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Biomedical subjects

K Shimamoto

Publications and source records attributed to K Shimamoto.

At least 163 records · Page 9Linked to original sources

[Involvement of glucose metabolism abnormalities and insulin resistance in atherosclerotic coronary artery disease: semiquantitative coronary angiography study].

Insulin resistance is known to be important in the aggravation of established coronary risk factors, but it is unclear whether insulin resistance might cause coronary artery disease as diabetes mellitus. To evaluate the relationship between insulin resistance and coronary atherosclerosis, the angiographic semiquantitative score of coronary atherosclerosis was investigated in 216 patients (175 males, 41 females) with coronary artery disease and the varying degrees of glucose metabolism including insulin resistance. Insulin resistance was estimated by plasma insulin level at 120 min after the 75g oral glucose tolerance test. Patients were divided into 3 groups according to the levels of glucose metabolism: 37 patients with treated diabetes mellitus, 48 with glucose intolerance and non-treated diabetes, and 131 with normal glucose tolerance. Multivessel disease was more frequently seen in the treated diabetes group (67.6%) than in the glucose intolerance and non-treated diabetes groups (43.8%) and in the normal glucose tolerance group (40.5%). The severity of coronary artery stenosis (8.5 +/- 3.9 vs 7.6 +/- 3.7 vs 6.6 +/- 3.7) and calcification (6.5 +/- 6.3 vs 3.3 +/- 3.3 vs 4.0 +/- 4.8) were significantly higher in the treated diabetes group than in other groups. Distal coronary lesions were significantly more frequent in the treated diabetes group (61.1% vs 17.6% vs 27.4%) than in other groups. Half of the patients in the normal glucose tolerance group had hyperinsulinemia. Multivessel disease was significantly more frequent in the insulin resistant subgroup than in the insulin non-resistant subgroup (59.4% vs 25.0%, p = 0.011). The severity of coronary artery stenosis was significantly higher in the insulin resistant subgroup than in the insulin non-resistant subgroup (8.6 +/- 3.9 vs 5.6 +/- 3.0, p < 0.001), but the severity of coronary artery calcification was not significant. Distal coronary lesions showed a tendency to increase in the insulin resistant subgroup (37.5% vs 12.0%, p = 0.081). These results suggest that insulin resistance is an important risk factor for coronary artery disease in patients with normal glucose tolerance, and is related to the severity and multiplicity of coronary atherosclerosis as in patients with diabetes.

Blood Glucose↗

Inhibition of annexin V-dependent Ca2+ movement in large unilamellar vesicles by K201, a new 1,4-benzothiazepine derivative.

Examination was made of the effect of annexin V on Ca2+ movement into large unilamellar vesicles (LUV) using fura-2, a calcium-sensitive fluorescent dye. To avoid the possible difficulties relating to the addition of annexin V and/or Ca2+ in fura-2-loaded LUV, the burst method was used. LUV, preincubated with rat annexin V in the presence of Ca2+, were collected by centrifugation and resuspended, and then burst with Triton X-100 in the presence of fura-2. Inward Ca2+ movement across the artificial lipid membrane was measured by determination of fura-2 fluorescence due to the leaked Ca2+ from ruptured LUV. The observed Ca2+ signal increased dependent on annexin V and Ca2+ concentrations, whereas bovine serum albumin did not affect this signal up to 1 microM. Thus, annexin V shows Ca2+ channel activity in LUV. K201, a novel 1,4-benzothiazepine, inhibited inward Ca2+ movement into LUV caused by annexin V in a dose-dependent manner. In the presence of 50 nM annexin V and 400 microM Ca2+, 3 microM K201 showed significant inhibition of Ca2+ movement due to annexin V, and 50% inhibition was achieved at 25 microM K201. On the other hand, diltiazem had no such effect even at 30 microM. K201 is thus shown to have inhibitory activity on inward Ca2+ movement due to annexin V in artificial vesicles and may prove useful as a probe for elucidating the functions of annexin V in vivo.

