Combined aerobic exercise and enzyme replacement therapy rejuvenates the mitochondrial-lysosomal axis and alleviates autophagic blockage in Pompe disease

A unifying feature in the pathogenesis of aging, neurodegenerative disease, and lysosomal storage disorders is the progressive deposition of macromolecular debris impervious to enzyme catalysis by cellular waste disposal mechanisms (e.g., lipofuscin). Aerobic exercise training (AET) has pleiotropic effects and stimulates mitochondrial biogenesis, antioxidant defense systems, and autophagic flux in multiple organs and tissues. Our aim was to explore the therapeutic potential of AET as an ancillary therapy to mitigate autophagic buildup and oxidative damage and rejuvenate the mitochondrial-lysosomal axis in Pompe disease (GSD II/PD). Fourteen weeks of combined recombinant acid α-glucosidase (rhGAA) and AET polytherapy attenuated mitochondrial swelling, fortified antioxidant defense systems, reduced oxidative damage, and augmented glycogen clearance and removal of autophagic debris/lipofuscin in fast-twitch skeletal muscle of GAA-KO mice. Ancillary AET potently augmented the pool of PI4KA transcripts and exerted a mild restorative effect on Syt VII and VAMP-5/myobrevin, collectively suggesting improved endosomal transport and Ca(2+)- mediated lysosomal exocytosis. Compared with traditional rhGAA monotherapy, AET and rhGAA polytherapy effectively mitigated buildup of protein carbonyls, autophagic debris/lipofuscin, and P62/SQSTM1, while enhancing MnSOD expression, nuclear translocation of Nrf-2, muscle mass, and motor function in GAA-KO mice. Combined AET and rhGAA therapy reactivates cellular clearance pathways, mitigates mitochondrial senescence, and strengthens antioxidant defense systems in GSD II/PD. Aerobic exercise training (or pharmacologic targeting of contractile-activity-induced pathways) may have therapeutic potential for mitochondrial-lysosomal axis rejuvenation in lysosomal storage disorders and related conditions (e.g., aging and neurodegenerative disease).

Dual energy x-ray absorptiometry and quantitative ultrasound are not interchangeable in diagnosing abnormal bones

OBJECTIVE

To evaluate whether dual energy x-ray absorptiometry (DXA) and quantitative ultrasound (QUS) classify the same children as 'abnormal' (SD (z) score (SDS) ≤-2).

METHODS

Speed of sound (SOS) was measured at the radius and tibia using QUS and lumbar spine bone mineral density (BMD) using DXA in 621 subjects aged 5-20 years; healthy 412, cystic fibrosis 117 and obese 92.

RESULTS

BMD SDS positively (p<0.001) and tibia SOS SDS negatively correlated with size (p<0.05). Disagreement between DXA and QUS for 'abnormal' scans occurred in 6-31%. Those with abnormal BMD and normal SOS SDS had lower mean BMI SDS than those with normal BMD and abnormal SOS SDS. SOS measurements were unobtainable in some children, especially in the obese group.

CONCLUSIONS

DXA and QUS identify different individuals as 'abnormal'. Agreement between BMD and tibia SOS is lower in obese subjects. Without a gold-standard, it is difficult to determine which technique is more 'correct'.

An unusual bifid origin of 1st lumbrical muscle of hand: anatomical and clinical perspectives

Lumbrical muscles are pivotal in execution of fine skillful movements of the hand. Anomalies in their morphology are not uncommon. We report an exceptional bifid origin of first lumbrical muscle of the left upper limb, discovered incidentally in gross anatomy dissection class. The 1st lumbrical was observed to comprise of two heads, the accessory one arising from the tendon of flexor digitorum superficialis of the index finger and the other main belly taking origin as usual from flexor digitorum profundus. The two heads joined to form a common muscle belly and were inserted normally in the dorsal digital expansion. The report highlights the surgical and phylogenetic significance of such variation. Additionally, notification of such muscular variants assumes importance in the event of surgical interventions in this region. Moreover, the anomalous origin, length and volume of the first lumbrical are important parameters for the outcome of operations on the carpal tunnel.

An accessory venous channel of abdomen: an anatomical insight

Variations in the venous architecture of the retro peritoneum is not uncommon, mostly those of Inferior Vena Cava (IVC). In this report we describe an extremely rare anatomical entity, where the IVC is formed by the union of the right common iliac vein and the left internal iliac vein. This is associated with a parallel venous channel which is the upward continuation of the left external iliac vein, which finally drains into the IVC at the level of renal veins. Awareness of such unusual variation of abdominal venous channels is helpful during retroperitoneal and laparoscopic surgeries of the abdomen, in staging of abdominal neoplasm, in radiological interpretation as well as therapeutic intervention in cases of recurrent pulmonary embolism.

