Protein loss in critically ill patients during continuous veno-venous hemofiltration / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate protein loss in critically ill patients with acute renal failure during continuous veno-venous hemofiltration (CVVH) and analysis the major factor impacting protein clearance.</p><p><b>METHODS</b>A analysis was carried out in eighteen (twelve male and six female) sepsis or severe acute pancreatitis patients with acute renal failure from September 2008 to September 2009. The average age was 45 years (39 - 62 years). CVVH was conducted for 24 h in all patients. Effluent volume, blood speed, ultrafiltration rate and transmembrane pressure (TMP) were 4000 ml/h, (277 ± 89) ml/h, (179 ± 4) ml/min and (173 ± 48) mm Hg (1 mm Hg = 0.133 kPa) respectively. Blood samples were collected before and after filtration in order to detect protein concentration. Ultrafiltrate was obtained hourly to measure protein concentration and calculate protein loss during session.</p><p><b>RESULTS</b>Mean protein concentration was (231 ± 67) mg/L and protein loss was (22 ± 6) g/d in ultrafiltrate samples. The difference in serum protein level during hemofiltration was not significant [(56 ± 6) g/L vs. (55 ± 10) g/L, P > 0.05], while there was a weak, but statistically significant correlation between the ultrafiltrate protein concentration and the corresponding value for serum protein (r = 0.481, P < 0.05). However, there was a strong and statistically significant correlation between the ultrafiltrate protein concentration and the TMP (r = 0.564, P < 0.01). Stepwise multiple regression analysis showed that TMP and serum protein concentration played a pivotal role in ultrafiltrate protein loss.</p><p><b>CONCLUSIONS</b>In addition to renal replacement therapy, serum protein would be cleared through hemofilter during CVVH. TMP and serum protein concentration are the main factors that affect protein loss in ultrafiltrate. As a result, it is necessary to take account of the protein loss in ultrafiltrate when setting nutritional schedule.</p>

Effects of glutamine supplementation on patients undergoing abdominal surgery / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To evaluate the effects of supplementation of glutamine (GLN) on maintaining glutathione (GSH) level, immune system function, liver function, and clinical outcome of patients receiving abdominal operation.</p><p><b>METHODS</b>Forty patients undergoing elective abdominal surgical treatment were randomly divided into 2 groups: study group (n = 20) and control group (n = 20). All patients received total parenteral nutrition (TPN) for up to 7 days during perioperative period. The study group received TPN supplemented with GLN dipeptide while the control group received TPN without GLN dipeptide. Patients in both groups received equivalent nitrogen and caloric intake. Blood sample was taken on preoperative day, and the 1st, 3rd, 6th postoperative day to measure GSH level, immune indexes, and liver function indexes.</p><p><b>RESULTS</b>The decrease of GSH level in plasma and red blood cell (RBC) in study group was less than that in control group during postoperative period. Ratio of GSH/glutathione disulfide (GSSG) in plasma in study group was higher than that in control group on the 3rd postoperative day (52.53 +/- 11.46 vs. 31.43 +/- 7.27, P = 0.001). Albumin level in study group was higher than that in control group on the 3rd postoperative day (37.7 +/- 3.8 g/L vs. 33.8 +/- 4.2 g/L, P = 0.02). There was no significant difference in the levels of immunoglobin (IgG, IgM, IgA) or T lymphocyte subgroup (CD4, CD8, CD4/CD8) in both groups during postoperative period. There was one case with infectious complication in control group, while none in study group. A trend of shortened hospital stay was observed in study group compared with control group (22.3 +/- 2.1 d vs. 24.9 +/- 1.7 d, P = 0.32).</p><p><b>CONCLUSIONS</b>Supplementation of GLN-enriched TPN has beneficial effects on maintaining GSH levels in plasma and RBC, sustaining GSH/GSSG ratio and albumin level, and keeping antioxidant abilities during postoperative period in patients with abdominal operation, with the trends of decreasing incidence of infectious complication and shortening hospital stay.</p>

Noninvasive quantification of glutamine and glutamate in skeletal muscles of perioperative rabbits with proton magnetic resonance spectroscopy / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the feasibility of noninvasive quantification of the metabolic changes of glutamine (Gln) and glutamate (Glu) in the skeletal muscles caused by abdominal surgery with proton magnetic resonance spectroscopy (MRS).</p><p><b>METHODS</b>Abdominal surgery were performed on 15 healthy Zelanian rabbits. MRS data, blood specimens, and muscular tissues were obtained on the day before surgery and the second day after surgery. MRS data included peak amplitude and peak area of Gln + Glu (Glx) and total creatine (TCr). The reproducibility of peak amplitude with peak area was compared and the better one was chosen to calculate the ratio of Glx to TCr. Free Gln and Glu concentrations in serum and muscles were analyzed by reversed phase high-performance liquid chromatography (RP-HPLC). The results of MRS were compared with those of RP-HPLC to evaluate the feasibility of MRS application in Gln and Glu metabolism.</p><p><b>RESULTS</b>Peak amplitude had better reproducibility than peak area under our conditions. The coefficient of variation (CV) of the ratio of the amplitude of Glx to TCr was (15.62 +/- 9.87)%. The ratio of the amplitude of Glx to TCr significantly decreased on the second day after surgery (P <0.05, P <0.01). The mean free Glx concentrations in both the serum and the muscles different were not significant between on the second day after surgery and on the day before surgery.</p><p><b>CONCLUSIONS</b>The results of MRS application in reflecting the effects of surgical trauma on muscular Glx metabolism are consistent with those of RP-HPLC. It is feasible to apply MRS in the study of muscular Gln and Glu metabolism.</p>

