Standardization of honey as a tissue fixative for histopathology: A morphometric study.

Background: Tissue fixation is a crucial step to preserve the tissues in a life-like state with minimal disruption to its cellular and chemical composition for histopathological examination. The search for an effective alternate tissue fixative to the routinely used formaldehyde has gained interest as constant exposure to formaldehyde has proven to be toxic. Honey, an organic substance with high acidity and hygroscopic nature, exhibits tissue fixative properties and has been used in the present study. The present study aimed to standardize honey as a tissue fixative for histopathology by comparing it with formalin. Materials and Methods: In vitro study Oral tissue samples of goat were fixed in 10% honey and 10% formalin solution, respectively, for 24-48 h, followed by routine tissue processing and microscopic examination of 37 slides per group. 2200 epithelial cells (1100 per group) were selected for the computer-aided morphometric image analysis (Fiji-Image J) by three observers. Cell area (CA), cell perimeter (CP), nuclear area (NA), nuclear perimeter (NP), cytoplasmic area (Cyt A), and nuclear-cytoplasmic ratio were the parameters studied. Mann-Whitney U-test (STATA/IC version 16) for inter-group comparison was done and P < 0.05 was considered statistically significant. Results: The probability of epithelial cells in the honey-fixed group to have greater NA, NP, and N/C ratio was about 50%-60%. The probability of epithelial cells in formalin-fixed tissues to have greater CA, CP, and Cyt A was about 70%. Conclusion: Honey is a better nuclear fixative than formalin. Cytoplasmic shrinkage of epithelial cells should be taken into consideration while fixing tissues with honey.

Acclimation Protocol to Minimize Stress in Immobilized Rats During Non-Invasive Multimodal Sensing of the Autonomic Nervous System.

INTRODUCTION: Rodent models are often used in spinal cord injury investigations to measure physiological parameters but require rats to be restrained during data collection to prevent motion and stress-induced artifacts. MATERIALS AND METHODS: A 4-week acclimation protocol was developed to reduce sympathetic activity during experimentation to collect clean data. Physiological parameters were analyzed throughout the acclimation protocol using surface-based electrodes and an implanted sensor. The sensor was used to extract systolic blood pressure, skin nerve activity, and heart rate variability parameters. RESULTS: Our protocol exposed a minimal increase in sympathetic activity during experimentation despite long periods of restraint. The data suggest that the acclimation protocol presented successfully minimized changes in physiological parameters because of prolonged restraint. CONCLUSIONS: This is necessary to ensure that physiological recordings are not affected by undue stress because of the process of wearing the sensor. This is important when determining the effects of stress when studying dysautonomia after spinal cord injury, Parkinson's disease, and other neurological disorders.

Childhood maltreatment and DNA methylation: A systematic review.

Child maltreatment (CM) encompasses sexual abuse, physical abuse, emotional abuse, neglect, and exposure to domestic and family violence. Epigenetic research investigating CM has focused on differential DNA methylation (DNAm) in genes associated with the stress response, but there has been limited evaluation of the specific effects of subtypes of CM. This systematic review of literature investigating DNAm associated with CM in non-clinical populations aimed to summarise the approaches currently used in research, how the type of maltreatment and age of exposure were encoded via methylation, and which genes have consistently been associated with CM. A total of fifty-four papers were eligible for review, including forty-one candidate gene studies, eight epigenome-wide association studies, and five studies with a mixed design. The ways in which the various forms of CM were conceptualised and measured varied between papers. Future studies would benefit from assessments that employ conceptually robust definitions of CM, and that capture important contextual information such as age of exposure and subtype of CM.

Bilateral Tapetal Reflex in a 12-Year-Old Girl.

This case report describes a diagnosis of Oguchi disease in a girl aged 12 years with a history of high myopia and golden-metallic tapetal sheen noted on bilateral retinal examination.

Inter-observer agreement in grading severity of diabetic retinopathy in wide-field fundus photographs.

OBJECTIVE: To examine the inter-observer agreement between two retina specialists in grading diabetic retinopathy (DR) severity in ultra-wide-field fundus photographs. METHODS: Two hundred and seventy patients with diabetes, who visited the vitreoretinal specialty at a tertiary eye care hospital, with or without DR underwent comprehensive ophthalmic examination, dilated retinal exam and Optos ultra-wide-field (UWF) retinal photography. Optos images were graded for DR severity based on the International Clinical Diabetic Retinopathy Disease Severity Scale by two retina specialists with same number of years of experience, masked to the clinical details of the participants. RESULTS: The two graders showed agreement in 229/270 images (84.8%) and disagreement in 41/270 images (15.2%). The unweighted kappa for agreement between graders was k = 0.715, SE = 0.037 and the weighted kappa was k = 0.838, SE = 0.022. No DR was identified in 170/270 (62.9%) patients, mild NPDR in 15/270 (5.6%) patients, moderate NPDR in 35/270 (12.9%) patients, severe NPDR in 4/270 (1.48%) patient and PDR in 5/270 (1.85%) patients by both graders. Disagreement was neither related to the learning curve of graders nor with the patient's age (p = 0.574), gender (p = 0.169), duration of diabetes (0.660) or the lens being phakic or pseudophakic (p = 0.171) on logistic regression. CONCLUSIONS: The impact of disagreement noted between observers in grading DR on UWF fundus photographs should be considered when utilizing UWF system in clinical studies.

