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Biomedical subjects

N Nakamura

Publications and source records attributed to N Nakamura.

At least 217 records · Page 12Linked to original sources
PubMed2000

Four new saponins from the root bark of Aralia elata.

Four new saponins, 3-O-[beta-D-glucopyranosyl(1-->3)-alpha-L-arabinopyranosyl]-16a lpha-hydroxyoleanolic acid 28-O-beta-D-glucopyranosyl ester (called aralia-saponin I), 3-O-[beta-D-glucopyranosyl(1-->3)-alpha-L-arabinopyranosyl]-16a lpha-hydroxyhederagenin 28-O-beta-D-glucopyranosyl ester (aralia-saponin II), 3-O-[beta-D-glucopyranosyl(1-->3)-beta-D-glucopyranosyl(1-->3)-alpha-L-+ ++arabinopyranosyl]-16alpha-hydroxyoleanolic acid 28-O-beta-D-glucopyranosyl ester (aralia-saponin III), 3-O-[beta-D-glucopyranosyl(1-->3)-beta-D-gucopyranosyl(1-->3)-beta -D-glucucopyranosyl]-16alpha-hydroxyoleanolic acid 28-O-beta-D-glucopyranosyl ester (aralia-saponin IV), were isolated from the root bark of Aralia elata (Miq.) Seem., together with nineteen known compounds including glycosides of (20S)-protopanaxadiol and (20S)-protopanaxatriol. Their structures were determined on the basis of chemical and spectroscopy methods.

Carbohydrate Conformation↗
PubMed2000

Overproduction of microbial transglutaminase in Escherichia coli, in vitro refolding, and characterization of the refolded form.

(MTG) The Streptoverticillium transglutaminase gene, synthesized previously for yeast expression, was modified and resynthesized for overexpression in E. coli. A high-level expression plasmid, pUCTRPMTG-02(+), was constructed. Furthermore, to eliminate the N-terminal methionine, pUCTRPMTGD2 was constructed. Cultivation of E. coli transformed with pUCTRPMTG02(+) or pUCTRPMTGD2 yielded a large amount of MTG (200-300 mg/liter) as insoluble inclusion bodies. The N-terminal amino acid residue of the expressed protein was methionine or serine (the second amino acid residue of the mature MTG sequence), respectively. Transformed E. coli cells were disrupted, and collected pellets of inclusion bodies were solubilized with 8 M urea. Rapid dilution treatment of solubilized MTG restored the enzymatic activity. Refolded MTG, purified by ion-exchange chromatography, which had an N-terminal methionine or serine residue, showed activity equivalent to that of native MTG. These results indicated that recombinant MTG could be produced efficiently in E. coli.

Amino Acid Sequence↗
PubMed2000

An encephalopathy with argyrophilic inclusions in a Holstein-Friesian cow.

The brain of a 6-year-old Holstein cow, which showed progressive neurologic symptoms during several months, was examined by histopathologic methods. Many round or oval-shaped cytoplasmic inclusions were observed, mainly in neurons of the temporal lobe and the hippocampus. Those inclusions were faintly eosinophilic with hematoxylin and eosin and positive with Bielschowsky's silver stain. Immunohistochemically, the inclusions were recognized by antiubiquitin and antiphosphorylated tau antibodies. Ultrastructurally, the inclusions were globular and well demarcated from the rest of the cytoplasm, lacked limiting membranes, and were mainly composed of straight fibrils about 15 nm in width. The structure of the inclusions was similar to that of Pick bodies in Pick's disease of humans. The pathogenesis of this bovine condition is not known.

Animals↗
PubMed2000

Soluble form of fas and fas ligand in BAL fluid from patients with pulmonary fibrosis and bronchiolitis obliterans organizing pneumonia.

