1,721,005 research outputs found
The innervation of human muscularis mucosae: an ultrastructural study
Full text linkThe muscularis mucosae, a thin band of smooth muscle located at the base of the gastrointestinal mucosa, has been the topic of very few studies .The muscularis mucosae might regulate the absorptive and secretory functions of the gut through movements of the mucosal surface (1).The autonomic innervation of this tissue is almost completely unknown.Therefore we have carried out an ultrastructural study on nerve fibers of muscolaris mucosae by using archived mucosal rectal biopsies of children of different age , examined in the past for the diagnosis of neurometabolic disease and resulted negative. Nerve fibers of muscularis mucosae were unmyelinated. They contain several axons with the characteristics of intervaricose tract completely or almost surrounded by Schwann cells . Other axons in the nerve fibers appear as varicosities partly covered with Schwann cell cytoplasm or naked, and filled with vesicles and mitochondria .The vesicles in the same varicosity appear pleomorphic: small clear-core vesicles , dense -core of small diameter or less often dense-core of larger type. The membrane of muscle cells often protruded toward the varicosity . No synaptic specialization was observed.With very low frequency we found varicosities in intimate contact with the plasmalemma . Pleomorphic vesicles inside the same varicosity suggest a complex neurotransmission based on the release of classical transmitter and cotransmitters.The physiological relevance of these nerves remains unclear. Strips of longitudinal muscularis mucosae isolated from the human, guinea pig and rat colon responded with concentration-dependent contractions to the application of several spasmogens (1). In the human muscularis mucosae, neurokinin A was most potent, followed by carbachol, prostaglandin F2 and acetylcholine. These findings suggest the possibility that the muscularis mucosae is innervated by excitatory cholinergic nerves (1).On the other hand in oesophagus exogenously applied adrenaline inhibited spontaneous activities of the muscularis mucosae motor activity. Adrenergic nerves might inhibit spontaneous motility via the inhibition of cholinergic neurotransmission. VIP- , NPY-, CGRP- and galanin-immunoreactive nerve fibers were observed in the human esophageal muscularis mucosae but their function remains unknown (2)
Geometric complexity identifies platelet activation in familial hypercholesterolemic patients
No full textFamilial hypercholesterolemia (FH), a genetic disease, is associated with a severe incidence of athero-thrombotic events, related, also, to platelet hyperreactivity. A plethora of methods have been proposed to identify those activated circulating platelets, none of these has proved really effective. We need efficient methods to identify the circulating platelet status in order to follow the patients after therapeutic procedures. We propose the use of computerized fractal analysis for an objective characterization of the complexity of circulating platelet shapes observed by means of transmission electron microscopy in order to characterize the in vivo hyperactivated platelets of familial hypercholesterolemic patients, distinguishing them from the in vivo resting platelets of healthy individuals. Platelet boundaries were extracted by means of automatically image analysis. Geometric complexity (fractal dimension, D) by box counting was automatically calculated. The platelet boundary observed by electron microscopy is fractal, the shape of the circulating platelets is more complex in FH (n = 6) than healthy subjects (n = 5, P < 0.01), with 100% correct classification in selected individuals. In vitro activated platelets from healthy subjects show an analogous increase of D. The observed high D in the platelet boundary in FH originates from the in vivo platelet activation. Computerized fractal analysis of platelet shape observed by transmission electron microscopy can provide accurate, quantitative data to study platelet activation in familial hypercholesterolemia and after administration of drugs or other therapeutic procedures. © 2015 Wiley Periodicals, Inc
Scleredema adultorum con coinvolgimento muscolare in paziente diabetica. G Ital Dermatol Venereol. (Suppl.1 al N°1): 49-50, 2004
No full textPeptidergic innervation of mesenteric lymphatics in guinea pigs: an immunocytochemical and pharmacological study.
