Damaged chromatin does not prevent the exit from metaphase I in fused mouse oocytes

The presence of checkpoint mechanisms which are able to recognize damaged chromatin and thereafter to prevent exit from metaphase I has been investigated in giant mouse oocytes produced by fusion of a normal metaphase I oocyte with an equivalent oocyte with damaged chromatin. The presence of damaged chromatin did not prevent the onset of anaphase I in both sets of chromatin in the fused cells. Interestingly, fused or unfused cells containing only damaged chromatin failed to enter anaphase and persisted instead in a metaphase-like state. These results demonstrate the fragility of checkpoint controls in mammalian female germ cells.      

Hepatoprotective treatment attenuates oxidative damages induced by carbon tetrachloride in rats

The present study evaluated the hepatoprotective effect of an N-acetyl dl-methionine + choline chloride + caffeine + thiamine hydrochloride + nicotinamide + pyridoxine hydrochloride compound at doses of 0.2, 0.6 and 1.0 mL/kg of b.w., and the assessment was done by the investigation of serum-enzymatic activity, metabolic functions of the liver and histophatological changes in female Wistar rats, which were subjected to experimental intoxication with CCl₄. One hundred and nineteen rats were randomly distributed into 17 groups, performing five different treatments, being evaluated seven animals per treatment in four periods: 2, 4, 6 and 8 days after CCl₄-induced intoxication. Treated rats with the hepatoprotective medicine (HM) presented a significant reduction in infiltration of inflammatory cells, steatosis, necrosis and liver congestion when compared to non-treated rats (control). Beside these results, the treatment showed a positive effect on circulatory alterations in the intoxicated animals, with reduction of spleen and renal congestion, as well as, promotion of a significant improvement in ALT, AST, LDH, ALP, GGT enzymatic serum activity reduction and in recovering liver function regarding the metabolism of urea, triglycerides and glucose. These findings indicate therapeutic usefulness of the compound when administered at dose 0.6 and 1.0 mL/kg of b.w. in female Wistar rats.     

Thrombopoietin stimulates colony-forming unit-megakaryocyte proliferation and megakaryocyte maturation independently of cytokines that signal through the gp130 receptor subunit

Thrombopoietin (Tpo), the ligand for the c-Mpl receptor, is a major regulator of megakaryopoiesis. Treatment of mice with Tpo raises the platelet count fourfold within a few days. Conversely, c-mpl knock-out mice have platelet counts that are 15% that of normal. The subunit structure of the c-Mpl receptor is not fully understood. Some cytokines that stimulate megakaryopoiesis (IL-6, IL-11, leukemia inhibitory factor, and oncostatin M) bind to receptors that use gp130 as a signal transduction subunit. For these reasons, we determined whether gp130 function was required for Tpo-induced signal transduction. Murine marrow cells were cultured in semi-solid media in the presence of Tpo or IL-3, with or without a neutralizing anti-gp130 monoclonal antibody (RX187) or a soluble form of c-Mpl receptor (soluble Mpl) that blocks Tpo bioactivity, and the numbers of colony-forming unit-megakaryocyte (CFU-Meg) colonies were counted on day 5. Murine marrow cells were also cultured in suspension under serum-free conditions for 5 days, and megakaryocyte DNA content was measured by flow cytometry, as an index of nuclear maturation. The addition of RX187 did not block Tpo-induced CFU-Meg colony growth nor CFU-Meg nuclear maturation in suspension culture. However, IL-3-induced CFU-Meg colony growth and megakaryocyte nuclear maturation decreased in the presence of RX187. Soluble Mpl completely ablated Tpo-induced CFU-Meg growth, and partially blocked IL- 3-stimulated CFU-Meg growth. Thus the effects of Tpo on megakaryopoiesis in vitro do not depend on cytokines that signal through gp130. Furthermore, it is unlikely that gp 130 serves as a beta chain for the c-Mpl receptor, as Tpo signalling is unimpaired in the presence of RX187. In contrast, the effects of IL-3 on CFU-Meg growth are mediated in part through Tpo and through gp130-signalling cytokines.     

A double mobility acetabular implant for primary hip arthroplasty in patients at high risk of dislocation

IntroductionDislocation following total hip replacement continues to be a problem for which no completely satisfactory solution has been found. Several methods have been proposed to reduce the incidence of hip dislocations with varying degrees of success, including elevated rim liners, constrained liners and large diameter bearings. We present our experience with the double mobility acetabular component in patients at high risk of instability.MethodsThis was a retrospective review of 65 primary total hip arthroplasties in 55 patients (15 men, 40 women), performed between October 2005 and November 2009. The majority (80%) of patients had at least two and 26% had at least three risk factors for instability. The mean age was 76 years (range: 44–92 years). The patients were followed up for a mean duration of 60 months (range: 36–85 months).ResultsFourteen patients died and one was lost to follow-up, leaving fifty hips for final assessment. Until the final follow-up appointment, no patients had dislocation and none required revision surgery. The mean Oxford hip score improved from 45.0 to 26.5 (p<0.0001). The mean Merle d’Aubigné pain score improved from 1.4 to 4.9 (p<0.0001), the walking score from 2.3 to 3.1 (p<0.07) and the absolute hip function score from 5.4 to 10.8 (p<0.0001). There were no clinical or radiographic signs of loosening.ConclusionsThe double mobility acetabular component was successful at preventing dislocation during early to medium-term follow-up. However, as data are still lacking with regard to polyethylene wear rates at the additional bearing surface, it would be prudent to restrict the use of this implant to selected patients at high risk of instability.     

Colonic duplication in an adult mimicking a tumor of pancreas

Duplications of the alimentary tract are uncommon congenital malformations that can present diagnostic difficulties. We report a rare case of a cystic colonic duplication in a female adult. Preoperative investigations were suggestive of pancreatic tumor. The diagnosis was established based on the histopathological examination of the resected specimen. We concluded that, though uncommon, intestinal duplication should be considered in differential diagnosis of abdominal mass.