Ototoxicity among cisplatin, carboplatin, and oxaliplatin in zebrafish model.

Platinum-based antineoplastic drugs, including cisplatin, carboplatin, and oxaliplatin, are widely used in the treatment of various cancers. Ototoxicity is a common adverse effect of platinum-based drugs. Ototoxicity leads to irreversible hearing impairment. We hypothesize that different platinum-based drugs exhibit varying ototoxic concentrations, time effects, and ototoxic mechanisms. We tested this hypothesis by using a zebrafish model (pvalb3b: TagGFP) to assess the viability of hair cells collected from zebrafish larvae. Cisplatin, carboplatin, and oxaliplatin were administered at dosages of 100, 200, or 400 µM, and the ototoxic effects of these drugs were assessed 1, 2, or 3 h after administration. Fm4-64 and a TUNEL assay were used to label the membranes of living hair cells and to detect cell apoptosis, respectively. We observed that >50% of hair cells were damaged at 1 h after cisplatin (100 µM) exposure, and this ototoxic effect increased at higher dosages and over time. Owing to the smaller ototoxic effects of carboplatin and oxaliplatin, we conducted higher-strength and longer-duration experiments with these drugs. Neither carboplatin nor oxaliplatin was obviously ototoxic, even at 1600 µM and after 6 h. Moreover, only cisplatin damaged the membranes of the hair cells. Cell apoptosis and significantly increased antioxidant gene expression were observed in only the cisplatin group. In conclusion, cisplatin significantly damages sensory hair cells and has notable dosage and time effects. Carboplatin and oxaliplatin are less ototoxic than cisplatin, likely due to having different ototoxic mechanisms than cisplatin.

High-Risk Pulmonary Embolism: Management for the Intensivist.

High-risk pulmonary embolism (PE) also known as massive PE carries a high rate of morbidity and mortality. The incidence of high-risk PE continues to increase, yet the outcomes of high-risk PE continue to remain poor. Patients with high-risk PE are often critically ill, with complex underlying physiology, and treatment for the high-risk PE patient almost always requires care and management from an intensivist. Treatment options for high-risk PE continue to evolve rapidly with multiple options for definitive reperfusion therapy and supportive care. A thorough understanding of the physiology, risk stratification, treatment, and support options for the high-risk PE patient is necessary for all intensivists in order to improve outcomes. This article aims to provide a review from an intensivist's perspective highlighting the physiological consequences, risk stratification, and treatment options for these patients as well as providing a proposed algorithm to the risk stratification and acute management of high-risk PE.

Antimicrobial resistance and virulence profiles of staphylococci isolated from clinical bovine mastitis.

Staphylococci, mainly including Staphylococcus aureus and coagulase-negative staphylococci (CNS), are one of the most common pathogens causing bovine mastitis worldwide. In this study, we investigated the antimicrobial resistance and virulence profiles of staphylococci from clinical bovine mastitis in Ningxia Hui Autonomous Region of China. Antimicrobial resistance was determined by disc diffusion combined with E-test method. Genes of antimicrobial resistance and virulence factors were determined by PCR. A total of 332 staphylococcal isolates were confirmed from 1,519 mastitic milk samples, including 172 S. aureus and 160 CNS isolates. Fifteen CNS species were identified, with S. chromogenes being the most frequent found (49.4%), followed by S. equorum (13.8%). Noticeably, 2 S. agnetis isolates were found among the CNS isolates. To our knowledge, this is the first report documenting the presence of S. agnetis from bovine mastitis in China. The S. aureus and CNS isolates showed high resistance against penicillin, followed by erythromycin and tetracycline. Multidrug resistance was found in 11.6 and 16.3% of the S. aureus and CNS isolates, respectively. Resistance to penicillin was attributed to the presence of blaZ, erythromycin resistance to ermC (alone or combined with ermB) and tetracycline resistance to tetK (alone or combined with tetM). Notably, one S. equorum isolate and one S. saprophyticus isolate were both methicillin-resistant and mecA positive. Additionally, all S. aureus isolates carried the adhesin genes fnbpA, clfA, clfB, and sdrC, and most of them contained cna and sdrE. Conversely, only a few of the CNS isolates carried clfA, cna, and fnbA. Regarding toxin genes, all S. aureus isolates harbored hlb, and most of them were hlg positive. The lukE-lukD, lukM, sec, sed, sei, sen, seo, tst, seg, seh, and sej were also detected with low frequencies. However, no toxin genes were observed in CNS isolates. This study reveals high species diversity of staphylococci from clinical bovine mastitis in Ningxia Hui Autonomous Region of China. The findings for the genetic determinants of antimicrobial resistance and virulence factor provide valuable information for control and prevention of staphylococcal bovine mastitis.

Gene cloning, expression and homology modeling of first fibrinolytic enzyme from mushroom (Cordyceps militaris).

