Biomedical subjects

M Takasaki

Publications and source records attributed to M Takasaki.

At least 163 records · Page 9Linked to original sources

PubMed1997

[The effects of caffeine on the respiratory depression by morphine].

The effects of intravenous administration of caffeine on the discharge of the phrenic nerve were studied following vagotomy in 7 pentobarbital anesthetized mechanically ventilated rats. Morphine (0.4 mg.kg-1.min-1) was administered until the respiratory rate decreased to about half of the baseline respiratory rate. In those state, we first administered caffeine (20 mg.kg-1), intravenously and then administered naloxone (0.02 mg) intravenously. The increase of inspiratory time from 0.49 +/- 0.16 to 2.01 +/- 0.47 s by morphine recovered to 0.86 +/- 0.38 s by caffeine and 0.50 +/- 0.22 s by naloxone. Expiratory time did not change during each drug administration. The decrease of respiratory rate from 46.6 +/- 5.9 to 20.6 +/- 4.1 breaths.min-1 by morphine recovered to 39.6 +/- 6.1 breaths.min-1 by caffeine and 47.6 +/- 4.6 breaths.min-1 by naloxone. Amplitude of integrated phrenic nerve discharge increased to 117 +/- 32% by caffeine and 156 +/- 39% by naloxone compared to the baseline. These results suggest that caffeine acts as a respiratory stimulant on the respiratory depression by morphine.

Analgesics, Opioid↗

PubMed1996

Anti-tumor promoting activity of Dryopteris phlorophenone derivatives.

As a part of screening studies for cancer chemopreventive agents (anti-tumor promoters) 33 Dryopteris phlorophenone derivatives have been evaluated. The compounds tested comprised of monomeric acylphloroglucinols (e.g. desaspidinol, aspidinol) as well as dimeric (e.g. aspidin, desaspidin), trimeric (e.g. filixic acids), and tetrameric (e.g. dryocrassin) phlorophenone, wherein hexacyclic rings are bound together by a methylene bridge. These compounds were examined for their in vitro anti-tumor promoting effect on Epstein-Barr virus antigen activation induced by the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). The two dimeric compounds aspidin and desaspidin, which were found to be the most active among the tested phlorophenones, were also examined in vivo on two stage mouse skin carcinogenesis, and found to show significant inhibitory effect on 7,12-dimethylbenz[alpha]anthracene (DMBA)-TPA tumor promotion.

Animals↗

PubMed1996

Simultaneous determination of alpha-tocopherol and alpha-tocopherolquinone by high-performance liquid chromatography and coulometric detection in the redox mode.

A simple, selective and highly sensitive assay method for the simultaneous determination of alpha-tocopherol and alpha-tocopherolquinone in plasma or erythrocyte membrane by high-performance liquid chromatography (HPLC) with a series of multiple coulometric working electrodes (CWE) was investigated. For good separation of alpha-tocopherol and alpha-tocopherolquinone, an MC MEDICAL C18 reversed-phase column and a mobile phase consisting of 96% methanol [methanol-HPLC-grade distilled water (96:4, v/v)] with 40 mM sodium perchlorate were used. Also, selective, highly sensitive and simultaneous detection of these substances was performed in redox mode using a series of four CWE. In this detection mode, the first, second and third CWE were set at -0.45 V for pre-reaction and to prevent interference, the fourth CWE was used as an electrode for actual measurement with its potential set at +0.40 V against a palladium reference electrode. The detection limits were 50-100 pg. Excellent chromatograms of alpha-tocopherol and alpha-tocopherolquinone were obtained within 8 min. The usefulness of reversed-phase HPLC with the redox detection mode was confirmed by application to the determination of the concentrations of alpha-tocopherol and alpha-tocopherolquinone in a crude ethanol-hexane extract of rat plasma or erythrocyte membrane. These findings suggest that reversed-phase HPLC with the redox detection mode using a series of four CWE is applicable to study the preventive effect of alpha-tocopherol on lipid peroxidation.

Animals↗

PubMed1996

Endoscopic injection sclerotherapy for esophageal variceal hemorrhage in a patient with idiopathic myelofibrosis.

