Papular dermatitis due to Leishmania infantum infection in seventeen dogs: diagnostic features, extent of the infection and treatment outcome

BACKGROUND: This study describes immunological responses, diagnostic features, follow up and treatment outcomes from seventeen dogs with papular dermatitis due to Leishmania infection diagnosed by cytology or real time-PCR. METHODS: Specific Leishmania humoral and cellular immune responses were evaluated by means of an immunofluorescence antibody test in all cases and a delayed-type hypersensitivity (DTH) reaction to leishmanin in eight cases. The extent of infection was studied in several tissues including blood, lymph node, conjunctival and oral swabs, by means of PCR, at the time of diagnosis and during follow-up. Culture was performed on nine dogs from cutaneous lesions and lymph node aspirates and molecular typing was carried out on isolates based on ITS-1, ITS-2 and Haspb gene sequencing analysis. RESULTS: Cytological and molecular results from fine needle aspirates of papules were diagnostic in 8 out of 13 (61.5%) cases and in 14 out of 15 dogs (93.3%), respectively. In all dogs, specific anti-Leishmania antibody levels were low or absent. Blood and lymph node PCRs and lymph node culture were negative in all dogs. Three out of the nine dogs (33%) were positive by culture from cutaneous lesions. The three isolates were identified as ITS type A, however, polymorphism was observed in the Haspb gene (PCR products of 626 bp, 962 bp and 371 bp). DTH response was positive in all tested dogs at the time of diagnosis. The majority of dogs were successfully treated with only N-methylglucamine antimoniate, after which cutaneous lesions disappeared or were reduced to depigmented, flattened scars. All dogs remained seronegative and the majority of dogs were negative by PCR in several tissues during follow-up. CONCLUSIONS: This study points out that papular dermatitis due to L. infantum is probably an underestimated benign cutaneous problem, associated with a parasite specific cell mediated immunity and a poor humoral immune response. Papular dermatitis is seen in young dogs, and appears to be a mild disease with restricted parasite dissemination and a good prognosis. PCR can be used as a non-invasive method to routinely evaluate papules if Leishmania infection is suspected in cases in which parasites are not visualized by cytology.The authors thank Dr. Carmen Cañavate (Instituto de Salud Carlos III, Madrid, Spain) for kindly providing L. infantum promastigotes for leishmanin skin test; Laura Perillo for her collaboration in cytopathology; Antonino Lombardo (Studio Veterinario Lombardo, Mascalucia, CT, Italy) for his collaboration in collecting the clinical cases. The authors are grateful to Francesca Soutter (Royal Veterinary College) for the English revision of the manuscript. The authors are also grateful to technicians of the CreNaL laboratory, IZS, Sicily for their technical help. The authors also thank the reviewers for the constructive critical revision of the manuscript. Laia Solano-Gallego holds a Ramón y Cajal senior researcher contract awarded by the Spanish Ministerio de Economia y Competitividad and the European Social Fund. Publication of the CVBD9 thematic series has been sponsored by Bayer HealthCare - Animal Health division.S

Evidence of electron wave function delocalization in CdSe/CdS asymmetric nanocrystals

Abstract We studied the delocalization of electron wave function in asymmetric CdSe/CdS nanocrystals, consisting of a spherical CdSe dot embedded in an elongated CdS shell, by means of a pump–probe technique. By comparing the transient spectra obtained upon pumping the band edge transition of the CdSe in CdSe/CdS heterostructure and in a bare CdSe dot, we observed the delocalization of electron wave function at the CdSe/CdS interface

Tetrapod-shaped colloidal nanocrystals of II-VI semiconductors prepared by seeded growth.

We report a general synthetic approach to tetrapod-shaped colloidal nanocrystals made of various combinations of II-VI semiconductors. Uniform tetrapods were prepared using preformed seeds in the sphalerite structure, onto which arms were grown by coinjection of the seeds and chemical precursors into a hot mixture of surfactants. By this approach, a wide variety of core materials could be chosen (in practice, most of the II-VI semiconductors that could be prepared in the sphalerite phase, namely, CdSe, ZnTe, CdTe); in contrast, the best materials for arm growth were CdS and CdTe. The samples were extensively characterized with the aid of several techniques

CdSe/CdS/ZnS Double Shell Nanorods with High Photoluminescence Efficiency and Their Exploitation As Biolabeling Probes

