Preparation of Highly Energetic Coordination Compounds with Rich Oxidants and Lower Sensitivity Based on Methyl Groups

Revamping the structure of energy storage is an efficient strategy for striking a balance between the performance and sensitivity of energetic materials to achieve high energy and reduced sensitivity. In continuation of prior research, this study utilized the ligand 3,5-dimethyl-1H-pyrazole-4-carbonhydrazide (DMPZCA) and innovatively designed and synthesized the compound ECCs [Cu(HDMPZCA)2(ClO4)2](ClO4)2·2H2O (ECCs-1·2H2O). Compared with the former research, solvent-free compound ECCs-1 refers to an innovative material characterized by a dual structure involving ionic salts and coordination compounds. Due to these unique structures, ECCs-1 exhibits an increased [ClO4-] content, a higher oxygen balance constant (OB = -7.9%), and improved mechanical sensitivity (IS = 8 J, FS = 32 N). Theoretical calculations support the superior detonation performance of ECCs-1. Additionally, experimental results confirm its ignition capability through lower-threshold lasers and highlight the outstanding initiation potential and explosive power, making it a suitable candidate for primary explosives.

[Effectiveness of 13-valent pneumococcal conjugate vaccine against invasive disease caused by serotype 19A in children: a meta-analysis]

Objective: Using Meta-analysis to evaluate the vaccine effectiveness of 13-valent pneumococcal conjugate vaccine (PCV13) against invasive Streptococcus pneumoniae disease (IPD) caused by serotype 19A in children <5 years old. Methods: "Streptococcus pneumoniae infection""invasive pneumococcal disease""13-valent pneumococcal polysaccharide conjugate vaccine""PCV13""effectiveness""infant""child" and related terms were searched from China National Knowledge Infrastructure (CNKI), WANFANG DATA, PubMed, SCOPUS and Web of science with no limited on language, region and research institution. The retrieval time was limited from January 2010 to February 2023 and cohort study, case-control study and randomized controlled trial were included. Data were extracted from eligible studies by two independent reviewers, and after study quality assessment by NOS scale, Meta-analysis was completed using Stata 16.0 software. Results: A total of 2 340 related literatures were searched, and 10 literatures were finally included, including 5 case-control studies and 5 indirect cohort studies, which showed good literature quality. The vaccine effectiveness against serotype 19A IPD of PCV13 in children was 83.91% (95%CI: 78.92%-88.89%), and the subgroup analysis (P=0.240) showed there was no significant difference among the case-control study (VE=87.34%, 95%CI:79.74%-94.94%) and the indirect cohort study (VE=81.30%, 95%CI:74.69%-87.92%). The funnel plot and Egger test suggested that the possibility of publication bias was small. Conclusion: The present evidence indicates that PCV13 has a good vaccine effectiveness against serotype 19A IPD in children, and it is recommended to further increase the vaccination rate of PCV13 to reduce the disease burden of IPD in children <5 years old.

[Clinical and pathological features of 20 cases of congenital hepatic fibrosis]

Objective: To investigate the clinical and pathological features of congenital hepatic fibrosis (CHF). Methods: The clinical and pathological findings of 20 patients diagnosed with CHF from 2017 to 2023 were retrospectively analyzed. Results: Among the 20 patients, 8 were males and 12 were females with a median age of 21.5 years. Mostly patients were admitted to the hospital with cirrhosis, portal hypertension and upper gastrointestinal bleeding. Pathological features were diffuse fibrosis in the portal area, formation of fibrous septa of varying width, segmentation of the liver parenchyma, with hyperplasia of small bile ducts. Among them, 1 case (5%) was complicated with Caroli's disease, and 1 case (5%) was HNF1α hepatocellular adenoma. IHC GS showed that was positively expressed in acinar region 3 in 75% cases. Conclusion: CHF is mainly manifested by portal hypertension and its complications. Histopathology is the gold standard for diagnosis. The possibility of CHF should be considered first in children and adolescents with portal hypertension but no history of hepatitis, and complicated kidney disease. The positive pattern of acinus-3 region of GS in IHC is helpful for the diagnosis of CHF.

Optimization of performance and sensitivity: preparation of two Ag(I)-based ECPs by using isomeric ligands

For energetic compounds, their structure determines their performance, and even minor variations in their structure can have a significant impact on their performance. The application scenarios for energetic materials are diverse, and their performance requirements vary as well. To investigate the influence of different substituent positions on the performance of primary explosives, we prepared two Ag(I)-based complexes, [Ag(2-IZCA)ClO4]n (ECPs-1) and [Ag(4-IZCA)ClO4]n (ECPs-2), using structurally isomeric ligands, 1H-imidazole-2-carbohydrazide (2-IZCA) and 1H-imidazole-4-carbohydrazide (4-IZCA). The structures were confirmed using infrared, elemental analysis, and single-crystal X-ray diffraction. Experimental results demonstrate that both ECPs exhibit good thermal stability. However, compared to ECPs-1, ECPs-2 exhibits a lower thermal initial decomposition temperature (Td = 210 °C), lower mechanical sensitivity (IS = 27 J, FS = 84 N), and more concentrated energy output. Although theoretical predictions suggest similar detonation velocities and pressures for both compounds, actual detonation performance tests indicate that ECPs-2 has stronger explosive power and initiating capability, with potential for use as a laser initiator (E = 126 mJ). The simple preparation method and inexpensive starting materials enrich the research on primary explosives.

Combining the advantages of 1,3,4-oxadiazole and tetrazole enables achieving high-energy insensitive materials

Combining the advantages of energetic heterocycles to achieve high-energy insensitive explosives is a significant challenge. Herein, based on high-energy tetrazole rings and highly stable 1,3,4-oxadiazole rings, a series of novel nitrogen rich energetic compounds 5-9 were successfully constructed. The related compounds were fully characterized by EA, FT-IR, NMR, DSC, and MS, and compounds 6-9 were further confirmed by X-ray single crystal diffraction. Among them, the energetic ion salts 6-8 show high thermal stability (Tdec > 250 °C) and low mechanical sensitivity (IS > 40 J, FS > 360 N), as well as good energy properties (7552-8050 m s-1, 19.4-23.3 GPa). In particular, the azo compound 9 exhibits competent comprehensive performances (Tdec = 226.2 °C, D = 8502 m s-1, P = 28.9 GPa, IS = 32 J, FS = 320 N). These results suggest that the strategy of integrating tetrazole and 1,3,4-oxadiazole and employing an azo structure as a bridging unit are effective approaches to construct high-energy insensitive materials.

