Deletion of the ectodomain unleashes the transforming, invasive, and tumorigenic potential of the MET oncogene

The c-MET proto-oncogene, encoding the p190 hepatocyte growth factor tyrosine kinase receptor, can acquire oncogenic potential by multiple mechanisms, such as gene rearrangement, amplification and overexpression, point mutation, and ectopic expression, all resulting in its constitutive activation. Hepatocyte growth factor receptor truncated forms are generated by post-translational cleavage: p140 and p130 lack the kinase domain and are inactive. Their C-terminal remnant fragments are generally undetectable in normal cells, but a membrane-associated truncated form is recognized by anti-C-terminus antibodies in some human tumors, suggesting that a hepatocyte growth factor receptor lacking the ectodomain, but retaining the transmembrane and intracellular domains (Met-EC-), could acquire oncogenic properties. Herein we show that NIH-3T3 cells transduced with MET-EC- expressed a membrane-associated constitutively tyrosine-phosphorylated 60-kDa protein and, similarly to NIH-3T3 cells expressing the cytosolic oncoprotein Tpr-Met, showed activated extracellular regulated kinase 1/2 mitogen-activated protein kinase and Akt downstream transducers. Compared to control NIH-3T3 cells, NIH-3T3-Met-EC- cells grew faster and showed anchorage-independent growth and invasive properties in all aspects similar to cells expressing the transforming TPR-MET. Nude female mice injected subcutaneously with NIH-3T3-Met-EC- cells developed visible tumors, displaying the typical morphology of carcinomas with polygonal cells, in contrast to sarcomas with spindle-shaped cells induced by the injection of NIH-3T3-Tpr-Met cells. It is suggested that the different subcellular localization of the oncoproteins, more than differences in signal transduction, could be responsible for the tumor phenotype. All together, these data show that deletion of the ectodomain activates the hepatocyte growth factor receptor and its downstream signaling pathways, unleashing its transforming, invasive, and tumorigenic potential.

Influence of contact angle on slow evaporation in two-dimensional porous media

We study numerically the influence of contact angle on slow evaporation in two-dimensional model porous media. For sufficiently low contact angles, the drying pattern is fractal and can be predicted by a simple model combining the invasion percolation model with the computation of the diffusive transport in the gas phase. The overall drying time is minimum in this regime and is independent of contact angle over a large range of contact angles up to the beginning of a transition zone. As the contact angle increases in the transition region, the cooperative smoothing mechanisms of the interface become important and the width of the liquid gas interface fingers that form during the evaporation process increases. The mean overall drying time increases in the transition region up to an upper bound which is reached at a critical contact angle thetac. The increase in the drying time in the transition region is explained in relation with the diffusional screening phenomenon associated with the Laplace equation governing the vapor transport in the gas phase. Above thetac the drying pattern is characterized by a flat traveling front and the mean overall drying time becomes independent of the contact angle. Drying time fluctuations are studied and are found to be important below thetac, i.e., when the pattern is fractal. The fluctuations are of the same order of magnitude regardless of the value of contact angle in this range. The fluctuations are found to die out abruptly at thetac as the liquid gas interface becomes a flat front.

Nonuniversal conductivity exponents in continuum percolating Gaussian fractures

We study the electrical and hydraulic conductivity percolation exponents in a Gaussian fracture using the method proposed in Plouraboué [Phys. Rev. E 73, 036305 (2006)]. Nonuniversal conductivity percolation exponents are found: they differ from the theoretical predictions for infinite system size for frozen power-law distributions of local conductivities, as with their finite size corrections. In the hydraulic case, we also find that the probability density function of the conductivity follows a power-law distribution near the percolation threshold.

