Association between health risks and frailty in relation to the degree of housing damage among elderly survivors of the great East Japan earthquake.

BACKGROUND: Many survivors of the Great East Japan Earthquake that occurred in 2011 were at risk of deteriorating health, especially elderly people living in disaster-stricken areas. The objectives of this prospective study were: a) to clarify the different lifestyle and psychosocial factors associated with frailty by sex among the non-disabled elderly survivors, and b) to describe the differences in characteristics stratified by the degree of disaster-related housing damage. METHODS: We followed 2261 Japanese survivors aged ≥65 years (45.3% male; mean age, 71.7 years) without disability or frailty who completed a self-administered questionnaire at baseline. All participants completed a baseline questionnaire in 2011 and at least one identical follow-up questionnaire between 2012 and 2015 regarding lifestyle (smoking status, alcohol intake, physical activity, sedentary lifestyle, and dietary intake) and psychosocial factors (self-rated health, standard of living, psychological distress, and social networks). Frailty was defined as a score of ≥5 on the Kihon Checklist, which is used by the Japanese government to certify the need for long-term care insurance. Adjusted odds ratios and 95% confidence intervals with frailty as the dichotomous dependent variable and health factors as the independent variables were calculated using a multilevel model for repeated measures by sex, followed by stratification analyses by the degree of housing damage. RESULTS: Over the 4-year study period, 510 participants (22.6%) developed frailty. In the post-disaster setting, many of the psychosocial factors remained more prevalent 4 years later among survivors with extensive housing damage. The presence of risk factors regarding the development of frailty differed by the degree of housing damage. Among men, psychological distress, in parallel with a poor social network, was related to frailty among only the participants with extensive housing damage and those living in temporary housing, whereas among women, worsening psychological distress was associated only with no damage and no displaced survivors. Among women with extensive damage and displacement, health outcomes such as overweight and diabetes and poor social networks were strongly related to frailty. CONCLUSIONS: Lifestyle and psychosocial factors associated with the risk of frailty differ by sex and the degree of housing damage.

Improvement of patient localization repeatability using a light-section based optical surface guidance system in a pre-positioning procedure.

PURPOSE: Surface-guided radiotherapy is useful for the pre-positioning and monitoring of radiotherapy. The purpose of this study was to investigate the impact of surface guidance on the repeatability of patient localization and to estimate the specific point at which high positional errors occur. MATERIALS AND METHODS: Ten patients without the VOXELAN system (non-VXLN group) and 10 patients with the VOXELAN as the pre-positioning procedure (VXLN group) were included in this analysis. Twelve regions of interest (ROI) were defined in all the patients to verify any misalignment during radiotherapy. Thirteen ROIs were defined on the isocenter. RESULTS: Compared with the non-VXLN group, the translational positional errors of the VXLN group were the same for all the ROIs. The mean translational positional errors of the VXLN group in the longitudinal direction were approximately 0.1mm, and the standard deviation was the largest among the three directions in all the ROIs. The magnitude of the standard deviation in the non-VXLN group varied independently of the ROI and direction. The standard deviations of the VXLN group in the longitudinal direction were large in all the ROIs, while the standard deviations in the vertical and lateral directions were small. CONCLUSION: Pre-positioning with a surface guidance system reduced the body twist and rotation, which could not be corrected by image-guided radiotherapy alone. Since the VOXELAN can detect positioning errors quickly and without additional radiation exposure to the patient, it can be used as a tool for pre-positioning in radiotherapy.

Subjective Well-Being Is Associated with Food Behavior and Demographic Factors in Chronically Ill Older Japanese People Living Alone.

