Comparison of infrared spectra of CLL cells with their ex vivo sensitivity (MTT assay) to chlorambucil and cladribine

Infrared Spectroscopy: A New Frontier in Hematological Disease Diagnosis

Hematological diseases, due to their complex nature and diverse manifestations, pose significant diagnostic challenges in healthcare. The pressing need for early and accurate diagnosis has driven the exploration of novel diagnostic techniques. Infrared (IR) spectroscopy, renowned for its noninvasive, rapid, and cost-effective characteristics, has emerged as a promising adjunct in hematological diagnostics. This review delves into the transformative role of IR spectroscopy and highlights its applications in detecting and diagnosing various blood-related ailments. We discuss groundbreaking research findings and real-world applications while providing a balanced view of the potential and limitations of the technique. By integrating advanced technology with clinical needs, we offer insights into how IR spectroscopy may herald a new era of hematological disease diagnosis.

Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (FTIR) and Artificial Neural Networks Applied to Investigate Quantitative Changes of Selected Soluble Biomarkers, Correlated with H. pylori Infection in Children and Presumable Consequent Delayed Growth

Helicobacter pylori infections causing gastroduodenal disorders are a common medical problem. The aim of this study was to determine the specific motives of infrared spectroscopy (IR) spectra of sera from H. pylori-infected and uninfected children applied to investigate quantitatively-selected soluble biomarkers correlated with H. pylori infection in children and presumable consequent delayed growth. Sera from 41 children infected with H. pylori (Hp(+)) and 43 uninfected (Hp(-)) under the care of the Polish Mother's Hospital in Lodz, Poland, were analyzed. The H. pylori status was confirmed by gastroscopy, ¹³C urea breath testing, and anti-H. pylori IgG antibodies. Infrared spectra were measured using an FTIR/FT-NIR Spectrum 400 spectrometer (PerkinElmer). The IR spectrum was measured in the wavenumber range 3000-750 cm^-1 and subjected to mathematical calculation of the first derivative. Based on the chi-square test, 10 wavenumbers of spectra correlating with H. pylori infection were selected for use in designing an artificial neural network. Ten parts of the IR spectra correlating with H. pylori infection were identified in the W2 and W3 windows associated mainly with proteins and the W4 window related to nucleic acids and hydrocarbons. Artificial neural networks for H. pylori infection were developed based on chemometric data. By mathematical modeling, children were classified towards H. pylori infection in conjunction with elevated levels of selected biomarkers in serum potentially related to growth retardation. The study concludes that IR spectroscopy and artificial neural networks may help to confirm H. pylori-driven growth disorders in children.

Indian Ginseng (Withania somnifera) supplementation ameliorates oxidative stress and mitochondrial dysfunctions in experimental model of stroke

Stroke is an increasingly prevalent clinical condition and second leading cause of death globally. The present study evaluated the therapeutic potential of Indian Ginseng, also known as Withania somnifera (WS), supplementation on middle cerebral artery occlusion (MCAO) induced mitochondrial dysfunctions in experimental model of ischemic stroke. Stroke was induced in animals by occluding the middle cerebral artery, followed by reperfusion injury. Ischemia reperfusion injury resulted in increased oxidative stress indicated by increased reactive oxygen species and protein carbonyl levels; compromised antioxidant system; in terms of reduced superoxide dismutase and catalase activity, along with reduction in GSH levels and the redox ratio, impaired mitochondrial functions and enhanced expression of apoptosis markers. Ischemia reperfusion injury induced mitochondrial dysfunctions in terms of (i) reduced activity of the mitochondrial respiratory chain enzymes, (ii) reduced histochemical staining of complex-II and IV, (iii) reduced in-gel activity of mitochondrial complex-I to V, (iv) mitochondrial structural changes in terms of increased mitochondrial swelling, reduced mitochondrial membrane potential and ultrastructural changes. Additionally, an increase in the activity of caspase-3 and caspase-9 was also observed, along with altered expression of apoptotic proteins Bcl-2 and Bax in MCAO animals. MCAO animals also showed significant impairment in cognitive functions assessed using Y maze test. WS pre-supplementation, on the other hand ameliorated MCAO induced oxidative stress, mitochondrial dysfunctions, apoptosis and cognitive impairments. The results show protective effect of WS pre-supplementation in ischemic stroke and are suggestive of its potential application in stroke management.

