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Scientific Reports Oct 2022The current prognosis for successful return to function in koalas with appendicular fractures is poor despite being the most common fracture type to result in successful...
The current prognosis for successful return to function in koalas with appendicular fractures is poor despite being the most common fracture type to result in successful rehabilitation. The forelimb, particularly the humerus, plays a critical role in stabilisation and support while climbing trees. Successful rehabilitation therefore requires adequate internal stabilisation to promote bone healing and faster return to function. Current knowledge of koala limb bone morphometry is lacking and would provide useful clinical insight for future orthopaedic research, particularly with regards to recommendations regarding implant size and type. In this study microcomputed tomography (micro-CT) was used to describe bone length, internal and external diameters, and cortical thickness at five transverse levels along the humerus of skeletally mature koala cadavers. Qualitative descriptions were also made regarding bone features deemed clinically relevant to potential fracture repair techniques. Mean humeral length was 114.3 mm (95% CI 107.29-121.31 mm). Mediolateral diameters were greater than craniocaudal diameters at each measurement level, and the diaphysis has a distally tapering medullary cavity. Diaphyseal cortices were relatively homogenous with slight distal thickening, and medial cortices were thickest along the entire bone. The bone protuberances of the deltoid and supinator ridges projected most of the way down the lateral surface of the bone while the medial surface remained relatively uniform. Distal to the deltoid ridge the humerus curved caudally, terminating at a craniocaudally flattened distal epiphysis. Morphometric descriptions provided in this study will serve as a useful reference for future research, guiding orthopaedic surgery and improving prognosis of koala humeral fractures.
Topics: Animals; Humans; X-Ray Microtomography; Phascolarctidae; Humerus; Humeral Fractures; Diaphyses
PubMed: 36302878
DOI: 10.1038/s41598-022-22944-0 -
Journal of Cell Science Aug 2017Organelles such as neuropeptide-containing dense-core vesicles (DCVs) and mitochondria travel down axons to supply synaptic boutons. DCV distribution among boutons in...
Organelles such as neuropeptide-containing dense-core vesicles (DCVs) and mitochondria travel down axons to supply synaptic boutons. DCV distribution among boutons in small axonal arbors is mediated by circulation with bidirectional capture. However, it is not known how organelles are distributed in extensive arbors associated with mammalian dopamine neuron vulnerability, and with volume transmission and neuromodulation by monoamines and neuropeptides. Therefore, we studied presynaptic organelle distribution in octopamine neurons that innervate ∼20 muscles with ∼1500 boutons. Unlike in smaller arbors, distal boutons in these arbors contain fewer DCVs and mitochondria, although active zones are present. Absence of vesicle circulation is evident by proximal nascent DCV delivery, limited impact of retrograde transport and older distal DCVs. Traffic studies show that DCV axonal transport and synaptic capture are not scaled for extensive innervation, thus limiting distal delivery. Activity-induced synaptic endocytosis and synaptic neuropeptide release are also reduced distally. We propose that limits in organelle transport and synaptic capture compromise distal synapse maintenance and function in extensive axonal arbors, thereby affecting development, plasticity and vulnerability to neurodegenerative disease.
Topics: Animals; Axonal Transport; Axons; Biogenic Monoamines; Drosophila melanogaster; Neuropeptides; Secretory Vesicles; Synapses
PubMed: 28600320
DOI: 10.1242/jcs.201111 -
Translational Gastroenterology and... 2022The obesity epidemic continues to increase around the world with its attendant complications of metabolic syndrome and increased risk of malignancies, including...
The obesity epidemic continues to increase around the world with its attendant complications of metabolic syndrome and increased risk of malignancies, including pancreatic malignancy. The Roux-en-Y gastric bypass (RYGB) is an effective bariatric procedure for obesity and its comorbidities. We describe a report wherein a patient with previous RYGB was treated with a novel reconstruction technique following a pancreaticoduodenectomy (PD). A 59-year-old male patient with previous history of RYGB was admitted with painless progressive jaundice. Imaging revealed a distal common bile duct stricture and he underwent PD. There are multiple options for reconstruction after PD in patients with previous RYGB. The two major decisions for pancreatic surgeon are: (I) resection/preservation of remnant stomach and (II) resection/preservation of original biliopancreatic limb. This has to be tailored to the patient based on the intraoperative findings and anatomical suitability. In our patient, the gastric remnant was preserved, and distal part of original biliopancreatic limb was anastomosed to the stomach as a venting anterior gastrojejunostomy. A distal loop of small bowel was used to reconstruct the pancreaticojejunostomy and hepaticojejunostomy and further distally a new jejunojejunostomy performed. The post-operative course was uneventful, and the patient was discharged on 7 day. With the increase in number of bariatric procedures performed worldwide, pancreatic surgeons should be aware of the varied surgical reconstruction options for PD following RYGB. This should be tailored to the patient and there is no "one-size-fits-all".
