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Biomedical subjects

N Imai

Publications and source records attributed to N Imai.

At least 73 records · Page 4Linked to original sources
PubMed1997

Early increase of chondroitin sulfate glycosaminoglycan in the glomerular basement membrane of rats with diabetic glomerulopathy.

A decrease in anionic change and the loss of heparan sulfate proteoglycan have previously been observed in the glomerular basement membrane (GBM) during diabetic glomerulosclerosis. We studied the chronological changes in the anionic character and the glycosaminoglycan content in the GBM of WBN/ Kob rats with spontaneous diabetes. Two types of cationic probes were used: polyethyleneimine (PEI) and cationic colloidal gold (CCG). Immunogold labeling was performed with anti-monoclonal-heparan-sulfate-glycosaminoglycan (HS-GAG) and anti-chondroitin-sulfate-glycosaminoglycan (CS-GAG) antibodies. The GBM width, the anionic sites and the GAG sites were investigated in diabetic WBN/Kob rats at 2, 10 and 19 months, compared with control rats. Diabetes was confirmed in WBN/Kob rats after 8 months in this study. The GBM width gradually thickened with age. The PEI anionic sites significantly decreased in the lamina rara externa (LRE) at 19 months (vs. 2 and 10 months). The HS-GAG sites also significantly decreased in the LRE at 10 and 19 months (vs. 2 months). However, the CCG anionic sites and the CS-GAG sites significantly increased in the LRE and the lamina densa at 10 months (vs. 2 months) and, after 19 months, returned to the level seen at 2 months. Results indicate that there is an early transient increase in CS-GAG in the GBM while HS-GAG decreases. We noticed a transient increase in the CCG anionic sites at this early stage of diabetic glomerulosclerosis as well. The increase in CS-GAG may provide a marker for early diabetic changes in the GBM.

Animals↗
PubMed1997

Histological localization of advanced glycosylation end products in the progression of diabetic nephropathy.

We studied the immunohistochemical localization of advanced glycosylation end products (AGEs) in the progression of diabetic nephropathy. Fourteen NIDDM patients with diabetic nephropathy were evaluated: 2 patients with normoalbuminuria, 4 with microalbuminuria (MA) and 8 with overt proteinuria (OP). Three patients with minor glomerular abnormalities were used as nondiabetic controls. Immunoreactivity to a monoclonal anti-AGE antibody (6D12) was recognized on the internal elastic membranes of arterial walls in every diabetic group. Hyaline lesions of arterioles of the MA and OP groups demonstrated strong reactions with 6D12. A portion of the nodular and exudative lesions in glomeruli of OP group patients also revealed immunoreactivity to 6D12. No immunoreactivity to 6D12 was observed in nondiabetic control specimens. We confirm that the accumulation of AGEs began in arterial walls of the early stage and presented in glomerular lesions of the late stage of the progression of diabetic nephropathy.

Adult↗
PubMed1997

Cord blood IgE against milk and egg antigens.

The aim of the present study was to reevaluate the prenatal production of specific IgE for eggs and milk and, in those cases, to determine whether there is a relation to the amount of maternal egg and milk intake. Total and specific IgEs from 160 cord blood-samples were determined by immunoassays using a paramagnetic particle solid phase and an enzyme-mediated chemiluminescent reaction for signal detection. The levels of cord blood IgE for total, egg, and milk were 0.63 +/- (SD) 1.10 IU/ml, 0.020 +/- 0.055, and 0.036 +/- 0.053 IU/ml, respectively. IgE levels specific to egg and milk over 0.03 IU/ml were observed in 33 and 70 out of 160 cases, respectively. To address whether the maternal intake of eggs and milk affects the level of cord blood IgEs, all mothers except 9 were interviewed, and the amount of eggs and milk taken during pregnancy was recorded. No correlation was seen between egg and milk intakes and cord blood IgE levels. Our data demonstrate a high incidence of the prenatal production of specific IgE for eggs and milk which is independent of maternal egg and milk intakes.

Adult↗
PubMed1997

[Protective effect of nitric oxide on ischemic retina].

