Nanoscale Structure of the Oil-Water Interface

X-ray reflectivity (XR) and atomistic molecular dynamics (MD) simulations, carried out to determine the structure of the oil-water interface, provide new insight into the simplest liquid-liquid interface. For several oils (hexane, dodecane, and hexadecane) the XR shows very good agreement with a monotonic interface-normal electron density profile (EDP) broadened only by capillary waves. Similar agreement is also found for an EDP including a sub-Å thick electron depletion layer separating the oil and the water. The XR and MD derived depletions are much smaller than reported for the interface between solid-supported hydrophobic monolayers and water.

Multifocal splenic abscesses in immunocompetent adult due to cat-scratch disease

BACKGROUND

Cat-scratch disease is caused by Bartonella henselae and transmitted to humans via the cats. Patients usually present with cutaneous lesions, regional lymphadenopathy and a brief period of fever.

CASE REPORT

We report a rare case of an isolated splenic cat-scratch disease in an immunocompetent 27-year-old woman who presented with prolonged fever and multifocal splenic lesions. The patient was treated successfully with a long course of antibiotics.

CONCLUSION

Isolated splenic lesions and fever is a rare manifestation of the cat-scratch disease. There is need of high suspicion index by the physicians to diagnose the disease promptly without invasive methods. Hippokratia 2016, 20(4): 306-308.

Digital Radiography of the Chest by Self-Scanning Linear Diode Arrays

Diode array digital radiography DADR is a method of radiographic imaging that combines the advantages of computer technology with self-scanning linear diode arrays. These digital images are superior to those obtained by film in recording and displaying information in the lightest and the darkest areas of the film, resulting in a balanced image of the entire thorax without compromising detail, and at reduced radiation dose. This is a direct result of the wide dynamic range, high contrast sensitivity, fiber optic coupling, small diode size, short exposure time, and rejection of scattered x-rays of the system coupled with digital post-processing enhancement of the image displayed at 1024×1024 pixels.

Hydrogel microstructure live-cell array for multiplexed analyses of cancer stem cells, tumor heterogeneity and differential drug response at single-element resolution

Specific phenotypic subpopulations of cancer stem cells (CSCs) are responsible for tumor development, production of heterogeneous differentiated tumor mass, metastasis, and resistance to therapies. The development of therapeutic approaches based on targeting rare CSCs has been limited partially due to the lack of appropriate experimental models and measurement approaches. The current study presents new tools and methodologies based on a hydrogel microstructure array (HMA) for identification and multiplex analyses of CSCs. Low-melt agarose integrated with type I collagen, a major component of the extracellular matrix (ECM), was used to form a solid hydrogel array with natural non-adhesive characteristics and high optical quality. The array contained thousands of individual pyramidal shaped, nanoliter-volume micro-chambers (MCs), allowing concomitant generation and measurement of large populations of free-floating CSC spheroids from single cells, each in an individual micro-chamber (MC). The optical live cell platform, based on an imaging plate patterned with HMA, was validated using CSC-enriched prostate and colon cancer cell lines. The HMA methodology and quantitative image analysis at single-element resolution clearly demonstrates several levels of tumor cell heterogeneity, including morphological and phenotypic variability, differences in proliferation capacity and in drug response. Moreover, the system facilitates real-time examination of single stem cell (SC) fate, as well as drug-induced alteration in expression of stemness markers. The technology may be applicable in personalized cancer treatment, including multiplex ex vivo analysis of heterogeneous patient-derived tumor specimens, precise detection and characterization of potentially dangerous cell phenotypes, and for representative evaluation of drug sensitivity of CSCs and other types of tumor cells.

Identification of Unique, Heterozygous Germline Mutation, STK11 (p.F354L), in a Child with an Encapsulated Follicular Variant of Papillary Thyroid Carcinoma within Six Months of Completing Treatment for Neuroblastoma

