Decrease In Cross-sectional Area Research Articles

Association between surgical tracheostomy and chronic tracheal stenosis: A retrospective, single-center study.

Tracheal stenosis is a major complication of tracheostomy. Accordingly, anesthesiologists tend to select a smaller endotracheal tube (ETT) than usual for patients with a prior tracheostomy history, regardless of the presence or absence of respiratory symptoms. However, it likely comes from our trial and error, not scientific evidence. Therefore, in this study, we retrospectively examined the association between traditional surgical tracheostomy and tracheal stenosis as assessed by transverse computed tomography (CT). Patients who underwent surgery for head and neck cancer from January 2010 to December 2013, with a temporary tracheostomy closed within a couple of months, were included. Exclusion criteria were tracheostoma before surgery, permanent tracheostomy, or insufficient CT follow-up. Transverse CT slices were measured 2 cm above and below the tracheostomy site (0.5 cm/slice for a total of 9 slices). The minimum cross-sectional tracheal area and horizontal and vertical diameters in transverse CT slices were compared before (baseline: BL), 6 months (6M) and 12 months (12M) after tracheostomy. Tracheal stenosis was defined as a decrease in the minimum cross-sectional tracheal area compared to BL. Of 112 patients, 77 were included. The minimum tracheal area was significantly decreased at 6M and 12M compared to BL (BL: mean 285 [SD 68] mm2, 6M: 267 [70] mm2, P < 0.01 vs. BL, 12M: 269 [68] mm2, P < 0.01 vs. BL), and the localization was predominantly at or above the tracheostomy site at 6M and 12M. Tracheal stenosis was identified in 55 patients at 6M and in 49 patients at 12M without any respiratory symptoms. With regard to horizontal and vertical diameter, only horizontal diameter was significantly decreased at 6M and 12M compared to BL (BL: 16.8 [2.4] mm, 6M: 15.4 [2.7] mm, P < 0.01 vs. BL, 12M: 15.6 [2.8] mm, P < 0.01 vs. BL). Conventional surgical tracheostomy was associated with a decreased horizontal diameter of the trachea. It resulted in a decreased cross-sectional tracheal area in more than one-half of the patients; however, no patient complained of any respiratory symptoms. Therefore, even without respiratory symptoms, prior tracheostomy causes an increased risk of tracheal stenosis, and using a smaller ETT than usual could be reasonable.

Nasal Reactivity After Radiofrequency Ablation of Peripheral Branches of Posterior Nasal Nerve.

Transection or ablation of the posterior nasal nerve (TRPN) has been described as an adjunctive tool to reduce the symptoms of intractable allergic rhinitis (AR). The procedure, however, requires surgical skill and carries the risk of bleeding from the sphenopalatine artery. The aim of the present study is to describe radiofrequency ablation of the peripheral branches of the posterior nasal nerves within the inferior turbinates (RAPN) as an effective easier alternative to TRPN. The procedure was performed on 24 patients with intractable AR. Nasal reactivity was tested by cold dry air (CDA) provocation before and 12 months after the radiofrequency procedure. Visual analog scale and acoustic rhinometry were used to measure the changes in nasal reactivity subjectively and objectively. Worsening of nasal symptoms following CDA provocation had significantly decreased after the RAPN procedure. Likewise, postoperative decrease in nasal volumes and minimal cross-sectional areas after CDA provocation were significantly less than the corresponding preoperative values. RAPN effectively reduces nasal reactivity in patients with AR. The procedure is simple, minimally invasive, and can be performed under local or general anesthesia.

Changes in Cross-sectional Area of the Median Nerve and Boston Carpal Tunnel Questionnaire Scores After Carpal Tunnel Release.

