Information exchange of law enforcement agencies within the EU in context of COVID 19 outbreak.

This article discusses the readiness of information exchange of law enforcement agencies in the EU. In context of the outbreak of COVID-19 there is a need for effective information exchange between law enforcement agencies. The need for intensified information exchange and gathering relevant data is necessary in order to tackle organized crime in the EU. COVID-19 has shown the complexity of security and health issues and the limited institutional capacity of states to deal the crisis individually. The authors argue that the EU and its member states face a challenging security environment in which information exchange is the most relevant tool for managing the crisis.

Hyperspectral interference tomography of nacre.

Structural characterization of biologically formed materials is essential for understanding biological phenomena and their enviro-nment, and for generating new bio-inspired engineering concepts. For example, nacre-the inner lining of some mollusk shells-encodes local environmental conditions throughout its formation and has exceptional strength due to its nanoscale brick-and-mortar structure. This layered structure, comprising alternating transparent aragonite (CaCO3) tablets and thinner organic polymer layers, also results in stunning interference colors. Existing methods of structural characterization of nacre rely on some form of cross-sectional analysis, such as scanning or transmission electron microscopy or polarization-dependent imaging contrast (PIC) mapping. However, these techniques are destructive and too time- and resource-intensive to analyze large sample areas. Here, we present an all-optical, rapid, and nondestructive imaging technique-hyperspectral interference tomography (HIT)-to spatially map the structural parameters of nacre and other disordered layered materials. We combined hyperspectral imaging with optical-interference modeling to infer the mean tablet thickness and its disorder in nacre across entire mollusk shells from red and rainbow abalone (Haliotis rufescens and Haliotis iris) at various stages of development. We observed that in red abalone, unexpectedly, nacre tablet thickness decreases with age of the mollusk, despite roughly similar appearance of nacre at all ages and positions in the shell. Our rapid, inexpensive, and nondestructive method can be readily applied to in-field studies.

Circulating Tumor Cell Genomic Evolution and Hormone Therapy Outcomes in Men with Metastatic Castration-Resistant Prostate Cancer.

Men with circulating tumor cell (CTC) AR-V7-positive metastatic castration-resistant prostate cancer (mCRPC) have worse outcomes when treated with enzalutamide/abiraterone. However, most men lack CTC AR-V7 detection, and additional predictive biomarkers are needed. We conducted a retrospective secondary analysis of the prospective PROPHECY trial (NCT02269982) of men with mCRPC undergoing treatment with enzalutamide/abiraterone, analyzing pooled CTC and germline DNA for whole-genome copy-number alterations (CNA) in 73 samples from 48 men over time along with pooled CTC and germline whole-exome sequencing on 22 paired samples before and following progression on androgen receptor (AR) inhibitor therapy to identify somatic genomic alterations associated with acquired resistance. We observed broad interpatient and longitudinal CTC genomic heterogeneity from AR-V7-negative men with mCRPC, including common gains of KDM6A, MYCN, and AR, and loss of ZFHX3, BRCA1, and PTEN. Men who had progression-free survival of ≤3 months despite enzalutamide/abiraterone treatment were more likely to have baseline CTC genomic loss of CHD1, PTEN, PHLPP1, and ZFHX3 and gains of BRCA2, KDM5D, MYCN, and SPARC. After progression on abiraterone/enzalutamide, we observed clonal evolution of CTCs harboring TP53 mutations and gain of ATM, KDM6A, and MYC, and loss of NCOR1, PTEN, RB1, and RUNX2. CTC genomic findings were independently confirmed in a separate cohort of mCRPC men who progressed despite prior treatment with abiraterone/enzalutamide (NCT02204943). IMPLICATIONS: We identified common and reproducible genomic alterations in CTCs from AR-V7-negative mCRPC men associated with poor outcomes during enzalutamide/abiraterone treatment, including CNAs in genes linked to lineage plasticity and epigenetic signaling, DNA repair, AR, TP53/RB1, PTEN, and WNT pathways.

Discordant and heterogeneous clinically relevant genomic alterations in circulating tumor cells vs plasma DNA from men with metastatic castration resistant prostate cancer.

