Morphological and molecular evidence for a new species of the genus Cosmocercoides Wilkie, 1930 (Ascaridida: Cosmocercidae) from the Asiatic toad Bufo gargarizans Cantor (Amphibia: Anura)

Parasitology Research - A new cosmocercid species, Cosmocercoides qingtianensis sp. n., collected from the intestine of the Asiatic toad Bufo gargarizans Cantor (Amphibia: Anura) is described using...     

鞘内注入醋酸泼尼松龙对大鼠镇痛作用及脊髓c-fos表达的影响

目的 :探讨鞘内注入泼尼松龙镇痛作用及其对脊髓c fos表达的影响与神经毒性作用。方法 :慢性鞘内置管的SD大鼠 2 4只 ,随机分为实验组 2 0只 ,对照组 4只。实验组又分成两个亚组 ,用药组 (EP组 ,n =10 ) ,生理盐水组 (EN组 ,n =10 ) ;对照组分为二个亚组 ,用药组 (CP组 ,n =2 ) ,空白对照组 (CE组 ,n =2 )。EP组经导管鞘内注入泼尼松龙 2mg/kg ,1小时后行福尔马林试验 ,进行行为学评分并计算痛级均数 ;2小时后灌注、固定 ,取脊髓腰膨大用ABC法行c fos免疫组化反应及病理检验 ,记数脊髓背角c fos阳性神经元数 ,并与鞘内注入等量生理盐水组 (EN )相比较。结果 :实验各组痛级均数比较有显著差异 (P <0 .0 5 ) ;脊髓腰膨大背角Ⅰ、Ⅱ层c fos阳性神经元数EP组有减少趋势 ,但无显著差异 ;腰膨大病理检验未示异常。结论 :鞘内注入泼尼松龙有镇痛作用 ,无神经毒性作用。     

Blood and urinary metabolomic evidence validating traditional Chinese medicine diagnostic classification of major depressive disorder

Background

Major depressive disorder (MDD) is a highly heterogeneous disease. Further classification may characterize its heterogeneity. The purpose of this study was to examine whether metabolomic variables could differentiate traditional Chinese medicine (TCM) diagnostic subtypes of MDD.

Methods

Fifty medication-free patients who were experiencing a recurrent depressive episode were classified into Liver Qi Stagnation (LQS, n?=?30) and Heart and Spleen Deficiency (HSD, n?=?20) subtypes according to TCM diagnosis. Healthy volunteers (n?=?28) were included as controls. Gas chromatography-mass spectrometry (GC–MS) was used to examine serum and urinary metabolomic profiles.

Results

Twenty-eight metabolites were identified for good separations between TCM subtypes and healthy controls in serum samples. Both TCM subtypes had similar profiles in proteinogenic branched-chain amino acids (BCAAs) (valine, leucine, and isoleucine) and energy metabolism-related metabolites that were differentiated from healthy controls. The LQS subtype additionally differed from healthy controls in multiple amino acid metabolites that are involved in biosynthesis of monoamine and amino acid neurotransmitters, including phenylalanine, 3-hydroxybutric acid, o-tyrosine, glycine, l-tryptophan, and N-acetyl-l-aspartic acid. Threonic acid, methionine, stearic acid, and isobutyric acid are differentially associated with the two subtypes.

Conclusions

While both TCM subtypes are associated with aberrant BCAA and energy metabolism, the LQS subtype may represent an MDD subpopulation characterized by abnormalities in the biosynthesis of monoamine and amino acid neurotransmitters and closer associations with stress-related pathophysiology. The metabolites differentially associated with the two subtypes are promising biomarkers for predicting TCM subtype-specific antidepressant response [registered at http://www.clinicaltrials.gov (NCT02346682) on January 27, 2015].

     

A homozygous G insertion in MPLKIP leads to TTDN1 with the hypergonadotropic hypogonadism symptom

Background

Trichothiodystrophy nonphotosensitive 1 (TTDN1) is a disease with mental retardation, brittle hair. Some cases of the diseases are caused by mutations of the MPLKIP gene.

Methods

We carefully identified the clinic characteristics, the sulfur level and pattern of the hair shafts of a female patient of with the symptom of hypergonadotropic hypogonadism, and of her parents and brother whose are healthy. We also collected the blood sample of the patient and performed the exon sequencing. One G insertion in MPLKIP was identified after analyzing the obtained exon sequencing profile. The G insertion sites in the patient, her parents and brother, were verified using Sanger sequencing. The G insertion in MPLKIP were compared to the dbSNP.

Results

The female patient of TTDN1 carries a homozygous G insertion (rs747470385) in the MPLKIP gene. The parents and brother of the patient are heterozygous carriers of the same mutation, but are healthy. The hair shafts of the patient had a tiger-tail pattern with relatively low sulfur levels. To the best of our knowledge, this is the first report that autosomal recessive inheritance of the G insertion in the MPLKIP gene results in TTDN1.