A 74-year-old female with idiopathic myelofibrosis (IMF) was admitted to our hospital because of massive hematemesis and melena. Immediate upper gastrointestinal endoscopy revealed an intermittent spurting hemorrhage from extensive esophageal varices. Endoscopic injection sclerotherapy (EIS) was carried out and the bleeding ceased. After five courses of EIS, all the esophageal varices were eradicated. About 15 months later, the patient died, due to a cerebral hemorrhage, without further variceal bleeding. A postmortem examination was carried out and the portal hypertension was considered to be due not only to extramedullary hematopoiesis in the sinusoids, but also to increased splenic blood flow. We are confident that EIS is an effective therapeutic procedure for patients with IMF showing esophageal variceal hemorrhage. EIS should be the preferred choice of treatment for esophageal varices in patients with IMF, since it is less invasive than splenectomy.

Aged↗

PubMed1996

Epidural fentanyl improves the onset and spread of epidural mepivacaine analgesia.

PURPOSE: To determine the extent of enhanced blockade by the combined use of epidural fentanyl and mepivacaine. We compared the onset of hypoalgesia, analgesia and the threshold of pressure pain. METHODS: Thirty patients were randomly divided into three groups. The fentanyl group received 10 ml saline containing 0.1 mg fentanyl, mepivacaine group received 10 ml mepivacaine 1% and a mixed group received 10 ml mepivacaine 1% with 0.1 mg fentanyl. All solutions, without epinephrine, were injected through an epidural catheter at T5-6 to T6-7. The change in sensation, loss of pin-prick and pain threshold sensation, measured by pressure algometer, were assessed at 2.5-min intervals for 15 min at the T4 dermatome. Spread of analgesia was determined at 15 min. RESULTS: Loss of pinprick was more rapid in the mixed, 11.0 +/- 2.7 (SD) min, than in the mepivacaine group, 15.0 +/- 2.9 min, (P < 0.05), although there was no difference in change of sensation. Pressure pain threshold increased with time in the mepivacaine (P < 0.05) and mixed (P < 0.05) groups. It was higher in the mixed than in the fentanyl and mepivacaine groups at 5, 7.5 and 10 min (P < 0.05). The lower level of analgesia was lower in the mixed than in the mepivacaine groups (P < 0.05). Blood pressure was unchanged in the three groups, but heart rate decreased at 7.5, 10, 12.5, and 15 min in the mepivacaine and mixed groups (P < 0.05). CONCLUSIONS: The addition of fentanyl to mepivacaine accelerates the onset of analgesia and enhances the analgesic effect of epidural block.

Adult↗

PubMed1996

Urinary incontinence in elderly inpatients in Japan: a comparison between general and geriatric hospitals.

This is the first multi-hospital epidemiological study to elucidate the prevalence and characteristics of urinary incontinence in elderly inpatients throughout Japan. Of the 2586 subjects to whom questionnaires were issued, 1563 (60.4%) (65 to 102 years old, 598 men, 965 women) were suitable for the study. A total of 817 patients were hospitalized in geriatric hospitals; that is, geriatric facilities under the regulation of the Department of Health and Welfare. All patients were evaluated by medical doctors for the following items: age, sex, duration of hospitalization, activities of daily living, medical diagnosis, presence or absence of urinary incontinence, type of urinary incontinence, and therapy for urinary incontinence. The prevalence of urinary incontinence in patients under 70, 70-79, 80-89, and over 90 years old was 59.3%, 67.7%, 79.8%, and 82.2%, respectively. Overall, 1142 patients (72.0%) suffered from urinary incontinence. Cerebrovascular disease was the major cause of admission to hospital in patients with urinary incontinence (37.0%). The most frequent type of urinary incontinence was functional urinary incontinence in patients who were mentally and/or physically unable to go to the bathroom without aid (21.5%). Specifically, 38.1% of patients in geriatric hospitals were diagnosed as having functional urinary incontinence, in contrast to only 3.9% of patients in non-geriatric units. In patients with dementia, 88.7% were incontinent, whereas in patients without dementia, the prevalence of urinary incontinence was much lower (51.5%, p < 0.001). Another predisposing factor for urinary incontinence was urinary tract infection. The prevalence of urinary incontinence in patients with and without urinary tract infection was 87.8% and 59.5%, respectively (p < 0.001). Almost all patients with poor activities of daily living (who were bedridden) suffered from urinary incontinence (98.5%). On the other hand, urinary incontinence was not so frequent in patients who could walk (26.9%). Pad (42.8%) and indwelling bladder catheter (18.3%) were the major means of management of incontinence, whereas behavioral therapy (4.9%) and surgery (0.5%) were not common. These results suggest that elderly patients with treatable urinary incontinence do not receive adequate therapy in Japan.