Amino Acid Sequence↗

New beta-hydroxyaspartate derivatives are competitive blockers for the bovine glutamate/aspartate transporter.

Four subtypes of excitatory amino acid transporters (EAAT1-4) have been identified in the mammalian brain. A number of pharmacological agents have been developed to study their intrinsic properties and function. Up to now, blockers were available only for EAAT2, whereas all the inhibitors of glutamate uptake active on the other subtypes were proved to be substrates of the transporters. We synthesized five new derivatives of DL-threo-beta-hydroxyaspartic acid, a well known general substrate of EAATs, and investigated their potential blocking activity on the cloned bovine EAAT1 expressed in the Xenopus oocyte system, by using radiotracer and voltage-clamp techniques. Two of our derivatives proved to be substrates for bovine EAAT1, with reduced electrogenicity compared with their parent compound, and an affinity of 40 and 64 microM. The last three derivatives displayed a blocking activity on bovine EAAT1. The affinity of DL-threo-beta-benzoyloxyaspartate and DL-threo-beta-(1-naphthoyl)oxyaspartate was determined by Schild analysis as 17.2 and 52.1 microM, respectively. These blockers should help in the better understanding of the key intrinsic properties of EAAT1. Moreover, they appear as good candidates for a general blocking activity on EAATs.

ATP-Binding Cassette Transporters↗

Infarct size limitation by a new Na(+)-H+ exchange inhibitor, Hoe 642: difference from preconditioning in the role of protein kinase C.

OBJECTIVES: This study examined the effect of a new specific Na(+)-H+ exchange inhibitor, Hoe 642, on infarct size and the protective role of protein kinase C (PKC) by this agent. In addition, we assessed the possible alteration of Hoe 642-induced cardioprotection by commonly used animal anesthetic drugs. BACKGROUND: Earlier studies on the contribution of Na(+)-H+ exchange to ischemic injury were complicated by nonspecific actions of the Na(+)-H+ exchange inhibitors, and the role of this exchanger in myocardial infarction in vivo remains unclear. The difference in anesthetic agents used in experiments could have resulted in discrepant findings regarding cardioprotection of some interventions, such as preconditioning and adenosine triphosphate-sensitive potassium channel openers. METHODS: Infarction was induced by 30 min of coronary occlusion and 3 h of reperfusion in the rabbit heart. In the first series of experiments, rabbits were anesthetized with pentobarbital or ketamine/xylazine. Hoe 642 was injected intravenously 10 min before ischemia or 5 min before reperfusion. In the second series of experiments, rabbits received 25 mg/kg body weight of polymyxin B (polyB), Hoe 642 plus polyB, preconditioning with 5 min of ischemia and 5 min of reperfusion plus polyB or preconditioning alone before 30 min of ischemia. RESULTS: In pentobarbital-anesthetized rabbits, 0.3 mg/kg and 0.6 mg/kg of Hoe 642 given before ischemia limited infarct size (as percent area at risk [%IS/AR]) to 42.7 +/- 4.4% (SEM) and 26.2 +/- 5.4%, respectively, from the control value of 55.1 +/- 3.5%. However, injection of Hoe 642 before reperfusion did not change infarct size (%IS/AR 49.6 +/- 4.9%, p = 0.387; power 0.81 for detecting 50% reduction). Infarct size limitation by the preischemic treatment with Hoe 642 was similarly observed in the rabbits anesthetized with ketamine/xylazine. In the polyB-treated rabbits, 0.6 mg/kg of Hoe 642 significantly limited infarct size (%IS/AR was 28.3 +/- 3.8% with Hoe 642 and 50.1 +/- 7.5% without Hoe 642), although preconditioning was blocked by the same dose of polyB (%IS/AR was 39.3 +/- 6.1% with polyB and 11.3 +/- 2.4% without polyB). CONCLUSIONS: Hoe 642 enhanced myocardial tolerance against infarction, and this enhanced tolerance was not influenced by anesthetic agents commonly used for infarct size studies. Infarct size limitation by Hoe 642 was not inhibited by polyB, suggesting that cardioprotection by Na(+)-H+ exchange inhibition is not PKC mediated and thus may be unrelated to preconditioning.

