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Biomedical subjects

K Nakashima

Publications and source records attributed to K Nakashima.

At least 271 records · Page 15Linked to original sources
PubMed1998

A case of episodic angioedema associated with blood eosinophilia: upregulated C5a receptor expression on eosinophils.

A 47-year-old woman was admitted to hospital complaining of swelling and pain of the extremities, accompanied by high fever and generalized erythema. Laboratory examination showed marked blood eosinophilia with elevation of IgM, IgE, and C-reactive protein. All autoantibodies examined were negative. The heart and lungs showed no untoward findings. Biopsies of the skin and muscle revealed cellular infiltration of eosinophils around small blood vessels. Quantitation of C5a receptor (C5aR) expression by flow cytometry using anti-C5aR antibody showed upregulated expression of C5aR on blood eosinophils but downregulated expression on neutrophils. The abnormal C5aR expression on eosinophils and neutrophils became normal after spontaneous resolution of symptoms and blood eosinophilia. The possibility that C5aR expression on granulocytes is related to the pathogenesis of this syndrome may be considered.

Angioedema↗
PubMed1998

Three-dimensional reconstruction of the power flow Doppler imaging of intracranial vascular structures in the neonate.

Three-dimensional (3D) ultrasonography reconstructing from power flow Doppler imaging (PF) is able to image the 3D structures of the vascular systems. We tried to display the 3D images of intracranial vascular structures in 5 neonates with a portable data processor. Data acquisition was performed using PF through the anterior fontanel. We succeeded in reconstructing vivid 3D images of the anterior cerebral arteries (ACA), basilar artery (BA), internal carotid arteries (ICA), middle cerebral arteries (MCA), lenticulostriate arteries (LSA), internal cerebral vein (ICV), the vein of Galen (GV) and straight sinus (SS) in all subjects. The MCA could be displayed in only a proximal portion. The images of the LSAs were fainter than the other vessels. These problems are based on the character of PF; the flow signal, sampling from the small sized vessels and the perpendicular vessels to ultrasonic beam, is weak. The images of these vessels are fainter than other vessels. These limitations of PF performance directly influence the quality of the 3D images. The benefits and limitations of 3D ultrasonography system are discussed.

Cerebrovascular Circulation↗
PubMed1998

Enhanced responses of the chorda tympani nerve to nonsugar sweeteners in the diabetic db/db mouse.

Genetically diabetic db/db mice show greater neural and behavioral responses to sugars than lean control mice. The present study examined chorda tympani responses of db/db mice to nonsugar sweeteners and their inhibition by a sweet response inhibitor, gurmarin. The results showed that responses to sucrose, saccharin, glycine, L-alanine, and D-tryptophan, but not to D-phenylalanine, were approximately 1.5 times greater in db/db mice than in control mice. Treatment of the tongue with gurmarin suppressed responses to these sweeteners in db/db and control mice, but the extent of suppression was considerably smaller in db/db mice. The magnitudes of gurmarin-sensitive components of the response to sweeteners in db/db mice were not significantly different from those in control mice, whereas the magnitudes of gurmarin-insensitive components in db/db mice were about twice as large as those in control mice. These results suggest that the enhancement of chorda tympani responses in db/db mice to sucrose and other nonsugar sweeteners may occur through gurmarin-insensitive membrane components.

Animals↗
PubMed1998

Increase in inositol 1,4,5-triphosphate levels of the fungiform papilla in response to saccharin and bitter substances in mice.

Inositol 1,4,5-trisphosphate (IP3) levels of the mouse fungiform papilla and nonsensory epithelial tissue in response to various taste stimuli were measured by use of a competitive protein binding assay. Stimulation of the tongue with 20 mM saccharin induced a significant increase in IP3 levels of the fungiform papillae without affecting those of the nonsensory epithelial tissue, whereas stimulations with 20 mM quinine and denatonium raised IP3 levels in not only the fungiform papilla but slightly also nonsensory epithelial tissue. No such increases in IP3 levels were observed to lower concentrations of saccharin, denatonium and quinine, and other basic taste stimuli, such as 0.5 M sucrose, 0.1 M NaCl and 10 mM HCl. Pretreatment of the tongue with pronase, a proteolytic enzyme which inhibits sweet responses, completely eliminated the increase in IP3 levels induced by saccharin, but not those induced by quinine or denatonium. These results suggest that an IP3 pathway in taste cells of the mouse fungiform taste bud is involved in the transduction not only for denatonium and quinine, but also for 20 mM saccharin. The increase of IP3 induced by saccharin, but not by denatonium and quinine, may occur through pronase-sensitive membrane components.