Automatic Detection and Characterization of Autonomic Dysreflexia Using Multi-Modal Non-Invasive Sensing and Neural Networks.

Autonomic dysreflexia (AD) frequently occurs in persons with spinal cord injuries (SCIs) above the T6 level triggered by different stimuli below the level of injury. If improperly managed, AD can have severe clinical consequences, even possibly leading to death. Existing techniques for AD detection are time-consuming, obtrusive, lack automated detection capabilities, and have low temporal resolution. Therefore, a non-invasive, multi-modal wearable diagnostic tool was developed to quantitatively characterize and distinguish unique signatures of AD. Electrocardiography and novel skin nerve activity (skNA) sensors with neural networks were used to detect temporal changes in the sympathetic and vagal systems in rats with SCI. Clinically established metrics of AD were used to verify the onset of AD. Five physiological features reflecting different metrics of sympathetic and vagal activity were used to characterize signatures of AD. An increase in sympathetic activity, followed by a lagged increase in vagal activity during the onset of AD, was observed after inducing AD. This unique signature response was used to train a neural network to detect the onset of AD with an accuracy of 93.4%. The model also had a 79% accuracy in distinguishing between sympathetic hyperactivity reactions attributable to different sympathetic stressors above and below the level of injury. These neural networks have not been used in previous work to detect the onset of AD. The system could serve as a complementary non-invasive tool to the clinically accepted gold standard, allowing an improved management of AD in persons with SCI.

Feature Selection Techniques for a Machine Learning Model to Detect Autonomic Dysreflexia.

Feature selection plays a crucial role in the development of machine learning algorithms. Understanding the impact of the features on a model, and their physiological relevance can improve the performance. This is particularly helpful in the healthcare domain wherein disease states need to be identified with relatively small quantities of data. Autonomic Dysreflexia (AD) is one such example, wherein mismanagement of this neurological condition could lead to severe consequences for individuals with spinal cord injuries. We explore different methods of feature selection needed to improve the performance of a machine learning model in the detection of the onset of AD. We present different techniques used as well as the ideal metrics using a dataset of thirty-six features extracted from electrocardiograms, skin nerve activity, blood pressure and temperature. The best performing algorithm was a 5-layer neural network with five relevant features, which resulted in 93.4% accuracy in the detection of AD. The techniques in this paper can be applied to a myriad of healthcare datasets allowing forays into deeper exploration and improved machine learning model development. Through critical feature selection, it is possible to design better machine learning algorithms for detection of niche disease states using smaller datasets.

Automated Detection of Symptomatic Autonomic Dysreflexia Through Multimodal Sensing.

OBJECTIVE: Autonomic Dysreflexia (AD) is a potentially life-threatening syndrome which occurs in individuals with higher level spinal cord injuries (SCI). AD is caused by triggers which can lead to rapid escalation of pathophysiological responses and if the trigger is not removed, AD can be fatal. There is currently no objective, non-invasive and accurate monitoring system available to automatically detect the onset of AD symptoms in real time in a non-clinical setting. Technology or Method: We developed a user-independent method of symptomatic AD detection in real time with a wearable physiological telemetry system (PTS) and a machine learning model using data from eleven participants with SCI. RESULTS: The PTS could detect onset of AD symptoms with an average accuracy of 94.10% and a false negative rate of 4.89%. CONCLUSIONS: The PTS can detect the onset of the symptoms AD with high sensitivity and specificity to assist people with SCIs in preventing the occurrence of AD. It would enable persons with high level SCIs to be more independent and pursue vocational activities while granting continuous medical oversight. Clinical Impact: The PTS could serve as a supplementary tool to current solutions to detect the onset of AD and prepare individuals who are newly injured to be better prepared for AD episodes. Moreover, it could be translated into a system to encourage individuals to practice better healthcare management to prevent future occurrences.

CT-Guided Fine-Needle Aspiration Biopsy of Pulmonary Nodules 8 mm or Less Has a Higher Diagnostic Accuracy than Positron Emission Tomography-CT.

PURPOSE: To compare diagnostic accuracy of CT-guided fine-needle aspiration biopsy (FNA-B) with positron emission tomography (PET)-CT for pulmonary nodules ≤ 8 mm. MATERIALS AND METHODS: A retrospective review of all CT-guided lung FNA-Bs performed between 2011 and 2014 at a single institution was undertaken to evaluate patients who had FNA-B and PET-CT imaging of nodules of ≤ 8 mm. Patients without surgical pathology or 2-year follow-up CT scans were excluded. Of 1,896 patients, 41 patients with 43 subcentimeter pulmonary nodules met study criteria. The McNemar test was used to compare FNA-B with PET-CT results. RESULTS: FNA-B had a sensitivity and diagnostic accuracy of 88.9% and 81.4%, respectively. PET-CT had an overall sensitivity and diagnostic accuracy of 38.9% and 46.5%, respectively. FNA-B had a significantly higher sensitivity and diagnostic accuracy for malignant nodules compared with PET-CT (P < .001). Pneumothorax rate after FNA-B was 13.9%, and chest tube insertion rate was 0%. CONCLUSIONS: FNA-B is a safe procedure with superior sensitivity and higher diagnostic accuracy compared with PET-CT in pulmonary nodules ≤ 8mm in size.

