Biomedical subjects

X Zhu

Publications and source records attributed to X Zhu.

At least 379 records · Page 21Linked to original sources

PubMed1999

[Diagnosis and analysis of cyclodialysis by ultrasound biomicroscopy].

OBJECTIVE: To determine the morphologic changes and their clinical significance of cyclodialysis. METHODS: 173 eyes of 173 patients with cyclodialysis were examined by ultrasound biomicroscopy (UBM) for the morphologic changes, and the measurements of relative parameters were analyzed statistically. RESULTS: The cyclodialysis in all the cases was 360 degree. The characteristic manifestations of cyclodialysis found by UBM were as follows: no echoes between sclera and ciliary body, anterior displacement and rotation of ciliary process and displacement of pars plana toward the centre of eyeball. Superciliary effusion could be observed in some cases. In some patients, the ciliary body may be completely disintegrated from the scleral spur, but the disintegration may be quadrantal instead of 360 degree, resulting in a fistula between anterior chamber and superciliary cavity. The anterior chamber depth of the affected eye (2,115 +/- 589) microm was markedly shallower than that of the normal eye (2,736 +/- 441) microm (t = 4.49, P < 0.001). The shallowing of anterior chamber was caused by the anterior displacement and rotation of ciliary processes and the resulting anterior bulging of the iris root. CONCLUSIONS: UBM can be used to make a correct diagnosis of cyclodialysis irrespective of optic media condition, and can provide evidences for treatment.

Adolescent↗

PubMed1999

[A study of anterior segment structures in primary infantile glaucoma eyes by ultrasound biomicroscopy].

OBJECTIVE: To investigate anterior segment structures in primary infantile glaucoma (PIG) eyes by ultrasound biomicroscopy (UBM) in vivo. METHODS: UBM high frequency transducer (50 mHz) was used to measure and observe the anterior segment of 38 PIG cases (58 eyes). RESULTS: No matter the severity of the disease or the age at onset, the most significant characteristics of the diseased eyes are relative positional changes between scleral spur and angle apex. In three forth of the eyes, the scleral spur lay in the lateral or posterior-lateral site of the angle apex and in one forth of the eyes the site of the tip of scleral spur was parallel with the iris root insertion. The thickness and length of ciliary processes in the eyes of PIG were greater than that of the normal infantile eyes. The ciliary processes were anteriorly displaced, pulled towards the lens, and part of them got into contact with the iris. CONCLUSIONS: The relative positional changes between scleral spur and angle apex in diseased eyes indicate that the poor development of scleral spur and the iris anterior insertion are the basic pathogenesis in PIG.

Anterior Eye Segment↗

PubMed1999

[A study on ocular anterior segment structure after scleral buckling surgery for retinal detachment].

OBJECTIVE: To study the changes of the ocular anterior segment structure and the mechanism of angle-closure glaucoma after scleral buckling surgery. METHOD: 30 patients (33 eyes) who suffered from rhegmatogenous retinal detachment had been observed before and 3 - 7 days after the surgery. The quantitative measurement of the ocular anterior segment structure in vivo had been done by ultrasound biomicroscopy (UBM). The results were statistically analyzed. RESULTS: There was one eye with split-like ciliary body detachment before the surgery, there were 11 eyes with ciliary body detachment (33.3%) and the ciliary body was thickened and edematous after surgery. Before the surgery the thickness of the ciliary body was (821.32 +/- 64.21) microm and after the surgery it was (945.27 +/- 104.16) microm, the difference being statistically significant, P < 0.05. Parameters reflecting the changes of the anterior chamber angle before and after surgery were as follows: the anterior chamber angle became narrower, the angle open distance 500 decreased, the trabecular-iris angle decreased in degree, the angle of the scleral lateral side and iris long axis decreased, and all these differences were statistically significant, P < 0.05, but the depth of the central anterior chamber had no obvious change, and the difference was not statistically significant, P > 0.05. CONCLUSIONS: Ciliary body detachment and edema are often found after scleral buckling surgery, and post-operatively the central anterior chamber depth has no obvious change; ciliary body detachment and edema perhaps are related to the angle-closure glaucoma after the surgery.

