[Predictive value of plasma exosomal miR-124-3p for the risk of chronic cerebral hypoperfusion]

Objective: To investigate the predictive value of plasma exosomal microRNA (miR)-124-3p in the risk of chronic cerebral hypoperfusion (CCH). Methods: A case-control study. Thirty patients who were diagnosed with CCH (CCH group) based on cranial artery spin labeling (ASL) in the neurology outpatient clinic of Sichuan Provincial People's Hospital from March 2022 to June 2022 and 30 healthy volunteers (control group) were included. Age, gender, smoking history, alcohol consumption history, diabetes history, hypertension, hyperlipidemia history, uric acid, fasting blood glucose, homocysteine and plasma exosomal miR-124-3p expression level were compared between the two groups. Comparisons of categorical variables were analyzed by either χ2 test or Fisher's exact test. If the data of continuous variables followed a normal distribution, they were expressed as mean±standard deviation (SD) and compared by t-test for two independent samples; otherwise, the data were expressed as M(Q1, Q3), and analyzed by Mann-Whitney U test for comparison between two groups. The correlation between cerebral blood flow and exosomal miR-124-3p levels was analyzed by Pearson's correlation. Binary multifactorial logistic regression analysis was used to determine the risk factors associated with CCH, and corresponding odds ratios (OR) and 95% confidence intervals (CI) were calculated. P<0.05 was considered significant. Results: There was no significant difference in age (64±8 vs. 60±8 years old), gender (33.3% vs. 30.0%), history of smoking (20.0% vs. 3.3%), alcohol consumption (20.0% vs. 6.7%), diabetes mellitus (13.3% vs. 13.3%), hypertension (53.3% vs. 30.0%), history of hyperlipidemia (46.7% vs. 36.7%), uric acid (288±60 vs.319±67 μmol/L), and fasting glucose [4.99(4.63, 5.91) vs. 5.28(5.09, 6.05) mmol/L] and homocysteine [11.35(10.18, 13.08) vs.11.00(9.78, 13.03) μmol/L] between the CCH and control groups (P>0.05). Plasma exosomal miR-124-3p expression was significantly higher in the CCH group than in the control group [13.08 (8.59, 21.55) vs. 2.85 (1.44, 5.10), respectively; U=169.50, P<0.001]. Pearson's correlation test showed that the level of exosomal miR-124-3p was negatively correlated with cerebral blood flow in the hypoperfused region in patients with CCH (r=-0.932, P<0.001). Multi-factor logistic regression analysis showed that plasma exosomal miR-124-3p was independently associated with the risk of CCH (OR=1.169,95%CI 1.063-1.286,P=0.001). Conclusions: The expression of plasma exosomal miR-124-3p is negatively correlated with cerebral blood flow in areas of low perfusion and is an independent risk factor for CCH. Plasma exosomal miR-124-3p may thus serve as a valid biomarker for CCH risk prediction.

[TXNDC17 protein overexpression in uterine papillary serous carcinoma is associated with clinicopathological characteristics and prognosis]

Objective: To analyze clinicopathological characteristics of patients with uterine papillary serous carcinoma (UPSC) in China, and investigate roles of TXNDC17 protein in UPSC clinicopathological characteristics and prognosis. Methods: Fifty-five patients with UPSC treated in Women's Hospital School of Medicine Zhejiang University from 2003 to 2016 were analysed retrospectively. Immunohistochemistry (IHC) were performed to TXNDC17 and BECN1 (Beclin 1 protein, a key regulator of autophagy) protein expression respectively. Kaplan-Meier was used to calculate the cumulative survival rate, Log-rank test was performed to compare the difference in cumulative survival rate among patients with different clinicopathological characteristics, and Cox regression model was used to analyze the related between TXNDC17 expression and prognosis of UPSC patients. Results: The median age of the 55 UPSC patients was 63(49, 79) years, 43.6%(24/55) with late stages (stage Ⅲ/Ⅳ), and 32.7 % (18/55) exhibiting more than half of myometrium invasion were enrolled. Notably, 28 (50.9%) patients had TXNDC17 protein overexpression, and associated with BECN1 overexpression(P=0.023). Besides, co-expression of TXNDC17 and BECN1 occurred at an advanced stage and deep myometrial invasion (P=0.013,0.009). The cumulative survival rate of TXNDC17 overexpression(37.4% vs 91.5%),FIGO Ⅲ/Ⅳ stage(44.1% vs 70.1%), deep myometrium invasion(36.1% vs 75.4%) and BECN1 overexpression(0 vs 83.0%)patients was low (P<0.05). The multivariate proportional hazards model revealed that myometrial invasion and TXNDC17 overexpression were associated with prognosis of UPSC patients. Conclusions: This study shows that TXNDC17 overexpression is associate with poor survival in UPSC patients. Co-expression of TXNDC17 and BECN1 shows characteristics of advanced stages and deep myometrial invasion. TXNDC17 may be a potential predictor or target in UPSC therapeutics..

