[Clinical characteristics of asthmatics who stop peak expiratory flow monitoring (PFM)--analysis of patients who continued PFM more than eight weeks]

To estimate the effect of treatment and for patient education, we recommend 8 weeks PFM for all asthmatics when we start their treatments. To elucidate clinical characteristics of asthmatics who stop PFM, we analyzed 311 patients (145 males aged 15-76 years and 166 females aged 17-79 years) who could measure their PEFs twice daily for more than 8 consecutive weeks. The analysis of cumulative continuation rate of PEF monitoring revealed that the patients' withdrawal rate was 19% per year. The sixty asthmatics who gave up monitoring their PEFs (group A) showed significantly younger present ages (38.8 +/- 14.2, mean +/- S.D.) and younger ages of onset of their asthma (29.8 +/- 19.6) than the other 251 asthmatics who could continue to monitor their PEFs (group B). The present ages and ages of onset of asthma of group B were 46.2 +/- 16.7 and 37.6 +/- 21.2 years, respectively. Despite no significant differences in the severity of the asthma based on both clinical symptoms and PEF between groups A and B, the asthma severity based only on the clinical symptoms of group A were significantly less than those of group B. The analysis of Cox's proportional hazards model revealed that major factors which influence patients' stopping of PFM were present age and severity of their asthma which was estimated by the patients' symptoms only, without PEF assessment. These results suggest that asthmatics whose present age is young and whose ability of perception of asthma is poor will be apt to stop PFM.

Influenza vaccination levels and influenza-like illness in long-term-care facilities for elderly people in Niigata, Japan, during an influenza A (H3N2) epidemic

Surveys on influenza vaccination and illness in long-term-care facilities in Niigata Prefecture during an influenza A (H3N2) epidemic revealed that >20% of facilities had outbreaks and >10% of residents experienced influenza. Outbreaks and number of cases were significantly reduced by vaccination, which should be strongly recommended for institutionalized elderly people.

Role of positive airway pressure on pulmonary acinar perfusion heterogeneity

Perfusion of the pulmonary acinus has been shown to be generally homogeneous, but there is a significant component that is heterogeneous. To investigate the contribution of the alveolar septal capillary network to acinar perfusion heterogeneity, the passage of fluorescent dye boluses through the subpleural microcirculation of isolated dog lung lobes was videotaped using fluorescence microscopy. As the videotapes were replayed, dye-dilution curves were recorded from each of the tributary branches of Y-shaped venules that drained single acini. For each Y-shaped venule, the mean appearance time difference between the pair of tributary branches was calculated from the dye curves. When the complex septal capillary networks were derecruited by high positive airway pressure, venular perfusion became proportionally more homogeneous. This result shows that septal capillary resistance and pathlength differences are important contributors to intra-acinar perfusion heterogeneity.

[A case of primary pulmonary artery myxosarcoma associated with severe pulmonary hypertension]

A 50-year-old man presented with progressive dyspnea on exertion, but with no history of chest pain or syncope. Chronic pulmonary thromboembolism was suspected and he was referred to our hospital. On ausculation, a grade 3 systolic murmur was heard, that was loudest in the fifth intercostal space lateral to the right sternal border. Chest radiography showed mild cardiomegaly and ventilation-perfusion scan revealed absence of perfusion in the left lung and the upper field of the right lung. Contrast-enhanced helical CT showed large mural defects in both main pulmonary arteries, clearly delineated by contrast medium. The left pulmonary artery was nearly completely occluded, and eccentric defects were observed projecting into the lumen of the pulmonary trunk. A tumor originating in the pulmonary artery was suspected, but a definitive diagnosis of the mass could not be made with pulmonary angiography and magnetic resonance imaging. The mean pulmonary arterial pressure was 50 mmHg. Further radiologic examinations failed to reveal the source of the embolus or tumor. It was decided to attempt surgical excision under total cardiopulmonary bypass. At operation, a gelatinous, lustrous, yellowish mass was found partially occluding the right main pulmonary artery and completely occluding the left. The tumor adhered tightly to the intima of the vessel and was inoperable. The patient could not be weaned from percutaneous cardiopulmonary support and died 3 days after surgery. Histologic examination of the excised specimen revealed myxosarcoma.

