Since 1995, Trichinella larvae have been detected in 39.5% of farmed crocodiles (Crocodylus niloticus) in Zimbabwe. Morphological, biological, biochemical and molecular studies carried out on one ...isolate from a farmed crocodile in 2001 support the conclusion that this parasite belongs to a new species, which has been named Trichinella zimbabwensis n.sp. This species, whose larvae are non-encapsulated in host muscles, infects both reptiles and mammals. The morphology of adults and larvae is similar to that of Trichinella papuae. Adults of T. zimbabwensis cross in both directions with adults of T. papuae (i.e. male of T. zimbabwensis per female of T. papuae and male of T. papuae per female of T. zimbabwensis), producing F1 offspring which produce very few and less viable F2 larvae. Muscle larvae of T. zimbabwensis, like those of T. papuae, do not infect birds. Three allozymes (of a total of 10) are diagnostic between T. zimbabwensis and T. papuae, and five are diagnostic between T. zimbabwensis and Trichinella pseudospiralis, the third non-encapsulated species. The percentage of the pairwise alignment identity between T. zimbabwensis and the other Trichinella species for the cytochrome oxidase subunit I gene, the large subunit ribosomal-DNA (mt-lsrDNA) gene and the expansion segment five, shows that T. zimbabwensis is more similar to the two non-encapsulated species T. papuae (91% for cytochrome oxidase I; 96% for mt-lsrDNA; and 88% for expansion segment five) and T. pseudospiralis (88% for cytochrome oxidase I; 90% for mt-lsrDNA; and 66-73% for expansion segment five) than to any of the encapsulated species (85-86% for cytochrome oxidase I; 88-89% for mt-lsrDNA; and 71-79% for expansion segment five). This is the first non-encapsulated species discovered in Africa. The finding of a new Trichinella species that infects both reptiles and mammals suggests that the origin of Trichinella parasites dates back further than previously believed and can contribute to understanding the phylogeny and the epidemiology of the genus Trichinella.
Glioneuronal tumors (GNTs) are an increasingly recognized cause of focal epilepsies, particularly in children and young adults. GNTs consist of a mixture of glial and neuronal elements and most ...commonly arise in the temporal lobe, particularly in the temporo-anterior-basal mesial site. They are often associated with cortical dysplasia or other neuronal migration abnormalities. Epilepsy associated with GNT is poorly controlled by antiepileptic drugs in many cases; but, it is extremely responsive to surgical treatment. However, the best management strategy of tumor-related focal epilepsies remains controversial and still remain one of the contemporary issues in epilepsy surgery. Temporo-mesial GNT are associated with a widespread epileptic network, defining, therefore, a distinct anatomo-clinico-pathological group with complex epileptogenic mechanisms. By using an epilepsy surgery oriented strategy GNT associated with focal epilepsies may have an excellent seizure outcome and, therefore, surgical treatment can be offered early to avoid both the consequences of uncontrolled seizures as well as the side effects of prolonged pharmacological therapy and the rare risk of tumor growth or malignant transformation.
In most Arctic and subarctic regions, Trichinella nativa is a common zoonotic pathogen circulating among wild carnivores. The polar bear (Ursus maritimus) is one of the most important reservoirs for ...T. nativa in frigid zones. In Iceland, Trichinella infection has never been detected in the local wildlife, despite the presence of one of the host species, the arctic fox (Alopex lagopus). In 2008, one of two polar bears that had swum to Iceland's coast was found to have been infected with Trichinella sp. (8.5 larvae/g in the tongue, 6.8 larvae/g in the masseter and 4.4 larvae/g in the diaphragm); the larvae were identified as T. nativa. This is the second report of Trichinella infection in polar bears that reached the Icelandic coast. In the present work, we describe this case of infection and discuss the epidemiological features that have allowed T. nativa to spread in Arctic regions.
Abstract
BACKGROUND
Spinal ependymomas (SP-EPN) are group of primary central nervous system tumors recently re-classified by the WHO (CNS5 2021), located in spinal cord. SP-EPN are grade 2-3 tumors, ...found mainly in cervical and thoracic region, characterized mostly by NF2 mutations and classical histology: grade 3 tumors present also microvascular proliferation, necrosis and high mitotic rate. Recently, a novel subtype was discovered with a unique methylation profile (SP-EPN-MYCN) and characterized by the amplification of MYCN gene, grade 3 histology and a very aggressive behavior. Treatment of these tumors remains challenging: gross-total resection is not often achieved and radiation failed to give sacceptable results. Besides, no prognostic factors except the mitotic index and tumor location, are available, thus, new diagnostic and prognostic biomarkers would be very useful for their accurate classification and management.
