Biomedical subjects

Y Hishikawa

Publications and source records attributed to Y Hishikawa.

At least 19 recordsLinked to original sources

PubMed2003

CSF hypocretin measures in patients with obstructive sleep apnea.

The majority of patients with narcolepsy-cataplexy were reported to have very low cerebrospinal fluid (CSF) hypocretin-1 (orexin-A) levels. The hypocretin-1 levels of secondary excessive daytime sleepiness (EDS) disorders are not known. In this study, we found that CSF hypocretin levels in the patients with obstructive sleep apnea syndrome were within the control range. The low hypocretin levels seem to reflect only the presence of cataplexy and DR2 positive in narcoleptics but not EDS itself.

Adult↗

PubMed2001

Total sleep deprivation induces an acute and transient increase in NK cell activity in healthy young volunteers.

STUDY OBJECTIVES: To investigate the effects of one night's total sleep deprivation (TSD) on NK cell activity, with rigorous control of circadian phase of sampling points as well as physical exercise level in association with sleep deprivation. DESIGN: The mean sleep onset time of each subject before starting the study was defined as his 0000 h. This study was composed of a Sleep-Sleep session (sleep times, 00:00 h - 08:00 h and 24:00 h - 32:00 h) and a Sleep-Wake session (sleep time, 00:00 h - 08:00 h) with TSD (24:00 h - 32:00 h) placed in a cross-over design with 2-week interval between each session. In each session, the subjects were rested in the supine position under dim light from - 06:00 h to 36:00 h (for 42 hours). SETTING: University-based sleep and chronobiology laboratory PARTICIPANTS: 10 healthy adult men (mean age, 20.9 y; age range, 19-23 y) INTERVENTIONS: NA. MEASUREMENTS AND RESULTS: NK cell activity was measured every 4 hours from 12:00 h. NK cell activity during TSD (at 28:00 h) has been revealed to significantly increase (p=0.01) compared with the corresponding value in the Sleep-Sleep session. This effect was weaker at their usual waking time 32:00 h (p=0.07), and disappeared until 36:00 h (4 hours after awakening). The circadian rhythm phases (dim light melatonin onset time) were coincident between the 2 sessions. CONCLUSIONS: The present findings suggest that one night TSD induces an acute and transient increase in NK cell activity that is not influenced by the effects of circadian rhythm or the amount of physical exercise undertaken during TSD.

Adult↗

PubMed2001

Dosimetric predictors of radiation esophagitis in patients treated for non-small-cell lung cancer with carboplatin/paclitaxel/radiotherapy.

PURPOSE: To establish dosimetric predictors of radiation esophagitis (RE) in patients treated with a combination of carboplatin, paclitaxel, and radiotherapy. METHODS AND MATERIALS: Three-dimensional radiotherapy plans of 26 patients with non-small-cell lung cancer who received 50-60 Gy of radiotherapy concurrently with weekly administration of carboplatin (AUC 2) and paclitaxel (40-45 mg/m(2)) were reviewed in conjunction with RE. The factors analyzed included the following: percentages of organ volumes receiving >40 Gy (V40), >45 Gy (V45), >50 Gy (V50), and >55 Gy (V55); the length of esophagus (total circumference) treated with >40 Gy (LETT40), >45 Gy (LETT45), >50 Gy (LETT50), and >55 Gy (LETT55); the maximum dose in the esophagus (Dmax); and the mean dose in the esophagus (Dmean). Data were obtained on the basis of superposition algorithm. RESULTS: All factors except Dmax showed statistical correlation with RE. Good correlations were shown between RE and LETT45 (rho = 0.714) and V45 (rho = 0.686). CONCLUSIONS: LETT45 and V45 appear to be useful dosimetric predictors of RE. It is also suggested that Dmax does not predict RE.

Adult↗

PubMed2001

Endoscopic findings of radiation esophagitis in concurrent chemoradiotherapy for intrathoracic malignancies.

