In Vitro Assessment of Optical Properties of Blood by Applying the Extended Huygens-Fresnel Principle to Time-Domain Optical Coherence Tomography Signal at 1300 nm

A direct method for the measurement of the optical attenuation coefficient and the scattering anisotropy parameter based on applying the extended Huygens-Fresnel principle to optical coherence tomography images of blood is demonstrated. The images are acquired with a low-power probing beam at the wavelength of 1300 nm. Values of 12.15 mm−1 and 0.95 are found for the total attenuation coefficient and the scattering anisotropy factor, respectively. Also, as a preliminary step, the optical refraction index is determined with a precision of two decimal numbers directly from optical coherence images. The total attenuation coefficient and the scattering anisotropy factor are determined with precisions within experimental error margins of 5% and 2%, respectively. Readable OCT signal is obtained for a maximum propagation of light into blood of 0.25 mm. At the maximum probed depth, the measured signal is almost 103 smaller than its initial intensity when entering the sample

Making a case for mainstreaming environmental justice concerns in the mission of the Catholic Church in Sierra Leone in light of Laudato Si’

Recent research indicates that there is an increasing acknowledgement of the role of religious communities in promoting environmental care and sustainability. However, on the African continent, concern for the environment has had much less traction amongst the continent’s religious traditions, despite the continent being one of the world’s most vulnerable areas to the ecological crisis. With regards to the African Catholic Church, many have wondered aloud, since the ecological crisis poses immediate and enduring threats to the African continent, why the issue has not commanded decisive attention in the vast majority of the local churches of Africa. I would ask this question more pointedly: Why has the environmental question not gained much traction in the African Catholic Church – a church that prioritises the image of church as a ‘family of God’ and works within the framework of the church at the service of ‘reconciliation, justice and peace’? Both the model of Church as a ‘family of God’ and the missionary framework of the church at the service of reconciliation, justice, and peace’ emphasise the intricate link between the well-being of the human community and the well-being of the environment. This research thesis seeks to assess environmental justice concerns or the lack thereof in the pastoral priorities of the Catholic Church in Sierra Leone and to argue for the integration of environmental concern and care in its mission. Through critical engagement with Pope Francis’ landmark encyclical, On the Care of our Common Home – Laudato Si’ (2015) in concert with an analysis of my empirical research that I carried out in the four dioceses comprising the Catholic Church in Sierra Leone on the current state of Catholic Church’s engagement with environmental justice issues, I make the case that the environmental challenge confronting Sierra Leone is not only a socio-economic and political problem, but also a moral and spiritual problem that requires an urgent pastoral response from the Catholic Church and by extension other religious communities in the country. I argue that Pope Francis’ encyclical, Laudato Si’ offers a rare opportunity for the Catholic Church in Sierra Leone to reprise its prophetic role and respond to the cry of the earth together with the cry of the poor. In line with the goal of Pope Francis’ Laudato Si’, namely the cultivation of ecological virtues, I will propose that if the Catholic Church in Sierra Leone is to effectively engage with environmental justice issues, it should seek to re-enhance and promote ecological awareness, ecological conversion and environmental sustainability practices in Catholic institutions – parishes, schools, development agencies – and in its outward engagements in ecumenical and interfaith spaces, with governmental and non-governmental agencies, and civil society groups

Diagnosis and Monitoring of Gingivitis in vivo Using Non-Invasive Technology - Infrared Spectroscopy

Peer reviewed: YesNRC publication: Ye

Determining the Effect of Calculus, Hypocalcification, and Stain on Using Optical Coherence Tomography and Polarized Raman Spectroscopy for Detecting White Spot Lesions

