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Journal of Morphology Nov 2023Leposternon microcephalum is a species belonging to the Amphisbaenia, a group of burrowing reptiles. Amphisbaenia present various morphological and physiological...
Leposternon microcephalum is a species belonging to the Amphisbaenia, a group of burrowing reptiles. Amphisbaenia present various morphological and physiological adaptations that allow them to penetrate the ground and live underground, through a system of galleries and permanent chambers that they build themselves. Among the morphological adaptations in this group, those of the skull stand out as it serves as the main excavation tool. Four basic skull shapes are recognized: rounded, keeled, shovel-shaped, and spade-shaped. The skull of L. microcephalum belongs to this last type, which is considered the most specialized. The species inhabits soils that are highly compacted and difficult to penetrate. Among the species of Leposternon present in South America, L. microcephalum has the widest distribution, being found in all Brazilian biomes and neighboring countries such as Bolivia, Argentina, Paraguay, and Uruguay. The analysis of the skull of this species was carried out using three-dimensional geometric morphometrics (3D-GMM), a technique that allows comparative analysis, through robust statistical methods, of shape and its variations, using Cartesian coordinate data from a configuration of homologous landmarks. The technique allows the size and shape components of a structure to be analyzed separately. From an ontogenetic point of view, this methodology had also been used to investigate variations in Cynisca leucura, a member of the Amphisbaenidae with a rounded head. Our hypothesis is that the patterns of morphological differentiation in the skull, mainly in the intermediate and occipital regions, are similar in different Amphisbaenia species. Therefore, the objective of this study was to analyze cranial morphological variations in an ontogenetic series of L. microcephalum using 3D-GMM. Computed Tomographic scans of 13 specimens were analyzed: juveniles (N = 8) and adults (N = 5), based on 20 landmarks that characterize the skull. Principal components and regression analyses between shape (dependent variable) and size (independent variable) showed a clear difference between the cranial morphological pattern of juvenile individuals and that of adults. For instance, young specimens tend to have a dorsoventrally tall neurocranium, with the tip of the snout more anteriorly oriented and its dorsal border subtly curved. Dorsally, the parietal region is thicker and smoothly dome-shaped in juveniles. As in C. leucura, the variation was strongly correlated with the size change from juvenile to adult, indicating a dominant role for ontogenetic allometry in determining skull shape.
Topics: Humans; Animals; Skull; Head; Regression Analysis; Lizards; Brazil
PubMed: 37856276
DOI: 10.1002/jmor.21643 -
Indian Journal of Plastic Surgery :... Dec 2023Dorsal metacarpal artery perforator flap (DMAP), first described by Quaba and Davison, is a useful tool in the armamentarium of plastic surgeons. It provides like for...
Dorsal metacarpal artery perforator flap (DMAP), first described by Quaba and Davison, is a useful tool in the armamentarium of plastic surgeons. It provides like for like tissue for the reconstruction of dorsal finger defects. It is a simple and relatively easy flap to harvest with minimal donor site morbidity. In this case series, we present our experience, applications, and surgical technique of flap harvesting.
PubMed: 38105876
DOI: 10.1055/s-0043-1773771 -
Cerebral Cortex (New York, N.Y. : 1991) Oct 2023Causal perturbations suggest that primate dorsal pulvinar plays a crucial role in target selection and saccade planning, though its basic neuronal properties remain...
Causal perturbations suggest that primate dorsal pulvinar plays a crucial role in target selection and saccade planning, though its basic neuronal properties remain unclear. Some functional aspects of dorsal pulvinar and interconnected frontoparietal areas-e.g. ipsilesional choice bias after inactivation-are similar. But it is unknown if dorsal pulvinar shares oculomotor properties of cortical circuitry, in particular delay and choice-related activity. We investigated such properties in macaque dorsal pulvinar during instructed and free-choice memory saccades. Most recorded units showed visual (12%), saccade-related (30%), or both types of responses (22%). Visual responses were primarily contralateral; diverse saccade-related responses were predominantly post-saccadic with a weak contralateral bias. Memory delay and pre-saccadic enhancement was infrequent (11-9%)-instead, activity was often suppressed during saccade planning (25%) and further during execution (15%). Surprisingly, only few units exhibited classical visuomotor patterns combining cue and continuous delay activity or pre-saccadic ramping; moreover, most spatially-selective neurons did not encode the upcoming decision during free-choice delay. Thus, in absence of a visible goal, the dorsal pulvinar has a limited role in prospective saccade planning, with patterns partially complementing its frontoparietal partners. Conversely, prevalent visual and post-saccadic responses imply its participation in integrating spatial goals with processing across saccades.
