The role of topical antibiotics used as prophylaxis in surgical site infection prevention.

Compared with systemic antibiotic therapy, the topical or local delivery of an antibiotic has many potential advantages. However, local antibiotics at the surgical site have received very limited approval in any of the surgical prophylaxis consensus guidelines that we are aware of. A review of the literature was carried out through searches of peer-reviewed publications in PubMed in the English language over a 30 year period between January 1980 and May 2010. Both retrospective and prospective studies were included, as well as meta-analyses. With regard to defining 'topical' or 'local' antibiotic application, the application of an antibiotic solution to the surgical site intraoperatively or immediately post-operatively was included. A number of surgical procedures have been shown to significantly benefit from perioperative topical prophylaxis, e.g. joint arthroplasty, cataract surgery and, possibly, breast augmentation. In obese patients undergoing abdominal surgery, topical surgical prophylaxis is also proven to be beneficial. The selective use of topical antibiotics as surgical prophylaxis is justified for specific procedures, such as joint arthroplasty, cataract surgery and, possibly, breast augmentation. In selective cases, such as obese patients undergoing abdominal surgery, topical surgical prophylaxis is also proven to be beneficial. Apart from these specific indications, the evidence for use of topical antibiotics in surgery is lacking in conclusive randomized controlled trials.

The influence of cues and stimulus history on the non-linear frequency characteristics of the pursuit response to randomized target motion.

When humans pursue motion stimuli composed of alternating constant velocity segments of randomised duration (RD), they nevertheless initiate anticipatory eye deceleration before stimulus direction changes at a pre-programmed time based on averaging prior stimulus timing. We investigated, in both the time and frequency domains, how averaging interacts with deceleration cues by comparing responses to stimuli composed of segments that were either constant-velocity ramps or half-cycle sinusoids. RDs were randomized within 6 ranges, each comprising 8 RDs and having differing mean RD. In sine responses, deceleration cues could be used to modulate eye velocity for long-range stimuli (RD = 840-1,200 ms) but in the shortest range (RD = 240-660 ms) cues became ineffective, so that sine responses resembled ramp responses, and anticipatory timing was primarily dependent on averaging. Additionally, inclusion of short duration (240 ms) segments reduced peak eye velocity for all RDs within a range, even when longer RDs in the range (up to 1,080 ms) would normally elicit much higher velocities. These effects could be attributed to antagonistic interactions between visually driven pursuit components and pre-programmed anticipatory deceleration components. In the frequency domain, the changes in peak velocity and anticipatory timing with RD range were translated into non-linear gain and phase characteristics similar to those evoked by sum-of-sines stimuli. Notably, a reduction in pursuit gain occurred when high-frequency components associated with short duration segments were present. Results appear consistent with an adapted pursuit model, in which pre-programmed timing information derived from an internally reconstructed stimulus signal is stored in short-term memory and controls the initiation of predictive responses.

Predicting the unpredictable: weighted averaging of past stimulus timing facilitates ocular pursuit of randomly timed stimuli.

In motor control, prediction of future events is vital for overcoming sensory-motor processing delays and facilitating rapid and accurate responses in a dynamic environment. In human ocular pursuit this is so pervasive that prediction of future target motion cannot easily be eliminated by randomizing stimulus parameters. We investigated the prediction of temporally randomized events during pursuit of alternating constant-velocity (ramp) stimuli in which the timing of direction changes varied unpredictably over a given range. Responses were not reactive; instead, smooth eye velocity began to decelerate in anticipation of each target reversal. In the first experiment, using a continuous-motion stimulus, we found that the time at which this occurred was relatively constant regardless of ramp duration, but increased as mean ramp duration of the range increased. Regression analysis revealed a quantitative association between deceleration timing and the previous two or three ramp durations in a trial, suggesting that recent stimulus history was used to create a running average of anticipatory timing. In the second experiment, we used discrete motion stimuli, with intervening periods of fixation, which allowed both target velocity and reversal timing to be varied, thereby decoupling ramp duration and displacement. This enabled us to confirm that the timing of anticipatory deceleration was based on the history of timing, rather than displacement, within the stimulus. We conclude that this strategy is used to minimize error amid temporal uncertainty, while simultaneously overcoming inherent delays in visuomotor processing.

'TB or not TB': the conundrum of pre-European contact tuberculosis in the Pacific.

