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Biomedical subjects

J Fang

Publications and source records attributed to J Fang.

At least 307 records · Page 17Linked to original sources
PubMed1995

[Analysis of beta-thalassemia mutations and prenated diagnosis in Chengdu population].

Ninety-five of non-differential diagnostic patients were detected by dot-blot analysis on enzymatically amplified DNA with a number of allele specific oligonucleotide probes complementary to the most common mutations in Chengdu population. Prenatal diagnosis was accomplished by the same procedure on enzymatically amplified amniocyte DNA. The result revealed fifty-eight cases of beta-thalassemia. Of the 73 chromosomes tested, twenty-eight (38.4%) had the codon 17(A-->T) mutation, twenty-one (28.8%) had the codon 41-42(-TTCT) mutation, fourteen (19.0%) had the IVS-I-654(C-->T) mutation; nt--28(A-->G) and nt--29(A-->G) mutations were six (8.2%) and four (5.5%) respectively.

Base Sequence↗
PubMed1994

Inhibition of nitric oxide synthesis inhibits rat sleep.

Previous findings indicate that nitric oxide (NO) may play a role in the regulation of sleep-wake activity. In rabbits, blocking the production of endogenous NO by a nitric oxide synthase inhibitor, N omega-nitro-L-arginine (L-NAME) suppresses spontaneous sleep and interferes the somnogenic actions of interleukin 1. In the present experiments we extended our earlier work by studying the long-term effects of L-NAME treatment on sleep-wake activity including power spectra analyses of the electroencephalogram (EEG) in rats. Rats implanted with EEG electrodes, brain thermistor, and intracerebroventricular (i.c.v.) guide cannula were injected i.c.v. with vehicle or 0.2, 1, or 5 mg L-NAME at light onset. In separate experiments, rats were injected intraperitoneally (i.p.) with L-NAME three times (50, 50, 100 mg/kg), 12-12 h apart. Both i.c.v. and i.p. injections of L-NAME elicited decreases in time spent in NREMS and REMS. After i.c.v. injection of 5 mg L-NAME the sleep responses were long-lasting; NREMS did not return to baseline even 72 h after injection. EEG delta-wave activity during NREMS (slow wave activity) was also suppressed after 0.2 and 5 mg L-NAME. Brain temperature was slightly increased after the two lower doses of L-NAME, whereas there was a transient decrease in Tbr after 5 mg L-NAME. Acute i.p. injection of 50 mg/kg L-NAME elicited an immediate decrease in NREMS which lasted for approximately 2 h. The second injection of 50 mg/kg L-NAME and the following injection of 100 mg/kg L-NAME induced biphasic decreases in NREMS but not REMS.

Amino Acid Oxidoreductases↗
PubMed1994

Increase of prolactin mRNA in the rat hypothalamus after intracerebroventricular injection of VIP or PACAP.

Vasoactive intestinal peptide (VIP), the structurally homologous pituitary adenylate cyclase-activating peptide (PACAP) and the pituitary hormone, prolactin (PRL) enhance rapid eye movement sleep (REMS). VIP and PACAP are both inducers of PRL gene expression and release in the pituitary gland. Little is known about PRL regulation in the brain although it is hypothesized that the REMS-promoting activity of i.c.v. administered VIP may be mediated via the activation of cerebral PRL. To test whether VIP or PACAP in fact increase intracerebral mRNA, the peptides (VIP: 30 or 300 pmol; PACAP: 220 pmol) were injected i.c.v. into rats at dark onset. 1 h later, cDNA was synthesized from purified hypothalamic mRNA. Standardized amounts were analysed for PRL using the polymerase chain reaction followed by Southern blotting and hybridization. Compared with beta-actin mRNA levels, both VIP and PACAP increased PRL mRNA levels in a dose-dependent fashion though VIP was more effective on a molar basis. The previously reported alternatively spliced PRL mRNA (lacking exon 4) was not detected. The data support the hypothesis that the REMS-promoting activity of central VIP and PACAP might be mediated by cerebral PRL.

Animals↗
PubMed1994

Effect of L-deprenyl, its structural analogues and some monoamine oxidase inhibitors on dopamine uptake.