STUDY OBJECTIVES: The Fas-Fas ligand (FasL) pathway is a representative system of apoptosis-signaling receptor molecules. We previously described that this pathway may play an important role in the pathogenesis of fibrosing lung diseases. In this study, we hypothesized that soluble form of Fas (sFas) and FasL (sFasL) may also be associated with this disorder. MEASUREMENTS AND RESULTS: We measured sFas and sFasL levels in BAL fluid (BALF) from patients with idiopathic pulmonary fibrosis (IPF), interstitial pneumonia associated with collagen vascular diseases (CVD-IP), and bronchiolitis obliterans organizing pneumonia (BOOP), using enzyme-linked immunosorbent assay. BALF from all patients was obtained before prednisolone therapy. sFasL levels were relatively increased in IPF patients (p = 0.084), and significantly increased in CVD-IP patients (p < 0.05) and BOOP patients (p < 0.05), compared with control subjects. BALF sFasL levels were elevated in the IPF or CVD-IP subgroups with an indication for prednisolone therapy, compared with those without an indication for therapy. The BALF sFasL level in IPF patients was correlated with the number of total cells and lymphocytes. The BALF sFasL level in BOOP patients was relatively or significantly correlated with the number of total cells or lymphocytes, respectively. The BALF sFas level was significantly increased in BOOP patients, but not in IPF or CVD-IP patients. CONCLUSIONS: We conclude that BALF sFasL levels may be associated with the accumulation of inflammatory cells and reflect the degree of lymphocyte alveolitis in IPF. The elevation of sFasL may be associated with the deterioration of IPF and CVD-IP. The elevation of the BALF sFas level may abrogate the cytotoxicity of FasL in BOOP patients, which may be associated with better prognosis of BOOP, compared with IPF or CVD-IP.

Aged↗
PubMed2000

HLA-associated cellular response to GAD in type 2 diabetes with antibodies to GAD.

Proliferative response of peripheral blood mononuclear cells (PBMC) to glutamic acid decarboxylase (GAD), which has been reported in patients with type 1 diabetes, was measured in type 2 diabetes, especially in patients with antibodies to GAD initially diagnosed as having type 2 diabetes (anti-GAD+ type 2 diabetes). We studied 12 patients with type 1 diabetes, 22 with anti-GAD+ type 2 diabetes, 31 with type 2 diabetes who were negative for anti-GAD (anti-GAD+ type 2 diabetes), and 30 healthy control subjects for cellular responses in vitro to GAD. The mean stimulation index (SI) in response to GAD was significantly higher in type 1 diabetes than in anti-GAD+ type 2 diabetes or healthy controls (1.47+/-0.35 vs. 1.11+/-0.35, P<0.05, and 1.06+/-0.07, P<0.05, respectively). The mean

Adult↗
PubMed2000

Induction of apoptosis in vivo and in vitro in hairy cell leukemia treated by deoxycoformycin.

The leukemic cells of a patient with hairy cell leukemia were treated in vitro with 2'-deoxycoformycin (dCF), an inhibitor of adenosine deaminase, and deoxyadenosine (dAdo). Following this treatment, viability of the hairy cells progressively declined, and DNA fragmentation was observed. When the patient was treated with 4 mg/m2 dCF intravenously, hairy cells in his peripheral blood rapidly decreased, and a large number of TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP- biotin nick end-labeling)-positive cells were detected in a bone marrow biopsy specimen. These findings indicate that dCF induced apoptosis of hairy cells both in vivo and in vitro. Furthermore, bcl-2 mRNA was down-regulated by dCF and dAdo in the hairy cells in vitro. Our results suggest the importance of bcl-2 mRNA regulation in apoptotic cell death mediated by dCF in hairy cell leukemia.

Aged↗
PubMed2000

Response to combined modality treatment in a five-year survivor of extensive small cell lung cancer with severe complications.

We present a rare case of a five-year survivor of small cell lung cancer with severe complications who responded to combined modality treatment. Prior to initial chemotherapy, he experienced severe complications including sepsis, pneumonia, ileus, and a performance status of 4. He was treated with an ileus tube and IVH, and was managed by mechanical ventilation for four days. After his general condition improved, he received combination chemotherapy of carboplatin, with the target area under the plasma concentration versus the time curve (AUC) of 5 mg x min/ml day 1, and etoposide (80 mg/m2) on days 1, 2, 3 for four courses, and complete remission (CR) was obtained. Six months later, systemic relapse occurred, but he achieved complete remission again with nine courses of CODE (cisplatin, vincristine, adriamycin, and etoposide) chemotherapy and sequential chest radiotherapy. Five years after the initial chemotherapy, the patient is alive and disease free.

Carcinoma, Small Cell↗
PubMed2000

Molecular analysis of multidrug resistance in feline lymphoma cells.

