Larval pufferfish protected by maternal tetrodotoxin

Marine pufferfish contain tetrodotoxin (TTX), an extremely potent neurotoxin. All species of the genus Takifugu accumulate TTX in the liver and ovaries, although the tissue(s) in which it is localized can differ among species. TTX is the major defense strategy the pufferfish appears to use against predators. TTX is also used as a male-attracting pheromone during spawning. Here we demonstrate an additional (and unexpected) use of maternal TTX in the early larval stages of the Takifugu pufferfish. Predation experiments demonstrated that juveniles of all the species of fish used as predators ingested pufferfish larvae, but spat them out promptly. Liquid Chromatography-Tandem Mass Spectrometry (LC-MSMS) analysis revealed that the pufferfish larvae contain a small quantity of TTX, which is not enough to be lethal to the predators. Immunohistochemical analysis with anti-TTX monoclonal antibody revealed that the TTX is primarily localized in the body surface of the larvae as a layer of protection. Our study showed the female parent of the Takifugu pufferfish vertically transfers TTX to the larvae through its accumulation in the ovaries, and subsequent localization on the body surface of the larvae

Plasma Sex Steroid Levels and Steroidogenesis in the Gonad of the Self-fertilizing Fish Rivulus marmoratus

The mangrove killifish, Rivulus marmoratus, is the only known self-fertilizing vertebrate. This species is sexually dimorphic; sexually mature individuals are either hermaphrodite or primary and secondary males. Although the mangrove killifish has a unique reproductive strategy, there has been no study on the reproductive endocrinology of this species. Thus we investigated plasma sex steroid hormone levels and steroidogenesis in the gonads of R. marmoratus by enzyme linked immunosorbent assay (ELISA). Plasma 17β-estradiol (E2) and 11-ketotestosterone (11-KT) were detected both in hermaphrodite and in primary male. Ovarian follicles (follicle-enclosed oocytes) from hermaphrodites, which were categorized into early yolk stage and late yolk stage, and testis tissue of primary males were cultured with different concentrations of 17α-hydroxyprogesterone (OHP) or testosterone (T) for 24 h. Production of T, E2, 11-KT and 17α-20 β-dihydroxy-4-pregnen-3-one (17α,20β-P) in the medium from tissue culture were measured by ELISA. Early and late ovarian follicles of hermaphrodites and testis pieces of primary males synchronously secreted E2, 11-KT, and 17α,20β-P following incubation with OHP or T. We conclude that both hermaphrodite and primary male of the mangrove killifish secrete estrogen, androgen, and progestin synchronously

Plasma Steroid Hormone Profiles during HCG Induced Ovulation in Female Walking Catfish Clarias batrachus(Endocrinology)

Volume: 9Start Page: 607End Page: 61

Plasma Steroid Hormone Profiles in HCG-Injected Male Walking Catfish Clarias batrachus

Volume: 10Start Page: 329End Page: 33

Biosynthesis of 17α,20α-dihydroxy-4-pregnen-3-one from 17α-hydroxyprogesterone by Goldfish (Carassius auratus) Spermatozoa

Volume: 10Start Page: 381End Page: 38

Efficacy of perampanel for controlling seizures and improving neurological dysfunction in a patient with dentatorubral-pallidoluysian atrophy (DRPLA)

We administered perampanel (PER) to a bedridden 13-year-old male patient with dentatorubral-pallidoluysian atrophy (DRPLA). The DRPLA diagnosis was based on the presence of a CAG trinucleotide repeat in the ATN1 gene. The patient experienced continuous myoclonic seizures and weekly generalized tonic-clonic seizures (GTCs). PER stopped the patient's myoclonic seizures and reduced the GTCs to fragmented clonic seizures. The patient recovered his intellectual abilities and began to walk again with assistance. We suggest that PER be considered as one of the key drugs used to treat patients with DRPLA

Long-term follow up of AHC

Alternating hemiplegia of childhood (AHC) is a rare neurological disease mainly caused by mutations in the ATP1A3 gene and showing varied clinical severity according to genotype. Patients with a p.Gly755Ser (p.G755S) mutation, one of minor genotypes for AHC, were recently described as having a mild phenotype, although their long-term outcomes are still unclear due to the lack of long-term follow up. Here, we demonstrate the full clinical course of a 43-year-old female AHC patient with p.G755S mutation. Although her motor dysfunction had been relatively mild into her 30 s, she showed a subsequent severe aggravation of symptoms that left her bedridden, concomitant with a recent recurrence of seizure status. The seizures were refractory to anti-epileptic drugs, but administration of flunarizine improved seizures and the paralysis. Our case suggests that the phenotype of AHC with p.G755S mutation is not necessarily mild, despite such a presentation during the patient's younger years