OBJECTIVES: This study aimed to examine the relationships among subjective well-being, food and health behaviors, socioeconomic factors, and geography in chronically ill older Japanese adults living alone. DESIGN: The design was a cross-sectional, multilevel survey. A questionnaire was distributed by post and self-completed by participants. SETTING: The sample was drawn from seven towns and cities across Japan. PARTICIPANTS: A geographic information system was used to select a representative sample of older people living alone based on their proximity to a supermarket. Study recruitment was conducted with municipal assistance. MEASUREMENTS: To assess subjective well-being and food and health behaviors of respondents with disease, a logistic regression analysis was performed using stepwise variable analyses, adjusted for respondent age, socioeconomic status, and proximity to a supermarket. The dependent variable was good or poor subjective well-being. RESULTS: In total, 2,165 older people (744 men, 1,421 women) completed the questionnaire (63.5% response rate). Data from 737 men and 1,414 women were used in this study. Among people with a chronic disease, individuals with good subjective well-being had significantly higher rates than those with poor subjective well-being for satisfaction with meal quality and chewing ability, food diversity, food intake frequency, perception of shopping ease, having someone to help with food shopping, eating home-produced vegetables, preparing breakfast themselves, eating with other people, and high alcohol consumption. A stepwise logistic analysis showed that the factors strongly related to poor subjective well-being were shopping difficulty (men: odds ratio [OR] = 3.19, 95% confidence interval [CI], 1.94-5.23; P < 0.0001; women: OR = 2.20, 95% CI, 1.54-3.14; P < 0.0001), not having someone to help with food shopping (women: OR = 1.41, 95% CI, 1.01-1.97; P = 0.043), not preparing breakfast (women: OR = 2.36, 95% CI, 1.40-3.98; P = 0.001), and eating together less often (women: OR = 1.99, 95% CI, 1.32-3.00; P = 0.002). CONCLUSION: Subjective well-being of people with chronic diseases is associated with food intake and food behavior. The factors that affect poor subjective well-being in chronically ill older Japanese people living alone include food accessibility and social communication.

Association between Satisfaction with State of Health and Meals, Physical Condition and Food Diversity, Health Behavior, and Perceptions of Shopping Difficulty among Older People Living Alone in Japan.

OBJECTIVE: This study aimed to examine perceptions of shopping difficulty, and the relationships with satisfaction with state of health and meals, physical condition, food diversity and health behavior in older people living alone in Japan. DESIGN: A cross-sectional, multilevel survey was designed. The questionnaire was distributed by mail and self-completed by participants. SETTING: The sample was drawn from seven towns and cities across Japan. PARTICIPANTS: A geographic information system was used to select the sample of older people living alone, by proximity to a supermarket. In total, 2,346 older people (827 men and 1,519 women) completed the questionnaire. MEASUREMENTS: The dependent variable was whether shopping was easy or difficult. A logistic regression analysis was performed, adjusting for age, socioeconomic status and proximity of residence to a supermarket using stepwise variable analyses. RESULTS: The response rate was 67.8%. Overall, 14.5% of men and 21.7% of women considered shopping difficult. The stepwise logistic analysis showed that the factors most strongly related to shopping difficulty were a subjective feeling of poor health (men: OR = 3.01, women: OR = 2.16) and lack of satisfaction with meals (men: OR = 2.82, women: OR = 3.69). Other related physical condition and dietary factors were requiring nursing care (men: OR = 3.69, women: OR = 1.54), a high level of frailty, measured using the frailty index score (women: OR = 0.36) and low food diversity score (men: OR = 1.84, women: OR = 1.36). CONCLUSION: The study found that older people's assessment of their shopping difficulty was related to satisfaction aspects, including a subjective feeling of poor health, and lack of satisfaction with meals, as well as physical condition. These have a greater influence on shopping difficulty than income in both sexes, and proximity to a supermarket in women.

"Eating Together" Is Associated with Food Behaviors and Demographic Factors of Older Japanese People Who Live Alone.

OBJECTIVE: This study aimed to examine the relationships between eating together and subjective health, frailty, food behaviors, food accessibility, food production, meal preparation, alcohol intake, socioeconomic factors and geography among older Japanese people who live alone. DESIGN: A cross-sectional, multilevel survey was designed. The questionnaire was distributed by post and self-completed by participants. SETTING: The sample was drawn from seven towns and cities across Japan. PARTICIPANTS: A geographic information system was used to select a representative sample of older people who lived alone based on their proximity to a supermarket. Recruitment for the study was conducted with municipal assistance. MEASUREMENTS: A logistic regression analysis was performed that adjusted for the respondent's age, socioeconomic status and proximity to a supermarket using stepwise variable analyses. The dependent variable was whether the respondent ate together more or less than once a month. RESULTS: In total, 2,196 older people (752 men and 1,444 women) completed the questionnaire (63.5% response rate). It was found that 47.1% of men and 23.9% of women ate together less than once a month. Those who ate together less than once a month had a significantly lower rate of subjective health, food diversity and food intake frequency than those who ate together more often. A stepwise logistic analysis showed that the factors most strongly related to eating together less than once a month were not having any food shopping assistance (men: OR = 3.06, women: OR = 2.71), not receiving any food from neighbors or relatives (men: OR = 1.74, women: OR = 1.82), daily alcohol intake (women: OR = 1.83), frailty (men: OR = 0.48) and income (men: OR = 2.16, women: OR = 1.32). CONCLUSION: Eating together is associated with subjective health and food intake. Factors that affect how often older Japanese people who live alone eat together include food accessibility, daily alcohol intake, frailty and a low income.