Papillary thyroid carcinoma (PTC) is rare in children, although it is a known secondary malignancy after treatment for neuroblastoma (NB). The interval between NB treatment completion and PTC is usually more than 5 years. A 4-year-old, female patient with a high risk adrenal NB was found to have a 2.9-cm, right thyroid nodule on surveillance chest computed tomography (CT) 6 months after completion of her NB treatment (induction chemotherapy, tumor resection, autologous stem cell transplantation, external beam radiation to the abdominal tumor site, immunotherapy, and retinoic acid). Posttreatment surveillance included iodine-123-metaiodobenzylguanidine scans and CT scans. Fine-needle aspiration of the thyroid nodule diagnosed a follicular neoplasm, which was negative for BRAF, NRAS, KRAS, HRAS, PAX8/PPARg, and RET/PTC mutations, without evidence of metastatic NB. Nodule histology demonstrated an encapsulated follicular variant of PTC (FVPTC). Next-generation sequence analysis for a 46 cancer-gene profile was performed on both tumors with subsequent peripheral blood DNA testing. A heterozygous missense mutation in STK11 (F354L) was identified in both the NB and FVPTC. This mutation was also detected in peripheral blood mononuclear cells. Two additional heterozygous somatic missense mutations of uncertain significance were identified: KDR/VEGF receptor 2 (Q472H) on chromosome 4 and MET (N375S) on chromosome 7. To our knowledge, this is the shortest reported duration from completion of NB treatment to detection of thyroid cancer. The association of the STK11 gene with Peutz-Jeghers syndrome, lung adenocarcinomas, and medullary thyroid cancer leads to a possible association between this genetic variant and our patient's tumors.

Pseudoprogression of low-grade gliomas after radiotherapy

BACKGROUND

Increasing mass effect following radiation therapy (RT) in patients with low-grade gliomas (LGGs) can be mistaken for tumor progression and/or malignant degeneration. Distinguishing pseudoprogression (PP) from true progression is crucial, with vastly different treatment approaches and prognoses.

PROCEDURE

Patients treated with RT for LGGs through the Children's Hospital of Pittsburgh Neuro-Oncology Program are considered to have PP and managed conservatively if they develop increased mass effect within 3 years of RT. Pre-RT tumor area was compared to the maximum tumor size following RT and the size on the last follow-up scan by a central reviewer.

RESULTS

Twenty-four children, median age 13 years, received external beam RT for LGG between March 2000 and August 2011. Thirteen patients (54.2%) developed an increase in tumor size compared to baseline beginning at a median of 6 months after RT and lasting for a median of 2.1 years (range 6.5 months to 5.1 years). Maximum tumor enlargement occurred at a median of 8 months after RT, with a range (5 months to 4.2 years). In all 13 cases, the tumor eventually decreased in size without additional anti-tumor therapy. Two patients (8.3%) developed true tumor progression. With a median follow-up of 4.9 years (range 1.0-12.4 years), all patients are alive.

CONCLUSIONS

Pseudoprogression occurred in more than half of the children with LGG following RT, typically beginning within 8 months and often running a very protracted course. Late presentations can also occur.

Pseudorotational epitaxy of self-assembled octadecyltrichlorosilane monolayers on sapphire (0001)

The structure of octadecyltrichlorosilane self-assembled monolayers (SAMs) on sapphire (0001) was studied by Å-resolution surface-specific x-ray scattering methods. The monolayer was found to consist of three sublayers where the outermost layer corresponds to vertically oriented, closely packed alkyl tails. Laterally, the monolayer is hexagonally packed and exhibits pseudorotational epitaxy to the sapphire, manifested by a broad scattering peak at zero relative azimuthal rotation, with long powderlike tails. The lattice mismatch of ∼ 1%-3% to the sapphire's and the different length scale introduced by the lateral Si-O-Si bonding prohibit positional epitaxy. However, the substrate induces an intriguing increase in the crystalline coherence length of the SAM's powderlike crystallites when rotationally aligned with the sapphire's lattice. The increase correlates well with the rotational dependence of the separation of corresponding substrate-monolayer lattice sites.

The role of tenofovir in preventing and treating hepatitis B virus (HBV) reactivation in immunosuppressed patients. A real life experience from a tertiary center

INTRODUCTION/AIM

Patients who present HBV reactivation during immunosuppressive treatment are prone to develop life threatening decompensation of the liver function, therefore prophylaxis and treatment are strongly recommended. So far there are no data regarding the role of tenofovir in this context. Therefore, the aim of our study was to describe our "real life" experience with the use of tenofovir (TDF) in patients who underwent immunosuppressive treatment.