A multi-fused heat-resistant energetic compound constructed by hydrogen bonds

The design of heat-resistant energetic compounds generally employs symmetry, planarity, and multi-hydrogen bonds to obtain compounds with high density, good thermal stability, and low sensitivity. In this paper, a heat-resistant hydrazine-bridged compound, 6,6'-(hydrazine-1,2-diyl)bis(5-nitropyrimidine-2,4-diamine) (PHP), was designed and synthesized with the strategy of multi-fused conjugated structure constructed by hydrogen bonds. The compound featured high symmetry, high planarity, and strong conjugation with good thermal stability (364 °C). This strategy provides a basis for the design of heat-resistant energetic compounds.

Structural, vibrational and electronic properties of nitrogen-rich 2,4,6-triazide-1,3,5-triazine under high pressure

CONTEXT AND RESULTS

2,4,6-triazide-1,3,5-triazine (TAT) has received widespread attention for its great potential to synthesize or convert to nitrogen-rich high energy density materials (HEDMs). The TAT structure alteration in the compression process up to 30 GPa has characteristics as follows: (a) [N₃] groups straighten; (b) [N₃] groups gather toward the six-membered C-N heterocycles. At about 5 GPa, Raman peak split at 700 cm^-1 was observed both in calculation and in-situ Raman experiment, which is caused by pressure-induced intramolecular stress. Besides, the broad band of the amorphous two-dimensional C=N network (centered at 1630 cm^-1) occurred at about 12 GPa. Meantime, the study on electronic features suggests the pressure-induced deformation in TAT molecular structure cause the discontinuous change of band gap at about 4.5 GPa and 8.0 GPa, respectively.

COMPUTATIONAL AND THEORETICAL TECHNIQUES

The static compression process of TAT was explored in the range of 0-30 GPa by using dispersion corrected density functional theory (DFT-D) calculations combined with in-situ Raman experiment. The GGA/PBE+G06 method that has less errors than other calculation methods was used to predict the geometry structure, vibrational properties and electronic structure of TAT under pressure.

Preparation of High-Energy ECPs by Retaining the Coordination Ability of Carbohydrazide Groups

In order to preserve the coordinating ability of the hydrazide group, we used retrosynthetic analysis to design and synthesize ligand furan-2,5-dicarbohydrazide and its complex [Cu(FDCA)(H₂O)ClO₄]_n(ClO₄)_n·nH₂O (ECPs-1·H₂O). The structure of the product was confirmed by single-crystal X-ray diffraction, infrared spectroscopy, and elemental analysis. The solvent-free target material ECPs-1 exhibited good thermal stability, sensitivity to mechanical stimuli, and excellent explosive properties. Furthermore, it had good potential for laser ignition and comparable detonation power to LA. The simple preparation method and inexpensive starting materials enriched the research on primary explosives.

Preparation of Primary Explosive by Self-assembly of Combustible and Oxidizing Agents under Acid

In order to further explore the effect of ligands on the performance of primary explosives and gain a deeper understanding of the coordination mechanism, we designed furan-2-carbohydrazide (FRCA), a ligand, by using oxygen-containing heterocycles and carbohydrazide. Then, FRCA and Cu(ClO₄)₂ were used to synthesize coordination compounds [Cu(FRCA)₂(H₂O)(ClO₄)₂]·CH₃OH (ECCs-1·CH₃OH) and Cu(FRCA)₂(H₂O)(ClO₄)₂ (ECCs-1). The structure of the ECCs-1 was confirmed by single-crystal X-ray diffraction, IR and EA characterization. Further experiments on ECCs-1 show that ECCs-1 has good thermal stability, but is sensitive to mechanical stimuli (impact sensitivity = IS = 8 J, friction sensitivity = FS = 20 N). The predicted value of the detonation parameter is D_EXPLO 5 = 6.6 km s^-1, P_EXPLO 5 = 18.8 GPa, but the ignition test, laser test, and lead plate detonation experiment show that ECCs-1 has excellent detonation performance, which is very worthy of attention.

Preparation of Multi-functional Type Coordination Compounds: Spanning the quantitative restriction of Oxidizing Groups

Based on the ideas of coordination chemistry and design chemistry, we propose a new strategy to break through the limitation of the number of oxidizing acid radicals in energetic coordination...

[Epidemiological characteristics and spatiotemporal clustering of hepatitis A in Zhejiang Province from 2010 to 2019]

Objective: To analyze the epidemiological characteristics and spatiotemporal clustering of hepatitis A in Zhejiang Province from 2010 to 2019. Methods: The data of hepatitis A incidence in Zhejiang Province from 2010 to 2019 were collected from the infectious disease surveillance system of China Information System for Disease Control and Prevention. ArcGIS 10.7 software was used for spatial autocorrelation analysis. SaTScan 9.6 software was used for spatiotemporal scanning analysis. SPSS 25.0 software was used for additional analysis. Results: Zhejiang Province has reported 5 465 cases of hepatitis A in 2010-2019 years, with an average annual incidence rate of 1.00/100 000, and periodicity and seasonality are not obvious. The incidence of male was higher than that of female (P=0.023), and the highest incidence rate was 50-59 years old. Spatial autocorrelation analysis showed that there was a positive spatial correlation between the incidence of hepatitis A in Zhejiang Province from 2010 to 2017, with the weakest correlation in 2010 (Moran's I =0.103, Z=1.769, P=0.049), and the strongest correlation in 2016 (Moran's I=0.328, Z=4.979, P=0.001). Spatiotemporal scanning analysis showed that there was spatial aggregation of hepatitis A in Zhejiang Province from 2010 to 2019, with a total of three aggregation areas identified. Among them, the mostly aggregation area was concentrated in Xiangshan county of Ningbo city, which covered 10 counties (cities and districts), including Ninghai county and Yinzhou district, and appeared from January 1 to June 30, 2012. Conclusion: The incidence level of hepatitis A in Zhejiang Province shows a stable fluctuation trend from 2010 to 2019, and the seasonal regularity is not obvious. The population group aged 50-59 years old is the key population. There is spatial aggregation in the epidemic situation of hepatitis A. Targeted prevention and control measures of hepatitis A should be done based on the law of spatiotemporal aggregation and local incidence.

Detonation performance enhancement through a positional isomerism modification strategy

The design, synthesis, physical properties, and calculated detonation performances of two skeleton isomeric energetic compounds containing tetrazole were introduced. By changing the chemical modification sites of the original fused-pyrimidine skeleton,...

Synthesis and characterization of thermally stable energetic complexes with 3,5-diaminopyrazolone-4-oxime as a nitrogen-rich ligand

Two thermally stable complexes based on DAPO were synthesized. The thermal decomposition temperatures were 287 °C and 344 °C, respectively. The detonation properties of the complexes were excellent with good detonation velocity and detonation pressure superior to that of TNT.

