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Xi Peng

Publications and source records attributed to Xi Peng.

At least 19 recordsLinked to original sources

PEELing: an integrated and user-centric platform for spatially resolved proteomics data analysis.

SUMMARY: Molecular compartmentalization is vital for cellular physiology. Spatially resolved proteomics allows biologists to survey protein composition and dynamics with subcellular resolution. Here, we present PEELing, an integrated package and user-friendly web service for analyzing spatially resolved proteomics data. PEELing assesses data quality using curated or user-defined references, performs cutoff analysis to remove contaminants, connects to databases for functional annotation, and generates data visualizations-providing a streamlined and reproducible workflow to explore spatially resolved proteomics data. AVAILABILITY AND IMPLEMENTATION: PEELing and its tutorial are publicly available at https://peeling.janelia.org/ (Zenodo DOI: 10.5281/zenodo.15692517). A Python package of PEELing is available at https://github.com/JaneliaSciComp/peeling/ (Zenodo DOI: 10.5281/zenodo.15692434).

Proteomics↗

Beyond water and soil: Air emerges as a major reservoir of human pathogens.

Assessing the risk of human pathogens in the environment is crucial for controlling the spread of diseases and safeguarding human health. However, conducting a thorough assessment of low-abundance pathogens in highly complex environmental microbial communities remains challenging. This study compiled a comprehensive catalog of 247 human-pathogenic bacterial taxa from global biosafety agencies and identified more than 78 million genome-specific markers (GSMs) from their 17,470 sequenced genomes. Subsequently, we analyzed these pathogens' types, abundance, and diversity within 474 shotgun metagenomic sequences obtained from diverse environmental sources. The results revealed that among the four habitats studied (air, water, soil, and sediment), the detection rate, diversity, and abundance of detectable pathogens in the air all exceeded those in the other three habitats. Air, sediment, and water environments exhibited identical dominant taxa, indicating that these human pathogens may have unique environmental vectors for their transmission or survival. Furthermore, we observed the impact of human activities on the environmental risk posed by these pathogens, where greater amounts of human activities significantly increased the abundance of human pathogenic bacteria, especially in water and air. These findings have remarkable implications for the environmental risk assessment of human pathogens, providing valuable insights into their presence and distribution across different habitats.

Humans↗

Effects of early enteral arginine supplementation on resuscitation of severe burn patients.

OBJECTIVES: To investigate the effects of dietary supplementation of l-arginine (l-Arg) on shock in severely burned patients. METHODS: This was a prospective, randomized, single blind, controlled study. Forty-seven severely burned patients due to various causes with a total burn surface area (TBSA) more than 50% each admitted in early postburn phase (within 10h postburn) were included in this study. All patients were treated by the traditional resuscitation program of our institute. After the nasogastric feeding tube was placed, they were randomly divided into three groups-(1) group A400 (n = 16): giving gastrointestinal feeding with 500 ml 5% GNS, containing l-Arg (400 mg/ kgday) at equal pace with fluid resuscitation; (2) group A200 (n = 16): giving gastrointestinal feeding with 500 ml 5% GNS containing l-Arg (200 mg/ kgday); (3) group C (n = 15): giving gastrointestinal feeding with 500 ml 5% GNS without any supplementation. The feeding started within 12h after burn and lasted for 72 h, the feeding rate was controlled by an enteral feeding pump. The following parameters were observed on days (PBD) 1-4: serum nitric oxide content (NO), mean arterial blood pressure (MAP), oxygenation index (PO2/FiO2), and arterial blood content of lactic acid (LA). Gastric mucosal blood flow was measured by laser Doppler flow-metry on PBD1 and PBD2. RESULTS: (1) Enteral feeding of l-Arg did not change MAP of severely burned patients, with no difference in MAP between the l-Arg supplemented and control groups. (2) There were significant changes of the l-Arg supplemented groups (A400 and A200), with an increased gastric mucosa blood flow, oxygenation index, and a decreased LA content in arterial blood, compared with the control group. (3) The serous NO content was significantly decreased in the A400 group on PBD2-4 (P < 0.01), and in the A200 group on PBD4 (P < 0.05) compared with the control group. CONCLUSIONS: Enteral feeding with l-arginine supplementation on early stage of burn decreases NO production to a relatively normal level and exerts beneficial effects on the resuscitation of burned shock.

