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Biomedical subjects

G Fu

Publications and source records attributed to G Fu.

At least 55 records · Page 3Linked to original sources
PubMed1998

Analysis of the genomic organisation of a small chromosome of Leishmania braziliensis M2903 reveals two genes encoding GTP-binding proteins, one of which belongs to a new G-protein family and is an antigen.

Leishmania braziliensis M2903 contains a highly amplified small chromosome. This work is aimed at resolving its structural organization and determining whether this unusual chromosome contains specific genes encoding proteins with important functions in disease pathology or drug resistance. Our results show that the M2903 250-kb small chromosome contains LD1 sequences and has an inverted repeat structure. The LD1 sequences and two cDNAs (cDNA2 and cDNA53) were mapped on a cosmid contig, and the two cDNAs and the corresponding genomic fragments from the small chromosome were sequenced. The gene encoding cDNA2 predicts a putative GTP-binding protein with homology to other GTP-binding proteins only in the G-1 domain region; however, four other conserved motifs can be recognized. Sequence similarity to cDNA53 is located in at least five chromosomes, and its small chromosome copy is a pseudogene. An open reading frame downstream of the cDNA53 pseudogene predicts another GTP-binding protein that belongs to a new G-protein family with an unusual conserved GTP-binding domain and a newly characterized conserved sequence motif. A portion of this GTP-binding protein gene was studied previously in L. aethiopica as a recombinant antigen that reacts with human antibodies.

Amino Acid Sequence↗
PubMed1998

Phenylethanolamine N-methyltransferase mRNA in rat hypothalamus and cerebellum.

Using the reverse transcription polymerase chain reaction, we detected a single form of phenylethanolamine N-methyltransferase (PNMT) mRNA in hypothalamus and medulla/pons and two forms in cerebellum. These findings indicate that the PNMT gene is expressed in these brain areas and suggest that tissue specific splicing of PNMT mRNA may occur.

Animals↗
PubMed1998

Leishmania braziliensis: characterisation of a complex specific subtelomeric repeat sequence and its use in the detection of parasites.

A 1.6-kb tandem repeat sequence had previously been identified in the subtelomeric region of mini- and megabase chromosomes from Leishmania braziliensis. Southern hybridisation was used to demonstrate that the repeat is complex specific. The sequence was characterised in strains representing four species of the L. braziliensis complex. This data allowed an assessment of the evolutionary relationship of the four species. PCR primers targeted to the repeat amplify only DNA from species of the L. braziliensis complex. Titration assays indicate that a minimum of 50 fg of parasite DNA can be detected by PCR alone. Southern hybridisation increases the limit of detection to 5 fg. Interspecies variation in the repeat sequence enabled restriction enzyme digestion of PCR products to distinguish individual species within the L. braziliensis complex.

Animals↗
PubMed1998

The still-face effect in Chinese and Canadian 3- to 6-month-old infants.

Studies conducted in China examining cross-cultural differences in 3- to 6-month-olds used the still-face paradigm. In each study, 20 infants were in the experimental group (normal, still-face, normal interactions) and 20 in the control (3 normal periods). In Study 1, infants interacted with either their mother or their father; they looked and smiled less to the still-face of both parents. In Study 2, infants interacted with both their mother and a stranger, with order counterbalanced. Experimental groups showed similar still-face effects to both adults. The control group responded similarly to the stranger in both orders but responded less to their mother when she interacted 2nd. The data were compared with archival data from Canadian infants. Although Chinese infants took longer to begin smiling, responding was similar in both cultures, despite differences in mothers' behavior: Chinese mothers played with the infants' arms; Canadian mothers played with the legs.

Adult↗
PubMed1998

Secondary structures of synthetic peptides corresponding to the first membrane-contact portion of normal band 3 and its deletion mutant (Southeast Asian ovalocytosis).

The conformations of synthetic peptides corresponding to the first membrane-contact portion from Tyr390 to Lys430 of band 3 (band 3-1a) and the counterpart portion of South-East Asian ovalocytosis (SAO) band 3 (band 3-1b) in lipid bilayers were examined by means of circular dichroism (CD), Fourier transform infrared (FTIR) spectroscopy as well as a proteolytic digestion method. The CD and FTIR studies showed that band 3-1a and band 3-1b in a membrane lipid bilayer cannot assume an alpha-helix rich structure but instead assume a beta-structure rich conformation. The proteolytic digestion experiments demonstrated that the cleavage sites of Tyr392 and Phe423 were common to both the model and erythrocyte membranes. Taken together with our previous work, which indicated that the first membrane-contact portion was the portion embedded in the erythrocyte membrane without tight lipid-peptide interactions [Hamasaki et al. (1997) J. Biochem. 122, 577-585], we imply herein that the first membrane-contact portion of band 3 by itself can not assume the ordinary alpha-helix conformation in the membrane lipid bilayers. A proteinase-resistant portion, from Ser402 to Phe423, was observed when liposomes containing band 3-1a were digested with proteinase K, while no proteinase-resistant core portion was found in the case of band 3-1b (DeltaAla400-Ala408). This suggests the crucial role of the deleted portion, from Ala400 to Ala408, in the interaction of the first membrane-contact portion of band 3 with a membrane lipid bilayer.

