Acetylated tau exacerbates learning and memory impairment by disturbing with mitochondrial homeostasis

Increased tau acetylation at K274 and K281 has been observed in the brains of Alzheimer's disease (AD) patients and animal models, and mitochondrial dysfunction are noticeable and early features of AD. However, the effect of acetylated tau on mitochondria has been unclear until now. Here, we constructed three type of tau forms, acetylated tau mutant by mutating its K274/K281 into Glutamine (TauKQ) to mimic disease-associated lysine acetylation, the non-acetylation tau mutant by mutating its K274/K281 into Arginine (TauKR) and the wild-type human full-length tau (TauWT). By overexpression of these tau forms in vivo and in vitro, we found that, TauKQ induced more severe cognitive deficits with neuronal loss, dendritic plasticity damage and mitochondrial dysfunctions than TauWT. Unlike TauWT induced mitochondria fusion, TauKQ not only induced mitochondria fission by decreasing mitofusion proteins, but also inhibited mitochondrial biogenesis via reduction of PGC-1a/Nrf1/Tfam levels. TauKR had no significant difference in the cognitive and mitochondrial abnormalities compared with TauWT. Treatment with BGP-15 rescued impaired learning and memory by attenuation of mitochondrial dysfunction, neuronal loss and dendritic complexity damage, which caused by TauKQ. Our data suggested that, acetylation at K274/281 was an important post translational modification site for tau neurotoxicity, and BGP-15 is a potential therapeutic drug for AD.

[First report of invasive Pomacea snails in Shandong Province]

OBJECTIVE

To characterize the species of invasive Pomacea snails that were discovered for the first time in Shandong Province.

METHODS

Pomacea snails samples were collected in the field of Jining City, Shandong Province on October 2021 for morphological identification. Pomacea snails were randomly sampled and genomic DNA was extracted from foot muscle tissues of Pomacea snails for multiplex PCR amplification. The PCR amplification product was sequenced. Then, the sequence was aligned and a phylogenetic tree was created using the software MegAlign 7.1.0. In addition, Angiostongylus cantonensis infection was detected in Pomacea snails with the lung microscopy.

RESULTS

A total of 104 living Pomacea snails were collected, and all were characterized as Pomacea spp. based on morphological features. Of 12 randomly selected adult Pomacea snails, multiplex PCR assay and sequencing identified eleven snails as P. canaliculata and one as P. maculata. No A. cantonensis infection was detected in 104 Pomacea snails.

CONCLUSIONS

This is the first report of invasive Pomacea snails in Shandong Province, where P. canaliculata and P. maculata are found.

Soil microbiomes divergently respond to heavy metals and polycyclic aromatic hydrocarbons in contaminated industrial sites

Contaminated sites from electronic waste (e-waste) dismantling and coking plants feature high concentrations of heavy metals (HMs) and/or polycyclic aromatic hydrocarbons (PAHs) in soil. Mixed contamination (HMs + PAHs) hinders land reclamation and affects the microbial diversity and function of soil microbiomes. In this study, we analyzed HM and PAH contamination from an e-waste dismantling plant and a coking plant and evaluated the influences of HM and PAH contamination on soil microbiomes. It was noticed that HMs and PAHs were found in all sites, although the major contaminants of the e-waste dismantling plant site were HMs (such as Cu at 5,947.58 ± 433.44 mg kg^-1, Zn at 4,961.38 ± 436.51 mg kg^-1, and Mn at 2,379.07 ± 227.46 mg kg^-1), and the major contaminants of the coking plant site were PAHs (such as fluorene at 11,740.06 ± 620.1 mg kg^-1, acenaphthylene at 211.69 ± 7.04 mg kg^-1, and pyrene at 183.14 ± 18.89 mg kg^-1). The microbiomes (diversity and abundance) of all sites were determined via high-throughput sequencing of 16S rRNA genes, and redundancy analysis was conducted to investigate the relations between soil microbiomes and contaminants. The results showed that the microbiomes of the contaminated sites divergently responded to HMs and PAHs. The abundances of the bacterial genera Sulfuritalea, Pseudomonas, and Sphingobium were positively related to PAHs, while the abundances of the bacterial genera Bryobacter, Nitrospira, and Steroidobacter were positively related to HMs. This study promotes an understanding of how soil microbiomes respond to single and mixed contamination with HMs and PAHs.