Adolescent↗

Glutamine granule-supplemented enteral nutrition maintains immunological function in severely burned patients.

Glutamine is an important energy source for immune cells. It is a necessary nutrient for cell proliferation, and serves as specific fuel for lymphocytes, macrophages, and enterocytes when it is present in appropriate concentrations. The purpose of this clinical study was to observe the effects of enteral nutrition supplemented with glutamine granules on immunologic function in severely burned patients. Forty-eight severely burned patients (total burn surface area 30-75%, full thickness burn area 20-58%) who met the requirements of the protocol joined this double-blind randomized controlled clinical trail. Patients were randomly divided into two groups: burn control group (B group, 23 patients) and glutamine treated group (Gln group, 25 patients). There was isonitrogenous and isocaloric intake in both groups, Gln and B group patents were given glutamine granules or placebo (glycine) at 0.5 g/kgd for 14 days with oral feeding or tube feeding, respectively. The plasma level of glutamine and several indices of immunologic function including lymphocyte transformation ratio, neutrophil phagocytosis index (NPI), CD4/CD8 ratio, the content of immunoglobulin, complement C3, C4 and IL-2 levels were determined. Moreover, wound healing rate of burn area was observed and then hospital stay was recorded. The results showed significantly reduced plasma glutamine and damaged immunological function after severe burn Indices of cellular immunity function were remarkably decreased from normal controls. After taking glutamine granules for 14 days, plasma glutamine concentration was significantly higher in Gln group than that in B group (607.86+/-147.25 micromol/L versus 447.63+/-132.38 micromol/L, P<0.01). On the other hand, cellular immunity functions were improved in Gln group, such as lymphocyte transformation ratio, NPI, CD4/CD8 ratio and IL-2 compared those in the B group (P<0.05-0.01). However, for humoral immunity function such as the concentration of IgG, IgM, C3, C4, no marked changes were seen compared with the B group (P>0.05). In addition, wound healing was better and hospital stay days were reduced in Gln group (46.59+/-12.98 days versus 55.68+/-17.36 days, P<0.05). These indicated that immunological function damage is present after severe burn; supplemented glutamine granules with oral feeding or tube feeding abate the degree of immunosuppression, improve immunological function especially cellular immunity function, ameliorate wound healing and reduce hospital stay.

Adolescent↗

[Effects of glutamine given through different avenues on intestine mucosal barrier function in burned rats].

OBJECTIVE: To observe the effect of glutamine given through different avenues on intestine mucosal barrier damage induced by severe burn injury. METHODS: One hundred and sixty Wistar rats were randomly divided into four groups: namely normal control (C group), burned control (B group), parenteral nutrition with glutamine (PN+GLN group) and enteral nutrition with glutamine (EN+GLN group). Rats in B group, PN+GLN group, and EN+GLN group were subjected to 30% total body surface area (TBSA) full-thickness burn injury. In the latter three groups, nutritional intake was isonitrogenous and isocaloric. In PN+GLN group and EN+GLN group the nutrition were supplemented with glutamine 1.0 g.kg(-1).d(-1), and in B group tyrosine 1.0 g.kg(-1).d(-1). Indexes relevant to injury to the intestine were determined on postburn day (PBD) 1, 3, 5, 7 and 10. RESULTS: After burn injury, the index of intestinal mucosal injury, intestine mucosal permeability and the activity of plasma diamine oxidase (DAO) were significant increased compared with C group (all P<0.01). On the other hand, the intestine mucosal blood flow (IMBF), mucosa thickness, villous height, crypt depth and intestinal epithelial proliferation index were significantly decreased (P<0.05 or P<0.01). Compared with B group, the extent of changes in these indices were lowered in PN+GLN group and EN+GLN group (P<0.05 or P<0.01), and the effects were more marked in EN+GLN group than those in PN+GLN group. CONCLUSION: GLN is beneficial in minimizing intestinal injury, promoting intestinal mucosal repair. Enteral supplementation of GLN is a better way of administration.

