Sleep and circadian rhythms in Parkinson’s disease and preclinical models

The use of animals as models of human physiology is, and has been for many years, an indispensable tool for understanding the mechanisms of human disease. In Parkinson’s disease, various mouse models form the cornerstone of these investigations. Early models were developed to reflect the traditional histological features and motor symptoms of Parkinson’s disease. However, it is important that models accurately encompass important facets of the disease to allow for comprehensive mechanistic understanding and translational significance. Circadian rhythm and sleep issues are tightly correlated to Parkinson’s disease, and often arise prior to the presentation of typical motor deficits. It is essential that models used to understand Parkinson’s disease reflect these dysfunctions in circadian rhythms and sleep, both to facilitate investigations into mechanistic interplay between sleep and disease, and to assist in the development of circadian rhythm-facing therapeutic treatments. This review describes the extent to which various genetically- and neurotoxically-induced murine models of Parkinson’s reflect the sleep and circadian abnormalities of Parkinson’s disease observed in the clinic.

Histomorphological spectrum of ovarian tumors - A tertiary care center experience

Background: Ovarian tumors are a heterogeneous group of neoplasms with variable clinical, morphological, and histological features. Ovarian cancer is the leading cause of death in females. Aims and Objectives: (1) To study and characterize the ovarian tumors based on gross and histopathological features. (2) To study prevalence and age distribution of various ovarian tumors. (3) To study the clinical features in patients with ovarian tumors. (4)To compare the frequency of benign and malignant neoplasms of the ovary with other studies. Materials and Methods: This is a prospective study conducted in Upgraded Department of Pathology, Modern Government maternity hospital, and Osmania General Hospital, Hyderabad, Telangana from March 2018 to February 2021. A total of 200 ovarian tumors were studied. Results: Out of 200 ovarian tumors, 132 were benign, seven were borderline and 61 were malignant. The surface epithelial tumors were the most common tumors accounting for 159cases (79.5%), germ cell tumors were seen in 27 cases (13.5%), sex-cord stromal tumors formed 10 cases (5%), and metastasis in 4 cases (2%). Conclusion: Ovary is a common site of tumors in the female genital tract and usually presents with a variety of clinocomorphological and histological features. Benign are the most common, of these surface epithelial tumors are the commonest, affects mainly reproductive age group.

Adaptive morphogenesis of lamb liver under Anthropobiocenosis conditions lamb liver morphogenesis

Investigated the histological features of the structure of hepar of one-day-old lambs (ODL) using a complex of morphological techniques. It was found that hepar in ODL is formed by stroma and parenchyma. The stromal elements of the organ are formed by loose lugs of hematopoietic connective tissue, which in turn forms a capsule (2.80-7.23 microns thick), as well as the septa of the lobules, which include the hepar triads and paravasal tissue of efferent blood vessels. As a result of the studies, the prevalence of the stroma in the hematopoietic foci around large afferent blood vessels, especially in the hepar hilus, was revealed. The hepar parenchyma in ODL has structural incompleteness. It is formed by hepar cells and numerous resinusoidal cells located in the subcapsular, peripheral, central zones in the lobus hepatis. Hepar cells located in the subcapsular zone (SZ) have a more optically cleared (OC) cytoplasm, and the practically cleared cytoplasm of the hepatocyte diameter (HD) decreases towards the central zone (CZ). In the hepar parenchyma of the ODL, hematopoiesis foci (HF) are established in each of the lobes, which tend to decrease from the periphery to the center of the lobes. Hemopoetic cells (HC) are located between hepatocytes, densely layering on top of each other, and there are also cells located sparsely between the liver cells (LC). The number of hepatocytes per 1 mm2 of the area of the histological specimen in the left lobe (LL) of the ODL reaches the highest value 5983.79 ± 90.40, in the right lobe (RL) of the liver it is 5358.80 ± 646.60, while in the middle it has a minimum value and reaches 5133.10 ± 205.75.

Lethal Restrictive Dermopathy with ZMPSTE24 Mutation

Lethal restrictive dermopathy is genodermatoses associated with lamin protein defects resulting in connective tissue abnormalities of skin, musculoskeletal, and adipose tissue. We report one such case with a mutation in the ZMPSTE24 gene which is involved in lamin protein synthesis, resulting in fetal akinesia or hypokinesia deformation sequence. Early recognition in the perinatal period of distinctive clinical and skin histological features followed by molecular diagnosis enabled genetic counseling for the affected family.

HISTOLOGICAL FEATURES OF THE CECUM AND VERMIFORM APPENDIX IN RATS AND HUMANS: COMPARATIVE ASPECTS

Background. In recent years, there have emerged new directions in the study of the histological structure of the digestive tract in humans and mammals and, in particular, white rats, since non-inbred white rats are the main model for reproducing human pathology under experimental conditions as well as for preclinical testing of new drugs. Objective. A comparative study of the histological features of the cecum and appendix in rats and humans by means of bibliographic analysis. Material and methods. Bibliographic analysis is based on published peer-reviewed articles, books, textbooks, monographs, dissertation abstracts. For the purposes of a systematic review, the literature search (concerning the study of the histological structure of the cecum and appendix) was carried out on the Internet, in native literature sources, the scientific and electronic library of Poltava State Medical University using the following keywords: “histology”, “microscopic structure”, "digestive system", "cecum", "appendix", "white rats", "rat anatomy". Results. The mucous membrane of the gastrointestinal tract of white rats, in terms of its histological structure, is similar enough to that of humans to serve as an object in the experimental modeling of certain pathological conditions of the digestive system. Conclusions. There has been found an increased concentration of lymphoid nodules in cecal mucosa of white rats. In white rats and humans, the cecum and the appendix in humans are endowed with the same immune defense structures, which together represent the immune system of the digestive tract mucosa.

