity of the paraventricular nucleus (PVN) of freely moving rats by means of push-pull perfusion. The NA and NPY levels increased significantly in 30-60 min and reached the maximum level in 90-120 min after intraperitoneal administration of MAP. The effects were dose-dependent. The maximum levels were 1.6-fold of the pretreatment level for NPY and 7-fold for NA, respectively, when 5.0 mg/kg b.w. of methamphetamine was administered. It is concluded that MAP stimulates the releases of paraventricular NPY and NA, but the effect is more strong for NA than for NPY.

Animals↗
PubMed1996

Effect of aromatase inhibitor, TZA-2209, on the prostate of androstenedione-treated castrated dogs: changes in prostate volume and histopathological findings.

To determine whether the inhibition of estrogen-related effect in the prostate would be of value in the management of benign prostate hyperplasia (BPH), we examined the effect of TZA-2209, a new steroidal aromatase inhibitor, on the prostate in three of six castrated beagles that received 75 mg/week androstenedione. The three other animals served as controls. Sequential measurements of prostate volume by transrectal ultrasonography showed that the volume in TZA-treated dogs was significantly decreased compared with that in the controls. Prostatic aromatase activity was suppressed by TZA administration. Histopathologically, the stromal component was increased and glands were atrophied by androstenedione treatment. TZA administration increased the volume of the glands. Immunohistochemical detection of estramustine-binding protein showed more positive staining of the protein in the glands that were increased in volume by TZA administration. We concluded that the aromatase inhibitor effectively antagonized the estrogen-related stromal changes, however, this action was accompanied by stimulation of the glandular component due to the accumulation of androgens, the substrate of the aromatase. In the light of these findings, we suggest the simultaneous treatment for the androgen-glandular component route in the prostate is necessary for the effective management of BPH.

Androstenedione↗
PubMed1996

Effects of restricted daily feeding on neuropeptide Y release in the rat paraventricular nucleus.

Extracellular neuropeptide Y (NPY) in the vicinity of the paraventricular nucleus (PVN) and the NPY concentrations in the PVN, arcuate nucleus of the hypothalamus (ARC), and the nucleus tractus solitarius (NTS) were measured in rats under ad libitum and restricted daily feeding (RF) where meal was supplied at a fixed time of day. The extracellular NPY levels did not vary significantly between 0600 and 2200 in rats under ad libitum feeding but were increased before meal and decreased immediately after mean supply under the RF regimen. Similarly, the NPY concentrations in the PVN, ARC, and NTS were increased immediately before meal. When meal was omitted at the regular mealtime, the extracellular NPY levels were not decreased rapidly, and the NPY concentration in the PVN remained at a low level. Rats were subjected to the feeding-fasting paradigm after the termination of RF. The extracellular NPY levels were returned to basal levels during the feeding period but were elevated during the fasting period at almost the same time as that for meal supply under the RF regimen. It is concluded that the prefeeding enhancement of the NPY release in the PVN under the RF regimen is regulated by the feeding-associated circadian rhythm.

Animals↗
PubMed1996

Prefeeding release of paraventricular neuropeptide Y is mediated by ascending noradrenergic neurons in rats.

The neuronal system responsible for the release of neuropeptide Y (NPY) in the paraventricular nucleus (PVN) was examined in rats under food deprivation and restricted daily feeding (RF). The ascending noradrenergic bundle (NAB) of neurons from the brain stem were destructed by microinjection of 6-hydroxydopamine (6-OHDA), and the extracellular NPY level in the PVN was measured by push-pull perfusion. 6-OHDA significantly reduced the extracellular norepinephrine level in the PVN to 15% of the control value when injected into the PVN and to 40% when injected into the midbrain ventral NAB. 6-OHDA administration into the NAB affected neither the deprivation-induced increase nor the feeding-induced decrease in the extracellular NPY. The amount of food intake after refeeding was not changed by the 6-OHDA treatment. On the other hand, 6-OHDA injection into the PVN or NAB not only decreased the extracellular NPY level, the amount of food intake was not change by the 6-OHDA treatment. It is concluded that the NAB is involved in the prefeeding NPY release in rats under RF but not in the deprivation-induced NPY release.

Animals↗
PubMed1996

Dissociation of paraventricular NPY release and plasma corticosterone levels in rats under food deprivation.

Extracellular neuropeptide Y (NPY) in the vicinity of the paraventricular nucleus (PVN) as well as NPY concentrations in the PVN were measured in rats under ad libitum feeding and 2-day and 10-day food deprivation. Plasma corticosterone levels were not changed by 2-day food deprivation but were increased by subsequent refeeding. In contrast, the extracellular NPY levels were increased by 2-day food deprivation and were decreased rapidly by refeeding. The NPY concentrations were also increased and increased further by refeeding. On the other hand, plasma corticosterone levels were elevated by 10-day food deprivation and were decreased by subsequent refeeding. The extracellular NPY levels were also increased by food deprivation and decreased gradually after refeeding. However, the postprandial levels were still elevated when plasma corticosterone levels were returned to the basal levels. The NPY concentrations were also increased and increased further by refeeding. The amount of food intake after refeeding was positively correlated with the extracellular NPY levels. It is concluded that extracellular NPY levels in the PVN do not necessarily covariate with plasma corticosterone levels in rats under food deprivation.

Animals↗