C-termini of proteins often play an important role in various biological processes, such as the transcription and translation from DNA to protein and also participating in various biological regulations. The determination of protein C-terminus is so crucial because it provides not only distinct functional annotation, but also a way to monitor the proteolysis-modified proteins. Based on the biological mass spectrometry, a series of novel methods and technologies were developed both for qualitative and quantitative analyses of protein C-terminus. These methods or technologies can be applied to accurate and effective protein C-terminus profiling, including the sequences and quantitative information of C-termini, which reveals the biological function of C-termini in life's activities and provides a better understanding of the degradation of mature proteins. Combined with our research, this review highlights the improvements in C-terminal proteomics study in the past decades, including the methodologies for recognition and identification of C-terminus, as well as the enrichment strategies for protein C-terminus.
Mass Spectrometry ; Protein Processing, Post-Translational ; Proteins ; chemistry ; Proteolysis ; Proteomics

BACKGROUND:Fracture healing in diabetic patients is usual y unsatisfactory because of hormones and metabolic disorder, and an eventual multiple organ dysfunction resulting from high blood glucose. OBJECTIVE:To dynamical y observe the changes of cytokines during the fracture healing process in diabetic rats before and after insulin treatment. METHODS:A total of 120 Sprague-Dawley rats were included in this study. Of them, 90 rats intravenously injected with 5%tetraoxypyrimidine to induce rat models of diabetes were randomized into insulin treatment and diabetes groups, respectively. The remaining 30 rats were intravenously injected with equal volume of saline and selected as control group. The next day, blood glucose was determined. Healing at 1, 4, and 8 weeks after fracture were observed by the X-ray film. Biomechanical strength of the injured right tibia was measured at 4, 6, and 8 weeks after modeling. Cytokines in the osteotylus were determined by immunohistochemical staining and in situ hybridization technique. RESULTS AND CONCLUSION:The X-ray films showed that the speed of fracture healing in the diabetes group was slower than insulin treatment and control groups. Biomechanical strength of the osteotylus in the diabetes group was significantly decreased compared with the insulin treatment and control groups. However, there were no significant differences in above-mentioned parameters between the control and insulin treatment groups. Bone morphogenetic protein 2, basic fibroblast growth factor, transforming growth factor-beta, and vascular endothelial growth factor were widely expressed in the osteotylus and their expressions in diabetes group were significantly lower and slower than those in the control and insulin treatment groups. There was no statistical difference between control and insulin treatment groups. These results indicate that osteotylus formation speed, biomechanical strength, and growth factor expressions at the fracture site in diabetes rats were decreased compared with normal rats. Insulin treatment can enhance cytokine levels at the fracture site, thereby promoting the osteoblast proliferation and fracture healing.

Objective To quantitatively analyze the K-ras gene mutation at codon 12 in pancreatic cancer tissues and the relationship between K-ras gene mutation and clinicopathological parameters. Methods Quantitative detection of K-ras gene at codon 12 in 93 pairs of pancreatic cancer and adjacent tissues were performed by using PNA-mediated PCR clamping with two different fluorescence labeled probes. The quantity of mutation was expressed by percentage of mutation. The percentage of K-ras gene mutation = the copy of K-ras mutation/(copy of wild type K-ras + copy of K-ras mutation) × 100%. Results The percentage of mutation of K-ras gene at codon 12 in pancreatic cancer and adjacent tissues were 83.9% and 65.6%, and the difference was statistically significant(P ＜ 0. 05); and the quantity of mutation were (13.385 ± 1. 745) % and (2. 246 ±0. 728) %, and the difference was also statistically significant(P ＜ 0. 05). The quantity of mutation of K-ras gene at codon 12 was not associated with clinicopathological parameters. Conclusions The percentage of K-ras gene mutation, as well as the quantity of K-ras gene mutation was different in pancreatic carcinoma and adjacent tissues.

