Biomedical subjects

R Hara

Publications and source records attributed to R Hara.

At least 19 recordsLinked to original sources

PubMed2001

Risk factors for massive hemoptysis after endobronchial brachytherapy in patients with tracheobronchial malignancies.

BACKGROUND: Massive and mostly fatal hemoptysis is a frequently reported morbidity after endobronchial brachytherapy (EBB) for tracheobronchial malignancies. However, to the authors' knowledge, it remains controversial whether this morbidity is related directly to EBB. To investigate whether massive hemoptysis is related to EBB, the authors retrospectively analyzed risk factors for massive hemoptysis after EBB. METHODS: Thirty-six patients (30 men and 6 women) with a mean age of 70 years underwent high-dose rate EBB for tracheobronchial malignancy using a cobolt-60 (Co-60) afterloading machine. EBB was performed as primary therapy in 6 patients and as salvage treatment for recurrent disease in 30 patients. EBB was delivered to the tracheal lesions in 15 patients and to the main bronchial lesions in 21 patients. EBB was combined with external beam radiation therapy (EBRT) in 24 patients, with laser photocoagulation in 3 patients, and with EBRT plus laser photocoagulation in 5 patients. The dose of EBRT delivered with the EBB ranged from 16-69 grays (Gy), with a mean dose of 37 Gy. RESULTS: At a mean follow-up of 18 months, 33 of the 36 patients had died. Eight of the 33 patients had no evidence of local disease at the time of death. Seven patients died of massive hemoptysis. The cumulative rate of massive hemoptysis was 29.4% at 2 years. According to univariate analysis, no statistically significant correlation with massive hemoptysis was observed for EBRT dose delivered in combination with EBB, EBB fractional and total doses, EBB length, and the sum of all the EBRT doses including that used for the initial treatment. Local failure or persistent malignancy (P = 0.033) and delivery of laser photocoagulation (P = 0.032) were found to be statistically significantly associated with massive hemoptysis. Direct contact between the EBB applicator and the tracheobronchial walls at the vicinity of the great vessels was observed in 16 patients and was found to be statistically significantly associated with massive hemoptysis (P = 0.003). In six patients, the applicator was in direct contact with two or more tracheobronchial walls at the vicinity of the great vessels; all these patients died of massive hemoptysis. CONCLUSIONS: Direct contact between the EBB applicator and the tracheobronchial walls at the vicinity of the great vessels was one of the significant risk factors for massive hemoptysis. To prevent massive hemoptysis, a specific spacer should be employed to maintain a safe distance between the applicator and the bronchial wall.

Aged↗

PubMed2001

Restricted feeding entrains liver clock without participation of the suprachiasmatic nucleus.

BACKGROUND: There are two main stimuli that entrain the circadian rhythm, the light-dark cycle (LD) and restricted feeding (RF). Light-induced entrainment requires induction of the Per1 and Per2 genes in the suprachiasmatic nucleus (SCN), the locus of a main oscillator. In this experiment, we determined whether RF resets the expression of circadian clock genes in the mouse liver with or without participation of the SCN. RESULTS: Mice were allowed access to food for 4 h during the daytime (7 h advance of feeding time) under LD or constant darkness (DD). The peaks of mPer1, mPer2, D-site-binding protein (Dbp) and cholesterol 7alpha-hydroxylase (Cyp7A) mRNA in the liver were advanced 6-12 h after 6 days of RF, whereas those in SCN were unaffected. The advance of mPer expression in the liver by RF was still observed in SCN-lesioned mice. A 7 h advance in the LD cycle advanced the peaks of clock gene expression in both the liver and SCN, whereas, a shift in the LD did not move the phase of the liver clock when the shift was carried out under a fixed RF schedule during the night-time. CONCLUSIONS: These results suggest that restricted feeding strongly entrained the expression of circadian clock genes in the liver without the participation of an SCN clock function.

Animals↗

PubMed2001

Physical and inflammatory stressors elevate circadian clock gene mPer1 mRNA levels in the paraventricular nucleus of the mouse.

