Structural requirements for imidazo[1,2-a]pyrazine derivatives as Aurora A kinase inhibitors and validation of the model

Aurora kinases belong to the family of serine/threonine kinases. They are divided into three subclasses, Aurora A kinase, Aurora B kinase, and Aurora C kinase and are reported to be vital for cell proliferation. Abnormal expression of these enzymes leads to cancer. Predictive CoMFA and CoMSIA based quantitative structure activity relationship models have been developed on 51 imidazo[1,2-a]pyrazine derivatives reported previously by Merck Research Laboratories. AutoDock was used for docking of the most active compound (34) and the conformation thus obtained was used for the alignment of 3D structures. The developed (CoMSIA-SEHD) model showed good predictive ability with predictive squared correlation coefficient (r ²) value of 0.752. The best model was validated systematically using different validation parameters. The CoMSIA model gave useful information to understand features required to modify and develop new potential Aurora kinase inhibitors.     

Role of tumor necrosis factor inhibitor in granulomatous interstitial nephritis secondary to Crohn’s disease

A 17-year-old male with attention deficit hyperactivity disorder was admitted to the hospital with generalized weakness. Vital signs and physical examination were normal. Laboratory data were notable for a creatinine of 4.5 mg/dL (baseline 0.6 mg/dL), estimated glomerular filtration rate of 18 ml/min/1.73 m² and hemoglobin 10 g/dL. Urinalysis revealed only 30 mg/dL protein. Serology for autoimmune workup was negative. Renal ultrasound was normal. Kidney biopsy showed noncaseating granulomas and acute on chronic tubulointerstitial nephritis (TIN) with lymphocytes, macrophages, plasma cells and no eosinophils. Acid fast bacilli and Grocott’s methenamine silver stains were negative. Granulomatous interstitial nephritis (GIN) was diagnosed. Prednisone at 60 mg/day was started and tapered. He was then noted to have diarrhea. Colonoscopy showed active enteritis with granulomatous inflammation consistent with Crohn’s disease (CD). Azathioprine was started but due to worsening renal function and diarrhea, it was discontinued. He did not tolerate continued higher doses of prednisone because of mood swings and cushingoid features. Infliximab was initiated with improvement in renal function. There was rapid worsening of renal function when infliximab therapy was interrupted but improved when both prednisone and inflixamb were reinitiated.     

Chronic meningitis in systemic lupus erythematosus: An unusual etiology

Chronic aseptic meningitis is a rare manifestation of systemic lupus erythematosus (SLE). Apart from immunological causes and drugs, the aseptic meningitis group can include some unidentified viral infections that cannot be detected by routine microbiological testing. It is imperative to do complete cerebrospinal fluid (CSF) workup before implicating the symptoms to disease activity or drugs, as untreated infections cause significant mortality in SLE. We present a case of young female with SLE who presented with chronic meningitis of an uncommon etiology.     

Diverticular per oral endoscopic myotomy (DPOEM) for esophageal diverticular disease: a systematic review and meta-analysis

The traditional way to tackle Zenker’s diverticulum (ZD) has been flexible endoscopic septum division (FESD). Recently, the concept of per oral endoscopic myotomy has been found useful for managing diverticular diseases of the esophagus and has been termed DPOEM. We performed a systematic review and meta-analysis to evaluate the efficacy and safety of D-POEM in diverticular disease of the esophagus and to compare it with FESD. We systematically searched PubMed and Embase, for studies reporting clinical success, technical success and adverse events in D-POEM alone or D-POEM comparing with FESD. We computed pooled prevalence for D-POEM alone and risk ratio for D-POEM vs FESD using random effect method with inverse variance approach. Subgroup analysis for ZD, non-ZD and mixed diverticulum was conducted. Totally 19 studies including 341 patients were identified reporting on D-POEM. The pooled clinical, technical success and adverse event rates for D-POEM were 87.07%, 95.19% and 10.22%, respectively. The clinical success was significantly better than FESD while the technical success, adverse event rate, procedure time and length of hospital stay were comparable with FESD. The recurrence rate was negligible for D-POEM compared to FESD. On subgroup analysis by dividing into three groups of ZD, non-ZD and mixed, there was no difference between clinical, technical success and adverse event rate among the three groups. D-POEM is an effective and safe technique among both ZD and non-ZD patients and has better clinical success than FESD.