Low dose carvedilol inhibits progression of heart failure in rats with dilated cardiomyopathy

The cardioprotective properties of carvedilol (a vasodilating beta-adrenoceptor blocking agent) were studied in a rat model of dilated cardiomyopathy induced by autoimmune myocarditis. Twenty-eight days after immunization, surviving Lewis rats (32/43=74%) were divided into three groups to be given 2 mg kg(-1) day(-1) (Group-C2, n=10) or 20 mg kg(-1) day(-1) (Group-C20, n=10) of carvedilol, or vehicle (0.5% methylcellulose, Group-V, n=12). After oral administration for 2 months, body weight, heart weight (HW), heart rate (HR), rat alpha-atrial natriuretic peptide (r-ANP) in blood, central venous pressure (CVP), mean blood pressure (mean BP), peak left ventricular pressure (LVP), left ventricular end-diastolic pressure (LVEDP), +/-dP dt(-1) and area of myocardial fibrosis were measured. Values were compared with those for normal Lewis rats (Group-N, n=10). Two out of 12 (17%) rats in Group-V died from day 28 to day 42 after immunization. No rat died in Groups-C2, -C20 and -N. Although the CVP, mean BP, LVP and +/-dP dt(-1) did not differ among the three groups, the HW, HR and r-ANP in Group-C2 (1.14+/-0.03, 339+/-16 and 135+/-31) and Group-C20 (1.23+/-0.04, 305+/-8 and 156+/-24) were significantly lower than those in Group-V (1.36+/-0.04 g, 389+/-9 beats min(-1) and 375+/-31 pg ml(-1), respectively). The LVEDP in Group-C2 was significantly lower than that in Group-V (7.4+/-1.4 and 12.2+/-1.2 mmHg, respectively, P<0. 05). The area of myocardial fibrosis in Group-C2 was smaller than that in Group-V (12+/-1 and 31+/-2%, P<0.01). These results indicate that a low dose of carvedilol has beneficial effects on dilated cardiomyopathy.

Eye examinations at the National Institute for Longevity Sciences--Longitudinal Study of Aging: NILS-LSA

The National Institute for Longevity Sciences--Longitudinal Study of Aging (the NILS-LSA) started in 1997, and involves many kinds of examination. The objective of this paper is to outline the eye examinations in the NILS-LSA. The eye examinations consist of checks on refractometry, visual acuity, intraocular pressure, contrast sensitivity, kinetic visual acuity, visual fields, fundus photography, and lens estimation. The subjects were 1,077 men and women aged 40-79 years who participated in the first year examination of the NILS-LSA. All subjective measurements (distant visual acuity, kinetic visual acuity, contrast sensitivity, and mean sensitivity of visual field) declined significantly from the 50s. Age-related structural changes in the lens or hypertensive and arteriosclerotic changes in retinal vessels began at least in the 40s. It is suspected that aging affects the subjective visual functions from the 50s. However, changes in the structure of eye may begin before the 40s. The data from the eye examinations of the NILS-LSA are useful to assess the aging effects on vision and to investigate the relationship between visual function and physical or psychosocial health problems among the elderly.

Effects of collateral vessel occlusion on oral glucose tolerance test in liver cirrhosis

Alterations in carbohydrate metabolism associated with liver cirrhosis are characterized by a high serum insulin level and prolonged hyperglycemia on oral glucose tolerance test (OGTT). We measured plasma glucose, immunoreactive insulin (IRI), and C-peptide immunoreactivity (CPR) levels during a 75-g OGTT before and after varices obliteration in 10 cirrhotic patients with gastric varices. After obliteration, the indocyanine green retention rate was decreased and the portal flow velocity was increased. A significant decline in plasma glucose and IRI levels was also noted on OGTT. Moreover, the plasma glucose and IRI levels declined at 90 and 120 min in OGTT while they increased progressively by 120 min before obliteration. The levels of CPR were similar before and after treatment. These results indicate that decreased portal flow due to extrahepatic shunt and consequent impairment of insulin metabolism play a role in glucose intolerance observed in cirrhotic patients and that shunt occlusion improves glucose metabolism.