Adolescent↗

PubMed1999

[LASIK for high and moderate hyperopia].

OBJECTIVE: To evaluate safety and efficacy of excimer laser in situ keratomileusis (LASIK) for high and moderate hyperopia. METHODS: LASIK was performed on 17 eyes of 9 patients using the SCHWIND KERATOM-F excimer laser. The range of preoperative spherical equivalent was + 5.50 to + 9.00 D, and its mean value, (+ 7.18 +/- 1.00) D. All the cases were followed up for 12 months or longer. RESULTS: There was no serious complication during the operation. No eye lost more than 1 line of the best corrected visual acuity after surgery. At 12 months, the mean postoperative spherical equivalent was (+ 1.77 +/- 1.56) D. 52.9% of eyes reached 0 to + 1.00 diopter. 88.2% of eyes achieved an uncorrected far vision of >or= 0.5. 100.0% and 76.5% eyes got uncorrected near visual acuities of >or= 0.5 and >or= 1.0 respectively. CONCLUSION: It is demonstrated the LASIK is a safe and effective technique for the treatment of high and moderate hyperopia. Further algorithm calibration must be made to avoid undercorrection.

Adult↗

PubMed1999

[mRNA and protein expression of apoptosis-regulating gene bcl-x in lymphomas].

OBJECTIVE: To observe mRNA and protein expression of bcl-x and explore the role of bcl-x in the regulation of apoptosis and oncogenesis and their value in differential diagnosis of lymphomas. METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) and citric acid-microwave-ABC immunohistochemistry (ICH) were used to observe mRNA transcription forms and protein distributions of bcl-x in 30 frozen tissues and 109 paraffin embedded tissues (both including reactive hyperplasia and common types of lymphoma). RESULTS: RT-PCR revealed that all 30 frozen cases showed bcl-x transcription, of which 29 had bcl-x1 band and 13 had bcl-xs band. Bcl-x1 band was always stronger than bcl-xs band. IHC found that 97/109 cases had fine positive bcl-x granules in the cytoplasm. In lymphoid reactive hyperplasia, bcl-x exhibited weak immunoactivity in cells located in the germinal centers and interfollicular regions of the nodes but not in the mantle zone lymphocytes which surround germinal centers. In lymphomas, bcl-x immunoactivity was always strong and diffuse. The staining fractions in different types of lymphomas were significantly higher than those in lymphoid reactive hyperplasias (P > 0.05), but no significant difference was found between the positive rate and staining fraction of different types of lymphomas. CONCLUSION: Bcl-x shows active mRNA transcription and high protein expression in lymphomas. The long isoform of bcl-x (bcl-xl) is the predominant expression. The characteristics of bcl-x protein expression may be helpful in differential diagnosis of reactive hyperplasia and lymphoma.

Apoptosis↗

PubMed1999

[Histological grading in ductal carcinoma in situ of the breast].

OBJECTIVE: To study the significance of histological grading as a prognostic factor in ductal carcinoma in situ of the breast. METHODS: According to Van Nuy's classification, 32 cases of ductal carcinoma in situ (DCIS) of the breast were divided into three grades. RESULTS: Low grade (well differentiated, low grade DCIS) 12 patients (37.5%); Intermediate grade, 9 patients (28.1%); High grade (poorly differentiated DCIS) 11 patients (34.4%). Among the high grade DCIS, the histological subtypes were comedo (9 patients), micto papillary (1 patient) and solid (1 patient). The positive expression of c-erbB-2, p53 and MIB-1 in high grade DCIS was higher than that in intermediate and low grade DCIS. The difference between high grade and low grade DCIS was significant (P < 0.05). The expression of ER in high grade DCIS was lower than that in intermediate and low grade DCIS. CONCLUSIONS: Histological grading of breast ductal carcinoma in situ may be a good prognostic factor.

Adult↗

PubMed1999

[The clinical application of perfluorotributylamine liquid in the complicated retinal detachment].