Objective To observe the outcomes of toe amputations in diabetic patients and to analyze the affecting factors.Methods Two-hundred and forty-five patients were divided into 2 groups:202 cases with the wound healed after toe amputation,and 43 patients whose wound did not heal after toe amputation.The factors related to healing were analyzed.Patients with healed wounds after toe amputations ( n =202 ) were followed,regarding reappearance of new ulcers,reamputations,mortality,activities of daily life,and the affecting factors.Results The rate of wound healing was 82.4％.The rate of follow-up in the healed group was 91.6％.The rates of reappearance of new ulcers after 1,3,and 5 years of observation were 27.3％,57.2％,76.4％,respectively.The rates of reamputations after 1,3,and 5 years of observation were 17.5％,22.3％,47.1％,respectively.The mortality rates by 1,3,and 5 years after the toe amputations were 3.8％,15.1％,32.7％,respectively.Mean survival time of the fatal cases after the first amputation was 3.8 (95％ CI 3.4-4.1 )years.Multivariate analysis showed that HbA1c (＞9％)was an independent predictor of wound healing,reappearance of new ulcers,and reamputations after toe amputations,and age ( ＞ 70 years ) was an independent predictor of reamputations,mortality,and hampered daily activities.Conclusion Despite a satisfactory initial healing process after the first amputation,the long-term outcomes of the followed-up patients are not optimistic.Senile patients are often with poor prognosis,and good blood glucose control may improve the prognosis.

Objective To investigate the feasibility of repairing soft-tissue defects of the fifth phalange and the back of hand with ulnar palmar artery perforator flaps from the little finger.Methods Based on anatomic dissection,the fifth phalange ulnar palmar artery perforator flaps were created and transferred to repair soft-tissue defects at the little finger and the back of hand in 15 cases.Types of injury were stamping injury in 5 cases,planer injury in 4 cases,mechanical crash injury in 3 cases,blast injury in 2 cases,and cicatrical contracture following electric burn in 1 case.Injury involved in the palmar aspect near the middle segment of fifth phalange in 4 cases,dorsal aspect near the middle segment of fifth phalange in 6 cases,ulnar mesiodistal of the back of hand in 3 cases,and distal ulnar palmar aspect of hands in 2 cases.There were 6 patients wounded in left hands and 9 patients wounded in right hands.Results All flaps survived and all wounds healed by first intention.At the follow-up of 2-18 months,the flaps resurfaced the soft-tissue defects with good color and texture match and the maintenance of contour and function of donor and recipient sites were satisfactory.Conclusion The fifth phalange ulnar palmar artery perforator flap,as it has advantages of constant perforator vessels,rich blood supply and good texture and can be operated safely and easily,is considered an ideal treatment choice in repairing softtissue defects of the fifth phalange and the back of hand.

Objective To evaluate the effects of assisted reproduction technology ( ART) on gestational weight gain ( GWG) and glucose metabolism .Methods The study was performed in ART women with single-ton and full-term delivery .Age-and pre-pregnancy body mass index matched healthy women with spontaneous pregnancy, singleton, and full-term delivery were recruited as controls .Maternal characteristics (height, age, education level , pre-pregnancy body mass , pre-delivery body mass , medical history , history of abortion , fasting plasma glucose , triglyceride , total cholesterol , and glucose tolerance ) and fetal data ( delivery mode , gender , birth body mass , birth body length ) were collected by a trained nutritionist .Results A total of 200 women were recruited into this study (53 ART women and 147 controls).There was no significant difference in number of previous abortion ( the ratio between the women who had ≥3 abortions to those who had <3 abortions was 6∶47 in the ART group , and 10∶137 in the control group , χ2 =1.080 , P=0.299 ) .Compared with the control group, the ART group had higher education level (33 in the ART and 85 in the control group with un-dergraduate or higher education , 20 in the ART group and 62 in the control group with a college degree or lower education ,χ2 =6.303 , P=0.012 ) .There were no statistically significantly differences between the ART and the control groups in pre-pregnancy body mass index [ (22.00 ±3.05 ) kg/m2 vs.(21.81 ±2.62 ) kg/m2 , P=0.661] and average GWG [ (13.89 ±5.33) kg vs.(14.78 ±4.60) kg, P=0.247].GWG was appro-priate in 22 ART women, excess in 18, and inadequate in 13;in the control group, GWG was appropriate in 66 women, excess in 54, and inadequate in 27.The distribution of GWG showed no significant difference be-tween the two groups (χ2 =1.162 , P=0.247 ) .Oral glucose tolerance test in 24-28 gestational weeks showed no significant difference in fasting blood glucose between the ART and the control groups [ (4.66 ±0.39) mmol/L vs.(4.66 ±0.52) mmol/L, P=0.996], but 1-hour and 2-hour blood glucose levels were significantly in-creased in the ART women [ ( 7.87 ±1.83 ) mmol/L vs.( 7.31 ±1.51 ) mmol/L, P=0.034; ( 7.49 ± 1.29) mmol/L vs.(6.69 ±1.30) mmol/L, P=0.029].The overall prevalence of gestational diabetes melli-tus was 13.5%(27/200), with no significant difference between the ART and the control groups (18.9%vs. 11.6%, P=0.182 ) .Conclusion ART may not affect GWG , but it may cause changes of glucose metabo-lism during pregnancy .

nd hypermethylation of HHIP was detected in pancreatic juice,which may be a useful marker in the diagnosis of PCa.

