Hepatosplenic schistosomiasis. Pathophysiology and treatment.

HSS represents a special model of intrahepatic portal hypertension characterized by a presinusoidal portal block and a well-preserved liver parenchyma. Symmers' fibrosis appears in a small but significant proportion of patients with a high worm load. Its pathogenesis is not well established, although experimental and clinical studies point to egg granulomata as the main pathogenetic factor. The eggs carried continuously through the portal circulation produce inflammation and gross amputation of the intrahepatic veins, portal and periportal granulomas, and, eventually, a coarse perilobular fibrosis ("pipe-stem"). Portal hypertension, esophageal varices, and hepatosplenomegaly are the main consequences of these morphologic changes. Gastrointestinal bleeding is the most frequent cause of death. Unlike in cirrhosis, advanced liver failure is not seen except when HSS is associated with liver lesions from other causes such as virus and alcoholism. Helminthiasis treatment is based on chemotherapy with praziquantel or oxamniquine. Bleeding esophageal varices are managed by sclerotherapy or surgical procedures. Splenectomy with gastroesophageal devascularization seems to be the best choice.     

Wilson disease: novel mutations in the ATP7B gene and clinical correlation in Brazilian patients

Wilson disease (WD) is a rare inherited autosomal recessive disorder caused by a defect in a metal transporting P-type ATPase, resulting in copper overload in various tissues and cells. The aim was to assess both the phenotype in Brazilian WD patients and the corresponding ATP7B genotype. Sixty subjects belonging to 46 pedigrees diagnosed as WD were included in this study. Direct sequencing of all 21 exons within ATP7B and their flanking introns was performed. Demographic, clinical, laboratory and histopathological data at the time of diagnosis were obtained. We identified twenty-five mutations, twelve of them reported for the first time. The c.3402delC mutation had the highest allelic frequency (30.8%), followed by the c.2123T>C (p.L708P) (16.7%). Exons 8 and 15 were the site of 62.5% of the mutations. The common European mutation c.3207C>A (p.H1069Q) was not present at all. Phenotype varied greatly among individuals with the same ATP7B genotype. Our data confirm the heterogeneity of ATP7B genotype in Brazilian WD patients. The mutational spectrum is compatible with the Brazilian history of Mediterranean immigration; however, new mutations, and different frequencies and phenotype associated with the previously known mutations characterize this population. Exons 8 and 15 should be preferentially screened in WD cases from Brazil. Phenotype variation among subjects with the same ATP7B genotype suggests that modifying factors play an additional role in the pathogenesis of WD.     

Effect of resin hydrophilicity and water storage on resin strength

This study evaluated the change in the ultimate tensile strength (UTS) of five polymerised resin blends of increasing hydrophilicity, after ageing in distilled water or silicon oil. Resin blocks were prepared from each resin blend by dispensing the uncured resin into a flexible, embedding mould, containing multiple cavities. The resins were polymerised in the moulds under nitrogen at 551.6 kPa and light-activated at 125 degrees C for 10 min. After dry ageing for 24 h at 37 degrees C, the middle third of each resin specimen was trimmed into an 'I' shape. Fifteen control specimens were randomly selected from each resin blend for baseline UTS evaluation. The UTS of the experimental specimens were determined after 1, 3, 6 and 12 months of ageing in water or oil. The UTS of each group of resins at different storage periods in water or oil were analysed using the Friedman multiple ANOVA on ranks and Dunn's multiple comparison tests at 95% confidence level. Significant reduction (p < 0.01) in UTS was observed in Groups II-V resins after 12-month storage in water, while the most hydrophobic Group I resin showed no significant change (p > 0.05) in the same period. The percentage reduction in UTS increased with the hydrophilicity of the resin blends. Long-term water storage of hydrophilic resin blends such as those employed in dentine adhesives, resulted in a marked reduction in their mechanical strength that may compromise the durability of resin-dentine bonds.     

Characterization of human papillomavirus infection,P53 and Ki-67 expression in cervix cancer of Mozambican women

In this study, we aimed at evaluating the distribution of HPV types and the expression of P53 and Ki-67 in cervix carcinomas of Mozambican women. Fourty-seven invasive carcinomas, 10 CIN III, and 10 normal cervix were studied. P53 and Ki-67 expression was examined immunohistochemically. HPV infection and HPV types were detected by PCR (GP5+/bio-GP6+) and enzyme-immunoassay, respectively. Expression of P53 and Ki-67 and detection of HPV were as follows: normal cervix--0%, 10%, and 0%, respectively; CIN III--10%, 0%, and 100%, respectively; invasive carcinomas--50%, 55.5%, and 70%, respectively. HPV 16 was identified in 54% of invasive carcinomas, HPV 31, 33, 35, and 45 in 23%, "unidentified" HPV in 19%, and HPV 18 in 4% of invasive carcinomas. No significant associations were observed between P53 expression, Ki-67 expression, and HPV infection. In conclusion, we observed a high frequency of HPV infection in CIN III lesions and invasive carcinomas from Mozambican women, with HPV 16 representing the most frequent viral type. HPV status was not related to P53 and Ki-67 expression. Both P53 and Ki-67 are associated with invasive cervix carcinomas, mainly of the squamous keratinizing histotype.     

Novel L2HGDH mutations in 21 patients with L-2-hydroxyglutaric aciduria of Portuguese origin

We studied 21 patients, from 18 families, with L-2-hydroxyglutaric aciduria (L-2-HGA), a rare neurometabolic disorder with a homogeneous presentation: progressive neurodegeneration with extrapyramidal and cerebellar signs, seizures, and subcortical leukoencephalopathy. Increased levels of L-2-hydroxyglutaric acid in body fluids proved the diagnosis of L-2-HGA in all 21 patients. We analyzed the L-2-HGA gene (L2HGDH), recently found to be mutated in consanguineous families with L-2-HGA, and identified seven novel mutations in 15 families. Three mutations appeared to be particularly prevalent in this Portuguese panel: a frameshift mutation (c.529delC) was detected in 12 out of 30 mutant alleles (40%), a nonsense mutation (c.208C>T; p.Arg70X) in 7/30 alleles (23%), and a missense mutation (c.293A>G; p.His98Arg) in four out of 30 mutant alleles (13%), suggesting that common origin may exist. Furthermore, two novel missense (c.169G>A; p.Gly57Arg, c.1301A>C; p.His434Pro) and two splice error (c.257-2A>G, c.907-2A>G) mutations were found. All the mutations presumably lead to loss-of-function with no relationship between clinical signs, progression of the disease, levels of L-2-HGA and site of the mutation. In the three remaining families, no pathogenic mutations in the L-2-HGA were found, which suggests either alterations in regulatory regions of the gene or of its intervening sequences, compound heterozygosity for large genomic deletion and, or further genetic heterogeneity.     

Fine-needle aspiration diagnosis of Kaposi's sarcoma in a developing country

Fine-needle aspiration (FNA) cytology was performed on 15 patients with peripheral lymphadenopathy and/or skin lesions referred to the Department of Pathology of the Hospital Central of Maputo, Maputo, Mozambique. Epitrochlear lymph nodes were the most frequently aspirated site. All aspirates allowed diagnoses of Kaposi's sarcoma (KS). Smears contained loosely cohesive clusters of bland spindle cells, with a radial arrangement and nuclear crush artifacts. These diagnostic clues have not been described in other spindle-cell intranodal lesions that should be considered in differential diagnoses. Taking into consideration the high prevalence of AIDS and limited resources for diagnosis in Africa, FNA cytology appears to be a useful method for the diagnosis of KS in developing countries, reducing the necessity for surgical lymph node excision.