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Biomedical subjects

F Lu

Publications and source records attributed to F Lu.

At least 127 records · Page 7Linked to original sources

A gene-rich cluster between the CD4 and triosephosphate isomerase genes at human chromosome 12p13.

The genomic sequence of the human CD4 gene and its neighboring region, located at chromosome 12p13, was generated using the large-scale shotgun sequencing strategy. A total of 117 kb of genomic sequence and approximately 11 kb of cDNA sequence were obtained. Six genes, including CD4, triosephosphate isomerase, B3 subunit of G proteins (GNB3), and ubiquitin isopeptidase T (ISOT), with known functions, and two new genes with unknown functions were identified. Using a battery of strategies, the exon/intron boundaries, splice variants, and tissue expression patterns of the genes were determined. Various computer software was utilized for analyses of the DNA and amino acid sequences. The results of the analyses and sequence-based strategies for gene identification are discussed.

Alternative Splicing↗

Ethnocultural factors in the development of an Asian American psychiatrist.

Despite rising numbers of Asian American psychiatric trainees, little has been written about the specific problems arising in training for members of this ethnic minority group. The authors discuss some of the difficulties for the Asian American psychiatric trainee, in relation to the stigma of mental illness and its impact on the trainee's decision to enter psychiatry, ethnic identity and stereotyping, psychotherapy supervision, and career opportunities. Specific vignettes will describe each of these situations and the internal conflicts they engender during training. The resolution of these conflicts will be described within a transference and countransference framework with the intent of providing a starting point for process-oriented supervision geared toward the development of a professional identity. Specific recommendations will be given for the educational and career development process for Asian American psychiatric trainees.

Asian↗

A preliminary study on immune response to hepatitis E virus DNA vaccine in mice.

OBJECTIVE: In order to elicit immune response to hepatitis E virus (HEV) with the method of direct injection of naked DNA. METHODS: The gene encoding the structural protein of pORF3, a Chinese strain of HEV, was cloned into the eukaryotic expression plasmid pSVL. The resulted plasmid pSVL-HEV ORF3 was used as HEV DNA vaccine, to inoculate Balb/c mice intramuscularly with a dose of 100 micrograms. Mice injected with empty pSVL DNA served as control. RESULTS: After 1-2 times inoculation, twelve of 16 mice inoculated with pSVL-HEV ORF3 had anti-HEV IgG seroconversion. pSVL-HEV ORF3 was still detectable in the muscle of the inoculated mice 18 days after the injection, by the method of PCR. None of the control group had a detectable level of anti-HEV IgG. It is also found that the humoral immune response to HEV induced by DNA vaccine could be boostered by HEV recombinant fusion protein. CONCLUSION: Our present study demonstrated that nucleic acid vaccine is able to prime a specific humoral immune response to HEV in mice.

Animals↗

[Measurement of NOS activity by monitoring the conversion of 3H-arginine].

OBJECTIVE: To establish a method for measuring the constitutive and inducible nitric oxide synthase (NOS) through the conversion of L-3H arginine to L-3H citrulline. METHODS: NOS extracted from cerebellar of porcine and rat was purificated through DEAE cellulose or/and 2', 5', -ADP agarose. NOS activity was assayed by monitoring the conversion of 3H-arginine to 3H-citrulline. RESULTS: A 4,460 fold purification of the porcine cerebellar NOS was obtained with an activity of 669 pmol mg-1 min-1 and a 2.7% recovery. For purification of rat cerebellar NOS, affinity chromatography with 2', 5'-ADP agarose column provided a 2646 fold purification of enzyme activity with a 688 pmol.ml-1.min-1 and 27% recovery. The purified rat and porcine cerebellar NOS constituted a single band on SDS/PAGE at about 160,000. CONCLUSION: A stable and special method for measuring NOS activity was established.

Animals↗

[Effects of bilateral lesions of ventrolateral orbital cortex on the rat tail flick reflex inhibition evoked by electroacupuncture].

This study found that bilateral electrolytic lesions of the ventrolateral orbital cortex (VLO) markedly reduced the inhibitory effects of high intensity electroacupuncture (EA) at "Zusanli" point on tail flick reflex in lightly anesthetized rats, but did not influence the inhibitory effects of low intensity EA stimulation. The results show that the VLO is involved in acupuncture analgesia produced by activation of small afferent fibers with high intensity electroacupunture. Results of this study provide further support for a hypothesis that spinal cord-Sm-VLO-PAG-spinal cord may constitute a negative feedback loop of nociceptive modulation. The analgesic effects produced by high intensity electroacupuncture may be mediated by this loop leading to depression of the nociceptive inputs at the spinal cord level.

Acupuncture Analgesia↗

[Extraction of humic acid from drinking water in area with arsenosis in inner Mongolia and Taiwan and comparison of its spectrometry].