Nitric oxide (NO) is a free radical and was regarded as noxious to life. But recent studies show that NO is an important substance for transcellular signal transduction. It also seems to act as a neurotransmitter in the nervous system. In ischemic nerve tissue a release of glutamate is one of the critical factors that increase neuronal death, and some experiments suggest that NO may be involved in this process. Here we provide evidence that NO provides neuroprotection in ischemic retinas in vivo. Albino rabbits' eyes were subjected to 60 minutes of ischemia by raising intraocular pressure. Before ischemia the eyes were treated intravitreously with the NO-precursor L-arginine, the NO synthase-inhibitor nitro-L-arginine methyl ester hydrochloride (L-NAME), the NO-donor sodium nitroprusside (SNP), or solvent only. The amplitude of the b-wave was measured and the recovery ratio of the b-wave was analyzed hourly after reperfusion. The recovery ratio of b-wave in the eyes with L-arginine and with SNP increased more rapidly than in the controls, while the recovery ratio in the eyes with L-NAME increased in a way similar to that of the controls. These results suggest that NO plays a neuroprotective role in ischemic retina. It may be involved with S-nitrosylation of some proteins, including one of the glutamate receptors, the N-methyl-D-aspertate (NMDA) receptor.

Animals↗
PubMed1997

[A case of Guillain-Barré syndrome treated with plasma exchange and intravenous high-dose immune globulin].

We describe a 69-year-old female with Guillain-Barré syndrome (GBS) whose paresthesia and weakness improved after plasma exchange (PE) and intravenous high-dose immune globulin (i.v.I.G.). She felt a paresthesia in her right arm, and 7 days later she noticed right arm weakness followed by gait disturbance within 2 days. She received a series of 6 PEs, but paresthesia and weakness did not improve. Following the last PE trial of this series, she was treated by i.v.I.G. (0.4 g/kg) for 5 days. After i.v.I.G., paresthesia and weakness improved in a few days. After 2nd series of 6 PEs, she was able to walk. In this clinical course, the treatment of i.v.I.G. after PE seemed to be effective. This case raises the possibility that i.v.I.G. might be the treatment in GBS patients with insufficient effect of PE.

Aged↗
PubMed1996

Influence of CO2 tension on hepatic hemodynamics during portal arterialization.

We investigated the effect of portal arterialization (PA) on hepatic energy metabolism and hepatic hemodynamics. Portal perfusion flow rate with arterial blood was 25% of the preperfusion portal flow. During PA up to 120 min, hepatic energy metabolism was maintained from the aspects of ATP, energy charge, and arterial ketone body ratio. However, during this PA, carbon dioxide tension (25-35 mm Hg) in arterial blood was lower than that in normal portal vein blood and portal vein resistance (PVR) was significantly increased during perfusion compared with that at preperfusion. When carbon dioxide tension (50-63 mm Hg) in arterial blood was made equivalent to that in normal portal vein blood by controlling the respiratory conditions, PVR was not increased during PA up to 120 min. It was suggested that PCO2 in perfusion blood should change PVR, while it should not change hepatic energy metabolism when portal perfusion flow rate with arterial blood was 25% of the preperfusion portal flow.

Animals↗
PubMed1996

Subcellular distribution and phosphorylation of the nuclear localization signal binding protein, NBP60.

We previously purified a nuclear localization signal binding protein, NBP60, from rat liver (1993, J. Biochem. 113, 308-313). In this study, the subcellular localization of NBP60 was examined using anti-NBP60. Most NBP60 was found to be localized in the nuclear envelope fraction of rat liver obtained on cell fractionation followed by immunoblotting. Staining of the nuclei of cultured cells by the antibody was observed on immunofluorescence microscopy. NBP60 was widely detected in rat nuclear fractions prepared from other tissues and also in nuclei of cultured cells derived from other species. It was shown by immunoelectron microscopy that most NBP60 is present in the nuclear envelope and at least some of that is present on nuclear pore complexes. Although NBP60 was localized in the nuclear envelope in interphase cells, it diffused into the cytoplasm in the mitotic phase. The purified NBP60 was highly phosphorylated by a cdc2 mitotic kinase, whereas nuclear pore proteins p144, p62, p60, and p54 were not phosphorylated by the kinase directly. NBP60 was also phosphorylated by protein kinase A, calmodulin-dependent protein kinase II, and casein kinase II. The phosphorylation of NBP60 by cdc2 kinase and/or the other kinases may be related to the change in the protein's location during the mitotic phase.

Animals↗
PubMed1996

Characterization, molecular cloning and expression of megakaryocyte potentiating factor.

