Differential response of oxidative and glycolytic skeletal muscle fibers to mesterolone.

Oxidative and glycolytic muscle fibers differ in their ultrastructure, metabolism, and responses to physiological stimuli and pathological insults. We examined whether these fibers respond differentially to exogenous anabolic androgenic steroids (AASs) by comparing morphological and histological changes between the oxidative anterior latissimus dorsi (ALD) and glycolytic pectoralis major (PM) fibers in adult avian muscles. Adult female White Leghorn chickens (Gallus gallus) were randomly divided into five groups: a vehicle control and four mesterolone treatment groups (4, 8, 12, and 16 mg/kg). Mesterolone was administered orally every three days for four weeks. Immunocytochemical techniques and morphometric analyses were employed to measure the changes in muscle weight, fiber size, satellite cell (SC) composition, and number of myonuclei. Mesterolone increased both body and muscle weights and induced hypertrophy in glycolytic PM fibers but not in oxidative ALD fibers. Mesterolone induced SC proliferation in both muscles; however, the myonuclear accretion was noticeable only in the PM muscle. In both muscles, the collective changes maintained a constant myonuclear domain size and the changes were dose independent. In conclusion, mesterolone induced distinct dose-independent effects in avian oxidative and glycolytic skeletal muscle fibers; these findings might be clinically valuable in the treatment of age-related sarcopenia.

Myogenic regulatory factors: The orchestrators of myogenesis after 30 years of discovery.

Prenatal and postnatal myogenesis share many cellular and molecular aspects. Myogenic regulatory factors are basic Helix-Loop-Helix transcription factors that indispensably regulate both processes. These factors (Myf5, MyoD, Myogenin, and MRF4) function as an orchestrating cascade, with some overlapped actions. Prenatally, myogenic regulatory factors are restrictedly expressed in somite-derived myogenic progenitor cells and their derived myoblasts. Postnatally, myogenic regulatory factors are important in regulating the myogenesis process via satellite cells. Many positive and negative regulatory mechanisms exist either between myogenic regulatory factors themselves or between myogenic regulatory factors and other proteins. Upstream factors and signals are also involved in the control of myogenic regulatory factors expression within different prenatal and postnatal myogenic cells. Here, the authors have conducted a thorough and an up-to-date review of the myogenic regulatory factors since their discovery 30 years ago. This review discusses the myogenic regulatory factors structure, mechanism of action, and roles and regulations during prenatal and postnatal myogenesis. Impact statement Myogenic regulatory factors (MRFs) are key players in the process of myogenesis. Despite a considerable amount of literature regarding these factors, their exact mechanisms of actions are still incompletely understood with several overlapped functions. Herein, we revised what has hitherto been reported in the literature regarding MRF structures, molecular pathways that regulate their activities, and their roles during pre- and post-natal myogenesis. The work submitted in this review article is considered of great importance for researchers in the field of skeletal muscle formation and regeneration, as it provides a comprehensive summary of all the biological aspects of MRFs and advances a better understanding of the cellular and molecular mechanisms regulating myogenesis. Indeed, attaining a better understanding of MRFs could be utilized in developing novel therapeutic protocols for multiple myopathies.

Migration of the distal catheter of the ventriculoperitoneal shunt in hydrocephalus: A Comprehensive Analytical Review from an Anatomical Perspective.

There have been many reports on migration of the distal catheter of the ventriculoperitoneal shunt (VPS) since this phenomenon was recognized 50 years ago. However, there have been no attempts to analyze its different patterns or to assess these patterns in terms of potential risk to patients. We comprehensively reviewed all reports of distal VPS catheter migration indexed in PubMed and identified three different anatomical patterns of migration based on catheter extension and organs involved: (1) internal, when the catheter invades any viscus inside the thoracic, abdominal, or pelvic cavity; (2) external, when the catheter penetrates through the body wall either incompletely (subcutaneously) or completely (outside the body); and (3) compound, when the catheter penetrates a hollow viscus and protrudes through a pre-existing anatomical orifice. We also analyzed the association between each migration type and several key factors. External migration occurred mostly in infants. In contrast, internal migration occurred mostly in adults. A body wall weakness was not a risk factor for catheter protrusion. Shunt duration was a critical factor in the migration pattern, as most newly-replaced shunts tended to migrate externally. Clinicians must pay close attention to cases of large bowel perforation, since they were most often associated with intracranial infections. The organ involved in compound migration could determine the route of extrusion, as the bowel was involved in all trans-anal migrations and the stomach in most trans-oral cases. Clin. Anat. 30:821-830, 2017. © 2017Wiley Periodicals, Inc.