Amino Acid Sequence↗
PubMed1998

[Clinical observation of intrachamberal anesthesia].

PURPOSE: To observe the effect in operation and influence after operation of intrachamberal anesthesia. METHODS: 2 Percent lidocaine used for intravenous injection was diluted by Bss-plus to be 0.5 percent solution. Intraocular surgery of 63 cases(76 eyes) were performed intrachamberal anesthesia by anterior chamber puncture. RESULT: All of the operations were done well, the patients didn't feel painful. Complications were not found by following up ten months. CONCLUSION: This kind of anesthesial technique was regarded to be simple, safe, and efficient. It was worthy of searching in anterior intraocular surgery.

Administration, Topical↗
PubMed1997

Cloning of a gene (RIG-G) associated with retinoic acid-induced differentiation of acute promyelocytic leukemia cells and representing a new member of a family of interferon-stimulated genes.

In a cell line (NB4) derived from a patient with acute promyelocytic leukemia, all-trans-retinoic acid (ATRA) and interferon (IFN) induce the expression of a novel gene we call RIG-G (for retinoic acid-induced gene G). This gene codes for a 58-kDa protein containing 490 amino acids with several potential sites for post-translational modification. In untreated NB4 cells, the expression of RIG-G is undetectable. ATRA treatment induces the transcriptional expression of RIG-G relatively late (12-24 hr) in a protein synthesis-dependent manner, whereas IFN-alpha induces its expression early (30 min to 3 hr). Database search has revealed a high-level homology between RIG-G and several IFN-stimulated genes in human (ISG54K, ISG56K, and IFN-inducible and retinoic acid-inducible 58K gene) and some other species, defining a well conserved gene family. The gene is composed of two exons and has been mapped by fluorescence in situ hybridization to chromosome 10q24, where two other human IFN-stimulated gene members are localized. A synergistic induction of RIG-G expression in NB4 cells by combined treatment with ATRA and IFNs suggests that a collaboration exists between their respective signaling pathways.

Amino Acid Sequence↗
PubMed1997

[Identification of Scutellaria barbata D. Don and its adultrants].

Studies have been made on the comparison and identification of morphological and anatomical characteristics of six species Scutellaria barbata and its adultrants. Several tables and drawings are given. This paper may be helpful to pharmacognosists for identifying commercial crude drugs.

Drug Contamination↗
PubMed1997

[Determination of flavonoids in the leaves of Hippophae L. by HPLC].

A method for determination of three flavonoids in the leaves of Hippophae by high presure liquid chromatography was established. The contents of these flavonoids in the leaves of seven different species of Hippophae were determined and compared. The results provide a scientific basis for evaluating and utilizing the leaves of Hppophae.

Chromatography, High Pressure Liquid↗
PubMed1996

RIG-E, a human homolog of the murine Ly-6 family, is induced by retinoic acid during the differentiation of acute promyelocytic leukemia cell.

In vivo all-trans-retinoic acid (ATRA), a differentiation inducer, is capable of causing clinical remission in about 90% of patients with acute promyelocytic leukemia (APL). The molecular basis for the differentiation of APL cells after treatment with ATRA remains obscure and may involve genes other than the known retinoid nuclear transcription factors. We report here the ATRA-induced gene expression in a cell line (NB4) derived from a patient with APL. By differential display-PCR, we isolated and characterized a novel gene (RIG-E) whose expression is up-regulated by ATRA. The gene is 4.0 kb long, consisting of four exons and three introns, and is localized on human chromosome region 8q24. The deduced amino acid sequence predicts a cell surface protein containing 20 amino acids at the N-terminal end corresponding to a signal peptide and an extracellular sequence containing 111 amino acids. The RIG-E coded protein shares some homology with CD59 and with a number of growth factor receptors. It shares high sequence homology with the murine LY-6 multigene family, whose members are small cysteine-rich proteins differentially expressed in several hematopoietic cell lines and appear to function in signal transduction. It seems that so far RIG-E is the closest human homolog of the LY-6 family. Expression of RIG-E is not restricted to myeloid differentiation, because it is also present in thymocytes and in a number of other tissues at different levels.