We examined whether the conditioned media of 64 kinds of cell lines, which have been maintained by a protein-free culture system, could produce megakaryocyte potentiating (Meg-POT) activity. In these cell lines, HPC-Y5, established from human pancreatic cancer, was shown to have the highest level of activity. The megakaryocyte potentiating factor (MPF) was purified from its conditioned medium by a combination of ion-exchange chromatography, gel filtration and reversed-phase HPLC. The purified MPF showed Meg-POT activity almost equal to human (Hu) interleukin 6 (IL-6) in the presence of murine IL-3 in a colony-forming assay with mouse bone marrow cells. The molecular weight of MPF was estimated to be 33 kDa by SDS-PAGE. Glycopeptidase F digestion and amino sugar analysis of the factor demonstrated that MPF is a glycoprotein carrying at least one N-linked sugar chain. The N-terminal amino acid sequence of MPF was determined to be Leu-Ala-Gly-Glu-Thr-Gly-Gln-Glu-Ala-Ala-Pro-Leu-Asp-Gly-Val-Leu-Ala-Asn. The same or homologous amino acid sequence has not been found in known proteins, demonstrating that MPF may be a novel cytokine which has Meg-POT activity. Then, we isolated HuMPF cDNA from an HPC-Y5 cDNA library using polymerase chain reaction and plaque hybridization methods. The HuMPF cDNA encodes a polypeptide consisting of 622 amino acids, including a signal peptide of 33 amino acids, and with a deduced molecular weight of 68 kDa, although HPC-Y5 cells secrete a 33 kDa form of HuMPF. HuMPF cDNA does not show any significant homology with other known sequences. The cDNA was expressed in COS-7 and Chinese hamster ovary (CHO) cells, and Meg-POT activity was detected in their culture supernatant. The COS-7 cells secreted only a 33 kDa recombinant (r)HuMPF, however, an additional 30 kDa form was detected in the culture medium of CHO cells. The 33 kDa rHuMPF from CHO cells showed Meg-POT activity, but not the purified 30 kDa rHuMPF. The difference in structure and activity between the 33 and 30 kDa forms of HuMPF was ascribed to the existence in the 33 kDa form of the C-terminal 25 amino acid residues. The expression of MPF mRNA was examined by Northern blot analysis using labeled MPF cDNA as a probe. MPF mRNA was detected in HPC-Y5 cells, with an approximate molecular size of 2.4 kb. We also examined the expression of the MPF gene in various human tissues, and the 2.4 kb band was detected only in lung. Then, the immunohistocytochemical analysis and in situ hybridization revealed that MPF-producing cells were identified as lung macrophages. MPF may exhibit other biological activities such as regeneration of the lung tissues.

Amidohydrolases↗
PubMed1996

Primary biliary cirrhosis sera recognize not only gp210 but also proteins of the p62 complex bearing N-acetylglucosamine residues from rat liver nuclear envelope. Anti-p62 complex antibody in PBC.

We have recently observed reactivity of primary biliary cirrhosis (PBC) sera with several proteins bearing N-acetylglucosamine residues from rat liver nuclear envelopes. The aim of this study was to characterize the reactive antigens. Sera from 31 patients with PBC, 30 with rheumatoid arthritis (RA) and 30 with Sjögren's syndrome (SS) were examined. Rim-like immunofluorescence staining was observed in 15 of 31 (48%) sera from patients with PBC, in 1 of 30 with RA and in 1 of 30 with SS. Upon immunoblotting using preparations of whole rat liver nuclear envelopes and their Triton X 100-KCl extract as antigen sources, a 200 kDa protein band was observed in 9 of sera with PBC. Furthermore, upon immunoblotting using the wheat germ aggulutinin-bound fraction of rat liver envelope as antigen, 62, 60 and 54 kDa protein bands corresponding to components of the p62 complex in the nuclear pore complex (Kita et al. Biochem. 113, 377-382) were observed in 7, 5 and 6 samples respectively, of the 31 PBC sera. Our data suggest that PBC sera recognize not only the 210 kDa protein but also the p62 complex proteins.

Acetylglucosamine↗
PubMed1996

Simplification of the Elmslie-Trillat procedure for patellofemoral malalignment. Is medial capsulorraphy necessary?

We describe a modification of the Elmslie-Trillat operation which includes a lateral retinacular release and medial realignment of the tibial tuberosity, but omits medial capsulorraphy. Seventy-five patients were reviewed with a follow up longer than 2 years and the results compared with the conventional Elmslie-Trillat procedure, which consists of lateral release, medial realignment of the tuberosity and medial capsulorraphy. The simpler operation can work as well and the period of rehabilitation is shorter. The incidence of injury to the saphenous nerve is reduced and the cosmetic appearance is more satisfactory. We conclude that medial capsulorraphy is usually unnecessary in this type of procedure.