We hypothesized that postoperative Boston Carpal Tunnel Questionnaire (BCTQ) scores and ultrasound (US) measurements of the median nerve cross-sectional area (CSA) at the distal wrist crease are significantly decreased at 2-week, 6-week, and ≥ 6 months follow-up appointments, compared with baseline values. This study was a retrospective chart review of patients who presented to a single hand clinic with evidence of carpal tunnel syndrome over a 6-year period (2014-2020). Patients received baseline US measurements of the median nerve CSA as well as completion of the BCTQ, and for the patients who underwent carpal tunnel release (CTR), postoperative US measurements and questionnaire scores were obtained at 2 weeks, 6 weeks, or ≥ 6 months postoperatively. This study included 224 separate wrists. Median Nerve CSA measurements were 13.2 ± 4.5 mm2 at baseline, 11.9 ± 3.6 mm2 at 2 weeks postoperatively, 11.6 ± 4.5 mm2 at 6 weeks postoperatively, and 11.7 ± 4.3 mm2 at 6 months or more (P = .002). The BCTQ Symptom Severity Scale scores were 3.14 ± 0.76 at baseline, 1.76 ± 0.63 at 2 weeks, 1.68 ± 0.70 at 6 weeks, and 1.41 ± 0.64 at 6 months or longer (P < .001). The BCTQ Functional Status Scale scores were 2.56 ± 0.89 at baseline, 2.03 ± .1.0 at 2 weeks, 1.65 ± 0.77 at 6 weeks, and 1.36 ± 0.61 at 6 months or longer (P < .001). These findings demonstrated a sustained decrease in median nerve CSA and patient-reported outcomes following CTR at 2 weeks, 6 weeks, and between 6 and 12 months.

Multifidus muscle cross-sectional area adaptations over two volleyball seasons and one off-season in athletes with and without low back pain.

The multifidus muscle is important in spine stabilization. Atrophy of the multifidus muscle has been associated with low back pain. To examine multifidus muscle cross-sectional area (CSA) adaptations over two volleyball seasons and one off-season in volleyball athletes experiencing low back pain or no low back pain. Twelve female NCAA division 1 volleyball athletes participated. Athletes were placed into a low back pain or no low back pain group. Athlete's multifidus was imaged and measured using ultrasound at four time points across seasons. Imaging time points were before season one, following season one, following off-season, and following season two. A single level mixed-model analysis of variance was used for all analyses. A Tukey HSD post hoc test was used to determine differences between and within the low back pain and the no low back pain groups. Following off-season training the pain group had clinically significant smaller multifidus CSA at the L4 (-2.36 cm2 difference or 17.5%) and L5 (-2.40 cm2 or 12.5%) levels. Non-significant (p> 0.05) decreases in multifidus CSA were seen in both groups following season one and two. Athletes with pain had decreased multifidus CSA at the L4 and L5 vertebral levels at all time points which was non-significant (p> 0.05). Clinically significant decreases in multifidus CSA occurred in female volleyball athletes with low back pain at the L4 and L5 level following off-season training. Volleyball athletes with pain had smaller multifidus CSA averages at all time points measured of the two year period.

The influence of four rootstocks on the growth, yield and fruit quality of two plum cultivars

The influence of three clonal rootstocks (‘Pixyʼ, ‘Fereleyʼ and ‘St. Julien Aʼ) along with seedlings of Myrobalan(control) on growth, yield and fruit quality of plum cultivars ‘Čačanska Najboljaʼ and ‘Čačanska Lepoticaʼ was studied in the Belgrade region (Serbia) for the six year-period (2013–2018). In comparison to control, clonal rootstocks have shown a significant effect on the decrease of trunk cross-sectional area. The lowest vigor was found in trees on the ‘Pixyʼ rootstock, then on ‘Fereleyʼ and ‘St. Julien Aʼ. Yield per hectare on trees grafted on clonal rootstocks was higher for 62–82% in ‘Čačanska Najboljaʼ, and for 26–27% in ‘Čačanska Lepoticaʼ compared to Myrobalan. In cultivar ‘Čačanska Najboljaʼ significantly higher fruit weight compared to control was obtained in the trees on the ‘Fereleyʼ and ‘St. Julien Aʼ rootstocks. The effects of rootstocks on the contents of soluble solids and total acids in the fruit were not significant. All three studied clonal rootstocks showed better results than standard Myrobalan, and can be recommended for establishing intensive plum plantations with higher planting density.

Association between histological diaphragm atrophy and ultrasound diaphragm expiratory thickness in ventilated patients

