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Biomedical subjects

W Xu

Publications and source records attributed to W Xu.

At least 559 records · Page 31Linked to original sources
PubMed1991

[Radioimmunoassay of serum myelin basic protein].

Using purified human brain myelin basic protein (MBP) to raise antiserum in rabbits and to prepare 125I-labelled MBP (chloramine-T method), We have established a high specific, precise and sensitive double-antibody radioimmunoassay for the measurement of human serum MBP. The sensitivity was 0.5 ng/ml. In the present study, the serum samples of thirty patients with various neurological diseases were detected. An important clinical implication is that serum MBP level should serve as an index for the damage degree of central neurological diseases.

Animals↗
PubMed1991

Inhibited neoplastic phenotype by the c-Ha-ras antisense RNA.

A 2.0 kb fragment DNA plasmid which expresses antisense to the upstream first exon of c-Ha-ras oncogene was transfected into Ha-ras transformed cell lines, GCM-3T3 and REF-4.3. The transfection leads to the inhibition of malignant behaviour, shown by decreasing of growth speed, colony forming ability on soft agar, tumorigenicity in nude mice and increasing of differentiation degree. In GCM-3T3 cells the lung metastasis frequency became much less (from 60% to 12.5%) after the transfection and the expression of ras oncogene product, and p21 protein was obviously decreased in the transfected cells. This work has first shown the inhibitory effect of antisense RNA on neoplastic behaviour in China.

Animals↗
PubMed1991

[The amount of IgG synthesized within the central nervous system in patients with multiple sclerosis].

IgG-Alb ratio, IgG index and IgG synthesis rate were determined in 40 patients with multiple sclerosis (MS group), 20 patients with other neurologic diseases (OND group) and 22 normal persons (normal group) by using Beckman Immunochemistry System II. The results showed the average values and abnormal frequencies of the three parameters in MS group were significantly higher than those in the normal group and OND group (P less than 0.01), indicating the synthesis of IgG within the central nervous system (CNS) in MS. These parameters were increased in most of the MS patients. Therefore, they could be used in the diagnosis of MS. It was also found that the amount of IgG synthesized within CNS was decreased in patients treated with corticosteroids.

Adolescent↗
PubMed1991

An analysis of neuronal responses in nucleus centrum medianum to electrical stimulation of the superficial peroneal nerve.

Excitatory and inhibitory responses recorded extracellularly in neurons at various levels of the central nervous system induced by electrical noxious stimulation of peripheral nerves were frequently reported in studies on the mechanisms of acupuncture analgesia. However, the correlation between the responses and excitation of distinct afferent fibers was rarely investigated. The question whether the responses mentioned above are truly nociceptive in property is of significance to answer, and this is what we want to clarify in the present study. Sixty five neurons responding to electrical stimulation of the left superficial peroneal nerve were extracellularly recorded in the nucleus centrum medianum (CM) contralateral to the stimulation in 34 cats paralyzed with gallamine triethiodide and ventilated artificially under anaesthetics. Peristimulus histograms of the responses of CM neurons were plotted correspondingly, to the excitation of A delta and C-fibers, which was monitored by means of compound action potentials. To identify the nociceptive property of the responses ketamine or morphine was intravenously administered in some cases, capsaicin was topically applied at the superficial peroneal nerve proximal to the stimulated location in a few cases. Besides, the effect of electroacupuncture (EA) at Zusanli (St36) and Huantiao (GB30) points on the responses was observed. A total of 65 CM neurons recorded included 55 excited and 10 inhibited neurons.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1991

[Effects of electroacupuncture at different points on nociceptive responses of the ventro-basal complex].

The purpose of the present study was to compare the effects of electro-acupuncture at different points on nociceptive responses of VB neurons. The experiments were carried out on rats (280-320g) anaesthetized with urethane (19/kg,i.p.). Single unit activities of VB neurons were extracellularly recorded by means of glass microelectrodes. Noxious stimulation was subcutaneously applied at the left ankle joint by inserting two stainless needles. The experiments were divided into three groups: EA. I, EA. II and EA. III. The corresponding points being selected for electroacupuncture in the above three groups were the left "Huantiao" (G30) point, the right "Huantiao" point and the left "Jianlian" (T14) point. The results showed that electroacupuncture at the points in the three groups all could inhibit the nociceptive responses of VB neurons, but electroacupuncture an the left "Huantiao" point (n = 11) was more effective than either at the right "Huantian" point (n = 9) or at the left "Jianliao" point (n = 10). There was a significant difference among the three groups. However, there was no significant difference between EA. II and EA. III. Thus, the results indicate that there is a relative specificity of points in acupuncture analgesia.

Acupuncture Points↗
PubMed1990

Genetic and physical map of the von Recklinghausen neurofibromatosis (NF1) region on chromosome 17.

