Objective To compare the hematological parameters,biochemical profiles,histopathological characteristics,and cytokines associated with lipid metabolism in 8-weeks-old specific pathogen-free(SPF)grade and germ-free(GF)golden hamsters.Methods Twenty 8-weeks-old SPF grade and GF golden hamsters,with equal numbers of males and females,were utilized in this study.Serum cytokines associated with routine blood parameters,blood biochemistry,and lipid metabolism were quantified using automated hematology and biochemical analyzers,and enzyme-linked immunosorbent assay kits.The cecum,small intestine,lung,spleen,forestomach,and glandular stomach were examined by histopathology.Results We compared the result between SPF grade and GF golden hamsters at 8 weeks of age.Regarding hematological parameters,females showed significant differences(P＜0.05)in white blood cell count,hemoglobin concentration,mean corpuscular hemoglobin(MCH),and mean platelet volume between the two groups,and highly significant differences(P＜0.001)in MCH concentration(MCHC),platelet distribution width(PDW),and lymphocyte count(LYM).Males showed significant differences(P＜0.05)in mean corpuscular volume,MCH,LYM,neutrophil count,basophil count,and basophil percentage,and highly significant differences(P＜0.001)in MCHC,PDW,lymphocyte percentage,and neutrophil percentage.In terms of biochemical parameters,females showed significant differences(P＜0.05)in low-density lipoprotein cholesterol(LDL-C),high-density lipoprotein cholesterol,fasting insulin(FINS),and glycosylated serum protein(GSP),and highly significant differences(P＜0.001)in triglycerides(TG).Males showed significant differences(P＜0.05)in GSP levels and highly significant differences(P＜0.001)in total cholesterol,TG,LDL-C,FINS,and C-peptide levels.For serum cytokines related to lipid metabolism,females showed significant differences(P＜0.05)in interleukin(IL)-10,adiponectin(ADP),and IL-6 levels,and highly significant differences(P＜0.001)in high-sensitivity C-reactive protein(hs-CRP).Males showed significant differences(P＜0.05)in hs-CRP levels and highly significant differences(P＜0.001)in ADP and tumor necrosis factor-alpha levels.Hematoxylin/eosin staining showed that the cecal muscle layer was thinner and the number of crypts attached to the mucous membrane was reduced in GF compared with SPF grade golden hamsters.In addition,the ileocele was enlarged and the number of goblet cells was increased,the alveolar septum was widened,immune cells in the white pulp of the spleen were increased,and the blood content in the blood sinuses was increased.There was also thinning of the anterior gastric mucosa and the basophilic strength of the glandular gastric tube gland was weakened.Conclusions This study established the differences in routine blood parameters,blood biochemistry indicators,histopathological features,and cytokines associated with lipid metabolism between 8-weeks-old SPF grade and GF golden hamsters,to establish preliminary reference ranges.

In recent years,germ-free rats and mice have received extensive attention and application in the field of biomedical research,particularly in gut microbiota studies.The demand for germ-free rodents has been increasing,requiring many research institutions to establish quality germ-free animal populations.The process of breeding first-generation germ-free animals involves highly specialized and technically challenging work,such as using artificial rearing techniques to feed rodent pups.This review article provides an overview of key aspects of artificial rearing techniques,including nursing method,preparation of artificial milk,and sterilization method.It retrospectively summarizes the key technical points and,based on this foundation,offers prospects for further applications of artificial rearing techniques.

In recent years,germ-free rats and mice have received extensive attention and application in the field of biomedical research,particularly in gut microbiota studies.The demand for germ-free rodents has been increasing,requiring many research institutions to establish quality germ-free animal populations.The process of breeding first-generation germ-free animals involves highly specialized and technically challenging work,such as using artificial rearing techniques to feed rodent pups.This review article provides an overview of key aspects of artificial rearing techniques,including nursing method,preparation of artificial milk,and sterilization method.It retrospectively summarizes the key technical points and,based on this foundation,offers prospects for further applications of artificial rearing techniques.