Diabetes-associated periodontitis molecular features in infrared spectra of gingival crevicular fluid

BACKGROUND

It has been established previously that infrared spectroscopy (IRS) can be used to identify periodontitis-specific molecular signatures in gingival crevicular fluid (GCF) and to confirm clinical diagnoses. This follow-up study is designed to assess whether this novel technique is also able to differentiate diseased from healthy sites in patients with diabetes mellitus (DM) by analyzing the molecular fingerprints embedded in the GCF.

METHODS

A total of 65 patients with DM with moderate-to-severe chronic periodontitis (CP) was recruited, and 15 individuals without DM (65 sites) without periodontal diseases were used as control. Clinical examination and GCF samples were taken from a total of 351 sites, including periodontitis (109), gingivitis (115), and healthy (127) sites. Corresponding absorption spectra of GCF samples were acquired and processed, and the relative contributions of key functional groups in the infrared spectra were identified and analyzed. The qualitative assessment of clinical relevance of these GCF spectra was interpreted with multivariate statistical analysis: linear discriminant analysis (LDA).

RESULTS

Spectral analysis revealed several molecular signatures representing vibrations in protein (amide I and II), lipid ester, and sugar moieties in the GCF of patients with DM with CP and non-DM controls. The diagnostic accuracy for distinction between healthy and CP sites in patients with DM determined by LDA of GCF spectra was 95.3% for the training set of samples and 87.5% for the validation set. Additional LDA of GCF spectra from healthy sites of non-DM controls and patients with DM revealed 100% diagnostic accuracy for the training set and 86.7% for the validation set. The regions robotically selected by LDA for the two analyses were slightly different in that first LDA identified major regions clustered with the side chain vibrations originating from protein and DNA contents, whereas the second was predominantly the glycation and protein components.

CONCLUSION

IRS is a feasible method to differentiate disease-specific molecular signatures in GCF in the presence of DM and to generate a complex biochemical profile of GCF to identify DM-specific spectral features.

Periodontitis-specific molecular signatures in gingival crevicular fluid

BACKGROUND AND OBJECTIVE

Periodontitis is currently diagnosed almost entirely on gross clinical manifestations that have been in situ for more than 50 years without significant improvement. The general objective of this study was, therefore, to evaluate whether mid-infrared spectroscopy can be used to identify disease-specific molecular alterations to the overall biochemical profile of tissues and body fluids.

MATERIAL AND METHODS

A total of 190 gingival crevicular fluid samples were obtained from periodontitis (n = 64), gingivitis (n = 61) and normal sites (n = 65). Corresponding infrared absorption spectra of gingival crevicular fluid samples were acquired and processed, and the relative contributions of key functional groups in the infrared spectra were analysed. The qualitative assessment of clinical relevance of these gingival crevicular fluid spectra was interpreted with the multivariate statistical analysis-linear discriminant analysis.

RESULTS

Using infrared spectroscopy, we have been able to identify four molecular signatures (representing vibrations in amide I, amide II/tyrosine rings and symmetric and asymmetric PO2- stretching vibrations of phosphodiester groups in DNA) in the gingival crevicular fluid of subjects with periodontitis or gingivitis and healthy control subjects that clearly demarcate healthy and diseased periodontal tissues. Furthermore, the diagnostic accuracy for distinction between periodontally healthy and periodontitis sites revealed by multivariate classification of gingival crevicular fluid spectra was 98.4% for a training set of samples and 93.1% for a validation set.

CONCLUSION

We have established that mid-infrared spectroscopy can be used to identify periodontitis-specific molecular signatures in gingival crevicular fluid and to confirm clinical diagnoses. Future longitudinal studies will assess whether mid-infrared spectroscopy represents a potential prognostic tool, recognized as key to advancement of periodontics.

Vibrational spectroscopy: a clinical tool for cancer diagnostics

Vibrational spectroscopy techniques have demonstrated potential to provide non-destructive, rapid, clinically relevant diagnostic information. Early detection is the most important factor in the prevention of cancer. Raman and infrared spectroscopy enable the biochemical signatures from biological tissues to be extracted and analysed. In conjunction with advanced chemometrics such measurements can contribute to the diagnostic assessment of biological material. This paper also illustrates the complementary advantage of using Raman and FTIR spectroscopy technologies together. Clinical requirements are increasingly met by technological developments which show promise to become a clinical reality. This review summarises recent advances in vibrational spectroscopy and their impact on the diagnosis of cancer.

