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Biomedical subjects

N Ichikawa

Publications and source records attributed to N Ichikawa.

At least 91 records · Page 5Linked to original sources
PubMed1996

Titration of human cytomegalovirus (HCMV) DNA in urine by combined use of PCR and microplate hybridization in a renal transplant patient with HCMV pneumonitis.

We titrated human cytomegalovirus (HCMV) DNA in urine specimens obtained from 14 healthy individuals and a renal transplant patient with HCMV pneumonitis by modifying the method for titration of varicella-zoster virus DNA previously described (1,2). Of 14 HCMV seropositive healthy individuals, 13 had HCMV DNA under the detection limit of 10(2.0) copies/ml, whereas one person had 10(2.0) copies/ml. The viral DNA in urine samples was at a low level in healthy individuals with latent infection. In a case with HCMV pneumonitis after renal transplantation, the amount of HCMV DNA in urine gradually increased from the level under 10(2.0) copies/ml and reached a peak of 10(4.7) copies/ml one month prior to the manifestation of pneumonitis. It, thereafter, decreased with the course of clinical remission, and finally settled at under 10(2.0) copies/ml. Serial titrations of HCMV DNA in urine specimens proved to be useful in identifying recipients at risk of developing active HCMV infection after renal transplantation and as a guide for treatment of patients.

Cytomegalovirus↗
PubMed1996

Regulation of serum thrombopoietin levels by platelets and megakaryocytes in patients with aplastic anaemia and idiopathic thrombocytopenic purpura.

To clarify the regulatory mechanism of thrombopoietin (TPO, c-Mpl ligand) in chronic thrombocytopenic conditions, we determined TPO levels in the sera of patients with aplastic anaemia (AA; n = 26) and idiopathic thrombocytopenic purpura (ITP; n = 32) by an enzyme-linked immunosorbent assay. Despite a similarity in platelet counts, serum TPO levels in the AA group were markedly higher than those in the ITP group: 20.41 +/- 9.71 f mol/ml (mean +/- SD) and 1.66 +/- 0.55 f mol/ml, respectively, both of which were significantly elevated compared to normal subjects (n = 41; 1.22 +/- 0.37). In both groups, serum TPO level showed an inverse correlation with the platelet count. We determined the megakaryocyte volume using bone marrow clot section and found that it was markedly small in the AA group; while in the ITP group it was augmented with a correlation to serum TPO level. Our findings suggest that TPO levels may be regulated not only by platelets but also megakaryocytes in AA and ITP.

Adolescent↗
PubMed1996

Serum thrombopoietin (c-Mpl ligand) levels in patients with liver cirrhosis.

To clarify the role of c-Mpl ligand (thrombopoietin: TPO) in liver cirrhosis (LC), we examined serum TPO levels (sTPO) in patients with LC (N = 44), chronic hepatitis (CH; N = 13) and healthy controls (N = 41) by an enzyme-linked immunosorbent assay. Although platelet counts of all LC patients (89 +/- 59 x 10(9)/l; mean +/- SD) were lower than those of controls and CH patients, sTPO levels in LC patients (1.23 +/- 0.51 fmol/ml) were the same as those in controls (1.22 +/- 0.37) and CH patients (1.18 +/- 0.36). Platelet counts were significantly higher in splenectomized patients than in unsplenectomized patients, but the sTPO level did not differ between these two groups. In LC patients, the sTPO level was not correlated with the platelet count, but was correlated with prothrombin time, activated partial thromboplastin time, and total bilirubin, indicating that production of TPO in the liver decreases slightly with the development of liver dysfunction. Our findings suggest that production of TPO is maintained in LC patients and their thrombocytopenia is not due to a defect in platelet production.

Case-Control Studies↗
PubMed1995

Two-dimensional electrophoresis southern transfer method for detecting human genome variability using a LINE-1 sequence probe.

A "high-resolution, two-dimensional Southern transfer" method has been developed and was used to examine the distribution of a class of interspersed repeated sequences in human genomes. This method consists of two separate restriction enzyme digestions, including an in situ digestion, and two-dimensional electrophoresis using a large-sized agarose gel. The first 163-base-pair region of the human LINE-1 full-length sequence was used to probe human genomic DNA from placental tissue samples. About 900 LINE-1 signals were resolved from each DNA sample within a 2-D plane. The bulk of the fragments were between 0.5 to 23 kilobases in length. At a minimum 15 variant signals were detected between DNA samples from male and female individuals and at a minimum 16 variant signals were detected between two different female samples. This approach can potentially be used to perform high-resolution human genome fingerprinting analyses.

Base Sequence↗
PubMed1995

Genomic organization of 251 kDa acetyl-CoA carboxylase genes in Arabidopsis: tandem gene duplication has made two differentially expressed isozymes.