[Surveillance of Enterobius vermicularis infections among children in Shandong Province from 2016 to 2020]

OBJECTIVE

To investigate the prevalence and changing trend of Enterobius vermicularis infections among children in Shandong Province, so as to provide the scientific evidence for the adjustment and development of the enterobiasis control strategy.

METHODS

Soil-borne nematodiasis surveillance sites were assigned in 51 counties (districts, cities) in Shandong Province from 2016 to 2020, and the E. vermicularis infections were detected using a modified Kato-Katz technique and the cellophane tape method among children at ages of 3 to 9 years living in these surveillance sites. The epidemiological profiles of E. vermicularis-infected children were descriptively analyzed.

RESULTS

A total of 5 060 children at ages of 3 to 9 years were detected in 51 soil-borne nematodiasis surveillance sites in Shandong Province from 2016 to 2020, and the overall prevalence of E. vermicularis infections was 2.23%. The annual prevalence of E. vermicularis infections was 3.99% (26/651), 1.70% (14/824), 0.96% (8/837), 2.90% (45/1 552) and 1.67% (20/1 196) from 2016 to 2020, respectively, with a significant difference detected among years (χ² = 21.455, P < 0.01). The prevalence of E. vermicularis infections was 1.25% (15/1 198), 1.85% (14/755), 3.18% (84/2 640) and 0 (0/467) among children from central, eastern, southern and northern Shandong Province (χ² = 27.326, P < 0.01). In addition, there was no significant difference in the prevalence of E. vermicularis infections between male (1.98%, 56/2 831) and female children (2.56%, 57/2 229) (χ² = 1.916, P > 0.05); however, there was age-specific prevalence of E. vermicularis infections among children (χ² = 16.448, P < 0.05), with the greatest prevalence detected among children at ages of 6 years (3.18%, 25/786), and the lowest prevalence seen among children at ages of 3 years (0.75%, 6/800).

CONCLUSIONS

The prevalence of E. vermicularis infections remained at a medium level among children at ages of 3 to 9 years in Shandong Province from 2016 to 2020, with region-specific prevalence found across the province. An integrated strategy is required for enterobiasis control.

STAT3 ameliorates cognitive deficits via regulation of NMDAR expression in an Alzheimer's disease animal model

Background: Abnormal tau accumulation in the brain has a positively correlation with neurodegeneration and memory deterioration, but the mechanism underlying tau-associated synaptic and cognitive impairments remains unclear. Our previous work has found that human full length tau (hTau) accumulation activated signal transducer and activator of transcription-1 (STAT1) to suppress N-methyl-D-aspartate receptors (NMDARs) expression, followed by memory deficits. STAT3 also belongs to STAT protein family and is reported to involve in regulation of synaptic plasticity and cognition. Here, we investigated the role of STAT3 in the cognitive deficits induced by hTau accumulation. Methods: In vitro studies HEK293 cells were used. EMSA, Luciferase reporter assay, and Immunoprecipitation were applied to detect STAT3 activity. In vivo studies, AAV virus were injected into the hippocampal CA3 region of C57 mice. Western blotting, quantitative real-time polymerase chain reaction, and immunofluorescence were applied to examine the level of synaptic proteins. Electrophysiological analysis, behavioral testing and Golgi impregnation were used to determine synaptic plasticity and memory ability recovery after overexpressing STAT3 or non-acetylated STAT1. Results: Our results showed that hTau accumulation acetylated STAT1 to retain STAT3 in the cytoplasm by increasing the binding of STAT1 with STAT3, and thus inactivated STAT3. Overexpressing STAT3 or non-acetylated STAT1 ameliorated hTau-induced synaptic loss and memory deficits by increasing the expression of NMDARs. Conclusions: Taken together, our study indicates that hTau accumulation impaired synaptic plasticity through STAT3 inactivation induced suppression of NMDARs expression, revealing a novel mechanism for hTau-associated synapse and memory deficits.

