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Biomedical subjects

M Takasaki

Publications and source records attributed to M Takasaki.

At least 19 recordsLinked to original sources

Esophagoaortic fistula caused by esophageal tuberculosis: report of a case.

We report herein the case of a 73-year-old woman who was urgently admitted to hospital with severe hematemesis. An emergency endoscopy revealed a protruding lesion 36 cm from the incisors; however, respiratory insufficiency precluded surgery and despite aggressive medical treatment, the patient's respiratory status continued to deteriorate, leading to death on the 36th hospital day. An autopsy revealed the source of the hemorrhage to be a fistula connecting the esophagus and the descending aorta. Histopathologic studies showed that this fistula was caused by esophageal tuberculosis.

Aged

How are haemodynamic and metabolic responses to haemorrhage influenced by segmental thoracic and thoracolumbar epidural analgesia? An experimental study in dogs.

To determine the effects of the spread of sympathetic blockade administered prior to haemorrhage on haemodynamic and metabolic responses to haemorrhage, we compared these responses among dogs treated by segmental thoracic epidural analgesia, thoracolumbar epidural analgesia and general anaesthesia. Group 1 of six dogs received 0.2% halothane plus epidural analgesia ranging from C4 to T5, group 2 of seven 0.2% halothane plus epidural analgesia ranging from C5 to L7, and group 3 of eight 0.9% (1 MAC) halothane anaesthesia. A volume of 35 ml.kg-1 was bled over 30 min. The haemodynamic, metabolic and catecholamine variables were measured repeatedly at 30-min intervals for 2.5 h. The mean arterial pressure decreased significantly in all groups immediately after haemorrhage. It recovered to 80-90 mmHg at 2-2.5 h in groups 1 and 3 but remained at 20-30 mmHg in group 2. The cardiac output decreased significantly in all groups. The systemic vascular resistance increased significantly in group 1 but decreased significantly in group 2. In group 3 it decreased significantly but soon recovered. Arterial pH and base excess decreased significantly in all groups immediately after haemorrhage. After that, base excess recovered slowly in groups 1 and 3 but decreased further in group 2. The plasma epinephrine concentration increased immediately after haemorrhage and then decreased slowly in groups 1 and 3. In group 2 it remained unchanged at the lower level. The decreases in mean arterial pressure, systemic vascular resistance and base excess were significantly larger in group 2 than in groups 1 and 3.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid-Base Imbalance

Platelet activation in the cerebral circulation in different subtypes of ischemic stroke and Binswanger's disease.

BACKGROUND AND PURPOSE: The sites of platelet activation in ischemic stroke are still unclear because previous reports have not identified them and various factors accompanied by stroke can activate platelets. We therefore examined the sites of platelet activation in patients with various types of ischemic stroke. METHODS: The ratio of the plasma concentration of beta-thromboglobulin (BTG) in the internal jugular vein to that in the antecubital vein (BTG-B) was calculated as an indicator of platelet activation in the cerebral circulation. Plasma BTG concentration was determined in 75 control subjects and in 186 patients with various subtypes of ischemic stroke including lacunar, atherothrombotic, and cardioembolic strokes, transient ischemic attacks, and Binswanger's disease. The BTG ratio was evaluated with regard to subtype of stroke, time of blood sampling, size of infarct, presence of vascular lesions, and the effect of ticlopidine administration. RESULTS: The mean BTG ratio was increased even in the chronic phase of most subtypes of stroke with the exception of cardioembolic stroke, which exhibited a persistent elevation of BTG-B concentrations. Patients with Binswanger's disease showed a significant (P < .01) and frequent elevation of BTG ratio. High BTG ratios occurred in cases with vascular lesions observed on cerebral angiography. There was no correlation between the BTG ratio and infarct size. Use of ticlopidine was partially associated with a lower BTG ratio. CONCLUSIONS: Platelets were activated in the cerebral circulation of patients with stroke even in the chronic phase, which suggests the development of underlying vascular lesions and of thrombogenesis with or without infarction. Platelets were activated mainly within the heart in cases of cardioembolic stroke. An enhanced release reaction secondary to platelet activation was often seen in patients with Binswanger's disease, which indicates that its pathophysiology differs from that of other subtypes of stroke.

Aged

Effects of midazolam on heart rate variability during surgery under spinal anaesthesia.

