Antimicrobial activity of polyhexamethylene biguanide nanoparticles against mastitis-causing Staphylococcus aureus.

Postmilking teat disinfection is one of the main measures used to prevent mastitis caused by contagious pathogens, such as Staphylococcus aureus. The present study evaluated the antimicrobial activity of polyhexamethylene biguanide (PHMB) and PHMB nanoparticles (NP) against mastitis-causing Staph. aureus using a microdilution assay methodology. A total of 20 mastitis-causing Staph. aureus isolates were used to determine the minimum inhibitory concentrations (MIC) of PHMB and PHMB NP compared with 3 disinfectants commonly used for teat disinfection (chlorhexidine digluconate, povidone-iodine, and sodium dichloroisocyanurate). The MIC90 was defined at the concentrations required to inhibit the growth of 90% of Staph. aureus. Our results indicated that PHMB NP presented the lowest MIC value (<0.03 µg/mL) to inhibit 90% of Staph. aureus, followed by chlorhexidine digluconate (≥0.25 µg/mL) and PHMB (≥0.5 µg/mL). On the other hand, sodium dichloroisocyanurate (≥500 µg/mL) and povidone-iodine (≥8,000 µg/mL) presented the highest concentrations to inhibit the growth of most Staph. aureus. Our preliminary results suggested that both PHMB and PHMB NP have antimicrobial activity against mastitis-causing Staph. aureus, which indicates the potential for both to be used as a teat-dip disinfectant to prevent bovine mastitis.

CD44 targeted delivery of siRNA by using HA-decorated nanotechnologies for KRAS silencing in cancer treatment.

KRAS is a small GTPase that regulates cell proliferation and survival. In tumors, the KRAS gene is mutated, and leading to unregulated tumor growth. Despite the recognized importance of KRAS in cancer, attempts to develop small molecule inhibitors have proved unsuccessful. An alternative strategy is gene silencing and the use of small nucleic acid sequences (e.g. siRNA, shRNA), has been reported to successfully downregulate KRAS. In this study we developed ternary nanocomplexes to deliver an anti-KRAS siRNA to colorectal cancer cells, exploiting the interaction of hyaluronic acid (HA) with CD44 as a means to achieve selective targeting of CD44-positive cancer cells. Two different polycations, poly(hexamethylene biguanide) and chitosan, were complexed with siRNA and coated with HA. Physico-chemical properties and stability of nanoparticles were characterized, including size, surface charge, and degree of siRNA protection. We demonstrate nanoparticle internalization (flow cytometry), siRNA cytosolic release (confocal microscopy) and KRAS silencing (RT-qPCR) in CD44+/KRAS+ colorectal cancer cell line, HCT-116. Further we demonstrate that the uptake of HA-decorated nanoparticles in cancer cells is higher when co-cultured with fibroblasts.

Exposure Survey of Trends in Occupational Practice (EXPO-S.T.O.P.) 2015: A national survey of sharps injuries and mucocutaneous blood exposures among health care workers in US hospitals.

BACKGROUND: National blood exposure (BE) surveys are valuable to health care facilities striving to reduce percutaneous sharps injuries (SIs) or mucocutaneous (MC) exposures among their health care workers (HCWs). In the Exposure Survey of Trends in Occupational Practice (EXPO-S.T.O.P.) 2015 we surveyed hospital BE incidence among members of the Association of Occupational Health Professionals in Healthcare. METHODS: A 23-item electronic survey requested 2015 data on total SI and MC; SI in nurses, doctors, and surgery; staffed beds; teaching status; full time equivalent staff (FTE), nurse FTE, average daily census (ADC), and adjusted patient days (APD). RESULTS: One hundred eighty-one hospitals in 34 states reported 9,343 BE (71% SI and 29% MC exposures). SI rates were 25.2/100 ADC (17.5 in nonteaching hospitals and 30.4 in teaching hospitals), 2.1/100 FTE (significantly less than that in 2001), 3.2/100 nurse FTE, 0.36/1,000 APD, and 38% occurred during surgery. MC exposure incidence rates were 10.5/100 ADC (8.6 in nonteaching hospitals and 11.7 in teaching hospitals), 0.86/100 FTE, and 0.14/1000 APD. CONCLUSIONS: BE incidence rates have fallen slowly but significantly since 2001, but the reduction is far less than hoped. Occupied beds (ie, ADC) has become a less-useful denominator. We estimate more than 300,000 HCWs sustain SIs annually in hospital and nonhospital settings. Greater resources are needed for more frequent and correct use of safety devices, training to competency, and root-cause investigation of all SIs.

