Immunohistochemical expression of latent membrane protein 1 (LMP1) and p53 in nasopharyngeal carcinoma: Moroccan experience.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a malignant epithelial tumor intimately associated with Epstein-Barr virus (EBV). NPC is a characteristic tumor displaying epidemiological, genetic and regional distribution properties that makes it unique by its natural behavior. OBJECTIVES: To assess the expression pattern of LMP1 and p53 proteins in the different histological types of NPC in a sample of the Moroccan population and to define any association between the expression of those proteins with the sex, the age and the histological types of NPC. METHODS: Archival formalin-fixed, paraffin-embedded NPC biopsies were evaluated in 23 Moroccan patients for the presence of LMP1 and p53 using immunohistochemistry (IHC). RESULTS: No LMP1 expression was observed whereas 8 of 23 cases (34. 7%) had detectable p53 protein in the nuclei of tumor cells. After statistical analysis according to the Fisher's exact probability test, no significant association between p53 expression and histological type, age and sex distributions was demonstrated (p>0.05). CONCLUSION: This study confirms that p53 overexpression is present in a subset of Moroccan NPC patients. Our results are consistent with those reported by other studies concerning the same NPC endemic risk area and provide original data concerning Morocco.

Experimental infection of swine by Isospora suis Biester 1934 for species confirmation.

A survey of Isospora suis performed in 177 faecal samples from 30 swine farms detected thin wall type I. suis oocysts in seven samples. This type of oocyst measuring 23.9 by 20.7 microns had a retracted thin wall similar to that of the genus Sarcocystis. This type of oocysts, isolated from four different faecal samples, was inoculated in four-five-days-old piglets free of contamination in order to verify the life cycle and pathogenicity of the species. The pigs were kept in individual metal cages and fed with cow milk. Daily faecal collections and examinations were performed until the 21st day after infection. MacMaster and Sheather's methods were used for oocyst counting and identification. Infected piglets produced yellowish-pasty diarrhoea with slight dehydration. The prepatent and patent periods were respectively from 6 to 9 and 3 to 10 days after infection. Oocyst elimination was interrupted on the 10th and 11th days after infection with biphasic cycles. Thin and thick wall oocysts were detected in the same faecal samples. Thin walls were not observed in unsporulated oocytes. The observations suggest that this type of oocysts could appear in specific strains which occur in the later stages of their development. These oocysts seem to be responsible for clinical and pathogenic signs of neonatal isosporosis in pigs.

Prevalence of porcine neonatal isosporosis in Brazil.

The prevalence of Isospora suis and clinical signs of isosporosis were observed in 33 swine farms from 20 sites in the southeastern state of São Paulo, Brazil. The study was performed by collecting 177 faecal samples from nursing and weaned piglets. A history of clinical neonatal isosporosis, as well as the type of farrowing and nursery houses and the pig management in the farms were correlated to the prevalence of I. suis oocysts. Six faecal samples were collected in each of the farms (two from groups of 10- to 19-day-old piglets, two from groups of 20- to 29-day-old and another two from groups of 30- to 50-day-old pigs). Faecal consistency was also registered at the time of their collection. Chi-square tests were used for statistical analysis. Oocysts were more prevalent in farms with a history of neonatal isosporosis than in those without previous cases. Faecal consistency was not related to oocyst elimination. In farms with a history of clinical isosporosis, faecal samples from groups of 10- to 19-day-old piglets showed a higher prevalence of oocysts than the groups of other ages studied. There was no difference in the prevalence of oocysts between nursing and weaned piglets. Oocysts were more prevalent in faecal samples collected from dirty-cemented floors than from self-cleaning floors in the farrowing houses. Types of floor and pig management in nursery houses were not associated with the presence of oocysts in weaned pigs.