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Biomedical subjects

K Nakabayashi

Publications and source records attributed to K Nakabayashi.

At least 19 recordsLinked to original sources
PubMed2003

The imprinted region on human chromosome 7q32 extends to the carboxypeptidase A gene cluster: an imprinted candidate for Silver-Russell syndrome.

Imprinted gene(s) on human chromosome 7q32-qter have been postulated to be involved in intrauterine growth restriction associated with Silver-Russell syndrome (SRS) as 7-10% of patients have mUPD(7). Three imprinted genes, MEST, MESTIT1, and COPG2IT1 on chromosome 7q32, are unlikely to cause SRS since epigenetic and sequence mutation analyses have not shown any changes. One hundred kilobases proximal to MEST lies a group of four carboxypeptidase A (CPA) genes. Since most imprinted genes are found in clusters, this study focuses on analysing these CPAs for imprinting effects based on their proximity to an established imprinted domain. Firstly, a replication timing study across 7q32 showed that an extensive genomic region including the CPAs, MEST, MESTIT1, and COPG2IT1 replicates asynchronously. Subsequently, SNP analysis by sequencing RT-PCR products of CPA1, CPA2, CPA4, and CPA5 indicated preferential expression of CPA4. Pyrosequencing was used as a quantitative approach, which confirmed predominantly preferential expression of the maternal allele and biallelic expression in brain. CPA5 expression levels were too low to allow reliable evaluation of allelic expression, while CPA1 and CPA2 both showed biallelic expression. CPA4 was the only gene from this family in which an imprinting effect was shown despite the location of this family of genes next to an imprinted cluster. As CPA4 has a potential role in cell proliferation and differentiation, two preferentially expressed copies in mUPD patients with SRS syndrome would result in excess expression and could alter the growth profiles of these subjects and give rise to intrauterine growth restriction.

Alternative Splicing↗
PubMed2003

Autonomic nervous activity and stress hormones induced by hyperbaric saturation diving.

This study describes the changes in autonomic nervous activity and stress hormones during a hyperbaric saturation dive up to 4.1 MPa in six subjects. Their autonomic nervous activity was assessed by a power spectrum analysis of heart rate variability (HRV). The levels of plasma epinephrine (E) and norepinephrine (NE), and those of salivary chromogranin A and cortisol, were compared with the pre-dive control levels. Restrained activity of the cardiac vagal nerve was recognized in the early post-dive period by a decrease in high frequency power and by the standard deviation of the HRV. By contrast, enhanced activity of sympathetic nerve was recognized in the early post-dive period by an elevated plasma E, and also in the late 3.1 MPa, 4.1 MPa, and post-dive periods by elevated plasma NE. The levels of plasma E and NE were the most sensitive indicators of sympathetic nervous activity. A joint utilization of HRV parameters with stress hormones may be an effective means of estimating the adaptive responses between hyperbaric and normobaric environments.

Adult↗
PubMed2002

Nephrotic IgA nephropathy associated with disseminated tuberculosis.

A 35-year-old woman who had been suffering from ascites more than 3 months after the delivery of her first baby, developed generalized edema, pyrexia, pleural effusion, and right lower abdominal pain. The laboratory data revealed 5.6 g of 24-hour urinary protein, increased ESR and CRP, a positive skin test for tuberculosis, and a positive culture fortuberculous bacilli from pleural effusion. A renal biopsy showed mild proliferative glomerulonephritis, IgA and C3 depositions along the capillary loop, in the mesangium and also in the focal tubular basement membrane, and scattered membranolysis of the glomerular basement membrane in addition to paramesangial and intramembranous electron-dense deposits. A positive culture of tuberculous bacilli led anti-tuberculous drugs resulted in the complete disappearance of proteinuria, inflammation, and various organ manifestations. As far as we know, the association of tuberculosis with glomerulonephritis is an uncommon occurrence. In addition to describing this case, we also discussed the role of tuberculosis in the pathogenesis of glomerulonephritis, and reviewed the pertinent literature.

Adult↗
PubMed2001

The human contactin-associated protein-like 2 gene (CNTNAP2) spans over 2 Mb of DNA at chromosome 7q35.

