Dermatitis caused by arthropods in domestic environment: an Italian multicentre study.

BACKGROUND: Skin diseases caused by mites and insects living in domestic environments have been rarely systematically studied. OBJECTIVES: To study patients with dermatitis induced by arthropods in domestic environment describing their clinical features, isolating culprit arthropods and relating the clinical features to the parasitological data. METHODS: The study was performed in 105 subjects with clinical and anamnestic data compatible with the differential diagnosis of ectoparasitoses in domestic environments. Clinical data and arthropods findings obtained by indoor dust direct examination were studied. RESULTS: Indoor dust direct examination demonstrated possible arthropods infestation in 98 subjects (93.3%), more frequently mites (56.1%) (mainly Pyemotes ventricosus and Glycyphagus domesticus) than insects (43.9%) (mainly Formicidae and Bethylidae). Strophulus (46.9%) and urticaria-like eruption (36.7%) in upper limbs and trunk with severe extent were prevalent. Itch was mostly severe (66.3%) and continuous (55.1%). Ectoparasitoses occurred frequently with acute course in summer (44.9%) and spring (30.6%). CONCLUSIONS: Possible correlation between clinical and aetiological diagnosis of arthropods ectoparasitoses in domestic environments needs the close cooperation between dermatologist and parasitologist. This is crucial to successfully and definitely resolve skin lesions by eradicating the factors favouring infestation.

A survey on canine leishmaniasis and phlebotomine sand flies in central Italy.

Zoonotic visceral leishmaniasis (ZVL) is a vector-transmitted zoonosis caused by the parasitic protozoan Leishmania infantum. Bloodsucking sand flies of the subfamily Phlebotominae are the obligatory insect hosts, and the dog is the only domestic reservoir. This study reports data from a survey of canine infection and sand fly phlebotomine monitoring in the province of Perugia in central Italy. The overall seroprevalence in a total of 100 dogs tested was 8% (95% confidence interval: 3.8-15.6%). Data analysis revealed that serological positivity was statistically associated with age (p-value=0.03) and the area where dogs lived. Standard blacklight traps employed for sampling Culicoides midges in bluetongue disease surveillance were used in phlebotomine monitoring. A total of 5698 sand flies were collected and the two species, Leishmania competent vectors, were identified, Phlebotomus perfiliewi (50%) and Phlebotomus perniciosus (30%).

Involvement of multiple factors in the clonal deletion of self-reactive T cells.

Self-tolerance is primarily induced by the elimination of potentially self-reactive T cells during early development of the T cell repertoire. In the mouse, endogenous mouse mammary tumor viruses (MMTV), including minor lymphocyte-stimulating antigens and milk-transmitted exogenous MMTV, have been known to function as self-antigens inducing the clonal deletion of self-reactive T cells in a V beta-specific manner. We investigated the factors involved in the deletion of V beta 17a-bearing T cells. The results indicated that in addition to the previously reported V beta 17a deletion ligand, Mtv-3, there is a nonmilkborne gene product which progressively deletes V beta 17a (and V beta 3)-bearing T cells during aging. This suggests that clonal deletion is mediated by multiple factors and that a clonal deletion element associated with aging may play a significant role in shaping the T cell repertoire.

Pathological and immunological effects of ingesting L-tryptophan and 1,1'-ethylidenebis (L-tryptophan) in Lewis rats.

The eosinophilia-myalgia syndrome (EMS) has been associated with ingestion of L-tryptophan (L-TRP) produced by a single manufacturer. Epidemiological data implicated 1,1'-ethylidenebis (L-tryptophan) (EBT) (peak 97 or peak E) as a possible etiologic agent. We showed previously that Lewis rats treated with the L-TRP implicated in EMS develop fasciitis and perimyositis similar to those seen in human EMS. We now report the pathology associated with the treatment of Lewis rats with synthetic EBT and/or L-TRP. All animals treated for 6 wk with case-associated L-TRP or EBT developed significant myofascial thickening, compared with animals in the vehicle control and control L-TRP groups. However, even those animals receiving the control L-TRP showed a mild but significant increase in the thickness of the myofascia, compared with vehicle-treated control animals. All animals except vehicle controls also exhibited significant pancreatic pathology, including fibrosis and acinar changes. Only animals treated with case-associated L-TRP for 6 wk showed evidence of immune activation with increased frequency of CD8, Ia, and IL-2 receptor-positive cells in the peripheral blood. Animals receiving L-TRP or EBT for < 6 wk did not show significant differences in myofascial thickness, although these animals did show pancreatic acinar changes. Although these results demonstrate for the first time the pathological effects of EBT, they do not rule out the possibility that other impurities in the EMS-case-associated L-TRP may also contribute to some of the features of EMS.

Characterization of the Mlsf system. II. Identification of mouse mammary tumor virus proviruses involved in the clonal deletion of self-Mlsf-reactive T cells.

