The Impact of Active Site Mutations of South African HIV PR on Drug Resistance: Insight from Molecular Dynamics Simulations,Binding Free Energy and Per‐Residue Footprints

Molecular dynamics simulations and binding free energy calculations were used to provide an understanding of the impact of active site drug‐resistant mutations of the South African HIV protease subtype C (C‐SA HIV PR), V82A and V82F/I84V on drug resistance. Unique per‐residue interaction energy ‘footprints’ were developed to map the overall drug‐binding profiles for the wild type and mutants. Results confirmed that these mutations altered the overall binding landscape of the amino acid residues not only in the active site region but also in the flaps as well. Four FDA‐approved drugs were investigated in this study; these include ritonavir (RTV), saquinavir (SQV), indinavir (IDV), and nelfinavir (NFV). Computational results compared against experimental findings were found to be complementary. Against the V82F/I84V variant, saquinavir, indinavir, and nelfinavir lose remarkable entropic contributions relative to both wild‐type and V82A C‐SA HIV PRs. The per‐residue energy ‘footprints’ and the analysis of ligand–receptor interactions for the drug complexes with the wild type and mutants have also highlighted the nature of drug interactions. The data presented in this study will prove useful in the design of more potent inhibitors effective against drug‐resistant HIV strains.     

Neurocognitive Outcome and White Matter Anisotropy in Childhood Acute Lymphoblastic Leukemia Survivors Treated with Different Protocols

Neurocognitive outcome affects the quality of life of ALL survivors. This study is aimed to assess the prevalence of neurocognitive dysfunction by psychometric and imaging tools in survivors of childhood ALL, treated with 3 different protocols and the effect of time elapsed since the end of chemotherapy. Sixty-two ALL survivors aged 6–18 years and treated in the period 1997–2007 and 60 healthy age and sex matched controls were subjected to neurocognitive testing using Wechsler Intelligence Scale for Children, Benton visual retention (BVRT) and Trail Making test (TMT), followed by diffusion weighed and diffusion tensor MRI for calculation of fraction anisotropy (FA). Survivors underwent revision of protocol and type of CNS therapy. Three different protocols were used: modified BFM 83, BFM 90, and CCG. Survivors treated with modified CCG protocol showed a significant decrease in all cognitive tests compared to control (p<.05); BFM 90 group had a significant lower IQ and longer TMT compared to both control and BFM 83 group and no significant difference was found in results of cognitive tests between BFM 83 and control group. Frontal FA was lower in CCG treated group compared to control, BFM 90 and BFM 83 groups (p<.05); meanwhile it was significantly lower in BFM 90 and BFM 83 groups compared to control group. We concluded that patients treated with modified CCG protocol showed the worst neurocognitive outcome among three assessed protocols. Frontal lobe FA might be an early marker for predicting the neurotoxicity in childhood ALL survivors.     

Outcome of transcatheter aortic valve implantation in high risk patients with severe aortic stenosis

Aim

To assess outcome of TAVI in high risk patients with severe symptomatic aortic stenosis.

Efficacy of intralesional methotrexate in the treatment of plantar warts

Warts are tumors or growths caused by infection with human papilloma virus (HPV). Currently, over 170 HPV types have been identified. This study aimed to evaluate the efficacy and safety of intralesional injection of methotrexate (MTX) for the treatment of plantar warts. Sixty patients presented with plantar warts were divided into two groups. Group A patients were injected with intralesional MTX (2 mg/ml). Group B patients were injected with intralesional saline as a placebo. The injections were repeated every week for a maximum of six sessions or until complete clearance, whichever was earlier. The patients were followed up for 6 months after the last injection. In the intralesional MTX group, 2 patients (6.7%) showed complete improvement, 8 patients (26.7%) showed partial improvement, and 20 patients (66.7%) showed no improvement. In the intralesional saline group, 3 patients (10%) showed complete improvement, 4 patients (13.3%) showed partial improvement, and 23 patients (76.7%) showed no improvement. Reported adverse events were local reactions in the form of swelling, pain, and infection in both groups. There was no statistically significant difference between the therapeutic responses to intralesional MTX injection and saline.     

