Biomedical subjects

F Xu

Publications and source records attributed to F Xu.

At least 127 records · Page 7Linked to original sources

PubMed2000

[Application of Conners Rating Scales in the study of lead exposure and behavioral effects in children].

OBJECTIVE: To seek specific indices reflecting individual level of long-term exposure to lead and its behavioral effects. METHODS: Ninety-eight children of grades one to four in primary schools in the areas polluted by lead were chosen as exposed group and 100 children from areas without lead pollution as control group. Levels of blood lead, hair lead and blood zinc protoporphyrin (ZPP) in both groups were determined to evaluate their exposure to lead. Their urinary homovanillic acid (HVA) and vanillylmandelic acid (VMA) were determined by a method combined high-performance liquid chromatography (HPLC) with electric chemistry (EC) technique. Behavioral effects in children exposed to lead were assessed by Conners' Rating Scales for Teachers and Parents. RESULTS: Levels of blood lead, hair lead and blood ZPP in the exposed group increased to 2.39-2.42 mumol/L, 81.81-83.77 mumol/kg and 0.55-0.65 mumol/L in average, respectively, and levels of HVA and VMA decreased to 0.53 mmol/mol creatinine and 0.68 mmol/mol creatinine in average, respectively, both with a very significant difference as compared with those in the control group. There were significant differences in the scores of behavioral factors between the two groups. Factors I, IV and VI in Conners' Parents' Rating Scales correlated positively with levels of hair lead, while factors I, II, IV and VI correlated positively with blood ZPP levels in girls. CONCLUSION: Conners' Rating Scales for Teachers and Parents can be used to assess their behavioral effects in children, and levels of hair lead and blood lead can be used as good markers to reflect level of exposure to lead in children.

Attention Deficit Disorder with Hyperactivity↗

PubMed2000

[Detection and significance of interleukin-8,6, tumor necrosis factor-alpha in sputa from patients with chronic obstructive pulmonary disease].

OBJECTIVE: To evaluate the role of cytokines in the pathogenesis of COPD. METHODS: Induced sputum samples were obtained from 20 patients with stable COPD, 10 healthy smokers (HS) and 10 healthy nonsmokers (HNS). Total and differential cell counts were examined, and sputum interleukin (IL)-8, tumor necrosis factor (TNF)-alpha, IL-6 level were measured by radioimmunoassay technique. RESULTS: Sputum IL-8, TNF-alpha level and neutrophil percentages (PMN) in the COPD group were significantly higher than those in the HS group and the HNS group (P < 0.01). Compared with the HNS group, there was a significant increase in the PMN and the level of IL-8 in the HS group (P < 0.05). The sputum level of IL-6 did not differ significantly among three groups (P > 0.05). In the COPD group, the sputum level of IL-8 was correlated positively with the level of TNF-alpha and the PMN (r's = 0.5999, 0.6737). In the HS group the sputum level of IL-8 was also correlated positively with the PMN (rs = 0.8424). The sputum IL-8, TNF-alpha levels and the PMN were all correlated negatively with FEV1% and FEV1/FVC in the COPD group (r's = -0.6453, -0.7341, -0.7341, -0.7624, -0.5262, -0.7353). CONCLUSIONS: IL-8, TNF-alpha and neutrophil are involved in airway inflammation which results in airflow obstruction, thus playing an important role in the pathogenetic process of COPD.

Aged↗

PubMed2000

[Effect of Weikangfu granule on ultrastructure of gastric mucosa in patients of precancerosis with spleen deficiency syndrome].

OBJECTIVE: To observe the effect of Weikangfu Granule (WKFG) on the ultrastructure of gastric mucosa. METHODS: WKFG was used to treat 61 patients with gastric mucosa intestinal metaplasia or atypical proliferation, and histopathological and ultrastructural examination on gastric mucosa of antral region obtained through gastroscopy were conducted before and after treatment. RESULTS: After treatment, the histopathology and intestinal metaplasia subset of antral focal region, and the background lesion in ultrastructure of the mucosa in the nonfocal region were all improved in the 4 groups, The effects of Spleen-Qi Deficiency syndrome group and Spleen-Yang Deficiency group were superior to Ying-Deficiency group as well as Spleen-Deficiency and Qi-Stagnation group (P < 0.05, P < 0.01), and approached to those in the healthy control group. CONCLUSION: WKFG improves the quantitative balance of internal bioactive substances to maintain the homeostasis, promotes the ultrastructural normalization of mucosa so as to cure the clinical symptoms and reverse the intestinal metaplasia and atypical proliferation of mucosa.

