Environmental bacteria produce abundant and diverse antibiofilm compounds.

AIMS: The aim of this study was to isolate novel antibiofilm compounds produced by environmental bacteria. METHODS AND RESULTS: Cell-free extracts were prepared from lawns of bacteria cultured on agar. A total of 126 bacteria isolated from soil, cave and river habitats were employed. Extracts were tested for their ability to inhibit Staphylococcus aureus biofilm in a 96-well microtitre plate assay. A total of 55/126 extracts (44%) significantly inhibited Staph. aureus biofilm. Seven extracts were selected for further analysis. The antibiofilm activities in all seven extracts exhibited unique patterns of molecular mass, chemical polarity, heat stability and spectrum of activity against Staph. aureus, Staphylococcus epidermidis and Pseudomonas fluorescens, suggesting that these seven antibiofilm activities were mediated by unique chemical compounds with different mechanisms of action. CONCLUSIONS: Environmental bacteria produce abundant and diverse antibiofilm compounds. SIGNIFICANCE AND IMPACT OF THE STUDY: Screening cell-free extracts is a useful method for identifying secreted compounds that regulate biofilm formation. Such compounds may represent a novel source of antibiofilm agents for technological development.

Obesity and sex influence insulin resistance and total and multimer adiponectin levels in adult neutered domestic shorthair client-owned cats.

In this study, we estimated insulin sensitivity and determined plasma concentrations of total-, low-molecular-weight (LMW), and high-molecular-weight (HMW) adiponectin and leptin in 72 domestic shorthair, neutered, client-owned cats. Glucose tolerance was assessed with an intravenous glucose tolerance test and body fat percentage (BF%) was measured with dual-energy x-ray absorptiometry. Total adiponectin was measured with 2 different ELISAs. Low-molecular-weight and HMW adiponectin plasma concentrations were determined by Western blot analysis after sucrose-gradient velocity centrifugation, and the adiponectin multimer ratio [SA = HMW/(HMW + LMW)] was calculated. Differences in glucose tolerance, leptin, total adiponectin, and multimer ratio among lean (BF% <35; n = 26), overweight (35 45; n = 18) cats as well as between male (n = 34) and female (n = 38) neutered cats were evaluated by linear regression and 2-way ANOVA. Sex and age were included as covariates for analysis of BF%, whereas BF%, fat mass, and lean body mass were covariates for analysis of sex differences. Increased BF% was negatively correlated with multimer ratio (SA, r = -45; P < 0.002), whereas no differences were found in total adiponectin concentrations among BF% groups (P > 0.01). Male cats had indices of decreased insulin tolerance and significantly lower total adiponectin concentrations than did female cats (mean ± SEM, 3.7 ± 0.4 vs 5.4 ± 0.5 µg/mL; P < 0.02). Altered SAs could contribute to an obesity-associated decreasing glucose tolerance in cats, and low total adiponectin concentrations may relate to increased risk of diabetes mellitus in neutered male cats.

Quality defects in market beef and dairy cows and bulls sold through livestock auction markets in the Western United States: II. Relative effects on selling price.

