[Relationship between gut microbiota and its metabolite dysregulation and postoperative cognitive dysfunction in elderly male C57BL/6J mice after laparotomy exploration]

Objective: To explore the relationship between gut microbiota and its metabolite dysregulation and postoperative cognitive dysfunction in elderly male C57BL/6J mice after laparotomy exploration. Methods: A total of 48 specific pathogen-free (SPF) male C57BL/6J mice, aged 16-17 months, were divided into two groups by random number table method: control group (n=24) and operation group (n=24). Mice in the operation group were induced with 1.4% isoflurane for 15 minutes, followed by a 10 minutes exploratory laparotomy anesthetized with 1.4% isoflurane and 100% oxygen, and anesthesia continued for 2 hours after surgery. Mice in control group were put in 100% oxygen for 2 hours. Feces and venous blood samples of both groups were collected 48 hours after surgery. Changes in the abundance and diversity of intestinal bacteria in the feces were detected by 16S rDNA gene sequencing. Functional changes of fecal metabolic profiles were detected by liquid chromatography tandem mass spectrometry (LC/MS) metabolomics and differential metabolite functions were analyzed. The serum level of interleukin (IL)-6, IL-1β and tumor necrosis factor-α (TNF-α) were detected by Enzyme-linked immunosorbent assay (ELISA). The cognitive function of the mice was detected by Morris water maze test 3 days after operation. Results: The postoperative escape latency of mice in control group and operation group was (22.0±4.9) and (35.0±5.1) s, and the target quadrant residence time was (26.0±3.7) and (16.0±2.9) s, respectively. Compared with the control group, the postoperative escape latency of mice in the operation group was prolonged (P=0.035), and the residence time in the target quadrant was reduced (P=0.006). The difference of intestinal flora between the two groups was comparable. The expression levels of Escherichia coli, shigella and clostridium in the operation group were up-regulated, while the expression levels of rumen bacteria and butyricobacteria were down-regulated. Fecal metabolic profiles of mice in control group and operation group were obtained by LC/MS, and 14 and 21 different metabolites were screened in positive and negative ion modes, respectively. The different metabolites in positive ion mode were glutamic acid, 2-indoleic acid, kynuuric acid and glyceraldehyde. The negative ion pattern differential metabolites are methionine, aspartic acid, L-threonine, tyrosyl-threonine and 5-hydroxyindole-3-acetic acid. The identified differential metabolite pathways are mainly involved in amino acid, fatty acid and tryptophan metabolism and nucleotide synthesis. There were no significant differences in serum levels of IL-1β, IL-6 and TNF-α between the two groups (all P>0.05). Conclusion: The dysregulated changes of gut microbiota and its metabolites are correlated with the occurrence of postoperative cognitive dysfunction in elderly male C57BL/6J mice. Anesthesia and surgery alter the structure of mice intestinal bacteria on the level of abundance, and change the metabolic balance and feces metabolomic phenotype.

Features of synchronous and metachronous dual primary gastric and colorectal cancer

BACKGROUND

Studies evaluating the characteristics of dual primary gastric and colorectal cancer (CRC) (DPGCC) are limited.

AIM

To analyze the clinicopathologic characteristics and prognosis of synchronous and metachronous cancers in patients with DPGCC.

METHODS

From October 2010 to August 2021, patients with DPGCC were retrospectively reviewed. The patients with DPGCC were divided into two groups (synchronous and metachronous). We compared the overall survival (OS) between the groups using Kaplan-Meier survival methods. Univariate and multivariate analyses were performed using Cox’s proportional hazards model to identify the independent prognostic factors for OS.

RESULTS

Of the 76 patients with DPGCC, 46 and 30 had synchronous and metachronous cancers, respectively. The proportion of unresectable CRC in patients with synchronous cancers was higher than that in patients with metachronous cancers (28.3% vs 3.3%, P = 0.015). The majority of the second primary cancers had occurred within 5 years. Kaplan-Meier survival analysis showed that the patients with metachronous cancers had a better prognosis than patients with synchronous cancers (P = 0.010). The patients who had undergone gastrectomy (P < 0.001) or CRC resection (P < 0.001) had a better prognosis than those who had not. In the multivariate analysis, synchronous cancer [hazard ratio (HR) = 6.8, 95% confidence interval (95%CI): 2.0-22.7, P = 0.002)] and stage III-IV gastric cancer (GC) [HR = 10.0, 95%CI: 3.4-29.5, P < 0.001)] were risk prognostic factor for OS, while patients who underwent gastrectomy was a protective prognostic factor for OS [HR = 0.2, 95%CI: 0.1-0.6, P = 0.002].

