Urinary Amino Acid Alterations in 3-Year-Old Children with Neurodevelopmental Effects due to Perinatal Dioxin Exposure in Vietnam: A Nested Case-Control Study for Neurobiomarker Discovery

In our previous study of 3-year-old children in a dioxin contamination hot spot in Vietnam, the high total dioxin toxic equivalent (TEQ-PCDDs/Fs)-exposed group during the perinatal period displayed lower Bayley III neurodevelopmental scores, whereas the high 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-exposed group displayed increased autistic traits. In autistic children, urinary amino acid profiles have revealed metabolic alterations in the amino acids that serve as neurotransmitters in the developing brain. Therefore, our present study aimed to investigate the use of alterations in urinary amino acid excretion as biomarkers of dioxin exposure-induced neurodevelopmental deficits in highly exposed 3-year-old children in Vietnam. A nested case-control study of urinary analyses was performed for 26 children who were selected from 111 3-year-old children whose perinatal dioxin exposure levels and neurodevelopmental status were examined in follow-up surveys conducted in a dioxin contaminated hot spot. We compared urinary amino acid levels between the following 4 groups: (1) a high TEQ-PCDDs/Fs and high TCDD-exposed group; (2) a high TEQ-PCDDs/Fs but low TCDD-exposed group; (3) a low TEQ-PCDDs/Fs exposed and poorly developed group; and (4) a low TEQ-PCDDs/Fs exposed and well-developed group. Urinary levels of histidine and tryptophan were significantly decreased in the high TEQ-PCDDs/Fs and high TCDD group, as well as in the high TEQ-PCDDs/Fs but low TCDD group, compared with the low TEQ-PCDDs/Fs and well-developed group. However, the ratio of histidine to glycine was significantly lower only in the high TEQ-PCDDs/Fs and high TCDD group. Furthermore, urinary histidine levels and the ratio of histidine to glycine were significantly correlated with neurodevelopmental scores, particularly for language and fine motor skills. These results indicate that urinary histidine is specifically associated with dioxin exposure-induced neurodevelopmental deficits, suggesting that urinary histidine may be a useful marker of dioxin-induced neurodevelopmental deficits and that histaminergic neurotransmission may be an important pathological contributor to dioxin-mediated neurotoxicity.     

The helicase activity associated with hepatitis C virus nonstructural protein 3 (NS3).

To assess the RNA helicase activity of hepatitis C virus (HCV) nonstructural protein 3 (NS3), a polypeptide encompassing amino acids 1175 to 1657, which cover only the putative helicase domain, was expressed in Escherichia coli by a pET expression vector. The protein was purified to near homogeneity and assayed for RNA helicase activity in vitro with double-stranded RNA substrates prepared from a multiple cloning sequence and an HCV 5' nontranslated region (5'-NTR) or 3'-NTR. The enzyme acted successfully on substrates containing both 5' and 3' single-stranded regions (standard) or on substrates containing only the 3' single-stranded regions (3'/3') but failed to act on substrates containing only the 5' single-stranded regions (5'/5') or on substrates lacking the single-stranded regions (blunt). These results thus suggest 3' to 5' directionality for HCV RNA helicase activity. However, a 5'/5' substrate derived from the HCV 5'-NTR was also partially unwound by the enzyme, possibly because of unique properties inherent in the 5' single-stranded regions. Gel mobility shift analyses demonstrated that the HCV NS3 helicase could bind to either 5'- or 3'-tailed substrates but not to substrates lacking a single-stranded region, indicating that the polarity of the RNA strand to which the helicase bound was a more important enzymatic activity determinant. In addition to double-stranded RNA substrates, HCV NS3 helicase activity could displace both RNA and DNA oligonucleotides on a DNA template, suggesting that HCV NS3 too was disposed to DNA helicase activity. This study also demonstrated that RNA helicase activity was dramatically inhibited by the single-stranded polynucleotides. Taken altogether, our results indicate that the HCV NS3 helicase is unique among the RNA helicases characterized so far.     

Identification of urine metabolites of TFAP,a cyclooxygenase-1 inhibitor

Only a few COX-1-selective inhibitors are currently available, and the research on COX-1 selective inhibitors is not fully developed. The authors have produced several COX-1 selective inhibitors including N-(5-amino-2-pyridinyl)-4-trifluoromethylbenzamide: TFAP (3). Although 3 shows potent analgesic effect without gastric damage, the urine after administration of 3 becomes red–purple. Since the colored-urine should be avoided for clinical use, in this research we examined the cause of the colored-urine. UV–vis spectra and LC–MS/MS analyses of urine samples and metabolite candidates of 3 were performed to afford information that the main reason of the colored urine is a diaminopyridine (4), produced by metabolization of 3. This information is useful to design new COX-1 selective inhibitors without colored urine based on the chemical structure of 3.     

Structure-based virtual screening of novel tubulin inhibitors and their characterization as anti-mitotic agents

Microtubule cytoskeletons are involved in many essential functions throughout the life cycle of cells, including transport of materials into cells, cell movement, and proper progression of cell division. Small compounds that can bind at the colchicine site of tubulin have drawn great attention because these agents can suppress or inhibit microtubule dynamics and tubulin polymerization. To find novel tubulin polymerization inhibitors as anti-mitotic agents, we performed a virtual screening study of the colchicine binding site on tubulin. Novel tubulin inhibitors were identified and characterized by their inhibitory activities on tubulin polymerization in vitro. The structural basis for the interaction of novel inhibitors with tubulin was investigated by molecular modeling, and we have proposed binding models for these hit compounds with tubulin. The proposed docking models were very similar to the binding pattern of colchicine or podophyllotoxin with tubulin. These new hit compound derivatives exerted growth inhibitory effects on the HL60 cell lines tested and exhibited strong cell cycle arrest at G2/M phase. Furthermore, these compounds induced apoptosis after cell cycle arrest. In this study, we show that the validated derivatives of compound 11 could serve as potent lead compounds for designing novel anti-cancer agents that target microtubules.     