[Experience and thoughts on digestive tract reconstruction after radical resection of adenocarcinoma of the esophagogastric junction]

In the surgical treatment of adenocarcinoma of the esophagogastric junction (AEG), the scope of lymph node dissection, surgical approach selection, extent of tumor resection and digestive tract reconstruction have always been controversial, with the digestive tract reconstruction in AEG facing many challenges especially. The digestive tract reconstruction is related to the extent of resection. At present, the digestive tract reconstruction after total gastrectomy includes Roux-en-Y anastomosis, jejunum interposition and its derivatives. According to different reconstruction methods, they can be divided into tube anastomosis, linear anastomosis and manual anastomosis. Anti-reflux digestive tract reconstruction after proximal gastrectomy mainly includes esophagogastric anastomosis, interposition jejunum and double channel anastomosis. At present, double channel anastomosis is the most common reconstruction method in China. Based on the concept of interposition tubular stomach and reconstruction of gastric angle for anti-reflux, we propose "Giraffe" anastomosis, which moves artificial fundus and His angle downward to retain more residual stomach, showing good gastric emptying and anti-reflux effect. In this paper, combined with our clinical experience and understanding, we discuss the selection and technical key points of digestive tract reconstruction methods in AEG, and suggest that composite anti-reflux mechanism design may be the development trend of anti-reflux reconstruction in the future. The composite mechanism includes the retention of gastric electrical pacemaker in greater curvature of the middle part of gastric body to increase the emptying capacity of residual stomach, the reconstruction of gastric fundus and His angle anti-reflux barrier, and the establishment of an interposition tubular stomach acting as a buffer zone in Giraffe construction, and so on.

[Functional outcomes of 100 patients with adenocarcinoma of the esophagogastric junction undergoing Cheng's GIRAFFE(®) reconstruction after proximal gastrectomy]

Objective: To investigate the functional outcomes and postoperative complications of Cheng's GIRAFFE reconstruction after proximal gastrectomy. Methods: A descriptive case series study was conducted. Clinical data of 100 patients with adenocarcinoma of the esophagogastric junction who underwent Cheng's GIRAFFE reconstruction after proximal gastrectomy in Cancer Hospital of University of Chinese Academy of Sciences (64 cases), Zhejiang Provincial Hospital of Chinese Medicine (24 cases), Lishui Central Hospital (10 cases), Huzhou Central Hospital (1 case) and Ningbo Lihuili Hospital (1 case) from September 2017 to June 2021 were retrospectively analyzed. Of 100 patients, 64 were males and 36 were females; the mean age was (61.3 ± 11.1) years and the BMI was (22.7±11.1) kg/m(2). For TNM stage, 68 patients were stage IA, 24 were stage IIA and 8 were stage IIB. Postoperative functional results and postoperative complications of radical gastrectomy with Giraffe reconstruction were analyzed and summarized. Gastroesophageal reflux disease questionnaire (RDQ) score and postoperative endoscopy were used to evaluate the occurrence of reflux esophagitis and its grade (grade N, grade A, grade B, grade C, and grade D from mild to severe reflux). The continuous data conforming to normal distribution were expressed as (mean ± standard deviation), and those with skewed distribution were presented as median (Q1, Q3). Results: All the 100 patients successfully completed R0 resection, including 77 patients undergoing laparoscopic surgery and 23 patients undergoing laparotomy. The Giraffe anastomosis time was (38.6±14.0) min; the blood loss was (73.0±18.4) ml; the postoperative hospital stay was 9.5 (8.2, 13.0) d; the hospitalization cost was (6.0±0.3) ten thousand yuan. Fourteen cases developed perioperative complications (14.0%), including 7 cases of pleural effusion or pneumonia, 3 cases of anastomotic leakage, 2 cases of gastric emptying disorder, 1 case of gastrointestinal hemorrhage and 1 case of anastomotic stenosis, who were all improved and discharged after symptomatic management. Patients were followed up for (33.3±1.6) months. Eight patients were found to have reflux symptoms by RDQ scale six months after surgery, and 11 patients (11/100,11.0%) were found to have reflux esophagitis by gastroscopy, including 6 in grade A, 3 in grade B, and 2 in grade C. All the patients could control their reflux symptoms with behavioral guidance or oral PPIs. Conclusion: Cheng's GIRAFFE reconstruction has good anti-reflux efficacy and gastric emptying function; it can be one of the choices of reconstruction methods after proximal gastrectomy.

