Lake-wide assessment of microplastics in the surface waters of Lake Baikal,Siberia

Limnology - Small microplastic particles < 330 µm, sometimes called mini-microplastics (MMP), are far more abundant than those larger than 330 µm....     

Axenic culture of <Emphasis Type="Italic">Brachionus plicatilis</Emphasis> using antibiotics

The rotifer Brachionus plicatilis culture is composed of complex microcosms including bacteria, protozoans, algae, and fungi. Previous studies reported methods to establish axenic rotifer cultures, but further refinement of these techniques is needed, for molecular biological research which requires pure culture to isolate nucleic acids from rotifers only. In order to render rotifer culture axenic, we tested five antibiotics: ampicillin (Amp), chloramphenicol (Cp), kanamycin (Km), nalidixic acid (Na), and streptomycin (Sm) at 30–100 μg/ml. Except for Cp, which reduces rotifer reproduction, all other antibiotics at the tested concentrations did not affect rotifer reproduction or show any toxic effects. A rotifer disinfection method was finally established by treating the resting eggs with 0.25% (w/v) sodium hypochlorite (NaOCl) for 3 min, washing with sterilized sea water, and then exposing the neonates to an Amp, Km, Na, and Sm mixture. Using four nutrient media, we confirmed that this protocol renders the rotifer culture bacterial and fungus free. The axenic rotifer culture generated here is useful not only for genetic analysis of Brachionus plicatilis, but for studying the rotifer life cycle without bacterial influence.     

Ethical Obligations in the Face of Dilemmas Concerning Patient Privacy and Public Interests: The Sasebo Schoolgirl Murder Case

A murder case that had some features in common with the Tarasoff case occurred in Sasebo City, Japan, in 2014. A 15‐year‐old high school girl was murdered and her 16‐year‐old classmate was arrested on suspicion of homicide. One and a half months before the murder, a psychiatrist who had been examining the girl called a prefectural child consultation centre to warn that she might commit murder, but he did not reveal her name, considering it his professional duty to keep it confidential. Article 134 of the Japanese Criminal Law states that doctors should not disclose patient information obtained in clinical practice without a legitimate reason, but the Japanese Supreme Court has not specified what constitutes a legitimate reason. Mass media and commentators suggested that the murder could have been prevented if the psychiatrist had disclosed the girl's name to the authorities or had isolated her coercively in a psychiatric ward. However, the authors disagree with such claims. This article discusses obligations imposed on concerned individuals and third party members in cases involving ethical dilemmas regarding patient confidentiality and information disclosure. It is concluded that everyone should fulfill their obligations to prevent such tragedies and one should judge the appropriateness of others’ actions based not on the consequences of their actions, but on the processes used to decide on a course of action and their commitment. It is necessary for us to establish a society in which concerned parties can do what they think is ethically best without fearing ungrounded charges.     

Analysis of genes induced in peripheral nerve after axotomy using cDNA microarrays

One of the most striking features of neurons in the mature peripheral nervous system is their ability to survive and to regenerate their axons following axonal injury. To perform a comprehensive survey of the molecular mechanisms that underlie peripheral nerve regeneration, we analyzed a cDNA library derived from the distal stumps of post-injured sciatic nerve which was enriched in non-myelinating Schwann cells using cDNA microarrays. The number of up- and down-regulated genes in the transected sciatic nerve was 370 and 157, respectively, of the 9596 spotted genes. In the up-regulated group, the number of known genes was 216 and the number of expressed sequence tag (EST) sequences was 154. In the down-regulated group, the number of known genes was 103 and that of EST sequences was 54. We obtained several genes that were previously reported to be involved in regeneration of the injured neurons, such as cathepsin D, ninjurin 1, tenascin C, and co-receptor for glial cell line-derived neurotrophic factor family of trophic factors. In addition to unknown genes, there seemed to be a lot of annotated genes whose role in nerve regeneration remains unknown.