Retinal ganglion cell distribution and visual acuity in alpacas (Vicugna pacos).

OBJECTIVE: To investigate the distribution of retinal ganglion cells (RGCs) and visual acuity in alpacas (Vicugna pacos) through Brn-3a immunofluorescent labeling. PROCEDURES: Five eyes from four healthy alpacas with normal ophthalmic examination findings were included in the study. The axial length of the globes was measured before fixation. All five retinas were treated with Brn-3a antibodies to label RGCs. Images taken with a fluorescent microscope were used for RGC counting. RGC density maps were reconstructed by computer software. Visual acuity was estimated based on the results of peak RGC density and ocular anatomical parameters. RESULTS: The reconstructed retinal maps from Brn-3a labeling showed a horizontal streak across the retinal meridian superior to the optic nerve head with a temporal, upward extension. The highest RGC densities were in the temporal retinas. The maximal visual acuity was located in the temporal retina and was estimated to range between 12.5 and 13.4 cycles per degree. CONCLUSIONS: Alpacas have a horizontal streak across the retinal meridian superior to the optic disk with a temporal, upward extension based on the Brn-3a labeling of RGCs. The maximal visual acuity was located in the temporal retina. The reconstructed retinal maps indicate the RGC topography of alpacas is similar to that of other herbivores, but is different from that of dromedary camels.

New ketamine analogue: 2-fluorodeschloro-N-ethyl-ketamine and its suggested metabolites.

Identifying new psychoactive substances (NPSs) and their metabolites is essential for regulating such substances for purposes of law enforcement and forensics. NPSs can be regulated on the basis of their chemical structures before they become a critical threat to society. Further, NPS metabolites can be targeted for analysis in urine, blood, and hair. This case study reports an incident in which 10 bags with approximately 15 g of crystalline material were seized from suspects by law enforcement officers and sent to the laboratory for confirmation. Gas chromatography-mass spectrometry, liquid chromatography-high-resolution mass spectrometry, and nuclear magnetic resonance (NMR) were employed to analyze these materials. The analyses revealed that the materials were a new ketamine analog, 2-fluorodeschloro-N-ethyl-ketamine (2-FDCNEK). Single-crystal X-ray diffraction (SXRD) analysis was also employed to confirm this result. In addition, metabolites of 2-FDCNEK were investigated using a fungal model and a urine sample from an abuser. The results suggest that 2-FDCNEK and 2-fluorodeschoro-norketamine are optimal metabolites for biological samples. This report presents the mass fragmentation, NMR analysis, and SXRD data of 2-FDCNEK. In addition, it provides suggestions regarding metabolites of 2-FDCNEK for law enforcement and forensic purposes, thereby facilitating the detection of this new ketamine analog.