PubMed Health⌕ Search

Biomedical subjects

C L Xu

Publications and source records attributed to C L Xu.

18 recordsLinked to original sources
PubMed2006

Effects of a dried Bacillus subtilis culture on egg quality.

The effects of a dried Bacillus subtilis culture on the egg qualities of layers were studied. Nine hundred and sixty 25-wk-old Lohmann Brown layers were randomly divided into 5 groups with 192 layers in each group. Layers in group 1 were fed a control diet. The remaining groups received the control diet that contained either 20 mg of zinc bacitracin/kg and 4 mg of colistin sulfate/kg or 500, 1,000, or 1,500 mg of B. subtilis culture/ kg, respectively. The results showed improvements in egg production, feed consumption, and feed conversion (P < 0.05) of layers when 500 mg of B. subtilis culture/kg was added to the diets. The results also showed some special improvements in this group, including increases in eggshell thickness, yolk color, and Haugh unit, and decreases in yolk cholesterol concentration (P < 0.05). However, excessive doses of B. subtilis culture did not improve the performance of layers.

Animals↗
PubMed2002

Direct synthesis of long single-walled carbon nanotube strands.

In the processes that are used to produce single-walled nanotubes (electric arc, laser ablation, and chemical vapor deposition), the typical lengths of tangled nanotube bundles reach several tens of micrometers. We report that long nanotube strands, up to several centimeters in length, consisting of aligned single-walled nanotubes can be synthesized by the catalytic pyrolysis of n-hexane with an enhanced vertical floating technique. The long strands of nanotubes assemble continuously from arrays of nanotubes, which are intrinsically long.

Journal Article↗
PubMed2001

Intraurethral brachytherapy for prevention of recurrent urethral stricture after internal urethrotomy or transurethral resection of scar.

BACKGROUND PURPOSE: Restricture after internal urethrotomy is the major limitation to the long-term success of the procedure. The objective of this study was to evaluate the effect of intraurethral brachytherapy after internal urethrotomy or transurethral scar resection on recurrent urethral stricture. PATIENTS AND METHODS: From January 1998 to June 1999, catheter-based intraurethral brachytherapy with 192-iridium was performed in 17 patients with recurrent urethral stricture to prevent restricture after internal urethrotomy or transurethral resection of scar. The radiation was repeated within 3 days after surgery to reach a total dosage of 1000 to 1500 cGy. RESULTS: During the follow-up (range 14-27 months; mean 20 months), two patients had dysuria, including one patient with an atonic detrusor muscle. The other patient needed self-dilation. Fifteen patients presented normal voiding. The stricture recurred 3 months later in only one patient, so the restricture rate is 7%. No significant complication was observed associated with brachytherapy during the follow-up. CONCLUSION: Intraurethral brachytherapy after internal urethrotomy or transurethral resection of scar is a safe and effective treatment for recurrent urethral strictures.

Adolescent↗
PubMed1999

C-fos expression in the spinal cord of rats exhibiting allodynia following contusive spinal cord injury.

Contusive spinal cord injury (SCI) may result in central neuropathic pain marked by allodynia-like features in the dermatomes close to the level of injury. The aim of this study was to compare the laminar distribution of activated neurons (as determined by c-fos immediate early gene expression) in the spinal cord immediately above the level of a SCI in rats with or without allodynia-like features. Non-noxious mechanical stimulation was applied to half the animals in the dermatomes corresponding to the level of injury prior to perfusion. Stimulation resulted in a significant increase in c-fos labelling in all laminae of the spinal dorsal horn in the segment immediately above the level of injury only in allodynia animals. Animals that had allodynia also demonstrated a significant increase in the level of c-fos labelling in lamina III, IV and V of the dorsal horn without stimulation. Thus, allodynia following SCI is associated with significant increases in basal and evoked c-fos expression ("neuronal activity") in response to non-noxious mechanical stimulation. The data also suggest that allodynia-like behaviour following SCI cannot be accounted for solely by changes occurring at a spinal level.

Animals↗
PubMed1997

Effect of oral feeding of essence of chicken on the level of 5-hydroxyindole acetic acid in the cerebrospinal fluid of the rat.

The effect of oral feeding of a commercial preparation of essence of chicken (Brand's Essence of Chicken, BEC) on the level of 5-hydroxyindole acetic acid (5-HIAA) in the cerebrospinal fluid (CSF) of the rat was investigated. BEC, when fed to the rat for a period of 3 days, significantly increased the CSF level of 5-HIAA in seven out of 12 animals studied. As the level of CSF 5-HIAA is taken as an indication of 5-hydroxytryptamine (5-HT) activity in the brain, it is possible that BEC increased brain 5-HT activity. This increase was not due to the ingestion of tryptophan, the primary precursor of 5-HT, because BEC contains undetectable level of tryptophan. The data indicate that by causing an increase in brain 5-HT activity, consumption of BEC may lead to the activation of 5-HT-dependent physiological process like sleep improvement, mood elevation, analgesia, facilitation of motor output and regulation of circadian rhythm. However, such a possibility remains to be further investigated.

Animals↗
PubMed1995

Reduction of dihydroxyphenylacetic acid by a novel enzyme in the rat brain.