Contactin-associated genes are members of the neurexin superfamily that encode a group of transmembrane proteins that mediate cell-cell interactions in the nervous system. To study the human contactin-associated protein-like 2 gene (CNTNAP2), we have determined its complete DNA sequence and its genomic organization to comprise 25 exons spanning greater than 2.0 Mb of DNA at 7q35. Our results indicate that CNTNAP2 encompasses almost 1.5% of chromosome 7 and is one of the largest genes in the human genome.

Base Sequence↗
PubMed2001

Identification of the human cortactin-binding protein-2 gene from the autism candidate region at 7q31.

Human chromosome 7q31 contains putative susceptibility loci for autism (AUTS1) and speech and language disorder (SPCH1). We report here the identification and characterization of a novel gene encoding cortactin-binding protein-2 (CORTBP2), which is located 45 kb telomeric to the cystic fibrosis transmembrane conductance regulator gene (CFTR) at 7q31.3. The full-length (5975-bp) gene was isolated and found to be composed of 23 exons encompassing 170 kb of DNA. In addition to being a positional candidate for AUTS1, CORTBP2 was expressed at highest levels in the brain, as shown by northern blot analysis. Subsequent mutation analysis of CORTBP2 in 90 autistic patients identified two polymorphisms, including a leucine to valine change caused by a T to G substitution in exon 15. However, comparison of allele frequencies between autistic and control populations (n=96) showed no significant difference, suggesting that this variant is not a susceptibility factor for autism.

Amino Acid Sequence↗
PubMed2001

Perioperative intravenous flurbiprofen reduces postoperative pain after abdominal hysterectomy.

PURPOSE: To assess whether perioperative intravenous administration of flurbiprofen, a non-steroidal anti-inflammatory drug, reduced postoperative pain after abdominal hysterectomy. METHODS: Forty-five patients undergoing abdominal hysterectomy were randomly assigned to one of three groups of equal size. A control group (CONT) received a placebo 30 min before and at the end of surgery. The other two groups, PRE and POST, received 1 mg x kg(-1) flurbiprofen iv 30 min before and at the end of surgery, respectively. All patients received identical general and epidural anesthesia. Postoperatively, 50 mg diclofenac pr was given for pain relief on patient demand. One of the authors assessed pain using a 10 cm visual analog scale at rest and during coughing at the first request for diclofenac, and at 15, 24, 48, and 72 hr after surgery. The number of times diclofenac was required during the first 24 hr after surgery was also recorded. RESULTS: The number of diclofenac requests in the PRE (1.8 +/- 0.4) and POST groups (2.0 +/- 0.4) were less than in the CONT group (3.0 +/- 0.4). The PRE group showed lower visual analog scale at rest at 15 and 24 hr and on coughing at 24, 48, and 72 hr after surgery than the CONT and POST groups. CONCLUSION: Intravenous 1 mg x kg(-1) flurbiprofen administered during anesthesia reduces postoperative rescue analgesic requirement after abdominal hysterectomy. Moreover, flurbiprofen is more effective when given before than after surgery.

Adult↗
PubMed2001

Mutation analysis of the origin recognition complex subunit 5 (ORC5L) gene in adult patients with myeloid leukemias exhibiting deletions of chromosome band 7q22.

The ORC5L gene encoding a subunit of the human origin recognition complex (ORC) maps to chromosome band 7q22, a region frequently deleted in adult acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). Because of its localization within a region that is commonly deleted in patients with myeloid malignancies and because of the implication of its protein product in cell cycle control (DNA replication) and regulation of gene expression (transcriptional silencing), ORC5L appeared to be a candidate tumor suppressor gene for myeloid disorders associated with 7q22 deletions. Polymerase chain reaction amplification and sequencing analysis of the coding region of the remaining ORC5L allele has not revealed any mutations in nine patients with AML or MDS exhibiting 7q22 deletions. Allelic expression analysis indicates that ORC5L is not imprinted. These data suggest that ORC5L does not function as a tumor suppressor in patients with myeloid neoplasms.

Acute Disease↗
PubMed2001

Analgesic effect of epidural neostigmine after abdominal hysterectomy.

