PubMed Health⌕ Search

Biomedical subjects

D M Myers

Publications and source records attributed to D M Myers.

At least 19 recordsLinked to original sources
PubMed1997

Identification of a region in the integrin beta3 subunit that confers ligand binding specificity.

Many integrin adhesion receptors bind ligands containing the Arg-Gly-Asp (RGD) peptide motif. Most integrins exhibit considerable specificity for particular ligands and can distinguish among the many conformations of RGD. In this study we identify the domain of the integrin beta subunit involved in determining ligand binding specificity. Chimeras of beta3 and beta5, the most homologous integrin beta subunits, were expressed with alphav on the surface of human 293 cells. The ligand binding phenotype of each chimera was assessed using the ligands Fab-9 and fibrinogen, both of which have a binding preference for alphavbeta3. The results of the study show that when exons C and D of the beta3 subunit (residues 95-233) are substituted into beta5, the chimera gained the ability to bind Fab-9 with an affinity close to that of wild-type alphavbeta3. This chimera was able to mediate cell adhesion to fibrinogen. Furthermore, the swap of only a 39-residue segment of this larger domain, beta3 residues 164-202, into the backbone of beta5 enabled the chimeric integrin to bind soluble Fab-9. This small domain is highly divergent among the integrin beta subunits, suggesting that it may play a role in determining ligand selection by all integrins.

Amino Acid Sequence↗
PubMed1987

Serodiagnosis of human leptospirosis by counterimmunoelectrophoresis.

The counterimmunoelectrophoresis (CIE) technique employing a soluble extract antigen was found useful in screening human sera for antileptospiral antibodies to multiple leptospiral serovars. The CIE test results with sera from patients with suspected cases of leptospirosis and sera from a control group compared favorably (97.9%) with those obtained by the microscopic agglutination test using a battery of live leptospiral antigens. CIE is easy to perform, is highly sensitive, uses an antigen which is very stable at room temperature, and permits the screening of many sera in a short period of time. The CIE technique appears to be ideally suited to a small laboratory where facilities may be too limited for examining sera by the microscopic agglutination test.

Agglutination Tests↗
PubMed1985

Leptospiral agglutinins among cattle in the Republic of Guyana.

Cattle sera collected in the Republic of Guyana during 1981 to 1982 were examined for serologic evidence of leptospirosis. Significant leptospiral agglutinins (1:100 or higher) were disclosed in 49.1% of 2,935 apparently normal cattle from 734 farms in the three major cattle-raising regions of the country. Seroreactions principally involved hardjo and wolffi of the Sejroe serogroup, icterohaemorrhagiae, pomona, tarassovi, canicola and grippotyphosa. A high proportion of reactions to one or more of different leptospiral serovars were observed in each of the three regions. These variations were attributed to differences in environmental conditions and farming practices. The findings provided evidence for the first time of the widespread occurrence of leptospirosis in cattle in Guyana caused by multiple leptospiral serovars.

Agglutinins↗
PubMed1984

Evaluation of hyperimmune rabies sera by the counterimmunoelectrophoresis test.

This study demonstrates that the counterimmunoelectrophoresis test is a rapid and reliable method for the determination of antibody titres in hyperimmune antirabies sera. The application of this method to the selection of human sera for the production of antirabies globulin and for the final standardization of serum batches is discussed.

Animals↗
PubMed1981

Comparison between a modified counterimmunoelectrophoresis test and the indirect fluorescent-antibody test for detection of antibodies to rabies virus in human sera.

The correlation between the modified counterimmunoelectrophoresis test and the indirect fluorescent-antibody test for detecting rabies virus antibodies in human sera was studied, using as a reference the standard mouse neutralization test. Higher sensitivity was observed with the counterimmunoelectrophoresis technique than with the indirect fluorescent-antibody method. The counterimmunoelectrophoresis test provides a practical quantitative alternative to the indirect fluorescent-antibody method.

Antibodies, Viral↗
PubMed1980

Determination of serum neutralization antibodies to rabies virus by a modified counterimmunoelectrophoresis test.

