scholarly journals Does the frontal sensory organ in adults of the hoplonemertean Quasitetrastemma stimpsoni originate from the larval apical organ?

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Timur Yu Magarlamov ◽  
Vyacheslav Dyachuk ◽  
Alexey V. Chernyshev
Keyword(s):  
Sensory Function ◽  
Apical Organ ◽  
Sensory Organ ◽  
Neural Structure ◽  
Free Swimming ◽  
Frontal Gland ◽  
Gland Cells ◽  
Apical Plate ◽  
Frontal Organ ◽  
Functional Features

Abstract Background The apical organ is the most prominent neural structure in spiralian larvae. Although it has been thoroughly investigated in larvae of the class Pilidiophora in phylum Nemertea, studies on its structure in other nemertean larvae are limited. Most adult hoplonemertean worms have a frontal organ located in a position corresponding to that of the larval apical organ. The development and sensory function of the frontal organ has not been thoroughly characterized to date. Results The apical organ in the early rudiment stage of Quasitetrastemma stimpsoni larvae consists of an apical plate enclosed by ducts of frontal gland cells and eight apical neurons. The apical plate is abundantly innervated by neurites of apical neurons. During the late rudiment stage, the larval apical organ has external innervation from below by two subapical-plate neurons, along with 11 apical neurons, and its plate contains serotonin-like immunoreactive (5-HT-lir) cells. In the vermicular stage (free-swimming juvenile), the number of apical neurons is reduced, and their processes are resorbed. Serotonin is detected in the apical plate with no visible connection to apical neurons. In adult worms, the frontal organ has a small apical pit with openings for the frontal gland ducts. The organ consists of 8 to 10 densely packed 5-HT-lir cells that form the roundish pit. Conclusions Although the ultrastructure of the Q. stimpsoni larval apical organ closely resembles that of the apical organ of Polycladida larvae, the former differs in the presence of flask-shaped neurons typical of Spiralia. Significant differences in the structure of the apical organs of hoplonemertean and pilidia larvae point to two different paths in the evolutionary transformation of the ancestral apical organ. Ultrastructural and immunoreactive analyses of the apical organ of a hoplonemertean larva in the late rudiment and vermicular stages and the frontal organ of the adult worms identified common morphological and functional features. Thus, we hypothesize that the larval apical organ is modified during morphogenesis to form the adult frontal organ, which fulfills a sensory function in the hoplonemertean worm. This unique developmental trait distinguishes the Hoplonemertea from other nemertean groups.

scholarly journals Small Molecules Facilitate Single Factor-Mediated Sweat Gland Cell Reprogramming

2021 ◽  
Author(s):  
Shuaifei Ji ◽  
Yan Li ◽  
Laixian Zhou ◽  
Jiangbing Xiang ◽  
Huating Chen ◽  
...  
Keyword(s):  
Small Molecules ◽  
Small Molecule ◽  
Sweat Gland ◽  
Gland Cell ◽  
Dermal Fibroblasts ◽  
Cell Phenotype ◽  
Skin Defect ◽  
Single Factor ◽  
Gland Cells ◽  
Functional Features

Abstract Background: Large skin defect caused severe disruption to the overall skin structure and irreversible damage of sweat gland (SG), resulting in destroy of physiological function of the skin. Reprogramming fibroblasts into sweat gland lineages may provide a promising strategy to obtain the desirable cell types for functional repair and regeneration of damaged skin. Methods: A direct reprogramming strategy of single factor ectodermal dysplasia antigen (EDA) in combination with small molecule cocktails promoting cell-fate conversion to regenerate SG cells from human dermal fibroblasts (HDFs) was developed. Quantitative PCR (qPCR), flow cytometry, calcium activity analysis, immunocytochemical analyses and starch-iodine sweat tests were used to characterize the phenotype, gene expression and function features of the induced sweat gland cells (iSGCs). Results: EDA overexpression drove HDFs toward SG lineages, and HDFs transfected with EDA acquired sweat gland cell phenotype in sweat gland conditional medium (SGM). Small-molecule cocktails favoring SG lineages greatly accelerated the SG fate program in SGM-treated HDF-EDA cells and further induced the regeneration of iSGCs. The HDFs-derived iSGCs exhibited similar phenotypical and functional features of native sweat gland cells. Eventually, in vivo transplantation experiment confirmed that iSGCs had the ability to regenerate SG structurally and functionally.Conclusion: We developed a SG reprogramming strategy to generate functional iSGCs from HDFs by using single factor EDA in combination with small molecules. The generation of iSGCs has important implications for in situ skin regeneration with restoration of sweat glands in the future.