Towards an integrated food safety surveillance system: a simulation study to explore the potential of combining genomic and epidemiological metadata.

Foodborne infection is a result of exposure to complex, dynamic food systems. The efficiency of foodborne infection is driven by ongoing shifts in genetic machinery. Next-generation sequencing technologies can provide high-fidelity data about the genetics of a pathogen. However, food safety surveillance systems do not currently provide similar high-fidelity epidemiological metadata to associate with genetic data. As a consequence, it is rarely possible to transform genetic data into actionable knowledge that can be used to genuinely inform risk assessment or prevent outbreaks. Big data approaches are touted as a revolution in decision support, and pose a potentially attractive method for closing the gap between the fidelity of genetic and epidemiological metadata for food safety surveillance. We therefore developed a simple food chain model to investigate the potential benefits of combining 'big' data sources, including both genetic and high-fidelity epidemiological metadata. Our results suggest that, as for any surveillance system, the collected data must be relevant and characterize the important dynamics of a system if we are to properly understand risk: this suggests the need to carefully consider data curation, rather than the more ambitious claims of big data proponents that unstructured and unrelated data sources can be combined to generate consistent insight. Of interest is that the biggest influencers of foodborne infection risk were contamination load and processing temperature, not genotype. This suggests that understanding food chain dynamics would probably more effectively generate insight into foodborne risk than prescribing the hazard in ever more detail in terms of genotype.

Estimating phosphorus loss in runoff from manure and fertilizer for a phosphorus loss quantification tool.

Nonpoint-source pollution of fresh waters by P is a concern because it contributes to accelerated eutrophication. Given the state of the science concerning agricultural P transport, a simple tool to quantify annual, field-scale P loss is a realistic goal. We developed new methods to predict annual dissolved P loss in runoff from surface-applied manures and fertilizers and validated the methods with data from 21 published field studies. We incorporated these manure and fertilizer P runoff loss methods into an annual, field-scale P loss quantification tool that estimates dissolved and particulate P loss in runoff from soil, manure, fertilizer, and eroded sediment. We validated the P loss tool using independent data from 28 studies that monitored P loss in runoff from a variety of agricultural land uses for at least 1 yr. Results demonstrated (i) that our new methods to estimate P loss from surface manure and fertilizer are an improvement over methods used in existing Indexes, and (ii) that it was possible to reliably quantify annual dissolved, sediment, and total P loss in runoff using relatively simple methods and readily available inputs. Thus, a P loss quantification tool that does not require greater degrees of complexity or input data than existing P Indexes could accurately predict P loss across a variety of management and fertilization practices, soil types, climates, and geographic locations. However, estimates of runoff and erosion are still needed that are accurate to a level appropriate for the intended use of the quantification tool.

Validation of a haemoglobin dilution method for estimation of blood loss.

BACKGROUND AND OBJECTIVES: Analysis of haemoglobin (Hb) dilution after bleeding is a simple, inexpensive and non-invasive method to estimate blood loss. Blood volume is estimated, taking sex, weight and height into account. The Hb concentration before and after blood loss is analysed and, from the difference, the blood loss volume can be calculated assuming a normovolemic subject. Although widely used this method has never been validated. MATERIAL AND METHODS: The Hb concentration of 21 blood donors was analysed before and up to 4 days after a standard blood donation and in another 18 blood donors the Hb concentration was analysed before and on day 4, 6, 8, 11 and 14 after blood donation. The blood volume of each donor was calculated and the donated blood volume was estimated by weighing. We calculated the blood loss by the Hb dilution method and compared the calculated value with the donated blood volume. RESULTS: The mean donated blood volume was 442 +/- 10 ml, whereas the mean calculated blood loss was 152 +/- 214 ml using the Hb concentration of the first day after donation and 301 +/- 145 ml with the Hb concentration of day 6 after blood donation after which no further Hb decrease was observed. The directly measured Hb concentration was always higher than the calculated/expected Hb concentration based on the blood donation volume. CONCLUSIONS: The Hb dilution method underestimates the true blood loss by more than 30% after a moderate blood loss of approximately 10% of the total blood volume.

Long-term results after primary repair or non-surgical treatment of anterior cruciate ligament rupture: a randomized study with a 15-year follow-up.