TLR4 Deficiency Exacerbates Biliary Injuries and Peribiliary Fibrosis Caused by Clonorchis sinensis in a Resistant Mouse Strain

Mice with different genetic backgrounds have various susceptibilities to infection with Clonorchis sinensis, although the mechanisms underlying are largely unknown. Toll-like receptor 4 (TLR4) as one of the most important pattern recognition receptors (PPRs) is essential for the invasion, survival, pathogenesis, and elimination of worms. The roles played by TLR4 in C. sinensis infection may vary due to the different genetic backgrounds of mice. In the present study, a relatively resistant mouse strain-C57BL/10 to C. sinensis was used for investigation on the possible roles of TLR4 in the biliary injuries and peribiliary fibrosis. TLR4 wild type (TLR4^wild) and TLR4 defective (TLR4^def) mice were orally infected with 45 metacercariae of C. sinensis, and all C. sinensis-infected mice and non-infected groups were anesthetized on day 28 post-infection. The liver and serum from each mouse were collected for assessment of the biliary injuries and biliary fibrosis. Meanwhile, hepatic leukocytes were isolated and detected for the activation of M1 or M2 macrophage using flow cytometry. The hepatic type 1 immune response and type 2 immune responses -relative molecules were also evaluated using ELISA and quantitative PCR. The data showed that TLR4^def aggravated liver inflammatory cell infiltrations, bile duct proliferation, biliary and hepatocellular injuries, and ECM deposition in C. sinensis-infected mice, compared with TLR4^wild mice when they were intragastrically administered with the same amounts of C. sinensis metacercaria. Furthermore, the M2-like macrophages and type 2 immune responses were significantly predominant induced in TLR4^def mice, compared with that of TLR4^wild mice following C. sinensis infection. But the type 1 immune response were significantly decreased in TLR4^def mice, compared with TLR4^wild mice after C. sinensis infection. These data demonstrate that TLR4 deficiency exacerbates biliary injuries and peribiliary fibrosis caused by C. sinensis in C57BL/10 strain mice, which is contributed by augments of type 2 immune responses and decrease pro-inflammatory responses.

[Preliminary efficacy analysis of Cheng's Giraffe reconstruction after proximal gastrectomy in adenocarcinoma of esophagogastric junction]

