Cholelithiasis in children with sickle cell disease

Abdominal ultrasonography was performed on 305 children with sickle cell disease (SCD) (285 SS and 20 S-beta-thalassemia) to establish the prevalence of cholelithiasis in Saudi children with SCD. Their ages ranged from 1 to 18 years (mean 10.45 years). Gallstones were demonstrated in 60 children, giving a prevalence of 19.7%. An additional 50 patients (16.4%) had only biliary sludge. The youngest patient with gallstones was 3 years old. There was a correlation between the presence of gallstones and increasing age. Patients with gallstones were also found to have higher serum bilirubin levels, but their hemoglobin, hematocrit, reticulocyte count, hemoglobin S, and hemoglobin F levels were not significantly different from those of patients without gallstones.

Sonographic assessment of spleen size in Saudi patients with sickle cell disease

BACKGROUND

In patients with SCD, the spleen commonly enlarges during the first two decades of life but then undergoes autosplenectomy due to repeated attacks of vaso-occlusion and infarction. This, however, is not the case in Saudi patients with SCD, where splenomegaly sometimes persists into adult life.

PATIENTS AND METHODS

Ultrasonography was used to evaluate spleen size in 363 Saudi patients with SCD (340 SCD and 23 sickle I(2)-thalassemia). A total of 363 patients were evaluated. Their ages ranged from 1-60 years (mean 16 years).

RESULTS

Only 24 (6.6%) of our patients had autosplenectomy. The splenic index increased with age until about 40 years of age and then gradually decreased, indicating persistence of splenomegaly in our patients into an older age group. Forty-three patients (11.8%) had marked-massive splenomegaly (splenic index >120 cm 2) and these had higher HbF levels (mean HbF=22.2%) when compared with those who had autosplenectomy (mean HbF=14.6). This is significant (P-value=0.0169) and confirms the effect of HbF on persistence of splenomegaly in SCD patients.

CONCLUSIONS

Ultrasonography is a simple, safe and accurate method of assessing splenic size in patients with sickle cell disease. Patients with persistent splenomegaly should be followed closely for development of complications which may necessitate splenectomy.

Working title: Molecular involvement of p53-MDM2 interactome in gastrointestinal cancers

The interaction between murine double minute 2 (MDM2) and p53, marked by transcriptional induction and feedback inhibition, orchestrates a functional loop dictating cellular fate. The functional loop comprising p53-MDM2 axis is made up of an interactome consisting of approximately 81 proteins, which are spatio-temporally regulated and involved in DNA repair mechanisms. Biochemical and genetic alterations of the interactome result in dysregulation of the p53-mdm2 axis that leads to gastrointestinal (GI) cancers. A large subset of interactome is well known and it consists of proteins that either stabilize p53 or MDM2 and proteins that target the p53-MDM2 complex for ubiquitin-mediated destruction. Upstream signaling events brought about by growth factors and chemical messengers invoke a wide variety of posttranslational modifications in p53-MDM2 axis. Biochemical changes in the transactivation domain of p53 impact the energy landscape, induce conformational switching, alter interaction potential and could change solubility of p53 to redefine its co-localization, translocation and activity. A diverse set of chemical compounds mimic physiological effectors and simulate biochemical modifications of the p53-MDM2 interactome. p53-MDM2 interactome plays a crucial role in DNA damage and repair process. Genetic aberrations in the interactome, have resulted in cancers of GI tract (pancreas, liver, colorectal, gastric, biliary, and esophageal). We present in this article a review of the overall changes in the p53-MDM2 interactors and the effectors that form an epicenter for the development of next-generation molecules for understanding and targeting GI cancers.