2-Amino-N-pyrimidin-4-ylacetamides as A2A receptor antagonists: 2. Reduction of hERG activity, observed species selectivity, and structure-activity relationships

Previously we have described a series of novel A 2A receptor antagonists with excellent water solubility. As described in the accompanying paper, the antagonists were first optimized to remove an unsubstituted furyl moiety, with the aim of avoiding the potential metabolic liabilities that can arise from the presence of an unsubstituted furan. This effort identified a series of potent and selective methylfuryl derivatives. Herein, we describe the further optimization of this series to increase potency, maintain selectivity for the human A 2A vs the human A 1 receptor, and minimize activity against the hERG channel. In addition, the observed structure-activity relationships against both the human and the rat A 2A receptor are reported.

Synthesis of N-pyrimidinyl-2-phenoxyacetamides as adenosine A2A receptor antagonists

A series of N-pyrimidinyl-2-phenoxyacetamide adenosine A(2A) antagonists is described. SAR studies led to compound 14 with excellent potency (K(i) = 0.4 nM), selectivity (A(1)/A(2A) > 100), and efficacy (MED 10 mg/kg p.o.) in the rat haloperidol-induced catalepsy model for Parkinson's disease.

Identification of novel, water-soluble, 2-amino-N-pyrimidin-4-yl acetamides as A2A receptor antagonists with in vivo efficacy

Potent adenosine hA2A receptor antagonists are often accompanied by poor aqueous solubility, which presents issues for drug development. Herein we describe the early exploration of the structure-activity relationships of a lead pyrimidin-4-yl acetamide series to provide potent and selective 2-amino-N-pyrimidin-4-yl acetamides as hA2A receptor antagonists with excellent aqueous solubility. In addition, this series of compounds has demonstrated good bioavailability and in vivo efficacy in a rodent model of Parkinson's disease, despite having reduced potency for the rat A2A receptor versus the human A2A receptor.

[Hereditary syndrome of hyperferritinemia and cataract]

This report describes a family with hereditary hyperferritinemia cataract syndrome. Inheritance is autosomal dominant and clinical characteristics of this syndrome are familial cataracts of early development and elevated serum ferritin levels but otherwise normal iron studies and haematological parameters. It is important to increase awareness of this entity in order to diagnose new cases and avoid unnecessary diagnostic tests and inadequate treatments.

Influence of wettability conditions on slow evaporation in two-dimensional porous media

We study numerically the influence of the wettability condition on slow evaporation in two-dimensional pore square networks of aspect ratio 1. We show how evaporation in a hydrophobic network can be simulated numerically by combining imbibition rules and the computation of diffusion transport in the gas phase. Then we conduct a statistical study of drying in hydrophilic or hydrophobic networks based on pore network simulations. We concentrate on the situation where the external transfer resistance and liquid film effect are negligible and the invasion is dominated by capillary effects. It is found that drying in a hydrophilic network is significantly faster than in a hydrophobic one. The dimensionless overall drying time is found to be network size dependent, approaching exponentially a limit for large size hydrophilic networks. The dimensionless average overall drying time is 0.93 and 0.75 in hydrophobic and hydrophilic large networks, respectively. Other properties, such as the overall saturation and the evaporation flux (through the concept of equivalent flat front position) are also studied. In a last part the impact of liquid film flow on the overall drying time fluctuation is briefly investigated for the case of hydrophilic networks. It is found that the films dampen the drying time fluctuations.

Caspase-independent death of meiotic and postmeiotic cells overexpressing p53: calpain involvement

In a model of male sterility (MTp53) owing to enforced p53 expression in spermatocytes II and spermatids of transgenic mice, we focused on the role of caspases. Most of them are expressed in all differentiation stages, but only the transcriptional levels of caspase-2 and caspase-3 are modified in MTp53 germ cells. In normal testis, cleaved caspase-3 and caspase-9 are detected during the elongation of spermatids. Despite this constitutive presence of caspases during terminal differentiation, calpains are the main effectors of germ cell loss in MTp53 testes: calpain 1 RNA levels are increased, caspase-3-like activity is markedly decreased while calpain activity is higher and the calpain inhibitor E64d ((2S, 3S)-trans-epoxysuccinyl-L-leucylamido-3-methylbutane ethyl ester) reduces TUNEL labeling in MTp53 testis, whereas pancaspase inhibitor zVADfmk (N-benzyloxycarbonyl-Val-Ala-Asp(OMe)-fluoromethylketone) has no effect. Our work suggests that despite the presence, and potent involvement, of caspases in male haploid cell maturation, calpains are the executioners of the death of terminally differentiating germ cells.