We investigated the long-term outcome of 100 patients 15 years after having been randomly allocated to primary repair (augmented or non-augmented) or non-surgical treatment of an anterior cruciate ligament (ACL) rupture. The subjective outcome was similar between the groups, with no difference regarding activity level and knee-injury and osteoarthritis outcome score but with a slightly lower Lysholm score for the non-surgically treated group. This difference was attributed to more instability symptoms. The radiological osteoarthritis (OA) frequency did not differ between surgically or non-surgically treated patients, but if a meniscectomy was performed, two-thirds of the patients showed OA changes regardless of initial treatment of the ACL. There were significantly more meniscus injuries in patients initially treated non-surgically. One-third of the patients in the non-surgically treated group underwent secondary ACL reconstruction due to instability problems. In this study, ACL repair itself could not reduce the risk of OA nor increase the subjective outcome scores. However, one-third of the non-surgical treated patients were later ACL reconstructed due to instability. The status of the menisci was found to be the most important predictor of developing OA. Early ACL repair and also ACL reconstruction can reduce the risk of secondary meniscus tears. Indirectly this supports the hypothesis that early stabilization of the knee after ACL injury is advantageous for the long-term outcome.

Does everything now make (anti)sense?

The data generated by the FANTOM (Functional Annotation of Mouse) consortium, Compugen and Affymetrix have collectively provided evidence that most of the mammalian genomes are actively transcribed. The emergence of an antisense RNA world brings new practical complexities to the study and detection of gene expression. However, we also need to address the fundamental questions regarding the functional importance of these molecules. In this brief paper, we focus on non-coding natural antisense transcription, as it appears to be a potentially powerful mechanism for extending the complexity of the protein coding genome, which is currently unable to explain inter-species diversification.

Prevalence of parkinsonism and relationship to exposure in a large sample of Alabama welders.

OBJECTIVE: To estimate the prevalence of parkinsonism in welders in Alabama and to compare this prevalence with that in a general population sample. METHODS: The authors screened 1,423 welders from Alabama who were referred for medical-legal evaluation for Parkinson disease (PD). Standardized videotaped assessments using the Unified Parkinson's Disease Rating Scale motor subsection 3 (UPDRS3) were obtained. Patients provided information regarding exposure to welding fumes and job titles. Job titles were matched with Department of Labor Standard Occupational Codes (SOCs). Diagnoses were assigned based on quantitative criteria for the diagnosis of PD using two thresholds for diagnosis. With use of the number of active welders in this screening with parkinsonism as the numerator and the age-adjusted number of welders in each SOC as the denominator, the prevalence of parkinsonism in Alabama welders was estimated using conservative assumptions and compared with general population data from Copiah County, MS. RESULTS: With use of conservative and liberal case definitions of parkinsonism, the estimated prevalence of parkinsonism among active male welders age 40 to 69 statewide was 977 to 1,336 cases/100,000 population. The prevalence of parkinsonism was higher among welders vs age-standardized data for the general population (prevalence ratio = 10.19, 95% CI 4.43 to 23.43). CONCLUSION: The estimated prevalence of parkinsonism was higher within a sample of male Alabama welders vs the general population of male residents of Copiah County, MS.

Brain dynamical disentrainment by anti-epileptic drugs in rat and human status epilepticus.

In this paper, we utilize a measure of brain dynamics, namely the short-term largest Lyapunov exponent (STLmax) to evaluate the efficacy of treatment in epileptic animals and humans with known antiepileptic drugs (AED) like diazepam and phenobarbital during status epilepticus (SE). This measure is estimated from analysis of electroencephalographic (EEG) recordings at multiple brain locations in both an SE patient and a cobalt/homocysteine thiolactone SE-induced animal. Techniques from optimization theory and statistics are applied to select optimal sets of brain sites, whose dynamics are then measured over time to study their entrainment/disentrainment. Results from such analysis indicate that the observed abnormal spatio-temporal dynamical entrainment in SE is reversed by AED administration (resetting of brain dynamics). These results may provide a potential use of nonlinear dynamical measures in the evaluation of the efficacy of AEDs and the development of new treatment strategies in epilepsy.

Translation repression by antisense sequences.

Antisense sequences that hybridize to messenger RNA can inhibit target gene expression in a variety of ways. The best-known antisense mechanisms trigger messenger RNA (mRNA) degradation; however, translation repression by ribosome interference is a common natural antisense mechanism. In bacteria, there are fascinating examples of cis-encoded and trans-encoded antisense sequences that reversibly repress translation. In eukaryotes, microRNAs that bind 3'UTR target sequences also repress translation, although the mechanism is unclear. An important feature of translation repression is that the mRNA can remain intact during periods of repression, and rapid expression switching can occur in response to cellular and environmental signals. Recent genome analyses indicate many new short noncoding RNAs with predicted antisense activities. Therefore, translation repression by antisense sequences is likely to be a common and important form of posttranscriptional gene control, and such natural mechanisms provide a basis for the development of synthetic antisense gene control in research and drug development.

