Effect of high-BDNF microenvironment stem cells therapy on neurogenic bladder model in rats

BackgroundThe purpose of this study is to explore the effects of high-BDNF microenvironment produced by engineered immortalized mesenchymal stem cells (imMSCs) on the neurogenic bladder (NB) and investigate underlying mechanism.MethodsMale Sprague-Dawley rat (12-week-old, weighing about 370–400 g) were purchased from a Korean company (Orient Bio Co. Seongnam, Korea) and divided into the following groups (n=32): sham control group (n=8), NB group (n=8), NB + ImMSCs group (n=8), NB + ImMSCs (BDNF) group (n=8). The major pelvic ganglion (MPG) was observed under anesthesia. Three NB groups of rats were then subjected to bilateral MPG injury. The sham control group of rats was treated with sham surgery. Cystometry were performed before the rats were sacrificed, and then MPG and bladder were collected for histochemical and Western blot analysis.ResultsMSCs treatment improves lower urinary tract function, and the NB + ImMSCs (BDNF) group is better than the NB + ImMSCs group (P<0.01). MSCs treatment accelerates recovery of injured nerve tissue, and the NB + ImMSCs (BDNF) group is better than the NB + ImMSCs group (P<0.01). In high BDNF environment, apoptosis was reduced more significantly and muscle tissue recovered more rapidly (P<0.01). High-BDNF microenvironment activates more BDNF/TrkB/CREB signaling pathways (P<0.01).ConclusionsIn a rat NB model caused by nerve injury, imMSCs have certain effects on nerve tissue repair. At the same time, it was proved that increasing the expression of BDNF which had specific effect on nerve injury repair could more effectively repair injured MPG in local microenvironment. The mechanism may be related to the activation of the BDNF/TrkB/CREB signaling pathway and the reduction of apoptosis by highly expressed BDNF.     

Transurethral Foley catheter misplacement into the upper urinary tract in a patient with a history of lung cancer and chemotherapy: a case report and considerations to keep in mind

Indwelling urethral catheter placement is a common and comparatively safe procedure. Misplacement of a urethral catheter into the upper urinary tract is unusual, and only a few cases have been reported. We describe the case of a 43-year-old man who presented with oliguria and had a history of chemotherapy for known metastatic lung cancer. As he had no history of urological disease, urethral catheterization was expected to be uneventful. The catheter was unable to be pulled back to the bladder neck once the balloon was inflated, and the patient expressed discomfort. Subsequent computed tomography revealed that the tip of the catheter was placed in the middle of the right ureter. Unbeknownst to the physicians before urethral catheterization, the patient had severe lower urinary tract symptoms and urinary bladder dysfunction with hydronephrosis, likely due to chemotherapy. Based on the patient’s symptoms and imaging results, we judged the possibility of severe ureteral injury to be low. The malpositioned catheter was removed uneventfully after complete balloon deflation and then reinserted properly. He was admitted to the medical department but died as a result of an exacerbation of the underlying disease unrelated to the incident. If urethral catheter placement seems abnormal, physicians should aspirate and irrigate to confirm correct positioning before balloon inflation; then, they should carefully pull the inflated balloon near the neck of the bladder while monitoring the patient’s symptoms. Although urethral catheter placement is comparatively safe, physicians must keep in mind that patients who have undergone chemotherapy might be at a risk for this rare complication.     

The establishment of the Korean medical device safety information monitoring center: Reviewing ten years of experience

Medical devices may revolutionize healthcare delivery but can lead to serious adverse events for treated patients and users. While reporting of adverse events related to medical devices is an essential starting point for post-market surveillance, underreporting of medical device adverse events is a global problem. Korea introduced a voluntary medical device adverse event reporting system in 2010, called the Medical Device Safety Information Monitoring Center, which has led to an increase in adverse event reports. For 10 years, the Medical Device Safety Information Monitoring Center has analyzed medical device adverse events systematically and has provided active feedback to the manufacturers and education on safe use. Recently, the Medical Device Safety Information Monitoring Center contributed to harmonization of international medical device vigilance through the sharing of adverse events. This experience of Korea might contribute to improvements in medical device vigilance, which is a critical prerequisite for improving medical device policies and regulations.     