OBJECTIVE: To evaluate the clinical application value of perfluorotributylamine liquid (PFTL) made in China in the complicated retinal detachment. METHODS: PFTL was injected into eyeball after vitreoretinal surgery, it could open funnel of retinal detachment, push subretinal fluid out from peripheral hole and flat and immobilize the posterior retinal during vitreoretinal surgery. In eyes with giant tears, PFTL could unfold and fix retinal flap. RESULTS: The retinas in all cases with giant tears were reattached, and sixty per cent in the eyes with PVR-D2-D3 reattached. In 8 eyes the visual acuity was improved. CONCLUSION: PFTL is valuable in treatment of complicated retinal detachment. It facilitates vitreoretinal surgery, obviates the potential complications.

Adolescent↗

PubMed1999

[Acceleration of wound healing in diabetic rats by PDWHF and its relation with its activity to stimulate procollagen I (alpha 1) gene expression].

OBJECTIVE: The effect of platelet-derived wound healing factor (PDWHF) on wound healing in diabetic rats was studied. METHODS: Forty-four male SD rats were randomly divided into 2 groups. Thirty-two rats of experimental group accepted intraperitoneal injection of alloxan (1.5 mg/10 g body weight). Within one or two days after injection, while the blood sugar of the rats was higher than 180 mg/dl, the animal model of diabetic rat should have been established. Then a dorsal incision was given to every rat. After the addition of PDWHF (the experimental group) or bovine albumin (the control group), the incision was sutured up. Seven, ten and fourteen days after operation, the breaking strength of the wound was measured. On another hand, specimen from the wound was taken for the culture of fibroblasts. When the cultured fibroblasts have been incubated with 10% PDWHF for 4, 8 and 12 hours, the procollagen I (alpha 1) mRNA levels were examined respectively, and compared with those of control. RESULTS: Significant difference in wound breaking strength had been observed between PDWHF-treated incisions and the control on 7, 10 and 14 days after wounding (P < 0.01). Experiment in vitro demonstrated that the procollagen I (alpha 1) mRNA levels in wound fibroblasts incubated with 10% PDWHF for 4, 8 and 12 hours were 0.9, 3.7 and 2.2 folds higher than those in fibroblasts in control. CONCLUSION: It was suggested that direct stimulation of procollagen I (alpha 1) gene expression was one of the ways that PDWHF played its role in accelerating wound healing.

Animals↗

PubMed1999

[Significance of programmed cell death in C57BL/6N strain mouse palate process development and cleft palate formation].

OBJECTIVE: To observe the changes of programmed cell death (PCD) in C57BL/6N strain mouse cleft palate formation and study related gene of PCD in future. METHODS: 16 mice (gestation of 10 days, GD10) were divided into the experimental and control groups randomly, then the mice of the experimental group were dosed with retinoic acid(RA) 80 mg/kg, and the tissue slices of the embryo mouse were prepared for TdT-mediated dUTP nick end labeling (TUNEL) staining at GD13(14)(the 14th hour of the 13th day gestation), GD13(22), GD14(8), GD14(14), GD14(22), GD15(8), GD15(22) and GD16(8) respectively. RESULTS: In the early development of palate process, the positive index of PCD was significantly higher in the experimental group than in the control group (P < 0.05). CONCLUSION: The effects of RA on mesenchymal cells of the early development of palate process in the experimental group induce PCD, which result in the formation of small palate process and failure of fusing of the shelves.

Animals↗

PubMed1999

[Clinical study of capsaicin in the treatment of allergic rhinitis].

OBJECTIVE: To study the clinical effect of capsaicin of nasal administration in 100 cases of allergic rhinitis. METHOD: Capsaicin was applied by nostril, once 5 days and 5 times as a therapeutic course. Acidophil were measured and nasal airflow resistance was analysed before and after capsaicin therapy. RESULT: It showed that nasal symptoms of patients were obviously relieved and 94% of the cases in the measure of acidophil changed to negative from positive. Moreover, capsaicin induced decrease in nasal airflow resistance from (0.6272 +/- 0.3534) kPa.s/L before therapy to (0.4057 +/- 0.2419) kPa.s/L after therapy (P < 0.001). 90 cases of 100 patients were fellowed up one year, the total effective rate was 89%. CONCLUSION: Our study suggests that capsaicin possessed remarkable effects in the treatment of allergic rhinitis; analyse of nasal airflow resistance may be used as one of the objective guideline in the determinant of therapeutic effects.