[A case of preoperatively diagnosed primary pulmonary leiomyosarcoma]

A 29-year-old woman had been suffering from right back pain for 3 months. Chronic pulmonary thromboembolism was suspected and she was referred to our hospital. She presented with no risk factors for thromboembolism, and during the previous 6 months had lost 4 kg in body weight. Chest radiography showed nodular shadows in the lower field of the right lung. Contrast-enhanced computed tomography demonstrated a filling defect in the right pulmonary artery and nodular lesions in the lower field of the right lung, which were considered to be signs of pulmonary infarction. Absence of perfusion into the right lung was demonstrated by a perfusion scan. Right heart catheterization showed normal pressure in the pulmonary arteries, and pulmonary angiography showed an abrupt cutoff of the right pulmonary artery, which was similar to the finding of pulmonary thromboembolism. A transvenous catheter suction biopsy was performed in the right pulmonary artery and the histopathologic findings yielded a diagnosis of leiomyosarcoma. The patient underwent surgical resection under total cardiopulmonary bypass. A large tumor completely filled the right main pulmonary artery and invaded the posterior wall of the pulmonary trunk close to the left main pulmonary artery. Primary pulmonary leiomyosarcoma is a rare tumor and its prognosis is very poor. Radical surgical resection is the only effective treatment, but early diagnosis is very difficult. Transvenous catheter suction biopsy is a useful procedure for the early diagnosis of pulmonary artery sarcoma.

Risk factors and triggers of sudden death in the working generation: an autopsy proven case-control study

In Japan, studies on the risk factors of sudden death in the working generation have been rarely carried out, especially among extremely rare cases of causative disease. Thus, the present study aimed to identify the risk factors and triggers of sudden death in cases whose causes of death were definitely proven by autopsy. We investigated the legal medical records for four years from May 1994 to February 1998. Out of 271 cases, 176 patients 20 to 59 years were enrolled as cases of sudden death in the working generation. Among these, 91 cases, 52%, could be analyzed by telephone interviews from close family members. Only one examiner undertook all phone questions to the case subjects. As control subjects, 1167 persons who consulted us for a health check were employed. Of the sudden death cases, the final diagnosis in 29 cases was coronary artery disease (31.9%), 18, acute cardiac dysfunction (19.8%), 6, other cardiac diseases (6.6%), 4, acute aortic dissection (4.4%), 4, cerebrovascular disease (4.4%) and 30, other diseases (32.9%). Through conditional logistic analysis, the following risk factors emerged as candidates: Long-term stress, history of heart disease, hypertension, chest symptoms, autonomic disturbance, short-term stress and a smoking habit. Short-term stress, autonomic disturbance and a smoking habit increased the risk of sudden death due to coronary artery disease. Long-term stress was associated with an increased risk of sudden death due to acute cardiac dysfunction. It was also demonstrated that autonomic disturbance and stress were closely related to the occurrence of sudden death. Therefore, to prevent sudden death, it would be helpful to identify subjective symptoms to relieve such stress in some way.

Sr2+ induce a release of divalent cation from internal Ca2+ store by nerve stimulation at frog neuromuscular junction

The effects of Sr2+ on the transmitter release at the frog neuromuscular junction were examined electrophysiologically. The nerve trunk was stimulated by paired pulses at various time intervals after replacing extracellular Ca2+ by Sr2+, the paired-pulse facilitation at the 10 ms interval was smaller than that at 20-30 ms intervals. Administration of several intracellular Ca2+ mobilizers decreased the paired-pulse facilitation. These results suggest that the transmitter release in Sr2+ solution is caused, at least partly, by the release of divalent cations from the intracellular stores.

[Analysis of actual coverage of the immunization program in Niigata Prefecture and development of a simple estimation of its coverage]

OBJECTIVE

We investigated measles immunization coverage and the actual situation of immunization in Niigata Pref.

METHOD

We distributed questionnaires to all parents of pediatric outpatients who went to hospitals and clinics in Niigata Pref. from January 20 to 31. In the questionnaire, we asked parents about the measles immunization status of not only patients but also their sisters and brothers in each household, reasons for their immunization failure, and sources of information on immunization. We were able to collect 4,840 questionnaires from the parents who lived in Niigata Pref. and analyzable data obtained from 9,783 children. Furthermore we compared these with data from official annual reports of public health centers in Niigata Pref.

