Two-dimensional gel electrophoresis and surface-enhanced laser desorption ionization-time of flight-mass spectrometry for detection of protein expression profiles in the hippocampus following closed brain injury

Gene expression profile changes in brain regions following traumatic brain injury at the gene level cannot sufficiently elucidate gene expression time, expression amount, protein post-translational processing or modification. Therefore, it is necessary to quantitatively analyze the gene expression profile using proteomic techniques. In the present study, we established a rat model of closed brain injury using Marmarou＇s weight-drop device, and investigated hippocampal differential protein expression using two-dimensional gel electrophoresis and surface-enhanced laser desorption ionization-time of flight-mass spectrometry. A total of 364 protein peaks were detected on weak cation exchange-2 protein chips, including 37 differential protein peaks. 345 protein peaks were detected on immobilized metal affinity capture arrays-Cu, including 12 differential protein peaks Further examination of these differential proteins revealed that glucose-regulated protein and proteasome subunit alpha type 3 expression were significantly upregulated post-injury. These results indicate that brain injury can alter protein expression in the hippocampus, and that glucose-regulated protein and proteasome subunit alpha type 3 are closely associated with the occurrence and development of traumatic brain injury.

Nocardia cyriacigeorgica infection in a patient with repeated fever and CD4+T cell deficiency:A case report

BACKGROUND Nocardia pneumonia shares similar imaging and clinical features with pulmonary tuberculosis and lung neoplasms,but the treatment and anti-infective medication are completely different.Here,we report a case of pulmonary nocardiosis caused by Nocardia cyriacigeorgica(N.cyriacigeorgica),which was misdiagnosed as community-acquired pneumonia(CAP)with repeated fever.CASE SUMMARY A 55-year-old female was diagnosed with community-acquired pneumonia in the local hospital because of repeated fever and chest pain for two months.After the anti-infection treatment failed in the local hospital,the patient came to our hospital for further treatment.Enhanced computed tomography showed multiple patchy,nodular and strip-shaped high-density shadows in both lungs.A routine haematological examination was performed and showed abnormalities in CD19+B cells and CD4+T cells.Positive acid-fast bifurcating filaments and branching gram-positive rods were observed in the bronchoalveolar lavage fluid of the patient under an oil microscope,which was identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry as N.cyriacigeorgica.The patient’s condition quickly improved after taking 0.96 g compound sulfamethoxazole tablets three times a day.CONCLUSION The antibiotic treatment of Nocardia pneumonia is different from that of common CAP.Attention should be given to the pathogenic examination results of patients with recurrent fever.Nocardia pneumonia is an opportunistic infection.Patients with CD4+T-cell deficiency should be aware of Nocardia infection.

Maternal peripartum bacteremia caused by intrauterine infection with Comamonas kerstersii:A case report

BACKGROUND Comamonas kerstersii(C.kerstersii)infections have considered as non-pathogenic to humans,however due to new techniques such as matrix-assisted laser desorption ionization-time of flight mass spectrometry(MALDI-TOF-MS),more cases have been identified.CASE SUMMARY This is the first report of a maternal patient with a C.kerstersii bacteremia following caesarean section.Due to the severity of the patient’s condition;high fever and rapidly progressing organ damage,the patient was transferred to the intensive care unit.C.kerstersii was detected by metagenomic next-generation sequencing testing.Based on the drug sensitivity test,appropriate antibiotic treatment was given and the patient recovered fully.CONCLUSION This case report confirms that the detection via MALDI-TOF-MS and metagenomic next-generation sequencing testing provides a reliable basis for the diagnosis of this rare bacterial infection.