[Epidemiological characteristics of imported malaria in Shandong province, 2017-2018]

Objective: To understand epidemiological characteristics of imported cases of malaria in Shandong province and provide scientific basis for timely adjustment of prevention and control measures. Methods: The incidence data of malaria, case investigation data and case review data by Shandong Provincial Reference Laboratory for Malaria Diagnosis from 2017 to 2018 were collected. Software SPSS 18.0 was used for statistical analysis and software QGIS 2.18 was used for mapping. Results: A total of 442 imported cases of malaria were reported in Shandong from 2017 to 2018, and the main infection source was in Africa (97.96%, 433/442). All the 17 prefectures in Shandong reported imported malaria cases, mainly in Jining (88 cases), Yantai (65 cases), Weihai (46 cases), Qingdao (44 cases) and Dezhou (42 cases), accounting for 64.48% (285/442). The cases were distributed in 77.37%(106/137) of counties of the province. The cases were reported in every month without seasonal characteristics. The median (M) of time interval between onset and the first medical care seeking was 2 days, and the interquartile range (IQR) was 3 days. The M of time interval between the first medical care seeking and final diagnosis was 0 day, and the IQR was 3 days. The proportion of medical care seeking on onset day was only 27.83% (123/442). Only 69.68% (308/442) of cases were diagnosed with malaria in the first medical care seeking, and the diagnostic accuracy of medical institutions below the county level was lower than other medical institutions (all P<0.01). Only 51.13% (226/442) of cases were diagnosed with malaria in the first medical care seeking, the differences in the rates among medical institutions at different levels were not significant (P>0.05). Conclusions: The imported malaria in Shandong was characterized by a large number of cases, multiple infection sources and wide area distribution during 2017-2018. The awareness of timely medical care seeking in the cases was low, meanwhile the awareness and ability of malaria diagnosis and treatment in primary medical institutions were still inadequate. It is necessary to adjust the prevention and control measures accordingly.

[Analysis of drug - resistant gene polymorphisms in Plasmodium falciparum imported from Equatorial Guinea to Shandong Province in 2015 and 2016]

OBJECTIVE

To investigate the drug-resistant gene polymorphisms in Plasmodium falciparum imported from Equatorial Guinea to Shandong Province.

METHODS

From 2015 to 2016, blood samples were collected from imported P. falciparum malaria patients returning from Equatorial Guinea to Shandong Province, and genome DNA of the malaria parasite was extracted. The drug-resistant Pfcrt, Pfmdr1, Pfdhfr, Pfdhps, and K13 genes of P. falciparum were amplified using a PCR assay, followed by DNA sequencing, and the sequences were aligned.

RESULTS

The target fragments of all 5 drug-resistant genes of P. falciparum were successfully amplified and sequenced. There were 72.8%, 18.6%, and 8.6% of P. falciparum parasites carrying the wild-, mutant-, and mixed-type Pfcrt gene, respectively, and all mutant haplotypes were CVIET (the underline indicates the mutation site). There were 20.0%, 61.4% and 18.6% of P. falciparum parasites carrying the wild-, mutant-, and mixed-type Pfmdr1 gene, respectively, and the mutant haplotypes mainly included YF and NF (the underlines indicate the mutation sites). There were 1.4%, 98.6%, and 0 of P. falciparum parasites carrying the wild-, mutant-, and mixed-type Pfdhfr gene, respectively, and AIRNI was the predominant mutant haplotype (the underline indicates the mutation site). There were 1.4%, 94.3%, and 4.3% of P. falciparum parasites carrying the wild-, mutant-, and mixed-type Pfdhps gene, respectively, and SGKAA was the predominant mutant haplotype (the underline indicates the mutation site). The complete drug-resistant IRNGE genotype consisted of 8.6% of the Pfdhfr and Pfdhps genes, and the K13 gene A578S mutation occurred in 1.4% of the parasite samples.

