Molecular Mechanisms of Neurofilament Alterations and its Application in Assessing Neurodegenerative Disorders.

Neurofilaments are intermediate filaments present in neurons. These provide structural support and maintain the size and shape of the neurons. Dysregulation, mutation, and aggregation of neurofilaments raise the levels of these proteins in the blood and cerebrospinal fluid, which are characteristic features of axonal damage and certain rare neurological diseases, such as Giant axonal neuropathy and Charcot-Mare-Tooth disease. Understanding the structure, dynamics, and function of neurofilaments has been greatly enhanced by a diverse range of biochemical and preclinical investigations conducted over more than four decades. Recently, there has been a resurgence of interest in post-translational modifications of neurofilaments, such as phosphorylation, aggregation, mutation, oxidation, etc. Over the past twenty years, several rare disorders have been studied from structural alterations of neurofilaments. These disorders are monitored by fluid biomarkers such as neurofilament light chains. Currently, there are many tools, such as Enzyme-Linked Immunosorbent Assay, Electrochemiluminescence Assay, Single-Molecule Array, Western/immunoblotting, etc., in use to assess the neurofilament proteins in Blood and CSF. However, all these techniques utilize expensive, non-specific, or antibody-based methods, which make them unsuitable for routine screening of neurodegenerative disorders. This provides room to search for newer sensitive, cost-effective, point-of-care tools for rapid screening of the disease. For a long time, the molecular mechanisms of neurofilaments have been poorly understood due to insufficient research attempts, and a deeper understanding of them remains elusive. Therefore, this review aims to highlight the available literature on molecular mechanisms of neurofilaments and the function of neurofilaments in axonal transport, axonal conduction, axonal growth, and neurofilament aggregation, respectively. Further, this review discusses the role of neurofilaments as potential biomarkers for the identification of several neurodegenerative diseases in clinical laboratory practice.

Assessing Breast Cancer through Tumor Microenvironment Mapping of Collagen and Other Biomolecule Spectral Fingerprints─A Review.

Breast cancer is a major challenge in the field of oncology, with around 2.3 million cases and around 670,000 deaths globally based on the GLOBOCAN 2022 data. Despite having advanced technologies, breast cancer remains the major type of cancer among women. This review highlights various collagen signatures and the role of different collagen types in breast tumor development, progression, and metastasis, along with the use of photoacoustic spectroscopy to offer insights into future cancer diagnostic applications without the need for surgery or other invasive techniques. Through mapping of the tumor microenvironment and spotlighting key components and their absorption wavelengths, we emphasize the need for extensive preclinical and clinical investigations.

Machine Learning Enabled Photoacoustic Spectroscopy for Noninvasive Assessment of Breast Tumor Progression In Vivo: A Preclinical Study.

Breast cancer is a dreaded disease affecting women the most in cancer-related deaths over other cancers. However, early diagnosis of the disease can help increase survival rates. The existing breast cancer diagnosis tools do not support the early diagnosis of the disease. Therefore, there is a great need to develop early diagnostic tools for this cancer. Photoacoustic spectroscopy (PAS), being very sensitive to biochemical changes, can be relied upon for its application in detecting breast tumors in vivo. With this motivation, in the current study, an aseptic chamber integrated photoacoustic (PA) probe was designed and developed to monitor breast tumor progression in vivo, established in nude mice. The device served the dual purpose of transporting tumor-bearing animals to the laboratory from the animal house and performing PA experiments in the same chamber, maintaining sterility. In the current study, breast tumor was induced in the nude mice by MCF-7 cells injection and the corresponding PA spectra at different time points (day 0, 5, 10, 15, and 20) of tumor progression in vivo in the same animals. The recorded photoacoustic spectra were subsequently preprocessed, wavelet-transformed, and subjected to filter-based feature selection algorithm. The selected top 20 features, by minimum redundancy maximum relevance (mRMR) algorithm, were then used to build an input feature matrix for machine learning (ML)-based classification of the data. The performance of classification models demonstrated 100% specificity, whereas the sensitivity of 95, 100, 92.5, and 85% for the time points, day 5, 10, 15, and 20, respectively. These results suggest the potential of PA signal-based classification of breast tumor progression in a preclinical model. The PA signal contains information on the biochemical changes associated with disease progression, emphasizing its translational strength toward early disease diagnosis.

A comprehensive review of protein misfolding disorders, underlying mechanism, clinical diagnosis, and therapeutic strategies.