The defensive adaptations of Lima hians (Mollusca, Bivalvia)

1967 ◽  
Vol 47 (1) ◽  
pp. 209-221 ◽  
Author(s):  
T. H. J. Gilmour
Keyword(s):  
Hydrostatic Pressure ◽  
Soft Tissues ◽  
The Body ◽  
Nest Building ◽  
Defensive Behaviour ◽  
Bivalve Molluscs ◽  
Free Swimming ◽  
Gland Cells ◽  
Adductor Muscles ◽  
Epidermal Gland

The inability of Lima Mans Gmelin to enclose the soft tissues of the body within the shell is correlated with the development of other defensive adaptations.L, Mans can automize entire pallial tentacles or parts of tentacles which subsequently secrete a viscous mucus distasteful to potential predators. Autotomy takes place at transverse septa along the length of the tentacles and mucus is secreted by epidermal gland cells.The transverse septa of the tentacles also regulate the hydrostatic pressure of blood within the tentacles and permit the performance of complex locomotory movements. It is suggested that the septa were originally developed to serve this locomotory function and, secondarily, function as planes of weakness at which autotomy may take place.L. Mans builds protective nests. The nests are constructed by burrowing into a gravel substratum and consolidating the walls of the burrow with byssal threads. When disturbed in the nest L. Mans performs locomotory movements which lead to enlargement of the nest. If the nest is broken the locomotory activities result in free swimming followed by attempts to burrow into the substratum to form a new nest. It is unlikely that L. Mans swims freely in nature except when displaced from the nest.IntroductionMost bivalve molluscs react to unfavourable stimuli by retracting the soft parts of the body within the shell valves and contracting the adductor muscles to oppose the valve margins. In Lima hians Gmelin the mantle margin, even with its numerous long tentacles fully retracted, cannot be accommodated within the shell valves. In this paper the inability of L. hians to retract the soft parts within the valves is correlated with two types of defensive behaviour: (i) the secretion of mucus by the tentacles of the mantle margin and the autotomy of these tentacles, and (ii) the interrelated activities of swimming and nest-building.

The life-cycle of Echinoparyphium serratum sp.nov. (Digenea: Echinostomatidae)

Parasitology ◽  
1968 ◽  
Vol 58 (3) ◽  
pp. 573-582 ◽  
Author(s):  
M. J. Howell
Keyword(s):  
Life Cycle ◽  
Granular Material ◽  
Ventral Sucker ◽  
Natural Host ◽  
Circumstantial Evidence ◽  
Free Swimming ◽  
Bile Composition ◽  
Gland Cells ◽  
Experimental Infections

Echinoparyphium serratum sp.nov., with 37 collar spines, is described from experimentally infected ducklings and chickens. It appears to be most closely related to E. aconiatum but differs from it in having smaller eggs, fewer tegument spines, almost confluent vitellaria in the post-testicular region, and the inner margin of the ventral sucker is serrated. The natural host is unknown but thought to be a bird.Bile composition may account for the markedly different recovery percentages of adult worms from the two experimental hosts.Miracidia hatch between 9 and 11 days at 22 °C. Experimental infections of snails with miracidia have not been obtained.Rediae occur naturally in Isidorella brazieri Smith, and free-swimming cercariae encyst in the pericardium of the same species of snail.This latter part of the life-cycle is based on strong circumstantial evidence. A few cysts were occasionally found in the pericardium of Lenameria sp. but the enclosed metacercariae were dead.The cercaria can be distinguished from Cercaria echinata, the cercaria of E. aconiatum, and C. equispinosa in having cystogenous gland cells containing granular material only, and the inner margin of the ventral sucker serrated.I would like to record my sincere thanks to Professor J. D. Smyth for his advice, and comments on the manuscript.

