Influenza B: Prospects for the Development of Cross-Protective Vaccines

In this review, we analyze the epidemiological and ecological features of influenza B, one of the most common and severe respiratory infections. The review presents various strategies for cross-protective influenza B vaccine development, including recombinant viruses, virus-like particles, and recombinant proteins. We provide an overview of viral proteins as cross-protective vaccine targets, along with other updated broadly protective vaccine strategies. The importance of developing such vaccines lies not only in influenza B prevention, but also in the very attractive prospect of eradicating the influenza B virus in the human population.     

Lymphangiogenesis requires Ang2/Tie/PI3K signaling for VEGFR3 cell-surface expression

Vascular endothelial growth factor C (VEGF-C) induces lymphangiogenesis via VEGF receptor 3 (VEGFR3), which is encoded by the most frequently mutated gene in human primary lymphedema. Angiopoietins (Angs) and their Tie receptors regulate lymphatic vessel development, and mutations of the ANGPT2 gene were recently found in human primary lymphedema. However, the mechanistic basis of Ang2 activity in lymphangiogenesis is not fully understood. Here, we used gene deletion, blocking Abs, transgene induction, and gene transfer to study how Ang2, its Tie2 receptor, and Tie1 regulate lymphatic vessels. We discovered that VEGF-C–induced Ang2 secretion from lymphatic endothelial cells (LECs) was involved in full Akt activation downstream of phosphoinositide 3 kinase (PI3K). Neonatal deletion of genes encoding the Tie receptors or Ang2 in LECs, or administration of an Ang2-blocking Ab decreased VEGFR3 presentation on LECs and inhibited lymphangiogenesis. A similar effect was observed in LECs upon deletion of the PI3K catalytic p110α subunit or with small-molecule inhibition of a constitutively active PI3K located downstream of Ang2. Deletion of Tie receptors or blockade of Ang2 decreased VEGF-C–induced lymphangiogenesis also in adult mice. Our results reveal an important crosstalk between the VEGF-C and Ang signaling pathways and suggest new avenues for therapeutic manipulation of lymphangiogenesis by targeting Ang2/Tie/PI3K signaling.     

Bioceramics Based on β-Calcium Pyrophosphate

Ceramic samples based on β-calcium pyrophosphate β-Ca₂P₂O₇ were prepared from powders of γ-calcium pyrophosphate γ-Ca₂P₂O₇ with preset molar ratios Ca/P = 1, 0.975 and 0.95 using firing at 900, 1000, and 1100 °C. Calcium lactate pentahydrate Ca(C₃H₅O₃)₂⋅5H₂O and monocalcium phosphate monohydrate Ca(H₂PO₄)₂⋅H₂O were treated in an aqua medium in mechanical activation conditions to prepare powder mixtures with preset molar ratios Ca/P containing calcium hydrophosphates with Ca/P = 1 (precursors of calcium pyrophosphate Ca₂P₂O₇). These powder mixtures containing calcium hydrophosphates with Ca/P = 1 and non-reacted starting salts were heat-treated at 600 °C after drying and disaggregation in acetone. Phase composition of all powder mixtures after heat treatment at 600 °C was presented by γ-calcium pyrophosphate γ-Ca₂P₂O₇ according to the XRD data. The addition of more excess of monocalcium phosphate monohydrate Ca(H₂PO₄)₂·H₂O (with appropriate molar ratio of Ca/P = 1) to the mixture of starting components resulted in lower dimensions of γ-calcium pyrophosphate (γ-Ca₂P₂O₇) individual particles. The grain size of ceramics increased both with the growth in firing temperature and with decreasing molar ratio Ca/P of powder mixtures. Calcium polyphosphate (t _melt = 984 °C), formed from monocalcium phosphate monohydrate Ca(H₂PO₄)₂⋅H₂O, acted similar to a liquid phase sintering additive. It was confirmed by tests in vitro that prepared ceramic materials with preset molar ratios Ca/P = 1, 0.975, and 0.95 and phase composition presented by β-calcium pyrophosphate β-Ca₂P₂O₇ were biocompatible and could maintain bone cells proliferation.     

Latent Subclinical Medullary Thyroid Carcinoma: Diagnosis and Treatment

n = 11), palpable metastatic lymph node ( n = 6), distant metastases ( n = 4). In nine cases the diagnosis was made by both fine-needle aspiration cytology and serum CT measurement. In the four other cases the initial cytology was incorrect, but the diagnosis was revised on the basis of elevated basal CT values. In 11 patients (group 2) presenting with nodular thyroid disease, SMTC was not clinically detectable. SMTC was preoperatively suspected by elevated CT levels: basal CT > 10 pg/ml and pentagastrin-stimulated CT peak > 100 pg/ml. One patient in group 1 with distant metastases was not operated on. All of the other 12 patients underwent total thyroidectomy and extensive lymph node dissection. The mean size of the tumors was 27 mm. Lymph node involvement was found in nine patients. After surgery, CT levels returned to normal in five patients but remained elevated in five others; the two remaining patients died of distant metastases. All 11 patients in group 2 underwent total thyroidectomy and central neck dissection. None of the 11 patients had nodal extension. All 11 patients are biochemically cured. It was concluded that routine measurement of basal serum CT in those with nodular thyroid disease allows early, preoperative diagnosis of subclinical SMTC and improves the results of surgery.     