We report the synthesis, the structural and optical characterization of CdSe/CdS/ZnS "double shell" nanorods and their exploitation in cell labeling experiments. To synthesize such nanorods, first "dot-in-a-rod" CdSe(dot)/CdS(rod) core/shell nanocrystals were prepared. Then a ZnS shell was grown epitaxially over these CdSe/CdS nanorods, which led to a fluorescence quantum yield of the final core-shell-shell nanorods that could be as high as 75%. The quantum efficiency was correlated with the aspect ratio of the nanorods and with the thickness of the ZnS shell around the starting CdSe/CdS rods, which varied from 1 to 4 monolayers (as supported by a combination of X-ray diffraction, elemental analysis with inductively coupled plasma atomic emission spectroscopy and high resolution transmission electron microscopy analysis). Pump-probe and time-resolved photoluminescence measurements confirmed the reduction of trapping at CdS surface due to the presence of the ZnS shell, which resulted in more efficient photoluminescence. These double shell nanorods have potential applications as fluorescent biological labels, as we found that they are brighter in cell imaging as compared to the starting CdSe/CdS nanorods and to the CdSe/ZnS quantum dots, therefore a lower amount of material is required to label the cells. Concerning their cytotoxicity, according to the MTT assay, the double shell nanorods were less toxic than the starting core/shell nanorods and than the CdSe/ZnS quantum dots, although the latter still exhibited a lower intracellular toxicity than both nanorod samples

Oltre il Segno/OltreMare

La realizzazione di un volume contenente le incisioni scelte all’interno della Scuola di Grafica d’Arte dell’Accademia di Belle Arti di Palermo, coordinata dai Proff. Giovanni D’Alessandro e Riccardo Mazzarino rappresenta motivo di orgoglio e di soddisfazione per la nostra Istituzione che costruisce i percorsi didattici dei propri corsi a partire dall’esperienza laboratoriale. L’incisione grafica è tra le tecniche artistiche più antiche ma nel contempo più contemporanee. La gestualità intrinseca al segno, che si manifesta nella carta, svela universi della visione inaspettati.(Mario Zito - Direttore dell’Accademia di Belle Arti di Palermo) Il segno è il risultato di un gesto a volte deciso, a volte contorto, a volte leggero, i cui risultati spesso sono inattesi e sorprendenti. Il volume contiene esemplari di incisioni fortemente caratterizzanti della scuola di Grafica d’Arte che vanta all’interno del proprio corso di studi docenti-artisti che consapevoli della ricchezza del loro bagaglio esperienziale offrono agli studenti gli strumenti necessari per far sì che l’arte del saper fare artigianale, si trasformi in mera poetica artistica

Neutralizing antibodies to Omicron after the fourth SARS-CoV-2 mRNA vaccine dose in immunocompromised patients highlight the need of additional boosters

IntroductionImmunocompromised patients have been shown to have an impaired immune response to COVID-19 vaccines.MethodsHere we compared the B-cell, T-cell and neutralizing antibody response to WT and Omicron BA.2 SARS-CoV-2 virus after the fourth dose of mRNA COVID-19 vaccines in patients with hematological malignancies (HM, n=71), solid tumors (ST, n=39) and immune-rheumatological (IR, n=25) diseases. The humoral and T-cell responses to SARS-CoV-2 vaccination were analyzed by quantifying the anti-RBD antibodies, their neutralization activity and the IFN-γ released after spike specific stimulation.ResultsWe show that the T-cell response is similarly boosted by the fourth dose across the different subgroups, while the antibody response is improved only in patients not receiving B-cell targeted therapies, independent on the pathology. However, 9% of patients with anti-RBD antibodies did not have neutralizing antibodies to either virus variants, while an additional 5.7% did not have neutralizing antibodies to Omicron BA.2, making these patients particularly vulnerable to SARS-CoV-2 infection. The increment of neutralizing antibodies was very similar towards Omicron BA.2 and WT virus after the third or fourth dose of vaccine, suggesting that there is no preferential skewing towards either virus variant with the booster dose. The only limited step is the amount of antibodies that are elicited after vaccination, thus increasing the probability of developing neutralizing antibodies to both variants of virus.DiscussionThese data support the recommendation of additional booster doses in frail patients to enhance the development of a B-cell response directed against Omicron and/or to enhance the T-cell response in patients treated with anti-CD20