Effects of midazolam on the cardiac autonomic nervous system were studied by power spectral analysis of electrocardiographic R-R intervals in patients undergoing elective lower abdominal surgery under spinal anaesthesia. Patients were randomly assigned into two groups: 10 patients in group A received spinal anaesthesia only and 10 in group S received spinal anaesthesia and midazolam of 0.05 mg/kg when surgery started. In the frequency domain power spectra, low (Lo; 0.04-0.15 Hz) and high (Hi; 0.15-0.40 Hz) frequency components were integrated to ascertain sympathetic and parasympathetic activity, respectively. There was no intergroup difference in starting time of surgery, ventilatory frequency, arterial pressure, heart rate, mean and variance of R-R interval, and cephalad level of analgesia. In spectral component, Lo decreased (P < 0.05) and Hi/Lo ratio increased (P < 0.05) relative to their baselines in group S. These were also different from group A (P < 0.05). We concluded that intravenous midazolam depressed sympathetic activity to produce a vagotonic cardiac autonomic nervous system under spinal anaesthesia.

Abdomen

Inhibitory effects of cucurbitane triterpenoids on Epstein-Barr virus activation and two-stage carcinogenesis of skin tumor. II.

To search for possible anti-tumor-promoters, we carried out a primary screening of twenty-four 29-nor-cucurbitacin glucosides isolated from the roots of Cayaponia tayuya (Cucurbitaceae) using an in vitro synergistic assay system. Of these glucosides, cayaponosides B (5), B3 (7), D (8), D3b (22) and C2 (23) exhibited significant inhibitory effects on Epstein-Barr virus (EBV) activation induced by the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA). Furthermore, 5 and 23 exhibited remarkable anti-tumor-promoting effects on mouse skin tumor promotion in an in vivo two-stage carcinogenesis test.

Animals

Inhibitors of skin-tumor promotion. XIII. Inhibitory effects of euglobals and their related compounds on Epstein-Barr virus activation and on two-stage carcinogenesis of mouse skin tumors. (2).

One hundred and fifteen synthesized mono, di, and trihydroxybenzamide and thiobenzamide derivatives having structures related to euglobals were examined for their inhibitory effects on Epstein-Barr virus (EBV) activation by 12-O-tetradecanoylphorbol-13-acetate (TPA) as a primary screening test for anti-tumor-promoters. In general, 3-acyl-2,4,6-trihydroxybenzamide and 3-acyl-2,4,6-trihydroxythiobenzamide derivatives exhibited strong or moderate activities, and the latter compounds were less cytotoxic than the former. Meanwhile, little or no activity was observed with mono and dihydroxybenzamide and dihydroxythiobenzamide derivatives. Structural requirements for the activities of these compounds have been discussed in detail. Among the above compounds, compounds 36 and 73, which were significantly active on the inhibition of EBV activation, were investigated using a two-stage mouse skin carcinogenesis test induced by 7,12-dimethylbenz[a]anthracene (DMBA) and TPA. The results of the in vivo test showed that both compounds have a stronger inhibitory effect than that of the well-known anti-tumor-promoter, glycyrrhetic acid. These results suggested that the two compounds might be valuable as anti-tumor-promoters in chemical carcinogenesis.

9,10-Dimethyl-1,2-benzanthracene

Anti-tumor-promoting activities of euglobals from Eucalyptus plants.

To search for possible anti-tumor-promoters (chemopreventive agents), we carried out a primary screening of 21 euglobals (acylphloroglucinol-monoterpene or -sesquiterpene structures) isolated from the juvenile leaves of five species of Eucalyptus plants using an in vitro synergistic assay system. Of these compounds, euglobal-G1--G5 (1-5), -Am-2 (15) and -III (16) exhibited significant inhibitory effects on Epstein-Barr virus (EBV) activation induced by the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA). Furthermore, the effects of compounds 1 and 16 on the cell cycle of Raji cells were also examined by a flow cytometer, and both compounds 1 and 16 exhibited strong inhibition on the effect of the cell cycle induced by TPA. These two euglobals (1 and 16) exhibited remarkable anti-tumor-promoting effects on mouse skin tumor promotion in an in vivo two-stage carcinogenesis test.

9,10-Dimethyl-1,2-benzanthracene

[A case of Binswanger's disease in which an acute infarcted lesion was detected by diffusion-weighted magnetic resonance imaging].

Diffusion-weighted magnetic resonance imaging (DWI) was carried out on a patient with Binswanger's disease suffering from acute cerebral infarction. Though an acute infarcted lesion was demonstrated as a high signal area on the T2-weighted image, it was impossible to determine whether it was acute or chronic because of extensive deep white matter lesions (periventricular hyperintensity and white matter hyperintensity lesions). However, only the acute infarcted lesion was detected on DWI which showed it as a high signal area, suggesting reduced molecular diffusion of water. The apparent diffusion coefficient (ADC), a physiological parameter that characterizes the self-diffusion on water in tissue, was lower in the acute lesion and higher in the chronic lesion. DWI can differentiate acute from chronic infarcts, which is not possible by conventional CT and MRI.

