Extracellular vesicles released from irradiated neonatal mouse cheek tissue increased cell survival after radiation

Alopecia is one of the common symptoms after high-dose radiation exposure. In our experiments, neonatal mice that received 7 Gy X-ray exhibited defects in overall hair growth, except for their cheeks. This phenomenon might suggest that some substances were secreted and prevented hair follicle loss in the infant tissues around their cheeks after radiation damage. In this study, we focused on exosome-like vesicles (ELV) secreted from cheek skin tissues and back skin tissues, as control, and examined their radiation protective effects on mouse fibroblast cell lines. We observed that ELV from irradiated cheek skin showed protective effects from radiation. Our results suggest that ELV from radiation-exposed cheek skin tissue is one of the secreted factors that prevent hair follicle loss after high-dose radiation.     

Outcomes of adjunctive therapy with intrathecal or intraventricular administration of colistin for post-neurosurgical meningitis and ventriculitis due to carbapenem-resistant acinetobacter baumannii

The efficacy and safety of intrathecal (ITH) or intraventricular (IVT) colistin in addition to intravenous (IV) colistin for meningitis and ventriculitis due to carbapenem-resistant Acinetobacter baumannii (CRAB) is unclear. In this retrospective observational study of 40 patients with post-neurosurgical meningitis and ventriculitis due to CRAB, 33 patients without concomitant infection received appropriate dosage regimens of IV colistin. Of the 33 patients, 17 received additional ITH/IVT colistin and 16 received only IV colistin. The 14-day, 30-day and in-hospital mortality rates were nominally lower for patients who received ITH/IVT colistin adjunctive therapy versus patients who received only IV colistin (24% vs. 38%, 29% vs. 56% and 29% vs. 56%, respectively). The costs of treatment were significantly lower, the lengths of hospital and intensive care unit (ICU) stay were significantly shorter, and the number of ventilator days was significantly less among patients who received ITH/IVT colistin compared with patients who did not receive ITH/IVT colistin. The initial Acute Physiology and Chronic Health Evaluation (APACHE) II and Glasgow Coma Scale (GCS) scores were associated with 30-day mortality with odds ratios (95% confidence intervals) of 1.21 (1.08–1.46) and 0.77 (0.44–0.85), respectively. Chemical meningitis from ITH/IVT colistin was mild and resolved spontaneously. Treatment of post-neurosurgical CRAB meningitis and ventriculitis with ITH/IVT colistin as an adjunct to IV colistin was associated with shorter lengths of hospital and ICU stay and a trend to lower mortality, especially among severely ill patients.     

Susceptibility of colistin-resistant pathogens to predatory bacteria

The increase in multidrug-resistant Gram-negative bacterial infections has forced the reintroduction of antibiotics such as colistin. However, the spread of the plasmid-borne mcr-1 colistin resistance gene have moved us closer to an era of untreatable Gram-negative infections. To evaluate whether predatory bacteria could be used as a potential therapeutic to treat this upcoming threat, the ability of Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus to prey on several clinically relevant mcr-1-positive, colistin-resistant isolates was evaluated. No change in the ability of the predators to prey on free swimming and biofilms of prey cells harboring mcr-1 was measured, as compared to their mcr-1 negative strain.     

Elucidation of demographic,clinical and trichoscopic features for early diagnosis of self-healing acute diffuse and total alopecia

The term “acute diffuse and total alopecia” (ADTA) has been often used as a synonym for self-regressing severe alopecia areata (AA). However, ADTA is originally defined as a rapidly-progressive subtype of AA (RP-AA) with short recovery time and favorable prognosis irrespective of interventions. Indeed, a subpopulation of ADTA recovers spontaneously. We focused on this unique subset of AA, which we coined as “self-healing ADTA” (sADTA). Prompt and accurate differentiation of sADTA from other RP-AA is important to avoid unnecessary treatments, which is still challenging due to the lack of predictive diagnostic hallmarks. In this study, 18 sADTA patients were retrospectively analyzed to delineate their demographics and clinical features, including gentle hair pull test and trichoscopic findings, followed by statistical comparison with those of RP-AA. All sADTA cases were female and the average age was 38.1 ± 15.9 years. The progression of hair loss areas peaked at 3.6 ± 1.5 months, and complete hair regrowth was achieved in 7.9 ± 1.7 months. The identified factors supporting the diagnosis of sADTA included being female; the absence of scalp pain and itch; the absence of extra-scalp hair loss; club hair predominance in hair pull test; predominant short vellus hairs; and increase in vacant follicular ostia on trichoscopy. Subsequently, a scoring system for early diagnosis of sADTA was developed by counting the number of six identified factors present in a tested case. When analyzed by the developed system, all sADTA cases, including an additional four cases, had scores of 4 or above, while all RP-AA cases had scores below 3 except one case. Therefore, the system successfully differentiated sADTA from RP-AA (P < 0.01). Despite some technical limitations, the current study suggested that sADTA is a distinctive entity with unique pathophysiology and that early diagnosis before intervention is feasible based on the characteristics.