Animals↗

[Analysis of the influence on the prognosis and safety of arginine in patients with severe trauma and burns--a multi-center randomized double blinded, placebo controlled, clinical trail in 86 patients].

OBJECTIVE: To observe the influence on prognosis and possible side-effects of arginine in METHODS: Multi-center clinical trial, randomized double blinded patients with severe trauma and burns. and placebo control methods were employed in the study. Eighty-six patients with severe trauma and burns were randomly divided into control (C, n = 45) and arginine treatment (Arg, n = 41) groups. The patients in Arg group received arginine in dose of 0. 4 g x kg(-1) x d(-1) orally, while those in C group received same dose of placebo (tyrosine) for 7 days. All the patients in both groups were given diet with equal calories and equal nitrogen content. The changes in the wound healing time, hospital stay, and the incidence of side-effects of the medication in both groups of patients were observed and compared before and after the supplementation of arginine. RESULTS: The wound healing time and hospital stay days of severe trauma patient in Arg group (n = 29) were 11. 1+/-2. 8 d and 19+/-6 d, which were all obviously shorter than those in C group (13. 2+/-5. 5 d, 22 +/-6 d, n =33, P <0.05). On the other hand, in severe burn patients there were no significant difference of the wound healing time (20+/-5 d vs 22+/-8 d, n = 12, P > 0. 05) and hospital stay days (28+/-6 d vs 29+/-8 d, n = 12, P >0. 05) between the Arg and C groups. In addition, in C and Arg groups, the occurrence of the side-effects were seldom (2. 44% vs 2. 22% , P = 1. 000) and it disappeared when the supplementation of drugs was stopped. CONCLUSION: Oral feeding of arginine is beneficial in enhancing wound healing, reduction of hospital stay days in severe trauma patients and with little side-effects, but it is not beneficial to improve the prognosis of severe burn patients. Maybe this is due to inadequate number of case involved in the study.

Administration, Oral↗

[Effects of glutamine granules on immunofunction in trauma patients: a double-blind randomized controlled, multi-center clinical trail with 120 patients].

OBJECTIVE: To evaluate the effect of glutamine granules on immunofunction in severe burns and trauma patients. METHODS: One hundred and twenty patients with severe burns, multiple trauma and post operation who met the requirements of the protocol joined this double-blind randomized controlled, multi-center clinical trail. Patients were randomly divided into two groups: placebo control group (P group, 60 patients) and glutamine granules treatment group (GLN group, 60 patients). There was isonitrogenous and isocaloric intake in both groups. GLN and P group patients had been given glutamine granules or placebo (glycine) at 0.5 g.kg(-1).d(-1) for 7 days, respectively. The level of plasma glutamine and some index of immunofunction were determined, and the complication and side effect were also observed. RESULTS: After 7 days of taking glutamine granules orally, plasma GLN concentration was significantly higher than that in P group [(593 +/- 185) micromol/L vs (407 +/- 190) micromol/L)] (P < 0.01). IL-2 level, CD(4)/CD(8) ratio, PMN swallow ratio in GLN group were significantly higher than those in P group (P < 0.05-0.01), but the concentration of IgG, IgM, C(3)/C(4) were not significantly different when compared with P group (P > 0.05). In addition, the occurrence of side effect in both groups was seldom. CONCLUSION: Taking glutamine granules could increase plasma GLN concentration, enhance body immunofunction, and using glutamine granules is safe.