INTRODUCTION: Proteins are the most common biological macromolecules in living system and are building blocks of life. They are extremely dynamic in structure and functions. Due to several modifications, proteins undergo misfolding, leading to aggregation and thereby developing neurodegenerative and systemic diseases. Understanding the pathology of these diseases and the techniques used to diagnose them is therefore crucial for their effective management . There are several techniques, currently being in use to diagnose them and those will be discussed in this review. AIM/OBJECTIVES: Current review aims to discuss an overview of protein aggregation and the underlying mechanisms linked to neurodegeneration and systemic diseases. Also, the review highlights protein misfolding disorders, their clinical diagnosis, and treatment strategies. METHODOLOGY: Literature related to neurodegenerative and systemic diseases was explored through PubMed, Google Scholar, Scopus, and Medline databases. The keywords used for literature survey and analysis are protein aggregation, neurodegenerative disorders, Alzheimer's disease, Parkinson's disease, systemic diseases, protein aggregation mechanisms, etc. DISCUSSION /CONCLUSION: This review summarises the pathogenesis of neurodegenerative and systemic disorders caused by protein misfolding and aggregation. The clinical diagnosis and therapeutic strategies adopted for the management of these diseases are also discussed to aid in a better understanding of protein misfolding disorders. Many significant concerns about the role, characteristics, and consequences of protein aggregates in neurodegenerative and systemic diseases are not clearly understood to date. Regardless of technological advancements, there are still great difficulties in the management and cure of these diseases. Therefore, for better understanding, diagnosis, and treatment of neurodegenerative and systemic diseases, more studies to identify novel drugs that may aid in their treatment and management are required.

New species and new records of Miroculis Edmunds, 1963 (Ephemeroptera: Leptophlebiidae) from Chacoan Domain in northeastern Brazil.

The genus Miroculis Edmunds, 1963 (Ephemeroptera: Leptophlebiidae) is endemic to South American with 27 described species. In Brazil, 21 of these are known to occur. The present paper describes three new species of Miroculis Edmunds, 1963. Miroculis (Miroculis) botafora sp. nov. is described based on a male imago collected in a transition area between the Cerrado and Caatinga biomes in Piauí State, Brazil. Two species are described based on nymphs and adults: Miroculis (Miroculis) azevedoi sp. nov. and Miroculis (Miroculis) quilombola sp. nov.; both were collected in a Cerrado region of Maranhão State, Brazil. Additionally, new distribution records of Miroculis (Miroculis) fittkaui Savage & Peters, 1983 are provided.

An updated distribution list of Leptophlebiidae Banks, 1900 (Ephemeroptera: Insecta) for Piauí state / Uma lista de distribuição atualizada de Leptophlebiidae Banks, 1900 (Ephemeroptera: Insecta) para o estado do Piauí

Abstract Leptophlebiidae is the second most diverse family within Ephemeroptera, with species distributed across various States in Brazil, but with gaps in distribution records in others. Currently, nine species of Leptophlebiidae are recorded for the state of Piauí. Based on this information gap, the objective of this study was to present an updated species list of the family Leptophlebiidae new occurrence records and distributional sites for the state of Piauí, Brazil. By analyzing 447 specimens, we have significantly expanded our knowledge about the distribution of Leptophlebiidae species in the state of Piauí, increasing the recorded species from nine to 17. We have also added new occurrence records for six species and, for the first time, documented the presence of four genera. It is important to highlight that there is still an extensive area within the Cerrado and Brazilian semiarid regions where the occurrence of Ephemeroptera is unknown, confirming that the diversity in this area is underestimated and that knowledge of Ephemeroptera species and their distributions can expand with increased sampling efforts in the coming years, reducing the Linnean and Wallacean shortfall regarding this group. Our results also demonstrate the urgent need for inventories in the southern part of the state of Piauí, particularly in the sub-basins of the middle and upper Parnaíba river, which are considered suitable for monoculture expansion in Brazil.

Resumo Leptophlebiidae é a segunda família mais diversa de Ephemeroptera, com espécies distribuídas em vários estados do Brasil, mas com lacunas no registro de distribuição em outros. Por exemplo, no estado do Piauí tem registrado apenas nove espécies de Leptophlebiidae. Baseada nessa lacuna de informação, o objetivo deste estudo foi apresentar uma lista atualizada de espécies da família Leptophlebiidae, novos registros de ocorrência e sítios de distribuição para o estado do Piauí, Brasil. Ao analisar 447 exemplares, ampliamos significativamente nosso conhecimento sobre a distribuição das espécies de Leptophlebiidae no estado do Piauí, aumentando o número de espécies registradas de nove para 17. Também adicionamos novos registros de ocorrência para seis espécies e, pela primeira vez, documentamos a presença de quatro gêneros. Destacamos que ainda existe uma extensa área do Cerrado e semiárido brasileiro que se desconhece a ocorrência de Ephemeroptera, confirmando que a diversidade nessa área é subestimada e que o conhecimento sobre as espécies de Ephemeroptera e suas distribuições podem se expandir com o aumento do esforço amostral nos próximos anos, diminuindo as lacunas Lineana e Wallaceana sobre esse grupo. Nossos resultados também demonstram a necessidade emergencial de inventários no sul do Estado do Piauí, principalmente nas sub-bacias do médio e alto rio Parnaíba que é considerado adequado para a expansão da monocultura no Brasil.