The ultrastructure of the scolex–neck syncytium, neck cells and frontal gland cells of Caryophyllaeus laticeps (Caryophyllidea: Cestoda)

Parasitology ◽  
1981 ◽  
Vol 83 (3) ◽  
pp. 477-487 ◽  
Author(s):  
K. Sylvia Richards ◽  
C. Arme
Keyword(s):  
Granular Material ◽  
The Body ◽  
Frontal Gland ◽  
Dense Ring ◽  
Gland Cells ◽  
Neck Cell ◽  
Cell Processes ◽  
Lined Ducts ◽  
Electron Lucent ◽  
Narrow Cell

SUMMARYThe syncytium of the scolex and neck regions of Caryophyllaeus laticeps differs from that of the remainder of the body in a number of ways. The microtriches have short shafts and lamellated spines and the surface cytoplasm is characterized by numerous elongated granules, occasional lipid-like bodies and, in the scolex region, is penetrated by ducts from the frontal glands. The elongated granules arise from the tegumentary neck cells and pass into the syncytium via narrow cell processes possessing extensions of the neck cell microtubule system. The granules have a peripheral sub-structure of regularly spaced electron-lucent areas. Evidence suggests that the granular material becomes more diffuse before extrusion. The spherical, lipid-like bodies also arise from the neck cells, but extrusion from the syncytium was not observed. Homology of the neck cells with the tegumentary cells of the rest of the body is discussed. The frontal glands are restricted to the scolex apex and secrete spherical or sub-spherical, homogeneous granules. The cells, with microtubule-lined ducts, open to the surface via pores which possess an electron-dense ring at which point the microtubule system terminates. Sensory bulbs are also present and will be described in a subsequent communication. The inter-relationships of the gland distribution, scolex morphology and host pathology are discussed.

A comparative study of the anatomy of the oncomiracidia of the hexabothriid monogeneans Rajonchocotyle emarginata and Hexabothrium appendiculatum

1987 ◽  
Vol 67 (4) ◽  
pp. 757-772 ◽  
Author(s):  
I. D. Whittington
Keyword(s):  
Comparative Study ◽  
Gland Cell ◽  
Anatomical Study ◽  
Cell System ◽  
Ciliated Cells ◽  
Head Region ◽  
Free Swimming ◽  
Flame Cell ◽  
Gland Cells ◽  
Egg Shell

Previous studies of the anatomy of the oncomiracidia of the hexabothriids Rajonchocotyle emarginata and Hexabothrium appendiculatum have been made on unhatched larvae viewed through the egg shell or on larvae pushed out of the egg by coverslip pressure. A study of freshly hatched, free-swimming oncomiracidia has permitted a more detailed anatomical study especially of the gland cell system, the distribution of locomotory ciliated cells and surface sensilla and the flame cell system. Anatomically, the two larvae are closely similar but the oncomiracidium of R. emarginata possesses spherical refringent droplets in the locomotory ciliated cells and, in the head region, a pair of translucent bodies which may be photoreceptors. The oncomiracidia of both parasites possess posterior body gland cells with ducts entering the haptor. Such gland cells have not been recorded previously in the larvae of hexabothriids or in those of other polyopisthocotyleans and the function of these and other gland cells is discussed.

