The Diagnostic Value of CEUS in Assessing Non-Ossified Thyroid Cartilage Invasion in Patients with Laryngeal Squamous Cell Carcinoma.

Background: Accurate assessment of thyroid cartilage invasion in squamous cell carcinoma (SCC) of the larynx remains a challenge in clinical practice. The aim of this study was to assess the diagnostic performance of contrast-enhanced ultrasound (CEUS), contrast-enhanced computed tomography (CECT), and magnetic resonance imaging (MRI) in the detection of non-ossified thyroid cartilage invasion in patients with SCC. Methods: CEUS, CECT, and MRI scans of 27 male patients with histologically proven SCC were evaluated and compared. A total of 31 cases were assessed via CEUS and CECT. The MR images of five patients and six cases were excluded (one patient had two suspected sites), leaving twenty-five cases for analysis via MRI. Results: CEUS showed the highest accuracy and specificity compared with CECT and MRI (87.1% vs. 64.5% and 76.0% as well as 84.0% vs. 64.0% and 72.7%, respectively). The sensitivity and negative predictive value of CEUS and MRI were the same (100%). CEUS yielded four false-positive findings. However, there were no statistically significant differences among the imaging modalities (p > 0.05). Conclusions: CEUS showed better diagnostic performance than CECT and MRI. Therefore, CEUS has the potential to accurately assess non-ossified thyroid cartilage invasion and guide appropriate treatment decisions, hopefully leading to improved patient outcomes.

Exposure to polystyrene nanoplastics reduces bacterial and fungal biomass in microfabricated soil models.

Nanoplastics have been proven to induce toxicity in diverse organisms, yet their effect on soil microbes like bacteria and fungi remains largely unexplored. In this paper, we used micro-engineered soil models to investigate the effect of polystyrene (PS) nanospheres on Pseudomonas putida and Coprinopsis cinerea. Specifically, we explored the effects of increasing concentrations of 60 nm carboxylated bovine serum albumin (BSA) coated nanospheres (0, 0.5, 2, and 10 mg/L) on these bacterial and fungal model organisms respectively, over time. We found that both microorganisms could disperse through the PS solution, but long-distance dispersal was reduced by high concentrations. Microbial biomass decreased in all treatments, in which bacteria showed a linear dose response with the strongest effect at 10 mg/L concentration, and fungi showed a non-linear response with the strongest effect at 2 mg/L concentration. At the highest nanoplastics concentration, the first colonizing fungal hyphae adsorbed most of the PS nanospheres present in their vicinity, in a process that we termed the 'vacuum cleaner effect'. As a result, the toxicity effect of the original treatment on subsequently growing fungal hyphae was reduced to a growth level indistinguishable from the control. We did not find evidence that nanoplastics are able to penetrate bacterial nor fungal cell walls. Overall, our findings provide evidence that nanoplastics can cause a direct negative effect on soil microbes and highlight the need for further studies that can explain how the microbial stress response might affect soil functions.

Nanoscale chemical mapping of exometabolites at fungal-mineral interfaces.

Mineral-associated organic matter is an integral part of soil carbon pool. Biological processes contribute to the formation of such organo-mineral complexes when soil microbes, and in particular soil fungi, deposit a suite of extracellular metabolic compounds and their necromass on the mineral surfaces. While studied in bulk, micro- to nanoscale fungal-mineral interactions remain elusive. Of particular interest are the mutual effects at the interface between the fungal exometabolites and proximal mineral particles. In this work, we have grown saprotrophic and symbiotic fungi in contact with two soil minerals with contrasting properties: quartz and goethite, on top of X-ray transparent silicon nitride membrane windows and analyzed fungal hyphae by synchrotron-based scanning transmission X-ray microscopy in combination with near edge X-ray fine structure spectroscopy at C(K) and Fe(L) absorption edges. In the resultant chemical maps, we were able to visualize and differentiate organic compounds constituting the fungal cells, their extracellular metabolites, and the exometabolites adsorbing on the minerals. We found that the composition of the exometabolites differed between the fungal functional guilds, particularly, in their sugar to protein ratio and potassium concentration. In samples with quartz and goethite, we observed adsorption of the exometabolic compounds on the mineral surfaces with variations in their chemical composition around the particles. Although we did not observe clear alteration in the exometabolite chemistry upon mineral encounters, we show that fungal-mineral interaction result in reduction of Fe(III) in goethite. This process has been demonstrated for bulk systems, but, to our knowledge, this is the first observation on a single hypha scale offering insight into its underlying biological mechanisms. This demonstrates the link between processes initiated at the single-cell level to macroscale phenomena. Thus, spatially resolved chemical characterization of the microbial-mineral interfaces is crucial for an increased understanding of overall carbon cycling in soil.

Computed tomographic features of the proximal petrous facial nerve canal in recurrent Bell's palsy.