Characterization of a melanoma antigen with a mouse-specific epitope recognized by a monoclonal antibody with antimetastatic ability.

We have characterized properties of a melanoma antigen with a mouse-specific melanoma epitope expressed on B16 melanoma by using syngeneic monoclonal antibodies with antimetastatic ability. The molecule recognized by the antibody is a membrane glycoprotein with a molecular weight of 80,000. Studies on tunicamycin treatment indicated that the core size of the molecule appeared to have a molecular weight of 69,000 and also suggested that the carbohydrate moiety was greatly responsible for the conformation of the mouse melanoma epitope. The antigen was released or shed into the culture medium from the cell surface, and the turnover rate of the antigen was within 1.5 h.

Food Accessibility and Perceptions of Shopping Difficulty among Elderly People Living Alone in Japan.

OBJECTIVES: This aim of this study was to describe the association between shopping difficulty and food accessibility for elderly people living alone in Japan. DESIGN: A cross-sectoral, multilevel survey was designed to measure shopping difficulty from a food accessibility perspective. The questionnaire was distributed by mail. SETTING: The sample was drawn from seven towns and cities across Japan. PARTICIPANTS: A geographic information system was used to select the sample: it identified the proximity of elderly people living alone to a supermarket. In total, 2,028 elderly people (725 men and 1,303 women) responded to the questionnaire. MEASUREMENTS: The binary dependent variables were shopping is easy/shopping is difficult. A logistic regression analysis adjusting for age and area of residence and using stepwise variable analyses was performed. RESULTS: The response rate was 58.6%. Overall, 14.6% of elderly men and 21.7% of elderly women consider shopping difficult. The stepwise logistic analysis showed that the food accessibility factors strongly related to shopping difficulty are infrequent car use (women: OR = 6.97), walking difficulties (men: OR = 2.81, women: OR = 3.48), poor eyesight (men: OR = 2.26, women: OR = 1.75), not cooking lunch by oneself (men: OR = 1.63, women: OR = 1.72), not having anyone to help with food shopping (women: OR = 1.45) and living over 1 km away from a supermarket (men: OR = 2.30, women: OR = 2.97). CONCLUSION: The study concludes that elderly people's assessment of shopping difficulty is related to their food accessibility. Important food accessibility aspects include car or motorbike ownership, walking continuously for 1 km, poor eyesight, and having cooking skills and having someone to help with shopping. These physical activity restrictions have a greater influence on shopping difficulty than do either income or proximity to a supermarket.

Prognostic significance of perirectal lymph node micrometastases in Dukes' B rectal carcinoma: an immunohistochemical study by CAM5.2.

Lymph node metastasis is an important prognostic factor for rectal carcinoma, but only a few attempts at defining the relationship between lymph node micrometastases and prognosis have been made. The purpose of this study was to examine the correlation between the presence of micrometastases and prognosis in patients with rectal carcinoma. Six hundred forty-four lymph nodes were dissected from 42 patients with Dukes' B rectal carcinoma and stained immunohistochemically using a monoclonal antibody, CAM5.2, that binds cytokeratin. Clinicopathological factors, rate of recurrence, and prognosis were compared among patients with and without micrometastases. Micrometastases were detected in 19 lymph nodes (19 of 644 = 2.9%) from 9 patients (9 of 42 = 21.4%). The presence of micrometastases was not related to clinicopathological factors. There were significant differences in recurrence rates (5 of 9 versus 5 of 33, P = 0.02), relapse-free survival rates (P = 0.04), and 10-year survival rates (P = 0.03) between patients with and without micrometastases. Immunohistochemistry successfully identified micrometastatic foci in lymph nodes missed with conventional staining methods. The existence of micrometastases influenced the prognosis in patients with Dukes' B rectal carcinoma.

pO(2) measurement in murine tumors by Eppendorf 'Histograph'.

