Home About us Contact
|
Home About us Contact | ||
|
|
||
Focal Necrosis (focal + necrosis)
Selected AbstractsDisappearance of gender-related difference in the toxicity of benzotriazole ultraviolet absorber in juvenile ratsCONGENITAL ANOMALIES, Issue 4 2009Mutsuko Hirata-Koizumi ABSTRACT 2-(2,-hydroxy-3,,5,-di- tert -butylphenyl)benzotriazole (HDBB) is an ultraviolet absorber used in plastic resin products, such as building materials and automobile components. In oral repeated dose toxicity studies using 5- or 6-week-old rats, this chemical induced hepatic histopathological changes, such as hypertrophy accompanied with eosinophilic granular changes and focal necrosis of hepatocytes, and male rats showed nearly 25 times higher susceptibility to the toxic effects than females. Castration at approximately 4 weeks of age markedly reduced the sex-related variation in HDBB toxicity, but some difference, less than five times, remained between male and female castrated rats. Following oral HDBB administration to male and female juvenile rats from postnatal days 4,21, such gender-related difference in toxic susceptibility was not detected; therefore, it is speculated that the determinants of susceptibility to HDBB toxicity are differentiated between sexes after weaning. In young rats given HDBB, there was no gender-related difference in plasma HDBB concentration, and no metabolites were detected in the plasma of either sex. HDBB induced lauric acid 12-hydroxylase activity in the liver and this change was more pronounced in males than in females. These findings indicate that HDBB could show hepatic peroxisome proliferation activity, and the difference in the susceptibility of male and female rats to this effect might lead to marked gender-related differences in toxicity. [source] Investigation of histopathological and cytogenetic effects on Lepomis gibbosus (Pisces: Perciformes) in the Çine stream (Ayd,n/Turkey) with determination of water pollutionENVIRONMENTAL TOXICOLOGY, Issue 6 2005Yücel Ba, lu Koca Abstract Water quality and the distribution of some heavy metals in three different organs of Lepomis gibbosus from the Çine Stream were studied. Also, histopathological changes in gill, liver, and muscle tissue were examined at light microscopical level. Micronucleus (MN) formation in fish erytrocytes, as an indicator of chromosomal damage, has been increasingly used to detect the genotoxic potential of environmental contaminants. The frequency of MN was examined from samples of fish from the Çine Stream and a control group. MN frequency was higher in fish samples caught from the Çine Stream than that in the control group. The chemicals ammonia, nitrite, nitrate, orthophosphate, and sulphate were determined as parameters that possibly affect the gill, liver, and muscle morphology. Zn was the most accumulated metal in tissues as well as in water. Maximum metal accumulation occured in both liver and gills. For histopathological examinations, samples of gills, liver, and muscle tissues of L. gibbosus were studied by using light microscopy. In this study, a significant decrease in mean length of primary and secondary lamellae were observed. Moreover, cellular proliferation developed with secondary lamellae fusion, ballooning degenerations or club deformation of secondary lamellae, as well as distribution of necrotic, hyperplastic and clavate secondary lamellae. In the liver, altered staining, swollen and ruptured parenchymal cells, loss of cord structure, reduce of glycogen in hepatocytes, and vacuolar structure filled with cellular debris and many dark particles were seen. In muscle tissue, focal necrosis, cellular dissolution, and a decline or loss of striatation in muscle fibres were found. © 2005 Wiley Periodicals, Inc. Environ Toxicol 20: 560,571, 2005. [source] Sea-urchin granuloma: histologic profile.JOURNAL OF CUTANEOUS PATHOLOGY, Issue 5 2001A pathologic study of 50 biopsies Background: Sea-urchin granuloma is a chronic granulomatous skin lesion caused by injury with sea-urchin spines. Frequently these lesions occur on the hands and develop several months after the initial injury. Classified as an allergic foreign-body reaction, their most common histological pattern resembles sarcoid. The purpose of this study was to evaluate the light microscopic features of biopsies from lesions clinically diagnosed of sea-urchin granolomas. Methods: We retrospectively reviewed 50 biopsy specimens corresponding to 35 patients with sea-urchin granulomas. These lesions were caused by injuries with the spines of the sea-urchin Paracentrotus lividus. Data were collected between 1990 and 1999 from patients in the seashore of Galicia (NW Atlantic coast, Spain). Results: The cohort consisted of 35 patients (31 males, 4 females), with a median age of 35 years (range 14,60 years). The median duration of the disease was 7.5 months (range 2,60 months). We identified different histopathologic patterns. A granulomatous reaction was observed in 39 biopsies (78%). In 70% corresponding to 35 biopsies this