     

Genetics of P450 oxidoreductase: sequence variation in 842 individuals of four ethnicities and activities of 15 missense mutations

P450 oxidoreductase (POR) is an electron-donating flavoprotein required for the activity of all microsomal cytochrome P450 enzymes. We sequenced 5,655 bp of the POR gene in a representative population of 842 healthy unrelated individuals in four ethnic groups: 218 African Americans, 260 Caucasian Americans, 179 Chinese Americans, and 185 Mexican Americans. One hundred forty SNPs were detected, of which 43 were found in >/=1% of alleles. Twelve SNPs were in the POR promoter region. Fifteen of 32 exonic variations altered the POR amino acid sequence; 13 of these 15 are previously undescribed missense variations. We found eight indels, only one of which was in the coding region. A previously described variant, A503V, was found on 27.9% of all alleles with some ethnic predilection (19.1% in African Americans, 26.4% in Caucasian Americans, 36.7% Chinese Americans, and 31.0% in Mexican Americans). We built cDNA expression vectors for the 13 previously undescribed missense variants, expressed each protein lacking 27 N-terminal residues in Escherichia coli, and assayed the apparent K(m) and V(max) of each in four assays: reduction of cytochrome c, oxidation of NADPH, 17alpha-hydroxylase activity of P450c17, and 17,20 lyase activity of P450c17. The catalytic activities of several missense mutants differed substantially in these assays, indicating that each POR mutant must be assayed separately with each potential target P450 enzyme. The activity of A503V was reduced to a modest but statistically significant degree in all four assays, suggesting that it may play an important role in interindividual variation in drug response.     

Correlating surgical clerkship evaluations with performance on the National Board of Medical Examiners examination

Background

Evaluation of medical students during the surgical clerkship is controversial. Performance is often based on subjective scoring, whereas objective knowledge is based on written examinations. Whether these measures correspond or are relevant to assess student performance is unknown. We hypothesized that student evaluations correlate with performance on the National Board Of Medical Examiners (NBME) examination.

Methods

Data were collected from the 2011–2012 academic year. Medical students underwent a ward evaluation using a seven-point Likert scale assessing six educational competencies. Students also undertook the NBME examination, where performance was recorded as a percentile score adjusted to national standards.

Results

A total of 129 medical students were studied. Scores on the NBME ranged from the 52nd to the 96th percentile with an average in the 75th percentile (±9). Clerkship scores ranged from 3.2–7.0 with a mean of 5.7 (±0.8). There was a strong positive association between higher NBME scores and higher clerkship evaluations shown by a Pearson correlation coefficient of 0.47 (P < 0.001). Students clustered with below average ward evaluations (3.0–4.0) were in the 69.5th percentile of NBME scores, whereas students clustered with above average ward evaluations (6.0–7.0) were in the 79.2th percentile (P < 0.001).

Conclusions

A strong positive relationship exists between subjective ward evaluations and NBME performance. These data may afford some confidence to surgical faculty and surgical resident ability to accurately evaluate medical students during clinical clerkships. Understanding factors in student performance may help in improving the surgical clerkship experience.     

Angiographic success and procedural complications in patients undergoing retrograde percutaneous coronary chronic total occlusion interventions: A weighted meta-analysis of 3482 patients from 26 studies

Background

The efficacy and safety profile of retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study. We sought to perform a weighted meta-analysis of the success and complication rates of retrograde CTO PCI.

Methods

We conducted a meta-analysis of 26 studies published between 2006 and April 2013 reporting in-hospital outcomes of retrograde CTO PCI. Data on procedural success, frequency of death, emergent coronary artery bypass graft surgery (CABG), stroke, myocardial infarction (MI), perforation, tamponade, stent thrombosis, major vascular or bleeding events, contrast nephropathy, and radiation skin injury were collected.

Results

A total of 26 studies with 3482 patients and 3493 target CTO lesions were included. Primary retrograde CTO PCI was attempted in 52.4%. Pooled estimates of outcomes were as follows: procedural success 83.3% [95% confidence interval (CI): 79.0% to 87.7%]; death 0.7% (95% CI: 0.5% to 1.2%); urgent CABG 0.7% (95% CI: 0.4% to 1.2%); tamponade 1.4% (95% CI: 1.0% to 2.2%); collateral perforation 6.9% (95% CI: 4.6% to 10.4%); coronary perforation 4.3% (95% CI: 1.2% to 15.4%); donor vessel dissection 2% (95% CI: 0.9% to 4.5%); stroke 0.5% (95% CI: 0.2% to 1.0%); MI 3.1% (95% CI: 0.2% to 5.0%); Q wave MI 0.6% (95% CI: 0.4% to 1.1%); vascular access complications 2% (95% CI: 0.9% to 4.5%); contrast nephropathy 1.8% (95% CI: 0.8% to 3.7%); and wire fracture and equipment entrapment 1.2% (95% CI: 0.6% to 2.5%).

Conclusions

Retrograde CTO PCI is associated with high procedural success rate and acceptable risk for procedural complications.