Intranasal immunization with SAG1 and nontoxic mutant heat-labile enterotoxins protects mice against Toxoplasma gondii

Effective protection against intestinal pathogens requires both mucosal and systemic immune responses. Intranasal administration of antigens induces these responses but generally fails to trigger a strong protective immunity. Mucosal adjuvants can significantly enhance the immunogenicities of intranasally administered antigens. Cholera toxin (CT) and heat-labile enterotoxin (LT) are strong mucosal adjuvants with a variety of antigens. Moreover, the toxicities of CT and LT do not permit their use in humans. Two nontoxic mutant LTs, LTR72 and LTK63, were tested with Toxoplasma gondii SAG1 protein in intranasal vaccination of CBA/J mice. Vaccination with SAG1 plus LTR72 or LTK63 induced strong systemic (immunoglobulin G [IgG]) and mucosal (IgA) humoral responses. Splenocytes and mesenteric lymph node cells from mice immunized with LTR72 plus SAG1, but not those from mice immunized with LTK63 plus SAG1, responded to restimulation with a T. gondii lysate antigen in vitro. Gamma interferon and interleukin 2 (IL-2) production by splenocytes and IL-2 production by mesenteric lymph node cells were observed in vitro after antigen restimulation, underlying a Th1-like response. High-level protection as assessed by the decreased load of cerebral cysts after a challenge with the 76K strain of T. gondii was obtained in the group immunized with LTR72 plus SAG1 and LTK63 plus SAG1. They were as well protected as the mice immunized with the antigen plus native toxins. This is the first report showing protection against a parasite by using combinations of nontoxic mutant LTs and SAG1 antigen. These nontoxic mutant LTs are now attractive candidates for the development of mucosally delivered vaccines.     

In vitro production of IgE by human peripheral blood mononuclear cells. I. Rate of IgE biosynthesis

IgE protein and grass-specific IgE antibodies were detected in the supernatants of 7-day cultures of unstimulated and pokeweed mitogen (PWM) stimulated human blood mononuclear cells from non-atopic and grass pollen-sensitive individuals. Significant amounts of IgE protein were detected in culture supernatants of grass-sensitive individuals and, even at lower levels, in those of non-atopic subjects. In contrast, detectable amounts of grass-specific antibodies were found only in the culture supernatants of grass-sensitive subjects. The mean values of total and grass-specific IgE detected in the supernatants of unstimulated and PWM-stimulated cultures did not differ statistically. Time sequence studies showed that IgE concentrations, measured in the 7-day supernatants, were due to a continuous release from the cells of IgE quantities progressively decreasing up to days 7 or 8. Comparison of the IgE protein and IgE antibody found in the 7-day culture supernatants to those released from initial cell pellets by treatment with acid buffer or freezing and thawing, showed that the IgE detected in 7-day supernatants could result, in part, from the release of cytophilic IgE bound to basophil or other cell types and in part also from the release of preformed lymphocyte cytoplasmic IgE into the supernatant fluids during the course of culture. In most non-atopic subjects and in some grass-sensitive patients the preformed IgE accounted virtually for the total IgE detected in the 7-day culture supernatants. However, the increase of IgE above the levels measured in the initial cell pellets, which was found in most grass-sensitive subjects, clearly reflected newly synthesized IgE. Both cycloheximide and puromycin were capable of reducing significantly the IgE concentration in culture supernatants when it was greater than the amount found in the initial cell pellets. The treatment of cells with mitomycin C was also able to decrease significantly the amount of IgE released in the supernatant after day 3 of culture.     