Objective To evaluate the impact of total parenteral nutrition(TPN)on nutrition status and inflammatory markers in hospitalized fasted patients with inflammatory bowel disease(IBD).Methods A retrospective study was performed and 82 hospitalized fasted IBD patients [male/female=58/24,(39.4±14.5)years] who received TPN entered the study.Among them,38 patients had ulcerative colitis(UC)and 44 patients suffered from Crohn`s disease(CD).Clinical data(gender,age,duration of disease,history of disease,prednisone,immuno-suppressor,and antibiotics)were obtained from medical records.Nutritional parameters,C-creative protein(CRP),and erythrocyte sedimentation rate(ESR)before and after TPN were also obtained.Average caloric supplementation by TPN was(4 437.3±1 199.1)kJ/d and the nitrogen amount was(9.9±1.7)g/d.Median PN length was 15 days(7-54 days).67 IBD patients received a TPN formula with glutamine(≥14 d,25 patients vs.0-14 d,42 patients)and 15 IBD subjects received TPN without glutamine.Malnutrition was diagnosed by body mass index(BMI)and serum albumin level.Results The prevalence of undernutrition was 90.2％(74/82)in the study population.CD patients had a significantly longer history of disease [84(3-288)months vs.24(1-324)months,P<0.001] and a significantly lower BMI [(15.6±1.8)kg/m2 vs.(19.1±3.5)kg/m2,P<0.001] compared with those in UC patients.TPN improved nutritional parameters [serum albumin:(28.7±6.6)g/L before TPN vs.(31.7±5.8)g/L after TPN,P<0.001;pre-albumin:(174.1±85.5)mg/L before TPN vs.(227.2±82.8)mg/L after TPN,P<0.001].Conclusions TPN improves nutritional status in hospitalized fasted IBD patients.However,prospective randomized controlled trials are required to estimate the role of low-to-middle dosage of glutamine in IBD patients.

OBJECTIVE: To explore the genetic basis for a fetus with renal abnormalities through whole exome sequencing and imaging examination. METHODS: Clinical data and result of medical imaging of the fetus was collected. Amniotic fluid sample was collected for the extraction of fetal DNA. Whole exome sequencing was carried out. Candidate variants were verified by Sanger sequencing. RESULTS: Prenatal ultrasonography showed that the fetus had bilateral enlargement of the kidneys with hyperechogenicity and diffuse renal cysts. Whole exome sequencing revealed that the fetus carried compound heterozygous variants of the PKHD1 gene, namely c.5137G>T and c.2335_2336delCA, which were derived from its mother and father, respectively. CONCLUSION The fetus was diagnosed with autosomal recessive polycystic kidney disease through combined prenatal ultrasonography and whole exome sequencing. The compound heterozygous variants of the PKHD1 gene probably underlay the pathogenesis in the fetus. The results have enabled prenatal diagnosis and genetic counseling for its parents.
Female ; Genetic Testing ; Humans ; Polycystic Kidney, Autosomal Recessive/genetics* ; Pregnancy ; Prenatal Diagnosis ; Receptors, Cell Surface/genetics* ; Whole Exome Sequencing

NOD-like receptor protein 3 (NLRP3) inflammasomes play an important role in innate immunity.It can induce the maturation and release of cytokines interleukin (IL)-1β and IL-18 by activating caspase-1,and participate in a variety of host immunoinflammatory responses.Once the regulation of NLRP3 inflammasomes is unbalanced,excessive IL-1β and IL-18 may be produced,triggering a series of inflammatory diseases.NLRP3 inflammasome activation plays important roles in skin diseases such as acne,psoriasis,pyoderma gangrenosum,polymyositis/dermatomyositis and bullous pemphigoid.This review summarizes research progress in NLRP3 inflammasomes in skin diseases.