Shoaling in eyed and blind morphs of the characin Astyanax fasciatus under light and dark conditions

NK-5962 is a key component of photoelectric dye-based retinal prosthesis (OUReP). In testing the safety and efficacy, NK-5962 was safe in all tests for the biological evaluation of medical devices (ISO 10993) and effective in preventing retinal cells from death even under dark conditions. The long-term implantation of the photoelectric dye-coupled polyethylene film in the subretinal space of hereditary retinal dystrophic (RCS) rats prevented neurons from apoptosis in the adjacent retinal tissue. The intravitreous injection of NK-5962 in the eyes of RCS rats, indeed, reduced the number of apoptotic cells in the retinal outer nuclear layer irrespective of light or dark conditions. In this study, we reviewed the in vitro and in vivo evidence of neuroprotective effect of NK-5962 and designed pharmacokinetic experiments. The in vitro IC50 of 1.7 μM, based on the protective effect on retinal cells in culture, could explain the in vivo EC50 of 3 μM that is calculated from concentrations of intravitreous injection to prevent retinal neurons from apoptosis. Pharmacokinetics of NK-5962 showed that intravenous administration, but not oral administration, led to the effective concentration in the eye of rats. NK-5962 would be a candidate drug for delaying the deterioration of retinal dystrophy, such as retinitis pigmentosa.

Download Full-text

Effect of noisy galvanic vestibular stimulation on dynamic posture sway under visual deprivation in patients with bilateral vestibular hypofunction

Scientific Reports ◽

10.1038/s41598-021-83206-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Po-Yin Chen ◽

Ying-Chun Jheng ◽

Chien-Chih Wang ◽

Shih-En Huang ◽

Ting-Hua Yang ◽

...

Keyword(s):

Clinical Trial ◽

Light Exposure ◽

Light Condition ◽

Vestibular Stimulation ◽

Galvanic Vestibular Stimulation ◽

Lateral Deviation ◽

Clinical Trial Registration ◽

Vestibular Hypofunction ◽

Dark Conditions ◽

Bilateral Vestibular Hypofunction

AbstractA single-blind study to investigate the effects of noisy galvanic vestibular stimulation (nGVS) in straight walking and 2 Hz head yaw walking for healthy and bilateral vestibular hypofunction (BVH) participants in light and dark conditions. The optimal stimulation intensity for each participant was determined by calculating standing stability on a force plate while randomly applying six graded nGVS intensities (0–1000 µA). The chest–pelvic (C/P) ratio and lateral deviation of the center of mass (COM) were measured by motion capture during straight and 2 Hz head yaw walking in light and dark conditions. Participants were blinded to nGVS served randomly and imperceivably. Ten BVH patients and 16 healthy participants completed all trials. In the light condition, the COM lateral deviation significantly decreased only in straight walking (p = 0.037) with nGVS for the BVH. In the dark condition, both healthy (p = 0.026) and BVH (p = 0.017) exhibited decreased lateral deviation during nGVS. The C/P ratio decreased significantly in BVH for 2 Hz head yaw walking with nGVS (p = 0.005) in light conditions. This study demonstrated that nGVS effectively reduced walking deviations, especially in visual deprived condition for the BVH. Applying nGVS with different head rotation frequencies and light exposure levels may accelerate the rehabilitation process for patients with BVH.Clinical Trial Registration This clinical trial was prospectively registered at www.clinicaltrials.gov with the Unique identifier: NCT03554941. Date of registration: (13/06/2018).

Download Full-text

Methylmercury Production and Degradation Under Light and Dark Conditions in the Water Column of the Hells Canyon Reservoirs, USA

Environmental Toxicology and Chemistry ◽

10.1002/etc.5041 ◽

2021 ◽

Author(s):

Chris S. Eckley ◽

Todd P. Luxton ◽

Christopher D. Knightes ◽

Vishal Shah

Keyword(s):

Water Column ◽

Dark Conditions ◽

Methylmercury Production ◽

Hells Canyon

Download Full-text

Correction to: Inter-transformation between silver nanoparticles and Ag+ induced by humic acid under light or dark conditions

Ecotoxicology ◽

10.1007/s10646-021-02412-7 ◽

2021 ◽

Author(s):

Yujia Liu ◽

Chao Li ◽

Si Luo ◽

Xi Wang ◽

Qingmei Zhang ◽

...

Keyword(s):

Silver Nanoparticles ◽

Humic Acid ◽

Dark Conditions

Download Full-text

The Molecular Genetics and Evolution of Red and Green Color Vision in Vertebrates

Genetics ◽

10.1093/genetics/158.4.1697 ◽

2001 ◽

Vol 158 (4) ◽

pp. 1697-1710 ◽

Cited By ~ 1

Author(s):

Shozo Yokoyama ◽

F Bernhard Radlwimmer

Keyword(s):

Color Vision ◽

Homo Sapiens ◽

Amino Acid Sequences ◽

Capra Hircus ◽

Sciurus Carolinensis ◽

Cave Fish ◽

Vitro Assay ◽

Green Color ◽

Astyanax Fasciatus

Abstract To better understand the evolution of red-green color vision in vertebrates, we inferred the amino acid sequences of the ancestral pigments of 11 selected visual pigments: the LWS pigments of cave fish (Astyanax fasciatus), frog (Xenopus laevis), chicken (Gallus gallus), chameleon (Anolis carolinensis), goat (Capra hircus), and human (Homo sapiens); and the MWS pigments of cave fish, gecko (Gekko gekko), mouse (Mus musculus), squirrel (Sciurus carolinensis), and human. We constructed these ancestral pigments by introducing the necessary mutations into contemporary pigments and evaluated their absorption spectra using an in vitro assay. The results show that the common ancestor of vertebrates and most other ancestors had LWS pigments. Multiple regression analyses of ancestral and contemporary MWS and LWS pigments show that single mutations S180A, H197Y, Y277F, T285A, A308S, and double mutations S180A/H197Y shift the λmax of the pigments by −7, −28, −8, −15, −27, and 11 nm, respectively. It is most likely that this “five-sites” rule is the molecular basis of spectral tuning in the MWS and LWS pigments during vertebrate evolution.

Download Full-text