Handheld hyperspectral imaging as a tool for the post-mortem interval estimation of human skeletal remains.

In forensic medicine, estimating human skeletal remains' post-mortem interval (PMI) can be challenging. Following death, bones undergo a series of chemical and physical transformations due to their interactions with the surrounding environment. Post-mortem changes have been assessed using various methods, but estimating the PMI of skeletal remains could still be improved. We propose a new methodology with handheld hyperspectral imaging (HSI) system based on the first results from 104 human skeletal remains with PMIs ranging between 1 day and 2000 years. To differentiate between forensic and archaeological bone material, the Convolutional Neural Network analyzed 65.000 distinct diagnostic spectra: the classification accuracy was 0.58, 0.62, 0.73, 0.81, and 0.98 for PMIs of 0 week-2 weeks, 2 weeks-6 months, 6 months-1 year, 1 year-10 years, and >100 years, respectively. In conclusion, HSI can be used in forensic medicine to distinguish bone materials >100 years old from those <10 years old with an accuracy of 98%. The model has adequate predictive performance, and handheld HSI could serve as a novel approach to objectively and accurately determine the PMI of human skeletal remains.

Long-Term Comparison of Two- and Three-Dimensional Computed Tomography Analyses of Cranial Bone Defects in Severe Parietal Thinning.

Parietal thinning was detected in a 72-year-old with recurrent headaches. Quantification of bone loss was performed applying two- and three-dimensional methods using computerized tomographies. Two-dimensional methods provided accurate measurements using single-line analyses of bone thicknesses (2.13 to 1.65 and 1.86 mm on the left and 4.44 to 3.08 and 4.20 mm on the right side), single-point analyses of bone intensities (693 to 375 and 403 on the left and 513 to 393 and 411 Houndsfield Units on the right side) and particle-size analyses of low density areas (16 to 22 and 12 on the left and 18 to 23 and 14 on the right side). Deteriorations between days 0 and 220 followed by bone stability on day 275 were paralleled using the changed volumes of bone defects to 1200 and finally 1133 mm3 on the left side and to 331 and finally 331 mm3 on the right side. Interfolding as measurement of the bones' shape provided changes to -1.23 and -1.72 mm on the left and to -1.42 and -1.30 mm on the right side. These techniques suggest a stabilizing effect of corticosteroids between days 220 and 275. Reconstruction of computerized tomographies appears justified to allow for quantification of bone loss during long-term follow-up.

Comparison of Mid-Infrared Handheld and Benchtop Spectrometers to Detect Staphylococcus epidermidis in Bone Grafts.

Bone analyses using mid-infrared spectroscopy are gaining popularity, especially with handheld spectrometers that enable on-site testing as long as the data quality meets standards. In order to diagnose Staphylococcus epidermidis in human bone grafts, this study was carried out to compare the effectiveness of the Agilent 4300 Handheld Fourier-transform infrared with the Perkin Elmer Spectrum 100 attenuated-total-reflectance infrared spectroscopy benchtop instrument. The study analyzed 40 non-infected and 10 infected human bone samples with Staphylococcus epidermidis, collecting reflectance data between 650 cm-1 and 4000 cm-1, with a spectral resolution of 2 cm-1 (Agilent 4300 Handheld) and 0.5 cm-1 (Perkin Elmer Spectrum 100). The acquired spectral information was used for spectral and unsupervised classification, such as a principal component analysis. Both methods yielded significant results when using the recommended settings and data analysis strategies, detecting a loss in bone quality due to the infection. MIR spectroscopy provides a valuable diagnostic tool when there is a tissue shortage and time is of the essence. However, it is essential to conduct further research with larger sample sizes to verify its pros and cons thoroughly.

Morphological and Tissue Characterization with 3D Reconstruction of a 350-Year-Old Austrian Ardea purpurea Glacier Mummy.

