A case of maternal tetanus in Korea

Tetanus is uncommon in Korea due to the introduction of vaccination programs and advances in public health. A case of maternal tetanus occurred on the 9 day postpartum in a 29-yr-old woman, who had not received a 10-yr-booster of tetanus-diphtheria toxoid after receiving the primary series of tetanus-toxoid-containing vaccine. There has hitherto been no reports on maternal tetanus in Korea. This case illustrates that tetanus remains a medical problem, principally among non- and under-immunized adults. The only way to fully prevent this disease is to ensure adequate immunization in all adults.     

Reactivating and protective effects of pyridinium compounds in human erythrocyte acetylcholinesterase inhibition by organophosphates in vitro

The reactivation of human erythrocyte acetylcholinesterase (AChE, EC 3.1.1.7) inhibited by O-ethyl-S-2-di-isopropylaminoethyl methylphosphonothioate (VX) and the protection against AChE inhibition by O-1,2,2-trimethylpropyl methylphosphonofluoridate (Soman) was studied with sixteen quaternized pyridinium compounds. TMB-4 which is known as a good reactivator of AChE inhibited by organophosphates proved to be the most effective reactivator. Of the tested newly synthetised compounds 3 were fairly good reactivators of methylethoxyphosphonylated AChE. These compounds have 2 pyridinium rings connected by a dimethylether link and a hydroxiiminomethyl group in position 2 of one pyridinium ring, while the radicals of the other pyridinium ring are benzoylcarbonyl, cyclohexylcarbonyl or amidocarbonyl residue.The rate of reactivation with these compounds followed a two-phase pattern, being fast at the beginning and then slowing down to an equilibrium. Kinetic treatment of the first-phase reaction course yielded the second-order rate constants of reactivation. All 3 compounds had similar reactivating efficiency (k _r values range from 0.8×10³ to 3.6×10³ M^–1 min^–1) and in effective concentrations (1 to 100 M) they also inhibited AChE (K _i(app) values range from 0.11 to 0.19 mM). Their reactivating properties were not better than those revealed by TMB-4 (k _r= 19.4×10³ M^–1 min^–1) which was tested as a reference compound.HGG-12, HGG-42 and HI-6 were also found to exert a good protective effect against AChE inhibition by Soman; no protection was obtained with TMB-4.     

Usage of nanoparticles with their potential toxicity assessment and regulatory guidelines

In recent times engineered nanoparticles have been receiving much attention from researchers due to their extensive use in a variety of chemical, biological, and industrial areas. Their physiochemical properties have led to a number of uses in commercial products. Considering their broad applications, with increasing human contact the risks of exposure are also increasing. In vivo toxicity experiments involving administering nanoparticles to living organisms have shown their adverse effects on organ development and reproduction. Nanoparticles can be considerably more toxic than the large-sized particles since they can move relatively freely compared to bulkier molecules. Henceforth, it is our duty to assess the harmful health consequences associated with human exposure to nanoparticles in order to improve safe production and use. We will review the current applications of nanoparticles, and issues related to their toxicity. We will focus on safety regulations, risk assessment and regulatory guidelines of nanoparticles. The validation and standardization of nanotoxicity tests will further promote safe applications of nanotechnology in our daily lives.     

Cutaneous Mycobacterium massiliense Infection of the Sole of the Feet

Mycobacterium massiliense which is recognized as a separate species from M. abscessus is little known regarding its clinical patterns and the response to treatment. We present a case of a localized cutaneous infection due to M. massiliense of the sole associated with acupuncture. M. massiliense was identified via polymerase chain reaction-hybridization analysis. We treated the patient with single-drug therapy consisting of clarithromycin for 4 months and the patient showed a significant response to this treatment.     

Harmful at non-cytotoxic concentrations: SiO2-SPIONs affect surfactant metabolism and lamellar body biogenesis in A549 human alveolar epithelial cells

The pulmonary delivery of nanoparticles (NPs) is a promising approach in nanomedicine. For the efficient and safe use of inhalable NPs, understanding of NP interference with lung surfactant metabolism is needed. Lung surfactant is predominantly a phospholipid substance, synthesized in alveolar type II cells (ATII), where it is packed in special organelles, lamellar bodies (LBs). In vitro and in vivo studies have reported NPs impact on surfactant homeostasis, but this phenomenon has not yet been sufficiently examined. We showed that in ATII-like A549 human lung cancer cells, silica-coated superparamagnetic iron oxide NPs (SiO₂-SPIONs), which have a high potential in medicine, caused an increased cellular amount of acid organelles and phospholipids. In SiO₂-SPION treated cells, we observed elevated cellular quantity of multivesicular bodies (MVBs), organelles involved in LB biogenesis. In spite of the results indicating increased surfactant production, the cellular quantity of LBs was surprisingly diminished and the majority of the remaining LBs were filled with SiO₂-SPIONs. Additionally, LBs were detected inside abundant autophagic vacuoles (AVs) and obviously destined for degradation. We also observed time- and dose-dependent changes in mRNA expression for proteins involved in lipid metabolism. Our results demonstrate that non-cytotoxic concentrations of SiO₂-SPIONs interfere with surfactant metabolism and LB biogenesis, leading to disturbed ability to reduce hypophase surface tension. To ensure the safe use of NPs for pulmonary delivery, we propose that potential NP interference with LB biogenesis is obligatorily taken into account.     

Chin Tuck for Prevention of Aspiration: Effectiveness and Appropriate Posture

Chin tuck has been has been widely used to prevent aspiration in the patients with dysphagia. This study was performed to investigate the effectiveness and the degree of optimal neck flexion of chin tuck. Ninety-seven patients who showed aspiration in the videofluoroscopic swallow study (VFSS). Participants were grouped into the effective (patients who showed effect with chin tuck) and ineffective group (those who did not show effect with chin tuck). VFSS was performed in neutral and chin tuck position and findings were compared between the groups. Severity of aspiration was assessed by the point penetration-aspiration scale. Duration of dysphagic symptoms, history of tracheostomy, and other possible contributing factors were also compared. Neck flexion angle was measured to find appropriate posture in which aspiration was prevented with chin tuck. Aspiration was reduced or eliminated in only 19 patients (19.6 %) with chin tuck. Oral transit time, pharyngeal delayed time and pharyngeal transit time were significantly shortened in both groups (p < 0.05), but the difference between the groups was not significant. Female sex and absence of residue in pyriform sinus favored the effect of chin tuck (p < 0.05). At least 17.5° of neck flexion was required to achieve an effect with chin tuck. The effectiveness of chin tuck was less than anticipated. Patients without residue in pyriform sinus were more likely to benefit from chin tuck. Sufficient neck flexion was important in chin tuck to prevent aspiration.