Objective: To investigate the safety and feasibility of proximal partial gastrectomy with Cheng's Giraffe esophagogastric reconstruction for the treatment of early Siewert II adenocarcinoma of esophagogastric junction (AEG). Methods: Indication of Cheng's Giraffe esophagogastric reconstruction: (1) Siewert II AEG or Siewert III AEG with diameter < 4 cm; (2) preoperative staging as cT1-2N0M0. A descriptive case series study was carried out. Clinical data of 34 patients with Siewert II AEG undergoing proximal partial gastrectomy and Cheng's Giraffe esophagogastric reconstruction at Department of Abdominal Surgery of Zhejiang Cancer Hospital and Department of Gastrointestinal Surgery, The First Affiliated Hospital of Zhejiang University of Traditional Chinese Medicine from February to July 2018 were retrospectively collected and analyzed, including 14 cases in IA stage, 11 cases in IIA stage and 8 cases in IIB stage. Brief procedure of Cheng's Giraffe esophagogastric reconstruction was as follows: Firstly, 12 cm long tubular stomach was formed by longitudinal incision 4 cm away from the great curvature of the stomach. Secondly, the gastric fundus and His angle were formed. Finally, the distance from His angle to esophagal-tubular gastric anastomosis should be more than 5 cm. The reflux disease questionare (RDQ) scores, radionuclide gastric emptying scintigraphy, and 24-hour multichannel intraluminal (MII)-pH monitoring technology were used to evaluate postoperative gastric emptying and gastroesophageal reflux. Result: All 34 patients successfully completed proximal partial gastrectomy with Cheng's Giraffe esophagogastric reconstruction, including 13 cases by open surgery and 21 cases by laparoscopic surgery. The operation time was (144.6±39.8) minutes, the blood loss during operation was (35.4±17.2) ml. No laparoscopic case was converted to open surgery and no postoperative complication was observed. The postoperative hospital stay was (8.4±2.5) days. The postoperative RDQ score was 4.4±3.1 one month after operation, and 3.3±2.5 six months after operation. Gastric-half emptying time was (67.0±21.5) minutes, and the residual ratio was (52.2±7.7)% in 1 hour, (36.4±3.1)% in 2 hours and (28.8±3.6)% in 3 hours at postoperative 1-month. The 24-hour MII-pH monitoring at postoperative 2-month revealed the frequency of acid reflux was (12.6±7.9) times, frequency of non-acid reflux was (19.6±9.7) times, DeMeester score was 5.8±2.9. Conclusion: Cheng's Giraffe esophagogastric reconstruction is safe and feasible in the treatment of Siewert type II AEG, and has good dynamic and anti-reflux effects.

[EMA/CO regimen for chemotherapy 24 patients with ultra high-risk gestational trophoblastic neoplasia]

Objective: To evaluate etoposide, methotrexate and dactinomycin (EMA) /cyclophosphamide and vincristine (CO) regimen for treatment of ultra high-risk gestational trophoblastic neoplasia (GTN) . Methods: A total of twenty-four ultra high-risk patients who had International Federation of Gynecology and Obstetrics (FIGO) prognostic scores greater or equal to 12 with liver, brain, or extensive metastases did poorly when treated with primary chemotherapy admitted in Women's Hospital, School of Medicine, Zhejiang University from January 2001 to December 2015. All of the patients were treated by EMA/CO regimen and followed up to death or December 2017. The clinical data of patients were analyzed retrospectively and the efficacy and toxicity of EMA/CO were evaluated. Results: All of the cases with ultra high-risk GTN had FIGO prognostic scores ≥12 (ranged 12-18, median 13.0) . Twenty patients (83%, 20/24) received EMA/CO regimen as primary treatment and 4 patients (17%, 4/24) had a history of failed chemotherapy. Seven patients (29%, 7/24) had metastasis of liver or brain and 17 patients (71%, 20/24) had no metastasis of liver and brain. Twenty-four patients received totally 167 courses of EMA/CO regimen (average 7.0 courses) . Sixteen patients achieved complete remission and 8 patients showed drug-resistant. The complete remission rate was 67% (16/24) and the resistance rate was 33% (8/24) . Of the 16 patients who got complete remission, 6 cases were treated with EMA/CO regimen alone, and 10 cases were treated by chemotherapy combined with surgery. For the 8 patients who showed drug-resistant to EMA/CO, 5 cases of them received EMA/etoposide and cisplatin (EP) regimen and 3 cases got remission, 1 case received methotrexate, dactinomycin and cyclophosphamide (MAC) regimen and got remission, 2 cases gave up treatment because of economic factors. The side effects of EMA/CO mainly included Ⅲ-Ⅳ degree neutropenia, anemia and alopecia. The incidence of Ⅲ-Ⅳ degree neutropenia during the treatment of EMA/CO was 21.6% (36/167) , the incidence of anemia was 96.4% (161/167) , and the incidence of alopecia was 60.5% (101/167) . In these 24 ultra high-risk GTN patients, 4 patients died during follow-up. In the 20 patients who got complete remission, no recurrence or secondary tumor by chemotherapy were occurred. Conclusion: EMA/CO is an effective regimen with manageable toxicity for patients with ultra high-risk GTN.

