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Biomedical subjects

O Sakai

Publications and source records attributed to O Sakai.

267 records · Page 15Linked to original sources
PubMedDate not supplied

Effect of polyaspartic acid on CdCl2-induced nephrotoxicity in the rat.

We produced an animal model of CdCl2 nephrotoxicity in rats, and treated them with polyaspartic acid (PAA) to prevent renal damage. Male Sprague-Dawley (SD) rats (190-200 g) were used to induce proximal renal tubular damage by daily injection of CdCl2 3.0 mg/1,000 g body wt for 2 wk. CdCl2-exposed SD rats exhibited significant increases in urine volume, urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG), alanine aminopeptidase (AAP), and fractional excretion of sodium (FENa) and a decrease in the percentage of tubular reabsorption of phosphate (%TRP). Of these indicators of proximal tubular function, AAP and %TRP are more sensitive than NAG or FENa. No glycosuria or aminoaciduria, however, were observed. PAA markedly improved these indicators of proximal tubular function. Daily urinary protein excretion and creatinine clearance, on the other hand, did not change after administration of PAA. Cd concentrations in the cortex were 3 times higher than in the medulla, however, there were no differences between Cd-treated rats and PAA-treated rats. Our animal model is an excellent one for determining the effect of cadmium on renal proximal tubule damage. PAA appears to be useful in the treatment of CdCl2 nephrotoxicity.

Acetylglucosaminidase↗
PubMedDate not supplied

The use of deblurring technique for improving the longitudinal resolution in helical CT of the head and neck region.

We evaluated the use of deblurring technique by digital deconvolution for improving the longitudinal resolution in helical CT in a phantom and CT images of head and neck patients. After performing the helical scanning, overlapped axial images were reconstructed at 1/10 of the actual collimation. Then, the deblurring technique was performed. Results revealed that the resolution of slice profiles was improved after deblurring. Further, the longitudinal resolution increased as the strength of the deconvolution increased, at the expense of an increase in helical artifacts. The sharpness and visualization of horizontally running structures were improved in the reconstructed MPR, MPVR, MIP and 3D images in both the phantom and the images of all patients. Also, visualization of the peripheral vessels in CTAs was improved.

Angiography↗
PubMedDate not supplied

Stimulatory effect of serum on 86Rb washout from vascular smooth muscle cells in culture.

In order to elucidate the effect of serum on passive K permeability of vascular smooth muscle cells (VSMC) membrane, outward passive K permeability yielded as washout rate constant (Kc) of 86Rb washout, was measured in the presence and in the absence of cation transport modulators using VSMC in culture. The overall Kc of 86Rb washout subjected to 1% serum was significantly larger than that in controls. This stimulated Kc was substantially blunted in the presence of 10(-4) M amiloride and was partially inhibited with 5 x 10(-4) M bumetanide. Angiotensin II of 10(-5) M exerted to a lesser extent, a similar significant stimulatory effect on Kc of 86Rb washout, which effect was inhibited with application of amiloride. Additionally, Ca-antagonist, 10(-5) M nifedipine reduced serum-stimulated Kc to the basal level. It is concluded that both serum and angiotensin II increase K permeability in cultured VSMC. A part of this effect of serum may be attributable to angiotensin II in the serum. Furthermore, it is suggested that the stimulatory effect of serum on membrane permeability may be exerted, at least in part, via activation of both Na-H antiport and Na-K co-transport, possibly through mechanisms in conjunction with intracellular Ca.

Angiotensin II↗
PubMedDate not supplied

Effect of water fraction in selection of optimal TI value for STIR sequences.

OBJECTIVE: This article describes the effect of the water fraction in the selection of the optimal TI value in a STIR sequence. This effect has been given little consideration in previous studies. MATERIALS AND METHODS: Therefore, using both STIR combined with the Dixon method (opposed-phase STIR) and conventional STIR (in-phase STIR), we have investigated the effect of the water fraction in the selection of an optimal TI value for the STIR sequence. RESULTS: Our findings have indicated that the water protons rather than the olefinic protons (-CH = CH-) play a major role in the opposed-phase effect in vivo. CONCLUSION: Thus, it has been concluded that the most effective fat suppression can be achieved when the intravoxel phase cancellation effect between the water and lipid protons is maximal, rather than when the longitudinal magnetization of the lipid protons is minimal.

Adipose Tissue↗
PubMedDate not supplied

Effect of cyclophosphamide pulse therapy in a patient with intractable lupus nephritis.

A 32-year-old female was suffering from intractable lupus nephritis (LN). Prednisolone at 30 mg per day had been prescribed for two months because of massive proteinuria and edema. After that, anasarca and orthopnea were induced, and hypoproteinemia, hypercholesteremia, and anti-cardiolipin antibody were observed. Prednisolone at a dose of 60 mg per day was necessary. However, there was no improvement of the nephrotic state and renal pathological changes shown as diffuse proliferative lupus nephritis were followed by moderate crescent formation as determined by serial needle biopsy. Cyclophosphamide (CYP) pulse therapy was started and marked improvement of LN was obtained clinically and serologically without significant adverse effects.

