Antibiotic resistance has evolved over the past 50 years from a merely microbiological curiosity to a serious medical problem in hospitals all over the world. Resistance has been reported in almost all species of gram-positive and -negative bacteria to various classes of antibiotics including recently developed ones. Bacteria acquire resistance by reducing permeability and intracellular accumulation, by alteration of targets of antibiotic action, and by enzymatic modification of antibiotics. Inappropriate use of an antibiotic selects resistant strains much more frequently. Once resistant bacteria has emerged, the resistance can be transferred to other bacteria by various mechanisms, resulting in multiresistant strains. MRSA is one of the typical multiresistant nosocomial pathogens. A study of the PFGE pattern of endonuclease-digested chromosomal DNA showed that MRSA of a few clones were disseminated among newborns in the NICU of a Japanese hospital. In this regard, it is important to choose appropriate antibiotics and then after some time, to change to other classes to reduce the selection of resistant strains. Since the development of epoch-making new antibiotics is not expected in the near future, it has become very important to use existing antibiotics prudently based on mechanisms of antibiotic action and bacterial resistance. Control of nosocomial infection is also very important to reduce further spread of resistant bacteria.
Cross Infection/physiopathology ; Drug Resistance, Microbial/physiology* ; Enzymes/physiology ; Methicillin Resistance/physiology ; Staphylococcus aureus/physiology

The ubiquitin-proteasome system (UPS) is a proteasome system widely present in the human body, which is composed of ubiquitin (Ub), ubiquitin activating enzymes (E1), ubiquitin conjugating enzymes (E2), ubiquitin protein ligases (E3), 26S proteasome, and deubiquitinating enzymes (DUBs) and involved in cell cycle regulation, immune response, signal transduction, DNA repair as well as protein degradation. Sperm DNA is vulnerable to interference or damage in the progression of chromosome association and homologous recombination. Recent studies show that UPS participates in DNA repair in spermatogenesis by modulating DNA repair enzymes via ubiquitination, assisting in the identification of DNA damage sites, raising damage repair-related proteins, initiating the DNA repair pathway, maintaining chromosome stability, and ensuring the normal process of spermatogenesis.
Cell Cycle Proteins ; physiology ; DNA Damage ; DNA Repair ; physiology ; Humans ; Male ; Proteasome Endopeptidase Complex ; physiology ; Signal Transduction ; physiology ; Spermatogenesis ; physiology ; Spermatozoa ; Ubiquitin ; physiology ; Ubiquitin-Conjugating Enzymes ; physiology ; Ubiquitin-Protein Ligases ; physiology ; Ubiquitination

Brain is a logical target of free radical damage, considering the large lipid content of myelin sheaths and the high rate of brain oxidative metabolism. Thus, the hypothesis that free radicals may be involved in the pathogenesis of certain CNS diseases has gained increasing popularity in recent years. In CNS ischemia-reperfusion injury, the role of free radicals appears to be well established, however, involvement of other factors, such as excitatory amino acids and prostaglandins, may also contribute to the production of neuronal necrosis following ischemia. Liberation of free iron appears to play a crucial role in the generation of reactive oxygen species in posttraumatic epilepsy. Although there is no direct evidence to indicate free radical involvement in the pathogenesis of Alzheimer's disease, brain trauma with release of iron, amyloid angiopathy and disturbances in blood-brain barrier function all appear to contribute to the development of ischemic episodes with free radical generation and neuronal degeneration. In Parkinson's disease, the substantia nigra appears to be under oxidative stress as evidenced by the findings of increased lipid peroxidation, reduced GSH levels, high concentration of iron and free radical generation via autocatalytic mechanisms within neuromelanin-containing catecholaminergic neurons. Regardless of the initial insult, a cascade of events involving both reactive oxygen radicals and mitochondrial metabolism is likely to contribute to cell injury.
Brain Diseases/*chemically induced ; Enzymes/physiology ; Free Radical Scavengers ; Human ; Iron/physiology ; Oxygen/*antagonists & inhibitors ; *Reactive Oxygen Species ; Support, U.S. Gov't, P.H.S.

T cells efficiently respond to foreign antigens to mediate immune responses against infections but are tolerant to self-tissues. Defect in T cell activation is associated with severe immune deficiencies, whereas aberrant T cell activation contributes to the pathogenesis of diverse autoimmune and inflammatory diseases. An emerging mechanism that regulates T cell activation and tolerance is ubiquitination, a reversible process of protein modification that is counter-regulated by ubiquitinating enzymes and deubiquitinases (DUBs). DUBs are isopeptidases that cleave polyubiquitin chains and remove ubiquitin from target proteins, thereby controlling the magnitude and duration of ubiquitin signaling. It is now well recognized that DUBs are crucial regulators of T cell responses and serve as potential therapeutic targets for manipulating immune responses in the treatment of immunological disorders and cancer. This review will discuss the recent progresses regarding the functions of DUBs in T cells.
Cell Differentiation ; drug effects ; Deubiquitinating Enzymes ; metabolism ; Drug Discovery ; Humans ; Neoplasms ; drug therapy ; pathology ; Signal Transduction ; T-Lymphocytes ; physiology ; Ubiquitination ; drug effects ; physiology