Acute Disease

[Endoscopic placement of self-expandable metallic stents (Wallstent) for malignant biliary stenosis, with special reference to preventive endoscopic nasal bile drainage against acute obstruction after stenting].

From December 1993 to December 1994, we inserted 14 biliary endoprostheses (Wallstent) endoscopically in 12 consecutive patients (5 men and 7 women; 55-91 years [mean 69.8 years] of age) with malignant biliary stenosis. Successful placement of Wallstent was achieved in all 12 patients. Procedure related death was encountered in one patient (8.3%) who was complicated with emphysematous cholecystitis, combined with a slipping migration of the stent. In 11 of the 12 patients, serum bilirubin levels reduced to less than 2.0 mg/dl. Acute obstruction, which was defined as the obstruction of the stent within 24 hours after the stent placement, occurred in 2 patients (16.7%). Endoscopic nasal bile drainage (ENBD) following stent placement was performed in 4 patients and acute obstruction was not developed in these cases. After endoprosthesis 8 patients were discharged with 6-47 hospital days and the average hospitalized period excluding a case with cerebral infarction was 12.7 days. Excluding one procedure related death, 6 patients died of primary malignancy 39-189 days (average 90.7 days) after endoprosthesis and in 2 cases recurrence of jaundice was observed. The other 4 patients have been alive for 60-174 days (average 102.5 days) without jaundice. The survival rate of the all patients was 64% for 3 months and 32% for 6 months, respectively. In conclusion, we suggested that the endoscopic Wallstent placement would contribute to the improvement of the quality of life for patients with malignant biliary stenosis. However, acute obstruction may be developed in some cases. For the purpose of managing acute obstruction, we recommend ENBD for a few days following the placement of a Wallstent.

Acute Disease

[Differential diagnosis of Alzheimer-type dementia and vascular dementia based on neuroimaging study].

A new method for differential diagnosis of Alzheimer-type dementia (AD) and vascular dementia (VD) based on neuroimaging studies was developed by Hayashi's quantification theory II. Fifty-five patients with AD and 36 patients with VD underwent both SPECT and MRI studies. Both images in each subject were scored according to the extent of hypoperfusion in areas including frontal and temporoparietal regions and the severity of deep white matter lesions and medial temporal lobe atrophy. The scores of AD and VD patients were significantly different, and this difference was considered to contribute most to the differential diagnosis of AD and VD. The weight of each score of SPECT and MRI items was computed, and the sum of the weights was calculated as a score for each subject to best distinguish AD from VD patients. This method was designed to simplify the calculation of the sample scores, and the sum of the weights was established so that a positive score (0 < or =) indicated the probability of AD, while a negative score (< 0) indicated the probability of VD. The correct diagnosis rate was 91% (50/55) for AD and 89% (32/36) for VD, for an overall discrimination of 90%. The present method seemed to be practically useful in the differential diagnosis of AD and VD.

Aged

Euglobal-In-1, a new euglobal from Eucalyptus incrassata.

From the juvenile leaves of Eucalyptus incrassata, a new euglobal having an acylphloroglucinol-sesquiterpene structure, euglobal-In-1 (1), has been isolated along with the known euglobal-III (2) and -V (3). The structure and stereochemistry of 1 were established by spectroscopic methods.

Antigens, Viral

[The role of platelet in the etiology of Binswanger's disease].

White matter changes, which are noted in Binswanger's disease and which may be due to ischemia, have previously been explained mainly on the basis of the hemodynamic mechanism. To elucidate the etiopathophysiology of Binswanger's disease from the hemorheology viewpoint, platelet activation in the cerebral circulation was studied in 30 patients with Binswanger's disease, who satisfied the diagnostic criteria of Binswanger's disease proposed by Bennett et al. Plasma beta-thromboglobulin concentration gradients (delta BTG) between the jugular vein and the antecubital vein, as indicators of platelet activation in the cerebral circulation, were determined in these patients (Binswanger's disease group) compared with those of different stroke subtypes groups (lacunar, atherothrombotic, cardioembolic) in the chronic phase and 25 patients with various diseases other than stroke (non-stroke group). Among these groups, the elevation of delta BTG levels in the Binswanger's disease group (4.55 +/- 6.95) were so frequent and prominent that differences were significant, especially in comparison to those of the cardioembolic group, and the non-stroke group. The enhanced platelet activation in the cerebral circulation observed in Binswanger's disease indicated not only the widespread development of underlying vascular lesions, but also accelerated release reaction of vasoactive substances from platelets into the blood stream, which could biochemically injure the vascular wall and neurons downstream, resulting in Binswanger's disease.

Aged

[Neuroimaging in the diagnosis of Alzheimer's disease].

