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Frontiers in Bioengineering and... 2023The liver, as the body's primary organ for maintaining internal balance, is composed of numerous hexagonal liver lobules, each sharing a uniform architectural framework.... (Review)
Review
The liver, as the body's primary organ for maintaining internal balance, is composed of numerous hexagonal liver lobules, each sharing a uniform architectural framework. These liver lobules serve as the basic structural and functional units of the liver, comprised of central veins, hepatic plates, hepatic sinusoids, and minute bile ducts. Meanwhile, within liver lobules, distinct regions of hepatocytes carry out diverse functions. The construction of liver lobule models, faithfully replicating their structure and function, holds paramount significance for research in liver development and diseases. Presently, two primary technologies for constructing liver lobule models dominate the field: 3D bioprinting and microfluidic techniques. 3D bioprinting enables precise deposition of cells and biomaterials, while microfluidics facilitates targeted transport of cells or other culture materials to specified locations, effectively managing culture media input and output through micro-pump control, enabling dynamic simulations of liver lobules. In this comprehensive review, we provide an overview of the biomaterials, cells, and manufacturing methods employed by recent researchers in constructing liver lobule models. Our aim is to explore strategies and technologies that closely emulate the authentic structure and function of liver lobules, offering invaluable insights for research into liver diseases, drug screening, drug toxicity assessment, and cell replacement therapy.
PubMed: 38144540
DOI: 10.3389/fbioe.2023.1303053 -
The Annals of Otology, Rhinology, and... Jan 2020In this paper, the author describes a novel step-by-step setback procedure for correcting protruding lobules; the success of correcting protruding lobules depends on the...
BACKGROUND
In this paper, the author describes a novel step-by-step setback procedure for correcting protruding lobules; the success of correcting protruding lobules depends on the nature and severity of the auricular lobule deformity. Although the auricular lobules occupy small areas on either side of the head, protruding or misshapen lobules exert a significant and sometimes exaggerated disfiguring influence on the otherwise aesthetically pleasing appearance of the ears. Because the lobule is a soft structure without a cartilage skeleton, the correction of a protruding ear and lobule is always a challenge.
METHODS
Protruding lobule abnormalities stem from deformities of the cauda helicis (cartilaginous helical tail) of the auricular lobule, soft tissue, and/or a shortage of anterior skin; however, the abnormalities are usually a combination of all of the above. Therefore, surgical procedures should address all of the causes of lobule deformity and preserve as much tissue and blood supply as possible. Achieving a successful intervention depends on reducing the tension that affects the entire lobule.
RESULTS
This is a retrospective analysis of 660 patients who had otoplasty performed by the first author between January 2010 and December 2017. Correction of the ear lobule was needed in 398 (60.3%) patients. Of these, 44.6% patients were male, 55.4% female and the average age was 9 years (range 4-18 years). In this patient cohort, 356 (89.4%) required bilateral and 42 (10.5%) unilateral ear lobule correction. Standardized pre- and postoperative images were recorded for each patient.
CONCLUSION
The goal of a setback procedure is a natural and harmonious auricular lobule appearance that is achieved through simple, optimal surgery that addresses all of the features of the auricular anatomy.
Topics: Adolescent; Child; Child, Preschool; Cohort Studies; Ear Auricle; Female; Humans; Male; Otologic Surgical Procedures; Plastic Surgery Procedures; Retrospective Studies
PubMed: 31502854
DOI: 10.1177/0003489419875160 -
Nature Reviews. Gastroenterology &... Jul 2019Hepatocytes operate in highly structured repeating anatomical units termed liver lobules. Blood flow along the lobule radial axis creates gradients of oxygen, nutrients... (Review)
Review
Hepatocytes operate in highly structured repeating anatomical units termed liver lobules. Blood flow along the lobule radial axis creates gradients of oxygen, nutrients and hormones, which, together with morphogenetic fields, give rise to a highly variable microenvironment. In line with this spatial variability, key liver functions are expressed non-uniformly across the lobules, a phenomenon termed zonation. Technologies based on single-cell transcriptomics have constructed a global spatial map of hepatocyte gene expression in mice revealing that ~50% of hepatocyte genes are expressed in a zonated manner. This broad spatial heterogeneity suggests that hepatocytes in different lobule zones might have not only different gene expression profiles but also distinct epigenetic features, regenerative capacities, susceptibilities to damage and other functional aspects. Here, we present genomic approaches for studying liver zonation, describe the principles of liver zonation and discuss the intrinsic and extrinsic factors that dictate zonation patterns. We also explore the challenges and solutions for obtaining zonation maps of liver non-parenchymal cells. These approaches facilitate global characterization of liver function with high spatial resolution along physiological and pathological timescales.
