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Biomedical subjects

W Mao

Publications and source records attributed to W Mao.

At least 55 records · Page 3Linked to original sources
PubMed1995

Augmentation of carcinoembryonic antigen release from intact, viable tumor cells by a factor in human serum.

BACKGROUND: Measurement of carcinoembryonic antigen (CEA) levels in human serum is frequently used to detect tumor recurrence in patients with resected primary colorectal cancers. These levels are highly variable from patient to patient, and the mechanism that determines these levels is still poorly understood. METHODS: Using a 6-h in vitro CEA-release assay, we determined that a factor in human and fetal bovine sera significantly augments the release of CEA from the tumor cell surface into cell culture supernatants. RESULTS: As little as 1% serum admixed with tumor cells results in CEA release up to 200% greater than that of serum-free controls. It is not inhibited by 1,10-phenanthroline or heat inactivation (of serum) but is calcium dependent. The electrophoretic mobility and membrane linkage of CEA released by serum appear to be identical to those of CEA released by bacterial phospholipase C. Because bacterial phospholipase C is known specifically to cleave the phosphoinositol (PI) glycan moiety that anchors CEA to the tumor cell surface, a mechanism of action for serum cleaving this anchor is suggested. CONCLUSIONS: The large range of CEA levels observed in patients with colorectal cancers may be related to differential sensitivity of the CEA membrane anchor to the CEA-releasing factor in serum.

Biological Factors↗
PubMed1995

[Comparison of simple methods to screen predisposing eye of primary angle-closure glaucoma].

6,584 population over 40 years old in Canton universities and factories were screened for the predisposing eyes of primary angle-closure glaucoma (PACG). In the screening, three methods for the measurement of anterior chamber depth were used and compared and the critical limits of two simple ones of them [peripheral anterior chamber depth (PACD) and oblique illumination test with a flashlight] were evaluated. It was found that the incidence of PACG is as high as 10.0% in eyes with axial anterior chamber depth (AACD) < or = 2.0 mm, it is 6.7% in eyes with peripheral anterior chamber depth (PACD) < or = 1/4 corneal thickness (CT) and is 6.9% in eyes with iris light band ratio (ILBR) < or = 1/4. Also, we found that the incidence of PACG is as high as 77.8% in eyes with AACD < or = 1.6 mm and 100.0% in, AACD < or = 1.4 mm. The authors propose that PACD < or = 1/4 CT and ILBR < or = 1/4 can be the critical values of the two methods for the primary step of PACG screening.

Adult↗
PubMed1994

Phospholipase C-gamma 1 is present on the surface of human colorectal cancer cells.

Using murine monoclonal antibodies, we have detected the novel signal transducing enzyme, phospholipase C-gamma 1, on the surface of cultured human colorectal cancer cells. We have also demonstrated the presence of this enzyme on the surface of fresh human tumor cells derived from primary and metastatic colorectal tumors. This enzyme has previously been described to be associated only with the inner face of the plasma membrane and the cell cytosol. The finding of an enzyme critical to the signal transduction pathway may have important implications for additional functions of this protein.

Antibodies, Monoclonal↗
PubMed1993

[The 43KD polypeptide in the proteins of human lens].

The total proteins, water--soluble proteins and the urea--soluble proteins of the lens from fetal, adult and senile cataract were determined by SDS--PAGE. It was found that there was a 43KD polypeptide in the capsular--epithelium of all lens stated above. The band on SDS-PAGE corresponding to 43KD polypeptide was wide in the water--soluble proteins of the cortex and nucleus of the lenses obtained from over 14-year-old individuals. It became blurred in the urea--soluble proteins of cortex and nucleus of lens with aging, whereas it became almost disappeared in the senile cataract lens.

Adolescent↗
PubMed1993

[Amino acid analysis of retinal S-antigen and interphotoreceptor retinoid-binding protein].

Retinal S-antigen and interphotoreceptor retinoid-binding protein (IRBP) were purified by DEAE-Sephacel ionexchange chromatography and Con A Sepharose affinity chromatography. Amino acid analysis of the S-antigen and IRBP was carried out and compared with that presented by others. The possible reason for difference with regard to some amino acids and related problems were analyzed and discussed.

Amino Acids↗
PubMed1993

[Effect of superoxide dismutase on experimental allergic uveitis].

In this study, experimental allergic uveitis (EAU) in guinea pigs was induced by an injection of bovine serum albumin (BSA) into the vitreous after having pre-immunized them intradermally with BSA plus incomplete Freund adjuvant, and the effect of superoxide dismutase (SOD) on EAU was observed. The result showed that, histopathologically, the phlogistic cell infiltration and exudation within the anterior ocular part of the SOD- treated animals reduced notably. It is suggested that SOD which can scavenge the free radical superoxide anion may alleviate the cellular reaction in the pathological process of uveitis.

Animals↗
PubMed1992

The study of G6PD in erythrocyte and lens in senile and presenile cataract.