[Triptolide reverses apatinib resistance in gastric cancer cell line MKN45 via inhibition of heat shock protein 70]

Objective: To investigate the effect of triptolide, a specific inhibitor of heat shock protein 70 (HSP70), on apatinib resistance in gastric cancer cells line MKN45. Methods: The apatinib-resistant cells (MKN45/AR) and MKN45 parental cells were treated with apatinib, triptolide and apatinib combined with triptolide, respectively. CCK-8 assay was performed to determine the half maximal inhibitory concentration (IC(50)) of MKN45/AR and MKN45 cells in the presence of different treatment. The mRNA expression of heat shock protein gene (HSPA1A and HSPA1B) was detected by RT-PCR, while the protein expression of heat shock protein 70 was analyzed using Western blot in MKN45/AR and MKN45 cells. Results: The IC(50) values of apatinib-sensitive and apatinib-resistant MKN45 cells were 10.411 μmol/L and 70.527 μmol/L, respectively, showing a significant difference (P<0.05). The mRNA expression of HSPA1A and HSPA1B in MKN45/AR cells was significantly higher than that in MKN45 cells (P<0.001). The protein expression of heat shock protein 70 was significantly decreased after 0.25 μmol/L triptolide treatment in MKN45/AR cells (P<0.01). When heat shock protein 70 was inhibited by triptolide, the IC(50) value of apatinib in MKN45/AR cells was reduced to 11.679 μmol/L, which was significantly lower than cells treated with apatinib alone (P<0.05). Conclusions: The apatinib-resistant MKN45 cells have high levels of heat shock protein 70. Low doses of triptolide can significantly inhibit heat shock protein 70, leading to reverse the resistance phenotype of MKN45/AR cells. Therefore, inhibition of heat shock protein 70 provides a new therapy strategy for patients with apatinib resistance.

Expression and potential roles of IL-33/ST2 in the immune regulation during Clonorchis sinensis infection

During clonorchiasis, immune responses of hosts are responsible for the removal of the worms and also are involved in the progress of the pathological damage caused by Clonorchis sinensis. Interleukin-33 (IL-33), a recently described cytokine signaling through the ST2 receptor, has emerged as a potent inducer to bile duct proliferation and fibrosis; however, little is known of this signaling in the pathogen-caused periductal inflammation and fibrosis. In the present study, using immunohistochemistry, real-time PCR, enzyme-linked immunosorbent assay (ELISA), and flow cytometry, we studied the expression of IL-33/ST2 during C. sinensis infection, as well as their potential roles in C. sinensis-induced host immune responses. The results showed that a higher level of IL-33 was detected in the sera of patients of clonorchiasis (n = 45), compared with in those of healthy donors (n = 16). Similarly, in FVB mice experimentally infected with C. sinensis, a higher level of IL-33 was detected at latent stage both in the serum and in the liver, as well as the up-regulated expression of ST2 receptor on the inflammatory cells, especially on CD4(+) T cells in the liver of infected mice. Our results, for the first time, indicated that the increased IL-33/ST2 may be involved in the regulation of immunopathology induced by C. sinensis.

Clonorchis sinensis excretory/secretory products promote the secretion of TNF-alpha in the mouse intrahepatic biliary epithelial cells via Toll-like receptor 4

Background

Toll-like receptor 4 (TLR4), as one of the most important pathogen pattern recognitions (PPRs) plays a central role in elicitation of innate immunity and mediation of adaptive responses against foreign antigens. However, little is known of the roles of TLR4 in the immune responses of biliary epithelial cells (BECs) induced by Clonorchis sinensis, a parasite of significance in human health.

Methods

In the present study, the primary mouse intrahepatic biliary epithelial cells (MIBECs) were pre-treated with TLR4 inhibitor peptide or control peptide and then stimulated by excretory/secretory products (ESP) of C. sinensis, respectively. The expressions of TLR4 and relative cytokines were determined using western blot and a bead-based analytic detection system, respectively.

Results

The results showed that ESP of C. sinensis significantly increased the expression of TLR4 which promoted the expression of MyD88 and NF-κB in BECs; the levels of TNF-α but not IL-6 from MIBECs stimulated by ESP alone were also considerably increased, compared with the group of the medium stimulated. However, the concentration of TNF-α was significantly decreased when MIBECs were pre-treated with TLR4 inhibitor. In addition, ESP could depress the level of IL-6 in MIBECs which was elevated by LPS.

Conclusions

Our data for the first time demonstrate that ESP of C. sinensis can potently induce secretion of pro-inflammatory cytokines via TLR4 in MIBECs, which suggests that TLR4 plays an important role in host defenses against C. sinensis and the pathogenesis of clonorchiasis.