A modified counterimmunoelectrophoresis (CIE/SN) technique was developed as a diagnostic procedure for the detection of serum-neutralizing antibodies to rabies virus. CIE/SN test results with sera from individuals undergoing postexposure rabies immunization compared favorably with those obtained by the standard mouse neutralization test procedure. Fractionation of selected sera by Sephadex G-200 column chromatography demonstrated that serological activity involved in both procedures was present in the immunoglobulin G-containing fractions of the sera. The mean advantage of the CIE/SN over the standard mouse neutralization test consists in considerably reducing the time required for results, a factor which can be of clinical importance in evaluating antibody levels to rabies virus. In addition, the CIE/SN method is simple to perform and inexpensive.

Animals↗
PubMed1980

Serological and bacteriological detection of Brucella canis infection of stray dogs in Moreno, Argentina.

A focus of B. canis infection was identified in Moreno, Argentina, among the stray dog population by serologic methods and confirmed in a second survey which included cultural isolations. A counterimmunoelectrophoresis technique using a specific rough Brucella surface antigen was applied to the serodiagnosis of canine brucellosis. This method was found to be as effective as the mercaptoethanol tube agglutination test and the gel diffusion test in detecting B. canis antibodies in natural and experimentally infected animals. The results are discussed in terms of the diagnostic significance of the three tests employed.

Agglutination Tests↗
PubMed1980

The isolation of leptospires from stray dogs in the city of São Paulo, Brazil.

The search of leptospires was conducted in kidneys of 1,415 stray dogs in the city of São Paulo--Brazil. From them 35 isolations were got, serovar canicola was the most frequent (32 samples) followed by copenhageni (2 samples) and pomona (1 sample). For the first time serovar pomona was isolated from dog in Latin America. Also, monthly and seasonal variations are discussed in relation to the prevalence of leptospirosis.

Animals↗
PubMed1979

A study of leptospirosis among animals in Barbados W.I.

Microscopic agglutination tests performed during 1971 and 1972 on Barbadian livestock showed positive serological reactions for leptospirosis as follows: cattle 51%, pigs 13%, sheep 18%, horses 64% and goats 19%. The serogroup Autumnalis predominated in all but horses in which the reactions to the Pyrogenes group appeared slightly higher. After the isolation of a strain of Leptospira serotype fort-bragg (Barbadian strain No. 119) of the Autumnalis serogroup in 1973, and its subsequent inclusion in our test battery of leptospiral antigens, high percentages of cattle, dogs, mongooses and man showed sero-positive reactions against the strain. Attention is called to the wide dissemination of the fort-bragg serotype on the island and to the role of rodents and the mongoose in its spread. 74 clinically affected Barbadian cattle from three herds were studied during 1975-76; 60 (81%) were serologically positive and nine different serogroups were represented. Predominant sero-positive reactions to Hebdomadis, Autumnalis, Ballum and Pyrogenes antigens were recorded. The highest titres were against Autumnalis, Hebdomadis and Pomona. Hebdomadis and Pomona serogroup antibodies may be due to many importations of cattle with those infections into Barbados.

Agglutination Tests↗
PubMed1979

The problem of human leptospirosis in Barbados.

The results of a retrospective study of human leptospirosis cases occurring in Barbados during the period 19-68-74, and of serological findings among high risk occupational groups, fever cases and health centre patients monitored for the disease during 1975-77, indicate that infection by serotype fort-bragg of the Autumnalis group is widespread in this Caribbean island. The occupational groups most affected are sanitation workers and sugar-cane workers. Results of serological tests conducted at the principle hospital are comparable with the results obtained by the microscopic agglutination reference test procedure conducted at the Pan American Zoonosis Centre (CEPANZO).

Adolescent↗
PubMed1979

Serodiagnosis of ram epididymitis by counterimmunoelectrophoresis, using Brucella ovis surface R antigen.

The counterimmunoelectrophoresis (CIE) technique was developed as a diagnostic procedure for ram epididymitis caused by Brucella ovis. CIE test results with sera from naturally and experimentally infected male sheep compared favorably with those obtained by gel diffusion and complement fixation employing the same B. ovis surface R antigen. The main advantage of CIE over gel diffusion consists in a significant reduction of the time required to detect precipitin formation, whereas both methods obviate several of the difficulties encountered with complement fixation tests for B. ovis.

Animals↗