Stress induces secretion of corticosterone through activation of the hypothalamic-pituitary-adrenal axis. This corticosterone secretion is thought to be controlled by a circadian clock in the suprachiasmatic nucleus (SCN). The hypothalamic paraventricular nucleus (PVN) receives convergent information from both stress and the circadian clock. Recent reports demonstrate that mammalian orthologs (Per1, Per2, and Per3) of the Drosophila clock gene Period are expressed in the SCN, PVN, and peripheral tissues. In this experiment, we examined the effect of physical and inflammatory stressors on mPer gene expression in the SCN, PVN, and liver. Forced swimming, immobilization, and lipopolysaccharide injection elevated mPer1 gene expression in the PVN but not in the SCN or liver. A stress-induced increase in mPer1 expression was observed in the corticotropin-releasing factor-positive cells of the PVN; however, the stressors used in this study did not affect mPer2 expression in the PVN, SCN, or liver. The present study suggests that a stress-induced disturbance of circadian corticosterone secretion may be associated with the stress-induced expression of mPer1 mRNA in the PVN.

Animals↗

PubMed2001

Detection of nasopharyngeal carcinoma: fast short time inversion recovery images compared with fat suppression, contrast enhanced T(1) weighted spin echo images.

The aim was to compare fast short time inversion recovery (FSTIR) images and fat suppression, contrast enhanced T(1) weighted (FSCE T1W) spin echo images in the diagnosis of nasopharyngeal carcinoma (NPC). 102 MR studies were obtained with a 1.0 T or a 1.5 T system in 28 patients with NPC. The MR studies comprised both FSTIR and FSCE T1W images. FSTIR and FSCE T1W images were compared for detection of NPC by means of a receiver operating characteristic (ROC) analysis. The areas under the ROC curves of FSTIR and FSCE T1W images showed no statistical difference (0.87 vs 0.87). There was also no statistical difference in the sensitivity, specificity and accuracy of each sequence (0.74 vs 0.77, 0.81 vs 0.77 and 0.79 vs 0.77, respectively). Both sequences had the same performance for detection of NPC. FSTIR is as useful as FSCE T1W images, especially in the detection of recurrent tumours, but without the cost of contrast medium.

Adult↗

PubMed2000

Preparation of diynes via selective bisalkynylation of zirconacycles

Reaction of alkynyl halides with in situ prepared zirconacyclopentanes, -pentenes, and -pentadienes in the presence of CuCl under mild reaction conditions afforded alkynes or diynes. Control of the reaction conditions selectively afforded monoalkynylation products of zirconacycles. Reaction of zirconacycles with 2 equiv of alkynyl halides resulted in the formation of diynes. Selective monoalkynylation of zirconacycle with an alkynyl halide, followed by reaction with a different alkynyl halide, afforded unsymmetrical diynes. Bisalkynylation product of zirconacyclopentadiene was gradually converted into a tricyclic compound.

Journal Article↗

PubMed2000

Target volume definition for upper abdominal irradiation using CT scans obtained during inhale and exhale phases.

PURPOSE: To evaluate the clinical utility of a treatment-planning technique involving the use of CT images obtained during both the static exhalation phase and static inhalation phase (two-phase planning). METHODS AND MATERIALS: Ten patients with pancreatic or liver tumors underwent CT scanning under static exhale and inhale conditions, after a period of mild ventilation. By setting image positions differently, we were able to treat the two-phase images as one dataset. Each gross tumor volume (GTV) was contoured separately and the mixed GTV was used for the two-phase treatment planning. Treatment plans were constructed to compare the two-phase plans with the plans constructed using static exhalation images. The shift of the center of the GTV and kidneys and the minimum dose of GTV were then calculated. RESULTS: The shift of the GTV ranged from 2.6 to 27. 3 mm and that of the kidneys from 2.2 to 24 mm. In some patients whose treatment was planned using exhalation planning, the minimum dose of GTV at inhalation was less than 90% of the isocenter dose. CONCLUSION: Two-phase planning is a simple technique that can visualize tumor and organ movement simultaneously using CT. It further defines adequate field margins around the tumor and prevents unexpected radiation exposure to critical organs. Routine use of this technique for upper abdominal irradiation is recommended.

Abdominal Neoplasms↗

PubMed2000

Acylated delphinidin 3-rutinoside-5-glucosides in the flowers of Petunia reitzii.