Glaciers are dwindling archives, releasing animal mummies preserved in the ice for centuries due to climate changes. As preservation varies, residual soft tissues may differently expand the biological information content of such mummies. DNA studies have proven the possibility of extracting and analyzing DNA preserved in skeletal residuals and sediments for hundreds or thousands of years. Paleoradiology is the method of choice as a non-destructive tool for analyzing mummies, including micro-computed tomography (micro-CT) and magnetic resonance imaging (MRI). Together with radiocarbon dating, histo-anatomical analyses, and DNA sequencing, these techniques were employed to identify a 350-year-old Austrian Ardea purpurea glacier mummy from the Ötztal Alps. Combining these techniques proved to be a robust methodological concept for collecting inaccessible information regarding the structural organization of the mummy. The variety of methodological approaches resulted in a distinct picture of the morphological patterns of the glacier animal mummy. The BLAST search in GenBank resulted in a 100% and 98.7% match in the cytb gene sequence with two entries of the species Purple heron (Ardea purpurea; Accession number KJ941160.1 and KJ190948.1) and a 98% match with the same species for the 16 s sequence (KJ190948.1), which was confirmed by the anatomic characteristics deduced from micro-CT and MRI.

Radiographic and clinical outcome of tibial plateau fractures treated with bone allograft.

BACKGROUND: To determine the clinical outcome of patients who had been treated with bone allografts during open reduction and internal fixation (ORIF) of tibial head fractures. METHODS: Patients who suffered a medial, lateral, or bicondylar fracture of the tibial plateau and underwent surgical treatment by open reduction and internal fixation (ORIF) using human femoral head bone allografts were included. Patients were invited to provide information for the following: Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), EuroQol Five Dimension score (EQ-5D), Lower Extremity Functional Scale (LEFS) and Parker Mobility Score. Bone mineral density (BMD) of the allograft area and the healthy human bone tissue were measured by quantitative computed tomography. RESULTS: A total of 22 patients with a mean follow-up time of 2.88 ± 2.46 years were included in our study. The most common fractures observed in this study were classified as Schatzker II (11 patients, 50.0%) or AO/OTA 41.B3 (12 patients, 54.5%) fractures. Postoperative WOMAC total was 13.0 (IQR = 16.3, range 0-33). Median quality of life (EQ-5D) score was 0.887 ± 0.121 (range 0.361-1.000). Median Lower Extremity Functional Scale (LEFS) score was 57.5 ± 19.0 (range 33-79). Mean Parker Mobility Score was 9 (range 6-9). Median bone mineral density (BMD) for the whole group was 300.04 ± 226.02 mg/cm3 (range - 88.68 to 555.06 mg/cm3) for region of interest (ROI 5) (central), 214.80 ± 167.45 mg/cm3 (range - 7.16 to 597.21 mg/cm3) for ROI 1-4 (marginal zones: medial, lateral, ventral, dorsal) and 168.14 ± 65.54 mg/cm3 (range 17.47-208.97 mg/cm3) for healthy bone tissue (femur and tibia). CONCLUSION: Based on WOMAC scores, LEFS, ambulatory status, and quality of life findings, it can be concluded that following tibial head ORIF with allograft bone patients has promising results.

Enhancing Bone Infection Diagnosis with Raman Handheld Spectroscopy: Pathogen Discrimination and Diagnostic Potential.

Osteomyelitis is a bone disease caused by bacteria that can damage bone. Raman handheld spectroscopy has emerged as a promising diagnostic tool for detecting bone infection and can be used intraoperatively during surgical procedures. This study involved 120 bone samples from 40 patients, with 80 samples infected with either Staphylococcus aureus or Staphylococcus epidermidis. Raman handheld spectroscopy demonstrated successful differentiation between healthy and infected bone samples and between the two types of bacterial pathogens. Raman handheld spectroscopy appears to be a promising diagnostic tool in bone infection and holds the potential to overcome many of the shortcomings of traditional diagnostic procedures. Further research, however, is required to confirm its diagnostic capabilities and consider other factors, such as the limit of pathogen detection and optimal calibration standards.

Post-Mortem Interval of Human Skeletal Remains Estimated with Handheld NIR Spectrometry.

Estimating the post-mortem interval (PMI) of human skeletal remains is a critical issue of forensic analysis, with important limitations such as sample preparation and practicability. In this work, NIR spectroscopy (NIRONE® Sensor X; Spectral Engines, 61449, Germany) was applied to estimate the PMI of 104 human bone samples between 1 day and 2000 years. Reflectance data were repeatedly collected from eight independent spectrometers between 1950 and 1550 nm with a spectral resolution of 14 nm and a step size of 2 nm, each from the external and internal bone. An Artificial Neural Network was used to analyze the 66,560 distinct diagnostic spectra, and clearly distinguished between forensic and archaeological bone material: the classification accuracies for PMIs of 0−2 weeks, 2 weeks−6 months, 6 months−1 year, 1 year−10 years, and >100 years were 0.90, 0.94, 0.94, 0.93, and 1.00, respectively. PMI of archaeological bones could be determined with an accuracy of 100%, demonstrating the adequate predictive performance of the model. Applying a handheld NIR spectrometer to estimate the PMI of human skeletal remains is rapid and extends the repertoire of forensic analyses as a distinct, novel approach.