CONCLUSIONS

There are mutations in the Pfcrt, Pfmdr1, Pfdhfr, Pfdhps, and K13 genes of P. falciparum imported from Equatorial Guinea to Shandong Province, with a low frequency in the Pfcrt gene mutation and a high frequency in the Pfmdr1, Pfdhfr, and Pfdhps gene mutations, and the K13 gene A578S mutation is detected in the parasite samples.

[Quality of malaria blood smears from fever patients in Zibo City, Shandong Province from 2011 to 2018]

OBJECTIVE

To analyze the quality of malaria blood smears from fever patients in Zibo City from 2011 to 2018, so as to provide the scientific evidence for the development of the malaria post-elimination surveillance strategy.

METHODS

All negative malaria blood smears from fever patients reexamined in the municipal microscopic examination station and all positive blood smears in Zibo City during the period from 2011 to 2018 were reexamined, and the blood smear preparation, dyeing, cleanliness and reexamination results were analyzed.

RESULTS

A total of 2 141 negative malaria blood smears and 39 positive blood smears were re-reviewed by the municipal microscopic examination station of Zibo City from 2011 to 2018, with a 99.44% qualification rate of negative blood smears preparation, a 97.62% qualification rate of dyeing, a 93.65% qualification rate of cleanliness, and a 100% consistence with the re-review, and no missing diagnosis was found. A total of 39 positive blood smears were re-reviewed, with a 46.15% qualification rate of blood smears preparation, a 61.54% qualification rate of dyeing, a 76.92% qualification rate of cleanliness, and a 97.44% consistence with the re-review, and a blood smear mistaking the Plasmodium species was found. There were significant differences in the qualification rate of blood smears preparation and dyeing among all districts (counties) in Zibo City (all P values < 0.05), and no significant difference was detected in the qualification rate of blood smear cleanliness (χ² = 13.72, P >0.05), while significant differences were seen in the qualification rate of blood smears preparation, dyeing and cleanliness each year from 2011 to 2018 (all P values < 0.05).

CONCLUSIONS

The quality of malaria blood smears is high in all districts of Zibo City; however, the quality of city-level blood smears remains to be improved. Further actions to improve the training of grassroots microscopic examinations and quality control of malaria blood smears are required to ensure the capability of microscopic examinations of Plasmodium during the malaria post-elimination stage.

[The progress of narrow band imaging endoscopy in diagnosis of vocal cord leukoplakia]

SummaryThe appearances of vocal cord leukoplakia are largely identical in the macroscopic examination even though the pathological character may differ. This makes it difficult for physicians to evaluate the extent of dysplasia of vocal cord leukoplakia and detect the occurrence of canceration using the conventional laryngoscopy, which might result in overtreatment or undertreatment of vocal cord leukoplakia in different patients. Therefore, an accurate preoperative assessment of the pathological character of vocal cord leukoplakia shows clinical significance in the selection of an appropriate treatment plan and predicting the prognosis of a patient. Recent studies have found that narrow band imaging（NBI） endoscopy can facilitate the early and differential diagnosis of head and neck cancers by observing the intraepithelial papillary capillary loop（IPCL） patterns at the mucosal surfaces. In this paper, the recent progress of NBI endoscopy in the diagnosis of vocal cord leukoplakia is reviewed.

[Effects of low temperature on trehalose and trehalase contents in Culex pipiens pallens]

OBJECTIVE

To examine the effect of low temperature on trehalose and trehalase levels in Culex pipiens pallens.