Administration, Oral↗

Clinical and protein metabolic efficacy of glutamine granules-supplemented enteral nutrition in severely burned patients.

As an abundant amino acid in the human body, glutamine has many important metabolic roles that may protect or promote tissue integrity and enhance the immune system. A relative deficiency of glutamine in such patients could compromise recovery and result in prolonged illness and an increase in late mortality. The purpose of this clinical study is to observe the effects of enteral supplement with glutamine granules on protein metabolism in severely burned patients. Forty-eight severe burn patients (total burn surface area 30-75%, full thickness burn area 20-58%) who met the requirements of the protocol joined this double-blind randomized controlled clinical trial. Patients were randomly divided into two groups: burn control group (B group, 23 patients) and glutamine treated group (Gln group, 25 patients). There was isonitrogenous and isocaloric intake in both groups, glutamine and B group patents were supplemented with glutamine granules or placebo (glycine) at 0.5 g/kg per day for 14 days with oral feeding or tube feeding, respectively. The level of plasma glutamine, plasma protein content, urine nitrogen and urine 3-methylhistidine (3-MTH) excretion were determined, wound healing rate of the burned area and hospital stay were recorded. The results showed that there were significant reductions in plasma glutamine level and abnormal protein metabolism. After supplement with glutamine granules for 14 days, the plasma glutamine concentration was significantly higher than that in B group (607.86+/-147.25 micromol/L versus 447.63+/-132.38 micromol/L, P<0.01) and the plasma prealbumin and transferrin in Gln group were remarkably higher than those in B group (P<0.01), but the concentration of total protein and albumin were not significantly changed compared with B group (P>0.05). On the other hand, the amount of urine nitrogen and 3-MTH excreted in Gln group were significantly lower than that in B group. In addition, wound healing was faster and hospital stay days were shorter in Gln group than B group (46.59+/-12.98 days versus 55.68+/-17.36 days, P<0.05). These indicated that supplement glutamine granules with oral feeding or tube feeding could abate the degree of glutamine depletion, promote protein synthesis, inhibit protein decompose, improve wound healing and reduce hospital stay.

Adolescent↗

[Influence of the enteral feeding of levorotatory arginine on severely burned patients during shock stage].

OBJECTIVE: To investigate the effects and the mechanism of action of postburn dietary supplementation of levorotatory arginine (L-Arg) on burn shock resuscitation in severely burned patients. METHODS: This study was designed to be a prospective, randomized, single blinded and controlled one. Twenty burn patients with total burn surface area (TBSA) more than 30% were enrolled and randomized into two groups; 1) Group A (n = 10): enteral feeding of 50 g/L glucose normal saline (GNS) 500 ml per day containing L-Arg (400 mg/kg.day) at equal pace with fluid infusion for shock resuscitation for 4 days. 2) Group C (n = 10): enteral feeding with only 50 g/L GNS 500 ml per day for 4 days. All of the twenty patients received equal amount of enteral feeding via an intra-gastric tube with the aid of an enteral feeding pump, started within 24 postburn hours (PBH). Venous blood was harvested from all the patients in both groups on 1, 2, 3 and 4 postburn day (PBD) for the determination of serum content of nitric oxide (NO), malondialdehyde (MDA) and the activity of serum superoxide dismutase (SOD). And the arterial content of lactate (BL) was also determined concomitantly. RESULTS: The results indicated that the serum SOD activity in group A was increased after burns, peaked on 4 PBD (68 +/- 23 U/ml), and it was obviously higher than that in group C (31 +/- 9 U/ml, P < 0.01). The serum contents of MDA and NO were decreased in both groups after burns. On 2 PBD, the serum NO level in group A decreased to the lowest level (50 +/- 14 micromol/L), which was obviously lower compared with group C (78 +/- 22 micromol/L, P < 0.01). On 4 PBD, serum MDA levels in group A (3.4 +/- 0.8 micromol/L) and group C (3.5 +/- 1.3 micromol/L) were decreased to the lowest level. The BL content in group A was obviously lower than that in group C on 2 and 3 PBD (P < 0.05 or 0.01). CONCLUSION: Enteral supplementation of L-arginine can decrease excessive NO production to a relatively normal level, and it might be beneficial to resuscitation of burn shock. It might also exert a protective effect against ischemia/reperfusion injury to burn patients.

