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Abstract Background Utilizing a computer algorithm, information from calls to an ambulance service was used to calculate the risk of patients being in a life-threatening condition (life threat risk), at the time of the call. If the estimated life threat risk was higher than 10%, the probability that a patient faced a risk of dying was recognized as very high and categorized as category A+. The present study aimed to review the accuracy of the algorithm. Methods Data collected for six months from the Yokohama new emergency system was used. In the system, emergency call workers interviewed ambulance callers to obtain information necessary to assess triage, which included consciousness level, breathing status, walking ability, position, and complexion. An emergency patient's life threat risk was then estimated by a computer algorithm applying logistic models. This study compared the estimated life threat risk occurring at the time of the emergency call to the patients' state or severity of condition, i.e. death confirmed at the scene by ambulance crews, resulted in death at emergency departments, life-threatening condition with occurrence of cardiac and/or pulmonary arrest (CPA), life-threatening condition without CPA, serious but not life-threatening condition, moderate condition, and mild condition. The sensitivity, specificity, predictive values, and likelihood ratios of the algorithm for categorizing A+ were calculated. Results The number of emergency dispatches over the six months was 73,992. Triage assessment was conducted for 68,692 of these calls. The study targets account for 88.8% of patients who were involved in triage calls. There were 2,349 cases where the patient had died or had suffered CPA. The sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio of the algorithm at predicting cases that would result in a death or CPA were 80.2% (95% confidence interval: 78.6% - 81.8%), 96.0% (95.8% - 96.1%), 42.6% (41.1% - 44.0%), 99.2% (99.2% - 99.3%), 19.9 (18.8 - 21.1), and 0.21 (0.19 - 0.22), respectively. Conclusion A patient's life threat risk was quantitatively assessed at the moment of the emergency call with a moderate level of accuracy.

Abstract Background Unnecessary ambulance use has become a socioeconomic problem in Japan. We investigated the possible relations between socioeconomic factors and medically unnecessary ambulance calls, and we estimated the incremental demand for unnecessary ambulance use produced by socioeconomic factors. Methods We conducted a self-administered questionnaire-based survey targeting residents of Yokohama, Japan. The questionnaire included questions pertaining to socioeconomic characteristics, dichotomous choice method questions pertaining to ambulance calls in hypothetical nonemergency situations, and questions on the city's emergency medical system. The probit model was used to analyze the data. Results A total of 2,029 out of 3,363 targeted recipients completed the questionnaire (response rate, 60.3%). Probit regression analyses showed that several demographic and socioeconomic factors influence the decision to call an ambulance. Male respondents were more apt than female respondents to state that they would call an ambulance in nonemergency situations (p < 0.05). Age was an important factor influencing the hypothetical decision to call an ambulance (p < 0.05); elderly persons were more apt than younger persons to state that they would call an ambulance. Possession of a car and hesitation to use an ambulance negatively influenced the hypothetical decision to call an ambulance (p < 0.05). Persons who do not have a car were more likely than those with a car to state that they would call an ambulance in unnecessary situations. Conclusion Results of the study suggest that several socioeconomic factors, i.e., age, gender, household income, and possession of a car, influence a person's decision to call an ambulance in nonemergency situations. Hesitation to use an ambulance and knowledge of the city's primary emergency medical center are likely to be important factors limiting ambulance overuse. It was estimated that unnecessary ambulance use is increased approximately 10% to 20% by socioeconomic factors.

Aim: The purpose of this study was to examine the trend in human papillomavirus (HPV) vaccination rates in Japan before and after a policy change in 2022, involving resumption of active recommendation and start of catch-up vaccination., Methods: From 2021 to 2023, a web-based questionnaire survey was administered to newly enrolled female college students in Yokohama, Japan. The questionnaire included items such as age, HPV vaccination status, HPV vaccine awareness, and awareness of catch-up vaccination. We compared knowledge about the HPV vaccine and cervical cancer in 2021 and 2023, before and after resumption of the national vaccination program., Results: The HPV vaccination rates were 5.4% in 2021, 7.5% in 2022, and 35.3% in 2023, with a significant upward trend (p < 0.001). A similar upward trend was observed for HPV vaccine awareness (p < 0.001). Comparing 2022 and 2023 after the start of catch-up vaccination, there was no significant difference in awareness of catch-up vaccination (p = 0.669), but there was a significant increase in awareness of free vaccination tickets (p < 0.001). After resumption of the national vaccination program with adoption of the catch-up vaccination program, there was no difference in knowledge of cervical cancer, but there was a difference in knowledge of the HPV vaccine., Conclusions: Although the HPV vaccination rate has increased after the policy change, it has not recovered to the level before the suspension of active recommendation. It is important for healthcare providers and school educators to actively communicate the safety and effectiveness of the HPV vaccine., (© 2024 Japan Society of Obstetrics and Gynecology.)

Aim: We aimed to conduct a fixed-point observation questionnaire survey of changes in young women's human papillomavirus (HPV) vaccination status over the course of 10 years. We also investigated the influence of suspension of governmental recommendation for HPV vaccination since June 2013., Methods: During 2011-2020, we conducted a self-completed questionnaire survey among newly enrolled female medical school students in Yokohama, Japan. The questionnaire featured items regarding HPV vaccination status, age, previous sex education, and knowledge about cervical cancer and HPV vaccination., Results: HPV vaccine uptake rates in 2011 (5.4%) and 2012 (13.5%), when vaccination was self-funded, increased after 2013 (48.7%), when vaccination fees were subsidized. The rate dropped drastically in 2019 (14.3%) and 2020 (5.1%), after suspension of recommendation by the government. Comparisons between new students in 2015/2016, who had high vaccination rates (65.2%), and new students in 2019/2020, who had low vaccination rates (9.8%), showed decreased levels of HPV vaccination awareness, with fewer students having covered cervical cancer prevention in sex education and with respondents having less knowledge about the details of HPV vaccination., Conclusions: After the suspension of proactive HPV vaccine recommendation, markedly fewer students have been vaccinated against HPV, even those at the vaccination target age. This situation has substantially influenced the lower awareness about cervical cancer prevention, even among medical school students. To protect young women from cervical cancer in Japan, it is crucial for the government to resume proactive recommendation of HPV vaccines as soon as possible., (© 2021 Japan Society of Obstetrics and Gynecology.)