Altered ATP-dependent mitochondrial Ca2+ uptake in cold ischemia is attenuated by ruthenium red

BACKGROUND: Graft dysfunction as a result of preservation injury remains a major clinical problem in liver transplantation. This is related in part to accumulation of mitochondrial calcium (Ca(2+)), which has been linked to activation of proapoptotic factors. We hypothesized that cold ischemia increases mitochondrial Ca(2+) uptake in a concentration dependent fashion and that ruthenium red (RR) will attenuate these changes by inhibiting the mitochondrial Ca(2+) uniporter. METHODS: Rat livers perfused with cold University of Wisconsin (UW) solution (4 degrees C) with or without RR (10 microM) via the portal vein (n = 3 per group) were processed immediately (no ischemia) or after 24 h cold-storage (24 h cold ischemia). Mitochondria were separated by differential centrifugation, and adenosine triphosphate (ATP)-dependent (45)Ca(2+) uptake was determined in the presence of ATP (5 mM), adenosine diphosphate (ADP), or adenosine 5'-beta,gamma-imidotriphosphate (AMP-PNP); variable concentrations of extramitochondrial (45)Ca(2+) were used. All measurements were performed in triplicate. Student's t test with P < 0.05 was taken as significant. RESULTS: Our data demonstrate the following: 1) ATP-dependent (45)Ca(2+) uptake in mitochondria separated from livers following 24 h of cold ischemia in UW alone was higher than in mitochondria isolated from non-ischemic livers; the increased uptake was dependent on the concentration of (45)Ca(2+) in the incubation buffer. 2) There was no difference in ATP-dependent (45)Ca(2+) uptake between nonischemic mitochondria and those separated from livers stored in UW-RR for 24 h. 3) (45)Ca(2+) uptake in mitochondria from livers subjected to 24 h of cold ischemia in UW-RR was significantly lower compared to those from livers stored in UW alone when (45)Ca(2+) concentrations were greater than 1 microM. CONCLUSION: 1) Cold ischemia affects mitochondrial Ca(2+) handling, especially when it is challenged by high extramitochondrial Ca(2+) concentrations. 2) The addition of RR in preservation solution attenuates the effects of cold ischemia on mitochondrial Ca(2+) handling. 3) Inhibition of mitochondrial Ca(2+) uniporter with RR protects mitochondria from Ca(2+) overload at high Ca(2+) concentrations. These findings may offer a potentially effective strategy for prevention of ischemia-reperfusion injury in liver transplantation.     

Mutation of alpha1G T-type calcium channels in mice does not change anesthetic requirements for loss of the righting reflex and minimum alveolar concentration but delays the onset of anesthetic induction

BACKGROUND: T-type calcium channels regulate neuronal membrane excitability and participate in a number of physiologic and pathologic processes in the central nervous system, including sleep and epileptic activity. Volatile anesthetics inhibit native and recombinant T-type calcium channels at concentrations comparable to those required to produce anesthesia. To determine whether T-type calcium channels are involved in the mechanisms of anesthetic action, the authors examined the effects of general anesthetics in mutant mice lacking alpha1G T-type calcium channels. METHODS: The hypnotic effects of volatile and intravenous anesthetics administered to mutant and C57BL/6 control mice were evaluated using the behavioral endpoint of loss of righting reflex. To investigate the immobilizing effects of volatile anesthetics in mice, the minimum alveolar concentration (MAC) values were determined using the tail-clamp method. RESULTS: The 50% effective concentration for loss of righting reflex and MAC values for volatile anesthetics were not altered after alpha1G channel knockout. However, mutant mice required significantly more time to develop anesthesia/hypnosis after exposure to isoflurane, halothane, and sevoflurane and after intraperitoneal administration of pentobarbital. CONCLUSIONS: The 50% effective concentration for loss of righting reflex and MAC values for the volatile anesthetics were not altered after alpha1G calcium channel knockout, indicating that normal functioning of alpha1G calcium channels is not required for the maintenance of anesthetic hypnosis and immobility. However, the timely induction of anesthesia/hypnosis by volatile anesthetic agents and some intravenous anesthetic agents may require the normal functioning of these channel subunits.     

Inhibitory smads and tgf-Beta signaling in glomerular cells

Smad6 and Smad7 are inhibitory SMADs with putative functional roles at the intersection of major intracellular signaling networks, including TGF-beta, receptor tyrosine kinase (RTK), JAK/STAT, and NF-kappaB pathways. This study reports differential functional roles and regulation of Smad6 and Smad7 in TGF-beta signaling in renal cells, in murine models of renal disease and in human glomerular diseases. Smad7 is upregulated in podocytes in all examined glomerular diseases (focal segmental glomerulosclerosis [FSGS], minimal-change disease [MCD], membranous nephropathy [MNP], lupus nephritis [LN], and diabetic nephropathy [DN]) with a statistically significant upregulation in "classical" podocyte-diseases such as FSGS and MCD. TGF-beta induces Smad7 synthesis in cultured podocytes and Smad6 synthesis in cultured mesangial cells. Although Smad7 expression inhibited both Smad2- and Smad3-mediated TGF-beta signaling in podocytes, it inhibited only Smad3 but not Smad2 signaling in mesangial cells. In contrast, Smad6 had no effect on TGF-beta/Smad signaling in podocytes and enhanced Smad3 signaling in mesangial cells. These data suggest that Smad7 is activated in injured podocytes in vitro and in human glomerular disease and participates in negative control of TGF-beta/Smad signaling in addition to its pro-apoptotic activity, whereas Smad6 has no role in TGF-beta response and injury in podocytes. In contrast, Smad6 is upregulated in the mesangium in human glomerular diseases and may be involved in functions independent of TGF-beta/Smad signaling. These data indicate an important role for Smad6 and Smad7 in glomerular cells in vivo that could be important for the cell homeostasis in physiologic and pathologic conditions.