Establishment of a secondary infection laboratory model of Echinococcus shiquicus metacestode using BALB/c mice and Mongolian jirds (Meriones unguiculatus).

Echinococcus shiquicus is peculiar to the Qinghai­Tibet plateau of China. Research on this parasite has mainly focused on epidemiological surveys and life cycle studies. So far, limited laboratory studies have been reported. Here, experimental infection of E. shiquicus metacestode in BALB/c mice and Mongolian jirds (Meriones unguiculatus) was carried out to establish alternative laboratory animal models. Intraperitoneal inoculation of metacestode material containing protoscoleces (PSCs) obtained from infected plateau pikas were conducted on BALB/c mice. Furthermore, metacestode material without PSCs deriving from infected BALB/c mice was intraperitoneally inoculated to Mongolian jirds. Experimental animals were dissected for macroscopic and histopathological examination. The growth of cysts in BALB/c mice was infiltrative, and they invaded the murine entire body. Most of the metacestode cysts were multicystic, but a few were unilocular. The cysts contained sterile vesicles, which had no PSCs. The metacestode materials were able to successfully infect new mice. In the jirds model, E. shiquicus cysts were typically formed freely in the peritoneal cavity; the majority of these cysts were free while a small portion adhered loosely to nearby organs. The proportion of fertile cysts was high, and contained many PSCs. The PSCs produced in Mongolian jirds also successfully infected new ones, which confirms that jirds can serve as an alternative experimental intermediate host. In conclusion, a laboratory animal infection was successfully established for E. shiquicus using BALB/c mice and Mongolian jirds. These results provide new models for the in-depth study of Echinococcus metacestode survival strategy, host interactions and immune escape mechanism.

A novel vertebral trench technique (VTT) involving transforaminal endoscopic lumbar foraminotomy (TELF) for very highly up-migrated lumbar disc herniation above L5.

BACKGROUND: Percutaneous endoscopic lumbar discectomy (PELD) has become popular for the treatment of symptomatic lumbar disc herniation (LDH). The very highly up-migrated lumbar disc herniation (VHUM-LDH) is difficult to remove under PELD. The purpose of this research is to investigate the feasibility, clinical efficacy and operative nuances of a novel VTT involving TELF for this type of herniation. METHODS: Eleven patients with very highly up-migrated LDH who underwent VTT involving TELF discectomy from May 2016 to May 2019 were included in this study. The operative time, length of hospital stay, and postoperative complications were recorded. Pre-and postoperative radiologic findings were investigated. All the patients were followed more than 1 year. The visual analogue score (VAS), Oswestry Disability Index (ODI), Japanese Orthopaedic Association (JOA) scores and modified MacNab criteria were used to assess surgical efficacy. RESULTS: All the 11 patients underwent successful surgery. We compared the VAS, ODI, and JOA scores before and after surgery. The differences were statistically significant (P < 0.05). According to the modified MacNab criteria, 10 patients were assessed as "excellent", 1 patient was assessed as "good" at the last follow up. CONCLUSION: The novel VTT involving TELF discectomy is a supplement to the traditional PELD. This technique enables the endoscope with working cannula to get closer the sequestrated nucleus pulposus without irritating the exiting nerve root, and facilitates the nucleus pulposus be removed successfully under direct visualization. The VTT involving TELF discectomy can be a safe, effective and feasible surgical procedure for the treatment of LDH with very highly up-migrated.

The adaptation strategies of Herpetospermum pedunculosum (Ser.) Baill at altitude gradient of the Tibetan plateau by physiological and metabolomic methods.

BACKGROUND: Herpetospermum pedunculosum (Ser.) Baill is annual scandent herbs. They are used in the treatment of piles, inflammation of the stomach and the intestines. It can survive the extreme environment of the Tibetan Plateau (TP). However, the underlying mechanisms of this adaptation to H. pedunculosum from TP remain unclear. Here, we combined physiological and metabolomics methods to analyze H. pedunculosum response to altitude gradient differences. RESULTS: At high altitude, increases in the activities of Ascorbate peroxidase (APX), Glutathione reductase (GR), Dehydroascorbate reductase (DHAR), Monodehydroascorbate reductase (MDHAR), Superoxide dismutase (SOD) have been observed in leaves. Total Glutathion content, total Ascorbate content and the ASA (ascorbic acid)/docosahexaenoic acid (DHA) ration were highly elevated from low altitude to high altitude. In addition, high altitude induces decrease of the Anthocyanidin content (ANTH) and increase of abscisic acid content (ABA). The GC-MS analyses identified of 50 metabolites from leaves of H. pedunculosum. In addition, a metabolic network was constructed based on metabolomic datasets using a weighted correlation network analysis (WGCNA) approach. The network analysis uncovered 4 distinguished metabolic modules highly associated with I, II, III and IV respectively. Furthermore, the analysis successfully classified 50 samples into seven groups: carbohydrates, amino acids, organic acids, lipid components, polyamine, secondary metabolism and others. CONCLUSIONS: In the present study, the content of parts of amino acid components increased in samples collected at higher altitudes, and most of metabolites, including carbohydrates and organic acids were assigned to the carbon metabolic pathway comprising reductive pentose phosphate pathway, glycolysis and TCA cycle, indicating the direct relationship between adaptability and the carbon metabolic pathway and amino acids in H. pedunculosum response to high altitude. The results of this study laid the foundation of the molecular mechanism on H. pedunculosum from high altitude.