Geodesic network method for flows between two rough surfaces in contact

A discrete network method based on previous asymptotic analysis for computing fluid flows between confined rough surfaces is proposed. This random heterogeneous geodesic network method could be either applied to surfaces described by a continuous random field or finely discretized on a regular grid. This method tackles the difficult problem of fluid transport between rough surfaces in close contact. We describe the principle of the method as well as detail its numerical implementation and performances. Macroscopic conductances are computed and analyzed far from the geometrical percolation threshold. Numerical results are successfully compared with the effective medium approximation, the application of which is also studied analytically.

Quasi-static liquid–air drainage in narrow channels with variations in the gap

This paper studies the shape of an air bubble quasi-statically flowing in the longitudinal direction of narrow channels. Two bottom topographies are treated, i.e., linear and quadratic variations of the gap along the transverse direction. This work analyses the main characteristics of the gas-liquid interface with respect to the wedge aspect ratio. From the convergence of asymptotic, numerical and experimental analyses, we found simple dependences for the finger width and total curvature as a function of channel aspect ratio. These results provide simple and general expressions for the pressure drop needed to overcome capillary forces and push the air finger inside the channel.

An outbreak of airborne tularaemia in France, August 2004

Fifteen tularaemia cases were identified after a holiday spent at a converted mill in the Vendee region in France, between 9 and 12 August 2004. The mill was visited, and descriptive, retrospective cohort and environmental investigations were conducted. The 39 people who had stayed at the mill between 24 July and 11 August were asked about symptoms, exposure to food and animals, and leisure activities. A case was defined as a person with evidence of fever and a positive serology (seroconversion or significant rise in antibody titre, or a single titre) = 40. Culture for Francisella tularensis and polymerase chain reaction (PCR) diagnosis was carried out for drinking water, firewood, and domestic animals at the mill. Fifteen cases of tularaemia (38%) were confirmed. Twelve of the cases (80%) had the pulmonary form. None of the patients was admitted to hospital. There was a strong association between infection and participation in a dinner at the mill on 4 August (p<10-8). One of the three dogs present in the dining room was serologically positive for F. tularensis. Results of analysis of environmental samples were negative. These investigations confirmed the occurrence of a cluster of 15 tularaemia cases, in patients who were infected on the evening of 4 August, in a mill in Vend¨¦e, an endemic area for tularaemia. The investigations highlight the existence of nonspecific and benign pulmonary forms of the illness in France. The pulmonary form of infection in the human cases and the positive serology of the dog suggest contamination by inhalation of contaminated particles from the dog¡¯s fur disseminated by the dog shaking itself.

An outbreak of airborne tularaemia in France, August 2004

Fifteen tularaemia cases were identified after a holiday spent at a converted mill in the Vendee region in France, between 9 and 12 August 2004. The mill was visited, and descriptive, retrospective cohort and environmental investigations were conducted. The 39 people who had stayed at the mill between 24 July and 11 August were asked about symptoms, exposure to food and animals, and leisure activities. A case was defined as a person with evidence of fever and a positive serology (seroconversion or significant rise in antibody titre, or a single titre) = 40. Culture for Francisella tularensis and polymerase chain reaction (PCR) diagnosis was carried out for drinking water, firewood, and domestic animals at the mill. Fifteen cases of tularaemia (38%) were confirmed. Twelve of the cases (80%) had the pulmonary form. None of the patients was admitted to hospital. There was a strong association between infection and participation in a dinner at the mill on 4 August (p < 10(-8)). One of the three dogs present in the dining room was serologically positive for F. tularensis. Results of analysis of environmental samples were negative. These investigations confirmed the occurrence of a cluster of 15 tularaemia cases, in patients who were infected on the evening of 4 August, in a mill in VendAe, an endemic area for tularaemia. The investigations highlight the existence of nonspecific and benign pulmonary forms of the illness in France. The pulmonary form of infection in the human cases and the positive serology of the dog suggest contamination by inhalation of contaminated particles from the dogos fur disseminated by the dog shaking itself.