BackgroundDiaphragm fiber atrophy has been evidenced after short periods of mechanical ventilation (MV) and related to critical illness-associated diaphragm weakness. Atrophy is described as a decrease in diaphragm fiber cross-sectional area (CSA) in human diaphragm biopsy, but human samples are still difficult to obtain in clinics. In recent years, ultrasound has become a useful tool in intensive care to evaluate diaphragm anatomy. The present study aimed to evaluate the ability of diaphragm expiratory thickness (Tdi) measured by ultrasound to predict diaphragm atrophy, defined by a decrease in diaphragm fiber CSA obtained through diaphragm biopsy (the gold standard technique) in ventilated patients.MethodsDiaphragm biopsies and diaphragm ultrasound were performed in ventilated donors and in control subjects. Demographic variables, comorbidities, severity on admission, treatment, laboratory test results and evolution variables were evaluated. Immunohistochemical analysis to determine CSA and ultrasound measurements of Tdi at end-expiration were performed, and median values of the control group were used as thresholds to determine agreement between them in further analysis. Sensitivity, specificity, and positive and negative predictive values of an ultrasound Tdi cutoff for detecting histologic atrophy were calculated. Agreement between two ultrasound observers was also assessed.ResultsThirty-five ventilated organ donors and 5 ventilated controls were included, without differences in basic characteristics. CSA and Tdi were lower in donors than in controls. All donors presented lower CSA, but only 74% lower Tdi regarding control group thresholds. The cut-off value for lower diaphragm expiratory thickness (Tdi < 1.7 mm) presented a sensitivity of 73%, a specificity of 67%, a positive predictive value of 96% and a negative predictive value of 17% for determining the presence of diaphragm atrophy (CSA < 2851 μm2).ConclusionsDiaphragm atrophy and thickness reduction is associated to MV. While a lower Tdi in diaphragm ultrasound is a good tool for diagnosing atrophy, normal or increased Tdi cannot rule atrophy out showing that both parameters should not be considered as synonymous.

EVALUATION OF MELTING PROPERTIES FOR PARAFFIN PREDICTION IN THE MULTI SOLID SOLUTION (MSS) MODEL

This article presents the calculation and modification of melting properties for a certain Kazakh oil for the subsequent calculation of the Multisolid model. The bulk of crude oil in Kazakhstan contains heavy hydrocarbons that precipitate as a solid paraffin phase at low temperatures. The deposition of deposited paraffin on the pipe walls is one of the complex flow assurance problems that causes a decrease and complete blockage of oil rates due to a decrease in the flow cross-sectional area in pipelines. In addition, above ground facilities require higher power consumption and equipment failure due to paraffin plugs. Wax precipitation also increases the viscosity of the oil mixture, resulting in an increase in the energy requirement for transporting the crude oil. The main purpose of this study is to investigate melting properties and their influence on predictive wax deposition. The solution of the set goal is achieved by solving the problems of modifying and adapting existing thermodynamic models for Kazakhstani oils. At the moment, one of the main limitations of existing models is their applicability to a wide range of crude oil types. While this modified paraffin forecasting model will focus on Kazakh crude oil. As a result, modified equations have been developed to determine melting properties, namely melting point, pour point and enthalpy. The obtained results of the absolute average deviation showed the effectiveness of using the proposed correlation for measuring the pour point and melting point for Kazakhstani oils.

Sonographic Changes in the Median Nerve Predict Conversion to Surgery after Corticosteroid Injection of the Carpal Tunnel.

Risk factors for conversion to surgical management of moderate severity carpal tunnel syndrome are poorly understood. The authors hypothesized that sonographic findings along the carpal tunnel could predict failure of conservative management for carpal tunnel syndrome. The authors report on 96 wrists with moderate clinical signs and symptoms of carpal tunnel syndrome. Sonographic evaluation with measurement of median nerve cross-sectional area was performed at three consistent anatomic locations. The authors recorded median nerve morphology, inlet and outlet dimensions of the carpal tunnel, and maximal thickness of the transverse carpal ligament. Steroid injection was performed. Patients were followed up for a minimum of 1 year after injection and progression to surgical management was recorded. A total of 54 percent ( n = 52) of patients converted to surgical management within 1 year after injection. Median nerve cross-sectional area decreased over the course of the carpal tunnel from proximal to distal in 81 of 96 wrists. A greater decrease in cross-sectional area of the median nerve between the pisiform and the hamate was associated with conversion to operative intervention for carpal tunnel syndrome, with the average decrease in median nerve cross-sectional area among those whose conservative treatment failed being 5.01 mm 2 compared with 2.97 mm 2 among those who did not progress to surgical treatment. This study demonstrates that ultrasound may be an additional tool used by clinicians to better counsel patients about the severity and progression of their disease. Patients who demonstrate a decrease in cross-sectional area of the median nerve along the carpal tunnel demonstrate a higher likelihood of progression to operative management. Risk, III.

Role of Thigh Muscle Changes in Knee Osteoarthritis Outcomes: Osteoarthritis Initiative Data.