Two acylated anthocyanins were isolated from selected individuals of Petunia reitzii, and identified to be delphinidin 3-O-[6-O-(4-O-(4-O-(6-O-(trans-caffeoyl)-beta-D-glucopyranosyl)-tr ans-p-coumaroyl)-alpha-L-rhamnopyranosyl)-beta-D-glucopyranoside]- 5-O-[beta-D-glucopyranoside] and delphinidin 3-O-[6-O-(4-O-(4-O-(beta-D-glucopyranosyl)-trans-p-coumaroyl)-alph a-L-rhamnopyranosyl)-beta-D-glucopyranoside]-5-O-[beta-D-glucopyranoside ]. Nine known anthocyanins were also identified.

Acylation↗

PubMed2000

Differences in the floral anthocyanin content of red petunias and Petunia exserta.

In order to resolve a conflict between previous papers regarding the floral anthocyanins of red flowers of Petunia exserta, a naturally occurring species, the HPLC profile of this species was compared with that of commercial red garden petunias. Both HPLC profiles extremely superficially resemble each other in terms of relative amounts and retention times of the major anthocyanins. However, co-elution on HPLC of the mixed sample resulted in clear separation of the components. Three major anthocyanins in red petunias were determined to be cyanidin 3-sophoroside, cyanidin 3-glucoside and peonidin 3-glucoside, which exhibited similar behaviors on HPLC to delphinidin 3-glucoside. delphinidin-3-rutinoside and petunidin 3-rutinoside, respectively, the major floral anthocyanins of P. exserta.

Anthocyanins↗

PubMed2000

Treatment for pyothorax-associated lymphoma.

In eight patients with pyothorax-associated lymphoma (PAL), which resulted from artificial pneumothorax for the treatment of pulmonary tuberculosis, seven patients received radiotherapy and five showed no local recurrence. All four patients treated by primary chemotherapy had disease progression. Radiotherapy of 50 Gy with wide margins is recommended to treat PAL.

Aged↗

PubMed2000

Postoperative radiation therapy for pituitary adenoma.

BACKGROUND: We evaluated the efficacy of postoperative radiation therapy (RT), prognostic factors for local control probability, dose response relationship and treatment sequelae in 75 patients with pituitary adenoma. MATERIALS AND METHODS: A total dose of 48-60 Gy (median: 50 Gy) was delivered with a conventional fractionation schedule after surgery. Of 75 patients, 55 (73%) were followed for more than 5 years and 27 (36%) were followed for more than 10 years with a median of 95 months. RESULTS: Five- and 10-year local control probabilities were 87.1% and 85.0%, respectively. Univariate analysis revealed that age (p = 0.007), tumor volume smaller than 30 cm3 (p = 0.018) and the absence of prolactin secretion (p = 0.003) were significantly favorable prognostic factors for local control probability. After multivariate analysis combining these 3 factors, tumor volume smaller than 30 cm3 (p = 0.017) and age (p = 0.039) were statistically significant. Patients with prolactinoma greater than 30 cm3 showed particularly poor local control rates. No significant improvement of the local control rate was detected with increasing total irradiation doses between 48 and 60 Gy (p = 0.29). The most common side effect was hypopituitarism, and there were no severe sequelae such as optic neuropathy or brain necrosis. CONCLUSION: Except with prolactinoma, the dose of postoperative RT for pituitary adenoma should not exceed 50 Gy. Large prolactinoma, however, was very difficult to control with the irradiation doses between 50 and 60 Gy, and would be good candidates for stereotactic radiosurgery or stereotactic radiation therapy.

Adenoma↗

PubMed2000

DNA damage in the nucleosome core is refractory to repair by human excision nuclease.

To investigate the effect of nucleosomes on nucleotide excision repair in humans, we prepared a mononucleosome containing a (6-4) photoproduct in the nucleosome core and examined its repair with the reconstituted human excision nuclease system and with cell extracts. Nucleosomal DNA is repaired at a rate of about 10% of that for naked DNA in both systems. These results are in agreement with in vivo data showing a considerably slower rate of repair of overall genomic DNA relative to that for transcriptionally active DNA. Furthermore, our results indicate that the first-order packing of DNA in nucleosomes is a primary determinant of slow repair of DNA in chromatin.

Animals↗

PubMed1999

Human transcription release factor 2 dissociates RNA polymerases I and II stalled at a cyclobutane thymine dimer.