Female↗
PubMed1996

Second transplantation with CD34+ bone marrow cells selected from a two-loci HLA-mismatched sibling for a patient with chronic myeloid leukaemia.

A 43-year-old man with chronic myeloid leukaemia underwent a second transplant with CD34+ bone marrow cells selected from his two-loci HLA-mismatched sibling after rejection of the first graft from an HLA-matched unrelated donor. By immunomagnetic positive selection, CD34+ marrow cells at 0.95 x 10(6)/kg with 97% purity and CD3+ T lymphocytes at 1.3 x 10(4)/kg were collected and transplanted. Engraftment was confirmed to be of CD34+ cell-donor origin. The patient developed only grade I acute graft-versus-host disease (GVHD) and no chronic GVHD to date. These observations suggest that allogeneic CD34+ bone marrow cells are capable of reconstituting haemopoiesis and that CD34+ selection could be applicable to T-cell depletion.

Adult↗
PubMed1996

Magnetic resonance imaging of neurogenic tumors of the thoracic inlet: determination of the parent nerve.

To investigate the value of magnetic resonance imaging (MRI) in determining the parent nerves of neurogenic tumors in the thoracic inlet, analysis of MR images was performed in nine patients with surgically resected neurogenic tumors in the thoracic inlet (two neurofibromas and one schwannoma of the vagus nerve, three schwannomas of the brachial plexus, and two schwannomas and one ganglioneuroma of the sympathetic nerves). These MR images were compared with surgical and pathologic findings. The multidirectional capability and excellent tissue contrast of MRI facilitated recognition of the location, shape, and extent of the tumors. MRI, which permitted an easy understanding of the spatial relation between the tumors and the subclavian vessels, scalenus muscles, and brachial plexus, was useful in determining the nerves of origin. Two neurofibromas, four of six schwannomas, and one ganglioneuroma were recognized to extend along the axes of the parent nerves on MR images. MRI is useful in determining the parent nerve of neurogenic tumors in the thoracic inlet and is helpful in planning surgical treatment of these tumors.

Brachial Plexus↗
PubMed1996

[Experience with and prospects for emergency Ippan kensa (urinalysis, fecal tests and body fluid tests].

Ippan Kensa (defined as urinalysis, fecal tests, and tests of cerebrospinal fluid, pleural fluid, ascites, and other body fluids) are done of fresh samples, as a rule, and such samples should be tested as soon as possible. Even for tests not ordered in an emergency, rapid results are desirable. In these two senses, all tests are somewhat urgent. Along with the rest of the hospital, our section moved into a new hospital complex in 1993, and that time, an order-entry and reporting system was implemented. Urinalysis was totally systematized from the start with two automated analyzers connected to an automated transportation system, and other tests were gradually automated and computerized. Time and labor were saved without decreased quality. Most routine tests are now done within 2.5 hours of sampling. Emergency tests are not handled by a special, formally established procedure in our laboratory, but at the request of a physician, any test can be done rapidly when necessary, because the system allows interruption at any time for testing of samples out of order. Our experience with this system suggests that automation and computerization are essential if emergency and urgent tests are to be done rapidly by a small staff. Further improvements in the high-quality automated analyzers already available, speeding results but allowing fewer false-positives and false-negatives can be expected.

Automation↗
PubMed1996

[Report on the accuracy and the reliability of dip sticks].

Urinary examination with dip sticks is essential for clinical screening test and primary health care. Recently Japanese Society of Clinical Pathology has stressed the clinical use of dip sticks. Many dip sticks are available in Japan. However, few attempts have been done for external quality control of dip sticks. It is well known that there are considerable differences in the accuracy, sensitivity and stability of dip sticks. Makers are at variance in indicating concentration levels in accordance with the given color charts. Some urine chemistry analyzers for dip sticks have been developed. There was a few cases of simultaneous study on dip sticks from various makers. We, four technologists have attempted external quality control of eleven dip sticks for protein, glucose and occult blood with the same lot number (one was only for glucose) using the four different pooled urine samples and two artificial urine samples. Based on the results of this study, the following proposal to improve the accuracy and reliability of dip sticks was derived. 1) Users should have a plenty of knowledge on the difference of the quality of dip sticks of each makers. 2) Makers of dip sticks should clarify to users the method of examination, standard materials and errors. 3) Users should perform internal quality control using different pooled urine samples or different artificial urine samples on a daily basis before going with the routine work.

Glycosuria↗