Circulating tumor cell (CTC) and cell-free (cf) DNA-based genomic alterations are increasingly being used for clinical decision-making in oncology. However, the concordance and discordance between paired CTC and cfDNA genomic profiles remain largely unknown. We performed comparative genomic hybridization (CGH) on CTCs and cfDNA, and low-pass whole genome sequencing (lpWGS) on cfDNA to characterize genomic alterations (CNA) and tumor content in two independent prospective studies of 93 men with mCRPC treated with enzalutamide/abiraterone, or radium-223. Comprehensive analysis of 69 patient CTCs and 72 cfDNA samples from 93 men with mCRPC, including 64 paired samples, identified common concordant gains in FOXA1, AR, and MYC, and losses in BRCA1, PTEN, and RB1 between CTCs and cfDNA. Concordant PTEN loss and discordant BRCA2 gain were associated with significantly worse outcomes in Epic AR-V7 negative men with mCRPC treated with abiraterone/enzalutamide. We identified and externally validated CTC-specific genomic alternations that were discordant in paired cfDNA, even in samples with high tumor content. These CTC/cfDNA-discordant regions included key genomic regulators of lineage plasticity, osteomimicry, and cellular differentiation, including MYCN gain in CTCs (31%) that was rarely detected in cfDNA. CTC MYCN gain was associated with poor clinical outcomes in AR-V7 negative men and small cell transformation. In conclusion, we demonstrated concordance of multiple genomic alterations across CTC and cfDNA platforms; however, some genomic alterations displayed substantial discordance between CTC DNA and cfDNA despite the use of identical copy number analysis methods, suggesting tumor heterogeneity and divergent evolution associated with poor clinical outcomes.

Pharmacodynamic study of radium-223 in men with bone metastatic castration resistant prostate cancer.

BACKGROUND: Radium-223 is a targeted alpha-particle therapy that improves survival in men with metastatic castration resistant prostate cancer (mCRPC), particularly in men with elevated serum levels of bone alkaline phosphatase (B-ALP). We hypothesized that osteomimicry, a form of epithelial plasticity leading to an osteoblastic phenotype, may contribute to intralesional deposition of radium-223 and subsequent irradiation of the tumor microenvironment. METHODS: We conducted a pharmacodynamic study (NCT02204943) of radium-223 in men with bone mCRPC. Prior to and three and six months after radium-223 treatment initiation, we collected CTCs and metastatic biopsies for phenotypic characterization and CTC genomic analysis. The primary objective was to describe the impact of radium-223 on the prevalence of CTC B-ALP over time. We measured radium-223 decay products in tumor and surrounding normal bone during treatment. We validated genomic findings in a separate independent study of men with bone metastatic mCRPC (n = 45) and publicly accessible data of metastatic CRPC tissues. RESULTS: We enrolled 20 men with symptomatic bone predominant mCRPC and treated with radium-223. We observed greater radium-223 radioactivity levels in metastatic bone tumor containing biopsies compared with adjacent normal bone. We found evidence of persistent Cellsearch CTCs and B-ALP (+) CTCs in the majority of men over time during radium-223 therapy despite serum B-ALP normalization. We identified genomic gains in osteoblast mimicry genes including gains of ALPL, osteopontin, SPARC, OB-cadherin and loss of RUNX2, and validated genomic alterations or increased expression at the DNA and RNA level in an independent cohort of 45 men with bone-metastatic CRPC and in 150 metastatic biopsies from men with mCRPC. CONCLUSIONS: Osteomimicry may contribute in part to the uptake of radium-223 within bone metastases and may thereby enhance the therapeutic benefit of this bone targeting radiotherapy.

Prospective Multicenter Validation of Androgen Receptor Splice Variant 7 and Hormone Therapy Resistance in High-Risk Castration-Resistant Prostate Cancer: The PROPHECY Study.