Topics: Animals; Gene Expression Profiling; Genome; Hepatocytes; Humans; Liver; Single Molecule Imaging; Single-Cell Analysis; Transcriptome
PubMed: 30936469
DOI: 10.1038/s41575-019-0134-x -
Facial Plastic Surgery : FPS Nov 2004Many techniques have been described for the correction of protruding ears. Most of them concentrate on correcting the form and position of auricular cartilage. The...
Many techniques have been described for the correction of protruding ears. Most of them concentrate on correcting the form and position of auricular cartilage. The lobule is a soft tissue structure. Skin resections of its posterior surface have been propagated for the correction of its position; however, these cause tension on the wound and might increase the already relatively high risk for the development of keloids. We have modified the technique for correcting the protruding lobule for its exact positioning and minimizing the risk for relapse and keloids. Starting from the incision performed for the anthelix plasty, a subcutaneous pocket is prepared between the anterior and posterior sides of the lobule. Afterwards, the subcutaneous layer of the postlobular skin is adjusted and fixed to the cartilage of the conchal cavum with a special mattress suture. This technique is a refinement of otoplasty for bat ears. It is indicated for precise modification of form and position of protruding lobules.
Topics: Dermatologic Surgical Procedures; Ear Cartilage; Ear, External; Esthetics; Follow-Up Studies; Humans; Keloid; Plastic Surgery Procedures; Recurrence; Suture Techniques
PubMed: 15778917
DOI: 10.1055/s-2005-865388 -
Cells Feb 2023Purkinje cells (PCs) are the principal cells of the cerebellar cortex and form a central element in the modular organization of the cerebellum. Differentiation of PCs...
Purkinje cells (PCs) are the principal cells of the cerebellar cortex and form a central element in the modular organization of the cerebellum. Differentiation of PCs based on gene expression profiles revealed two subpopulations with distinct connectivity, action potential firing and learning-induced activity changes. However, which basal cell physiological features underlie the differences between these subpopulations and to what extent they integrate input differentially remains largely unclear. Here, we investigate the cellular electrophysiological properties of PC subpopulation in adult and juvenile mice. We found that multiple fundamental cell physiological properties, including membrane resistance and various aspects of the action potential shape, differ between PCs from anterior and nodular lobules. Moreover, the two PC subpopulations also differed in the integration of negative and positive current steps as well as in size of the hyperpolarization-activated current. A comparative analysis in juvenile mice confirmed that most of these lobule-specific differences are already present at pre-weaning ages. Finally, we found that current integration in PCs is input history-dependent for both positive and negative currents, but this is not a distinctive feature between anterior and nodular PCs. Our results support the concept of a fundamental differentiation of PCs subpopulations in terms of cell physiological properties and current integration, yet reveals that history-dependent input processing is consistent across PC subtypes.
Topics: Mice; Animals; Purkinje Cells; Action Potentials; Cerebellum; Learning
PubMed: 36831290
DOI: 10.3390/cells12040623 -
JAMA Facial Plastic Surgery 2014Correction of the protruded lobule in otoplasty continues to represent an important challenge. The lack of skeletal elements within the lobule makes a controlled lobule...
IMPORTANCE
Correction of the protruded lobule in otoplasty continues to represent an important challenge. The lack of skeletal elements within the lobule makes a controlled lobule repositioning less predictable. OBJECTIVE To present a new surgical technique for lobule correction in otoplasty.
DESIGN, SETTING, AND PARTICIPANTS
Human cadaver studies were performed for detailed anatomical analysis of lobule deformities. In addition, we evaluated a novel algorithmic approach to correction of the lobule in 12 consecutive patients. INTERVENTIONS/EXPOSURES: Otoplasty with surgical correction of lobule using the fillet technique.
MAIN OUTCOMES AND MEASURES
The surgical outcome in the 12 most recent consecutive patients with at least 3 months of follow-up was assessed retrospectively. The postsurgical results were independently reviewed by a panel of noninvolved experts.
RESULTS
The 3 major anatomic components of lobular deformities are the axial angular protrusion, the coronal angular protrusion, and the inherent shape. The fillet technique described in the present report addressed all 3 aspects in an effective way. Clinical data analysis revealed no immediate or long-term complications associated with this new surgical method. The patients' subjective rating and the panel's objective rating revealed "good" to "very good" postoperative results.