Aim: A questionnaire survey was conducted at fixed points to describe changes over a 3-year period in the human papillomavirus (HPV) vaccination uptake rate among young women. Several factors obtained from the questionnaire were investigated in relation to HPV vaccination., Methods: The study was conducted at two universities in Yokohama City, Japan. Newly enrolled female students of the universities were recruited to participate in this study in 2011, 2012 and 2013. The study participants were asked about their HPV vaccination status. They were also questioned about factors that potentially influenced HPV vaccination, such as current age, place of residence during high school, and knowledge related to cervical cancer and HPV vaccination., Results: The proportion of vaccinated participants dramatically increased in 2013 (48.7%) in comparison to 2011 (5.4%) and 2012 (13.5%). Three factors were positively related to HPV vaccination: being 18 years old in 2013, which means that they were eligible for a financial support program (P < 0.001); living in the study city, in which HPV vaccination was well conducted (P < 0.001); and proper knowledge of cervical cancer and HPV vaccination (P < 0.001)., Conclusion: The HPV vaccination uptake rate in 2013 dramatically increased from that in 2011. Official financial support and publicity work were likely to have had an effect on the HPV vaccination uptake rate., (© 2014 The Authors. Journal of Obstetrics and Gynaecology Research © 2014 Japan Society of Obstetrics and Gynecology.)

Objective: Right-sided type colonic diverticulosis has been predominant in Japan, in contrast to European counties where the left-sided type is predominant. Considering the recent change in the dietary habits of Japanese people to a more Western diet in urban areas of Japan, the features of colonic diverticulosis may also change to reflect a more Western type. Therefore, we attempted to clarify the current situation., Methods: A total of 435 consecutive outpatients who agreed to a barium enema and complete examination were enrolled in this study., Results: 113 patients (26.0%) revealed colon diverticulosis; 50.4% of the patients had more than ten diverticula. The percentage of man with ten or more diverticula (67.4%) was significantly higher than that of women patients (40.0%, p<0.01). Among the 88 patients who had four or more diverticula, 39 patients (44.3%) were right-side dominant, 27 (30.7%) left-side dominant and 22 (25.0%) were both-sides. Thirteen (68.4%) of the 19 patients who had more than 30 diverticula were left-side dominant., Conclusion: The clinical features of colon diverticulosis in the patients living in Yokohama may be changing to reflect a more Western type, in particular decreased right-side dominance, increases in the left-side and both-sides dominant patients, and the emergence of patients with crowded diverticula in the left-side colon was observed.

Objective: It is accepted that inflammation promotes malignant progression in the development of cancers. Whether, this is true for hepatocellular carcinoma (HCC) remains as an open question. We examined the relationship between the inflammatory histology activity index (HAI) in the background liver cirrhosis (LC) and the histological grading of the HCC in the hepatectomized HCC patients with HCV-associated LC., Material and Methods: Out of 264 HCC patients who underwent curative hepatic resection, 197 had HCV-associated LC. Among them, 52 patients with a small solitary HCC nodule (< 5 cm in diameter) were studied. Inflammation in the background LC was evaluated by modified Knodell's HAI. To evaluate the inflammation, piece meal necrosis, intra lobular cellular degeneration and focal necrosis, portal cellular inflammation (0-4, each) were estimated. The average HAI was calculated. The grade of malignancy of HCC was determined by WHO classification., Results: The average HAI in the 15 patients with moderately differentiated HCC (4.3 ± 0.8, mean ± SD) was significantly larger than that in 11 patients with well differentiated HCC (3.5 ± 0.6, p = 0.036). The HAI in the 24 patients whose HCC nodules contained poorly differentiated HCC (5.2 ± 1.1) was significantly larger than that in patients with moderately differentiated HCC (p = 0.025). Thus, the HAI order was well differentiated group < moderately differentiated group < poorly differentiated group., Conclusions: Inflammation in the background non-cancerous cirrhotic portion would evoke malignant progression in HCC development from HCV-associated LC.

Aim: A reduced risk of type 2 diabetes has been reported following treatment with pravastatin. Adiponectin is an adipocyte-derived protein that has an antidiabetic property. The objective of this study was to evaluate the effect of pravastatin on serum adiponectin concentration and other influencing factors., Methods: This study was a multicenter observational study: Dyslipidemia Open-labeled observational study by Lipid-lowering therapy with Pravastatin of the effect on High-molecular weight adiponectin in Nippon Yokohama (DOLPHIN). The protocol was registered in the UMIN Clinical Trial Registry as UMIN000000791. All patients received pravastatin 10 mg/day for 6 months and the change in concentration of total and high molecular weight adiponectin was assessed before and after follow-up. The difference in the change in total adiponectin concentration by patient characteristics was analyzed by an unpaired t-test. Influences of continuous variable factors on the change in total adiponectin concentration were estimated by simple linear regression analyses. Finally, in order to estimate the influences of factors that potentially affect the change in total adiponectin concentration induced by pravastatin, multiple linear regression analysis was conducted., Results: After 6 months, total adiponectin concentration was increased significantly by 23.2% from 11.7±6.4 to 13.7±8.6 µg/mL (p=0.002). The use of thiazolidinedione as a concomitant medication was the only significant influencing factor (β=0.580, p<0.001)., Conclusion: Pravastatin increased the serum adiponectin concentration in Japanese dyslipidemic patients without previous coronary artery disease. Interestingly, this effect was seen synergistically in combination with thiazolidinedione.