PubMed: 35243120
DOI: 10.21037/tgh.2020.02.11 -
The Journal of Thoracic and... Aug 2021In this study we aimed to propose a new computed tomography-based hemodynamic indicator to quantify the functional significance of aortic dissection and predict post...
OBJECTIVE
In this study we aimed to propose a new computed tomography-based hemodynamic indicator to quantify the functional significance of aortic dissection and predict post intervention luminal remodeling.
METHODS
Computational hemodynamics and 3D structural analyses were conducted in 51 patients with type B aortic dissection, at initial presentation and at approximately 1 month, 3 months, and 1 year post intervention. A functional index was proposed on the basis of luminal pressure difference. Statistical relationships between the proposed indicator and longitudinal luminal development were analyzed.
RESULTS
The computed luminal pressure difference (true lumen pressure minus false lumen pressure) varied overall from positive to negative along the aorta. The first balance position at which the pressure difference equals 0 was proposed as the functional indicator. A more distally located first balance position indicated better functional status. Implantation of stent graft distally shifted this balance position. Patients with the balance position shifted out of the dissected region (43%) presented the highest functional improvement after intervention; whereas those with the balance position shifted to the abdominal region (25%) showed unsatisfactory results. The magnitude of distal shifting of the first balance position at 3 months post intervention was statistically related to the subsequent true lumen expansion and false lumen reduction.
CONCLUSIONS
The first balance position of luminal pressure difference quantified the hemodynamic status of the dissected aorta. The magnitude of distal shifting of the balance position after intervention was associated with functional improvement and might be used predict longitudinal aortic remodeling.
Topics: Adult; Aged; Aortic Dissection; Aortic Aneurysm; Aortography; Arterial Pressure; Blood Vessel Prosthesis Implantation; Computed Tomography Angiography; Endovascular Procedures; Female; Hemodynamics; Humans; Male; Middle Aged; Predictive Value of Tests; Time Factors; Treatment Outcome
PubMed: 32217023
DOI: 10.1016/j.jtcvs.2020.02.034 -
International Journal of Dentistry 2020Miniscrews have proved quite effective in fixed orthodontic treatment. They can be placed in areas like palatal interradicular zones or midpalatal suture. Despite the...
Characteristics and Dynamics of Full Arch Distalization Using Transpalatal Arches with Midpalatal and Interradicular Miniscrews as Temporary Anchorage Devices: A Preliminary Finite Element Analysis.
INTRODUCTION
Miniscrews have proved quite effective in fixed orthodontic treatment. They can be placed in areas like palatal interradicular zones or midpalatal suture. Despite the value of these methods and their ever-increasing use, their characteristics are not assessed before when implanted in palatal interradicular areas or in the midpalatal suture. We aimed to assess, for the first time, the dynamics of full arch distalization using such miniscrews.
METHODS
A 3D model of maxilla with all permanent dentition was created from a CT scan volume. Tissues were segmented and differentiated. Afterward, miniscrews and appliances were designed, and the whole model was registered within a finite element analysis software by assigning proper mechanical properties to tissues and orthodontic appliances. The full arches were distalized using transpalatal arches with miniscrews as anchorage devices (in two different models). The extents of stresses and patterns of movements of various elements (teeth, miniscrews, appliances, tissues) were estimated. . Comparing the two models, it is obvious that in both models, the stress distribution is the highest in the TPA arms and the head of the miniscrew where the spring is connected. In comparison with the displacement in the , the "mesial in" rotation is seen in the first molar of both models. But there is one exception and that is the "mesial out" rotation of the right second molar. In all measurements, the amount of movement in Model 2 (with palatal interradicular miniscrews) is more than that in Model 1 (with midpalatal miniscrew). In the -axis, more tipping is seen in Model 2, especially the anterior teeth (detorque) and the first molar, but in Model 1, bodily movement of the first molar is more evident. Along the -axis, the mesial intrusion of the first molar and the distal extrusion of this tooth can be seen in both models. Again, the displacement values are higher in the second model (with interradicular miniscrews). In comparison with micromotion and stress distribution of miniscrews, in Model 1, maximum stress and micromotion is observed at the head of the miniscrew where it is attached to the spring. Of course, this amount of micromotion increases over time. The same is true for Model 2, but with a lower micromotion. As for the amount of stress, the stress distribution in both miniscrews of both models is almost uniform and rather severe.