Amino Acid Sequence↗
PubMed1996

Human papillomavirus DNA in malignant and hyperplastic prostate tissue of black and white males.

This study hypothesized that human papillomavirus (HPV) infection is associated with increased prostate cancer risk, and that the 40% higher incidence rate in blacks is attributable to a greater prevalence of oncogenic viral DNA in prostatic tissues. Viral L1 and E6 gene sequences were polymerase chain reaction (PCR) amplified in archival tissues from 56 prostate cancer cases and 42 hyperplastic controls. L1 amplimers were hybridized by dot blot to HPV L1 generic probes, as were E6 amplimers to E6 probes specific for HPV 6, 11, 16, 18, 31, 33, and 45. 12.5% of cases and 9.5% of controls were HPV positive by L1 hybridization (age/race adjusted odds ratio = 1.66, 95% confidence interval = 0.33, 8.37). Four of 52 (7.7%) blacks were HPV positive compared to 7 of 46 (15.2%) whites. However, none of the L1-positive samples hybridized to the E6 type-specific probes, and positive results were not replicable using a broader spectrum of PCR primers and probes. These data suggest that HPV infection is not a significant risk factor for prostate cancer and does not explain the excess cancer risk in blacks.

Adenocarcinoma↗
PubMed1996

[Effects of rotating stimuli on electronystagmogram and electrogastrogram in guinea pigs].

The purpose of this study is to investigate the effects of repeated rotating stimuli on electronystagmogram (ENG) and electrogastrogram (EGG) in guinea pigs. ENG and EGG were separately recorded prior to the stimuli and on the next day and 30 days after repeated stimuli in 14 guinea pigs with normal pinna reflexes. The results showed that the numbers of the bilateral vestibular nystagmus (L and R separately represented the numbers of left and right nystagmus) of postrotation (L = 682, R = 657) were obviously less than that of prerotation (L = 857, R = 842) (P < 0.01, pairing t-test), and EGG amplitude of postrotation (4506 microV) during the whole course of rotating stimuli was lower than that of prerotation (5279 microV) (P < 0.01, pairing t-test). The numbers of bilateral nystagmus (L = 845, R = 826) were obviously raised again 30 days after stopping rotating stimuli (P < 0.01, compared with next day after stopping repeated stimuli; P > 0.05 compared with before rotating stimuli). It was concluded that repeated rotating stimuli can decrease the vestibulo-ocular and vestibulo autonomic reflexes in guinea pigs, but the effects were not timeless.

Animals↗
PubMed1995

[Study on metabolite of 5-ethyl-5-(para-fluorobenzoylpropyl) barbituric acid in rabbits].

The metabolite of 5-ethyl-5-(p-fluorobenzoylpropyl) barbituric acid (coded as F-B-1) in rabbit has been separated with HPLC. UV-spectra of F-B-1 and its metabolite obtained with DAD, in combination with EI-MS and CI-MS of F-B-1, its metabolite and their derivatives were examined. Possible structure of the metabolite was obtained. Possible metabolic way of F-B-1 is the reduction of carbonyl on the benzene ring with formation of hydroxyl group. This was further confirmed by identity of HPLC and MS behavior of the metabolite and NaBH4 reductive product. In the structure of the latter, the carbonyl on the benzene ring was reduced, as proved by NMR (1H-NMR and 13C-NMR) spectra.

Animals↗
PubMed1995

[The damped torsion swing test in guinea pigs].

The damped torsion swing test (DTST) was carried out for assessing the vestibular function in guinea pigs. Twenty guinea pigs which had normal pinna reflexes and normal tympanic membranes were used. In the formula, L represented the number of the left nystagmus, and R the right nystagmus during DTST. The symmetric rate [formula: see text] between left and right nystagmus was calculated. Then the animals were randomly divided into two groups: (1) Gentamicin group (n = 10): DTST was reexamined, Animals were injected with gentamicin (250 mg/kg) for three days. (2) Endolymphatic hydrops group (n = 10): Surgical obliteration of the right endolymphatic sac and duct was done, 30 days later DTST was carried out again. The results showed: (1) The normal value [formula: see text] of DTST in the 20 healthy guinea pigs is less than 8.25%. (2) Both of left and right nystagmus were reduced (P < 0.01) in gentamicin group. (3) The number of the right nystagmus was reduced in endolymphatic hydrops group (P < 0.01) and the symmetric rate of 6 animals was more than 8.25%. It is concluded that DTST is an important method of evaluating vestibular function in guinea pigs.

Animals↗