Combined propidium monoazide pretreatment with high-throughput sequencing evaluated the bacterial diversity in chicken skin after thermal treatment

AIMS

The purpose of this experiment was to study the bacterial diversity and predominance of spoilage bacteria in chicken skin at different thermal treatment temperatures (60, 70, 80, 90, 100, 110, 120°C).

METHOD AND RESULTS

Bacteria in chicken skin was collected, then propidium monoazide treatment to remove the DNA of dead cell, total DNA was extracted by Tiandz Bacterial DNA Kit, and investigated by high-throughput sequencing of the v3/v4 regions of the 16S rDNA gene. A total of 796 008 high-quality bacterial sequences were obtained for assessing the microbial diversity of chicken skin from seven thermal treatment group and control group. The results showed that the bacterial diversity in chicken skin at 90°C was lowest. And Acinetobacter (25·88%), Clostridium (20·70%), Bacteroides (13·93%) and Myroides (13·13%) were the main flora at 25°C; The Clostridium was dominant genus of the samples heat-treated by 60, 70, 80 and 90°C, the proportion of this genus were up to 64·86, 77·42, 52·22 and 87·30% respectively. The Bacillus was the main flora of the samples heat-treated by 100, 110 and 120°C, and the relative percentages were 39·44, 79·61 and 45·96% respectively. In addition, high-temperature-resistant Serratia was found in chicken skin.

CONCLUSIONS

The study revealed that the relationship between thermal treatment temperature and bacterial diversity and dominant spoilage bacteria in chicken skin, which had a strong guiding significance for the control and prediction of micro-organisms in foods.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of this paper could provide a theoretical basis for meat products containing chicken skin, including the safe use of chicken skin, determination of sterilization process parameters and selection of preservatives for compounding, which has strong practicality in China.

[Change of esophageal length measured on computed tomography after corrective osteotomy for cervicothoracic kyphosis in patients with ankylosing spondylitis and its clinical significance]

Objective: To investigate the change of esophageal length measured on computed tomography after C(7) pedicle subtraction osteotomy (PSO) for cervicothoracic kyphosis in ankylosing spondylitis (AS) patients and its clinical significance. Methods: Eight male AS patients with cervicothoracic kyphosis, who underwent PSO at C(7) level from December 2014 to November 2018 at Nanjing Drum Tower Hospital, were retrospectively reviewed. The mean age was (35±7) years (range, 26-49 years). The cervicothoracic kyphosis, C(2)-T(1) sagittal vertical axis (SVA) and angle of fusion levels (AFL) were measured on lateral cervical radiographs and chin-brow vertical angle (CBVA) was measured on clinical photographs preoperatively and postoperatively. Anterior height of the osteotomized vertebra (AHOV) and esophageal length from the lower endplate of C(6) to the inferior endplate of the lower instrumented vertebrae were measured on sagittal plane of reconstructed computed tomography preoperatively and postoperatively. Oswestry Disability Index (ODI), Neck Disability Index (NDI) and Numerical Rating Scale (NRS) were collected to evaluate the clinical outcomes. Results: The average follow-up duration was (15±9) months (range, 3-51 months). The average correction of cervicothoracic kyphosis, C(2)-T(1)SVA, AFL and CBVA was 35.9°±7.3°, (44.7±11.6) mm, 32.0°±4.8° and 38.1°±11.5°, respectively. The average reduction of AHOV was (5.6±1.6) mm. ODI was improved from 17±14 preoperatively to 13±10 at the final follow-up. The NDI before operation and at the final follow-up was 18±15 and 10±6, respectively. The preoperative NRS was 4.8±2.4, and it decreased to 1.0±1.2 at the final follow-up. The change of esophageal length showed significant correlation with the improvement of cervicothoracic kyphosis, C(2)-T(1)SVA, AFL and CBVA(r=0.84, 0.83, 0.83, 0.73, all P<0.05). Conclusions: The operation of C(7)PSO increases esophageal length after cervicothoracic kyphosis in AS patients. The esophageal elongation is closely related with changes of parameters measured on radiographs and clinical photographs. Spine surgeons should be aware of the potential risk of esophagus-related complications caused by esophagus lengthening after C(7)PSO.

Downregulation of miR-145-5p contributes to hyperproliferation of keratinocytes and skin inflammation in psoriasis

BACKGROUND

The extensive involvement of microRNAs (miRNAs) in the pathogenesis of psoriasis is well documented. However, little is known about the contribution of specific miRNAs to the prevalence of this disease.

