The presence of circulating genetically abnormal cells in blood predicts risk of lung cancer in individuals with indeterminate pulmonary nodules

PURPOSE

Computed tomography is the standard method by which pulmonary nodules are detected. Greater than 40% of pulmonary biopsies are not lung cancer and therefore not necessary, suggesting that improved diagnostic tools are needed. The LungLB™ blood test was developed to aid the clinical assessment of indeterminate nodules suspicious for lung cancer. LungLB™ identifies circulating genetically abnormal cells (CGACs) that are present early in lung cancer pathogenesis.

METHODS

LungLB™ is a 4-color fluorescence in-situ hybridization assay for detecting CGACs from peripheral blood. A prospective correlational study was performed on 151 participants scheduled for a pulmonary nodule biopsy. Mann-Whitney, Fisher's Exact and Chi-Square tests were used to assess participant demographics and correlation of LungLB™ with biopsy results, and sensitivity and specificity were also evaluated.

RESULTS

Participants from Mount Sinai Hospital (n = 83) and MD Anderson (n = 68), scheduled for a pulmonary biopsy were enrolled to have a LungLB™ test. Additional clinical variables including smoking history, previous cancer, lesion size, and nodule appearance were also collected. LungLB™ achieved 77% sensitivity and 72% specificity with an AUC of 0.78 for predicting lung cancer in the associated needle biopsy. Multivariate analysis found that clinical and radiological factors commonly used in malignancy prediction models did not impact the test performance. High test performance was observed across all participant characteristics, including clinical categories where other tests perform poorly (Mayo Clinic Model, AUC = 0.52).

CONCLUSION

Early clinical performance of the LungLB™ test supports a role in the discrimination of benign from malignant pulmonary nodules. Extended studies are underway.

Systemic Amyloid A Amyloidosis in Island Foxes (Urocyon littoralis): Severity and Risk Factors

Systemic amyloid A (AA) amyloidosis is highly prevalent (34%) in endangered island foxes (Urocyon littoralis) and poses a risk to species recovery. Although elevated serum AA (SAA) from prolonged or recurrent inflammation predisposes to AA amyloidosis, additional risk factors are poorly understood. Here we define the severity of glomerular and medullary renal amyloid and identify risk factors for AA amyloidosis in 321 island foxes necropsied from 1987 through 2010. In affected kidneys, amyloid more commonly accumulated in the medullary interstitium than in the glomeruli (98% [n= 78 of 80] vs 56% [n= 45], respectively;P< .0001), and medullary deposition was more commonly severe (19% [n= 20 of 105]) as compared with glomeruli (7% [n= 7];P= .01). Univariate odds ratios (ORs) of severe renal AA amyloidosis were greater for short- and long-term captive foxes as compared with free-ranging foxes (ORs = 3.2, 3.7, respectively; overall P= .05) and for females as compared with males (OR = 2.9;P= .05). Multivariable logistic regression revealed that independent risk factors for amyloid development were increasing age class (OR = 3.8;P< .0001), San Clemente Island subspecies versus San Nicolas Island subspecies (OR = 5.3;P= .0003), captivity (OR = 5.1;P= .0001), and nephritis (OR = 2.3;P= .01). The increased risk associated with the San Clemente subspecies or captivity suggests roles for genetic as well as exogenous risk factors in the development of AA amyloidosis.

Cell cycle-specific cleavage of Scc2 regulates its cohesin deposition activity

Sister chromatid cohesion (SCC), efficient DNA repair, and the regulation of some metazoan genes require the association of cohesins with chromosomes. Cohesins are deposited by a conserved heterodimeric loading complex composed of the Scc2 and Scc4 proteins in Saccharomyces cerevisiae, but how the Scc2/Scc4 deposition complex regulates the spatiotemporal association of cohesin with chromosomes is not understood. We examined Scc2 chromatin association during the cell division cycle and found that the affinity of Scc2 for chromatin increases biphasically during the cell cycle, increasing first transiently in late G1 phase and then again later in G2/M. Inactivation of Scc2 following DNA replication reduces cellular viability, suggesting that this post S-phase increase in Scc2 chromatin binding affinity is biologically relevant. Interestingly, high and low Scc2 chromatin binding levels correlate strongly with the presence of full-length or amino-terminally cleaved forms of Scc2, respectively, and the appearance of the cleaved Scc2 species is promoted in vitro either by treatment with specific cell cycle-staged cellular extracts or by dephosphorylation. Importantly, Scc2 cleavage eliminates Scc2-Scc4 physical interactions, and an scc2 truncation mutant that mimics in vivo Scc2 cleavage is defective for cohesin deposition. These observations suggest a previously unidentified mechanism for the spatiotemporal regulation of cohesin association with chromosomes through cell cycle regulation of Scc2 cohesin deposition activity by Scc2 dephosphorylation and cleavage.