Engaging DBFO as a C1N1 “two-atom synthon” in [3 + 2] cycloaddition reaction: synthesis of the energetic material 5-azidotetrazolate 1N-oxide

Employing 1,1-dibromoformaloxime as a novel C1N1 “two-atom synthon” for the synthesis of tetrazole-based energetic materials via an intramolecular [3 + 2] annulation in aqueous solution.

Isolation and identification of bioactive substance 1-hydroxyphenazine from Pseudomonas aeruginosa and its antimicrobial activity

A strain named as Pseudomonas aeruginosa 2016NX1, which could produce phenazine and cereusitin, was isolated from the root of Millettia specisoa. Phenazines were extracted, isolated and purified by chloroform, thin-layer chromatography, column chromatography and high-performance liquid chromatography. Then the purified materials were identified by analysis of nuclear magnetic resonance. The major yellow component is 1-hydroxyphenazine and the minor blue component is cereusitin A. The tests of antimicrobial activity of yellow component showed that the growth of several common plant pathogenic fungi and bacteria (such as Cochliobolus miyabeanus, Diaporthe citri, Salmonella sp., Klebsiella oxytoca) could be strongly inhibited. This study suggested that Pseudomonas aeruginosa strain 2016NX1 had a significant potential for biological control of phytopathogenic fungi. SIGNIFICANCE AND IMPACT OF THE STUDY: In this study, one bioactive substance from Pseudomonas aeruginosa 2016NX1 was identified and its antimicrobial activity was verified. This study demonstrated that one bioactive substance from P. aeruginosa can strongly inhibit the growth of plant pathogenic fungi and bacteria. This study suggested that P. aeruginosa strain 2016NX1 has a significant potential for biological control of phytopathogenic fungi.

[Complications of critically ill children supported by venoarterial extracorporeal membrane oxygenation]

OBJECTIVE

To study the complications occurred in the process of venoarterial extracorporeal membrane oxygenation (VA-EMCO) in critically ill children.

METHOD

To analyze retrospectively 25 children who were admitted to PICU of Children's Hospital of Fudan University from December 2011 to December 2015. They were all treated with VA-ECMO with incision and catheterization in right internal carotid artery and jugular vein. Complications were recorded during ECMO process.

RESULT

The duration of ECMO treatment was 14 to 567 h (153 (112, 204) h). Seventeen cases (68%) withdrew from ECMO successfully and 15 cases (60%) survived to discharge. Thirty-three complications occurred during ECMO treatment. Of which, mechanical complications occurred 9 times, including oxygenator leakage (n=3), hemolysis (n=2), water tank failure (n=2), pump head rupture (n=1) and piping thrombosis (n=1). Somatic complications appeared 24 times, including neurological complications (n=8) which included cerebral infarction (n=2), convulsions (n=2), intracranial hemorrhage (n=2), thrombosis after ligation of internal jugular vein (n=1) and cerebral atrophy (n=1); bleeding complications (n=8) which included bleeding at puncture sites (n=4), ECMO canalized site bleeding (n=3), and spontaneous (n=1), intracranial hemorrhage or hematoma cases(n=2) in mechanical complications; acute kidney injury (n=5) and microcirculation thrombosis (n=3).

CONCLUSION

ECMO technique may cause complications, which mainly include neurological, mechanical and clotting complications. Advanced equipments and materials and well-managed teamwork are helpful in decreasing complications.

[Effects and mechanisms of high-volume hemofiltration on endotoxin-induced acute lung injury of piglets]

Objective: To compare the effects of high-volume hemofiltration (HVHF) and continuous veno-venous hemofiltration (CVVH) on cardiopulmonary functions, lung fluid balance, lung damage and cytokine expression in endotoxin-induced acute lung injury piglet model, and to further evaluate the value of high-volume hemofiltration in acute lung injury. Method: Eighteen piglets were randomly divided into the control group (6 piglets), the CVVH group (6 piglets) and the HVHF group (6 piglets). By general anesthesia, the intravenous infusion of 0.15 mg/kg endotoxin were received in all the animals and induced acute lung injury.High-volume hemofiltration and continuous veno-venous hemofiltration were addressed to different groups.Subsequently, hemodynamic parameters (heart rate, mean arterial blood pressure, central venous pressure, pulse contour cardiac index, systemic venous resistance index and extravascular lung water index) as well as gas exchange and lung mechanics parameters (respiratory rate, partial pressure of carbon dioxide, partial pressure of oxygen/fraction of inspired oxygen, dynamic lung compliance and airway resistance) were intermittently measured.Lung tissues were collected for further analysis (the lung wet-to-dry weight ratio, lung injury scoring). The plasma protein levels of cytokines (interleukin(IL) -6, 10 and tumor necrosis factors alpha(TNF-α)) were also assessed.Two-way analysis of variance (ANOVA) and Bonferroni post-test were conducted to identify significant differences among the control, CVVH and HVHF group. Result: Compared with CVVH, HVHF had the capacity to improve significantly the index of Cdyn(HVHF (2.3±0.5) vs. CVVH (1.5±0.5) ml/(cmH(2)O·kg), 1 cmH(2)O=0.098 kPa, P<0.05)and Rrs(HVHF (22.0±1.9) vs.CVVH (29.5±1.5) cmH(2)O/(L·s), P<0.05)at the time of 6 h, and decreased lung water accumulation(index of EVLWI in HVHF (22.7±2.1) vs.CVVH (39.5±2.6) ml/m(2,) P<0.01) at the time of 6 h, and the plasma concentration of cytokines(IL-6, IL-10, TNF-α)in the HVHF group had an obvious decline compared with those in the CVVH group at the time of 6 h( (200±55) vs. (280±61), (74±17) vs. (102±21), (54±13) vs. (73±21) pg/ml, all P<0.05). The lung injury scoring of HVHF group was significantly lower than those of CVVH group((7.8±1.9) vs. (11.3±2.2) scores, P<0.05). Although the plasma concentration of cytokines(IL-6, IL-10, TNF-α) in the CVVH group were lower than those in the control group at the time of 6 h((374±55), (137±25), (98±17) pg/ml, all P<0.05), the indexes of respiratory function were not improved (all P<0.05). Conclusion: Different doses hemofiltration can reduce plasma inflammatory mediators indicators in piglets.Early high volume hemofiltration can improve respiratory function of piglets with endotoxin-induced acute lung injury and reduce lung injury pathological score.

[Application of right jugular vessels to build extracorporeal membrane oxygenation for treating the critically ill children]

OBJECTIVE

To summarize the experience in applying a technique of inserting a cannula through right internal jugular vein and common carotid artery to build extracorporeal membrane oxygenation (ECMO) for critically ill children.