Background Longitudinal data on the association of quantitative thigh muscle MRI markers with knee osteoarthritis (KOA) outcomes are scarce. These associations are of clinical importance, with potential use for thigh muscle-directed disease-modifying interventions. Purpose To measure KOA-associated longitudinal changes in MRI-derived muscle cross-sectional area (CSA) and adipose tissue and their association with downstream symptom worsening and knee replacement (KR). Materials and Methods In a secondary analysis of the Osteoarthritis Initiative multicenter prospective cohort (February 2004 through October 2015), knees of participants with available good-quality thigh MRI scans at baseline and at least one follow-up visit were included and classified as with and without KOA according to baseline radiographic Kellgren-Lawrence grade of 2 or higher and matched for confounders with use of propensity score matching. An automated deep learning model for thigh MRI two-dimensional segmentation was developed and tested. Markers of muscle CSA and intramuscular adipose tissue (intra-MAT) were measured at baseline and 2nd- and 4th-year follow-up (period 1) and compared between knees with and without KOA by using linear mixed-effect regression models. Furthermore, in knees with KOA, the association of period 1 changes in muscle markers with risk of KR (Cox proportional hazards) and symptom worsening (mixed-effect models) during the 4th to 9th year (period 2) was evaluated. Results This study included 4634 matched thighs (2317 with and 2317 without KOA) of 2344 participants (mean age, 62 years ± 9 [SD]; 1292 women). Compared with those without, knees with KOA had a decrease in quadriceps CSA (mean difference, -8.21 mm2/year; P = .004) and an increase in quadriceps intra-MAT (1.98 mm2/year; P = .007). Decreased CSA and increased intra-MAT of quadriceps during period 1 was predictive of downstream (period 2) KOA symptom worsening (Western Ontario and McMaster Universities Osteoarthritis Index total score: odds ratio, 0.24 [negative association] [P < .001] and 1.38 [P = .012], respectively). Quadriceps CSA changes were negatively associated with higher future KR risk (hazard ratio, 0.70; P < .001). Conclusion Knee osteoarthritis was associated with longitudinal MRI-derived decreased quadriceps cross-sectional area and increased intramuscular adipose tissue. These potentially modifiable risk factors were predictive of downstream symptom worsening and knee replacement. Clinical trial registration no. NCT00080171 © RSNA, 2022 Online supplemental material is available for this article.

Pneumatic equiaxial compression device for mechanical manipulation of epithelial cell packing and physiology.

It is well established that mechanical cues, e.g., tensile- compressive- or shear forces, are important co-regulators of cell and tissue physiology. To understand the mechanistic effects these cues have on cells, technologies allowing precise mechanical manipulation of the studied cells are required. As the significance of cell density i.e., packing on cellular behavior is beginning to unravel, we sought to design an equiaxial cell compression device based on our previously published cell stretching system. We focused on improving the suitability for microscopy and the user-friendliness of the system. By introducing a hinge structure to the substrate stretch generating vacuum chamber, we managed to decrease the z-displacement of the cell culture substrate, thus reducing the focal plane drift. The vacuum battery, the mini-incubator, as well as the custom-made vacuum pressure controller make the experimental setup more flexible and portable. Furthermore, we improved the efficiency and repeatability of manufacture of the device by designing a mold that can be used to cast the body of the device. We also compared several different silicone membranes, and chose SILPURAN® due to its best microscopy imaging properties. Here, we show that the device can produce a maximum 8.5% radial pre-strain which leads to a 15% equiaxial areal compression as the pre-strain is released. When tested with epithelial cells, upon compression, we saw a decrease in cell cross-sectional area and an increase in cell layer height. Additionally, before compression the cells had two distinct cell populations with different cross-sectional areas that merged into a more uniform population due to compression. In addition to these morphological changes, we detected an alteration in the nucleo-cytoplasmic distribution of YAP1, suggesting that the cellular packing is enough to induce mechanical signaling in the epithelium.

GHz Ultrasound and Electrode Chip-Scale Arrays Stimulate and Influence Morphology of Human Neural Cells.