The purpose of this study was to assess the usefulness of the Eppendorf 'Kistograph' as a device for measuring pO(2) in tumor and normal tissues of the laboratory mouse. To determine the appropriate calibration and electrode condition, nitrogen bubbling time was changed, and the current during calibration was recorded. Reproducibility of pO(2) measurements was tested in the series of human xenografts and murine isoplants at different time points or in the same tumor in successive determinations. pO(2) values obtained with the Eppendorf 'Histograph' were compared to those obtained with a manually controlled needle-type electrode manufactured by the Diamond-General Company. The pO(2) values after 9 min of nitrogen bubbling were closer to the expected values than those after 3 min bubbling. The current during nitrogen bubbling in calibration declined following the pO(2) measurement by an amount corresponding to 0.8 mm Hg. Good reproducibility of pO(2) measurement was shown in i) pO(2) values in the same cell line at different time points and ii) pO(2) values in two or three consecutive measurements in related regions within the same tumor. The Eppendorf 'Histograph' and the Diamond-General device showed no significant differences in pO(2) distribution in either subcutaneous tissue or MCaIV tumors. In conclusion, results of the Eppendorf 'Histograph' were consistent and reproducible and were similar to those obtained by the Diamond-General set-up.

Transition and improvement in surgical treatment for rectal cancer during the last 21 years in our department.

The subject of this study was to examine the net effect of numerous changes in basic strategies, personnel and devices, upon the clinical courses and outcomes of rectal cancer patients. A total of 151 rectal cancer patients who underwent low anterior resection were divided into 4 groups (period 1 to 4) based upon the time period of the operation. They were compared among groups based upon the following parameters: blood loss, operation time, incidence of leakage and urinary dysfunction, incidence of ileus, duration of naso-gastric tube insertion, timing of initial oral feeding and survival. The blood loss during the operations, urinary dysfunction and duration of naso-gastric tube insertion tended to decrease in every period. Timing of initial oral feeding became faster. The operation times, incidence of leakage and ileus were nearly the same in each period. The 5-year survival rates on Dukes' C cases were 100% in period 4, 82.4% in period 3 and 50% in period 2. Survival rates became better. Our net outcome for rectal cancer treatment was satisfactory, because the survival rates became better under function preserving strategies.

Expression of costimulatory molecules, B7-1 and B7-2 on human gastric carcinoma.

Costimulation of T cells via B7-1 and B7-2 molecules on a tumor has been shown to be important for eliciting cell-mediated antitumor immunity. We studied the surface expression of B7-1 and B7-2 in 24 cases of gastric carcinoma from the primary locus, 20 cases of metastatic carcinoma from malignant ascites, 20 cases of benign gastric mucosa and 7 gastric carcinoma cell lines by two-color flow cytometry with mAb CD80 and CD86. The B7-1 and B7-2 molecules were expressed by 6 cell lines, and 1 cell line showed the predominant expression of B7-2 but not B7-1. Almost all patients with primary gastric carcinoma and benign gastric mucosa showed high levels of expression of the B7-1 and B7-2, revealing approximately 40%-60% positive cells. However, the percentage of B7-1-positive cells of poorly differentiated primary carcinomas was significantly lower than that of well-differentiated carcinoma and normal mucosa (P < 0.01). Furthermore, all of the metastatic carcinoma cells revealed consistently very low or undetectable levels of expression of the B7-1 molecule, only 8% (mean) of cells being positive, despite showing higher levels of B7-2 expression. Thus, it seems likely that decreased or deleted expression of B7-1 correlates with the grade of tumor differentiation, tumor progression and metastasis. These results suggest that the B7-1 molecule on the gastric carcinoma bearing CD80+CD86+ is abrogated during tumor invasion and/or metastasis, and the tumor finally acquires the CD80-CD86+ phenotype. Consequently, inadequate B7-1 costimulation may contribute to the escape of tumors from destruction by the host's immune system.

Ulcerative colitis associated with Weber-Christian panniculitis and musculitis: a case report.