RESULT

Our survey showed that around 90% of the children who had been born since 1979 to 1993 had received measles vaccine, while the official annual reports indicated low immunization coverage (around 70%). The age at which children received measles vaccine was one year old (38.2% of the vaccinated) and two years old (37.5%), and finally 93.6% of children were immunized by three years old. The primary reason for failure to receive immunization was that he or she was infected with measles before immunization (30.4%). Around 53% of these were infected with measles by 2 years old. With regard to sources of information on immunization, public announcements and letters were the greatest sources, whereas the contribution of doctors and paramedical staffs which was expected to be the main providers of the information to parents was quite low.

CONCLUSIONS

1) It was shown that there was a difference of measles immunization coverage between our results (90%) and the official record (70%), indicating that the current coverage survey method does not reflect the actual situation of immunization. Since more than 90% of children were immunized by three years old, we recommend that measles immunization coverage should be surveyed through interviews and data in maternity record book at the health examination for three year-old children which is operated by the government and has good attendance. 2) More than 50% of children who were infected with measles before immunization were infected by two years old, suggesting further promotion of measles immunization before two years old. 3) The main source of information on immunization was public announcements and publications. Further participation of doctors and paramedical staffs in disseminating information and providing education activities is desired.

Survey of Japanese physicians' attitudes towards the care of adult patients in persistent vegetative state

OBJECTIVES

Ethical issues have recently been raised regarding the appropriate care of patients in persistent vegetative state (PVS) in Japan. The purpose of our study is to study the attitudes and beliefs of Japanese physicians who have experience caring for patients in PVS.

DESIGN AND SETTING

A postal questionnaire was sent to all 317 representative members of the Japan Society of Apoplexy working at university hospitals or designated teaching hospitals by the Ministry of Health and Welfare. The questionnaire asked subjects what they would recommend for three hypothetical vignettes that varied with respect to a PVS patient's previous wishes and the wishes of the family.

RESULTS

The response rate was 65%. In the case of a PVS patient who had no previous expressed wishes and no family, 3% of the respondents would withdraw artificial nutrition and hydration (ANH) when the patient did not require any other life-sustaining treatments, 4% would discontinue ANH, and 30% would withhold antibiotics when the patient developed pneumonia. Significantly more respondents (17%) would withdraw ANH in the case of a PVS patient whose previous wishes and family agreed that all life support be discontinued. Most respondents thought that a patient's written advance directives would influence their decisions. Forty per cent of the respondents would want to have ANH stopped and 31% would not want antibiotics administered if they were in PVS.

CONCLUSIONS

Japanese physicians tend not to withdraw ANH from PVS patients. Patients' written advance directives, however, would affect their decisions.

[Pulmonary hemodynamic and gas exchange effects of various oxygen concentrations in patients with severe pulmonary hypertension primarily affecting the pulmonary vasculature]

The aim of this study was to evaluate pulmonary hemodynamic and gas exchange response to oxygen inhalation in patients with severe pulmonary hypertension primarily affecting the pulmonary vasculature. This study included 7 patients with primary pulmonary hypertension (PPH), 11 with pulmonary hypertension related to collagen vascular diseases (CoPH), and 18 with chronic thromboembolic pulmonary hypertension (CTEPH). All patients had mean pulmonary arterial pressure (PPAm) of greater than 25 mm Hg. We divided the patients into two groups: a PPH + CoPH group comprising the 7 PPH and 11 CoPH patients, and the CTEPH group. We measured cardiopulmonary variables after 10 min inhalation of various oxygen concentrations (FiO2 0.24, 0.28, 0.4, 1.0). In the PPH + CoPH group, PPAm significantly decreased after the inhalation of oxygen concentrations of 40% or more. This was associated with a significant reduction in pulmonary arteriolar resistance (PAR), and suggested active pulmonary vasodilation was caused by oxygen inhalation. In the CTEPH group, on the other hand, PPAm significantly decreased after the inhalation of oxygen concentrations of 28% or more, apparently in association with a significant fall of cardiac output. However, PAR was unchanged regardless of the inspired oxygen concentration, indicating an absence of pulmonary vasodilation in the CTEPH group. When breathing room air, 7 patients in the PPH + CoPH group (38.9%) and 10 in the CTEPH group (55.6%) demonstrated mixed venous oxygen tension (PvO2) values of less than 35 Torr. Extra attention should be paid to PvO2 when administering oxygen therapy to patients with severe pulmonary hypertension.