A novel enzyme that converts dihydroxyphenylacetic acid (DOPAC) to dihydroxyphenylethanol (DOPET) was found to be present in the microdialysate of the rat brain. The enzyme, named DOPAC reductase, was inhibited by EDTA and stimulated by divalent cations like Zn2+, Mn2+, Co2+ and Cu2+. Its Km, pH optimum and temperature optimum were found to be 32 +/- 2 microM, 7.5 and 40 degrees, respectively. The equivalent acid metabolite of noradrenaline, 3,4-dihydroxymandelic acid, and the methoxylated acids of both noradrenaline and dopamine, 3-methoxy-4-hydroxymandelic acid and 3-methoxy-4-hydroxyphenylacetic acid, were found not to be substrates of DOPAC reductase. Thus, DOPAC reductase may be an enzyme that is specifically involved in the one-step conversion of DOPAC to DOPET in the central metabolism of dopamine.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1995

Allodynia following traumatic spinal cord injury in the rat.

A weight-drop model of spinal cord injury was used to characterize the sensory changes that occur following mechanical trauma to the spinal cord and to determine the relationship of these changes to the extent of lesion. Weight-drop from different heights resulted in significant differences in motor dysfunction between experimental groups. These groups also demonstrated significant differences in the incidence of allodynia (decreased vocalization threshold to mechanical pressure). The incidence of allodynia was higher in the group that had incomplete spinal cord lesions confined to the central and dorsal regions of the spinal cord and lower in the groups that had either more extensive spinal cord damage or no apparent damage.

Animals↗
PubMed1994

Effect of perfusate pH on reduction of quinidine capillary permeability by albumin in isolated perfused rat heart.

It has been suggested that albumin reduces quinidine capillary permeability (PS) in the single-pass perfused heart preparation by reducing paracellular transport of quinidine ions. Using this preparation, we examined the effect of albumin (0.1 per cent) on quinidine PS at perfusate pH's of 7.1 and 7.9 during uptake of quinidine (19 microM) and also during washout of the drug using a randomized design. Quinidine PS was approximately 16 ml/min/g heart at pH 7.9 and was not altered by the presence of albumin in perfusate. At pH 7.1, in the absence of albumin, quinidine PS was also 16 ml/min/g, but in the presence of albumin (0.1 per cent) PS was reduced significantly to approximately 5 ml/min/g (P < 0.001). In the absence of albumin PS was the same at pH 7.1 and 7.9 in spite of a greater degree of ionisation of quinidine at pH 7.1. This suggests that there is significant uptake of ionised quinidine at pH 7.1. The greater effect of albumin on PS at pH 7.1 supports the hypothesis that albumin reduces paracellular transport of quinidine ions.

Animals↗
PubMed1992

[Effect of total saponins of Panax ginseng on hematopoietic progenitor cells in normal human and aplastic anemia patients].

Ginseng was said to be benefit for anemia in TCM. Proliferation effects of total saponins of panax ginseng (TSPG) on hematopoietic progenitor cell in normal individuals and 29 patients with aplastic anemia (AA) were observed by bone marrow culture of BFU-E, CFU-E, CFU-GM in vitro compared with methyltestosterone (MT). The results showed that TSPG might prompt proliferation of normal progenitor cells at the concentration of 20 micrograms/ml. The number of BFU-E, CFU-E and CFU-GM had increased by 37.8 +/- 2.9%, 31.4 +/- 2.9% and 33.3 +/- 4.0% over the controls respectively; furthermore TSPG was still useful to BFU-E, CFU-E growth without Epo in vitro, although the colony numbers were very lower. Otherwise MT was useless to CFU-GM. 14 of the 29 patients with AA who responded to MT showed sensitivity to TSPG in marrow culture (the rising rate of colony formation exceeded 30%), but immune-mediated AA (patient's PBMNC suppressed normal hematopoiesis) and stem cell-decreased AA (few of colony was formed) showed almost no expression for TSPG activity because of immunological suppression system and absence of progenitors.

Adolescent↗
PubMed1989

[Variability of Apo B-containing lipoprotein in the plasma of experimental atherosclerotic rabbits].

The effects of dietary cholesterol on plasma Apo B-containing lipoprotein was studied in 18 rabbits. When atherosclerosis was induced by dietary cholesterol, the cholesterol and peroxide lipids were increased in the intima of aortae (P less than 0.05). The increased plasma Apo B was positively correlated with hypercholesterolemia (r = 0.879, P less than 0.005). In the pre-stain lipoprotein electrophoresis and immunoelectrophoresis with Apo B antiserum, electrophoretic mobility of Apo B-containing lipoprotein was slower than those of the control rabbits and this band was wide and stained deeper. In Sephadex G-200 exclusion chromatography there was evidence showing that the reduction in electrophoretic mobility of Apo B-containing lipoprotein is due to the increase particle size.

Animals↗
PubMed1987

[Diagnosis and taxonomy of periodical psychosis].

The concept and taxonomy of periodic psychosis still remains in controversy for the past 100 years. In China, it was first reported by Ji, and thereafter various rinds of terminology and views were given by different authors. In the presentation, clinical investigation and follow up were carried out in 62 cases. In many of these cases, the so-called "periodic psychosis" or "phasophrenia" was early clinical features of schizophrenia or manic-depression. In those cases with apparent symptoms and signs of diencephalic function, differential diagnosis should be carried out from organic brain syndrome. In a small number of cases, their clinical manifestations, conforming to previous diagnostic criteria, might be an uncommon syndrome. It was concluded by the authors that until now periodic could be considered only as a clinical syndrome rather than a disease entity.

Bipolar Disorder↗