The time course of calcium deposition in shells of the barnacle (Balanus amphititre amphititre) during cyprid-juvenile metamorphosis

1994 ◽  
Vol 52 ◽  
pp. 178-179
Author(s):  
Nancy R. Wallace ◽  
Craig C. Freudenrich ◽  
Karl Wilbur ◽  
Peter Ingram ◽  
Ann LeFurgey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Time Course ◽  
Vertical Plane ◽  
Mantle Cavity ◽  
Qualitative Assessment ◽  
Calcium Deposition ◽  
Free Swimming ◽  
Freeze Dried ◽  
Scanning Electron

The morphology of balanomorph barnacles during metamorphosis from the cyprid larval stage to the juvenile has been examined by light microscopy and scanning electron microscopy (SEM). The free-swimming cyprid attaches to a substrate, rotates 90° in the vertical plane, molts, and assumes the adult shape. The resulting metamorph is clad in soft cuticle and has an adult-like appearance with a mantle cavity, thorax with cirri, and incipient shell plates. At some time during the development from cyprid to juvenile, the barnacle begins to mineralize its shell, but it is not known whether calcification occurs before, during, or after ecdysis. To examine this issue, electron probe x-ray microanalysis (EPXMA) was used to detect calcium in cyprids and juveniles at various times during metamorphosis.Laboratory-raised, free-swimming cyprid larvae were allowed to settle on plastic coverslips in culture dishes of seawater. The cyprids were observed with a dissecting microscope, cryopreserved in liquid nitrogen-cooled liquid propane at various times (0-24 h) during metamorphosis, freeze dried, rotary carbon-coated, and examined with scanning electron microscopy (SEM). EPXMA dot maps were obtained in parallel for qualitative assessment of calcium and other elements in the carapace, wall, and opercular plates.

Development of Neural Structure and Function in Autism Spectrum Disorder: Potential Implications for Learning Language

2020 ◽  
Vol 29 (4) ◽  
pp. 1783-1797
Author(s):  
Kelly L. Coburn ◽  
Diane L. Williams
Keyword(s):  
Autism Spectrum Disorder ◽  
Language Development ◽  
Diffusion Tensor ◽  
Autism Spectrum ◽  
Language Intervention ◽  
Spectrum Disorder ◽  
Autistic Children ◽  
Neural Structure ◽  
Complex Information ◽  
And Function

Purpose Neurodevelopmental processes that begin during gestation and continue throughout childhood typically support language development. Understanding these processes can help us to understand the disruptions to language that occur in neurodevelopmental conditions, such as autism spectrum disorder (ASD). Method For this tutorial, we conducted a focused literature review on typical postnatal brain development and structural and functional magnetic resonance imaging, diffusion tensor imaging, magnetoencephalography, and electroencephalography studies of the neurodevelopmental differences that occur in ASD. We then integrated this knowledge with the literature on evidence-based speech-language intervention practices for autistic children. Results In ASD, structural differences include altered patterns of cortical growth and myelination. Functional differences occur at all brain levels, from lateralization of cortical functions to the rhythmic activations of single neurons. Neuronal oscillations, in particular, could help explain disrupted language development by elucidating the timing differences that contribute to altered functional connectivity, complex information processing, and speech parsing. Findings related to implicit statistical learning, explicit task learning, multisensory integration, and reinforcement in ASD are also discussed. Conclusions Consideration of the neural differences in autistic children provides additional scientific support for current recommended language intervention practices. Recommendations consistent with these neurological findings include the use of short, simple utterances; repetition of syntactic structures using varied vocabulary; pause time; visual supports; and individualized sensory modifications.

Oral and Oropharyngeal Sensory Function in Adults With Chronic Obstructive Pulmonary Disease

2020 ◽  
Vol 29 (2) ◽  
pp. 864-872
Author(s):  
Fernanda Borowsky da Rosa ◽  
Adriane Schmidt Pasqualoto ◽  
Catriona M. Steele ◽  
Renata Mancopes
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Oral Cavity ◽  
Pulmonary Disease ◽  
Thermal Sensation ◽  
Sensory Function ◽  
Control Group ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Age Related ◽  
Copd Patients

