Multidrug-resistant (MDR) bacterial infections, especially those caused by Gram-negative pathogens, have emerged to be one of the world's greatest health threats. However, not only have recent decades shown a steady decline in the number of approved antimicrobial agents but a disappointing discovery also void. The development of novel antibiotics to treat MDR Gram-negative bacteria has been stagnated over the last half century. Though few compounds have shown activities in vitro, in animal models or even in clinical studies, the global antibiotic pipeline is not encouraging. There are a plethora of unexpected challenges that may arise and cannot always be solved to cause promising drugs to fail. This review intends to summarize recent research and development activities to meet the inevitable challenge in restricting the proliferation of MDR Gram-negative bacteria, with focus on compounds that have entered into clinical development stage. In addition to new analogues of existing antibiotic molecules, attention is also directed to alternative strategies to develop antibacterial agents with novel mechanisms of action.
Aminoglycosides ; pharmacology ; therapeutic use ; Animals ; Anti-Bacterial Agents ; pharmacology ; therapeutic use ; Antibodies, Monoclonal ; pharmacology ; therapeutic use ; Drug Discovery ; Drug Resistance, Multiple, Bacterial ; Enzyme Inhibitors ; pharmacology ; therapeutic use ; Ferrous Compounds ; pharmacology ; therapeutic use ; Gram-Negative Bacteria ; drug effects ; Gram-Negative Bacterial Infections ; drug therapy ; Humans ; Peptides ; pharmacology ; therapeutic use ; Peptidomimetics ; pharmacology ; therapeutic use ; Tetracyclines ; pharmacology ; therapeutic use ; beta-Lactamase Inhibitors ; beta-Lactams ; pharmacology ; therapeutic use

A strain of P. Aeruginosa,which was seperated from clinical environment,shows a special characteristic. It keeps normal short rod shape when cultured at 37℃, however,it forms filament without pyocyanin producing when cultured at 25℃ overnight. The filaments will divide and form short rods, simultaneously, produce pyocyanin when culture time is prolonged to over 72h or culture temperature is raised to 37℃. The preliminary study indicates that this phenomenin has nothing to do with nutritive conditions and could the inbluenced by inoculating density and irradiating with ultraviolet rays The absence of pyocyanin was not the cause of filamentous formation by the test results.

OBJECTIVETo investigate the effect of puerarin on the neural function and the histopathological changes after ischemic spinal cord injury in rabbits.

METHODSThirty male New Zealand white rabbits were randomly divided into three groups as follows: puerarin group (n=10) receiving intravenous infusion of 30 mg/kg puerarin for 10 minutes, control group (n=10) receiving intravenous infusion of the same volume of normal saline as puerarin for 10 minutes, and sham operation group (n=10) undergoing only the surgical exposure of the abdominal aorta. Temporary spinal cord ischemia was induced by infrarenal aortic occlusion for 20 minutes and followed by reperfusion. The neural status was scored with the Tarlov criteria at 8, 12, 24 and 48 hours after reperfusion. All the animals were killed at 48 hours after reperfusion and the spinal cords (L5) were removed immediately for histopathological study.

RESULTSThe neural function scores at 8, 12, 24 and 48 hours after reperfusion were higher in the puerarin group and sham operation group than those in the control group (P<0.05). More normal motor neurons in the anterior horn of spinal cord were present in the puerarin group and sham operation group than those in the control group (P<0.01). There was a strong correlation between the final neural function scores and the number of normal motor neurons in the anterior horn of spinal cord (r=0.839, P<0.01).

CONCLUSIONSPuerarin can significantly ameliorate the neural function and the histopathological damages after transient spinal cord ischemia in rabbits.

Animals ; Isoflavones ; pharmacology ; Male ; Motor Neurons ; pathology ; Rabbits ; Spinal Cord Ischemia ; drug therapy ; pathology ; physiopathology ; Vasodilator Agents ; pharmacology

BACKGROUNDCongestive heart failure (CHF) is a major cause of morbidity and mortality worldwide and angiotensin converting-enzyme inhibitor (ACEI) is the cornerstone in its treatment. However, CHF continues to progress despite this therapy, perhaps because of production of angiotensin II (Ang II) by alternative pathways. The present study was conducted to examine the combined effects of a chronic ACEI, ramipril, and a chronic Ang II type 1 receptor blocker, TCV116, on rat CHF after myocardial infarction (MI).