STUDY OBJECTIVE: To evaluate the effects of epidurally administered neostigmine on pain after abdominal hysterectomy. DESIGN: Prospective, randomized, double-blind study. SETTING: Teaching hospital. PATIENTS: 45 ASA physical status I adult patients scheduled for abdominal hysterectomy. INTERVENTIONS: All patients received identical general and epidural anesthesia. At the end of the surgery, they received epidural bupivacaine (10 mg) with either saline (control group, n = 15), 5 micro g/kg (5-micro g group, n = 15), or 10 micro g/kg neostigmine (10-micro g group, n = 15). Postoperatively, 50 mg diclofenac suppository was given for pain relief on patient demand. MEASUREMENTS AND MAIN RESULTS: The time to first diclofenac administration and the number of times diclofenac was required during the first 24 postoperative hours were recorded. Pain was assessed using a 10-cm visual analog pain scale (VAS) at rest at the first diclofenac request, and at 15 and 24 hours after surgery. The time to first diclofenac administration was significantly longer (p < 0.05) in the 10-micro g group (223 +/- 15 min) than in the control (78 +/- 17 min) or 5-micro g groups (88 +/- 18 min). However, epidural neostigmine at both doses did not reduce the number of postoperative diclofenac administrations. There were no differences in VAS among the three groups. CONCLUSIONS: Epidural neostigmine of 10 micro g/kg in bupivacaine provides a longer duration of analgesia than does bupivacaine alone or with 5 micro g/kg of neostigmine after abdominal hysterectomy.

Analgesia, Epidural↗
PubMed2001

An Arabidopsis sigma factor (SIG2)-dependent expression of plastid-encoded tRNAs in chloroplasts.

A eubacteria-type RNA polymerase (PEP) plays crucial roles for chloroplast development in higher plants. The core subunits are encoded on plastid DNA (rpo genes) while the regulatory sigma factors are encoded on the nuclear DNA (SIG genes). However, the definite gene specificity of each sigma factor is unknown. We recently identified an Arabidopsis recessive pale-green mutant abc1 in which T-DNA is inserted in SIG2 (sigB). In this mutant, almost normal etioplasts were developed under dark conditions while the small chloroplasts with poor thylakoid membranes and stacked lamellar were developed under light conditions. The sig2-1 mutant was deficient in accumulating enough photosynthetic and photosynthesis-related proteins as well as chlorophyll. However, mRNAs of their structural genes were not significantly reduced. Further analyses revealed that several plastid-encoded tRNAs including trnE-UUC that has dual function for protein and ALA biosyntheses were drastically reduced in the sig2-1 mutant. In contrast, nucleus-encoded T7 phage-type RNA polymerase (NEP)-dependent gene transcripts were steadily accumulated in the mutant. These results indicate that progress of chloroplast development requires SIG2-dependent expression of plastid genes, particularly some of the tRNA genes.

Arabidopsis↗
PubMed2001

Chloroplast and mitochondrial proteases in Arabidopsis. A proposed nomenclature.

The identity and scope of chloroplast and mitochondrial proteases in higher plants has only started to become apparent in recent years. Biochemical and molecular studies suggested the existence of Clp, FtsH, and DegP proteases in chloroplasts, and a Lon protease in mitochondria, although currently the full extent of their role in organellar biogenesis and function remains poorly understood. Rapidly accumulating DNA sequence data, especially from Arabidopsis, has revealed that these proteolytic enzymes are found in plant cells in multiple isomeric forms. As a consequence, a systematic approach was taken to catalog all these isomers, to predict their intracellular location and putative processing sites, and to propose a standard nomenclature to avoid confusion and facilitate scientific communication. For the Clp protease most of the ClpP isomers are found in chloroplasts, whereas one is mitochondrial. Of the ATPase subunits, the one ClpD and two ClpC isomers are located in chloroplasts, whereas both ClpX isomers are present in mitochondria. Isomers of the Lon protease are predicted in both compartments, as are the different forms of FtsH protease. DegP, the least characterized protease in plant cells, has the most number of isomers and they are predicted to localize in several cell compartments. These predictions, along with the proposed nomenclature, will serve as a framework for future studies of all four families of proteases and their individual isomers.

Arabidopsis↗
PubMed2001

Decrease in platelet count during saturation diving.