Adult↗
PubMedDate not supplied

Immunogenetical penetrance in patients with primary biliary cirrhosis.

Two family cases of primary biliary cirrhosis (PBC) followed by the existence of autoantibodies such as anti-mitochondrial antibody, anti-nuclear antibody and anti-thyroid antibody are reported. Case O M has typical PBC, however, case H E is complicated by asymptomatic polymyositis. Common haplotypes of human leukocyte antigen (HLA) were observed as A24-Bw61 in the family members of case O M who had autoantibodies. Only the mother of case H E had identical HLA haplotypes such as A2, Aw31, Bw46, Bw61, DRw8, DRw52 and DQw1. From these results, it can be suggested that immunogenetic penetrance might be associated with the occurrence of familial PBC.

Autoantibodies↗
PubMedDate not supplied

Two cases of Reiter's syndrome.

Two characteristic cases of Reiter's syndrome are reported. One (case T.M) was a 64-year-old female with ulcerative colitis and the other (case O.M) was a 20-year-old male with serum antistreptococcal lysine O (ASLO) and antistreptokinase (ASK) titers of 480x and 2560x, respectively. These cases were both histocompatibility antigen HLA-B27 positive. The ulcerative colitis and iritis were inactive in case T.M. However, case O.M required aggressive treatment for fever and arthralgia. These patients have recently shown no evidence of Reiter's syndrome; however, case T.M has had recurrent bowel hemorrhages due to ulcerative colitis.

Adult↗
PubMedDate not supplied

Herpes zoster ophthalmicus with delayed contralateral hemiparesis.

A 35-year-old previously healthy woman developed left hemiparesis sixteen weeks after the onset of right herpes zoster ophthalmicus. Cerebral angiography showed complete occlusion of right middle cerebral artery at the origin and segmental narrowing of the right posterior cerebral artery. Computerized tomography (CT) and magnetic resonance imaging (MRI) also revealed a right hemispheric lesion consistent with angiographic findings. Reports from the literature along with the present case suggest that arteritis followed by cerebral infarction is the most probable cause of delayed contralateral hemiparesis.

Adult↗
PubMedDate not supplied

A case with renal tubular damage: differentiation of Na reabsorption function by lithium clearance.

The recovery of the renal proximal and distal tubular sodium (Na) reabsorption was evaluated by analysis of the physiological metabolism of lithium reabsorbed by the renal tubules in a patient with toxic interstitial nephropathy. Administration of glucocorticoid facilitated the rapid recovery of the proximal tubular Na reabsorption (-0.63 to 3 mmol/min for 2 wk) followed by recovery of phosphate reabsorption (51 to 82% for 2 months). Distal Na reabsorption was not altered for 2 months. Although Li clearance has been previously performed in healthy volunteers, we could differentiate the recovery of the proximal and distal renal tubular function even in a diseased patient.

Absorption↗
PubMedDate not supplied

Effect of serum on cell membrane Na-K transport of vascular smooth muscle in culture--a comparative study between normotensive and hypertensive rats.

In order to elucidate the effect of serum and its differential characteristics in primary hypertension, we investigated the influence of serum from spontaneously hypertensive rats (SHR) on the cell membrane Na-K pump, Na-H antiport and passive K permeability of cultured vascular smooth muscle cells (VSMC) from SHR and Wistar-Kyoto rats (WKY). In the absence of serum, the Na-K pump activity, described as ouabain-sensitive 86Rb uptake (OS), was greater in the VSMC of the SHR than that of the WKY. Addition of serum to the quiescent VSMC stimulated the OS, of which activation was significantly greater with the SHR serum than with the WKY serum. Determination of intracellular Na concentrations in the presence of 1 mM ouabain showed that Na uptake in the absence of serum of the SHR VSMC was greater than that of the WKY VSMC. Subjecting the VSMC to rat serum stimulated Na uptake, which effect was more profound with SHR serum than with WKY serum. A greater stimulation of 5-(N,N-hexamethylene) amiloride(HMA)-sensitive Na uptake by SHR serum accounted for this difference. When the Na-K pump was active, intracellular Na concentrations were unchanged in the presence of serum. Furthermore, serum from either of the two strains produced a substantial increase in the washout rate constant of 86Rb washout (Ke), which effect was also larger in SHR serum than in WKY serum. In the absence of serum, basal Ke of the SHR VSMC was greater than that of the WKY VSMC. It is concluded that serum from SHR produced a more pronounced activation of the Na-K pump, Na-H antiport and passive K permeability in cultured VSMC. The study suggests that in addition to an innate augmented activity of Na-K transporters in the VSMC of SHR, there are humoral factors in SHR serum which elicit the stimulation of the Na-H antiport, leading to either the activation of the Na-K pump or secondary stimulation of passive K permeability across the cell membrane.

Animals↗