Introduction The oral cavity and pharynx have a rich sensory system composed of specialized receptors. The integrity of oropharyngeal sensation is thought to be fundamental for safe and efficient swallowing. Chronic obstructive pulmonary disease (COPD) patients are at risk for oropharyngeal sensory impairment due to frequent use of inhaled medications and comorbidities including gastroesophageal reflux disease. Objective This study aimed to describe and compare oral and oropharyngeal sensory function measured using noninstrumental clinical methods in adults with COPD and healthy controls. Method Participants included 27 adults (18 men, nine women) with a diagnosis of COPD and a mean age of 66.56 years ( SD = 8.68). The control group comprised 11 healthy adults (five men, six women) with a mean age of 60.09 years ( SD = 11.57). Spirometry measures confirmed reduced functional expiratory volumes (% predicted) in the COPD patients compared to the control participants. All participants completed a case history interview and underwent clinical evaluation of oral and oropharyngeal sensation by a speech-language pathologist. The sensory evaluation explored the detection of tactile and temperature stimuli delivered by cotton swab to six locations in the oral cavity and two in the oropharynx as well as identification of the taste of stimuli administered in 5-ml boluses to the mouth. Analyses explored the frequencies of accurate responses regarding stimulus location, temperature and taste between groups, and between age groups (“≤ 65 years” and “> 65 years”) within the COPD cohort. Results We found significantly higher frequencies of reported use of inhaled medications ( p < .001) and xerostomia ( p = .003) in the COPD cohort. Oral cavity thermal sensation ( p = .009) was reduced in the COPD participants, and a significant age-related decline in gustatory sensation was found in the COPD group ( p = .018). Conclusion This study found that most of the measures of oral and oropharyngeal sensation remained intact in the COPD group. Oral thermal sensation was impaired in individuals with COPD, and reduced gustatory sensation was observed in the older COPD participants. Possible links between these results and the use of inhaled medication by individuals with COPD are discussed.

Two-Point Discrimination in the Use of Upper Extremity Nerve Function in the AMA Guides

2015 ◽  
Vol 20 (1) ◽  
pp. 9-11
Author(s):  
Richard Katz
Keyword(s):  
Case Report ◽  
Sensory Function ◽  
Sixth Edition ◽  
Steel Manufacturing ◽  
Nerve Recovery ◽  
Nervous System Function ◽  
Tunnel Syndrome ◽  
Nocturnal Awakening ◽  
Subjective Reports ◽  
Obese Male

Abstract This article presents a case report regarding a 34-year-old obese male who works as a chipper and grinder at a steel manufacturing mill and uses high-frequency vibratory power tools. He presents with typical complaints of carpal tunnel syndrome, including numbness in all five digits, wrist pain, nocturnal awakening/numbness, and others. Two-point discrimination (2PD) using a caliper was tested in the digits of the upper extremities and was 5 mm throughout. 2PD first appeared in the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fifth Edition, and the Sixth Edition states, “sensory deficits can be challenging to grade, since the clinical examination is based on subjective reports by the patient. Grading is based on the results of sensibility testing and two-point discrimination, to improve inter-rater reliability.” The discussion of “sensibility” involves a concept of sensory perception that is more appropriate in surgery literature than neurological literature, and the discussion of the case report in this article reflects the recent literature regarding 2PD as a measure of sensibility. The authors report that sensibility is not a simple recovery of sensory function following nerve injury but rather is a complex interaction between nerve recovery and modulation of central nervous system function in spinal cord, subcortical, and cortical structures. The authors ask if the value of 2PD in the clinical assessment of impairment has been overrated within the AMA Guides, as was range of motion in the assessment of spine impairment.

Motor and sensory function of the rectum in different types of irritable bowel syndrome

2001 ◽  
Vol 120 (5) ◽  
pp. A399-A399
Author(s):  
J STEENS ◽  
P SCHAAR ◽  
C LAMERS ◽  
A MASCLEE
Keyword(s):  
Irritable Bowel Syndrome ◽  
Sensory Function ◽  
Different Types ◽  
Irritable Bowel
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