Objective To compare the hematological parameters,biochemical profiles,histopathological characteristics,and cytokines associated with lipid metabolism in 8-weeks-old specific pathogen-free(SPF)grade and germ-free(GF)golden hamsters.Methods Twenty 8-weeks-old SPF grade and GF golden hamsters,with equal numbers of males and females,were utilized in this study.Serum cytokines associated with routine blood parameters,blood biochemistry,and lipid metabolism were quantified using automated hematology and biochemical analyzers,and enzyme-linked immunosorbent assay kits.The cecum,small intestine,lung,spleen,forestomach,and glandular stomach were examined by histopathology.Results We compared the result between SPF grade and GF golden hamsters at 8 weeks of age.Regarding hematological parameters,females showed significant differences(P＜0.05)in white blood cell count,hemoglobin concentration,mean corpuscular hemoglobin(MCH),and mean platelet volume between the two groups,and highly significant differences(P＜0.001)in MCH concentration(MCHC),platelet distribution width(PDW),and lymphocyte count(LYM).Males showed significant differences(P＜0.05)in mean corpuscular volume,MCH,LYM,neutrophil count,basophil count,and basophil percentage,and highly significant differences(P＜0.001)in MCHC,PDW,lymphocyte percentage,and neutrophil percentage.In terms of biochemical parameters,females showed significant differences(P＜0.05)in low-density lipoprotein cholesterol(LDL-C),high-density lipoprotein cholesterol,fasting insulin(FINS),and glycosylated serum protein(GSP),and highly significant differences(P＜0.001)in triglycerides(TG).Males showed significant differences(P＜0.05)in GSP levels and highly significant differences(P＜0.001)in total cholesterol,TG,LDL-C,FINS,and C-peptide levels.For serum cytokines related to lipid metabolism,females showed significant differences(P＜0.05)in interleukin(IL)-10,adiponectin(ADP),and IL-6 levels,and highly significant differences(P＜0.001)in high-sensitivity C-reactive protein(hs-CRP).Males showed significant differences(P＜0.05)in hs-CRP levels and highly significant differences(P＜0.001)in ADP and tumor necrosis factor-alpha levels.Hematoxylin/eosin staining showed that the cecal muscle layer was thinner and the number of crypts attached to the mucous membrane was reduced in GF compared with SPF grade golden hamsters.In addition,the ileocele was enlarged and the number of goblet cells was increased,the alveolar septum was widened,immune cells in the white pulp of the spleen were increased,and the blood content in the blood sinuses was increased.There was also thinning of the anterior gastric mucosa and the basophilic strength of the glandular gastric tube gland was weakened.Conclusions This study established the differences in routine blood parameters,blood biochemistry indicators,histopathological features,and cytokines associated with lipid metabolism between 8-weeks-old SPF grade and GF golden hamsters,to establish preliminary reference ranges.

Objective To evaluate the effects of fecal status and transplantation method on the intestinal flora structure after fecal microbiota transplantation in germ-free mice.Methods Thirty-six C57BL/6 mice were divided randomly into three groups:fresh fecal gavage transplantation(group A),frozen fecal gavage transplantation(group B),and frozen fecal rectal transplantation groups(group C).Feces were collected at 2,4 and 6 weeks after transplantation.All mice were sacrificed at 6 weeks to obtain the contents of the small and large intestines.The structure and function of the gut microbiota and dynamic trends in microbial changes were analyzed by 16 S rRNA sequencing.Results The diversity of the small intestine microbes in both the group A and group C were similar to those in the group B,according to α-diversity analysis(P＞0.05),but the diversity of large intestine microbes was significantly increased(P＜0.001).According toβ-diversity analysis,small intestine samples from the group A and group B clustered in the same area,indicating that the microbial community compositions were similar(P＞0.05),but samples from the large intestine were distributed in different areas,showing significant differences(P＜0.001).Small and large intestine samples from the group B and group C were distributed in different areas,with significant differences(P＜0.001).Linear discriminant analysis effect size showed that Bacteroidota were relatively dominant in the group A,while Verrucomicrobiota and Proteobacteria were relatively dominant in the group B and Firmicutes were relatively dominant in the group C.Functional prediction using PICRUSt2 software showed that neither fecal status nor the method of transplantation affected the functions of the microbial community.Conclusions Both fresh fecal gavage and frozen fecal rectal transplantation can enhance the microbial diversity of the large intestine,compared with frozen fecal gavage transplantation.Fecal status does not affect the gut function and colonization trends of the microbiota,whereas the method of transplantation affects the colonization trends but not the functions of the microbiota.

Objective A sterile golden hamster model was established by cesarean section purification.Methods SPF-grade donor female golden hamsters were selected,and males and females were mated 1∶1 and separated after mating.The cage time of the surrogate mothers was 1 week earlier than that of the donor mothers.Parturient golden hamsters underwent hysterectomy on a sterilized workbench,and the uteruses were transferred into isolation kits and stripped.To obtain sterile milk for milk replacement,sterile ICR mice and sterile SD rats were used.After successful separation,the hamsters were transferred to isolation kits to prepare for feeding.The sterility status of the feeding isolation kits was tested monthly.Results Three caesarean sections were performed,but the first and second lactations failed.The third milk replacement was successful,and 18 young hamsters were obtained with survival rates of 88%and 66%after weaning.All hamsters were quality tested by GB/T 14926.41-2001.Conclusions Using a cesarean section purification technique and sterile ICR mice and SD rats for microbial-free milk replacement,a sterile golden hamster model was obtained.