RESULTS

38 patients with immunosuppression received antiviral treatment with tenofovir (25 patients as prophylaxis and 13 patients as treatment of HBV reactivation). In all 25 patients in whom prophylactic treatment with tenofovir was administered no HBV flare occurred during immunosuppression and the levels of serum HBV-DNA became or remained undetectable during the follow up period (mean follow up 17.2 months, range 6-54). One patient experienced HBsAg seroconversion. In the 13 patients who exhibited HBV reactivation TDF treatment resulted in complete biochemical and virological response within 6 months except two patients with high pretreatment HBV-DNA levels who became HBV-DNA negative at 9 months. No exacerbation of liver disease or liver related death has been observed. One patient who presented with decompensated cirrhosis during HBV reactivation returned into a compensated state after treatment. No side effects of tenofovir have been documented.

CONCLUSION

Tenofovir seems to be highly effective and safe in the prophylaxis and rescue treatment of HBV reactivation in patients who receive immunosuppression therapy.

Donut-shaped chambers for analysis of biochemical processes at the cellular and subcellular levels

In order to study cell-cell variation with respect to enzymatic activity, individual live cell analysis should be complemented by measurement of single cell content in a biomimetic environment on a cellular scale arrangement. This is a challenging endeavor due to the small volume of a single cell, the low number of target molecules and cell motility. Micro-arrayed donut-shaped chambers (DSCs) of femtoliter (fL), picoliter (pL), and nanoliter (nL) volumes have been developed and produced for the analysis of biochemical reaction at the molecular, cellular and multicellular levels, respectively. DSCs are micro-arrayed, miniature vessels, in which each chamber acts as an individual isolated reaction compartment. Individual live cells can settle in the pL and nL DSCs, share the same space and be monitored under the microscope in a noninvasive, time-resolved manner. Following cell lysis and chamber sealing, invasive kinetic measurement based on cell content is achieved for the same individual cells. The fL chambers are used for the analysis of the same enzyme reaction at the molecular level. The various DSCs were used in this proof-of-principle work to analyze the reaction of intracellular esterase in both primary and cell line immune cell populations. These unique DSC arrays are easy to manufacture and offer an inexpensive and simple operating system for biochemical reaction measurement of numerous single cells used in various practical applications.

The usefulness of transient elastography in the assessment of patients with HBeAg-negative chronic hepatitis B virus infection

Histological severity is often mandatory for the management of HBeAg-negative chronic HBV patients. We evaluated the performance of transient elastography (TE) in this setting. We included 357 untreated HBeAg-negative patients with ≥ 1 reliable liver stiffness measurement (LSM-kPa) by TE: 182 inactive carriers with HBV-DNA < 2000 (n = 139) or 2000-19 999 IU/mL (n = 43) and 175 patients with chronic hepatitis B (CHB). In carriers, HBV-DNA > 2000 and/or LSM > 6.5 were considered as biopsy indications. LSMs did not differ between carriers with low and high viremia, but were lower in carriers than in patients with CHB (5.8 ± 1.7 vs 9.0 ± 5.6, P < 0.001) offering moderate differentiation between these two groups (AUROC: 0.705). LSMs did not change significantly in carriers after 16 (12-24) months. In carriers with a liver biopsy, Ishak's staging scores were similar between cased with low and high viremia but higher in cases with LSM > 6.5 than ≤ 6.5 kPa. Moderate fibrosis (stages: 2-3) was detected in 0/10 carriers with only HBV-DNA > 2000 IU/mL, 2/10 (20%) carriers with only LSM > 6.5 and 5/10 (50%) carriers with both HBV-DNA > 2000 and LSM > 6.5 (P = 0.009). In patients with CHB, LSMs correlated significantly with grading and staging scores and offered excellent accuracy for ≥ moderate, ≥ severe fibrosis or cirrhosis (AUROC ≥ 0.919-0.950). TE can be helpful for the noninvasive assessment of HBeAg-negative chronic HBV patients. In conclusion, LSMs offer excellent accuracy for fibrosis severity in HBeAg-negative patients with CHB and can identify carriers with high risk of moderate fibrosis, which may be present in up to 35% of carriers with LSM > 6.5 kPa and 50% of carriers with LSM > 6.5 kPa and HBV-DNA > 2000 IU/mL.