Tuberculosis (TB) is a major global health threat, infecting one-third of the world's population. Despite this prominence, the age, origin and spread of the disease have been topics of contentious debate. Molecular studies suggest that Mycobacterium tuberculosis 'sensu stricto', the most common strain of TB infecting humans today, originated in Africa and from there spread into Europe and Asia. The M. tuberculosis strains most commonly found across the Pacific and the Americas today are most closely related to European strains, supporting a hypothesis that the disease only reached these regions relatively recently via European sailors or settlers. However, this hypothesis is inconsistent with palaeopathological evidence of TB-like lesions in human remains from across the Pacific that predate European contact. Similarly, genetic evidence from pre-European South American mummies challenges the notion of a European introduction of the disease into the Pacific. Here, we review the complex evidence for the age and origin of TB in the Pacific, and discuss key gaps in our knowledge and how these may be addressed. This article is part of the theme issue 'Insights into health and disease from ancient biomolecules'.

Ancient mitogenomes of Phoenicians from Sardinia and Lebanon: A story of settlement, integration, and female mobility.

The Phoenicians emerged in the Northern Levant around 1800 BCE and by the 9th century BCE had spread their culture across the Mediterranean Basin, establishing trading posts, and settlements in various European Mediterranean and North African locations. Despite their widespread influence, what is known of the Phoenicians comes from what was written about them by the Greeks and Egyptians. In this study, we investigate the extent of Phoenician integration with the Sardinian communities they settled. We present 14 new ancient mitogenome sequences from pre-Phoenician (~1800 BCE) and Phoenician (~700-400 BCE) samples from Lebanon (n = 4) and Sardinia (n = 10) and compare these with 87 new complete mitogenomes from modern Lebanese and 21 recently published pre-Phoenician ancient mitogenomes from Sardinia to investigate the population dynamics of the Phoenician (Punic) site of Monte Sirai, in southern Sardinia. Our results indicate evidence of continuity of some lineages from pre-Phoenician populations suggesting integration of indigenous Sardinians in the Monte Sirai Phoenician community. We also find evidence of the arrival of new, unique mitochondrial lineages, indicating the movement of women from sites in the Near East or North Africa to Sardinia, but also possibly from non-Mediterranean populations and the likely movement of women from Europe to Phoenician sites in Lebanon. Combined, this evidence suggests female mobility and genetic diversity in Phoenician communities, reflecting the inclusive and multicultural nature of Phoenician society.

Complex history of dog (Canis familiaris) origins and translocations in the Pacific revealed by ancient mitogenomes.

Archaeological evidence suggests that dogs were introduced to the islands of Oceania via Island Southeast Asia around 3,300 years ago, and reached the eastern islands of Polynesia by the fourteenth century AD. This dispersal is intimately tied to human expansion, but the involvement of dogs in Pacific migrations is not well understood. Our analyses of seven new complete ancient mitogenomes and five partial mtDNA sequences from archaeological dog specimens from Mainland and Island Southeast Asia and the Pacific suggests at least three dog dispersal events into the region, in addition to the introduction of dingoes to Australia. We see an early introduction of dogs to Island Southeast Asia, which does not appear to extend into the islands of Oceania. A shared haplogroup identified between Iron Age Taiwanese dogs, terminal-Lapita and post-Lapita dogs suggests that at least one dog lineage was introduced to Near Oceania by or as the result of interactions with Austronesian language speakers associated with the Lapita Cultural Complex. We did not find any evidence that these dogs were successfully transported beyond New Guinea. Finally, we identify a widespread dog clade found across the Pacific, including the islands of Polynesia, which likely suggests a post-Lapita dog introduction from southern Island Southeast Asia.

A cryogenic optical feedthrough using polarization maintaining fibers.

Polarization maintaining optical fibers can be used to transmit linearly polarized light over long distances but their use in cryogenic environments has been limited by their sensitivity to temperature changes and associated mechanical stress. We investigate experimentally how thermal stresses affect the polarization maintaining fibers and model the observations with Jones matrices. We describe the design, construction, and testing of a feedthrough and fiber termination assembly that uses polarization maintaining fiber to transmit light from a 633 nm HeNe laser at room temperature to a homodyne polarization-based interferometer in a cryogenic vacuum. We report on the efficiency of the polarization maintaining properties of the feedthrough assembly. We also report that, at cryogenic temperatures, the interferometer can achieve a sensitivity of 8 × 10(-10) rad/√Hz at 0.05 Hz using this feedthrough.

