Biomedical subjects

H Sakuma

Publications and source records attributed to H Sakuma.

At least 127 records · Page 7Linked to original sources

PubMed1994

[Two cases of asymptomatic primary biliary cirrhosis (PBC) accompanied with CREST syndrome].

Two cases of asymptomatic primary biliary cirrhosis (PBC) combining CREST syndrome. We have had encountered two primary biliary cirrhosis (PBC) patients overlapped with CREST syndrome. Case 1 was a 51-year-old female, who was suffering from Raynaud's phenomenon, esophageal dysmotility and sclerodactyly. Case 2 was a 67-year-old female, who was suffering from Raynaud's phenomenon, esophageal dysmotility, sclerodactyly and telangiectasia. They were free from itching and icterus. The histology of their biopsied liver specimen should stage I-II of Scheuer's classification. Their immunological findings showed anti-centromere antibody, (ACA) at a high titer (1 : 1280 dilution) and anti-mitochondrial antibody (AMA) at a low titer (1 : 40 dilution) positive in both. HLA DR types included DR2 and DRW8 in case 1, and did DR1 and DRW6 in case 2. Both patients are having good prognosis.

Aged↗

PubMed1994

Pressor effect of recombinant human erythropoietin: results of home blood pressure measurements in hemodialysis patients.

We investigated whether the treatment of anemic hemodialysis patients with a low dose of recombinant human erythropoietin (rHEpo) for a short period would increase the blood pressure (BP). Home BP measurements were used to detect minute increases in BP. Fifty-one anemic patients on maintenance hemodialysis with a hematocrit of 25% or less received rHEpo at the dose of 4500 IU/week by the intravenous route for 8 weeks. Overall, rHEpo did not increase the BP whether measured at home or in the clinic (causal BP). Hemoglobin concentration increased significantly from 7.1 +/- 0.7 to 8.8 +/- 0.7 g/dl. Patients were classified into two groups according to the change in mean (M) home BP induced by rHEpo: a pressor group (delta MBP > or = 5 mmHg, n = 17) and a non-pressor group (delta MBP < 5 mmHg, n = 34). The hemoglobin concentration rose significantly in both groups, but there was no change in casual BP. Home blood pressure measurements showed a gradual and continuous rise in BP in the pressor group, but not in the non-pressor group. Patients administered antihypertensive medications before rHEpo treatment accounted for 88% of the former and 50% of the latter groups. Two patients with malignant nephrosclerosis were included in the pressor group. The findings indicate that rHEpo, even given at a low dose for a short period, elevates the BP, as determined by home BP measurement, but not by casual measurements obtained in the clinic.

Adult↗

PubMed1994

[A case of acute subdural hematoma due to dural metastasis from malignant pleural mesothelioma].

A rare case of acute subdural hematoma due to dural metastasis from malignant pleural mesothelioma is reported. A 65-year-old man was brought to a nearby hospital complaining of lumbago. He suddenly complained of headache on the third hospital day and fell into a deep coma within a short while. Computed tomography showed a crescent shaped high density area in the right fronto-temporo-parietal region with midline shift to the left side. He was admitted as an emergency case to our clinic on April 24, 1989. Under the diagnosis of acute spontaneous subdural hematoma, emergency operation was performed. Nests of malignant sarcomatous cells were found in the clot obtained during the procedure, but the origin of the tumoral cells could not be identified. The patient failed to recover from the comatose state and died with pancytopenia on the 17th hospital day. General autopsy showed wide-spread malignant pleural mesothelioma with metastases to the lung, liver and bone marrow. Examination of the head revealed dural metastatic tumor and a subdural hematoma over the left hemisphere. Histopathology showed that many tumor cell nests were found only within the dilated veins of the dura. There, acute subdural hematoma was assumed to have developed suddenly and there was massive bleeding from the capillaries of the inner vascular layer of the dura. The relevant literature about intracranial metastasis of malignant pleural mesothelioma was reviewed, and the mechanism of subdural hematoma due to dural metastasis from malignant tumor was discussed.

Acute Disease↗

PubMed1994

[The clinical effect of factor XIII on drug-induced hemorrhagic cystitis].