Topics: Animals; Saccades; Pulvinar; Prospective Studies; Macaca mulatta; Eye Movements
PubMed: 37724430
DOI: 10.1093/cercor/bhad333 -
International Journal of Molecular... Mar 2024The dorsal root ganglion (DRG) serves as a pivotal site for managing chronic pain through dorsal root ganglion stimulation (DRG-S). In recent years, the DRG-S has... (Review)
Review
The dorsal root ganglion (DRG) serves as a pivotal site for managing chronic pain through dorsal root ganglion stimulation (DRG-S). In recent years, the DRG-S has emerged as an attractive modality in the armamentarium of neuromodulation therapy due to its accessibility and efficacy in alleviating chronic pain refractory to conventional treatments. Despite its therapeutic advantages, the precise mechanisms underlying DRG-S-induced analgesia remain elusive, attributed in part to the diverse sensory neuron population within the DRG and its modulation of both peripheral and central sensory processing pathways. Emerging evidence suggests that DRG-S may alleviate pain by several mechanisms, including the reduction of nociceptive signals at the T-junction of sensory neurons, modulation of pain gating pathways within the dorsal horn, and regulation of neuronal excitability within the DRG itself. However, elucidating the full extent of DRG-S mechanisms necessitates further exploration, particularly regarding its supraspinal effects and its interactions with cognitive and affective networks. Understanding these mechanisms is crucial for optimizing neurostimulation technologies and improving clinical outcomes of DRG-S for chronic pain management. This review provides a comprehensive overview of the DRG anatomy, mechanisms of action of the DRG-S, and its significance in neuromodulation therapy for chronic pain.
Topics: Humans; Chronic Pain; Ganglia, Spinal; Pain Management; Afferent Pathways; Sensory Receptor Cells
PubMed: 38612402
DOI: 10.3390/ijms25073591 -
International Immunopharmacology Jan 2024Proinflammatory cytokines are crucial contributors to neuroinflammation in the development of chronic pain. Here, we identified il16, which encodes interleukin-16...
Proinflammatory cytokines are crucial contributors to neuroinflammation in the development of chronic pain. Here, we identified il16, which encodes interleukin-16 (IL-16), as a differentially expressed gene in spinal dorsal horn of a complete Freund's Adjuvant (CFA) inflammatory pain model in mice by RNA sequencing. We further investigated whether and how IL-16 regulates pain transmission in the spinal cord and contributes to the development of inflammatory pain hypersensitivity. RNA sequencing and bioinformatics analysis revealed elevated IL-16 transcript levels in the spinal dorsal horn after CFA injection. This increase was further confirmed by qPCR, immunofluorescence, and western blotting. Knockdown of IL-16 by intrathecal injection of IL-16 siRNA not only attenuated CFA-induced mechanical and thermal pain hypersensitivity, but also inhibited enhanced c-fos expression and glial activation in the spinal dorsal horn in male mice injected with CFA. Moreover, exogenous IL-16 induced nociceptive responses and increased c-fos expression and glial activation in spinal dorsal horn. This effect was largely impaired when CD4, the binding receptor for IL-16, was inhibited. In addition, CD4 expression was upregulated in the spinal dorsal horn after CFA injection and CD4 was present in microglia and in contact with astrocytes and activated spinal neurons. Taken together, these results suggest that enhanced IL-16-CD4 signaling triggers pain and activates microglia and astrocytes in the spinal dorsal horn, thus contributing to inflammatory pain. IL-16 may serve as a promising target for the treatment of inflammatory pain.
Topics: Mice; Male; Animals; Interleukin-16; Hyperalgesia; Pain; Spinal Cord Dorsal Horn; Spinal Cord; Neurons; Freund's Adjuvant; Inflammation
PubMed: 38113689
DOI: 10.1016/j.intimp.2023.111411 -
American Journal of Physical Medicine &... Nov 2023Spinal cord stimulation is an increasingly used treatment for a number of chronic pain states. Dorsal column stimulation is historically and currently the anatomical...
Spinal cord stimulation is an increasingly used treatment for a number of chronic pain states. Dorsal column stimulation is historically and currently the anatomical target of choice for most chronic pain conditions, including postlaminectomy syndrome and radicular pain. However, early studies suggested that stimulation of an alternative target, the ventral columns that carry pain fibers in the anterior and lateral spinothalamic tracts, may offer comparable or superior pain relief. A patient undergoing standard-of-care spinal cord stimulation trial had an additional lead placed on the right ventrolateral aspect of the spinal cord. After the usual 7-day trial of dorsal column stimulation, the dorsal leads were removed and ventrolateral column stimulation was applied through the retained ventral lead for a period of 3 days. The Brief Pain Index Short Form and Numeric Rating Scale were recorded for both dorsal and ventral stimulation. Ventrolateral spinal cord stimulation provided comparable outcomes compared with dorsal column stimulation using nonparesthesia-based stimulation. The results suggest further investigation into spinal cord stimulation anatomical placement and mechanism of action is warranted.
PubMed: 37126791
DOI: 10.1097/PHM.0000000000002268 -
Journal of Experimental Zoology. Part... Dec 2023Freeze tolerant animals survive the winter by tolerating the freezing and thawing of up to 70% of body water and the respective cessation and resumption of essential...