METHOD

The data of critically ill patients received ECMO support through right internal jugular vein and common carotid artery between December 2011 and December 2015 from Children's Hospital of Fudan University were analyzed retrospectively.The data included diagnosis, age, body weight, time of cannula and ECMO running, complication and prognosis.

RESULT

In total 28 patients received ECMO support, 3 patients of post-cardiac surgery with transthoracic cannula were excluded.Twenty-five patients inserted cannula through neck vessels were enrolled, 15 boys and 10 girls, the median age was 1.8 years (range, 1 d-13 years), the median weight was 12.0 (2.8-50.0) kg.All the cannula sites were right internal jugular vein and right common carotid artery, before cannula use 5 patients had been inserted central vein tube and 3 patients with blood filter tube in right internal jugular vein, in one case cannula was applied during cardiopulmonary resuscitation.V-A ECMO had been built for all the cases successfully, the median operation time was (45±26) min.The pump flow was 80-150 ml/(kg·min), the median duration of ECMO support was 153(14-567) h. Sixteen (64%) patients weaned off ECMO successfully, 15(60%) survived to hospital discharge.About the complication of cannula, six patients developed cannula site bleeding, and two patients required re-fixation of cannula, one patient's external jugular vein had been hurt and sutured for bleeding.

CONCLUSION

Application of right jugular vessels to build ECMO is easy and safe for treating the sick children. The skill should be proficient to assure ECMO run and reduce the complications.

Functional up-regulation of P2X3 receptors in dorsal root ganglion in a rat model of bone cancer pain

BACKGROUND

Cancer-induced bone pain remains a clinical challenge due to the poor understanding of the mechanisms. Recent study revealed extracellular adenosine triphosphate (ATP) and P2X receptors may be implicated in nociceptive signalling under cancer pain state. Therefore, here we investigated the potential role of P2X(3) receptor in a rat model of bone cancer pain.

METHODS

Walker 256 tumour cells were inoculated into the left tibia of Wistar rats. The model was verified by X-ray imaging, pathology and behaviour examinations. The expression of P2X(3) receptors in dorsal root ganglia (DRG) was examined. Functional significance of altered P2X(3) receptors was investigated by measuring influx upon α,β-meATP stimulation in acutely dissociated DRG neurons. Moreover, A-317491, an antagonist of P2X(3) receptors, was administrated intrathecally or locally to evaluate its analgesia effect in the cancer pain animals.

RESULTS

The P2X(3) receptor was up-regulated for about 50% in DRG neurons in rats with bone cancer at both protein and mRNA levels and correlated with the pain behaviour in bone cancer rats. A 51.9% increase of α,β-me ATP (10 μM, for 4 s) evoked transient response currents and a higher percentage of neurons responsive to the application of α,β-me ATP was detected in bone cancer rats. Intrathecal or local injection of A-317491 significantly attenuated pain behaviour induced by bone cancer.

CONCLUSIONS

These results suggest that the P2X(3) receptor is functionally up-regulated in DRG in cancer rats. P2X(3) receptor is a promising target for therapeutic intervention in cancer patients for pain management.

The efficacy and safety of vildagliptin in patients with type 2 diabetes: a meta-analysis of randomized clinical trials

WHAT IS KNOWN AND OBJECTIVE

Dipeptidyl peptidase-4 (DPP-4) inhibitors are a relatively new class of drugs for the management of type 2 diabetes (T2DM). Vildagliptin is an oral DPP-4 inhibitor approved in more than 70 countries. The purpose of this meta-analysis is to provide an update on the clinical efficacy and safety of vildagliptin in patients with T2DM.

METHODS

A literature search identified 30 randomized controlled trials comparing vildagliptin with comparators (placebo or other hypoglycaemic agents). Meta-analyses were conducted for HbA1c, weight, fasting plasma glucose (FPG), hypoglycaemia and other adverse events. The outcomes of HbA1c, weight and FPG were analysed as weighted mean differences (WMD), and the number of ADRs events as relative risks (RR).

RESULTS

Compared with placebo, vildagliptin lowered HbA1c {WMD, -0·77% [95% confidence interval (CI), -0·96% to -0·58%] for 100 mg/day of vildagliptin and -0·58% [95% CI, -0·72% to -0·44%] for 50 mg/day of vildagliptin}. The effect was non-inferior to thiazolidinediones, sulfonylureas and α-glycosidase inhibitors, but inferior to metformin. Compared with placebo, treatment with 50 mg/day of vildagliptin caused neutral weight changes, while 100 mg/day of vildagliptin resulted in slight weight gain [0·95 kg (95% CI, 0·73-1·17 kg)]. In addition, compared to comparators, vildagliptin was not associated with an increase in overall risk for any adverse events [RR, 0·97 (95% CI, 0·94-0·99)]. The incidence of hypoglycaemia was low with vildagliptin, and the risk with vildagliptin was not significantly different from the comparators [0·85 (95% CI, 0·49-1·47)]. The use of vildagliptin did not display any increased risks of infection [1·03 (95% CI, 0·94-1·13) for nasopharyngitis and 1·07 (95% CI, 0·90-1·27) for upper respiratory tract infection].

WHAT IS NEW AND CONCLUSION

Vildagliptin is effective in glycaemic control with a low risk of hypoglycaemia and other adverse reactions. This may have an important impact on patient adherence to this medication.

Effect of the route of foot-and-mouth disease virus infection of piglets on the course of disease

Three different routes of Foot-and-mouth disease virus (FMDV) infection of piglets, namely intranasal (i.n.) through drops, intradermal (i.d.) into the foot, and intramuscular (i.m.) were compared regarding the onset and severity of the disease. The results showed that the i.d. injection of the virus resulted in the fastest onset of the disease. The i.m. injection led to a delayed onset, but the final effect was identical with i.d. injection. Moreover, the i.m. injection was simpler to perform and easier to evaluate. Therefore, the i.m. injection of piglets is recommended as the optimal infection route for evaluation of the FMDV vaccine potency.

A comparison of liver function after hepatectomy with inflow occlusion between sevoflurane and propofol anesthesia

BACKGROUND

In this study, we compared liver function tests after hepatectomy with inflow occlusion as a function of propofol versus sevoflurane anesthesia.

METHODS

One hundred patients undergoing elective liver resection with inflow occlusion were randomized into a sevoflurane group or a propofol group. General anesthesia was induced with 3 μg/kg fentanyl, 0.2 mg/kg cisatracurium, and target-controlled infusion of propofol, set at a plasma target concentration of 4 to 6 μg/mL, or sevoflurane initially started at 8%. Anesthesia was maintained with target-controlled infusion of propofol (2-4 μg/mL) or sevoflurane (1.5%-2.5%). The primary end point was postoperative liver injury assessed by peak values of liver transaminases.