The therapeutic effects of Factor XIII (F XIII) concentrate against drug-induced hemorrhagic cystitis (HC) was investigated. HC occurred in 4 children with malignant disease during anti-cancer chemotherapy. Two (CML and T-ALL) of 4 patients developed HC after the administration of high dose cyclophosphamide as conditioning for allo bone marrow transplantation or peripheral blood stem cell autografts, and the other 2 patients (rhabdomyosarcoma, Wilm's tumor) developed HC after the administration of ifosfamide for relapse. When F XIII concentrate at a dose of 20 to 230 U/kg was administrated immediately after the onset of HC, the symptoms, i.e., bladder irritability and macrohematuria disappeared within a few days. The F XIII serum levels of those patients were low (27-57%), and the levels increased (63-230%) after administration of F XIII concentrate. The two patients with relapsed solid tumor showed no symptoms of HC during subsequent ifosfamide treatment when F XIII concentrate was administrated to maintain a normal F XIII range. These results suggest that the administration of F XIII concentrate may be useful for the prophylaxis and treatment of drug-induced HC in patients with a low F XIII level.

Adolescent↗

PubMed1994

Diffusional anisotropy of the human brain assessed with diffusion-weighted MR: relation with normal brain development and aging.

PURPOSE: To analyze diffusional anisotropy in frontal and occipital white matter of human brain quantitatively as a function of age by using diffusion-weighted MR imaging. METHODS: Ten neonates (< 1 month), 13 infants (1-10 months), 9 children (1-11 years), and 16 adults (20-79 years) were examined. After taking axial spin-echo images of the brain, diffusion-sensitive gradients were added parallel or perpendicular to the orientation of nerve fibers. The apparent diffusion coefficient parallel to the nerve fibers (0) and that perpendicular to the fibers (90) were computed. The anisotropic ratio (90/0) was calculated as a function of age. RESULTS: Anisotropic ratios of frontal white matter were significantly larger in neonates as compared with infants, children, or adults. The ratios showed rapid decrease until 6 months and thereafter were identical in all subjects. In the occipital lobe, the ratios were also greater in neonates, but the differences from other age groups were not so prominent as in the frontal lobe. Comparing anisotropic ratios between frontal and occipital lobes, a significant difference was observed only in neonates. CONCLUSIONS: Diffusion-weighted images demonstrated that the myelination process starts earlier in the occipital lobe than in the frontal lobe. The changes of diffusional anisotropy in white matter are completed within 6 months after birth. Diffusion-weighted imaging provides earlier detection of brain myelination compared with the conventional T1- and T2-weighted images.

Adolescent↗

PubMed1993

X-arrestin: a new retinal arrestin mapping to the X chromosome.

We have been using a differential cDNA cloning approach to isolate human retina-specific and retina-enriched genes [1]. A 1,314 bp cDNA was isolated by this approach, representing a highly retina-specific message encoding a 388 amino acid protein showing 58%, 50%, and 49% homology to bovine beta-arrestin, and bovine and human retinal arrestin (S-antigen), respectively. Chromosomal mapping localized this new arrestin gene to the proximal long arm of the X chromosome, hence it was named X-arrestin. In situ hybridization demonstrated its expression in the inner and outer segments and the inner plexiform regions of the retina.

Amino Acid Sequence↗

PubMed1993

[MR tractography--visualization of structure of nerve fiber system from diffusion weighted images with maximum intensity projection method].

We developed a new noninvasive technique to visualize the anatomical structure of the nerve fiber system in vivo, and named this technique magnetic resonance (MR) tractography and the acquired image an MR tractogram. MR tractography has two steps. One is to obtain diffusion-weighted images sensitized along axes appropriate for depicting the intended nerve fibers with anisotropic water diffusion MR imaging. The other is to extract the anatomical structure of the nerve fiber system from a series of diffusion-weighted images by the maximum intensity projection method. To examine the clinical usefulness of the proposed technique, many contiguous, thin (3 mm) coronal two-dimensional sections of the brain were acquired sequentially in normal volunteers and selected patients with paralyses, on a 1.5 Tesla MR system (Signa, GE) with an ECG-gated Stejskal-Tanner pulse sequence. The structure of the nerve fiber system of normal volunteers was almost the same as the anatomy. The tractograms of patients with paralyses clearly showed the degeneration of nerve fibers and were correlated with clinical symptoms. MR tractography showed great promise for the study of neuroanatomy and neuroradiology.

Aged↗

PubMed1993

Measurement of T1 relaxation times of cardiac phosphate metabolites using BIR-4 adiabatic RF pulses and a variable nutation method.