[The apoptosis of K562 cells induced by IL-3 and hydroxyurea cooperatively]

The effect of IL-3 and hydroxyurea on human erythroleukemia cell line (K562 cells) was demonstrated by using the electro-microscopy and flow cytometry. Our data showed that neither IL-3 nor hydroxyurea could induce the apoptosis of K562 cells alone. However, the IL-3 and hydroxyurea could induce the apoptosis of K562 cells cooperatively. Analysis with flow cytometry showed that the percentage of apoptotic cells was about 31.90% after K562 cells were induced by IL-3 and hydroxyurea cooperatively for 5 days, and the sub-G1 peak (apoptotic peak) was detected in the induced K562 cells. Meanwhile, the percentage of S-phase in the IL-3 and hydroxyurea induced K562 cells was increased, and the proliferation of the induced K562 cells was inhibited significantly. Furthermore, the IL-3 and hydroxyurea induced K562 cells showed chromatin condensation with regular crescents at the nuclear edges and apoptotic bodies. It suggested that IL-3 could enhance the sensitivity of K562 cells to hydroxyurea and the apoptosis of K562 cells could be induced by IL-3 and hydroxyurea cooperatively.

Effect of electroacupuncture on the activities of tyrosine protein kinase in subcellular fractions of activated T lymphocytes from the traumatized rats

The present study was to observe the dynamic changes of tyrosine protein kinase (TPK) activity in subcellular fractions in the early stage of activation of T lymphocytes from normal and traumatized rats, and the regulatory effect of electroacupuncture (EA) stimulation on it. The results showed that the activities of TPK in membranous and cytosolic fractions of activated T lymphocytes were increased on second 5, and the peak was on scond 45 after ConA stimulation. Then it was decreased gradually. Comparing with the control group, the activities of TPK in membranous and cytosolic fractions of activated T lymphocytes from the traumatized rats were inhibited in various degrees especially in membrane. EA of "Zusanli"(ST-36) and "Lanwei"(Extra 33) points could enhance the activity of TPK in subcellular fractions of activated T lymphocytes from the traumatized rats. The results indicated that EA stimulation could prevent the inhibition of activation of TPK induced by trauma stress, and contribute to transmembrane signal transduction of T lymphocytes.

[Study on therapeutic effect and immunological mechanism of fuzhengfang herbs in mice with Lewis lung cancer]

OBJECTIVE

To observe the therapeutical effect of Fuzhengfang (FZF).

METHODS

Therapeutic effect of FZF herbs on mice with Lewis lung cancer was observed, and its regulation on function of red blood cell immune system of the mice was also studied.

RESULTS

FZF herbs could inhibit the growth of tumor, and increase the weight of mice with Lewis lung cancer. The quality of life of the mice was improved after treatment with FZF herbs. FZF herbs could increase the activity of red blood cell C3b receptors, reduce the quantity of red blood cell immune complexes, elevate the immune adherent function of red blood cells to tumor cells, raise activity of red blood cell immune adherent enhancing factors in serum, and lower the activity of red blood cell immune adherent inhibitory factors. Chemotherapy could inhibit the growth of tumor, but decrease the weight of mice with Lewis lung cancer. The quality of life of the mice was decreased after chemotherapy. Chemotherapy could reduce the activity of red blood cell C3b receptors, increase the quantity of red blood cell immune complexes, depress the immune adherent function of red blood cells to tumor cells, lower the activity of red blood cell immune adherent enhancing factors in serum, and raise the activity of red blood cell immune adherent inhibitory factors in serum. There was a significant difference between FZF herbs and chemotherapy.

CONCLUSION

FZF herbs have a positive therapeutic effect in mice with Lewis lung cancer, and its mechanism might be associated with improving function of red blood cell immune system of mice with Lewis lung cancer.

Effect of continued electroacupuncture on induction of interleukin-2 production of spleen lymphocytes from the injured rats

The present study was to investigate the dynamic changes of the induction of interleukin-2 (IL-2) production of spleen lymphocytes from the rats after operative trauma stress and the regulatory effect of continued electroacupuncture (EA) stimulation of "Zusanli" (St. 36) and "Lanwei" (Extra 33) points on the induction of IL-3 production of spleen lymphocytes from the injured rats. The results showed that the induction of IL-2 production of the rat spleen lymphocytes was significantly decreased on day 1, 3, 5, 7 (P < 0.05), and the minimum level was on day 3 after operative trauma at both dilution 1:8 and dilution 1:16. The induction of IL-2 production was reserved to nearly normal on day 10. Continued stimulation by EA on "St. 36" and "Extra 33" points on day 3, 5, 7 increased the induction of IL-2 production in various degrees at the two dilutions (P < 0.01), or P < 0.05). The results mentioned above implied that the immune function could be depressed by trauma stress. Continued EA stimulation could improve the immunosuppression induced by trauma stress.