Systematic assessment of South Korea’s capabilities to control COVID-19

South Korea’s COVID-19 control strategy has been widely emulated. Korea’s ability to rapidly achieve disease control in early 2020 without a “Great Lockdown” despite its proximity to China and high population density make its achievement particularly intriguing. This paper helps explain Korea’s pre-existing capabilities which enabled the rapid and effective implementation of its COVID-19 control strategies. A systematic assessment across multiple domains demonstrates that South Korea’s advantages in controlling its epidemic are owed tremendously to legal and organizational reforms enacted after the MERS outbreak in 2015. Successful implementation of the Korean strategy required more than just a set of actions, measures and policies. It relied on a pre-existing legal framework, financing arrangements, governance and a workforce experienced in outbreak management.     

Bone Graft Alternatives for Spinal Fusion

Bone grafting to achieve fusion is frequently performed in spinal surgery. Autograft is the gold standard bone graft material. However, due to limitations of supply and morbidity associated with the harvest of autograft, alternatives are being considered. Osteoconductive matrices, such as allograft, calcium or ceramic preparations are one such class of potential bone graft alternatives, but generally they lack osteoinductive properties. Recent attention has focused on osteoinductive materials such as demineralised bone matrix, recombinant bone morphogenetic proteins and bone marrow aspirates or blood product concentrates. These products may be combined with osteoconductive carriers and are clearly finding a place in the clinical arena.     

Changes of nitric oxide synthase activity and free methylarginines contents in regenerating rat liver after partial hepatectomy

In the present study, liver regeneration rate (%) was increased up to 70% 3 days after partial hepatectomy (PH). Nitric oxide synthase (NOS) activity in liver tissue as well as serum nitrite/nitrate content had no timed response, revealing no significant difference between shamoperated and partially hepatectomized rat liver. Contents of free methylarginines in liver tissue were increased biphasically in a time-dependent manner after PH. However, those in serum did not exhibit the same patterns as in liver. Taken together, the results suggest that N^G-monomethyl-L-arginine (MMA) and N^G, N^G-dimethylarginine (DMA) play a role in inhibiting nitric oxide (NO) synthesis in regenerating rat liver because the increase of their contents was synchronized with NOS expression.     

Gastrointestinal absorption of phenytoin from an oil-in-water microemulsion

The absorption profile of phenytoin Na emulsion were examined compared to that of phenytoin suspension after oral administration in the rat. The corn oil-in-water emulsion, particle size of 184±57.8 nm, was prepared using a microfludizer, and phenytoin Na added by shaft homogenizer. The phenytoin emulsion or suspension, 100 mg/kg, were intubated intragastrically using oral dosing needle and blood samples were withdrawn via an indwelling cannula from the conscious rat. Plasma concentrations of phenytoin were measured with HPLC using phenacetin as an internal standard. The plasma concentration versus time data were fitted to a one compartment open model and the pharmacokinetic parameters were calculated using the computer program, Boomer. The phenytoin plasma concentrations from the emulsion at each observed time were about 1.5–2 times higher than those from the suspension, significantly at time of 5, 6 and 7 hr after administration. The absorption (k_a) and elimination rate constant (k_e) were not altered significantly, however the AUC increased from 65.6 to 106.7 μg·hr/ml after phenytoin suspension or emulsion oral administration, respectively. From an equilibrium dialysis study, the diffusion rate constant (k_IE) was considerably higher from the phenytoin Na emulsion (0.0439 hr⁻¹) than phenytoin suspension (0.0014 hr⁻¹).     

Cytotoxic constituents ofPilea mongolica

Bioassay-guided fractionation of the aerial parts ofPilea mongolica (Urticaceae) afforded two cytotoxic triterpenoids, epi-oleanolic acid (I) and oxo-oleanolic acid (II). The structures of the compounds were confirmed by spectral and synthetic evidences. CompoundI and compoundII exhibited cytotoxicity against cultured human tumor cell lines, A549 (non small cell lung adenocarcinoma), SK-OV-3 (ovarian), SK-MEL-2 (skin melanoma), XF498 (CNS) and HCT15 (colon) with ED(50) values of 3.2 approximately 8.1 mug/ml and 0.7 approximately 6.8 mug/ml, respectively.