BACKGROUND AND PURPOSE: The incidence and extent of radiation esophagitis were assessed endoscopically in patients treated with concurrent chemoradiotherapy. PATIENTS AND METHODS: Eighty-two patients who received thoracic radiotherapy for lung, thymic, or esophageal cancer were investigated endoscopically from July 1991 to the end of 1997. Among them, 23 esophageal cancer patients were treated with radiation alone, and the others were treated with concurrent chemoradiotherapy. Esophageal endoscopy was performed during or just after radiotherapy. The presence of radiation esophagitis was assessed and assigned an endoscopic score (i.e. grade 0 for normal, 1 for erythema, 2 for erosion or sloughing, 3 for ulcer, hemorrhage, or stricture). The symptomatic grade was assessed using the RTOG (Radiation Therapy Oncology Group) acute radiation morbidity score. RESULTS: A correlation was seen between endoscopic and RTOG scores. However, even some patients with RTOG grade 0 to 1 had endoscopic grade 3 esophagitis. Endoscopic grade 3 was observed in 16 (27.1%) patients in the concurrent chemoradiotherapy group, whereas it did not occur in any patient in the radiation alone group (P=0.004). CONCLUSIONS: Our results suggest that (1) RTOG score correlates closely to esophageal mucosal damage, and (2) more severe esophagitis occurs in those undergoing concurrent chemoradiotherapy than those undergoing radiotherapy alone [corrected].

Adult↗

PubMed2001

Hypersomnia due to acute disseminated encephalomyelitis in a 5-year-old girl.

A 5-year-old girl suffering from hypersomnia due to acute disseminated encephalomyelitis (ADEM) is reported. Brain CT revealed a large low-density lesion involving the lentiform nucleus, posterior limb of the internal capsule, thalamus, posterior hypothalamus and midbrain in the left side. She was treated with intravenous dexamethazone. After the initial dose of dexamethazone, hypersomnia was dramatically and rapidly improved. A later brain CT study disclosed that the lesion in the brain disappeared. The brain lesion in this case involved the waking center in the brain, which was described by Von Economo. We concluded that hypersomnia in this case was due to ADEM involving the neural mechanism for maintaing wakefulness, probably in the thalamus and posterior hypothalamus. Repeat all night polysomnograpy in this case disclosed prolonged total sleep time and increased amount of stage 3-4 sleep in the hypersomniac state.

Journal Article↗

PubMed2001

Partial tolerance of subcutaneously transplanted xenogeneic tumour cell graft by Fas-mediated immunosuppression.

Certain anti-Fas antibodies, such as RMF2, induce apoptosis of Fas-expressing cells. We applied the Fas/anti-Fas system to induce killing of Fas-expressing immunocytes with resultant immunosuppression. W7TM-1 tumour cells, a rat T-cell line, were inoculated subcutaneously in BALB/c mice and tumour growth was monitored in untreated mice and in mice treated with RMF2. Prior to treatment with RMF2, we examined the expression of Fas in isolated splenocytes and in tumour-infiltrating lymphocytes by flow cytometry and immunohistochemistry, respectively. There was a remarkable increase in Fas-positive lymphocytes, including natural killer (NK) cells, among splenocytes at day 5 after tumour cell inoculation. The number of Fas-positive infiltrating lymphocytes also increased markedly, from day 5 to day 10. We then examined whether RMF2 could induce apoptosis of Fas-positive activated lymphocytes isolated from the spleen at day 5 in vitro. Terminal deoxy (d) -UTP nick end labelling (TUNEL) and Annexin V staining methods showed apoptosis of isolated cells when incubated with RMF2, and typical apoptotic features were confirmed by 4',6-diamidino-2-phenylindole dihydrochloride (DAPI) staining. Furthermore, suppression of cellular and humoral immunity was noted in RMF2-treated mice by mixed lymphocyte reaction and assay of serum levels of immunoglobulin G, respectively. Finally, treatment of animals with RMF2 daily from day 5 to day 9 could maintain the tumour size, while the tumour mass began to diminish in untreated mice immediately after reaching a maximum size. We confirmed the enhancing effects of long-term treatment with RMF2, through the induction of immunosuppression, on the growth of unvascularized xenogeneic tumour cell grafts.

Animals↗

PubMed2001

Expression of Fas and Fas ligand in normal and ischemia-reperfusion testes: involvement of the Fas system in the induction of germ cell apoptosis in the damaged mouse testis.

