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Biomedical subjects

W Xing

Publications and source records attributed to W Xing.

At least 19 recordsLinked to original sources
PubMed2006

Intraoperative complications of cataract surgery in the very old.

AIM: To identify whether the risk of an intraoperative complication of phakoemulsification cataract surgery increases with age. METHODS: 1441 consecutive patients undergoing phakoemulsification cataract surgery were assessed preoperatively, and data on the occurrence of intraoperative complications were collected prospectively. Data were entered into a computerised database, and logistic regression was used to examine evidence of an association between age and the risk of an intraoperative complication. In addition, the rates of intraoperative complications were compared between patients > or =88 years and those <88 years, and between patients > or =96 years and those <96 years. RESULTS: No significant association was found between age and the risk of an intraoperative complication. The authors found little evidence that patients > or =88 years were at a greater risk of an intraoperative complication than those <88 years, or that those > or =96 years are at increased risk; however, numbers were small. CONCLUSIONS: These results suggest that age alone is not a major risk factor for any intraoperative complications occurring during phakoemulsification cataract surgery. This has implications not just for tailoring the risk of complications occurring to individual patients but also for meaningful comparisons between national complication rates and those of individual surgeons, and better selection of cases suitable for instruction.

Age Distribution↗
PubMed2006

Blepharospasm and hemifacial spasm: a protocol for titration of botulinum toxin dose to the individual patient and for the management of refractory cases.

PURPOSE: To evaluate a protocol for the treatment of facial dystonias. METHOD: A retrospective noncomparative interventional case series of all patients who attended a specialised tertiary referral clinic between January 2000 and January 2003. At the start of treatment, patients were seen and treated at weekly intervals until their symptoms were controlled or they developed complications. The sum of the weekly doses was taken as the individual patient dose and then given at 3-4 monthly intervals as required for the individual patient. Refractory cases of spasm underwent orbicularis muscle reduction. Pretarsal spasm was treated with pretarsal botulinum toxin. If the spasm was relieved but the patient could not open their eyelids, a trial of ptosis props was undertaken and the toxin injections continued, before considering a brow suspension. If patients could not see because of a spastic Bell's phenomenon, they were given centrally acting systemic medication. RESULTS: Of 182 new patients, 63 (35%) required two or more sets of injections to titrate their optimum dose of toxin. Symptoms improved in 169 patients (93%). Of a total 332 new patients and follow-up patients, 47 (14%) underwent surgery during their management, 36 protractor myectomy, and 13 brow suspension. Protractor myectomy improved symptoms in 23 (64%). Brow suspension improved symptoms in 12 patients (92%). CONCLUSIONS: The dose of botulinum toxin can be titrated to the individual patient, and the refractory cases managed satisfactorily if a logical protocol is followed.

Adolescent↗
PubMed2006

Agreement between optometrists and ophthalmologists on clinical management decisions for patients with glaucoma.

BACKGROUND/AIMS: Although optometrists have become an accepted part of the team in many hospital glaucoma clinics, their decision making ability has not been assessed formally. This study aims to document the accuracy and safety of clinical work undertaken by optometrists in the hospital setting by investigating their management decisions on follow up of patients with glaucoma. METHODS: Four optometrists and three medical clinicians examined 50 patients each. Clinical findings were recorded as usual in the hospital records but management decisions were documented separately on a specially designed data collection form. Subsequently, the patient records and clinical findings were reviewed retrospectively and independently by two consultant ophthalmologists, who were masked to the management decisions of the optometrists and medical clinicians. The consultants' management decisions were then compared with those made by the optometrists and medical clinicians. Percentage agreements were computed together with kappa (kappa), or weighted kappa, statistics where appropriate. RESULTS: Agreement between consultants and optometrists was 55% (kappa = 0.33) for evaluation of visual field status, 79% (kappa = 0.67) for medical management, 72-98% for other aspects of patient management, and 78% (weighted kappa = 0.35) for scheduling of next clinic appointment. Very similar levels of agreement were found between consultants and medical clinicians. CONCLUSION: Agreement between optometrists and consultants, in glaucoma clinical decision making, was at least as good as that between medical clinicians and consultants. Within an appropriate environment, optometrists can safely work as part of the hospital glaucoma team in outpatient clinics.