Relative effects of Beef Quality Assurance (BQA)-related defects in market beef and dairy cows and bulls on selling price at auction was evaluated during 2008. The presence and severity of 23 BQA-related traits were determined during sales in Idaho, California, and Utah. Overall, 18,949 unique lots consisting of 23,479 animals were assessed during 125 dairy sales and 79 beef sales. Mean sale price ± SD (per 45.5 kg) for market beef cows, beef bulls, dairy cows, and dairy bulls was $45.15 ± 9.42, $56.30 ± 9.21, $42.23 ± 12.26, and $55.10 ± 9.07, respectively. When combined, all recorded traits explained 36% of the variation in selling price in beef cows, 35% in beef bulls, 61% in dairy cows, and 56% in dairy bulls. Premiums and discounts were determined in comparison with a "par" or "base" animal. Compared with a base BCS 5 beef cow (on a 9-point beef scale), BCS 1 to 4 cows were discounted (P < 0.0001), whereas premiums (P < 0.05) were estimated for BCS 6 to 8. Compared with a base BCS 3.0 dairy cow (on a 5-point dairy scale), more body condition resulted in a premium (P ≤ 0.001), whereas a less-than-desirable BCS of 2.0 or 2.5 was discounted (P < 0.0001). Emaciated or near-emaciated cows (beef BCS 1 or 2; dairy BCS 1.0 or 1.5) were discounted (P < 0.0001). Compared with base cows weighing 545 to 635 kg, lighter BW beef cows were discounted (P < 0.0001), whereas heavier beef cows received (P < 0.05) a premium. Compared with a base dairy cow weighing 636 to 727 kg, lighter BW cows were discounted (P < 0.0001), whereas heavier cows (727 to 909 kg) received a premium (P < 0.01). Beef and dairy cows with any evidence of lameness were discounted (P < 0.0001). Presence of ocular neoplasia in the precancerous stage discounted (P = 0.05) beef cows and discounted (P < 0.01) dairy cows, whereas at the cancerous stage, it discounted (P < 0.0001) all cows. Hide color influenced (P < 0.0001) selling price in beef cattle but had no effect (P = 0.17) in dairy cows. Animals that were visibly sick were discounted (P < 0.0001). Results suggest that improving BCS and BW, which producers can do at the farm or ranch level, positively affects sale price. Furthermore, animals that are visibly sick or have a defect associated with a possible antibiotic risk will be discounted. Ultimately, animals with minor quality defects should be sold in a timely manner before the defect advances and the discount increases.

Survey of quality defects in market beef and dairy cows and bulls sold through livestock auction markets in the Western United States: I. Incidence rates.

A survey was conducted to quantify incidence of Beef Quality Assurance (BQA)-related defects in market beef and dairy cows and bulls selling at auction during 2 seasons in 2008. Twenty-three BQA-related traits were evaluated by 9 trained personnel during sales at 10 livestock auction markets in Idaho (n = 5; beef and dairy), California, (n = 4; dairy only), and Utah (n = 1; beef and dairy). Overall, 18,949 unique lots (8,213 beef cows, 1,036 beef bulls, 9,177 dairy cows, and 523 dairy bulls,) consisting of 23,479 animals (9,299 beef cows, 1,091 beef bulls, 12,429 dairy cows, and 660 dairy bulls) were evaluated during 125 sales (64 spring, 61 fall) for dairy and 79 sales (40 spring, 39 fall) for beef. The majority of market beef cows and bulls (60.9 and 71.3%, respectively) were predominantly black-hided, and the Holstein hide pattern was observed in 95.4 and 93.6% of market dairy cows and bulls, respectively. Market cattle weighed 548 ± 103.6 kg (beef cows), 751 ± 176.1 kg (beef bulls), 658 ± 129.7 kg (dairy cows), and 731 ± 150.8 kg (dairy bulls). Most beef cows (79.6%) weighed 455 to 726 kg, and most beef bulls (73.8%) weighed 545 to 954 kg, respectively. Among market beef cattle, 16.0% of cows and 14.5% of bulls weighed less than 455 and 545 kg, respectively, and 63.7% of dairy cows and 81.5% of dairy bulls weighed 545 to 817 kg or 545 to 954 kg, respectively. However, 19.5% of dairy cows and 13.1% of dairy bulls weighed less than 545 kg. Mean BCS for beef cattle (9-point scale) was 4.7 ± 1.2 (cows) and 5.3 ± 0.9 (bulls), and for dairy cattle (5-point scale) was 2.6 ± 0.8 (cows) and 2.9 ± 0.6 (bulls). Some 16.5% of beef cows and 4.1% of beef bulls had a BCS of 1 to 3, whereas 34.8% of dairy cows and 10.4% of dairy bulls had a BCS of 2 or less. Emaciation (beef BCS = 1, dairy BCS = 1.0) or near-emaciation (beef BCS = 2, dairy BCS = 1.5) was observed in 13.3% of dairy cows and 3.9% of beef cows. Among beef cattle, 15.1% of cows and 15.4% of bulls were considered lame. In contrast, 44.7% of dairy cows and 26.1% of dairy bulls were lame. Ocular neoplasia (cancer eye) was observed in only 0.6% of beef cows, 0.3% of beef bulls, 0.3% of dairy cows, and 0.0% of dairy bulls. However, among animals with ocular neoplasia, it was cancerous in 34.4% of beef bulls, 48.0% of dairy cows, and 73.3% of beef cows. In conclusion, numerous quality defects are present in market beef and dairy cattle selling at auction in the Western United States, which could influence their value at auction.