Mode of interaction of calcium oxalate crystal with human phosphate cytidylyltransferase 1: a novel inhibitor purified from human renal stone matrix

Nephrolithiasis is a common clinical disorder, and calcium oxalate (CaOx) is the principal crystalline component in approximately 75% of all renal stones. It is widely believed that proteins act as inhibitors of crystal growth and aggregation. Acidic amino acids present in these proteins play a significant role in the inhibition process. In this study, interaction of cal-cium oxalate with human phosphate cytidylyltrans-ferase 1(CCT), a novel calcium oxalate crystal growth inhibitor purified from human renal stone matrix has been elucidated in silico and involvement of acidic amino acids in the same. As only sequence of CCT is available, henceforth its 3-D structure was modeled via Homology modeling using Prime module of Schrodinger package. Molecular dynamic simulation of modeled protein with solvation was done by mac-romodel (Schrodinger). The quality of modeled pro-tein was validated by JCSG protein structure valida-tion (PROCHECK & ERRAT) server. To analyze the interaction of modeled protein CCT with calcium oxalate along with role played by acidic amino acids, ‘Docking simulation’ was done using MOE–Dock. Interaction between calcium oxalate and CCT was also studied by substituting acidic amino acid in the active sites of the protein with neutral and positively charged amino acids. The in silico analysis showed the bond formation between the acidic amino acids and calcium atom, which was further substantiated when substitution of these acidic amino acids with alanine, glycine, lysine, arginine and histidine com-pletely diminished the interaction with calcium ox-alate.

Gene Expression Profile Changes in Germinating Rice

Water absorption is a prerequisite for seed germination. During imbibition, water influx causes the resumption of many physiological and metabolic processes in growing seed. In order to obtain more complete knowledge about the mechanism of seed germination, two-dimensional gel electrophoresis was applied to investigate the protein profile changes of rice seed during the first 48 h of imbibition. Thirty- nine differentially expressed proteins were identified, including 19 down-regulated and 20 up-regulated proteins. Storage proteins and some seed development- and desiccation-associated proteins were down regulated. The changed patterns of these proteins indicated extensive mobilization of seed reserves. By contrast, catabolism-associated proteins were up regulated upon imbibition. Semi-quantitative real time polymerase chain reaction analysis showed that most of the genes encoding the down- or up- regulated proteins were also down or up regulated at mRNA level. The expression of these genes was largely consistent at mRNA and protein levels. In providing additional information concerning gene regulation in early plant life, this study will facilitate understanding of the molecular mechanisms of seed germination.

Prognosis of the short-term efficacy of thymectomy for myasthenia gravis with serum protein profiles

Background The extended thymectomy for myasthenia gravis （MG） is currently available, but in 20%-40% of the patients the results were not satisfactory. There are no ideal indicators forecasting surgical results before operation. The surface enhanced laser desorption ionization-time of flight-mass spectroscopy （SELDI-TOF-MS） is a currently new technique for detection of protein profiles, and some progresses have been made in cancer diagnosis and efficacy evaluation, but there is no report on efficacy forecasting of MG surgery. This study aimed to establish an efficacy prognosis model for forecasting the efficacy of surgery for MG by analysis of serum protein profiles of MG patients before surgery. Methods Fifty-six MG patients 6 months after extended thymectomy were enrolled in the study. They were classified into effective or non-effective groups according to symptoms and medication. Their pre-operative blood samples were analyzed for protein profiles by the SELDI-TOF MS technique, and protein peaks were identified for establishment of the efficacy prognosis model of MG surgery. Additional 100 MG patients were subjected to model validation and their pre-operation protein profiles reviewed for post-operative results. The results were compared with those of the post-operative follow-up so as to validate the prognosis model. Results For the model establishment, symptoms were improved in 33 patients and not improved in 18 patients, with an effective rate of 64.7%. Five （8.9%） patients were lost to follow-up. Within the molecular weight range of 1 000 to 20 000, 3 specific protein peaks were found to be significantly different between the effective and non-effective groups, ie M4110-76, M3394-58, and M1258-55. Using the efficacy prognosis model constructed with these data, the accuracy rate of classification was 87.9% for the effective group, and 83.3% for the non-effective group, with a total accuracy rate of 86.3%. For the model evaluation, 2 （8.9%） patients were lost to follow-up, 62 patients were effective and 36 were non- effective. By comparing with the real results of follow-up with 65 effective and 33 non-effective patients with an effective rate of 66.3%, the accuracy rate of prediction by the prognosis model was 86.2% for the effective group, and was 81.8% for the non-effective group with a total accuracy rate of 84.5%. Conclusions By protein profiles analysis of pre-operative blood samples taken from MG patients with the SELDI-TOF MS technique, protein peaks correlated with surgery efficacy in MG patients can be found for primary forecasting short-term efficacy of surgery for MG patients.