METHODSCongestive heart failure was caused by MI in rats, which was induced by ligating the left anterior descending coronary artery. The experiment protocol included sham-operated rats (Sham), MI-control rats (MI-control), MI rats treated with ramipril 3 mg/kg (MI-ramipril) or TCV116 2 mg/kg (MI-TCV116) per day, half dosage (MI-1/2R&T) or full dosage (MI-R&T) combination of the two. At 22 weeks, cardiac hemodynamic parameters such as mean arterial pressure (MAP), left ventricular systolic pressure (LVSP), maximal rate of left ventricule pressure development and decline (LV dP/dtmax) and left ventricular end diastolic pressure (LVEDP), and cardiac morphometric parameters such as heart weight (HW), left ventricular weight (LVW) and left ventricular cavity area (LVCA) were measured, mRNA expressions of cardiac molecule genes such as beta myosin heavy chain (betaMHC), B-type natriuretic peptide (BNP), transforming growth factor-beta1 (TGF-beta1), collagen I and III were quantified with reverse transcription polymerase chain reaction (RT-PCR) in the surviving septum myocardium, and survival rates were calculated.

RESULTSThere were no significant differences in MI sizes (%) among each MI related experimental groups (33 +/- 13, 34 +/- 14, 33 +/- 13, 35 +/- 13 and 33 +/- 14 for MI-control, MI-ramipril, MI-TCV116, MI-1/2R&T and MI-R&T, respectively, no statistical significance for all). Compared with sham-operated rats, MI rats without therapy showed significant increases in morphometric parameters as well as in mRNA expressions of cardiac molecule genes (P < 0.01); while their hemodynamic parameters were significantly impaired (P < 0.01), and in terms of spontaneous deaths survival rate shortened (P < 0.05). Compared with MI rats without therapy, MI rats treated with each single drug showed significant attenuation of mRNA expressions of cardiac molecule genes (P < 0.01); while their hemodynamic parameters were significantly improved (P < 0.05 or P < 0.01), and in terms of spontaneous deaths survival rate prolonged (P < 0.05). Both half and full dosage combined treatments exerted more powerful effects on improvement of cardiac phenotypic changes and on attenuation of betaMHC, BNP mRNA expressions (P < 0.05 vs monotherapy); while LVEDP was further lowered (P < 0.05 vs monotherapy). However, the total death in MI rats with full dosage combined treatment was more though there were no significant differences when compared with other treatments.

CONCLUSIONSThe results suggest that treatment with appropriate dosage combination of a chronic ACEI and a chronic ARB may further improve cardiac remodeling and cardiac function after MI.

Angiotensin-Converting Enzyme Inhibitors ; administration & dosage ; Animals ; Benzimidazoles ; administration & dosage ; Biphenyl Compounds ; administration & dosage ; Blood Pressure ; drug effects ; Drug Therapy, Combination ; Heart Failure ; drug therapy ; pathology ; physiopathology ; Male ; Myocardial Infarction ; complications ; Myocardium ; pathology ; Ramipril ; administration & dosage ; Rats ; Rats, Sprague-Dawley ; Receptor, Angiotensin, Type 1 ; drug effects ; Tetrazoles ; administration & dosage ; Ventricular Function, Left ; drug effects