PURPOSE: Androgen receptor splice variant 7 (AR-V7) results in a truncated receptor, which leads to ligand-independent constitutive activation that is not inhibited by anti-androgen therapies, including abiraterone or enzalutamide. Given that previous reports suggested that circulating tumor cell (CTC) AR-V7 detection is a poor prognostic indicator for the clinical efficacy of secondary hormone therapies, we conducted a prospective multicenter validation study. PATIENTS AND METHODS: PROPHECY ( ClinicalTrials.gov identifier: NCT02269982) is a multicenter, prospective-blinded study of men with high-risk mCRPC starting abiraterone acetate or enzalutamide treatment. The primary objective was to validate the prognostic significance of baseline CTC AR-V7 on the basis of radiographic or clinical progression free-survival (PFS) by using the Johns Hopkins University modified-AdnaTest CTC AR-V7 mRNA assay and the Epic Sciences CTC nuclear-specific AR-V7 protein assay. Overall survival (OS) and prostate-specific antigen responses were secondary end points. RESULTS: We enrolled 118 men with mCRPC who were starting abiraterone or enzalutamide treatment. AR-V7 detection by both the Johns Hopkins and Epic AR-V7 assays was independently associated with shorter PFS (hazard ratio, 1.9 [95% CI, 1.1 to 3.3; P = .032] and 2.4 [95% CI, 1.1 to 5.1; P = .020], respectively) and OS (hazard ratio, 4.2 [95% CI, 2.1 to 8.5] and 3.5 [95% CI, 1.6 to 8.1], respectively) after adjusting for CTC number and clinical prognostic factors. Men with AR-V7-positive mCRPC had fewer confirmed prostate-specific antigen responses (0% to 11%) or soft tissue responses (0% to 6%). The observed percentage agreement between the two AR-V7 assays was 82%. CONCLUSION: Detection of AR-V7 in CTCs by two blood-based assays is independently associated with shorter PFS and OS with abiraterone or enzalutamide, and such men with mCRPC should be offered alternative treatments.

Circulating Tumor Cell Phenotyping via High-Throughput Acoustic Separation.

The study of circulating tumor cells (CTCs) offers pathways to develop new diagnostic and prognostic biomarkers that benefit cancer treatments. In order to fully exploit and interpret the information provided by CTCs, the development of a platform is reported that integrates acoustics and microfluidics to isolate rare CTCs from peripheral blood in high throughput while preserving their structural, biological, and functional integrity. Cancer cells are first isolated from leukocytes with a throughput of 7.5 mL h-1 , achieving a recovery rate of at least 86% while maintaining the cells' ability to proliferate. High-throughput acoustic separation enables statistical analysis of isolated CTCs from prostate cancer patients to be performed to determine their size distribution and phenotypic heterogeneity for a range of biomarkers, including the visualization of CTCs with a loss of expression for the prostate specific membrane antigen. The method also enables the isolation of even rarer, but clinically important, CTC clusters.

Whole Genomic Copy Number Alterations in Circulating Tumor Cells from Men with Abiraterone or Enzalutamide-Resistant Metastatic Castration-Resistant Prostate Cancer.

Purpose: Beyond enumeration, circulating tumor cells (CTCs) can provide genetic information from metastatic cancer that may facilitate a greater understanding of tumor biology and enable a precision medicine approach.Experimental Design: CTCs and paired leukocytes from men with metastatic castration-resistant prostate cancer (mCRPC) were isolated from blood through red cell lysis, CD45 depletion, and flow sorting based on EpCAM/CD45 expression. We next performed whole genomic copy number analysis of CTCs and matched patient leukocytes (germline) using array-based comparative genomic hybridization (aCGH) from 16 men with mCRPC, including longitudinal and sequential aCGH analyses of CTCs in the context of enzalutamide therapy.Results: All patients had mCRPC and primary or acquired resistance to abiraterone acetate or enzalutamide. We compiled copy gains and losses, with a particular focus on those genes highly implicated in mCRPC progression and previously validated as being aberrant in metastatic tissue samples and genomic studies of reference mCRPC datasets. Genomic gains in >25% of CTCs were observed in AR, FOXA1, ABL1, MET, ERG, CDK12, BRD4, and ZFHX3, while common genomic losses involved PTEN, ZFHX3, PDE4DIP, RAF1, and GATA2 Analysis of aCGH in a sample with sequential enzalutamide-resistant visceral progression showed acquired loss of AR amplification concurrent with gain of MYCN, consistent with evolution toward a neuroendocrine-like, AR-independent clone.Conclusions: Genomic analysis of pooled CTCs in men with mCRPC suggests a reproducible, but highly complex molecular profile that includes common aberrations in AR, ERG, c-MET, and PI3K signaling during mCRPC progression, which may be useful for predictive biomarker development. Clin Cancer Res; 23(5); 1346-57. ©2016 AACR.