CONCLUSION

Regular surveillance for metachronous cancer is necessary during postoperative follow-up. Surgical resection is the mainstay of therapy to improve the prognosis of DPGCC. The prognosis appears to be influenced by the stage of GC rather than the stage of CRC. Patients with synchronous cancer have a worse prognosis, and its treatment strategy is worth further exploration.

[Comparative analysis on prevalence of tobacco and e-cigarettes uses in junior middle school students in Shanghai, 2013 and 2019]

Objective: To examine the prevalence and trend of tobacco and e-cigarettes uses and identify the influencing factors for smoking behavior in junior middle school students in Shanghai, and provide data support and scientific basis for the development of tobacco control intervention strategy in adolescents. Methods: Multi-stage stratified random sampling method was used to select junior middle school students in 8 districts and 10 districts in Shanghai in 2013 and in 2019 respectively. Information about tobacco and e-cigarettes uses in the students were collected by using self-administrated questionnaire. The prevalence of tobacco and e-cigarettes uses were calculated, the difference between two years was compared with χ² test. The influencing factors were identified by multivariate logistic regression analysis. Results: In 2019, the current smoking rate was 0.6% in junior middle school students in Shanghai, and the smoking attempt rate was 2.9%, both were lower than the levels in 2013 (0.7% and 6.9%). The current use rate of e-cigarettes was 0.6% in 2019,with no significant change compared with 2013 (0.6%). The proportion of the students who had heard of e-cigarettes in 2019 (78.4%) was higher than that in 2013 (47.2%). In 2019, the second-hand smoke (SHS) exposure rate at home, in both indoor and outdoor public places and on public transportations was 72.5%, which was slightly lower than the level in 2013 (73.0%), the differences were all significant (P<0.05). In 2019, the students seeing close friend smoking (OR=27.381, 95%CI: 12.037-62.287), seeing someone smoking in school (OR=2.477, 95%CI: 1.155-5.312), believing that SHS may not be harmful (OR=8.471, 95%CI: 1.464-49.005) had higher possibility of smoking. Being aged ≥15 years (compared with being aged ≤12 years, OR=8.688, 95%CI: 1.922-39.266), exposure to SHS in outdoor public place (OR=8.608, 95%CI: 1.048-70.692), close friend smoking (OR=8.115, 95%CI: 1.754-37.545) were positively associated with e-cigarettes use, and believing that smoking results in uncomfortable social contact [compared with believing that smoking results in comfortable social contact (OR=0.105,95%CI: 0.018-0.615)] were negatively associated with e-cigarettes use, the difference was significant (P<0.05). Conclusion: The prevalence of tobacco and e-cigarette uses in junior middle school students in Shanghai remained at a low level in recent years. The SHS exposure rate in junior middle school students is high. Smoking behavior of junior middle school students is closely related to personal attitude and awareness of tobacco, exposure to SHS, peer smoking and the situation of tobacco control in schools. Prevention and intervention should be carried out from multi-dimensions to effectively protect teenagers from tobacco hazards.

[Investigation on freshwater crab populations and Paragonimus infections in the Minjiang River basin along the middle section of Wuyi Mountain]

OBJECTIVE

To investigate the populations of freshwater crabs, the intermediate host of Paragonimus and Paragonimus infections in freshwater crabs in the Minjiang River basin along the middle section of Wuyi Mountain, so as to provide baseline data for parasitic disease control and research and expansion of the parasite resource bank.

METHODS

From November 2020 to April 2021, freshwater crabs were sampled from streams and ditches neighboring residential areas in Jianning County and its neighboring Ninghua, Shaowu, Jiangle and Shunchang counties. The crab species was identified based on the morphological features of the terminal segment of the first abdominal appendage of male crabs, and Paragonimus infections were detected in freshwater crabs. The Paragonimus metacercariae were isolated, and the types of metacercariae were identified based on the metacercaria size, cystic wall thickness, and the excretory bladder and intestinal tract morphology. In addition, the prevalence, intensity and index of metacercaria infections were calculated in freshwater crabs.

