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N Kuroda

Publications and source records attributed to N Kuroda.

At least 145 records · Page 8Linked to original sources
PubMed1995

Novel mutation at the initiation codon in the Norrie disease gene in two Japanese families.

We have identified a new mutation of Norrie disease (ND) gene in two Japanese males from unrelated families; they showed typical ocular features of ND but no mental retardation or hearing impairment. A mutation was found in both patients at the initiation codon of exon 2 of the ND gene (ATG to GTG), with otherwise normal nucleotide sequences. Their mothers had the normal and mutant types of the gene, which was expected for heterozygotes of the disease. The mutation of the initiation codon would cause the failure of ND gene expression or a defect in translation thereby truncating the amino terminus of ND protein. In view of the rarity and marked heterogeneity of mutations in the ND gene, the present apparently unrelated Japanese families who have lived in the same area for over two centuries presumably share the origin of the mutation.

Base Sequence↗
PubMed1995

Estimating blood alcohol from urinary alcohol at autopsy.

Urine alcohol concentration (UAC) and blood alcohol concentration (BAC) measured by gas chromatography were available from 435 medicolegal autopsies. Simple linear regression with BAC as outcome variable and UAC as predictor variable (range, 3-587 mg%) gave the regression equation BAC = -5.6 + 0.811UAC with 95% prediction interval +/- 0.026 square root of [9465804 + (UAC-213.3)2] and 99% prediction interval +/- 0.034 square root of [9465804 + (UAC-213.3)2]. The standard error of the slope was 0.013 and the 95% confidence interval for the slope 0.785-0.837. In practice, a BAC of 80 mg% is predicted with 95% certainty by a UAC of 204 mg% and similarly a BAC of 150% by a UAC of 291 mg%. The prediction interval is too wide to be helpful in the assessment of an individual case fatality. The UAC is useful in corroborating but not in predicting BAC.

Alcoholic Intoxication↗
PubMed1994

High-performance liquid chromatographic determination of short-chain aliphatic aldehydes using 4-(N,N-dimethylaminosulphonyl)-7-hydrazino-2,1, 3-benzoxadiazole as a fluorescence reagent.

High-performance liquid chromatographic determination of four short-chain aliphatic aldehydes using fluorescence detection was carried out with 4-(N,N-dimethylaminosulphonyl)-7-hydrazino-2, 1,3-benzoxadiazole (DBD-H). DBD-H derivatives with three aliphatic aldehydes--formaldehyde, acetaldehyde and propionaldehyde--were synthesized and their fluorescence properties were examined. Relative fluorescence intensities of these compounds in acetonitrile were ca. ten-fold larger than those in aqueous acetonitrile. DBD-hydrazones could be separated by reversed-phase chromatography using aqueous acetonitrile as eluent and detection at 560 nm with excitation at 445 nm. Submicromolar levels of formaldehyde, acetaldehyde, propionaldehyde and butyladehyde could be determined. The HPLC procedure using propionaldehyde as internal standard was applied to the measurement of acetaldehyde levels in normal human plasma before and 30 min after ingestion of ethanol.

Adult↗
PubMed1994

Vitreous alcohol is of limited value in predicting blood alcohol.

Vitreous humour alcohol concentration (VHAC) and blood alcohol concentration (BAC) measured by gas chromatography were available from 345 medico-legal autopsies. Simple linear regression with BAC as outcome variable and VHAC as predictor variable (range 1-705 mg%) gave the regression equation BAC = 3.03 + 0.852 VHAC with 95% prediction interval +/- 0.019 square root of [7157272 + (VHAC - 189.7)2] and 99% prediction interval +/- 0.025 square root of [7157272 + (VHAC - 189.7)2]. The residual standard deviation of VHAC was 26 mg%, the standard error of the slope 0.0098 and the 95% confidence interval for the slope 0.833-0.871. In practice a BAC of 80 mg% is predicted with 95% certainty by a VHAC of 150 mg% and similarly a BAC of 150 mg% by a VHAC of 232 mg%. The prediction interval is too wide to be of real practical use. Previous authors have provided various formulae, including a simple conversion factor, to predict BAC from VHAC without taking into account the uncertainty of the prediction for an individual subject. A re-analysis of the raw data from previous publications gave in most instances regression equations significantly different from the authors' own.