OBJECTIVES

To explore the role of miR-145-5p in psoriasis.

METHODS

miRNA microarray analysis was performed in four patients with psoriasis and four controls. Quantitative reverse-transcriptase polymerase chain reaction and fluorescence in situ hybridization were used to identify the dysregulated miRNAs. Luciferase assays were performed to determine whether miR-145-5p targets mixed-lineage kinase (MLK)3. CCK-8 assay and Magnetic Luminex Assay were performed to measure cell proliferation and chemokine secretion. Western blot analysis was used to investigate the protein levels of MLK3 and its downstream effectors. Mouse models of psoriasis were established for in vivo experiments.

RESULTS

miR-145-5p was downregulated in psoriatic lesional skin. Luciferase assays showed that MLK3 is a direct target of miR-145-5p. Overexpression of miR-145-5p in normal human epidermal keratinocytes (NHEKs) suppressed cell proliferation and secretion of chemokines. In contrast, silencing miR-145-5p promoted NHEK proliferation and increased chemokine secretion. Silencing MLK3 abrogated miR-145-5p inhibitor-induced promotion of cell proliferation and chemokine expression. miR-145-5p regulates nuclear factor-κB and signal transducer and activator of transcription 3 by targeting MLK3. Delivery of agomiR-145-5p into the skin decreased epidermal hyperplasia and ameliorated psoriasis-like dermatitis. Delivery of antagomiR-145-5p led to the opposite effects.

CONCLUSIONS

Our findings indicate that miR-145-5p negatively regulates proliferation and chemokine secretion of NHEKs by targeting MLK3, and downregulation of miR-145-5p contributes to skin inflammation in psoriasis lesions.

Gene Expression in the Hippocampus in a Rat Model of Premenstrual Dysphoric Disorder After Treatment With Baixiangdan Capsules

Objective: To explore the targets, signal regulatory networks and mechanisms involved in Baixiangdan (BXD) capsule regulation of premenstrual dysphoric disorder (PMDD) at the gene transcription level, since the etiology and pathogenesis of PMDD are not well understood.

Methods: The PMDD rat model was prepared using the resident-intruder paradigm. The rats were tested for aggressive behavior, and those with scores in the lowest 30% were used as controls, while rats with scores in the highest 30% were divided into a PMDD model group, BXD administration group and fluoxetine administration group, which were evaluated with open-field tests and aggressive behavior tests. We also analyzed gene expression profiles in the hippocampus for each group, and verified differential expression of genes by real-time PCR.

Results: Before and after BXD or fluoxetine administration, scores in the open-field test exhibited no significant differences. The aggressive behavior of the PMDD model rats was improved to a degree after administration of both substances. Gene chip data indicated that 715 genes were differentially expressed in the control and BXD groups. Other group-to-group comparisons exhibited smaller numbers of differentially expressed genes. The effective targets of both drugs included the Htr2c, Cdh3, Serpinb1a, Ace, Trpv4, Cacna1a, Mapk13, Mapk8, Cyp2c13, and Htr1a genes. The results of real-time PCR tests were in accordance with the gene chip data. Based on the target genes and signaling pathway network analysis, we have elaborated the impact and likely mechanism of BXD in treating PMDD and premenstrual irritability.

Conclusion: Our work contributes to the understanding of PMDD pathogenesis and the mechanisms of BXD treatment. We speculate that the differentially expressed genes could participate in neuroactive ligand-receptor interactions, mitogen-activated protein kinase, calcium, and gamma-aminobutyric acid signal transduction.

Social defeat stress before pregnancy induces depressive-like behaviours and cognitive deficits in adult male offspring: correlation with neurobiological changes

BACKGROUND

Epidemiological surveys and studies with animal models have established a relationship between maternal stress and affective disorders in their offspring. However, whether maternal depression before pregnancy influences behaviour and related neurobiological mechanisms in the offspring has not been studied.

