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J T Pedersen

Publications and source records attributed to J T Pedersen.

15 recordsLinked to original sources

BIOSITE: a program for the interactive comparison of aligned homologous protein sequences.

A program, BIOSITE, providing for the interactive visual comparison of aligned homologous amino-acid sequences is presented, including an example of its application. The program allows for two types of comparison sequence to be generated: an 'identity' sequence and a 'difference' sequence. These may be used on subsets of sequences and in further comparisons to identify candidate sites involved in a distinct functional property. The program should prove a useful tool for biologists engaged in understanding sequence--function relationships.

Amino Acid Sequence

[Smoking habits among Danish physicians, nurses and midwives in 1989].

Health staff play a central role in distribution of knowledge about the injurious effects of tobacco by influencing the smoking habits of the population. The danish council on smoking and health has therefore chosen health staff as one of the first targets for its activities. One of these was conduct of a questionnaire investigation among a representative section of Danish doctors, nurses and midwives about smoking habits and attitudes to the tobacco problem. The random sample consisted of 2,997 persons, of whom 2,606 (87%) replied to the question about daily smoking habits. In all of the age groups, the frequency of smoking was considerably lower among health staff than in the population as a whole, primarily because many had stopped smoking. The frequency among men was 23% for doctors as compared with 50% in the normal population (age 20-69 years) and 15% for female doctors, 29-30% for nurses and midwives as compared with 46% in the normal population. The frequency of smoking among doctors has decreased considerably since 1980. Very few heavy smokers were found among health staff, particularly among doctors, and many male doctors smoked pipes (47% of the smokers). Even though health staff smoke less than the rest of the population, attention must still be focussed on this group on account of its function for establishing opinions in the health sector.

Adult

Octapeptide segments from the amino terminus of glycophorin A contain the antigenic determinants of the M and N blood groups systems.

Human red blood cells with phenotype N/N and M/M were tested in an agglutination assay with anti-N and anti-M antibodies, respectively. After incubation of the synthesized octapeptide (Leu-Ser-Thr-Thr-Glu-Val-Ala-Met) from the N-amino terminus of glycophorin A, with anti-N antibody, there was significant inhibition of the agglutination of the N-positive cells. There was also inhibition of the agglutination of the M-positive cells with anti-M antibody by the synthesized octapeptide (Ser-Ser-Thr-Thr-Gly-Val-Ala-Met) from the M-amino terminus of glycophorin A. There was no inhibition, however, of the agglutination of M-positive cells with anti-M antibodies by the N-amino terminal octapeptide. Likewise, the M-amino terminal octapeptide did not inhibit agglutination of N-positive cells with anti-N. Because the synthesized octapeptides contained no carbohydrate, the anti-N and anti-M specificity appears to be determined principally by the peptides themselves. Further studies with the use of chimeric peptides indicate that the amino terminal amino acid leucine of N-glycophorin A is a primary determinant of the N antigen, whereas the amino terminal serine of M-glycophorin A is a primary determinant for the M antigen.

Amino Acid Sequence

Evaluation of an automated blood smear analyzer.

The performance of a diff3 System prototype instrument that does automated leukocyte differential counts, erythrocytic morphology determinations, and leukocyte count and platelet count estimates, was compared with performance by laboratory personnel for a five-week period in an active general hospital. Using experienced supervisors as the referee method, this instrument performed as well as the routine laboratory staff in all aspects of leukocyte differential counting. With respect to erythrocytic morphology, estimates of hypochromia were inferior to those of the routine laboratory staff; comparisons of estimates of macrocytosis and polychromasia were not significantly different. Leukocyte and platelet numerical estimate performance by the diff3 System was not as good as that of automated cell-counting instruments, but categorization of platelet concentration as normal or abnormal did compare favorably with estimation by laboratory personnel. The flagging of abnormal slides by the instrument was comparable in sensitivity to that by the routine laboratory staff; however, specificity was less, with a significantly greater number of false positives obtained by use of the instrument.

Blood Cell Count