Patient follow-up is a major problem at genetics clinics

Children with genetic diseases must be followed for long periods of time to seek new findings. Other patients require further check-ups and studies to be diagnosed. Some patients never return for medical care after the first consultation, which may have serious consequences. We reviewed 400 medical charts of patients with genetic disease to analyze overall attendance to the genetics clinic, investigate some of the causes of failure to seek medical advice, and determine the differences between those first seen as outpatients or as inpatients. The mean follow-up period was 8.3 months (range 0-79), and the average number of visits was 2.8 (range 1-16). Forty eight percent of the cases first seen as inpatients were evaluated only once and 14% twice; while 22 and 21% of the 300 cases first seen as outpatients attended once and twice, respectively (P = 0.0). Appointment keeping was apparently not affected by the presence or absence of diagnosis. Overall, 97 patients were discharged, 7 died, 55 continued on follow-up, 62 attended other hospital services-but not genetics-and 179 were completely lost to follow-up. Diagnosed patients were counseled more frequently than undiagnosed patients (62 vs. 5%); and 71% of the diagnosed patients first seen as outpatients but only 36% of undiagnosed cases first seen as inpatients were counseled, differences between these two groups were significant (P = 0.005). We conclude that keeping the patient with genetic disease on follow-up is a difficult task. New educational strategies must be planned to improve this worrisome situation.     

Occupational rhinoconjunctivitis and bronchial asthma due to Phoenix canariensis pollen allergy

We report a case of occupational bronchial asthma and rhinoconjunctivitis caused by Phoenix canariensis (PC) pollen. The canary palm is a type of palm tree, belonging to the Arecaceae family, which is widely distributed in frost-free regions as an ornamental tree. Our patient was referred because he suffered symptoms of bronchial asthma, rhinoconjunctivitis, and contact urticaria when pruning dried leaves from PC during the pollination months. The skin prick test (SPT) with a PC pollen extract was positive, as was the specific IgE to PC pollen determined by Phadezym RAST, indicating an IgE-mediated sensitization. The nonspecific bronchial provocation test (BPT) performed with methacholine disclosed a mild bronchial hyperreactivity, and specific BPT with PC pollen elicited an immediate fall of 25% in FEV₁ with respect to baseline. On RAST inhibition studies, a significant cross-reactivity was found between PC pollen and date palm ( P. dactylifera ) pollen. These results suggest that PC pollen could be a potential allergen in PC-growing areas.     

Human subcutaneous dirofilariasis in Italy. First case in the Marche region]

The first case of human subcutaneous dirofilariasis in the Marche region (Central Italy) is described. It was caused by Dirofilaria repens and localised in the abdominal wall of a 23 years old university student from Pesaro. The presence of many histological sections of the nematode in strong regression, suggests that the death of the parasite occurred inside the nodule many months before the surgical intervention.     

Direct induction of human B-cell differentiation by recombinant interleukin-2.

Recombinant interleukin-2 (rIL-2) induced highly purified human tonsillar B cells to differentiate into immunoglobulin (Ig)-producing cells in vitro. The B-cell response was not due to rIL-2-contaminating substances, but reflected the activity of IL-2 itself, since it was inhibited by addition to the cultures of anti-TAC monoclonal antibody. The rIL-2-induced B-cell response was apparently not mediated by factors released by residual T cells present in B-cell suspensions at undetectable levels, since supernatants (SN) from unstimulated autologous T cells cultured at concentrations even much higher than those possibly contaminating B-cell suspensions did not induce any detectable Ig production. In addition, the Ig production by B cells cultured with SN prepared from high numbers of autologous T cells stimulated with rIL-2, as well as from allo-activated or mitogen-stimulated T cells, was of the same magnitude as the Ig production resulting from direct addition of rIL-2 concentrations comparable with those present in the supernatants. After centrifugation on Percoll density gradients, most of the tonsillar B cells responsive to rIL-2 were recovered in the lower density cell fraction containing a number of larger activated B cells. Moreover, B-cell enriched suspensions from peripheral blood (PB) (which usually contains a lower number of in vivo activated B cells than tonsil) showed poor or no response to rIL-2 alone, but displayed significant Ig production when rIL-2 was added to the cultures in the presence of Staphylococcus aureus Cowan I (SAC) bacteria.(ABSTRACT TRUNCATED AT 250 WORDS)     