Fibrinolytic enzymes are important thrombolytic agents for blood-clotting disorders like cardiovascular diseases. Availability of novel recombinant fibrinolytic enzymes can overcome the shortcomings of current thrombolytic drugs. With the objective of facilitating their cost-effective production for therapeutic applications and for gaining deeper insight into their structure-function, we have cloned and expressed the first fibrinolytic protease gene from Cordyceps militaris. Cordyceps militaris fibrinolytic enzyme (CmFE) has one open reading frame of 759 bp encoding "pre-pro-protein" of 252 amino acids. Recombinant CmFE was expressed as 28 kDa extracellular enzyme in Pichia pastoris which was capable of degrading fibrin clot. A structure homology model of CmFE was developed using urokinase-type plasminogen activator. The active site contains catalytic triad His41, Asp83, Ser177 and consensus sequence of GDSGG. The substrate binding residues are Asp (171), Gly (194) and Ser (192). Its trypsin-like specificity is determined by the critical Asp171 in S1 subsite. The "oxyanion hole" is formed by backbone amide hydrogen atoms of Gly-175 and Ser-177. CmFE contains six conserved cysteines forming three disulfide linkages. This is the first study describing cloning, expression and prediction of structure-function relationship of a mushroom fibrinolytic protease. Hence it has great relevance in application of fibrinolytic enzymes as thrombolytic agents.

Characterization and modeling of transcriptional cross-regulation in Acinetobacter baylyi ADP1.

Synthetic biology involves reprogramming and engineering of regulatory genes in innovative ways for the implementation of novel tasks. Transcriptional gene regulation systems induced by small molecules in prokaryotes provide a rich source for logic gates. Cross-regulation, whereby a promoter is activated by different molecules or different promoters are activated by one molecule, can be used to design an OR-gate and achieve cross-talk between gene networks in cells. Acinetobacter baylyi ADP1 is naturally transformable, readily editing its chromosomal DNA, which makes it a convenient chassis for synthetic biology. The catabolic genes for salicylate, benzoate, and catechol metabolism are located within a supraoperonic cluster (-sal-are-ben-cat-) in the chromosome of A. baylyi ADP1, which are separately regulated by LysR-type transcriptional regulators (LTTRs). ADP1-based biosensors were constructed in which salA, benA, and catB were fused with a reporter gene cassette luxCDABE under the separate control of SalR, BenM, and CatM regulators. Salicylate, benzoate, catechol, and associated metabolites were found to mediate cross-regulation among sal, ben, and cat operons. A new mathematical model was developed by considering regulator-inducer binding and promoter activation as two separate steps. This model fits the experimental data well and is shown to predict cross-regulation performance.

[Minimally invasive surgery to treat severe acromioclavicular dislocation combined with coracoid process fracture].

OBJECTIVE: To discuss the diagnosis and minimally invasive surgical treatment on severe acromioclavicular dislocation combined with coracoid process fracture. METHODS: Using 2 incisions of shoulder to expose and fix coracoid process and acromioclaricular joint and to repair damaged acromioclavicular ligament in 7 cases from March 1998 to March 2009. There was 2 males and 5 females in the patients. The age was from 23 to 57 years with an average of 44 yeas. The time from injury to operation was 3-7 d with an average of 4 days. According to Eyres typing, 2 cases were type 11 B, 5 cases were type III B. RESULTS: Seven patients were followed up from 6 months to 2 years with an average of 1 year. According to Karlsson criteria, 7 cases got grade A. CONCLUSION: Using 2 incisions of shoulder to expose and fix acromioclaricular joint and coracoid process with strong pertinence, reliable fixation and small tissue injury, which is a minimally invasive and effective method for severe acromioclavicular dislocation combined with coracoid process fracture.

Simultaneous determination of steroid composition of human testicular fluid using liquid chromatography tandem mass spectrometry.

A rapid, sensitive, and specific method using liquid chromatography tandem mass spectrometry (LC/MS/MS) has been developed for simultaneous determination of testosterone (T), dihydrotestosterone (DHT), estradiol (E2), and 5alpha-androstan-3alpha, -17beta-diol (3alpha-Diol) within human testicular fluid. Sample pretreatment involved a one-step extraction with diethyl ether. The analytes were separated on a Waters X-Terra C18 (150 mm x 2.1 mm i.d., 3.5 microm) analytical column with acetonitrile/water mobile phase (70:30, v/v) containing 0.1% formic acid using isocratic flow at 0.15 ml/min for 8 min. The column effluent was monitored by tandem mass spectrometry with electrospray positive ionization. Linear calibration curves were generated over the range of 0.1-50 ng/ml for T, 0.02-1 ng/ml for DHT, 0.05-2 ng/ml for E2, and 0.2-10 ng/ml for 3alpha-Diol, with values for the coefficient of determination of >0.99. The overall extraction efficiency was greater than 86% for T, 75% for DHT, 66% for E2, and 60% for 3alpha-Diol. The values for within-day and between-day precision and accuracy were <15%. We measured each of the four steroids in testicular sample volumes of only 20 microl, obtained by percutaneous testicular aspiration. The mean intratesticular testosterone concentration found by LC/MS/MS, 572 +/- 102 ng/ml, was similar to that previously obtained by radioimmunoassay (RIA). The mean intratesticular estradiol concentration was 15.7 +/- 2.3 ng/ml, which also correlated well with RIA measurement. Both DHT and 3alpha-Diol were below the limits of detection by RIA, but could be measured accurately by LC/MS/MS. In conclusion, LC/MS/MS represents a sensitive and accurate means by which to measure four separate steroids within small volume samples of testicular fluid.