Clinical Implication of Toll-Like Receptors (TLR2 and TLR4) in Acute Myeloid Leukemia Patients

Backgrounds: Toll-like receptors 2; 4 (TLR2;4) are an essential component of the innate immunity and play an important role in immune-surveillance and immune response to various microorganisms. This study aimed to investigate the association between TLR2 and TLR4 polymorphism and the risk of acquiring severe infections, and impact on AML patient’s outcome. Subjects and methods: Using polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP); we analyzed three SNPs in the TLR2 (Arg753Gln) and TLR4 (Asp299Gly and Thr399Ile) in 120 AML patients and 100 healthy control subjects. Results: No significant differences in genotype or alleles frequency between healthy controls and AML patients regarding TLR2 Arg753Gln, TLR4 Asp299Gly and TLR4 Thr399Ile polymorphisms (P>0.05 for all). Neutropenic fever was detected in 110 out of 120 (91.7%) of the studied AML patients. The sepsis and pneumonia were identified in 20 out of 120 patients (16.7%). The incidence of sepsis was associated with TLR2 Arg753Gln: AG genotypes, A allele and TLR4 Asp299Gly: CT genotype and C allele as compared to other genotypes and alleles. Moreover; TLR2 (Arg753Gln) GG polymorphisms significantly associated with shortest overall survival (OS) and shortest disease-free survival (DFS); while TLR4 polymorphisms affect the DSF only but not OS. In AML patients TLR2 Arg753Gln gene polymorphism is associated with high susceptibility to sepsis and TLR4 (Asp299Gly and Thr399Ile) gene polymorphism is associated with high susceptibility for both pneumonia; and sepsis. Conclusion: TLR2 Arg753Gln (AG; GG genotype) polymorphisms are associated with shortest OS and DFS. Moreover; significant association between TLR2 polymorphisms, TLR4 Arg753Gln polymorphisms and risk of severe infections in AML patients was documented.     

Pharmacovigilance in developing countries (part I): importance and challenges

The thalidomide disaster was the significant historical event that acted as a catalyst for pharmacovigilance activity. Following this event developed countries initiated drug monitoring systems that evolved and now extend their scope to broader drug-related safety issues; however, this was not the case in developing countries. Pharmacovigilance is still a relatively new concept with low priority in developing countries although various issues are raising concerns that magnify the need for systems to monitor post marketing drug safety in these countries. This article analyzes the barriers to introducing robust pharmacovigilance systems in developing countries.     

Hepatitis E virus coinfection with hepatotropic viruses in Egyptian children

BACKGROUND AND PURPOSE: Major hepatotropic viruses continue to be important causes of acute viral hepatitis in developing countries. This work was carried out to detect the seroprevalence of hepatitis E virus (HEV) markers in children with acute viral hepatitis due to hepatotropic viruses (A, B and C) and non-A, non-B, non-C acute hepatitis, and to ascertain the influence of HEV superinfection in individuals infected with hepatitis viruses (A, B and C). METHODS: We studied prospectively 162 children with sporadic acute hepatitis who reported to our hospital. Thirteen healthy controls were also included in the study. Laboratory investigations were performed, including complete liver function tests. Complete serological profiles for hepatitis viruses A, B, C and E were evaluated. RESULTS: HEV immunoglobulin G was detected with highest percentage among patients with hepatitis B (56.7%), followed by patients with hepatitis C virus (52.0%), hepatitis A virus (34.1%) and combined hepatitis B and C viruses (30.0%). The detection rate among patients with non-A, non-B, non-C hepatitis was 7.1%. HEV immunoglobulin M was found in 4.5% of hepatitis A virus patients and in 3.3% of hepatitis B patients. The prevalence of HEV immunoglobulin G and immunoglobulin M correlated with the levels of hepatic aspartate aminotransferase and alanine aminotransferase in patients with dual markers of infection with hepatitis E and other viruses compared to patients with acute hepatitis due to A and C viruses. CONCLUSIONS: HEV serological markers are common among children with acute viral hepatitis, especially from hepatitis C and B viruses. There may be increased sensitivity to HEV coinfection in association with hepatitis B and C infections. Dual infection with HEV and other hepatotropic viruses was associated with greater elevation of aspartate and alanine aminotransferases.