Muramyl Dipeptide Induces NOD2-Dependent Ly6Chigh Monocyte Recruitment to the Lungs and Protects Against Influenza Virus Infection

Bacterial peptidoglycan-derived muramyl dipeptide (MDP) and derivatives have long-recognized antiviral properties but their mechanism of action remains unclear. In recent years, the pattern-recognition receptor NOD2 has been shown to mediate innate responses to MDP. Here, we show that MDP treatment of mice infected with Influenza A virus (IAV) significantly reduces mortality, viral load and pulmonary inflammation in a NOD2-dependent manner. Importantly, the induction of type I interferon (IFN) and CCL2 chemokine was markedly increased in the lungs following MDP treatment and correlated with a NOD2-dependent enhancement in circulating monocytes. Mechanistically, the protective effect of MDP could be explained by the NOD2-dependent transient increase in recruitment of Ly6Chigh “inflammatory” monocytes and, to a lesser extent, neutrophils to the lungs. Indeed, impairment in both Ly6Chigh monocyte recruitment and survival observed in infected Nod2-/- mice treated with MDP was recapitulated in mice deficient for the chemokine receptor CCR2 required for CCL2-mediated Ly6Chigh monocyte migration from the bone marrow into the lungs. MDP-induced pulmonary monocyte recruitment occurred normally in IAV-infected and MDP-treated Ips-1-/- mice. However, IPS-1 was required for improved survival upon MDP treatment. Finally, mycobacterial N-glycolyl MDP was more potent than N-acetyl MDP expressed by most bacteria at reducing viral burden while both forms of MDP restored pulmonary function following IAV challenge. Overall, our work sheds light on the antiviral mechanism of a clinically relevant bacterial-derived compound and identifies the NOD2 pathway as a potential therapeutic target against IAV

Mean Duration of Pregnancy in Spontaneous Deliveries in Ahwaz University Affiliated Hospitals in 2007

Abstract: Background & Aims: Accurate knowledge about gestational age is very important in taking decision for pregnancy management and termination. According to Naegele’s rule the length of pregnancy is 280 days after LMP and according to studies performed in Harvard University, duration of pregnancy in nullipare and multipare women has been respectively 288 and 283 days and according to a study performed in Oxford University it is influenced by factors such as age, parity, some illnesses and personal habits. Materials and methods: In this retrospective study, all laboring women admitted in Ahwaz Medical University Hospitals in 2007 including 689 nulliparas and 774 multiparas with true labor pain and reliable LMP were studied for pregnancy duration. Data were analyzed by SPSS software. Results: Mean duration of pregnancy was 273.17, 274.31and 273.77 days in nulliparas, multiparas and overall respectively. Parity has no significant association with pregnancy duration. According to the sonography below 26 weeks duration of pregnancy is calculated 270.07 days which had no significant relationship with LMP. Conclusion: According to this study parity has no effect on pregnancy duration. Mean pregnancy duration was shorter comapared to Naegele’s rule and Harvard University studies. Keywords: Gestational age, Labor, Parit

Uterine Septum Dimensions in Patients with Infertility and Recurrent Abortion and the Outcomes of Hystroscopic Metroplasty

Abstract: Background & Aims: It is believed that uterine septum, because of its effect on infertility and recurrent abortion is very important and pregnancy outcome is obviously improved by hysteroscopic metroplasty (HM). In this study, the probable relationship of uterine septum dimensions (length and width) with infertility and recurrent abortion has been investigated. Methods: This clinical trial was carried out from Jan. 2004 to Feb. 2007 on all patients referred to Ahwaz educational hospitals for evaluation of infertility and recurrent abortion and underwent hysterosalpingography (HSG). Patients with suspected uterine septum were referred to Imam Khomeyni Hospital and underwent simultaneous hysteroscopy and laparoscopy. After that hysteroscopic metroplasy was done. The participants were checked by new HSG after one month and were evaluated for pregnancy outcome after one year. Results: In whole, 50 patients (28 cases with infertility and 22 cases with recurrent abortion) were studied. In 62.5% septum width was equal or less than 3cm and in 48% length of septum occupied two thirds of uterine cavity and there was no significant difference between the tow groups in regard to septum's width and length. Rate of pregnancy occurrence was 71.4% in patients with infertility and 76.5% in patients with recurrent abortion and no significant difference was found between the two groups in this regard. Conclusion: According to the findings, it seems that septum dimensions (width and length) have no role in infertility and abortion. Therefore, resection of uterine septum regardless of its size is recommended. In patients with uterine septum who suffer from infertility and recurrent abortion, HM is an appropriate approach. Keywords: Infertility, Hysteroscopy, Recurrent abortion, Septate uteru

Water Flooding Performance Evaluation Using Percolation Theory

Water flooding is a well-known secondary mechanism for improving oil recovery. Conventional approach to evaluate the performance of a water flooding process (e.g. breakthrough and post breakthrough behavior) is to establish a reliable geological reservoir model, upscale it, and then perform flow simulations. To evaluate the uncertainty in the breakthrough time or post breakthrough behavior, this procedure has to be repeated for many realizations of the geological model, which takes many hours of CPU time. Moreover, during the early stage of reservoir life, when data is scare, breakthrough and post breakthrough time behavior prediction are usually based on analogues or rules of thumb. Alternative statistical approach is to use percolation theory to predict breakthrough and post breakthrough bahavior. The main contribution is to evaluate the applicability of the existing scaling laws of the breakthrough time by the numerical flow simulation results using the Burgan formation dataset of Norouz offshore oilfield in the south of Iran. Moreover, we extend the scaling to the post breakthrough behavior. There is good agreement between the predictions from the percolation based expressions and the numerical simulation results. Moreover, the prediction from the scaling law took a fraction of a second of CPU times (as it only needs some algebraic calculations) compared with many hours required for the conventional numerical simulations

Estimation of the Effective Permeability of Heterogeneous Porous Media by Using Percolation Concepts

In this paper we present new methods to estimate the effective permeability (k_eff) of heterogeneous porous media with a wide distribution of permeabilities and various underlying structures, using percolation concepts. We first set a threshold permeability (k_th) on the permeability density function (pdf) and use standard algorithms from percolation theory to check whether the high permeable grid blocks (i.e. those with permeability higher than k_th) with occupied fraction of “p” first forms a cluster connecting two opposite sides of the system in the direction of the flow (high permeability flow pathway). Then we estimate the effective permeability of the heterogeneous porous media in different ways: a power law (k_eff=k_th p^m), a weighted power average (k_eff=[p.k_th^m+(1-p).k_g^m ]^(1/m) with k_g the geometric average of the permeability distribution) and a characteristic shape factor multiplied by the permeability threshold value. We found that the characteristic parameters (i.e. the exponent “m”) can be inferred either from the statistics and properties of percolation sub-networks at the threshold point (i.e. high and low permeable regions corresponding to those permeabilities above and below the threshold permeability value) or by comparing the system properties with an uncorrelated random field having the same permeability distribution. These physically based approaches do not need fitting to the experimental data of effective permeability measurements to estimate the model parameter (i.e. exponent m) as is usually necessary in empirical methods. We examine the order of accuracy of these methods on different layers of 10th SPE model and found very good estimates as compared to the values determined from the commercial flow simulators