RESULTS

Transaminase levels peaked between the first and the third postoperative day. Peak alanine aminotransferase was 504 and 571 U/L in the sevoflurane group and the propofol group, respectively. Peak aspartate aminotransferase was 435 U/L after sevoflurane and 581 U/L in the propofol group. There were no significant differences in peak alanine aminotransferase or peak aspartate aminotransferase between groups. Other liver function tests including bilirubin and alkaline phosphatase, and peak values of white blood cell counts and creatinine, were also not different between groups.

CONCLUSIONS

Sevoflurane and propofol anesthetics resulted in similar patterns of liver function tests after hepatectomy with inflow occlusion. These data suggest that the 2 anesthetics are equivalent in this clinical context.

The effects of obstructive jaundice on the pharmacodynamics of propofol: does the sensitivity of intravenous anesthetics change among icteric patients?

BACKGROUND

Some studies suggest that certain clinical symptoms of cholestasis, such as fatigue and pruritus, result from altered neurotransmission. Patients with obstructive jaundice also have labile blood pressure and heart rate. In the present study, the authors investigated whether obstructive jaundice affects a patient's sensitivity to hypnotics and the haemodynamic profile of propofol.

METHODS

Thirty-six ASA physical status I/II/III patients with serum total bilirubin (TBL) from 7.8 to 362.7 micromol/l scheduled for bile duct surgery were recruited. A computer-controlled propofol infusion programmed for effect site target was used to rapidly attain and maintain sequential increase of the compartment concentration (from 1 to 3 microg/ml). Each target-controlled concentration was maintained for about 12 min, and arterial blood samples were drawn for propofol concentration determination. The bispectral index (BIS) and mean arterial pressures (MAP) were used as indices of the propofol effect. The relation between the concentration and the effects was described by the Hill equation. The pharmacodynamic parameters were optimized using a nonlinear mixed-effect model.

RESULTS

TBL was not a significant covariate of EC(50) for the pharmacodynamic model. For BIS and MAP, the parameters of the pharmacodynamic model were E(max)=75.77%, EC(50)=2.34 microg/ml, and gamma=1.82, and E(max)=47.83%, EC(50)=1.49 microg/ml, and gamma=1.88, respectively.

CONCLUSIONS

We demonstrated that obstructive jaundice with serum TBL from 7.8 to 362.7 micromol/l had no effect on propofol pharmacodynamics observed by BIS and MAP.

Reliability and validity of a patient self-administered daily questionnaire to assess impact of oral mucositis (OM) on pain and daily functioning in patients undergoing autologous hematopoietic stem cell transplantation (HSCT)

Oral mucositis (OM) is a frequent complication of myeloablative therapy and HSCT. We evaluated the feasibility, reliability, and validity of a new patient self-reported daily questionnaire on OM and its impact on daily functions. This OM Daily Questionnaire (OMDQ), containing 10 items, was developed for use in palifermin clinical trials. In a phase 3 study, 212 patients received palifermin or placebo for three consecutive days before conditioning and three consecutive days after HSCT. Compliance rates were consistently >80% for most patients. Mouth and throat soreness (MTS) and MTS-Activity Limitations (MTS-AL) (swallowing, drinking, eating, talking, and sleeping) scores on consecutive days were highly correlated (days 7,8 = 0.70-0.86; test-retest reliability). Correlations among items measuring the same construct ranged between 0.5 and 0.8 (internal consistency reliability). The WHO Oral Toxicity scale was the clinical comparator to assess the criterion, discriminative, and evaluative validities of MTS-related questions. Most correlation coefficients between the WHO and MTS ranged between 0.45 and 0.55. Patients with more severe WHO OM grades had higher MTS mean scores. Changes in MTS scores were similar, but patients detected changes 1-3 days earlier than clinicians. In conclusion, the OMDQ is a feasible, reliable, valid, and responsive patient-reported measure of OM severity.

Observation of a near-threshold enhancement in the pp mass spectrum from radiative J/psi-->gammapp decays

We observe a narrow enhancement near 2m(p) in the invariant mass spectrum of pp pairs from radiative J/psi-->gammapp decays. No similar structure is seen in J/psi-->pi(0)pp decays. The results are based on an analysis of a 58 x 10(6) event sample of J/psi decays accumulated with the BESII detector at the Beijing electron-positron collider. The enhancement can be fit with either an S- or P-wave Breit-Wigner resonance function. In the case of the S-wave fit, the peak mass is below 2m(p) at M=1859(+3)(-10) (stat)+5-25(syst) MeV/c(2) and the total width is Gamma<30 MeV/c(2) at the 90% confidence level. These mass and width values are not consistent with the properties of any known particle.

Measurements of the cross section for e(+)e(-) --> hadrons at center-of-mass energies from 2 to 5 GeV

We report values of R = sigma(e(+)e(-)-->hadrons)/sigma(e(+)e(-)-->mu(+)mu(-)) for 85 center-of-mass energies between 2 and 5 GeV measured with the upgraded Beijing Spectrometer at the Beijing Electron-Positron Collider.

Disruption of cytoskeletal integrity impairs Gi-mediated signaling due to displacement of Gi proteins

beta1 integrins play a crucial role as cytoskeletal anchorage proteins. In this study, the coupling of the cytoskeleton and intracellular signaling pathways was investigated in beta1 integrin deficient (-/-) embryonic stem cells. Muscarinic inhibition of the L-type Ca2+ current (ICa) and activation of the acetylcholine-activated K+ current (IK,ACh) was found to be absent in beta1 integrin-/- cardiomyocytes. Conversely, beta adrenoceptor-mediated modulation of ICa was unaffected by the absence of beta1 integrins. This defect in muscarinic signaling was due to defective G protein coupling. This was supported by deconvolution microscopy, which demonstrated that Gi exhibited an atypical subcellular distribution in the beta1 integrin-/- cardiomyocytes. A critical role of the cytoskeleton was further demonstrated using cytochalasin D, which displaced Gi and impaired muscarinic signaling. We conclude that cytoskeletal integrity is required for correct localization and function of Gi-associated signaling microdomains.

[Neocartilage formation in vitro using transduced mesenchymal stem cells cultured on biomimetic biodegradable polymer scaffolds]

OBJECTIVE

To investigate the effect of transforming growth factor (TGF) beta 1 gene transfection on the growth of mesenchymal stem cells(MSCs) and to evaluate a new biomimetic biodegradable polymer as scaffolds for applications in articular cartilage tissue engineering.

