Three-dimensional bioprinting is not only about cell-laden structures.

In this review, we focused on a few obstacles that hinder three-dimensional (3D) bioprinting process in tissue engineering. One of the obstacles is the bioinks used to deliver cells. Hydrogels are the most widely used bioink materials; however, they aremechanically weak in nature and cannot meet the requirements for supporting structures, especially when the tissues, such as cartilage, require extracellular matrix to be mechanically strong. Secondly and more importantly, tissue regeneration is not only about building all the components in a way that mimics the structures of living tissues, but also about how to make the constructs function normally in the long term. One of the key issues is sufficient nutrient and oxygen supply to the engineered living constructs. The other is to coordinate the interplays between cells, bioactive agents and extracellular matrix in a natural way. This article reviews the approaches to improve the mechanical strength of hydrogels and their suitability for 3D bioprinting; moreover, the key issues of multiple cell lines coprinting with multiple growth factors, vascularization within engineered living constructs etc. were also reviewed.

Does upper blepharoplasty affect frontalis tonicity?

BACKGROUND: Frontalis hypertonicity has long been implicated in patients with significant dermatochalasia or blepharoptosis, as evidenced by eyebrow changes that occur after the resection of redundant skin or after blepharoptosis operation. However, whether upper blepharoplasty affects the forehead muscle has not been reported. Thus, this study investigated electrophysiology of the frontalis muscle and eyebrow morphology in a population of patients undergoing double-eyelid blepharoplasty. METHOD: Patients wishing to undergo upper blepharoplasty were recruited for this prospective study between June 2011 and February 2012. The subjects were excluded for complaints of visual obstruction, trauma history, and for any underlying medical condition that would affect eyebrow height or electromyogram (EMG) findings. Eyebrow morphology was ascertained in a standardized photogrammetric evaluation, and the frontalis muscle activity was recorded with needle EMG. These assessments were carried out at preoperation and at 2 weeks, 3 months, and 6 months. Root-mean-square (RMS) indices of various facial expressions were used to normalize the frontalis activity values across individuals. RESULTS: Thirteen patients with a mean age of 55.5 years were recruited. No statistical significance was observed for eyebrow heights at various assessment points. However, EMG recordings have demonstrated a gradual decrease in the proportional RMS index of the frontalis muscle activity. This difference was statistically significant between preoperation and 6 months postoperation (p < 0.05). CONCLUSION: Upper blepharoplasty was associated with gradual decreases in the frontalis muscle activity. A longer follow-up study is needed to evaluate whether this decreased tonicity results in morphologic changes such as decreased forehead wrinkles and depressed eyebrows. This research indicates that upper blepharoplasty has the potential to interfere with those human-computer interaction designs with facial EMG readings as an input.

Spinal accessory neuropathy associated with the tumor located on the jugular foramen.

Spinal accessory neuropathy is commonly caused by iatrogenic injury or secondary to trauma or infection. Nevertheless, the tumor related palsy is rare. We present a case of an 18-year-old male patient suffering from paralysis of his right trapezius and sternocleidomastoid muscle. An electrophysiologic diagnostic study confirmed the spinal accessory neuropathy of the proximal segment. In addition, magnetic resonance imaging showed the location of tumor on the jugular foramen. However, the type of the tumor was not confirmed through biopsy because the patient refused surgical procedure. Based on the study, it is hypothesized that the tumor located on the jugular foramen should be considered as a cause of the spinal accessory nerve of the proximal segment.

A case of central cord syndrome related status epilepticus - a case report -.

Central cord syndrome (CCS) is extremely rare as a direct consequence of generalized epileptic seizure. CCS is associated with hyperextension of the spinal cord and has characteristic radiologic findings including posterior ligamentous injury and prevertebral hyperintensity following magnetic resonance imaging (MRI). We experienced the case of a 25-year-old man who suffered CCS after status epilepticus. Cervical spinal MRI revealed high signal intensity at the C1 level but with no signal or structural changes in other sites. After rehabilitation management, the patient significantly improved on the ASIA (American Spinal Injury Association) motor scale and bladder function. We proposed that epilepsy related CCS may be caused by muscle contractions during generalized seizure, which can induce traction injury of the spinal cord or relative narrowing of spinal canal via transient herniated nucleus pulposus or transient subluxation of vertebra. We also suggest CCS without radiologic findings of trauma has good prognosis compared with other CCS.