Long-term administration of cyclosporin A to HCV-antibody-positive patients with dermatologic diseases

BACKGROUND

Cyclosporine A (CYA) is an immunosuppressive agent which is being used in the treatment of an increasingly wide range of dermatologic diseases, but its use has been avoided in carriers of hepatitis C virus (HCV).

METHODS

We administered small doses of CYA (maximum, 3 mg/kg/day) for a long time to treat dermatologic diseases in one HCV-antibody-positive patient with no HCV-RNA in the blood, one patient with a small amount of HCV-RNA in the blood, and two patients with large amounts of HCV-RNA in the blood.

RESULTS

Skin lesions improved in all patients, but recurred upon complete or partial withdrawal of CYA. In the absence of HCV-RNA in the blood, or when only a small quantity of HCV-RNA was present in the blood, HCV-RNA load showed no apparent change. In one patient with a large blood HCV-RNA load, CYA dosage reduction was followed by increases in alanine aminotransferase (ALT) levels and decreases in blood HCV-RNA. Aggravation of hepatitis due to immunologic reactivation was suspected in this patient.

CONCLUSIONS

The reduction of CYA dosage is a key element in the use of this agent for cutaneous diseases.

Pulmonary capillary perfusion: intra-alveolar fractal patterns and interalveolar independence

Pulmonary capillary perfusion was analyzed from videomicroscopic recordings to determine flow switching characteristics among capillary segments in isolated, blood-perfused canine lungs. Within each alveolus, the rapid switching pattern was repetitive and was, therefore, nonrandom (fractal dimensions near 1.0). This self-similarity over time was unexpected in a network widely considered to be passive. Among adjacent alveoli, the relationship among the switching patterns was even more surprising, for there was virtually no relationship between the perfusion patterns (coefficients of determination approaching zero). These findings demonstrated that the perfusion patterns in individual alveolar walls were independent of their next-door neighbors. The lack of dependence among neighboring networks suggests an interesting characteristic: the failure of one alveolar-capillary bed would leave its neighbors relatively unaffected, a feature of a robust design.

Abnormal fatty acid metabolism in patients with coronary vasospasm

Although various noninvasive methods have been used to detect vasospasm, none of them are sensitive enough for patients with sporadic attacks. Since abnormal fatty acid metabolism is observed in ischemic myocardium, 123I-beta-methyl-p-iodophenyl pentadecanoic acid (BMIPP), a radiolabeled fatty acid analog, has recently been proposed as a useful tracer for detecting myocardial damage. The aim of this study was to clarify the clinical implications of decreased myocardial BMIPP uptake in patients with vasospastic angina. We evaluated 53 patients with vasospastic angina (32 with clinically documented vasospasm [Group-A] and 21 with vasospasm induced by ergonovine provocation [Group-B]) and 27 control subjects, 20 in Group-A were re-evaluated 6 months after medical treatment. The territorial regions of vasospasm-induced coronary artery, the wall motion by left ventriculography, and BMIPP uptake were compared. Vasospasm was induced in multiple coronary arteries in 29 (55%) patients. Reduced wall motion and decreased BMIPP uptake were observed in 19 (36%) patients and 47 (89%) patients, respectively. The sensitivity and specificity of determination of vasospasm-induced coronary arteries with BMIPP scintigraphy were 71% (69/97 coronary arteries) and 88% (126/143), respectively. Vasospasm was re-induced by ergonovine provocation in 8 patients (Group-I) and not re-induced in 12 (Group-II) after treatment. In Group-I, improvement of decreased BMIPP uptake was lower than in Group-II (19+/-11 vs. 59+/-22%, mean+/-SD, p < 0.001). The regions in which vasospasm was re-provoked exhibited decreased BMIPP uptake. Abnormal fatty acid metabolism was more often observed than wall motion abnormality in the vasospastic region in patients with vasospastic angina. BMIPP scintigraphy is a highly accurate and non-invasive technique for determining the presence and location of vasospasm.

