Macro-Microscopic Features of the Leg Muscles Innervation

The purpose of the study was to disclose topographic anatomical features of the extra- and intramuscular innervation points of the leg. Materials and methods. 15 adult human subjects and one-month old baby legs at three levels were studied using such methods: cross-sections according to N.I. Pirogov technique, histotopographic sections, macro-microscopic method, histological staining with hematoxylin-eosin and Krutsay. Results. In our macro-microscopic study, the main attention was paid to the individual anatomical variability in the innervation of the lower leg muscles. Study of the nerves of the leg muscles allowed to clarify the course of the neurovascular bundle of the leg at its three levels, taking into account individual age characteristics, and also to show the myeloarchitectonics of both the main nerve trunks and their intramuscular branches. Such differences in the location of the leg muscles of an adult and of one month-old baby undoubtedly related to the fact that the child’s muscular belly is longer in relation to the tendon. The histotopography of intramuscular nerves on total transverse sections of antagonistic muscles was studied: flexor and extensor digitorum longus, longus flexor and extensor of the big toe, and also the spectrum of myelin fibers contained in these nerves in a one-month-old baby and an adult was investigated. On histotopographic sections of the extensor digitorum longus nerve in a one-month-old baby, thick-diameter myelin fibers are absent, whereas in the long finger flexor nerve, on average, they are 0.5%. The number of thin and medium is respectively 8%, 13% and 83.5%, 16%. However, we have determined individual anatomical variability in the location of the vessels in relation to the main nerve trunks, as well as differences in the topography of the nerve in the corresponding muscles. Conclusion. In the nerves of the leg muscles, features were found, both in quantitative and qualitative composition of the conductors forming them; in the nerves of the flexor muscles, the composition of the nerve fibers is more diverse (with a slight predominance of the number of medium, thick and very thick fibers), which is associated with the peculiarity of their functions; in adulthood, the % ratio in the spectrum of myelin fibers in the nerves of the lower leg changes significantly

Antihyperglycemic Activity of Aqueous Extract of Euphorbia guyoniana in Streptozotocin-Induced Diabetic Rats

Aims: This work assessed the antihyperglycemic effect of Euphorbia guyoniana. Background: Euphorbia guyoniana (Boss. and Reut.) is widely used in traditional medicine. Objective: This study was designed to confirm this traditional use by assessing its antihyperglycemic capacity in vivo. Methods: The effect of the aqueous extract of Euphorbia guyoniana (Boss. and Reut.) (60 mg/kg) on glycemia in both normal and diabetic rats was evaluated. The glycogen content in the liver and skeletal muscles (extensor digitorum longus and soleus) was measured. Furthermore, liver histopathological analysis was performed. Results: The findings showed that Euphorbia guyoniana (Boss. and Reut.) exhibited a significant decrease in glycaemia in diabetic rats (from 20±2 mmol/l to 5.5 mmol/l after 6 hours of oral administration; p<0.0001 and from 20±2 mmol/l to 4.5 mmol/l after 7 days of once-daily repeated oral administration of the aqueous Euphorbia guyoniana extract; p<0.0001). In addition, the extract increased the glycogen content in the liver (41±4 mg/g versus 70±5 mg/g in normal and diabetic rats respectively) and extensor digitorum longus (39±4 mg/g versus 60±1 mg/g in normal and diabetic rats, respectively), and partially restored corporal weight in diabetic rats. Furthermore, this aqueous extract has been shown to suppress hyperglycemia induced by glucose load in treated diabetic rats. Additionally, hepatic histology in diabetic rats has been improved. This plant revealed the presence of several phytochemical constituents and possessed antioxidant activity. Conclusion: The current study evidenced that Euphorbia guyoniana (Boss. and Reut.) has a beneficial effect on improving hyperglycemia and glycogen depletion in the diabetic state.

