Determination of Clopidol Residues in Chicken Tissues by Liquid Chromatography: Collaborative Study

Eighteen laboratories participated in a collaborative study on the determination of clopidol residues in chicken muscle tissues by liquid chromatography. Of these, results from 16 laboratories which rigorously followed the method were subjected to statistical analysis. The method performance was assessed by all participants using 14 samples of chicken muscle fortified at concentrations ranging from 0.1 to 5.0 mg/kg. In addition, 9 participants each reported results for 6 clopidol-incurred samples in chicken muscle. Test portions were extracted with acetonitrile, and the extracts were purified with alumina and anion exchange resin solid-phase extraction cartridges in sequence. Clopidol was separated by reversed-phase liquid chromatography and quantified at 270 nm. Average recoveries ranged from 81.8 to 85.4%, reproducibility relative standard deviation (RSDR) ranged from 11.9 to 22.6%, and repeatability relative standard deviation (RSDr) ranged from 9.9 to 15.1%. For clopidol-incurred samples at concentrations of 0.100–0.687 mg/kg, the mean determination value range was 0.099–0.659 mg/kg; RSDR was 12.6–19.8%, RSDr was 3.1–8.5%; and HORRAT values were 0.7–1.1. The accuracy and precision of the method are in conformity with the requirements specified by AOAC INTERNATIONAL. The method was adopted Official First Action in April 2003.

Arbuscular mycorrhizal fungus alleviates alfalfa leaf spots caused by Phoma medicaginis revealed by RNA-seq analysis

AIMS

One of the major limitations to the production of alfalfa (Medicago sativa) is the fungus Phoma medicaginis, which infects alfalfa and causes leaf spots. This study aims to understand alfalfa's response to P. medicaginis infection, the colonization of arbuscular mycorrhizal fungus (AMF) and the effect of AMF on plant-pathogen interactions.

METHODS AND RESULTS

Transcriptome analysis (RNA-seq) was used to identify differentially expressed genes (DEGs) in alfalfa infected by P. medicaginis and colonized by AMF Rhizophagus intraradices. AMF ameliorated the effects of P. medicaginis infection on alfalfa by reducing leaf spot incidence and disease index by 39·48 and 56·18% respectively. Inoculation with pathogen and AMF induced the activity of defence pathways, including peroxidase (POD), polyphenol oxidase activities and jasmonic acid (JA), salicylic acid concentration. Plants showed differential expression of P. medicaginis resistance-related genes, including genes belonging to pathogenesis-related (PR) proteins, chitinase activity, flavonoid biosynthesis, phenylpropanoid biosynthesis, glutathione metabolism, phenylalanine metabolism and photosynthesis. Inoculation with AMF led to changes in the expression of genes involved in PR proteins, chitinase activity, phenylalanine metabolism and photosynthesis.

CONCLUSION

The physiological and transcriptional changes caused by P. medicaginis infection in non-mycorrhizal and mycorrhizal alfalfa provides crucial information for understanding AMF's association with pathogenic systems.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study showed that AMF alleviated alfalfa leaf spots demonstrating that AMF can serve as a biocontrol strategy for alfalfa disease management.

The autophagy-related gene Atg101 in Drosophila regulates both neuron and midgut homeostasis

Atg101 is an autophagy-related gene identified in worms, flies, mice, and mammals, which encodes a protein that functions in autophagosome formation by associating with the ULK1-Atg13-Fip200 complex. In the last few years, the critical role of Atg101 in autophagy has been well-established through biochemical studies and the determination of its protein structure. However, Atg101's physiological role, both during development and in adulthood, remains less understood. Here, we describe the generation and characterization of an Atg101 loss-of-function mutant in Drosophila and report on the roles of Atg101 in maintaining tissue homeostasis in both adult brains and midguts. We observed that homozygous or hemizygous Atg101 mutants were semi-lethal, with only some of them surviving into adulthood. Both developmental and starvation-induced autophagy processes were defective in the Atg101 mutant animals, and Atg101 mutant adult flies had a significantly shorter lifespan and displayed a mobility defect. Moreover, we observed the accumulation of ubiquitin-positive aggregates in Atg101 mutant brains, indicating a neuronal defect. Interestingly, Atg101 mutant adult midguts were shorter and thicker and exhibited abnormal morphology with enlarged enterocytes. Detailed analysis also revealed that the differentiation from intestinal stem cells to enterocytes was impaired in these midguts. Cell type-specific rescue experiments disclosed that Atg101 had a function in enterocytes and limited their growth. In summary, the results of our study indicate that Drosophila Atg101 is essential for tissue homeostasis in both adult brains and midguts. We propose that Atg101 may have a role in age-related processes.

