Clinical heart transplantation. Total lymphoid irradiation for resistant rejection after heart transplantation: only moderate success medium-term

Total lymphoid irradiation (640 cGy) was given to 19 heart and 1 heart-lung recipients on maintenance triple therapy at a mean of 4.9 +/- 4 months after transplantation (range 46 to 519 days). Mean number of treated rejection episodes before, during, and after total lymphoid irradiation was 6.4 +/- 1.7, 0.8 +/- 1.2, and 1.2 +/- 1.3 episodes per patient, respectively. During total lymphoid irradiation, 37% had at least one episode of rejection requiring treatment; after total lymphoid irradiation, 42% had no further rejection episodes, 21% had one further episode, and 37% had 2 or more episodes. Metastatic squamous cell carcinoma in one patient and coronary artery disease in three of five patients studied to date is of concern and requires longer follow-up.

Bone marrow gene transfer in three patients with adenosine deaminase deficiency

Adenosine deaminase (ADA) deficiency results in severe combined immune deficiency disease (SCID), which is fatal without treatment. Allogeneic bone marrow transplantation (BMT) is the treatment of choice if an HLA-identical sibling bone marrow donor is available, resulting in almost 100% cure rate. BMT-related mortality is high in patients lacking such a donor. For these patients, efficient transfer of a recombinant ADA gene into hematopoietic stem cells is a therapeutic option if it results in the outgrowth of a 'genetically repaired' lymphoid system. Based on successful gene transfer studies in monkeys, we performed retrovirus-mediated gene transfer into CD34+ bone marrow cells of three patients with ADA deficiency. Two patients received bovine ADA conjugated to polyethylene glycol (PEG-ADA); in the third patient, PEG-ADA was started 4 months after gene transfer. Gene transfer resulted in a 5-12% transduction frequency of in vitro colony forming cells (CFU-Cs). No toxicity was observed during and after infusion of the graft. Following infusion of the transduced CD34+ cells, transduced granulocytes and mononuclear cells persisted in the circulation for 3 months. In addition, the gene was present in the marrow of one of the patients at 6 months after gene transfer. Expression of the gene was not detected. After this period, the gene could not be detected. In monkey studies we showed that myeloablation, which was not performed in the patients, may enhance engraftment of genetically modified cells. We hypothesize that lack of myeloablation, administration of bovine ADA and low numbers of transduced progenitor cells all may have contributed to the relative low numbers of transduced cells in the patients. Under these conditions, no selective advantage of the genetically corrected progenitor cells was observed.

Mutation analysis in CD40 ligand deficiency leading to X-linked hypogammaglobulinemia with hyper IgM syndrome

Mutations in the gene encoding CD40 ligand have been shown to be the cause of X-linked hypogammaglobulinemia with hyper IgM (HIGM1). We have used the technique of single strand conformational polymorphism (SSCP) analysis to screen for mutations in this gene in affected boys from nineteen unrelated families. Sixteen novel mutations were identified in patients, comprising six patients with single base substitutions, two patients with single base insertions, six patients with deletions ranging from one to seven bases and two patients with large deletions at the 5' end of the gene. These mutations were distributed throughout the gene SSCP band shifts and/or alterations in restriction enzyme digestion sites could be used for unambiguous determination of carrier status in at-risk female relatives of most of the affected boys and, in some cases, prenatal diagnosis also can be offered.

Functional specialization in the ruminant placenta: evidence for two populations of fetal binucleate cells of different selective synthetic capacity

Trophoblast binucleate cells (BNC) in the ruminant placenta demonstrate a characteristic development, mature structure and migratory capacity whether situated in cotyledonary or intercotyledonary regions of the placenta. However, previous immunocytochemical studies demonstrated clear differences in gene expression in granule contents of BNC according to their anatomical location with some proteins being expressed in all BNC (e.g. ovine placental lactogen) whereas others were unique to a particular origin (e.g. SBU3 antigen in cotyledonary BNC only). We have used enriched preparations of binucleate cells and showed differences in steroid metabolic capacity in vitro which is more related to their species origin (sheep or goat) than to their anatomical location. The predominant product from [3H]pregnenolone is progesterone (sheep) and 5 beta-pregnane-3 alpha, 20 alpha-diol (goat) and the amount formed (corrected for the number of BNC) is similar irrespective of whether BNC were derived from the cotyledonary or intercotyledonary regions. These studies indicate specific forms of regional functional specialization of BNC and emphasize their multifunctional role in the ruminant placenta.

Deleterious effects of prostaglandin E2 in reflux oesophagitis

There is good evidence in the medical literature that nonsteroidal anti-inflammatory drugs exert salutory effects in animal models of reflux oesophagitis. This hypothesis accounts for these observations by describing the biochemical mechanism of nonsteroidal anti-inflammatory drugs. Since nonsteroidal anti-inflammatory drugs inhibit the synthesis of prostaglandins, it is proposed that prostaglandins exert deleterious effects during oesophagitis. This hypothesis is supported by clinical observations and can explain several features of oesophagitis, especially the relationship between inflammation and dysmotility. The controversial implication of this hypothesis is that nonsteroidal anti-inflammatory drugs may be useful in the therapy of severe oesophagitis.