Vibrio vulnificus infection can result in necrotizing fasciitis and sepsis and is associated with high mortality. Most patients infected with this microbe have liver dysfunction as an underlying disease. However, because of the sporadic nature of outbreaks and unidentified cases, extensive evaluation of clinical features and identification of factors affecting prognosis have not been performed. We retrospectively analyzed 37 cases in Japan from 1984 to 2008 to review clinical features and to identify risk factors associated with prognosis. Statistical differences between clinical features (patient's characteristics, initial clinical laboratory data, symptoms upon admission, and other risk indicators) and prognosis were analyzed by use of the chi(2) test or the Mann-Whitney U test. Multivariate logistic regression analysis was also performed to assess factors which potentially affect hospital mortality. The mortality rate was 64.9%. An underlying liver disease was observed in 91.6% of the patients. The presence of liver cirrhosis tended to be related to hospital mortality; however, statistical significance was not achieved. Advanced age, lower platelet counts, and the presence of extensive skin lesions at onset affected outcomes with statistical significance. The prognosis of this disease is poor, because septic shock and necrotizing fasciitis often develop within a few days. Early diagnosis and treatment are needed to improve the prognosis of V. vulnificus infection.

Background: Utilizing a computer algorithm, information from calls to an ambulance service was used to calculate the risk of patients being in a life-threatening condition (life threat risk), at the time of the call. If the estimated life threat risk was higher than 10%, the probability that a patient faced a risk of dying was recognized as very high and categorized as category A+. The present study aimed to review the accuracy of the algorithm., Methods: Data collected for six months from the Yokohama new emergency system was used. In the system, emergency call workers interviewed ambulance callers to obtain information necessary to assess triage, which included consciousness level, breathing status, walking ability, position, and complexion. An emergency patient's life threat risk was then estimated by a computer algorithm applying logistic models. This study compared the estimated life threat risk occurring at the time of the emergency call to the patients' state or severity of condition, i.e. death confirmed at the scene by ambulance crews, resulted in death at emergency departments, life-threatening condition with occurrence of cardiac and/or pulmonary arrest (CPA), life-threatening condition without CPA, serious but not life-threatening condition, moderate condition, and mild condition. The sensitivity, specificity, predictive values, and likelihood ratios of the algorithm for categorizing A+ were calculated., Results: The number of emergency dispatches over the six months was 73,992. Triage assessment was conducted for 68,692 of these calls. The study targets account for 88.8% of patients who were involved in triage calls. There were 2,349 cases where the patient had died or had suffered CPA. The sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio of the algorithm at predicting cases that would result in a death or CPA were 80.2% (95% confidence interval: 78.6% - 81.8%), 96.0% (95.8% - 96.1%), 42.6% (41.1% - 44.0%), 99.2% (99.2% - 99.3%), 19.9 (18.8 - 21.1), and 0.21 (0.19 - 0.22), respectively., Conclusion: A patient's life threat risk was quantitatively assessed at the moment of the emergency call with a moderate level of accuracy.

Background: Studies of the characteristics, risk factors, prognostic factors, and outcomes of diastolic heart failure (DHF) have yielded inconsistent findings. Moreover, few epidemiological studies of DHF have been performed in Japan., Methods and Results: We studied patients with heart failure who were admitted consecutively to Yokohama City University Hospital from 2000 through 2003. Heart failure with a left ventricular ejection fraction (LVEF) of > or = 50% was classified as DHF (n=67), and that with an LVEF of < or = 35% was classified as systolic heart failure (SHF; n=72). Relative wall thickness (RWT) (0.61 vs. 0.34, p<0.0001) and left ventricular mass index (210.3 vs. 152.1, p<0.0001) were greater in DHF than in SHF. Age (odds ratio [OR]=1.068, 95% CI=1.020-1.119; p=0.006) and RWT (OR=17.945, CI=5.883-54.745; p<0.0001) were positive risk factors for DHF. A history of myocardial infarction was a negative risk factor for DHF (OR=0.053, CI=0.008-0.342; p=0.002). Left ventricular mass index was slightly but not significantly related to DHF (OR=1.010, CI=1.000-1.019; p=0.053). Survival did not differ significantly between patients with DHF and those with SHF. Advancing age and a greater RWT were positive risk factors for DHF., Conclusion: LV geometry of DHF and SHF are quite different. DHF is characterized by concentric hypertrophy of the left ventricle, whereas SHF is characterized by eccentric hypertrophy. Age and RWT were positive risk factors for DHF. Survival is similar in DHF and SHF.

Abstract Objective. To assess retrospectively whether continuously high serum alanine aminotransferase (ALAT) levels (<80 IU) in the first three successive years after the diagnosis of liver cirrhosis (LC) are predictive of a subsequent high incidence of hepatocellular carcinoma (HCC) in patients with Child Stage A hepatitis C virus (HCV)-LC. Material and methods. The study comprised 132 HCV-LC (Child Stage A) patients who had not received interferon therapy but had been treated with anti-inflammatory agents. At the end of a 3-year follow-up after the diagnosis of LC, the patients were subdivided into three groups according to their serum ALAT levels and the subsequent incidence of HCC was assessed. Results. The cumulative incidence of HCC starting from 3 years after the diagnosis of LC in the continuously high ALAT group (annual average over 3 years always > or =80 IU; n=41; Group A) was markedly higher than that in the continuously low ALAT group (always <80 IU; n=48; Group B) (p<0.005) during an observation period of 7.9+/-3.7 years. The incidence of HCC in Group A was 11.8%/year. The odds ratios of developing HCC in Group A and Group C (mixed high and low ALAT levels; n=43) were 5.1-fold and 1.5-fold that of Group B, respectively. A multivariate analysis revealed that the ALAT group was independently associated with HCC development. Conclusions. Continuously high ALAT levels for three successive years following the diagnosis of LC can be predictive of a very high incidence of HCC in Child A HCV-LC patients. Prospective trials using therapeutic approaches aimed at decreasing ALAT levels are necessary in order to confirm a positive impact of ALAT reduction on the incidence of HCC in patients with HCV-LC.