Objective:To observe the effects of electroacupuncture (EA) of three different frequencies (2 Hz,80 Hz and 2 Hz/80 Hz) on the free radicals in hippocampus of vascular dementia (VD) model mice.Methods:A total of 100 Kunming mice were randomly divided into a sham operation group,a model group,a 2 Hz EA group,an 80 Hz EA group and a 2 Hz/80 Hz EA group,with 20 mice in each group.The ischemia-reperfusion VD model was established by repeated blockade of bilateral common carotid arteries.Mice in EA groups began EA treatment on the 4th day after the operation.Baihui (GV 20),Dazhui (GV 14),Geshu (BL 17) and Zusanli (ST 36) were punctured and then connected to EA instrument,with different waves of 2 Hz,80 Hz or 2 Hz/80 Hz (10 min/time) applied accordingly,once a day.During the jumping stand experiment,the learning performance,memory performance and hippocampal calcitonin gene-related peptide (CGRP),nitric oxide synthase (NOS),malondialdehyde (MDA),changes in superoxide dismutase (SOD) and true choline esterase (TChE) were observed.In hippocampus,the CGRP level was determined by radioimmunoassay;the MDA level was determined by thiobarbituric acid colorimetric method;the activities of NOS and TChE were determined by spectrophotometry;the activity of SOD was determined by xanthine oxidase method.Results:Compared with the sham operation group,the performances of learning and memory decreased significantly in the model group (P＜0.01);in hippocampus,the CGRP level decreased,the MDA level increased,the activities of NOS and TChE increased,and the activity of SOD decreased in the model group.Compared with the model group,the learning and memory performances of the EA groups were significantly improved (P＜0.05 or P＜0.01);in hippocampus,the CGRP level increased,the MDA level decreased,the NOS and TChE activities decreased,and the SOD activity increased (P＜0.05 or P＜0.01).Among EA groups,the 2 Hz/80 Hz EA group was superior to the 2 Hz EA group and the 80 Hz EA group (P＜0.05 or P＜0.01).Conclusion:EA can improve the cognitive impairment of mice with ischemia-reperfusion VD.The mechanism may be related to the improvement of cerebral blood circulation,regulation of the central neurotransmitters,fighting lipid peroxidation and promoting nerve cell repair.The therapeutic effects of EA with different frequencies were different,and the intervention effect by EA at 2 Hz/80Hz is the most significant.

OBJECTIVETo explore the role of HOXB2 gene in the proliferation of primary human umbilical vein endothelial cells (HUVECs) and the protective effects of VEGF on the endothelia against radiation injury.

METHODSHUVECs were isolated, cultured, subcultured and identified. (1) Liposome coated oligodeoxynucleotide (odn) and homeoboxB2 antisense oligodeoxyncleotide (HOXB2asodn) were prepared prepared in the concentrations of 0.25, 0.5, 1.0 and 2.5 mg/L for the stimulation of HUVEC. (3)H-TdR incorporation test and MTT method were employed to determine the proliferation activity of HUVECs after activation. The cell cycle analysis of HUVECs was determined by flow cytometry. The expression level of HOXB2mRNA within HUVECs was detected by RT-PCR (reverse transcription polymerase chain reaction). (2) HUVECs were separately treated with the addition of VEGF in concentration of 50 microg/L, by radiation in the dose of 6 Gy or 12 Gy (60)Co gamma gamma ray, or radiation with 12 Gy (60)Co gamma gamma ray followed by the addition of VEGF in dose of 50 microg/L. The cellular morphology was observed and the cellular proliferation activity was determined by MTT method.

RESULTS(1) The proliferation activity of HUVECs could be markedly inhibited by liposome coated HOXB2asodn in comparison to liposome-odn (P < 0.05 or 0.001), and the inhibition effect was positively correlated with the increase in asodn concentration. The cell ratio in S phase and the expression level of the HOXB2mRNA could be lowered by asodn in dose of 2.5 mg/L (P < 0.05 or 0.001). (2) Radiation by (60)Co gamma ray could lead to the nuclear enlargement, vacuolation in the cytoplasm, multiplicity of nucleus and nuclear swelling. The proliferative activity of HUVECs was increased from 0.365 +/- 0.047 and 0.487 +/- 0.022 without radiation to 0.557 +/- 0.042 and 0.648 +/- 0.021 24 and 48 hours after 6 Gy radiation However it was decreased to 0.263 +/- 0.038 and 0.306 +/- 0.024 (P < 0.01) after 12 Gy (60)Co gamma ray radiation. Nevertheless, the cell morphology was obviously improved and the proliferation was enhanced by the addition of VEGF after 12 Gy radiation.