The effect on dopamine uptake by L-deprenyl, its structural analogues and different types of monoamine oxidase (MAO) inhibitors was investigated. Both direct [3H]dopamine uptake into rat striatal slices and binding of a specific dopamine uptake inhibitor [3H]GBR-12935 were used in the present study. L-Deprenyl exhibits a relatively weak dopamine uptake inhibitory effect in vitro, while D-deprenyl possesses a very potent inhibitory effect. The potent effect of D-deprenyl on dopamine uptake may be responsible, at least in part, for its behavioral effects and abuse liability. L-Methamphetamine, a metabolite of L-deprenyl, does not inhibit [3H]GBR-12935 binding but it reduces the retention of [3H]dopamine in striatal tissues, suggesting that it may enhance dopamine release. The MAO-A inhibitors clorgyline and brofaromine also exhibit dopamine uptake inhibitory effects. Irreversible and reversible MAO-B inhibitors, however, such as pargyline, aliphatic N-methylpropargylamines, Ro 19-6327 and MDL-72974A and MAO-A inhibitor moclobemide do not possess any appreciable inhibitory effects on dopamine uptake. Dopamine uptake is probably unrelated to the pharmacological actions of L-deprenyl.

Animals↗
PubMed1994

Neuroprotective effects of some monoamine oxidase-B inhibitors against DSP-4-induced noradrenaline depletion in the mouse hippocampus.

DSP-4 [N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine], a selective noradrenaline (NA) uptake blocker, is capable of inducing long-lasting depletion of NA in some noradrenergic axon terminals and of subsequently causing cell death to NA neuronal cell bodies in rodents. R(-)-Deprenyl, a selective monoamine oxidase (MAO)-B inhibitor, has been shown to be capable of protecting animals against this DSP-4-induced neuronal degeneration. Its action, however, has been claimed to be unrelated to the inhibition of MAO-B activity but rather due to competition for the NA uptake sites. The effects of several types of MAO inhibitors against DSP-4 toxicity, MAO-B activity both in vivo and in vitro, and NA uptake into the hippocampus have been assessed. N-(2-Hexyl)-N-methylpropargylamine (2-HxMP), a potent MAO-B inhibitor, for example, exerts no appreciable effect on NA uptake but is quite potent in counteracting the NA-depleting effect of DSP-4. Such results rule out the possibility that the neuroprotective effect of the MAO-B inhibitors is due mainly to their effect on NA uptake. The in vitro inhibition of MAO-B activity seems to correlate positively with their neuroprotective effects against DSP-4. In comparison to the MAO-B inhibitors, NA uptake blockers, such as desipramine and S(+)-deprenyl, exhibit relatively low efficacy in protecting the NA axon terminals from the effects of DSP-4-induced damage. The restoration of hippocampal NA levels is significantly enhanced with repeated treatments of R(-)-deprenyl or 2-HxMP even at very low doses following the DSP-4 insult.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

[Preparation and application of ELISA kit for detection of G-CSF].

By adding monoclonal antibodies from BALB/c mice to the granulocyte colony-stimulating factor (G-CSF), we established a sandwich ELISA for detecting G-CSF levels in human serum samples. G-CSF was measured in 157 normal serum samples and in 153 serum samples from patients with no clinical manifestation of bacterial infection and in 269 serum samples from patients with clinical diagnosis of bacterial infection and in 31 serum samples from patients with positive bacterial infection according to cell culture. It was found that the positive rates of G-CSF were zero in normal serum samples, only 6.5% in patients with no clinical manifestation of bacterial infection, 89.2% in patients with clinical diagnosis of bacterial infection and 100% in patients with bacterial culture positive for infection. Our results reveal that the sandwich ELISA for detection of G-CSF levels in human serum samples may be useful for diagnosing patients with bacterial infection and for clinically guiding the rational use of antibiotics.

Animals↗
PubMed1994

[A primary study of the factors related to the patients' adherence of anti-hypertensive therapy].

An interview covering demographic information, history of hypertension as well as medical and health-related questions was conducted on 540 hypertension patients in Chengdu. The objective of the study was to analyse the factors related to the adherence to antihypertensive therapy of these patients. The simple analysis showed that the education level of the patients, the type of payment for visiting physician, the convenience of visiting physician, the awareness of the severity of hypertension, the average family income of the patients were related to the adherence to therapy. The step multi-regression analysis showed that the type of payment for visiting physician, the convenience of visiting physician and the average family income were related to the adherence to antihypertensive therapy.

Adult↗
PubMed1994

[Influence of acupuncture at zusanli point on function of 5-HT and M receptor in rat's brain and spleen].

