A Two-Week Insulin Infusion in Intrauterine Growth Restricted Fetal Sheep at 75% Gestation Increases Skeletal Myoblast Replication but Did Not Restore Muscle Mass or Increase Fiber Number

Intrauterine growth restricted (IUGR) fetuses are born with lower skeletal muscle mass, fewer proliferating myoblasts, and fewer myofibers compared to normally growing fetuses. Plasma concentrations of insulin, a myogenic growth factor, are lower in IUGR fetuses. We hypothesized that a two-week insulin infusion at 75% gestation would increase myoblast proliferation and fiber number in IUGR fetal sheep. Catheterized control fetuses received saline (CON-S, n=6), and the IUGR fetuses received either saline (IUGR-S, n=7) or insulin (IUGR-I, 0.014 ± 0.001 units/kg/hr, n=11) for 14 days. Fetal arterial blood gases and plasma amino acid levels were measured. Fetal skeletal muscles (biceps femoris, BF; and flexor digitorum superficialis, FDS) and pancreases were collected at necropsy (126 ± 2 dGA) for immunochemistry analysis, real-time qPCR, or flow cytometry. Insulin concentrations in IUGR-I and IUGR-S were lower vs. CON-S (P ≤ 0.05, group). Fetal arterial PaO2, O2 content, and glucose concentrations were lower in IUGR-I vs. CON-S (P ≤ 0.01) throughout the infusion period. IGF-1 concentrations tended to be higher in IUGR-I vs. IUGR-S (P=0.06), but both were lower vs. CON-S (P ≤ 0.0001, group). More myoblasts were in S/G2 cell cycle stage in IUGR-I vs. both IUGR-S and CON-S (145% and 113%, respectively, P ≤ 0.01). IUGR-I FDS muscle weighed 40% less and had 40% lower fiber number vs. CON-S (P ≤ 0.05) but were not different from IUGR-S. Myonuclear number per fiber and the mRNA expression levels of muscle regulatory factors were not different between groups. While the pancreatic β-cell mass was lower in both IUGR-I and IUGR-S compared to CON-S, the IUGR groups were not different from each other indicating that feedback inhibition by endogenous insulin did not reduce β-cell mass. A two-week insulin infusion at 75% gestation promoted myoblast proliferation in the IUGR fetus but did not increase fiber or myonuclear number. Myoblasts in the IUGR fetus retain the capacity to proliferate in response to mitogenic stimuli, but intrinsic defects in the fetal myoblast by 75% gestation may limit the capacity to restore fiber number.

Efficiency of using the biological potential of fiber flax varieties of the Tomsk school of breeding in flax straw processing

The information on the structure of the areas cultivated with fiber flax in Russia in 2016-2020 is presented. The varieties of the Tomsk school of breeding occupy almost 30% of the total area under crops. The study was carried out in the flax-growing regions of Russia in 2001-2020. The technological value of flax raw material of the studied varieties of fiber flax for processing flax of various quality at flax processing enterprises was determined. The indicators for the total fiber yield, long and short fiber yield, long fiber number and short fiber number, and the combination of these features were studied. The efficiency of using the potential capabilities of the studied varieties in relation to the data of the State Variety Testing was established. According to the results of flax straw processing and the rating assessment of these varieties in relation to the best and worst ones, it was found that the following varieties can be referred to as the ones with low-quality flax straw: Tomsk 18 - by the yield of short fiber (24.9%), Tomsk 16 - by the number of long fiber (11.08 N), Tost - by the number of short fiber (3.42 N) and the complex of features (average rating index of 9.8 positions). The group of the best varieties for the total fiber yield includes Tomsk 18 (33.2%) and Tost (32.2%), for the long fiber yield - Tost (13.1%), for the short fiber yield (23.2%) and the number of short fiber (5.20 N) - Tomsk 18 (high-quality flax). None of the varieties presented fulfil the biological potential in the processing of flax straw under production conditions in terms of the total fiber yield and the yield of long fiber, established by the State Variety Testing. Its value for the varieties of the Tomsk school of breeding is 65.2-86.3% for the total fiber yield, 17.6-31.4% for the long fiber yield (low-quality flax straw), 77.7-94.2 and 30.5-52.2%, respectively (high-quality flax straw).

