Atypical case of bow hunter’s syndrome linked to aberrantly coursing vertebral artery: A case report

BACKGROUND In bow hunter’s syndrome(BHS),also known as rotational vertebral artery(VA)syndrome,there is dynamic/rotational compression of the VA producing verte-brobasilar insufficiency.Most occurrences involve atlantoaxial rather than mid-cervical VA compromise,the latter being rarely reported.Herein,we detail successful VA decompression at mid-cervical spine,given a departure from its usual course.CASE SUMMARY The patient,a 45-year-old man,presented to our hospital with occipital headache and vertigo.Computed tomography angiography showed anomalous C4 entry of right VA,with compression upon head rotation to that side.Thyroid cartilage and anterior tubercle of C5 transverse process were visibly at fault.We opted for sur-gery,using an anterior cervical approach to remove the anterior tubercle.Patient recovery was uneventful and brought resolution of all preoperative symptoms.CONCLUSION BHS is an important consideration where aberrant coursing of VA and neurologic symptoms coexist.

Tonsil-derived stem cells as a new source of adult stem cells

Located near the oropharynx, the tonsils are the primary mucosal immune organ. Tonsil tissue is a promising alternative source for the high-yield isolation of adult stem cells, and recent studies have reported the identification and isolation of tonsil-derived stem cells (T-SCs) from waste surgical tissue following tonsillectomies in relatively young donors (i.e., under 10 years old). As such, TSCs offer several advantages, including superior proliferation and a shorter doubling time compared to bone marrow-derived mesenchymal stem cells (MSCs). T-SCs also exhibit multi-lineage differentiation, including mesodermal, endodermal (e.g., hepatocytes and parathyroid-like cells), and even ectodermal cells (e.g., Schwann cells). To this end, numbers of researchers have evaluated the practical use of T-SCs as an alternative source of autologous or allogenic MSCs. In this review, we summarize the details of T-SC isolation and identification and provide an overview of their application in cell therapy and regenerative medicine.

Improved method for synthesis of low molecular weight protamine–siRNA conjugate

RNAi technology has aroused wide public interest due to its high efficiency and specificity to treat multiple types of diseases. However, the effective delivery of siRNA remains a challenge due to its large molecular weight and strong anionic charge. Considering their remarkable functions in vivo and features that are often desired in drug delivery carriers, biomimetic systems for siRNA delivery become an effective and promising strategy. Based on this, covalent attachment of synthetic cell penetrating peptides(CPP) to siRNA has become of great interest. We developed a monomeric covalent conjugate of low molecular weight protamine(LMWP, a well-established CPP) and siRNA via a cytosol-cleavable disulfide linkage using PEG as a crosslinker. Results showed that the conjugates didn't generate coagulation, and exhibited much better RNAi potency and intracellular delivery compared with the conventional charge-complexed CPP/siRNA aggregates. Three different synthetic and purification methods were compared in order to optimize synthesis efficiency and product yield. The methodology using hetero-bifunctional NHS–PEG–OPSS as a crosslinker to synthesize LMWP–siRNA simplified the synthesis and purification process and produced the highest yield. These results pave the way towards siRNA biomimetic delivery and future clinical translation.

Curcumin based combination therapy for anti-breast cancer： from in vitro drug screening to in vivo efficacy evaluation

While drug resistance appears to be an inevitable problem of an increasing number of anticancer drugs in monotherapy, combination drug therapy has become a prosperous method to reduce the administered total drug dosages as well as overcome the drug resistance of carcinoma cells. Curcumin, considered to possess multi- faceted roles in cancer treatment according to its multiple anti-neoplastic mechanisms as a depressor of chemo- resistance, can significantly facilitate its anti-cancer functions and improve therapeutic effects via combination usage with a variety of other drugs with different reaction mechanisms. To explore this possibility, four anti-cancer chemotherapeutic agents that all possess a certain degree of drug resistance problems, including three tyrosine kinase inhibitors （erlotinib, sunitinib and sorafenib） that are acting on different cell pathways and a typical anticancer drug doxorubicin, were combined with curcumin individually to examine the synergistic anti-tumor effect both in vitro and in vivo. Results revealed that sunitinib combined with curcumin at the molar ratio of 0.46 yielded the most potent synergistic effect in vitro, and was therefore chosen for further animal evaluation. To further enhance the anti- cancer effect, bovine serum albumin （BSA） nanoparticles were utilized as a carrier to deliver the selected drug combination in situ. Preliminary in vivo findings confirmed our hypothesis of being able to maintain a similar injected drug ratio for prolonged time periods in tested animals by our approach, thereby maximizing the therapeutic potency yet minimizing the toxicity of these drugs. This work could open up a new avenue on combination drug therapy and realization the clinical utility of such drugs.