Limitations of SCID-Hu mouse model for antiretinal autoantibody responses

The transfer of human peripheral blood mononuclear cells (PBMC) to mice with severe combined immune deficiency (SCID) allows the investigation of immune function. The authors investigated the potential of SCID mice to produce anti-retinal antibodies from PBMC derived from retinal vasculitis patients, and in vivo primed with retinal antigen on days 2 and 22 following transfer. Using Western blotting they could not detect any anti-retinal humoral response in sera from reconstituted animals. Human CD(4)(+) or CD8(+) T cells in spleen or lymph nodes from reconstituted animals were not detected by histological examination. Similarly, no ocular pathology was apparent. The possible mechanisms involved in the lack of an anti-retinal specific antibody response in reconstituted SCID mice are discussed.

Immunological studies of herpes simplex virus infection in children with atopic eczema

This study examines the role of immune defence mechanisms in herpes simplex virus (HSV) infections in atopic eczema and whether impairment of these mechanisms explains the susceptibility of some children with atopic eczema to cutaneous HSV infections. Ten children with eczema herpeticum and 13 with atopic eczema and recurrent HSV infection affecting multiple skin sites were studied, together with relevant control groups. In all children with atopic eczema, in vitro lymphoproliferation in response to stimulation with concanavalin A (Con A) was significantly decreased and natural killer (NK) cells (CD16 + 56) were reduced compared with non-atopic controls. IL-2 receptors, a marker for lymphocyte activation, were decreased during the acute phase of eczema herpeticum, and for 1 month thereafter. A positive stimulation index (> 3) to HSV antigen, and high HSV IgG antibody titres measured by ELISA, Western blotting and neutralization assay, were seen in children with eczema herpeticum by 6 weeks, and also in children with atopic eczema and recurrent HSV infections. No evidence of an HSV-specific immune defect (either cell-mediated or humoral) was found in atopic eczema. Impairment of cell-mediated immunity in atopic eczema was suggested by the reduced response to Con A. It is likely that reduced numbers of circulating NK cells and a decrease in IL-2 receptors during early eczema herpeticum contribute to the susceptibility of children with atopic eczema to cutaneous HSV infections.

Quantitative analysis of intraepithelial large granular lymphocyte distribution and maternofetal cellular interactions in the synepitheliochorial placenta of the deer

Intraepithelial lymphocytes are a constant feature of ruminant uterine epithelium in nonpregnant animals. Quantitation in 6 species of deer shows that the proportion of large granular lymphocytes (LGL) in this population increases markedly and continuously from the earliest implantation to the latest (midpregnant) stage examined. The size of individual granules also increases. Fetal trophectodermal binucleate cells are also present from the earliest stage in all deer examined and follow a usual ruminant life cycle: migrating and fusing with uterine epithelial cells to form trinucleate cells before releasing their granules to the maternal compartment and finally degenerating and being reabsorbed by the trophectodermal uninucleate cells. Deer LGLs were usually closely associated with the degranulating fetomaternal hybrid trinucleate cells but showed no ultrastructural changes themselves. This association indicates a dynamic interaction between deer LGL and trinucleate cells which could serve as one of the factors restricting the extent of trinucleate cell progression to a continuous syncytium as found in sheep and goats.

BCL-2 expression by leukaemic blasts in a SCID mouse model of biphenotypic leukaemia associated with the t(4;11)(q21;q23) translocation

Acute leukaemia of infancy is associated with abnormalities at chromosome band 11q23, and has a poor prognosis. The gene involved. Mixed Lineage Leukaemia (MLL), has been identified and has the characteristics of a transcription factor. The BCL-2 gene responsible for blocking of programmed cell death is highly expressed in a number of haematological malignancies, both with and without the t(14;18) translocation. Those without the translocation include acute lymphoblastic leukaemia (ALL), acute myeloid leukaemia (AML) and chronic lymphocytic leukaemia (CLL). In these diseases the BCL-2 protein is implicated in drug resistance to apoptosis-inducing chemotherapeutic agents. High BCL-2 expression is also associated with autonomous growth of leukaemic blasts in culture and predicts a poor prognosis. The SEM cell line, established using blood lymphoblasts from a 5-year-old girl in first relapse with t(4;11) ALL, expresses lymphoid (CD19) and myeloid (CD13) cell surface markers. In cell culture, a subpopulation of cells (< 30%) express the BCL-2 protein. A reproducible model of true biphenotypic leukaemia in the SCID mouse has been established using the SEM-K2 cell line (a subclone of the SEM cell line). Between 5 and 50 million cells injected intravenously (i.v.) produce complete replacement of the murine bone marrow by day 30, associated with blood lymphoblastosis and infiltration of the spleen. No tumour masses were seen. Fluorescence in situ hybridization (FISH) analysis of the cell line and blood from the SCID-human (SCID-hu) chimaera has confirmed the presence of the t(4;11). Reverse transcriptional-polymerase chain reaction (RT-PCR) reveals that the breakpoint lies between exons 7 and 8 of the MLL-1 gene on chromosome 11 (the main breakpoint region). A further translocation, t(7;13), has been identified. Fluorescent antibody cell sorter (FACS) analysis of tumour material recovered from the SCID-hu model confirms expression of CD19 and CD13 identical to that of the cell line. In addition, BCL-2 expression in SCID-hu marrow is now seen in the majority of tumour cells. BCL-2 expression appears to confer a survival advantage to the blast cells in vivo. This reproducible model of biphenotypic leukaemia suggests that BCL-2 expression may play a role in leukaemogenesis. The model is suitable for the investigation of gene-targeted therapy, including antisense oligonucleotides, directed towards the MLL and BCL-2 genes.

