The VEGF receptor flt-1 (VEGFR-1) is a positive modulator of vascular sprout formation and branching morphogenesis

Sprouting angiogenesis is critical to blood vessel formation, but the cellular and molecular controls of this process are poorly understood. We used time-lapse imaging of green fluorescent protein (GFP)-expressing vessels derived from stem cells to analyze dynamic aspects of vascular sprout formation and to determine how the vascular endothelial growth factor (VEGF) receptor flt-1 affects sprouting. Surprisingly, loss of flt-1 led to decreased sprout formation and migration, which resulted in reduced vascular branching. This phenotype was also seen in vivo, as flt-1(-/-) embryos had defective sprouting from the dorsal aorta. We previously showed that loss of flt-1 increases the rate of endothelial cell division. However, the timing of division versus morphogenetic effects suggested that these phenotypes were not causally linked, and in fact mitoses were prevalent in the sprout field of both wild-type and flt-1(-/-) mutant vessels. Rather, rescue of the branching defect by a soluble flt-1 (sflt-1) transgene supports a model whereby flt-1 normally positively regulates sprout formation by production of sflt-1, a soluble form of the receptor that antagonizes VEGF signaling. Thus precise levels of bioactive VEGF-A and perhaps spatial localization of the VEGF signal are likely modulated by flt-1 to ensure proper sprout formation during blood vessel formation.     

Genetic and clinical characterization of sporadic cystic parathyroid tumours

objective The hyperparathyroidism–jaw tumour (HPT–JT) syndrome is one of the familial disorders characterized by primary hyperparathyroidism and has been linked to the chromosomal region of 1q32–q21. The parathyroid tumours related to this syndrome have shown loss of wild‐type alleles at this locus suggesting that inactivation of a tumour suppressor gene might be responsible for the disease. In the majority of these tumours cysts are a prominent feature. By loss of heterozygosity (LOH) studies, we investigated the region of interest in an attempt to clarify its possible role in a series of cystic sporadic parathyroid adenomas. design and subjects A total of 30 patients diagnosed with sporadic hyperparathyroidism were included in the study, genotyped with 17 polymorphic microsatellite markers at chromosome 1q, and additional markers from 1p and 11q13 which are commonly involved in sporadic parathyroid tumours. The cystic parathyroid tumours were characterized clinically, and immunohistochemistry against PTH was carried out to confirm the parathyroid origin of the cysts. results LOH was found in six of 30 tumours (20%) on 1q, six of 30 tumours (20%) on 1p and five of 30 tumours (17%) on 11q13. We found a significant correlation between allelic alterations and the clinical parameters, tumour weight and PTH. Furthermore, we found a significant difference between tumour weight and PTH in cases of cystic parathyroid tumours compared with unselected sporadic cases. conclusions These results suggest that cystic parathyroid tumours might represent a new subgroup among parathyroid tumours based on the genetic and clinical findings. Loss of heterozygosity at 1q further supports the presence of a tumour suppressor gene at this locus.     

Plasma homocysteine in 80-year-olds: relationships to medical, psychological and social variables

Plasma homocysteine concentrations in a group of 80-year-old persons were related to symptoms and signs. Plasma homocysteine concentrations higher than 15 mumol/l were associated with lower total life satisfaction (P<0.01), mood (P<0.05), zest for life (P<0.05), lower scores for reasoning (P<0.05), spatial ability (P<0.05), memory recognition (P<0.05), and subjective health (P<0.01). In an instrument comprising of 30 symptoms, plasma homocysteine concentrations higher than 15 mumol/l were associated with impaired concentration (P<0.05), restlessness (P<0.05), feeling cold (P<0.05), loss of weight (P<0.05), and feeling depressed (P<0.01). The above data indicate that plasma homocysteine values over 15 mumol/l could be relevant markers for clinical intervention.     

Complement gene expression is regulated by pro-inflammatory cytokines and the anaphylatoxin C3a in human tenocytes

Interplay between complement factors, regulatory proteins, anaphylatoxins and cytokines could be involved in tendon healing and scar formation. The expression and regulation of complement factors by cytokines or anaphylatoxins are completely unclear in tendon.Hence, the gene expression of the anaphylatoxin receptors C3aR, C5aR and cytoprotective complement regulatory proteins (CRPs) was analysed in human tendon, cultured primary tenocytes and to directly compare the general expression level, additionally in human leukocytes. Time-dependent regulation of complement by cytokines and the anaphylatoxin C3a was assessed in cultured tenocytes.Gene expression of the anaphylatoxin receptors C3aR, C5aR and the CRPs CD46, CD55 and CD59 was detected in tendon, cultured tenocytes and leukocytes, whereas CD35 could only be found in tendon and leukocytes. Compared with cultured tenocytes, complement expression was higher in tendon and compared with leukocytes C3aR, C5aR, CD35 and CD55, but not CD46 and CD59 gene expression levels were lower in tendon. C3aR mRNA was up-regulated by both TNFα and C3a in cultured tenocytes in a time-dependent manner whereby C5aR gene expression was only induced by C3a. IL-6 or C3a impaired the CRP gene expression. C3a stimulation lead to an up-regulation of TNFα and IL-1β mRNA in tenocytes. Degenerated tendons revealed an increased C5aR and a reduced CD55 expression.The expression profile of the investigated complement components in tendon and cultured tenocytes clearly differed from that of leukocytes. Tenocytes respond to the complement split fragment C3a with CRP suppression and enhanced pro-inflammatory cytokine gene expression suggesting their sensitivity to complement activation.     

In vivo targeting of human DC‐SIGN drastically enhances CD8+ T‐cell‐mediated protective immunity

Vaccination is one of the oldest yet still most effective methods to prevent infectious diseases. However, eradication of intracellular pathogens and treatment of certain diseases like cancer requiring efficient cytotoxic immune responses remain a medical challenge. In mice, a successful approach to induce strong cytotoxic CD8⁺ T‐cell (CTL) reactions is to target antigens to DCs using specific antibodies against surface receptors in combination with adjuvants. A major drawback for translating this strategy into one for the clinic is the lack of analogous targets in human DCs. DC‐SIGN (DC‐specific‐ICAM3‐grabbing‐nonintegrin/CD209) is a C‐type lectin receptor with potent endocytic capacity and a highly restricted expression on human immature DCs. Therefore, DC‐SIGN represents an ideal candidate for DC targeting. Using transgenic mice that express human DC‐SIGN under the control of the murine CD11c promoter (hSIGN mice), we explored the efficacy of anti‐DC‐SIGN antibodies to target antigens to DCs and induce protective immune responses in vivo. We show that anti‐DC‐SIGN antibodies conjugated to OVA induced strong and persistent antigen‐specific CD4⁺ and CD8⁺ T‐cell responses, which efficiently protected from infection with OVA‐expressing Listeria monocytogenes. Thus, we propose DC targeting via DC‐SIGN as a promising strategy for novel vaccination protocols against intracellular pathogens.     

The combined self- and parent-rated SDQ score profile predicts care use and psychiatric diagnoses

European Child & Adolescent Psychiatry - The Strengths and Difficulties Questionnaire (SDQ) is widely used, based on evidence of its value for screening. This evidence primarily regards the...