Three patients with hallucal polydactyly and WAGR syndrome, including discordant expression of Wilms tumor in MZ twins

The WAGR contiguous gene deletion syndrome is a combination of Wilms tumor, Aniridia, Genito-urinary abnormalities, and growth and mental retardation which is invariably associated with an 11p13 deletion. We report two monozygotic twins and a third, unrelated patient with WAGR syndrome and additional clinical features not usually associated with WAGR. Both twins had developmental delay, growth deficiency, severe ocular involvement (nystagmus, aniridia, cataracts), atrial septal defect and two uncommon findings: agenesis of the corpus callosum and duplication of the halluces. One twin developed Wilms tumors aged 19 months while her sister remained tumor free by the age of 6.5 years. The singleton patient showed typical WAGR syndrome and preaxial hallucal polydactyly. Molecular cytogenetic studies refined the identification of the extent of the deleted segments, which were not identical in the two families. The two deletions included the PAX6 and WT1 genes as previously reported in typical WAGR patients. The unusual anomalies described in this report, may represent the expression of low penetrant traits associated with haploinsufficency of one or more of the genes present in the deletion (PAX6 is expressed in CNS) or may indicate epistatic influences of modifier genes on the expression of gene(s) present in the WAGR region.     

A microplate assay for <Emphasis Type="Italic">Leishmania amazonensis</Emphasis> promastigotes expressing multimeric green fluorescent protein

Convenient and economical assays capable of screening many compounds are vital to advance the development of drug therapy. This is particularly important for many of the infections that occur mainly in the Third World. The development of such a spectrofluorometric assay for the protozoan parasite Leishmania is presented here. Using multimeric (four monomers) green fluorescent protein (GFP), Leishmania amazonensis promastigotes were generated with brightness measurable in 96-well microtiter plates. The promastigotes maintained the parental characteristics, were infective to murine macrophages and to mice, and the level of GFP fluorescence corresponded to the number of inoculated cells. The feasibility of using this assay for testing drugs kinetically and in a concentration-dependent manner, under microplate culture condition, was demonstrated with amphotericin B and the herbicide oryzalin, respectively. This assay is the first to allow a real-time analysis of antileishmanial agents with live promastigotes. The method of expressing multimeric GFP for in vitro drug screening is likely to be extendable to many species of parasitic protozoa.     

B-cell activation and allosensitization after left ventricular assist device implantation is due to T-cell activation and CD40 ligand expression

Left ventricular assist device (LVAD) implantation is frequently complicated by B-cell activation and allosensitization, posing a significant risk to successful transplant outcome. This study investigated whether B-cell hyperreactivity and alloantibody production in LVAD recipients involves T-cell dependent pathways. T-cell calcium flux and nuclear translocation of NFATc were used to determine states of T-cell activation. Flow cytometry was used to assess human T- and B-cell activation after culture with LVAD-derived biomaterial particles. Sera from LVAD recipients and controls were tested for the presence of anti-HLA antibodies, and for soluble CD40 ligand. LVAD-derived biomaterial induced rapid and sustained calcium flux into normal T cells, resulting in calcineurin-dependent nuclear translocation of NFATc. This resulted in increased T-cell expression of CD40 ligand and subsequent B-cell activation, which was reduced by inhibitors of T-cell activation (CsA or anti-CD25 mAb) or by anti-CD40 ligand mAb. LVAD recipients demonstrated higher frequencies of anti-HLA antibodies and serum levels of soluble CD40 ligand compared with heart failure controls. The results indicate that exposure of human mononuclear cells to LVAD-derived biomaterial leads to T-cell dependent B-cell activation via CD40--CD40 ligand interaction, and suggest that treatment with calcineurin inhibitors or monoclonal antibodies against either CD25 or CD40 ligand could be effective at preventing B-cell hyperreactivity and allosensitization after LVAD implantation.     

C1-esterase inhibitor blocks T lymphocyte proliferation and cytotoxic T lymphocyte generation in vitro

We have previously shown that activated C1s complement and activated T cells cleave beta2-microglobulin (beta2m) in vitro leading to the formation of desLys58 beta2m. This process can specifically be inhibited by C1-esterase inhibitor (C1-inh). Furthermore we showed that exogenously added desLys58 beta2m in nanomolar amounts to a one-way allogenic mixed lymphocyte culture (MLC) increased the endogenous production of IL-2 and the generation of allo-specific cytotoxic T lymphocytes. C1-inh was purified from fresh human plasma and added to human or murine MLC and mitogen-stimulated lymphocyte cultures grown in the presence of complement-inactivated serum. Read-outs were cell proliferation, lymphokine production and development of T cell-mediated cytotoxicity. We found that addition of C1-inh to MLC and mitogen- exposed murine and human lymphocyte cultures inhibited proliferation, the development of allospecific cytotoxic activity, and changed the endogenous production of IL-2, IL-4, IL-10, IL-12 and IFN-gamma. These data clearly demonstrate a regulatory function of C1-inh on T cell- mediated immune functions.      

Investigation of the infertile couple: when is the appropriate time to explore female infertility?