Objective To evaluate the effects of fecal status and transplantation method on the intestinal flora structure after fecal microbiota transplantation in germ-free mice.Methods Thirty-six C57BL/6 mice were divided randomly into three groups:fresh fecal gavage transplantation(group A),frozen fecal gavage transplantation(group B),and frozen fecal rectal transplantation groups(group C).Feces were collected at 2,4 and 6 weeks after transplantation.All mice were sacrificed at 6 weeks to obtain the contents of the small and large intestines.The structure and function of the gut microbiota and dynamic trends in microbial changes were analyzed by 16 S rRNA sequencing.Results The diversity of the small intestine microbes in both the group A and group C were similar to those in the group B,according to α-diversity analysis(P＞0.05),but the diversity of large intestine microbes was significantly increased(P＜0.001).According toβ-diversity analysis,small intestine samples from the group A and group B clustered in the same area,indicating that the microbial community compositions were similar(P＞0.05),but samples from the large intestine were distributed in different areas,showing significant differences(P＜0.001).Small and large intestine samples from the group B and group C were distributed in different areas,with significant differences(P＜0.001).Linear discriminant analysis effect size showed that Bacteroidota were relatively dominant in the group A,while Verrucomicrobiota and Proteobacteria were relatively dominant in the group B and Firmicutes were relatively dominant in the group C.Functional prediction using PICRUSt2 software showed that neither fecal status nor the method of transplantation affected the functions of the microbial community.Conclusions Both fresh fecal gavage and frozen fecal rectal transplantation can enhance the microbial diversity of the large intestine,compared with frozen fecal gavage transplantation.Fecal status does not affect the gut function and colonization trends of the microbiota,whereas the method of transplantation affects the colonization trends but not the functions of the microbiota.

Objective Using different sterilization method to sterilize pig specific formula milk powder,exploring the sterilization method and conditions that minimize the loss of nutritional components in formula milk powder.Methods Pig-specific formula milk powder was divided into high-pressure sterilization and irradiation sterilization groups.Formula milk powder in the high-pressure group was sterilized using different sterilization conditions and that in the irradiation group was sterilized using different 60 Co γ-radiation doses.The sterility and the nutritional contents of the sterilized formula milk powders were determined according to national standards.Results The sterility tests for both groups of formula milk powder were negative.Compared to control group,the crude protein contents were significantly lower in formula in the high-pressure group sterilized at 121℃for 30 min and in the irradiation liquid group sterilized at 50 kGy(P<0.01).The water,crude protein,and calcium contents were significantly lower(P<0.001)in the irradiation group sterilized at 50 kGy.There was no significant difference in the valine,isoleucine,or leucine content under 50 kGy sterilization conditions in the irradiation sterilized group,but all amino acid contents were decreased in the high-pressure sterilization and irradiation sterilized liquid groups(P<0.001).Analysis of trace elements showed an increased iron content(P<0.001)in formula sterilized at 121℃for 30 min in the high-pressure sterilization group,increased iron and potassium contents(P<0.001)under 25 kGy sterilization conditions in the irradiation sterilization liquid group,and increased magnesium content(P<0.01).The magnesium(P<0.05)and sodium contents(P<0.01)differed significantly in formula treated under 50 kGy sterilization conditions in the irradiation sterilized powder group.VE and VB2 contents were increased in formula sterilized at 121℃for 30 min in the high-pressure sterilization group(P<0.001),the VE content was increased(P<0.05)and the VB2 content was decreased(P<0.001)in formula sterilized under 50 kGy conditions in the irradiation sterilization liquid group,and the VE and VA contents were decreased in formula sterilized at 25 kGy in the irradiation sterilized powder group(P<0.001).Conclusions Sterilization at 121℃for 30 min result ed in the least loss of nutritional components in the high-pressure sterilization group,while irradiation sterilization result ed in the least loss of nutrients at a dose of 50 kGy.Comparing the two sterilization method,irradiation of milk powder at 50 kGy result ed in the least loss of nutrient content.