Adult↗

PubMed2000

[Clinical study on lixin pill in treating congestive heart failure].

OBJECTIVE: To observe the clinical therapeutic effect of Lixin Pill (LXP) in treating patients with congestive heart failure (CHF). METHODS: Ninety CHF patients with heart function of III-IV grade were randomly divided into 3 groups. Group A was treated with LXP, Group B with LXP plus small dosage of digoxin and Group C with ordinary dosage of digoxin. The therapeutic course for all the three groups was 1 month. Meanwhile, all patients were given ordinary dosage of diuretics, nitrates and angiotensin-converting enzyme inhibitors (ACEI) as basic therapy. RESULTS: The total effective rate in improving heart function in Group A, B and C was 83.3%, 93.3% and 90.0% respectively. In respect of improving myocardial contraction and dilation, the left ventricular ejection fraction (LVEF) was improved in all the three groups but was more superior in Group B (P < 0.05); the ratio of maximum blood flow between the advanced and the early diastolic stage (A/E) was improved, and the complicated supraventricular and ventricular premature contraction in Group A and B were reduced markedly after treatment (P < 0.01 or P < 0.05), and the effect in Group B was superior to that in Group A. CONCLUSION: Using LXP combined with small dosage of digoxin could improve the therapeutic effect in treating patients suffering from congestive heart failure.

Adult↗

PubMed2000

[Primary non-specific ureteritis].

OBJECTIVE: To better understand primary non-specific ureteritis. METHODS: The etiological, clinical, and pathological manifestations, diagnosis, and treatment of 3 cases of primary non-specific ureteritis were discussed. RESULTS: Preoperative diagnosis failed. Uretero-ureterostomy was performed in 2 cases, and ureteroneocystostomy in one. The patients were free from hydronephrosis and ureteral dilatation. CONCLUSIONS: Diagnosis depends on pathological manifestations, differentiation from secondary non-specific ureteritis, ureteral tuberculosis, negative X-ray of ureteral stone and ureteral carcinoma. Surgical intervention is effective with good prognosis.

Adult↗

PubMed2000

[Determinations and analysis of masticatory performance in unilateral cleft lip and palate].

OBJECTIVE: Masticatory function is one of the most important physical functions in craniomaxilla system. Masticatory performance is evaluated with the degree of broken dawn tested food in a limited period of time. Unilateral cleft lip and palate (UCLP) is a congenital abnormality in craniofacial growth and developing. It seriously damages face esthetics and masticatory function in UCLP patients. METHODS: 28 UCLP patients (male 17, female 11, permanent teeth) were selected, which all had received plastic operation treatments and never received any orthodontic therapy. The masticatory performance was determined by the advanced light absorbtion method and took peanuts as tested food. Meanwhile, malocclusal patterns and castings were identified in clinic. All of the data were treated with t-test and step wise-regression in statistics. RESULTS: 1. Masticatory performance of male was higher than that of female in normal people, but there was no sexual difference in UCLP. 2. Masticatory performance in UCLP was lower about 53.97% than that in normal people. 3. Different masticatory times within limited time had no effects on masticatory performance. 4. Different Patterns of malocclusion had different effects on masticatory performance. CONCLUSION: Orthodontic therapy is necessary to improve masticatory function in UCLP after plastic surgery.

Adolescent↗

PubMed2000

[Influence of organic modifier on the retention behaviour in soil leaching column chromatography].

