Antibiotic hyper-resistance in a class I aminoacyl-tRNA synthetase with altered active site signature motif.

Antibiotics target key biological processes that include protein synthesis. Bacteria respond by developing resistance, which increases rapidly due to antibiotics overuse. Mupirocin, a clinically used natural antibiotic, inhibits isoleucyl-tRNA synthetase (IleRS), an enzyme that links isoleucine to its tRNAIle for protein synthesis. Two IleRSs, mupirocin-sensitive IleRS1 and resistant IleRS2, coexist in bacteria. The latter may also be found in resistant Staphylococcus aureus clinical isolates. Here, we describe the structural basis of mupirocin resistance and unravel a mechanism of hyper-resistance evolved by some IleRS2 proteins. We surprisingly find that an up to 103-fold increase in resistance originates from alteration of the HIGH motif, a signature motif of the class I aminoacyl-tRNA synthetases to which IleRSs belong. The structural analysis demonstrates how an altered HIGH motif could be adopted in IleRS2 but not IleRS1, providing insight into an elegant mechanism for coevolution of the key catalytic motif and associated antibiotic resistance.

Heparanase link between vasculogenesis and angiogenesis as well as a predictive factor of a shorter survival rate.

Heparanase concentration is low in normal epithelia cells but its overexpression is reported in many carcinomas, including sarcomas and haematological malignancies. The purpose of this study was to investigate the association with selected angiogenic parameters as well as in the number of circulating endothelial progenitors (EPCs) in respect to low, moderate and high concentrations of heparanase. Also, we estimated the diagnostic usefulness of the heparanase concentration for disease recurrence prediction in breast cancer cases. Eighty-six patients with IA-IIB stage invasive breast carcinoma who passed a comprehensive clinicopathologic evaluation were included in the study. The median tumour diameter was 1.5 cm. Twenty cases showed lymph node metastasis (N1). Follow-up was completed in all patients a median follow-up was 33.5 months with a 11.6% recurrence rate. An immunoassay of selected angiogenic parameters, heparanase, as well as an immunohistochemistry of oestrogen and progesterone receptors, human epidermal growth factor receptor 2 (HER2), Ki67 and E-cadherin was performed in all cases. Circulating EPCs were determined by flow cytometry. Higher levels of heparanase in oestrogen and progesterone receptor negative cancers than in positive ones were noted. A higher concentration of heparanase was observed in T2 cases than T1 subjects. Significant positive associations between circulating EPCs, soluble forms of VEGF receptors and increasing plasma levels of heparanase were obtained. Follow-up revealed a significantly higher incidence of disease relapse in breast cancer patients with high baseline concentrations of heparanase. Heparanase was the most accurate biomarker with an AUCROC = 0.72. The cut-off value of 213.74 pg/mL was identified in order to discriminate between disease recurrence patients and those without disease relapse. We suggest, that a high concentration of heparanase next to tumour size and oestrogen and progesterone receptor expression may serve as an indicator of a more an aggressive character of tumour cells and a shorter survival rate.

An anthropometric study of Serbian metal industry workers.

BACKGROUND: There are recent studies using new industrial workers' anthropometric data in different countries, but for Serbia such data are not available. OBJECTIVE: This study is the first anthropometric study of Serbian metal industry workers in the country, whose labor force is increasingly employed both on local and international markets. The metal industry is one of Serbia's most important economic sectors. METHODS: To this end, we collected the basic static anthropometric dimensions of 122 industrial workers and used principal components analysis (PCA) to obtain multivariate anthropometric models. To confirm the results, the dimensions of an additional 50 workers were collected. The PCA methodology was also compared with the percentile method. RESULTS: Comparing both data samples, we found that 96% of the participants are within the tolerance ellipsoid. According to this study, multivariate modeling covers a larger extent of the intended population proportion compared to percentiles. CONCLUSIONS: The results of this research are useful for the designers of metal industry workstations. This information can be used in dimensioning the workplace, thus increasing job satisfaction, reducing the risk of injuries and fatalities, and consequently increasing productivity and safety.

Increased number of endothelial progenitors in peripheral blood as a possible early marker of tumour growth in post-menopausal breast cancer patients.

The aim of the study was to evaluate the number of circulating endothelial progenitor cells (circulating EPCs) in the blood of patients diagnosed with breast cancer and to make an attempt at finding associations with the number of circulating EPCs and selected clinic-pathological factors; TNM and histological grading, molecular subtype of breast cancer, hormonal status, the expression of Ki-67 and the size of tumour. The study involved 96 Caucasian ethnicity post-menopausal women. Sixty-six women aged 48 - 63 (mean age 55) with breast cancer diagnosis without distant metastases (M0). The median value of the tumour diameter was 1.51 cm. The control group consisted of 30 healthy, non-smoking, post-menopausal women, mean age 49, range 44 - 54 years of age. The exclusion criteria for all the participants were hypertension, hyperlipidaemia, and hyperglycaemia, acute and chronic infection. With regard to the fresh blood samples the number of circulating endothelial progenitors was determined using flow cytometry. The fluorescence of 100,000 cells was measured during the analysis. Circulating EPCs were identified with the immune-phenotype CD45-, CD34+, CD133+, CD31+. A significantly higher number of circulating EPCs in the study group, as compared to the controls (P = 0.0001) and a significantly higher number of circulating EPCs in women over 60 with breast cancer than in the younger women (P = 0.0029) were reported. A positive correlation was noted between circulating EPCs and age as well as between circulating EPCs and HER-2 (P = 0.0231, P = 0.0414, respectively), and a negative correlation between circulating EPCs and histological grading of breast cancer (P = 0.0272). The study has shown a higher number of circulating EPCs in breast cancer patients, which indicates stimulation of neovascularization. Additionally, since bone morrow-derived circulating EPCs are more intensively mobilised in older and overweight breast cancer patients, we can speculate that more aggressive neo-angiogenesis can occur in those patients.

