Biomedical subjects

J F Lu

Publications and source records attributed to J F Lu.

30 records · Page 2Linked to original sources

PubMed1995

Molecular cloning of a cDNA for proctase B from Aspergillus niger var. macrosporus and sequence comparison with other aspergillopepsins I.

A cDNA for proctase B from Aspergillus niger var. macrosporus was isolated and sequenced. The deduced amino acid sequence (394 residues) of the preproform of the enzyme was highly homologous (98% identify) with those of aspergillopepsins I from A. awamori and A. saitoi, and moderately homologous (68% identity) with that of A. oryzae. Most of the sequence differences were found in the carboxyl-terminal domain.

Amino Acid Sequence↗

PubMed1994

The MOS 36-item Short-Form Health Survey (SF-36): III. Tests of data quality, scaling assumptions, and reliability across diverse patient groups.

The widespread use of standardized health surveys is predicated on the largely untested assumption that scales constructed from those surveys will satisfy minimum psychometric requirements across diverse population groups. Data from the Medical Outcomes Study (MOS) were used to evaluate data completeness and quality, test scaling assumptions, and estimate internal-consistency reliability for the eight scales constructed from the MOS SF-36 Health Survey. Analyses were conducted among 3,445 patients and were replicated across 24 subgroups differing in sociodemographic characteristics, diagnosis, and disease severity. For each scale, item-completion rates were high across all groups (88% to 95%), but tended to be somewhat lower among the elderly, those with less than a high school education, and those in poverty. On average, surveys were complete enough to compute scales scores for more than 96% of the sample. Across patient groups, all scales passed tests for item-internal consistency (97% passed) and item-discriminant validity (92% passed). Reliability coefficients ranged from a low of 0.65 to a high of 0.94 across scales (median = 0.85) and varied somewhat across patient subgroups. Floor effects were negligible except for the two role disability scales. Noteworthy ceiling effects were observed for both role disability scales and the social functioning scale. These findings support the use of the SF-36 survey across the diverse populations studied and identify population groups in which use of standardized health status measures may or may not be problematic.

Aged↗

PubMed1994

Pharmacokinetic-pharmacodynamic modeling of electroencephalographic effects of midazolam in eight Chinese men.

The effects of midazolam (Mid) on the electroencephalogram (EEG) were related to Mid concentrations in serum in 8 Chinese healthy male volunteers for the assessment of concentration-effect relationship. The total number of waves per second within the frequency range of 12-30 Hz (TNW12-30) in the central-occipital (C1-O1) lead EEG obtained by aperiodic analysis was used as EEG effect of the drug. The PK-PD parameters were calculated by PK-PD software using the sigmoid Emax model. They were: T1(2)keo = 1.3 +/- 0.9 min-1, EC50 = 254 +/- 54 micrograms.L-1, N = 2.9 +/- 0.6. E0 and Emax were calculated from the observed values, being 3.4 +/- 1.3 and 11.4 +/- 2.2 TNW12-30, respectively. Our results showed that the concentration-EEG effect relationship of Mid could be characterized in individual Chinese man using TNW12-30 as a measure of pharmacological response.

Adult↗

PubMed1993

Midazolam pharmacokinetics and electroencephalographic changes in eight Chinese men.

Eight Chinese healthy male volunteers aged 27 +/- s 4 a were injected i.v. midazolam (Mid) 15 mg. Blood samples were collected at 0, 2, 5, 7, 10, 20, 30, 45, 60, 90, 120, 180, and 240 min. A HPLC method was established for determining the Mid concentrations in serum. The concentration-time data was fitted with biexponential curve. Pharmacokinetic parameters were: T1/2 alpha = 6.8 +2- 2.5 min, T1/2 beta = 118 +/- 27 min, Vc = 25 +/- 7 L, Cl = 393 +/- 79 ml.min-1, Vdss = 59 +/- 13 L, AUC0-infinity = 39.6 +/- 8.6 g.min.L-1. The electroencephalogram (EEG) showed a decrease in alpha activity and an increase in beta activity. The EEG pattern reverted toward baseline after 2-3 h. Pharmacokinetic and EEG findings suggest that Mid is a preferable anesthesia inducing agent.