We sought to identify a marker for Alzheimer's disease (AD) for antemortem diagnosis. To determine whether the detection of reduced blood flow in the parietotemporal cortex, shown by single photon emission CT (SPECT), and of medial temporal lobe atrophy, shown by magnetic resonance imaging (MRI), would be useful in diagnosis, we studied 38 patients with AD diagnosed by the NINCDS-ADRDA criteria and 26 healthy elderly controls. Parietotemporal hypoperfusion was qualitatively assessed by physicians who were unaware of the clinical diagnosis, and the severity of medial temporal lobe atrophy was quantitated by planimetric and linear measurements. Although an accurate diagnosis of AD was made in 80% or more of the patients by SPECT or MRI studies alone, the combination of SPECT and MRI gave a higher diagnostic accuracy, with a sensitivity of 95% and a specificity of 92%. Since regional functional or structural changes were detected in 92% of early or mild patients, including possible AD, the combination of SPECT and MRI studies were useful in the early diagnosis of AD. Findings suggest that a functional abnormality in the parietotemporal lobe and an atrophic change in the medial temporal lobe are characteristic of AD, and that SPECT and MIR regional changes may be useful as antemortem diagnostic markers.

Aged

[A case of hypophosphatemia induced by intravenous administration of saccharated iron oxide].

An 81-year-old woman was hospitalised because of pneumonia in December 1989. In February 1991, an iliac bone biopsy was performed on the suspicion of disturbed bone metabolism due to chronic renal failure. Since she developed anemia due to continuous bleeding from the surgical wounds, saccharated iron oxide was administered beginning in March. Hypophosphatemia was noted 23 days after the beginning of administration. Due to the possibility of osteomalacia, active vitamin D was given but the hypophosphatemia persisted. Following an EDTA-2 Na load test performed to evaluate the reabsorption of phosphorus in the renal tubules, it was considered that the patient had a functional disorder of the parathyroid glands and that reabsorption of phosphorus was interrupted in the renal tubules. Furthermore, abnormal distributions of phosphorus seemed to occur in the same areas where sucrose was metabolized and iron was stored. Therefore, it was considered that these abnormalities induced hypophosphatemia following the intravenous administration of saccharated iron oxide. In addition to these actions, the possibility remained that phosphate absorption was inhibited in the small intestine by calcium lactate.

Aged

[Brain MRI findings in patients with initial cerebral thrombosis and the relationship between incidental findings, aging and dementia].

To estimate the relationship between aging, dementia and changes observed on magnetic resonance imaging (MRI) seen in elderly patients with cerebral thrombosis, MRI findings in 103 patients with an initial stroke event (thrombosis group) were compared with those of 37 patients with hypertension/diabetes (high risk group) and 78 patients without those disorders (low risk group). In addition to the causative lesions in the thrombosis group, periventricular hyperintensities (PVH), spotty lesions (SL), silent infarctions (SI), ventricular dilatation (VD), and cortical atrophy (CA) were analyzed in these groups. Infarctions located in the internal capsule/corona radiata were the most frequent causative lesion. Compared to the low risk group, a high incidence of patchy/diffuse PVH, SI, and severe CA was seen in both the thrombosis group and the high risk group. Widespread PVH and multiple SL increased with age in the thrombosis group, while severe CA was seen in each group. SI and VD tended to increase after age 60, though they were not significant. Dementia, diagnosed in 40 out of 78 patients, increased with age. Multivariate analysis revealed the degree of the effects of MRI findings on dementia to be marked in PVH, brain atrophy, causative lesions, and SL, in that order. These results indicated that diffuse PVH and brain atrophy, developing with age, promoted dementia in the elderly with vascular lesions. Moreover, they suggested that a variety of silent brain lesions recognized on MRI other than infarction can affect symptoms in the elderly.

Aged

[Effect of deliberate hypotension on renal functions during epidural block plus inhalation anesthesia: a comparison of prostaglandin E1 and trimethaphan].

To clarify the effect of prostaglandin E1 (PGE1) or trimethaphan (TMP) on the kidney during deliberate hypotension induced with epidural block plus inhalation anesthesia, we compared renal functions and renal tubular injury between the patient with PGE1-induced hypotension (n = 22) and those with TMP-induced hypotension (n = 18) undergoing spherical acetabular osteotomy. Hypotension was maintained at 75-80 mmHg of the systolic radial artery pressure for two hours. The urine volume, creatinine clearance, fractional sodium excretion and free water clearance were maintained within normal limits and they were not different between the two groups. The mean NAG index increased significantly to normal upper limits during hypotension in the PGE1 group but did not increase in the TMP group. However, there was no difference in the NAG index between the two groups. The changes in serum ADH level were not different between the two groups perioperatively. These results suggest that renal functions are not influenced by controlled hypotension induced with PGE1 or TMP during epidural plus general anesthesia.

Adult