RESULTS

There were seven crab species found in Jianning County and six neighboring water systems along the Minjiang River basin, including Sinopotamon jianglense, S. fukinense, Huananpotamon lichuanense, H. lini, H. shenni, H. planopodum, Bottapotamon engelhardti, and there were metacercariae of three Paragonimus species detected in these crabs, including P. westermani, P. skrjabini and P. sanpingensis, with a prevalence rate of 43.6% (125/287). The infection rates of P. westermani, P. sanpingensis and P. skrjabini were 57.1% (48/84), 26.2% (22/84) and 61.8% (21/34) in S. jianglense, and the infection rates of P. westermani and P. sanpingensis were 52.6% (51/97) and 30.9% (30/97) in S. fukinense, while the rate of P. westermani infection was 6.9% (5/72) in H. lichuanense, which is the first record of P. westermani infections in H. lichuanense. Mixed P. westermani and P. sanpingensis infections were predominantly found in freshwater crabs sampled from Jianning County, where the rate of Paragonimus infections was 70.4% (76/108), with 15.3 metacercariae identified in each crab with Paragonimus infections and 1.9 metacercariae found in each gram of crabs with Paragonimus infections, and the index of metacercariae infections was 20.5. In addition, P. westermani, P. skrjabini and P. sanpingensi metacercariae were found in freshwater crabs sampled from Jianning-neighboring counties, where the rate of Paragonimus infections was 52.3% (56/107), with 9.8 metacercariae identified in each crab with Paragonimus infections and 0.9 metacercariae found in each gram of crabs with Paragonimus infections, and the index of metacercariae infections was 4.6.

CONCLUSIONS

There are multiple freshwater crab species and Paragonimus infection is high in freshwater crabs in Jianning County and its neighboring Minjiang River basin, which is a high-risk natural focus for Paragonimus infections.

Generating high-power Lissajous structured modes and trochoidal vortex beams by an off-axis end-pumped Nd:YVO4 laser with astigmatic transformation

High-power structured beams with the transverse morphologies as the Lissajous figures are generated by an Nd:YVO₄ laser under two-dimensional off-axis pumping. By fine-tuning the cavity length in the neighborhood around the condition of longitudinal-transverse coupling, different cases of accidental degeneracies from the intracavity astigmatism are achieved to lead the output emission to be various Lissajous modes with different transverse frequency ratios. The generated Lissajous modes reveals good power performance with slope efficiency up to 47% and optical-to-optical conversion efficiency to be higher than 37.5% at a pump power of 16 W. Moreover, by applying beam transformation via a single-lens astigmatic mode converter, the generated Lissajous modes are further converted into structured vortex beams with transverse patterns localized on the trochoidal curves. The transformed trochoidal vortex beams are confirmed to preserve well-defined mode structures even when the average output power has been scaled up to be higher than 4 W.

Homology cloning, sequence characterization, and expression analysis of cDNA encoding electron transfer flavoprotein beta polypeptide in mud crab (Scylla paramamosain)

Electron transfer flavoproteins (ETFs) are αβ-heterodimers found in eukaryotic mitochondria and bacteria. Herein we report a full-length complementary DNA of a mud crab (Scylla paramamosain) ETF β subunit (Scpa-ETFB) isolated with a homology cloning strategy. The complete complementary DNA of the Scpa-ETFB contains a 17-nt 5'-untranslated region, a 765-nt open reading frame encoding 254 amino acids, and a 248-nt 3'-untranslated region. The high identity of Scpa-ETFB with ETFB in other organisms indicated that Scpa-ETFB is a new member of the ETFB family. Although the conserved motif associated with flavin adenine dinucleotide binding is absent in Scpa-ETFB, the signature sequences of the ETF superfamily were identified. Using reverse transcriptase polymerase chain reaction, we detected the messenger RNA transcript of Scpa-ETFB in high levels in the tissues of the hepatopancreas, ovary, heart, and muscle. Phylogenetic analysis showed that Scpa-ETFB is most closely related to the ETFB genes of Caligus rogercresseyi and Lepeophtheirus salmonis. These results provided basic information for elucidating the molecular mechanism of energy production in the mud crab.

Universal primers for amplification of the complete mitochondrial control region in marine fish species

Through multiple alignment analysis of mitochondrial tRNA-Thr and tRNA-Phe sequences from 161 fishes, new universal primers specially targeting the entire mitochondrial control region were designed. This new primer set successfully amplified the expected PCR products from various kinds of marine fish species, belonging to various families, and the amplified segments were confirmed to be the control region by sequencing. These primers provide a useful tool to study the control region diversity in economically important fish species, the possible mechanism of control region evolution, and the functions of the conserved motifs in the control region.