Adult↗

PubMed1993

[Effects of jiang tang tong mai ning on serum ascorbyl radical, superoxide dismutase activity, lipid peroxide level and tissue free oxygen radical in diabetic rats].

The effect of Jiang Tang Tong Mai Ning treatment on body weight, the level of blood sugar, the serum ascorbyl radical, SOD activity, LPO level and peroxidic radial (O2.-) of heart and kidney tissue in alloxan induced diabetic rats were observed. The results were also compared with that of Jiang Tang Jia Pian and vitamin E treated groups, which showed that the level of blood sugar, the level of serum ascorbyl radical, the concentration of LPO and peroxidic radical (O2.-) of myocardium and kidney tissue decreased significantly respectively (P < 0.01, 0.01, 0.01, 0.05), and the body weight, SOD activity increased obviously after the treatment (P < 0.05). For the first time, a W-wave between S-peak and T-peak of ESR spectrum in the tissue of rat, which is similar to the form of Fe-Mo-flavoprotein has been observed in this investigation, a positive correlation appears to exist between A value and the corresponding G value of W-wave.

Animals↗

PubMed1992

The t(15;17) breakpoint in acute promyelocytic leukemia cluster within two different sites of the myl gene: targets for the detection of minimal residual disease by the polymerase chain reaction.

The retinoic acid receptor alpha (RAR alpha) and the myl gene are involved in the translocation breakpoint t(15;17)(q22;q21) in acute promyelocytic leukemia (APL). The majority of the breakpoint sites have been mapped within the second intron of the RAR alpha gene; however, the breakpoint sites on the myl gene are variable. Using primer sets derived from exon 2 or exon 3 of the RAR alpha gene and a primer derived from the myl cDNA, we were able to amplify the breakpoint sites of the fusion transcripts of all six APL RNA samples by the reverse transcriptase-polymerase chain reaction (RT-PCR). A DNA fragment of 290 bp (breakpoint A) was amplified using RNA samples from three patients, whereas two DNA fragments of 630 and 774 bp (breakpoint B) were amplified using RNA samples from the other three APL patients. DNA sequence analysis of the amplified fragments suggests that the APL breakpoints clustered within two different introns of the myl gene. Northern blot analysis demonstrated that fusion transcripts RAR alpha/myl and myl/RAR alpha of varying sizes were detected in patients with different breakpoint sites on the myl gene. In addition, we analyzed five APL samples in complete remission and detected t(15;17)-positive cells. We conclude that the t(15;17) breakpoints in APL can be amplified by PCR using a single primer set and that minimal residual disease can be demonstrated in APL using RT-PCR.

Base Sequence↗

PubMed1992

The influence of bilirubin on fluidity and rotational correlation times of human erythrocyte membrane.

The effects of bilirubin on the membrane motion parameters of human erythrocyte membrane were determined by the spin labelled ESR method. It causes a decrease in the order parameter and an increase in the corresponding fluidity of the lipid molecules. Bovine serum albumin was found to inhibit effectively the effects due to bilirubin. The disturbance to the organization of membrane molecules by bilirubin as well as the protective effects of serum albumin are discussed on the basis of the experimental results.

Bilirubin↗

PubMed1992

The validity and relative precision of MOS short- and long-form health status scales and Dartmouth COOP charts. Results from the Medical Outcomes Study.

This study estimated the validity and relative precision (RP) of four methods (MOS long- and short-form scales, global items, and COOP Poster Charts) in measuring six general health concepts. The authors also tested whether and how precisely each method discriminated relatively well adult patients (N = 638) from those with only severe chronic medical (N = 168) and only psychiatric conditions (N = 163), as clinically defined. For comparisons between the well group and both medical and psychiatric groups, RP estimates favored long-form over short-form, multi-item scales, and favored multi-item scales over single-item global measures and poster charts. In relation to long forms, short-form multi-item scales achieved a median RP of .93; RP estimates for global items and poster charts were .81 and .67, respectively. Variations in RP across methods and concepts were linked to differences in the coarseness of measurement scales, reliability, and content (including the effects of chart illustrations). These variations in RP have implications for the interpretation of scores, the statistical power of comparisons between clinical groups, and the size of confidence intervals around individual patient scores.