PubMed: 33381182
DOI: 10.1155/2020/6648526 -
Neonatology 2017In human neonates rapid adaptation from an aqueous intrauterine environment to permanent air breathing is the rate-limiting step for extrauterine life, failure of which... (Review)
Review
In human neonates rapid adaptation from an aqueous intrauterine environment to permanent air breathing is the rate-limiting step for extrauterine life, failure of which justifies the existence of neonatal intensive care units. The lung develops at about 4-6 weeks' gestation in humans as a ventral outpouching of the primitive foregut into the surrounding ventral mesenchyme, termed the laryngotracheal groove. At its posterior end lie progenitor cells that form a pair of bronchial tubes, from which arise all the distal epithelial structures of the lung. In humans, formation of the distal gas exchange surfaces begins in utero at about 20 weeks' gestation and is substantially established by term. Stereotypic branching of the proximal airway ends relatively early at 16-18 weeks at the bronchoalveolar duct junctions. Distally, about 5 finger-like alveolar ducts arise from each bronchoalveolar duct junction and ramify outwards towards the pleura. The majority of alveolar air sacs arise from the sides of the alveolar ducts and each of these alveoli can have up to 5 daughter alveoli arising from the outer surface as subsequent buds. At the end of each alveolar duct lie the mouths of 5 interconnected alveoli. Each family of alveoli arising from each bronchoalveolar duct junction has a different shape depending upon the limitations imposed by the pleural surface as well as the interstitial fascial planes.
Topics: Animals; Fetal Development; Gestational Age; Humans; Infant, Newborn; Lung
PubMed: 28538234
DOI: 10.1159/000458465 -
Clinical Biomechanics (Bristol, Avon) Feb 2020Percutaneous osseointegrated devices for skeletal fixation of prosthetic limbs have the potential to improve clinical outcomes in the transhumeral amputee population....
BACKGROUND
Percutaneous osseointegrated devices for skeletal fixation of prosthetic limbs have the potential to improve clinical outcomes in the transhumeral amputee population. Initial endoprosthesis stability is paramount for long-term osseointegration and safe clinical introduction of this technology. We evaluated an endoprosthetic design featuring a distally porous coated titanium stem with proximal slots for placement of bicortical interlocking screws.
METHODS
Yield load, ultimate failure load, and construct stiffness were measured in 18 pairs of fresh-frozen and thawed cadaver humeri, at distal and proximal amputation levels, without and with screws, under axial pull-out, torsion, and bending loads. Paired statistical comparisons were performed without screws at the two resection levels, and at distal and proximal levels with and without screws.
FINDINGS
Without screws, the location of the amputation influenced the stability only in torsional yield (p = 0.032) and torsional ultimate failure (p = 0.033). Proximally, the torsional yield and the torsional ultimate failure were 44% and 47% of that distally. Screws improved stability. In axial pull-out, screws increased the distal ultimate failure 3.2 times (p = 0.003). In torsion, screws increased the yield at the proximal level 1.9 times (p = 0.035), distal ultimate failure load 3.3 times (p = 0.016) and proximal ultimate failure 6.4 times (p = 0.013). In bending, screws increased ultimate failure at the proximal level 1.6 times (p = 0.026).
INTERPRETATION
Proximal slots and bicortical interlocking screws may find application in percutaneous osseointegrated devices for patients with amputations, especially in the less stable proximal bone of a short residual limb.
Topics: Amputees; Biomechanical Phenomena; Bone Plates; Bone Screws; Female; Humans; Humerus; Male; Mechanical Phenomena; Osseointegration
PubMed: 31862604
DOI: 10.1016/j.clinbiomech.2019.12.005 -
Bioengineering (Basel, Switzerland) Dec 2023The current review aims to evaluate the scientific evidence relating to the effectiveness of treatment with clear aligners (CAs) in controlling distalization orthodontic... (Review)
Review
The current review aims to evaluate the scientific evidence relating to the effectiveness of treatment with clear aligners (CAs) in controlling distalization orthodontic tooth movement. "Orthodontics, aligners" and "distalization" were the search terms used on the Scopus, Web of Science and Pubmed databases with the Boolean operator "AND". The results of the last ten years of research were 146 studies; of these, 19 publications were included for this review. The distalization movement is possible with invisible masks alone, but the risk of losing anchorage in the anterior sectors is very probable. The stability of the results and the reduction of unwanted effects can be guaranteed by the use of skeletal anchoring devices and interproximal enamel reduction (IPR), with which compensations are obtained to reduce the initial overjet. Temporary anchorage devices (TADs) can be used to manage posterior anchorage after distalization of maxillary molars with aligners. This hybrid approach has demonstrated the greatest orthodontic success. TADs are useful aids to provide direct and indirect skeletal anchorage. The opposite effect must be considered when planning dental distalization, especially of the molars, in patients with large overjet, and corrective measures or the use of auxiliaries may be necessary to prevent midcourse corrections. This systematic review provides a critical evidence-based assessment of the predictability of dental distalization with CAs, an ever-evolving orthodontic technique.