Development of a Novel c-MET-Based CTC Detection Platform.

UNLABELLED: Amplification of the MET oncogene is associated with poor prognosis, metastatic dissemination, and drug resistance in many malignancies. We developed a method to capture and characterize circulating tumor cells (CTC) expressing c-MET using a ferromagnetic antibody. Immunofluorescence was used to characterize cells for c-MET, DAPI, and pan-CK, excluding CD45(+) leukocytes. The assay was validated using appropriate cell line controls spiked into peripheral blood collected from healthy volunteers (HV). In addition, peripheral blood was analyzed from patients with metastatic gastric, pancreatic, colorectal, bladder, renal, or prostate cancers. CTCs captured by c-MET were enumerated, and DNA FISH for MET amplification was performed. The approach was highly sensitive (80%) for MET-amplified cells, sensitive (40%-80%) for c-MET-overexpressed cells, and specific (100%) for both c-MET-negative cells and in 20 HVs. Of 52 patients with metastatic carcinomas tested, c-MET CTCs were captured in replicate samples from 3 patients [gastric, colorectal, and renal cell carcinoma (RCC)] with 6% prevalence. CTC FISH demonstrated that MET amplification in both gastric and colorectal cancer patients and trisomy 7 with gain of MET gene copies in the RCC patient. The c-MET CTC assay is a rapid, noninvasive, sensitive, and specific method for detecting MET-amplified tumor cells. CTCs with MET amplification can be detected in patients with gastric, colorectal, and renal cancers. IMPLICATIONS: This study developed a novel c-MET CTC assay for detecting c-MET CTCs in patients with MET amplification and warrants further investigation to determine its clinical applicability. Mol Cancer Res; 14(6); 539-47. ©2016 AACR.

A phase II trial of temsirolimus in men with castration-resistant metastatic prostate cancer.

BACKGROUND: Phosphatase and tensin homologue (PTEN) loss is common in advanced prostate cancer, leading to constitutive activation of the PI3 kinase pathway. Temsirolimus blocks mammalian target of rapamycin (mTOR)/target of rapamycin complex 1 (TORC1), a key signaling node in this pathway; its activity in men with advanced castration-resistant metastatic prostate cancer (mCRPC) is unknown. METHODS: We conducted a single-arm trial of weekly intravenous temsirolimus administration in men with chemorefractory mCRPC who had ≥ 5 circulating tumor cells (CTCs) at baseline. The primary end point was the change in CTCs at 8 weeks; secondary end points were composite progression-free survival (PFS) (excluding prostate-specific antigen [PSA]), PSA and radiographic response rates, safety, and survival. At PSA/CTC progression, an anti-androgen could be added while continuing temsirolimus. RESULTS: Eleven patients were accrued out of a planned 20; the trial was stopped prematurely because of lack of efficacy/feasibility. Median age was 61 years, with 55% African-Americans and 36% Caucasian patients. Median baseline PSA level was 390 ng/dL, median baseline number of CTCs was 14 cells; 50% of patients had pain, and 63% had undergone ≥ 2 previous chemotherapy regimens. Median CTC decline was 48% and 3 patients experienced decline in CTCs to < 5. However, 73% of men had a persistently unfavorable number of CTCs (≥ 5) and only 1 patient had a ≥ 30% PSA decline. Median PFS was 1.9 months (95% confidence interval [CI], 0.9-3.1) and median overall survival (OS) was 8.8 months (95% CI, 3.1-15.6). Toxicities included grade 4 hypophosphatemia and central nervous system (CNS) hemorrhage, and frequent grade 3 fatigue, anemia, stomatitis, hypokalemia, weakness, and hyperglycemia. CONCLUSION: Temsirolimus lacked sufficient clinical activity in men with mCRPC, despite transient CTC improvements in some men. Future studies should focus on combination approaches or novel PI3K pathway inhibitors.