OBJECTIVE: To evaluate the mechanism of multidrug resistance in feline lymphoma cell lines. SAMPLE POPULATION: A feline lymphoma cell line (FT-1) and its adriamycin (ADM)-resistant subline (FT-1/ADM). PROCEDURES: The FT-1 cell line was cultivated in the presence of a gradually increasing concentration of ADM to generate its ADM-resistant subline (FT-1/ADM). Susceptibility of cells from the parental FT-1 cell line and the FT-1/ADM subline to antineoplastic drugs was determined. From the complementary DNA (cDNA) template of FT-1/ADM cells, feline MDR1 cDNA was amplified by use of polymerase chain reaction (PCR) and sequenced. Reverse transcription (RT)-PCR and Western blot analyses were performed to assess expression of the MDR1 gene and P-glycoprotein (P-gp) in FT-1/ADM cells, compared with that in FT-1 cells. RESULTS: A drug sensitivity assay revealed that FT-1/ADM cells were much more resistant to ADM and vincristine than the parental FT-1 cells. The feline MDR7 cDNA amplified by use of PCR was 3,489 base pairs long, corresponding to approximately 90% of the whole open reading frame of human MDR1 cDNA; its amino acid sequence was 91.5, 87.0, and 79.4% identical to that of human MDR1, mouse mdr1a, and mdr1b cDNA, respectively. By RT-PCR analysis, expression of MDR1 messenger RNA was clearly detected in FT-1/ADM cells but not in the parental FT-1 cells. Western blot analysis also revealed the expression of P-gp encoded by the MDR1 gene in FT-1/ADM cells but not in FT-1 cells. CONCLUSIONS: The basic structure of the feline MDR1 gene was essentially the same as that of multidrug-resistance genes of other species. Expression of P-gp appeared to be one of the mechanisms responsible for the development of multidrug resistance in feline lymphoma cell lines in vitro.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2000

Clinical evaluation of a radioimmunoprecipitation assay for IA-2 antibody and comparison of GAD antibody in type 1 diabetes mellitus.

We evaluated a insulinoma-associated protein (IA-2) antibody assay kit using 125I-labelled recombinant IA-2. IA-2 antibodies were present in patients with early-onset type 1 diabetes mellitus (DM) at frequencies of 74%, 67%, 57%, and 50% for respective periods <1 year, 1 < or =years<2, 2< or =years<3, and 3< or =years<4 after onset. IA-2 antibody frequency was low throughout the DM course as compared with glutamic acid decarboxylase (GAD) antibody frequency. No one had IA-2 antibody, but 29% still had positive GAD antibody titers after 11 years. Of the patients with 0<years<7 duration, 42% had IA-2 Ab+/GAD Ab+, 9% IA-2 Ab+/GAD Ab-, and 24% IA-2 Ab-/GAD Ab+. Prevalence of IA-2 and GAD antibody in 1243 patients with type 2 DM were 1.5% and 3.1%, respectively, and 1.1% had both. This new IA-2 antibody kit is easy to use and provides a specific, sensitive method for making routine assays. Furthermore, the combined analysis of GAD antibody provides high detection of type 1 DM.

Adolescent↗
PubMed2000

[A study on stress processes for college students during semester-end examinations].

The present study examined individual differences in psychological and physiological stress responses to the same stressor. In Study 1, psychological stress responses were assessed at three time periods: four weeks before, the day before, and the middle day of the semester-end examination period (N = 69). Both stress coping and MPI were assessed once during the study. In Study 2, 15 subjects were exposed to the same psychological stressor in an experiment to measure heart rate. The stressors were memorization of material relevant to the examination (Test 1), and mental calculation irrelevant to the examination (Test 2). Subjects were divided into 2 groups on the basis of their Study 1 psychological stress response scores: the low stress group (LS, N = 10) and the high stress group (HS, N = 5). The results of Study 1 and Test 1 of Study 2 suggested that there were significant differences between LS and HS in stress responses. These findings were discussed in light of cognitive appraisal and controllability of time. Further studies are needed to clarify the aspect of time span in cognitive appraisal.

Adolescent↗
PubMed2000

[Renal cell carcinoma in a horseshoe kidney with abdominal aortic aneurysm: a case report].

We herein report a case of renal cell carcinoma in a horseshoe kidney with an abdominal aortic aneurysm in a 69-year-old man. Radiological examinations showed a left renal tumor, horseshoe kidney and abdominal aortic aneurysm. We performed a left radical nephrectomy with the division of the isthmus and artificial graft through an abdominal transperitoneal approach. Histological findings revealed clear cell type renal cell carcinoma without invasion of the capsule or renal pelvis. Only 31 cases of renal cell carcinoma in a horseshoe kidney have been reported in Japan, and our case is the 32nd. No case with abdominal aortic aneurysm has been reported previously. We assume that abdominal aortic aneurysm was associated with renal cell carcinoma by chance in the horseshoe kidney in this case. The arterial and venous supplies vary from case to case. We emphasize that arteriography and venography are very important preoperative procedures.

Aged↗
PubMed2000

[Feasibility study of CdTe Semiconductor detector for gamma camera--evaluation of planar images].