METHODS

Principles of tissue engineering were combined organically with principles of gene therapy to produce cultured periosteum-derived MSCs transduced with the full-length rat TGF-beta 1 cDNA in vitro. These cells were then seeded onto three-dimensional porous poly-DL-lactide scaffolds modified with poly-L-lysine that mimicked cell-binding domains found on natural extracellular matrix to promote specific cell adhesion. The adhesion, proliferation, and differentiation of the transfected MSCs were examined with scanning electron microscope within 2 weeks.

RESULTS

All cells adhered to the biomimetic matrices well, but more cartilage-like tissue was formed for TGF-beta 1 gene modified MSCs/scaffolds composites than for the control groups. Transfer of gene encoding TGF-beta 1 to MSCs promoted its proliferation and differentiation significantly.

CONCLUSIONS

The TGF-beta 1 gene transduced MSCs/biomimetic matrix composites used in this study was the first attempt to apply the principles of molecular tissue engineering for articular cartilage repair. This new molecular tissue engineering approach could be of potential benefit to repair damaged articular cartilage, especially in osteoarthritis. The new biomimetic biodegradable polymer matrices modified with biomolecules not only have good structural compatibility, but also have better interfacial compatibility and bioactivity, and can be used as scaffolds for articular cartilage tissue engineering.

Effectiveness of breast self-examination nursing interventions for Taiwanese community target groups

BACKGROUND

Because of the increasing morbidity and mortality from breast cancer, the Health Department in Taiwan in 1992 has identified early detection of breast cancer as one of the national health objectives. The effectiveness of Breast Self-Examination (BSE) in detecting breast cancer depends not only on frequency, but also on accuracy. This study explored the effects of nursing intervention on the BSE intention, BSE frequency and BSE accuracy among beauticians as community target groups.

DESIGN

This study was comprised of two stages. In the first stage, 198 beauticians in Taipei County were surveyed. Those women with perceived barrier scores > or =15 points in the first stage were selected for the second stage with the quasi-experimental design. The experimental group was provided with BSE instruction for the enhancement of BSE competence, personalized strategies to reduce barriers to BSE and monthly telephone reminders after BSE instruction class for 3 months. The study instruments were Champion's BSE questionnaire, Lashley's 15 BSE steps and BSE items of social norm referenced Lierman et al.

RESULTS

The mean age of the 198 beauticians was 28 (+/-8.6), the mean year of education was 10 (+/-2.4) and 60% of participants were married. The results of the study indicate that the program significantly increased BSE frequency, BSE accuracy, perceived benefit of BSE, perceived competence in BSE and decreased perceived susceptibility to breast cancer and perceived barriers to practice BSE. Multiple regression analysis indicated that the perceived competency, susceptibility and social normative influence accounted for 25% of the variance in BSE intention. Perceived competency and social normative influence accounted for 15% of the variance in BSE frequency, while intention, social normative influence and perceived competency accounted for 21% of the variance in BSE accuracy.

The relationship between menstrual attitudes and menstrual symptoms among Taiwanese women

AIM OF THE STUDY

This study explored characteristics of the menstrual cycle including duration, prevalence and severity of symptoms and examined the relationship of these characteristics with attitudes toward menstruation.

BACKGROUND

Conceptualization of menstrual phenomena and attitudes toward menstruation may vary among cultures. While data about menstrual health among American women are widely available, there are little data concerning menstrual health in Taiwanese women.

DESIGN/METHODS

A total of 30 healthy women with a mean age of 24.4 years participated in the study and made daily records of symptoms over a 90-day period with the Woods Daily Health Diary (WDHD). They then retrospectively completed the Moos Menstrual Distress Questionnaire (MMDQ) and the Menstrual Attitudes Questionnaire (MAQ).

RESULTS

The mean age of menarche of these women was 13 years, their mean cycle duration was 5.8 days and the cycle length was 31.1 days. The mean scores of five subscales for MAQ ranged from 2.19 to 3.28. Forty-six percent of the surveyed Taiwanese women agreed that the onset of menstruation can be predicted and anticipated, and 78% of these women agreed that menstruation was a natural event.

CONCLUSIONS

Menstrual attitudes in Taiwanese women are multidimensional, and that significant cross-cultural differences are present. Attitudes toward menstruation in Taiwanese women are related to their physical, cognitive, behavioural and psychological changes in the premenstrual and menstrual phases.

Outwards currents in embryonic stem cell-derived cardiomyocytes

The aim of the present study was to investigate the expression and functional role of outwards currents during the early stages of cardiomyogenesis. The predominant repolarizing current in early-stage, embryonic stem (ES) cell-derived cardiomyocytes was a 4-aminopyridine (4-AP) sensitive [concentration for half-maximal inhibition (IC50) 1.7 mM], transient outward current (Ito) with a current density of 10.3+/-2.1 pA/pF (n=72). We observed two additional, rapidly activating, outwardly rectifying current components, I(K),sus and Ires, in early- and late-stage cardiomyocytes. These currents were characterized by slow and no inactivation, respectively, during the depolarizing voltage step. I(K),sus was detected in about 25% of cells investigated and displayed 4-AP hypersensitivity (IC50 29 microM), whereas Ires was found in all cells of both differentiation stages and was 4-AP insensitive. In contrast to early-stage cells, Ires formed the larger portion of the aggregate, whole-cell current in late-stage, ES cell-derived cardiomyocytes. The current densities of all three current components increased during development, however, the most prominent increase was observed for I(res) from 3.6+/-0.8 pA/pF (n=72) to 8+/-1.1 pA/pF (n=35). In current-clamp recordings in early-stage, spontaneously contracting cardiomyocytes, 4-AP depolarized the cells, lengthened the action potential duration (APD) and increased the action potential frequency. In late-stage cells 4-AP had no effect on action potential frequency. We conclude that in early-stage cardiomyocytes I(to) plays an important role in controlling electrical activity.

