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Biomedical subjects

H Tabata

Publications and source records attributed to H Tabata.

89 records · Page 5Linked to original sources

Stimulatory effect of CD5 antibody on B cells from patients with rheumatoid arthritis.

In order to clarify the role of CD5 antigen on B cell in autoimmunity, we examined B cells from patients with rheumatoid arthritis (RA). The percentages of CD5 positive B cells were increased in peripheral blood from RA compared with normal. Normal and RA B cells were stimulated with two kinds of monoclonal antibodies to CD5 (Leu-1, SL-1) which recognize different epitopes. RA B cells proliferated and secreted IgM by CD5 antibody stimulation in combination with IL-1. Our observations imply that CD5 positive B cells in RA are in their differentiation stage and that CD5 antigen might be one of the triggers to activate CD5 positive B cells in vivo to produce autoantibody.

Adjuvants, Immunologic↗

Inhibitory effect of human recombinant interleukin-1 alpha and beta on growth of human vascular endothelial cells.

Endothelial cell growth factor (ECGF) is a potent polypeptide mitogen which stimulates the growth of endothelial cells. The mitogenic effect of ECGF was inhibited by addition of recombinant interleukin-1 (rIL-1) alpha or beta in a concentration dependent manner. The morphological change was not observed distinctly. In the condition without ECGF, both types of rIL-1 enhanced [3H]-thymidine uptake slightly, but failed to increase cell numbers. These data suggest the possibility that the effect of rIL-1 on EC is modulated by the presence of ECGF.

Cell Division↗

Incorporation of plasma palmitate into the brain of the rat during development.

Jpalm, the rate of incorporation of plasma palmitate into brain, was determined in awake Fischer-344 rats at 15, 20, 25 and 38 days of age, by a modification of the method of Kimes et al. [14C]palmitate was injected intravenously and plasma-specific activity of unesterified palmitate was followed until the animals were killed at 4 h, when radioactivity was determined by quantitative autoradiography in 45 individual brain regions. Jpalm was calculated as the 4 h brain radioactivity divided by integrated plasma palmitate-specific activity to 4 h. Jpalm rose between 15 and 20 days of age in gray and white matter regions, then declined 4-5-fold in gray matter and 7-10-fold in white matter by 38 days and reached adult levels by 3 months. The white/gray ratio for Jpalm declined significantly between 20 and 38 days, and between 38 days and 3 months of age, consistent with a lower rate of turnover of white matter lipids in the mature brain. The results support the use of the Jpalm technique to measure brain lipid synthesis and turnover. They show that Jpalm corresponds to the time course of myelination during development of the rat brain, when there are parallel changes in the rates of palmitate incorporation into gray and white matter regions.

Aging↗

Regional cerebral blood flow in awake beagles of different ages.

Regional cerebral blood flow (rCBF) was measured in 35 brain regions of awake beagles of different ages, by infusing 14C-iodoantipyrine intravenously. Between 1-3 and 6-12 yrs of age, rCBF was reduced significantly (P less than 0.01) in only 6 of the 35 regions, by 16 to 25%, and mean weighted CBF was not significantly altered. At 14-15 yrs, rCBF was reduced significantly by 25 to 50% in 13 of 28 grey matter regions examined, but in no white matter region, as compared with rCBF at 1-3 yrs of age, and mean weighted CBF was reduced by 30% (P less than 0.01). The course of rCBF during ageing of the beagle corresponded to the reported course of the regional cerebral metabolic rate for glucose. The results demonstrate that cerebral functional activity in most brain regions is constant during much of the adult life of the beagle, and that coupling between blood flow and metabolism also is constant. Compensatory morphological and neurochemical mechanisms may account for this homeostasis of CBF. In extreme senescence, generalized reductions in rCBF are found, and probably reflect reduced sensory input to the brain as well as systemic disease.

Aging↗

Topographic cerebral blood flow mapping in children with ischemic cerebrovascular diseases using xenon-enhanced computed tomography.

A non-invasive technique using xenon-enhanced computed tomography (Xe-CT) for obtaining topographic regional cerebral blood flow (rCBF) maps has been developed. During the past 3 years, the Xe-CT has been performed in 22 children with ischemic cerebrovascular diseases, including 17 cases with moyamoya disease. In moyamoya disease, rCBF maps revealed low flow in the bilateral frontal and temporal cortices, and high flow in the thalamus and putamen on both sides. Other diseases showed low perfused areas. Xe-CT can be easily performed even in infants and children and it gives valuable information that may be of clinical use.

