CD34+-selected peripheral blood progenitor cell transplantation in patients with multiple myeloma: tumour cell contamination and outcome.

Thirty-six patients with multiple myeloma (23 PR1, nine PR2, four stable disease) were entered into a pilot study evaluating the use of CD34+-selected peripheral blood progenitor cell transplantation (PBPCT) following high-dose melphalan alone or high-dose melphalan and total body irradiation. Peripheral blood progenitor cells (PBPCs) were mobilized with cyclophosphamide and granulocyte colony stimulating factor (G-CSF). CD34+ selection using the Cellpro Ceprate-SC system was performed in 22 cases with an adequate yield in 20. 10 patients failed to mobilize sufficient cells to permit selection and in four cases selection was not performed for other reasons. 16 patients therefore received unselected PBPC. Tumour cell contamination was evaluated by IgH gene fingerprinting (fpPCR). Harvested PBPC were fpPCR positive in 13/20 CD34+-selected cases and remained positive after selection in seven. Harvested PBPC were studied in 9/16 patients receiving unselected cells; fpPCR was positive in five and negative in four. There was no difference in event-free survival (EFS) between the CD34+-selected group and the unselected group (median 21 and 26 months, respectively, P=ns). The CD34+-selection process therefore reduced contamination but did not eliminate it completely, and in this small non-randomized study there was no apparent clinical benefit of CD34+ selection.

The MNSs antigen Ridley (Ria).

After more than 20 years the extended pedigree of the only known kindred carrying the low frequency antigen Ria (Ridley) was reinvestigated. It is established that Ria is governed by a gene which is part of or very closely linked to the MNSs locus. Further serological and frequency studies are reported.

Response to immunization with A and B human glycoproteins for the procurement of blood grouping reagents.

37 subjects have been immunized with A or B human blood group substances. All subjects showed at least a threefold increase in potency of their ABO antibodies. Use of the resulting plasma has considerably improved the quality of our ABO grouping reagents. The IgG component of these antibodies increased in all subjects and an IgA component was seen in the majority of post-immunization samples. All group O subjects developed cross-reacting anti-A,B antibodies.

Diencephalic sites from which calling can be evoked with small currents in Japanese quail.

A systematic stimulation survey f the diencephalon in Japanese quail, showed that calling could be evoked with currents as low as in the midbrain (less than 50 microA). These low threshold areas were located in the pre-optic area and posterior hypothalamus. Both are likely to influence output, but are not on a calling motor pathway from the forebrain. Putative pathways for calling had somewhat higher thresholds, than the preoptic area and posterior hypothalamus. Calling was evoked from much of the diencephalon with currents up to 200 microA, but positive sites tended to be located posteriorly. A few of the calls elicited resembled natural calls subjectively, but statistical analyses showed significant differences. Most elicited calls were unlike any spontaneous call and could be produced in both sexes.

The fetal sound environment of sheep.

Hydrophones implanted inside the intact amniotic sac recorded sounds available to fetal lambs. Unlike recordings made from outside the intact amnion in human subjects, sounds produced at levels similar to normal conversation from outside the ewe were picked up without masking by maternal cardiovascular sounds. Noises from inside the mother were intermittent and linked to her activity.

Sound stimulation available to the sheep foetus.

Work on the uterine sound environment has been carried out by implanting a hydrophone on the neck of the foetus in two pregnant ewes a few weeks before term. Stimulation with sounds of known amplitude and the use of calibrated microphones and a frequency analyser enabled us to assess (1) the amount of attenuation of sounds of different frequency when they had passed through the maternal tissues and amniotic fluid to become available to the foetus, (2) the absolute level of sound entering the amnion from within the mother and (3) the recognizability of external sound such as speech, when recorded from within the uterus. One puzzling feature of the results has been our inability to hear those sounds which are commonly believed to constitute a predominant stimulus for the foetus: those produced by the maternal cardiovascular system.

The incidence of antibodies to low frequency antigens (LFA) in plasmapheresis donors with hyperimmune Rh antisera.

Over 50% of plasmas from plasmapheresis donors hyperimmunized for Rh antibodies were found to contain antibodies to low frequency red cell antigens (LFA). The majority of these plasmas contained antibodies to more than one LFA. On the other hand, the incidence of these antibodies in immune plasma from control plasmapheresis donors was markedly lower. The significance of the high incidence of these antibodies in grouping reagents is discussed.

Further data on the Pta antigen.

The second Pt(a+) family is described. Pta is shown to segregate independently from several genetic markers.