Engineered biosynthesis of milbemycins in the avermectin high-producing strain Streptomyces avermitilis

Additional file 3 : Figure S2. HPLC analysis of milbemycins produced from S. avermitilis mutant strains and authentic standard milbemycins

Chemoenzymatic Synthesis of Glycosylated Macrolactam Analogues of the Macrolide Antibiotic YC‐17

YC‐17 is a 12‐membered ring macrolide antibiotic produced from Streptomyces venezuelae ATCC 15439 and is composed of the polyketide macrolactone 10‐deoxymethynolide appended with D‐desosamine. In order to develop structurally diverse macrolactam analogues of YC‐17 with improved therapeutic potential, a combined approach involving chemical synthesis and engineered cell‐based biotransformation was employed. Eight new antibacterial macrolactam analogues of YC‐17 were generated by supplying a novel chemically synthesized macrolactam aglycone to S. venezuelae mutants harboring plasmids capable of synthesizing several unnatural sugars for subsequent glycosylation. Some YC‐17 macrolactam analogues were active against erythromycin‐resistant bacterial pathogens and displayed improved metabolic stability in vitro. The enhanced therapeutic potential demonstrated by these glycosylated macrolactam analogues reveals the unique potential of chemoenzymatic synthesis in antibiotic drug discovery and development.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113147/1/adsc_201500250_sm_miscellaneous_information.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/113147/2/2697_ftp.pd

The Value of Measuring Eustachian Tube Aeration on Temporal Bone CT in Patients with Chronic Otitis Media

ObjectivesTo evaluate that the cross-sectional area of the air space in the Eustachian tube (ET) on computed tomography (CT) images could be useful for predicting the postoperative aeration of the middle ear.MethodsThe patient group consisted of 80 patients (80 ears) with chronic otitis media and who underwent middle ear surgery from 2006-2007 and who were followed up for more than 1 yr. The control group consisted of 100 ears of 50 individuals with normal tympanic membranes and who underwent CT for other causes (such as tinnitus or hearing loss). The largest cross-sectional areas of the aerated ET were measured on the coronal images of the temporal bone CT by a single otologist using the computer-based "Region of Interest" picture archiving and communications system. The patient group was divided into two subgroups, 1) those with good postoperative aeration and 2) those with poor postoperative aeration. The largest cross-sectional areas of the aerated ETs were compared between the patients and the controls, and between the patients with good aeration and the patients with poor aeration.ResultsThe mean cross-sectional areas significantly differed between the patient group and the control group, and between the good and poor aeration subgroups (P<0.05 each). The mean area of the poor aeration subgroup was smaller than that of the control group (P<0.05), but the mean area of the good aeration subgroup did not significantly differ from that of the controls.ConclusionThe cross-sectional area of the aerated ET, as measured on the preoperative coronal images of temporal bone CT scans, may be useful for predicting the postoperative condition of the tympanic cavity

Whole-genome sequencing and analysis of Streptomyces strains producing multiple antinematode drugs

Background : Nematodes are parasitic animals that cause over 100 billion US dollars loss in agricultural business. The whole-genomes of two Streptomyces strains, Streptomyces spectabilis KCTC9218T and Streptomyces sp. AN091965, were sequenced. Both strains produce spectinabilin, an antinematode drug. Its secondary metabolism was examined to aid the development of an efficient nematicidal drug-producing host strain. Results : The whole-genome sequences of S. spectabilis KCTC9218T and Streptomyces sp. AN091965 were analyzed using PacBio and Illumina sequencing platforms, and assembled using hybrid methodology. The total contig lengths for KCTC9218T and AN091965 were 9.97 Mb and 9.84 Mb, respectively. A total of 8,374 and 8,054 protein-coding genes, as well as 39 and 45 secondary metabolite biosynthetic gene clusters were identified in KCTC9218T and AN091965, respectively. 18.4 ± 6.45 mg/L and 213.89 ± 21.30 mg/L of spectinabilin were produced by S. spectabilis KCTC9218T and Streptomyces sp. AN091965, respectively. Pine wilt disease caused by nematode was successfully prevented by lower concentration of spectinabilin injection than that of abamectin recommended by its manufacturer. Production of multiple antinematode drugs, including spectinabilin, streptorubin B, and undecylprodigiosin was observed in both strains using high-resolution liquid chromatography mass spectrometry (LC–MS) analysis. Conclusions : Whole-genome sequencing of spectinabilin-producing strains, coupled with bioinformatics and mass spectrometry analyses, revealed the production of multiple nematicidal drugs in the KCTC9218T and AN091965 strains. Especially, Streptomyces sp. AN091965 showed high production level of spectinabilin, and this study provides crucial information for the development of potential nematicidal drug producers.This work was supported by Korea Institute of Planning and Evaluation for Technology in Food, Agriculture and Forestry (IPET) through“Crop Viruses and Pests Response Industry Technology Development” Program (No.321110–4) funded by Ministry of Agriculture, Food and Rural Afairs (MAFRA), National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (No.2022R1A2C3004621) and the Ministry of Education (2022R1I1A1A01068507), and the Bio & Medical Technology Development Program of the National Research Foundation (NRF) funded by the Korean government (MSIT) (No. 2020M3H1A1073304)