T1 relaxation times of PCr and beta-ATP in human cardiac and skeletal muscle were evaluated using a variable nutation method. This allows T1 measurements with a constant TR and a significant reduction in acquisition time compared with the partial saturation method. Four 1D CSI datasets were obtained using 30 degrees, 45 degrees, 60 degrees, and 90 degrees BIR-4 adiabatic RF pulses within 40 min. The T1 of the phosphate phantom obtained with this method agreed with values obtained with the partial saturation method. The T1s of PCr and beta-ATP in heart are 3.98 +/- 0.18 s and 1.86 +/- 0.16 s (mean +/- SE). Our results demonstrated that T1 values in heart and skeletal muscle are not significantly different.

Adenosine Triphosphate↗

PubMed1993

Effects of cicletanine on the urinary excretion of prostanoids and kallikrein, and on renal function in man.

The effects of cicletanine, a new antihypertensive agent, on the prostaglandin-kallikrein system and the renin-angiotensin system were studied. A single oral dose of 200 mg cicletanine or placebo was administered to 9 healthy male volunteers, with samples of blood and urine obtained before and 2 hours after drug administration. Cicletanine increased the urine flow, urinary excretion of sodium, and fractional excretion of sodium by 47%, 115%, and 104%, respectively. While the excretion of 6-keto-prostaglandin-F1 alpha was enhanced significantly, urinary excretion of thromboxane-B2, prostaglandin-E2, and kallikrein were unchanged. Cicletanine also did not alter plasma renin activity, plasma aldosterone concentration, or creatinine clearance. These observations suggest that cicletanine may suppress sodium reabsorption at the nephron, and it may stimulate prostacyclin generation with no effect on that of thromboxane-A2. Thus cicletanine may be beneficial in the management of cardiovascular disorders in which the equilibrium between prostacyclin and thromboxane is disturbed.

Administration, Oral↗

PubMed1993

31P MR spectroscopy in hypertrophic cardiomyopathy: comparison with Tl-201 myocardial perfusion imaging.

Abnormal phosphate metabolism of the myocardium was evaluated in patients with hypertrophic cardiomyopathy (HCM) using 31P magnetic resonance (MR) spectroscopy. The results were compared with those from left ventricular function and thallium 201 (Tl-201) perfusion scintigraphy. Six normal volunteers and 19 patients with HCM were studied with a 1.5 T MR system. The spectra were localized to the myocardium using volume selection with the depth-resolved surface coil spectroscopy (DRESS) technique. Peak areas of 2,3-diphosphoglycerate (DPG), phosphodiesters (PDE), phosphocreatine (PCr), and beta-ATP were determined by fitting Gaussian functions to the phased spectra. The peak areas were corrected for contamination of blood adenosine triphosphate (ATP) and PDE. The corrected PCr/beta-ATP ratio in patients (1.07 +/- 0.10, mean +/- SE) was significantly lower compared with that in normal volunteers (1.71 +/- 0.13, p < .01). The PCr/beta-ATP ratio showed an abnormal decrease (< mean -2 SD of the controls) in 11 (58%) of 19 patients. The averaged PCr/beta-ATP ratio in 15 patients with normal left ventricular ejection fraction (LVEF) was 1.14 +/- 0.10, significantly lower than in healthy subjects. By contrast, the corrected PDE/PCr ratio in HCM did not differ significantly compared with that in healthy subjects (0.46 +/- 0.09 vs 0.36 +/- 0.09). The PDE/PCr ratio was abnormally elevated (> mean + 2 SD of the controls) in only four (21%) of the patients. On Tl-201 myocardial single-photon emission computed tomography (SPECT) imaging, the perfusion of the left ventricular wall looked normal in 6 and abnormal in 5 of 11 HCM patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗

PubMed1993

Magnetic resonance imaging and spectroscopy of the human heart.

Magnetic resonance imaging and spectroscopy have a great potential both for clinical cardiac diagnostics and for research in cardiac physiology, metabolism and disease. At the present time, cardiac MRI already is the method of choice in several clinical conditions, especially in imaging central vasculature and intra- and paracardiac masses. With the recent development of contrast agents and ability to measure both flow velocities and flow volume, the cardiac MRI is likely to have a profound role in evaluating coronary arterial disease as well as valvular heart disease. The limitations due to long imaging times of cardiac MRI-studies are likely to be overcome with the development of ultrafast imaging techniques in the near future. On the other hand, cardiac MRS is still a research tool, which needs technical improvements before it can be widely utilized in clinical work. However, attempts to this aim are highly justified, when the possibility that MRS will provide metabolic information of the heart is considered and bearing in mind, that MR-magnets with sufficient field strength for MRS are increasingly in use in most modern hospitals. The role of magnetic resonance imaging (MRI) and spectroscopy (MRS) in the evaluation of heart diseases is still evolving. Some clear indications for clinical use of cardiac MRI have already become apparent, whereas cardiac MRS is still confined to research applications. The current paper consists of a review of the role of MRI for cardiovascular diagnosis together with a review of the currents status of cardiac MRS.