METHODS

The fourth instar larvae and female adult mosquitoes of Cx. pipiens pallens were exposed at 4 ℃ for 0, 1, 3, 6, 12, 18, 24 h and 0, 1, 3, 6, 12, 18, 24, 36, 48, 72 h, respectively. Then, the trehalose and trehalase contents were detected by enzyme-linked immunosorbent assay (ELISA) in mosquitoes.

RESULTS

The contents of trehalose and trehalase significantly increased in the larval and female adult mosquitoes post-exposure to low temperature. The changing trend of trehalose levels was consistent in the larval and female adult mosquitoes, and the highest levels were (2.458 8 ± 0.379 2) mg/g and (2.825 7 ± 0.211 1) mg/g 3 h post-exposure to low temperature, respectively. The trehalose and trehalase levels fluctuated greatly within the first 6 h post-exposure to low temperature. Following adaptation for a period of time, the trehalose and trehalase levels remained at a relatively high level.

CONCLUSIONS

Low temperature may induce the production of trehalose and trehalase in Cx. pipiens pallens, and the trehalose and trehalase may play an important role in the improvement of the cold resistance.

Clinical measurement of antibodies against acetylcholine receptor (AchR), SOD and LPO in patients with myasthenia gravis (MG) before and after thymectomy

The antibodies against acetylcholine receptor AchR and levels of SOD and LPO were measured in 11 patients with myasthenia gravis (MG), and the results were compared with normal controls and patients with diseases other than MG. The results showed that the antibodies against AchR were higher as compared with other groups before and after operation. The post-operative level of antibodies was obviously lower than the pre-operative value. An slight increase in SOD and significant decrease in mean value of LPO after surgery were noted. The possible mechanism was discussed.

Rupture of thoracic aortic aneurysm into the lung with formation of pseudoaneurysm: diagnosis and treatment

Three patients with rupture of thoracic aortic aneurysm into the lung with formation of pseudoaneurysm were admitted to our hospital in 1991, of whom, 2 had ascending aortic aneurysms which ruptured into the right upper pulmonary lobe, and another one had descending aortic aneurysm rupturing into the left upper lobe. All 3 cases were misdiagnosed as having pulmonary carcinoma or mediastinal tumor by the other hospital as well as by us. Correct diagnosis was made by aortography or at exploratory thoracotomy. Our preliminary experiences in the diagnosis and treatment of the disease are presented in this paper.

Surgical treatment of double-chamber right ventricle and its associated anomalies

A report on the results of surgical treatment of 5 cases of DCRV and its associated anomaly was presented in this paper. No definite diagnosis of DCRV was made prior to operation. It was found that 2 cases had DCRV as an isolated anomaly, another 2 had the disease associated with VSD, and the remaining 1 had DCRV with right ventricle to left atrium cannulation. Muscular membrane septum type was found in 3 cases, and muscular bundle type in 2.4 cases diagnosed as having DCRV or DCRV with other heart anomalies during operation were treated properly and discharged fully recovered. 1 case died of acute heart insufficiency. Pathologic anatomy and physiology, associated anomalies of DCRV, and some experience with the operative approach were discussed in this article.

Octopamine selectively modifies the slow component of sensory adaptation in an insect mechanoreceptor

The effects of octopamine were studied on the dynamic behavior of the sensory neuron in the cockroach femoral tactile spine. The neuron is a rapidly adapting mechanoreceptor in which adaptation occurs by elevation of the threshold for action potential encoding. The threshold follows increases or decreases of membrane potential, with a delay that involves two separate exponential components. Previous evidence has associated the slow component with sodium pumping and the fast component with sodium channel inactivation. Octopamine reversibly raised the resting threshold and increased but slowed the slow component. These data indicate that octopamine has specific effects on membrane-ionic processes in insect sensory neurons.