Activities of Daily Living↗

PubMed1996

Intravenous trimethaphan during epidural plus general anesthesia decreases the direct radial artery pressure lower than the brachial artery pressure.

STUDY OBJECTIVE: To determine whether vasodilators such as sodium nitroprusside (SNP) and trimethaphan (TMP) produce a pressure difference between the radial artery and the brachial artery during epidural plus general anesthesia or simple general anesthesia. DESIGN: Randomized study and prospective study. SETTING: Operating rooms of two hospitals. PATIENTS: 36 and 6 adult patients in the first and second studies, respectively, who received spherical acetabular osteotomy with induced hypotensive anesthesia. INTERVENTIONS: In the first study, 18 patients received epidural plus general anesthesia (epidural group) and 18 patients received general anesthesia alone (general group). All patients received the hypotensive drugs for more than 50 minutes each. In the second study, 6 patients received TMP-induced hypotension for 20 minutes under epidural plus general anesthesia. MEASUREMENTS AND MAIN RESULTS: In the first study, radial intra-arterial blood pressure (RIBP) and tonometric blood pressure (TBP) calibrated with oscillometric blood pressure of the arm were compared. In the second study, RIBP and the brachial intra-arterial blood pressure (BIBP) were compared. In the first study, the bias between RIBP and TBP for systolic, mean and diastolic blood pressure were significantly less during TMP-induced hypotension in the epidural group (-11.5 +/- 2.5 (mean +/- SD), -6.0 +/- 3.1, and -2.8 +/- 3.7 mmHg, respectively] than during SNP-induced hypotension in the epidural group and SNP- and TMP-induced hypotension in the general group (p < 0.01). The precision of systolic and mean pressures were significantly greater during TMP-induced hypotension in the epidural group (11.8 +/- 2.3 and 7.1 +/- 1.9 mmHg, respectively) than the other three hypotension groups (p < 0.01). In the second study, the bias between RIBP and BIBP for systolic, mean, and diastolic pressures were significantly less (p < 0.01), and precision was significantly greater during hypotension than during normotension (p < 0.01). CONCLUSIONS: Our results demonstrate that TMP decreases the direct radial artery systolic and mean pressures to levels below the brachial artery systolic and mean pressures in patients who received epidural plus general anesthesia.

Adult↗

PubMed1996

Dural puncture with a 26-gauge spinal needle affects spread of epidural anesthesia.

Combined spinal and epidural anesthesia may increase the risk of epidurally administered drugs spreading into the subarachnoid space through the dural hole. We studied the effect of dural puncture with a 26-gauge needle on the spread of analgesia induced by epidural injection of local anesthetics. Forty patients were randomly assigned to control and dural puncture groups. In the dural puncture group, the dura was punctured with a 26-gauge Whitacre spinal needle at L2-3 but no drug was injected. In both groups, an 18-gauge epidural catheter was inserted 4 cm cephalad into the epidural space at L2-3 and 15 mL of 2% mepivacaine without epinephrine was injected. Analgesia was assessed by pinprick at 5, 10, 15, and 20 min after injection and at the end of surgery. The caudal spread of analgesia was significantly greater in the dural puncture group than in the control group 15 and 20 min after injection (P < 0.01), but the cranial spread of analgesia was not different between the two groups. We conclude that dural puncture (without drugs) using a 26-gauge Whitacre spinal needle before epidural injection increases caudal spread of analgesia induced by epidural local anesthetics.

Adult↗

PubMed1996

Identification of a putative mechanosensory neuron in Lymnaea: characterization of its synaptic and functional connections with the whole-body withdrawal interneuron.