Tranexamic acid decreases external blood loss but not hidden blood loss in total knee replacement.

BACKGROUND: Total knee arthroplasty (TKA) is often carried out using a tourniquet and shed blood is collected in drains. Tranexamic acid decreases the external blood loss. Some blood loss may be concealed, and the overall effect of tranexamic acid on the haemoglobin (Hb) balance is not known. METHODS: Patients with osteoarthrosis had unilateral cemented TKA using spinal anaesthesia. In a double-blind fashion, they received either placebo (n=24) or tranexamic acid 10 mg kg(-1) (n=27) i.v. just before tourniquet release and 3 h later. The decrease in circulating Hb on the fifth day after surgery, after correction for Hb transfused, was used to calculate the loss of Hb in grams. This value was then expressed as ml of blood loss. RESULTS: The groups had similar characteristics. The median volume of drainage fluid after placebo was 845 (interquartile range 523-990) ml and after tranexamic acid was 385 (331-586) ml (P<0.001). Placebo patients received 2 (0-2) units and tranexamic acid patients 0 (0-0) units of packed red cells (P<0.001). The estimated blood loss was 1426 (1135-1977) ml and 1045 (792-1292) ml, respectively (P<0.001). The hidden loss of blood (calculated as loss minus drainage volume) was 618 (330-1347) ml and 524 (330-9620) ml, respectively (P=0.41). Two patients in each group developed deep vein thrombosis. CONCLUSIONS: Tranexamic acid decreased total blood loss by nearly 30%, drainage volume by approximately 50% and drastically reduced transfusion. However, concealed loss was only marginally influenced by tranexamic acid and was at least as large as the drainage volume.

Ptosis as a remote effect of therapeutic botulinum toxin B injection.

The authors report a patient with cervical dystonia, previously treated with botulinum toxin A (BTX-A), who developed bilateral ptosis and difficulty with accommodation only after botulinum toxin B (BTX-B). High-frequency repetitive nerve stimulation of the abductor digiti minimi demonstrated a 34% increment in compound muscle action potential. No increment in 20 people injected with BTX-A and no cases of ptosis in a chart review of 1,606 BTX-A injections for cervical dystonia were found. The authors conclude that systemic spread of BTX-B can cause symptomatic involvement of autonomic neurons.

Range of motion training in brace vs. plaster immobilization after anterior cruciate ligament reconstruction: a prospective randomized comparison with a 2-year follow-up.

The purpose of this prospective and randomized study was to compare rehabilitation with early range of motion (ROM) training vs immobilization following anterior cruciate ligament (ACL) reconstruction. Fifty patients, undergoing an ACL reconstruction with a bone-patellar tendon-bone graft, were postoperatively allocated randomly to either a plaster cast or a brace for 5 weeks. The brace group had ROM exercises from postoperative day 7. The commencement of ROM exercises was postponed 4 weeks for the plaster group compared to the brace group, but progressed subsequently with equal speed. There was no difference between the groups in the ROM of flexion or extension 20 weeks after the ACL reconstruction and later. Twenty-four months after surgery, the muscle strength deficit in the hamstring muscles (isokinetic measurements; percent difference, injured vs uninjured) was significantly larger in the brace group (mean +/- SD: 5.9 +/- 7.8%, P < 0.01) than in the plaster group (- 0.9 +/- 11.8%, NS) (brace vs plaster group, P < 0.05). Furthermore, there was also a tendency in the brace group to a larger strength deficit in the quadriceps muscle (brace: 11.1 +/- 13.2%, P < 0.001; plaster: 3.8 +/- 12.9%, NS) (brace vs plaster group, P= 0.07). There was no difference between the groups in the total sagittal knee laxity, as measured with an arthrometer, or in the subjective knee function or activity level (Lysholm score together with the Tegner activity level) between the groups. It is concluded that the postoperative treatment with early range of motion training after ACL reconstruction gave as good ROM, knee stability, subjective knee function and activity level as the treatment with immobilization. It is hypothesized that the larger strength deficit observed after rehabilitation with early range of motion training is secondary to the more intensive training and physical therapist involvement that was demanded in order to achieve full ROM following immobilization.

Postural control after anterior cruciate ligament reconstruction and functional rehabilitation.