Appointments and Schedules↗
PubMed2005

Assessment of the reproducibility and repeatability of a method of grading macular subretinal fluid using optical coherence tomography.

AIM: To devise a quantative method for the measurement of the extent of macular subretinal fluid using optical coherence tomography (OCT), and to assess the interobserver and intraobserver agreement for this grading system. METHODS: Observational cohort series. Patients were a cohort who underwent retinal detachment surgery over an 18-month period. All patients had OCT scan at 6 weeks after surgery. The scans were graded by two independent observers experienced in OCT interpretation and each grader was masked to the others findings. Observer 1 then regraded the scans on a later day masked to his previous findings. The interobserver and intraobserver agreement was assessed using weighted Kappa (Kw) statistics. RESULTS: In all, 116 patients were analysed. Both the intraobserver and interobserver agreement was very high, with Kw being 0.9631 and 0.9070, respectively. CONCLUSIONS: The grading system for assessment of the extent of macular subretinal fluid using OCT appears to have very good reproducibility and repeatability. We propose that this grading system would be clinically useful when applied to pathologies visible on OCT scan of the macula.

Exudates and Transudates↗
PubMed2005

Outcomes of macular hole surgery: implications for surgical management and clinical governance.

PURPOSE: The optimal method and timing of the surgical treatment for idiopathic macular holes remains unknown. The aim of this retrospective study was to identify factors associated with anatomical and visual success in macular hole surgery. METHODS: Case records of 55 patients undergoing macular hole surgery at three units in the 2-year period up to July 2002 were reviewed to identify factors associated with anatomical and visual success. The following potential prognosticators were evaluated: patient age, hole stage, hole latency prior to surgery, preoperative acuity, simultaneous phacoemulsification, and intraocular lens implantation, internal limiting membrane peeling with and/or without indocyanine green, and postoperative posturing. RESULTS: The duration of preoperative symptoms, indocyanine green-assisted internal limiting membrane peeling, hole stage, and better preoperative visual acuity were associated with both anatomical success and regaining a postoperative visual acuity of 6/12 or better. DISCUSSION: The closure rate in patients undergoing surgery within 1 year of onset was 94.0%, and in those waiting 1 year or more it was 47.4%. Clinical governance and quality issues should dictate that NHS macular hole surgery is available to all within 1 year of onset. This study showed no adverse effect of ICG dye retinal staining. The results support the use of a 'patient-friendly' approach of simultaneous cataract surgery with no prone postoperative posturing.

Adult↗
PubMed2002

Cytomegalovirus infection in pregnancy.

OBJECTIVES: To investigate the effects of intrauterine human cytomegalovirus (HCMV) infection on pregnancy outcomes and infant development. METHODS: The study group consisted of the HCMV-IgM-positive offspring of 75 pregnant women, and a control group of the non-infected offspring of 73 pregnant women. Chorionic villi, amnionic fluid, and umbilical blood were obtained to detect HCMV-late mRNA with a reverse transcriptase-polymerase chain reaction (RT-PCR) assay. The pregnancy outcomes were followed up. For all offspring, neurological development was evaluated with neurosonography, audiologic development with the brainstem auditory evoked potential (BAEP), and psychomotor development with the Beyley Scale of Infant Development (BSID). RESULTS: In the study group the positive rate of late mRNA was 50% in the chorionic villi and 67.65% in the amnionic fluid and the umbilical blood; the incidence of abnormal pregnancy outcomes (abortion, preterm delivery, stillbirth, etc.) was much higher than in the control group (40% vs. 6.57%; chi(2)=24.06; P=0.001); the abnormal rate of neurosonography results at birth and 3 months after birth was higher in the study group than in the control group (P<0.05), as were BAEP values 4 months after birth (chi(2)=8.960; P=0.003). Scores for the Infant Mental Development Index (MDI) were apparently lower than in the control group. When congenitally infected children were tested at the age of 5.5-6.5 years with the Wechsler Preschool and Primary Scale of Intelligence (WPPSI), their rate of mental retardation was still found to be approximately 20%. CONCLUSIONS: Intrauterine HCMV infection is closely related to abnormal pregnancy outcomes, infant neurological damage, mental retardation, and hearing loss.