granulomatous reaction was predominant. Foreign-body, sarcoidal, tuberculoid, necrobiotic and suppurative granulomas were identified. The remaining 15 biopsies (30%) showed a predominant inflammatory reaction with features of non-specific chronic inflammation or suppurative dermatitis. A panel of histopathologic features, including epidermal and dermal changes were evaluated. Presence of focal necrosis and microabscesses were common findings. In 50% of our specimens we found umbilication and/or perforation. Additional features included the presence of inclusion epidermoid cysts in four cases and squamous syringometaplasia in one case. Conclusions: Our observations suggest that sea-urchin granuloma span a wide morphologic spectrum. A granulomatous inflammatory reaction was predominant, with the foreign body and sarcoidal types the most frequent patterns. Other histopathologic patterns with non granulomatous inflammation can be noted. Some features, such as the frequency of perforation and the presence of necrobiotic granulomas have not previously been recognized in the literature. [source] Acute generalized exanthematous pustulosis (AGEP) , A clinical reaction patternJOURNAL OF CUTANEOUS PATHOLOGY, Issue 3 2001Alexis Sidoroff Background: A wide range of diseases or reactions can cause pustular eruptions of the skin. In this spectrum there seems to be a subgroup with characteristic clinical features and a typical course which is mostly caused by drugs for which the term acute generalized exanthematous pustulosis (AGEP) has been established. Objective: To describe the clinical features of AGEP. Methods: The authors' experience from a multinational epidemiological study on severe cutaneous adverse reactions and a comprehensive review of the literature were used to provide an overview of the disease and it's possible causes. An algorithm for validating cases which was established for this study is also presented. Results: AGEP typically presents with at least dozens of non follicular sterile pustules occurring on a diffuse, edematous erythema predominalty in the folds and/or on the face. Fever and elevated blood neutrophils are common. Histopathology typically shows spongiform subcorneal and/or intraepidermal pustules, a marked edema of the papillary dermis, and eventually vasculitis, eosinophils and/or focal necrosis of keratinocytes. Onset is acute, most often following drug intake, but viral infections can also trigger the disease. Pustules resolve spontaneously in less than 15 days. Conclusion: The diagnosis AGEP should be considered in cases of acute pustular rashes and detection of the causative drug should be strived for. Knowledge of the clinical features and usual course of this disease can often prevent unnecessary therapeutical measures. [source] Hepatic arterial flow becomes the primary supply of sinusoids following partial portal vein ligation in ratsJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 10 2006Yukihiro Yokoyama Abstract Background and Aim:, Partial portal vein ligation (PPVL) is a commonly used procedure to induce prehepatic portal hypertension in animal models. The aim of this study was to test the hypothesis that the hepatic arterial flow becomes the primary source feeding the sinusoids in the liver after PPVL. Methods:, Sprague,Dawley rats underwent either sham operation or partial portal vein ligation (PPVL). The number of vessels in the liver at 2 weeks postoperatively was determined by factor VIII immunolocalization and the gene expression of angiogenic factors was assessed by RT-PCR. The total hepatic arterial supply to the liver was measured using the fluorescent microsphere injection technique. To further test the hypothesis, two additional groups of rats underwent hepatic artery ligation (HAL) or PPVL plus HAL (PPHAL). The integrity of hepatic microcirculation was then evaluated in all four groups by intravital microscopy. Results:, At 2 weeks after operation, the number of vessels detected by factor VIII staining was significantly higher in PPVL compared to sham. Densitometric analysis of RT-PCR bands revealed a significant increase of vascular endothelial growth factor gene expression in PPVL compared to sham. Arterial flow to the liver measured by fluorescent microspheres was increased by 190% in PPVL compared to sham. When all four groups were compared, no prominent histological abnormality was observed in sham, HAL, and PPVL groups; however, PPHAL livers showed focal necrosis and inflammatory cell infiltration around the portal triads. Additionally, only the PPHAL livers showed a decreased sinusoidal diameter and significantly lower perfusion index (PPHAL 42.9 ± 6.1; sham 85.7 ± 7.0, PPVL 80.2 ± 6.5, HAL 70.9 ± 4.5). Conclusions:, These results suggest that the hepatic artery flow becomes the primary source for the blood supply of sinusoids and the compensatory change in the hepatic arterial system plays a critical role in maintaining microcirculatory perfusion following the restriction of the portal vein flow by PPVL. [source] | ||||||||||