Anomalous constitution of the brachioradialis muscle: a potential site of radial nerve entrapment

The anatomical relationships of structures in the elbow region in the context of surgical approaches require to be studied carefully and diligently. The main aim of the present study is to report an accessory muscle in the elbow region which was detected during routine anatomical dissection and discuss its clinical importance. The muscle belly measured 4.8 x 2.1cm and it fused with the brachioradialis distally. Proximally, it was seen to blend with the deltoid and the brachialis muscles. The radial nerve was observed to interpose between this accessory muscle and the brachioradialis. This could act as a potential site of compression neuropathy. The present study seeks to elucidate the morphology and potential function of an additional muscle belly in relation to the brachioradialis muscle. A comprehensive knowledge of the anatomical characteristics of brachialis, brachioradialis and radial nerve should prove extremely helpful for the hand surgeons to considerably reduce the risk of injury during operative maneuvers.

Bitendinous insertion of abductor pollicis longus coexistent with a rare accessory antebrachial muscle: clinico-anatomical considerations

Reports of the anomalous orientation of the musculature of the fi rst osseofi brous extensor compartment of the wrist are not uncommon; especially that of Abductor Pollicis Longus (APL) muscle. Such variations can be explained phylogenetically; owing to a synonymous occurrence in primates. In this report, we highlight a unique variation in the APL muscle of the left side in an adult male cadaver. The present anomaly consisted of a bitendinous insertion of APL on the base of the fi rst metacarpal, complemented by an additional muscle belly arising from the fascia covering Extensor Carpi Radialis Longus (ECRL). Such an accessory muscle is speculated to greatly alter kinematics at the wrist and thumb, thus affecting the daily activities of the hand. Such multiple tendons of APL are benefi cial clinically in providing additive support to the fi rst carpo-metacarpal joint and act as effective aids in tendon transfers and reconstructive procedures of the hand. In contrast, they can pose as surgical hazards in post-operative cases of De Quervain's disease. Thus, it is imperative for surgeons and clinicians to acquire a prior substantial knowledge of such anatomical variants of APL before attempting any treatment of this region.

Growth in children with cystic fibrosis-related diabetes

Cystic fibrosis-related diabetes (CFRD) is associated with a shortened life expectancy and greater deterioration in lung function than in CF patients with normal glucose metabolism. There are few published data on how CFRD affects growth in childhood. We carried out a retrospective case controlled study of growth and lung function in 34 children with CFRD attending three specialist centers in London. We found that for the 2 years leading to CFRD diagnosis (at a mean age of 13.1 years), the mean height velocity was significantly less compared to controls: 4.9 (standard deviation-SD 1.6) cm/year vs. 6.0 (SD 1.9) cm/year (P = 0.005). For the 2 years following diagnosis, height velocity remained significantly lower (3.4 (SD 2.2) cm/year vs. 4.4 (SD 2.2) cm/year, P = 0.02). Mean FEV(1) was reduced prior to diagnosis and at diagnosis, but was similar to controls 2 years after diagnosis. This study highlights the compromise in height velocity and lung function that occurs prior to diagnosis of CFRD in children with CF, and a reduction in height velocity should be considered an indicator of impaired glucose metabolism. It would be useful to know whether early treatment with insulin can help promote catch up growth.

A new variant in the brachium musculature with reinforced innervation from a median-musculocutaneous nerve communication

Neural variations of the brachium constitute an important anatomical and clinical entity. Although frequently reported, if accompanied by other anomalies, they deserve special mention in anatomical literature. The goal of this present study is to report a communication between the median (MN) and musculocutaneous nerve (MCN), concomitant with an accessory muscle belly. Interestingly, an important proximal connection between the lateral and medial roots of the MN was also observed. The MCN joined the MN at mid humeral level. The peculiarity of the current report arises due to the presence of a twig passing from the site of communication between the two nerves, to supply the coracobrachialis. Concomitantly, an accessory muscle measuring 5cm in length originating from the short head of biceps brachii, fusing with the coracobrachialis was seen in the mid brachium. The observations of the current study may cause a perplexing situation for anesthetists attempting brachial plexus blocks and for surgeons who operate on this vital anatomical arena.

Abnormal spicules on the inferior aspect of anterior arch of atlas vertebra

Anterior arch of the atlas vertebra is known to exhibit various developmental anomalies. Bony outgrowths, osteophytes, clefts and aplasia of the anterior and posterior arches of the atlas have received special attention by research workers. To the best of our knowledge, not many osteological studies have defined the spicules on the anterior arch of the atlas. The present study describes an abnormal atlas vertebra with 2 spicules on the inferior aspect, 2 additional facets inferior to the superior articular facets and a peculiar facet to the left of the posterior tubercle. These abnormal spicules may cause dysphagia or involve atlanto-occipital movements. Such anomalies may be misinterpreted in routine X rays as a degenerative disease. However, asymptomatic cases remain undetected throughout life. Such anomalies may be important in radiological, clinical, forensic and anthropological studies.