5-HT and muscarine (M) receptors total binding capacities (Rt) in different brain areas and spleen were determined using receptor radioligand binding assay (RLBA) after needling zusanli of rats. And the rats without needling and needling Taichong point were used as control. These results showed that 5-HT and M receptors Rt were decreased obviously than control group in rat's cerebral cortex, hippocampus, striatum, spinal cord and spleen when needling zusanli can produce obvious acupuncture analgesia. 5-HT Rt in brain stem and medulla oblongata was obviously decreased and not changed in thalamus. M receptor Rt value was not changed clearly in brain stem and medulla oblongata as well, but it was obviously decreased in thalamus. These results showed that effects of acupoints on Various meridians are different, thus the results of acupuncture at Zusanli are distinct from taichong.

Acupuncture Points↗
PubMed1994

[The influence of acupuncture at zusanli on cyclic nucleotide contents of plasma, different brain regions and spleen in rats].

We observed cyclic nucleotide content of plasma, brain and Spleen tissues when analgesia was produced by acupuncture at the Zusanli. The restrained group without acupuncture was as blank control and acupuncture at Taichong as acupuncture control. We found that after acupuncture at Zusanli the concentration of cyclic nucleotide in plasma was increased significantly (P < 0.05) and the cAMP concentration of spleen had a tendency of enhancement, but the content of cAMP in the cortex had a tendency of decrease. The concentration of cAMP, cGMP and its ratio cAMP/cGMP was different in cortex and spinal cord between acupuncture at Zusanli and Taichong groups. These results showed that acupuncture at Zusanli and Taichong could induce different changes of concentration of cAMP and cGMP.

Acupuncture Points↗
PubMed1994

Characterization of a pseudorabies virus that is defective in the early protein 0 and latency genes.

A recombinant pseudorabies virus that is defective in the early protein 0 (EP0) and large latency transcript (LLT) genes was constructed. A portion of the EP0 and LLT genes was replaced by the lacZ gene of Escherichia coli that had been placed under the control of the pseudorabies virus gX gene promoter. This recombinant virus produces smaller size plaques and yields less virus than does the parent virus on Madin-Darby bovine kidney cells. Although the time course of virus replication and release into the medium of the recombinant and parent viruses are similar, the recombinant virus did not reach as high a titer. Similar to the parent virus, the recombinant virus replicates in the upper segment of the respiratory tract of swine, but the amount of progeny viruses produced is significantly reduced. The data indicated that the EP0 and LLT genes of pseudorabies virus are nonessential for replication. Virus that lacks these 2 genes has impaired growth in tissue culture and is attenuated for swine, compared with the parent virus.

Animals↗
PubMed1994

Clinical observation and treatment of hyperkinesia in children by traditional Chinese medicine.

Sixty-six children with hyperkinesia were treated with the Yizhi (wit-increasing) syrup, after which their scores on behavior dropped, their school records improved, and the rate of appearance of soft neurotic signs lowered, all three changes being significant, giving a total effectiveness rate of 84.8%. After the treatment, examination of the 24-hour urine showed significant increases in its content of norepinephrine (NE), dopamine (DA), 3-4 dihydroxy phenylacetic acid (DOPAC), cyclic adenosine monophosphate (cAMP), and creatinine (Cr).

Adolescent↗
PubMed1994

[Inhibitory effects of esculentoside A on mouse macrophages and antibody production].

Esculentoside A (EsA) is a kind of saponin isolated from Phytolacca esculenta Van Houtte. It was shown to significantly inhibit phagocytic activity, intracellular and extracellular production of interleukin-1 by thioglycollate primed murine peritoneal macrophages in vitro at the concentration 0.01-1.0 mumol.L-1. In vivo experiments showed that EsA 2.5-5 mg.kg-1 markedly decreased serum hemolysin concentration in sensitized mice challenged with sheep red blood cells. Inhibition of antibody production by B lymphocytes, phagocytosis and the production of inflammatory mediators by macrophages may partially explain the wide and strong anti-inflammatory effect of EsA.

Animals↗
PubMed1994

Leflunomide inhibits cytokine-induced DNA synthesis of rabbit synovial cells in culture.

The effects of interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF alpha) and granulocyte-macrophage colony-stimulating factor (GM-CSF) on DNA synthesis of rabbit synovial cells were studied. IL-1 beta 1000-10,000 U.ml-1, IL-6 10-1000 U.ml-1, TNF alpha 0.5-50 U.ml-1 and GM-CSF 1-100 ng.ml-1 concentration-dependently stimulated DNA synthesis in rabbit synovial cells in culture. Leflunomide (LFM) and its metabolite A77 1726 elicited an inhibitory effect on such cytokine-induced DNA synthesis of synovial cells. These results suggested that IL-1 beta, IL-6, TNF alpha and GM-CSF play a key role in the pathogenesis of rheumatoid arthritis. Inhibition of cytokine-induced proliferation of synovial cells by LFM may partially explain its antirheumatic activity.