Adolescent↗

[Comparative study on the influence of arginine hydrochloride and arginine acetate on the immune function and acid-base balance in rabbits with severe burns].

OBJECTIVE: To investigate the influence of arginine hydrochloride and arginine acetate on the immune function and acid-base balance in rabbits with severe burns. METHODS: One hundred and ten flap-eared rabbits were used in the study, in which 8 served as normal control, while the rest were inflicted with 30% TBSA full thickness burn. All the rabbits were divided into 10 groups, i.e. normal control (C, n = 14), burn control (B, n = 14, with intravenous infusion of Ringer's solution), 0.3 g/kg arginine hydrochloride (AH, n = 12), 0.3 g/kg arginine acetate (AA, n = 10), 0.6 g/kg AH (n = 10), and 0.6g/kg AA (n = 10) groups, 1.2 g/kg AH (n = 10), 1.2 g/kg AA (n = 10), 2.4 g/kg AA (n = 14) and 2.4 g/kg AH (n = 12) groups. AA and AH in different doses were fed to rabbits in corresponding groups 2 times a day for 7 days. The changes in the immune function, acid-base balance, chloride ion metabolism, and mortality were determined. RESULTS: Disorder in immune system was found after severe burns, with enhanced immune function at the beginning and weakening afterwards. The lymphocytic transformation rate, the CD4/CD8 ratio, the phagocytosis rate and the chemotactic index of white blood cells on 7 post burn day (PBD) were obviously lower in B group compared with C group (P < 0.05 or 0.01). These indices were obviously higher in 1.2, 2.4 g/kg AA and AH groups than those in B group on 7 PBD (P < 0.05 or 0.01). There was no difference in improvement of immune functions between 0.3, 0.6g/kg AH, AA group and B group. The values of blood pH, base excess (BE), buffer base (BB), HCO(3)(-) level in AH group were significantly lower than those in C group on 7 PBD (P < 0.05 or 0.01), while there were no obvious changes in AA group, they were obviously higher than those in AH group (P < 0.05 or 0.01). The contents of chloride ion in but 2.4 g/kg AH group during 5 to 7 PBD were obviously higher than those in C group and 2.4 g/kg AA group (P < 0.05 or 0.01), while no difference was found between 2.4 g/kg AA and C groups. The mortality in B group was obviously higher than that in 0.3, 0.6, 1.2 g/kg AH and AA groups (P < 0.05 or 0.01), but significantly lower than that in 2.4 g/kg AA and AH groups (P < 0.05). CONCLUSION: Disorders in immune functions were observed in severely burned rabbits. Administration of arginine acetate as well as arginine hydrochloride could enhance the immune function, but arginine acetate seemed to be safer than arginine hydrochloride. Excessive dosage should be avoided to prevent a rise of the mortality.

Acetates↗

[Effects of glutamine granules on protein metabolism in trauma patients].