Metabolic fingerprinting as a diagnostic tool

Within the framework of systems biology, functional analyses at all 'omic levels have seen an intense level of activity during the first decade of the twenty-first century. These include genomics, transcriptomics, proteomics, metabolomics and lipidomics. It could be said that metabolomics offers some unique advantages over the other 'omics disciplines and one of the core approaches of metabolomics for disease diagnostics is metabolic fingerprinting. This review provides an overview of the main metabolic fingerprinting approaches used for disease diagnostics and includes: infrared and Raman spectroscopy, Nuclear magnetic resonance (NMR) spectroscopy, followed by an introduction to a wide range of novel mass spectrometry-based methods, which are currently under intense investigation and developmental activity in laboratories worldwide. It is hoped that this review will act as a springboard for researchers and clinicians across a wide range of disciplines in this exciting era of multidisciplinary and novel approaches to disease diagnostics.

Application of multivariate data-analysis techniques to biomedical diagnostics based on mid-infrared spectroscopy

The objective of this contribution is to review the application of advanced multivariate data-analysis techniques in the field of mid-infrared (MIR) spectroscopic biomedical diagnosis. MIR spectroscopy is a powerful chemical analysis tool for detecting biomedically relevant constituents such as DNA/RNA, proteins, carbohydrates, lipids, etc., and even diseases or disease progression that may induce changes in the chemical composition or structure of biological systems including cells, tissues, and bio-fluids. However, MIR spectra of multiple constituents are usually characterized by strongly overlapping spectral features reflecting the complexity of biological samples. Consequently, MIR spectra of biological samples are frequently difficult to interpret by simple data-analysis techniques. Hence, with increasing complexity of the sample matrix more sophisticated mathematical and statistical data analysis routines are required for deconvoluting spectroscopic data and for providing useful results from information-rich spectroscopic signals. A large body of work relates to the combination of multivariate data-analysis techniques with MIR spectroscopy, and has been applied by a variety of research groups to biomedically relevant areas such as cancer detection and analysis, artery diseases, biomarkers, and other pathologies. The reported results indeed reveal a promising perspective for more widespread application of multivariate data analysis in assisting MIR spectroscopy as a screening or diagnostic tool in biomedical research and clinical studies. While the authors do not mean to ignore any relevant contributions to biomedical analysis across the entire electromagnetic spectrum, they confine the discussion in this contribution to the mid-infrared spectral range as a potentially very useful, yet underutilized frequency region. Selected representative examples without claiming completeness will demonstrate a range of biomedical diagnostic applications with particular emphasis on the advantageous interaction between multivariate data analysis and MIR spectroscopy.

Biomolecular characterisation of leucocytes by infrared spectroscopy

Over the last 15 years, infrared (IR) spectroscopy has developed into a novel and powerful biomedical tool that has multiple applications in the field of haematology. By revealing subtle alterations in both the conformation and concentration of key macromolecules, such as DNA, protein and lipids, IR spectroscopy has been employed to investigate multiple aspects of leucocyte physiology. IR spectroscopy has been used, for example, to diagnose and prognose leukaemia; to characterise differentiation and apoptotic processes; to predict drug sensitivity and resistance in leukaemic patients undergoing chemotherapy; to monitor the response of leucocytes to chemotherapy and to perform human leucocyte antigen matching for bone marrow transplant patients. Such studies have provided insight into pathogenic mechanisms underlying specific leucocyte disorders, especially leukaemia. While it is likely to be some considerable time before IR spectroscopy is sufficiently developed to displace the established technologies, IR spectroscopy has the potential to become a valuable analytic tool in basic and clinical haematology.