Aniline Compounds↗
PubMed1994

Inhibitory effects of triazolodiazepine on mouse splenocytes and peritoneal macrophages in vitro.

Effects of triazolodiazepine (Tri) on mouse splenocyte proliferation and macrophage phagocytosis were studied. Tri 0.1-10 mumol.L-1 significantly inhibited concanavalin A (Con A) 5 micrograms.ml-1 and lipopolysaccharides (LPS) 10 micrograms.ml-1-induced splenocyte proliferation and phagocytic activity of activated peritoneal macrophages. Tri 10 mumol.L-1 reduced Con A-induced colony stimulating factor release from mouse splenocytes and LPS-challenged intracellular and extracellular interleukin-1 production from peritoneal macrophages. These results partially explain the wide and strong anti-inflammatory effects of Tri.

Animals↗
PubMed1994

[Leflunomide inhibits PAF induced DNA synthesis in rabbit synovial cells and PAF production from rat peritoneal macrophages].

Leflunomide (LFM, HWA 486) is an isoxazol derivative with antiphogistic and novel immunomodulating properties. It has been shown to be very effective in preventing and curing arthritis. In this report we found that platelet-activating factor (PAF) at 0.1-10 micrograms.ml-1 significantly stimulated DNA synthesis in cultured rabbit synovial cells. While LFM and its metabolite A771726 elicited inhibitory effects on this action of PAF. These two agents were also shown to markedly inhibit A23187 induced PAF production from rat peritoneal macrophages. The inhibition was dose and time-dependent. The inhibitory effects of LFM and A771726 on DNA synthesis in synovial cells and PAF production from macrophages may play an important role in the antiinflammatory effects of LFM.

Aniline Compounds↗
PubMed1993

Cortical and spinal motor excitability during the transcranial magnetic stimulation silent period in humans.

We investigated the electromyographic silent period in abductor pollicis brevis (APB) and flexor carpi radialis muscles following transcranial magnetic stimulation of human motor cortex. In APB, we measured cortical stimulation silent period (CSSP) duration as a function of stimulus intensity, motor-evoked potential (MEP) amplitude and muscle twitch force. We used peri-stimulus-time histograms to study the effect of cortical stimulation on single-motor unit firing patterns. We compared F-waves, H-reflexes and magnetic MEPs elicited during the CSSP to control responses elicited at rest and during voluntary contraction. CSSP duration depended on the intensity of cortical stimulation. However, we found no relationship between CSSP duration and MEP amplitude or muscle twitch force, thus the CSSP is not dependent solely on Renshaw cell inhibition or on changes in Ia and Ib afferent activity following the cortically induced muscle twitch. At low intensities of stimulation, the interval to resumption of motor unit firing following the peak in the peri-stimulus-time histogram corresponding to MEP latency sometimes exceeded that which could be accounted for by the motor unit's firing rate prior to the stimulus, suggesting that synchronization of motor unit firing by cortical stimulation cannot account for the CSSP. We found brief inhibition of F-waves during the CSSP in some subjects, reflecting activation of inhibitory corticospinal projections or segmental effects. In contrast, we observed longer inhibition of H-reflexes during the CSSP in all subjects, perhaps resulting from presynaptic inhibition of Ia afferents. Magnetic MEPs also were inhibited during the CSSP, suggesting inhibition of cortical elements by transcranial magnetic stimulation.

Adult↗
PubMed1993

Investigation of the metabolism of the neuroleptic drug haloperidol by capillary electrophoresis.

Free solution capillary electrophoresis (FSCE) conditions were previously reported to be of limited use for the separation of pharmaceuticals, since many of these compounds are neutral. We show that by consideration of compound hydrophobicity and ionisable functional groups, FSCE conditions can be developed to effect the separation of a drug and its phase I metabolites. This is brought about by adding a suitable organic modifier to aid solubility, and modifying pH to effect a change in the mass to charge ratio of the metabolites present. Furthermore, we show that in this drug metabolism study, FSCE presents an advantage over both reversed-phase HPLC and micellar electrokinetic chromatography. We also demonstrate the use of FSCE for investigation of the phase I metabolites produced by the in vitro incubation of haloperidol (a neuroleptic agent) with both mouse and guinea pig hepatic microsomes and show that such an approach can be used to detect both qualitative and quantitative differences in species metabolism.

Animals↗