The von Recklinghausen neurofibromatosis 1 (NF1) locus has been previously assigned to the proximal long arm of chromosome 17, and two NF1 patients have been identified who have constitutional balanced translocations involving 17q11.2. We have constructed a cosmid library from a chromosome-mediated gene transfectant, KLT8, that contains approximately 10% of chromosome 17, including 17q11.2. Cosmids isolated from this library have been mapped across a panel of somatic cell hybrids, including the hybrids from the two patients, and have been localized to seven small regions of proximal 17q. We have 5 cosmids that map directly above the two NF1 translocations, and 11 cosmids that map directly below. Of these, 2 cosmids in each region are linked to the disease locus and 3 of these cosmids show no recombination. One distal cosmid, 2B/B35, detects the two NF1 translocations by pulsed-field gel analysis and has been used to produce a long-range restriction map that covers the translocations.

Blotting, Southern↗
PubMed1990

Clastogenic effects of known and suspect spindle poisons studied by chromosome analysis in mouse bone marrow cells.

The present study was performed within the project 'Genomic Mutations' (sponsored by the Commission of the European Communities) in order to gather all possible experimental information on 10 chemicals selected on the basis of their possible capacity to induce aneuploidy. An analysis of chromosomal aberrations was carried out in bone marrow cells of mice with the first five chemicals: colchicine (COL), econazole (EZ), chloralhydrate (CH), hydroquinone (HQ) and diazepam (DIAZ). The experiments were performed in parallel to micronucleus tests with the objective to distinguish a positive micronucleus response due to chromosomal breakage from that obtained by lagging chromosomes. The results of the micronucleus tests will be reported elsewhere. COL, CH, EZ and DIAZ showed no clastogenic effects in mouse bone marrow cells after single intraperitoneal injection. Polyploid cells were significantly more frequent after COL treatment. HQ showed a dose-dependent induction of chromosomal aberrations at 6 and 24 h after treatment. After 24 h, cells with multiple aberrations up to complete chromosome fragmentation were frequently observed. They indicate that a small fraction of the cell population, probably related to a specific stage of the cell cycle, was particularly sensitive to HQ. A sex difference in clastogenic response to HQ was not observed. It is concluded that of the five chemicals tested only HQ was clastogenic in mouse bone marrow cells under the present experimental conditions.

Aneuploidy↗
PubMed1990

[Evaluation of T cell subsets in myasthenia gravis by anti-T cell monoclonal antibodies].

In this paper, T lymphocyte subsets were measured in the peripheral blood of 46 patients with myasthenia gravis (MG) and 86 healthy controls, by using a modified microcytotoxicity assay and OKT monoclonal antibodies. The results showed that the OKT+3, OKT+4, OKT+8 cells of the patients with MG decreased significantly as compared with those of the controls (57.71% versus 66.42%; 34.50% versus 41.65%; 21.23% versus 27.19% respectively, P less than 0.01), and the OKT4/OKT8 ratio increased significantly (2.19 versus 1.64, P less than 0.05). Furthermore, the patients with the ocular type had less OKT+8 cells than those with the general type (14.19% versus 23.47%, P less than 0.05 and had a high OKT4/OKT8 ratio (3.27 versus 1.57, P less than 0.01). No correlating changes of T cell subsets with clinical conditions in that age, sex, and severity showed, and also that there was no difference between the patients whether prednisone was used or not (P greater than 0.05).

Adolescent↗
PubMed1990

Pharmacokinetic study of radioactive antineoplaston A10 in rats and mice.

Fifteen Wistar rats were divided into three groups: low dose--150 mg/kg, medium dose--300 mg/kg and high dose--600 mg/kg. 3H-labelled antineoplaston A10 (3H-A10) was administered to the rats in all three groups. Blood was withdrawn from the tail vein, while urine and faeces were collected at different time intervals for the determination of radioactivity. The volume of distribution (Vd) was evaluated in the rats by intravenous dosage of 150 mg/kg of 3H-A10 dissolved in dimethyl sulfoxide. Thirty mice were divided into six groups and sacrificed at 1, 3, 6, 12, 24 and 36 h respectively after oral administration of H3-A10 for the study of radioactivity in various organs. It was observed that the concentration-time curves of A10 in the blood support a dicompartmental model of pharmacokinetics, and calculated values are very close to experimental values. The binding rate of A10 to plasma protein is 5.05% at 3 h after oral administration. Organ distribution studies indicated the highest accumulation of radioactivity in the bladder, followed by kidney, stomach, genitals and liver, whereas there was lower accumulation of radioactivity in the spleen, heart, brains and lungs.

Administration, Oral↗
PubMed1990

Studies of the release rate and bioavailability of antineoplaston A10 capsule.

The effect of Tween-80 on the release rate of antineoplaston A10 capsule in vitro was measured. When 0.1% Tween-80 was added to A10 capsule, the cumulative release rate of A10 was doubled in artificial gastric juice and tripled in artificial enteric juice within 2 h. The bioavailability of A10 capsules was determined with tritium-labelled A10 in rabbits. The results showed that the bioavailability of A10 capsule containing 0.1% Tween-80 increased 44.05%. The highest concentration of A10 in the blood was increased 35%. The time to reach peak was reduced 1 h.

Administration, Oral↗
PubMed1990

[Relationship between the precruciate cortex and the ventral lateral posterior nucleus of the thalamus in acupuncture analgesia].