Alcoholic Intoxication↗
PubMed1993

2-(4-Hydrazinocarbonylphenyl)-4,5-diphenylimidazole as a versatile fluorescent derivatization reagent for the high-performance liquid chromatographic analysis of free fatty acids.

A new fluorescent derivatization reagent with a lophine skeleton, 2-(4-hydrazinocarbonylphenyl)-4,5-diphenylimidazole (HCPI), has been synthesized and applied to the assay of saturated free fatty acids. The HCPI derivatives with five representative saturated fatty acids [caproic acid (C6), lauric acid (C12), palmitic acid (C16), stearic acid (C18) and arachidic acid (C20)] were synthesized to examine their fluorescence properties. The fluorescence spectra (lambda ex ca. 335 nm, lambda em ca. 455 nm) of the derivatives were almost identical in methanol, n-heptane and acetonitrile. For the high-performance liquid chromatographic assay, fatty acids were derivatized with HCPI using a condensing agent, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, and pyridine at room temperature. The HCPI derivatives were separated on a C18 column with a gradient elution of methanol-water, and the eluates were monitored at 455 nm using an excitation wavelength of 335 nm. By this method, seven kinds of free fatty acid (C6, C10, C12, C14, C16, C18 and C20) could be determined using margaric acid (C17) as an internal standard. Calibration curves were linear over the range 0.2-400 pmol per 20-microliters injection (r = 0.994-1.000). Relative standard deviations of the peak-height ratio for five replicate measurements of fatty acids (100 pmol per injection) were 0.7-2.6%. Detection limits were 7-57 fmol at a signal-to-noise ratio of 3. The method could be successfully applied to the determination of four saturated fatty acids (C12, C14, C16 and C18) in normal human serum.

Chromatography, High Pressure Liquid↗
PubMed1993

Long-standing follow-up electroretinographic studies after surgical resection of optic nerve glioma.

We followed up electrophysiological findings in 2 patients who underwent optic nerve glioma resection. Case 1 showed a normal flash electroretinogram (ERG) 6 months after surgery. Case 2 showed a negative-type flash ERG and nonrecordable pattern ERG and flash visual-evoked cortical potentials 13 and 20 years after surgery. The flash ERG after surgical resection of the optic nerve was considered to be affected by the interruption of the central retinal artery during the surgery, and the preserved ERG suggested the possibility of developing the collateral circulation of the ciliary artery.

Child↗
PubMed1993

Preparation and evaluation of fatty acid esters of 2-(4-hydroxyphenyl)-4,5-diphenylimidazole as fluorescent substrates for measurement of lipase activity.

A series of four aliphatic carboxylic acid esters (acetate, caproate, laurate and palmitate) of 2-(4-hydroxyphenyl)-4,5-diphenylimidazole (HDPI) was prepared. Usefulness of these esters as fluorescent substrates for the measurement of lipase activity was evaluated using a high performance liquid chromatographic method. The hydrolysate, HDPI, could be well separated from each substrate by a reversed-phase column and detected at 440 nm emission (cutoff-filter) with 360 nm excitation. Lipase from Candida cylindracea was used for the investigation. From their kinetic parameters, the caproate and laurate were found to be suitable for the lipase. Using the laurate, from 5 to 500 mU per assay tube of the lipase was determined.

Candida↗
PubMed1992

Preparation of a fluorescent derivative of benzoylecgonine, and preliminary studies of its application to the analysis of urine.