Metabolic fingerprinting in disease diagnosis: biomedical applications of infrared and Raman spectroscopy

The ability to diagnose the early onset of disease, rapidly, non-invasively and unequivocally has multiple benefits. These include the early intervention of therapeutic strategies leading to a reduction in morbidity and mortality, and the releasing of economic resources within overburdened health care systems. Some of the routine clinical tests currently in use are known to be unsuitable or unreliable. In addition, these often rely on single disease markers which are inappropriate when multiple factors are involved. Many diseases are a result of metabolic disorders, therefore it is logical to measure metabolism directly. One of the strategies employed by the emergent science of metabolomics is metabolic fingerprinting; which involves rapid, high-throughput global analysis to discriminate between samples of different biological status or origin. This review focuses on a selective number of recent studies where metabolic fingerprinting has been forwarded as a potential tool for disease diagnosis using infrared and Raman spectroscopies.

Molecular and chemical characterization of blood cells by infrared spectroscopy: a new optical tool in hematology

Infrared (IR) spectroscopy has made important contributions to the arena of hematology in the past decade. The normal physiology and pathologic modifications of the three cellular elements in blood, i.e., leukocytes, erythrocytes and platelets, have been thoroughly investigated by this recently emerged optical tool. By revealing subtle alterations in the structures of macromolecules in these blood cells, IR spectroscopy has become an ideal complementary analytical tool to conventional biochemical assays used to diagnose various common hematological disorders. Such traditional assays include molecular structure measurements that determine erythrocyte membrane fluidity and conformational changes, lipid profiling of platelet membranes, as well as assays of leukocyte proliferation and differentiation. IR spectroscopic-based techniques can be used to analyze DNA alterations, secondary structural changes in proteins, and to profile cellular lipids. From a molecular and biomedical perspective, IR spectroscopy has been explored for the diagnosis and prognosis of leukemia and beta-thalassemia, to predict drug sensitivity and resistance in chemotherapy patients, and more recently to examine apoptotic processes in blood cells. These studies have shown great promise in the early identification of drug-resistant patients and the early diagnosis of hematological disorders, especially malignancies. Furthermore, IR spectroscopic-based investigations will enable specific mechanisms underlying hematological disorders to be elucidated by revealing the molecular changes in the blood cells at a very early pathogenesis stage.

Pexiganan-incorporated collagen matrices for infected wound-healing processes in rat

The use of peptide-based drugs is limited by their rapid degradability and toxicity at high concentration during their therapeutic application. These problems could be managed by the use of a peptide delivery agent for sustained release in the site of action. Collagen is one of the most proven biomaterials of good biocompatibility with an exceptional ligand encapsulating property. In this work, we have shown that pexiganan, an antimicrobial, 22-amino-acid peptide could be incorporated and delivered to the wound-healing site against bacterial strains Pseudomonas aeruginosa and Staphylococcus aureus. The release profiles of pexiganan collagen films with different collagen concentration were studied. The release of pexiganan from 2.5% w/w of collagen film showed a sustainable activity over 72 h with effective antimicrobial concentrations. Pexiganan-incorporated collagen (PIC)-treated groups were compared with open wound (OW)- and collagen film (CF)-treated rats. PIC-treated animals showed a diminishing level of bacterial growth as compared with OW- and CF-treated animals. The biochemical parameters such as hydroxyproline, protein, DNA, uronic acid, hexosamine, SOD, and catalase content in the granulation tissue of the healing wound revealed increased proliferation of cells involved in tissue reconstruction in PIC-treated groups when compared with OW- and CF-treated groups. Furthermore, spectroscopic studies suggested that collagen structure is not perturbed by pexiganan incorporation. This study provides rationale for application of collagen membrane for antimicrobial peptide delivery in infected wounds.

Infrared spectroscopic identification of beta-thalassemia

BACKGROUND

The aim of this study was to investigate the potential of infrared (IR) spectroscopy as a fast and reagent-free adjunct tool in the diagnosis and screening of beta-thalassemia.

METHODS

Blood was obtained from 56 patients with beta-thalassemia major, 1 patient with hemoglobin H disease, and 35 age-matched controls. Hemolysates of blood samples were centrifuged to remove stroma. IR absorption spectra were recorded for duplicate films dried from 5 microL of hemolysate. Differentiation between the two groups of hemoglobin spectra was by two statistical methods: an unsupervised cluster analysis and a supervised linear discriminant analysis (LDA).