Abortion, Spontaneous↗
PubMed2001

Glycine betaine involvement in freezing tolerance and water stress in Arabidopsis thaliana.

Levels of endogenous glycine betaine in the leaves were measured in response to cold acclimation, water stress and exogenous ABA application in Arabidopsis thaliana. The endogenous glycine betaine level in the leaves increased sharply during cold acclimation treatment as plants gained freezing tolerance. When glycine betaine (10 mM) was applied exogenously to the plants as a foliar spray, the freezing tolerance increased from -3.1 to -4.5 degrees C. In addition, when ABA (1 mM) was applied exogenously, the endogenous glycine betaine level and the freezing tolerance in the leaves increased. However, the increase in the leaf glycine betaine level induced by ABA was only about half of that by the cold acclimation treatment. Furthermore, when plants were subjected to water stress (leaf water potential of approximately -1.6 MPa), the endogenous leaf glycine betaine level increased by about 18-fold over that in the control plants. Water stress lead to significant increase in the freezing tolerance, which was slightly less than that induced by the cold acclimation treatment. The results suggest that glycine betaine is involved in the induction of freezing tolerance in response to cold acclimation, ABA, and water stress in Arabidopsis plants.

Journal Article↗
PubMed2001

Characterization of regulatory elements of ovine follicle-stimulating hormone (FSH) receptor gene: the role of E-box in the regulation of ovine FSHreceptor expression.

Expression and activation of follicle-stimulating hormone receptor (FSHR) in the granulosa and Sertoli cells are required for normal development of the ovarian follicles and germ cells. However, little is known regarding the mechanisms by which FSHR expression is regulated. We fused an ovine FSHR promoter to a luciferase gene to understand the promoter regulation in two gonadal cell lines. Deletion studies revealed that the strongest promoter was at -200 to +163 relative to the transcription start site. One of cis-elements protected from DNase I digestion was mapped to between +32 and +54 of the 174-base pair (bp) minimal promoter. Electrophoretic mobility shift assay with a 26-bp probe (+32 to +57) and nuclear extracts from Sertoli (15P1) and granulosa (JC-410) cell lines demonstrated a sequence-specific DNA-protein complex. Southwestern analysis detected a 43-kDa protein bound to the 26-bp probe. Gel supershift with upstream stimulatory factor 1 and 2 (USF-1/2) antibodies revealed that the DNA-protein complex contained these two transcription factors. Mutation within the E-box of the promoter abolished the sequence-specific binding and the minimal promoter activity but also greatly reduced the transcription of the proximal promoters by 49%-70%. These data suggest that the USF-1/2 binding to the promoter is required for the expression of the ovine FSHR in the gonadal cells.

5' Untranslated Regions↗
PubMed2001

Role of CACC-box in the regulation of ovine follicle-stimulating hormone receptor expression.