This study describes the effects of chip-scale gigahertz (GHz) ultrasound (US) and electrical stimulus on the morphology, functionality, and viability of neural cells in vitro. The GHz frequency stimulation is achieved using aluminum nitride piezoelectric transducers fabricated on a silicon wafer, operating at 1.47 GHz, corresponding to the film's thickness mode resonance. These devices are used to stimulate SH-SY5Y neural cells in vitro and observe effects on the morphology and viability of the stimulated cells. It is possible to use these devices to deliver either ultrasonic stimulus alone or US stimulus in conjunction with electrical stimulus. Viability tests demonstrated that the neurons retained structural integrity and viability across a wide range of GHz US stimulus intensities (0-1.2 W/cm2), validating that measurements occur at nontoxic doses of US. Neural stimulation is validated with these devices following the outputs of a previous study, with the normalized fluorescence intensity of activated cells between 1.9 and 2.4. The 300-s ultrasonic stimulation at 1.47 GHz and 0.05 W/cm2 peak intensity led to a decrease in nuclear elongation by 17.5% and a cross-sectional area decrease by 17.8% across three independent trials of over 150 cells per category ( ). The F-actin governed cellular elongation increased in length by up to 16.3% in cells exposed to an ultrasonic stimulus or costimulus ( ). Neurite length increased following ultrasonic stimulation compared with control by 75.8% ( ). This article demonstrates new GHz US and electrical chip-scale arrays with apparent effects in both neural excitation and cell morphology.

Investigation of the effect of the slag system of coated electrodes on the efficiency of metal inoculation of a welding bath of low-carbon steel

Welded joints are subject to increased requirements for structural condition, as well as a complex of mechanical and special properties. A promising way to regulate the structure of the deposited metal directly in the welding process is its inoculation with ultrafine refractory components. This article presents the results of a study of the structure and mechanical properties of metal deposited with electrodes with basic and rutile coatings containing 5% ultrafine titanium monocarbide powder. It is shown that the addition of ultrafine TIC powder to the electrode coating of the basic type leads to a decrease in the average cross-sectional area of crystallites in the deposited metal by 5 times, from 73000 - 74000 &mu;m2 to 14,000 - 15,000 &mu;m2&nbsp;and an increase in the shape factor by 1,5 times, from 0,27 to 0,46. The addition of TiC to the rutile-type electrode coating leads to a decrease in the average cross-sectional area of crystallites in the deposited metal by 12-13 times, from 163000 - 164000 &mu;m2 to 11000 to 12000 &mu;m2&nbsp;and an increase in the shape factor by 2 times, from 0,28 to 0,57. It is established that the effect of inoculation is manifested when using both basic-type coatings and rutile-type coatings. This is due to the fact that the viscosity of liquid welding slags in the crystallization temperature range of a steel welding bath is at the same level of 0,15 &ndash; 0,2 Pa&middot;s, and remains so in the flesh up to temperatures of 1325 - 1350 &deg;С, both for basic and rutile slag systems, and equally affects the process of assimilation of ultrafine refractory particles by the metal of the welding bath. It is shown that, despite the inoculation of the metal of the welding bath with refractory particles and the realization of the effect of volumetric crystallization, the final shape of the crystallites depends on the temperature gradient when the heat of the bath is removed into the base metal.The work was carried out within the framework of state support for young Russian&nbsp;scientists &mdash; grant of the President of the Russian Federation (No. MK-3849.2021.4).

Ambra1 deficiency impairs mitophagy in skeletal muscle.

BackgroundMaintaining healthy mitochondria is mandatory for muscle viability and function. An essential surveillance mechanism targeting defective and harmful mitochondria to degradation is the selective form of autophagy called mitophagy. Ambra1 is a multifaceted protein with well‐known autophagic and mitophagic functions. However, the study of its role in adult tissues has been extremely limited due to the embryonic lethality caused by full‐body Ambra1 deficiency.MethodsTo establish the role of Ambra1 as a positive regulator of mitophagy, we exploited in vivo overexpression of a mitochondria‐targeted form of Ambra1 in skeletal muscle. To dissect the consequence of Ambra1 inactivation in skeletal muscle, we generated muscle‐specific Ambra1 knockout (Ambra1 fl/fl:Mlc1f‐Cre) mice. Mitochondria‐enriched fractions were obtained from muscles of fed and starved animals to investigate the dynamics of the mitophagic flux.ResultsOur data show that Ambra1 has a critical role in the mitophagic flux of adult murine skeletal muscle and that its genetic inactivation leads to mitochondria alterations and myofibre remodelling. Ambra1 overexpression in wild‐type muscles is sufficient to enhance mitochondria clearance through the autophagy‐lysosome system. Consistently with this, Ambra1‐deficient muscles display an abnormal accumulation of the mitochondrial marker TOMM20 by +76% (n = 6–7; P < 0.05), a higher presence of myofibres with swollen mitochondria by +173% (n = 4; P < 0.05), and an alteration in the maintenance of the mitochondrial membrane potential and a 34% reduction in the mitochondrial respiratory complex I activity (n = 4; P < 0.05). Lack of Ambra1 in skeletal muscle leads to impaired mitophagic flux, without affecting the bulk autophagic process. This is due to a significantly decreased recruitment of DRP1 (n = 6–7 mice; P < 0.01) and Parkin (n = 6–7 mice; P < 0.05) to the mitochondrial compartment, when compared with controls. Ambra1‐deficient muscles also show a marked dysregulation of the endolysosome compartment, as the incidence of myofibres with lysosomal accumulation is 20 times higher than wild‐type muscles (n = 4; P < 0.05). Histologically, Ambra1‐deficient muscles of both 3‐ and 6‐month‐old animals display a significant decrease of myofibre cross‐sectional area and a 52% reduction in oxidative fibres (n = 6–7; P < 0.05), thus highlighting a role for Ambra1 in the proper structure and activity of skeletal muscle.ConclusionsOur study indicates that Ambra1 is critical for skeletal muscle mitophagy and for the proper maintenance of functional mitochondria.

