Acquired Left Atrial-to-Right Ventricular Shunt with Mitral Valve Incompetence: A Rare Sequela after Repair of Atrioventricular Septal Defect

Acquired left ventricular-to-right atrial communication is encountered periodically. This condition is chiefly attributable to surgical mishaps, trauma, endocarditis, or endomyocardial biopsy. In a few instances, a Gerbode-like defect develops after the repair of an atrioventricular septal defect. Our search of the worldwide medical literature revealed just 1 report of a “mirror” occurrence of a Gerbode-like defect: a shunt between the left atrium and the right ventricle.Herein, we present the case of a 22-year-old woman who had severe mitral valve incompetence accompanying an acquired shunt between the left atrium and the right ventricle—a late sequela of the earlier repair of an atrioventricular septal defect. After surgical correction of the shunt and the associated mitral incompetence, the patient experienced a good outcome.Echocardiographic and intraoperative findings are presented, along with a plausible explanation for the mechanism and presentation of the condition in our patient. To our knowledge, this is only the 2nd report of an acquired shunt between the left atrium and the right ventricle, and the 1st such case to be accompanied by severe mitral valve incompetence.Key words: Cardiac surgical procedures, cardiomyopathies/etiology/ultrasonography, heart septal defects, atrial/physiopathology/surgery/ultrasonography, heart septal defects, ventricular/complications, postoperative complications/etiology, mitral valve insufficiency/etiology/surgery, reoperation, time factors, treatment outcomeAcquired left ventricular-to-right atrial communications are encountered from time to time. These are chiefly attributable to surgical mishaps, trauma, endocarditis, or even endomyocardial biopsy.¹ A few cases are on record wherein endocarditis was thought to have led to a Gerbode-like defect after the repair of an atrioventricular septal defect (AVSD).² However, we could find just 1 report of an acquired shunt between the left atrium (LA) and the right ventricle (RV).³ Here, we report a 2nd such case, that of a 22-year-old woman who also had late-onset severe mitral valve regurgitation. A point of interest is not merely the rare occurrence of this condition, but also the quest for a plausible explanation for its mechanism and presentation.     

Glioma test array for use with formalin-fixed, paraffin-embedded tissue: array comparative genomic hybridization correlates with loss of heterozygosity and fluorescence in situ hybridization

Array-based comparative genomic hybridization (aCGH) is a powerful, high-throughput tool for whole genome analysis. Until recently, aCGH could only be reproducibly performed on frozen tissue samples and with significant tissue amounts. For brain tumors however, paraffin-embedded tissue blocks from small stereotactic biopsies may be the only tissue routinely available. The development of methods to analyze formalin-fixed, paraffin-embedded (FFPE) material therefore has the potential to impact molecular diagnosis in a significant way. To this end, we constructed a BAC array representing chromosomes 1, 7, 19, and X because 1p/19q deletion and EGFR gene amplification provide clinically relevant information for glioma diagnosis. We also optimized a two-step labeling procedure using an amine-modified nucleotide for generating aCGH probes. Using this approach, we analyzed a series of 28 FFPE oligodendroglial tumors for alterations of chromosomes 1, 7, and 19. We also independently assayed these tumors for 1p/19q deletion by fluorescence in situ hybridization and by loss of heterozygosity analyses. The concordance between aCGH, standard loss of heterozygosity and fluorescence in situ hybridization was nearly 100% for the chromosomes analyzed. These results suggest that aCGH could offer an improved molecular diagnostic approach for gliomas because of its ability to detect clinically relevant molecular alterations in small FFPE specimens.     

Epidemiologic, experimental, and clinical links between respiratory syncytial virus infection and asthma

Virtually all children experience respiratory syncytial virus (RSV) infection at least once during the first 2 years of life, but only a few develop bronchiolitis and more severe disease requiring hospitalization, usually in the first 6 months of life. Children who recover from RSV-induced bronchiolitis are at increased risk for the development of recurrent wheeze and asthma in later childhood. Recent studies suggest that there is an association between RSV-induced bronchiolitis and asthma within the first decade of life but that this association is not significant after age 13. Despite the considerable progress made in our understanding of several aspects of respiratory viral infections, further work needs to be done to clarify the molecular mechanisms of early interactions between virus and host cell and the role of host gene products in the infection process. This review provides a critical appraisal of the literature in epidemiology and experimental research which links RSV infection to asthma. Studies to date demonstrate that there is a significant association between RSV infection and childhood asthma and that preventing severe primary RSV infections can decrease the risk of childhood asthma.     

Diagnostic dilemma of antineutrophil cytoplasmic antibody seropositivity in human immunodeficiency virus infection

We present a case of a 48-year-old male who was diagnosed and treated for Wegener's granulomatosis on the basis of history, clinical features, computed tomography (CT) and antineutrophil cytoplasmic antibodies (ANCA) positivity. The patient initially improved and later on during course of the disease he was found to be human immunodeficiency virus (HIV) seropositive. The potential pitfalls of cANCA in a HIV-infected patient are discussed.     