Analysis of Histological Features of the Cerebral Cortex and Hippocampus of Albino Rats Using Haematoxylin & Eosin Stain- An Observational Study

Background: The study determined the histological layers of the cerebral cortex and hippocampus of the albino rat brain samples has been used in the study. The Cerebral cortex is composed of the Molecular layer, external granular, external pyramidal layer, internal granular layer and interior pyramidal layer. The layers of the hippocampus are alveus, stratum oriens, stratum pyramidale, stratum radiatum, stratum lacunosum and stratum moleculare. The aim of the study is to analyze the detailed histological features of the cerebral cortex and hippocampus layers of albino rats at the magnification of 10X,100X,40X. By using haematoxylin and eosin stain as an observational study. Materials and Methods: The samples were preserved and fixed with the formalin and stained by haematoxylin and eosin and observed with a light microscope. Results: The molecular layer is the superficial layer containing neurons. The outer granular layer of the cells are densely packed. Outer pyramidal layer contains rich pyramidal cells, Inner granular layer contains stellate cells, Inner pyramidal layer contains glial cells and the deeper multiform layer is composed of pyramidal cells. The hippocampus contains three layers of cornu Ammonia CA1, CA2, CA3. CA1 responds to memory and is covered by the choroid plexus. CA2 contains 3 major cell dentate gyrus, pyramidal cells, pyramidal neurons and CA3 composed of stratum lucidum. Conclusion: The study of brain analysis of histological features of the cerebral cortex and hippocampus of the brain adds a greater insight in understanding the histology of various types of layers in rat brain and morphology of brain cells.

Nodular trichoblastoma or basal cell carcinoma: A diagnostic dilemma of clinical significance

Nodular Trichoblastoma (TB) is a rare and benign adnexal tumor originating from rudimentary hair follicles. Adnexal neoplasms show complex clinical and histological features. A panel of immunohistochemical (IHC) markers helps in distinguishing tumors of follicular origin from other cutaneous tumors especially Basal cell carcinoma (BCC). We herein describe the histological and immunohistochemical features of TB which clinically and histologically mimiced BCC.

Dermatomyositis: Muscle Pathology According to Antibody Subtypes

Background and Objectives:Discoveries of dermatomyositis specific antibodies (DMSAs) in dermatomyositis patients raised awareness of various myopathological features among antibody subtypes. However, only perifascicular atrophy and perifascicular myxovirus resistant protein A (MxA) overexpression were officially included as the definitive pathological criteria for dermatomyositis classification. We aimed to demonstrate myopathological features in MxA-positive dermatomyositis to determine characteristic myopathological features in different DMSA subtypes.Method:We performed a retrospective pathology review of muscle biopsies of dermatomyositis patients diagnosed between January 2009 and December 2020 in a tertiary laboratory for muscle diseases. We included all muscle biopsies with sarcoplasmic expression for MxA and seropositivity for DMSAs. MxA-positive muscle biopsies which tested negative for all DMSAs were included as seronegative dermatomyositis. We evaluated histological features stratified according to four pathology domains (muscle fiber, inflammatory, vascular, and connective tissue) and histological features of interest by histochemistry, enzyme histochemistry, and immunohistochemical study commonly used in the diagnosis of inflammatory myopathy. We performed ultrastructural studies of 54 available specimens.Result:A total of 256 patients were included. Of these, 249 patients were positive for one of the five DMSAs (seropositive patients: 87 anti-TIF1-γ; 40 anti-Mi-2; 29 anti-MDA5; 83 anti-NXP-2; and 10 anti-SAE DM) and 7 patients were negative for all five DMSAs (seronegative patients). Characteristic myopathological features in each DMSA subtype were as follows: anti-TIF1-γ with vacuolated/punched out fibers (64.7%, P<.001) and perifascicular enhancement in HLA-ABC stain (75.9%, P<.001); anti-Mi-2 with prominent muscle fiber damage (score 4.8±2.1, P<.001), inflammatory cell infiltration (score 8.0±3.0, P=.002), perifascicular atrophy (67.5%, P=.02), perifascicular necrosis (52.5%, P<.001), increased perimysial alkaline phosphatase activity (70.0%, P<.001), central necrotic peripheral regenerating fibers (45.0%, P<.001), and sarcolemmal membrane attack complex deposition (67.5%, P<.001); anti-MDA5 with scattered/diffuse staining pattern of MxA (65.5%, P<.001) with less muscle pathology and inflammatory features; anti-NXP2 with microinfarction (26.5%, P<.001); and anti-SAE and seronegative DM with HLA-DR expression (50.0%, P=.02 and 57.1%, P=.02, respectively).Discussion:We described a comprehensive serological-pathological correlation of DM primarily using MxA expression as an inclusion criterion. In our study, DMSAs were associated with distinctive myopathological features suggesting different underlying pathobiological mechanisms in each subtype.