Apoptosis of germ cells is very common in normal and injured mammalian testes. The aim of this study was to examine the possible involvement of the Fas and Fas ligand (FasL) system in the induction of germ cell apoptosis in normal and ischemia-reperfusion testes of adult mice. Apoptosis was assessed by the TUNEL method and by DNA gel electrophoresis. Fas and FasL mRNAs were detected by Northern blotting and reverse transcription polymerase chain reaction techniques, and proteins were analyzed by Western blotting and immunohistochemistry. Apoptosis of germ cells was identified in the normal testis especially around stages XI and XII, whereas the expression of Fas and FasL was largely confined to Leydig cells and Sertoli cells, respectively. However, in the testes reperfused after 1 h of ischemia, a high number of TUNEL-positive cells were identified in parallel with increased Fas-positive germ cells, whereas FasL expression in Sertoli cells was almost constant irrespective of the duration of reperfusion. Moreover, i.p. injection of anti-Fas antibody, which blocks the interaction between Fas and FasL, inhibited apoptosis, as indicated by the reduced number of TUNEL-positive cells, except for apoptosis at stages XI and XII. Our results indicate that the Fas/FasL system mediates apoptosis of spermatogenic cells in the injured testis but not spontaneous apoptosis in the normal testis.

Animals↗

PubMed2001

Expression of metallothionein in colorectal cancers and synchronous liver metastases.

The aim of this study is to clarify whether the expression of metallothionein (MT) is related with the malignant potential in primary colorectal cancer and/or synchronous liver metastasis. Immunohistochemical staining for MT was performed on the specimens of adenocarcinoma of the colon and rectum and its liver metastases in 34 patients treated with curative surgery, respectively. Expression of MT was compared with clinicopathological variables and patient survival. In patients with primary colorectal cancer, positive expression was found in 7 of 34 (20.6%) patients, but MT was not detected in any of the cases of liver metastases (0%; p = 0.0111). In the primary tumor, positive MT expression was significantly associated with a higher degree of lymph node involvement (mean +/- SD: 48.4 +/- 33.8 vs. 18.6 +/- 24.4% in MT-positive and MT-negative tumors, respectively; p = 0.0122). The survival rate in the patients with MT-negative tumors was significantly better than that in those with MT-positive tumors as primary sites (p = 0.0198). MT expression in colorectal cancer may be a potential marker affecting lymph node metastases and may be a predictor of a poor prognosis, particularly in patients with synchronous liver metastases.

Adenocarcinoma↗

PubMed2001

Diminished melatonin secretion in the elderly caused by insufficient environmental illumination.

The pineal hormone melatonin has some circadian regulatory effects and is assumed to have a close relation with sleep initiation and maintenance. Many previous reports have described age-related decreases in melatonin levels, especially in elderly insomniacs (EIs), which may act as causal or exacerbating factors in sleep disturbances in the elderly. Ten elderly residents with psychophysiological insomnia (mean age, 74.2 yr), 10 healthy residents of the same home [elderly control (EC) group; mean age, 72.7 yr], and 10 healthy young control subjects (mean age, 20.9 yr) living at home participated in this study. The elderly persons, especially the EIs, were exposed to significantly less environmental light and simultaneously suffered from significantly diminished nocturnal melatonin secretion. Supplementary exposure to 4 h (1000 to 1200 h, 1400 to 1600 h) of midday bright light in the EI group significantly increased melatonin secretion to levels similar to those in the young control group without circadian phase-shifting. There was a tendency for the magnitude of the increase in nocturnal melatonin secretion stimulated by bright light to parallel amelioration of sleep disturbances in these subjects. The present findings suggest that we need to pay attention to elderly individuals who suffer under conditions of poor environmental light resulting in disorganized circadian rhythms, including the sleep-wake cycle.

Adult↗

PubMed2001

Localization in situ of specific RNA by electron microscopy.

