[Application of Structural Biology in Research on Toxoplasma gondii].

Structural biology is a rapidly-developing comprehensive discipline that interprets the atom-level assembling, interaction and movement between molecules. This paper summarizes basic methods in structural biology, with a focus on structure research progress of Toxoplasma gondii rhoptry and calmodulin-like domain protein kinase, to illustrate the application of structural biology in research on important virulence factors and drug targets of T. gondii.

[Application of Nested PCR in the Diagnosis of Imported Plasmodium Ovale Infection].

OBJECTIVE: To identity Plasmodium ovale infection by 18S rRNA gene nested PCR. METHODS: Whole blood and filter paper blood samples of malaria patients in Shandong Province were collected during 2012-2013. The parasites were observed under a microscope with Giemsa staining. The genome DNA of blood samples were extracted as PCR templates. Genus- and species-specific primers were designed according to the Plasmodium 18S rRNA gene sequences. Plasmodium ovale-positive specimens were identified by nested PCR as well as verified by sequencing. RESULTS: There were 7 imported cases of P. ovale infection in the province during 2012-2013. Nested PCR results showed that the P. ovale specific band (800 bp) was amplified in all the 7 specimens. Blast results indicated that the PCR products were consistent with the Plasmodium ovale reference sequence in GenBank. CONCLUSION: Seven imported cases of ovale malaria in Shandong Province in 2012-2013 are confirmed by nested PCR.

N-palmitoylethanolamide attenuates negative emotions induced by morphine withdrawal in mice.

Depression and anxiety are prominent symptoms of withdrawal syndrome, often caused by the abuse of addictive drugs like morphine. N-palmitoylethanolamide (PEA), a biologically active lipid, is utilized as an anti-inflammatory and analgesic medication. Recent studies have highlighted PEA's role in mitigating cognitive decline and easing depression resulting from chronic pain. However, it remains unknown whether PEA can influence negative emotions triggered by morphine withdrawal. This study seeks to explore the impact of PEA on such emotions and investigate the underlying mechanisms. Mice subjected to morphine treatment underwent a 10-day withdrawal period, followed by assessments of the effect of PEA on anxiety- and depression-like behaviors using various tests. Enzyme-linked immunosorbent assay was conducted to measure levels of monoamine neurotransmitters in specific brain regions. The findings indicate that PEA mitigated anxiety and depression symptoms and reduced 5-hydroxytryptamine, noradrenaline, and dopamine levels in the hippocampus and prefrontal cortex. In summary, PEA demonstrates a significant positive effect on negative emotions associated with morphine withdrawal, accompanied with the reduction in levels of monoamine neurotransmitters in key brain regions. These insights could be valuable for managing negative emotions arising from morphine withdrawal.

Opioid receptors modulate parallel fiber-Purkinje cell synaptic transmission in mouse cerebellum.

Opioid receptors play important roles in, among others, learning and memory, emotional responses, addiction, and pain. In recent years, the cerebellum has received increasing attention for its role in non-motor functions. The Purkinje cell (PC) is the only efferent neuron in the cerebellar cortex, and receives glutamatergic synaptic inputs from the parallel fibers (PF) formed by the axons of granule cells. Studies have shown that opioid receptors are expressed during the development of cerebellar cells. However, the distribution of opioid receptors, their subtypes in cerebellar PF-PC synapses, and their effects on synaptic transmission remain unclear. To examine these questions, we used whole-cell patch clamp recordings and pharmacological methods to determine the effects of activating three different opioid receptor subtypes on synaptic transmission at PF-PC synapses. In the presence of picrotoxin, mouse cerebellar slices were perfused with agonists or blockers of different opioid receptor subtypes, and the changes in excitatory postsynaptic currents (EPSCs) were examined. Both agonists of µ-opioid receptors (MOR) and δ-opioid receptors (DOR) significantly reduced the amplitude and area under the curve of PF-PC EPSCs in a concentration-dependent manner, accompanied by an increase in the paired-pulsed ratio (PPR). These effects could be blocked by respective receptor antagonists. In contrast, no significant changes were found after the application of κ-opioid receptor (KOR) agonists. In conclusion, MOR and DOR are present at the axon terminals of PF in the mouse cerebellar cortex, whereas no or negligible amounts of KOR are found. Activation of MOR and DOR regulates PF-PC synaptic transmission via inhibition of glutamate (Glu) release in cerebellar cortex in mice. We also found that endogenous opioid peptides are present in PF-PC synapses of mouse cerebellum, which also can inhibit the release of Glu.

[Therapeutic effect of 138 imported falciparum malaria patients].

OBJECTIVES: To summarize the clinical characteristics of imported falciparum malaria patients and the treatment, so as to provide the evidences for improving the diagnosis and treatment of the disease. METHODS: A total of 138 imported falciparum malaria patients who received the treatment in Shandong Institute of Parasitic Diseases from January 2007 to February 2013 were adopted as the observation subjects, and their clinical data were collected and analyzed. RESULTS: All the 138 patients were back from African countries. The main manifestations were fever, headache, asthenia, and hepatosplenomegaly, and most of them were with decreased RBC, PLT levels and increased LDH levels, and 36.96% of them were misdiagnosed as respiratory diseases, nephritis, hepatitis and so on. Through antimalarial treatment of artemether or artesunate or dihydroartemisinin and primaquine, or dihydroartemisinin and piperaquine, and symptomatic treatment, the short-term and long-term cure rates were 98.55% and 94.93% respectively, with 1 case unrecovered and 1 died. CONCLUSIONS: Artemisinins are still the most effective antimalarial drugs for falciparum malaria. However, some patients recrudesce as the Plasmodium in their body is resistant or insensitive to these drugs. We should pay more attention to the antimalarial and symptomatic treatments in the early stage of severe malaria so as to improve the cure rate.

[Dipylidium caninum infection in an infant: one case report].

This paper reports the diagnosis and therapy of one case of Dipylidium caninum infection in an infant.

Characterization of a bio-oil from pyrolysis of rice husk by detailed compositional analysis and structural investigation of lignin.

Detailed compositional analysis of a bio-oil (BO) from pyrolysis of rice husk was carried out. The BO was extracted sequentially with n-hexane, CCl(4), CS(2), benzene and CH(2)Cl(2). In total, 167 organic species were identified with GC/MS in the extracts and classified into alkanes, alcohols, hydroxybenzenes, alkoxybenzenes, dioxolanes, aldehydes, ketones, carboxylic acids, esters, nitrogen-containing organic compounds and other species. The benzene ring-containing species (BRCCs) were attributed to the degradation of lignin while most of the rests were derived from the degradation of cellulose and hemicellulose. Along with guaiacyl and p-hydroxyphenyl units as the main components, a new type of linkage was suggested, i.e., C(ar)-CH(2)-C(ar) in 4,4'-methylenebis(2,6-dimethoxyphenol). Based on the species identified, a possible macromolecular structure of the lignin and the mechanism for its pyrolysis are proposed. The BO was also extracted with petroleum ether in ca. 17.8% of the extract yield and about 82.1% of the extracted components are BRCCs.