CONCLUSIONS AND RELEVANCE
This newly described fillet technique represents a safe and efficient method to correct protruded ear lobules in otoplasty. It allows precise and predictable positioning of the lobule with an excellent safety profile.
LEVEL OF EVIDENCE
4.
Topics: Algorithms; Cadaver; Child, Preschool; Dissection; Ear, External; Female; Humans; Male; Plastic Surgery Procedures; Retrospective Studies
PubMed: 24264799
DOI: 10.1001/jamafacial.2013.2146 -
Neuromodulation : Journal of the... Apr 2020Aging is associated with a decline in cognitive and motor performances, which are a part of geriatric syndromes. Since aging is associated with morphological changes in...
Lobule-Specific Dosage Considerations for Cerebellar Transcranial Direct Current Stimulation During Healthy Aging: A Computational Modeling Study Using Age-Specific Magnetic Resonance Imaging Templates.
OBJECTIVE
Aging is associated with a decline in cognitive and motor performances, which are a part of geriatric syndromes. Since aging is associated with morphological changes in the cerebellum and cerebellar morphology is a good predictor of cognitive and motor performances, so the study of cerebellar role in age-related decline in performance is necessary. Cerebellar transcranial direct current stimulation (ctDCS) has been proposed to study and facilitate the cerebellar function. However, lobule-specific dosing has not been investigated in healthy aging. This is important because the same electrode montage across different individuals for ctDCS (called the "one-size-fits-all" approach) can lead to inter-individual differences in the lobule-specific dosing of the electric field (EF). These differences can be due to the inter-individual variability and age-related changes in the cerebellar structure. To investigate such lobule-specific dosing differences in healthy aging, we modeled the lobular EF distribution across groups of 18 to 89 years for a commonly used "one-size-fits-all" ctDCS montage.
MATERIALS AND METHODS
A fully automated open-source pipeline performed age-group specific computational modeling of EF using 18 age-appropriate human brain magnetic resonance imaging (MRI) templates. The 18 age-appropriate human brain MRI templates were obtained from a database found online at https://jerlab.sc.edu/projects/neurodevelopmental-mri-database/. We extracted the EF magnitude (called EF strength) across the 28 cerebellar lobules based on a spatially unbiased cerebellar atlas. We investigated the aging effects on various measures of specificity including the ratio of the mean lobular EF at the lobules beneath the active electrode (ipsilateral [right] lobules VIIIa, VIIIb, IX) divided by the mean EF across both the targeted (ipsi) and the contralateral (contra) cerebellar hemisphere.
RESULTS
Two-way ANOVA showed that the lobules as well as the age group (and their interaction term) had a significant effect (p < 0.01) on the EF strength. Specifically, EF strength increased significantly at the neighboring cerebellar lobules (e.g., ipsilateral [right] lobules VIIb, Crus I and Crus II) of the targeted cerebellar hemisphere at an old age (70-74, 75-79, and 85-89 years) that reduced the specificity of ctDCS at the ipsilateral (right) lobules VIIIa, VIIIb, IX beneath the active electrode. We also found that the maximum EF strength in the cerebellar hemispheres decreased with an increase in the volume of the cerebrospinal fluid (CSF) and a decrease in the cerebellar volume with aging in a linear manner.
DISCUSSION
We found that cerebellar shrinkage and increasing thickness of the highly conductive CSF during healthy aging can lead to the dispersion of the current away from the lobules underlying the active electrode. We concluded that an individualized ctDCS approach for dosimetry is critical when ctDCS is used as an adjuvant treatment for active aging to address age-related lobule-specific cerebellar geriatric syndromes effectively. Future work is necessary to investigate age-related effects of lobule-specific ctDCS on the large-scale cognitive and motor networks using functional neuroimaging that is expected due to the cerebellum's extensive reciprocal connectivity with the cerebral cortex.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Cerebellum; Computer Simulation; Female; Healthy Aging; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Transcranial Direct Current Stimulation; Young Adult
PubMed: 31995268
DOI: 10.1111/ner.13098 -
The Journal of Physiology Jan 2012Cerebellar Purkinje cells (PCs) are the sole output of the cerebellar cortex and function as key to a variety of learning-related behaviours by integrating... (Comparative Study)
Comparative Study
Cerebellar Purkinje cells (PCs) are the sole output of the cerebellar cortex and function as key to a variety of learning-related behaviours by integrating multimodal afferent inputs. Intrinsic membrane excitability of neurons determines the input-output relationship, and therefore governs the functions of neural circuits. Cerebellar vermis consists of ten lobules (lobules I-X), and each lobule receives different sensory information. However, lobule-specific differences of electrophysiological properties of PC are incompletely understood. To address this question, we performed a systematic comparison of membrane properties of PCs from different lobules (lobules III-V vs. X). Two types of firing patterns (tonic firing and complex bursting) were identified in response to depolarizing current injections in lobule III-V PCs, whereas four distinct firing patterns (tonic firing, complex bursting, initial bursting and gap firing) were observed in lobule X. A-type K(+) current and early inactivation of fast Na(+) conductance with activation of 4-aminopyridine-sensitive conductances were shown to be responsible for the formation of gap firing and initial bursting patterns, respectively, which were observed only in lobule X. In response to current injection, PCs in lobule X spiked with wider dynamic range. These differences in firing pattern and membrane properties probably contribute to signal processing of afferent inputs in lobule-specific fashion, and particularly diversity of discharge patterns in lobule X, as a part of the vestibulocerebellum, might be involved in strict coordination of a precise temporal response to a wide range of head movements.
