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Biomedical subjects

N Akiyama

Publications and source records attributed to N Akiyama.

At least 19 recordsLinked to original sources
PubMed2005

Human proinsulin C-peptide prevents proliferation of rat aortic smooth muscle cells cultured in high-glucose conditions.

AIMS/HYPOTHESIS: Proinsulin C-peptide is involved in several biological activities. However, the role of C-peptide in vascular smooth muscle cells is unclear. We therefore investigated its effects, in vascular smooth muscle cells in high-glucose conditions. METHODS: Rat aortic smooth muscle cells were cultured with 5.5 or 20 mmol/l glucose with or without C-peptide (1 to 100 nmol/l) for 3 weeks. Proliferation activities, the protein expression of platelet-derived growth factor (PDGF)-beta receptor, the phosphorylation of p42/p44 mitogen-activated protein (MAP) kinases, and glucose uptake were measured. RESULTS: The proliferation activities increased approximately three-fold under high-glucose conditions (p<0.05). C-peptide suppressed hyperproliferation activities that were induced by high glucose. This happened in a dose-dependent manner from 1 to 100 nmol/l of C-peptide. C-peptide (10 and 100 nmol/l) inhibited the increased protein expression of PDGF-beta receptor and the phosphorylation of p42/p44 MAP kinases that had been induced by high glucose (p<0.05). Furthermore, 100 nmol/l of C-peptide augmented the impaired glucose uptake in the high-glucose conditions. CONCLUSIONS/INTERPRETATION: These observations suggest that C-peptide could prevent diabetic macroangiopathy by inhibiting smooth muscle cell growth and ameliorating glucose utilisation in smooth muscle cells. C-peptide may thus be a novel agent for treating diabetic macroangiopathy in patients with type 1 and type 2 diabetes.

Animals↗
PubMed2005

Acute inflammatory sensorimotor polyradiculoneuropathy associated with immune thrombocytopenic purpura.

Although acute inflammatory polyneuropathy (AIP) and immune thrombocytopenic purpura (ITP) are both believed to be immune-mediated disorders, only a few cases have been reported in which these two diseases co-existed. We describe a case of a 67-year-old patient who developed quadriparesis, ophthalmoplegia and severe sensory impairment along with thrombocytopenia. Detailed examinations, including the measurement of anti-ganglioside antibodies and anti-glycoprotein-IIb-IIIa-IgG-producing B-cells, revealed that he developed AIP and ITP. By reviewing past similar reports, we noticed that AIP associated with ITP tends to manifest severe sensory impairment and is often preceded by upper respiratory tract infection, but not by gastrointestinal infection.

Acute Disease↗
PubMed2004

Randomized trial of cefepime monotherapy or cefepime in combination with amikacin as empirical therapy for febrile neutropenia.

A multicenter open randomized trial was conducted to compare cefepime monotherapy with cefepime/amikacin combination (dual) therapy in treating febrile neutropenic patients with hematologic disorders. Among the 189 evaluable patients, 5.8% had microbiologically and 10.6% had clinically documented infections. Excellent response was seen in 32.6% and 45.7% of monotherapy and dual therapy recipients, respectively, at day 3 (P=.065). At day 3, patients with neutrophil counts of <500/ mu L receiving dual therapy had a better response than did those receiving monotherapy (45% vs. 27.6%; P=.024). The same was true for patients with leukemia. Adverse events were minimal, and early death was observed in 7 patients in the dual therapy group and 5 patients in the monotherapy group. Overall, cefepime monotherapy is as effective as dual therapy for the initial treatment of febrile neutropenic patients. Further study is warranted for patients with severe neutropenia and leukemia who may benefit from dual therapy.

Amikacin↗
PubMed2001

Dipyrimidine-copper(II) dinitrate complexes showing magnetic interactions.

