Malignant osteopetrosis: bone marrow transplantation

A osteopetrose é uma osteopatia hereditária caracterizada pela deficiência na reabsorção óssea que ocorre por disfunção dos osteoclastos. Com o acúmulo de material osteóide que oblitera o canal medular, ocorre hematopoiese extramedular (hepato-esplenomegalia), obliteração dos forames dos nervos cranianos (cegueira, surdez, paralisias faciais), macrocefalia, protusão da fronte, hipertelorismo, exoftalmo, aumento da pressão intracraniana, retardo na erupção dentária, atraso no crescimento, atraso no desenvolvimento neuropsicomotor, e a morte ocorre precocemente nos primeiros anos de vida. A única alternativa terapêutica curativa é o transplante de medula óssea (TMO) de doador HLA idêntico, pois restabelece a hematopoiese e a função monócito-macrófago, com melhora das lesões ósseas e anormalidades hematopoiéticas, embora não reverta as alterações sensoriais já instaladas. Os autores relatam casos de duas crianças portadoras de osteopetrose maligna submetidas ao transplante de medula óssea com sucesso. A primeira encontra-se no dia +1260 do TMO, com melhora evidente da radiologia esquelética, sem progressão das deficiências neurológicas que apresentava, e com biópsia óssea sem sinais de osteopetrose. O segundo paciente encontra-se no dia + 700, com sinais de reabsorção óssea e sem progressão dos danos neurológicos. Os autores chamam a atenção para a necessidade de diagnóstico precoce da osteopetrose e o rápido encaminhamento para o transplante de medula óssea antes da instalação de seqüelas neurológicas definitivas.Osteopetrosis is an inherited disorder characterized by the inability to reabsorb and remodel bone due to osteoclast dysfunction. The encroachment by bone and mineralized cartilage of the medullary cavities leads to extramedullary hematopoiesis (hepatosplenomegaly) and cranial-nerve foramina leads to blindness, auditory nerve damage, and occulomotor and facial nerve palsies. Defective bone re-absorption also leads to macrocephaly, frontal bossing, hypertelorism, exophthalmos, increased intracranial pressure, retarded tooth eruption, retarded linear growth and psychomotor delay. Death occurs within the first years of life. The only curative therapy is allogeneic bone marrow transplantation with a HLA-identical donor, which restores hematopoiesis, monocyte-macrophage function and bone recovery, but there is no sensorial deficit restoration once present. The authors report two cases of allogeneic bone marrow transplant for infantile malignant osteopetrosis. The first child, on day 1260 after bone marrow transplantation (BMT), showed radiologic bone recovery and no progression of neurological deficits with a bone biopsy showing no signs of osteopetrosis. The second child showed signs of bone re-absorption and no progression of neurological deficits on day 700. The authors emphasize the importance of early diagnosis of osteopetrosis and the necessity of bone marrow transplantation before neurological deficits have begun

A genome survey of Moniliophthora perniciosa gives new insights into Witches' Broom Disease of cacao

<p>Abstract</p> <p>Background</p> <p>The basidiomycete fungus <it>Moniliophthora perniciosa </it>is the causal agent of Witches' Broom Disease (WBD) in cacao (<it>Theobroma cacao</it>). It is a hemibiotrophic pathogen that colonizes the apoplast of cacao's meristematic tissues as a biotrophic pathogen, switching to a saprotrophic lifestyle during later stages of infection. <it>M. perniciosa</it>, together with the related species <it>M. roreri</it>, are pathogens of aerial parts of the plant, an uncommon characteristic in the order Agaricales. A genome survey (1.9× coverage) of <it>M. perniciosa </it>was analyzed to evaluate the overall gene content of this phytopathogen.</p> <p>Results</p> <p>Genes encoding proteins involved in retrotransposition, reactive oxygen species (ROS) resistance, drug efflux transport and cell wall degradation were identified. The great number of genes encoding cytochrome P450 monooxygenases (1.15% of gene models) indicates that <it>M. perniciosa </it>has a great potential for detoxification, production of toxins and hormones; which may confer a high adaptive ability to the fungus. We have also discovered new genes encoding putative secreted polypeptides rich in cysteine, as well as genes related to methylotrophy and plant hormone biosynthesis (gibberellin and auxin). Analysis of gene families indicated that <it>M. perniciosa </it>have similar amounts of carboxylesterases and repertoires of plant cell wall degrading enzymes as other hemibiotrophic fungi. In addition, an approach for normalization of gene family data using incomplete genome data was developed and applied in <it>M. perniciosa </it>genome survey.</p> <p>Conclusion</p> <p>This genome survey gives an overview of the <it>M. perniciosa </it>genome, and reveals that a significant portion is involved in stress adaptation and plant necrosis, two necessary characteristics for a hemibiotrophic fungus to fulfill its infection cycle. Our analysis provides new evidence revealing potential adaptive traits that may play major roles in the mechanisms of pathogenicity in the <it>M. perniciosa</it>/cacao pathosystem.</p