OBJECTIVE: To evaluate the effect of glutamine granules on protein metabolism in severe burns and trauma patients. METHODS: 120 patients with severe burns, multiple trauma and post operation who met the requirements of the protocol joined this double-blind randomized controlled, multi-center clinical trail. Patients were randomly divided into two groups: placebo control group (P group, 60 patients) and glutamine granules treatment group (GLN group, 60 patients). There was isonitrogenous and isocaloric intake in both groups, GLN and P group patents had been given glutamine granules or placebo (glycine) at 0.5 g.kg(-1).d(-1) for 7 days, respectively. The level of plasma glutamine, protein and urine nitrogen exclude were determined, wound healing rate of burn area and hospital stay were recorded, and then observed the complication and side effect. RESULTS: After 7 days of taking glutamine granules orally, plasma GLN concentration was significant higher than that in P group (592.50 +/- 185.23 micro mol/L vs. 407.41 +/- 190.22 micro mol/L) (P < 0.01). Plasma prealbumin and transferrin in GLN group were significant higher than those in P group (P < 0.01), but the concentration of total protein and albumin were no marked changes compare with P group (P > 0.05). The capacity of urine nitrogen exclude in GLN group were significant lower than that in P group. Additional, the wound healing rate was faster and hospital stay days was shorter than P group (P < 0.05), and the occurrence of glutamine granules side effect was seldom. CONCLUSION: Taking glutamine could promote protein synthesis, abate protein decompose, ameliorate wound healing rate and reduce hospital stay obviously.

Adult↗

Effects of enteral supplementation with glutamine granules on intestinal mucosal barrier function in severe burned patients.

Glutamine is an important energy source in intestinal mucosa, the small intestine is the major organ of glutamine uptake and metabolism and plays an important role in the maintenance of whole body glutamine homeostasis. The purpose of this clinical study is to observe the protection effects of enteral supplement with glutamine granules on intestinal mucosal barrier function in severe burned patients. Forty-eight severe burn patients (total burn surface area 30-75%, full thickness burn area 20-85%) were randomly divided into two groups: burn control group (B group, 23 patients) and glutamine treated group (Gln group, 25 patients). Glutamine granules 0.5 g/kg were supplied orally for 14 days in Gln group, and the same dosage of placebo were given for 14 days in B group. The plasma level of glutamine, endotoxin and the activity of diamine oxidase (DAO), as well as intestinal mucosal permeability were determined. The results showed that the levels of plasma endotoxin, activity and urinary lactulose and mannitol (L/M) ratio in all patients were significant higher than that of normal control. After taking glutamine granules for 14 days, plasma glutamine concentration was significantly higher in Gln group than that in B group (607.86+/-147.25 microM/l versus 447.63 +/- 132.28 microM/l, P < 0.01). On the other hand, the levels of plasma DAO activity and urinary L/M ratio in Gln group were lower than those in B group. In addition, the wound healing was better and hospital stay days were reduced in the Gln group (46.59 +/- 12.98 days versus 55.68 +/- 17.36 days, P < 0.05). These results indicated that glutamine granules taken orally could abate the degree of intestine injury, lessen intestinal mucosal permeability, ameliorate wound healing and reduce hospital stay.

Administration, Oral↗

[Effects of enteral supplementation with glutamine on mitochondria respiratory function of intestinal epithelium in burned rats].

OBJECTIVE: To investigate the effects of enteral supplementation with glutamine on mitochondria respiratory function of intestinal epithelium in burned rats. METHODS: Wistar rats inflicted with 30% total body surface area (TBSA) full thickness thermal injury were randomly divided into three groups, i.e. burn with enteral nutrition (EN), burn with glutamine treatment (GLN), and normal control (C) groups. Burned rats were infused 732.2 kJ.kg-1.d-1 solution for intravenous nutrition and oral administration, in which the supply energy ratio of glucose, fat and protein was 55:30:15 respectively, glucose was 15.3% and the proportion of calorie to nitrogen was 183:1. The following indices including respiratory control rate (RCR), oxygen extraction (Oext), P/O ratio and intestine mucosal blood flow (IMBF) were measured on postburn days 1, 3, 5, 7, 10. RESULTS: After burn injury, the RCR, Oext, P/O ratio, and IMBF were significant decreased in both EN and GLN groups, but all above indices were markedly increased in GLN group compared to those in EN group. CONCLUSION: After burn injury, the IMBF and Oext were declined, resulting in mitochondria respiratory oxidative dysfunction and phosphorylation discoupling in intestinal epithelium. GLN supplementation appears to be beneficial to improving IMBF, increasing Oext, abating the extent of mitochondria respiration dysfunction, and promoting oxidative phosphorylation.