MATERIAL AND METHODS
We have collected 170 patients operated at our Institute from 1997 to 2019 of spinal ependymomas located in the cervical and thoracic region, excluded conus/filum mixopapillary ones. All tumors were revised according to the new WHO CNS5 2021 classification. In a cohort of 50 grade 2/3 SP-EPN we have evaluated by immunohistochemistry the expression of MYCN, H3K27me3, CDK4 and EZH2: the latter is a component of the PRC2 complex, which regulates the histone H3 methylation at Lys27 (K27) and recently described as a transcription factor which controls the expression of MYCN and CDK4 genes. We have also evaluated the amplification of MYCN and CDK4 genes by Copy Number Variation Assay and MLPA techniques. Clinical data were collected and related to the results obtained.
RESULTS
We have found strong overexpression of MYCN only in grade 3 SP-EPN (3/50), while grade 2 tumors showed low or no expression; amplification of MYCN gene was similarly confirmed by CNV assay and MLPA only in grade 3. Interestingly, also CDK4 overexpression was found only in grade 3 ependymomas (1/50), but it is expressed oppositely to MYCN: in tumors were MYCN is overexpressed, CDK4 was completely absent. Amplification of CDK4 gene was confirmed only in those with CDK4 overexpression. These results were both related to an interesting overexpression of EZH2 only in grade 3 SP-EPN (4/50), while H3K27me3 is expressed in all grades without differences. Finally, in our study both MYCN and CDK4-amplified ependymomas were related to a very aggressive behaviour and poor outcome with high recurrence rate, dissemination and metastases.
CONCLUSION
In this study we confirmed the prognostic role of MYCN as indicated by WHO classification and we have showed that CDK4 and EZH2 overexpression could be considered as new promising prognostic and predictive factors in SP-EPN. Since many trials with EZH2 and CDK4 inhibitors have been set up in the last years, these analyses could suggest a new therapeutic approach.
Abstract
Background
Hemangiopericytoma (HPC) is an extremely rare aggressive tumor of mesenchymal origin, which constitutes less than 1% of primary tumors of the central nervous system. Typically it ...occurs in young adults (mean age at diagnosis 30-50 years). Initially described as gemmangiomas, was first called hemangiopericytoma in 1942 but it was considered as a variant of meningioma until 1993 when it was finally recognized as a distinct clinical-pathological entity by the World Health Organization (WHO). In 2016, there was the unification of both HPC and Solitary Fibrous Tumor (SFT) in a single spectrum of rare and thick mesenchymal tumors due to the identification, in both tumoral types, of a molecular alteration called NAB2-STAT6 fusion.
Material and Methods
The present study is a case series of patients that received a pathological diagnosis of SFT/HPC at our Institute from 1981 to 2020. Clinical data included: demographic data, tumor characteristics and treatment modality. Hystological diagnosis and immunohistochemistry allowed to confirm diagnosis, based on the 2016 WHO classification. Haematoxylin staining was completed with immunohistochemistry with primary antibodies for STAT 6 and evaluation of presence of tumor necrosis. Statistical analysis was conducted considering age at first diagnosis, treatment modality, extent of tumor resection, presence of necrosis in histological analysis compared to PFS-1, OS and relapses number.
Results
The case series was composed by 82 patients (46 men and 36 women) with median age of 43 (± 20) that accede to our Institute from 1981 to 2020. Our statistical analysis showed significative correlation between age, extend of tumor resection and presence of necrosis with OS and relapses number.
Conclusion
Hemangiopericytoma is a very rare cerebral tumors, and for this reason large case series are not disposable in literature. In our study we collected all disposable data of every patient with pathological diagnosis of SFT/HPC acceded to our hospital in the long period of 39 years in the aim to verify the presence of significative correlations. We observed strong correlation between tumor resection and presence of necrosis in tumor tissue with prognosis parameters (OS and number of relapses). This result it could be important to conduct the decisional process about treatment after surgical resection, considering also pathological features, rather than only surgical resection.
The discovery of Trichinella zimbabwensis in farm crocodiles of Zimbabwe has opened up a new frontier in the epidemiology of the Trichinella genus. The objective of the present study was to ...investigate the infectivity of encapsulated species (T. spiralis, T. nativa, T. britovi, T. murrelli and T. nelsoni) and non-encapsulated species (T. pseudospiralis, T. papuae and T. zimbabwensis) in caimans (Caiman crocodilus), varans (Varanus exanthematicus), pythons (Python molurus bivittatus) and turtles (Pelomedusa subrufa) raised at their natural temperature range (26-32 degrees C). Mice and chickens were used as controls. At 6 days post-infection (p.i.), adult worms were detected in the small intestine of reptiles infected with T. papuae and T. zimbabwensis, of chickens infected with T. pseudospiralis and of mice infected with all encapsulated and non-encapsulated species. At 60 days p.i., T. papuae and T. zimbabwensis adult worms were collected from the intestine of varans and caimans and larvae from muscles of the four reptile species, T. pseudospiralis larvae from muscles of chickens, and larvae of all Trichinella species from mouse muscles. The highest reproductive capacity index of both T. papuae and T. zimbabwensis was observed in varans. The results show that T. papuae and T. zimbabwensis are able to complete their entire life-cycle in both poikilothermic and homoiothermic animals.
