A green, facile, and rapid method for microextraction and Raman detection of titanium dioxide nanoparticles from milk powder

A green, facile, and rapid method for microextraction and Raman detection of titanium dioxide nanoparticles from milk powder is reported.

Characterizing the correlations between local phase fractions of gas-liquid two-phase flow with wire-mesh sensor

Understanding of flow patterns and their transitions is significant to uncover the flow mechanics of two-phase flow. The local phase distribution and its fluctuations contain rich information regarding the flow structures. A wire-mesh sensor (WMS) was used to study the local phase fluctuations of horizontal gas-liquid two-phase flow, which was verified through comparing the reconstructed three-dimensional flow structure with photographs taken during the experiments. Each crossing point of the WMS is treated as a node, so the measurement on each node is the phase fraction in this local area. An undirected and unweighted flow pattern network was established based on connections that are formed by cross-correlating the time series of each node under different flow patterns. The structure of the flow pattern network reveals the relationship of the phase fluctuations at each node during flow pattern transition, which is then quantified by introducing the topological index of the complex network. The proposed analysis method using the WMS not only provides three-dimensional visualizations of the gas-liquid two-phase flow, but is also a thorough analysis for the structure of flow patterns and the characteristics of flow pattern transition. This article is part of the themed issue 'Supersensing through industrial process tomography'.

Differentiating origins of outflow tract ventricular arrhythmias: a comparison of three different electrocardiographic algorithms

Our objective is to evaluate the accuracy of three algorithms in differentiating the origins of outflow tract ventricular arrhythmias (OTVAs). This study involved 110 consecutive patients with OTVAs for whom a standard 12-lead surface electrocardiogram (ECG) showed typical left bundle branch block morphology with an inferior axis. All the ECG tracings were retrospectively analyzed using the following three recently published ECG algorithms: 1) the transitional zone (TZ) index, 2) the V₂ transition ratio, and 3) V₂ R wave duration and R/S wave amplitude indices. Considering all patients, the V₂ transition ratio had the highest sensitivity (92.3%), while the R wave duration and R/S wave amplitude indices in V₂ had the highest specificity (93.9%). The latter finding had a maximal area under the ROC curve of 0.925. In patients with left ventricular (LV) rotation, the V₂ transition ratio had the highest sensitivity (94.1%), while the R wave duration and R/S wave amplitude indices in V₂ had the highest specificity (87.5%). The former finding had a maximal area under the ROC curve of 0.892. All three published ECG algorithms are effective in differentiating the origin of OTVAs, while the V₂ transition ratio, and the V₂ R wave duration and R/S wave amplitude indices are the most sensitive and specific algorithms, respectively. Amongst all of the patients, the V₂ R wave duration and R/S wave amplitude algorithm had the maximal area under the ROC curve, but in patients with LV rotation the V₂ transition ratio algorithm had the maximum area under the ROC curve.

Abstract P2-09-25: Constitutional mosaicism in hereditary cancer genes

Background: Mutations conferring cancer risk are typically inherited from one biological parent. Alternatively, a mutation may be constitutional mosaic, meaning that a fraction of cells in the body carry the mutation. This can result e.g. from a de novo mutation early in embryogenesis. Constitutional mosaicism may be an underreported cause of genetic disease [1,2] for 2 reasons: Family histories can be uninformative (mosaic mutations are typically not inherited, but can be passed on to children). Also, germline laboratory tests (if performed) are traditionally not optimized to detect low allele frequency events (in contrast to tumor tests for somatic mutations). Following our recent identification of a mosaic BRCA1 cancer patient [3], we sought to characterize additional such cases in our laboratory population.

Methods: We examined high-depth next-generation sequencing (NGS) data for pathogenic or suspected pathogenic mutations with unequal allele balance (i.e., not the expected 50-50 ratio) in blood-derived DNA. Because many factors can cause unequal allele balance in NGS, we reviewed the lab and clinical data in detail to remove cases likely due to (a) technical artifacts in NGS, (b) other somatic events, as may happen in response to chemotherapy, or (c) undiagnosed, residual or progressing blood cancers. An orthogonal assay was used for confirmation.

Results: To date, 14 cases with mosaic mutations (7-29% allele frequency) have been confirmed: 8 of these patients have breast/ovarian cancer and 6 have other cancers. These allele frequencies are unlikely to be caused by circulating tumor DNA or cells. These findings include our published BRCA1 case, 7 TP53 cases, 1 NF1 case, 2 CHEK2, 2 MLH1, and 1 PTCH1. 3 additional mutations were determined to be part of a haematopoietic neoplasm (1 previously undiagnosed). Cases of note include (i) a young breast cancer patient, with no cutaneous findings, positive for NF1 at 9%, and (ii) a patient presenting with the Muir-Torre variant of Lynch syndrome who had negative MLH1/MSH2 Sanger sequencing 14 years ago, identified to be positive for MLH1 at 25% by NGS.

Conclusion: Constitutional mosaic mutations may be an under-recognized cause of cancer and unique clinical considerations apply to such cases. First, a mosaic patient may not show the same gene-associated phenotypes as patients with inherited heterozygous mutations in the same gene. Second, patients with syndromic presentations who tested negative for the indicated gene(s) by traditional methodologies may warrant reexamination by NGS. Similarly, patients with heterozygous mutations (50-50) may have a mosaic parent, for whom the mutation could be missed by traditional testing. Testing of family members beyond first degree relatives of a mosaic patient is unlikely to modify risk assessments, unlike the situation for patients with inherited heterozygous mutations. Finally, apparent mosaicism may warrant an evaluation for a underlying haematologic malignancy. We note that the prevalence of mosaic findings in hereditary cancer genes is currently unclear but may higher than once thought. Further clinical research on this topic is clearly warranted.