Conclusion

Our results indicate that the homozygotic G insertion in MPLKIP results in the TTDN1 with hypergonadotropic hypogonadism, while heterozygous carriers of the same mutation have no symptoms and healthy. These results provide novel insights into the association of mutations in MPLKIP and TTDN1 with hypergonadotropic hypogonadism.

     

Unusual Mott transition in multiferroic PbCrO3

The Mott insulator in correlated electron systems arises from classical Coulomb repulsion between carriers to provide a powerful force for electron localization. Turning such an insulator into a metal, the so-called Mott transition, is commonly achieved by “bandwidth” control or “band filling.” However, both mechanisms deviate from the original concept of Mott, which attributes such a transition to the screening of Coulomb potential and associated lattice contraction. Here, we report a pressure-induced isostructural Mott transition in cubic perovskite PbCrO₃. At the transition pressure of ∼3 GPa, PbCrO₃ exhibits significant collapse in both lattice volume and Coulomb potential. Concurrent with the collapse, it transforms from a hybrid multiferroic insulator to a metal. For the first time to our knowledge, these findings validate the scenario conceived by Mott. Close to the Mott criticality at ∼300 K, fluctuations of the lattice and charge give rise to elastic anomalies and Laudau critical behaviors resembling the classic liquid–gas transition. The anomalously large lattice volume and Coulomb potential in the low-pressure insulating phase are largely associated with the ferroelectric distortion, which is substantially suppressed at high pressures, leading to the first-order phase transition without symmetry breaking.Early transition-metal (TM) oxides with partially filled d electrons are strongly correlated (1, 2). Such correlated systems often present exciting new physics and technologically useful electronic and magnetic properties. Mott transition, characterized by delocalization of d electrons, is an attractive phenomenon for exploring the correlated nature of electrons (2, 3). Since the early failure of band theory in the 1930s, the Coulomb repulsion (U) has been proposed to be a strong force that causes electron localization (4, 5). In such electrostatic interaction, the repulsion energy decreases with the compressed lattice because of the screening effect (5–7). Consequently, as originally predicted by Mott (5), the Mott transition is controlled by U at pressures (P).Despite several decades of intensive study, it is still challenging to experimentally validate this view of Mott transition, because U is experimentally difficult to determine, and for most correlated materials it is independent of the pressure. For the known Mott systems, they are found to be controlled by either the bandwidth [e.g., the organic compound κ-Cl (8–10) and Cr-doped V₂O₃ (11, 12)] or band filling (i.e., doping of charge carriers into the parent insulator) (2). Recently, electronic transitions have frequently been reported in late 3d TM oxides (e.g., MnO) (13–16), which are theoretically attributed to bandwidth control (15) or crystal-field splitting (17). For those oxides, a U-controlled mechanism has also been proposed by Gavriliuk et al. (14) and Gavriliuk and coworkers (18); however, the spin cross-over, instead of the screening effect, is believed to contribute to the decreased U (14, 18). Complicating matter further is that the U of (Mg_1–xFe_x)O was computed to increase with pressures (13).TM oxides with a perovskite structure (ABO₃) often exhibit intriguing structural, magnetic, and electronic properties for the study of correlated systems. Among them, PbCrO₃ is such a material that can only be synthesized at high pressures. At ambient pressure, it adopts a paramagnetic (PM), cubic structure at room temperature (T) with an anomalously large unit-cell volume and transforms to an antiferromagnetic (AFM) ground state at low temperatures (19, 20). The magnetic properties arise from unpaired 3d electrons in Cr (i.e., nominally 3d²) with a large U value of 8.28 eV (19–21). Under high pressures, an isostructural phase transition (i.e., no symmetry breaking) has recently been reported in PbCrO₃ with ∼9.8% volume reduction at ∼1.6 GPa; it is the largest volume reduction known in transition-metal oxides (22). Compared with the low-P phase, the high-P phase possesses a more “normal” unit-cell volume (see refs. 21 and 22) and a moderate U of ∼3 eV (23), suggesting a collapse of Coulomb repulsion energy at the phase transition. Because of the reduced U, the mobility of 3d electrons at high pressures is energetically more favorable, which would lead to d-electron delocalization. Apparently, this is a U-driven Mott transition in PbCrO₃ as conceived by Mott. However, to date, the electronic properties of both PbCrO₃ phases have only poorly been explored. In particular, controversial electronic states, including semiconductor (24, 25), half-metal (21), or insulator (20), have been reported for the low-P phase. Besides, the crystal structure and elastic and magnetic properties, as well as the underlying mechanism for the isostructural transition, are still unsettled issues, calling for rigorous investigation into this material.With these aims, in this work we present a comprehensive study on PbCrO₃ with a focus on the P-induced electronic transition. Our findings unveil a unique Mott transition in this perovskite and a new mechanism underlying the isostructural transition.