Functional expression and regulation of the hyperpolarization activated non-selective cation current in embryonic stem cell-derived cardiomyocytes

1. The biophysical and pharmacological characteristics of the hyperpolarization activated non- selective cation current (If) were recorded using whole-cell voltage clamp in embryonic stem (ES) cell-derived cardiomyocytes at different stages of development. 2. The cation current was detected in a large percentage (65 %) of early stage (EDS, differentiated for 7 + 3-4 days) cells at a current density of 11.4 +/- 0.6 pA pF-1 (n = 47). In late stage (LDS, differentiated for 7 + 9-12 days) cells the percentage of cells expressing If decreased (45 %), but If densities (15.5 +/- 0.9 pA pF-1, n = 20) were increased. 3. The muscarinic agonist carbachol (CCh, 1 microM) depressed basal If in EDS cells by 45.7 +/- 6.5 %, n = 5) and was without effect in LDS cardiomyocytes (n = 4). The beta-adrenoceptor agonist isoprenaline (ISO, 1 microM) stimulated If in LDS cells by 33 +/- 5.2 % (n = 6) but not in EDS cells (n = 5). 4. Cell infusion with the catalytic subunit of the cAMP-dependent protein kinase (PKA, 7 microM) stimulated If in EDS cells by 37.0 +/- 2.9 %, (n = 4), but subsequent superfusion of 8-bromo-cAMP (200 microM) was without effect. Intracellular perfusion of LDS cardiomyocytes with the highly selective peptide inhibitor of PKA (PKI, 20 microM) completely inhibited the stimulation of the L-type Ca2+ current (ICa,L) as well as of If by ISO (1 microM). 5. Extracellular superfusion with phosphodiesterase (PDE) inhibitors - IBMX, a non-selective antagonist, Erythro-9-(2-hydoxy-3-nonyl)adenine (EHNA), a PDE2 antagonist and rolipram, a PDE4 antagonist - resulted in stimulation of ICa,L and If in EDS cells. By contrast, milrinone and cilostamide, two PDE3 antagonists, stimulated ICa,L, but not If. 6. The present work demonstrates that If is functionally expressed during early cardiomyogenesis. Similar to ICa,L, If is regulated during embryonic development by phosphorylation via PKA. In contrast to ICa,L, If is not regulated by PDE3 suggesting different localization of these ion channels with respect to PDE3.

Identification of a highly diverged class of S-adenosylmethionine synthetases in the archaea

S-adenosylmethionine is the primary alkylating agent in all known organisms. ATP:L-methionine S-adenosyltransferase (MAT) catalyzes the only known biosynthetic route to this central metabolite. Although the amino acid sequence of MAT is strongly conserved among bacteria and eukarya, no homologs have been recognized in the completed genome sequences of any archaea. In this study, MAT has been purified to homogeneity from the archaeon Methanococcus jannaschii, and the gene encoding it has been identified by mass spectrometry. The peptide mass map identifies the gene encoding MAT as MJ1208, a hypothetical open reading frame. The gene was cloned in Escherichia coli, and expressed enzyme has been purified and characterized. This protein has only 22 and 23% sequence identity to the E. coli and human enzymes, respectively, whereas those are 59% identical to each other. The few identical residues include the majority of those constituting the polar active site residues. Each complete archaeal genome sequence contains a homolog of this archaeal-type MAT. Surprisingly, three bacterial genomes encode both the archaeal and eukaryal/bacterial types of MAT. This identification of a second major class of MAT emphasizes the long evolutionary history of the archaeal lineage and the structural diversity found even in crucial metabolic enzymes.

Empirical criteria for the selection of quality-of-life instruments for the evaluation of peripheral blood progenitor cell transplantation

We propose a method for selecting quality-of-life instruments for use in phase III trials using the convergent validity of patient responses collected in phase I and II clinical trials. Two generic and two disease-specific instruments were administered to patients with breast cancer undergoing peripheral blood progenitor cell mobilization and transplantation. They included the visual analog scale from the EuroQoL EQ5D instrument, the SF-36, the European Organization for Research and Treatment of Cancer (EORTC)-QLQ-C30, and the Functional Assessment of Cancer Therapy instrument. No single instrument was found to have superior convergent validity in all domains, but the EORTC-QLQ-C30 seemed to perform better than the SF-36.

Social support and breast self-examination

Declining practice of breast self-examination (BSE) among women over the age of 55 years dramatically decreases the probability of early detection of breast cancer. About two-thirds of women who die of breast cancer are over the age of 55 years. Social support has been found to be associated with health behaviors. Although a woman's health may benefit from supportive relationships, the effect of diminished social networks on practices of BSE among older women has not been examined. Thus, the purpose of this study was to determine the relationship between social support and the frequency and accuracy of BSE practice. The sample consisted of 22 women, 55 years of age and older, who were having routine examinations at a small Midwestern gynecologic clinic. Social support was assessed by the Norbeck Social Support Questionnaire, and two tools assessed the accuracy and frequency of BSE. Social support was found to be significantly related to the frequency of BSE (r = 0.45, p < 0.05), but not to the accuracy of BSE (r = 0.28). The results also indicated that these women had lower social support scores compared with younger women. Planners of nursing intervention for BSE should consider health care providers as important resources in social support networks for the reinforcement of frequency and accuracy of BSE for older women.

Variables associated with breast self-examination among Chinese women

Asians are the fastest growing minorities in the U.S. To deliver culturally sensitive care is a significant challenge to the nursing profession. Research identifying variables associated with breast self-examination (BSE) in the U.S. has been conducted on Caucasian women, but little is known about Asian women. Based on the health belief model (HBM) and Bandura's social learning theory, the purpose of this study was to identify barriers to the practice of BSE among Chinese women. The Chinese women (n = 174; mean age, 31 years) were surveyed with a 38-item, five-point Likert scale developed by Champion, and Lauver and Angerame, as well as a six-step accuracy check. The factors included susceptibility; seriousness for breast cancer; general efficacy for BSE; specific efficacy of BSE for oneself; competence; comfort; and control. The results showed that only 15% of these Chinese women practiced BSE monthly, and 48% reported never having performed BSE. Approximately 50% had no opinion on perceived susceptibility to and seriousness of breast cancer; nevertheless, > 80% recognize the efficacy of BSE. Perceived competence significantly accounted for 10% of the variance on BSE frequency (p < 0.001). Implications for nursing interventions that foster competence in BSE for this population are suggested. The study also demonstrates culturally specific methodological considerations.

ESR dating of tooth enamel: comparison with U-series, FT and TL dating at the Peking man site

Deer tooth samples from Zhoukoudian, the Peking Man Cave, were studied. Non-linear fitting is used to determine AD, from which ESR ages were calculated by both the disequilibria model (DU) and linear uptake model (LU). Comparison of ESR ages with those from U-series, FT and TL methods show that the enamel of deer teeth is a suitable material for ESR dating.

Regulation of the GTPase activity of the ras-like protein p25rab3A. Evidence for a rab3A-specific GAP

The rab3A gene product is a 25-kilodalton guanine nucleotide-binding protein, expressed at high levels in neural tissue, which has about 30% homology to ras. Recombinant rab3A protein and p25rab3A purified from bovine brain membranes have been used as substrates to look for factors that regulate its biochemical activity. A detergent-soluble factor associated with rat brain membranes exists that accelerates the GTPase activity of both mammalian and recombinant p25rab3A. The activity was thermolabile, sensitive to trypsin, and behaved like an integral membrane protein. GTPase-activating protein (GAP) activity toward p25rab3A was also detected in the cytosolic fraction. This activity was observed in all other tissues examined, in addition to brain. Based upon dose-response data, the rab3A-GAP activity from rat brain was approximately equally distributed between cytosolic and membrane fractions; no activity was found in the nuclear fraction. Recombinant ras-specific GAP had no effect upon the GTPase activity of p25rab3A. By gel filtration chromatography, the factor in rat brain cytosol has a molecular size of 400,000 daltons.