While the appropriate method for the investigation of female infertility continues to be debated, the timing of the investigation has received less attention. The current approach is time-consuming, and paradoxically may lead to overtreatment as well as undertreatment. Recent findings on fecundity and the conception window in humans have important implications for the timing of the investigation of female infertility. The findings support the view that fertility-oriented intercourse may have a major impact in reducing the time to pregnancy. Procedures for the investigation of female infertility are becoming less invasive and more accurate, while the therapies for infertility are more effective. It is proposed that under appropriate circumstances female infertility should be investigated after 6 months of fertility-oriented intercourse.     

Surgical sperm retrieval and intracytoplasmic sperm injection as treatment of obstructive azoospermia

Male genital tract obstructions may result from infections, previous inguinal and scrotal surgery (vasectomy) and congenital bilateral absence of the vas deferens (CBAVD). Microsurgery can sometimes be successful in treating the obstruction. In other cases and in cases of failed surgical intervention, the patient can be treated by microsurgical or percutaneous epididymal sperm aspiration (MESA, PESA) or testicular sperm extraction (TESE) and intracytoplasmic sperm injection (ICSI). We present the results of 39 ICSI procedures for obstructive azoospermia in 24 couples. The aetiology of the obstruction was failed microsurgery in 11 patients, CBAVD in nine and genital infections in four. Sperm retrieval was accomplished via MESA in four cases, PESA in 18 cases and via TESE in 11 cases. TESE was only applied when PESA failed to produce enough spermatozoa for simultaneous ICSI. In six patients, the ICSI procedure was performed with cryopreserved spermatozoa after an initial PESA procedure. Fertilization occurred in 47% of the metaphase II oocytes; embryo transfer was performed in 92% of procedures and resulted in a clinical pregnancy in 13/39 procedures. Ongoing pregnancy was achieved in 10/39 procedures. One pregnancy was terminated early after prenatal investigation showed a cytogenetic abnormality (47,XX+18, Edwards syndrome). The other nine pregnancies resulted in the live birth of 10 children, without any congenital abnormalities. Epididymal and testicular retrieved spermatozoa were successfully used for ICSI to treat obstructive azoospermia, and resulted in an ongoing pregnancy in 10 of 24 couples (41.6%) after 39 ICSI procedures, a success rate of 25.6% per treatment cycle and of 27.7% per embryo transfer.      

Matched adaptations of electrophysiological, physiological, and histological properties of skeletal muscles in response to chronic hypoxia

This study tried to differentiate the consequences of chronic hypoxia on the electrophysiological and physiological properties and the histological characteristics of slow and fast muscles in rats. Animals inhaled a 10% O₂ concentration for a 1-month period. Then, slow [soleus (SOL)] and fast [extensor digitorum longus (EDL)] muscles were analyzed in vitro by physiological and electrophysiological measurements and histological analyses. The results were compared to those obtained in corresponding muscles of an age-matched normoxic group. After exposure to hypoxia: (1) in SOL, there was a tendency to elevated F_max, a significant increase in twitch force and tetanic frequency and a shortening of M-wave duration, and a reduced percentage of type I fibres, whereas the proportion of type IIa fibres doubled; (2) in EDL, F_max and tetanic frequency were lowered, the muscle became less resistant to fatigue, and the proportion of type IId/x fibres was halved. Then, after 1 month of hypoxia, in the SOL muscle, both the contractile and histological properties resemble those of a fast muscle. By contrast, the EDL became slower, despite its histology was modestly affected. Reduced muscle use in hypoxia could explain the tendency for deteriorating adaptations in EDL, and the faster properties of SOL could result from hypoxia-induced inhibition of the growth-related fast-to-slow shift in muscle fibre types.     

Detection of serum antibodies to bovine norovirus in veterinarians and the general population in the Netherlands

The close genetic relationship of human and animal strains of norovirus has raised the possibility of transmission of noroviruses from animals to humans and may explain the emergence of certain norovirus strains. To assess if exposure to bovine noroviruses (NoV) might result in infection in humans, an enzyme immunoassay (EIA) was designed and validated in order to detect antibodies against bovine norovirus. This and two other EIAs were used to test sera from 210 veterinarians and 630 matched population controls for IgG and IgA antibodies to recombinant capsid protein of bovine NoV (rBoV), Norwalk virus (rNV), and Lordsdale virus (rLDV). Of 840 participants, IgG reactivity to rBoV was found in 185 (22%), to rNV in 638 (76%) and to rLDV in 760 (90%). IgG reactivity to rBoV was more common in veterinarians (58/210: 28%) than in controls (127/630: 20% [P = 0.03]). IgA reactivity to rBoV was similar in both veterinarians and controls. Cross-reactivity of IgA and IgG antibodies to rBoV and rNV was seen, but 26% of all specimens positive rBoV antibodies showed high IgG reactivity to rBoV but low reactivity to rNV, suggesting a specific response to bovine antigen. No evidence of overall cross-reactivity of antibodies to rBoV and rLDV was seen. Among veterinarians, youth spent on farm (Odds Ratio [OR] = 1.8) and membership of the bovine practitioners' society (OR = 2.7) were significantly associated with IgG seroreactivity to rBoV. These data indicate that bovine strains of NoV may infect humans though less frequently than human strains.