To better understand the metabolism of RNA in nuclei, the analysis of precise nuclear distribution of specific RNA would be essential. For this purpose, nonradioactive electron microscopic (EM) in situ hybridization may be the most appropriate technique while the details required for the technique have not been fully established. In the present study, we attempted to localize 28S and 18S rRNAs in the nuclei of mouse Sertoli cells by EM in situ hybridization as a model system. After various preliminary experiments we chose the pre-embedding method; fresh-frozen sections of mouse testis were fixed with a mixture of 4% paraformaldehyde and 0.1% glutaraldehyde, digested with 10 microg/ml of proteinase K and hybridized with thymine-thymine (T-T) dimerized oligodeoxynucleotides (oligo-DNA) complementary to a part of 28S and 18S rRNAs. Then, the T-T dimers were detected enzyme-immunohistochemically with horseradish peroxidase (HRP) labeled anti-T-T dimer. After osmification of HRP products, the sections were embedded in Epon resin, cut into 100 nm ultra-thin sections and observed under a transmission electron microscope. As a result, we successfully localized both 28S and 18S rRNAs in the dense fibrillar and granular components of the nucleolus, showing the usefulness of nonradioactive EM in situ hybridization in the nuclear localization of specific RNA.

Animals↗

PubMed2000

Clinical outcomes of orbital irradiation combined with or without systemic high-dose or pulsed corticosteroids for Graves' ophthalmopathy.

PURPOSE: To evaluate the outcomes of orbital irradiation with or without high-dose or pulsed corticosteroids in patients with Graves' ophthalmopathy (GO). METHODS AND MATERIALS: One hundred and twenty-one patients with moderate to severe GO who received orbital irradiation from 1987 to 1997 were retrospectively analyzed. A total dose of 20 Gy in 10 fractions was delivered to the bilateral retrobulbar volume. Eighty-six patients were treated in combination with high-dose or pulsed corticosteroids and irradiation. Univariate and multivariate analyses were performed to assess the prognostic variables. RESULTS: The median follow-up period was 26 months. The overall clinical response was evaluated as excellent in 17 patients (14%), good in 65 (54%), fair in 31 (25%), no response in 7 (6%), and worse in 1 (1%). The best responses were noted for soft-tissue signs, extraocular muscle involvement, and sight loss, while a limited response was noted for proptosis. Multivariate analysis revealed that the use of high-dose corticosteroid or pulsed corticosteroids, female gender, and a shorter duration of ophthalmopathy before radiotherapy were significantly correlated with favorable outcomes. No long-term complications related to radiotherapy were observed. CONCLUSION: Orbital irradiation combined with high-dose or pulsed corticosteroids is an effective treatment for moderate to severe GO, especially in cases with major manifestations of soft-tissue signs, extraocular muscle impairment, or sight loss.

Adolescent↗

PubMed2000

Concurrent expressions of metallothionein, glutathione S-transferase-pi, and P-glycoprotein in colorectal cancers.

PURPOSE: Because the status of the inherent drug-resistance of colorectal cancers remains obscure, human colorectal cancers with no neoadjuvant therapy were retrospectively investigated regarding the expression of three drug-resistant proteins: metallothionein, glutathione S-transferase-pi, and P-glycoprotein. METHODS: Paraffin-embedded tissues of 130 colorectal cancers (Dukes A, 20; B, 49; C, 41; D, 20) obtained by surgical resections from 1982 to 1989 were used. The three proteins were immunostained by the streptavidin-biotin complex method. The immunostaining was judged to be positive if more than 5 percent of cells showed positive staining by use of cell analysis system. The data were compared with clinicopathologic features (Dukes A-D) and patients' prognosis (Dukes AC). RESULTS: Metallothionein, glutathione S-transferase-pi, and P-glycoprotein were positively expressed in 91 (70 percent), 30 (23 percent), and 98 (75 percent), respectively. A total of 120 (86 percent) expressed at least one drug-resistant protein. No intergroup differences were observed between positive and negative expressions of the proteins and their clinicopathologic features except tumor location. Rectal cancers positively expressed P-glycoprotein and three proteins more frequently. Twenty-six (20 percent), 65 (50 percent), and 21 (16 percent) cancers positively expressed one, two, and three proteins, respectively. The disease-free survival rates of patients with Dukes A through C cancer with positive staining for one, two, and three proteins were 100, 94, and 83 percent (at 1 year); 100, 72, and 51 percent (at 3 years); and 94, 66, and 38 percent (at 5 years), respectively (Kaplan-Meier with log-rank test; P = 0.016). In the multivariate Cox analysis, age, Dukes stage, tumor size, and glutathione S-transferase-pi were independent prognostic factors. CONCLUSIONS: The patients with concurrent expression of drug-resistant proteins in their cancers had worse prognoses. Examining drug-resistant proteins in colorectal cancers may be useful in selecting adjuvant chemotherapy and in predicting prognosis more accurately.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2000

Effects of various decalcification protocols on detection of DNA strand breaks by terminal dUTP nick end labelling.

