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Biomedical subjects

R L Schaefer

Publications and source records attributed to R L Schaefer.

5 recordsLinked to original sources

Red cell exchange in the pregnancy complicated by a major hemoglobinopathy.

A new method of partial erythrocyte exchange for pregnancies complicated by a major hemoglobinopathy is described. The Haemonetics 30 Cell Separator allows efficient withdrawal and discard of the patient's erythrocytes. The patient's leukocytes, platelets, and plasma are conserved and returned with washed, compatible donor red cells which contain Hb AA. Three pregnant black women with significant hemoglobinopathies were treated by this modality during their pregnancies. Vaginal term deliveries were accomplished in each case. The method offers advantages in the efficiency of blood quantity displacement, patient comfort, adaptability to the patient with severe anemia, and the use of outpatient facilities. The method is suggested for use whenever a patient with an obstetrically significant hemoglobin variant needs transfusions of erythocytes.

Anemia, Sickle Cell↗

Lectins in diagnostic microbiology: use of wheat germ agglutinin for laboratory identification of Neisseria gonorrhoeae.

A lectin slide agglutination test has been developed for the confirmatory identification of Neisseria gonorrhoeae. With wheat germ lectin as an agglutinin, 164 of 165 clinical isolates of N. gonorrhoeae gave a 3 to 4+ reaction within 6 to 8 min. Four gonococcal isolates, even though negative by the fluoresecent-antibody method, gave strong positive reactions with the wheat germ lectin. Among 23 isolates of Neisseria meningitidis tested, which included representatives of sero-groups A, B, C,D, X, Y, and Z, only one strain in group X gave a false-positive reaction. The nonpathogenic species of Neisseria, as well as Branhamella catarrhalis, all showed negative reactions with the wheat germ agglutinin. The novel method provides a simple, rapid, and inexpensive means for the laboratory diagnosis of gonorrhea and obviates the need for performing second-stage sugar fermentation studies or utilizing the more expensive fluorescent-antibody techniques.

Acetylglucosamine↗

Bias correction in maximum likelihood logistic regression.

This paper provides an expression for bias of the maximum likelihood logistic regression estimates for use with small sample sizes. This bias correction is based on an expansion of the maximum likelihood equation. Simulation results show these corrections to be highly effective in small samples.

Probability↗