(1) Campbell et al., AJHG, 2014

(2) Acuna-Hildago et al., AJHG, 2015

(3) Friedman et al., SABCS 2014; BJC 2015.

Citation Format: Lincoln S, Tan C, Kennemer M, Powers M, Monzon F. Constitutional mosaicism in hereditary cancer genes. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-09-25.

X-exome sequencing of 405 unresolved families identifies seven novel intellectual disability genes

X-linked intellectual disability (XLID) is a clinically and genetically heterogeneous disorder. During the past two decades in excess of 100 X-chromosome ID genes have been identified. Yet, a large number of families mapping to the X-chromosome remained unresolved suggesting that more XLID genes or loci are yet to be identified. Here, we have investigated 405 unresolved families with XLID. We employed massively parallel sequencing of all X-chromosome exons in the index males. The majority of these males were previously tested negative for copy number variations and for mutations in a subset of known XLID genes by Sanger sequencing. In total, 745 X-chromosomal genes were screened. After stringent filtering, a total of 1297 non-recurrent exonic variants remained for prioritization. Co-segregation analysis of potential clinically relevant changes revealed that 80 families (20%) carried pathogenic variants in established XLID genes. In 19 families, we detected likely causative protein truncating and missense variants in 7 novel and validated XLID genes (CLCN4, CNKSR2, FRMPD4, KLHL15, LAS1L, RLIM and USP27X) and potentially deleterious variants in 2 novel candidate XLID genes (CDK16 and TAF1). We show that the CLCN4 and CNKSR2 variants impair protein functions as indicated by electrophysiological studies and altered differentiation of cultured primary neurons from Clcn4(-/-) mice or after mRNA knock-down. The newly identified and candidate XLID proteins belong to pathways and networks with established roles in cognitive function and intellectual disability in particular. We suggest that systematic sequencing of all X-chromosomal genes in a cohort of patients with genetic evidence for X-chromosome locus involvement may resolve up to 58% of Fragile X-negative cases.

The effects of plasmalyte-148 vs. Hartmann's solution during major liver resection: a multicentre, double-blind, randomized controlled trial

BACKGROUND

The acid-base, biochemical and hematological effects of crystalloid solutions have not been comprehensively evaluated in patients with liver resection.

DESIGN

multicenter, prospective, double-blind randomized controlled trial investigating the biochemical effects of Hartmann's solution (HS) or Plasmalyte-148 (PL) in 60 patients undergoing major liver resection.

PRIMARY OUTCOME

base excess immediately after surgery.

SECONDARY OUTCOMES

changes in blood biochemistry and hematology.

RESULTS

At completion of surgery, patients receiving HS had equivalent mean standard base excess (-1.7±2.2 vs. -0.9±2.3 meq/L; P=0.17) to those treated with PL. However, patients treated with HS were more hyperchloremic (difference 1.7 mmol/L, 95% CI: 0.2 to 3.2, P=0.03) and hyperlactatemic (difference 0.8 mmol/L, 95% CI: 0.2 to 1.3; P=0.01). In contrast, patients receiving PL had higher mean plasma magnesium levels and lower ionized calcium levels. There were no significant differences in pH, bicarbonate, albumin and phosphate levels. Immediately after surgery, mean PT and aPTT were significantly lower in the PL group. Intraoperatively, the median (IQR) blood loss in the PL group was 300 mL (200:413) vs. 500 mL (300:638) in the HS group (P=0.03). Correspondingly, the postoperative hemoglobin was higher in the PL group. Total complications were more frequent in the HS Group (56% vs. 20%, relative risk 2.8; 95% CI: 1.3 to 6.1; P=0.007).

CONCLUSION

In liver resection patients, HS and PL led to similar base excess values but different post operative plasma biochemistry and hematology values. Understanding of these effects may help clinicians individualize fluid therapy in these patients.

Effects of nitrogen stress on the photosynthetic CO2 assimilation, chlorophyll fluorescence, and sugar-nitrogen ratio in corn

A field experiment was conducted using three corn cultivars (Jingyu7, Nongda80, and Tangyu10) and three nitrogen (N) application rates (0, 75, and 150 kg N ha(-1)). The objectives of this study were to investigate the responses of photosynthetic CO2 assimilation (Ph), the maximum quantum yield of photosystem II (Fv/Fm), leaf dry weight (LDW), leaf nitrogen concentration (LNC), leaf sugar concentration (LSC), and the sugar-to-nitrogen concentration ratio (S/N) to N levels in three different field-grown corn cultivars on three sampling dates. The results showed that the LDW, Fv/Fm, Ph, LNC, and LSC increased with increasing N levels, and the variation patterns of Fv/Fm, Ph, and LNC were "low-high-low". In contrast, S/N decreased with increasing N levels, and its variation pattern was "high-low-high". The values of LDW, Fv/Fm, Ph, LNC, LSC, and S/N were greatest under high N conditions, followed by medium N conditions, and finally low N conditions. Significant interactions occurred between Ph, Fv/Fm, LNC, LSC, LDW, and S/N, with the exception of the interaction between LSC and S/N and between LSC and LDW. The correlation coefficients between Ph and S/N and between Fv/Fm and S/N were -0.714 and -0.798, respectively.