Does Motor Tract Integrity at 1 Month Predict Gait and Balance Outcomes at 6 Months in Stroke Patients?

Recovery of balance and gait ability is important in stroke patients. Several studies have examined the role of white matter tracts in the recovery of gait and balance, but the results have been inconclusive. Therefore, we examined whether the integrity of the corticospinal tract (CST), corticoreticular pathway (CRP), and cortico-ponto-cerebellar tract (CPCT) at 1 month predicted balance and gait function 6 months after stroke onset. This retrospective longitudinal observational clinical study assessed 27 patients with first-ever unilateral supratentorial stroke. The subjects underwent diffusion tensor imaging 1 month after the stroke, and the Functional Ambulation Categories (FAC) and Berg Balance Scale (BBS) scores were assessed after 6 months. The normalized fiber number (FN) and fractional anisotropy (FA) results for the CST, CRP and CPCT were also obtained. The FN and FA results for the CST, CRP, or CPCT at 1 month were not related to the gait or balance at 6 months. There was also no difference in FAC values at 1 month after stoke onset among three groups differing in degree of independence of ambulation. The integrity of the CST, CRP, and CPCT on 1 month after stroke onset was not associated with gait or balance after 6 months. The white matter integrity did not predict the clinical outcome.

Endoscopic Surgery for Supratentorial Deep Cavernous Malformation Adjacent to Cortical Spinal Tract: Preliminary Experience and Technical Note

In this study, we aimed to introduce a technical note and to explore the efficacy of endoscopic surgery combined with diffusion tensor imaging (DTI) navigation for supratentorial deep cerebral cavernous malformations (CCM). A prospectively maintained database of CCM patients was reviewed to identify all CCM patients treated by endoscopic surgery. The sagittal T1-weighted anatomical magnetic resonance imaging (MRI) and DTI were acquired before surgery. Endoscopic surgery was planned and performed based on preoperative DTI images and intraoperative DTI navigation. All patients were followed up more than 6 months. Motor function deficit and modified Rankin scale (mRS) scores were documented on follow-up. A final mRS score of 0–2 was considered a good outcome, and a final mRS score >2 was considered a poor outcome. Second DTI and 3DT1 were performed at 3 months after surgery. We tracked the ipsilateral corticospinal tract (CST) on pre- and postoperative DTI images. The overall mean FA values and the number of fibers of tracked CST were compared on pre- and postoperative DTI images. Risk factors associated with motor deficits and poor outcomes were analyzed. Seven patients with deep CCM and treated by endoscopic surgery were enrolled in this study. The mean value of preoperative mRS was 1.5 ± 0.98, but that score recovered to 0.86 ± 1.22 3 months later. The mRS scores were improved significantly according to statistical analysis (p = 0.012). According to the Spearman non-parametric test, only the fiber number of ipsilateral CST on postoperative DTI was significantly associated with muscle strength 6 months after surgery (p = 0.032). Compared with preoperative CST characteristics on DTI, the change of FA value (p = 0.289) and fiber number (p = 0.289) of ipsilateral CST on postoperative DTI was not significant It meant that the CST was protected during endoscopic surgery. Endoscopic surgery based on DTI navigation might be an effective method to protect fiber tracts in supratentorial deep CCM patients and improve long-term outcomes. However, more studies and cases are needed to confirm our findings.

Age-Related Alterations at Neuromuscular Junction: Role of Oxidative Stress and Epigenetic Modifications