Administration, Intranasal↗

PubMed1999

[Investigation of association parameters of basic drugs to human serum albumin by capillary zone electrophoresis/frontal analysis].

A CZE/FA method was applied to the study of association parameters of basic drugs, verapamil (VER) and propranolol (PRO), to human serum albumin (HSA) under drug-HSA association equilibria. After the direct hydrodynamic injection of a drug-HSA mixed solution into a coated capillary (effective length, 32 cm; 50 microns i.d.), the basic drug is eluted as a zonal peak with a plateau region under condition of phosphate buffer (pH 7.4, ionic strength = 0.17) at 10 kV running voltage. The unbound concentration of drug can be determined from the plateau peak height with good linear response, r = 0.999 for both VER(n = 6) and PRO(n = 8), respectively. Six VER-HSA solutions (containing 50-175 mumol/L of VER and 450-325 mumol/L of HSA) and eight PRO-HSA solutions (containing 50-400 mumol/L of VER and 450-100 mumol/L of HSA) were investigated. Three analytical methods were used for the present CZE/FA system including Scatchard, Klotz and non-linear regression analyses. The estimated association parameters were as follows: the numbers of HSA binding site n for VER were over 1.21(0.04)-1.30(0.09), binding constant, K, was between 1,690(130) and 1,790(70). Whereas for PRO, n = 0.54(0.04)-0.62(0.03), and K = 1,390(70)-1,690(180). The data deduced from these three analyses agreed well with each other.

Drug Interactions↗

PubMed1999

[Determination of plasma homocysteine in normal adults by high performance liquid chromatography with fluorescence detection].

A rapid, isocratic high performance liquid chromatographic(HPLC) method with fluorescence detection was used for the determination of total homocysteine (Hcy) levels in human plasma. Prior to reversed-phase HPLC analysis, the plasma thiols were derivatized with ABDF(7-fluoroben30-2-oxa-1,3-diazole-4-sulfonamide), a thiol specific fluorogenic probe. A mobile phase consisted of 0.1 mol/L potassium dihydrogen phosphate (pH 2.1, containing 10% of acetonitrile) ensured base line separation of plasma Hcy. The mean recovery of this method was 97.75%. The intraday and interday coefficient of variations were 4.49% and 9.79%, respectively. The method is simple, sensitive, reproducible and very suitable for routine determination of plasma Hcy in human.

Adult↗

PubMed1999

[Chiral resolution by capillary electrophoresis].

The application and development in the field of chiral resolution by capillary electrophoresis are reviewed according to recent references, including different operating models and different chiral selectors. The study on mechanism of chiral resolution is summarized as well. It appears that capillary electrophoresis is one of the most effective, fast and simple methods in chiral resolution.

Cyclodextrins↗

PubMed1999

[The application quantitative structure-retention relationship of GC to aid MS qualitative analysis].

In this paper, a method, based on the prediction of the Kovats retention indices of related polysubstituted alkylbenzenes from the indices of benzene, monsubstituted alkylbenzenes and disubstituted alkylbenzenes, was used to aid qualitative analysis with mass spectrometry alone. A disproportinated aromatic product and the basic compounds of alkylbenzene were analyzed with gas chromatography isothermally at 100 degrees C separately. In order to cut down the analysis time and increase the resolution, the disproportionated aromatic product was analyzed using temperature programming with gas chromatographymass spectrometry (GC-MS). The Kovats retention indices of the basic compounds were determined and those of the polysubstituted alkylbenzenes were predicted with the method which was proposed by us previously. The isomers of polysubstituted alkylbenzenes have similar mass spectra, so they can not be identified unambiguously by MS alone. For the differences of the Kovats retention index between isomers of polysubstituted alkylbenzenes are larger, it can be identified by matching the experimental retention indices with the predicted ones. The positional isomers of polysubstituted alkylbenzenes which are very difficult to be interpreted by MS alone have been identified explicitly.

