Morphologic changes in the spinal cord following intrathecal palonosetron-HCl injection in rats

BACKGROUND: Intravenous palonosetron-HCl, a second-generation antagonist of selective serotonin type 3 (5-HT3) receptors, can prevent chemotherapy-induced nausea and vomiting (CINV) and postoperative nausea and vomiting (PONV). 5-HT3 receptors are abundant in the lower brainstem and the substantia gelatinosa of the spinal cord, which provides a theoretical rationale for neuraxial administration of 5-HT3 receptor antagonists for CINV, PONV, and opioid-induced nausea and vomiting. However, there are no reports of neuraxial administration of palonosetron-HCl. Before neuraxial administration of a drug is accepted for clinical use, its safety must be proven. This study was conducted to determine whether neuraxial administration of palonosetron-HCl produces neurologic injury. METHODS: Male Sprague-Dawley rats under general anesthesia were catheterized intrathecally and the catheter tip was advanced caudally to the L1 vertebra. After 7 days, 20 µl of normal saline (N group, n = 6) or 20 µl (1 µg) of palonosetron-HCl (P group, n = 6) were injected intrathecally once per day for 2 weeks. Neurotoxic changes were evaluated by light microscopy (LM) and electron microscopy (EM) of the spinal cord. Behavioral changes were also evaluated in both groups. RESULTS: One of the N group rats and three of the P group rats demonstrated abnormal behavior during intrathecal drug injection, but otherwise their behavior was normal. The spinal cords of the N group did not have any abnormal findings by LM or EM. The spinal cords of the P group had multiple vacuoles in the white matter by LM, especially in the dorsal funiculus, and EM revealed myelin, axonal, and mitochondrial swelling. CONCLUSIONS: Results suggest that chronic intrathecal administration of palonosetron-HCl produced microscopic morphologic changes in the spinal cords of rats.

Larval Chigger Mites Collected from Small Mammals in 3 Provinces, Korea

A total of 9,281 larval chigger mites were collected from small mammals captured at Hwaseong-gun, Gyeonggi-do (Province) (2,754 mites from 30 small mammals), Asan city, Chungcheongnam-do (3,358 mites from 48 mammals), and Jangseong-gun, Jeollanam-do (3,169 for 62 mammals) from April-November 2009 in the Republic of Korea (= Korea) and were identified to species. Leptotrombidium pallidum was the predominant species in Hwaseong (95.8%) and Asan (61.2%), while Leptotrombidium scutellare was the predominant species collected from Jangseong (80.1%). Overall, larval chigger mite indices decreased from April (27.3) to June (4.9), then increased in September (95.2) and to a high level in November (169.3). These data suggest that L. pallidum and L. scutellare are the primary vectors of scrub typhus throughout their range in Korea. While other species of larval chigger mites were also collected with some implications in the transmission of Orientia tsutsugamushi, they only accounted for 11.2% of all larval chigger mites collected from small mammals.

Identification of Leptospira species of Korean Isolates using Phylogenetic Analysis of Polymerase Chain Reaction-amplified 16S rDNA and LipL32 Genes

In this study, we selected only serologically identified 15 Leptosira interrogans isolates in the past and analyzed and identified them by using molecular method. The partial 16S rDNA and LipL32 genes were amplified from the bacteria by polymerase chain reaction (PCR) and sequenced. Sizes of the PCR products were 529 bp and 819 bp respectively and analysis of the nucleotide sequence of 16S rDNA and LipL32 genes showed that 14 out the 15 Leptospira showed 99.4~100% and 99.2~99.9% similarity respectively to those of L. interrogans lai and one isolate named HS-7 showed 100% and 100% similarity to L. interrogans canicola. The phylogenetic tree based on the 16S rDNA and LipL32 genes obtained the study revealed that 14 of the Leptospira composed a cluster distinct to that of L. interrogans lai and HS-7 composed to L. interrogans canicola.

A Survey on Laboratory Biosafety Status of Public Healthcare Centers in Korea

The purpose of this study was to explore the laboratory biosafety status of Public Health Centers (PHCs) in Korea during Oct.7~26, 2012. We surveyed the environment of biosafety management, especially for the recognition level for biosafety of workers in the organizations. The questionnaires given out to 98 workers who are working for PHCs are to research the recognition level of workers for the knowledge of biosafety, related laws and regulations. The level was the highest in the Research Institute of the Public Health & Environment (RIPHE) followed by quarantine station, and the health center was assessed as the last. It was turned out that the biosafety educational program in the RIPHE was implemented on a regular basis (65.2%) with irregular cases (21.7%), and some outsourcing chances (8.7%). However, quarantine stations and health centers didn't practice actively biosafety training programs compared to RIPHE. In addition, there was a majority of opinions that the most important thing to improve biosafety level of PHCs is to strengthen current poor training and education system. In conclusion, it is necessary to develop more improved training system for biosafety on exposure risks including injuries, personal protective equipment, and chemical hazards.