RESULTS

The IR spectra revealed changes in the secondary structure of hemoglobin from beta-thalassemia patients compared with that from controls, in particular, a decreased alpha-helix content, an increased content of parallel and antiparallel beta-sheets, and changes in the tyrosine ring absorption band. The hemoglobin from beta-thalassemia patients also showed an increase in the intensity of the IR bands from the cysteine -SH groups. The unsupervised cluster analysis, statistically separating spectra into different groups according to subtle IR spectral differences, allowed separation of control hemoglobin from beta-thalassemia hemoglobin spectra, based mainly on differences in protein secondary structure. The supervised LDA method provided 100% classification accuracy for the training set and 98% accuracy for the validation set in partitioning control and beta-thalassemia samples.

CONCLUSION

IR spectroscopy holds promise in the clinical diagnosis and screening of beta-thalassemia.

Preliminary results of evaluation of progress in chemotherapy for childhood leukemia patients employing Fourier-transform infrared microspectroscopy and cluster analysis

Acute lymphoblastic leukemia (ALL) is the most common malignancy in children, but remarkable progress in methods of chemotherapy has increased the cure rate to 80%. The leukemic cells called blasts are eliminated within 7 days of chemotherapy. Clinically, the blast count is monitored directly with the use of blood smears on the basis of specific genetic markers and immunophenotyping methods such as flow cytometry. In this article, we present preliminary results, obtained with the use of Fourier-transform infrared microspectroscopy and cluster analysis, of an approach to monitoring the progress made with chemotherapy in 1 B-cell and 2 T-cell pediatric ALL patients. Our results indicated that the biological marker derived from the spectra did not provide accurate prediction of the progress made with chemotherapy. However, cluster analysis of FTIR-MSP spectra provided good classification of the samples with and without blasts, which correlate satisfactorily with clinical data. Extensive studies are required to substantiate our findings statistically which may have potential application of FTIM in the diagnosis and follow-up of various types of malignancies.

The potential role of Fourier transform infrared spectroscopy and imaging in cancer diagnosis incorporating complex mathematical methods

Infrared spectroscopy and imaging technology can provide new diagnostic capabilities for cancer research applications and to physicians directly involved in patient treatment. A methodology that permits the phenotypical description of cells and tissues is introduced, as well as a variety of new evaluation techniques that allow researchers and physicians to evaluate the infrared data at different levels of sophistication. The detection of cell alterations in the case of Chronic Lymphocytic Leukemia (CLL) demonstrates the capability of infrared spectroscopy to identify and stage this type of cancer, providing new prospects for diagnosis and treatment. The pathological study of oral tissue affected by Squamous Cell Carcinoma (SCC) illustrates the potential of Infrared Spectroscopy and Imaging for tissue diagnosis and cancer staging based in altered cell biochemistry, without using stains or any other marker technology. An example of combined fluid, cell and tissue analysis of thyroid cancers based on infrared technology is introduced to demonstrate the possibility of earlier detection of gland abnormalities and biochemical alterations in cell extracts using fine needle aspirates. Simple statistical techniques such as bivariate histogram analysis can distinguish between normal and altered cells and tissues when applied to infrared spectra and images. More complex mathematical techniques such as Principal Component Analysis (PCA) or Artificial Neural Networks (ANN) provide additional evaluation capabilities that can relate spectra of an unknown sample to an infrared reference database of known cell states. It is documented how this new infrared technology could enhance the diagnoses, treatment decisions and prognoses of patients in the field of cancer medicine.

Pgp-positive leukaemic cells have increased mtDNA but no increased rate of proliferation

Cells of solid tumours tend to rely on glycolysis for energy. On the other hand, increased glycolysis in solid tumour cells expressing the multidrug resistance protein MDR-1 has been associated with increased malignancy in tumours. We have previously shown that cells of the MDR-1-positive CEM/VLB100 leukaemic cell line have increased mitochondrial electron transport chain (mtETC) activity compared with parental CEM cells. In the present study we used infrared (IR) spectroscopy to demonstrate that the mitochondrial DNA (mtDNA) content in the CEM/VLB100 cell line was significantly increased compared to that in the parental CEM cells. The increase in mtDNA was not accompanied by an increase in mitochondrial protein as both lipid and protein levels were decreased in CEM/VLB100 mitochondria. The ATP content was similar in these two cell lines. However, the ATP-dependent membrane efflux pump function in CEM/VLB100 cells was significantly reduced when mitochondrial ATP synthesis was inhibited by oligomycin, a specific inhibitor of mitochondrial F0F1-ATPase. Proliferation of CEM/VLB100 cells was significantly decreased compared to parental CEM cells, and was independent of p53 expression. Thus, we conclude that: (1) IR spectroscopy is a potential powerful technique for detecting mtDNA, protein and lipid contents simultaneously; (2) leukaemic cells mainly rely on mtDNA for energy; (3) increased expression of an ATP-dependent membrane efflux pump such as Pgp may up-regulate ATP generation and mtDNA content. These metabolic perturbations may exist merely to serve the efflux pump and do not result in an increase in leukaemic cell proliferation. In addition, the associated reduction in mitochondrial lipid and protein may contribute to sensitize the cells to cytochrome c release.