To analyse DNA strand breaks by terminal deoxy(d)-UTP nick-end labelling (TUNEL) in calcified tissues including bones and teeth, it is important to decalcify the tissues first. However, the effects of decalcifying reagents on the integrity of DNA are largely unknown. In the present study, we evaluated the usefulness of various decalcifying reagents including 10% EDTA (pH 7.4), 5% trichloroacetic acid (TCA), 5% formic acid, 5% HCl, 10% nitric acid, Plank-Rychlo's solution, Morse's solution and K-CX solution in TUNEL staining. Mouse maxilla was selected as the experimental system. Apoptotic cells naturally occurring in the epithelium were analysed. Tissues were assessed by soft X-ray imaging to confirm complete decalcification. The time required for decalcification of the tissue was 7 days with 10% EDTA and 2 days with other decalcifiers. Decalcified tissues were stained with Methyl/Green-Pyronine Y or 4',6-diamidino-2-phenylindole for assessment of DNA integrity. Nuclei of epithelial cells were strongly positive for both dyes after decalcification with 10% EDTA, 5% TCA, Morse's solution and 5% formic acid. The other reagents failed to retain DNA. Our results demonstrated good TUNEL staining of the maxilla treated with 10% EDTA or 5% TCA. Based on the required time for processing and the signal-noise ratio, we recommend 5% TCA as the decalcifying reagent to analyse for DNA strand breaks.

Animals↗

PubMed2000

Supplementary administration of artificial bright light and melatonin as potent treatment for disorganized circadian rest-activity and dysfunctional autonomic and neuroendocrine systems in institutionalized demented elderly persons.

Increased daytime napping, early morning awakening, frequent nocturnal sleep interruptions, and lowered amplitude and phase advance of the circadian sleep-wake rhythm are characteristic features of sleep-waking and chronobiological changes associated with aging. Especially in elderly patients with dementia, severely fragmented sleep-waking patterns are observed frequently and are associated with disorganized circadian rhythm of various physiological functions. Functional and/or organic deterioration of the suprachiasmatic nucleus (SCN), decreased exposure to time cues such as insufficient social interaction and reduced environmental light, lowered sensitivity of sensory organs to time cues, and reduced ability of peripheral effector organs to express circadian rhythms may cause these chronobiological changes. In many cases of dementia, the usual treatments for insomnia do not work well, and the development of an effective therapy is an important concern for health care practitioner and researchers. Recent therapeutical trials of supplementary administration of artificial bright light and the pineal hormone melatonin, a potent synchronizer for mammalian circadian rhythm, have indicated that these treatments are useful tools for demented elderly insomniacs. Both bright light and melatonin simultaneously ameliorate disorganized thermoregulatory and neuroendocrine systems associated with disrupted sleep-waking times, suggesting a new, potent therapeutic means for insomnia in the demented elderly. Future studies should address the most effective therapeutic design and the most suitable types of symptoms for treatment and investigate the use of these tools in preventive applications in persons in early stages of dementia.

Aged↗

PubMed2000

Enantioresolution of aliphatic alcohols by lithocholamide.

Lithocholamide (LCAM) forms inclusion compounds with aliphatic alcohols involving over five carbon atoms. Enantioresolution of the racemic alcohols was studied in channels of the inclusion compounds. X-ray crystallographic study clarified that host assemblies exhibit guest-dependent polymorphism. In each polymorphic crystal, the more longer or bulkier groups the alcohols have, the effective the resolutions become. The inclusion spaces were analyzed by a computed tomographic method, explaining the chiral recognition mechanism from a stereochemical viewpoint.

Alcohols↗

PubMed1999

Multi-institutional randomized trial of external radiotherapy with and without intraluminal brachytherapy for esophageal cancer in Japan. Japanese Society of Therapeutic Radiology and Oncology (JASTRO) Study Group.