Effective line tension and contact angles between membrane domains in biphasic vesicles

Inhomogeneities in membranes give rise to localized interactions at the interface between domains in two-component vesicles. The corresponding energy is expressed as a line tension between the two phases. In this paper we study the implications of the thickness mismatch between domains which has been experimentally reported to be of order 20-30% and the conditions under which the induced line tension can destabilize the domains in inhomogeneous vesicles. For asymmetric lipidic membranes we prove an increase of the line tension and the existence of a contact angle. Adsorption of impurities is also examined, our scope being the extension of the Canham-Helfrich model to describe elastic deformations and chemical interactions arising at microscopic scales. This mismatch effect may have important consequences for the stability of very small domains.

Pattern formation and localized structures in reaction-diffusion systems with non-Fickian transport

We study the robust dynamical behaviors of reaction-diffusion systems where the transport gives rise to non-Fickian diffusion. A prototype model describing the deposition of molecules in a surface is used to show the generic appearance of Turing structures which can coexist with homogeneous states giving rise to localized structures through the pinning mechanism. The characteristic lengths of these structures are in the nanometer region in agreement with recent experimental observations.

Spiral patterns in the packing of flexible structures

Spiral patterns are found to be a generic feature in close-packed elastic structures. We describe model experiments of compaction of quasi-1D sheets into quasi-2D containers that allow simultaneous quantitative measurements of mechanical forces and observation of folded configurations. Our theoretical approach shows how the interplay between elasticity and geometry leads to a succession of bifurcations responsible for the emergence of such patterns. Both experimental forces and shapes are also reproduced without any adjustable parameters.

Dendritic development in the neocortex of adult rats following a maintained prenatal and/or early postnatal life undernutrition

The Golgi-Cox method was used to study the maturation of the large pyramidal cells of the Vth cortical layer in three groups of adult rats: one subjected to undernutrition during the first month of life, another throughout the first 2 mth of life, and the last one during gestation and the suckling period. The main alterations consist of a decrease in the number and span of dendritic basilar processes of large pyramidal cells. In animals malnourished during prenatal life and the suckling period the reduction of the basal dendritic arborization was more apparent. It is postulated that the vulnerable period for the basal dendritic development occupies the period from the end of pregnancy until the first 3 wk of postnatal life in the rat (suckling period). Noxious influences acting during this phase induce sequelae that cannot be reversed by subsequent refeeding. A maintained nutritional insult during prenatal and early postnatal life induces the most severe changes in dendritic arborizations, compared to those resulting from a prolonged postnatal malnutrition.

Dendritic development in the neocortex of adult rats subjected to postnatal malnutrition

The Golgi-Cox method was used to study the maturation of the large pyramidal cells of the Vth cortical layer in two groups of adult rats, one subjected to early postnatal malnutrition and another malnourished only during the second month of life. The main alterations were observed in the pyramidal cells of cortical layer V of rats malnourished during the first month of life. They consist of a decrease in the number and span of dendritic basilar processes. In animals malnourished during the second month of life, the number and span of basilar dendritic processes in pyramidal cells of layer V, were normal. It is postulated that early postnatal malnutrition induced immediately after birth, profoundly disturbs the process of neuronal maturation in the neocortex of the rat brain, probably with permanent effects.

Histological maturation of the neocortex in phenylketonuric rats

The histological maturation of pyramidal cells from the deeper layer of the neocortex was studied in phenylketonuric rats. The main alterations consist of a decrease in the number of span and dendritic basilar processes of large pyramidal cells, and changes in the structural organization of the cerebral cortex. It is postulated that high levels of phenylalanine induced immediately after birth disturb profoundly the process of neuronal maturation in the neocortex of the rat brain, probably with long-term effects.