No full textBy immunocytochemistry, substance P immunoreactive (SP-IR) and vasoactive intestinal peptide immunoreactive (VIP-IR) nerve fibers were examined in guinea pig mesenteric lymph collectors. The immunoreactive nerve fibers, located in the adventitia of lymphatics, were few and were irregularly distributed along the vessel wall. These fibers appeared to be more numerous and more evenly distributed along the corresponding artery and vein walls within the same area. SP immunoreactivity in the vascular nerves was depleted in guinea pigs injected with capsaicin but was unaffected by the injection of 6-hydroxydopamine. By contrast, VIP-IR nerve fibers were unaffected by both treatments. It is concluded that SP-IR nerve fibers in the lymphatics are likely to be of sensory origin and that VIP containing nerves in the lymph collectors are distinct from SP-containing and noradrenergic nerves. It is also suggested that lymph collectors possess a complex although limited innervation pattern not only of autonomic nerve fibers containing classic neurotransmitters but also of peptidergic nerve fibers of a different origin with a vasomotor and/or sensory action
Study of total duration of distal compound muscle action potential in demyelinating and axonal Guillain-Barre' syndrome
No full textObjectives: Electrophysiology plays a crucial role in Guillain-Barré syndrome (GBS) diagnosis and subtype classification. The aim of our study was to assess the potential role of distal compound muscle action potential (dCMAP) for early differentiation between acute inflammatory demyelinating polyneuropathy (AIDP) and axonal GBS. Methods: We retrospectively reviewed the medical records of 24 subjects with AIDP and 18 subjects with axonal GBS. We built up receiver operating characteristic curves for total dCMAP duration and negative phase of dCMAP duration, in order to derive cut-off values able to differentiate between AIDP and axonal GBS. Results: The total duration of dCMAP was significantly prolonged in AIDP compared to axonal GBS. AUCs, odds ratio and positive predictive values were higher for total duration than for negative peak duration. Nerve conduction parameters in the lower limbs were more sensitive than those in the upper limbs in distinguishing AIDP from axonal GBS. Discussion: Total duration of dCMAP dispersion may capture an adjunctive component of distal demyelination, not measured by the more traditional parameters and may thus represent a useful tool for early differentiation between AIDP and axonal GBS. © 2022 Informa UK Limited, trading as Taylor & Francis Group
Parenchima innervation of human white adipose tissue studied by digital deconvolution,for optical three-dimensional reconstruction of fluorescent imagines and transmission electron microscopy
No full textIn humans there is a lack of morphological evidence of white
adipose tissue (WAT) innervation also if electrophysiological study
in human suggests it. Therefore we search for parenchyma innervation
of human subcutaneous WAT by fluorescence immunohistochemistry
for protein gene product 9.5 (PGP 9.5) a pan axonal
marker. Considering the low percentage of adipocytes innervated,
we use digital deconvolution of wide-field fluorescence threedimensional
image stacks of thick sections .We employed Transmission
Electron Microscopy (TEM) to examine at high resolution the
morphology of nerve fiber terminal and neuroeffector junction in
adipose tissue. We use an indirect immunofluorescence method to
show nerve fibers immunoreactive in frozen sections .The primary
antibody employed was a Rabbit anti- PGP 9.5 before characterized.
For immunofluorescence we utilized a sample of skin taken in
the course of a diagnostic quadriceps muscle biopsy from an adult
patient (age: 40 years) and 3 archival skin biopsies from the child’s
forearm (age 1–3 years) , for TEM observation. PGP .9.5 immunoreactive
varicose nerve fibers appear in close apposition with single
adipocyte. The nerve fibers often were at the boundary between
flanking adipocytes and unrelated from contiguous blood vessels
.Tem observation shows unmyelinated nerve fibers near single
adipocytes. Terminal axons containing mostly small dense core
vesicles face fat cell membrane, which did not present any specialization.Our results show the existence in human WAT of a parenchyma
innervation for the first time. The innervation is already present in children adipose tissue and appears unambiguously of
adrenergic type from ultrastrucure
Heat shock protein 70 in human ocular muscles: immunocytochemical, and immunochemical study
No full textEosinophils in inflammatory muscle disorders: a morphologic and immunohistological study.
No full textLymphatic vessels in human sural nerve: immunohistochemical detection by D2-40
No full textLymphatics were detected in the epineurium of human sural nerve by D2-40 immunostaining and confirmed by ultrastructural examination
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