Activities of Daily Living↗

PubMed1991

[Combined pharmacokinetic-pharmacodynamic model of procainamide in rabbits with induced ventricular fibrillation threshold (VFT) changes].

The change of electrically induced VFT was chosen as index of effect in anesthetized rabbits for study of pharmacodynamics of PA and NAPA. We analyzed the pharmacokinetic properties of PA and NAPA and elucidated their effect kinetics with a pharmacokinetic-pharmacodynamic (PK/PD) model in view of different transfer qualities. A linear-addition effect model was used to describe the relationship between the effect and the amount of drug and its metabolite in the effect compartment. PA was found to be eliminated faster than NAPA and distributed more extensively in rabbits. The effect per unit concentration of PA was shown to be larger than that of NAPA.

Acecainide↗

PubMed1991

[Pharmacokinetic-pharmacodynamic model of magnesium sulfate in treatment of pregnancy-induced hypertension].

Ten pregnancy-induced hypertension gravidas aged 24-36 (28.1 +/- 3.31) yr were infused iv with fast (7.5 g in 1 h) and slow (7.5 g in 5 h) rates consecutively. Blood pressure were measured and blood samples were collected at 0, 1, 6, 7, 9, 11, 15 h. The drug concentration of each sample in the serum was determined by colorimetric method. The integrated pharmacokinetic and pharmacodynamic model was used to analyze the data. The serum data were fitted to a biexponential equation and the effect data were fitted to a sigmoid Emax model. Their pharmacodynamic parameters were: Kco = 0.52.h-1, T1/2(kco) = 1.33 h, Emax = 20.5% Cc (50) = 6.15 micrograms.ml-1), y = 3.64. kco was not equal to k21 of the mammillary model. It shows that the site of action is situated in the effect compartment. The predicted effect could last 24 h.

Adult↗

PubMed1991

Down regulation of myeloperoxidase gene associated with specific nuclease hypersensitive sites during TPA induced differentiation of HL-60.

The level of myeloperoxidase (MPO) mRNA is reduced significantly after HL-60 induced differentiation with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). We examined the chromatin structural changes of the MPO gene during TPA induction. Before TPA induction about nine DNase I hypersensitive sites (HS) were found on the 5' upstream and at various intron regions of the MPO gene. A new HS was found on intron 8 within 4 h of induction; its appearance preceded down regulation of the MPO gene. At the same time DNase I HS found in 0.3 and 1-1.5 kb upstream of the MPO CAP site, were significantly reduced or disappeared after TPA induction. These chromatin structural changes could be closely linked to the mechanism which regulates the MPO gene expression.

Blotting, Southern↗

PubMed1990

Hemoglobins of the Lucina pectinata/bacteria symbiosis. II. An electron paramagnetic resonance and optical spectral study of the ferric proteins.

We report an optical and EPR spectral study of three hemoglobins, Hb I, II, and III, from the gill of the clam Lucina pectinata. Hemoglobin I reacts much more avidly with hydrogen sulfide than do Hbs II and III. The proximal ligand to the heme iron of each hemoglobin is histidyl imidazole. The acid/alkaline transition of ferric Hb I occurs with pK 9.6; those of ferric Hbs II and III with pK 6.6 and 5.9, respectively. At their acid limits each ferric hemoglobin exists as aquoferric hemoglobin. Broadening of the g = 6 resonance suggests that the bound water enjoys great positional freedom. Ferric Hb I, at the alkaline limit (pH 11), exists as ferric hemoglobin hydroxide. Ferric Hbs II and III, at their alkaline limit (pH 7.5), each exist as equal mixtures of two species. The low spin species with optical maxima near 541 and 576 nm and g values of 2.61, 2.20, and 1.82, are identified as ferric hemoglobin hydroxide. The high spin species, with optical maxima near 486 and 603 nm and g values of 6.71, 5.87, and 5.06, resemble Dicrocoelium hemoglobin and hemoglobin MSaskatoon. Here we show that Hbs II and III resemble hemoglobin MSaskatoon in which a distal tyrosinate oxygen ligated to the ferric heme iron at alkaline pH is displaced by water at acid pH. The H2S product of ferric Hb I is identified as ferric hemoglobin sulfide.

Animals↗