1. In this study, we identified a putative mechanosensory neuron in the freshwater pond snail Lymnaea stagnalis. This sensory neuron, termed right parietal dorsal 3 (RPD3), mediates part of the whole-body withdrawal behavior via the activation of a withdrawal interneuron. 2. RPD3 is located in the central ring ganglia, where its soma is situated on the dorsal surface of the right parietal ganglion. Intracellular injection of the dye Lucifer yellow revealed that RPD3 has both central and peripheral axonal projections. 3. In isolated-CNS preparations, RPD3 was quiescent. In semi-intact preparations, however, a gentle/moderate mechanical touch (by a pair of blunt forceps) to the mantle cavity or columellar musculature elicited action potentials in RPD3 in the absence of prepotential activity. Furthermore, mechanical stimulus-induced action potentials in RPD3 persisted in the presence of zero Ca2+/ high Mg2+ and high Ca2+/high Mg2+ salines. Together, these data suggest that RPD3 is most likely to be a primary sensory neuron. 4. In both isolated-CNS and semi-intact preparations, intracellular depolarization of RPD3 excited the whole-body withdrawal interneuron right pedal dorsal 11 (RPeD11). This synaptic connection persisted in the presence of high Ca2+ and high Mg2+ saline, suggesting that it is likely to be monosynaptic. Moreover, when stimulated electrically, the interneuron RPeD11 induced an hyperpolarizing response in RPD3. The possibility of this connection being monosynaptic was not tested, however, in the present study. Together, these data demonstrate that RPD3 excites RPeD11, which in turn may inhibit RPD3 activity. 5. In the semi-intact preparation, a mechanical touch to the mantle edge excited RPD3, which in turn generated action potentials in RPeD11. Zero Ca2+ saline blocked this synaptic connection between RPD3 and RPeD11, suggesting that it is chemical. 6. To demonstrate that RPD3 was sufficient to induce the withdrawal response and that the withdrawal behavior was mediated indirectly via RPeD11, we made simultaneous intracellular recordings from these two neurons while monitoring muscle contractions via a tension transducer. Intracellular depolarization of RPD3 elicited action potentials in RPeD11, followed by the contraction of the columellar muscle. Similar stimulation of RPD3 failed to excite a simultaneously hyperpolarized RPeD11 and as a result, no contraction of the columellar muscle occurred. Direct intracellular depolarization of RPeD11, however, induced the contraction of the columellar muscle. These data suggest that RPD3-induced withdrawal behavior is mediated in part via RPeD11.

Animals↗

PubMed1996

Inhibition of the respiratory pattern-generating neurons by an identified whole-body withdrawal interneuron of Lymnaea stagnalis

Respiration and the whole-body withdrawal are two incompatible behaviors in the freshwater snail Lymnaea stagnalis. Whole-body withdrawal behavior is believed to be higher on the behavioral hierarchy than respiratory behavior. A central pattern generator (CPG) underlies respiratory behavior; whole-body withdrawal is mediated by a network of electrically coupled neurons. In this study, we provide evidence that the behavioral hierarchy between the whole-body withdrawal and the respiratory behaviors is established at the interneuronal level. We demonstrate that an identified whole-body withdrawal interneuron inhibits both muscular and neuronal components of the respiratory behavior in Lymnaea stagnalis. A pair of identified, electrically coupled interneurons, termed left and right pedal dorsal 11 (L/RPeD11), coordinates the whole-body withdrawal behavior in Lymnaea stagnalis. In the present study, RPeD11 inhibited spontaneously occurring respiratory CPG activity in isolated brain preparations. In addition, electrical stimulation of RPeD11 in a semi-intact preparation also inhibited respiratory CPG interneuron RPeD1. The synaptic connections between RPeD11 and the respiratory CPG neurons RPeD1 and visceral dorsal 4 (VD4) persisted in the presence of high-Ca2+/high-Mg2+ saline, suggesting the possibility that they may be monosynaptic. In a semi-intact preparation (lungmantle, pneumostome and central nervous system), electrical stimulation of RPeD11 induced pneumostome and columellar muscle contractions while inhibiting the activity of RPeD1. Moreover, mechanical stimulation of the respiratory orifice, the pneumostome, excited RPeD11, while its effects on the respiratory CPG neuron (RPeD1) were inhibitory. To determine the monosynaptic nature of connections between RPeD11 and the respiratory CPG neurons in the intact nervous system, we constructed these synapses in culture. RPeD11 and individual respiratory interneurons were isolated from their respective ganglia and co-cultured under conditions that support neurite outgrowth. Following neuritic overlap, RPeD11 was found to establish inhibitory synapses with the respiratory interneurons, supporting the hypothesis that these synaptic connections are likely to be monosynaptic in the intact central nervous system.