New species and records of Caenidae Newman, 1853 (Insecta: Ephemeroptera) from Northeastern Brazil.

New distributional records for four species and the description of a new species of Caenis Stephens from Parnaba River Basin, in a semiarid region of the state of Piau, Northeastern Brazil are given. Characters and illustrations to distinguish Caenis marataoan sp. nov. from all other species in Caenis are provided. The new species can be distinguished by the following combination of characters: 1) body length of male 1.52.0 mm, female 2.52.8 mm; 2) base of antennal flagellum not dilated; 3) forceps apically rounded, covered with trichomes and with 23 minute spines at apex; 4) styliger plate short with posterior margin convex; 5) penis fused and not laterally projected; 6) eggs oval-shaped; micropyle linear with narrow and long micropylar canal, preceded by an oval sperm guide.

Probing nonenzymatic glycation of proteins by deep ultraviolet light emitting diode induced autofluorescence.

The suitability of deep-UV-LED (285 nm) as an excitation source to induce autofluorescence in nonenzymatically glycated proteins has been reported for the first time in this study. Non-enzymatically glycated proteins show high autofluorescence when excited with deep-UV light, i.e., deep-UV-induced autofluorescence (deep-UV-IAF). Multiple autofluorescence peaks of nonenzymatically glycated proteins between 300 and 600 nm when excited using the deep-UV-LED revealed structural and biochemical modifications. The partial unfolding of proteins in which Tryptophan (Trp) is either absent (e.g., RibonucleaseA) or the emission maxima of Trp is insensitive to nonenzymatic glycation (e.g., Human Serum Albumin and Bovine Serum Albumin) were elucidated using their Tyrosine (Tyr) emission (λem = ~320 nm). Also, the deep-UV-LED-induced autofluorescence (deep-UV-LED-IAF) is shown to detect and track a wide range of clinically relevant advanced glycation end-products (AGEs) such as Pentosidine (λem = ~380 nm), Argpyrimidine (λem = ~395 nm), Vesperlysine C (λem = ~405 nm), Vesperlysine A/B (λem = ~440 nm), Crossline (λem = ~480 nm), and Arginine derived AGEs (λem = ~525 nm) which is also supported by the chemometric analysis (PCA). The relevance of Trp/Tyr makeup of proteins in tracking AGEs using deep-UV-IAF has been carefully examined with proteins such as RibonucleaseA (RNaseA:zero Trp and six Tyr), Human Serum Albumin (HSA: one Trp and eighteen Tyr), Bovine Serum Albumin (BSA: two Trp and twenty Tyr) and Hemoglobin (Hb: four Trp and twelve Tyr). The Molecular Dynamic (MD) simulation revealed a high root-mean-square deviation (RMSD: 4.6 Å) and an increased average distance between Tyr residues and Trp214 (23.2 Å) in methylglyoxal (MG) treated HSA. This confirms the MG-induced protein unfolding and decreased fluorescence resonance energy transfer (FRET) from Tyr to Trp (Tyr â†’ Trp). The study also used systematic steady-state and time-resolved fluorescence (TRF) to explain the sudden decrease in AGEs specific fluorescence intensity and lifetime at higher concentrations of MG due to inter-AGEs FRET.

A comprehensive review on LED-induced fluorescence in diagnostic pathology.

Sensitivity, specificity, mobility, and affordability are important criteria to consider for developing diagnostic instruments in common use. Fluorescence spectroscopy has been demonstrating substantial potential in the clinical diagnosis of diseases and evaluating the underlying causes of pathogenesis. A higher degree of device integration with appropriate sensitivity and reasonable cost would further boost the value of the fluorescence techniques in clinical diagnosis and aid in the reduction of healthcare expenses, which is a key economic concern in emerging markets. Light-emitting diodes (LEDs), which are inexpensive and smaller are attractive alternatives to conventional excitation sources in fluorescence spectroscopy, are gaining a lot of momentum in the development of affordable, compact analytical instruments of clinical relevance. The commercial availability of a broad range of LED wavelengths (255-4600 nm) has opened up new avenues for targeting a wide range of clinically significant molecules (both endogenous and exogenous), thereby diagnosing a range of clinical illnesses. As a result, we have specifically examined the uses of LED-induced fluorescence (LED-IF) in preclinical and clinical evaluations of pathological conditions, considering the present advancements in the field.

Hagenulopsis Ulmer (Ephemeroptera: Leptophlebiidae): re-description, morphological notes and a new species from South America, Brazil.