RESULTS

A social defeat stress (SDS) maternal rat model was established using the resident-intruder paradigm with female specific pathogen-free Wistar rats and evaluated with behavioural tests. SDS maternal rats showed a significant reduction in sucrose preference and locomotor and exploratory activities after 4 weeks of stress. In the third week of the experiment, a reduction in body weight gain was observed in SDS animals. Sucrose preference, open field, the elevated-plus maze, light-dark box, object recognition, the Morris water maze, and forced swimming tests were performed using the 2-month-old male offspring of the female SDS rats. Offspring subjected to pre-gestational SDS displayed enhanced anxiety-like behaviours, reduced exploratory behaviours, reduced sucrose preference, and atypical despair behaviours. With regard to cognition, the offspring showed significant impairments in the retention phase of the object recognition test, but no effect was observed in the acquisition phase. These animals also showed impairments in recognition memory, as the discrimination index in the Morris water maze test in this group was significantly lower for both 1 h and 24 h memory retention compared to controls. Corticosterone, adrenocorticotropic hormone, and monoamine neurotransmitters levels were determined using enzyme immunoassays or radioimmunoassays in plasma, hypothalamus, left hippocampus, and left prefrontal cortex samples from the offspring of the SDS rats. These markers of hypothalamic-pituitary-adrenal axis responsiveness and the monoaminergic system were significantly altered in pre-gestationally stressed offspring. Brain-derived neurotrophic factor (BDNF), cyclic adenosine monophosphate response element binding protein (CREB), phosphorylated CREB (pCREB), and serotonin transporter (SERT) protein levels were evaluated using western blotting with right hippocampus and right prefrontal cortex samples. Expression levels of BDNF, pCREB, and SERT in the offspring were also altered in the hippocampus and in the prefrontal cortex; however, there was no effect on CREB.

CONCLUSION

We conclude that SDS before pregnancy might induce depressive-like behaviours, cognitive deficits, and neurobiological alterations in the offspring.

Pharmacological Effects and Chemical Constituents of Bupleurum

Radix Bupleuri has been used in traditional Chinese medicine for thousands of years, with confirmed curative effects. This plant is also used in healthy food and cosmetics. A recent increase in studies of Radix Bupleuri's chemical constituents (mainly comprising flavonoids, lignins, phenyl propanol derivatives, triterpenoid saponins, and volatile oils) and pharmacological effects motivates the aim of the present study: to review the chemical components and pharmacological effects of Radix Bupleuri. Our review found that Radix Bupleuri exhibits diverse pharmacological effects. More than 281 components have been isolated from Radix Bupleuri, including 15 flavonoids, 430 lignins, 12 phenyl propanol derivatives, 66 triterpenoid saponins, and 158 volatile oils.

Shuyu capsules relieve liver-qi depression by regulating ERK-CREB-BDNF signal pathway in central nervous system of rat

The purpose of this study was to investigate the possible therapeutic mechanism of Shuyu capsules in liver-qi depression. Liver-qi depression rats were prepared based on chronic unpredictable mild stress (CUMS) and delayed constraint. Rats were gavaged with Shuyu capsule, fluoxetine, Radix Bupleuri and Radix Paeoniae Alba to constrct rat models. Body weight test, sucrose preference test and open-field test were applied to test rat models. Western blot analysis and quantitative real-time PCR was applied to determine the relative expression of extracellular signal-regulated protein kinase (ERK), cyclic AMP response element binding protein (CREB) and brain-derived neurotrophic factor (BDNF) in hippocampus and frontal lobe tissues. ELISA was used to detect the content of BDNF in serum. Body weight, sugar intake and total distance were significantly decreased in depression group compared with control. The four drugs significantly increased levels of these factors. Compared with control group, ERK, CREB and BDNF expression were significantly decreased in depression group in both hippocampus and frontal lobe tissues at both mRNA and protein level. Shuyu capsule and fluoxetine group showed a significant increase in the expression of ERK, CREB and BDNF at mRNA, p-ERK and p-BDNF at protein level. Compared with Radix Paeoniae Alba, Radix Bupleuri were better in the rescue of ERK, CREB and BDNF expression. In conclusion, the pathogenesis of liver-qi depression associated with lower expression of ERK, CREB and BDNF in hippocampus and frontal. Shuyu capsule and main constitution alleviated the depressive-like behaviors and reversed the disruptions of the p-ERK, p-CREB and BDNF in stressed rats.