The relationship between capacity factors (k') of 55 nonionic compounds and broad methanol volume percentage (psi) of methanol-water eluent in soil leaching column chromatography (SLCC) was systematically investigated. The compounds consist of 11 chlorobenzenes, 14 alkylbenzenes, 22 polyphenyls and polycyclic aromatic hydrocarbons, and 8 pesticides. Reference soil was dry-packed into a stainless steel chromatographic column (10 mm i.d. x 100 mm) by a homemade pressurizing device, and isocratic methanolwater mixture with psi from 0.0 to 0.80 eluated through the column at a flow-rate of 1 mL.min-1. The column was thermostated at (25.0 +/- 0.1) degree C, and chromatographic peak was monitored by an online ultraviolet detector. The results show that both equations, log k' = log k'w + a psi + b psi 2(1) and log k' = log k'w - S psi (2), well fit the retention values. Equation (2) can be used practically due to few experimental data needed and simpler in formula. Explanation is also given for the existence of the carbon (or chlorine) number rule for two classes of homologous series (i.e. methylbenzenes, n-alkylbenzenes) and weak-polar chlorobenzenes in the SLCC process. The slope and intercept of the rule are also well correlated, and both decreases linearly with increasing eluent psi value.

Chlorobenzenes↗

PubMed2000

[The long-term effect of augmentation rhinoplasty with silicone].

OBJECTIVE: To evaluate the long-term effect of augmentation rhinoplasty with silicone. METHOD: 360 patients underwent augmentation rhinoplasty with silicone. Improved "L" shaped implants were used in 343 patients. RESULT: Among 360 patients, 334 cases were successful enough (92.83%). CONCLUSION: The key to the maintenance of the long-term effect is to use properly improved "L"-shaped implant, to choose a suitable tunnel, to prevent various complications and to ask patient's opinions for implant design.

Adolescent↗

PubMed2000

[Prevention and treatment of bladder tumors recurrence with furtulon].

OBJECTIVE: To inquire into the value of oral furtulon therapy for bladder tumors. METHODS: 103 patients were randomized into four groups and have been undergoing a long term follow-ups. RESULTS: Recurrent rate of oral furtulon therapy for bladder tumors (8.8%) and instillation of mitomycin C for preventing the recurrence of bladder tumors (12.5%) as compared to recurrent rate of control group(40%), which was statistically significant(P < 0.01). Overall, 4 patients (33.3%) had an effective response with furtulon. CONCLUSIONS: Furtulon has more effective for treatment and prophylaxis of bladder tumors.

Administration, Oral↗

PubMed1999

Lobster G-protein coupled receptor kinase that associates with membranes and G(beta) in response to odorants and neurotransmitters.

A cDNA clone (lobGRK2) encoding a protein of 690 amino acids with significant similarity to the GRK2 subfamily of G-protein coupled receptor kinases was isolated. lobGRK2 was widely expressed as a 9-kb major transcript and a protein of 80 kDa. It was most abundant in the brain and the olfactory organ but was absent in the eye/eyestalk. Immunocytochemistry revealed lobGRK2 immunoreactivity in the outer dendritic segments of the olfactory receptor neurons, the site of olfactory transduction. LobGRK2 immunoreactivity was observed in most neuronal structures in the brain, although with varying intensity. It was strongest in neuropil, especially the olfactory and accessory lobes but was also detectable in neuronal cell bodies. Stimulation of brain homogenates with a mixture of neurotransmitters increased the association of lobGRK2 with membranes and with G(beta). Similarly, stimulation of olfactory dendrite homogenates with an odorant mixture caused lobGRK2 to associate with G(beta). These results support the conclusion that lobGRK2 responds to odorants and to neurotransmitters and may act to initiate desensitization by phosphorylating G-protein-coupled receptors in the olfactory organ and the brain, respectively.

Animals↗

PubMed1999

Cell type-specific autoregulation of the Caudal-related homeobox gene Cdx-2/3.