Short-term effect of elevated CO2 concentration (0.5%) on mitochondria in diploid and tetraploid black locust (Robinia pseudoacacia L.).

Recent increases in atmospheric CO 2 concentration have affected the growth and physiology of plants. In this study, plants were grown with 0.5% CO 2 for 0, 3, and 6 days. The anatomy, fluorescence intensity of H2O2, respiration rate, and antioxidant activities of the mitochondria were analyzed in diploid (2×) and tetraploid (4×) black locust (Robinia pseudoacacia L.). Exposure to 0.5% CO 2 resulted in clear structural alterations and stomatal closure in the mitochondria. Reduced membrane integrity and increased structural damage were observed in 2× plants at 6 days. However, after 0.5% CO 2 treatment, little structural damage was observed in 4× plants. Under severe stress, H2O2 and malondialdehyde were dramatically induced in both 2× and 4× plants. Proline remains unchanged at an elevated CO 2 concentration in 4× plants. Moreover, the total respiration and alternative respiration rates decreased in both 2× and 4× plants. In contrast, the cytochrome pathway showed no decrease in 2× plants and even increased slightly in 4× plants. The antioxidant enzymes and nonenzymatic antioxidants, which are related to the ascorbate-glutathione pathway, were inhibited following CO 2 exposure. These analyses indicated that 4× and 2× plants were damaged by 0.5% CO 2 but the former were more resistant than the latter, and this may be due to increases in antioxidant enzymes and nonenzymatic antioxidants and stabilized membrane structure.

The effects of elevated CO2 (0.5%) on chloroplasts in the tetraploid black locust (Robinia pseudoacacia L.).

Some ploidy plants demonstrate environmental stress tolerance. Tetraploid (4×) black locust (Robinia pseudoacacia L.) exhibits less chlorosis in response to high CO 2 than do the corresponding diploid (2×) plants of this species. We investigated the plant growth, anatomy, photosynthetic ability, chlorophyll (chl) fluorescence, and antioxidase activities in 2× and 4× black locusts cultivated under high CO 2 (0.5%). Elevated CO 2 (0.5%) induced a global decrease in the contents of total chl, chl a, and chl b in 2× leaves, while few changes were found in the chl content of 4× leaves. Analyses of the chl fluorescence intensity, maximum quantum yield of photosystem II (PSII) photochemistry (Fv/Fm), K-step (Vk), and J-step (VJ) revealed that 0.5% CO 2 had a negative effect on the photosynthetic capacity and growth of the 2× plants, especially the performance of PSII. In contrast, there was no significant effect of high CO 2 on the growth of the 4× plants. These analyses indicate that the decreased inhibition of the growth of 4× plants by high CO 2 (0.5%) may be attributed to an improved photosynthetic capacity, pigment content, and ultrastructure of the chloroplast compared to 2× plants.

Physiological and proteomic responses to salt stress in chloroplasts of diploid and tetraploid black locust (Robinia pseudoacacia L.).

Salinity is an important abiotic stressor that negatively affects plant growth. In this study, we investigated the physiological and molecular mechanisms underlying moderate and high salt tolerance in diploid (2×) and tetraploid (4×) Robinia pseudoacacia L. Our results showed greater H2O2 accumulation and higher levels of important antioxidative enzymes and non-enzymatic antioxidants in 4× plants compared with 2× plants under salt stress. In addition, 4× leaves maintained a relatively intact structure compared to 2× leaves under a corresponding condition. NaCl treatment didn't significantly affect the photosynthetic rate, stomatal conductance or leaf intercellular CO2 concentrations in 4× leaves. Moreover, proteins from control and salt treated 2× and 4× leaf chloroplast samples were extracted and separated by two-dimensional gel electrophoresis. A total of 61 spots in 2× (24) and 4× (27) leaves exhibited reproducible and significant changes under salt stress. In addition, 10 proteins overlapped between 2× and 4× plants under salt stress. These identified proteins were grouped into the following 7 functional categories: photosynthetic Calvin-Benson Cycle (26), photosynthetic electron transfer (7), regulation/defense (5), chaperone (3), energy and metabolism (12), redox homeostasis (1) and unknown function (8). This study provides important information of use in the improvement of salt tolerance in plants.