CONCLUSIONHOXB2 gene played important roles in the biological activities of HUVECs. Small dose (6 Gy) gamma-radiation could promote, but large dose (12 Gy) could decrease the mRNA expression of HOXB2 gene in HUVECs. In addition, VEGF could protect HUVECs against radiation injury.

Cell Proliferation ; drug effects ; radiation effects ; Cells, Cultured ; Endothelial Cells ; drug effects ; radiation effects ; Endothelium, Vascular ; cytology ; drug effects ; radiation effects ; Genes, Homeobox ; genetics ; Homeodomain Proteins ; genetics ; Humans ; Liposomes ; pharmacology ; Oligonucleotides, Antisense ; genetics ; Radiation Injuries ; Transcription Factors ; genetics ; Umbilical Veins ; cytology ; Vascular Endothelial Growth Factors ; pharmacology

OBJECTIVETo explore the role of beta-catenin in the pathogenesis of mesial temporal lobe epilepsy.

METHODSKainic acid-induced rat models of medial temporal lobe epilepsy was established. The expression of beta-catenin in the normal mice and the model mice were detected using Western blot analysis. The expression of beta-catenin at human hippocampus was detected using immunohistochemical analysis and immunofluorescence and compared between patients with non-hippocampal sclerosis temporal lobe epilepsy and those with hippocampal sclerosis epilepsy.

RESULTSThe pathologies of model mice were similar with those in mice with hippocampal sclerosis temporal lobe epilepsy, demonstrating that the mice model was successfully established. Western blot analysis showed no significant difference of beta-catenin expression between normal mice and model mice. As shown by immunohistochemical analysis and immunofluorescence, beta-catenin expression in human hippocampus was also not significantly different between patients with temporal lobe epilepsy without hippocampal sclerosis and those with hippocampal sclerosis.

CONCLUSIONBeta-catenin may not be involved in the development of hippocampal sclerosis of mesial temporal lobe epilepsy.

Animals ; Disease Models, Animal ; Epilepsy, Temporal Lobe ; metabolism ; pathology ; Male ; Mice ; Mice, Inbred C57BL ; beta Catenin ; metabolism

OBJECTIVETo explore the efficiency and side-effects of the combination of cyclosporine A (CsA) and thalidomide in patients with myelodysplastic syndromes (MDS).

METHODSA total of thirty-seven patients with MDS-RCMD or-RAEB-I were treated with CsA in combination with thalidomide. The initial CsA dose of 3 mg×kg(-1)×d(-1) was administered, all patients had their CsA blood concentration concurrently monitored until it reached and maintained between 100 and 200 µg/L. The initial dose of thalidomide was 50 mg/d, with increasing dose of 50 mg every week until the maximum of 200 mg/d. The hematological response was assessed according to the modified criteria of the International Working Group, and adverse events were graded with the Common Toxicity Criteria (v3.0) of the National Cancer Institute. The response duration and overall survival of the patients were also observed.

RESULTS19/37 cases (51.4%) achieved hematologic improvement (HI)-erythroid response (HI-E), 9/29 cases (31.0%) HI-platelet response (HI-P) and 7/33 cases (21.2%) HI-neutrophil response (HI-N). 15 of 32 transfusion-dependent patients (46.9%) achieved transfusion independence. The median response duration of HI-E, HI-P and HI-N were 88 (4 - 88) weeks, 78 (8 - 84(+)) weeks and 78 (10 - 84(+)) weeks respectively. The median overall survival was 52 months on a 29 (4 - 103) months median follow-up. Some patients developed grades I-II hepatic or nephritic impairment, constipation, lethargy, dizziness, edema, rashes or numbness, and all were tolerable and reversible. No grade III or severer adverse events were observed.

CONCLUSIONCsA in combination with thalidomide appears to be effective mainly in inducing HI-E and relatively well-tolerated for the treatment of patients with MDS.