Animals↗

[Analysis of the therapeutic effect and the safety of glutamine granules per os in patients with severe burns and trauma].

OBJECTIVE: To observe the therapeutic effect and possible side effects of glutamine granules per os in patients with trauma, burns and major operations. METHODS: Patients inflicted with severe burns, trauma and major operations were enrolled in the study. One hundred and twenty patients were randomly divided into two groups, 60 in control group (C) and 60 in glutamine group (Gln). Randomized double blind and placebo control methods were employed in the study. All the patients in both groups were given diet with equal calories and equal nitrogen content. The patients in Gln group received glutamine granules in dose of 0.5 g.kg(-1).d(-1) orally or by gavage, while those in C group received same dose of placebo (glycine) for 7 days. The changes in the intestinal mucosal barrier function, the protein metabolism, the immune function, hepatic and renal functions, and the incidence of side effects of the medication in both groups of patients were observed and compared before and after the supplementation of glutamine or glycine. RESULTS: The plasma contents of glutamine, proteins and interleukin 2 in both groups were all lower than normal values. But the plasma diamine oxidase (DAO) activity, endotoxin content, intestinal mucosal permeability (urine lactose/mannitol, L/M) and urine excretion of nitrogen increased obviously in both groups. The plasma glutamine concentration in Gln group increased by 38.04% after the administration of Gln for 7 days (P < 0.01). The plasma contents of pro-albumin, transferrin, and IL-2 were obviously higher than those in the C group (the increase rates were 21.19%, 51.11%, 57.54%, respectively, P < 0.01). The plasma DAO activity, L/M ratio, endotoxin content and urine nitrogen excretion in Gln group were evidently lower than those in C group (the decrease rates were 47.26%, 52.18, 22.22% and 27.78%, respectively, P < 0.05 or 0.01). There was no obvious difference in the plasma levels of total protein and albumin, the indices in blood and urine test, or the hepatic and renal functions between the two groups before and after the amino acid supplementation. Mild side effects such as nausea, diarrhea, constipation occurred in both groups, but all of them disappeared spontaneously afterwards (P > 0.05). CONCLUSION: Oral administration of glutamine could be helpful to increase plasma concentration of glutamine and to ameliorate obviously the intestinal mucosal injury, to promote systemic protein synthesis and to inhibit protein catabolism and to upgrade systemic immune function with little side effect in patients with severe injury.

Administration, Oral↗

[Influence of glucagon-like peptide-2 on the proliferation of the intestinal mucosal cells in scalded rats].

OBJECTIVE: To explore the influence of glucagon-like peptide-2 (GLP-2) on the proliferation of the intestinal mucosal cells in scalded rats. METHODS: Fifty-five Wistar rats were employed in the study and were randomly divided into normal control (C), simple scald (S) and scald with GLP-2 treatment (G) groups. The rats in G group received GLP-2 introperitoneally in a dose of 200 micro g/kg two times a day. The rats in S and G groups were sacrificed at 6 postburn hours (PBHs), 12 PBHs, 1 postburn day (PBD1), PBD3 and PBD5 and the rats in C group were also sacrificed. Plasma diamine oxidase (DAO) activity, cell cycle protein cyclin D expression and the proliferating cell nuclear antigen (PCNA) in all groups were determined. And the histological change in the intestinal mucosal tissue was observed simultaneously. with all the above determinations. RESULTS: Compared with those in C group, the PCNA expression at 6 and 12 PBHs in S group was enhanced slightly and weakened at PBD1, reaching the lowest level at PBD3 and it was still lower than that in C group at PBD5. Changes in PCNA in G group were similar to that in S group, except that the expression at PBD3 and PBD5 was stronger than that in S group. The intestinal mucosal cyclin D protein expression was increased at 6 and 12 PBHs in S group, but decreased by 40% before injury at PBD1. Nevertheless, the cyclin D protein expression in G group was much higher than that in S group at PBD1, PBD3 and PBD5. The plasma DAO activity increased significantly in rats after burn injury. But the activity decreased obviously after GLP-2 treatment for 5 days (P < 0.01). It was observed histologically in G group that the lining of Exogenous intestinal villi was regular and well arranged without evident epithelial exfoliation. CONCLUSION: Exogenous GLP-2 might ameliorate intestinal mucosal injury in scalded rats, and promotion of the expression of PCNA and cyclin D, resulting in proliferation of injured intestinal mucosal cells, might be the underlying mechanisms.