Alkanesulfonic Acids↗

PubMed1999

[Gas chromatographic method for the analysis of polychlorinated biphenyls in pine needles].

Polychlorinated biphenyls (PCBs) are a class of 209 chemical compounds, in which 1-10 chlorine atoms are attached to a biphenyl molecule. PCBs are members of halogenated aromatic group of environmental pollutants that have been identified worldwide in diverse environmental matrices. PCBs in air, soils, sediment, water, transformer oils and other environmental matrices have been determined in the past years. In this work a method for routine analysis of PCBs in pine needles has been developed. First, extractions were carried out in Soxhlet apparatus with n-hexane as solvent. Then, a silica gel chromatographic column was applied to pretreat the pine needle samples. The reference standard used was clophen 50. The recovery was about 90%, so the feasibility and reliability were assured. After the analysis of PCBs in pine needle samples from four different regions, the distribution of PCBs in environment can be discussed and monitored. In this method, a Shimadzu GC-7A gas chromatograph equipped with a 63Ni electron capture detector was used for the analysis of PCBs. From the results, we can see the PCB pollution in different regions. So evaluation of air pollution level through foliage data is feasible. The sample preparation and analytical method mentioned in this paper is reliable and simple.

Chromatography, Gas↗

PubMed1999

[Preliminary study of a new concept for left ventricular assistance dynamic aortic valve].

Dynamic aortic valve, a novel design for left ventricular assistance is proposed. An impeller similar to the airscrew is placed in the position of aortic valve. The impeller is held by a pair of bearings in the center of a cylindrical supporting cage which is located in the lumen of the aorta ascendens. The supporting cage is attached to the valve annulus by a sewing ring of textile cuff around the outside of the cage. A rotor is fitted into the cage and connected to the impeller with a common shaft. The cage supports the aortic wall, thus prevents the rotor from founching the wall and allows the rotor to rotate freely. A stator, functioning as that of the electric motor, is located outside the aortic wall. When actuated, the magnetic field generated by the stator would drive the rotor to turning, and the axial flow of blood from ventricular to the aorta would be produced, resulting in the reduction of the ventricular load. We studied this concept in a simulating model. The result suggests that this design be reasonable. Further exploration of this concept is justified.

Heart Valve Prosthesis↗

PubMed1999

[Immunoregulation of IL-2 in Trichinella-infected mice].

AIM: To study the immunoregulation of IL-2 in Trichinella-infected mice. METHODS: Mice infected respectively with HL strain and AM strain larvae of Trichinella spiralis were treated i.p. with IL-2 from the second day postinfection for 3 days. Serum IgG antibody levels were determined by ELISA and the infection capacity was determined using reproductive capacity index (RCI). RESULTS: In HL, higher dosage of IL-2 injection induced lower RCI and showed apparent anti-Trichinella effect. In AM, both low and high dose of IL-2 had no measurable effect on RCI, however, high dose of IL-2 reduced the infectivity of newborn larvae. CONCLUSION: IL-2 exhibits apparent suppressive effect on the infectivity of T. spiralis of HL strain.

Animals↗

PubMed1999

[Genotype and sequence analysis of merozoite surface protein 1 of Plasmodium falciparum isolates in Yunnan province].

AIM: To identify the genotype of merozoite surface protein 1 of Plasmodium falciparum in Yunnan Province and explore the polymorphism of MSP1 genes in geographical characteristics and genetics. METHODS: Nested polymerase chain reaction was applied to genotyping of P. falciparum isolated in Yunnan Province. Some of parasite alleles were sequenced by dye primer cycle sequencing. RESULTS: In 30 P. falciparum infections, 38 different alleles were found. Of them, the dominant allele was a variant of MAD20, while was K1 less and the RO33 was few. In addition, incidences of mixed allele infections were observed. Sequence analysis showed that DNA sequences of MAD20, K1 and RO33 alleles from Yunnan were highly homologous with those of international standard strains, respectively. CONCLUSION: Composition and sequence characteristics of P. falciparum arasite population in the endemic area can be detected by genotyping with MSP1 as genetic marker, which would be useful for the prevention and treatment of malaria.

Alleles↗