Isolation and characterization of a full-length cDNA encoding the 55-kDa rabbit zona pellucida protein

A full-length cDNA (rc55) encoding the major rabbit zona pellucida (ZP) glycoprotein (55 kDa) has been cloned and sequenced. A lambda gt11 expression library was constructed using poly(A)+ mRNA isolated from sexually immature rabbit ovaries which contain large numbers of developing follicles. The rc55 cDNA was identified using affinity purified polyclonal antibodies specific to ZP antigens which are shared among mammalian species. The deduced amino acid sequence of the full-length rc55 clone was matched to the NH2-terminal 25-amino acid sequence obtained for this protein. The predicted amino acid sequence consists of 540 amino acids including a putative signal peptide of 18-24 residues and six potential N-glycosylation sites. The cDNA hybridizes to a 2000-base species of mRNA from rabbit ovary which is not detected in other rabbit tissues. The message is present early in ovarian follicular development and is approximately 600-fold greater in sexually immature as compared with sexually mature rabbit ovaries. This cDNA was expressed as a cro-beta-galactosidase fusion protein using the pEX expression vector. Antibodies against native rabbit ZP, affinity-purified on the recombinant 55-kDa ZP protein, were found to recognize the native rabbit ZP glycoprotein, indicating partial conservation of native epitopes in the expressed recombinant protein.

Chronic myelomonocytic leukaemia associated with T cell receptor delta gene rearrangement

Morphological, immunophenotypic, and genetic analyses were carried out on peripheral blood, bone marrow, and pharyngeal biopsy material from a patient with chronic myelomonocytic leukaemia (CMML). Morphological analysis of bone marrow was diagnostic of CMML; immunophenotypic analysis of peripheral blood and bone marrow were negative for B and T cell antigens, and immunochemistry performed on the pharyngeal extramedullary infiltrate showed the presence of large monocytoid cells which stained positively for muramidase. Genotypic analysis, however, showed clonal rearrangement of the T cell receptor (TCR) delta chain gene, a marker of T cell or, less commonly, B cell lymphoid neoplasms. Other TCR genes, beta and gamma, were germline in all tissues examined. TCR delta is rearranged in precursor B cell and most T lymphoid neoplasms. A small proportion of cases (10%) of acute myeloid leukaemia (AML) also show rearrangement of the TCR delta gene. To date TCR delta rearrangement has not been described in CMML. The aberrant TCR delta rearrangement shown in this patient with CMML provides further evidence of the clonal nature of this disorder.

Toxic shock syndrome

Presenting features and clinical manifestations of six patients with toxic shock syndrome are reported. In four of the six cutaneous injury, sometimes trivial, occurred before the onset of symptoms and may have been a causal factor. All six children recovered. The need for early recognition and intensive management in this life threatening condition is discussed.

The nerve deaf child--intrauterine rubella or not?

We describe a laboratory test which is useful in determining whether deafness is due to intrauterine rubella. The study group consisted of 8 deaf patients with proved intrauterine rubella, 12 patients with familial deafness, and 17 controls. Blood was taken at time 0 from all of them. All the deaf children and 5 controls were immunised and further blood samples taken at 2 and 6 weeks. Each blood sample was analysed for the lymphocyte response to rubella in vitro and for the presence of rubella haemagglutination inhibition. All the rubella-affected patients had antibody titres to rubella at time 0 and there was no notable change after immunisation. None of these patients had a significant lymphocyte response to rubella antigen at any time. Eight of the familial deaf patients and 13 of the controls had positive antibody titres. With the exception of one patient whose results were equivocal, all the familial deaf patients and controls in whom antibodies were detected had lymphocyte responses to rubella. In those with undetectable antibodies the lymphocytes failed to respond in vitro to rubella antigen.

Bone rarefaction and crush fractures in juvenile chronic arthritis

Seventy children with juvenile chronic arthritis have had measurements of cortical and trabecular bone density in one or both radii. In 7 children with unilateral disease of one wrist, there was a substantial reduction in growth on the affected side. Trabecular bone density in the distal radius was reduced in the main group of 63 patients compared with controls, and this deficit was appreciably worse if the wrist was clinically affected by disease or if the child was being treated with steroids. Cortical bone density in the midshaft was less affected. Crush fractures of the spine were associated with more prolonged periods of bed rest, steroid therapy, radial trabecular bone density more than 2 standard deviations below normal, and subnormal 25-hydroxycholecalciferol concentrations in the serum. Since steroid therapy is often mandatory the main therapeutic implications are that the more severely affected child often needs vitamin D supplementation in "physiological" dosage, and that early mobilisation and reduction of steroid dosage should be constant aims.

Lymphocyte blastoid transformation assay by cytofluorography

This rapid, automated, micromethod quantitates blastoid transformation using a supra vital stain, acridine orange, in quantitating the ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) before and after cell stimulation. Only 0.2 ml of culture containing 1.0 X 10(5) to 1.5 X 10(5) lymphocytes is required to obtain results every 5 minutes. These results include a total cell count and cell counts of the populations with increased RNA (I-RNA), and increased DNA (I-DNA). The I-RNA and I-DNA lymphocyte populations, as determined by the cytofluorometric method, correlate well with the accepted H3 uridine and C14 thymidine uptake methodology. The phytohemagglutinin dose response measurements by the 2 methods also correlate well. Blast cell counts, by Wright-Giemsa staining, showed near identity to the I-RNA cell population.

Improved measurement of erythrocyte volume distribution by aperture-counter signal analysis

In aperture counters, particles in fluid suspension flow through a small orifice or aperture, causing a change in the electrical resistance of the aperture. This change is sensed by an external electronic circuit and translated into a voltage pulse, the signal height of which is proportional to the volume of the particle in the aperture. These signal pulses are collated into a spectrum of pulse heights by a multichannel pulse-height analyzer. The channel number (voltage increment) spectrum is proportional to the volume distribution of the particles sensed. A problem is that pulse height not only depends on cell volume, but also on the orientation and shape of the particle sensed and the current density along the path taken by the particle through the aperture. Uneven current density exists, primarily at the aperture entrance and exit, close to the wall. Orientation and shape of particles are altered near the wall by the unbalanced shear forces there. Toward the center of the aperture, the shear forces act so as not to induce continuous change in the orientation of the particles sensed. Thus introduction into the pulse-height spectrum of pulses that do not show a good proportionality to volume is primarily caused by particles that are traveling near the aperture wall. Residence time in the aperture for a particle traveling near the wall will be longer than that for a particle traveling down the center of the aperture, because of the smaller fluid velocity near the wall. Duration of the signal pulse created by a particle traveling near the wall will be correspondingly greater. We discuss an electronic filter to remove from the pulse-height spectrum those pulses that appear to result from particles traveling near the wall and the effect of the filter on the measured signal height and hence the volume distribution of erythrocytes. Use of this technique to characterize erythrocytes by volume distribution is described.