A single high dose of escitalopram increases mismatch negativity without affecting processing negativity or P300 amplitude in healthy volunteers.

Information processing deficits are commonly found in psychiatric illnesses, while at the biochemical level serotonin seems to play a role in nearly all psychiatric disorders. Processing negativity (PN), mismatch negativity (MMN) and P300 amplitude are electrophysiological measures of information processing. The present study was designed to replicate and further extent the results of our initial study on the effects of a low dose of escitalopram (10 mg) on MMN, PN and P300 amplitude. In a randomised, double-blind, cross-over experiment, 20 healthy male volunteers received either a single, orally administered dose of 15 mg escitalopram (a highly selective serotonin reuptake inhibitor (SSRI)) or placebo, after which their PN, MMN and P300 amplitude were assessed. Similar to our initial study with 10 mg escitalopram, 15 mg escitalopram significantly increased MMN, while it did not affect P300 amplitude. In contrast to our initial study, however, the currently higher dose of escitalopram did not increase PN. Results support the view that a broad range of increased serotonergic activity enhances MMN, while the relationship between serotonin and PN seems more complex. The current study does not support a serotonergic involvement in P300 amplitude.

Community-associated meticillin-resistant Staphylococcus aureus as a cause of hospital-acquired infections.

The worldwide emergence of community-associated meticillin-resistant Staphylococcus aureus (CA-MRSA) during the last decade represents a significant change in the biology of MRSA strains and is changing the epidemiology of MRSA infections. CA-MRSA infections are caused by strains belonging to lineages distinct from HA-MRSA. In the community, CA-MRSA strains typically cause skin and soft tissue infections in children and younger adults. However, CA-MRSA strains increasingly cause healthcare-acquired infections including surgical site infections, ventilator-associated pneumonia and bacteraemia. A mathematical model showing the influence of MRSA transmission in the community on the prevalence of MRSA in hospitals is presented. The increasing prevalence of MRSA in the community also results in an increase in community-onset MRSA (CO-MRSA) among S. aureus bacteraemia and other invasive infections. These patients do not have typical risk factors for MRSA. Such changes may have profound implications for the choice of empirical therapy for serious infections where S. aureus is a possible cause. The new and potentially very large reservoir of MRSA in production animals with subsequent transmission to humans represents an additional serious threat to the control of MRSA both in general and as a cause of healthcare-acquired infections. CA-MRSA is thus a matter of serious concern and should be suppressed.

Aspects of the barley seed proteome during development and germination.

Analysis of the water-soluble barley seed proteome has led to the identification of proteins by MS in the major spots on two-dimensional gels covering the pI ranges 4-7 and 6-11. This provides the basis for in-depth studies of proteome changes during seed development and germination, tissue-specific proteomes, cultivar differences related to quality parameters, analysis of the genetic basis for spot variations and targeted investigations of specific proteins.

Modulation of activity and substrate binding modes by mutation of single and double subsites +1/+2 and -5/-6 of barley alpha-amylase 1.