With advancing aging, a decline in physical abilities occurs, leading to reduced mobility and loss of independence. Although many factors contribute to the physio-pathological effects of aging, an important event seems to be related to the compromised integrity of the neuromuscular system, which connects the brain and skeletal muscles via motoneurons and the neuromuscular junctions (NMJs). NMJs undergo severe functional, morphological, and molecular alterations during aging and ultimately degenerate. The effect of this decline is an inexorable decrease in skeletal muscle mass and strength, a condition generally known as sarcopenia. Moreover, several studies have highlighted how the age-related alteration of reactive oxygen species (ROS) homeostasis can contribute to changes in the neuromuscular junction morphology and stability, leading to the reduction in fiber number and innervation. Increasing evidence supports the involvement of epigenetic modifications in age-dependent alterations of the NMJ. In particular, DNA methylation, histone modifications, and miRNA-dependent gene expression represent the major epigenetic mechanisms that play a crucial role in NMJ remodeling. It is established that environmental and lifestyle factors, such as physical exercise and nutrition that are susceptible to change during aging, can modulate epigenetic phenomena and attenuate the age-related NMJs changes. This review aims to highlight the recent epigenetic findings related to the NMJ dysregulation during aging and the role of physical activity and nutrition as possible interventions to attenuate or delay the age-related decline in the neuromuscular system.

Functional and electron-microscopic changes after differential traction injury in the sciatic nerve of a rat

Background During maxillofacial trauma or oral cancer surgery, peripheral nerve might be damaged by traction injury. The purpose of this study was to evaluate functional and histomorphometric changes after traction nerve injury in the sciatic nerve of a rat model. Methods A total of 24 Sprague-Dawley rats were equally divided into three groups: unstretched (sham/control, group A), stretched with 0.7N (group B) and 1.5N (group C). Traction injury was performed for 10 min in B and C groups. Functional recovery of the sciatic nerve was evaluated by walking track analysis, toe spread test, and pinprick test 2 weeks after injury. The weight of gastrocnemius muscles of both sides was measured to evaluate weight ratio (ipsilateral/contralateral). Total number of axons, axon fiber size, myelin thickness, G-ratio, axon number/mm2, diameter of fiber, changes of longitudinal width, and formation of the edema and hematoma were evaluated by transmission electron microscopy. Results The sciatic function indexes were −11.48±4.0, −15.11±14.84, and −49.12±35.42 for groups A, B, and C, respectively. Pinprick test showed 3.0, 2.86±0.38, and 1.38±0.52 for A, B, and group C. Muscle weight ratios were 0.98±0.13 for group A, 0.70±0.10 for group B, and 0.54±0.05 for group C. There were significant differences in toe spread test, pinprick test, and muscle weight ratio between control group and experimental group (p<0.001). In the experimental group, fiber number, fiber size, G-ratio, fiber number/mm2, myelin thickness, diameter of fiber, and longitudinal width were decreased with statistical significance. Conclusion The present study demonstrated that the nerve traction injury in the rat sciatic nerve damaged the motor and sensory function and axonal integrity. The amount of functional nerve damage was proportional to the amount of traction power and dependent on the initial tensile strengths (0.7N and 1.5N).

An Examination of Lactobacillus paracasei GKS6 and Bifidobacterium lactis GKK2 Isolated from Infant Feces in an Aged Mouse Model

Supplementary which could maintain normal physiological mechanisms and functions while aging has drawn our attention due to the population aging in recent years. Probiotics have been believed with desirable properties such as antioxidation and anti-inflammatory for delaying the aging process. However, the age-related experiments conducted in the mammalian models with probiotics were few. In this study, we demonstrated the effects of administration of probiotics Lactobacillus paracasei GKS6 (GKS6) and Bifidobacterium lactis GKK2 (GKK2), respectively, at the dosage of 5.0 × 109 cfu/kg BW/day for fourteen weeks in senescence-accelerated mouse prone 8 (SAMP8) mice. The three-month-old SAMP8 mice were divided into three groups: control, mice fed with GKS6, and mice fed with GKK2. There were ten females and ten males in each group. The SAMP8 mice fed with probiotics GKS6 and GKK2 showed a significantly lower degree of aging followed by Takeda’s grading method on the eleventh week of the experiment. The GKK2 group showed significantly increased forelimb grip strength in male SAMP8 mice and muscle fiber number in both genders. Compared to the control, both GKS6 and GKK2 presented a significant increase in liver superoxide dismutase and catalase activities. In addition, a significant decrease in the levels of liver thiobarbituric acid-reactive substances was observed in the probiotics group. These results suggested that probiotics GKS6 and GKK2 could act as antioxidants in delaying the process of aging and preventing age-related muscle loss.