Journal Article↗

PubMed1996

Anti-tumor-promoting activities of triterpenoids from ferns. I.

To search for possible anti-tumor-promoters (cancer chemopreventive agents), we carried out primary screening of 23 triterpenoid hydrocarbons (1-23) isolated from ferns using an in vitro synergistic assay system. Of these triterpenoids, hop-17(21)-ene (2), neohop-13(18)-ene (3), neohop-12-ene (4), taraxerane (17), multiflor-9(11)-ene (18), multiflor-8-ene (19), glutin-5(10)-ene (21) and taraxastane (23) exhibited remarkable inhibitory effects on Epstein-Barr virus (EBV) activation induced by the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA). Further, compounds 2 and 3 exhibited remarkable anti-tumorpromoting effects on mouse skin tumor promotion in an in vivo two-stage carcinogenesis test using 7,12-dimethybenz[a]anthracene (DMBA) as an initiator and TPA as a promoter.

Animals↗

PubMed1996

[Correlation between periventricular lucency and extracranial arterial lesions].

This study was done to clarify relationships between the degree of periventricular lucency (PVL), and lesions in the carotid arteries and the legs as detected with B-mode ultrasonography and the ankle pressure index, respectively. According to the distribution of PVL on computed tomography, 45 patients were divided into 2 groups: 22 patients with diffuse PVL (from the periventricular white matter to the subcortical area, DPVL group) and 23 patients with PVL localized in the frontal deep white matter (LPVL group). Plaque, defined as a thickened intima-media complex of 2.1 mm or more, was divided into two types; mural plaque and nodular plaque. Hypertension was more common in the DPVL group than in control groups, which consisted of 70 age-matched patients with cerebral thrombosis without PVL (CTH group) and 50 controls with neither PVL nor cerebrovascular lesions (NCT group). All patients in the DPVL group met the diagnostic criteria for Binswanger's disease proposed by Bennett DA. The incidence of low API indices (< 0.9) in the DPVL group (45%) was significantly higher than that in the NCT group, and it was slightly higher than that in the LPVL group. Carotid lesions, mainly nodular plaques, were seen in 82% of patients in the DPVL group and in 74% of those in the LPVL group; these percentages were significantly higher than those in the CTH (49%) and NCT (40%) groups. In particular, bilateral carotid lesions were more common in the DPVL group than in the other three groups. The degree of PVL correlated with lesions in the carotid arteries and the legs. These correlations suggest that the arterial lesions not only resulted from a risk factor (hypertension) for PVL, but also promoted PVL by causing extra- and intra-cranial arterial lesions. Furthermore, they imply that LPVL is a precusor to DPVL.

Aged↗

PubMed1996

[Serum sodium imbalance in the bedridden elderly. Part One: Realities and problem of management].

Symptoms and other abnormalities associated with serum sodium imbalance were studied in bedridden elderly and healthy elderly subjects. 1. A significantly higher number of the bedridden elderly suffered from chronic wasting disease. 2. The average serum sodium concentration in bedridden elderly subjects was significantly lower than in healthy subjects, as was the sodium intake and the sodium content in urine, which indicate that the bedridden elderly subjects suffered from chronic sodium deficiency. 3. The bedridden elderly subjects had high levels of plasma PRA and antidiuretic hormone, and their aldosterone levels were low, which indicate that their condition was associated with a decrease in available circulating plasma, hypersecretion of antidiuretic hormone, and a decline in the ability to retain sodium. 4. Measurement of 24-hr creatinine clearance, albumin, and beta 2-microglobulin in urine revealed that bedridden elderly subjects had high levels of renal dysfunction, the result of which may a disturbance in water excretion. Abnormalities in serum sodium levels in the bedridden elderly subjects were related to a chronic deficiency in sodium intake, which reduced their ability to maintain sodium levels and impaired their renal function. Iatrogenic factors are likely to play an important role in the genesis of this condition, and should be taken into account in during management.