Response to cladribine in previously treated patients with chronic lymphocytic leukaemia identified by ex vivo assessment of drug sensitivity by DiSC assay

The ability to identify non-responders to cytotoxic chemotherapy has significant clinical and economic benefits. Differential staining cytotoxicity (DiSC) assays were performed in 34 previously treated patients with chronic lymphocytic leukaemia prior to treatment with cladribine. Of the 28 identified as ex vivo sensitive, 26 achieved a complete (CR) or partial response (PR) (median length of response 1. 5 years, median survival 3.37 years) and two had a >70% fall in lymphocytes: six identified as ex vivo resistant failed to respond. The DiSC assay can accurately identify a subgroup of patients resistant to cladribine.

Simultaneous quantitation from infrared spectra of glucose concentrations, lactate concentrations, and lecithin/sphingomyelin ratios in amniotic fluid

OBJECTIVE

The purpose of this study was to assess the feasibility of using infrared spectroscopy to simultaneously predict preterm infection, fetal distress, and fetal lung maturity.

STUDY DESIGN

A total of 189 infrared spectra were acquired from amniotic fluid obtained by amniocentesis. The concentrations of glucose and lactate and the lecithin/sphingomyelin ratios were determined separately by accepted clinical chemistry methods for each sample. Infrared spectra were recorded with a commercial spectrometer and 35 microL amniotic fluid was used for each spectrum. Calibration models (partial least squares) were derived from the correlation between 102 infrared spectra and clinical standard analyses; the model was then validated with the remaining 87 spectra.

RESULTS

By means of the multivariate technique of partial least squares regression, calibration models for glucose and lactate were developed that had excellent correlation coefficients (r = 0.97 for glucose and r = 0. 91 for lactate); the SEs of calibration were 0.04 mmol/L for glucose and 0.09 mmol/L for lactate. The validation sets for the quantitation of glucose and lactate predicted by the calibration models also yielded good outcomes (r = 0.95 for glucose and r = 0.71 for lactate, with SEs of prediction of 0.06 mmol/L and 0.18 mmol/L, respectively).

CONCLUSION

Infrared spectroscopy has the potential to become the clinical method of choice for simultaneously predicting preterm infection, fetal distress, and fetal lung maturity.

Similarities between the sensitivity to 2-chlorodeoxyadenosine of lymphocytes from CLL patients and bryostatin 1-treated WSU-CLL cells: an infrared spectroscopic study

Infrared (IR) spectroscopy was used to compare the drug resistance mechanism of cells from chronic lymphocytic leukemia (CLL) patients with that of WSU-CLL cells. Bryostatin 1 (Bryo 1), a macrocyclic lactone and protein kinase C activator, was used to render WSU-CLL cells more susceptible to 2-chlorodeoxyadenosine (2-CdA). The IR spectroscopic analysis revealed some changes in protein and DNA content in Bryo 1-treated WSU-CLL cells, however, the most significant alterations were observed in the membrane lipids, which resemble those found between 2-CdA-sensitive and 2-CdA-resistant cells from CLL patients. In addition, Bryo 1 treatment induced WSU-CLL cells to become CD11c, CD25 and tartrate-resistant acid phosphatase-positive, specific markers for hairy cell leukemia, a disease exquisitely sensitive to 2-CdA. Our results suggest that 2-CdA-sensitive CLL cells have cellular characteristics resembling the hairy cell stage. The similarity between the membrane lipids in 2-CdA-sensitive CLL cells and the Bryo 1-treated WSU-CLL cell line supports the suggestion that membrane lipid alteration might be an important step in the drug resistance mechanism of CLL cells.