BACKGROUND: The change in platelet count (PC) occurring during saturation diving has rarely been discussed. We set out to clarify the details of this change in PC, and its relationship with: i) the storage depth and duration of the saturation dive, and ii) the presence of decompression bubbles. METHODS: In a total of 42 divers, the change in PC was measured in 8 simulated saturation dives (1992-1998) using a Deep Diving Simulator with decompression procedures based on the modified DUKE-GKSS schedule. Blood samples were taken before the dive, at the bottom (twice), during decompression, on surfacing, and about 1 wk after surfacing. Decompression bubbles were examined by ultrasonic M-mode echocardiography. RESULTS: PC (mean +/- SD x 10(4) x microl(-1)) was 23.9 +/- 4.85, 24.9 +/- 4.9, 24.2 +/- 4.8, 19.2 +/- 4.4*, 20.1 +/- 4.5*, 25.0 +/- 5.1 on the occasions listed above (*= p < 0.05 vs. pre-dive). The PC showed no correlation with either storage depth or dive duration. Decompression bubbles were detected during decompression in only 2 divers (4.8%), and the bubbles disappeared immediately after surfacing. In these 2 divers the decreases in PC values from baseline to the middle of decompression and on surfacing were 2 and 2.7 x 10(4) x microl(-1), and 3.4 and 1.7 x 10(4) x microl(-1) respectively. No diver complained of decompression sickness. CONCLUSION: The magnitude of the decrease in PC (< 5 x 10(4) x microl(-1)) and the time to recover to the pre-dive value (< 1 wk) suggests that changes in PC during saturation diving should not cause any clinical problems. The mechanisms underlying the decrease in PC remain unclear.

Adult↗
PubMed2001

[Anti-neutrophil cytoplasmic antibody--enzyme immunosorbent assay].

Enzyme immunosorbent assay(ELISA) is a very useful method to determine anti-neutrophil cytoplasmic antibody(ANCA), which is an important serological marker for pauci-immune type systemic vasculitis and necrotizing glomerulonephritis. A test was made using new myeloperoxidase(MPO)-ANCA ELISA(A), employing native MPO purified from the neutrophils in sputum as a liquid phase antigen. Furthermore, the ELISA(B) using MPO, composed of one large and one small subunit, was tested as solid phase antigen. The intra-assay and inter-assay CV of the new ELISA(A) were 3.92 to 6.75% and 5.0 to 8.1%, respectively. Close ANCA titer correlation was shown between the new MPO-ANCA ELISA(A) and the conventional ELISA, using native MPO from peripheral neutrophils as solid phase antigen. ELISA(B) showed low MPO-ANCA detection sensitivity compared to ELISA(A) and to conventional ELISA. ELISA using native MPO from neutrophils in sputum as liquid phase antigen is useful for MPO-ANCA detection. There might be an ANCA which recognizes only native form MPO.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed2001

[A case of IgA nephropathy associated with silicosis].

A 51-year-old male who had been working as a building wrecker for 20 years, was admitted to our hospital in June 1999 for proteinuria and hematuria examination. He started this work in 1978. Twelve years later, severe coughing and bloody sputum began and he was diagnosed as having silicosis in 1995. Urinalysis on admission showed proteinuria(294 mg/day), microhematuria(20-30/hpf), RBC cast and granular cast. High serum IgA(770 mg/dl) and high serum interleukin-6(IL-6) (3,280 pg/dl) were found. A renal biopsy showed mild mesangial matrix expansion and mesangial cell proliferation with IgA deposition, which was diagnosed as IgA nephropathy. Chest X-rays showed multiple small nodular lesions on both lung fields indicating silicosis. In Nov. 1999, he resigned from his job as a building wrecker because of increasing coughing and bloody sputum associated with body weight loss. Within 3 months after stopping this work, coughing and bloody sputum disappeared and the abnormal urinalysis findings returned to normal. Serum IgA and serum IL-6 data improved to 462 mg/dl and 2.5 pg/dl, respectively. It is suggested that silicon exposure might be related to the pathogenesis of IgA nephropathy in this patient.

Biomarkers↗
PubMed2001

[The effect of lidocaine on the bispectral index during anesthesia induction with propofol].

