The diagnostic value of hepatobiliary scintigraphy for choledochal cysts in the era of magnetic resonance imaging with cholangiopancreatography and contrast-enhanced hepatobiliary phase: a case report and review.

Objective: Choledochal cysts (CCs) represent cystic dilatations of the intra- or extrahepatic biliary tract. The diagnosis of CCs may not always be straightforward particularly for the intrahepatic subtype. Whereas the gold standard for diagnosing CCs is endoscopic retrograde cholangiopancreatography (ERCP), magnetic resonance cholangiopancreatography (MRCP) is commonly used as primary diagnostic tool for delineation of biliary pathologies including CCs. Methods: We report a case of cystic hepatic lesion near the confluence of bilateral intrahepatic ducts. MRCP shows direct anatomical communication between the lesion and the biliary tract, raising suspicion of a CC. Endoscopic ultrasound shows no communication between the lesion and biliary system. 99mTc-hepatic iminodiacetic acid scintigraphy (hepatobiliary scintigraphy) was subsequently performed, showing no tracer uptake in the concerned cystic hepatic lesion despite visualisation of gallbladder and transit of tracer into the intestine. Overall scintigraphic findings speak against a CC. Conclusion: The case showed conflicting anatomical findings of a CC on MRCP and endoscopic ultrasound. Hepatobiliary scintigraphy and hepatobiliary contrast MRI may both functionally demonstrate communication of a hepatic lesion with the biliary tract. But hepatobiliary scintigraphy offers the advantage of much higher hepatic extraction and hence higher resistance to competition from plasma bilirubin compared with hepatobiliary contrast MRI. The better pharmacokinetics of HIDA confer superior lesion contrast that may offset inferior image spatial resolution, in particular for large lesions and patients with hyperbilirubinaemia. Hepatobiliary scintigraphy should be considered a suitable functional diagnostic modality for CCs even in the era of magnetic resonance imaging with cholangiopancreatography and contrast-enhanced hepatobiliary phase.

Cardiopulmonary morbidity of streptococcal infections in a PICU.

AIM: The streptococci are important bacteria that cause serious childhood infections. We investigated cardiopulmonary morbidity associated with streptococcal infection and pediatric intensive care unit (PICU) admission. METHODS: A retrospective study between 2002 and 2013 of all children with a laboratory isolation of streptococcus. RESULTS: There were 40 (2.3%) PICU patients with streptococcal isolations including Streptococcus pyogenes (Group A streptococcus, GAS, n = 7), Streptococcus agalactiae (Group B streptococcus, GBS, n = 5), Streptococcus pneumoniae (SP, n = 20), alpha-hemolytic (n = 4), beta-hemolytic (n = 2) and gama-hemolytic (n = 2) streptococci. Comparing among GAS, GBS and SP, respiratory isolates were more likely positive for GAS or SP (P = 0.033), whereas cerebrospinal fluid was more likely positive for GBS (P = 0.002). All GAS and GBS, and the majority of SP (90%) were sensitive to penicillin. All SP specimens were sensitive to cefotaxime and vancomycin. These infections were associated with high PICU mortality of 43%, 20% and 25%, respectively. Isolation of streptococci was associated with a 30% mortality and high rates of need for mechanical ventilatory and inotropic supports. Patients with GAS, SP or any streptococcal isolation had relative risks [95% confidence interval (CI), P value] of PICU deaths of 7.5 (CI 3.1-18.1, P < 0.0001), 4.5 (CI 2.0-9.8, P < 0.0002) and 5.7 (CI 3.4-9.5, P < 0.0001), respectively. In SP, older children had significantly higher prevalence of premorbid conditions such as malignancy, mental retardation/cerebral palsy ± seizure disorders, chromosomal or genetic disorders (P = 0.003) than children <5 years of age. Serotypes were available for some of these specimens that included 19A, 6B, 3 and 6C. There were four SP deaths with multiorgan system failure and hemolytic uremic syndrome (two 19A and two serotype 3). CONCLUSIONS: Severe streptococcal infections are associated with significant morbidity and mortality despite treatment with systemic antibiotics and intensive care unit support. GAS and SP affect the lungs of children, whereas GBS more likely causes meningitis in infants. The expanded coverage of newer polyvalent pneumococcal vaccines can probably prevent infections by serotypes 19A, 19F, 6B and 3.

Factorial analysis of adaptable properties of self-assembling peptide matrix on cellular proliferation and neuronal differentiation of pluripotent embryonic carcinoma.

An integrative and quantitative approach for systematically studying the effects of changing the matrix environment on pluripotent cell viability and neuronal differentiation was demonstrated. This approach, based on factorial analysis and a self-assembling peptide (SAP) matrix, was exemplified using P19 as a pluripotent cell model. In a two-level, three-factor factorial design of experiments, three niche factors, namely, culture dimensionality, fixed biochemical signal and mechanical stiffness, were simultaneously investigated. We found that cell growth was slowed in matrices containing IKVAV epitopes on the SAP constructs, and neuronal differentiation was promoted synergistically by culturing in a three-dimensional matrix and in the presence of IKVAV. Variation of the storage modulus from around 262 Pa to 672 Pa had no significant effect on either viability or differentiation. This approach should be applicable to studying how niche properties that are tunable using SAPs affect the behavior of pluripotent cells in general, thus generating guidelines for constructing artificial matrices. FROM THE CLINICAL EDITOR: In this basic science study, an integrative and quantitative approach to study the effects of matrix environment on pluripotent cell viability and neuronal differentiation is demonstrated. Approaches, like the one described in this paper, are applicable to studying how self assembling peptides affect the behavior of pluripotent cells in general.

Conjugation of latent membrane protein (LMP)-2 epitope to gold nanoparticles as highly immunogenic multiple antigenic peptides for induction of Epstein-Barr virus-specific cytotoxic T-lymphocyte responses in vitro.

Nasopharyngeal carcinoma is a neoplasm with a high incidence in Southeast Asia, and it is strongly associated with Epstein-Barr virus (EBV) activation involving the expression of a weakly immunogenic protein, namely, latent membrane protein (LMP)-2. Previous immunological studies already identified the human leukocyte antigen (HLA)-A11 restricted peptide epitope (SSCSSCPLSK) in the LMP-2 antigen. In this work, we prepared gold nanoparticle (AuNP)-peptide conjugate 1 by treating the nanoparticles with the N-cysteinated LMP-2 epitope. The AuNP-peptide conjugates have been characterized by TEM (15-24 nm in diameter) and UV-vis spectroscopy (surface plasmon resonance absorption band at lambda(max) = 520 nm). In the presence of a CALNN capping peptide, the AuNP-peptide conjugates are stable in solution without aggregation at room temperature for at least 48 h. By ELIspot studies, AuNP-peptide conjugate 1 was found to elicit a significantly stronger INF-gamma response [number of spot forming cells (SPC) = 727 +/- 198] from peripheral blood mononuclear cells of healthy HLA-A11 donors when compared to that induced by the unconjugated LMP-2 peptides (SFC = 73 +/- 28). Further studies showed that dendritic cells treated with conjugate 1 can effect CD8+ T-cell activation leading to epitope-specific cytotoxic T lymphocyte killing responses in vitro.