To evaluate the performance of a semiconductor detector for use in a gammacamera system, we assembled a detector with a small field of view--1 inch x 1 inch and 1 inch x 2 inch--made from CdTe (Cadmium telluride). We then compared the planar images and energy resolution of the resulting detectors against those of a conventional gammacamera. Pixel pitch of the detector was 1.6 mm x 1.6 mm, and was manufactured by Acrorad Corporation. Average FWHM of the energy spectrum for the semiconductor detector was 5.11% (SD: 0.80%, Best: 3.26%, Worst: 6.68%). The planar images obtained were of a letter phantom made from pieces of lead and of an IMP brain phantom. Since the field of view of the semiconductor detector was small, the image of the IMP brain phantom was acquired by moving the semiconductor over the collimated detector module until the area of the entire phantom was covered. The images from the semiconductor assembly were compared with those from a conventional gammacamera using the same conditions, and it was found that visual image quality was superior to those of the conventional camera system.

Brain↗
PubMed2000

[Anesthetic management of a patient with latex allergy diagnosed preoperatively].

Since the first report in 1979, the number of patients with latex allergy has progressively increased. We experienced an anesthetic management of a 3 year-old child who underwent the repair of anal atresia. The first operation was performed in newborn period. After the surgery, the patient developed skin rash and the loss of consciousness every time anal irrigation was made with latex-containing catheter. Latex-allergy was diagnosed at the age of 3 years, with the positive skin test by latex extract. It took enormous time and efforts to find out the possibility of latex-contamination in a wide variety of medical equipments and supplies to prevent allergic reaction during perioperative period. In this patient, perioperative cause was uneventful. It is suggested that preoperative preparation is essential and caution should be also paid to prevent allergic reaction in daily life.

Anesthesia, General↗
PubMed2000

[Feasibility study of SPECT quantification using CdTe semiconductor detector].

Quantification of SPECT using CdTe semiconductors as a detector head in nuclear medicine equipment was investigated. A prototype of semiconductor detectors with an effective field-of-view as small as 2.54 cm x 5.08 cm was constructed, and a cylindrical phantom containing four spherical phantoms with capacities 71, 56, 42, and 15 ml, was used. Water was placed in three of these spherical phantoms (71, 56, and 42 ml), and 8.362 MBq of 99mTc was poured into the remaining 15 ml phantom. In the outer cylindrical phantom, 925 MBq (6200 ml) of 99mTc was placed. A Toshiba LEHR (Low Energy High Resolution) collimator was attached to the semiconductor detectors, and SPECT acquisition with a rotation radius 132 mm was performed. It was found that in the data thus acquired using the semiconductor detector, the amount of scattered gamma-rays decreased by 33% as compared to data acquired using NaI(Tl) scintillators under the same condition. Moreover, when attenuation correction was applied to SPECT data from the CdTe semiconductor detector, the measurement accuracy of radioactivity improved by 16% as compared to SPECT data from NaI(Tl) scintillators with the same acquisition and post-correction conditions. Finally, the CdTe detector data with only attenuation correction was found to have almost the same grade of accuracy as NaI scintillator data with both attenuation and TEW scatter corrections.

Feasibility Studies↗
PubMed2000

[Velopharyngeal palsy: a case report].

Here we present a case of velopharyngeal palsy. An 18-year-old man had hyperemia in his left conjunctivum. One or two weeks later he experienced nasal speech and difficulty in swallowing. General physical examination was normal. The only abnormal neurological finding was palato-pharyngeal paralysis on the right side. MRI of the head and neck had no abnormalities. Acute and convalescent sera showed no rise in viral antibody titer. CSF examination was normal except for the increased IgG% and IgG.albumin index. Treatment consisted of glycerol and steroid, and his symptom improved within two or three weeks. We think immunological mechanism is important because CSF examination showed increased IgG% and IgG.albumin index in our case. Acquired and isolated velopharyngeal palsy is uncommon. Only 26 cases have been reported so far. This is the first case in Japan. The disease has some characteristics. This occurs in childhood and adolescence. Onset is sudden, consisting in rhinolalia and dysphagia. On examination there is asymmetry of the pharynx and deviation of the uvula contralateral to the affected side. There is no other neurological abnormalities. Complete spontaneous recovery is usual. In some cases viral infection is the cause, but in most cases the cause is unknown. In contrast, the disease with both acquired velopharyngeal palsy and vocal cord palsy is relatively common. This occurs in the middle aged or elderly people. In addition to dysphagia and hoarse voice, this disease often accompanies neurological abnormalities such as other cranial nerve palsy and meningitis, fever, and pain in the pharyngeal region. In most cases viral infection is the cause.

Adolescent↗