A taxonomy of risk-associated alternative health practices: A Delphi study.

Defining alternative health care and the recording of associated adverse events and harm remains problematic. This Canadian study aimed to establish and classify risk-associated alternative health practices in a Delphi study undertaken with an interdisciplinary panel of 17 health experts in 2020. It provides a new functional definition of alternative health care and an initial taxonomy of risk-associated alternative health care practices. A number of risk-associated practices were identified and categorized into general practices that conflict with biomedical care or largely untested therapies, alternative beliefs systems, physical manipulative alternative therapies, and herbal and nutritional supplements. Some risk significant harms including major physical injuries or even death. The lack of systematic methods for recording adverse events in alternative health care makes establishing the frequency of such events challenging. However, it is important that people engaging with alternative health care understand they are not necessarily risk-free endeavours, and what those risks are.

Ltrk is differentially expressed in developing and adult neurons of the Lymnaea central nervous system.

The Trk receptor family plays diverse roles in both development and plasticity of the vertebrate nervous system. Ltrk is a related receptor that is expressed in the CNS of the mollusk Lymnaea, although little is known of its cellular distribution. This study provides three independent lines of evidence (based on RT-PCR, in situ hybridization, and immunohistochemistry) that Ltrk is universally expressed by neurons and dorsal body cells of both the juvenile and the adult Lymnaea CNS. The highest level of expression by neuronal somata occurs in the late juvenile stage, whereas axon collaterals express high levels throughout the animal's life span. Our data support multifunctional roles for Ltrk that parallel those of its mammalian counterparts.

ApTrkl, a Trk-like receptor, mediates serotonin- dependent ERK activation and long-term facilitation in Aplysia sensory neurons.

The Trk family of receptor tyrosine kinases plays a role in synaptic plasticity and in behavioral memory in mammals. Here, we report the discovery of a Trk-like receptor, ApTrkl, in Aplysia. We show that it is expressed in the sensory neurons, the locus for synaptic facilitation, which is a cellular model for memory formation. Serotonin, the facilitatory neurotransmitter, activates ApTrkl, which, in turn, leads to activation of ERK. Finally, inhibiting the activation of ApTrkl with the Trk inhibitor K252a or using dsRNA to inhibit ApTrkl blocks the serotonin-mediated activation of ERK in the cell body, as well as the cell-wide long-term facilitation induced by 5-HT application to the cell body. Thus, transactivation of the receptor tyrosine kinase ApTrkl by serotonin is an essential step in the biochemical events leading to long-term facilitation in Aplysia.

Characterization of a novel molluskan tyrosine kinase receptor that inhibits neurite regeneration.

Receptor tyrosine kinases play many important roles in neuronal signaling including regulating neurite outgrowth. We have identified a novel receptor tyrosine kinase, neurite outgrowth regulating kinase (nork) from Aplysia californica. A fragment of this kinase was also identified in another mollusk, Lymnaea. The kinase domain is equally homologous to the Ret (rearranged during transformation) and fibroblast growth factor receptor families, but the extracellular domain is entirely novel, suggesting that it binds a nonconserved ligand. Overexpression of neurite outgrowth regulating kinase, but not a kinase dead form, causes a reduction in neurite outgrowth of Aplysia sensory neurons. Thus, we have identified a novel receptor tyrosine kinase implicated in regulating neurite outgrowth.