The G6PD activity of erythrocytes in 113 male patients with senile and presenile cataract and 86 controls, and G6PD activity of lens in 30 patients with senile cataract and 42 controls were reported. The cataractous group had higher frequency of G6PD deficiency and lower average G6PD level in erythrocytes and lenses, but without statistical significance. The frequency of G6PD deficiency of erythrocytes in presenile cataractous group was higher than that of senile cataractous group but with no statistical significance too. However, the average G6PD level of erythrocytes in presenile cataractous group was lower than that of senile cataractous group and with statistical significance (P < 0.05). The G6PD activity of lenses only presenile in the cortex and have a positive correlation with that of erythrocytes. There was a case with deficiency of G6PD both of erythrocytes and cataractous lenses in both eyes. The results indicate that the deficiency of G6PD might be one of the cataractous pathogenetic factor for presenile cataract. Measurement of G6PD activity of erythrocytes among population might be of significance in finding the risk factor for cataract.

Adult↗
PubMed1992

Purification of bovine interphotoreceptor retinoid-binding protein and its uveitogenicity in Lewis rats.

Interphotoreceptor retinoid-binding protein, IRBP, not only functioning as a shuttle to carry the retinoid between photoreceptor cells and pigment epithelium, but also inducing experimental autoimmune uveoretinitis (EAU), was purified by ConA Sepharose affinity chromatography from the fractions containing IRBP obtained in the course of ion-exchange chromatography by which the bovine retinal S-antigen was purified. This much simplified method allows more rapid purification of the two kinds of protein. EAU was successfully induced with injecting 50 micrograms of IRBP emulsified with Freund's complete adjuvant into the right hind footpads of Lewis rats. It was characterized by panophthalmia or endophthalmia with the severest damage in the posterior retina. Lymphocytes, mononuclear and polymorphonuclear cells were found to be the inflammatory cells of infiltration, with lymphocytes being predominant.

Animals↗
PubMed1992

Detection of gene alteration for color vision defects by polymerase chain reaction.

According to the fact that the abnormalities of visual pigment genes were always involved in the changing of the exon 5, two oligonucleotide primers were designed to amplify the exon 5 of red pigment gene and green pigment gene. After electrophoresis of the PCR products digested with Rsal or Sau3A, the DNA fragments from the exon 5 of red pigment gene (RPG) and green pigment gene (GPG) were separated since there are different restriction endonuclease sites. On the other hand, we analyzed the exon 5 related fragment by Southern blot hybridization with probe out of the 3' end of the fourth intron of green pigment gene. The results of PCR are consistent with nucleic acid hybridization. PCR technique will be of value in prenatal evaluation and genetic counselling.

Base Sequence↗
PubMed1992

Molecular basis of congenital color vision defects in Chinese patients.

Applying Southern blot hybridization, the structures of the red pigment gene (RPG) and the green pigment gene (GPG) were analyzed in 43 Chinese patients with red-green color vision defects, including 3 female cases of deuteranopia. The same analysis was carried out in 4 normal relatives and 3 carriers from 3 affected families, as well as in 11 normal controls. Among the 43 patients, abnormalities of the RPG were detected in all 19 protans, and abnormalities of the GPG were found in 14 of the 24 deutans. In about 80% of the protans and deutans, an alteration of exon 5 in RPG or GPG was discovered. All 19 protans had anomalous RPG and in one protan the normal RPG was replaced by a 5' red-3' green hybrid gene. However, no protans showed deletion of the whole RPG. Some deutans had no GPG; some had a 5' green-3' red hybrid gene with or without the GPG. The exon 5 of RPG and GPG was amplified by polymerase chain reaction (PCR) and the amplified fragments were further analyzed by RsaI digestion. The results of PCR were identical to those of nucleic acid hybridization. PCR will be a useful tool in prenatal diagnosis and genetic counseling.

Adolescent↗
PubMed1992

Effects of qingkailing on experimental allergic uveitis in rabbits.

Experimental allergic uveitis (EAU) in rabbits was induced by single intraocular injection of bovine serum albumin (BSA). The average of protein concentration in aqueous humor of untreated group of rabbits was 14.33 +/- 1.21 mg/ml and the count of tritiated thymidine (3H-TdR) incorporated into lymphocyte T was 3,987 +/- 1,156cpm/10(6). The specific antibody responses to BSA in the serum and the aqueous were 0.508 +/- 0.034 and 0.369 +/- 0.019 (OD) respectively. Meanwhile, the effect of Qingkailing on EAU was observed in comparison with dexamethasone as the positive control. The inflammatory reactions of rabbits treated with Qingkailing were remarkably diminished clinically and pathologically. The amount of protein concentration in aqueous of the treated rabbits was 5.79 +/- 2.19 mg/ml (P < 0.01) and the count of 3H-TdR incorporation was 2,455 +/- 981cpm/10(6) (P < 0.05). The responses of antibody in the serum and the aqueous were 0.414 +/- 0.059 and 0.253 +/- 0.041 (P < 0.01) respectively. Our observations indicate that Qingkailing has a positive therapeutic effect on EAU in the rabbits and sustain the suggestion that this drug is capable of suppressing immune and phlogistic reactions.