Hagenulopsis diptera Ulmer, type species of the genus Hagenulopsis, was originally described based on imagos from Santa Catarina State, Southern Brazil. Misconceptions of H. diptera circumscription led to erroneous attribution of material from Minas Gerais and Esprito Santo, Southeastern Brazil, to H. diptera. Despite the increase in the number of species attributed to Hagenulopsis, little attention has been given to the type species. After comparative examination of photographs of the holotype and fresh material of H. diptera from Southeastern Brazil, we conclude that many specimens previously assigned to H. diptera represent a new species. Thus, we redescribe H. diptera and describe a new species Hagenulopsis perere sp. nov. based on eggs, nymphs and imagos. Diagnostic features of Hagenulopsis perere sp. nov. include cross veins between C and RP1 strongly clouded with brown and outer surface of mid femur with a brown spot at midlength. Finally, comments and new records are presented for Hagenulopsis minuta Spieth.

Fluorescence and Photoacoustic Spectroscopy-Based Assessment of Mitochondrial Dysfunction in Oral Cancer Together with Machine Learning: A Pilot Study.

The current study reports an integrated approach of machine learning and tryptophan fluorescence and photoacoustic spectral properties to assess the mitochondrial status under oral pathological conditions. The mitochondria in the study were isolated from oral cancer tissues and adjacent normal counterparts, and the corresponding fluorescence and photoacoustic spectra of tryptophan were recorded at 281 nm pulsed laser excitations. A set of features were selected from the pre-processed spectra and were used to classify the data using support vector machine (SVM) learning in the MATLAB platform. SVM analysis demonstrated clear differentiation between mitochondria isolated from normal and cancer tissues for fluorescence (sensitivity, 86.6%; specificity, 90%) and photoacoustic (sensitivity, 86.6%; specificity, 96.6%) measurements. Further investigation into the influence of change in protein conformation on the nature of tryptophan spectral properties was evaluated by 8-anilino-1-naphthalene sulfonic acid (ANS) fluorescence assay. The impact of protein structural changes on the mitochondrial functions was also estimated by mitochondrial membrane potential (MMP), reactive oxygen species (ROS), and cytochrome c oxidase (COX) assays, suggesting an altered mitochondrial function. The findings indicate that tryptophan fluorescence and photoacoustic spectral properties together with machine learning algorithms may delineate the mitochondrial functional status in vitro, indicating its translational potential.

Exploring photoacoustic spectroscopy-based machine learning together with metabolomics to assess breast tumor progression in a xenograft model ex vivo.

In the current study, a breast tumor xenograft was established in athymic nude mice by subcutaneous injection of the MCF-7 cell line and assessed the tumor progression by photoacoustic spectroscopy combined with machine learning tools. The advancement of breast tumors in nude mice was validated by tumor volume kinetics and histopathology and corresponding image analysis by TissueQuant software compared to controls. The ex vivo tumors in progressive conditions belonging to time points, day 5th, 10th, 15th & 20th, were excited with 281 nm pulsed laser light and recorded the corresponding photoacoustic spectra in time domain. The spectra were then pre-processed, augmented for a 10-fold increase in the data strength, and subjected to wavelet packet transformation for feature extraction and selection using MATLAB software. In the present study, the top 10 features from all the time point groups under study were selected based on their prediction ranking values using the mRMR algorithm. The chosen features of all the time-point groups were then subjected to multi-class Support Vector Machine (SVM) algorithms for learning and classifying into respective time point groups under study. The analysis demonstrated accuracy values of 95.2%, 99.5%, and 80.3% with SVM- Radial Basis Function (SVM-RBF), SVM-Polynomial & SVM-Linear, respectively. The serum metabolomic levels during tumor progression complemented photoacoustic patterns of tumor progression, depicting breast cancer pathophysiology.

Climatological aspects and changes in temperature and precipitation extremes in Viçosa-Minas Gerais.

Extreme climatic events and their hazards have strong impact on society. Urban areas in Brazil are especially vulnerable to the impact of such events due to their rapid growth and inappropriate infrastructure. Viçosa is a mid-sized city in Southeastern Brazil that has been experiencing issues associated with urban expansion and population growth since the 1960s. Thus, this study aims to identify patterns of extreme climate events in Viçosa based on daily temperature and precipitation time series (1968-2017). Homogeneity tests were carried out in order to identify breaking points in these climate variables. Climate trends were analyzed through Mann-Kendall test and their magnitude was checked based on Sen's slope. Results have evidenced statistically significant and increasing trends in annual minimum temperature since the 1990s. Moreover, statistically significant breaking points in extreme temperature indices have shown increasing number of warm days, and decreasing number of cold nights, in both annual and seasonal analyses. Extreme climatic events have been observed more often in recent years, mainly in the number of consecutive dry days and maximum and heavy precipitation days. Based on results, Viçosa experiences warmer conditions throughout the year, whereas more (less) torrential rainfall events have been occurring during Summer (Winter).