Animals↗

Combined use of detachable coil against persistent mechanical hemolysis after transcatheter occlusion using Rashkind umbrella device in adult patient with patent ductus arteriosus.

Mechanical hemolysis after transcatheter occlusion of the patent ductus arteriosus using the Rashkind umbrella device has been postulated as a rare, but serious complication, even necessitating surgical repair. A rare, case of an adult patient with massive hemolytic anemia, successfully controlled by the combined use of several detachable coil devices is reported. The use of coil devices might be considered as a therapeutic option in such cases.

Anemia, Hemolytic↗

New technique for time series analysis combining the maximum entropy method and non-linear least squares method: its value in heart rate variability analysis.

A new technique for time series analysis, which is a combination of the maximum entropy method (MEM) for spectral analysis and the non-linear least squares method (LSM) for fitting analysis, is described. In this technique, the MEM power spectral density (MEMPSD) is calculated using a very large lag that could diminish the lag dependence of dominant periods estimated by the MEM analysis. The validity of this large lag is confirmed by the LSM, given that the ten dominant MEM periods are known quantities. To validate the MEM plus LSM technique, it is compared with autoregressive (AR) modelling, by analysing heart rate variability under pharmacological interventions (phenylephrine and trinitroglycerine), using 16 young males. The results indicate that the MEMPSD, when compared with the ARPSD, has numerous periods that could reproduce the original time series much more accurately, as revealed by the LSM analysis. However, both the low- and high-frequency powers with MEMPSD and ARPSDs shift in the expected directions in accordance with the pharmacological effects on the cardiovascular system. The implications of these results are discussed from the theoretical and practical standpoints of the MEM plus LSM technique, compared with AR modelling.

Adolescent↗

Eye-tracking device comparisons of three methods of magnetic resonance image series displays.

This study evaluated the effectiveness of three kinds of display methods for magnetic resonance (MR) image interpretation using an eye-tracking device. Seven radiologists interpreted head MR studies by using a single monitor (17-inch, 1,024 X 1,280 bit) in the 4 images/screen display format. Three paging modes were compared: (A) rapid paging only, (B) multiple image series display at the same slice position with consecutive rapid paging, and (C) simultaneous display of multiple series with each image series being browsed independently. Using an eye-mark camera, the radiologist's point of fixation and the duration of fixation were recorded during actual image interpretation. In mode A, the duration of fixation was short, and the points of fixation were distributed randomly over the visual field. In mode B, the points of fixation were clustered chiefly on a specific image series. In mode C, the points of fixation were not clustered on a specified series, but the duration of viewing the T2 series was relatively long. The total tracing area in mode B and C was smaller than that in mode A. Multiple series display, in which selected key series of slices could be viewed effectively, was found to be suitable for MR image interpretation.

Data Display↗

Silencing of waxy genes in rice containing Wx transgenes.

In order to study gene silencing in a monocot system we introduced a waxy (Wx) gene into rice. In the pollen grain of the transgenic wild-type plants, two types of Wx gene silencing were observed: Type I in which all the pollen grains showed the mutant (wx) phenotype, and Type II in which 50% of the pollen grains showed the wx phenotype. Analysis of Wx gene expression in the progeny of selfing and outcrossing indicated that Wx gene silencing was meiotically transmitted to the offspring. The number of transgene copies and transgene loci was determined by Southern blot analysis and suggested that the Wx transgene may have a paramutagenic effect on the endogenous Wx genes. In contrast to the pollen grain, the wx phenotype was not observed in the endosperm. However, the level of WAXY (WX) protein in the endosperm of Type I lines was similar to that in non-transgenic seed, while in Type II lines two classes of seeds, showing high and low levels of the protein segregated. When the same transgene was introduced into wx mutants in which no Wx transcript was detectable, the transgene behaved as a dominant Mendelian factor and no silencing was found, suggesting that the activity of the endogenous Wx gene influences the silencing phenomenon. Our study of Wx gene silencing in rice extends the well-known phenomenon of gene silencing, so far observed mainly in dicots, to a cereal.