Enzymatic properties of barley alpha-amylase 1 (AMY1) are altered as a result of amino acid substitutions at subsites -5/-6 (Cys95-->Ala/Thr) and +1/+2 (Met298-->Ala/Asn/Ser) as well as in the double mutants, Cys95-->Ala/Met298-->Ala/Asn/Ser. Cys95-->Ala shows 176% activity towards insoluble Blue Starch compared to wild-type AMY1, kcat of 142 and 211% towards amylose DP17 and 2-chloro-4-nitrophenyl beta-d-maltoheptaoside (Cl-PNPG7), respectively, but fivefold to 20-fold higher Km. The Cys95-->Thr-AMY1 AMY2 isozyme mimic exhibits the intermediary behaviour of Cys95-->Ala and wild-type. Met298-->Ala/Asn/Ser have slightly higher to slightly lower activity for starch and amylose, whereas kcat and kcat/Km for Cl-PNPG7 are < or = 30% and < or = 10% of wild-type, respectively. The activity of Cys95-->Ala/Met298-->Ala/Asn/Ser is 100-180% towards starch, and the kcat/Km is 15-30%, and 0.4-1.1% towards amylose and Cl-PNPG7, respectively, emphasizing the strong impact of the Cys95-->Ala mutation on activity. The mutants therefore prefer the longer substrates and the specificity ratios of starch/Cl-PNPG7 and amylose/Cl-PNPG7 are 2.8- to 270-fold and 1.2- to 60-fold larger, respectively, than of wild-type. Bond cleavage analyses show that Cys95 and Met298 mutations weaken malto-oligosaccharide binding near subsites -5 and +2, respectively. In the crystal structure Met298 CE and SD (i.e., the side chain methyl group and sulfur atom) are near C(6) and O(6) of the rings of the inhibitor acarbose at subsites +1 and +2, respectively, and Met298 mutants prefer amylose for glycogen, which is hydrolysed with a slightly lower activity than by wild-type. Met298 AMY1 mutants and wild-type release glucose from the nonreducing end of the main-chain of 6"'-maltotriosyl-maltohexaose thus covering subsites -1 to +5, while productive binding of unbranched substrate involves subsites -3 to +3.

Filters involving derivatives with application to reconstruction from scanned halftone images.

This paper presents a method for designing finite impulse response (FIR) filters for samples of a 2-D signal, e.g., an image, and its gradient. The filters, which are called blended filters, are decomposable in three filters, each separable in 1-D filters on subsets of the data set. Optimality in the minimum mean square error sense (MMSE) of blended filtering is shown for signals with separable autocorrelation function. Relations between correlation functions for signals and their gradients are derived. Blended filters may be composed from FIR Wiener filters using these relations. Simple blended filters are developed and applied to the problem of gray value image reconstruction from bilevel (scanned) clustered-dot halftone images, which is an application useful in the graphic arts. Reconstruction results are given, showing that reconstruction with higher resolution than the halftone grid is achievable with blended filters.

Rapid onset of hypoxic vasoconstriction in isolated lungs.

A fast-response O2 analyzer that samples air at low flow rates allows the quasi-instantaneous measurement of O2 concentration change in the airways of isolated blood-perfused rat lungs. This instrument and an oximeter were used to measure the stimulus-response delay time of hypoxic pulmonary vasoconstriction when the lungs were challenged with 10, 5, or 3% O2. The estimate for the shortest delay time between accomplished fall in airway O2 concentration and the onset of hypoxia-induced vasoconstriction was approximately 7 s. We found that the slope of pressure rise, but not the stimulus-response delay time, correlated with the magnitude of hypoxic vasoconstriction. Oscillations in pulmonary arterial pressure were observed when the lungs were challenged with 10% O2 but not when the challenge was 12, 5, or 3%, indicating perhaps that these oscillations were a threshold phenomenon. Established hypoxic vasoconstriction was sensitive to brief changes in airway O2 concentration. Vasodilation occurred when the gas mixture was switched from 3 to 21% O2 for two to five breaths, and vasoconstriction occurred when the gas was changed during a single breath from 5 to 3% O2.

Standardization of tibial fractures in the rat.

The influence of the fracture level on the biomechanical properties of healing rat tibial fractures has not been investigated so far, despite the widespread use of rats in fracture healing studies. Fractures were produced in four different zones in the right rat tibia and immobilized with a K-wire. A fifth group of rats was not fractured. After 40 days of healing the fractures and the non-fractured bones were tested in three-point bending. A distinct correlation was found between fracture level and mechanical parameters: maximum load, maximum stiffness, and maximum stress decreased the more distal the fracture was located. In the non-fractured bones, maximum load and maximum stress were constant in all four zones tested, whereas energy absorption increased in the distal part of the tibia. No influence of the healing fracture was found on the contralateral, non-fractured tibia, compared with the animals left undisturbed, and the mechanical properties of the right and the left tibia were found to be symmetrical in terms of mean values. Four different methods of determining the area moment of inertia were investigated, and the simple method of approximating the cross section to an elliptical annulus was found to correlate well with the area moment of inertia, determined from computer tracings of bone slices prepared from the test specimens after the bending test. The computer tracings were corrected for the compression of the specimens caused by the mechanical test.