Animals↗

[Experimental study on the effects of intestinal trefoil factor on intestinal epithelial proliferation and its signal transduction mechanism].

OBJECTIVE: To explore the effects of intestinal trefoil factor (ITF) on intestinal epithelial proliferation and its possible signal transduction mechanism. METHODS: 1). The intestinal epithelial cytoplasmic membrane was isolated and harvested from Wistar rats, and it was treated with various doses of ITF in the concentration of 0.01, 0.10, 1.00 and 10.00 micro g/ml. The tyrosine protein kinase (TPK) activity from cytoplasmic membrane ITF receptor was determined by membrane-bound method. 2). The intestinal epithelial cells 6 (IEC-6) cultured in vitro were employed in the study. Some of the cells were used as normal control, while a group of cells were stimulated by 1 micro g/ml ITF, and others were treated by PD098059, SB202190 and SB202474, respectively. The last three agents were inhibitors of three members of mitogen-activated protein kinase family (MAPKs), i.e. extracellular signal regulated protein kinases (ERKs), protein kinase p38 (p38), and stress-activated protein kinase (SAPK). They were used before the addition of 1 micro g/ml of ITF. The changes in DNA synthetic rate and the MAPK activity of IEC-6 after being treated by above agents were assessed by (3)H-TdR incorporation method. RESULTS: ITF receptor possessed TPK activity. TPK activity of ITF receptor, MAPKs activity and DNA synthetic rate of IEC-6 were increased obviously under the stimulation of ITF (P < 0.01). The above ITF effects could be evidently blocked by PD098059 and partially attenuated by SB202474. But SB202190 showed no effect in this respect. CONCLUSION: ITF could promote intestinal epithelial proliferation and transmit extracellular signals mainly by means of ERKs signalling pathway.

Animals↗

[Effect of different nutritional routes on the intestinal mucus barrier in scalded rats].

OBJECTIVE: To observe the effect of different nutritional routes of giving nutrition on the intestinal mucus barrier in severely scalded rats. METHODS: Wistar rats inflicted with 30% TBSA III degree scalding on the back were employed as the model and were randomly divided into 3 groups, i.e. control (C), parenteral nutrition (PN) and enteral nutrition (EN) groups. The rats in PN and EN groups were supplied with equal amount of nitrogen and calories and with equal volume of nutrition solution. The dynamic changes in the thickness of intestinal mucus layer and the contents of protein, hexose and acetylneuraminate in the mucus were examined. RESULTS: When compared with those in C group, the intestinal mucus layer became thinner and the contents of protein, hexose and acetylneuraminate in the mucus in both PN and EN groups decreased evidently after scalding. When compared between two nutritional groups, the thickness of intestinal mucus layer and the contents of the hexose and acetylneuraminate in the mucus in EN were much thicker and higher than those in PN group, while the mucus protein content exhibited no obvious difference between PN and EN groups. CONCLUSION: It was suggested that intestinal goblet cell synthesized and secreted less mucus after scalding in rats resulting in thinning of intestinal mucus layer and the change in mucus components. When compared with those in PN group, less injury to the intestinal goblet cells occurred and the intestinal mucus synthesis was less affected in EN group, and the components of intestinal mucus were maintained stable.

Animals↗