Brain Ischemia↗

[Effects of indirect EC/IC bypass operations on adult moyamoya patients].

We have performed indirect EC/IC operations, mainly the EDAS, on 50 pediatric and 4 adult moyamoya patients. In this paper, we report on the effects of the indirect EC/IC operations performed on the 4 adult patients, three females presented with intracranial hemorrhage and a male presented with intracranial hemorrhage and a male presented with infarction. The procedures performed were 6 EDAS, one EAS and a simple hematoma removal which was revealed later to have effected as indirect EC/IC bypass surgery. The patients were all in their twenties. All the patients had pre- and postoperative angiography and the result were compared and was correlated with changes in CT and neurological signs. Case 1 had hematoma removal right after the hemorrhagic attack. Angiograms taken 10 months later showed marked revascularization of the brain through the dural arteries on the operated side. EDAS which was performed later on the other side worked well and the postoperative angiograms taken 9 months later, showed satisfactory revascularization of the operated brain with decrease in moyamoya vessels. The patient has Rt. hemiparesis but she can enjoy skiing. Case 2 had been asymptomatic preoperatively, 10 months after the initial hemorrhagic attack. Bilateral EDAS was done. Angiograms 12 months later showed marked revascularization of the brain through the EC system and marked decrease in moyamoya vessels was seen in the Rt. side in which better revascularization presented. The patient lives a normal life as a housewife.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Evaluation of periventricular hypodensity in experimental hydrocephalus by metrizamide CT ventriculography.

Hydrocephalus was induced in 13 dogs by injecting kaolin into the cisterna magna and was evaluated by computerized tomography (CT) scans. Modification of periventricular hypodensity was observed by metrizamide-enhanced CT ventriculography. Periventricular hypodensity was seen as early as 12 hours after kaolin injection. On CT ventriculography, metrizamide stayed longer in the ventricles of hydrocephalic dogs than in those of normal dogs, and migrated into the areas of periventricular hypodensity; the changes became significant within 12 to 24 hours. Four of the dogs were killed immediately after CT ventriculography, and the iodine concentration was measured. Iodine concentration was highest in the periventricular white matter, followed by the basal ganglia, and it was low in the cerebral and cerebellar cortex. When the change in Hounsfield units found by CT ventriculography at the regions of interest was compared to the actual iodine concentrations, the figures were quite compatible. Similarly, the specific gravity was measured in tissue from various parts of the brain of two hydrocephalic dogs, and compared against the value of that from five normal dogs. The specific gravity values were particularly low in the periventricular white matter of the hydrocephalic brains, suggesting a higher water content in that region. Since the increased migration of metrizamide occurred at the same region, it is suggested that development of periventricular hypodensity is due to increased transit of cerebrospinal fluid from the ventricles to the white matter.

Animals↗

[Pediatric metrizamide CT cisternography and CT ventriculography (author's transl)].

We have studied the diagnostic value of computed tomography with metrizamide CSF enhancement in 37 infants. According to the method of injection, we called CT cisternography, CT ventriculography and CT cystography. These methods were useful for the morphologic and dynamic evaluation of the CSF pathways. We used them especially for the evaluation of hydrocephalus, skull base tumor, infantile subdural hematoma and its allied diseases, or congenital cystic lesion such as Dandy-Walker syndrome. The side effects in children are much less than those in adults.

Adolescent↗

Acute parietal and chief cell changes induced by a lethal dose of lipopolysaccharide in mouse stomach before thrombus formation.

The common lipopolysaccharide (LPS)-induced gastric lesions, such as erosions or ulcers, have been investigated in depth. Little is known, however, about the acute gastric lesions following a high dose of LPS. In a time-course study, ICR female mice were given a high subcutaneous dose of LPS (50 mg/kg). Mice were sacrificed at 4, 6, 12, and 24 hours after dosing and were assessed histopathologically for acute gastric lesions. The major gastric changes were seen in the fundic region and included vacuolar degeneration of parietal cells and apoptosis of chief cells. The vacuole in parietal cells was apparent as early as 4 hours postinjection (PI), and apoptosis of chief cells was apparent at 12 hours PI. Thrombus formation, in contrast, was not seen until 24 hours PI. No erosion, ulcer, or hemorrhage was seen in any gastric region in any of the treated animals at 24 hours PI. These results indicate that a subcutaneous high dose of LPS in mice causes vacuolar degeneration of parietal cells and apoptosis of chief cells before thrombus formation or subsequent ulcerative lesions.

Acute Disease↗