Ex Vivo Evaluation of the Cranial Tibial Artery and Its Compression through Fragment Rotation during Tibia Plateau Levelling Osteotomy: An Angiographic Three-Dimensional Reconstruction.

To illustrate the arterial vascularity of the proximal tibia three-dimensionally and to evaluate the impact of fragment rotation on the cranial tibial artery by tibia plateau levelling osteotomy (TPLO). Radiographic angiography and computed tomography (CT) were performed on 12 pelvic limbs from six large-breed canine cadavers before and after TPLO. Three-dimensional (3D) models of the stifle, including osseous and vascular structures, were obtained, and the integrity of the cranial tibial artery was assessed. Post-TPLO CT images were used to analyze compression of the cranial tibial artery by the rotated fragment. The uncompressed cranial tibial artery caliber, measured proximally and distally to the osteotomy, was 9.52 mm2 (6.07-18.90 mm2). In all adequately rotated fragments, the mean caliber of the artery on the level of the osteotomy was 1.57 mm2 (0.89-2.93 mm2) after TPLO. This represented a significant decrease of approximately 81%. Only slight cross-sectional area decrease (8.8%) was seen in one limb, which was revealed to have insufficient fragment rotation (2.83 mm). Another limb only showed signs of stretching of the artery (31.51%), which was under-rotated and medially displaced. Pre-TPLO 3D reconstructions were mainly consistent with previous anatomic studies except for the distance between tibial cortex and cranial tibial artery, which appeared closer. Sufficient fragment rotation leads to compression of the cranial tibial artery. Intraoperative hemorrhage can be caused by laceration of the main cranial tibial artery or by multiple small branches reaching craniolaterally.

Inflammation and Wasting of Skeletal Muscles in Kras-p53-Mutant Mice with Intraepithelial Neoplasia and Pancreatic Cancer-When Does Cachexia Start?

Skeletal muscle wasting critically impairs the survival and quality of life in patients with pancreatic ductal adenocarcinoma (PDAC). To identify the local factors initiating muscle wasting, we studied inflammation, fiber cross-sectional area (CSA), composition, amino acid metabolism and capillarization, as well as the integrity of neuromuscular junctions (NMJ, pre-/postsynaptic co-staining) and mitochondria (electron microscopy) in the hindlimb muscle of LSL-KrasG12D/+; LSL-TrP53R172H/+; Pdx1-Cre mice with intraepithelial-neoplasia (PanIN) 1-3 and PDAC, compared to wild-type mice (WT). Significant decreases in fiber CSA occurred with PDAC but not with PanIN 1-3, compared to WT: These were found in the gastrocnemius (type 2x: −20.0%) and soleus (type 2a: −21.0%, type 1: −14.2%) muscle with accentuation in the male soleus (type 2a: −24.8%, type 1: −17.4%) and female gastrocnemius muscle (−29.6%). Significantly higher densities of endomysial CD68+ and cyclooxygenase-2+ (COX2+) cells were detected in mice with PDAC, compared to WT mice. Surprisingly, CD68+ and COX2+ cell densities were also higher in mice with PanIN 1-3 in both muscles. Significant positive correlations existed between muscular and hepatic CD68+ or COX2+ cell densities. Moreover, in the gastrocnemius muscle, suppressor-of-cytokine-3 (SOCS3) expressions was upregulated >2.7-fold with PanIN 1A-3 and PDAC. The intracellular pools of proteinogenic amino acids and glutathione significantly increased with PanIN 1A-3 compared to WT. Capillarization, NMJ, and mitochondrial ultrastructure remained unchanged with PanIN or PDAC. In conclusion, the onset of fiber atrophy coincides with the manifestation of PDAC and high-grade local (and hepatic) inflammatory infiltration without compromised microcirculation, innervation or mitochondria. Surprisingly, muscular and hepatic inflammation, SOCS3 upregulation and (proteolytic) increases in free amino acids and glutathione were already detectable in mice with precancerous PanINs. Studies of initial local triggers and defense mechanisms regarding cachexia are warranted for targeted anti-inflammatory prevention.

