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Biomedical subjects

N Tanabe

Publications and source records attributed to N Tanabe.

At least 37 records · Page 2Linked to original sources
PubMed1999

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.

Adult↗
PubMed1999

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.

Animals↗
PubMed1999

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.

Adult↗
PubMed1999

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.

Adolescent↗
PubMed1999

[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.

Collagen Diseases↗
PubMed1999

[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.

Actuarial Analysis↗
PubMed1999

[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.

Adult↗
PubMed1998

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.

Adult↗
PubMed1998

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.

Antigens, Viral↗
PubMed1998

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.

Adult↗
PubMed1998

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.

Aged↗
PubMed1998

Perfusion heterogeneity in the pulmonary acinus.

There is little information on the distribution of acinar perfusion because it is difficult to resolve blood flow within such small regions. We hypothesized that the known heterogeneity of arteriolar blood flow and capillary blood flow would result in heterogeneous acinar perfusion. To test this hypothesis, the passage of fluorescent dye boluses through the subpleural microcirculation of isolated dog lobes was videotaped by 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 an acinus. From the dye curves, we calculated the mean appearance time of each curve. The difference in mean appearance times between venular tributary branches was small in most cases. In 43% of the observed venular branch pairs, the dye curves were essentially superimposable (the mean appearance-time difference was <5%); and in another 42%, the mean appearance-time difference between curves was 5-10%. From these results, we conclude that acinar perfusion is unexpectedly homogeneous.

Algorithms↗
PubMed1998

Arterial and mixed venous oxygen desaturation during incremental exercise in patients with chronic pulmonary disease.

We evaluated arterial and mixed venous oxygen desaturation during symptom-limited exercise in patients with chronic pulmonary disease. Patients were divided into five groups according to disease: [chronic pulmonary emphysema (CPE), chronic bronchitis (CB), pulmonary tuberculosis sequalae (TB-seq), fibrosing lung disease (FLD), and pulmonary vascular disease (PVD)]. There were no significant difference in the values of arterial (PaO2) and mixed venous (PvO2) oxygen tension before and at the end of exercise among the five groups, whereas absolute decreases in PvO2 were significantly larger in PVD and FLD. The changes in PvO2 were similar to the changes in the coefficient of oxygen delivery (COD) which is equal to oxygen transport divided by oxygen consumption. These results suggest that the relative decrease in oxygen transport during exercise due to the high ratio of oxygen extraction by tissues is an important factor to determine decreases in PvO2 in pulmonary hypertensive disease and fibrosing lung disease.

Aged↗
PubMed1998

Malignant lymphoma demonstrating sick sinus syndrome.

We report a case of T-cell-rich large B-cell lymphoma demonstrating sick sinus syndrome as a single initial symptom, followed by the retention of pericardial and pleural effusions. Intrapleural administration of interferon-alpha prevented reaccumulation of the pleural effusion for one and a half months, whereas systemic chemotherapy failed to control tumor growth in the skin and lymph nodes. The autopsy revealed involvement of the sinoatrial node of the heart by lymphoma cells.

Aged↗
PubMed1998

[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.

Chronic Disease↗
PubMed1998

[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.

Acute Disease↗
PubMed1997

Familial aggregation and covariation of diseases in a Japanese rural community: comparison of stomach cancer with other diseases.

PURPOSE: We investigated familial aggregation as well as familial covariation of diseases by means of a questionnaire survey dealing with family histories of stomach cancer, stroke, hypertension, diabetes and tuberculosis as well as life style among 2,769 inhabitants of a rural community (84% of census population). METHODS: The strength of familial aggregation was shown by an odds ratio (OR) that compared the number of families in which siblings suffered from one of the above diseases among families in which at least one parent suffered from it, and among families in which neither did. Probands were divided into two groups for analysis: an under-55 "young group," and a 55-and-older "old group." RESULTS: The OR for stomach cancer was lowest and insignificant in the young group, and significant (2.2, p < 0.05) only in the old group. The OR for stroke, hypertension, and tuberculosis was 4.5-5.1 (p < 0.05) in the young group but decreased to 2.3-3.2 in the old group. Diabetes increased from 3.9 to 5.7 (p < 0.05) with advancing age. Age-related OR trends were not affected by exposure to cigarette smoke in the past. Stomach cancer showed a borderline familial covariation with diabetes and a borderline inverse covariation with hypertension. Hypertension showed a familial covariation with stroke and diabetes. CONCLUSIONS: Among the investigated diseases, familial aggregation was weakest for stomach cancer. The results suggest that stomach cancer may share a common familial etiologic factor with diabetes and hypotension.

Adult↗