PubMed: 38135981
DOI: 10.3390/bioengineering10121390 -
Journal of Clinical and Experimental... Jul 2019Maxillary molar distalization is the most frequently used nonextraction treatment in the correction of Class II malocclusion. The use of traditional intra-oral devices...
BACKGROUND
Maxillary molar distalization is the most frequently used nonextraction treatment in the correction of Class II malocclusion. The use of traditional intra-oral devices shows unreliable results. Nowadays the use of miniscrew-supported appliances helps prevent anchorage loss. The aim of this pilot study is to compare the amount of upper first molar distalization and the dentoalveolar side effects using traditional distal jet appliance and miniscrew-supported distal jet appliance.
MATERIAL AND METHODS
20 patients were randomly assigned to receive a treatment with miniscrew-supported distal jet appliance (Group A) or with traditional distal jet appliance (Group B). To ensure a safe and minimally invasive miniscrew insertion a surgical guide was used. Digital models and lateral cephalograms were obtained and analyzed before orthodontic treatment and at 6-month follow-up. Intergroup differences were determined using T- test. The significance was set at ≤0.05. The intra-operator reliability was evaluated using a 2 sample T-test. The difference was not statistically significant ( ≤0.05 ), demonstrating an intra-operator reliability.
RESULTS
In Group A, a greater maxillary first molar distalization was recorded (=0.002). Considering the dentoalveolar side effects, in Group A, a spontaneous distalization of the first premolars and a retroclination of central incisors were determined. In Group B, the first premolars tipped mesially with a proclination of the maxillary central incisors.
CONCLUSIONS
Miniscrew-supported distal jet appliance achieved a greater first molar distalization at 6-month follow-up and did not cause dento-alveolar side effects, such as the mesial drift of the premolars and the incisors. Molar distalization, distal jet appliance, skeletal anchorage, miniscrew, 3D printed surgical guide.
PubMed: 31516664
DOI: 10.4317/jced.55780 -
Bioengineering (Basel, Switzerland) May 2024The purpose of the present study is the three-dimensional (3D) analysis of molar and incisor movements that occur during the correction of the upper midline deviation by...
AIM
The purpose of the present study is the three-dimensional (3D) analysis of molar and incisor movements that occur during the correction of the upper midline deviation by using the Mesial-Distalslider appliance.
MATERIALS AND METHODS
A total of 20 consecutive patients (12 women and 8 men; mean age 19.6 ± 11.1 years) were selected from the Orthodontic Department of Heinrich-Heine University of Düsseldorf. To correct the upper midline deviation (>2 mm), the patients were treated with asymmetric mechanics (mesialization on one side and distalization on the contralateral side) with the aid of Mesial-Distalslider. Dental casts were taken for each patient before (T0) and after the treatment (T1). The casts were 3D digitized and the models were superimposed on the palatal anterior region. Three-dimensional molar movements and sagittal incisor movements (proclination and retroclination) were assessed for T0 and T1.
RESULTS
At the end of the treatment, the total movements of the molars resulted in 4.5 ± 2.2 mm (antero-posterior direction), -0.4 ± 2.4 mm (transverse direction) and 0.3 ± 0.9 mm (vertical direction) on the mesialization side, and -2.4 ± 1.7 mm (antero-posterior direction), -0.5 ± 1.5 mm (transverse direction) and 0.2 ± 1.4 mm (vertical direction) on the distalization side. Incisor displacement was 0.9 mm ± 1.7 (mesialization side) and 0.6 mm ± 0.7 (distalization side).
CONCLUSION
The Mesial-Distalslider appliance could be considered a valuable tool in orthodontic treatment for upper midline correction. Within the limits of a retrospective study, asymmetric molar movements appeared possible without clinically relevant anchorage loss.
PubMed: 38790317
DOI: 10.3390/bioengineering11050450