Tissue-specific and stage-specific expression of follicle-stimulating hormone receptor (FSH-R) in granulosa and Sertoli cells is required for normal development of ovarian follicles and germ cells. However, little is known of the transcription factors that regulate the FSH-R gene and its promoter. Using an ovine FSH-R promoter as a model system, we have identified a second DNase I footprinting 2 (FP2) region from -46 to -67 of the strongest ovine FSH-R promoter (-200 to +163) relative to the transcription start site. Electrophoretic mobility shift assay with a 22-base pair DNA probe (-46 to -67) and nuclear extracts from Sertoli (15P1) and granulosa (JC-410) cell lines demonstrated a sequence-specific DNA-protein complex. Further Southwestern and UV cross-linking analyses detected three predominant proteins of molecular weights 87, 60, and 50 kDa present in both Sertoli and granulosa cells bound to a 32P-labeled DNA probe as a complex. Gel competition experiments with DNA probes containing known Krupple-like factor binding sites revealed that the testis-specific zinc finger protein, ZNF202-like factor, Ras-responsive element binding protein-like factor, or both, may be among the potential candidate regulators. Mutation within the CACC box of the promoter abolished Krupple-like factor binding and significantly diminished promoter activity in both gonadal cells. These data suggest that Krupple-like transcription factors may play a role in the regulation of ovine FSH-R expression.

Animals↗
PubMed2001

[Sequencing-based typing of HLA-DPB1 and DQB1 exon 2 in patients with type 1 diabetes mellitus].

OBJECTIVE: To investigate the correlation between type 1 diabetes mellitus susceptibility and HLA-DPB1 and DQB1 genes in Shandong Han population. METHODS: HLA-DPB1 and DQB1 genes analysis were performed by sequencing-based typing in 52 type 1 diabetes mellitus patients and 38 normal controls. RESULTS: The frequency of DPB1*2201 in diabetics was significantly higher than that in controls(26.92% vs 5.26%, P<0.01), but the frequency of DPB1*0402 in diabetics was significantly lower than that in controls(11.54% vs 34.21%, P<0.01). The frequencies of DQB1*0201, *0303 and *0604 in diabetics were higher than those in controls (24.04% vs 10.53%, P< 0.01; 22.12% vs 6.58%, P<0.05; 19.23% vs 7.89%, P<0.05), while the frequency of DQB1*0301 in diabetics was significantly lower than that in controls (4.81% vs 25.00%, P<0.01). CONCLUSION: DPB1*2201, DQB1*0201, *0303 and *0604 may be susceptible alleles, and DPB1*0402 and DQB1*0301 may be protective alleles in patients with type 1 diabetes mellitus.

Adolescent↗
PubMed2001

[Identification of red kojic from different habitats with clustering analysis by near-infrared diffuse reflectance spectrometry].

OBJECTIVE: To provide a new method for identifying Red kojic. METHODS: Being controled with the Aspergillus terreus, near-infrared diffuse reflectance spectroscopy combining with clusering analysis was used in the identification of Red Kojic made by M. purpureus fermentation from 18 different habitats. RESULTS: We can easily distinguish the Red Kojic from different habitats and the Aspergillus terreus. The results are consistent in some degree with that of morphologic study. CONCLUSION: This method is a new, rapid, simple and low cost assay technique being able to be used in the quality control of Red Kojic.

Cluster Analysis↗
PubMed2000

Estrogen deficiency, obesity, and skeletal abnormalities in follicle-stimulating hormone receptor knockout (FORKO) female mice.

Targeted disruption of the receptor for glycoprotein hormone, FSH (FSH-R) causes a gene dose-related endocrine and gametogenic abnormality in female mice. The resulting FSH-R knockout (FORKO) mutants have disordered estrous cycles, ovulatory defects, and atrophic uterus. The heterozygous animals that initially show reduced fertility undergo early reproductive senescence and stop breeding altogether. Lack of FSH-R signaling in females causes severe ovarian underdevelopment producing chronic estrogen deficiency. This was accompanied by increases in serum testosterone levels. Ovarian aromatase gene transcription and translation are unaltered in the mutants. Early loss of estrogen in the null mutants leads to obesity and skeletal abnormalities that intensify with age producing (kyphosis), a hunchback appearance. Both these changes also become apparent in older heterozygous mice coincident with early reproductive senescence. The expression of nuclear estrogen receptor(s) alpha and beta genes and the corresponding proteins in the ovary and uterus of FORKO mice appear to be intact. The loss of ovarian estrogen creates an imbalance in A and B forms of the progesterone receptor in the uterus of both heterozygotes and null mutants. Some of the changes we have documented here in FORKO mice are reminiscent of the ovarian dysfunction and other major symptoms that are usually associated with estrogen deficiency. In null mutants, estradiol-17beta administration promptly induced uterine growth and reversed the accumulation of adipose tissue indicating that estrogen receptors are functional. Thus, the phenotypes evident in these genetically altered FSH-R mutants may provide an experimental system to explore the effects of estrogenic compounds on different targets including the ovary in a nonsurgical setting.