The caudal-related homeobox gene Cdx-2/3 is a critical "master" control gene in embryogenesis. Mice heterozygous for a null mutation in Cdx-2/3 exhibit multiple malfunctions including tail abnormalities, stunted growth, a homeotic shift in vertebrae, and the development of multiple intestinal adenomatous polyps, indicating that Cdx-2/3 is haplo-insufficient. In vitro studies have identified more than a half-dozen downstream target genes expressed in pancreatic and intestinal cells for this transcription factor. We have examined the transcriptional properties of the mouse Cdx-2/3 promoter. This promoter could be autoregulated in pancreatic and intestinal cells that express endogenous Cdx-2/3. In contrast, Cdx-2/3 transfection represses the Cdx-2/3 promoter in fibroblasts, which do not express endogenous Cdx-2/3. Since Cdx-2/3 activates proglucagon gene promoter in both pancreatic and intestinal cells and in fibroblasts, we suggest that some, yet to be identified, cell type-specific components are required for activating selected target gene promoters of Cdx-2/3, including the Cdx-2/3 promoter itself. Cdx-2/3 binds to the TATA box and another AT-rich motif, designated as DBS, within an evolutionarily conserved proximal element of the Cdx-2/3 promoter. The DBS motif is critical for the autoregulation, whereas the TATA box may act as an attenuating element for the autoregulatory loop. Finally, overexpression of Cdx-2/3 in a pancreatic cell line activated the expression of the endogenous Cdx-2/3. Taken together, our results indicate that the dose-dependent phenotype of Cdx-2/3 expression on its downstream targets in vivo could be regulated initially via a transcriptional network involving cell type-specific autoregulation of the Cdx-2/3 promoter.

3T3 Cells↗

PubMed1999

Genetic approaches to studying norepinephrine function: knockout of the mouse norepinephrine transporter gene.

Norepinephrine is an important chemical messenger in the nervous system. It regulates affective states, learning and memory, endocrine and autonomic functions. It has been implicated in depression, aggression, and addiction, as well as cardiac and thermal dysregulation. The norepinephrine transporter functions by uptaking norepinephrine back into the cell for cyclic use, and is a direct target of a number of antidepressants and psychostimulants. Functional deletion (knockout) of monamine transporters results in increases in extracellular levels of neurotransmitters, thereby prolonging their actions. For the norepinephrine transporter knockout mice, this altered state of the norepinephrine system should simulate the therapeutic effects of norepinephrine selective antidepressants and some of the effects of psychostimulants. Careful use of such an animal model can hopefully provide valuable insight into the multiple roles norepinephrine plays in normal and pathological physiology.

Animals↗

PubMed1999

[Effects of strontium in drinking water on the growth of school-age children].

An epidemiological study on the effect of strontium in drinking water on body shape development, bone age, prevalence of caries and dental fluorosis was carried out. The results show: there is a certain promotion on the development of bone age of school-age children, especially of girls, and there is no obvious impact on body shape developing when the concentration of strontium in drinking water is only 10 mg/L. The correlation between strontium in drinking water and the prevalence of caries in children could not get a conclusive evidence in this paper. A further epidemiological investigation is necessary if the role of strontium against caries should be proved.

Adolescent↗

PubMed1999

Water: foldase activity in catalyzing polypeptide conformational rearrangements.

Polypeptide conformer interconversion in a low dielectric environment is shown to be highly dependent on water concentration. Water increases this rate by 10(3), apparently by catalyzing hydrogen bond exchange, and thereby presenting functional properties analogous to that of a foldase. This catalytic effect is demonstrated on the interconversion of a parallel gramicidin dimer into an antiparallel dimer. A Hill coefficient of 6.5 is observed, illustrating the highly cooperative nature of the process. Protein folding in nonpolar environs, such as the hydrophobic core of a protein or the hydrophobic domain of a lipid bilayer, may be contingent on and rate-limited by the scarcity of water.

Dioxanes↗

PubMed1999

Wettability, Oil Recovery, and Interfacial Tension with an SDBS-Dodecane-Kaolin System.