OBJECTIVES: The primary objective was to determine whether the narrowest dimensions of the labyrinthine facial nerve (LFN) canal on the symptomatic side in patients with unilateral recurrent Bell's palsy (BP) differ from those on the contralateral side or in asymptomatic, age- and gender-matched controls on computed tomography (CT). The secondary objectives were to assess the extent of bony covering at the geniculate ganglion and to record inter-observer reliability of the CT measurements. METHODS: The dimensions of the LFN canal at its narrowest point perpendicular to the long axis and the extent of bony covering at the geniculate ganglion were assessed by two radiologists. Statistical analysis was performed using the Wilcoxon signed-rank and Mann-Whitney U tests (LFN canal dimensions) and the Chi-squared test (bony covering at the geniculate ganglion). Inter-observer reliability was evaluated using Intra-Class Correlation (ICC) and Cohen's kappa. RESULTS: The study included 21 patients with unilateral recurrent BP and 21 asymptomatic controls. There was no significant difference in the narrowest dimensions of the ipsilateral LFN canal when compared to the contralateral side or controls (P = .43-.94). Similarly, there was no significant difference in the extent of bony covering at the geniculate ganglion when compared to either group (P = .19-.8). Good inter-observer reliability was observed for LFN measurements (ICC = 0.75-0.88) but not for the bony covering at the geniculate ganglion (Cohen's kappa = 0.53). CONCLUSION: The narrowest dimensions of the LFN canal and the extent of bony covering at the geniculate ganglion do not differ in unilateral recurrent BP, casting doubt over their etiological significance. LEVEL OF EVIDENCE: Level IV.

Microfluidic chips provide visual access to in situ soil ecology.

Microbes govern most soil functions, but investigation of these processes at the scale of their cells has been difficult to accomplish. Here we incubate microfabricated, transparent 'soil chips' with soil, or bury them directly in the field. Both soil microbes and minerals enter the chips, which enables us to investigate diverse community interdependences, such as inter-kingdom and food-web interactions, and feedbacks between microbes and the pore space microstructures. The presence of hyphae ('fungal highways') strongly and frequently increases the dispersal range and abundance of water-dwelling organisms such as bacteria and protists across air pockets. Physical forces such as water movements, but also organisms and especially fungi form new microhabitats by altering the pore space architecture and distribution of soil minerals in the chip. We show that soil chips hold a large potential for studying in-situ microbial interactions and soil functions, and to interconnect field microbial ecology with laboratory experiments.

Deuterium-Enhanced Raman Spectroscopy for Histidine pKa Determination in a pH-Responsive Hydrogel.

We report here a method for the determination of the pKa of histidine in complex or heterogeneous systems amenable to neither solid-state nor solution NMR spectroscopy. Careful synthesis of a fluorenylmethyloxycarbonyl- and trityl-protected, C2-deuterated histidine produces a vibrational-probe-equipped amino acid that can readily be incorporated into any peptide accessible by standard solid-phase methods. The frequency of the unique, Raman-active stretching vibration of this C2-D probe is a clear reporter of the protonation state of histidine. We investigate here a pH-sensitive peptide that self-assembles to form a hydrogel at neutral pH. The pKa of the lone histidine residue in the peptide, which is likely responsible for this pH-dependent behavior, cannot be investigated by NMR spectroscopy because of the supramolecular, soft nature of the gel. However, after synthesizing a C2-deuterated-histidine-containing peptide, we were able to follow the protonation state of histidine throughout a pH titration using Raman difference spectroscopy, thereby precisely determining the pKa of interest.

The Cochlear Cleft: CT Correlation With Histopathology.

OBJECTIVE: To show the histologic correlate of the cochlear cleft, a small low density focus just anterior to the oval window seen on computed tomography (CT) in three temporal bone specimens. PATIENTS: Three temporal bone specimens donated to the National Temporal Bone Registry from patients aged 34 weeks gestation, 42 years, and 89 years with cochlear clefts seen on CT were studied. INTERVENTION: Review and comparison of postmortem high-resolution CT and temporal bone histopathology MAIN OUTCOME MEASURE:: Correlation of CT findings with temporal bone histopathology. RESULTS: The cochlear cleft visible on CT as a pericochlear lucency anterior to the oval window corresponds to fatty marrow in areas of incomplete endochondral ossification of the otic capsule. The cochlear cleft is distinct from the fissula ante fenestram and can be present in adults. CONCLUSION: In these three cases, the cochlear cleft represents an area of fatty marrow from incomplete ossification of the otic capsule and can be present in adults. Care should be taken when interpreting temporal bone CT to avoid mistaking the cochlear cleft for true pathology (otosclerosis) of the temporal bone.

Rapid intra-operative diagnosis of kidney cancer by attenuated total reflection infrared spectroscopy of tissue smears.