Assessing various Infrared (IR) microscopic imaging techniques for post-mortem interval evaluation of human skeletal remains.

Due to the influence of many environmental processes, a precise determination of the post-mortem interval (PMI) of skeletal remains is known to be very complicated. Although methods for the investigation of the PMI exist, there still remains much room for improvement. In this study the applicability of infrared (IR) microscopic imaging techniques such as reflection-, ATR- and Raman- microscopic imaging for the estimation of the PMI of human skeletal remains was tested. PMI specific features were identified and visualized by overlaying IR imaging data with morphological tissue structures obtained using light microscopy to differentiate between forensic and archaeological bone samples. ATR and reflection spectra revealed that a more prominent peak at 1042 cm-1 (an indicator for bone mineralization) was observable in archeological bone material when compared with forensic samples. Moreover, in the case of the archaeological bone material, a reduction in the levels of phospholipids, proteins, nucleic acid sugars, complex carbohydrates as well as amorphous or fully hydrated sugars was detectable at (reciprocal wavelengths/energies) between 3000 cm-1 to 2800 cm-1. Raman spectra illustrated a similar picture with less ν2PO43-at 450 cm-1 and ν4PO43- from 590 cm-1 to 584 cm-1, amide III at 1272 cm-1 and protein CH2 deformation at 1446 cm-1 in archeological bone material/samples/sources. A semi-quantitative determination of various distributions of biomolecules by chemi-maps of reflection- and ATR- methods revealed that there were less carbohydrates and complex carbohydrates as well as amorphous or fully hydrated sugars in archaeological samples compared with forensic bone samples. Raman- microscopic imaging data showed a reduction in B-type carbonate and protein α-helices after a PMI of 3 years. The calculated mineral content ratio and the organic to mineral ratio displayed that the mineral content ratio increases, while the organic to mineral ratio decreases with time. Cluster-analyses of data from Raman microscopic imaging reconstructed histo-anatomical features in comparison to the light microscopic image and finally, by application of principal component analyses (PCA), it was possible to see a clear distinction between forensic and archaeological bone samples. Hence, the spectral characterization of inorganic and organic compounds by the afore mentioned techniques, followed by analyses such as multivariate imaging analysis (MIAs) and principal component analyses (PCA), appear to be suitable for the post mortem interval (PMI) estimation of human skeletal remains.

MALDI-MS tissue imaging identification of biliverdin reductase B overexpression in prostate cancer.

New biomarkers are needed to improve the specificity of prostate cancer detection and characterisation of individual tumors. In a proteomics profiling approach using MALDI-MS tissue imaging on frozen tissue sections, we identified discriminating masses. Imaging analysis of cancer, non-malignant benign epithelium and stromal areas of 15 prostatectomy specimens in a test and 10 in a validation set identified characteristic m/z peaks for each tissue type, e.g. m/z 10775 for benign epithelial, m/z 6284 and m/z 6657.5 for cancer and m/z 4965 for stromal tissue. A 10-fold cross-validation analysis showed highest discriminatory ability to separate tissue types for m/z 6284 and m/z 6657.5, both overexpressed in cancer, and a multicomponent mass peak cluster at m/z 10775-10797.4 overexpressed in benign epithelial tissue. ROC AUC values for these three masses ranged from 0.85 to 0.95 in the discrimination of malignant and non-malignant tissue. To identify the underlying proteins, prostate whole tissue extract was separated by nano-HPLC and subjected to MALDI TOF/TOF analysis. Proteins in fractions containing discriminatory m/z masses were identified by MS/MS analysis and candidate marker proteins subsequently validated by immunohistochemistry (IHC). Biliverdin reductase B (BLVRB) turned out to be overexpressed in PCa tissue. BIOLOGICAL SIGNIFICANCE: In this study on cryosections of radical prostatectomies of prostate cancer patients, we performed a MALDI-MS tissue imaging analysis and a consecutive protein identification of significant m/z masses by nano-HPLC, MALDI TOF/TOF and MS/MS analysis. We identified BLVRB as a potential biomarker in the discrimination of PCa and benign tissue, also suggesting BVR as a feasible therapeutic target.