Ploidy of Cell-Sorted Trophic and Cystic Forms of Pneumocystis carinii

Once regarded as an AIDS-defining illness, Pneumocystis pneumonia (PcP) is nowadays prevailing in immunocompromised HIV-negative individuals such as patients receiving immunosuppressive therapies or affected by primary immunodeficiency. Moreover, Pneumocystis clinical spectrum is broadening to non-severely-immunocompromised subjects who could be colonized by the fungus while remaining asymptomatic for PcP, thus being able to transmit the infection by airborne route to susceptible hosts. Although the taxonomical position of the Pneumocystis genus has been clarified, several aspects of its life cycle remain elusive such as its mode of proliferation within the alveolus or its ploidy level. As no long-term culture model exists to grow Pneumocystis organisms in vitro, an option was to use a model of immunosuppressed rat infected with Pneumocystis carinii and sort life cycle stage fractions using a high-through-put cytometer. Subsequently, ploidy levels of the P. carinii trophic and cystic form fractions were measured by flow cytometry. In the cystic form, eight contents of DNA were measured thus strengthening the fact that each mature cyst contains eight haploid spores. Following release, each spore evolves into a trophic form. The majority of the trophic form fraction was haploid in our study. Some less abundant trophic forms displayed two contents of DNA indicating that they could undergo (i) mating/fusion leading to a diploid status or (ii) asexual mitotic division or (iii) both. Even less abundant trophic forms with four contents of DNA were suggestive of mitotic divisions occurring following mating in diploid trophic forms. Of interest, was the presence of trophic forms with three contents of DNA, an unusual finding that could be related to asymmetrical mitotic divisions occurring in other fungal species to create genetic diversity at lower energetic expenses than mating. Overall, ploidy data of P. carinii life cycle stages shed new light on the complexity of its modes of proliferation

A sampling plan for phycotoxins surveillance in bivalve mollusc farms along the Santa Catarina coast, Brazil

Bivalve molluscs are filter-feeders and have a wide range of phytoplankton species as main food source. Some of these species are toxic, producing the so-called phycotoxins, that can get concentrated in edible parts of mussels, oysters, scallops, and clams, causing severe intoxication syndromes in consumers. Since 2008, harmful algae and phycotoxins occurrence related to three shellfish poisoning syndromes: Diarrhetic (DSP), Amnesic (ASP), and Paralytic (PSP) shellfish poisonings have been monitored in Santa Catarina State, Brazil. The objectives of this study were: (1) to identify representative sampling areas from which shellfish samples should be collected each round of the monitoring cycle and (2) to define an alternative sampling strategy for phycotoxins detection that requires less samples and/or smaller pool sizes according to different laboratorial methods officially recognized. Using geographic information system, we designed 24 sampling areas. To calculate sample sizes for phycotoxins detection in mollusc soft tissues, we simulated six scenarios with different values of prevalence and test sensitivity. Considering High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD) and mice bioassays, the most realist scenario was the one of 6520% of prevalence and highly sensitive tests, which resulted in one pool of 20 Perna perna mussels each to detect ASP toxins, two pools of 15 to detect PSP, and two pools of 30 to detect Lipophilic Toxins (DSP + Yessotoxin). With the use of liquid chromatography with mass spectrometry (LC-MS/MS) analysis, only one pool of 15 mussels would be enough for target phycotoxins detection. The strategy of sampling using the defined areas associated with LC-MS/MS analysis requires less samples and a smaller pool size without losing area representativeness and surveillance system sensitivity

Preneoplastic non-papillary lesions and conditions of the urinary bladder: an update based on the Ancona International Consultation.

BACKGROUND AND AIMS: This paper summarizes the work done by the members of the Committee no. 2 at the International Consultation on the Diagnosis of Non-Invasive Urothelial Neoplasms held in Ancona, Italy (11-12 May 2001). The committee members discussed and reached consensus regarding the optimal contemporary diagnosis and classification of the preneoplastic non-papillary lesions of the urothelium. An important objective was to promote a precise terminology and to use it consistently in daily practice in pathology and urology. RESULTS AND CONCLUSIONS: The result of the meeting is represented by a refined classification of the non-papillary intraepithelial lesions and conditions of the urothelium. This classification includes epithelial abnormalities (reactive urothelial atypia and flat urothelial hyperplasia), presumed preneoplastic lesions and conditions (keratinizing squamous and glandular metaplasia, and malignancy-associated cellular changes), as well as preneoplastic (dysplasia) and neoplastic non-invasive (carcinoma in situ) lesions. Each of these lesions is defined with strict morphological criteria in order to provide more accurate information to urologists in managing patients