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Biomedical subjects

J T Pedersen

Publications and source records attributed to J T Pedersen.

At least 37 records · Page 2Linked to original sources
PubMed1994

Mutational and structural analysis of the lectin activity in binding domain 2 of ricin B chain.

The study of the lectin binding sites of ricin B chain and of other homologous members of the small gene family that make up ricin-like molecules has revealed a number of key contact residues involved in sugar binding. In particular, on the basis of data generated by the X-ray crystallographic structure of ricin, comparisons of sequence homologies to other ricin-like molecules and substrate binding studies with these molecules, it has been proposed that His248 of Ricinus communis agglutinin (RCA) B chain may interfere with galactose binding in the second binding domain of that lectin. To test that hypothesis, single binding domain 2 (SBD2) of ricin B chain was expressed as a gene 3 fusion protein on the surface of fd phage to measure directly the effect of mutational changes on this binding site. Replacement of tyrosine with histidine at amino acid position 248 of SBD2 of ricin B chain was shown to reduce lectin activity. The sequences of RCA and ricin B chains were aligned and compared with the tertiary structure of ricin B chain to select various mutations that were introduced as controls in the study. One of these controls, Leu247 to Val247, displayed increased affinity for galactosides. The role of sequence changes is discussed in relation to the structural and functional divergence in these molecules.

Amino Acid Sequence↗
PubMed1992

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↗
PubMed1990

[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↗
PubMed1990

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↗
PubMed1989

Colo-pleural fistula.

A case of non-traumatic colo-pleural fistula is recorded for the first time as the cause of a long-standing pleural empyema. The patient was treated with drainage, antibiotics and parenteral nutrition. The fistula was the result of a diverticulitis coli and/or a pancreatitis.

Colonic Diseases↗
PubMed1988

Follow-up in general practice of patients treated for precancer of the cervix uteri.

It is known that some patients with invasive cancer of the cervix uteri have previously had a positive vaginal cytology, which was not followed up. More recent investigations have also shown that invasive cancer has developed in patients who were treated for premalignant stages of cervical cancer, but who were not followed up adequately. In Denmark, these patients are advised to attend their practitioner for an annual check. The aim of the present study was to find out if 39 women, treated in a hospital for early cervical cancer, did in fact attend their practitioner for adequate follow-up. Fifteen per cent attended less frequently, and 21% more frequently than recommended, while 64% attended as per the schedule. Women who had undergone surgery for the early stages were significantly better attenders. Women over 30 years of age had a similar tendency, but the difference was not significant. It is suggested that, in the interest of more effective follow-up, registration should be computer-controlled.

Adult↗
PubMed1979

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↗