Aged↗

PubMed1996

[An elderly patient with Ph1-positive chronic myelomonocytic leukemia].

An 80-year-old man with leukocytosis was admitted to our hospital on February 20, 1995. There were no blasts in the peripheral blood, but leukocytosis, associated with marked monocytosis, anemia, and thrombocytopenia was observed. The bone marrow was hyperplastic and there was a slight decrease in megakaryocytes. The myelogram showed 5.6% blasts + promyelocytes, and there was no basophilia. Mild dysplasia of third-line cells was observed. Chromosome analysis yielded 47, XY, +8, t (9;22) (q34;q11), and the Philadelphia (Ph1) chromosome and trisomy 8 were detected. Fluorescence in-situ hybridization revealed a large ber. Because the French-American-British (FAB) cooperative group diagnostic criteria for chronic myelomonocytic leukemia (CMMoL) were fulfilled and the Ph1 chromosome was detected, a diagnosis of Ph1-positive CMMoL was made. Hydroxyurea was given for cytoreduction and the patient has been followed with no evidence of acute transformation for about one year. CMMoL is classified as a myelodysplastic syndrome. However, it is rare to find the Ph1 chromosome in patients with these syndromes, and there have been very few reports of its detection in CMMoL. CMMoL may not be a single disease entity, and it may be useful to investigate more cases like the present one, to reassess this disease.

Aged↗

PubMed1996

[Diffusional anisotropy in cerebral white matter in patients with dementia].

We studied changes in water diffusion in cerebral white matter in 10 patients with Binswanger's disease (BD), 8 patients with Alzheimer's disease (AD) who had periventricular hyperintensity lesions on T2-weighted images, and 8 age-matched controls. The apparent diffusion coefficients measured in the anterior and posterior white matter were significantly higher in the patients than in the controls, but there was no significant difference between patients with BD and those with AD. The anisotropy ratios, difined as diffusion perpendicular to the nerve fiber direction, were higher in the patients than in the controls. The anisotropy ratio in the anterior white matter was significantly higher in patients with BD than in those with AD, while in the posterior white matter the ratio was significantly higher in patients with AD than in those with BD. These results suggest that in BD and AD cerebral white matter lesions such as periventricular hyperintensity lesions reflect a loss of myelin and axons, and that loss of myelin occurs preferentially in the anterior white matter in BD and in the posterior white matter in AD.

Aged↗

PubMed1996

[Guidelines on treatment of hypertension in the elderly, 1995--a tentative plan for comprehensive research projects on aging and health-- Members of 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 of Japan].