RNA polymerase II stalled at a lesion in the transcribed strand is thought to constitute a signal for transcription-coupled repair. Transcription factors that act on RNA polymerase in elongation mode potentially influence this mode of repair. Previously, it was shown that transcription elongation factors TFIIS and Cockayne's syndrome complementation group B protein did not disrupt the ternary complex of RNA polymerase II stalled at a thymine cyclobutane dimer, nor did they enable RNA polymerase II to bypass the dimer. Here we investigated the effect of the transcription factor 2 on RNA polymerase II and RNA polymerase I stalled at thymine dimers. Transcription factor 2 is known to release transcripts from RNA polymerase II early elongation complex generated by pulse-transcription. We found that factor 2 (which is also called release factor) disrupts the ternary complex of RNA polymerase II at a thymine dimer and surprisingly exerts the same effect on RNA polymerase I. These findings show that in mammalian cells a RNA polymerase I or RNA polymerase II transcript truncated by a lesion in the template strand may be discarded unless repair is accomplished rapidly by a mechanism that does not displace stalled RNA polymerases.

DNA Footprinting↗

PubMed1999

[The effect of substance P with insulin-like growth factor-1 on corneal epithelial cell proliferation].

PURPOSE: To elucidate the pathogenesis of neuroparalytic keratopathy, we examined the effect of substance P (SP) on corneal epithelial cell proliferation in comparison with that of insulin-like growth factor-1 (IGF-1) in vivo and in vitro. METHODS: In the in vivo study, the epithelium of rabbit cornea was removed mechanically and treated with eye drops containing SP, IGF-1, SP + IGF-1, or physiological saline as a control. Corneas were excised 48 hours after the removal of the epithelium, labeled with 3H-thymidine, and subjected to autoradiography. An in vitro study was also performed by culturing rabbit corneal epithelial cells in culture medium containing SP with or without IGF-1 and labeling cells with 3H-thymidine for a subsequent autoradiographical study. FINDINGS: In the in vivo study, SP in combination with IGF-1 enhanced the healing of rabbit corneal epithelial defect. 3H-thymidine autoradiography revealed that in both in vivo and in vitro studies, SP + IGF-1 stimulated corneal epithelial cell proliferation, but SP or IGF-1 alone did not. CONCLUSION: These results indicate that SP enhances the stimulatory effect of IGF-1 on corneal epithelial cell proliferation and accelerates corneal epithelial healing.

Animals↗

PubMed1998

Assignment of three Chinese xeroderma pigmentosum patients to complementation group C and one to group E.

Four Chinese patients with xeroderma pigmentosum (XP), who had different degrees of skin symptoms, were tested for their genetic complementation groups. Skin fibroblasts obtained from the patients were used for complementation analysis done by a cell-fusion technique. Three of the patients belonged to group C and one, who had the mildest cutaneous manifestations, to group E. This is the first report of a group E XP patient in China. Our present findings together with previous reports suggest that group C XP is more common in China, similar to the distribution among Caucasian XP patients but markedly different from the Japanese distribution.

Adolescent↗

PubMed1998

Advanced nasopharyngeal carcinoma treated with chemotherapy and radiotherapy: distant metastasis and local recurrence.

One hundred and twenty-nine patients with NPC treated at the Department of Radiology, Chiba University Hospital and Keio University Hospital from 1980 through 1993 were selected for this study. Forty-four patients received cisplatin (CDDP)- or carboplatin-based chemotherapy, and 58 patients received adriamycin (ADM)- and/or 5-FU-based chemotherapy. The remaining 27 patients were treated with radiotherapy alone. The median radiation dose to the nasopharyngeal region was 64 Gy, and to the initially involved cervical node, 60 Gy. The 5 year survival rates for the CDDP, the ADM/5-FU and the radiation alone groups were 61%, 47% and 42%, respectively. The cumulative incidences of local control in the CDDP, the ADM/5-FU and the radiation alone groups were 77%, 49% and 53% respectively. The CDDP group achieved the significantly better local control (CDDP vs ADM: p=0.001). The overall incidence of distant metastases was 54% in the CDDP group. On the other hand, it was 24% in the ADM/5-FU group and 22% in the radiation alone group (CDDP vs ADM: p=0.048). While the locoregional control rate was significantly better in the CDDP given group, more distant metastases were seen in this group.