Image-based Bilateral Beard Method for measuring weight-based short fiber contents in raw cotton and semi-finished slivers

In this paper, an economical way for accurately determining weight-based short fiber contents in raw cotton and semi-finished slivers by utilizing special bilateral beard specimens and image processing was introduced. In the specimen preparation, cotton fibers were drawn by a manual device into a sliver, then the sliver was combed to form a bilateral beard specimen, and finally the bilateral beard was scanned to generate a grayscale image from which a relative fiber number curve was extracted. An algorithm for calculating the weight-based short fiber contents based on the curve was proposed. Five types of cottons were repetitively measured to investigate the robustness of the results of [Formula: see text] and [Formula: see text], with the weight ratio of fibers shorter than 12.7 and 16 mm, respectively. The results showed that measuring two bilateral beards for each sample could keep the error rate lower than 15%, while four specimens kept the error rate lower than 10%. Compared with AFIS Pro 2, this Image-based Bilateral Beard Method provided results with lower standard deviations and variable coefficients, signifying its analogous or better robustness. In addition, 37 samples from some of the world’s major producing areas were measured by this method and AFIS Pro 2, and a Bland–Altman analysis confirmed a good agreement between the results from the two methods. As only a manual fiber drawing device and an office scanner are needed, this Image-based Bilateral Beard Method is clearly a cheap approach for accurately determining the short fiber contents in raw cotton and semi-finished slivers.

Differentiation in the genetic basis of stem trichome development between cultivated tetraploid cotton species

BackgroundCotton stem trichomes and seed fibers are each single celled structures formed by protrusions of epidermal cells, and were found sharing the overlapping molecular mechanism. Compared with fibers, cotton stem trichomes are more easily observed, but the molecular mechanisms underlying their development are still poorly understood.ResultsIn this study,Gossypium hirsutum(Gh) andG. barbadense(Gb)were found to differ greatly in percentages of varieties/accessions with glabrous stems and in trichome density, length, and number per trichopore.Ghvarieties normally had long singular and clustered trichomes, whileGbvarieties had short clustered trichomes. Genetic mapping using five F2populations from crosses between glabrous varieties and those with different types of stem trichomes revealed that much variation among stem trichome phenotypes could be accounted for by different combinations of genes/alleles on Chr. 06 and Chr. 24. The twenty- six F1generations from crosses between varieties with different types of trichomes had varied phenotypes, further suggesting that the trichomes of tetraploid cotton were controlled by different genes/alleles. Compared to modern varieties, a greater proportion ofGhwild accessions were glabrous or had shorter and denser trichomes; whereas a smaller proportion ofGbprimitive accessions had glabrous stems. A close correlation between fuzz fiber number and stem trichome density was observed in bothGhandGbprimitive accessions and modern varieties.ConclusionBased on these findings, we hypothesize that stem trichomes evolved in parallel with seed fibers during the domestication of cultivated tetraploid cotton. In addition, the current results illustrated that stem trichome can be used as a morphological index of fiber quality in cotton conventional breeding.

Pten regulates collagen fibrillogenesis by fibroblasts through SPARC

Collagen deposition contributes to both high mammographic density and breast cancer progression. Low stromal PTEN expression has been observed in as many as half of breast tumors and is associated with increases in collagen deposition, however the mechanism connecting PTEN loss to increased collagen deposition remains unclear. Here, we demonstrate that Pten knockout in fibroblasts using an Fsp-Cre;PtenloxP/loxP mouse model increases collagen fiber number and fiber size within the mammary gland. Pten knockout additionally upregulated Sparc transcription in fibroblasts and promoted collagen shuttling out of the cell. Interestingly, SPARC mRNA expression was observed to be significantly elevated in the tumor stroma as compared to the normal breast in several patient cohorts. While SPARC knockdown via shRNA did not affect collagen shuttling, it notably decreased assembly of exogenous collagen. In addition, SPARC knockdown decreased fibronectin assembly and alignment of the extracellular matrix in an in vitro fibroblast-derived matrix model. Overall, these data indicate upregulation of SPARC is a mechanism by which PTEN regulates collagen deposition in the mammary gland stroma.