[Clinical study of the effect of free gingival graft and apically repositioned flap surgery on peri-implant keratinized gingival augmentation]

Objective: To compare and analyze the clinical outcomes of apically repositioned flap surgery and free gingival graft on keratinized gingival augmentation. Methods: Totally 30 partially edentulous patients treated with submerged implant surgery in mandibular molar area were recruited and divided into three groups: group 1(mean age: 41 years) and group 2 (mean age: 25 years) received free gingival graft 1 month after submerged implant surgery and second stage implant surgery3 months after submerged implant surgery; group 3(mean age: 44 years) received apically repositioned flap and second stage implant surgery 3 months after submerged implant surgery. The widths of keratinized gingiva were measured respectively at the time before the apically repositioned flap surgery/free gingival graft and 1 month, 6 months after the surgery. The thickness of keratinized gingiva was measured during the operation. Results: The widths of peri-implant keratinized gingiva of group 1 and group 2 were (3.1±1.2) mm and (3.5±1.0) mm 1 month after the free gingival graft surgery, (3.0±1.3) mm and (3.5±1.0) mm 6 months after the free gingival graft surgery, respectively. The widths of peri-implant keratinized gingiva in group 1 and group 2 demonstrated no statistically significant differences(P>0.05). The widths of peri-implant keratinized gingiva of group 3 was (2.6±0.5) mm 1 month after the apically repositioned flap surgery, (1.9±0.3) mm 6 months after the apically repositioned flap surgery, respectively. The widths of peri-implant keratinized gingiva(1 month and 6 months after the apically repositioned flap surgery) in group 3 showed statistically significant differences when compared with group 1 and group 2(P=0.008, P=0.000). Conclusions: The implant area treated with free gingival graft or apically repositioned flap exhibited increased width of the keratinized gingiva. The implants treated with free gingival graft exhibited more increased width of the keratinized gingiva compared with those treated with apically repositioned flap. Age showed little impact on keratinized gingival augmentation.

Inhibition of Duck Hepatitis B Virus Replication in vivo by the Nucleoside Analogue Ganciclovir (9-[2-hydroxy-1-(hydroxymethyl) ethoxymethyl] Guanine)

Treatment of ducks congenitally infected with the duck hepatitis B virus (DHBV) using the guanosine analogue ganciclovir resulted in prompt and profound inhibition of viral DNA replication in serum and liver. By the end of the treatment period all the replicative intermediates, except the supercoiled DNA form, could not be detected. Within 2 weeks of cessation of treatment viral replication returned and, in some cases, rebound occurred. Sequential treatment with prednisolone followed by ganciclovir also resulted in inhibition of viral replication and, even though relapse was observed after therapy was discontinued, the rebound phenomenon was reduced. Ganciclovir significantly and selectively inhibited DHBV DNA replication but may be more efficacious if used in combination with compounds targeted to the viral supercoiled DNA form.

Promoting inflammatory lymphangiogenesis by vascular endothelial growth factor-C (VEGF-C) aggravated intestinal inflammation in mice with experimental acute colitis

Angiogenesis and lymphangiogenesis are thought to play a role in the pathogenesis of inflammatory bowel diseases (IBD). However, it is not understood if inflammatory lymphangiogenesis is a pathological consequence or a productive attempt to resolve the inflammation. This study investigated the effect of lymphangiogenesis on intestinal inflammation by overexpressing a lymphangiogenesis factor, vascular endothelial growth factor-C (VEGF-C), in a mouse model of acute colitis. Forty eight-week-old female C57BL/6 mice were treated with recombinant adenovirus overexpressing VEGF-C or with recombinant VEGF-C156S protein. Acute colitis was then established by exposing the mice to 5% dextran sodium sulfate (DSS) for 7 days. Mice were evaluated for disease activity index (DAI), colonic inflammatory changes, colon edema, microvessel density, lymphatic vessel density (LVD), and VEGFR-3mRNA expression in colon tissue. When acute colitis was induced in mice overexpressing VEGF-C, there was a significant increase in colonic epithelial damage, inflammatory edema, microvessel density, and neutrophil infiltration compared to control mice. These mice also exhibited increased lymphatic vessel density (73.0±3.9 vs 38.2±1.9, P<0.001) and lymphatic vessel size (1974.6±104.3 vs 1639.0±91.5, P<0.001) compared to control mice. Additionally, the expression of VEGFR-3 mRNA was significantly upregulated in VEGF-C156S mice compared to DSS-treated mice after induction of colitis (42.0±1.4 vs 3.5±0.4, P<0.001). Stimulation of lymphangiogenesis by VEGF-C during acute colitis promoted inflammatory lymphangiogenesis in the colon and aggravated intestinal inflammation. Inflammatory lymphangiogenesis may have pleiotropic effects at different stages of IBD.