Pulmonary artery hypertension (PAH) causes right ventricular failure and possibly even death by a progressive increase in pulmonary vascular resistance. Bone marrow-derived mesenchymal stem cell therapy has provided an alternative treatment for ailments of various organs by promoting cell regeneration at the site of pathology. The purpose of this study was to investigate changes of pulmonary haemodynamics, pathology and expressions of various genes, including ET (endothelin)-1, ET receptor A (ERA), endothelial nitric oxide synthase (NOS) 3, matrix metalloproteinase (MMP) 2, tissue inhibitor of matrix metalloproteinase (TIMP), interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha in monocrotaline (MCT)-induced PAH rat models after bone marrow cell (BMC) transfusion. The rats were grouped as the control (C) group, monocrotaline (M) group, and BMC transfusion (B) group. M and B groups received subcutaneous (sc) injection of MCT (60 mg/kg). BMCs were transfused by intravenous injection at the tail 1 week after MCT injection in B group. Results showed that the average RV pressure significantly decreased in the B group compared with the M group. RV weight and the ratio of RH/LH+septum significantly decreased in the B group compared to the M group. Gene expressions of ET-1, ERA, NOS 3, MMP 2, TIMP, IL-6, and TNF-alpha significantly decreased in week 4 in the B group compared with the M group. In conclusion, BMC transfusion appears to improve survival rate, RVH, and mean RV pressure, and decreases gene expressions of ET-1, ERA, NOS 3, MMP 2, TIMP, IL-6, and TNF-alpha.
Animals ; Bone Marrow Cells/*cytology ; *Bone Marrow Transplantation ; Cytokines/genetics/metabolism ; Enzymes/genetics/metabolism ; Gene Expression Regulation ; Hypertension, Pulmonary/chemically induced/*metabolism/pathology ; Lung/metabolism ; Male ; Monocrotaline/toxicity ; Pulmonary Artery/physiology ; Rats ; Rats, Sprague-Dawley ; Survival Rate ; Ventricular Function/physiology

OBJECTIVETo determine whether vitamin D receptor(VDR) gene start codon polymorphisms and 3'-end region polymorphisms exerted a combined influence on bone mineral density(BMD) in Han postmenopausal women in Beijing area.

METHODSThe VDR Fok I and 3'-end region genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism in 110 unrelated postmenopausal women. BMD was measured at the lumbar spine (L(2-4)), femoral neck(Neck), Ward's triangle(Ward's) and trochanter (Troch) using duel-energy X-ray absorptiometry.

RESULTSThe frequencies distribution of Fok I, Apa I, Bsm I and Taq I alleles in this cohort all followed the Hardy-Weinberg equilibrium. No significant association of Fok I, Apa I or Taq I genotype with BMD in postmenopausal women was found when these polymorphisms were considered independently, except for Bsm I genotype. When a combined analysis of VDR gene Fok I and 3'-end region polymorphisms was carried out, cross-genotyping Fok I and Apa I polymorphisms was significantly associated with BMD at the L(2-4) (P<0.001), and cross-genotype of Fok I and Taq I was also significantly associated with BMD at the Neck and Troch sites (P<0.05). However, cross-genotyping Fok I and Bsm I polymorphisms was not significantly associated with BMD. Cross-genotyping Apa I and Bsm I or Taq I polymorphisms was not associated with BMD in postmenopausal women, either.

CONCLUSIONAlthough Fok I polymorphisms of VDR gene were not significantly associated with BMD in postmenopausal women, VDR gene Fok I and 3'-region polymorphisms (Apa I and Taq I) had a combined effect on the BMD in postmenopausal women.

3' Flanking Region ; genetics ; Aged ; Analysis of Variance ; Bone Density ; physiology ; China ; Codon, Initiator ; genetics ; DNA ; genetics ; metabolism ; DNA Restriction Enzymes ; metabolism ; Female ; Gene Frequency ; Genotype ; Humans ; Middle Aged ; Polymorphism, Genetic ; Polymorphism, Restriction Fragment Length ; Postmenopause ; genetics ; physiology ; Receptors, Calcitriol ; genetics