Evaluation of the performance of nitrate reductase assay for rapid drug-susceptibility testing of mycobacterium tuberculosis in north India

The objective of the study was to evaluate the performance of nitrate reductase assay (NRA) as a rapid, reliable and inexpensive method for drug-susceptibility testing (DST) of Mycobacterium tuberculosis against first-line antitubercular drugs, such as rifampicin (RIF), isoniazid (INH), streptomycin (STR), and ethambutol (EMB). In total, 286 isolates were subjected to test by proportion method (PM) and NRA. By comparing the results of NRA with those of the gold standard PM, sensitivities and specificities were 98.4%, 97%, 88.5%, and 94.2% and 100%, 100%, 94%, and 99% for RIF, INH, STR, and EMB respectively. The positive predictive values were 100%, 100%, 95%, and 98% for RIF, INH, STR, and EMB respectively. The negative values were 99%, 98%, 87%, and 96% for RIF, INH, STR, and EMB respectively. The median time of obtaining results was shorter using NRA (10 days) compared to PM (28 days). An excellent agreement was observed between the two phenotypic tests with the K values of 0.98, 0.97, 0.81, and 0.93 for RIF, INH, STR, and EMB respectively. The results demonstrated that NRA is suitable for the early determination of INH and RIF resistance and has the potential to be a useful tool for rapid drug-sensitivity test of M. tuberculosis in resource-constrained settings.     

Locking versus non-locking plating system in the treatment of mandibular fractures: A randomized comparative study

To evaluate fracture stability and complications such as infections, need for hardware removal, malunion, and nonunion when using 2.0-mm locking plating system in fixation of mandible fractures and to compare these to those associated with the 2.0-mm non-locking plating system.A prospective clinical study was conducted in a cohort of mandible fracture patients who were randomly assigned to two groups. Patients in the non-locking group were treated with 2.0-mm non-locking plating system, and those in locking group were treated with 2.0-mm locking plating system. Fracture stability, need for maxillomandibular fixation (MMF) and postoperative complications were assessed and compared.A total of 60 patients (30 in each group) were recruited. Significant differences were found between the two groups with respect to postoperative fracture stability (P = 0.001) and need for MMF (P = 0.005). Multivariate analysis revealed that type of fixation was not the only dependent variable which affected fracture stability. There were no significant differences in postoperative complications between the two groups.The 2.0-mm locking plating system provides greater stability and early functional restoration than the 2.0-mm non-locking plating system, with similar rates of postoperative complications. Thus, it can be used as a reliable and effective treatment modality for treating mandibular fractures.     

High Prevalence of Biofilm-Forming MRSA in the Conjunctival Flora in Chronic Dacryocystitis

Objectives: To report the microbiological spectrum of conjunctival flora and prevalence of biofilm-forming Methicillin-resistant Staphylococcus aureus (MRSA) in conjunctival flora in chronic dacryocystitis.

Design: Prospective, case-control study.

Methods: We included patients with unilateral chronic dacryocystitis, and their unaffected eyes as control. Microbiological profile and antibiotic susceptibility of the isolates was determined by standard microbiological procedures. S. aureus isolates were further evaluated for Methicillin resistance by Oxacillin resistance screening agar method and mecA polymerase chain reaction (PCR) and for biofilm synthesis by Congo red agar method, Microtitre plate (MTP) assay, and ica A and ica D PCR.

Results: We found 95 patients with unilateral chronic dacryocystitis. Aerobic Gram-positive isolates (74.2%, n = 72) were more than Gram-negative (25.7%, n = 25) or anaerobic isolates (20.5%, n = 25). S. aureus was most common (46.4%, n = 45), followed by Pseudomonas aeruginosa (10.3%, n = 10). Gram-positive isolates showed highest sensitivity to Linezolid (100%) and higher generation fluoroquinolones. Gram-negative isolates showed good sensitivity (>90%) to all tested antibiotics. S. aureus isolates showed MRSA prevalence as 93.5% and 96.9% by Oxacillin resistance screening agar method and mecA PCR, respectively. Biofilm formation was found in 71.8% MRSA isolates by MTP assay and 58.1% MRSA isolates were resistant to ≥3 classes of antibiotics.

Conclusions: Gram-positive organisms, specifically S. aureus, are the major etiological agent in chronic dacryocystitis. There is high prevalence of MRSA in these isolates and concurrent biofilm formation.     

Potential of mesenchymal stem cells alone,or in combination,to treat traumatic brain injury

Traumatic brain injury (TBI) causes death and disability in the United States and around the world. The traumatic insult causes the mechanical injury of the brain and primary cellular death. While a comprehensive pathological mechanism of TBI is still lacking, the focus of the TBI research is concentrated on understanding the pathophysiology and developing suitable therapeutic approaches. Given the complexities in pathophysiology involving interconnected immunologic, inflammatory, and neurological cascades occurring after TBI, the therapies directed to a single mechanism fail in the clinical trials. This has led to the development of the paradigm of a combination therapeutic approach against TBI. While there are no drugs available for the treatment of TBI, stem cell therapy has shown promising results in preclinical studies. But, the success of the therapy depends on the survival of the stem cells, which are limited by several factors including route of administration, health of the administered cells, and inflammatory microenvironment of the injured brain. Reducing the inflammation prior to cell administration may provide a better outcome of cell therapy following TBI. This review is focused on different therapeutic approaches of TBI and the present status of the clinical trials.