Maternal inheritance of BDNF deletion, with phenotype of obesity and developmental delay in mother and child.

Childhood obesity is a significant world health problem. Understanding the genetic and environmental factors contributing to the development of obesity in childhood is important for the rational design of strategies for obesity prevention and treatment. Brain-derived neurotrophic factor (BDNF) plays an important role in the growth and development of the central nervous system, there is also an evidence that BDNF plays a role in regulation of appetite. Disruption of the expression of this gene in a child has been previously reported to result in a phenotype of severe obesity, hyperphagia, impaired cognitive function, and hyperactivity. We report a mother and child, both with micro-deletions encompassing the BDNF gene locus, who both have obesity and developmental delay, although without hyperactivity. This report highlights the maternal inheritance of a rare genetic cause of childhood obesity.

A systematic review of novel technology for monitoring infant and newborn heart rate.

Heart rate (HR) is a vital sign for assessing the need for resuscitation. We performed a systematic review of studies assessing novel methods of measuring HR in newborns and infants in the neonatal unit. Two investigators completed independent literature searches. Identified papers were independently evaluated, and relevant data were extracted and analysed. CONCLUSION: This systematic review identified seven new technologies, including camera-based photoplethysmography, reflectance pulse oximetry, laser Doppler methods, capacitive sensors, piezoelectric sensors, electromyography and a digital stethoscope. Clinicians should be aware of several of these, which may become available for clinical use in the near future.

Socs1 deficiency enhances hepatic insulin signaling.

Suppressor of cytokine signaling 1 (SOCS1) is an intracellular inhibitor of cytokine, growth factor, and hormone signaling. Socs1-/- mice die before weaning from a multiorgan inflammatory disease. Neonatal Socs1-/- mice display severe hypoglycemia and hypoinsulinemia. Concurrent interferon gamma gene deletion (Ifng-/-) prevented inflammation and corrected the hypoglycemia. In hyperinsulinemic clamp studies, however, Socs1-/- Ifng-/- mice had enhanced hepatic insulin sensitivity demonstrated by greater suppression of endogenous glucose production compared with controls with no difference in glucose disposal. Socs1-/- Ifng-/- mice had elevated liver insulin receptor substrate 2 expression (IRS-2) and IRS-2 tyrosine phosphorylation. This was associated with lower phosphoenolpyruvate carboxykinase mRNA expression. These effects were not associated with elevated hepatic AMP-activated protein kinase activity. Hepatic insulin sensitivity and IRS-2 levels play central roles in the pathogenesis of type 2 diabetes. Socs1 deficiency increases IRS-2 expression and enhances hepatic insulin sensitivity in vivo indicating that inhibition of SOCS1 may be a logical strategy in type 2 diabetes.

The lack of suppressor of cytokine signalling-1 (SOCS1) protects mice from the development of cerebral malaria caused by Plasmodium berghei ANKA.

Cerebral malaria is a severe complication of infection with Plasmodium berghei ANKA involving the Th1 cytokines TNF-alpha and IFN-gamma. Suppressor of cytokine signalling-1 (SOCS1) is an important component in the regulatory cascade controlling inflammatory responses and signalling through IFN-gamma. Contrary to the expectation that SOCS1-deficient mice, in which IFN-gamma responses are uncontrolled and which are more sensitive to IFN-gamma, may show heightened susceptibility, mice lacking SOCS1 were protected from cerebral malaria. Unlike the controls and despite similar parasitaemia, infected SOCS1 null mice showed no inflammation or haemorrhaging in the brains. Mice lacking SOCS1 exhibited decreased splenic cellularity and a reduced ratio of CD4 : CD8 lymphocytes, which were maintained during infection. However, the ratio of IFN-gamma to IL-4 mRNA expression during infection was similar in SOCS1 -/- and control mice suggesting that a dramatic shift in the ratio of Th1 : Th2 responses does not account for the resistance to disease. Resistance conferred by the lack of SOCS1 is specific since the related SOCS2, also implicated in Th1-mediated responses, did not seem to be involved in the development of disease. Understanding the mechanism by which SOCS1 deficiency protects mice from cerebral malaria may allow the manipulation of its activity and alleviate pathology.

Persistence of lesions in suppressor of cytokine signaling-1-deficient mice infected with Leishmania major.

To investigate the role of the cytokine IFN-gamma and its negative regulator, the suppressor of cytokine signaling-1 (SOCS1) in the progression of cutaneous leishmaniasis, we infected mice lacking a single copy of the gene encoding SOCS1 (SOCS1(+/-)), mice lacking both copies of IFN-gamma (IFN-gamma(-/-)), or mice lacking copies of both SOCS1 and IFN-gamma (SOCS1(-/-) IFN-gamma(-/-)), with a moderate dose of 10(3) or 10(4) of the most virulent stage of parasites, metacyclic promastigotes. Surprisingly, SOCS1(+/-) mice developed larger lesions than wild-type mice, although the parasite load in the draining lymph node was not significantly altered. These mice also developed apparently normal Th1 responses, as indicated by elevated levels of IFN-gamma and low levels of IL-4 and IL-10. The persistence of lesions and the enlargement of draining lymph nodes despite a normal Th1 response and control of parasitemia indicate that there may be a dissociation of the inflammatory pathology and clearance of parasites in SOCS1(+/-) mice. We also investigated the role of the related suppressor of cytokine signaling, SOCS2, which has been implicated in the development of Th1 immunity. The progression of disease in SOCS2(-/-) mice did not differ from that in C57BL/6 control mice, suggesting that it is not involved in the host response to Leishmania major infection and supporting the specific role of SOCS1. These results suggest that SOCS1 plays an important role in the regulation of appropriate inflammatory responses during the resolution of L. major infection.

Interaction of Leishmania with the host macrophage.

The leishmaniases are a group of diseases with a spectrum of clinical manifestations ranging from self-healing cutaneous ulcers to severe visceral disease and even death. In mammals, the macrophage is the main host for the Leishmania amastigote. However, the macrophage is also the immune effector cell that, upon activation, is able to kill intracellular organisms. Therefore, understanding the parasite mechanisms which allow establishment of infection, and the host immune mechanisms that are responsible for parasite recognition and killing should lead to the development of new drugs and vaccines.