We investigated the effect of premixing lidocaine with propofol on a bispectral index (BIS) during propofol infusion. We studied 40 adult patients given mixture of 1% propofol 20 ml with 2 ml of normal saline (control group) or 2% lidocaine (lidocaine group) infused at 2 ml.kg-1.hr-1 for 10 minutes. Heart rate, mean arterial pressure, and BIS were measured every minute. The addition of lidocaine to propofol reduced the incidence of injection pain from 85% to 10% but did not change the induction time. Propofol significantly decreased mean arterial pressure and BIS but there was no difference between the groups. In conclusion, premixing lidocaine with propofol reduces injection pain without affecting the hypnotic effect.

Adult↗
PubMed2001

[Efficacy of bispectral index for anesthetic management of combined off-pump coronary artery bypass grafting and abdominal aortic aneurysm replacement].

A 57-year-old female patient underwent combined off-pump coronary artery bypass grafting and abdominal aortic aneurysm replacement. Anesthesia was maintained with propofol, fentanyl, and thoracic epidural anesthesia. Propofol doses were adjusted to maintain bispectral index (BIS) between 40-60. Despite the remarkable hemodynamic changes, BIS remained stable at about 50 during the surgery. The average dose of propofol was 3.3 mg.kg-1.hr-1. The patient awoke an hour after the surgery and was extubated 1.5 hours thereafter. This case report suggests that BIS is a useful index to determine the depth of anesthesia during surgeries which induce marked hemodynamic changes.

Anesthesia↗
PubMed2000

Activation of the luteinizing hormone receptor following substitution of Ser-277 with selective hydrophobic residues in the ectodomain hinge region.

Glycoprotein hormone receptors are G protein-coupled receptors with ligand-binding ectodomains consisting of leucine-rich repeats. The ectodomain is connected by a conserved cysteine-rich hinge region to the seven transmembrane (TM) region. Gain-of-function mutants of luteinizing hormone (LH) and thyroid-stimulating hormone receptors found in patients allowed identification of residues important for receptor activation. Based on constitutively active mutations at Ser-281 in the hinge region of the thyroid-stimulating hormone receptor, we mutated the conserved serine in the LH (S277I) and follicle-stimulating hormone receptors (S273I) and observed increased basal cAMP production and ligand affinity by mutant receptors. For the LH receptor, conversion of Ser-277 to all natural amino acids led to varying degrees of receptor activation. Hydropathy index analysis indicated that substitution of neutral serine with selective nonpolar hydrophobic residues (Leu>Val>Met>Ile) confers constitutive receptor activation whereas serine deletion or substitution with charged Arg, Lys, or Asp led to defective receptor expression. Furthermore, mutation of the angular proline near Ser-273 to flexible Gly also led to receptor activation. The findings suggest the ectodomain of glycoprotein hormone receptors constrain the TM region. Point mutations in the hinge region of these proteins, or ligand binding to these receptors, could cause conformational changes in the TM region that result in G(s) activation.

Amino Acid Sequence↗
PubMed2000

Aortitis syndrome associated with positive perinuclear antineutrophil cytoplasmic antibody: report of three cases.

We recently experienced three cases of aortitis syndrome that were associated with perinuclear antineutrophil cytoplasmic antibody (ANCA). In the three cases, roentgenographic examination revealed the typical appearance of stenosis or occlusive subclavian arteries. In addition, two cases showed a thickened thoracic aorta wall and the remaining case had irregular stenosis of both common iliac arteries. All three cases had persistently increased ESR and CRP over the years. These findings suggested the diagnosis of aortitis syndrome. ANCA tests were performed because of rapidly progressive glomerulonephritis symptoms in two patients and marked excretion of beta(2)-microglobulin in urine in one patient. The test showed P-ANCA in all three patients, with two patients identified as anti-MPO antibody and the third patient as non-MPO antibody. The implication of ANCA in the pathogenesis of aortitis syndrome is presumed to be: ANCA, which plays an important role in the pathogenesis of small vessel vasculitis, induces vasculitis of the vasa vasorum in the aorta or main branches (or both) and this pathologic process results in the pathogenesis of aortitis syndrome.

Aged↗