Acute experimental allergic encephalomyelitis in SJL/J mice induced by a synthetic peptide of myelin proteolipid protein

Clinical, histologic, and ultrastructural characteristics of acute experimental allergic encephalomyelitis (EAE) induced by sensitization with a synthetic peptide corresponding to mouse myelin proteolipid protein (PLP) residues 139-151 HCLGKWLGHPDKF were studied in SJL/J mice. Groups of mice were immunized with 20, 50, or 100 nmol of the peptide and were killed from seven to 28 days after sensitization or when they were moribund. Beginning on Day 9, the mice showed signs of EAE and the disease progressed rapidly to paralysis. Central nervous system (CNS) inflammation, edema, gliosis, and demyelination were found in all mice killed between Days 10 and 28 and white matter lesion areas correlated with clinical score at the time the mice were killed. Peripheral nerve roots and the cauda equina did not have lesions. Within the range studied, the severity of clinical or histologic disease was the same regardless of the PLP peptide dose. Two of ten mice immunized with 100 nmol and none of 14 mice given smaller doses of a synthetic peptide of mouse myelin basic protein (MBP) showed clinical EAE. These mice had small numbers of CNS lesions that were indistinguishable from those in PLP peptide-sensitized mice. These findings demonstrate that immunization of SJL/J mice with PLP peptide 139-151 produces a disease with the clinical and morphologic features of CNS tissue-, whole PLP-, whole MBP-, and MBP peptide-induced acute EAE. Thus, PLP is a major encephalitogen and immune reactions to epitopes of different myelin proteins may induce identical patterns of injury in the CNS.

Inhibition of murine relapsing experimental autoimmune encephalomyelitis by immune tolerance to proteolipid protein and its encephalitogenic peptides

Tolerization of SJL/J mice with splenocytes coupled with proteolipid protein (PLP), the major protein component of central nervous system myelin, resulted in dramatic inhibition of relapsing experimental autoimmune encephalomyelitis (R-EAE) induced by mouse spinal cord homogenate (MSCH). Mice tolerized with splenocytes coupled with MSCH (a complex mixture of neuroantigens) or with purified PLP, but not purified myelin basic protein, were resistant to the development of clinical and histologic R-EAE. In addition, mice rendered tolerant to an encephalitogenic peptide of PLP were significantly protected, whereas mice tolerized to a nonencephalitogenic peptide of PLP were highly susceptible, to the induction of MSCH-induced R-EAE. Thus, immune responses directed against encephalitogenic regions of PLP appear to play a major role in the development of R-EAE induced by MSCH in SJL/J mice. These results also indicate that determinant-specific immune tolerance is a feasible approach to the regulation of a disease that involves autoimmune responses to a variety of Ag.

Inhibition of murine relapsing experimental autoimmune encephalomyelitis by immune tolerance to proteolipid protein and its encephalitogenic peptides

Tolerization of SJL/J mice with splenocytes coupled with proteolipid protein (PLP), the major protein component of central nervous system myelin, resulted in dramatic inhibition of relapsing experimental autoimmune encephalomyelitis (R-EAE) induced by mouse spinal cord homogenate (MSCH). Mice tolerized with splenocytes coupled with MSCH (a complex mixture of neuroantigens) or with purified PLP, but not purified myelin basic protein, were resistant to the development of clinical and histologic R-EAE. In addition, mice rendered tolerant to an encephalitogenic peptide of PLP were significantly protected, whereas mice tolerized to a nonencephalitogenic peptide of PLP were highly susceptible, to the induction of MSCH-induced R-EAE. Thus, immune responses directed against encephalitogenic regions of PLP appear to play a major role in the development of R-EAE induced by MSCH in SJL/J mice. These results also indicate that determinant-specific immune tolerance is a feasible approach to the regulation of a disease that involves autoimmune responses to a variety of Ag.

A synthetic peptide from myelin proteolipid protein induces experimental allergic encephalomyelitis

Immunization of animals with proteolipid protein, the major protein constituent of central nervous system myelin, produces experimental allergic encephalomyelitis. The goal of the present study was to identify an encephalitogenic determinant of this protein. For this purpose, SWR mice were immunized with five groups of pooled synthetic peptides corresponding to various regions of the myelin proteolipid protein sequence. Clinical EAE was observed in only one group. Inguinal lymph node cells from animals in this group responded ([3H]thymidine incorporation) to a peptide within the pool containing residues 103-116 YKTTICGKGLSATV. Mice subsequently immunized with 50 nmol of this peptide developed severe EAE within 3 wk, and their T cell-enriched inguinal lymph node cells responded specifically to this peptide. Control mice immunized to proteolipid peptide 202-217 DARMYGVLPWNAFPGK did not develop experimental allergic encephalomyelitis, and their inguinal lymph node cells were unresponsive to either peptide. Thus, a peptide corresponding to a sequence within the proteolipid protein can produce classical acute experimental allergic encephalomyelitis. This is the first report of a synthetic encephalitogenic peptide from myelin proteolipid protein.

A synthetic peptide from myelin proteolipid protein induces experimental allergic encephalomyelitis

Immunization of animals with proteolipid protein, the major protein constituent of central nervous system myelin, produces experimental allergic encephalomyelitis. The goal of the present study was to identify an encephalitogenic determinant of this protein. For this purpose, SWR mice were immunized with five groups of pooled synthetic peptides corresponding to various regions of the myelin proteolipid protein sequence. Clinical EAE was observed in only one group. Inguinal lymph node cells from animals in this group responded ([3H]thymidine incorporation) to a peptide within the pool containing residues 103-116 YKTTICGKGLSATV. Mice subsequently immunized with 50 nmol of this peptide developed severe EAE within 3 wk, and their T cell-enriched inguinal lymph node cells responded specifically to this peptide. Control mice immunized to proteolipid peptide 202-217 DARMYGVLPWNAFPGK did not develop experimental allergic encephalomyelitis, and their inguinal lymph node cells were unresponsive to either peptide. Thus, a peptide corresponding to a sequence within the proteolipid protein can produce classical acute experimental allergic encephalomyelitis. This is the first report of a synthetic encephalitogenic peptide from myelin proteolipid protein.