Radiological appearances of lymphomas arising from mucosa-associated lymphoid tissue (MALT) in the lung

We review the radiological findings in 13 patients with histologically proven (n = 10) or clinically diagnosed (n = 3) lymphomas arising in mucosa-associated lymphoid tissue (MALT) of the lung. These rare B-cell lymphomas typically follow an indolent course, and many cases are still being incorrectly described in current radiological literature under the term pseudolymphoma. The patients frequently give a history of autoimmune disease involving the affected organ, and involvement of another mucosal site as part of a disseminated MALT lymphoma, is common. The radiographic patterns of pulmonary parenchymal involvement in lung MALT lymphomas have been reviewed, and correlation made with their clinical behaviour.

Hemorrhagic shock and encephalopathy syndrome. An unusual cause of sudden death in children

Hemorrhagic shock and encephalopathy syndrome (HSES) is a sudden-onset symptom complex occurring in previously healthy infants and children. It was first described in 1983 in the United Kingdom in 10 infants. Subsequently, > 140 cases have been reported worldwide, although no cases have been previously reported in the forensic literature. Typically the child presents with fever, shock, encephalopathy with coma and seizures, evidence of hemorrhage, and diarrhea. Laboratory investigation reveals falling hemoglobin and platelet counts, renal impairment, evidence of disseminated intravascular coagulation, metabolic acidosis, and raised serum transaminases. Microbiological cultures are uniformly negative. The condition has a high mortality and morbidity. The etiology is unknown and may be multifactorial. However, hyperpyrexia appears to play a central role in pathogenesis. The diagnosis of HSES in the deceased child is one of exclusion and requires a careful antemortem history as well as a thorough autopsy with toxicological and microbiological investigations. A case of HSES is reported and the literature reviewed.

Evaluating zona pellucida structure and function using antibodies to rabbit 55 kDa ZP protein expressed in baculovirus expression system

A cDNA encoding the rabbit 55 kDa ZP protein was expressed using a baculovirus expression system and was evaluated for its ability to elicit antibodies which may interfere with sperm-ZP interaction. The expressed glycosylated protein, BV55, was purified by wheat germ agglutinin lectin affinity chromatography. Antisera made in guinea pigs immunized with BV55 (GP-alpha-BV55) is specific for the 55 kDa rabbit ZP protein. Indirect immunofluorescence studies indicate that GP-alpha-BV55 localizes to a filamentous meshwork on the surface of the ZP of isolated rabbit eggs. Immunohistochemical analysis of rabbit ovaries demonstrated that this antigen is localized within the ZP of primary and more advanced stage ovarian follicles but is not detected in primordial follicles. In addition, the 55 kDa antigen was detected in the granulosa cells of secondary stage follicles but not in the oocyte. GP-alpha-BV55 effectively blocked the binding of rabbit sperm to rabbit eggs in vitro. However, Fab fragments generated from GP-alpha-BV55 failed to block sperm binding, suggesting that the inhibitory effect of GP-alpha-BV55 was due to stearic hindrance rather than specific blocking of a sperm receptor site. Although the Fab fragment did not inhibit sperm binding, additional studies demonstrated that biotinylated BV55 protein bound to rabbit sperm in the acrosomal region in a manner consistent with ligand activity in the sperm-ZP interaction, and that BV55 bound to rabbit sperm in a dose-dependent manner. These studies therefore demonstrate that antibodies against recombinant ZP proteins recognize the native intact ZP and inhibit sperm-ZP interaction. They also provide evidence that the rabbit 55 kDa ZP protein, which is the homolog of the pig ZP3 alpha sperm receptor protein, has sperm receptor activity.

Effectiveness of HB2 (anti-CD7)--saporin immunotoxin in an in vivo model of human T-cell leukaemia developed in severe combined immunodeficient mice

The transplantation of the human T-cell acute lymphoblastic leukaemia (T-ALL) cell line HSB-2 into severe combined immunodeficient (SCID) mice was found to produce a disseminated pattern of leukaemia similar to that seen in man. The intravenous injection of 10(7) HSB-2 cells was associated with a universally fatal leukaemia. Histopathological examination of animals revealed the spread of leukaemia initially from bone marrow to involve all major organs including the meninges. An immunotoxin (HB2-Sap) was constructed by conjugating the anti-CD7 MAb HB2 to the ribosome-inactivating protein saporin. An in vitro protein synthesis inhibition assay revealed specific delivery of HB2-Sap immunotoxin (IT) to CD7+ HSB-2 target cells with an IC50 of 4.5 pM. When SCID mice were injected with 10(6) HSB-2 cells and then treated 8 days later with a single intravenous dose of 10 micrograms of immunotoxin there was a significant therapeutic effect evidenced by the numbers of animals surviving in the therapy group compared with untreated controls (chi 2 = 5.348, P = 0.021). These results demonstrate the useful application of human leukaemia xenografts in SCID mice and the potential therapeutic effect of an anti-CD7 immunotoxin in human T-ALL.

The mammalian zona pellucida: its biochemistry, immunochemistry, molecular biology, and developmental expression

Many studies of the molecular and biochemical aspects of mammalian fertilization have focused on the interaction of the spermatozoa with the zona pellucida (ZP). The zona pellucida, a unique extracellular matrix surrounding the mammalian oocyte, is formed during ovarian follicular development. Following ovulation of the mature ovum, the spermatozoa must bind to and penetrate this matrix before the fertilization process is completed and the male and female genetic information combine. Although numerous models for this interaction have been proposed, the complete process has yet to be elucidated. The precise mechanisms by which these interactions occur also vary markedly among different mammalian species, making it more difficult to establish a unified model. To a great extent, the study of the molecules involved in these interactions have been limited because small numbers of female gametes are available for these studies. The recent development of techniques to isolate large numbers of zonae pellucidae as well as advances in immunological and molecular biology techniques have permitted the detailed characterization of ZP proteins. Although there is a paucity of information on the post-translational modification and extracellular processing of these molecules which result in matrix formation, a number of properties have been elucidated allowing better correlation between the structure and function of different ZP proteins among species. This review reflects these studies in relation to protein nomenclature and the molecular complexity of ZP antigens.

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.