Persistent fifth aortic arch: the "great pretender" in clinical practice.

Persistence of the embryonic "fifth aortic arch" in postnatal life is a rare, enigmatic - and at times controversial - condition, with variable anatomical forms and physiological consequences. First described in humans over 40 years ago by Van Praagh, the condition was labelled the "great pretender" by Gerlis 25 years later, because of its apparent propensity to mimic anatomically similar structures. Despite many subsequent case reports citing the condition, the true developmental origin of these structures remains unresolved, and has been the subject of debate among embryologists for more than a century. A persistent fifth aortic arch has been defined as an extrapericardial structure, arising from the ascending aorta opposite or proximal to the brachiocephalic artery, and terminating in the dorsal aorta or pulmonary arteries via a persistently patent arterial duct. This description may therefore encompass various anatomical forms, such as a unilateral double-lumen aortic arch, an unrestrictive aortopulmonary shunt, or a critical vascular channel for either the systemic or pulmonary circulation. The physiological properties of these vessels, such as their response to prostaglandins, may also be unpredictable. In this article, we demonstrate a number of cases that fulfil the contemporary definition of "persistent fifth aortic arch" while acknowledging the embryological controversies associated with this term. We also outline the key diagnostic features, particularly with respect to the use of new cross-sectional imaging techniques.

Tackling breast cancer with gold nanoparticles: twinning synthesis and particle engineering with efficacy.

The World Health Organization identifies breast cancer as the most prevalent cancer despite predominantly affecting women. Surgery, hormonal therapy, chemotherapy, and radiation therapy are the current treatment modalities. Site-directed nanotherapeutics, engineered with multidimensional functionality are now the frontrunners in breast cancer diagnosis and treatment. Gold nanoparticles with their unique colloidal, optical, quantum, magnetic, mechanical, and electrical properties have become the most valuable weapon in this arsenal. Their advantages include facile modulation of shape and size, a high degree of reproducibility and stability, biocompatibility, and ease of particle engineering to induce multifunctionality. Additionally, the surface plasmon oscillation and high atomic number of gold provide distinct advantages for tailor-made diagnosis, therapy or theranostic applications in breast cancer such as photothermal therapy, radiotherapy, molecular labeling, imaging, and sensing. Although pre-clinical and clinical data are promising for nano-dimensional gold, their clinical translation is hampered by toxicity signs in major organs like the liver, kidneys and spleen. This has instigated global scientific brainstorming to explore feasible particle synthesis and engineering techniques to simultaneously improve the efficacy and versatility and widen the safety window of gold nanoparticles. The present work marks the first study on gold nanoparticle design and maneuvering techniques, elucidating their impact on the pharmacodynamics character and providing a clear-cut scientific roadmap for their fast-track entry into clinical practice.

Shift in the hepatitis B virus genotype distribution in the last decade among the HBV carriers from eastern India: possible effects on the disease status and HBV epidemiology.

In a previous study from eastern India, the prevalence of HBV/C has been increasing among the blood donors. In order to analyze whether there has been any shift in HBV genotype distributions in recent years, the HBV genotypes prevalent during the periods 2000-2002 (Group-I; n=176) and 2007-2009 (Group-II; n=203) were compared, with special attention to changes in the proportion of HBV/C. The rate of prevalence of the three HBV genotypes (A, C, and D; percent prevalence 19.9/21.6/58.5 in Group-I vs. 31.0/28.6/40.4 in Group-II) underwent significant changes with increases in HBV/A and HBV/C among the HBV carriers (0.002). Among the asymptomatic carriers, the prevalence of these two genotypes (P=0.021 for HBV/A and P=0.005 for HBV/C) was significantly high. A notable increase was also observed among the chronic liver disease cases. HBV/A increased significantly among the older age Groups (≥ 51 years), whereas the increase of HBV/C was significant among the younger age Groups (≤ 20 years). With the increase of HBV/A and HBV/C, the rates of basal core promoter double mutation (1762T/1764A) also increased considerably. Binary logistic regression analysis revealed that both HBV/A and 1762T/1764A mutations are predictors of chronic liver disease state over asymptomatic carrier state. Thus, this study highlights the possible influence of HBV genotype shift on the changing scenario of HBV epidemiology and disease in the population.

Detection of a premature stop codon in the surface gene of hepatitis B virus from an HBsAg and antiHBc negative blood donor.