Optical coherence tomography (OCT) and polarized Raman spectroscopy (PRS) have been shown as useful methods for distinguishing sound enamel from carious lesions ex vivo. However, factors in the oral environment such as calculus, hypocalcification, and stain could lead to false-positive results. OCT and PRS were used to investigate extracted human teeth clinically examined for sound enamel, white spot lesion (WSL), calculus, hypocalcification, and stain to determine whether these factors would confound WSL detection with these optical methods. Results indicate that OCT allowed differentiating caries from sound enamel, hypocalcification, and stain, with calculus deposits recognizable on OCT images. ANOVA and post-hoc unequal N HSD analyses to compare the mean Raman depolarization ratios from the various groups showed that the mean values were statistically significant at P < .05, except for several comparison pairs. With the current PRS analysis method, the mean depolarization ratios of stained enamel and caries are not significantly different due to the sloping background in the stained enamel spectra. Overall, calculus and hypocalcification are not confounding factors affecting WSL detection using OCT and PRS. Stain does not influence WSL detection with OCT. Improved PRS analysis methods are needed to differentiate carious from stained enamel

Classification of burn injuries using near-infrared spectroscopy.

Early surgical management of those burn injuries that will not heal spontaneously is critical. The decision to excise and graft is based on a visual assessment that is often inaccurate but yet continues to be the primary means of grading the injury. Superficial and intermediate partial-thickness injuries generally heal with appropriate wound care while deep partial- and full-thickness injuries generally require surgery. This study explores the possibility of using near-infrared spectroscopy to provide an objective and accurate means of distinguishing shallow injuries from deeper burns that require surgery. Twenty burn injuries are studied in five animals, with burns covering <1% of the total body surface area. Carefully controlled superficial, intermediate, and deep partial-thickness injuries as well as full-thickness injuries could be studied with this model. Near-infrared reflectance spectroscopy was used to evaluate these injuries 1 to 3 hours after the insult. A probabilistic model employing partial least-squares logistic regression was used to determine the degree of injury, shallow (superficial or intermediate partial) from deep (deep partial and full thickness), based on the reflectance spectrum of the wound. A leave-animal-out cross-validation strategy was used to test the predictive ability of a 2-latent variable, partial least-squares logistic regression model to distinguish deep burn injuries from shallow injuries. The model displayed reasonable ranking quality as summarized by the area under the receiver operator characteristics curve, AUC = 0.879. Fixing the threshold for the class boundaries at 0.5 probability, the model sensitivity (true positive fraction) to separate deep from shallow burns was 0.90, while model specificity (true negative fraction) was 0.83. Using an acute porcine model of thermal burn injuries, the potential of near-infrared spectroscopy to distinguish between shallow healing burns and deeper burn injuries was demonstrated. While these results should be considered as preliminary and require clinical validation, a probabilistic model capable of differentiating these classes of burns would be a significant aid to the burn specialist

Surface expression, peptide repertoire, and thermostability of chicken class I molecules correlate with peptide transporter specificity.

The chicken major histocompatibility complex (MHC) has strong genetic associations with resistance and susceptibility to certain infectious pathogens. The cell surface expression level of MHC class I molecules varies as much as 10-fold between chicken haplotypes and is inversely correlated with diversity of peptide repertoire and with resistance to Marek's disease caused by an oncogenic herpesvirus. Here we show that the average thermostability of class I molecules isolated from cells also varies, being higher for high-expressing MHC haplotypes. However, we find roughly the same amount of class I protein synthesized by high- and low-expressing MHC haplotypes, with movement to the cell surface responsible for the difference in expression. Previous data show that chicken TAP genes have high allelic polymorphism, with peptide translocation specific for each MHC haplotype. Here we use assembly assays with peptide libraries to show that high-expressing B15 class I molecules can bind a much wider variety of peptides than are found on the cell surface, with the B15 TAPs restricting the peptides available. In contrast, the translocation specificity of TAPs from the low-expressing B21 haplotype is even more permissive than the promiscuous binding shown by the dominantly expressed class I molecule. B15/B21 heterozygote cells show much greater expression of B15 class I molecules than B15/B15 homozygote cells, presumably as a result of receiving additional peptides from the B21 TAPs. Thus, chicken MHC haplotypes vary in several correlated attributes, with the most obvious candidate linking all these properties being molecular interactions within the peptide-loading complex (PLC).This work was originally supported by core funding to the Basel Institute for Immunology (which was founded and supported by F. Hoffmann-La Roche & Co. Ltd., CH-4005 Basel, Switzerland), then by core funding to the Institute for Animal Health [now re-branded the Pirbright Institute, sponsored by the Biotechnology and Biological Sciences Research Council (BBSRC) of the UK] and finally by programme grant 089305 from the Wellcome Trust to JK.This is the author accepted manuscript. The final version is available from PNAS via http://dx.doi.org/10.1073/pnas.151185911

