Made available in DSpace on 2014-06-11T19:27:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2005Bitstream added on 2014-06-13T19:57:00Z : No. of bitstreams: 1 sanches_oc_me_botfmvz.pdf: 854358 bytes, checksum: 39b64088c65063724feff29da0e935b5 (MD5) / Universidade Estadual Paulista (UNESP) / A insuficiência renal crônica é a principal afecção renal dos cães e a anemia é a principal seqüela desta infecção. Os rins são os principais responsáveis pela produção do hormônio estimulador e regulador da eritropoiese - eritropoetina. O presente estudo teve por objetivos investigar e descrever as alterações histopatológicas dos rins e da linhagem eritróide na medula óssea de cães portadores de insuficiência renal crônica (IRC), identificando e quantificando as células precursoras das hemácias na medula óssea. Foram utilizados 15 animais controle e 15 animais portadores de insuficiência renal crônica. As amostras foram analisadas em microscopia ótica, tendo como auxílio à coloração de Giemsa, que foi utilizada para diferenciar os precursores eritróides. Os animais do grupo controle apesar de apresentarem alterações morfológicas nos rins, estas não foram suficientes para promover alterações nos parâmetros hematológicos, bem como na bioquímica sérica. Já nos animais do grupo com IRC as alterações morfológicas se caracterizaram por glomerulonefrite crônica, seguida da glomerulonefrite proliferativa mesangial, glomerulonefrite membranoproliferativa e da glomerulonefrite membranosa com 46,66%, 26,66%, 13,33% e 13,33% dos animais respectivamente. Vale ressaltar ainda que 73,33% dos animais exibiam nefrite intersticial crônica e 20% apresentavam nefrite intersticial focal. Dos quinze animais do grupo com IRC, 80% exibiam quadro de anemia, sendo 46,66% do tipo normocítica normocrômica, 20% macrocítica hipocrômica, 6,66% com anemia microcítica normocrômica e 6,66% do tipo macrocítica hipocrômica. As alterações morfológicas túbulo-intersticiais apresentaram maior correlação com as concentrações de uréia e creatinina e com a contagem dos precursores eritróides. / The chronic renal failure, the main renal afection of the dogs and the anemia is the main sequel of this afection. The kidneys are the main responsible for the production of the hormone stimulator and regulator of the erythropoiesis - erythropoietin. The present work had as objectives to investigate and to describe the histopathologics alterations of the kidneys and of the erythroid lineage in the bone marrow of dogs bearers of chronic renal failure (CRF), identifying and quantifying the precursory cells of the erythrocytes in the bone marrow. 15 control animals and 15 animals bearers of chronic renal failure were used. The samples were analyzed in optic microscopy, with the use of the Giemsa coloration, used to differentiate the erythroid precursors. The animals of the control group inspite of the morphologic alterations presented in the kidneys, were not enough to promote alterations in the hematological parameters, as well as in the serum biochemistry. In the animals of the group with CRF the morphologic alterations are characterized by chronic glomerulonephritis, following by proliferative mesangial glomerulonephritis, membranousproliferative glomerulonephritis and the membranous glomerulonephritis with 46,66%, 26,66%, 13,33% and 13,33% of the animals respectively. It is worth to stand out that 73,33% of the animals exhibited chronic interstitial nephritis and 20% presented focal interstitial nephritis. Of the 15 animals of the group with CRF, 80% exhibited anemia, being 46,66% of the type normocytic normochromic, 20% macrocytic hypochromic, 6,66% with anemia microcytic normochromic and 6,66% of the type macrocytic hypochromic. The morphologic tubulo-interstitial alterations presented larger correlation with the urea concentrations and creatinine and with the counting of the erythroid precursors.