Synthesis of Co3O4 nanoparticles with block and sphere morphology, and investigation into the influence of morphology on biological toxicity.

In the present study, cobalt oxide (Co3O4) magnetic nanoparticles with block and sphere morphologies were synthesized using various surfactants, and the toxicity of the particles was analyzed by monitoring biomarkers of nanoparticle toxicity in zebrafish. The use of tartarate as a surfactant produced highly crystalline blocks of Co3O4 nanoparticles with pores on the sides, whereas citrate lead to the formation of nanoparticles with a spherical morphology. Co3O4 structure, crystallinity, size and morphology were studied using X-ray diffractogram and field emission scanning electron microscopy. Following an increase in nanoparticle concentration from 1 to 200 ppm, there was a corresponding increase in nitric oxide (NO) generation, induced by both types of nanoparticles [Co3O4-NP-B (block), r=0.953; Co3O4-NP-S (sphere), r=1.140]. Comparative analyses indicated that both types of nanoparticle produced significant stimulation at ≥5 ppm (P<0.05) compared with a control. Upon analyzing the effect of nanoparticle morphology on NO generation, it was observed that Co3O4-NP-S was more effective compared with Co3O4-NP-B (5 and 100 ppm, P<0.05; 200 ppm, P<0.01). Exposure to both types of nanoparticles produced reduction in liver glutathione (GSH) activity with corresponding increase in dose (Co3O4-NP-B, r=-0.359; Co3O4-NP-S, r=-0.429). However, subsequent analyses indicated that Co3O4-NP-B was more potent in inhibiting liver GSH activity compared with Co3O4-NP-S. Co3O4-NP-B proved to be toxic at 5 ppm (P<0.05) and GSH activity was almost completely inhibited at 200 ppm. A similar toxicity was observed with both types of Co3O4-NPs against brain levels of acetylcholinesterase (AChE; Co3O4-NP-B, r=-0.180; Co3O4-NP-S, r=-0.230), indicating the ability of synthesized Co3O4-NPs to cross the blood-brain barrier and produce neuronal toxicity. Co3O4-NP-B showed increased inhibition of brain AChE activity compared with Co3O4-NP-S (1,5, and 10 ppm, P<0.05; 50, 100 and 200 ppm, P<0.01). These results suggested that the morphology of nanoparticle and surface area contribute to toxicity, which may have implications for their biological application.

Retention of Ejaculate by Drosophila melanogaster Females Requires the Male-Derived Mating Plug Protein PEBme.

Within the mated reproductive tracts of females of many taxa, seminal fluid proteins (SFPs) coagulate into a structure known as the mating plug (MP). MPs have diverse roles, including preventing female remating, altering female receptivity postmating, and being necessary for mated females to successfully store sperm. The Drosophila melanogaster MP, which is maintained in the mated female for several hours postmating, is comprised of a posterior MP (PMP) that forms quickly after mating begins and an anterior MP (AMP) that forms later. The PMP is composed of seminal proteins from the ejaculatory bulb (EB) of the male reproductive tract. To examine the role of the PMP protein PEBme in D. melanogaster reproduction, we identified an EB GAL4 driver and used it to target PEBme for RNA interference (RNAi) knockdown. PEBme knockdown in males compromised PMP coagulation in their mates and resulted in a significant reduction in female fertility, adversely affecting postmating uterine conformation, sperm storage, mating refractoriness, egg laying, and progeny generation. These defects resulted from the inability of females to retain the ejaculate in their reproductive tracts after mating. The uncoagulated MP impaired uncoupling by the knockdown male, and when he ultimately uncoupled, the ejaculate was often pulled out of the female. Thus, PEBme and MP coagulation are required for optimal fertility in D. melanogaster. Given the importance of the PMP for fertility, we identified additional MP proteins by mass spectrometry and found fertility functions for two of them. Our results highlight the importance of the MP and the proteins that comprise it in reproduction and suggest that in Drosophila the PMP is required to retain the ejaculate within the female reproductive tract, ensuring the storage of sperm by mated females.

Pitfalls in diagnosing specific subtypes of carcinoma breast on fine needle aspiration cytology: a report of two cases with review of literature.

Fine needle aspiration cytology (FNAC) is a useful procedure that can be conveniently performed in the outpatient department (OPD) and can be used in the subtyping of breast carcinomas. However, some specific subtypes can cause a hindrance to that. We present two such cases, one of tubulolobular carcinoma breast and the other of squamous cell carcinoma breast that were missed on FNAC, and subsequently diagnosed on histopathology and by immunohistochemistry. A thorough knowledge of the cytological features of the subtypes and the use of immunocytochemistry can appropriately make FNAC a standard, accurate, and simple OPD procedure, thus helping us in arriving at specific diagnosis.