Prediction of life expectancy in patients with primary pulmonary hypertension. A retrospective nationwide survey from 1980-1990

Primary pulmonary hypertension (PPH) is a progressive disease of unknown etiology usually followed by death within 5 years after diagnosis. Although heart-lung or lung transplantation is now offered to patients with advanced PPH, adequate criteria assessing an accurate prediction of life expectancy in PPH has been difficult to establish. The aims of this study were to identify the characteristic features associated with a poor prognosis in patients with PPH, and to attempt to establish an individual prognostic index that predicts with great accuracy survival or death of PPH after one year, thereby helping to define criteria for patient selection for transplantation. In 1991, a retrospective nation-wide survey on PPH was conducted in Japan, and the clinical and cardiorespiratory variables of 223 PPH cases (female; 144, male; 79) in the period from 1980-1990 were obtained. The mean pulmonary arterial pressure (PPA) was 57.5+/-17.2 mm Hg (mean+/-SD), and the overall median survival time was 32.5 months since the first diagnostic catheterization. The characteristic features of 61 patients who died within one year of catheterization (Nonsurvivors group) were compared to 141 patients who survived one year or more from the time of catheterization (Survivors group). Among several clinical and cardiorespiratory variables, heart rate, PPA, right atrial pressure (PRA), stroke volume index (SI), pulmonary vascular resistance, and partial pressure of carbon dioxide (PaCO2) were significantly different between the two groups. As the independent factors, PPA, PRA, SI, and PaCO2 were selected for the multiple logistic analysis. Using a 0.7 probability cut-point to separate Nonsurvivors from Survivors, 84.6% of Nonsurvivors and Survivors could be correctly predicted from this logistic regression equation. Predictive equations like the present preliminary one can be used in the future to better assess life expectancy in patients with PPH in whom transplantation will be considered.

[Estimated numbers of patients with intractable respiratory diseases]

To estimate the number of patients with intractable respiratory diseases, we conducted a two-stage nationwide epidemiological survey in 1997. The first survey was performed at randomly sampled hospitals to identify the number of patients treated. The second survey sought detailed clinico-epidemiological data on the patients reported in the first survey. The response rates were 54% for the first survey and 62% for the second. Based on the survey findings, we derived the following nationwide estimates: 450 patients (95% confidence interval: 360-530) with chronic thromboembolic pulmonary hypertension; 230 (200-260) with primary pulmonary hypertension; 180 (150-210) with obesity-associated hypoventilation syndrome; 40 (30-50) with primary alveolar hypoventilation syndrome; 160 (140-180) with histiocytosis X; and 190 (150-230) with juvenile pulmonary emphysema.

Myocardial CD36 expression and fatty acid accumulation in patients with type I and II CD36 deficiency

Long-chain fatty acids (LCFA) are one of the major cardiac energy substrates, so understanding LCFA metabolism may help in elucidating the mechanisms of various heart diseases. CD36 is a multifunctional membrane glycoprotein that acts not only as a receptor for thrombospondin, collagen and oxidized low density lipoprotein but also as a receptor for LCFA. We investigated the relationship between CD36 expression in myocardial capillary endothelial cells and myocardial LCFA uptake in patients with CD36 deficiency. We analyzed CD36 expression in blood cells from 250 patients with heart diseases by means of a flow cytometer. In 218 patients, myocardial LCFA scintigraphy was performed with 123I-beta-methyl-p-iodophenyl pentadecanoic acid (BMIPP). In 5 patients, myocardial capillary endothelial cells were examined immunohistochemically for CD36 expression. Eleven patients (4%) showed signs of type I CD36 deficiency (neither platelets nor monocytes expressed CD36). Twenty patients (8%) had type II CD36 deficiency (monocytes expressed CD36 but platelets did not). In all 11 patients with type I CD36 deficiency, no BMIPP accumulation was observed in the heart, but in 13 patients with type II CD36 deficiency, BMIPP accumulation in the heart was focally reduced, but there were no patients without BMIPP accumulation in the heart. Although the myocardial capillary endothelial cells from two CD36-positive patients expressed CD36, those from two patients with type I CD36 deficiency did not. In a patient with type II CD36 deficiency, some capillary endothelial cells displayed patchy CD36 expression. CD36 deficiency was documented in 31 (12%) patients with heart diseases. Because CD36 was not expressed in the myocardial capillary endothelial cells in patients with type I CD36 deficiency, type I CD36 deficiency is closely related to lack of myocardial LCFA accumulation and metabolism in the myocardium.