Topics: Action Potentials; Animals; Cell Membrane; Cerebral Cortex; Electric Stimulation; Electrophysiological Phenomena; Membrane Potentials; Models, Animal; Neurons, Afferent; Patch-Clamp Techniques; Purkinje Cells; Rats; Rats, Sprague-Dawley
PubMed: 22083600
DOI: 10.1113/jphysiol.2011.221846 -
Cell and Tissue Research May 2022The mammalian liver has a lobule structure with a portal triad consisting of the portal vein, hepatic artery, and bile duct, which exhibits zonal gene expression,...
The mammalian liver has a lobule structure with a portal triad consisting of the portal vein, hepatic artery, and bile duct, which exhibits zonal gene expression, whereas those of teleosts do not have a portal triad. It remains to be demonstrated what kind of the unit structures they have, including their gene expression patterns. The aims of the present study were to demonstrate the unit structure of the teleost liver and discuss it in terms of evolution and adaptation in vertebrates and the use of teleosts as an alternative model for human disease. The zebrafish liver was examined as a representative of teleosts with respect to its morphological architecture and gene expression. A novel, polygonal lobule structure was detected in the zebrafish liver. In it, portal veins and central veins were distributed at the periphery and center, respectively. Sinusoids connected both veins. Anxa4-positive preductules were incorporated into the tubular lumen of two rows of hepatocytes in sections. Intrahepatic bile ducts resided randomly in the liver lobule. Zebrafish livers did not have zonal gene expression for metabolic pathways examined. The lobules of the zebrafish liver with preductules located in the tubular lumina of hepatocytes may resemble the oval cell reaction of injured livers of mammals and might convey bile to the intestine more safely than mammalian livers. The gene expression pattern in liver lobules and our liver lobule model of the zebrafish may be important to discuss data obtained in experiments using this animal as an alternative model for human disease.
Topics: Animals; Liver; Mammals; Zebrafish
PubMed: 35258713
DOI: 10.1007/s00441-022-03607-y -
Frontiers in Neurology 2021This study aimed to investigate the potential connectivity mechanism between the cerebellum and anterior cingulate cortex (ACC) and the cerebellar structure in primary...
This study aimed to investigate the potential connectivity mechanism between the cerebellum and anterior cingulate cortex (ACC) and the cerebellar structure in primary dysmenorrhea (PDM). We applied the spatially unbiased infratentorial template (SUIT) of the cerebellum to obtain anatomical details of cerebellar lobules, upon which the functional connectivity (FC) between the cerebellar lobules and ACC subregions was analyzed and the gray matter (GM) volume of cerebellar lobules was measured by using voxel-based morphometry (VBM) in 35 PDM females and 38 age-matched healthy females. The potential relationship between the altered FC or GM volume and clinical information was also evaluated in PDM females. PDM females showed higher connectivity between the left perigenual ACC (pACC) and lobule vermis_VI, between the left pACC and left lobule IX, and between right pACC and right cerebellar lobule VIIb than did the healthy controls. Compared with healthy controls, no altered GM volume was found in PDM females. No significant correlation was found between altered cerebellum-ACC FC and the clinical variables in the PDM females. PDM females have abnormal posterior cerebellar connectivity with pACC but no abnormal structural changes. ACC-cerebellar circuit disturbances might be involved in the PDM females.
PubMed: 34239492
DOI: 10.3389/fneur.2021.645616