Search results for "Microscopy"
showing 10 items of 3390 documents
Hardwiring the Brain: Endocannabinoids Shape Neuronal Connectivity
2007
The roles of endocannabinoid signaling during central nervous system development are unknown. We report that CB 1 cannabinoid receptors (CB 1 Rs) are enriched in the axonal growth cones of γ-aminobutyric acid–containing (GABAergic) interneurons in the rodent cortex during late gestation. Endocannabinoids trigger CB 1 R internalization and elimination from filopodia and induce chemorepulsion and collapse of axonal growth cones of these GABAergic interneurons by activating RhoA. Similarly, endocannabinoids diminish the galvanotropism of Xenopus laevis spinal neurons. These findings, together with the impaired target selection of cortical GABAergic interneurons lacking CB 1 Rs, identify endoc…
Noninvasive diagnostic techniques of port wine stain.
2021
Port-wine stain (PWS) is a benign capillary malformation that most commonly occurs in the head and neck. It is present at birth and progresses over time. It is formed by progressive dilatation of post-capillary venules and is associated with hypertrophy and nodularity with increasing age, leading to cosmetic disfigurement and psychological aggravation. It is caused by genetic mosaicism in GNAQ and GNA11 genes. Histopathology is the gold standard for assessment of PWS but it is invasive and may cause scarring. Inadequate characterization of the lesions may predispose to inadequate treatment protocols as well as higher treatment dosages. Clinical evaluation of treatment efficacy is subjective…
Pigmented esthesioneuroblastoma showing dual differentiation following transplantation in nude mice
1989
Esthesioneuroblastoma (ESTH) is a neuroepithelial-cell-derived neoplasm of the olfactory mucosa composed of homogeneous small round cells which contain neurosecretory granules. Melanin has been detected in such tumours only occasionally. Here we describe a new case of ESTH with divergent differentiation. The primary neoplasm was found in a 67 year-old female, involving the left nasal and maxillary sinus; she died of cerebral metastasis ten months after diagnosis. Histologically only small round cells were seen, with S-100 and NSE positivity. Electron microscopy revealed neurosecretory granules and filaments, as well as the occasional presence of melanosomes. A nude mice xenograft line has b…
Uniform response of c-raf expression to differentiation induction and inhibition of proliferation in a rat rhabdomyosarcoma cell line
1990
The clonal rat rhabdomyosarcoma cell line BA-HAN-1C is composed of proliferating mononuclear cells, some of which spontaneously fuse to terminally differentiated myotube-like giant cells. Both the induction of differentiation by retinoic acid (RA) and by sodium butyrate (NaBut), as well as the inhibition of proliferation by fetal calf serum (FCS)-depleted medium uniformly resulted in the same effects. There was a significant (p less than 0.001) inhibition of proliferation and induction of cellular differentiation, as evidenced by a significant (p less than 0.05) increase in creatine kinase activity. Furthermore, after exposure to RA-supplemented or FCS-depleted medium, a significant (p less…
Application of remote online learning in oral histopathology teaching in China
2021
Background The aim of this study was to investigate the application of remote learning and virtual microscopy in oral histopathology teaching, a unique experience in China. The oral histopathology teaching in Nanjing Medical University has been extraordinary. Material and Methods 98 third-year dental students of Grade 2016 took oral histopathology theoretical course face-to-face in 2019 (Traditional group). The 94 participants of Grade 2017 took online oral histopathology course using digital methods(E-Learning platform and Virtual Simulation Experiment Teaching Center for Dentistry) in 2020. During the practical laboratory sessions, the students in both Traditional group and Online group o…
Primary ciliary dyskinesia assessment by means of optical flow analysis of phase-contrast microscopy images
2014
Primary ciliary dyskinesia implies cilia with defective or total absence of motility, which may result in sinusitis, chronic bronchitis, bronchiectasis and male infertility. Diagnosis can be difficult and is based on an abnormal ciliary beat frequency (CBF) and beat pattern. In this paper, we present a method to determine CBF of isolated cells through the analysis of phase-contrast microscopy images, estimating cilia motion by means of an optical flow algorithm. After having analyzed 28 image sequences (14 with a normal beat pattern and 14 with a dyskinetic pattern), the normal group presented a CBF of 5.2 +/- 1.6 Hz, while the dyskinetic patients presented a 1.9 +/- 0.9 Hz CBF. The cutoff …
Preparation and karyotype analysis of mitotic chromosomes of the freshwater sponge Spongilla lacustris.
1993
The present study documents for the first time the karyotype and mitotic chromosomes of a sponge. For the studies the freshwater sponge Spongilla lacustris (Lin. 1758) was used. Its karyotype comprises nine different chromosome pairs ranging in size from 2.1 to < or = 0.7 microns. Changes in size and shape of the chromosomes during the progression of mitosis are documented both light and electron microscopically. The data reveal that the lowest multicellular eukaryotes, the sponges, have already reached a high level of evolution of the mitotic mechanism.
Ultrastructural evidence for protection of the outer hair cells of the inner ear during intense noise exposure by application of the organic calcium …
1999
Outer hair cells could be protected during intense noise exposure by the application of the calcium channel blocker diltiazem given before and after noise treatment. After various experimental approaches, the ultrastructural morphology was analysed for the different animal populations in the basal part of the second turn of the cochlea, which was the most destroyed area after an acute noise trauma caused by a gun shot (sound pressure at the ear drum 156 dB, frequency maximum between 4 and 6 kHz). Compared to untreated control specimens (experimental animal group I), the outer hair cells in the basal part of the second turn of the cochlea were mostly destroyed without any diltiazem applicati…
The influence of ossein-hydroxyapatite compound ('Ossopan') on the healing of a bone defect.
1986
A study was undertaken in 60 adult rabbits in order to determine the effects of ossein-hydroxyapatite compound on bone healing. Standardized bony defects were produced in the distal femoral epiphyses, after which animals were randomized into four equal groups. An untreated group served as a control. One group received ossein-hydroxyapatite compound, 830 mg per day, a second group received bone mineral (ossein-hydroxyapatite compound reduced to ash, to remove organic constituents), 510 mg per day, and a third group received calcium carbonate, 650 mg per day. A series of fluorescent vital markers was administered to the animals from the 7th to the 32nd day after production of the defect. A th…
New diagnostic and imaging technologies in dermatology
2021
INTRODUCTION Diagnosis of dermatological disorders is primarily based on clinical examination in combination with histopathology. However, clinical findings alone may not be sufficient for accurate diagnosis and cutaneous biopsies are being associated with morbidity. OBJECTIVE The objective of this article is to review the newer technologies along with their applications, limitation and future prospectus. METHODOLOGY Comprehensive literature search was performed using electronic online databases "PubMed" and "Google Scholar". Articles published in English language were considered for the review. RESULTS In order to improve and/or widen the armamentarium in dermatologic disease diagnosis and…