Acetyl-CoA carboxylase (ACCase) catalyzes the carboxylation of acetyl-CoA, forming malonyl-CoA a key intermediate in the biosynthesis of fatty acids and a variety of secondary metabolites. Based upon amino acid sequences conserved among rat, chicken, and E. coli ACCases, PCR-primers were used to amplify a genomic fragment which codes for an ACCase of Arabidopsis. The resulting fragment was used for isolation of genomic and cDNA clones. We have determined the complete cDNA sequence coding for an Arabidopsis ACCase consists of 2,254 amino acids with the molecular mass of 251 kDa. This enzyme contains no recognizable plastid transit-peptide sequence. Therefore, this ACCase is presumably the cytosolic isozyme. Southern analysis indicates that there are two ACCase genes in the Arabidopsis genome. Surprisingly, the results of RFLP analysis and physical mapping of the isolated genomic clones demonstrate that these two genes, acc1 and acc2, are contiguously located within a 25-kbp genomic region near the middle of chromosome 1. Both genes are transcriptionally active, as transcripts from each gene were detected by reverse transcription-PCR analysis using gene-specific primers. The acc1 and acc2 transcripts accumulate in leaves and seedlings but only the acc1 transcript accumulates in developing siliques, unexpectedly. The differences in the expression patterns may be indicative of the differential role of the two genes.

Acetyl-CoA Carboxylase↗
PubMed1995

Hepatic resection under in situ hemihepatic hypothermic perfusion with hepatoprotective agents.

Hepatectomy was performed under in situ right lobar hypothermic perfusion combined with hepatoprotective agents in six patients who had hepatocellular carcinoma and coexisting liver disease. Following occlusion of the right hepatic vein and the right portal pedicle, in situ cold perfusion was initiated using chilled Ringer's lactate infused through a cannula placed in the right main portal vein. The right superior segments were resected in a bloodless field. The liver was cooled to 22-26 degrees C for 40 to 80 minutes with no significant changes in systemic hemodynamics or body temperature. Postoperative liver functions showed no marked derangement; the mean peak GPT was 221 U and the mean peak total bilirubin 2.3 mg d/l. Local cooling minimizes the risk of ischemia/reperfusion injury in this very vulnerable population, yet gives the surgeon adequate time to perform a challenging resection in a bloodless field.

Aged↗
PubMed1994

Comparative study of permeability into rat cerebrospinal fluid of the quinolones: dependency on their lipophilicities.

Pharmacokinetic behavior involved in the entry of four quinolone antibacterial agents, norfloxacin (NFLX), ciprofloxacin (CPFX), ofloxacin (OFLX) and nalidixic acid (NA), into cerebrospinal fluid (CSF) was comparatively investigated in rats. Periodically, after the bolus i.v. dose of each quinolone (10 mg/kg), aliquots of CSF were collected by cisternal puncture and blood samples were then withdrawn from the jugular vein. CSF and serum (total and unbound) levels of the drugs were determined by HPLC method. Transport parameters for three new quinolones (NFLX, CPFX, OFLX) into CSF were obtained by physiological model analysis. Serum levels of OFLX and NFLX declined bi-exponentially with time, whereas the serum levels of NA and CPFX declined in mono-exponential and tri-exponential fashion, respectively. Fractions of each quinolone unbound to serum protein (approximately 0.7 for NFLX, CPFX, and OFLX, 0.12 for NA) were almost the same at any point in time. The CSF levels of these quinolones rose quite rapidly after drug administration, and then declined, along with their serum levels. Both the CSF level and the ratio of CSF concentration to serum unbound concentration were the highest for NA, followed by OFLX, CPFX and NFLX. These values of the four quinolones were almost proportional to the apparent partition coefficient (Papp) between n-octanol and phosphate buffer (pH 7.0) values of each reported in a previous paper [Tsuji et al., Antimicrob. Agents Chemother., 32, 190 (1988)]. In the three new quinolones, OFLX had a larger value of apparent diffusional clearance between blood and CSF (PAc) than CPFX and NFLX.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Responsiveness of single afferents in the infraorbital nerve to oral air pressures generated by consonants.

The responsiveness of receptors supplying the oral mucosa to air pressures generated during consonant production was investigated to obtain information about hypothetical mechanisms underlying speech deficits. The delay between the onset of the neural discharge and the pop puff of phonation (mouth-exist pressure) for /pa/ production was significantly shorter and less variable than it was for /ta/ and /ka/ production, suggesting that the discharge is more closely coupled to the onset of /pa/ production. The data were interpreted to imply that single fibers of the infraorbital nerve respond to the build-up of oral air pressure during /pa/ production. This, and similar sensory information, may be used by the central neural mechanisms which monitor and control the air pressures required for phonation.

Adult↗