Heterogeneity in cell proliferation and expression of p53 and bcl-2 during the indolent phase of germinal centre cell lymphoma: an explanation for clinical variability

Germinal centre cell lymphomas (GCCL) show a wide range of clinical outcomes from persistent indolent disease to large cell transformation. To investigate possible mechanisms of this heterogeneity, a combined morphometric and immunohistological study of p53, bcl-2 and cell proliferation was carried out. There was wide variation in p53 expression between biopsies and between individual follicles in the same tumour. A similar pattern of variation was seen using the cell-cycle marker MIB1, but this did not correlate with p53 expression. Even in cases in which a t(14;18) was demonstrated by PCR, variation occurred in the number of cells expressing bcl-2. On the basis of these results, we suggest that the probability of the clonal expansion of GCCL tumour cells carrying additional genetic abnormalities depends on a complex interaction of cell proliferation with p53 and bcl-2 expression, and that this may account for variation seen in the clinical behaviour seen in this group of tumours.

Demonstration of induction of erythrocyte inosine monophosphate dehydrogenase activity in Ribavirin-treated patients using a high performance liquid chromatography linked method

The activity of inosine monophosphate dehydrogenase (IMPDH: EC 1.2.1.14) was measured in erythrocyte lysates using a non-radiolabelled method linked to reversed-phase liquid chromatography (RPLC). The mean activity in erythrocytes from healthy controls using this sensitive method was extremely low (mean 85 pmol/h per mg protein, range 4-183). The elevated erythrocyte IMPDH activity reported previously in hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency was confirmed (mean 234 pmol/h per mg protein). Erythrocyte IMPDH activity of patients with other disorders of purine metabolism, or with leukaemias and lymphomas, showed no marked difference from controls, except in one instance--an immunodeficient child with purine nucleoside phosphorylase (PNP) deficiency, treated with Ribavirin, where a 30-fold increase in activity was found (2670 pmol/h per mg protein). Investigation of erythrocyte IMPDH in other immunodeficient children with normal PNP activity demonstrated that this grossly elevated erythrocyte activity was attributable to induction of IMPDH by Ribavirin therapy.

Gene transfer to primary chronic granulomatous disease monocytes

For somatic gene therapy to become a realistic therapeutic strategy for chronic granulomatous disease (CGD), we have to be able to assign the molecular lesion to a specific component of the NADPH oxidase and to confirm that transfer of a functional copy of the corresponding defective gene will result in correction of the cellular defect. We used an adenovirus vector expressing p47phox to transduce monocytes from patients with CGD. We showed by nitroblue-tetrazolium staining that NADPH-oxidase activity was restored to these cells. This technique offers a rapid means for molecular diagnosis. In the short term, this approach may have therapeutic potential.

Medical knowledge systems: applications to telemedicine

The application and form of electronically stored medical knowledge has a direct impact on the design of any healthcare delivery system. For those who plan for remote medical care or who work at the disaster relief level, there are specific requirements which will dictate the type of knowledge required and the vehicle best suited to deliver that information. The PC based multimedia biomedical library developed for NASA was originally intended for long-term space missions where complete isolation from each support was a distinct possibility. The library is a combination of traditional references and secondary databases structured within a primary care physician's workstation. The integration of the library and a point-of-care system allows optimal use of both resources and provides a basic building block for telemedicine networking.

Hypogammaglobulinaemia secondary to reflux oesophagitis

A 7 year old girl referred for investigation of hypogammaglobulinaemia had hypoalbuminaemia and severe necrotising oesophagitis on oesophagogastroduodenoscopy. Nissen fundoplication resolved all clinical and laboratory abnormalities, but she remains under surveillance because of histological findings of Barrett's oesophagus. Erosive reflux oesophagitis can present with minimal localising symptoms, and hypogammaglobulinaemia and hypoalbuminaemia, presumably from protein loss.