Total sagittal knee laxity and postural control in the sagittal and frontal planes were measured in 25 patients at a mean of 36 months (range, 27 to 44) after anterior cruciate ligament reconstruction and in a control group consisting of 20 uninjured age- and activity-matched subjects. Body sway was measured in the sagittal plane on a stable and on a sway-referenced force plate in single-legged stance, double-legged stance, or both, with the eyes open and closed. Postural reactions to perturbations in the sagittal and frontal planes were recorded in the single-legged stance with the eyes open. Total sagittal plane laxity was significantly greater in the anterior cruciate ligament-reconstructed knee (11.2 mm; range, 6 to 15) than in the uninjured knee (8.9 mm; range, 6 to 12) or in the control group (6.0 mm; range, 5 to 8). In spite of this, the patients, in comparison with the controls, exhibited normal postural control except in two variables-the reaction time and the latency between the start of force movement to maximal sway in the sagittal plane perturbations. This supports the hypothesis that rehabilitation, with proprioceptive and agility training, is an important component in restoring the functional stability in the anterior cruciate ligament-reconstructed knee.

Bactericidal antisense effects of peptide-PNA conjugates.

Antisense peptide nucleic acids (PNAs) can specifically inhibit Escherichia coli gene expression and growth and hold promise as anti-infective agents and as tools for microbial functional genomics. Here we demonstrate that chemical modification improves the potency of standard PNAs. We show that 9- to 12-mer PNAs, especially when attached to the cell wall/membrane-active peptide KFFKFFKFFK, provide improvements in antisense potency in E. coli amounting to two orders of magnitude while retaining target specificity. Peptide-PNA conjugates targeted to ribosomal RNA (rRNA) and to messenger RNA (mRNA) encoding the essential fatty acid biosynthesis protein Acp prevented cell growth. The anti-acpP PNA at 2 microM concentration cured HeLa cell cultures noninvasively infected with E. coli K12 without any apparent toxicity to the human cells. These results indicate that peptides can be used to carry antisense PNA agents into bacteria. Such peptide-PNA conjugates open exciting possibilities for anti-infective drug development and provide new tools for microbial genetics.

Expression of D-myo-inositol-3-phosphate synthase in soybean. Implications for phytic acid biosynthesis.

Phytic acid, a phosphorylated derivative of myo-inositol, functions as the major storage form of phosphorus in plant seeds. Myo-inositol phosphates, including phytic acid, play diverse roles in plants as signal transduction molecules, osmoprotectants, and cell wall constituents. D-myo-inositol-3-phosphate synthase (MIPS EC 5.5.1.4) catalyzes the first step in de novo synthesis of myo-inositol. A soybean (Glycine max) MIPS cDNA (GmMIPS1) was isolated by reverse transcriptase-PCR using consensus primers designed from highly conserved regions in other plant MIPS sequences. Southern-blot analysis and database searches indicated the presence of at least four MIPS genes in the soybean genome. Northern-blot and immunoblot analyses indicated higher MIPS expression and accumulation in immature seeds than in other soybean tissues. MIPS was expressed early in the cotyledonary stage of seed development. The GmMIPS1 expression pattern suggested that it encodes a MIPS isoform that functions in seeds to generate D-myo-inositol-3-phosphate as a substrate for phytic acid biosynthesis.

Activation of I-kappaB kinase by the HTLV type 1 Tax protein: mechanistic insights into the adaptor function of IKKgamma.

The Tax protein encoded by human T cell leukemia virus type 1 (HTLV-1) induces constitutive nuclear expression of the transcription factor NF-kappaB, causing aberrant expression of a large array of cellular genes. Tax activates NF-kappaB by stimulating the activity of the I-kappaB kinase (IKK), which in turn leads to phosphorylation and degradation of the NF-kappaB inhibitor I-kappaBalpha. In normal T cells, IKK activation occurs transiently on cellular stimulation through the T cell receptor (TCR) and the CD28 costimulatory molecule. However, this inducible kinase is constitutively activated in Tax-expressing and HTLV-1-infected T cells, which contributes to the deregulated nuclear expression of NF-kappaB. As a genetic approach to dissect the pathways mediating IKK activation by Tax and T cell activation signals, somatic cell mutagenesis was performed to isolate signaling-defective mutant Jurkat T cell lines. One of the mutant cell lines was shown to have a defect in NF-kappaB activation by both T cell mitogens and Tax. Interestingly, this mutant cell line lacks expression of the IKK regulatory protein, IKKgamma. Expression of exogenous IKKgamma in the mutant cells restored NF-kappaB activation, thus confirming the essential role of this regulatory factor in IKK activation by the cellular and viral stimuli. Mechanistic studies have shown that Tax physically interacts with IKKgamma via specific domains, including two homologous leucine zipper motifs present in IKKgamma. The Tax/IKKgamma interaction serves to recruit Tax to the IKK catalytic subunits, IKKalpha and IKKbeta, and this recruitment appears to be an essential mechanism by which Tax stimulates the activity of IKK.