Assessment of risk factors for postdural puncture headache in women undergoing cesarean delivery in Jordan: a retrospective analytical study.

PURPOSE: Postdural puncture headache (PDPH) is one of the most recognized complications after spinal anesthesia in women undergoing cesarean delivery. This study aimed to investigate the incidence of PDPH and its associated risk factors in women undergoing cesarean delivery in Jordan. PATIENTS AND METHODS: This study included all women who underwent cesarean delivery at King Abdullah University Hospital in Jordan during 2015. Patient characteristics including age, weight, occurrence of PDPH, needle type, repeated puncture attempt, history of spinal anesthesia and PDPH, presence of tension headache, preeclampsia, migraine, sinusitis, and caffeine withdrawal were collated from hospital records. Statistical analyses were performed to assess the association of these characteristics with PDPH. RESULTS: The study cohort consisted of 680 women. Among these, only 43 (6.3%) had developed PDPH. The only factors that showed significant association (P<0.01) with PDPH were repeated puncture attempt and presence of tension headache. The repeated puncture attempt increased the risk of PDPH 2.55-fold, while presence of tension headache increased the risk 4.60-fold. Furthermore, the use of the traumatic 27 G Spinostar needle increased the risk of repeated puncture attempt 28.45-fold (P<0.01) compared with the use of the pencil-point 25 G Whitacre needle. CONCLUSION: The major risk factors associated with the incidence of PDPH in women undergoing cesarean delivery in Jordan are repeated puncture attempt and presence of tension headache. The use of the pencil-point 25 G Whitacre needle is recommended since this was associated with a substantially reduced risk of repeated spinal puncture than the traumatic 27 G Spinostar needle.

Sustanon induces dose-independent hypertrophy and satellite cell proliferation in slow oxidative fibers of avian skeletal muscle.

Sustanon is a well-known anabolic drug that is used to treat hypogonadism and restore muscle mass and bone density. As research to date has been limited to its effects in glycolytic fibers, this study aimed to investigate the dose-related effects of Sustanon on the oxidative fibers of avian skeletal muscle. Adult female chickens were randomly divided into 4 groups: control (C), received a dose of 100 µl normal saline per injection; and Sustanon-1, -2, and -3 (S1, S2, and S3), that received a dose of 12.5, 25, or 50 mg/kg Sustanon per injection, respectively. Each bird received 4 injections at weekly intervals (1 injection/week). Robust histochemical and immunofluorescent techniques along with morphometric analyses were applied to determine the oxidative activity and morphological variations of the oxidative muscle fibers in all groups. Sustanon-treated groups exhibited significant increases in fiber size and numbers of satellite cells and myonuclei compared to the control group. However, no significant variations were found between Sustanon-treated groups in the aforementioned indices. In conclusion, Sustanon induced oxidative fiber hypertrophy that was associated with satellite cell proliferation and myonuclear accretion in avian skeletal muscle. Furthermore, the effects of Sustanon appeared to be dose-independent.

Successful Management of Intraoperative Acute Bilateral Pulmonary Embolism in a High Grade Astrocytoma Patient.

BACKGROUND Intraoperative pulmonary embolism (PE) is a rare life-threatening complication in patients undergoing surgical intervention. Generally, cancer patients have a higher risk for developing this complication. Unfortunately, there is no standard procedure for its management. CASE REPORT We report the case of a 39-year-old woman with high-grade glioma in the right frontal lobe who was admitted to the surgical theater for craniotomy and excision of the tumor. During the general anesthesia procedure and just before inserting the central venous line, her end-tidal CO2 and O2 saturation dropped sharply. The anesthesiologist quickly responded with an aggressive resuscitation procedure that included aspiration through the central venous line, 100% O2, and IV administration of ephedrine 6 mg, colloid 500 mL, normal saline 500 mL, and heparin 5000 IU. The patient was extubated and remained in the supine position until she regained consciousness and her vital signs returned to normal. Subsequent radiological examination revealed a massive bilateral PE. A retrievable inferior vena cava (IVC) filter was inserted, and enoxaparin anticoagulant therapy was prescribed to stabilize the patient's condition. After 3 weeks, she underwent an uneventful craniotomy procedure and was discharged a week later under the enoxaparin therapy. CONCLUSIONS The successful management of intraoperative PE requires a quick, accurate diagnosis accompanied with an aggressive, fast response. Anesthesiologists are usually the ones who are held accountable for the diagnosis and early management of this complication. They must be aware of the possibility of such a complication and be ready to react properly and decisively in the operation theater.