A positive role of Sin3A in regulating Notch signaling during Drosophila wing development

Notch is a transmembrane receptor that mediates intercellular signaling through a conserved signaling cascade in all animal species. Transcriptional and posttranscriptional regulation of Notch receptor are important for maintaining Notch signaling activity. Here, we show that depletion of Drosophila Sin3A leads to loss of the adult wing margin and downregulation of Notch target gene expression in the developing wing disc. Sin3A regulates the Notch pathway downstream of Delta and upstream of Notch activation. The role of Sin3A in the Notch pathway is partly mediated by its ability to modulate Notch receptor transcription. Furthermore, the transcriptional activation of Notch receptor is autoregulated by Notch itself. We also provide evidence that Sin3A is required for Notch activation mediated Notch transcription. Together, our data demonstrate that Sin3A activates Notch signaling by promoting Notch transcription and reveal a previously unknown autoregulatory mechanism for Notch signaling activation during Drosophila wing development.

The histone deacetylase HDAC1 positively regulates Notch signaling during Drosophila wing development

The Notch signaling pathway is highly conserved across different animal species and plays crucial roles in development and physiology. Regulation of Notch signaling occurs at multiple levels in different tissues and cell types. Here, we show that the histone deacetylase HDAC1 acts as a positive regulator of Notch signaling during Drosophila wing development. Depletion of HDAC1 causes wing notches on the margin of adult wing. Consistently, the expression of Notch target genes is reduced in the absence of HDAC1 during wing margin formation. We further provide evidence that HDAC1 acts upstream of Notch activation. Mechanistically, we show that HDAC1 regulates Notch protein levels by promoting Notch transcription. Consistent with this, the HDAC1-associated transcriptional co-repressor Atrophin (Atro) is also required for transcriptional activation of Notch in the wing disc. In summary, our results demonstrate that HDAC1 positively regulates Notch signaling and reveal a previously unidentified function of HDAC1 in Notch signaling.

Increased longevity and metabolic correction following syngeneic BMT in a murine model of mucopolysaccharidosis type I

Mucopolysaccharidosis type I (MPS I) is an autosomal recessive inherited disease caused by deficiency of the glycosidase α-L-iduronidase (IDUA). Deficiency of IDUA leads to lysosomal accumulation of the glycosaminoglycans (GAG) heparan and dermatan sulfate and associated multi-systemic disease, the most severe form known as Hurler syndrome. Since 1981, the treatment of Hurler patients has often included allogeneic bone marrow transplantation (BMT) from a matched donor. However, mouse models of the disease were not developed until 1997. To further characterize the MPS I mouse model and to study the effectiveness of BMT in these animals, we engrafted a cohort (n=33) of 4–8 week-old Idua^−/− animals with high levels (88.4 ± 10.3%) of wild-type donor marrow. Engrafted animals displayed an increased lifespan, preserved cardiac function, partially restored IDUA activity in peripheral organs, and decreased GAG accumulation in both peripheral organs and in the brain. However, levels of GAG and GM3 ganglioside in the brain remained elevated in comparison to unaffected animals. Since these results are similar to those observed in Hurler patients following BMT, this murine transplantation model can be used to evaluate the effects of novel, more effective methods of delivering IDUA to the brain as an adjunct to BMT.

The effects of classic antipsychotic haloperidol plus the extract of ginkgo biloba on superoxide dismutase in patients with chronic refractory schizophrenia

OBJECTIVES

To explore the association between schizophrenic symptoms and superoxide dismutase (SOD), and to investigate the effect of classic antipsychotic haloperidol plus the extract of Ginkgo biloba (EGb) on SOD.

METHODS

In 54 patients with chronic refractory schizophrenia, 27 were treated with haloperidol plus EGb (group 1), and the rest received haloperidol plus placebo (group 2). Superoxide dismutase (SOD) levels of these patients were measured before and after treatment and compared with the levels of 25 healthy volunteers. Therapeutic efficacy was equated with a change in clinical rating scores assessed by standardized measurement tools including the Scale for Assessment of Positive Symptoms (SAPS) and the Scale for Assessment of Negative Symptoms (SANS).

RESULTS

Patients in group 1 improved significantly as demonstrated by scores from both SAPS and SANS, while those in group 2 only by scores from SANS. Assessed by SAPS, the response of patients receiving haloperidol plus EGb was more significant than those receiving haloperidol only. SOD levels before treatment in all patients were significantly higher than those in normal controls. After treatment, SOD levels decreased significantly in group 1 but not in group 2. In addition, before treatment, SOD levels in all patients correlated significantly with SAPS score. The levels of SOD measured before treatment were also correlated with the improvement of patients as measured by SAPS and SANS after 12 weeks.

CONCLUSIONS

EGb may enhance the efficacy of classic antipsychotic haloperidol on schizophrenia, especially on positive symptoms. It may work through an antioxidant efficacy that is involved in the therapeutic mechanism.

Rapid and selective chelatometric titration of aluminium in non-ferrous alloys

A rapid chelatometric method for the determination of Al (4-20%) in magnesium, copper and chromium-aluminium-iron alloys is proposed. HEDTA is used as titrant and Zn solution as back-titrant, with hydrazidazol as indicator. Mn(II), Cu(II), Cd, Zn, Pb, Co(II), Ni, Hg(II), Fe(III), Bi, Cr(III), Sb(III), Ce(III), La, Sn(IV), Ti(IV), Zr and Mo(VI) do not interfere. High selectivity is achieved by a combination of group separation, masking and interference correction. The coefficient of variation varies from 0.2 to 1%.