A model of vertebral trabecular bone architecture and its mechanical properties.

An idealized, structural model of vertebral trabecular bone is presented. The architecture of the model (thick vertical columns and thinner horizontal struts) is based on studies of samples taken from the central part of vertebral bodies from normal individuals aged 30 to 90 years. With trabecular diameters and spacings typical for persons aged 40, 60, and 80 years respectively, the model accounts reasonably well for age-related changes in vertical and horizontal stiffness and trabecular bone volume, as seen in experimental data. By introducing a measure for the randomness of lattice joint positions in the modeled trabecular network, it is demonstrated that the apparent stiffness varies by a factor of between 5 and 10 from a perfect cubic lattice to a network of maximal irregularity, even though trabecular bone volume remains almost constant. A considerable change in mechanical behaviour is also seen, without changing the overall trabecular bone volume, when the bone material is slightly redistributed among vertical and horizontal trabeculae. It is concluded that measured bone mass should not be the sole indicator of trabecular bone biomechanical competence (stiffness and stress). It is crucial that measurements of bone density are considered in combination with a detailed description of the architecture.

Modeling absorption kinetics of subcutaneous injected soluble insulin.

Absorption of subcutaneously injected soluble insulin deviates markedly from simple first-order kinetics and depends both on the volume and concentration of the injected solution. This paper presents a model of the absorption process in which insulin is presumed to be present in subcutis in a low molecular weight form, a high molecular weight form, and an immobile form where the molecules are bound to the tissue. The model describes how diffusion and absorption gradually reduce the insulin concentrations in the subcutaneous depot and thereby shift the balance between the three forms in accordance with usual laws of chemical kinetics. By presuming that primarily low molecular weight insulin penetrates the capillary walls, the model can account for experimentally observed variations in the absorption rate over a wide range of volumes and of concentrations. The model is used to determine the effective diffusion constant D for insulin in subcutis, the absorption rate constant B for low molecular weight insulin, the equilibrium constant Q between high and low molecular weight insulin, the binding capacity C for insulin in the tissue, and the average life time T for insulin in its bound state. Typical values for a bolus injection in the thigh of fasting type I diabetic patients are D = 0.9 x 10(-4) cm2/min, B = 1.3 X 10(-2)/min, and Q = 0.13 (ml/IU)2. Binding of insulin in the tissue is significant only at small concentrations. The binding capacity is of the order of C = 0.05 IU/cm3 with a typical average life time in the bound state of T = 80.0 min. Combined with a simplified model for distribution and degradation of insulin in the body, the absorption model is used to simulate variations in plasma free insulin concentrations with different delivery schedules, i.e., bolus injection and dosage by means of an infusion pump. The simulations show that a pump repetition frequency of 1-2 per hr is sufficient to secure an almost constant plasma insulin concentration.

Lignocaine test and detrusor instability.

Detrusor instability in infravesical obstruction is well recognised and often resolves after surgery. The aetiology is not clearly understood but is probably due to increased vesical sensory input. Since intravesical lignocaine has been proved to have an effect (although shortlived) on detrusor instability in some patients, we have used it in order to differentiate between idiopathic detrusor instability and detrusor instability caused by infravesical obstruction. Our study showed that in patients with a positive lignocaine test pre-operatively, the detrusor instability and micturition disorder disappeared after operation, and in patients with a negative lignocaine test, it persisted. The differences were statistically significant (P less than 0.5).

Improvement of detrusor instability following repeated bladder distension with cystomat. A case report.

Treatment of idiopathic detrusor instability with drugs and prolonged distension of the bladder is often unsatisfactory. Some amelioration of symptoms was previously described after 24-hour bladder distension with use of the cystomat. A case is presented in which detrusor instability was successfully treated with continuous infusion via the cystomat, and thereby repeated bladder distension, for one week. The symptoms subsided, the cystometric bladder capacity was increased and there was no side effects. The improvement has persisted for six months. Though the mechanism by which the bladder distension exerts its effect is poorly understood, the technique of repeated distension offers an alternative in the treatment of patients with idiopathic detrusor instability.