Crystals of Cu(II)(NO(3))(2)(pm)(3) (1), and two crystalline forms of Cu(II)(NO(3))(2)(H(2)O)(2)(pm)(2), (2) and (3), showed ferromagnetic, antiferromagnetic and paramagnetic interactions at extremely low temperatures, respectively. Crystal structure analyses revealed that the complexes were catena-dinitrato[mu-pyrimidine-kappaN(1):kappaN(3)]-(pyrimidine-N(1))copper(II), [Cu(NO(3))(2)(pm)(2)](n), catena-diaquadinitrato[mu-pyrimidine-kappaN(1):kappaN(3)]copper(II), [Cu(NO(3))(2)(H(2)O)(2)(pm)](n), and diaquadinitratodipyrimidinecopper(II), Cu(NO(3))(2)(H(2)O)(2)(pm)(2) for (1), (2) and (3), respectively. In (1) the Cu atom is coordinated by the two nitrates and N atoms of the non-bridging pyrimidine and bridging pyrimidine to form a one-dimensional coordination polymer. The complex is a five-coordinated square pyramid and can be regarded as a pseudo-seven-coordinated complex, since other short non-bonding Cu.O contacts are observed. In the crystals of (2) the pyrimidine bridges the Cu atoms to form a one-dimensional coordination chain. On the other hand, complex (3) is not a coordination polymer. It is important to form a coordination polymer for the appearance of the magnetic interactions. Types of coordination of the bridging organic moieties should also play an important role in magnetic properties. Magnetic measurements of (1) and (2) show that they are good examples of uniform S = 1/2 ferro- and antiferromagnetic Heisenberg chains with exchange parameters 2J/kB = +1.8 and -36 K, respectively.

Journal Article↗
PubMed2001

Long-term follow-up results of anterior interbody fusion applied for cervical myelopathy due to ossification of the posterior longitudinal ligament.

STUDY DESIGN: A long-term follow-up study was carried out in 30 patients who underwent anterior interbody fusion for cervical myelopathy associated with ossification of the posterior longitudinal ligament (OPLL). OBJECTIVE: To investigate whether anterior interbody fusion without decompression is an appropriate surgical method for long-term relief of cervical OPLL myelopathy. SUMMARY OF BACKGROUND DATA: Several studies of operative results after posterior decompression for cervical myelopathy due to ossification of the posterior longitudinal ligament have been reported. There has been no report about anterior interbody fusion without decompression. The postoperative results of this treatment method applied in cervical OPLL myelopathy have been evaluated by the authors of the present study for more than 10 years. No reports on such a long-term follow-up study have been published in the literature. METHODS: Thirty patients who underwent anterior interbody fusion for cervical OPLL myelopathy were evaluated clinically and radiographically. The mean follow-up period was 14.7 years (range, 10-23 years). RESULTS: Clinical results were evaluated according to Okamoto's classification. At the time of the final follow-up evaluation, 16 patients had improved in functional score by two grades, and their surgical results were regarded as excellent; eight patients improved by one grade, and their clinical outcomes were regarded as good; five patients showed no change; and the condition of one patient deteriorated. As for radiographic analysis, the type of ossification had changed in four cases. Ossification width and thickness increased in 26 patients. Postoperative alignment of the cervical spine showed kyphosis in three patients, straight spine in 11 patients, and lordosis in 16 patients. CONCLUSION: Anterior interbody fusion without decompression is an effective treatment for cervical OPLL myelopathy that resulted in stable long-lasting conditions.

Adult↗
PubMed2001

c-IAP2 is induced by ionizing radiation through NF-kappaB binding sites.

Transcriptional promoters responsive to low doses of X-irradiation may be useful in developing a new strategy in gene therapy combined with conventional radiotherapy. The retrovirus-mediated gene trap screening identified c-IAP2 as one of genes possessing such promoters. The analysis of the cis-elements responsive to X-irradiation in c-IAP2 promoter revealed that the NF-kappaB binding sites were necessary and sufficient for the X-ray-responsiveness. We constructed the plasmid p4NFB-BAX, which had four tandem repeats of the NF-kappaB binding sites of c-IAP2 promoter (4NFB) and a suicide gene BAX under the control of 4NFB. The human tumor cells transfected with p4NFB-BAX significantly reduced the number of cells that survived 2 Gy irradiation.