Mixed connective tissue disease (MCTD) includes clinical features of systemic lupus erythematosus (SLE), dermatomyositis/polymyositis (DM/PM), and systemic sclerosis (SSc) occurring in conjunction with a high anti-U1-RNP antibody titer. Childhood MCTD rarely manifests the symptoms and signs of DM/PM and SSc, and mostly does those of SLE. Thus, the diagnosis of childhood MCTD is inevitably based on the two major findings, Raynaud's phenomenon and a high titer of anti-U1-RNP antibody. However, in clinical setting there exist patients who have both anti-dsDNA antibody, a SLE disease-marker, and anti-U1-RNP antibody, a MCTD disease-marker, and thus it is hard to differentiate MCTD patients from SLE. Eighty children were enrolled in this study, and divided into 3 groups ; group A, those who are positive for anti-dsDNA antibody/negative for anti-U1-RNP antibody (48 cases, 60.0%), group B : those who are positive for both anti-dsDNA and anti-U1-RNP antibody (22 cases, 27.5%), group C; those who are negative for anti-dsDNA antibody/positive for anti-U1-RNP antibody (10 cases, 12.5%), and each of the clinical characteristics among these 3 groups was mutually examined. The results indicated that the frequency of hypocomplementemia in group B was close to group A rather than group C, and the frequencies of both hyper-gamma-globulinemia and Raynaud's phenomenon were very close to group C, but not to group A. On the contrary, the findings which seemed to be specific to MCTD, high titers of speckled type anti-nuclear antibody and rheumatoid factor, located at the middle between group A and group C. Thus, children in group B essentially carried characteristic symptoms and signs of both SLE and MCTD, and it will be difficult to differentiate these two diseases at the onset of the disease. Taken together, children with high titers of both anti-dsDNA antibody and anti-U1-RNP antibody as well as clinical symptoms and signs such as hyper-gamma-globulinemia, Raynaud's phenomenon, membranous nephritis, positive speckled type anti-nuclear antibody and rheumatoid factor should be followed and treated as children with MCTD along with SLE.

Objective. This study aimed to determine whether mental stress influences the plasma total homocysteine level or blood pressure in young men. Method. Twenty-seven male university students were assigned to a normal blood pressure group (24-h systolic blood pressure <125 mmHg and diastolic blood pressure <75 mmHg; 13 subjects) or a high blood pressure group (24-h systolic blood pressure > or =125 mmHg, or 24-h diastolic blood pressure > or =75 mmHg; 14 subjects). Wearing an ambulatory blood pressure monitoring device, subjects rested for 30 minutes, underwent an arithmetic test for 15 minutes, and rested again for 15 minutes. Blood samples were taken before and after the test. Plasma total homocysteine levels were measured. Heart rate, blood pressure, and sympathovagal balance were determined during the test. Results. The mean total homocysteine level at rest in the high blood pressure group was slightly, but not significantly, higher than that in the normal blood pressure group. The resting total homocysteine level was significantly higher in subjects with parental history of hypertension than in those without (p < 0.01). Blood pressure, heart rate, and the plasma total homocysteine level were increased significantly by mental stress (p < 0.05). The change in total homocysteine correlated significantly with the changes in systolic blood pressure and sympathovagal balance (p < 0.05). Conclusion. Resting total homocysteine level was significantly higher in male students with a parental history of hypertension than in those without. It was shown that mental stress elevates heart rate, blood pressure, sympathovagal activity, and the plasma total homocysteine level in young men.

The aim of this study was to evaluate the relationship between the diagnosis of metabolic syndrome (MetS) or its components and the prevalence of microvascular and macrovascular complications in 130 Japanese type 2 diabetic patients. Out of the 130 patients, 58.5% satisfied the criteria of the MetS as defined by the IDF guideline. The results of logistic regression analysis with adjustment for three variables (age, gender and duration of diabetes) revealed that the presence of MetS as defined by the IDF guideline was not independently related to the presence of proliferative retinopathy, proteinuria, neuropathy, or macrovascular disease in the diabetic patients. The waist circumference per se was not associated with diabetic neuropathy, retinopathy, nephropathy, or macrovascular diseases. These results suggest that neither the presence of MetS, as defined by the IDF guideline, nor the waist circumference was associated with the presence of either microvascular or macrovascular complications in Japanese type 2 diabetic patients.

The aim of this study was to examine whether or not fluctuations in blood pressure (BP) differ by season. Subjects were 45 elderly individuals (20 men and 25 women; mean age, 66.5+/-4.9 [SD] years). Each subject's BP was recorded with an ambulatory BP monitoring device for 24 h during each of the four seasons. Subjects also wore a portable weather meter to obtain ambient temperature, relative humidity, and barometric pressure simultaneously with BP. The relationships between meteorologic values and BP were investigated at various parts of the day. Seasonal differences in BP fluctuation around wake-up-time were analyzed by means of the Tukey's test. The difference between the pre-wake-up-time systolic BP and the wake-up-time systolic BP was significantly greater in winter than in summer (8.7 mmHg greater, p<0.001). The difference between pre-wake-up-time and wake-up-time systolic BP was significantly greater in autumn than in spring (9.4 mmHg greater, p<0.001) or summer (13.1 mmHg greater, p<0.001). The difference between pre-wake-up-time heart rate and wake-up-time heart rate did not differ statistically between seasons. In conclusion, the present study showed that the difference between pre-wake-up-time systolic BP and wake-up-time systolic BP was greatest in the colder seasons, i.e., autumn and winter. There appears to be a large fluctuation in wake-up-time in the colder seasons. Low ambient temperature likely induces this large fluctuation.

Objectives: This study aimed to characterize the change in the upward trend in monthly ambulance transports that occurred during a citywide campaign for appropriate ambulance use. This study also investigated whether the number of ambulance transports for individuals with nonserious conditions decreased separately from the decrease in ambulance transports for individuals with serious conditions., Methods: A retrospective time series survey was carried out on the number of ambulance transports that occurred per month over a 10-year period (1997-2006). This study focused on individuals transported by ambulance because of illness. Seasonal decomposition was applied to adjust for the seasonal effect on ambulance transport. The shift in the trend during the campaign period (April 2005-December 2006) was examined by means of linear regression analysis., Results: The number of individuals transported by ambulance decreased during the campaign period. A decrease in the number of ambulance transports was observed for both nonserious and serious conditions. During the campaign period, the number of ambulance transports per month was estimated to have decreased by 530 (approximately 7%; 95% confidence interval [CI] = -729 to -331) for individuals with nonserious conditions and by 37 (approximately 8%; 95% CI = -53 to -22) for individuals with serious conditions., Conclusions: A campaign to educate the public on appropriate ambulance use may reduce ambulance calls for both nonserious and serious conditions.