Freeze tolerant animals survive the winter by tolerating the freezing and thawing of up to 70% of body water and the respective cessation and resumption of essential functions including circulation and respiration during each freeze-thaw cycle. Cope's gray treefrog Dryophytes chrysoscelis is a freeze tolerant anuran that uses a system of cryoprotectants to prevent intracellular freezing and mitigate osmotic stress during freezing and thawing episodes. Morphological features were documented in D. chrysoscelis using a repeated freeze-thaw protocol. Dorsal skin in frozen frogs was distinctly blue and green before reverting to brown during thawing. The dorsal color change in frozen frogs does not function similarly to other known color change events in amphibians. The return to brown skin color in thawing animals coincides with recovery of vital functions in freeze tolerant frogs, suggesting that dorsal color change is an indicator of postfreeze recovery in D. chrysoscelis. We also provide evidence of "freeze resistance" in D. chrysoscelis. Two individuals did not freeze following three successive bouts of ice inoculation at -2.5°C and maintained brown dorsal color despite ice crystallization on the dorsum and contact with frozen substrate. Both frogs had similar plasma osmolality, circulating cryoprotectants, and incidence of cryoinjury compared to frogs that were frozen and thawed once or three times. Freeze resistance may be explained by physical changes in the skin including lipid accumulation and dehydration. This integrative study presents novel attributes of organismal freeze tolerance in D. chrysoscelis.
Topics: Humans; Animals; Freezing; Ice; Acclimatization; Anura; Cryoprotective Agents
PubMed: 37661700
DOI: 10.1002/jez.2753 -
Aesthetic Surgery Journal. Open Forum 2023Rhinoplasty is one of the most commonly performed facial gender-affirming surgeries (FGASs) for transgender females, but well-established morphometric parameters...
BACKGROUND
Rhinoplasty is one of the most commonly performed facial gender-affirming surgeries (FGASs) for transgender females, but well-established morphometric parameters describing feminizing nasal changes do not exist.
OBJECTIVES
Describe the author's technique for feminization rhinoplasty, analyze the changes in 3-dimensional nasal anthropomorphic parameters, and describe patient-reported outcomes.
METHODS
Three-dimensional photogrammetric evaluation was performed both preoperatively and postoperatively in transgender female patients who underwent FGAS. Measurements assessed included the nasofrontal angle, nasolabial angle, dorsal height, mid-dorsal width, alar width, nasal tip width, and tip projection. Patients were surveyed preoperatively and postoperatively using the FACE-Q Nose module. Paired -tests were utilized to assess changes in postoperative measurements and FACE-Q Nose satisfaction scores.
RESULTS
Twenty patients underwent FGAS during the study period. The average time between surgery and postoperative 3-dimensional images was 13.6 ± 6.8 months. The nasofrontal angle increased by 8.2° (148.0 ± 7.4° to 156.1 ± 6.7°, < .001) and tip projection increased by 0.017 (0.58 ± 0.03 to 0.60 ± 0.04, < .01). Dorsal height, mid-dorsal width, and tip width all decreased significantly ( < .05). There were significant improvements in patients' "Satisfaction with Nose," "Satisfaction with Facial Appearance Overall," "Psychological Function," and "Social Function" on FACE-Q. One revision rhinoplasty was performed, and no documented surgical complications were reported.
CONCLUSIONS
There were statistically significant changes in the nasofrontal angle, tip projection, dorsal height, mid-dorsal width, and tip width in patients receiving feminization rhinoplasty. These data may help surgeons with preoperative planning and intraoperative decision making.
PubMed: 38075296
DOI: 10.1093/asjof/ojad095 -
Aesthetic Surgery Journal Dec 2023The latissimus dorsi flap (LDF) is a classic and efficient technique for breast reconstruction. However, its use has recently diminished in surgical practice due to...
BACKGROUND
The latissimus dorsi flap (LDF) is a classic and efficient technique for breast reconstruction. However, its use has recently diminished in surgical practice due to dorsal disadvantages and to the increased use of microsurgical techniques for breast reconstruction, such as the deep inferior epigastric artery perforator flap.
OBJECTIVES
The aim of this study was to evaluate the safety and efficacy of managing dorsal problems such as asymmetry, irregularities, and dysesthesia by lipomodeling the back region during the associated surgery for breast reconstruction.
METHODS
A series of 300 patients operated by the last author for dorsal lipomodeling to correct sequelae after harvesting the total LDF, between November 2012 and March 2019, was analyzed.
RESULTS
The results show a very good improvement in the dorsal region in 6.7% of cases, good improvement in 86.7% cases, and fair improvement in 6.7% of cases. There was a good improvement in dorsal comfort in 90% of cases, a very good improvement in 6.66% of cases, and a fair improvement in 6.66% of cases. In 5% of cases 2 sessions were required to obtain a satisfactory result. No major complications were registered, and the only complication encountered were oil cysts in 2.6% of cases that were treated during consultation with percutaneous puncture.
CONCLUSIONS
This study showed that lipomodeling in the back area after LDF harvesting is an efficient and safe technique that corrects secondary dorsal sequelae such as irregularities, asymmetry, sensitivity, and dysesthesia. This technique should increase the indications for LDF because it decreases donor site sequelae, which are some of the main drawbacks of the LDF approach.
Topics: Humans; Female; Superficial Back Muscles; Paresthesia; Surgical Flaps; Mammaplasty; Breast Neoplasms
PubMed: 37768715
DOI: 10.1093/asj/sjad302