Objective To investigate the characteristics of gut microbiota in SD rat model of diabetes mellitus induced by streptozotocin (STZ). Methods Twenty-five male SD rats were randomly divided into control (C) (n＝10) and diabetes (M) (n＝15) groups. Rats in the group M received intravenous injection of streptozotocin (30 mg/kg) once per day for 5 consecutive days. Fecal samples were collected and examined for the V3 region of the 16S rDNA gene by Illumina Miseq high-throughput sequencing. The abundance and composition of gut microbiota were analyzed by cluster analysis. Results DNA sequence analysis was successfully performed. The Chao 1 index was lower in the group M than group C (P＜ 0. 05). The Shannon index was lower and the Simpson index was higher in the group M than group C (P＜0. 05). At phylum level, the relative abundance of Proteobacteria, Cyanobacteria, Tenericutes, TM7, and Actinobacteria was lower in the group M than group C (P＜ 0. 05). At genus level, 4 weeks after injection,the abundance of Lactobacillus was lower and that of Bacteroidetes was higher in the group M than group C ( P＜ 0. 05). 12 weeks after injection, the relative abundance of Lactobacillus,Bacteroides and Ruminococcus was higher and that of Bifidobacterium was lower in the group M than group C ( P＜ 0. 05). Conclusions This STZ-induced diabetic SD rat model has a low abundance and diversity of gut microbiota. Quantitative analysis of gut microbiota composition in this animal model provides a basic data for the study of relationship between diabetes mellitus and gut microbiota.

Objective: To investigate the effect of irradiation to anastomosis from preoperative radiotherapy for patients with rectal cancer by studying the pathological changes. Methods: In this retrospective study, patients enrolled in the FOWARC study from January 2011 to July 2014 in the Sixth Affiliated Hospital of Sun Yat-Sen University were included. In the FOWARC study, enrolled patients with local advanced rectal cancer were randomly assigned to receive either neoadjuvant chemo-radiotherapy or chemotherapy. Among these patients, 23 patients were selected as radiation proctitis (RP)group, who fulfilled these conditions: (1) received neoadjuvant chemo-radiotherapy followed by sphincter-preserving surgery; (2) developed radiation proctitis as confirmed by preoperative imaging diagnosis; (3) had intact clinical samples of surgical margins. Twenty-three patients who had received neoadjuvant chemo-radiotherapy but without development of radiation proctitis were selected as non-radiation proctitis (nRP) group. Meanwhile, 23 patients received neoadjuvant chemotherapy only were selected as neoadjuvant chemotherapy (CT) group. Both nRP and CT cases were selected by ensuring the basic characteristics such as sex, age, tumor site, lengths of proximal margin and distal margin all maximally matched to the RP group. Both proximal and distal margins were collected for further analysis for all selected cases. Microscopy slices were prepared for hematoxylin & eosin staining and Masson staining to show general pathological changes, and also for immunohistochemistry with anti-CD-34 as primary antibody to reveal the microvessel. Microvessel counting in submucosal layer and proportion of macrovessel with stenosis were used to evaluate the blood supply of the proximal and distal end of anastomosis. A modified semi-quantitative grading approach was used to evaluate the severity of radiation-induced injury. Either ANOVA analysis, Kruskal-Wallis rank-sum test or χ² test was used for comparison among three groups, and Mann-Whitney U test was used for comparison between two groups. Results: Compared to group of neoadjuvant chemotherapy only, patients receiving neoadjuvant chemo-radiotherapy had lower microvessel count in both proximal and distal margins (M(Q_R): proximal, 25.5 (19.6) vs. 50.0 (25.0), Z=3.915, P=0.000; distal, 20.5 (17.5) vs. 49.0 (28.0), Z=3.558, P=0.000), higher proportions of macrovessel with stenosis (proximal, 9.5% (23.8%) vs. 0, Z=3.993, P=0.000; distal, 11.5%(37.3%) vs. 0 (2.0%), Z=2.893, P=0.004), higher histopathologic score (proximal, 4.0 (2.0) vs. 1.0 (2.0), Z=6.123, P=0.000; distal, 5.0 (3.0) vs. 2.0 (1.0), Z=4.849, P=0.000). In patients receiving neoadjuvant chemo-radiotherapy, compared to nRP group, RP group had lower microvessel count in both proximal and distal margins (proximal, 19.0 (23.0) vs. 30.4 (38.0), Z=2.845, P=0.004; distal, 19.0 (13.0) vs. 30.0(29.1), Z=2.022, P=0.043), higher proportions of macrovessel with stenosis (proximal, 23.0% (40.0%) vs. 0(11.0%), Z=3.248, P=0.001; distal, 27.0% (45.0%) vs. 3.0% (19.0%), Z=2.164, P=0.030). Rate of anastomotic leakage for CT, nRP and RP group were 8.7% (2/23), 30.4% (7/23), and 52.2% (12/23), and the differences among three groups were statistically significant (χ²=10.268, P=0.007). Conclusion Radiation-induced injury existed on both margins of the resected rectal site after preoperative radiotherapy, and those diagnosed as radiation proctitis had more severe microvascular injury.