Linfoma de Hodgkin em baixa faixa etária: relato de dois casos Hodgkin's lymphoma in young children: two cases report

Relato de dois casos de pacientes do sexo masculino com linfoma de Hodgkin (LH) e idades inferiores a 5 anos apresentando linfonodomegalias com evolução de alguns meses e seguimento em nosso serviço. Os estudos imuno-histopatológicos do tumor confirmaram linfoma de Hodgkin, esclerose nodular e positividade para o vírus Epstein-Barr (EBV) em material tumoral, em ambos os casos. Após período de 13 meses em remissão completa houve recidiva em um dos pacientes, mostrando doença agressiva. A análise laboratorial do tumor mostrou as mesmas características da doença inicial, e mantendo a positividade ao EBV. Uma exposição mais precoce e intensa ao EBV poderia aumentar o risco para formas muito precoces da doença e a inesperada evolução poderia estar ligada à associação do subtipo histológico e positividade ao EBV.The cases of two male under five-year-olds diagnosed with Hodgkin's lymphoma presenting as lymphadenopathy in evolution for some months and treated in our hospital are reported. Immunohistopathological findings of the tumors proved the existence of Hodgkin's lymphoma nodular sclerosis and positive Epstein-Barr virus in tumoral material in both cases. After 13 months of complete remission one of the patients relapsed and presented aggressive disease. Laboratorial analyses of the tumor showed the same characteristics as the initial disease including positive Epstein-Barr virus. Early and intense exposure to Epstein-Barr virus may increase the risk related to the very early development of the disease and the unexpected evolution may be connected to the association of the histological subtype and the positive Epstein-Barr virus

Hepatitis B virus genotypes circulating in Brazil: molecular characterization of genotype F isolates-1

<p><b>Copyright information:</b></p><p>Taken from "Hepatitis B virus genotypes circulating in Brazil: molecular characterization of genotype F isolates"</p><p>http://www.biomedcentral.com/1471-2180/7/103</p><p>BMC Microbiology 2007;7():103-103.</p><p>Published online 23 Nov 2007</p><p>PMCID:PMC2231365.</p><p></p>onding region of the sample (N: North region; NE: Northeast region; CW: Central-West region; SE: Southeast region) with RFLP pattern in brackets. International sequences are designated with their accession number followed by their countries of origin

Persistent bacterial infections and persister cells

Many bacteria can infect and persist inside their hosts for long periods of time. This can be due to immunosuppression of the host, immune evasion by the pathogen and/or ineffective killing by antibiotics. Bacteria can survive antibiotic treatment if they are resistant or tolerant to a drug. Persisters are a subpopulation of transiently antibiotic-tolerant bacterial cells that are often slow-growing or growth-arrested, and are able to resume growth after a lethal stress. The formation of persister cells establishes phenotypic heterogeneity within a bacterial population and has been hypothesized to be important for increasing the chances of successfully adapting to environmental change. The presence of persister cells can result in the recalcitrance and relapse of persistent bacterial infections, and it has been linked to an increase in the risk of the emergence of antibiotic resistance during treatment. If the mechanisms of the formation and regrowth of these antibiotic-tolerant cells were better understood, it could lead to the development of new approaches for the eradication of persistent bacterial infections. In this Review, we discuss recent developments in our understanding of bacterial persisters and their potential implications for the treatment of persistent infections