[Therapeutic effects of epimeric glycyrrhizic acids on hepatic injury in rats]

The effects of the epimeric glycyrrhizic acids (GA), 18 alpha-form and 18 beta-form, on D-galactosamine (Gal)-induced acute liver injury and fulminating hepatic failure (FHF) in rats were studied. In rats of acute liver injury, extensive liver parenchymal cell damage was observed by the elevation of alanine aminotransferase (ALT) activity and confirmed by significant histopathological changes 24 and 48 h after ip Gal 450 mg.kg-1. Moreover, marked elevation in the liver putrescine levels occurred along with that of serum ALT. The spermidine and spermine levels did not alter significantly. GA 18 alpha-form 300 mg.kg-1 ip suppressed the elevation of serum ALT and liver putrescine levels, and improved all the histopathologic features. On the other hand, GA 18 beta-form 300 mg.kg-1, which exhibited inhibitory effects 24 h after ip Gal, showed no action 48 h after ip Gal. The ALT levels in the serum from GA 18 alpha-form, 18 beta-form, vs control groups after 24 h were 70 +/- 24 (P < 0.01) and 78 +/- 42 (P < 0.01) vs 155 +/- 57, and after 48 h were 74 +/- 25 (P < 0.01) and 258 +/- 99 (P > 0.05) vs 293 +/- 110. The putrescine contents (nmol.g-1) in the liver from GA 18 alpha-form, 18 beta-form, vs control after 24 h were 34 +/- 9 (P < 0.01) and 51 +/- 12 (P < 0.01) vs 139 +/- 29, and after 48 h were 16 +/- 3 (P < 0.01) and 150 +/- 11 (P > 0.05) vs 156 +/- 23.(ABSTRACT TRUNCATED AT 250 WORDS)

Protective action of selenium and manganese on xanthine and xanthine oxidase induced oxidative damage to cultured heart cells

Ventricular myocytes from neonatal Wistar rats were cultured with 80% Dulbecoo's modified Eagle medium and 20% fetal bovine serum. An appropriate amount of xanthine and xanthine oxidase was added to the culture medium to increase the content of free radicals in cardiac cells. Variation in action potential and input impedance of cardiac myocytes indicated the oxidative damage to the membrane. The ultrastructure of heart cells, characteristically the myofilaments and mitochondria, was damaged. Electron spin resonance measurement demonstrated that xanthine and xanthine oxidase elevated the free radical content, while selenium (Se) and manganese (Mn) reduced the free radicals in cultured heart cells. Supplementation of 0.173 microgram/ml Se and 0.1 microgram/ml Mn into the culture medium separately or simultaneously antagonized the damage induced by xanthine and xanthine oxidase. The possible mechanism might be the production of superoxide anion free radical leading to free radical damage to cardiac cells. Se and Mn might play a role as scavengers through glutathione peroxidase and superoxide dismutase respectively and thus protect cardiac cells from free radical damage.

[Evolution of autologous graft interface in rats: experimental study]

With purpose to study the evolution of autologous venous graft interface, an experimental model utilizing an autologous venous patch to repair an infrarenal abdominal aortic defect in rats was developed. A small piece of both the jugular vein and the aorta were first excised. After implantation and reestablishment of blood flow, the animals were subsequently sacrificed in groups of 3 at the following intervals: 10 seconds, 1 minute, 10 minutes, 30 minutes, 1 hour, 6 hours, 12 hours, 24 hours, 7 days, 30 days and 90 days. All the patches and adjacent aortae were collected and studied using scanning electron microscopy, with the following results: 1) the endothelial lining of both the autologous vein patch and the adjacent aorta is destroyed before implantation due to operative manipulation; 2) after blood flow reestablishment, the patch and adjacent aortic interfaces are reactive to platelets and other blood cells; 3) New endothelial lining begins to appear from the 7th day after implantation, but the regeneration is not complete at 3 months. From the model, it is deducted that the endothelial repair of autologous venous patch and its adjacent aorta involves a very slow process.