Animals↗
PubMed1998

Apo A-I and apo E concentrations in cerebrospinal fluids of patients with acute meningitis.

It has been demonstrated that apolipoproteins found in cerebrospinal fluid (CSF) play an important role in lipid metabolism in the central nervous system (CNS). Previously we reported that CSF apo A-I levels increased with the severity of neurological damage in poliovirus-infected macaques. In the present study, apo A-I was quantitatively analysed in CSF from patients with or without neurological diseases. In controls, CSF apo A-I level was significantly higher in males; 3.83 (0.40) mg/L, mean (SEM) (n = 19) compared with females, 2.42 (0.26) mg/L (n = 23, P < 0.05). CSF apo A-I concentrations in patients with acute meningitis increased at the active stage, 7.74 (1.78) mg/L (n = 10), but returned to basal concentrations at the convalescent stage 2.72 (0.38) mg/L (n = 10), while the CSF apo A-I level in patients with other neurological diseases remained in the same range as in controls. By contrast, CSF apo E was consistently elevated at either stage of acute meningitis. Furthermore, it was found that the levels of CSF apo A-I, but not of apo E, correlated positively with CSF albumin concentrations. These findings suggest that the CSF apo A-I and apo E have different origins and may play different roles in the lipoprotein metabolism in CNS.

Acute Disease↗
PubMed1998

The growth hormone (GH) gene is expressed in the lateral hypothalamus: enhancement by GH-releasing hormone and repression by restraint stress.

Recent studies suggest that GH may modulate emotion, behavior, or stress response by its direct actions on the brain, and possible expression of the GH gene in the brain has been predicted. In this study we have investigated whether and where the GH gene is expressed in the brain and how it is regulated. Ribonuclease protection assay and 5'-rapid amplification of complementary DNA ends-PCR analyses indicated that the GH gene was expressed in rat brain, initiating at the identical transcription start point as that for pituitary GH gene expression. The brain GH messenger RNA was predominantly detected in the lateral hypothalamus (lh) by in situ reverse transcription-PCR analysis. GH gene expression in the brain was significantly enhanced by GH-releasing hormone administration and was rapidly repressed by exposure to restraint stress in the water, whereas the changes in pituitary GH messenger RNA contents in these circumstances were relatively smaller. The results of the present study suggest that the brain GH is predominantly expressed in lh under the control of physiological conditions to play a role in the modulation of brain functions.

Animals↗
PubMed1998

Use of fluid-attenuated inversion recovery (FLAIR) pulse sequences in perinatal hypoxic-ischaemic encephalopathy.

The purpose of this study was to evaluate the usefulness of fluid-attenuated inversion recovery (FLAIR) techniques in patients with perinatal hypoxic-ischaemic encephalopathy. 13 patients with a history of perinatal hypoxic-ischaemic encephalopathy (age range 1 month to 3.6 years) underwent T1 and T2 weighted spin echo and FLAIR imaging with a 1.5 T superconducting unit. FLAIR images were qualitatively evaluated in comparison with T1 and T2 weighted images by three experienced radiologists. Quantitative analysis (contrast and contrast-to-noise ratio) was also performed. FLAIR images were preferred to T1 and T2 weighted images in the demonstration of periventricular leukomalacia (PVL), cystic PVL and subcortical lesions near the brain surface. On T1 and T2 weighted images, almost all lesions were demonstrated as hypointense or hyperintense areas, respectively. However, FLAIR images could differentiate cystic lesions by their signal intensities. FLAIR images were not diagnostic in two cases with PVL. In conclusion FLAIR sequences provide useful information in patients with perinatal hypoxic-ischaemic encephalopathy.

Child, Preschool↗
PubMed1998

Effects of thyroid hormones on myofibrillar proteolysis and activities of calpain, proteasome, and cathepsin in primary cultured chick muscle cells.

The effects of thyroxine (T4) and triiodothyronine (T3) on growth, muscle protein degradation, and proteases activities in cultured chick muscle cells were studied. The cells were treated with a physiological level of T4 (60 ng/mL) or T3 (12 ng/mL) for 6 d. Calpain, cathepsins, and proteasome activities and N tau-methylhistidine release were measured as indexes of myofibrillar protein breakdown. Creatine kinase activity was also measured as an index of myotube formation. Calpain activity was increased by T4 and T3. Cathepsin D and proteasome activities and N tau-methylhistidine release were increased by T3, but not by T4. Neither were cathepsin B and B + L activities affected by T3 or T4. Creatine kinase activity was increased by T4 and T3. The results suggest that myotube formation is accelerated by T4 and T3, whereas myofibrillar protein degradation is accelerated by T3, but not by T4.