Development of a method to isolate circulating tumor cells using mesenchymal-based capture.

Epithelial tumor cells can become mesenchymal cells and vice versa via phenotypic transitions, a process known as epithelial plasticity. We postulate that during the process of metastasis, circulating tumor cells (CTCs) lose their epithelial phenotype and acquire a mesenchymal phenotype that may not be sufficiently captured by existing epithelial-based CTC technologies. We report here on the development of a novel CTC capture method, based on the biology of epithelial plasticity, which isolates cells based on OB-cadherin cell surface expression. Using this mesenchymal-based assay, OB-cadherin cellular events are detectable in men with metastatic prostate cancer and are less common in healthy volunteers. This method may complement existing epithelial-based methods and may be particularly useful in patients with bone metastases.

Fluorescence-based alternative splicing reporters for the study of epithelial plasticity in vivo.

Alternative splicing generates a vast diversity of protein isoforms from a limited number of protein-coding genes, with many of the isoforms possessing unique, and even contrasting, functions. Fluorescence-based splicing reporters have the potential to facilitate studies of alternative splicing at the single-cell level and can provide valuable information on phenotypic transitions in almost real time. Fibroblast growth factor receptor 2 (FGFR2) pre-mRNA is alternatively spliced to form the epithelial-specific and mesenchymal-specific IIIb and IIIc isoforms, respectively, which are useful markers of epithelial-mesenchymal transitions (EMT). We have used our knowledge of FGFR2 splicing regulation to develop a fluorescence-based reporter system to visualize exon IIIc regulation in vitro and in vivo. Here we show the application of this reporter system to the study of EMT in vitro in cell culture and in vivo in transgenic mice harboring these splicing constructs. In explant studies, the reporters revealed that FGFR2 isoform switching is not required for keratinocyte migration during cutaneous wound closure. Our results demonstrate the value of the splicing reporters as tools to study phenotypic transitions and cell fates at single cell resolution. Moreover, our data suggest that keratinocytes migrate efficiently in the absence of a complete EMT.

In vivo nitric oxide suppression of lipolysis in subcutaneous abdominal adipose tissue is greater in obese than lean women.

Mounting evidence suggests there is a reduced mobilization of stored fat in obese compared to lean women. It has been suggested that this decreased lipid mobilization may lead to, or perpetuate, the obese state; however, there may be a beneficial effect of reduced lipolysis, either by allowing for a sink of excess fatty acids, or by limiting a potentially harmful rise in interstitial and circulating fatty acid concentration. Nitric oxide (NO) may be responsible for a portion of the reduced in vivo rates of lipolysis in obese women because NO reduces adipose tissue lipolysis and adipose tissue nitric oxide synthase (NOS) mRNA is higher in obese than lean individuals. The purpose of this study was to determine if the inhibition of NOS by L-N(g)-monomethyl-L-arginine (L-NMMA) in the absence and presence of lipolytic stimulation would result in a larger increase in lipolytic rate in obese (OB) than lean (LN) women. Microdialysis probes were inserted into the subcutaneous abdominal adipose tissue of seven obese and six lean women to monitor lipolysis. Dialysate glycerol concentration increased in response to L-NMMA in OB (basal 125 ± 26 µmol/l; L-NMMA 225 ± 35 µmol/l) to a greater extent than in LN (basal 70 ± 18 µmol/l; L-NMMA 84 ± 20 µmol/l) women (P < 0.05). Dialysate glycerol increased to a similar extent in OB and LN in response to adrenergic stimulation by isoprenaline or norepinephrine in the presence of L-NMMA. The differential glycerol responses to L-NMMA between obese and lean could not be explained by differential blood flow responses. It can be concluded that NO suppresses basal lipolysis in obese women to a greater extent than in lean women.

Circulating tumor cells from patients with advanced prostate and breast cancer display both epithelial and mesenchymal markers.