Heart↗

PubMed1993

Age-specific characteristics of nocturnal blood pressure in a general population in a community of northern Japan.

The age- and gender-specific profile of circadian blood pressure variation was examined by monitoring ambulatory blood pressure (ABP) in 477 untreated subjects in a rural community of northern Japan. Autoregressive spectral analysis demonstrated three major peaks at around 24, 12, and 8 h. We fitted a truncated Fourier series with three harmonics to the blood pressure (BP) data using least squares regression. More than half of the BP and pulse rate periodic curves were bimodal, one-third were trimodal, and the remainder were unimodal. The nadir of BP appeared between 00:00 and 01:30, and that of pulse rate occurred between 00:30 and 02:00. The nadir of systolic and diastolic BP, as well as pulse rate, appeared earlier with increasing age, and the difference between subjects in their 20s and those in their 70s was about 1 h. The amplitude of 24 h BP decreased with increasing age in men, but not in women. This type of information on the circadian BP profile of a general population is useful for the diagnosis and treatment of hypertension.

Adult↗

PubMed1993

Characteristics of a community-based distribution of home blood pressure in Ohasama in northern Japan.

OBJECTIVE: To evaluate the distribution, reference values and day-to-day variation of blood pressure of untreated subjects measured at home. DESIGN: Cross-sectional study of a cohort. SETTING: General community in northern Japan. SUBJECTS: Blood pressure was measured in 871 subjects (mean +/- SD age 46.0 +/- 19.5 years, range 7-98, constituting 38.7% of the local population of Uchikawama region, Ohasama) who were not receiving antihypertensive medication. METHODS: Subjects measured their own blood pressure at home at least three times (mean +/- SD 19.7 +/- 8.4) each morning using a semi-automatic oscillometric blood pressure measuring device. Screening blood pressure was measured once. MAIN OUTCOME MEASURES: Distribution of home blood pressure in the study population as a whole and with respect to age and sex, and the distribution of day-to-day variation of home blood pressure were determined. RESULTS: Mean home blood pressure was 117.3 +/- 13.4/69.3 +/- 9.7 mmHg (95% confidence interval 116.4-118.2/68.7-70.0). The 95th centile value was 143/85 mmHg, mean+SD 131/79 mmHg and mean + 2SD 144/89 mmHg. Mean screening blood pressure was 126.2 +/- 18.9/72.1 +/- 11.7 mmHg (95th centile 159/92 mmHg). Age- and sex-specific 95th centile values as well as mean +/- SD were obtained. Mean+SD, mean + 2SD and the 95th centile values obtained as reference upper limits of home blood pressure from subjects identified as normotensive by screening blood pressure (n = 707) were 125/77, 137/86 and 134/83 mmHg, respectively. Home blood pressure increased gradually with increasing age in both men and women, although blood pressure was significantly higher in men until 50 years of age. Day-to-day variation of home systolic blood pressure also increased with age. CONCLUSION: Since the distribution of home blood pressure values was affected by age and sex, age- and sex-matched reference values for home blood pressure should be established. Home blood pressure values in elderly subjects should be evaluated carefully, since these exhibit greater day-to-day variation.

Adolescent↗

PubMed1993

Evaluation of left ventricular volume and mass with breath-hold cine MR imaging.

Left ventricular (LV) volumes and mass were evaluated in 10 healthy volunteers with breath-hold cine magnetic resonance (MR) imaging. The results were compared with those obtained with conventional cine MR imaging. The breath-hold studies showed no ghosting artifact, and cardiac edges were clearly identified because of the reduced blurring. Measurements of LV end-diastolic volume (LVEDV), LV end-systolic volume (LVESV), and LV mass obtained with breath-hold cine MR imaging showed close correlation with those obtained with conventional cine MR imaging (r = .98, .97, and .99, respectively). The interobserver variabilities for LVEDV, LVESV, and LV mass determined with breath-hold cine MR imaging (4.0%, 8.0%, and 3.7%, respectively) were equal to or less than those determined with conventional cine MR imaging (4.0%, 8.6%, and 5.0%, respectively). The authors conclude that breath-hold cine MR imaging is highly useful because an accurate assessment of cardiac function is obtained in less than 5 minutes.

Adult↗

PubMed1993

Ambulatory blood pressure of adults in Ohasama, Japan.