Animals↗
PubMed1998

Involvement of apoptosis and cyclin D1 gene repression in growth inhibition of T-47D human breast cancer cells by methylglyoxal bis(cyclopentylamidinohydrazone).

Polyamines are considered to be important intracellular molecules for the proliferation of the cancer cells. In this study, effects of methylglyoxal bis(cyclopentylamidinohydrazone) (MGBCP), a potent inhibitor of the polyamine biosynthetic pathway, on the growth and cell cycle of T-47D human breast cancer cells were investigated. MGBCP dose-dependently inhibited the growth of T-47D cells, in which the contents of spermine, spermidine and putrescine decreased concomitantly. The gene expression of cyclin D1 was also repressed by the MGBCP treatment. The MGBCP-treated cells clearly exhibited morphological changes indicating the blebbing and chromatin condensation which are characteristic of apoptosis. Flow cytometric analysis showed hypo-diploid subpopulations due to apoptotic cells, and characteristic oligonucleosomal-sized DNA fragments were clearly observed for MGBCP-treated cells as the concentration of the drug was increased. These findings suggest that the inhibition of polyamine synthesis results in the repressions of cyclin D1 expression and cell cycle progression, eventually inducing apoptosis in these human breast cancer cells.

Antineoplastic Agents↗
PubMed1998

Basic and clinical studies on ApoE gene typing by line probe assay (LiPA) as a biological marker for Alzheimer's disease and related disorders: multicenter study in Japan.

The fundamental reagent capability and clinical significance of ApoE gene typing has been investigated. The result of each test shows that the reagent capability satisfied the expected standard. Four-hundred thirty-nine samples classified into three groups (Alzheimer's disease (AD), other types of dementia and nondementia) were measured to examine the clinical significance. The rate of epsilon 4 genotype of each group was 31.5%, 14.6%, 10.4%, respectively. The AD group had a higher rate than the other groups (p < 0.001). The measurement of ApoE genotype is suggested to be useful as one of the guidelines in the diagnosis of AD.

Age Factors↗
PubMed1998

[Enhanced MR imaging with a nonionic contrast gadolinium complex, Gadoteridol, for lumbar disc herniation].

The aim of this study was to evaluate the usefulness for lumbar disc herniation of enhanced imaging with a nonionic contrast gadolinium complex (Gadoteridol). Among 130 discs in 26 patients, 27 herniated discs were shown on MR sagittal imaging. They were classified into 4 types according to the enhancement pattern of the disc on MR sagittal imaging (Type Ia: nonenhancement, Type Ib: globular enhancement, Type II: strong enhancement, Type III: ring enhancement). The results were as follows: Type Ia: 3, Type Ib: 15, Type II: 7, Type III: 2. A total of herniated discs were enhanced with Gadoteridol. Surgery was performed in 5 patients (Type Ib: 1, Type II: 4). The herniated disc of Type Ib extruded but did not rupture the posterior ligament, whereas the herniated discs of Type II extruded and ruptured the posterior ligament. Thus, the herniated discs were enhanced with the nonionic contrast agent Gadoteridol. If the disc herniates over the posterior ligament, it might be strongly enhanced. Therefore, enhanced MR imaging is thought to be useful to establish the diagnosis of lumbar disc herniation.

Adult↗
PubMed1998

Basic and clinical studies on the measurement of tau protein in cerebrospinal fluid as a biological marker for Alzheimer's disease and related disorders: multicenter study in Japan.

The development of a diagnostic marker for earlier and more accurate clinical diagnosis of Alzheimer's disease (AD) is essential to identify AD patients during life unequivocally. The purpose of this study was to investigate the basic performance and clinical significance of tau level measurement in the cerebrospinal fluid (CSF) using an enzyme-linked immunosorbent assay (ELISA) developed by Innogenetics. The ELISA system showed reliable reproducibility and good linearity. For clinical studies, the CSF samples from a variety of patients (n = 332) were examined. They were classified into the four groups: Alzheimer's disease (AD); neurodegenerative disease (ND); cerebrovascular diseases (VD); and a neurological control (NC) group. The CSF-tau levels for AD, ND, VD and NC were 426 +/- 234 pg/ml, 239 +/- 157 pg/ml, 216 +/- 136 pg/ml, and 188 +/- 103 pg/ml, respectively. The CSF-tau level of the AD group was significantly higher than that of the other groups (p < 0.001). The CSF-tau levels increased during follow-up. The measurement of the tau level in CSF is shown to be a useful marker to confirm a clinical diagnosis of AD.

Aged↗