A comparison of raloxifene and calcium plus vitamin D on vaginal atrophy after discontinuation of long-standing postmenopausal hormone therapy in osteoporotic women. A randomized, masked-evaluator, one-year, prospective study

OBJECTIVES

We assessed the effects of the discontinuation of long-standing transdermal estrogen replacement therapy (>4 years) and substitution of this treatment by calcium or raloxifene on the vaginal epithelium and climateric symptoms in a study population of osteoporotic women.

METHODS

A total of 136 women (mean age 55.5 years) were randomized to calcium (500 mg elemental calcium, 400 IU Vitamin D3) (n=40), raloxifene (60 mg/day) (n=48), or estrogen patches (3.9 mg estradiol) and progesterone (100 mg/day) (n=48). Treatment was given for 1 year. The vaginal maturation value (VMV), serum estradiol levels, and climateric symptoms using a 12-item modification of the SF-36 quality of life questionnaire were evaluated at baseline and at 6 and 12 months.

RESULTS

At 6 months, mean VMV decreased significantly (P<0.001) in the calcium (-51.8%) and raloxifene (-18.6%) groups compared with baseline and the estrogen/progesterone group. At 12 months, significant decreases of mean VMV in the calcium (-38.7%) and raloxifene groups (-32%) (P<0.001) were also observed. Serum estradiol levels and changes of VMV correlated significantly at 6 months (rho=0.361, P<0.01) and at 12 months (rho=0.269, P<0.035). A significantly higher number of patients complained of hot flushes and palpitations in the calcium and raloxifene groups than in the estrogen/progesterone group. Raloxifene-treated women reported a significantly higher number of adverse events at 6 months compared to the other treatment groups.

CONCLUSIONS

Withdrawal and change of long-standing transdermal hormone replacement therapy by treatment with calcium or raloxifene resulted in worsening of vaginal atrophy assessed by the VMV, although it was not clinically perceived by the patients. However, increases in dyspareunia and urinary leaks were reported. Menopausal complaints related to vasomotor symptoms worsened in the calcium- and raloxifene-treated groups and persisted throughout the study period.

Agonist Met antibodies define the signalling threshold required for a full mitogenic and invasive program of Kaposi's Sarcoma cells

We previously showed that the Kaposi Sarcoma line KS-IMM express a functional Met tyrosine kinase receptor, which, upon HGF stimulation, activates motogenic, proliferative, and invasive responses. In this study, we investigated the signalling pathways activated by HGF, as well as by Met monoclonal antibodies (Mabs), acting as full or partial agonists. The full agonist Mab mimics HGF in all biological and biochemical aspects. It elicits the whole spectrum of responses, while the partial agonist Mab induces only wound healing. These differences correlated with a more prolonged and sustained tyrosine phosphorylation of the receptor and MAPK evoked by HGF and by the full agonist Mab, relative to the partial agonist Mab. Since Gab1, JNK and PI 3-kinase are activated with same intensity and kinetics by HGF and by the two agonist antibodies, it is concluded that level and duration of MAPK activation by Met receptor are crucial for the induction of a full HGF-dependent mitogenic and invasive program in KS cells.

Met identification on human platelets: role of hepatocyte growth factor in the modulation of platelet activation

Circulating HGF is significantly increased in a number of thrombus-associated disorders. Since platelets play a pivotal role in thrombogenesis, the ability of HGF to interact with human platelets was investigated. This paper shows for the first time that human platelets express HGF receptor, the tyrosine kinase encoded by c-MET gene. At physiological concentrations HGF was found to inhibit both glycoprotein (alpha)IIb(beta)3 activation and thrombin-dependent platelet aggregation in a dose- and time-dependent manner. These results suggest that circulating HGF may counteract thrombogenesis by negatively modulating platelet functions.