Effect Mechanism of Electroacupuncture at ST36 on the Injured Extensor Digitorum Longus in the Jumping Rat Model Based on mRNA-Seq Analysis

The key target and regulatory mechanism of electroacupuncture of Zusanli (ST36) on extensor longus muscle injury in a jumping rat model were investigated. To this end, 24 female SD rats were randomly divided into the following four groups: no-treatment control group (NON), 6-week jumping group (J6O), electroacupuncture group after 6-week jumping (J6A), and natural recovery group after 6-week jumping (J6N). After 6 weeks of jumping, in the electroacupuncture group (J6A), electroacupuncture stimulation was applied at Zusanli(ST36) for 20 min per day over the course of 5 days. In the natural recovery group (J6N), rats were fastened with a special apparatus without electroacupuncture stimulation for 20 min at the same time. Transmission electron microscopy, transcriptome sequencing and analysis, Western blotting assay and immunofluorescence staining were performed at the end of our experiment. The recovery effect of J6A rats was more obvious than that of J6N rats and J6O rats as indicated by changes of infiltration of inflammatory cells and morphological structure. Notably, the morphological structure of J6A rats was closer to NON rats in the observation of transmission electron microscopy. CISH/STAT3 regulation was identified by mRNA-seq. The pro-inflammatory response to STAT3 activation was alleviated through up-regulating the expression of CISH protein in J6A rats relative to J6O rats. The level of BAX was decreased and the level of Bcl-2 level was increased in J6A rats relative to J6O rats. Moreover, when compared to J6N rats, the level of Bcl-2 was significantly up-regulated in J6A rats. Increased caspase-3 expression but decreased CDKN2α expression was shown in J6A rats relative to NON rats. These results indicate that the potential mechanism underlying electroacupuncture stimulation of Zusanli (ST36) in repairing the injured extensor digitorum longus following overused jumping may be attributed to CISH/STAT3 regulation of proteins associated with inflammation, apoptosis, and proliferation.

Novel Ultrasonographic Thickness and Strength Assessments of the Flexor Digitorum: A Reliability Analysis

OBJECTIVES: Clinical conditions such as focal dystonia often require the assessment of atrophy and weakness of the finger muscles. However, due to a lack of well-established protocols, the current investigation focused on assessing the reliability of thickness and strength assessments of the flexor digitorum (FD) muscle, including both the superficialis and profundus components. As a secondary assessment, the reliability of the strength measurement of the extensor digitorum muscle was examined as well. METHODS: Different thickness measurements of the FD were taken via ultrasonography and averaged to estimate the mean thickness of the FD. Likewise, individual finger strength measurements taken by a custom-made finger pressure device were averaged to compute the mean strength of the flexor and extensor digitorum muscles. Test-retest reliability of the above measurements performed at two different time points (about 6 months apart) were examined on the right and left hands of 10 participants. RESULTS: Findings indicated excellent test-retest reliability (ICC > 0.92) for the mean thickness assessment of the FD and mean strength of the flexor and extensor digitorum for both dominant and non-dominant hands. The standard error of measurement was ≤4.3% for all three mean assessments, indicating high sensitivity. Likewise, the smallest detectable change was also sufficiently small for the mean thickness and mean strength of the flexor digitorum (≤5.1%) and moderately small (≤12%) for the strength of the extensor digitorum. CONCLUSIONS: Results indicated an excellent relative and absolute reliability, for both hands, for the mean thickness and strength assessments of the flexor digitorum muscle and for the mean strength of the extensor digitorum (measured for both hands). These measurements can be used for future investigations and can contribute to the establishment of more precise methods for assessing the muscles in the forearms which serve the hand.

Measurement of Lateral Transmission of Force in the Extensor Digitorum Longus Muscle of Young and Old Mice

The main function of skeletal muscles is to generate force. The force developed by myofiber contraction is transmitted to the tendon. There are two pathways of force transmission from myofibers to tendons: longitudinal transmission that depends on tension elicited via the myotendinous junction and lateral transmission that depends on shear elicited via the interface between the myofiber surface and surrounding connective tissue. Experiments using animal muscle and mathematical models indicated that lateral transmission is the dominant pathway in muscle force transmission. Studies using rat muscle showed that the efficiency of lateral force transmission declines with age. Here, the lateral transmission of force was measured using the extensor digitorum longus muscle from young and old mice. Dependence on longitudinal transmission increased in the old muscle, and there was a trend for lower efficiency of lateral force transmission in the old muscle compared to the young muscle. There was a noticeable increase in the connective tissue volume in the old muscle; however, there was no significant change in the expression of dystrophin, a critical molecule for the link between the myofiber cytoskeleton and extracellular matrix. This study demonstrates the measurement of lateral force transmission in mouse muscles and that alteration in force transmission property may underlie age-related muscle weakness.