Gene Expression Regulation, Plant↗

Protection by diphenyliodonium against glutamate neurotoxicity due to blocking of N-methyl-D-aspartate receptors.

The protective effect of diphenyliodonium, known as an inhibitor of flavin enzymes including nitric oxide synthases, was examined against the neurotoxicity of excitatory amino acids on cultured spinal neurons of the rat. Diphenyliodonium reduced the neuronal damage induced by 15-min exposure to glutamate or N-methyl-D-aspartate in a dose-dependent manner; half effective concentrations (EC50) were about 3 microM for both. Protection was only observed when diphenyliodonium was added into the exposure medium. Diphenyliodonium showed no effect on the toxicity induced by 24 h exposure to non-N-methyl-D-aspartate receptor agonists. Using a microfluorometry technique with Fura 2, we observed that diphenyliodonium reversibly inhibited the N-methyl-D-aspartate-evoked intracellular Ca2+ elevation. The amount of 45Ca2+ influx induced by N-methyl-D-aspartate was also inhibited by diphenyliodonium in a dose-dependent manner; EC50 was about 3 microM. Furthermore, we examined the effect of diphenyliodonium on an opening activity of the N-methyl-D-aspartate receptors estimated by binding of dizocilpine maleate to membrane fractions from whole brain of adult rat and from cultured spinal neurons. Diphenyliodonium inhibited the binding of dizocilpine maleate dose-dependently; EC50 was 5-8 microM. These results suggest that diphenyliodonium is a new antagonist to the N-methyl-D-aspartate receptors and that diphenyliodonium protects neurons against glutamate toxicity due to a direct blocking of the Ca2+ influx. This conclusion is supported by the similarity of the stereochemical structures predicted by computer between diphenyliodonium and dizocilpine maleate.

Animals↗

Trp64Arg mutation of beta3-adrenergic receptor in essential hypertension: insulin resistance and the adrenergic system.

A putative pathogenic mutation in the beta3-adrenergic receptor gene (Trp64Arg) has been reported to be associated with higher diastolic blood pressure as well as clinical features of the insulin resistance syndrome and an earlier onset of non-insulin-dependent diabetes mellitus (NIDDM) in Pima Indians and Finns. Because essential hypertension is reported to be associated with insulin resistance, we studied the mutation in Japanese patients with essential hypertension to clarify associations of this mutation with hypertension, insulin resistance, and basal adrenergic state in hypertensive subjects. The allele frequency of the mutation (Arg) in patients with essential hypertension was similar to that in control subjects (35 of 202 alleles [17.3%] v 27 of 146 [18.5%], respectively, P > .7). Insulin sensitivity measured by hyperinsulinemic euglycemic glucose clamp and plasma norepinephrine and epinephrine levels were also similar in hypertensive subjects with and without the mutation. These data suggest that Trp64Arg mutation in the beta3-adrenergic receptor gene does not play a major role in susceptibility to essential hypertension or in insulin resistance and basal adrenergic state in hypertension.

Adult↗

High plasma immunoreactive leptin level in essential hypertension.