[Epidemiology of acute coronary syndrome]

We reviewed the epidemiology of ischemic heart disease (IHD) focusing on acute myocardial infarction (AMI) in Japan. The age-adjusted mortality from IHD and the age-adjusted incidence of AMI in Japan were nearly the lowest in the world. Vital statistics of Japan showed that the age-adjusted mortality from IHD and AMI had been decreasing since the 1970's until 1993. Rates of new patients of AMI per day have been stable since the early 1980's according to "patient survey". Several population-based studies reported the unchanged age-adjusted incidence of AMI since the late 1950's. In conclusion, the mortality from IHD and the incidence of AMI are very low in Japan, and there is no epidemiological evidence showing an increase in either one.

Evolutionary characteristics of influenza B virus since its first isolation in 1940: dynamic circulation of deletion and insertion mechanism

New antigenic variants of B/Yamagata/16/88-like lineage which appeared in the season of 1997 as a minor strain tended to predominate in the following season. Also, we could observe for the first time, three peaks of activity caused by H3N2 virus and two variants of B influenza virus. Antigenic and phylogenetic analyses revealed that B/Victoria/2/87-like variants appeared again in Japan in 1997 after a nine-year absence. Influenza B viruses evolved into three major lineages, including the earliest strain (I), B/Yamagata/16/88-like variants (II), which comprised of three sublineages (II-(i), II-(ii), II-(iii)), and B/Victoria/2/87-like variants (III). Evolution of influenza B virus hemagglutinin was apparently distinguishable from that of influenza A virus, showing a systematic mechanism of nucleotide deletion and insertion. This phenomenon was observed to be closely related to evolutionary pathways of I, II-(i), II-(ii), II-(iii) and III lineages. It was noteworthy to reveal that the nucleotide deletion and insertion mechanism of influenza B virus completed one cycle over a fifty-year period, and that a three nucleotide deletion was again observed in 1997 strains belonging to lineage II-(iii). It was evident that amino acid substitutions accompanying nucleotide insertions were highly conserved.

Advance directives and other medical decisions concerning the end of life in cancer patients in Japan

The purpose of our survey was to investigate the experience of physicians regarding advance directives and other medical decisions concerning the end of life. A postal questionnaire was sent to 500 Japanese physicians who were most involved in medical care of terminal patients. A total of 339 (68%) physicians responded. In dealing with terminal patients, approximately half gave priority to their patients' wishes for medical care, if known, regardless of the patient's competency. Of the respondents, 149 had been presented with advance directives by their patients and 35% followed all advance directives presented in their practice. Cardiopulmonary resuscitation (CPR) for arrested patients to enable their family to be at the bedside at the time of the death was common. More than 60% of the respondents thought that active euthanasia and assisted suicide were never ethically justified. Our study indicates that the wishes of patients are currently not always given top priority in medical decisions concerning the end of life.

Hepatocellular carcinomas supplied by inferior phrenic arteries

PURPOSE

To assess the arterial supply to hepatocellular carcinomas (HCCs) by inferior phrenic arteries (IPA).

MATERIAL AND METHODS

A total of 126 consecutive cases of HCC were studied by contract-enhanced CT and conventional arteriography. Blood supply from an IPA was suspected when the size of the HCC mass as seen on contrast-enhanced CT did not match the size of the tumor mass as seen on hepatic arteriography. Inferior phrenic arteriography was employed to confirm these findings. HCCs fed by the IPA were analyzed in terms of size, location, and history of prior treatment.

RESULTS

In 14 (11%) of the 126 cases, the tumor was found to have a blood supply from an IPA. Eleven of these tumors were located in segments 2 and 7. Three tumors, which had not been treated previously, had a blood supply from an IPA. Six tumors were almost exclusively fed by an IPA and were located in segments 1, 1, and 4.

CONCLUSION

HCCs located in segments which form the bare area of the liver (S1, S2, S7) can be supplied by an IPA. This should be suspected when a lesion or part of a lesion is identified on contrast-enhanced CT but not on hepatic arteriography.