Adenocarcinoma↗
PubMed2001

Identification of a novel thioredoxin-related transmembrane protein.

We recently identified a series of transforming growth factor-beta-responsive genes in A549 human adenocarcinoma cell line by a gene trap screening method. Here we report the molecular cloning and characterization of one of these genes, designated TMX, that encodes a novel protein of 280 amino acid residues. The TMX protein possesses an N-terminal signal peptide followed by one thioredoxin (Trx)-like domain with a unique active site sequence, Cys-Pro-Ala-Cys, and a potential transmembrane domain. There are putative TMX homologs with identical active site sequences in the Caenorhabditis elegans and Drosophila genomes. Using recombinant proteins expressed in Escherichia coli, we demonstrated the activity of the Trx domain of TMX to cleave the interchain disulfide bridges in insulin in vitro. The TMX transcript is widely expressed in normal human tissues, and subcellular fractionation and immunostaining for an epitope-tagged TMX protein suggest that TMX is predominantly localized in the endoplasmic reticulum (ER). When TMX was expressed in HEK293 cells, it significantly suppressed the apoptosis induced by brefeldin A, an inhibitor of ER-Golgi transport. This activity was abolished when two Cys residues in the active site sequence were mutated to Ser, suggesting that the Trx-like activity of TMX may help relieve ER stress caused by brefeldin A.

Adenocarcinoma↗
PubMed2001

Dermoid cyst of the colon.

Dermoid cysts are benign cystic teratomas lined by skin and epidermal appendages. We report a dermoid cyst occurring in a 26-year-old female whose chief complaint was irregular vaginal bleeding. Abdominal magnetic resonance image demonstrated a space-occupying lesion in the right lower abdomen. The mass showed hyperintensity on the T2 image and the signal was homogeneous for the interior. During abdominal surgery we made the diagnosis of subserous tumor of the colon and resected the ileocecal portion of the colon. The tumor measured 5.4 x 4.8 x 3.5 cm and was soft and elastic. On cross section, a unilocular cyst filled with atheromatous material was found. Pathological examination revealed a dermoid cyst. In the view of this diagnosis, a simple excision would have been an adequate treatment.

Adult↗
PubMed2001

Preparation and root growth-modulatory activity of N-substituted 2-acetylamino-2-ethoxycarbonyl-3-(2-furyl)propanamides.

N-Substituted 2-acetylamino-2-ethoxycarbonyl-3-(2-furyl)propanamides (8) were synthesized through the reaction of amines (13) with 2-acetylamino-2-ethoxycarbonyl-3-(2-furyl)propanoic acid (3b), which was prepared via condensation of 2-(bromomethyl)furan (10b) with diethyl acetamidomalonate, followed by partial hydrolysis of the resultant diethyl ester (3a) in the presence of barium hydroxide. However, bulky amines such as tert-butylamine or 2-trifluoromethylaniline did not afford the corresponding diamides (8). The biological activity of the prepared diamides (8) as root growth modulators was examined by germination assay using rape and leek seeds. N-(5-Bromo-2-thiazolyl)- and N-(4-chloro-2-benzothiazolyl)-2-acetylamino-2-ethoxycarbonyl-3-(2-furyl)propanamides (8h, i) both potently inhibited the root growth of rape seedlings, but were less effective in the case of leek seeds. The herbicide 2,4-dichlorophenoxyacetic acid completely inhibited root growth in both cases.

Alkanes↗
PubMed2001

[Long-term survival of a patient with postoperative liver metastasis of stage IVa gallbladder cancer responding to hepatic arterial infusion chemotherapy].