Neutron diffraction study of carbonmonoxymyoglobin

Neutron diffraction data from a crystal of carbonmonoxymyoglobin were refined by PROLSQ, a modern restrained least-squares procedure in reciprocal space, in conjunction with a solvent analysis technique, to a final R-factor of 11.3%. The ligand CO occupies two sites and its binding conformations are distorted from the linear conformation. The N epsilon atom of the distal histidine residue is deprotonated (not deuterated), and a water molecule is bound to the N delta atom of the distal histidine. The side-chain of Lys56 (D6) exists in two alternative charge-binding sites. His24 (B5) and His119 (GH1) share a hydrogen atom. His12 (A10) and His36 (C1) are deprotonated. The deprotonated imidazole ring of His12 (A10) may act as a hydrogen-bond acceptor. The heme group is planar within 0.09 A root-mean-square (r.m.s.) deviation from planarity. The solvent environments for the two propionic acid groups are different. The side-chain of Arg45 (CD3) forms hydrogen bonds with the side-chain of Asp60 (E3) and one of the two propionic acid groups. An average N-2H . . . O angle in helical regions is 147 (+/- 11) degrees. Eleven main-chain amide hydrogen atoms from hydrophobic residues do not exchange with deuterium. The overall atomic occupancy factors for the main-chain and side-chain atoms are quite uniform, at 0.97 (+/- 0.07) and 0.93 (+/- 0.10), respectively, as shown by an occupancy analysis made at the end of the refinement procedure.

Arginyl-tRNA synthetase from Escherichia coli affinity labeling with 3'-oxidized tRNA(Arg)

The covalent modification of E. coli arginyl-tRNA synthetase by the 2',3'-dialdehyde derivative of tRNA(Arg) (tRNA(oxArg)) resulted in the complete inactivation of the ATP-PPi exchange and aminoacylation activities of the enzyme. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of the ArgRS-tRNA(oxArg) covalent complexes indicated that two bands simultaneously appeared on the gel parallel with inactivation corresponding to different higher molecular weights. This result was different from that of the other aminoacyl-tRNA synthetase labeling systems as previously reported. Upon the ribonuclease treatment of the modified ArgRS, less than 15% of both the initial ATP-PPi exchange and aminocylation activities were recovered. During the whole process of labeling and RNase treatment, the two activities of the enzyme were closely associated.

Arginyl-tRNA synthetase from Escherichia coli, purification by affinity chromatography, properties, and steady-state kinetics

A Blue Sephadex G-150 affinity column adsorbs the arginyl-tRNA synthetase of Escherichia coli K12 and purifies it with high efficiency. The relatively low enzyme content was conveniently purified by DEAE-cellulose chromatography, affinity chromatography, and fast protein liquid chromatography to a preparation with high activity capable of catalyzing the esterification of about 23,000 nmol of arginine to the cognate tRNA per milligram of enzyme within 1 min, at 37 degrees C, pH 7.4. The turnover number is about 27 s-1. The purification was about 1200-fold, and the overall yield was more than 30%. The enzyme has a single polypeptide chain of about Mr 70,000 and binds arginine and tRNA with 1:1 stoichiometry. For the aminoacylation reaction, the Km values at pH 7.4, 37 degrees C, for various substrates were determined: 12 microM, 0.9 mM, and 2.5 microM for arginine, ATP, and tRNA, respectively. The Km value for cognate tRNA is higher than those of most of the aminoacyl-tRNA synthetase systems so far reported. The ATP-PPi exchange reaction proceeds only in the presence of arginine-specific tRNA. The Km values of the exchange at pH 7.2, 37 degrees C, are 0.11 mM, 2.9 mM, and 0.5 mM for arginine, ATP, and PPi, respectively, with a turnover number of 40 s-1. The pH dependence shows that the reaction is favored toward slightly acidic conditions where the aminoacylation is relatively depressed.