Clarification of the cyclic pattern of emergency events is useful for identifying risk factors for emergency events. We attempted to characterize the circadian variation in emergency calls for the elderly (aged 65 years or older) because the use of emergency transportation by elderly patients is increasing rapidly. The study targeted mainly patients with cardiovascular disease. Additionally, the study analyzed circadian variability in the occurrence of cardiopulmonary arrest (CPA) and heat stroke. Data for this study were obtained from computerized records of ambulance transport from 1997 to 2003 (a total of 874,495 transported patients) managed by the Emergency Medical Division of the Yokohama Fire Bureau. A partial Fourier model was used to analyze circadian patterns of emergency calls for each disease category and determine the peak time of occurrence of disease events. A prominent peak of cardiovascular disease and CPA in the morning was observed among elderly patients, whereas amplitudes of the morning and evening peaks were almost the same among younger patients. Heat stroke among elderly patients occurred frequently from 10:00 AM to 3:00 PM, and the occurrence peaked around noon. The increase in cardiovascular disease events and CPA during the morning among elderly patients may be due to a natural fluctuation in blood pressure. A morning increase in hemoconcentration induced by dehydration during the night is thought to be another cause of the frequent occurrence of cardiovascular disease, CPA, and heat stroke events in the morning hours. In conclusion, there was a prominent peak in the morning in the occurrence of emergency events such as cardiovascular disease, CPA, and heat stroke events among the elderly.

We assessed the influence of mental stress on cardiovascular parameters, including systolic blood pressure (SBP), heart rate (HR) and sympathetic activity (LF/HF), with the use of a quantitative indicator of energy expenditure (EE). Forty-four male university students underwent a mental arithmetic test. Their EE was 1.3-fold that at rest in response to the test. Change in EE (DeltaEE) in response to the test was compared between subjects with high blood pressure (BP) and those without and between subjects with high salt intake and those without. Changes in SBP (DeltaSBP), changes in HR (DeltaHR) and changes in LF/HF (DeltaLF/HF) in relation to DeltaEE were represented by linear regression. Regression analysis showed that the coefficients of DeltaEE were positively related to the dependent variables DeltaSBP, DeltaHR and DeltaLF/HF. The slopes of the regression curves for the high-BP group (24-h SBP >or=127 mmHg) and the high-salt-intake group (>or=11 g/day) were steeper than those for the normal BP group and the low-salt-intake group (p=0.11 and p=0.01, respectively). Thus, we were able to determine the influence of mental stress on cardiovascular function. The influence of mental stress on cardiovascular function likely differs according to a subject's environmental conditions. Our study implied that high salt intake increases the sensitivity of cardiovascular functions to mental stress.

Background: Unnecessary ambulance use has become a socioeconomic problem in Japan. We investigated the possible relations between socioeconomic factors and medically unnecessary ambulance calls, and we estimated the incremental demand for unnecessary ambulance use produced by socioeconomic factors., Methods: We conducted a self-administered questionnaire-based survey targeting residents of Yokohama, Japan. The questionnaire included questions pertaining to socioeconomic characteristics, dichotomous choice method questions pertaining to ambulance calls in hypothetical nonemergency situations, and questions on the city's emergency medical system. The probit model was used to analyze the data., Results: A total of 2,029 out of 3,363 targeted recipients completed the questionnaire (response rate, 60.3%). Probit regression analyses showed that several demographic and socioeconomic factors influence the decision to call an ambulance. Male respondents were more apt than female respondents to state that they would call an ambulance in nonemergency situations (p < 0.05). Age was an important factor influencing the hypothetical decision to call an ambulance (p < 0.05); elderly persons were more apt than younger persons to state that they would call an ambulance. Possession of a car and hesitation to use an ambulance negatively influenced the hypothetical decision to call an ambulance (p < 0.05). Persons who do not have a car were more likely than those with a car to state that they would call an ambulance in unnecessary situations., Conclusion: Results of the study suggest that several socioeconomic factors, i.e., age, gender, household income, and possession of a car, influence a person's decision to call an ambulance in nonemergency situations. Hesitation to use an ambulance and knowledge of the city's primary emergency medical center are likely to be important factors limiting ambulance overuse. It was estimated that unnecessary ambulance use is increased approximately 10% to 20% by socioeconomic factors.

Objective: Arterial oxygen saturation (SpO2) in volunteers had been previously investigated, and the possibility that a decrease in SpO2 leads to an increase in blood pressure (BP) in airline passengers experiencing oxygen desaturation at high altitudes was reported. It was also shown that mean nocturnal SpO2 was lower in subjects with high-normal BP or mild hypertension than in those with normal BP. The present study investigated nocturnal SpO2, evening BP, and morning BP of volunteers during daily life and examined the relation between nocturnal SpO2 and change in BP (morning BP minus evening BP) to determine the influence of SpO2 on BP., Methods: Sixty-two volunteers (31 men and 31 women) aged 40-87 years (mean: 55.9 +/- 12 [SD] years) underwent measurement of SpO2 and heart rate with a ring-shaped pulse oximeter during sleep at home. Evening BP and morning BP were measured by automatic BP recorder. Subjects that were classified as having high SpO2 (mean nocturnal SpO2 >or= 95%; n = 23, 10 men and 13 women; mean age: 53.2 +/- 12 years) or low SpO2 (mean nocturnal SpO2 < 94%; n = 21, 12 men and 9 women; mean age: 58.7 +/- 13 years) were compared. The relation between mean nocturnal SpO2 and morning BP and the relation between mean nocturnal SpO2 and change in BP were investigated., Results: There was a significant negative correlation between mean nocturnal SpO2 and morning systolic BP (SBP; r = -0.50, p < 0.01) and between mean nocturnal SpO2 and morning diastolic BP (DBP; r = -0.37, p < 0.01). A significant negative correlation between mean nocturnal SpO2 and change in SBP was observed (r = -0.57, p < 0.01). Morning BP was significantly higher in the low nocturnal SpO2 group than in the high nocturnal SpO2 group (p < 0.001)., Conclusion: The increase in morning BP from evening BP was significantly greater in subjects with a low nocturnal SpO2. The decrease in SpO2 during sleep may affect morning BP rise.