The genetic linkage of loci encoding stimulatory Mlsa and Mlsc determinants with proviruses of mouse mammary tumour viruses (MMTV) has been shown. We previously have reported that the ligand(s) for V beta 5, V beta 11, and V beta 12 behaves as a novel minor lymphocyte-stimulating (Mls) determinant(s), Mlsf, to induce the strong proliferation of unprimed T cells, and that this ligand(s) also functions as a self-Ag for the clonal deletion of self-reactive T cells. In the accompanying paper (Part I), a unique polymorphism characteristic of the Mlsf gene product is presented. In order to determine the genetic basis for this novel Mls system, we examined the progeny of multiple genetic crosses to identify the MMTV proviral loci involved in the clonal deletion of self-Mlsf-reactive T cells. Results from these investigations indicated that at least three known MMTV proviruses, Mtv-8, Mtv-9, and Mtv-11 are involved in the expression of Mlsf gene products. Presence of Mtv-9 results in the complete deletion of V beta 5, V beta 11, and V beta 12; Mtv-8 is associated with the complete deletion of V beta 12, but only a partial deletion of V beta 11 (primarily CD4-positive T cell subset) with little or no deletion of V beta 5; and Mtv-11 induces the complete deletion of V beta 11 and V beta 12, but no deletion of V beta 5. Given the significant sequence homology in the C-terminal portion of the open reading frame (ORF) region among these three MMTV and the almost equivalent effect of these three MMTV provirus upon the V beta 12 repertoire, their apparent hierarchic effect upon the V beta 5 and V beta 11 repertoires suggests that affinity differences in recognition of the same determinant by different TCR V beta may play a significant role in the clonal deletion of self-reactive T cells.

Transformation of murine bone marrow cells with combined v-raf-v-myc oncogenes yields clonally related mature B cells and macrophages.

Murine bone marrow cells infected with replication-defective retroviruses containing v-raf alone or v-myc alone yielded transformed pre-B cell lines, while a retroviral construct containing both v-raf and v-myc oncogenes produced clonally related populations of mature B cells and mature macrophages. The genealogy of these transformants demonstrates that mature myeloid cells were derived from cells with apparent B-lineage commitment and functional immunoglobulin rearrangements. This system should facilitate studies of developmental relationships in hematopoietic differentiation and analysis of lineage determination.

v-myc and v-raf act synergistically to induce B-cell tumors in pristane-primed adult BALBC mice.

In a variety of systems, evidence is accumulating which suggests that neoplastic transformation requires the action of two or more genes such as mutated or over-expressed proto-oncogenes. To determine whether the cytoplasmic serine/threonine kinase oncogene raf could complement a deregulated myc gene and induce tumors in adult mice, BALBC mice were primed with an intraperitoneal (ip.) injection of mineral oil (pristane) and then given an ip. injection of a retroviral construct, J1, J2 or J5, which expresses either v-raf (J1), v-myc (J5) or both (J2). The J1 virus induced no tumors in 150 days in 38 mice, except for 5 helper virus-associated T-cell lymphomas. Under identical conditions the J5 virus, which expresses only v-myc, induced exclusively monocytic neoplasms in 93% of 15 mice. The J2 virus expresses both v-myc and v-raf and caused equal numbers of monocytic and B cell tumors in 66% of 30 mice. Under these conditions, it appears that v-raf expression acts synergistically with v-myc to induce the transformation of B cells, which neither oncogene could do alone. The J3 virus, which originally contained a complete v-myc and an inactivated v-raf, can induce tumors of later stage B cells (plasmacytomas, Potter et al., 1987). Recent studies of virus recovered from these plasmacytomas (called the J3V1 virus, Troppmair et al., 1989) show that the J3 virus has undergone deletions which have reactivated v-raf in a mutated form. Only J3V1, not J3, induced tumors in vivo. Our data presented here corroborate Troppmair et al. and extend Potter et al. (1987) which reported that J3 (presumably J3V1) induced 10% myeloid tumors and 90% plasmacytomas. In light of the discovery, our J2 and J3 data indicate that in combination with the same form of v-myc, different forms of v-raf induce different spectra of tumors.

Pneumonyssoides caninum: a mite from the nasal cavities and frontal sinuses of the dog. A case report.

The dog nasal mite, Pneumonyssoides caninum, is reported from Italy for the first time. The identification of the mite was based upon the morphology of larvae and adults.

Observations on the occurrence of five species of Gasterophilus larvae in free-ranging horses in Umbria, central Italy.

Comparative data collected over 4 years show the most frequent species of Gasterophilus infesting free-ranging horses in Umbria (Central Italy) to be G. intestinalis (93.8%), G. nasalis (76.5%) and G. inermis (71%). G. pecorum and G. haemorrhoidalis were less frequent and appeared in 39.3 and 10.8% of the animals, respectively. For each of the 5 species, the duration of gastric and enteric lesions, the average numbers of larvae isolated throughout the year and the probable duration of oral lesions were discussed.

Classification of the main macroscopic lesions produced by larvae of Gasterophilus spp. (Diptera:Gasterophilidae) in free-ranging horses in Umbria.

Listed and described herein are the main macroscopic lesions produced along the whole digestive tract of free-ranging horses by larvae of the five Gasterophilus spp., occurring in Umbria, a region of central Italy: Gasterophilus intestinalis, Gasterophilus nasalis, Gasterophilus pecorum, Gasterophilus inermis, Gasterophilus haemorrhoidalis. Lesions are classified on the basis of their sizes and shapes and the host's anatomic sites infested, and they are examined in relation to the developmental stages of larvae causing them. The examination of the lesions shows that it is very difficult to differentiate the hemorrhagic impressions caused by migrating 1st and 2nd instar larvae of all the species in the absence of the specific parasite. It is also difficult to differentiate between the gastric lesions caused by Gasterophilus intestinalis and Gasterophilus pecorum. It has been found that an easy identification is possible even in the absence of parasites for gum lesions and for lesions on the soft palate produced respectively by Gasterophilus intestinalis and Gasterophilus pecorum, for duodenal lesions caused by Gasterophilus nasalis, for rectal lesions caused by Gasterophilus inermis and for duodenal and rectal lesions produced by Gasterophilus haemorrhoidalis.