Genetic diversity of Setipinna taty (Engraulidae) populations from the China Sea based on mitochondrial DNA control region sequences

The genetic diversity of Setipinna taty, which is commercially fished in the China Sea, was studied based on mitochondrial DNA control region sequences. PCR was used to amplify the control region fragment in 100 individuals of S. taty collected from Weihai (WH), Yantai (YT), Zhoushan (ZS), Xiangshan (XS), and Ninghai (NH) in China. A control region fragment of 656 bp was successfully sequenced in these 100 individuals. The A+T content of this S. taty control region was 71.7%; 172 variable sites and 62 haplotypes were found. Nucleotide diversity in the WH, YT, ZS, XS, and NH groups was 0.0228, 0.0247, 0.0441, 0.0126, and 0.0238, respectively. The haplotype diversity was 0.984, 0.911, 0.989, 0.926, and 0.979, respectively. Analysis of molecular variance showed that 97.95% of genetic variation was within populations, and only 2.05% among populations. The neighbor-joining phylogenetic tree obtained based on genetic distance showed that no significant genealogical structure exists throughout this range of S. taty. These results indicate no apparent geographical differentiation in the comparison of Yellow Sea and East China Sea populations of S. taty. Within the control region, we identified an extended termination-associated sequence domain, a central conserved sequence block domain and a conserved sequence block domain; insertions of short tandem repeat sequence segments were found at the 5' end of the control region.

[The development of a function-rehabilitation trainer for lower limb joints]

We'd like to introduce to you an exercising trainer for the recovery of functions of lower limb joints. It is beneficial to early-stage rehabilitation of lower limb joints after the operation. The light-weighted, portabl trainer is easy to operate duc to its innovative structure and design. In addition, the speed, angle and time of exercise of this trainer is automatically adjusted to best fit your needs, making it an advanced trainer for recovery purpose.

Early afterdepolarization induced by ryanodine in atrial fibers of mouse heart

The effects of ryanodine on the action potential and induction of early afterdepolarization (EAD) were studied in the atrial fibers of mouse heart. Under treatment with ryanodine, the duration of the action potential (ADP) was prolonged. The percentage of the prolongation of ADP25, APD50 and ADP100 were 83, 49 and 20%, respectively, at a cycle length of 1 sec driving stimulation. As the cycle length was prolonged (from 0.5-10 sec), EAD could be induced in 10 of 16 preparations showing exponential relationship with the cycle length. Tetrodotoxin, lidocaine and nifedipine inhibited the induction of EAD. In 6 preparations in which the EAD was not induced, more than one burst could respond to a single premature stimulation applied in the early phase of repolarization, which was defined as second plateau response. The mechanism of ryanodine-induced EAD has been investigated.

Early afterdepolarization in mouse atrial fibers induced by 3.0 mM K+ and the inhibitory effects of tetrodotoxin and nifedipine

Early afterdepolarization (EAD) was induced under superfusion of Tyrode solution (K+ = 3.0 mM) at a longer cycle length in mouse atrial fibers. The relationships between the duration and the number of triggered bursts and cycle length were exponential (n = 17). Thus, EAD possesses the property of cycle length dependence. Under a moderate concentration of TTX (4.0 microM) or nifedipine (5.0 microM) treatment, EAD was partially inhibited but maintained cycle length dependence. When a high concentration of the drugs (30 microM and 8.0 microM, respectively) was applied, EAD was abolished at all cycle lengths of driving stimulation. It is suggested that both inward currents (INa and ICa) are involved in the generation of EAD in mouse atrial fibers.

[Establishment and experimental study of a transplantable hepatocellular carcinoma model in 615-strain mice (H 615)]

H 615, the first transplantable mouse liver carcinoma model established in China, was derived from a spontaneous hepatocellular carcinoma of an inbred 615 mouse and has been successfully propagated for 52 generations during the past 7 years and more. Its biologic and pathologic features are relatively stable. H 615 was a syngenic transplantable tumor model of 615-strain mice with a successful transplantation rate of 85.6% without spontaneous regression. The course of tumor growth after subcutaneous inoculation was divided into 4 stages: latent, slowly growing, rapidly growing and terminal stages. Cancer metastasis was rare. The tumor-bearing host would die of cachexia finally. The mean survival time was 62.2 +/- 11.0 days regardless of sex or age. Histologically and ultrastructurally, H 615 was a well-differentiated hepatocellular carcinoma, rather resembling human liver carcinoma. The short-term primary passage culture of H 615 showed that, in vitro, tumor tissue could easily grow into monolayer, the majority of which appeared as epithelioid cells in cytomorphology. Therapeutic tests of 15 anticancer drugs showed that H 615 was sensitive, in varying degrees, to 5 drugs, i. e. MMC, Thio-Tepa, 5FU, CPT and DACT. The inhibition rate of MMC and Thio-Tepa could be as high as 100%. These experimental results are similar to those of the human liver cancer chemotherapy. Hence, the authors believe that H 615 may be a useful model in experimental study of the liver cancer and screening of anticancer drugs.