The wettability of kaolin with SDBS (sodium dodecyl benzene sulfonate) aqueous solutions was measured by the Washburn equation expressed as contact angles. The contact angle changes for SDBS aqueous solutions on kaolin surface was studied. The interfacial tension between the SDBS solutions and n-dodecane was measured using both drop volume and spinning drop methods. Then the oil recovery of n-dodecane on the kaolin surface was tested. It was found that the minimum contact angle (the most hydrophilic condition) and the maximum oil recovery occurred near the critical micelle concentration (CMC) of SDBS while the interfacial tension between the SDBS solution and n-dodecane was far from ultra-low. Copyright 1999 Academic Press.

Journal Article↗

PubMed1999

A lobster phospholipase C-beta that associates with G-proteins in response to odorants.

A cDNA clone encoding a protein of 1116 amino acids with significant homology to beta-isoforms of phospholipase C was isolated from lobster olfactory organ cDNA libraries and named lobPLCbeta. This cDNA hybridized predominantly to a 9 kb transcript in RNA from olfactory organ, pereiopod, brain, and eye-eyestalk and to several smaller minor transcripts only in eye-eyestalk. An antiserum raised to the C terminus of lobPLCbeta detected immunoreactivity in a single 130 kDa band in olfactory aesthetasc hairs, olfactory organ, pereiopod, dactyl, and brain. In eye-eyestalk this 130 kDa band was abundant, and minor bands of 100, 79, and 57 kDa also were detected. In cross sections of the aesthetasc hairs, immunoreactivity was detected in the outer dendritic segments of the olfactory receptor neurons, the site of olfactory transduction. A complex odorant caused lobPLCbeta immunoreactivity to increase in membrane fractions and decrease in soluble fractions of homogenates of aesthetasc hairs. The odorant also increased the amount of lobPLCbeta in immunoprecipitates of Galphaq and Gbeta from homogenates of aesthetasc hairs. These results support the conclusion that lobPLCbeta mediates olfactory transduction.

Animal Structures↗

PubMed1999

Targeted mutations in a Trametes villosa laccase. Axial perturbations of the T1 copper.

Trametes villosa laccase was mutated on a tetrapeptide segment near the type 1 site. The mutations F463M and F463L were at the position corresponding to the type 1 copper axial methionine (M517) ligand in Zucchini ascorbate oxidase. The mutations E460S and A461E were near the T1 copper site. The mutated Trametes laccases were expressed in an Aspergillus oryzae host and characterized. The E460S mutation failed to produce a transformant with meaningful expression. The F463L and A461E mutations did not significantly alter the molecular and enzymological properties of the laccase. In contrast, the F463M mutation resulted in a type 1 copper site with an EPR signal intermediate between that of the wild type laccase and plastocyanin, an altered UV-visible spectrum, and a decreased redox potential (by 0.1 V). In oxidizing phenolic substrate, the mutation led to a more basic optimal pH as well as an increase in kcat and Km. These effects are attributed to a significant perturbation of the T1 copper center caused by the coordination of the axial methionine (M463) ligand.

Base Sequence↗

PubMed1999

Immunogenicity of peptides derived from a fibronectin-binding protein of S. aureus expressed on two different plant viruses.

The D2 peptide derived from an S. aureus fibronectin-binding protein (FnBP) was expressed on the surface of the icosahedral cowpea mosaic virus (amino acids 1-30 of D2) or on the rod-shaped potato virus X (amino acids 1-38 of D2), termed CPMV-MAST1 and PVX-MAST8, respectively. Mice and rats were immunized subcutaneously with CPMV-MAST1 and mice with PVX-MAST8 in adjuvant and high titres of FnBP-specific antibody were obtained. The mouse IgG was predominantly of the IgG2a and IgG2b isotypes, which strongly bound complement component C1q, suggesting a TH1-bias in the peptide-specific responses. Sera from mice and rats immunized with CPMV-MAST1 and from mice immunized with PVX-MAST8 were shown to completely inhibit the binding of fibronectin to immobilised recombinant FnBP and rat sera against CPMV-MAST1 were able to block adherence of S. aureus to fibronectin. These studies demonstrate that the D2 peptide is highly immunogenic when expressed on 2 different plant viruses and highlight the potential of plant virus-based vaccines to protect against S. aureus infections.

Adhesins, Bacterial↗