A High-Fat Diet Induces Muscle Mitochondrial Dysfunction and Impairs Swimming Capacity in Zebrafish: A New Model of Sarcopenic Obesity.

Obesity is a highly prevalent disease that can induce metabolic syndrome and is associated with a greater risk of muscular atrophy. Mitochondria play central roles in regulating the physiological metabolism of skeletal muscle; however, whether a decreased mitochondrial function is associated with impaired muscle function is unclear. In this study, we evaluated the effects of a high-fat diet on muscle mitochondrial function in a zebrafish model of sarcopenic obesity (SOB). In SOB zebrafish, a significant decrease in exercise capacity and skeletal muscle fiber cross-sectional area was detected, accompanied by high expression of the atrophy-related markers Atrogin-1 and muscle RING-finger protein-1. Zebrafish with SOB exhibited inhibition of mitochondrial biogenesis and fatty acid oxidation as well as disruption of mitochondrial fusion and fission in atrophic muscle. Thus, our findings showed that muscle atrophy was associated with SOB-induced mitochondrial dysfunction. Overall, these results showed that the SOB zebrafish model established in this study may provide new insights into the development of therapeutic strategies to manage mitochondria-related muscular atrophy.

Effect of dietary probiotics supplementation on meat quality, volatile flavor compounds, muscle fiber characteristics, and antioxidant capacity in lambs.

This study investigated the effects of probiotics on growth performance, meat quality, muscle fiber characteristics, volatile compounds, and antioxidant capacity in lambs. A total of 24 Sunit lambs were randomly allocated into two groups, each consisting of three replicates of four lambs. Throughout the experiment period, the lambs were fed with based diet (CON) and 10 g probiotics/d supplemented diet (PRO). Compared with the CON group, the number of lactic acid bacteria in fecal samples of PRO group was significantly increased (p < .05) and the coliforms were significantly decreased (p < .05). Dietary probiotics supplementation decreased pH24h, L*, and shear force (p < .05). The muscle fibers were switched from type IIB to type I, with a decrease in the mean cross‐sectional area (CSA) (p < .05) of longissimus thoracis (LT) muscle. Also, probiotics altered the composition of meat volatile flavor compounds, such as nonanal, undecanal, 1‐pentanol, 1‐hexanol, and 2,3‐octanedione. In addition, probiotics increased the total antioxidative capacity (T‐AOC) and catalase (CAT) activity of LT muscle, while it decreased superoxide dismutase (SOD) activity (p < .05). Overall, these results indicated that probiotics could be used as an effective feed additive by improving meat tenderness and flavor.

99 Feasibility of Deep Learning-based Automatic Myofiber Size Measurement for Burn-induced Muscle Wasting and Its Reversal