A case of 22-year-old man suffering from ulcerative colitis, in whom Weber-Christian panniculitis and musculitis occurred simultaneously, is reported. He had suffered from ulcerative colitis for 7 years and he again had bloody stools 1 month before being admitted. Two weeks before admission, large (2-4 cm) subcutaneous tumors appeared. Weber-Christian panniculitis, musculitis, and active stage ulcerative colitis were diagnosed. All the symptoms went into remission after steroid therapy. The possibility of the existence of a common antigen in enterobacterial wall, colonic epithelium, and adipose tissue was suggested.

5-fu dose-dependency in mtx/s-fu sequential therapy assessed by in-vitro assay using gastric-cancer cell-lines.

The sequential administration of methotrexate (MTX) and 5-fluorouracil (5-FU) (MTX/5-FU therapy) on gastric cancers has shown higher response rates than standard chemotherapy. The response rate of these cancers, however, still showed from 18 to 48%. The purpose of this study was to determine the appropriate interval time and doses of MTX/5-FU therapy using a panel of 4 cell lines originated from the poorly-differentiated gastric cancers. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used as the chemosensitivity test. The sequential administration of MTX and 5-FU inhibited the growth of 2 cell lines more than 5-FU alone. In one cell line (GCIY), it inhibited the growth 6 times, and the longest interval time (6 h) was the most effective. In the other cell line (KATOIII), it inhibited growth 3 times, and the shortest interval time (O h) was the most effective. The growth inhibition in these cases did not depend on the dose of MTX (0.01 mu g/ml to 100 mu g/ml), but on the dose of 5-FU. In conclusion, 2 out of 4 cell lines showed a synergic effect between MTX and 5-FU. While the appropriate interval time between the two drugs varied between two cell lines, 5-FU dose was more critical than that of MTX. If 5-FU dose were to be increased in future trials with MTX, its efficacy might be higher. This model should also be good to screen other anti cancer drugs combined with MTX/5-FU therapy.

Over-expression of vascular endothelial growth factor after preoperative radiation therapy for rectal cancer.

Vascular endothelial growth factor expression before and after preoperative radiation therapy was examined in 16 stage III rectal carcinoma patients. The biopsied tissues before preoperative radiation therapy and the tissues at operation were immunohistochemically stained. Four cases were negative for VEGF expression before radiation, but the other 12 cases were positive, with 4 cases showing strong immunoreactivity. After radiation, all except 1 case showed VEGF positive patterns, in which 14 cases demonstrated strong staining. In 12 cases, VEGF expression became higher after radiation therapy than before, as compared to the only 1 case that showed lower expression than before.

Neurovascular decompression of the eighth cranial nerve in patients with hemifacial spasm and incidental tinnitus: an alternative way to study tinnitus.

OBJECT: The authors sought to clarify the clinical characteristics of tinnitus resulting from neurovascular compression (NVC) of the eighth cranial nerve. METHODS: The authors explored the eighth cranial nerve in the cerebellopontine cistern during neurovascular decompression (NVD) of the facial nerve in 10 patients with hemifacial spasm who suffered from incidental tinnitus on the same side. The diagnosis of NVC of the eighth cranial nerve was confirmed in all patients. This condition was found in only seven of 114 patients with hemifacial spasm alone, indicating that NVC of the eighth cranial nerve is one of the causes of tinnitus (p < 0.001, chi-square test). The tinnitus resolved or was markedly improved after NVD of the eighth cranial nerve in eight patients (80%). Both pulsatile and continuous tinnitus responded well to NVD. All patients experienced various degrees of sensorineural hearing disturbance, but other neurotological examinations provided poor diagnostic value. CONCLUSIONS: It is the authors' opinion that sensorineural hearing loss and positive findings on magnetic resonance imaging are the most reliable evidence for the presence of tinnitus caused by NVC of the eighth cranial nerve.

Bilateral primary malignant neoplasms of the maxillary sinus: report of a case and statistical analysis of the reports in Japan.

Although double primary malignant neoplasms of bilateral maxillary sinuses wee regraded as extremely rare, there have been 50 patients described in Japan since 1937. Among them only eight cases showed the histologic distinction between both sides. A 64-year-old man with double primary carcinomas had a mucoepidermoid carcinoma of the left maxillary sinus and a papillary adenocarcinoma of the right one with an interval of three years. He was treated with a combination of surgery, radiotherapy and regional chemotherapy. The histologic combination of these tumors could not be found so far. The advantage of this combination treatment for the carcinoma of the maxillary sinus is stressed.