We performed a cross-sectional study in a small town in northern Japan to evaluate the distribution, reference values, and daily variation in ambulatory blood pressure. A total of 705 subjects (229 men aged 61.3 +/- 13.4 years [mean +/- SD] and 476 women aged 57.5 +/- 13.3 years; 41.1% of the regional adult population, n = 1716), including those treated with antihypertensive drugs (n = 231, 66.5 +/- 9.5 years) as well as untreated subjects (n = 474, 55.0 +/- 13.5 years), participated in the study. Both ambulatory and screening blood pressures were measured in 659 subjects. Ambulatory blood pressure was measured with an automatic device (Colin ABPM-630). The 24-hour ambulatory blood pressure in the total population was 121.7 +/- 13.0/71.1 +/- 7.6 mm Hg (95th percentile value [95%] = 146/85 mm Hg). The corresponding value in the untreated subjects was 119.4 +/- 12.5/70.1 +/- 7.4 mm Hg (95% = 144/83 mm Hg). The 24-hour average ambulatory blood pressure was 118.0 +/- 11.1/69.4 +/- 6.8 mm Hg (95% = 139/81 mm Hg) in subjects identified as normotensive by their screening blood pressure (n = 448, 57.2 +/- 13.1 years) and 133.6 +/- 14.2/78.9 +/- 8.8 mm Hg in those identified as hypertensive by their screening blood pressure (n = 73, 63.1 +/- 10.6 years). Based on the mean+SD of the 24-hour ambulatory blood pressure in the normotensive subjects by their screening blood pressure (129/76 mm Hg), the 24-hour ambulatory blood pressures in 25 (34.2%) of these 73 hypertensive subjects by screening blood pressure were below this level. Nine (2%) of 448 normotensive subjects by screening blood pressure were above the mean+2 SDs (140/83 mm Hg) of the 24-hour ambulatory blood pressure in the normotensive group by screening blood pressure. Ambulatory and screening blood pressures increased with age. The age-dependent increase in ambulatory blood pressure was less apparent in men. The 24-hour average pulse rate decreased with age. The daily variation in ambulatory blood pressure (standard deviation) increased with age, whereas that of pulse rate decreased with age. Increases in blood pressure variation were observed in nighttime and daytime blood pressure values. The differences between day versus night ambulatory blood pressures decreased with age in men but not in women.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

PubMed1993

Relief of acute lower limb ischemia with percutaneous fenestration of intimal flap in a patient with type III aortic dissection--a case report.

Acute right lower limb ischemia developed in a patient with type III aortic dissection. Aortography revealed complete occlusion of the right common iliac artery by dissecting intima. Immediately percutaneous transfemoral fenestration with angioplasty balloon catheter was performed and marked improvement was obtained in clinical symptoms and angiographic findings. Unfortunately the patient died of rupture of the thoracic aorta about eleven hours after the procedure. The cause of death was not thought to be related to this procedure. The authors conclude that percutaneous fenestration should be considered as the treatment of choice for visceral or limb ischemia due to acute aortic dissection.

Aortic Dissection↗

PubMed1993

Evaluation of aortic regurgitation using cine magnetic resonance imaging.

Cine magnetic resonance imaging (MRI) was used to assess aortic regurgitation (AR) in 13 patients with valvular disease and 3 normal subjects, and the results were compared to color Doppler flow mapping findings. AR produced a signal void in the left ventricle during the diastolic phase in all patients by MRI. There were no false positive or negative results compared with echocardiographic findings. Visual grading of cine MRI gave results similar to color flow Doppler echocardiography (88%). The distance and the area of aortic regurgitation using MRI correlated well with color Doppler flow mapping (r = 0.82 and 0.88). However, measurements of distance and area by color flow Doppler tended to be larger than those by cine MRI. With current techniques echocardiography may overestimate the severity of AR as compared with cine MRI. In addition, MRI gives clinically useful information in patients in whom transthoracic Doppler echocardiography is not adequate.

Adult↗

PubMed1993

Treatment of GVHD after blood transfusion.

In this paper, we summarize methods of treatment of graft versus host disease (GVHD) after allo bone marrow transplantation (BMT) with drugs, which could be applied to the treatment of GVHD after blood transfusion. Corticosteroid, ATG, and cyclosporine have generally been used for the treatment of GVHD after allo BMT. Some of the immunosuppressive drugs, which are newly developed, are useful too. In future, anti-TNF alpha antibodies and anti-IL6 antibodies could be effective in patients with GVHD.

Bone Marrow Transplantation↗