In order to study etiology of blackfoot disease in Taiwan and to explore whether it can occur in the area with arsenosis in Inner Mongolia in the future, chemical components of specimens of drinking water from Taiwan and Inner Mongolia were determined and compared with infrared (IR), ultra-violet (UV) spectrometry and fluorescence spectrometry. Humic acid was extracted from the water samples by XAD-7 ion-exchange resin and Sephadex G-25 gel filtration chromatography, respectively, yielding the same results. Studies showed arsenic and humic acid levels in water samples both from Taiwan and Inner Mongolia all were higher, and their fluorescence and UV-spectra were similar, except a small difference in their IR spectra. Their effects on environment are under further studies.

Arsenic↗

[Early results of CABG operation in 110 patients].

Coronary artery bypass grafting (CABG) operations were performed in 110 consecutive patients. Most of them had extensive triple-vessel disease or left main coronary artery disease. Internal mammary artery (IMA) was used as a graft in 65 patients. Valvular replacement or valvuloplasty were performed in 8 patients and ventricular aneurysmectomy in 10 patients including post infarction VSD repaired in 1 patient simultaneously. Angina pectoris was relieved in all patients except one died from acute renal failure postoperatively. The IMA could be used safely and efficiently in nearly all patients. Using very fine technique, we suggested good exposure, and hemostasis to handle IMA. The key factor of success in CABG operation was complete revascularization by passing all significant stenosis larger than 1 mm diameter in all coronary artery branches.

Adult↗

[Study of nitric oxide synthases, nitric oxide and tumor necrosis factor in different types of ascites].

The purpose of this study was to elucidate the clinical significance of nitric oxide synthases (NOS), nitric oxide (NO) and tumor necrosis factor (TNF) in different types of ascites. NOS, NO and TNF in ascitic transudates of 21 patients with liver cirrhosis, ascitic exudate of 32 patients with liver cirrhosis and carcinogenesic ascites of 19 patients were measured by Griess, ELISA and colorimetric methods. Compares to the value in ascitic transudate of 21 patients with liver cirrhosis, NOS (7.32 +/- 3.13 nmol.min-1.g-1), NO (15.4 +/- 7.6 mumol/L) and TNF (331.7 +/- 121.2 mumol/L) in ascitic exudate of 32 patients with liver cirrhosis were significantly higher (P < 0.01). The NO (10.7 +/- 3.2 mumol/L) and TNF (185.6 +/- 84.1 mumol/L) in carcinogenesic ascites of 19 patients were between those in ascitic exudates and those in ascitic transudates of patients with liver cirrhosis (P < 0.05 or 0.01). The NOS activity was highest in carcinogenesic ascites. The decrease of 24h urine volume in patients with cirrhosis was relative to the increase of NO level in ascites. Those suggested that measurements of NOS, NO and TNF in ascites are helpful in differential diagnosis of ascites. The separation between NO level and NOS activity in ascites indicates that the ascites is carcinogenesis.

Adolescent↗

[Longitudinal evaluation of vocal function following thyroplasty type I for the treatment of unilateral vocal paralysis].

Longitudinal changes of vocal efficiency and stability following thyroplasty type I were analysed. Fifty-three patients with unilateral vocal fold paralysis underwent vocal function evaluation preoperatively and 1, 3 and 6 months postoperatively. Vocal function assessment included videostrobolaryngoscopic examination, acoustical and aerodynamic analyses, and perceptual ratings of voice. Parameters including glottic gag size, maximum phonation time, glottic flow rate, jitter, harmonic to noise ratio, breathness, hoarseness, loudness and phrasing showed significant improvement after thyroplasty and remained stable within 1 month with only slight fluctuations over a 6 month period. Postoperative voice outcome was not affected by age, sex, duration of vocal symptoms, etiology of paralysis, or preoperative pulmonary function.

Adolescent↗

Mechanism of corepressor-mediated specific DNA binding by the purine repressor.

The modulation of the affinity of DNA-binding proteins by small molecule effectors for cognate DNA sites is common to both prokaryotes and eukaryotes. However, the mechanisms by which effector binding to one domain affects DNA binding by a distal domain are poorly understood structurally. In initial studies to provide insight into the mechanism of effector-modulated DNA binding of the lactose repressor family, we determined the crystal structure of the purine repressor bound to a corepressor and purF operator. To extend our understanding, we have determined the structure of the corepressor-free corepressor-binding domain of the purine repressor at 2.2 A resolution. In the unliganded state, structural changes in the corepressor-binding pocket cause each subunit to rotate open by as much as 23 degrees, the consequences of which are the disengagement of the minor groove-binding hinge helices and repressor-DNA dissociation.