Objective: The basal blood pressure (BP) is more intimately related to hypertension severity than casual BP. BP values obtained by ambulatory blood pressure monitoring (ABPM) tend to be influenced by patients' physical activity because values are not always obtained with the patient at rest. The purpose of this study was to estimate the influence of physical activity on BP and determine daytime BP adjusted for activity as measured by ABPM., Methods: This study targeted three clinically different groups: healthy medical students (HS, n = 40), patients with hypertension (HT, n = 20), and patients with diabetes mellitus (DM, n = 7). The subjects' BP, heart rate (HR), and physical activity level were measured by a noninvasive portable multi-biomedical recorder. To identify the influence of physical activity on BP in the three study groups, a least squares regression analysis of the relation between BP and ACT (an index of activity with acceleration) was performed for each group., Results: ACT had a positive influence on systolic BP (SBP) in the HS, HT, and DM groups (R2 = 0.319, 0.576, 0.697, respectively). SBP adjusted for ACT (walking level) by means of the regression model with dummy variable was 0-24 mmHg lower than the value of SBP measured by ABPM, and daytime SBP (walking level) was overestimated by approximately 10 mmHg in comparison to the value of SBP at rest (ACT = 0)., Conclusion: Physical activity had a positive effect on SBP. The results showed that physical activity (walking-level) had a positive effect on SBP of about 10 mmHg.

Studying the relation between incidence of stroke and weather is difficult because it requires large-scale community-based data collection. Despite the lack of strong evidence that weather conditions influence stroke incidence, many clinicians feel that meteorological conditions influence the onset of stroke. This study examined whether emergency events related to stroke are influenced by meteorological factors and was based on computerized records of emergency medical transport services in a Japanese city during the period January 1992-December 2003. A total of 53,585 patients transported for an event coded as stroke were analyzed in relation to meteorological factors such as temperature, humidity, and barometric pressure. Poisson regression analysis was applied to clarify the influence of daily meteorological conditions on the daily incidence of emergency transport due to events coded as stroke. Ordinary least squares regression analysis was used to evaluate the influence of weather, defined as the combination of meteorological parameters, on the occurrence of emergency transport due to events coded as stroke. Daily mean ambient temperature and daily mean relative humidity showed a statistically significant negative effect on the incidence of the emergency transport events for both men and women (P<0.001). Daily mean barometric pressure was not significantly related to these events. The occurrence of a holiday was negatively related to the incidence (P<0.001). Dry weather and cool weather were likely to shift the circadian curve of the incidence upward. Thus, occurrence of emergency transport due to events coded as stroke is likely to be associated with weather conditions.

Objective: This study aimed at evaluating two emergency medical service systems, one in which emergency life-saving technicians (ELSTs) are allowed to administer epinephrine (adrenaline) to patients with out-of-hospital cardiac arrest and one in which ELSTs are allowed to administer epinephrine, lidocaine, and atropine., Methods: A modified, prospective community health trial was conducted from April 1 to October 31, 2003. Areas served by physician-manned ambulances, where out-of-hospital cardiopulmonary resuscitation (CPR) was performed with resuscitative drugs (experimental areas), were compared to areas served by ELST-manned ambulances, where resuscitative drugs were not administered outside the hospital (reference areas). The sequence of emergency procedures performed in the experimental areas was divided into three phases. Phase I included administration of epinephrine, which simulated administration of epinephrine by ELSTs. Phase II started with the use of lidocaine or atropine. Phases I and II simulated administration of epinephrine, lidocaine, and atropine by ELSTs. Phase III began with administration of another drug. Outcomes, resuscitation rates and 1-month survival rates were determined, and differences between the two types of areas were analyzed., Results: For non-traumatic cardiac arrest, outcomes through phase II in the experimental areas were significantly better than those in the reference areas. Phase I-only outcomes in the experimental areas were better, but not significantly better, than those in the reference areas., Conclusion: Use of resuscitative drugs for non-traumatic prehospital CPR appears to be effective in terms of resuscitation rates and 1-month survival rates.

Respiratory and cardiovascular functions show circadian and day-to-day changes. We have developed a wireless ring-shaped pulse oximeter in collaboration with MC Medical Inc. and Advanced Medical Inc. We investigated the accuracy of this pulse oximeter and its application in daily life. Percutaneous arterial oxygen saturation (SpO2) of 47 volunteers was measured simultaneously with the ring-shaped pulse oximeter and a standard pulse oximeter. A total of 103 volunteers underwent measurement of SpO2 for 24 hr, and 11 healthy volunteers underwent measurement of SpO2 and blood pressure (BP) during flight. SpO2 and heart rate (HR) were measured and recorded every 20 sec, cabin barometric pressure and cabin oxygen concentration equivalent to sea level were measured minute-to-minute, and BP was measured every 3 min with a portable BP recorder during each flight. The SpO2 values measured with the ring-shaped pulse oximeter were similar to those measured with the standard method. The mean SpO2 during sleep was significantly lower in the group with high-normal BP or mild hypertension than in the group with normal BP. During flight, the mean change in SpO2 was -2.4 +/- 1.7% during nose-up flight, and 2.1 +/- 2.6% during nose-down flight. There was a significant correlation between change in SpO2 and change in systolic BP during nose-up flight. The wireless ring-shaped pulse oximeter was useful for investigating changes in SpO2 and its effect on BP in daily life during sleep and during air travel.

We have developed a wristwatch-type heart rate (HR) recorder (WT-HR tachometer) with an acceleration-pickup sensor, which can record HR and body activity (ACT) minute by minute for a long time (> 120 h). To study its application, we compared these measurements with 24-h blood pressure (BP) and HR variability, sympathovagal balance, and resting energy expenditure (REE). The WT-HR tachometer incorporates a Seiko-blue sensor to measure HR at the wrist and an acceleration-pickup sensor to measure body ACT every 4 sec. Fifty healthy university students underwent measurement of HR and ACT by the WT-HR tachometer for 24 h. Then we calculated the minimum HR and mean HR during waking time and derived deltaHR. On the same day, 24-hr BP and LF/HF (low frequency component/high frequency component of ECG-RR interval power spectrum) were measured with a multibiomedical recorder, and REE was measured with a portable calorimeter. The WT-HR tachometer accurately measured HR, compared with the measurements by Holter-ECG. There was a significant correlation between deltaHR and deltaSBP. There also was a significant correlation between deltaHR and deltaLF/HF, (waking time = waking time without body movement) and a significant correlation between HR and REE. These results suggest that ACT and deltaHR are useful for evaluating mental and physical activity of daily life. The WH-HR tachometer will be useful for assessment of mental and physical activity in daily life.