Ex vivo detection and characterization of early dental caries by optical coherence tomography and Raman spectroscopy.

Early dental caries detection will facilitate implementation of nonsurgical methods for arresting caries progression and promoting tooth remineralization. We present a method that combines optical coherence tomography (OCT) and Raman spectroscopy to provide morphological information and biochemical specificity for detecting and characterizing incipient carious lesions found in extracted human teeth. OCT imaging of tooth samples demonstrated increased light backscattering intensity at sites of carious lesions as compared to the sound enamel. The observed lesion depth on an OCT image was approximately 290 mm matching those previously documented for incipient caries. Using Raman microspectroscopy and fiber-optic- based Raman spectroscopy to characterize the caries further, spectral changes were observed in PO 42 vibrations arising from hydroxyapa- tite of mineralized tooth tissue. Examination of various ratios of PO 42 n 2 , n 3 , n 4 vibrations against the n 1 vibration showed consistent in- creases in carious lesions compared to sound enamel. The changes were attributed to demineralization-induced alterations of enamel crystallite morphology and/or orientation. OCT imaging is useful for screening carious sites and determining lesion depth, with Raman spectroscopy providing biochemical confirmation of caries. The com- bination has potential for development into a new fiber-optic diagnos- tic tool enabling dentists to identify early caries lesions with greater sensitivity and specificity. © 2005 Society of Photo-Optical Instrumentation Engi

Over-Expression of LEDGF/p75 in HEp-2 Cells Enhances Autoimmune IgG Response in Patients with Benign Prostatic Hyperplasia : A Novel Diagnostic Approach with Therapeutic Consequence?

Lens epithelium-derived growth factor splice variant of 75 kDa (LEDGF/p75) is an autoantigen over-expressed in solid tumors and acts as a stress-related transcriptional co-activator. Participation of autoimmune responses in the pathophysiology of benign prostatic hyperplasia (PBH) and a corresponding immunosuppressive therapy by TNFalpha antagonists has been recently suggested. Thus, autoAb testing could aid in the diagnosis of BPH patients profiting from such therapy. We generated CRISPR/Cas9 modified HEp-2 LEDGF knock-out (KO) and HEp-2 LEDGF/p75 over-expressing (OE) cells and examined IgG autoantibody reactivity to LEDGF/p75 in patients with prostate cancer (PCa, n = 89), bladder cancer (BCa, n = 116), benign prostatic hyperplasia (BPH, n = 103), and blood donors (BD, n = 60) by indirect immunofluorescence assay (IFA). Surprisingly, we could not detect elevated binding of autoAbs against LEDGF/p75 in cancer patients, but autoAb reactivity to LEDGF/p75 OE cells in about 50% of patients with BPH was unexpectedly significantly increased. Furthermore, a line immunoassay enabling the detection of 18 different autoAbs revealed a significantly increased occurrence of anti-dsDNA autoAbs in 34% of BPH patients in contrast to tumor patients and BD. This finding was confirmed by anti-mitochondrial (mDNA) autoAb detection with the Crithidia luciliae immunofluorescence test, which also showed a significantly higher prevalence (34%) of anti-mDNA autoAbs in BPH. In summary, our study provided further evidence for the occurrence of autoimmune responses in BPH. Furthermore, LEDGF/p75 over-expression renders HEp-2 cells more autoantigenic and an ideal target for autoAb analysis in BPH with a potential therapy consequence