BACKGROUND: In blood donors, HBV infection is detected by the presence of serum hepatitis B surface antigen (HBsAg). However, some mutations in the surface gene region may result in altered or truncated HBsAg that can escape from immunoassay-based diagnosis. Such diagnostic escape mutants pose a potential risk for blood transfusion services. RESULTS: In the present study, we report a blood donor seronegative for HBsAg and antiHBc, but positive for antiHBs who was HBV DNA positive by PCR. Sequencing of the HBsAg gene revealed presence of a point mutation (T-A) at 207th nucleotide of the HBsAg ORF, which resulted in a premature stop codon at position 69. This results in a truncated HBsAg gene lacking the entire 'a' determinant region. However, follow-up of the donor after 2 years revealed clearance of HBV DNA from the serum. CONCLUSION: The case illustrates an unusual mutation, which causes HBsAg negativity. The finding emphasizes the importance of molecular assays in reducing the possibility of HBV transmission through blood transfusion. However, developing more sensitive serological assays, capable of detecting HBV mutants, is an alternative to expensive and complex amplification-based assays for developing countries.

Frequency and significance of hepatitis B virus surface gene variant circulating among 'antiHBc only' individuals in Eastern India.

BACKGROUND: Genetic mutation might account for the presence of hepatitis B virus (HBV) DNA among antiHBc only individuals. The aim of the study was to assess the prevalence and significance of surface gene mutations among antiHBc only cases in our population. METHODS: Three hundred and three antiHBc(+) sera of adults (mean age, 33.7+/-11.0; range 18-65 years) as well as HBsAg(+)/HBV DNA(+) (n=19) controls were included in this study. Surface gene and basal core promoter (BCP)-precore region were amplified and surface gene was analyzed after direct sequencing. RESULTS: One hundred and seventy-eight out of 303 (58.8%) was antiHBc only, 39/171 (22.8%) of them was HBV DNA(+). Genotypes A, C, D were found among both HBsAg(+) and antiHBc(+) samples. Single or multiple amino acids substitutions were found in 82% samples, however, G145R vaccine escape mutation was rare. Individuals having substitutions within as well as outside major hydrophilic loop (MHL) region were detected; some of these mutations were in overlapping RT domain of polymerase (Pol) gene. CONCLUSIONS: The existence of occult HBV infection among antiHBc only individuals could not be explained fully by mutations in the 'a' determinant region of surface gene in our population.

Antenatally Detected Congenital Pulmonary Airway Malformations: The Oxford Experience.

Congenital airway pulmonary malformations are increasingly being diagnosed, but their management continues to remain controversial. Our approach has been to offer surgery to mitigate the risk of infection and possible malignancy. All patients routinely undergo a CT scan of the chest postnatally and once the diagnosis is confirmed, minimal access surgery is offered. Our anesthetists provide single-lung ventilation to enhance the operative view. We conducted a retrospective review over a 10-year period, during which 91 patients were prenatally suspected to have a cystic lung lesion. There were 88 live births of which 29 (33%) cases were initially managed conservatively based on CT findings. Five of these patients, however, became symptomatic needing surgery. A total of 64 (73%) patients underwent surgery with the most common lesions being congenital pulmonary airway malformations (CPAMs) (24), hybrid lesions (19), and pulmonary sequestrations (12). The median age at surgery was 5 months (1 day to 17 months). Using a minimal access approach, 41 (64%) cases were completed with 17 performed open from the onset. Open surgery was indicated in neonates who became symptomatic within the first few weeks of life as well as patients in respiratory distress that would not tolerate either single-lung ventilation or gas insufflation. There were six further conversions to open from minimal access surgery due to poor visualization or technical difficulties. One patient needed a perioperative blood transfusion and one patient had a more prolonged stay due to persistent air leak managed conservatively. Among asymptomatic patients, evidence of microscopic disease was seen, which included infection as well as two cases of tumors, one pleuropulmonary blastoma seen as part of a CPAM, and one rhabdomyomatous dysplasia seen in the CPAM component of a hybrid lesion. In our experience, excising asymptomatic lesions is safe with minimal complications. Single-lung ventilation in combination with thoracoscopy provides excellent vision. There is a risk of infection and a definite, albeit low, risk of malignancy, which may outweigh the benefits of conservative management.

Imaging of congenital lung malformations.

Congenital lung malformations are a heterogeneous group of anomalies that involve the lungs and tracheobronchial tree (congenital airway pulmonary malformation, bronchial atresia, bronchogenic cyst, congenital lobar overinflation, pulmonary cyst, hamartoma, pulmonary isomerism and azygous lobe), vascular abnormalities (arteriovenous malformations, anomalous pulmonary venous return, pulmonary artery sling, interrupted pulmonary artery, pulmonary varix, pulmonary vein stenosis and pulmonary lymphangiectasia), or frequently both entities (pulmonary sequestration, pulmonary maldevelopment and scimitar syndrome). Advances in diagnostic imaging (including sonography, multi-detector computer tomography, magnetic resonance imaging and angiography) have increased their detection during both antenatal and postnatal periods, and radiological characterisation, which in turn influence patient counselling and management stratification. An educational illustration of the clinical application in characterisation of these malformations is presented.