A 58-year-old man was diagnosed as having advanced gallbladder cancer (T4, P0, H0, N0, stage IVa) with direct invasion to the liver, transverse colon and duodenum. Therefore, extended cholecystectomy and bile duct resection with a partial resection of the transverse colon and the duodenum were performed in March 1992. Histopathological examination revealed moderately differentiated tubular adenocarcinoma of si, ly1, v1, hinf3, binf3, n0. Three years and eight months after the operation, multiple liver metastases were diagnosed by abdominal CT. Repeated hepatic arterial infusion chemotherapy with 5-FU 500 mg/body/w, MMC 4 mg/body/2w and EPI 40 mg/body/4w was performed starting in January 1996. Four months later, the lesions in the liver were reduced in size, and abdominal CT 10 months after the chemotherapy showed a partial response. However, the liver metastasis of the right lobe was enlarged on an abdominal CT in August 1997. Repeated hepatic arterial infusion chemotherapy with the same regimen was performed again starting in March 1998. Ten months later, the liver metastasis was slightly enlarged, but the greater part of the metastasis showed necrosis on an abdominal CT in January 1999. However, peritonitis carcinomatosa was observed later and the patient died 8 years after the operation.

Adenocarcinoma↗
PubMed2001

[Role of ultrasonography in diagnosis of neutropenic enteritis: a study of 4 cases].

Neutropenic enteritis is a septic or inflammatory disease of the colon. It is usually encountered in patients with hematological malignancy who have undergone chemotherapy, and it presents as fever, diarrhea, and abdominal pain, although the symptoms are not always specific. The diagnostic features of neutropenic enteritis revealed by barium enema, CT and ultrasonography have been reported previously. Here we report 4 cases of neutropenic enteritis in which ultrasound was used for diagnosis, and also for monitoring the clinical course of the disease. Because neutropenic enteritis is rapidly progressive, early diagnosis and therapeutic intervention are required. We believe that ultrasonography is a useful method for examining patients with neutropenic enteritis, being noninvasive, mobile, and providing rapid results in real time, thus aiding early diagnosis and clinical follow-up.

Adult↗
PubMed2000

Transient over-expression of NGFI-A gene suppresses NGF-induced neurite outgrowth in PCI2 cells.

Using an inducible gene expression system (Tet-ON system), the role of NGFI-A gene during the neuronal differentiation of PCI2 cells was examined. When NGFI-A was transiently over-expressed, no obvious effects on cell proliferation or neurite outgrowth were observed. Interestingly, however, NGFI-A over-expression resulted in significant retardation in NGF-induced neurite outgrowth. Similar suppressive effects were observed also on the v-K-ras-induced neurite outgrowth. These results raise the possibility that NGFI-A protein may play some negative role in NGF signaling.

Animals↗
PubMed2000

Role of TGF-beta in EGF-induced transformation of NRK cells is sustaining high-level EGF-signaling.

We have been isolating and analyzing NRK cell mutants, which fail to transform by epidermal growth factor (EGF) and transforming growth factor (TGF)-beta. One such mutant, R14, can respond to the growth inhibitory signal of TGF-beta to the same extent as parental NRK but fail to respond to the growth stimulatory signal of EGF. This mutant has a defect in EGF receptor (EGFR) expression. When R14 mutant expressed a high level of EGFR, however, EGF not only induced proliferation in this mutant but also induced transformation without the aid of TGF-beta. These findings suggest that the major role of TGF-beta in this transformation system should be to counteract the ligand-dependent down-regulation of EGFR, thereby sustaining high-level EGF-signaling.

Animals↗
PubMed2000

Ultrasonographic evaluation of the influence of different postures on diaphragmatic motion in mechanically ventilated patients.

We confirmed a diaphragmatic motion during mechanical ventilation in four patients with central nervous system damage. The right hemidiaphragm were visualized with 3.5 MHz ultrasound, and motion was measured using time-motion analysis in separate postures. The dome was most impaired during the right decubitus posture. The crural region was most improving during the left decubitus posture. The costal region was most impaired during the sitting posture. The motion of the dependent region was impaired.

Adolescent↗
PubMed2000

Neutrophil activation in immunoadsorption.