Adolescent↗

PubMed1998

[Bleomycin, adriamycin, cyclophosphamide, vincristine, deacadron, etoposide (BACOD-E) chemotherapy for the treatment of non-Hodgkin's lymphoma: long-term survival rate and complications].

This study was performed to analyze the effect of Bleomycin, Adriamycin, Cyclophosphamide, Vincristine, Deacadron, Etoposide (BACOD-E) chemotherapy for patients with non-Hodgkin's lymphoma. Seventy patients with non-Hodgkin's lymphoma (stage I: 15, stage II: 23, stage III: 20, and stage IV: 12) were treated at the Department of Radiology, Chiba University Hospital, between 1987 and 1995. The response rates for treatment were CR: 63%, PR: 35%, and PD: 2%. The overall disease-free 5-year survival rate was 54%, and those for each stage were as follows: stage I: 78%, stage II: 55%, stage III: 51%, and stage IV: 28%. There were no significant differences between patients with and without B symptoms, or those with and without elevated LDH levels. Treatment associated deaths occurred in six patients. Two patients died due to side effects of chemotherapy during treatment, and one patient due to leukemia 2 years and 5 months after treatment. One patient died due to radiation pneumonitis, one patient due to heart failure, and one patient due to an unknown reason one month after treatment. This chemotherapy may be useful for patients with advanced disease or unfavorable prognostic factors such as B symptoms or elevated LDH. Moreover, the addition of radiation therapy may prolong survival.

Adolescent↗

PubMed1997

Radiotherapy for centrally recurrent cervical cancer of the vaginal stump following hysterectomy.

PURPOSE: This study was performed to establish the classification and the treatment modality for recurrent cervical cancer of the vaginal stump after hysterectomy. PATIENTS AND METHODS: Ninety patients with centrally recurrent cervical cancer of the vaginal stump following hysterectomy were treated with high-dose-rate intracavitary brachytherapy with or without external irradiation. The intervals between primary surgery and vaginal recurrences varied from 3 months to 36 years. Tumor size of the vaginal stump was determined by bimanual rectovaginal examination at the time of recurrence and was classified into three groups, i.e., small (no palpable tumor), medium (less than 3 cm), and large (3 cm or more). RESULTS: The 10-year survival rates for all patients were 52%. Survival was greatly influenced by the tumor sizes of the vaginal stump. The 10-year survival rates of patients with small, medium, and large size tumors were 72, 48, and 0%, respectively. All patients with large size tumors died within 5 years. Of 90 patients, 75 (83%) were determined by physical examination to be free of tumor on at least one visit within 2 months of the completion of treatment (CR). The remaining 15 patients (17%) had physical findings suggestive of residual tumor (Residual). The overall 10-year survival rate for all patients with CR was 63%, compared with 10% for the patients with Residual (P < 0.0001). The incidences of distant metastases of the patients with or without local failure were 55 and 13%, respectively (P < 0.0001). The patients with local failure had significantly higher incidence of metastases. Most patients with small size tumor were treated with brachytherapy alone, and the survival rates of these patients were not improved by combination with external irradiation. CONCLUSION: These results suggest that tumor size was a significant prognostic factor for recurrent cervical cancer of the vaginal stump. Patients with small size tumors were recommended to be treated with brachytherapy alone.

Adult↗

PubMed1997

Mutations induced in Drosophila during space flight.

To examine the possible effects of space radiation on living organisms, fruit flies Drosophila melanogaster were loaded on the US Space Shuttle Endeavour, and after the flight we have analyzed two types of mutations, sex-linked recessive lethal mutations induced in male reproductive cells and somatic mutations which give rise to morphological changes in hairs growing on the surface of wing epidermal cells. Wild type strains and a radiation-sensitive strain mei-41 were used. The frequencies of sex-linked recessive lethal mutations in flight groups were 2 and 3 times higher for wild type Canton-S and mei-41 strains, respectively, than those in ground control groups. By contrast, the frequencies of wing-hair somatic mutations differed little between flight and control groups. The possibility that the space environment causes mutations in certain types of cells such as male reproductive cells, is discussed.

Animals↗