We propose the following guidelines for treatment of hypertension in the elderly. 1. Indications for Treatment. 1) Age: Lifestyle modification is recommended for patients aged 85 years and older. Antihypertensive therapy should be limited to patients in whom the merit of the treatment is obvious. 2) Blood pressure: Systolic BP > 160 mmHg, diastolic BP > 90 approximately 10 mmHg. Systolic BP < age + 100 mmHg for those aged 70 years and older. Patients with mild hypertension (140-160/ 90-95 mmHg) associated with cardiovascular disease should be considered for antihypertensive drug therapy. 2. Goal of Therapy for BP: The goal BP in elderly patients is higher than that in younger patients (BP reduction of 10-20 mmHg for systolic BP and 5-10 mmHg for diastolic BP). In general, 140-160/< 90 mmHg is recommended as the goal. However, lowering the BP below 150/85 should be done with caution. 3. Rate of Lowering BP: Start with half the usual dose, observe at the same dose for at least four weeks, and reach the target BP over two months. Increasing the dose of antihypertensive drugs should be done very slowly. 4. Lifestyle Modification: 1) Dietary modification: (1) Reduction of sodium intake is highly effective in elderly patients due to their high salt-sensitivity. NaCl intake of less than 10 g/day is recommended. Serum Na+ should be occasionally measured. (2) Potassium supplementation is recommended, but with caution in patients with renal insufficiency. (3) Sufficient intake of calcium and magnesium is recommended. (4) Reduce saturated fatty acids. Intake of fish is recommended. (2) Regular physical activity: Recommended exercise for patients aged 60 years and older: peak heart rate 110/minute, for 30-40 minutes a day, 3-5 days a week. (3) Weight reduction. (4) Moderation of alcohol intake, smoking cessation. 5. Pharmacologic Treatment: 1) Initial drug therapy. First choice: Long-acting (once or twice a day) Ca antagonists or ACE inhibitors. Second choice: Thiazide diuretics (combined with potassium-sparing diuretic). 2) Combination therapy. (1) For patients without complications, either of the following is recommended. i) Ca antagoinst + ACE inhibitor, ii) ACE inhibitor + Ca antagonist (or low-dose diuretics), iii) diuretic + Ca antagonist (or ACE inhibitor), iv) beta-blockers, alpha 1-blockers, alpha + beta blockers can be used according to the patho-physiological state of the patient. (2) For patients with complications. Drug(s) should be selected according to each complication. 3) Relatively contraindicated drugs. beta-Blockers and alpha 1-blockers are relatively contraindicated in elderly patients with hypertension in Japan. Centrally acting agents such as reserpine, methyldopa and clonidine are also relatively contraindicated beta-Blockers are contraindicated in patients with congestive heart failure, arteriosclerosis obliterans, chronic obstructive pulmonary disease, diabetes mellitus (or glucose intolerance), or bradycardia. These conditions are often present in elderly subjects. Elderly subjects are susceptible to alpha 1-blocker-induced orthostatic hypotension, since their baroreceptor reflex is diminished. Orthostatic hypotension may cause falls and bone fractures in the elderly.

Aged↗

PubMed1996

[Cerebral hemodynamics in patients with dementia].

Cerebral blood flow (CBF) at rest was measured by 123I-IMP SPECT and the standing test was conducted by 99mTc-HMPAO SEPCT in patients with dementia of Alzheimer's type (DAT) and vascular dementia (VD) in order to evaluate cerebral autoregulation and to consider the diagnostic significance of this determination and test. CBF at rest decreased significantly in all regions in the DAT and VD groups compared to the control groups (healthy aged persons, group C). The value of mean CBF also decreased significantly in the DAT (40.1 micromilligrams/100 g/min) and VD groups (41.3) as compared to group C (51.0). In the DAT groups, the CBF was significantly lower in the parietal region compared to VD groups, and CBF and Hasegawa's dementia score showed a positive correlation in the temporal and parietal regions. Decreases in blood pressure upon standing were about 10 mmHg in all three groups, but the decrease rate in mean CBF was significantly greater in the VD groups (20.2%) than in the C (5.0%) and DAT groups (4.0%). The dysautoregulation index (D.I. delta; % CBF mmHg), used as a measurement of cerebral autoregulation, was significantly higher in the VD groups (1.7) than in the C(0.5) and DAT groups (0.3). This index made it possible to make differential diagnosis in some patients in whom it was impossible using CBF at rest, probably due to impaired cerebral autoregulation and atherosclerotic changes in VD patients. Our findings suggest that D.I. provides information on the condition of patients that cannot be obtained with CBF at rest and assists in differential diagnosis.

Aged↗

PubMed1996

[MR diffusion-weighted imaging of cerebral infarction].

MR diffusion-weighted imaging was performed to investigate changes in water diffusion in patients with cerebral infarction, and diffusion-weighted images (DWI) were compared with T2-weighted images (T2WI). Acute and subacute infarcts were seen as areas of high intensity on DWI and showed lower apparent diffusion coefficients (ADCs), while chronic infarcts showed a relative increase in ADCs. The relative ADC increased progressively over time, becoming renormalized at 3 to 4 weeks, and was elevated in the chronic state. On DWI, infarcts as small as 5 to 6 mm in diameter and lesions adjacent to the ventricular or subarachnoid space could be readily identified. DWI was useful for distinguishing acute lesions from chronic lesions in patients with multiple cerebral infarction, and provided valuable pathophysiologic information on the course of ischemic stroke evolution.

Aged↗