Retinoic acid-inducible gene-I (RIG-I) functions as an intracellular pattern recognition receptor (PRR) that recognizes the 5'-triphosphate moiety of single-stranded RNA viruses to initiate the innate immune response. Previous studies have shown that Lys63-linked ubiquitylation is required for RIG-I activation and the downstream anti-viral type I interferon (IFN-I) induction. Herein we reported that, RIG-I was also modified by small ubiquitin-like modifier-1 (SUMO-1). Functional analysis showed that RIG-I SUMOylation enhanced IFN-I production through increased ubiquitylation and the interaction with its downstream adaptor molecule Cardif. Our results therefore suggested that SUMOylation might serve as an additional regulatory tier for RIG-I activation and IFN-I signaling.
Adaptor Proteins, Signal Transducing ; physiology ; Base Sequence ; Binding Sites ; DEAD Box Protein 58 ; DEAD-box RNA Helicases ; chemistry ; genetics ; immunology ; physiology ; DNA Primers ; genetics ; Gene Knockdown Techniques ; HEK293 Cells ; HeLa Cells ; Humans ; Immunity, Innate ; Interferon Type I ; immunology ; physiology ; RNA Interference ; SUMO-1 Protein ; physiology ; Sendai virus ; immunology ; Signal Transduction ; Sumoylation ; Ubiquitin-Conjugating Enzymes ; antagonists & inhibitors ; genetics ; physiology

hUBEW, a newly identified class I ubiquitin conjugating enzyme, probably plays an important role in tumorigenesis and DNA repair processes. RNA interference (RNAi) is a process in cells to degrade specific homologous mRNA by forming duplex RNA and has been developed into a powerful tool to study gene functions. In this study, the H1-U6 dual promoter RNAi plasmid was constructed and the target sequence for hUbe2w could be transcribed from both strands and form a double stranded RNA with two 5'Uridine overhangs, which closely resembles endogenous functional siRNA. The hUbe2w cDNA was amplified from reverse transcription of the 293FT total RNA by RT-PCR, and then cloned into the pGL3-Control, pCMV-myc and pDsRed-express-C1 plasmids respectively, which were selected as report vectors to detect the RNAi effects. The plasmids were co-transfected into HEK293FT cells, and then the luciferase activity and hUBE2W protein expression were measured respectively. The Resulted reduction of mRNA and protein level demonstrate that the targets of 125 and 259 could significantly inhibit the hUbe2w expression.
Base Sequence ; Humans ; Molecular Sequence Data ; Plasmids ; genetics ; Promoter Regions, Genetic ; genetics ; RNA Interference ; RNA, Messenger ; biosynthesis ; genetics ; RNA, Small Interfering ; genetics ; physiology ; RNA, Small Nuclear ; genetics ; Ubiquitin-Conjugating Enzymes ; genetics ; metabolism

OBJECTIVETo assess the correlation of O6-methylguanine-DNA methyltransferase (MGMT) to radiation sensitivity of nasopharyngeal carcinoma (NPC).

METHODSEighty randomly selected NPC patients were divided into high (+/++, n=62) and low (-/+/+, n=18) MGMT groups according to the results of MGMT detection using immunohistochemistry. All the patients received irradiation with external beam radiotherapy, and the radiation sensitivity of NPC was analyzed after the irradiation.

RESULTSThe rates of high and low radiation sensitivity were 83.3% and 16.7% in low MGMT group, respectively, showing significant differences from those of the high MGMT group (45.2% and 54.8%, respectively, chi(2)=4.393, P=0.036).

CONCLUSIONThe content of MGMT correlates to the radiation sensitivity of NPC and may serve as valuable indicators for predicting the radiation sensitivity of NPC.

Adolescent ; Adult ; Aged ; Carcinoma, Squamous Cell ; enzymology ; radiotherapy ; DNA Modification Methylases ; blood ; DNA Repair Enzymes ; blood ; Female ; Humans ; Male ; Middle Aged ; Nasopharyngeal Neoplasms ; enzymology ; radiotherapy ; Radiation Tolerance ; physiology ; Tumor Suppressor Proteins ; blood ; Young Adult

OBJECTIVETo study hMSH2 genetic polymorphism in southern Chinese Han population.

METHODSThe basic materials and blood samples from 163 southern Chinese were collected. The mutations of exon 6 and exon 7 of hMSH2 gene were investigated by PCR-SSCP, followed by DNA sequencing.

RESULTSFragments of 250 bp including exon 6 and fragments of 323 bp including exon 7 of hMSH2 gene were amplified by multiple PCR. The allele frequencies of C18, A82 and B39 type mutations were 0.0184, 0.0031, 0.0031, respectively. The gene frequencies and gene type frequencies of three polymorphism sites in normal population accorded with Hardy-Weinberg equilibrium (P>0.05). The heterozygosity of C18 type mutation (0.0361) was the highest.

CONCLUSIONThere were three polymorphism sites in exon 7 of hMSH2 gene in southern Chinese Han population, among which the genotype frequency of C18 type was the highest, suggesting that C18 type mutation be a useful genetic mark.

Asian Continental Ancestry Group ; genetics ; Base Pair Mismatch ; DNA Ligase ATP ; DNA Ligases ; genetics ; DNA Mismatch Repair ; genetics ; physiology ; DNA Repair Enzymes ; genetics ; Exons ; genetics ; Female ; Humans ; Male ; Microsatellite Repeats ; genetics ; Middle Aged ; Polymorphism, Genetic