PURPOSE: With the aim of improving the results of treatment of esophageal cancer, we designed this multi-institutional, randomized trial to establish the optimal irradiation method in radical radiation therapy for esophageal cancer by clinically evaluating external irradiation alone and in combination with intraluminal brachytherapy. METHODS AND MATERIALS: The study population consisted of patients with squamous cell carcinoma who were expected to be successfully treated with radical radiation therapy. The patients who could be given intraluminal brachytherapy at the end of external irradiation of 60 Gy were stratified into 2 groups. Patients assigned to receive external irradiation alone received boost irradiation of 10 Gy/week on a schedule similar to the previous one, and with the same or smaller irradiation field. Intraluminal brachytherapy was performed, as a rule, with the reference dose point set at a depth of 5 mm of the esophageal submucosa, and a total of 10 Gy was irradiated at a daily dose of 5 Gy, on a once-weekly schedule with low-dose-rate or high-dose-rate brachytherapy equipment. RESULTS: A total of 103 patients were registered, 94 of whom were analyzable, with 8 ineligible, and 1 for whom complete information was unavailable. The overall cumulative survival rate was 20.3% at 5 years. The cause-specific survival rate was 31.8% at 5 years. The cause-specific survival rate at 5 years was 27% in the external irradiation alone group and 38% in intraluminal brachytherapy combined group. There was no significant difference between the 2 groups (p = 0.385). However, in the patients with 5 cm or less tumor length, the cause-specific survival rate was 64% at 5 years in the intraluminal brachytherapy combined group, which showed a significant improvement over 31.5% in the external irradiation alone group (p = 0.025). In the patients with Stage T1 and T2 disease, cause-specific survival rates tended to be better in the intraluminal brachytherapy combined group than in the external irradiation alone group (p = 0.088). In the patients with more than 5 cm tumor length or Stage T3-4 disease, there were no significant differences between the two groups by treatment methods (p = 0.290). The incidence of early and late complications did not differ according to whether intraluminal brachytherapy was used. CONCLUSION: For the purpose of establishing the usefulness of intraluminal brachytherapy, further prospective randomized studies are necessary to evaluate the efficacy in tumors with short length and those with shallow invasion, or to assess the usefulness of intraluminal brachytherapy, as additional irradiation in large advanced tumors have been shown to have disappeared by diagnostic imaging after chemoradiotherapy with 60 Gy/6w external irradiation.

Adult↗

PubMed1999

Melatonin secretion rhythm disorders in patients with senile dementia of Alzheimer's type with disturbed sleep-waking.

BACKGROUND: There is growing evidence that the dysregulation of circadian rhythms may play an important role in irregular sleep-waking in demented elderly. In this study, we investigated daily variation of the pineal hormone melatonin, which has been reported to possess hypnogenic and synchronizing effects, in patients with senile dementia of Alzheimer's type. METHODS: Serum melatonin secretion rhythms in inpatients with senile dementia of Alzheimer's type (SDAT group, n = 10, average age = 75.7 years) with disturbed sleep-waking and nondemented elderly (ND group, n = 10, age = 78.3 years) without clinical sleep disorders in the same facility were monitored under a dim light condition without excessive physical exercise. RESULTS: The SDAT group showed a significantly higher degree of irregularities in actigraphically recorded rest-activity (R-A) rhythm during the 7-day baseline period compared with the ND group. The SDAT group simultaneously showed significantly reduced amplitude, larger variation of peak times, and diminished amount of total secretion in the melatonin secretion rhythm compared with the ND group. There were significantly positive correlations between the severity of R-A rhythm disorder and the reduced amplitude as well as diminished amount of total melatonin secretion. CONCLUSIONS: The SDAT patients with disturbed sleep-waking possessed melatonin secretion rhythm disorders that may play an important role in irregular sleep-waking in demented elderly.

Aged↗

PubMed1999

Thalidomide increases both REM and stage 3-4 sleep in human adults: a preliminary study.

Polysomnography was used to assess the effect of thalidomide on human sleep. This compound significantly increased the time spent in REM and stage 3-4 sleep as compared with placebo. On the other hand, thalidomide significantly decreased the time spent in stage 1, while the time spent in stage 2 was unchanged. The effect of thalidomide on REM and stage 3-4 sleep is unique as compared with other hypnotics. Although the mode of action of this compound is unknown, further studies on thalidomide should help in our understanding of the mechanisms of sleep regulation.

Adult↗