Insulin resistance, the most important factor in metabolic syndrome X, has been considered to raise blood pressure. Recently it was reported that insulin resistance was related to an elevated plasma level of leptin, which is an adipocyte-specific ob gene product and which plays a role in food intake suppression, thermogenesis, and energy expenditure through the activation of the hypothalamus. However there are no reports that deal with the relationship of insulin resistance to plasma leptin and blood pressure. To evaluate the role of leptin in essential hypertensives, two groups of subjects who were carefully matched for body mass index (BMI) were studied; 22 normotensives (NT, age: 46.5 +/- 2.6 years, BMI: 23.9 +/- 0.4 kg/m2, male/female: 14/8) and 45 mild-to-moderate essential hypertensives (EHT, age: 51.9 +/- 2.0 years, BMI: 24.5 +/- 0.4 kg/m2, male/female: 21/24). We applied the euglycemic hyperinsulinemic glucose clamp technique to all subjects and insulin sensitivity was evaluated as the M value. EHT showed a significantly lower M value (160.2 +/- 7.4 v 184.3 +/- 7.3 mg/m2/min, P < .05) and higher basal plasma immunoreactive leptin level (7.6 +/- 0.8 v 5.0 +/- 0.8 ng/mL, P < .05) than NT, despite the fact that there was no significant difference between NT and EHT in age, gender, or BMI. The relationship between mean blood pressure and leptin showed a significant positive correlation in all of the subjects (r = 0.31, P < .05), suggesting that leptin may be related to a pathophysiology of essential hypertension.

Adult↗

Anaplastic Ki-1-positive large cell lymphoma of the pancreas: a case report and review of the literature.

A case of Ki-1-positive anaplastic large cell lymphoma of the pancreas is presented. The patient complained of abdominal pain and was jaundiced. Examination of a biopsy specimen obtained by duodenal endoscopy revealed malignant lymphoma, and surgery confirmed a large mass located in the region from the intra-pancreatic tissue around the lower common bile duct to the peri-pancreatic lymph nodes. Histologically, this tumor was composed mainly of large and giant neoplastic cells. Immunohistochemically, these cells were diffusely positive for Ki-1 and CD45RO antigens, indicating the features of Ki-1 anaplastic large cell lymphoma with a T-cell phenotype among non-Hodgkin's lymphoma. The histologic types of the majority of malignant lymphomas of the pancreas reported previously were considered to be diffuse-type non-Hodgkin lymphoma (probably with predominance of the B-cell phenotype), except for a single Japanese lymphoma case with a T-cell phenotype. This is therefore the first known case of Ki-1 anaplastic large cell lymphoma of the pancreas.

Antineoplastic Combined Chemotherapy Protocols↗

Role of the angiotensin II type 1 receptor in preconditioning against infarction.

OBJECTIVE: To assess the role of angiotensin II type 1 (AT1) receptor in the mechanism of limitation of infarct size by preconditioning. METHODS: Myocardial infarction was induced by 30 min coronary artery occlusion and 3 h reperfusion in the rabbit. The infarct size was determined by tetrazolium staining and expressed as a percentage of the area at risk (%ISAR). Rabbits were subjected to one of the following four treatments: no drug (i.e. control); administration of 1 mg/kg CV-11,974, a specific AT1 receptor antagonist, 20 min before ischemia; preconditioning with 5 min ischemia and then 5 min reperfusion; and administration of CV-11,974 plus preconditioning. RESULTS: It was confirmed that the same dose of CV-11,974 (i.e. 1 mg/kg) could block the pressor response to injection of 0.5 microgram/kg angiotensin II completely for 60 min. The %ISAR for the untreated control group was 45.1 +/- 3.9%, and administration of CV-11,974 alone did not modify the %ISAR (47.5 +/- 5.9%). The %ISAR for the group administered both CV-11,974 and subjected to preconditioning (30.4 +/- 3.5%) was modestly smaller than that for the controls, but was significantly larger than for the preconditioned group (12.0 +/- 1.8%). The angiotensin II level in arterial plasma did not differ before and after the 5 min preconditioning. It was shown with separate groups of rabbits that a modest protection conferred by preconditioning with 3 min ischemia was also attenuated by administration of CV-11,974 (%ISAR 28.4 +/- 4.3 with CV-11,974 versus 19.3 +/- 1.7% without CV-11,974, P < 0.05). CONCLUSION: These results suggest that activation of AT1 receptors by angiotensin II produced locally in the heart contributes to the limitation of infarct size by preconditioning.

