Mutation, fitness, viral diversity, and predictive markers of disease progression in a computational model of HIV type 1 infection

The aim of this study was to develop a computational model of HIV infection able to simulate the natural history of the disease and to test predictive parameters of disease progression. We describe the results of a numerical simulation of the cellular and humoral immune response to HIV-1 infection as an adaptive pathway in a "bit-string" space. A total of 650 simulations of the HIV-1 dynamics were performed with a modified version of the Celada-Seiden immune system model. Statistics are in agreement with epidemiological studies showing a log normal distribution for the time span between infection and the development of AIDS. As predictive parameters of disease progression we found that HIV-1 accumulates "bit" mutations mainly in the peptide sequences recognized by cytotoxic CD8 T cells, indicating that cell-mediated immunity plays a major role in viral control. The viral load set point was closely correlated with the time from infection to development of AIDS. Viral divergence from the viral quasispecies that was present at the beginning of infection in long-term nonprogressors (LTNP) was found to be similar to that found in rapid progressors at the time CD4 T cells drop below the critical value of 200 cells/microl. In contrast, the diversity indicated by the number of HIV strains present at the same time was higher for rapid and normal progressors compared to LTNP, suggesting that the early immune response can make the difference. This computational model may help to define the predictive parameters of HIV dynamics and disease progression, with potential applications in therapeutic and vaccine simulations.     

Primary Toxoplasma gondii infection in a pregnant human immunodeficiency virus-infected woman

We report a 36-year-old HIV-infected woman who developed primary Toxoplasma gondii infection during pregnancy that was treated with spiramycin and antiretroviral drugs. There was no vertical transmission of toxoplasmosis and HIV.     

Hepatocyte transplantation in the treatment of acute liver failure: microencapsulated hepatocytes versus hepatocytes attached to an autologous biomatrix

A liver transplant is considered today to be the only effective therapeutic solution for many otherwise intractable hepatic disorders. However, liver transplantation is beset by shortage of donors. Over the years, many liver support systems have been developed to supply the liver functions, mostly as a bridge to transplantation. Transplantation of isolated hepatocytes (HcTx) instead of whole liver has constituted one of the most appealing possibilities to treat several diseases. We compared two different models of HcTx in a surgical model of acute liver failure in pigs, using microencapsulated hepatocytes (MHcTx) and hepatocytes attached to a porcine biomatrix (PBMHcTx), both transplanted into peritoneum. The collected data were survival, laboratory findings, hemodynamic parameters, light microscopy, histology, MTT, and glycogen content. The group with PBMHcTx has a better outcome than the group with MHcTx (p < 0.05). Histology showed normal morphology of the hepatocytes, high glycogen content, 75% viability, positive MTT, and 95% adhesion of the hepatocytes to the biomatrix. Our biomatrix (PBM) provides cell-to-cell contact and interaction with extracellular matrix, which have been shown to play major roles in hepatocyte survival and physiologic regulation of gene expression, and guarantee a prompt engraftment and an adequate neovascularization. PBMHcTx is a useful method to treat acute liver failure and it indicates a possible liver-direct gene therapy in the treatment of inherited and acquired disorders.     

High proportion of immature oocytes in a cohort reduces fertilization,embryo development,pregnancy and live birth rates following ICSI

Research questionOoplasmic maturity has been studied for some time, but remains poorly defined. This study aimed to evaluate metaphase II (MII) oocyte competence in terms of fertilization, embryo development and cycle outcomes, according to the oocyte maturity ratio.DesignCouples treated by intracytoplasmic sperm injection (ICSI) between 1993 and 2017 with female partners ≤35 years old were included. Cycles were divided into four groups according to proportion of MII oocytes at the time of retrieval: optimal (76–100%), adequate (51–75%), partial (26–50%) and minimal (1–25%).ResultsA total of 7672 ICSI cycles (optimal: 4838; adequate: 2252; partial: 518; minimal oocyte maturity: 64) were included, in which 95,667 MII oocytes were injected using ejaculated spermatozoa. The decreasing proportion of MII significantly reduced normal fertilization (two pronuclei) (78.9% to 71.3%; P < 0.0001) with a corresponding increase in digynic three-pronuclei that rose from 2.6% in the optimal group to 4.7% in the minimal group (P = 0.003). Implantation (33% to 17%; P < 0.0001), clinical pregnancy (63.6% to 37.5%; P < 0.0001) and live birth rates (49.2% to 26.6%; P < 0.0001) were affected by the decreasing proportion of MII oocytes.ConclusionsA high proportion of immature sibling oocytes in the retrieved cohort affects the fertilization rate and embryo developmental competence of MII inseminated oocytes, clinical pregnancy and live birth rates, suggesting that, in addition to nuclear maturity, ooplasmic and membrane maturity are required for developmental competence of MII oocytes. These findings may provide guidance toward ovarian stimulation protocols aimed at achieving a greater proportion of MII oocytes, leading to higher fertilization rates and better pregnancy outcomes.     

Unusual presentation of intradural endodermal cysts in young children under 2 years of age. Report of two cases

Introduction Spinal endodermal cysts are congenital maldevelopmental lesions usually presenting in early adulthood. Whereas the diagnosis is rare in newborns and it is usually led by cardiopulmonary distress or other associated malformations, no characteristic clinical findings associated with these entities have been described in older patients where spinal endodermal cysts usually behave as intraspinal space occupying lesions. Discussion The authors report on two children under 2 years of age affected by cervical endodermal cysts that presented with a history of acute motor deficit following a laryngitis. The hypothesis about the pathogenesis is that the upper respiratory tract infection might have stimulated the secretion of the cyst lining, inducing growth of the cyst and the sudden appearance of the motor deficit. Because of the apparent lack of relation between the benign laryngitis and the motor deficit, the occurrence of such an association might have been underestimated in some of the previously reported cases.