A test of the submentalizing hypothesis : apes' performance in a false belief task inanimate control

Financial support came from Ministry of Education, Culture, Sports, Science and Technology (K-CONNEX to FK), Japan Society for Promotion of Science (KAKENHI 26885040, 16K21108 to FK), JSPS (KAKENHI 26245069, 24000001 to SH), and European Research Council (Synergy grant 609819 SOMICS to JC).Much debate concerns whether any nonhuman animals share with humans the ability to infer others' mental states, such as desires and beliefs. In a recent eye-tracking false-belief task, we showed that great apes correctly anticipated that a human actor would search for a goal object where he had last seen it, even though the apes themselves knew that it was no longer there. In response, Heyes proposed that apes' looking behavior was guided not by social cognitive mechanisms but rather domain-general cueing effects, and suggested the use of inanimate controls to test this alternative submentalizing hypothesis. In the present study, we implemented the suggested inanimate control of our previous false-belief task. Apes attended well to key events but showed markedly fewer anticipatory looks and no significant tendency to look to the correct location. We thus found no evidence that submentalizing was responsible for apes' anticipatory looks in our false-belief task.Publisher PDFPeer reviewe

The Clinical Outcome of FLAG Chemotherapy without Idarubicin in Patients with Relapsed or Refractory Acute Myeloid Leukemia

A refractory and resistant disease to conventional induction chemotherapy and relapsed disease are considered as the most important adverse prognostic factors for acute myeloid leukemia (AML). Sixty-one patients (median age, 33.6 yr) with relapsed or refractory AML were treated with the FLAG regimen that consisted of fludarabine (30 mg/m2, days 1-5), cytarabine (2.0 g/m2, days 1-5) and granulocyte colony-stimulating factor. Of the treated patients 29 patients (47.5%) achieved complete remission (CR). Higher CR rates were observed for patients with a first or second relapse as compared to patients with a primary refractory response or relapse after stem cell transplantation (HSCT). There was a significant difference in the response rates according to the duration of leukemia-free survival (pre-LFS) before chemotherapy (P=0.05). The recovery time of both neutrophils (≥500/µL) and platelets (≥20,000/µL) required a median of 21 and 18 days, respectively. Treatment-related mortality (TRM) occurred in seven patients (11.4%), of which 71.4% of TRM was caused by an invasive aspergillosis infection. After achieving CR, 18 patients underwent consolidation chemotherapy and six patients underwent allogeneic HSCT. In conclusion, FLAG chemotherapy without idarubicin is a relatively effective and well-tolerated regimen for relapsed or refractory AML and the use of FLAG chemotherapy has allowed intensive post-remission therapy including HSCT

SEALONE (Safety and Efficacy of Coronary Computed Tomography Angiography with Low Dose in Patients Visiting Emergency Room) trial: study protocol for a randomized controlled trial

Objective Chest pain is one of the most common complaints in the emergency department (ED). Cardiac computed tomography angiography (CCTA) is a frequently used tool for the early triage of patients with low- to intermediate-risk acute chest pain. We present a study protocol for a multicenter prospective randomized controlled clinical trial testing the hypothesis that a low-dose CCTA protocol using prospective electrocardiogram (ECG)-triggering and limited-scan range can provide sufficient diagnostic safety for early triage of patients with acute chest pain. Methods The trial will include 681 younger adult (aged 20 to 55) patients visiting EDs of three academic hospitals for acute chest pain or equivalent symptoms who require further evaluation to rule out acute coronary syndrome. Participants will be randomly allocated to either low-dose or conventional CCTA protocol at a 2:1 ratio. The low-dose group will undergo CCTA with prospective ECG-triggering and restricted scan range from sub-carina to heart base. The conventional protocol group will undergo CCTA with retrospective ECG-gating covering the entire chest. Patient disposition is determined based on computed tomography findings and clinical progression and all patients are followed for a month. The primary objective is to prove that the chance of experiencing any hard event within 30 days after a negative low-dose CCTA is less than 1%. The secondary objectives are comparisons of the amount of radiation exposure, ED length of stay and overall cost. Results and Conclusion Our low-dose protocol is readily applicable to current multi-detector computed tomography devices. If this study proves its safety and efficacy, dose-reduction without purchasing of expensive newer devices would be possible