Allosteric Regulation↗

The gene for a human microfibril-associated glycoprotein is commonly deleted in Smith-Magenis syndrome patients.

Smith-Magenis syndrome (SMS) is a clinically recognizable multiple congenital anomaly/mental retardation syndrome associated with deletion of chromosome 17p11.2. Here we report the identification of a novel gene encoding a human microfibril-associated glycoprotein (MFAP4), which has been mapped to the SMS region. A full-length cDNA corresponding to this gene has been sequenced, and reveals a coding region of 255 amino acids. MFAP4 has a fibrinogen-like domain and shares a high level of sequence homology to a fragment of a bovine 36 kDa microfibril-associated glycoprotein. The N-terminus of the protein bears an Arg-Gly-Asp sequence that serves as the ligand motif for cell surface receptor integrin. These structural features of MFAP4 suggest that it is an extracellular matrix protein involved in cell adhesion or intercellular interactions. Deletion analysis has been conducted on 31 SMS patients by polymerase chain reaction and Southern analysis of somatic cell hybrids retaining the del(17)(p11.2) chromosome or by fluorescence in situ hybridization. The MFAP4 locus is deleted in 30 of 31 SMS patients. Thus, the function of this gene must be considered in the pathogenesis of SMS. Given our previous hypothesis that SMS is a contiguous gene syndrome, complete and exhaustive definition of the critical deletion interval and a thorough phenotype-genotype correlation is required to demonstrate the role and importance of the MFAP4 gene in SMS.

Abnormalities, Multiple↗

130 kb of DNA sequence reveals two new genes and a regional duplication distal to the human iduronate-2-sulfate sulfatase locus.

Deficiency of IDs activity results in Hunter Syndrome (mucopolysaccharidosis type II), a fatal X-linked recessive disorder. We report characterization of 28 cosmids around the IDS locus in Xq28. Four overlapping cosmids have been sequenced in their entirety generating a 130-kb contig. These studies show the fine structure of the IDS gene and identify an IDS pseudogene-like structure located 20 kb distal to the active gene. Two novel genes have also been identified in this sequence, and one of these genes is also locally duplicated. Both homologs are expressed, and a number of alternative transcript products have been characterized. The presence of a highly conserved pseudogene-like structure within a larger duplicated region close to the IDS gene has significant implications for the study of mutations at this locus.

Base Sequence↗

Tn916 target DNA sequences bind the C-terminal domain of integrase protein with different affinities that correlate with transposon insertion frequency.

The conjugative transposon Tn916 inserts with widely different frequencies into a variety of target sites with related nucleotide sequences. The binding of chimeric proteins, consisting of maltose-binding protein fused to Tn916 integrase, to three different target sequences for Tn916 was examined by DNase I protection experiments. The C-terminal DNA binding domain of the Tn916 integrase protein was shown to protect approximately 40 bp, spanning target sites in the orfA and cat genes of the plasmid pIP501 and in the cylA gene of the plasmid pAD1. Competition binding assays showed that the affinities of the three target sites for Tn916 integrase varied over a greater than 3- but less than 10-fold range and that the cat target site bound integrase at a lower affinity than did the other two target sites. A PCR-based assay for transposition in Escherichia coli was developed to assess the frequency with which a defective minitransposon inserted into each target site. In these experiments, integrase provided in trans from a plasmid was the sole transposon-encoded protein present. This assay detected transposition into the orfA and cylA target sites but not into the cat target site. Therefore, the frequency of transposon insertion into a particular target site correlated with the affinity of the target for the integrase protein. Sequences within the target fragments similar to known Tn916 insertion sites were not protected by integrase protein. Analysis ot he electrophoretic behavior of circularly permuted sets of DNA fragments showed that all three target sites contained structural features consistent with the presence of a static bend, suggesting that these structural features in addition to the primary nucleotide sequence are necessary for integrase binding and, thus, target site activity.

Base Sequence↗

Complete sequence of a 38.4-kb human cosmid insert containing the polymorphic marker DXS455 from Xq28.

The complete DNA sequence of a cosmid mapping to human Xq28 (DXS455) has been determined using a shotgun approach (genbank accession number: L31948). The cosmid insert is 38.4 kb in length, and contains several repetitive sequences, including a highly repetitive region located in a fragment previously shown to contain a polymorphic VNTR locus, as well as short di- and tri-nucleotide repeats. In addition to the previously known VNTR locus, a CA-repeat and an unusual 800-bp repetitive region have been found to be polymorphic. The repeated sequence mapping to the site of the VNTR locus spans 480 bp in the cosmid. In addition to several AT-dinucleotide stretches, this repeat has four copies of a 25 bp repeat unit and flanking sequences similar to this 25-mer. No expressed sequences have so far been identified in this cosmid.

Bacteriophage M13↗