Perianal mucinous carcinoma successfully treated with a combination of external beam radiotherapy and high dose rate interstitial brachytherapy.

The case of an 84-year-old man with perianal mucinous carcinoma is presented. The tumour was 6 cm in diameter and extended into the surrounding tissues. Taking the patient's advanced age and disease into account, rectosigmoidectomy and colostomy were carried out without resection of most of the tumour. Radiotherapy consisted of pre-operative external beam radiotherapy (EBRT) of 40 Gy in 20 fractions, post-operative EBRT of 24 Gy in 12 fractions, and high dose rate interstitial brachytherapy of 12 Gy in a single fraction. The patient tolerated the entire course of radiotherapy well. The patient is doing well without regrowth or complications 7 years after radiotherapy. To our knowledge, there have been no reports on the successful outcome of radiotherapy for perianal mucinous carcinoma. This case suggests that a combination of EBRT plus interstitial brachytherapy boost may play a role in the definitive treatment of perianal mucinous carcinoma.

[Establishment and characterization of a human scirrhus type gastric cancer cell line, GCIY, producing CA19-9].

A human gastric cancer cell line, designated GCIY, was established from ascites of a patient with scirrhus type gastric cancer. Doubling time of this cell line was 55 hours. The karyotype indicated that these cells were human cells and the chromosome number varied widely, the mode being 57. GCIY cells were of moderate size and showed monolayer arrangement. They had a large nucleus and a clear nucleolus. Papanicolaou staining showed that they had the characteristics of adenomatous epithelia. They could be subcutaneously transplanted into nude mice, and they histologically resembled the original tumor. They were immunohistochemically recognized by anti-CA19-9 antibody and weakly by anti-CA125, CEA and alpha FP antibodies. Cultured medium also contained CA19-9, CA125, CEA and alpha FP.

M-31 mutant (virA::Tn5) of Agrobacterium tumefaciens is capable of transferring its T-DNA into the nucleus of host cell, but incapable of integrating it into the chromosome.

An avirulent mutant (M-31 strain) was produced by the transposon (Tn5) mutagenesis of Agrobacterium tumefaciens (A-208 strain). A binary vector, pIG121-Hm, containing a kanamycin resistance gene (nptII) and beta-glucuronidase (GUS) gene with an intron, was introduced into M-31 and A-208 strains. The resultant Agrobacteria were inoculated onto leaves of Kalanchoe daigremontiana and to tobacco BY-2 cells to assay GUS activity to monitor the T-DNA transfer into the nuclei of host cells. The results indicated that T-DNA was transferred into the nuclei of cells of both host plants inoculated with the M-31 mutant. The M-31 mutant strain had an insertion of Tn5 in the virA gene on its Ti plasmid. The introduction of the virA gene in the M-31 mutant complemented its avirulent phenotype. No kanamycin-resistant cells were observed when the M-31 mutant harboring the pIG121-Hm was inoculated to tobacco BY-2 cells. The M-31 mutant (virA::Tn5) seems to transfer T-DNA into the nucleus of the host cell, but is unable to integrate it to the chromosome.

Effect of arachidonic acid on the inner ear blood flow measured with a laser Doppler flowmeter.

The present study was undertaken to clarify the effect of arachidonic acid (AA) on the inner ear blood flow of rats as measured with a laser Doppler flowmeter. With the rats under anesthesia with sodium pentobarbital, the middle ear was approached ventrally and a laser Doppler probe was positioned over the lateral wall of the cochlea. Drugs were administered via the subclavicular artery. The dose range of each drug was determined so as not to affect the systemic blood pressure. The AA (20 to 70 micrograms) increased the inner ear blood flow dose-dependently; this effect was abolished by indomethacin (5 mg orally). Both prostaglandin E2 (PGE2; 1 to 50 ng) and CS-570, a PGI2 analogue (12.8 to 25.6 ng) caused a dose-dependent increase in the inner ear blood flow. The response of PGI2 was shorter than that of PGE2. On the other hand, a stable thromboxane A2 (STA2; 30 to 80 ng) decreased the inner ear blood flow dose-dependently. Administration of PGF2 alpha (0.2 to 3 micrograms) showed no effect on the inner ear blood flow. These results indicated that the effect of AA was mediated mainly via PGI2 and PGE2.