Measurement of glutamine concentration in Zelanian rabbits' skeletal muscle by non-invasive magnetic resonance spectroscopy / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the feasibility of non-invasive magnetic resonance spectroscopy (MRS) in measuring glutamine (GLN) level in Zelanian rabbits' skeletal muscle.</p><p><b>METHODS</b>Non-invasive MRS was used to get the data of peak height ratio of GLN + glutamic acid (GLx) at 3.8 ppm and creatine (Cr) at 3.0 ppm, peak area ratio of GLx at 3.8 ppm and Cr at 3.0 ppm. High performance liquid chromatography (HPLC) was used to examine the actual GLx levels of muscle from 22 Zelanian rabbits. The feasibility of MRS was then evaluated by HPLC method.</p><p><b>RESULTS</b>The ratio of peak height and peak area of GLx and Cr by means of MRS were 0.162 +/- 0.045 and 0.092 +/- 0.065, respectively. The average concentration of GLx in skeletal muscle by means of HPLC was (4.19 +/- 2.50) micromol/g. The ratio of GLx and plasma Cr level by means of HPLC was 4.576 -/+ 0.599. The ratio of peak height and peak area of GLx and Cr by means of MRS were correlated significantly with the ratio of concentration of GLx in skeletal muscle and plasma Cr by means of HPLC (r = 0.7, P = 0.001; r = 0.6, P = 0.001).</p><p><b>CONCLUSION</b>Non-invasive MRS is feasible to measure GLN level in skeletal muscle of rabbit.</p>

Effect of combination of glutamine and mitomycin C on human gastric carcinoma cell strain MGC-803 / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the effect of combination of glutamine (GLN) and mitomycin C (MMC) on the human gastric carcinoma cell line MGC-803 in vitro.</p><p><b>METHODS</b>The effects of GLN and MMC were measured by MTT assay, and the interaction between the two agents was evaluated by the median-effect principle. Flow cytometry was used for cell cycle analysis.</p><p><b>RESULTS</b>GLN did not significantly stimulate the cell growth in vitro. High-concentration of GLN could inhibit the cell growth. MMC could effectively inhibit the cell growth in a time-dependent manner. The interaction of these two agents showed a weak antagonistic activity (1 < CI < 1.2703). MMC induced remarkable S-phase arrest. Low-dose GLN has limited effect on the S-phase arrest of MMC, while high-dose GLN significantly attenuated the S-phase arrest and lowered the proliferation index of MGC-803 cell.</p><p><b>CONCLUSIONS</b>Combination of GLN and MMC has a a weak and dose-dependent antagonistic activity in the treatment of gastric carcinoma cell line MGC-803. The combination of high-dose MMC and low-dose GLN may achieve better efficacy.</p>

Effects on glutathione of patients received glutamine dipeptide enriched parenteral nutrition post abdominal surgery / 中华外科杂志

<p><b>OBJECTIVE</b>To observe the effects of glutamine (GLN) enriched parenteral nutrition (PN) on glutathione level, immune function, liver function, infectious complication and hospital stay of patients undergone abdominal operation.</p><p><b>METHODS</b>Forty patients with abdominal surgical disease undergoing elective surgical treatment were randomly divided into two groups (study and control group). All patients received total parenteral nutrition (TPN) for up to 7 days perioperatively. The control group received TPN while the study group received TPN including GLN dipeptide. Both groups received isonitrogen and isocaloric nutrition. Nonprotein caloric intake is 83.6 kJ.kg(-1).day(-1), glycogen: lipid ratio is 7:5, nitrogen intake is 0.16 g.kg(-1).d(-1), calories:nitrogen ratio is 489 kJ:1 g.</p><p><b>RESULTS</b>The decreasing degree of glutathione levels of plasma and red blood cell in study group is lower than that in control group postoperatively. GSH/GSSG ratio of plasma in study group is higher than that in control group on 3rd day postoperatively (53 +/- 11 vs 31 +/- 7, F = 4.725, P = 0.001). Albumin (ALB) of both groups decreased slightly postoperatively. ALB level of study group was higher than that of control group on 3rd day postoperatively [(3.8 +/- 0.4) g.dl(-1) vs (3.4 +/- 0.4) g.dl(-1), F = 2.128, P = 0.02]. No significant differences were noted between immunoglobin (IgG, IgM and IgA) and T lymphocyte subgroup (CD4, CD8, CD4/CD8) levels of both groups postoperatively. There was no infectious complication in study group, while one in control group. There was shorten trend of hospital stay in study group compared with control group [(22.3 +/- 2.1) d vs (24.9 +/- 1.7) d, t = -0.935, P = 0.32].</p><p><b>CONCLUSIONS</b>Glutamine enriched PN has the trend of maintaining glutathione level of plasma and red blood cell in patients having undergone abdominal operation, and can sustain GSH/GSSG ratio and ALB level, protect antioxidant ability, promote liver function postoperatively. Glutamine enriched PN has the trend of shortening hospital stay, decreasing incidence of infectious complication.</p>