Angiotensin II↗

Asp905Tyr polymorphism of protein phosphatase 1 G subunit gene in hypertension.

A possible pathogenic polymorphism in the gene for the G subunit of the glycogen-associated regulatory form of protein phosphatase 1 (PP1 G subunit), causing an Asp-to-Tyr substitution at codon 905 (Asp905Tyr), has been reported to be associated with insulin resistance and hypersecretion of insulin in the white population. Since marked heterogeneity has been reported in the association of mutations of candidate genes with essential hypertension between Japanese and other ethnic groups, we investigated the association of Asp905Tyr with essential hypertension in Japanese subjects. The frequency of the Tyr allele in Japanese control subjects (0.70) was much higher than that in the Danish population (0.10, P<1x10(-8)), indicating that the Tyr allele, previously reported as a rare variant in white subjects, is a common allele in our population. The genotype distribution in Japanese hypertensive patients (n=109; Asp/Asp=0.09, Asp/Tyr=0.39, Tyr/Tyr=0.52) was not significantly different (chi2=0.7, df=2, P>.6) from that in normotensive control subjects (n=148; Asp/Asp=0.12, Asp/Tyr=0.36, Tyr/Tyr=0.52). Among subjects with different PP1 G subunit genotypes, there was no difference in blood pressure, serum cholesterol, plasma glucose and insulin levels, and glucose disposal rate estimated by the euglycemic hyperinsulinemic clamp test. These data indicate that the Asp905Tyr polymorphism of the PP1 G subunit is not associated with essential hypertension, nor with insulin resistance and/or hyperinsulinemia in Japanese patients with essential hypertension, suggesting that the polymorphism plays little if any role in susceptibility to insulin resistance or hypertension.

Aged↗

[Treatment of elderly patients with hypertension--complications and current drug therapy].

To investigate current drug therapy for elderly hypertensive patients, we performed a case-card study at Sapporo Medical University and its branch hospitals. The case-card was designed to show prescriptions given for hypertension, complications, and blood pressure. In the 2897 valid cases, calcium antagonists were prescribed in 76.3%, followed by beta-blockers (31.4%), angiotensin-converting enzyme inhibitors (ACE-I) (25.1%) and natriuretic diuretics (18.1%). When the patients were divided into an elderly group (> or = 65 y.o., n = 1475), beta-blockers and ACE-I were found to be more frequently used in the non-elderly group, and diuretics were more frequently prescribed in the elderly group. Calcium antagonists were the most frequently used drugs, irrespective of age. As monotherapy drugs, calcium antagonists were chosen most frequently in both groups. Diuretics were the second most frequently used drug in the elderly group, but beta-blockers occupied that position in the younger group and these patients as a whole. In the elderly group, the manner of prescription was analyzed according to major complications. In patients with ischemic heart disease, beta-blockers and diuretics were used more frequently than in patients without that condition. Diuretics were prescribed more frequently in patients with renal dysfunction. Calcium antagonists and ACE-I were used more frequently in the patients with diabetes mellitus. The same differences were found in the non-elderly patients with those complications. However, among patients with stroke, calcium antagonists were more frequently used in the elderly group and ACE-I were performed in the younger patients. In conclusion, calcium antagonists were used very often regardless of age, and the other drugs were used according to age-dependent differences in pathophysiologic mechanism.

Adrenergic beta-Antagonists↗

[Glucose tolerance and insulin resistance in the elderly].