Length-weight relationships of four fish species from the Hei River in northwest China

Length-weight relationships (LWRs) were assessed from four fish species in Hei River in northwest China. All specimens were collected using (fishing1 km along the river and 3 meters along the river bank) and netting (gill nets, nets: 30 × 1.2 m; mesh size: 3 × 3 cm) and shrimp cages (nets: 20.0 × 0.5 × 0.4m; mesh size: 0.5 cm) seasonally from April 2019 to October 2020. The gill nets and shrimp cages were soaked in water in the afternoon and pulled in around 10 a.m. the next day after an overnight stay. These specimens were measured for total length (L, 0.1 cm) and body weight (W, 0.1 g) while the specimens were fresh. The parameters for the LWRs were estimated with the basic statistical analyses. The study provided the new maximum total length for Gymnocypris chilianensis (21.0 cm) and Triplophysa tenuis (17.0 cm).     

New Continuous Air Pumping Technique to Improve Clinical Outcomes of Descemet-Stripping Automated Endothelial Keratoplasty in Asian Patients with Previous Ahmed Glaucoma Valve Implantation

Background

To evaluate the outcomes of Descemet-stripping automated endothelial keratoplasty (DSAEK) with the use of continuous air pumping technique in Asian eyes with previous Ahmed glaucoma valve implantation.

Methods

The DSAEK procedure was modified in that complete air retention of the anterior chamber was maintained for 10 min using continuous air pumping at 30 mm Hg. The primary outcome measurement was graft survival, and postoperative clinical features including, rate of graft detachment, endothelial cell count, intraocular pressure (IOP), surgical time and cup/disc ratio were also recorded.

Results

A total of 13 eyes of 13 patients which underwent modified DSAEK and 6 eyes of 6 patients which underwent conventional DSAEK were included. There was a significant difference in graft survival curves between two groups (P = 0.029); the 1-year graft survival rates were estimated as 100% and 66.7% for patients with modified DSAEK and those with traditional DSAEK, respectively. The rate of graft detachment were 0% and 33.3% for the modified DSAEK and conventional DSAEK groups, respectively (P = 0.088). The significantly lowered surgical time for air tamponade was noted in the modified DSAEK group compared to that in the conventional DSAEK group [median (IQR): 10.0 (10.0, 10.0) min vs. 24.5 (22.0, 27.0) min; P<0.001] Postoperatively, patients in the modified DSAEK group had significantly lower IOP as compared to the conventional DSAEK group [12.0 (11.0, 15.0) mm Hg vs. 16.0 (15.0, 18.0) mm Hg; P = 0.047]. Modified DSAEK patients had higher endothelial cell counts as compared to conventional DSAEK patients [2148.0 (1964.0, 2218.0) vs. 1529.0 (713.0, 2014.0)], but the difference did not reach statistical significance (P = 0.072).

Conclusions

New continuous air pumping technique in DSAEK can be performed safely and effectively in patients with prior GDDs placement who have corneal failure.     

Comparative secretome analysis of human bone marrow‐derived mesenchymal stem cells during osteogenesis

Osteogenesis is a tightly regulated process that involves coordinated extracellular signals from autocrine and paracrine loops. Secretory proteins during osteogenesis can inhibit cell proliferation and activate cell differentiation toward mature osteoblasts, which are characterized by mineralization. In this study, we attempted to identify these secretory proteins during osteogenesis using LC–MS/MS analysis. We compared the secretome between undifferentiated human bone marrow‐derived mesenchymal stem cells (hBMSCs) and differentiated osteoblasts. Among 315 proteins that were identified, 177 proteins were present at increased levels in osteoblasts, whereas 88 proteins were present at decreased levels. Among the identified proteins, several were validated by quantitative RT‐PCR and immunoblot analysis. Of particular interest, calcium homeostasis‐related proteins were upregulated, whereas stem cell proliferation‐related proteins and other lineage‐related proteins were downregulated during osteogenesis. These findings provide information about the dynamic changes in the expression and secretion of proteins during osteogenesis and suggest the putative role of secretory proteins in osteogenesis. J. Cell. Physiol. 228: 216–224, 2013. © 2012 Wiley Periodicals, Inc.     

Daily activities and sleep quality in college students

There is growing evidence that social rhythms (e.g., daily activities such as getting into or out of bed, eating, and adhering to a work schedule) have important implications for sleep. The present study used a prospective measure of daily activities to assess the relation between sleep and social rhythms. College students (n=243) 18 to 39 yrs of age, completed the Social Rhythm Metric (SRM) each day for 14 d and then completed the Pittsburgh Sleep Quality Index (PSQI). The sample was divided into groups of good or poor sleepers, according to a PSQI cut‐off score of 5 points and was compared on the regularity, frequency, timing, and extent of social engagement during activities. There was a lower frequency and less regularity of social rhythms in poor sleepers relative to good sleepers. Good sleepers engaged more regularly in activities with active social engagement. Earlier rise time, first consumption of a beverage, going outdoors for the first time, and bedtime were associated with better sleep. Greater variability in rise time, consuming a morning beverage, returning home for the last time, and bedtime were associated with more disturbed sleep. The results are consistent with previous findings of reduced regularity in bedtime and rise time schedules in undergraduates, other age groups, and in clinical populations. Results augment the current thought that regulating behavioral zeitgebers may be important in influencing bed and rise times, and suggest that engaging in activities with other people may increase regularity.