During cancer progression, malignant cells undergo epithelial-mesenchymal transitions (EMT) and mesenchymal-epithelial transitions (MET) as part of a broad invasion and metastasis program. We previously observed MET events among lung metastases in a preclinical model of prostate adenocarcinoma that suggested a relationship between epithelial plasticity and metastatic spread. We thus sought to translate these findings into clinical evidence by examining the existence of EMT in circulating tumor cells (CTC) from patients with progressive metastatic solid tumors, with a focus on men with castration-resistant prostate cancer (CRPC) and women with metastatic breast cancer. We showed that the majority (> 80%) of these CTCs in patients with metastatic CRPC coexpress epithelial proteins such as epithelial cell adhesion molecule (EpCAM), cytokeratins (CK), and E-cadherin, with mesenchymal proteins including vimentin, N-cadherin and O-cadherin, and the stem cell marker CD133. Equally, we found that more than 75% of CTCs from women with metastatic breast cancer coexpress CK, vimentin, and N-cadherin. The existence and high frequency of these CTCs coexpressing epithelial, mesenchymal, and stem cell markers in patients with progressive metastases has important implications for the application and interpretation of approved methods to detect CTCs.

Endothelial nitric oxide synthase content in adipose tissue from obese and lean African American and white American women.

It has been demonstrated that the enzyme endothelial nitric oxide synthase (eNOS) is present in adipose tissue, resulting in nitric oxide production and subsequent inhibition of lipolysis. A higher eNOS content has also been reported in the subcutaneous abdominal adipose tissue of obese than in that of lean white men. Furthermore, a lower lipolytic rate in obese than in lean women and a lower lipolytic rate in African American (AA) than in white American (WA) women have been demonstrated. The purpose of this study was to determine if eNOS protein content is higher in the subcutaneous and omental adipose tissues of obese than in those of lean women and if eNOS protein content is higher in the subcutaneous and omental adipose tissues of AA than in those of WA women. Whole tissue homogenates were prepared from frozen omental and subcutaneous adipose tissue samples obtained from lean and obese and AA and WA elective abdominal surgery patients and were analyzed for eNOS protein content using enzyme-linked immunosorbent assay. The adipose tissue eNOS protein content was approximately 40% higher in obese than in lean individuals (omental, 326.9 +/- 40.5 pg/mL lean and 445.3 +/- 38.0 pg/mL obese; subcutaneous, 246.8 +/- 20.8 pg/mL lean and 343.1 +/- 19.0 pg/mL obese; P < .05). There was no difference between the races for eNOS protein content in omental adipose tissue. In subcutaneous adipose tissue, there was a higher eNOS content in obese (417.1 +/- 78.9 pg/mg total protein) than in lean (216.7 +/- 29.9 pg/mg total protein) (P < .05) WA women, but there was no difference in subcutaneous adipose eNOS content between obese and lean AA women (250.7 +/- 47.4 and 294.1 +/- 42.2 pg/mg total protein, respectively). The higher eNOS content in the adipose tissue of obese than in that of lean WA women in the fasted state may contribute to the reduced lipolytic activity in WA women; however, eNOS protein content probably does not contribute to differences in lipolytic rates between AA and WA women.

Hepatomegaly in transgenic mice expressing the homeobox gene Cux-1.

Cux-1 is a member of a family of homeobox genes structurally related to Drosophila Cut. Mammalian Cut proteins function as transcriptional repressors of genes specifying terminal differentiation in multiple cell lineages. In addition, mammalian Cut proteins serve as cell-cycle-dependent transcriptional factors in proliferating cells, where they function to repress expression of the cyclin kinase inhibitors p21 and p27. Previously we showed that transgenic mice expressing Cux-1 under control of the CMV immediate early gene promoter develop multiorgan hyperplasia. Here we show that mice constitutively expressing Cux-1 exhibit hepatomegaly correlating with an increase in cell proliferation. In addition, the increase in Cux-1 expression in transgenic livers was associated with a decrease in p21, but not p27, expression. Within transgenic livers, Cux-1 was ectopically expressed in a population of small cells, but not in mature hepatocytes, and many of these small cells expressed markers of proliferation. Transgenic livers showed an increase in alpha-smooth muscle actin, indicating activation of hepatic stellate cells, and an increase in cells expressing chromogranin-A, a marker for hepatocyte precursor cells. Morphological analysis of transgenic livers revealed inflammation, hepatocyte swelling, mixed cell foci, and biliary cell hyperplasia. These results suggest that increased expression of Cux-1 may play a role in the activation of hepatic stem cells, possibly through the repression of the cyclin kinase inhibitor p21.

