ABSTRACT
Background: The potential problems related to the use of formalin in histopathology; such as health hazards; deterioration of nuclei acids are well-known. The aim of this study was to evaluate the utilization of a Carnoy's solution fixation in comparison with formalin on subsequent tissue sectioning and histochemical staining. Materials and Methods: Corresponding sections of 25 tissue biopsies of rabbit's different organs were fixed in Carnoy's solution and in 10neutral buffered formalin. Samples were processed using the conventional method and then stained applying five histochemical methods. The degree of the quality of the staining was assessed for each method by scoring system (1-10) depending on comparison of the stained tissue sections with illustrated photomicrographs. Results: For the quality of cutting; the best quality was obtained by Formalin (mean = 4.76) then Carnoy's fixative (mean =3.84). The best quality of Haematoxylin and Eosin staining was obtained by formalin (mean =5.28) then Carnoy's (mean = 4.00). For Alcian blue and Perl's Prussian blue; the best staining qualities were obtained by Formalin (mean = 4.76 and 5.64 respectively) followed by Carnoy's (mean = 2.88 and 3.92 respectively). For periodic Acid Schiff's the best staining quality was obtained following Carnoy's fixation (mean = 4.52) then; the formalin (mean = 3.76). Conclusion: Although; Carnoy's fluid is a safe fixative and can rapidly penetrate the tissues; but it can't be a substitute for formalin
Subject(s)
Histocytochemistry , TissuesABSTRACT
The histochemical characterization of rain-forest strain of Onchocerca volvulus isolated in Akamkpa of Cross River State; Nigeria was studied. In a preliminary survey of 350 persons from eight villages; 75(21.4) were found to be positive for the parasite. Males (23.6) were more infected than the females but there was no statistically significant difference in the presence of infection by gender (p=0.506). Staining pattern of the parasite using Lead nitrate method for the demonstration of acid phosphatase activity revealed that of the six patterns; four corresponded to the enzyme types already described by some authors in West African rain-forest; and Sudan. One corresponded to the type found in Guinea savannas while the remaining did not correspond to any of the strains described elsewhere. The multiple enzyme staining patterns of Onchocerca volvulus microfilariae in the study area is indicative of polymorphic strain than that of West African strains. This variation in strain might contribute to the degree of pathogenicity and clinical manifestation of onchocerciasis in this endemic zone