Possibility of blocking n. ischiadicus within foramen ischiadicum majus in sheep.

The blocking of the ischiadic nerve within foramen ischiadicus majus of 8 sheep was performed with 6-12 ml 2% xylocain from three different places: 1. From the middle of a line joining the top of processus spinosus of the 1st sacral vertebra and the peak of trochanter major. The needle pierces vertically through the skin, gluteal fascia and m. gluteus medius till foramen ischiadicum majus. 2. Along the most prominent part of crista iliaca on the gluteal surface of ala ossis ilium along the medial side of well expressed linea glutea. The needle pierces by an angle of 45 degrees through the skin, gluteal fascia and m. gluteus medius till the nerve itself. When the nerve is touched the animal makes a jerk. 3. Along the caudal part of tuber sacrale with the needle orientated caudo-ventro-laterally through the skin, gluteal fascia and m. gluteus medius toward foramen ischiadicum majus. The most appropriate approach for blocking is along crista glutea on the gluteal surface of ala assis ilii. In this approach the success is complete. The symptoms of the blocking appear immediately after the application. The complete akinesia of the limb appears 15 minutes after the application of 6 ml, and 5-10 minutes after being applied 12 ml of 2% xylocain. The blocking symptoms disappear within 90-100 or 120-140 minutes. Beside the blocking of n. ischiadicus, a simultaneous blocking of n. gluteus cranialis, n. caudalis and n. cutaneus femoris caudalis as well was performed within foramen ischiadicus majus.

Anatomical possibilities of access to and blockade of m. femoralis in the dog.

The anesthesia (blockade) of canine n. femoralis may be performed either from lumbar or inguinal region. The insensibility of skin in the medial part of the thigh, tibia and tarsus as well as the akinesia of m. quadriceps femoris are attained by the anesthesia. The blockade of n. femoralis from the lumbar region often attains n. obturatorius as well. If the blockade of n. femoralis and n. ischiadicus was performed at the same time, almost all muscles of the hind limb (except m. pectineus, m. gracilis, m. obturatoris internus and m. adductor) would be inactivated, which may considerably facilitate minor surgical and postoperative interventions on the canine hind leg. Access to femoral nerve from lumbar can be recommended because of better results and easier performance and after the application of anesthetic the effect is faster and more efficient. The signs of the obturator nerve blockade were obtain in some dogs especially in dogs with long legs.

C1-INH and its effect on infarct size and ventricular function in an acute pig model of infarction, cardiopulmonary bypass, and reperfusion.

BACKGROUND: Recent studies suggest that complement inhibition reduces reperfusion injury. A clinical setting with local application of a C1 esterase inhibitor (C1-INH) has been modeled in an animal study in order to further investigate these findings. METHODS: In 21 pigs, the left anterior descending coronary artery (LAD) was occluded distally to the first diagonal branch for 2 hours (h), including 1 h of cardioplegic arrest during CPB. After release of the coronary snare, C1-INH or NaCl (control) was applied to the aortic root. Thereafter, the aortic cross-clamp was removed and the heart was reperfused for 30 minutes before weaning from CPB. Left ventricular pressure volume analysis was performed by a multielectrode conductance catheter and the area at risk and infarct size were determined from excised hearts. RESULTS: The following data were observed (mean+/-SEM) for the control group and the C1-INH group, respectively, after 1-h ligation of the LAD: heart rate (HR) 86+/-3 and 93+/-6 beats/min, stroke volume (SV) 1.2+/-0.1 and 1.2+/-0.1 ml/kg, aortic pressure (AoP) 83+/-6 and 87+/-5 mmHg, left ventricular end-diastolic pressure (LVedP) 12+/-1 and 11+/-2 mmHg; two hours after weaning from CPB: HR 106+/-9 and 123+/-4 beats/min, SV 0.9+/-0.1 and 0.9+/-0.1 ml/kg, AoP 65+/-5 and 79+/-7 mmHg, LVedP 9+/-1 and 8+/-1 mmHg. Conductance catheter measurements showed no improved left ventricular performance after C1-INH application. Infarct size to area at risk ratio was 61.5+/-4.2% for controls and 61.4+/-4.8% for C1-INH. CONCLUSIONS: Intracoronary application of complement inhibitor in an acute infarction model, which mimicked a clinical setting of urgent coronary bypass grafting after ischemia, has been shown to neither influence the area of infarction, nor the ventricular function.