Orientador: Julio Lopes Siqueira / Resumo: A insuficiência renal crônica é a principal afecção renal dos cães e a anemia é a principal seqüela desta infecção. Os rins são os principais responsáveis pela produção do hormônio estimulador e regulador da eritropoiese - eritropoetina. O presente estudo teve por objetivos investigar e descrever as alterações histopatológicas dos rins e da linhagem eritróide na medula óssea de cães portadores de insuficiência renal crônica (IRC), identificando e quantificando as células precursoras das hemácias na medula óssea. Foram utilizados 15 animais controle e 15 animais portadores de insuficiência renal crônica. As amostras foram analisadas em microscopia ótica, tendo como auxílio à coloração de Giemsa, que foi utilizada para diferenciar os precursores eritróides. Os animais do grupo controle apesar de apresentarem alterações morfológicas nos rins, estas não foram suficientes para promover alterações nos parâmetros hematológicos, bem como na bioquímica sérica. Já nos animais do grupo com IRC as alterações morfológicas se caracterizaram por glomerulonefrite crônica, seguida da glomerulonefrite proliferativa mesangial, glomerulonefrite membranoproliferativa e da glomerulonefrite membranosa com 46,66%, 26,66%, 13,33% e 13,33% dos animais respectivamente. Vale ressaltar ainda que 73,33% dos animais exibiam nefrite intersticial crônica e 20% apresentavam nefrite intersticial focal. Dos quinze animais do grupo com IRC, 80% exibiam quadro de anemia, sendo 46,66% do tipo normocítica normocrômica, 20% macrocítica hipocrômica, 6,66% com anemia microcítica normocrômica e 6,66% do tipo macrocítica hipocrômica. As alterações morfológicas túbulo-intersticiais apresentaram maior correlação com as concentrações de uréia e creatinina e com a contagem dos precursores eritróides. / Abstract: The chronic renal failure, the main renal afection of the dogs and the anemia is the main sequel of this afection. The kidneys are the main responsible for the production of the hormone stimulator and regulator of the erythropoiesis - erythropoietin. The present work had as objectives to investigate and to describe the histopathologics alterations of the kidneys and of the erythroid lineage in the bone marrow of dogs bearers of chronic renal failure (CRF), identifying and quantifying the precursory cells of the erythrocytes in the bone marrow. 15 control animals and 15 animals bearers of chronic renal failure were used. The samples were analyzed in optic microscopy, with the use of the Giemsa coloration, used to differentiate the erythroid precursors. The animals of the control group inspite of the morphologic alterations presented in the kidneys, were not enough to promote alterations in the hematological parameters, as well as in the serum biochemistry. In the animals of the group with CRF the morphologic alterations are characterized by chronic glomerulonephritis, following by proliferative mesangial glomerulonephritis, membranousproliferative glomerulonephritis and the membranous glomerulonephritis with 46,66%, 26,66%, 13,33% and 13,33% of the animals respectively. It is worth to stand out that 73,33% of the animals exhibited chronic interstitial nephritis and 20% presented focal interstitial nephritis. Of the 15 animals of the group with CRF, 80% exhibited anemia, being 46,66% of the type normocytic normochromic, 20% macrocytic hypochromic, 6,66% with anemia microcytic normochromic and 6,66% of the type macrocytic hypochromic. The morphologic tubulo-interstitial alterations presented larger correlation with the urea concentrations and creatinine and with the counting of the erythroid precursors. / Mestre

Background SARS-CoV-2 infection causes acute respiratory distress, which may progress to multiorgan failure and death. Severe COVID-19 disease is accompanied by reduced erythrocyte turnover, low hemoglobin levels along with increased total bilirubin and ferritin serum concentrations. Moreover, expansion of erythroid progenitors in peripheral blood together with hypoxia, anemia, and coagulopathies highly correlates with severity and mortality. We demonstrate that SARS-CoV-2 directly infects erythroid precursor cells, impairs hemoglobin homeostasis and aggravates COVID-19 disease. Methods Erythroid precursor cells derived from peripheral CD34+ blood stem cells of healthy donors were infected in vitro with SARS-CoV-2 alpha variant and differentiated into red blood cells (RBCs). Hemoglobin and iron metabolism in hospitalized COVID-19 patients and controls were analyzed in plasma-depleted whole blood samples. Raman trapping spectroscopy rapidly identified diseased cells. Results RBC precursors express ACE2 receptor and CD147 at day 5 of differentiation, which makes them susceptible to SARS-CoV-2 infection. qPCR analysis of differentiated RBCs revealed increased HAMP mRNA expression levels, encoding for hepcidin, which inhibits iron uptake. COVID-19 patients showed impaired hemoglobin biosynthesis, enhanced formation of zinc-protoporphyrine IX, heme-CO2, and CO-hemoglobin as well as degradation of Fe-heme. Moreover, significant iron dysmetablolism with high serum ferritin and low serum iron and transferrin levels occurred, explaining disturbances of oxygen-binding capacity in severely ill COVID-19 patients. Conclusions Our data identify RBC precursors as a direct target of SARS-CoV-2 and suggest that SARS-CoV-2 induced dysregulation in hemoglobin- and iron-metabolism contributes to the severe systemic course of COVID-19. This opens the door for new diagnostic and therapeutic strategies.