Animals↗
PubMed2000

[Clinical and experimental study on antiviral activity of reduqing against human cytomegalovirus].

OBJECTIVE: To investigate the therapeutic efficacy of traditional Chinese medicine Reduqing (RDQ) against human cytomegalovirus (HCMV) in clinical and its antiviral activity in vitro. METHODS: In clinical practice, HCMV antibody was detected to determine if the case was activity infected with HCMV. Fourteen patients were found and treated with RDQ. The drug was orally administered one dose, three times a day, for 18-30 days as one therapeutic course. And the efficacy was evaluated by ELISA, PCR and other methods. The in vitro inhibitory activity of RDQ against HCMV AD169 was carried out on human embryo lung fibroblasts (HEL) by cytopathic effect inhibition method. Ganciclovir (GCV) was used for positive control. RESULTS: Fourteen pre- or during pregnant women with HCMV infection were treated with RDQ. After 18-30 days of treatment, all of them showed HCMV-IgM negative conversion, HCMV DNA negative conversion in 7/10 cases, and virus excretion by urine and cervix secretion was inhibited in 4/4 and 1/1 case. Five women gave birth to 5 normal newborns at term after treatment, among them 2 were asymptomatic virus carrier, the other 3 were uninfected. Experimental study in vitro showed that the maximal tolerance dosage (TD0) of RDQ was 20 micrograms/L, the minimal therapeutic concentration (MTC) was 5 micrograms/L, 50% inhibitory concentration (IC50) was 5 micrograms/L and the therapeutic index (TI) was 4. It suggested that RDQ had anti-HCMV activity in vitro and the effect increased with its concentration. CONCLUSION: RDQ is a safe, valuable drug for inhibiting HCMV infection especially during pregnancy.

Adult↗
PubMed2000

[Study on the stability of N-alkyl-N'-(sodium p-aminobenzenesulfonate) thiourea].

In this work, the stability of 13 kinds derivative of thiourea were studied by the UV absorption spectra and IR spectra of thiourea compounds in acidic medium at pH = 4.00, neutrality medium at pH = 7.00, basic property medium at pH = 10.00, under the influence of diffeveut store time, oxygen and sun light. Their structures were discussed and the changing rules of stability were developed.

Anti-Bacterial Agents↗
PubMed1999

Chlorella virus PBCV-1 encodes a functional homospermidine synthase.

Sequence analysis of the 330-kb genome of chlorella virus Paramecium bursaria chlorella virus 1 (PBCV-1) revealed an open reading frame, A237R, that encodes a protein with 34% amino acid identity to homospermidine synthase from Rhodopseudomonas viridis. Expression of the a237r gene product in Escherichia coli established that the recombinant enzyme catalyzes the NAD(+)-dependent formation of homospermidine from two molecules of putrescine. The a237r gene is expressed late in PBCV-1 infection. Both uninfected and PBCV-1-infected chlorella, as well as PBCV-1 virions, contain homospermidine, along with the more common polyamines putrescine, spermidine, and cadaverine. The total number of polyamine molecules per virion ( approximately 539) is too small to significantly neutralize the virus double-stranded DNA (>660,000 nucleotides). Consequently, the biological significance of the homospermidine synthase gene is unknown. However, the gene is widespread among the chlorella viruses. To our knowledge, this is the first report of a virus encoding an enzyme involved in polyamine biosynthesis.

Alkyl and Aryl Transferases↗