Accurate wavelength measurements of a putative standard for near-infrared diffuse reflection spectrometry.

The diffuse reflection (DR) spectrum of a sample consisting of a mixture of rare earth oxides and talc was measured at 2 cm-1 resolution, using five different accessories installed on five different Fourier transform near-infrared (FT-NIR) spectrometers from four manufacturers. Peak positions for 37 peaks were determined using two peak-picking algorithms: center-of-mass and polynomial fitting. The wavenumber of the band center reported by either of these techniques was sensitive to the slope of the baseline, and so the baseline of the spectra was corrected using either a polynomial fit or conversion to the second derivative. Significantly different results were obtained with one combination of spectrometer and accessory than the others. Apparently, the beam path through the interferometer and DR accessory was different for this accessory than for any of the other measurements, causing a severe degradation of the resolution. Spectra measured on this instrument were removed as outliers. For measurements made on FT-NIR spectrometers, it is shown that it is important to check the resolution at which the spectrum has been measured using lines in the vibration-rotation spectrum of atmospheric water vapor and to specify the peak-picking and baseline-correction algorithms that are used to process the measured spectra. The variance between the results given by the four different methods of peak-picking and baseline correction was substantially larger than the variance between the remaining five measurements. Certain bands were found to be more suitable than others for use as wavelength standards. A band at 5943.13 cm-1 (1682.62 nm) was found to be the most stable band between the four methods and the six measurements. A band at 5177.04 cm-1 (1931.61 nm) has the highest precision between different measurements when polynomial baseline correction and polynomial peak-picking algorithms are used.

Hemoglobin correction for near-infrared pH determination in lysed blood solutions.

The near-infrared (NIR) measurement of blood pH relies on the spectral signature of histidine residing on the hemoglobin molecule. If the amount of hemoglobin in solution varies, the size of the histidine signal can vary depending on changes in either the pH or hemoglobin concentration. Multivariate calibration models developed using the NIR spectra collected from blood at a single hemoglobin concentration are shown to predict data from different hemoglobin levels with a bias and slope. A simple, scalar path length correction of the spectral data does not correct this problem. However, global partial least-square (PLS) models built with data encompassing a range of hemoglobin concentration have a cross-validated standard error of prediction (CVSEP) similar to the CVSEP of data obtained from a single hemoglobin level. It will be shown that the prediction of pH of an unknown sample using a global PLS model requires that the unknown have a hemoglobin concentration falling within the range encompassed by the global model. An alternative method for correcting the predicted pH for hemoglobin levels is also presented. The alternative method updates the single-hemoglobin-level models with slope and intercept estimates from the pH predictions of data collected at alternate hemoglobin levels. The slope and intercept correction method gave SEP values averaging to 0.034 pH units. Since both methods require some knowledge of the hemoglobin concentration in order for a pH prediction to be made, a model for hemoglobin concentration is developed using spectral data and is used for pH correction.

Lower skeletal muscle nutritive blood flow in older women is related to eNOS protein content.

The relationship between muscle endothelial nitric oxide synthase (eNOS) content and nutritive flow was investigated in nonobese sedentary young (27.7 +/- 2.6 years) and older (56.6 +/- 2.1 years) women matched for body composition and (2)peak. A muscle biopsy was taken and nutritive blood flow was determined under resting conditions in the vastus lateralis of the quadriceps femoris muscle group. Muscle eNOS protein content correlated with muscle nutritive blood flow (r =.66, p <.05) and body mass index (r =.74, p <.05), but it did not correlate with VO(2)peak. Muscle eNOS content was 35% lower in young than in older women (266 +/- 36 vs 407 +/- 53 pg/mg total protein; p <.05). The mean ethanol outflow-to-inflow ratio was higher (indicating lower nutritive flow) in older and young women (.666 +/-.042 and.546 +/-.043, respectively: p <.05). Resting skeletal nutritive blood flow and muscle eNOS content was lower in older than in young women. A low muscle eNOS protein content may be linked to a low muscle nutritive blood flow in healthy women.