Herein, a technique to analyze air-dried kidney tissue impression smears by means of attenuated total reflection infrared (ATR-IR) spectroscopy is presented. Spectral tumor markers-absorption bands of glycogen-are identified in the ATR-IR spectra of the kidney tissue smear samples. Thin kidney tissue cryo-sections currently used for IR spectroscopic analysis lack such spectral markers as the sample preparation causes irreversible molecular changes in the tissue. In particular, freeze-thaw cycle results in degradation of the glycogen and reduction or complete dissolution of its content. Supervised spectral classification was applied to the recorded spectra of the smears and the test spectra were classified with a high accuracy of 92% for normal tissue and 94% for tumor tissue, respectively. For further development, we propose that combination of the method with optical fiber ATR probes could potentially be used for rapid real-time intra-operative tissue analysis without interfering with either the established protocols of pathological examination or the ordinary workflow of operating surgeon. Such approach could ensure easier transition of the method to clinical applications where it may complement the results of gold standard histopathology examination and aid in more precise resection of kidney tumors.

Molecular signatures of fossil leaves provide unexpected new evidence for extinct plant relationships.

Gene sequences form the primary basis for understanding the relationships among extant plant groups, but genetic data are unavailable from fossils to evaluate the affinities of extinct taxa. Here we show that geothermally resistant fossil cuticles of seed-bearing plants, analysed with Fourier transform infrared (FTIR) spectroscopy and hierarchical cluster analysis (HCA), retain biomolecular suites that consistently distinguish major taxa even after experiencing different diagenetic histories. Our results reveal that similarities between the cuticular biochemical signatures of major plant groups (extant and fossil) are mostly consistent with recent phylogenetic hypotheses based on molecular and morphological data. Our novel chemotaxonomic data also support the hypothesis that the extinct Nilssoniales and Bennettitales are closely allied, but only distantly related to Cycadales. The chemical signature of the cuticle of Czekanowskia (Leptostrobales) is strongly similar to that of Ginkgo leaves and supports a close evolutionary relationship between these groups. Finally, our results also reveal that the extinct putative araucariacean, Allocladus, when analysed through HCA, is grouped closer to Ginkgoales than to conifers. Thus, in the absence of modern relatives yielding molecular information, FTIR spectroscopy provides valuable proxy biochemical data complementing morphological characters to distinguish fossil taxa and to help elucidate extinct plant relationships.

Structural studies of 1,1-dimethyl-2-oxy-1-silacyclohexane by means of matrix isolation infrared absorption spectroscopy.

Infrared spectra of gaseous, liquid, and matrix-isolated samples of newly synthesized 1,1-dimethyl-2-oxy-1-silacyclohexane were recorded. Raman spectra of 1,1-dimethyl-2-oxy-1-silacyclohexane in liquid and solid states were obtained in the temperature range from 170 to 340 K. Ab initio HF and DFT B3LYP calculations were performed in order to determine the possible conformations of 1,1-dimethyl-2-oxy-1-silacyclohexane and to make accurate assignment of the vibrational spectral bands. The study confirms the existence of only one chair-type conformer of 1,1-dimethyl-2-oxy-1-silacyclohexane.

Identification of kidney tumor tissue by infrared spectroscopy of extracellular matrix.

Fourier transform infrared (FT-IR) spectroscopy was applied to characterize the extracellular matrix (ECM) of kidney tumor tissue and normal kidney tissue. Freshly resected tissue samples from 31 patients were pressed on a CaF2 substrate. FT-IR spectra obtained from ECM of tumor tissue exhibit stronger absorption bands in the spectral region from 1000 to 1200 cm⁻¹ and around 1750 cm⁻¹ than those obtained from normal tissue. It is likely that the spectra of ECM of kidney tumor tissue with large increases in the intensities of these bands represent a higher concentration of fatty acids and glycerol. Amide I and amide II bands are stronger in the spectra of ECM from normal tissue, indicating a higher level of proteins. Our results suggest that FT-IR spectroscopy of the ECM is an innovative emerging technology for real-time intraoperative tumor diagnosis, which may improve margin clearance in renal cancer surgery.

Combined studies of chemical composition of urine sediments and kidney stones by means of infrared microspectroscopy.

Results of the structural analysis of urinary sediments by means of infrared spectral microscopy are presented. The results are in good agreement with the results of standard optical microscopy in the case of single-component and crystalline urinary sediments. It is found that for noncrystalline or multicomponent sediments, the suggested spectroscopic method is superior to optical microscopy. The chemical structure of sediments of any molecular origin can be elucidated by this spectroscopic method. The method is sensitive enough to identify solid particles of drugs present in urine. Sulfamethoxazole and traces of other medicines are revealed in this study among the other sediments. We also show that a rather good correlation exists between the type of urinary sediments and the renal stones removed from the same patient. Spectroscopic studies of urinary stones and corresponding sediments from 76 patients suffering from renal stone disease reveal that in 73% of cases such correlation exists. This finding is a strong argument for the use of infrared spectral microscopy to prevent kidney stone disease because stones can be found in an early stage of formation by using the nonintrusive spectroscopic investigation of urinary sediments. Some medical recommendations concerning the overdosing of certain pharmaceuticals can also be derived from the spectroscopic studies of urinary sediments.