IntroductionPatients with major burn injury (BI) often develop muscle wasting (MW) and mitochondrial dysfunctions (MD), which affect their prognosis. We have recently shown that auto/mitophagy response is defective in BI model and can be mitigate by trehalose treatment. Though auto/mitophagy is widely accepted as the quality control (QC) system of cellular components including mitochondria, the relationship among MD, auto/mitophagy response defect, and MW was unclear. Furthermore, to evaluate MW precisely by morphometric analyses was difficult, due to the ehavy workload of counting the size of muscle cross sectional area manually and analyzing the data. Thus, we have set up a streamline of whole section image capturing, analyzing with cutting edge deep learning-based method, processing it via image J-based program. Using this system, we have tested the efficacy of trehalose on mitigating MW in BI-treated mice.MethodsFirst, the effect of auto/mitophagy modulator on normalizing defective auto/mitiophagy maturation was confirmed by in vivo microscopy of tfLC3-expressing mice with BI (30% BSA) or sham-burn (SB) control. A mitophagy inducer, CCCP was injected to induce mitophagy, and the auto/mitophagosome maturation was monitored with or without trehalose treatment. In a separate experiment, tibialis muscles were harvested at post-burn day (PBD)-7, with or without trehalose treatment (2g/kg/day, i.p.), cryosectioned, and stained by anti-laminin antibody. The entire tissue cross-sectional microscopic images were captured, fed into a cellpose, and processed in ImageJ and Prizm for automatic calculation of the cross sectional area (CSA).ResultsIn vivo microscopic monitoring of auto/mitophagosome maturation revealed BI-induced maturation defect when treated by CCCP, which was rescued by trehalose treatment. Next, with MW analysis experiment, cross-sectional morphometric analysis of tibialis anterior myofibers showed a typical bi-phasic pattern of CSA distribution (large size population and small size population) in the control group. BI treatment showed a significant CSA decrease in both populations, which was effectively treated by trehalose. The average CSA was as follows (1843.0, 1245.3, 1683.9 for SB control, BI, BI+trehalose, respectively, in micron^2), and in accordance with manual counting measurement.ConclusionsNormalizing defective auto/mitophagy response was shown an effective therapeutic approach to mitigate BI-induced MW. Deep learning-based size counting method is a feasible technique for a systematic MW analysis. Note that in our data, trehalose does not function in increasing the basal level of autophagy, but it mitigates the defective response of auto/mitophagy to the auto/mitophagic stimulation, by normalizing the maturation process.

Epaxial muscle atrophy is more evident in large dogs with intervertebral disc disease than in dogs with ischaemic myelopathy

Cross-sectional area (CSA) decreases and fat infiltration increases in epaxial muscles of Dachshunds with intervertebral disc disease (IVDD), but less is known about large breed dogs with IVDD. The aim here was to investigate thoracolumbar epaxial muscle CSA and fat infiltration in large breed dogs with compressive IVDD and acute non-compressive nucleus pulposus extrusion (ANNPE) or fibrocartilaginous embolism (FCE).This retrospective study included large breed dogs with MRI-confirmed IVDD (n = 17) and ANNPE or FCE (n = 13). The CSA and fat infiltration of the thoracolumbar M. longissimus and Mm. multifidi were assessed from T1-weighted transverse MR images using Osirix.The CSA was significantly smaller in dogs with compressive IVDD than in dogs with non-compressive ANNPE or FCE for Mm. multifidi (p = 0.015), M. longissimus (p = 0.070), and these two muscles combined (p = 0.016). Fat infiltration in all muscle measurements was significantly higher in dogs with compressive IVDD than in dogs with non-compressive ANNPE or FCE (all P < 0.050). A significant positive correlation existed between age, duration of clinical signs, and fat infiltration, suggesting more fat infiltration in older dogs with more chronic signs.These signs of muscle atrophy are likely caused by denervation and secondary disuse due to chronic spinal cord compression and prolonged duration of clinical signs.

Reduced Cross-Sectional Muscle Growth Six Months after Botulinum Toxin Type-A Injection in Children with Spastic Cerebral Palsy.

Botulinum Neurotoxin type-A (BoNT-A) injections are widely used as first-line spasticity treatment in spastic cerebral palsy (SCP). Despite improved clinical outcomes, concerns regarding harmful effects on muscle morphology have been raised. Yet, the risk of initiating BoNT-A to reduce muscle growth remains unclear. This study investigated medial gastrocnemius (MG) morphological muscle growth in children with SCP (n = 26, median age of 5.2 years (3.5)), assessed by 3D-freehand ultrasound prior to and six months post-BoNT-A injections. Post-BoNT-A MG muscle growth of BoNT-A naive children (n = 11) was compared to (a) muscle growth of children who remained BoNT-A naive after six months (n = 11) and (b) post-BoNT-A follow-up data of children with a history of BoNT-A treatment (n = 15). Six months after initiating BoNT-A injection, 17% decrease in mid-belly cross-sectional area normalized to skeletal growth and 5% increase in echo-intensity were illustrated. These muscle outcomes were only significantly altered when compared with children who remained BoNT-A naive (+4% and −3%, respectively, p < 0.01). Muscle length growth persevered over time. This study showed reduced cross-sectional growth post-BoNT-A treatment suggesting that re-injections should be postponed at least beyond six months. Future research should extend follow-up periods investigating muscle recovery in the long-term and should include microscopic analysis.