The present study was designed to investigate the relationship between the precruciate cortex (PreCtx) and the ventral lateral posterior nucleus (VPL) of the thalamus in the mechanisms of acupuncture analgesia. Neuronal responses in the nucleus VPL to electrical noxious stimulation of the superficial peroneal nerve were extracellularly recorded. Lidocaine was topically applied at PreCtx. Twenty minutes after the application electroacupuncture (EA) was employed at "Zusanli" and "Huantiao" points for 5 minutes. The nociceptive responses were recorded immediately after cessation of EA and consecutively recorded at the interval of 2 minutes. Similar procedures were made in the control group, in which 0.9% Nacl was topically applied at PreCtx. It was found that topical application of lidocaine at PreCtx did not influence the nociceptive responses of VPL neurons. Following topical application of lidocaine at PreCtx, the nociceptive responses were obviously inhibited 0', 4', 6', 10', and 12' after cessation of EA. In the saline control group the remarkable inhibitory effect of EA was observed 0'-8' after ceasing EA, The results showed that the inhibitory effect of EA in the test group was weaker than that in the control group. However, the difference was not statistically significant. It is suggested that PreCtx participates in the corticofugal modulation of EA effects in the nucleus VPL only to small extent.

Acupuncture Analgesia↗
PubMed1990

[Changes in responses of parafascicular nuclei during adjuvant-induced acute arthritis and effect of acupuncture in the rat].

We have previously demonstrated that during acute arthritis in the rats induced by local intraplanter adjuvant, there are dramatic alterations in the behavioral responses to noxious stimulation. The purpose of this study was to observe the changes in responses of parafascicular nuclei (Pf) neurons during acute arthritis and effect of acupuncture (EA) in the rats. It was shown that: (1). for the whole populations of somatosensory neurons there was no statistical significant between arthritic rat and normal rat (P greater than 0.05). However, nociceptive neurons activated exclusively by noxious stimulation were less in the arthritic rat (21/60) than in the normal rat (35/46) (P less than 0.01); nociceptive-non-nociceptive neurons activated by both noxious and non-noxious stimulation were more in the arthritic rat (30/60) than in the normal rat (9/46) (P less than 0.01), and there was no statistical significant different for population of non-nociceptive neurons between two groups. (2). Nociceptive responses of Pf neurons (n = 16) could be markedly inhibited by EA at Xuanzhong (G39) and Kunlun (B60) in acute arthritic rat. In particular, the inhibitory effect was of great significance (P less than 0.01) during 0-10 and 20-35 minutes following cessation of EA. These results suggest that rats were hyperalgesic during adjuvant-induced acute arthritis and EA produces a fine analgesic effect in acute arthritic rats. The results also support the view that adjuvant-induced acute arthritic rat can be considered as a model for research of pain and analgesia.

Animals↗
PubMed1990

[Reduction of effects of stimulating SmI and electroacupuncture produced by intraperitoneal injecting atropine in the adjuvant-induced acute arthritic rat].

Using the adjuvant-induced acute arthritic rat as a pain model, we have previously shown that the SmI area is implicated in the inhibitory effect of acupuncture on the afferent nociceptive information of parafascicular nuclei (Pf). The purpose of this study was to determine whether acetylcholine (ACh) participates in this modulatory process. Experiments were conducted with adjuvant-induced acute arthritic rats and extracellular recordings from pf were obtained through microelectrodes stereotaxically. The results showed that: (1) After intraperitoneal-injecting atropine (5mg/kg), the effect of stimulating SmI on nociceptive responses of Pf neurons was decreased, while it was not decreased if saline was administered. Compared in the same neurons, the difference of nociceptive responses at 0' to 15' after cessation of stimulating SmI was statistically significant. This finding indicated that ACh was involved in descending modulation of SmI. (2) The effect of acupuncture was decreased after intraperitoneal-injecting atropine (5mg/kg), while it was not decreased if saline was administered. The difference of nociceptive response was statistically significant at 0' to 10' and 20' to 40' after cessation of EA in comparison between the background of atropine and saline. It indicated that ACh was involved in acupuncture analgesia. These results suggest that ACh may be participated in acupuncture analgesia as a neurotransmitter of the corticofugal modulation of pain.

Acupuncture Analgesia↗
PubMed1990

[Drug resistant plasmids of Pseudomonas pyocyanea in the respiratory tract].

This paper reports the results of the conjugating transmission test, the plasmid elimination test and the plasmid analysis of pseudomonas pyocyanea which were separated from the sputum of the patients with infection of respiratory tract. The result of the conjugating test and the plasmid elimination test of P6P8 strains indicated that the partial drug resistances of two strains are mediated by the drug resistant plasmids. The results of the plasmids analysis in 14 strains of pseudomonas pyocyanea showed that this pyocyanic infection was mainly caused by the bacillus pyocyanea carrying 38 x 10(6) dal plasmids. The technique of plasmid analysis is simple and good repetition. The specificity of this method is analogous to phage typing. This method is worth popular in the epidemic investigation of pathogenic bacteria tracing.

Anti-Bacterial Agents↗