Glucose tolerance is reported to be impaired in the elderly, and this is said to be mainly due to a decrease in insulin sensitivity (insulin resistance). Insulin resistance is known to be associated with atherosclerosis and coronary artery disease. To clarify whether or not age-dependent changes in glucose tolerance and insulin sensitivity are risk factors for coronary artery disease, as they are in the case of the insulin resistance syndrome, we studied age-dependent changes in glucose tolerance, insulin sensitivity, blood pressure, and serum lipids in a large number of subjects who underwent annual health check-ups, and then studied the relationships between coronary artery disease and aging, insulin sensitivity, and other risk factors in subjects who underwent coronary angiography. Aging was associated with an increased prevalence of noninsulin-dependent diabetes mellitus and impaired glucose tolerance; even in subjects with normal glucose tolerance, plasma glucose levels during an oral glucose tolerance test were significantly higher in the elderly. Insulin sensitivity, as assessed by the ratio of the sum of the plasma glucose divided by the sum of the serum insulin during the test (sigma PG/sigma IRI), was significantly lower in subjects over 60 years old than in younger subjects. Age-dependent impairment of insulin sensitivity and glucose tolerance was associated with increased blood pressure and serum cholesterol levels, but not with changes in boy mass index or serum triglyceride levels. As an independent variable, aging, but not insulin sensitivity, was related to the severity of coronary artery disease. These data suggest that aging is associated with glucose intolerance, insulin resistance, and an increased risk of coronary artery disease, but that the effect of aging on coronary artery disease cannot be explained by insulin resistance alone. Other factors, such as glucose intolerance and increased blood pressure, in addition to insulin resistance, appear to be responsible of the increased risk for coronary artery disease in the elderly.

Aged↗

[Evaluation by specialists of the Guidelines on Treatment of Hypertension in the Elderly--the second questionnaire survey].

The Guidelines on Treatment of Hypertension in the Elderly, 1995 was published by the Research Group for Guidelines on Treatment of Hypertension in the Elderly Comprehensive Research Projects on Aging and Health, the Ministry of Health and Welfare. To assess the guidelines, and to further investigate the changes in the therapeutic policy for hypertension in the elderly, we mailed a questionnaire to 133 Japanese hypertension specialists who had replied to the first mailed questionnaire in 1993. We received 102 replies (77%). Overall, the guidelines were scored 4.3/5.0. More than 95% of the specialists agreed with levels of blood pressure (BP) indicative for treatment, as well as the goal of BP control. The guidelines propose that the rate of increase of the drug dose should be very slow, at least every four weeks, and that the target BP be reached after two months. The majority of the specialists agreed with this. However, 10% of them preferred to follow patients every two weeks. The guidelines propose long-acting Ca antagonists and ACE inhibitors as the first choice of drug for the treatment of uncomplicated hypertension in the elderly. Two-thirds of the specialists agreed. However, 17% of specialists proposed adding diuretics or beta-blockers to the first line therapy. Ten specialists (10%) expressed concerns about Ca antagonists and three (3%) insisted on withdrowing them from the first line of drugs. In the guidelines, alpha and beta blockers are designated as relatively contraindicated in elderly patients with hypertension, but half the specialists answered that these drugs can be used safely in elderly patients. These findings indicate that the therapeutic policy of Japanese specialists in hypertension in the elderly has not changed substantially for three years.

Aged↗

Breast ultrasonography: computer-aided diagnosis using fuzzy inference.

On the basis of detailed analysis of ultrasonographic features in 105 breast masses (55 malignant, 50 benign), a computer-aided diagnostic system using fuzzy inference has been developed. Ultrasonographic features of a mass for the input data included shape, border, halo (boundary echoes), internal echoes, posterior echoes, and edge shadows (bilateral shadows). The probability of malignancy was described by an actual number ranging from 0.0 to 1.0. The algorithm of inference was constructed, and a sensitivity of 94.5% and specificity of 76.0% for cancer diagnosis were obtained.

Adolescent↗