Contribution of human hematopoietic stem cells to liver repair

Immune-deficient mouse models of liver damage allow examination of human stem cell migration to sites of damage and subsequent contribution to repair and survival. In our studies, in the absence of a selective advantage, transplanted human stem cells from adult sources did not robustly become hepatocytes, although some level of fusion or hepatic differentiation was documented. However, injected stem cells did home to the injured liver tissue and release paracrine factors that hastened endogenous repair and enhanced survival. There were significantly higher levels of survival in mice with a toxic liver insult that had been transplanted with human stem cells but not in those transplanted with committed progenitors. Transplantation of autologous adult stem cells without conditioning is a relatively safe therapy. Adult stem cells are known to secrete bioactive factors that suppress the local immune system, inhibit fibrosis (scar formation) and apoptosis, enhance angiogenesis, and stimulate recruitment, retention, mitosis, and differentiation of tissue-residing stem cells. These paracrine effects are distinct from the direct differentiation of stem cells to repair tissue. In patients at high risk while waiting for a liver transplant, autologous stem cell therapy could be considered, as it could delay the decline in liver function

Dense sampling of bird diversity increases power of comparative genomics (vol 587, pg 252, 2020)

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Measurement of knee joint motion using digital imaging

The measurement of joint motion is common practice in many aspects of orthopaedic surgery. A number of techniques and instruments have been developed for this purpose. We describe a method of recording and measuring knee joint motion using digital imaging which demonstrated high inter-observer reliability (r > 0.948) and intra-observer repeatability (r > 0.906). This technique may offer some practical advantages over other methods of measuring joint motion

O óxido nitrico como neurotransmissor no sistema nervoso entérico: fisiopatologia e implicações no íleo adinâmico

Nesta revisão do sistema nervoso entérico, enfatiza-se o mecanismo da inibição não-adrenérgica e não-colinérgica na contratilidade do sistema digestório. Introduz-se a síntese e metabolismo do óxido nítrico com apresentação das sintases do óxido nítrico. Atualiza-se mostrando o óxido nítrico como neurotransmissor do mecanismo inibitório não-adrenérgico e não-colinérgico, demonstrando sua atividade na musculatura lisa gastrointestinal e possível mecanismo intracelular através da cGMP. Após atualização do mecanismo do peristaltismo e do complexo motor migratório, faz-se uma descrição do íleo adinâmico. Por fim, todo raciocínio apresentado condensa-se na fisiopatologia do íleo adinâmico