Animals↗
PubMed1992

[Survey and treatment of the blind in Xinhui, Guangdong, China].

Co-operating with Helen Keller International (HKI) in 1987 and 1988, Zhongshan Ophthalmic Center made a large scale prevalent survey of the blind in Xinhui, Guangdong, China. Three screening methods were used in the project. The first was a house-to-house visit by ophthalmologists. The second was performed initially by trained country health workers and then checked by ophthalmologists. In the third one, the blind people were asked to come together to be examined by ophthalmologists. The second method was found to be the most effective. The survey revealed that the prevalent rate of blindness was 0.24% in the county. Of all the blind, 89% were over 50 years old, 73% were females. Cataract accounted for 47% of the blindness. Thirty percent of the blind from cataract received surgical treatment. The postoperative re-examination half a year later showed that the corrected visual acuity in 86% of the patients was more than 0.05.

Aged↗
PubMed1992

[Atmosphere pollution by sulfur dioxide during processing of zirantong].

This paper reports the colorimetric determination of total SO2 in Zirantong by the method of rosaniline hydrochlorid. Samper of processed Zirantong from the pharmacy have been analyzed and the quality specifications established. Optimum conditions for processing have been chosen and a procedure has been proposed for the recovery of the poisonous matter SO2 which is then transformed into a beneficial material.

Air Pollution↗
PubMed1991

HLA antigens and Vogt-Koyanagi-Harada's disease.

Thirty patients with Vogt-Koyanagi-Harada's disease were typed for HLA-A and HLA-B antigenic determinants by a microlymphocytotoxicity technique. HLA-B22 antigen showed an increased frequency of 43.3% in the patient group (relative risk = 8.69; exact P < 0.0001; corrected P < 0.0025) compared with normal control group (frequency = 7.69%). This association suggests that immunogenetic factor may play an important role in the pathogenesis of Vogt-Koyanagi-Harada's disease.

China↗
PubMed1991

[Determination of hydrocortisone and methylprednisolone in plasma by reversed-phase HPLC].

A sensitive and rapid method for the simultaneous measurement of both hydrocortisone (HC) and methylprednisolone (MP) using dexamethasone (DX) as the internal standard was presented. High-performance liquid chromatograph Model 344 (Beckman, USA) with a 254 nm wavelength UV detector and reversed-phase Ultrasphere ODS (5 microns) column was used. Sample was extracted with ethyl acetate and the organic layer was evaporated to dryness under an air stream in a 37 degrees C water bath. The residue was dissolved in 30 microliters mobile phase and 20 microliters injected. The mobile phase of methanol and 0.01 mol/L acetate buffer (pH 3.0) (64:36) was pumped at 1.0 ml/min through the column. The detector was operated at 0.005 aufs. The retention time for HC, MP and DX was 5.43 min, 7.7 min and 11.5 min, respectively. Standard curve was linear in the concentration range of 0.02 to 1.28 mg/L for HC and 0.05 to 12.8 mg/L for MP. Sensitivity was 1 ng for HC and 1.5 ng for MP; extraction recovery 76-83%; within day CV less than 4%, and inter-day CV less than 6% for both steroids.

Animals↗
PubMed1991

Nd:YAG laser treatment of congenital persistent pupillary membrane.

Five case of severe congenital persistent pupillary membrane were successfully treated with Nd:YAG laser. The patient's age ranged from 6 to 33 years. After operation, they not only improved their visual acuities, but also got a function of round pupil as well as cosmetic effect. The author describes his experience about the choice of laser energy and technical methods used in Nd:YAG laser treatment of persistent pupillary membrane, and discusses the intra- and post-operative complications, too. Finally, the author emphasizes that provided the operator is skillful, and the choice of laser energy used is appropriate, no severe complications will occur. The author believes that treatment of severe congenital persistent pupillary membrane with Nd:YAG laser is a safe more effective method with less complications as compared with the traditional surgical procedures, and recommends to popularize it.

Adolescent↗
PubMed1991

Inhibition of rat lens aldose reductase by quercetagetin and patuletin.

In this paper the results of inhibition of the Aldose reductase (AR) activity on Wistar rat lens by Quercetagetin extracted from Tagetes erects Linn and by Patuletin extracted from Tagetes patula Linn are reported. Quercetagetin inhibited AR of the rat lens by 93.9% at 10(-4) M, 76.0% at 10(-5) M and 13.3% at 10(-6) M. Patuletin inhibited AR of the rat lens by 100% at 10(-1) M, 80% at 10(-5) M and 22.7% at 10(-6) M respectively. The results show that these two flavones are lens AR Inhibitors, but further study should be done for the possibility of clinical application.

Aldehyde Reductase↗