Anemia, Refractory, with Excess of Blasts ; drug therapy ; Cyclosporine ; therapeutic use ; Humans ; Myelodysplastic Syndromes ; drug therapy ; Thalidomide ; therapeutic use ; Treatment Outcome

The purpose of this study was to compare monotonic biomechanical properties of gourd-shaped LCP fixation with LCP fixation of human tibial shaft in gap fracture mode. Twenty paired fresh cadaveric human tibias were randomly divided into 4 groups (5 pairs each): (1) axial loading single cycle to failure testing, (2) torsion single cycle to failure testing, (3) 4-point bending single cycle to failure testing, and (4) dynamic 4-point bending testing. A 7-hole 4.5 mm gourd-shaped LCP was secured on the anteromedial surface of 1 randomly selected bone from each pair, respectively, using 6 locking screws in the 1st, 2nd, 3rd, 5th, 6th and 7th hole with the middle hole unfilled and just located at the mid-diaphysis of the tibia. A 7-hole 4.5 mm LCP was secured on the other bone with the same method. Standard AO/ASIF techniques were used. After fixation finished, a 10 mm gap in the mid-diaphysis of tibia was created, centrally located at the unfilled hole. The axial, torsional, and bending stiffness and failure strengths were calculated from the collected data in static testings and statistically compared using paired Student's t-test. The 4-point bending fatigue lives of the two constructs were calculated from the dynamic testing data and also statistically compared using paired Student's t-test. Failure modes were recorded and visually analyzed. P<0.05 was considered significant. Results showed that the axial, torsional and bending stiffness of gourd-shaped LCP construct was greater (4%, 19%, 12%, respectively, P<0.05) than that of the LCP construct, and the axial, torsional and bending failure strengths of gourd-shaped LCP construct were stronger (10%, 46%, 29%, respectively, P<0.05) than those of the LCP construct. Both constructs failed as a result of plate plastic torsional deformation. After axial loading and 4-point bending testings, LCP failed in term of an obvious deformation of bent apex just at the unfilled plate hole, while the gourd-shaped LCP failed in term of a deformation of bent arc between the 3rd and 5th holes, which indicated a more consistent stress distribution on gourd-shaped LCP. Fatigue life of gourd-shaped LCP construct was significantly greater than LCP construct (153 836±2 228 vs. 132 471±6 460 cycles, P<0.01). All constructs failed as a result of fracture of the plate through the compression hole of the unfilled combination screw hole. The biomechanical testing showed that gourd-shaped LCP can provide greater stiffness and strength, and longer fatigue life than LCP. The gourd-shaped LCP may be more advantageous mechanically and may reduce the plate breakage rate clinically.
Bone Plates ; Compressive Strength ; Elastic Modulus ; Equipment Failure Analysis ; Fracture Fixation, Internal ; instrumentation ; Humans ; In Vitro Techniques ; Prosthesis Design ; Stress, Mechanical ; Tensile Strength ; Tibial Fractures ; physiopathology ; surgery

OBJECTIVETo determine the spatio-temporal expression of p70S6k activation in hippocampus in mesial temporal lobe epilepsy.

METHODSTemporal lobe epilepsy model was established by stereotaxically unilateral and intrahippocampal injection of kainite acid (KA) in adult male C57BL/6 mice. Latent and chronic epileptogenesis were represented by mice 5 days after KA injection (n = 5) and mice 5 weeks after KA injection (n = 8), respectively. Control mice (n = 5) were injected with saline. Immunohistochemical assays were performed on brain sections of the mice.

RESULTSHippocampus both ipsilateral and contralateral to the KA injection displayed significantly up-regulated pS6 immunoreactivity in dispersed granule cells in 5-day and 5-week model mice.

CONCLUSIONThe activation of p70S6k is mainly located in the dentate gyrus in KA-induced mouse model of temporal lobe epilepsy, indicating that the activation may be related with the disperse degree and hypertrophy of granule cells.

Animals ; Epilepsy, Temporal Lobe ; enzymology ; Hippocampus ; enzymology ; Immunohistochemistry ; Male ; Mice ; Mice, Inbred C57BL ; Phosphorylation ; Ribosomal Protein S6 Kinases, 70-kDa ; analysis ; metabolism