Objective: Whether the benefit of a public health program surpasses the cost of providing the program is an important question for public service providers. This study aimed to evaluate one health checkup program provided by a municipal government by measuring the public's willingness to pay (WTP) for maintaining the program., Methods: A questionnaire-based study of a health checkup program targeting people joining the National Health Insurance system was conducted. The WTP was estimated from a demand curve for the program, which was constructed by a revealed preference method, that is, by the travel cost method., Results: The WTP was calculated as 5410 yen per person, an amount substantially below the cost to the government of providing the service. The aggregate WTP was also estimated to be lower than the current expense of the municipal government., Conclusion: The amount users are willing to pay for a health checkup program provided by the municipal government appears to be less than the actual cost of the program. The travel cost method might reflect short-term private benefit produced by the health checkup program but cannot take into account long-term private benefit or overall social benefits which ensues.

Background: A double-blind randomized controlled trial was carried out to assess the effect of sour milk, containing two tripeptides (valine-proline-proline and isoleucine-proline-proline), on blood pressure (BP)., Methods: A total of 46 borderline hypertensive men aged 23 to 59 years were recruited at their workplace for this trial. Subjects were randomly allocated into two groups; sour milk drink group (S-group, n = 23) and placebo (acidified milk) drink group (P-group, n = 23) for 4 weeks. Blood pressure was measured twice at each occasion by a physician, at the health center of the company, with a mercury at baseline, 2 and 4 weeks. Statistical analysis was performed by SPSS 10.0J., Results: The S-group and P-group showed no significant difference in baseline systolic BP (mean [SD], S: 147.6 [9.6], P: 145.3 [13.0]) or diastolic BP (S: 95.3 [9.9], P: 91.5 [9.6]). In the S-group, change in systolic BP at 2 and 4 weeks were -4.3 mm Hg (95% confidence interval [CI] -8.3 to -0.4; P = .032) and -5.2 mm Hg (95% CI -10.1 to -0.3; P = .039), both statistically significant. Diastolic BP showed change from -1.7 mm Hg (95% CI -5.4 to 2.0) at 2 weeks and -2.0 (95% CI -5.4 to 1.5) at 4 weeks, respectively. In the P-group, change in systolic BP were -0.5 (95% CI -5.8 to 4.8) at 2 weeks and -3.7 (95% CI -8.3 to 0.9) and change in diastolic BP were -0.6 (95% CI -4.7 to 3.6) and -0.3 (95% CI -3.9 to 3.3), which were not statistically significant., Conclusions: This trial demonstrated the beneficial effect of sour milk on BP in borderline hypertensive men who were not taking antihypertensive medication., (Copyright 2004 American Journal of Hypertension, Ltd.)

Background: We have developed a new blood pressure (BP)-measuring device with a double-cuff, and evaluated its accuracy and applicability for practical use., Design: The double-cuff method features a small cuff placed in the centre of the compression cuff to detect the oscillation of arterial pulsation, by which algorithms for the determination of systolic BP (SBP) and diastolic BP (DBP) were rendered more objective than with the conventional oscillometric method. Algorithms for automatic BP determination were developed from the oscillation data taken with the small cuff from 217 men and 256 women, and then installed in the Terumo ES-H55 device (length: 17 cm, weight: 120 g). This ES-H55 device was tested on 87 subjects (65 hypertensives and 22 normotensives) to compare its accuracy with that of the auscultatory method according to the AAMI SP-10 protocol., Results: Using Bland and Altman scatter plots, the difference in SBP between the ES-H55 device and the auscultatory method was within +/- 5 mmHg in 88% of subjects, and within +/- 10 mmHg in 97% (mean difference +/- SD: 0.2 +/- 3.9 mmHg). The difference in DBP was within +/- 5 mmHg in 80%, and within +/- 10 mmHg in 97% (difference: -0.1 +/- 4.6 mmHg). These results satisfied AAMI guidelines, and this device was easy to use., Conclusions: The ES-H55 device is compact and light, with clear algorithms for the determination of BP, and satisfies AAMI criteria, so that it is considered a useful BP-measuring device that could be used instead of a mercury sphygmomanometer by nurses and doctors in hospital wards.

Purpose: We analyzed regional characteristics that potentially might affect regional demand for emergency medicine in Yokohama city and projected the number of future ambulance users., Methods: The number of patients transported by ambulance was regarded as an index of the demand for emergency medicine. Various factors that may affect regional demand for emergency medicine were used as dependent variables in multiple regression analysis. The future population was estimated by the cohort change rate method based on the 1995 and 2000 censuses. Data pertaining to ambulance use were obtained from the Annual Fire Fighting Bulletin, Yokohama. Data pertaining to regional factors were obtained from the Annual Health Statistics Report, Yokohama; the Annual Health Statistics Report, Kanagawa; and the Statistics Report, Yokohama., Results: Statistically significant relations were observed between ambulance use per 1000 population and particular regional characteristics, i.e. the proportion of persons undergoing health examinations conducted by public health centers, the number of educational health promotion programs managed by the public sector, the proportion of persons in receipt of livelihood protection, the proportions of roads and commercial areas in each district in relation to the total area, the mean land price, the age-adjusted mortality rate, and the proportion of persons aged 65 years or over. The demand for emergency medicine in Yokohama city was predicted to increase dramatically as the population ages. The number of patients transported by ambulance, which was 121,606 in 2000, was projected to exceed 250,000 in 2030 and to approximate 300,000 in 2050., Conclusion: The demand for emergency medicine will increase dramatically in Yokohama city as the society ages, Regional emergency medical systems should be improved accordingly.

