The impact of surveillance and rapid reduction in immunosuppression to control BK virus‐related graft injury in kidney transplantation

We prospectively screened 609 consecutive kidney (538) and kidney‐pancreas (71) transplant recipients for BK viremia over a 4‐year interval using polymerase chain reaction viral load detection and protocol kidney biopsies. We found that BK viremia is common at our center: total cases 26.7%, cases during first year 21.3% (mean 4 months), and recipients with ≥10 000 copies/ml 12.3%. We found few predictive clinical or demographic risk factors for any BK viremia or viral loads ≥10,000 copies/ml, other than prior treatment of biopsy confirmed acute rejection and/or higher immunosuppressive blood levels of tacrolimus (P = 0.001) or mycophenolate mofetil (P = 0.007). Viral loads at diagnosis (<10 000 copies/ml) demonstrated little impact on graft function or survival. However, rising copy numbers demand early reductions in immunosuppressive drug doses of at least 30–50%. Viral loads >185 000 copies/ml at diagnosis were predictive of BK virus‐associated nephropathy (BKVAN; OR: 113.25, 95% CI: 17.22–744.6, P < 0.001). Surveillance for BK viremia and rapid reduction of immunosuppression limited the incidence of BKVAN to 1.3%. The addition of leflunomide or ciprofloxacin to immunosuppressive dose reduction did not result in greater rates of viral clearance. These data support the role of early surveillance for BK viremia to limit the impact on transplant outcome, although the most effective schedule for screening awaits further investigation.     

Copper mediated one-pot synthesis of quinazolinones and exploration of piperazine linked quinazoline derivatives as anti-mycobacterial agents

A facile method was developed for the synthesis of quinazolinone derivatives in a one-pot condensation reaction via in situ amine generation using ammonia as the amine source and with the formation of four new C–N bonds in good to excellent yields. With the optimised method, we synthesized a library of piperazine linked quinazoline derivatives and the synthesized compounds were evaluated for their inhibitory activity against Mycobacterium tuberculosis. The compounds 8b, 8e, 8f, 8m, 8n and 8v showed potent anti-mycobacterial activity with MIC values of 2–16 μg mL⁻¹. All the synthesized compounds follow Lipinski''s rules for drug likeness.

A facile method was developed for the synthesis of quinazolinone derivatives in a one-pot condensation reaction via in situ amine generation using ammonia as the amine source and with the formation of four new C–N bonds in good to excellent yields.     

Living donor liver transplantation for biliary atresia – An Indian experience

LT has played a significant role in improving the outcome of children with BA. We review our five‐yr experience of LDLT for children with BA. Records of all children who underwent LDLT in our institution over a five‐yr period (August 2010–June 2015) were reviewed and those with a primary diagnosis of BA were selected for our study. Data were extracted from a prospectively maintained database. Additional data were collected by review of case notes and imaging studies. Analysis was carried out using standard statistical means. One hundred and thirty‐two children underwent LDLT at our center over the study period, of which 58 children (31 females) had a primary diagnosis of BA. Thirty‐three (56.9%) children had undergone a prior KPE and 25 (43.1%) had a primary LT. Thirty‐four children had at least one post‐op complication, of which 13 had minor complications (Clavien grades I and II) and 21 had major complications (Clavien grade >II). Thirty‐day survival was 96.6% and one‐yr survival was 91.4%. Univariate analysis of variables comparing children who did and did not have a KPE prior to LT showed that age at LT, weight at LT, PELD, and GRWR were significantly different. LDLT provides excellent outcomes in children with BA. Primary LDLT and LT after KPE provide equivalent results, although the former is technically more challenging as the child is younger.     

A case of rhabdomyosarcoma masquerading as acute leukemia at presentation: a case report

Non-hematopoietic malignancies infiltrating bone marrow have always been a source of erroneous diagnosis. Among these, the small round cell tumors like neuroblastomas and rhabdomyosarcomas mimick the hematopoietic blasts. Several case reports of rhabdomyosarcoma mimicking acute leukemia, clinically and morphologically at presentation have been reported in the literature. To the best of our knowledge such an entity has not been reported in Indian literature. We report here one such case of alveolar rhabdomyosarcoma masquerading as acute leukemia. A thorough clinical examination with high degree of suspicion on bone marrow morphology and judicious use of appropriate immunohistochemistry markers will solve many of these cases.     

Transition towards antigen-binding promiscuity of a monospecific antibody

Polyspecificity is defined as the ability of a given antibody molecule to bind a large panel of structurally diverse antigens. A fraction of circulating IgG in all healthy individuals acquires promiscuous antigen-binding activity only after a transient exposure to certain protein destabilizing factors. The molecular mechanisms of this phenomenon are not well understood. Exposures to protein destabilizing agents are common steps in immunoglobulin isolation and purification processes. We performed kinetic and thermodynamic analyses using surface plasmon resonance-based technique in order to characterize the interactions of a single mouse monoclonal antibody to its cognate antigen before and after induction of promiscuous antigen-binding activity. The obtained results, suggest that enhanced antigen binding activity induced by exposure to mild denaturing condition resulted from an increase in the structural flexibility of the antigen-binding site. Further pH and ionic strength-dependence analyses of the antibody/antigen interactions demonstrated that the transition to promiscuous antigen-binding was accompanied by a change in the type of non-covalent forces involved in the complex formation. Moreover, from this study, it is evident that an antibody molecule could use two distinct thermodynamic pathways for binding to the same antigen while retaining the same value of the binding affinity. The obtained results may contribute to the understanding of the molecular mechanisms that lay behind natural antibody polyspecificity.