Immunoadsorption therapy (IAT) is used in the treatment of autoimmune diseases. Although IAT has been reported to modify humoral immunity by inducing chemokines and activating complements, much remains unknown about the biological effects of IAT on cellular components in peripheral blood. To define the influence of IAT on leukocytes, we determined leukocyte L-selectin (CD62L) and Mac-1 (CD11b) as parameters for activation of leukocytes in peripheral blood during IAT. Peripheral leukocyte L-selectin and Mac-1 were determined continuously by flow cytometry in 6 patients with neuroimmunological disorders in whom IAT was conducted using a Plasma Flow OP-05 (Asahi Medical Corp., Tokyo, Japan) as a plasma separator and Immusorba TR-350 (Asahi Medical Corp., Tokyo, Japan) as an adsorption column. Expression of neutrophils (PMN) L-selectin was decreased 30 min after starting IAT, with the decreases particularly marked at the end of IAT, while expression of mononuclear cells (MNC) L-selectin slightly increased during IAT. Expression of PMN Mac-1 was markedly increased at the end of IAT, whereas expression of MNC Mac-1 did not change during IAT. Leukocyte counts decreased 30 min after starting IAT, and then increased to the initial level or higher in parallel with L-selectin downregulation and Mac-1 upregulation on PMN. L-selectin downregulation and Mac-1 upregulation on PMN suggested that activation of PMN associated with changes in peripheral leukocyte counts occurred during IAT and might play some role in modulating the human circulating blood and immune systems.

Adolescent↗
PubMed2000

Herpes zoster infection complicated by motor paralysis.

We reviewed a total of 1,432 patients diagnosed with cutaneous herpes zoster at Hyogo College of Medicine Hospital between 1989 and 1997 for epidemiologic assessment and outcome in patients with zoster paralysis referred for rehabilitation. Of the 1,432 herpes zoster patients (624 males and 808 females, mean age 54.3 years), 12 were referred to our department of rehabilitation medicine for muscle weakness: one had myelitis, and eleven others had lower motor neuron damage. Except for one 43-year-old man with myelodysplastic syndrome, all the lower motor neuron deficit patients were over 60 years of age. Involved myotomes were more widespread than involved dermatomes in eight patients. Electromyography in four patients demonstrated denervation of involved muscles. Five patients experienced complete or near complete recovery from their muscle weakness. The muscle weakness related to herpes zoster was occasionally diagnosed by electromyography as motor neuron damage. Manifestations of motor neuron complications were not noticed but might in fact be more common than was the clinical muscle weakness.

Adolescent↗
PubMed2000

Identification of a series of transforming growth factor beta-responsive genes by retrovirus-mediated gene trap screening.

Transforming growth factor beta (TGF-beta) plays important roles in the regulation of proliferation, differentiation, apoptosis, and carcinogenesis. To identify genes responsible for maintaining the phenotype induced by TGF-beta, we performed a retrovirus-mediated gene trap screening designed to isolate TGF-beta-responsive genes in human lung carcinoma cell line A549. After screening 249 trap lines, 21 were found to express the reporter beta-galactosidase gene in a TGF-beta-responsive manner. Interestingly, in large proportions of these trap lines, the reporter gene was responsive also to phorbol ester and was suppressed by gamma interferon. Fragments of all these trapped genes were recovered by 5'- and 3'-rapid amplification of cDNA ends (RACE), and in 15 out of 21 cases (71%), the TGF-beta responsiveness of the endogenous genes was confirmed by RNA blot hybridization. In at least five cases, the TGF-beta-induced upregulation was found to be cycloheximide resistant, suggesting the roles of the genes in the TGF-beta-induced primary responses. Sequence analyses revealed that 43% (9 of 21) of the trapped genes were novel and that the remainder included genes previously reported to be upregulated by TGF-beta, such as epidermal growth factor receptor and beta1 integrin, documenting the validity of this approach. Other known genes include the ones encoding the proteins associated with cell proliferation (ribosomal proteins S15a, hNRP/NAP-1, and lipocortin II), focal adhesions (paxillin), and transcriptional regulation (thyroid hormone receptor activator molecule 1 [TRAM-1]).

Blotting, Northern↗