A sensitive high-performance liquid chromatographic method using 3-bromomethyl-6,7-dimethoxy-1-methyl-2(1H)-quinoxalinone (Br-DMEQ) as a fluorescent labeling reagent is described for the determination of benzoylecgonine (BE) and ecgonine (EC). The Br-DMEQ derivatives of BE and EC were separated on a C18 column and detected at 455 nm with excitation at 370 nm. The detection limits of the proposed method were 18.7 fmol for BE and 12.5 pmol for EC at a signal-to-noise ratio of 3. Relative standard deviations of five replicate measurements were 1.94% (10 pmol) and 2.98% (50 pmol) for BE and 6.3% (250 pmol) and 5.62% (1.25 pmol) for EC. This method was applied to the determination of BE in human urine. BE was extracted from urine by solvent extraction with chloroform-isopropyl alcohol (9:1, v/v) solution. Levels of 2.5.10(-8) M BE in urine (25 pmol/ml) could be determined.

Chromatography, High Pressure Liquid↗
PubMed1992

Neutralizing activity of human antibodies against the structural protein of human T-cell lymphotropic virus type I.

We have identified and mapped the regions responsible for neutralization in the human T-cell leukemia virus type I (HTLV-I) structural proteins by using region-specific human antibodies derived from seropositive blood donors. We have obtained 18 kinds of region-specific antibody (2 in the p19 gag, 10 in the gp46 env and 6 in the gp21 env proteins) from seropositive human plasma by means of an affinity column coupled with the synthetic peptides corresponding to the antigenic regions of the HTLV-I structural proteins. These antibodies were highly specific in ELISA using synthetic peptides as an antigen. Subsequently, we examined the neutralizing activity expressed by the inhibition of virion-induced syncytium formation by region specific antibodies. Twelve of 16 antibodies derived from the env protein were able to inhibit syncytium formation induced by co-cultivation of 8C cells with HTLV-I antigen-positive T cells. The antibodies derived from the p19 gag protein and the seronegative plasma used as the control showed no significant activity. The sequences recognized by the 10 neutralizing antibodies were sites corresponding to amino acids 20 to 49, 89 to 115, 136 to 160, 175 to 199, 213 to 236, 235 to 254, 277 to 292, 332 to 352, 350 to 386, 382 to 403, 426 to 448 and 458 to 488 from the amino terminal of the env protein. These observations suggest that the neutralizing epitopes were widely distributed in the env proteins of HTLV-I.

Enzyme-Linked Immunosorbent Assay↗
PubMed1992

A structural study of the membrane domain of band 3 by tryptic digestion. Conformational change of band 3 in situ induced by alkali treatment.

Nine peptides derived from the transmembrane domain of band 3 were purified and sequenced. All of the sequences agreed completely with deduced sequences from cDNA of human erythroid band 3. Five peptides, KS-1 to KS-5, were released from the band 3 molecule when alkali-stripped membranes were digested with trypsin, while four other peptides, KM-6 to KM-9, were obtained following subsequent urea treatment. This indicates that at least 13 new in situ cleavage sites were demonstrable by these procedures, that the released peptides are parts of hydrophilic connector loops, and that the other peptide portions constitute membrane-spanning helices. The topological designations are consistent with the hydropathy prediction of murine band 3 according to Passow ((1986) Rev. Physiol. Biochem. Pharmacol. 103, 61-203). One mol of histidine residue was found/mole of KS-1, KS-2, KS-4, and KM-6. The conformation of band 3 in situ was apparently changed by alkali treatment of erythrocyte membranes, i.e. the amount of KS-1, KS-2, and KS-4 peptides released by trypsin treatment increased as NaOH concentration was raised from 10 to 100 mM. Similarly, [3H]dihydro-4,4'-diisothiocyanostilbene-2,2'-disulfonic acid was found to bind to band 3 in membranes treated with 10 mM NaOH as well as to band 3 in white ghosts, but not to membranes treated with 100 mM NaOH. In addition, alkali treatment of membranes tended to increase the amount of band 3 cross-linked by 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS). The conformational change in band 3 by alkali treatment was also supported by the interaction of antibodies against peptides released by trypsin. The release of KS-1, KS-2, and KS-4 from the membrane was strongly inhibited by pretreating the erythrocyte membrane with DIDS, suggesting that the DIDS-band 3 complex which is in the outward facing form, is more compact and becomes resistant to trypsin compared to band 3 without DIDS.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