Cost-effectiveness analysis is a method used to evaluate the outcomes and costs of treatments or interventions designed to improve health. It has been widely regarded as an important aid to providing health care services efficiently. This paper reviews several measures for controlling medical costs in Japan, where a fee-for-service system is employed to remunerate for medical services provision. From the point of view of cost-effectiveness, the first step in health care reform for controlling medical costs should be minimizing useless medical services because the cost-effectiveness ratio of these tends to infinity. For the purpose of minimizing unserviceable provision in the field of medicine, two approaches must be considered. One is establishing a system so that physicians can act as perfect agencies for their patients. The other is encouraging academic research on the effectiveness of medical services.

Objective: In recent years, the annual number of emergency ambulance (EA) calls has increased in Yokohama city, Japan. A questionnaire study was carried out to describe behavioral features of the users in Yokohama city, and to investigate their relationship with the increase in EA utilization., Methods: We randomly recruited 2,910 citizens, aged 15 years or older, for the questionnaire study and a total of 2,294 (78.8%) replied. The questionnaire included questions about their demographic characteristics, history of EA use, existence of family doctors, and knowledge of emergency medical services and emergency medical information centers. Additionally, respondents who had used EA previously were asked about their reasons for this., Results: A total of 513 (22.4%) respondents answered that they had used EA previously. A slightly higher rate of EA use was shown among elderly people, 65 years old or over (a rate of 26.2%). The major reason for requesting EA use was the urgency of the disease or the injury (61.8%). 182 respondents answered that they requested EA as a means of transportation. However, most of them also mentioned that the urgency of the disease or the injury was one of the reasons for their request. This survey showed no evidence that the citizens of Yokohama have used EA improperly. Elderly people, among whom the annual number of EA uses has increased rapidly over the years, tended to employ EA in a way more in line with regulations than other generations., Conclusion: This study suggested that the basic reason for the increase of EA utilization in Yokohama city was not due to inappropriate demand but to the aging of the population.

Objective: This study surveyed the sexual behaviour of commercial sex workers and their clients in an attempt to identify factors of transmission of STDs (including HIV/AIDS) and to control their epidemics in Cambodia and South-East Asia., Design: Cross-sectional study., Setting: Trained questioners asked items of the questionnaires to each objective subject in December 1996. Data were analysed to show the descriptive status by risk group of each person., Participants: 200 direct commercial sex workers, 220 indirect commercial sex workers, and 211 clients in Phnom Penh., Results: Prostitution was widely accepted by both young males and females, and this was an easy way for young girls to obtain money. Although commercial sex workers and clients were knowledgeable about prevention methods against STDs, they seldom used condoms. Some commercial sex workers had been infected with STDs many times, and many of them incompletely treated the diseases by themselves. Social support from governmental and non-governmental organisation was poor., Conclusions: It is very important to support both commercial sex workers in practicing preventive methods against STDs and also visiting physicians when they notice symptoms of STDs. It is strongly recommended that not only governmental but also non-governmental organisations should be more active in this area.

Objective: To describe epidemiological features of HIV prevalence among female commercial sex workers (CSWs) in Cambodia, a cross-sectional study using a questionnaire study and serological tests was carried out from December 1997 to January 1998. We report the main results of the analyses of serological tests in this article., Methods: Two hundred ninety six CSWs working in Sisophon and Poi Pet, located in northwest Cambodia, Bantey Mean Chey province, were recruited for interview based on a questionnaire on sexual behavior, and serological tests. The blood samples were examined for HIV antibody, Chlamydia trachomatis IgG antibody, TPHA, Hepatitis B surface antigen, and Hepatitis B surface antibody. The relationship between HIV and the other STD's was analyzed by using logistic regression analysis., Results: The HIV seroprevalence rate was 43.9% (130 out of 296). The seropositive rate of Chlamydia trachomatis IgG antibody (C.T.-IgG-Ab) was 73.3% (217 out of 296). Logistic regression analysis showed a significant association between C.T.-IgG-Ab positive and HIV prevalence. (Odds Ratio: 5.33; 95% Confidence Interval, 2.82-10.07)., Conclusions: This study suggests that the existence of Chlamydia trachomatis is closely related with HIV prevalence among CSWs in Cambodia. Other STDs may also increase susceptibility to male-to-female sexual transmission of HIV. This suggests that appropriate prevention against STDs will be needed for the control of HIV prevalence in Cambodia.

In December 1995 and March 1996, we visited institutes which were conducting epidemiological studied of HIV/AIDS in Cambodia, and obtained data for further collaborative study between Japan and Cambodia. Data included information on AIDS patients and HIV infected persons, and behavioral epidemiology of CSWs (Commercial Sex Workers). The cumulative reported number of AIDS patients and HIV infected persons in Cambodia was 86 and 2,536 cases respectively in 1995. The cause of infection was mostly heterosexual contact with very few cases from injecting drug use (IDU) and other causes. The seroprevalence rate of HIV antibody among donated blood rapidly increased from 0.08% in 1991 to 4.47% in 1995, and those among CSWs and pregnant women were 37.9% and 2.6%, respectively, in 1995. The average rate of condom use among CSWs was 66%, but the rate of usual usage was only 14%. These results indicate that the HIV/AIDS epidemic had spread rapidly through CSWs, that it had been spread among peoples in communities, and that usage of condoms among CSWs was insufficient in Cambodia. Without strong countermeasures against HIV/AIDS in this country, HIV/AIDS epidemic may spread significantly to not only peoples in this country but also those in neighbouring countries in the future.

A case of right ventricular aneurysm due to myocardial fatty infiltration was reported. A 39-year-old man was admitted to our hospital for evaluation of several episodes of syncopal attack presumably induced by malignant arrhythmia. There were frequent observations of ventricular premature beats, which occurred occasionally in couples. Cardiac catheterization disclosed the aneurysm situated at the outflow tract of the right ventricle. Aneurysmectomy was performed and the ventricular premature beats and syncopal attacks were effectively abolished. Etiology of the aneurysm was proved to be a fatty infiltration in the myocardium. To the best of our knowledge, there has been no case report of right ventricular aneurysm due to fatty infiltration in the myocardium.