The initial report of RTOG 0436: A phase III trial evaluating the addition of cetuximab to paclitaxel, cisplatin, and radiation for patients with esophageal cancer treated without surgery

LBA6

Background: RTOG 0436 is a randomized Ph III trial designed to evaluate the benefit of cetuximab added to the concurrent chemoradiation for patients undergoing non-operative management of esophageal carcinoma. Methods: Pts with biopsy-proven squamous cell or adenocarcinoma of the esophagus (T1N1M0; T2-4 AnyN M0; Any T/N M1a) were randomized to weekly concurrent cisplatin (50 mg/m2), paclitaxel (25 mg/m2), and daily radiation 50.4 Gy/1.8 Gy fractions ± weekly cetuximab (400 mg/m2 day 1 then weekly 250 mg/m2). Patients were stratified by histology, tumor size (< 5 cm vs > 5cm), and the status of celiac lymph nodal involvement. Overall survival (OS) was the primary endpoint, with a planned accrual of 420 pts to detect an increase in 2-year OS from 41% to 53%; 80% power and 1-sided 0.025 alpha. An interim analysis of cCR was planned for the first 150 of each histology. Results: The study accrued 344 pts from 2008-2013 and 328 were eligible. Based on interim analyses, the study stopped accruing adeno pts in 5/2012 and SCC pts in 1/2013. Pts were well matched for pretreatment characteristics: 80% with T3/4 disease, 66% N1, and 19% with celiac nodal involvement. Incidence of grade 3/4/5 treatment (tx) related AEs was 45%, 22%, 4% in Arm 1 (cetuximab) and 49%, 17%, 1% in Arm 2 (no cetuximab). A cCR rate of 56% was observed in Arm 1 vs 59% in Arm 2 (p=0.72). No differences were seen in cCR between tx arms for either histology. The 12 and 24 mo OS rates for cCR pts were 79% and 58% vs 53% and 30% for those with residual disease (p<0.0001). Median follow-up for all pts is 15.4 mos. The 12 and 24 mo OS (95% CI) for Arm 1 is 64% (56%, 71%) and 44% (36%, 52%) vs 65% (57%, 72%) and 42% (34%, 50%) for Arm 2 (p=0.70). Adeno pts (n=203) had a 12 and 24 mo OS of 65% and 43% for Arm 1 vs 64% and 41% for Arm 2 (p=0.37). The 12 and 24 mo OS for the 125 SCC pts was 62% and 46% for Arm 1 vs 67% and 43% for Arm 2 (p=0.97). Conclusions: The addition of cetuximab to concurrent chemoradiation did not improve OS. There were no differences in cCR rates by tx arm. These Ph III results point to little benefit for current EGFR targeted agents in the tx of esophageal cancer. Supported by RTOG CA21661 and CCOP CA3742 NCI grants and Bristol Myers Squibb. Clinical trial information: NCT00655876.

Cirrhosis but not neutropenia is associated with the development of infection in patients with chronic hepatitis C undergoing treatment with pegylated interferon-alpha and ribavirin

Peginterferon-alpha (PegIFNa) frequently causes neutropenia, mainly due to bone marrow suppression. The aim of this study was to explore factors that are associated with infections during antiviral treatment. We analysed data from 275 chronic hepatitis C (CHC) patients with compensated liver disease who underwent 318 courses of PegIFNa and ribavirin. Neutropenia was defined as neutrophils <1000 cells/μL. Mean leucocytes count significantly decreased from baseline to treatment nadir (7081 ± 2182 vs 3293 ± 1331 cells/μL, P < 0.001), while neutropenia was observed in 32% during treatment. Thirty-one infections were observed. The incidence rate for infection was assessed at 1.46 infections per 100 person-months of therapy. The hazard rate for infection did not correlate with the neutrophils' nadir or the decrease in white blood cells. In multivariate Cox's regression analysis, cirrhosis was the only factor that was significantly associated with the occurrence of infection. Our data show that the development of bacterial infections during treatment with PegIFNa and ribavirin in patients with compensated CHC is not associated with reduction or the nadir of white cells or neutrophil counts. Baseline cirrhosis is the only factor related with infection during treatment. The common practice of dose adjustment or discontinuation of interferon should be revised; careful assessment of liver damage before therapy and close monitoring during therapy are essential in all patients receiving interferon-based regimes, to minimize the detrimental consequences of infections.