Myeloid bodies in drug-induced acute tubular necrosis

A growing list of drugs, metals, and chemicals has been implicated as the cause of functional and structural damage specifically to the proximal tubular epithelium. Renal biopsies were obtained from three patients who had developed nephrotoxic agent-related acute renal failure. Two of the patients had received gentamicin and viomycin; the third patient had heavy exposure to chromium. All three biopsies showed acute tubular necrosis (ATN) on light microscopy. Electron microscopy revealed that the proximal tubular cells and, to a lesser degree, the distal tubular cells, contained abundant, variably sized myeloid bodies. In our previous experimental study of viomycin-induced ATN in rats, similar ultrastructural findings of a gradual increase in the number of myeloid bodies in the proximal tubular cells were also observed. The constant presence of myeloid bodies in the tubular epithelial cells following drug-induced tubular necrosis suggests that they may represent lysosomal isolation of drug-bound cytoplasmic structures, as a cellular mechanism to degrade toxic substances and, therefore, may serve as an ultrastructural marker of cellular drug uptake and drug disposition.     

Seasonal abundance of fleas (Siphonaptera: Pulicidae, Ceratophyllidae) on wild rabbits in a semiarid area of northeastern Spain

This paper reports the annual dynamics of wild rabbit fleas in a study site located in the Middle Ebro Valley, northeastern Spain. Fleas collected directly from wild rabbits included the species Spilopsyllus cuniculi (Dale), Xenopsylla cunicularis (Smit), Echidnophaga iberica (Ribeiro, Lucientes, Osácar, and Calvete), Caenopsylla laptevi (Beaucournu, Gil-Collado and Gilot), and Pulex irritans (L.). Monthly collections of adult and larval fleas made from within the first meter of selected burrow entrances also yielded fleas belonging to the same five species. Larval specimens of X. cunicularis, E. iberica, and C. laptevi were also found. Spilopsyllus cuniculi, a winter species that can only breed during the rabbit breeding season, was common on hosts from November to April. Xenopsylla cunicularis and E. iberica were summer species, whereas C. laptevi was abundant during the autumn and winter. Xenopsylla cunicularis and E. iberica larvae were found in burrows only during April and May, whereas those of C. laptevi were collected from October to January. The data suggested that X. cunicularis and E. iberica might diapause during the egg stage whereas C. laptevi diapauses during the pupal stage.     

The effects of an enhanced inflammatory reaction on the surface properties of cast Biomer

The ability of a biomaterial to withstand the rigors of the harsh biologic environment is an important consideration when considering a material for long-term biomedical applications. Using a cage implant system, the effects of an intense inflammatory reaction on cast Biomer have been investigated. The inflammatory response to cast Biomer was greatly increased by coimplanting Biomer films with a cytotoxic poly(vinyl chloride) (PVC) in rats for a period of 21 days. Cast Biomer films were characterized by weight, advancing contact angle with water in air, attenuated total reflectance infrared spectroscopy and scanning electron microscopy (SEM). The analyses were performed before any treatment, after autoclaving and sonication, and after 21 days implantation with the cytotoxic (PVC) in rats. The results of the study indicated that cast Biomer does not undergo significant chemical degradation when subjected to the effects of an intense inflammatory reaction for 21 days. Implantation does, however, lead to rearrangement that results in a more polar and hydrophilic surface, suggesting that the polymer adapts to the hydrophilic environment of the inflammatory exudate.     

6p23 deletion mosaicism in a woman with recurrent abortions and idiopathic hypoprolactinemia.

A woman with a history of recurrent abortions, idiopathic hypoprolactinemia, and an apparent 6p partial deletion mosaicism is described. The breakpoint in the short arm of chromosome 6 was in the p23 region. This deletion could have been caused by a fragile site in 6p23.