Joining of simian virus 40 DNA molecules at endonuclease R Eco Ri sites by polynucleotide ligase and analysis of the products by agarose gel electrophoresis.

DNA molecules cut with endonuclease R Eco Ri can be joined at Eco Ri cleavage sites by incubation with polynucleotide ligase. In order to define the optimum conditions for this reaction, linear Simian Virus 40 DNA molecules (SV40(Lri)) produced by endonuclease R Eco Ri cleavage of SV40 form i DNA were joined using polynucleotide ligases specified by bacteriophage T4 and Escherichia coli. We have determined that the concentration of the substrate DNA molecules is the most important factor determining the distribution of covalently joined product molecules into a variety of circular and linear monomeric and oligomeric species.

Attention and selection for predictive smooth pursuit eye movements.

Humans cannot typically produce smooth eye movements in the absence of a moving stimulus. However, they can produce predictive smooth eye movements if they expect a target of a known velocity to reappear. Here, we observed that participants could extract velocity information from two simultaneously presented moving targets in order to produce a subsequent predictive smooth eye movement for one of the two targets. Subjects fixated a stationary cross during the presentation of two targets, moving rightward at different velocities. In the next presentation, a single target was presented, which participants tracked with their eyes. A static cue, presented 700 ms before the moving target, indicated which of the two targets would be presented. Predictive eye movements were of an appropriate velocity, even when participants did not know in advance which of the two targets would subsequently be cued. However, the scaling of predictive eye velocity was marginally less accurate in this divided attention condition than when participants knew the identity of the cued target in advance, or a single target was presented during fixation. In a second experiment, we found that the velocity cued on the previous trial had a greater effect than the uncued velocity on the current trial. The negligible effect of the uncued velocity indicates that participants were extremely effective at selectively reproducing one of two recently viewed velocities. However, other influences, such as past history, also affected predictive smooth eye movements.

Conditions that enable human hematopoietic stem cell engraftment in all NOD-SCID mice.

BACKGROUND: Transplantation of human hematopoietic stem cells is the only true test of their long-term repopulation potential. Models are readily available to evaluate murine hematopoietic stem cells, but few exist that allow reliable quantification of human stem cells. The non-obese diabetic-severe combined immunodeficient (NOD-SCID) mouse model enables quantification of human hematopoietic stem cells, but the conditions that permit human engraftment in all animals have yet to be defined. The aims of the project were, therefore, to describe the variables that allow human engraftment in the NOD-SCID mouse model and the techniques that accurately quantify this engraftment. METHODS: NOD-SCID mice that had or had not received 250, 325, or 400 cGy irradiation received cord blood (CB) mononuclear or CD34+ cells i.v. or i.p. Mice were killed 6 weeks after transplantation, and the bone marrow, spleen, and thymus were harvested. Four-color flow cytometric analysis, semi-quantitative PCR, myeloid and erythroid progenitor, and stem cell assays were used to monitor human engraftment. RESULTS: A 250 or 325 cGy and i.v. injection of CB mononuclear or CD34+ cells is required to detect multilineage human engraftment in the bone marrow, spleen, or thymus of NOD-SCID mice. Four-color flow cytometric analysis and semi-quantitative PCR enable accurate detection of 0.1% human cells. Progenitor and stem cell assays provide functional information about the engrafted cells. CONCLUSIONS: Successful development of the NOD-SCID mouse model and techniques to assess human engraftment now allow it to be used reliably to analyze the effects of short-term cytokine exposure on the long-term repopulating capacity of CB stem cells.

Aminoborohydrides. 11. Facile reduction of N-alkyl lactams to the corresponding amines using lithium aminoborohydrides.

[reaction: see text] Various five- and six-membered N-alkyl lactams were reduced to the corresponding cyclic amines using lithium N,N-dialkylaminoborohydrides (LAB). Most of the reductions were essentially complete after refluxing in THF for 2 h. The cyclic amine products were easily isolated after an aqueous workup in very good to excellent yields. It is possible to selectively reduce most functional groups, such as esters, in the presence of a lactam using LAB reagents.

Effects of chronic inhalation of dimethyl ether in the rat.

Dimethyl ether (DME) is a colourless gas with an ethereal odour. It is used mainly as a liquid refrigerant and an aerosol dispersant. Little or no data exist on the toxicology of this material. In the present study, groups of male and female rats were exposed to 0.02%, 0.2% and 2% v/v of DME in air, 6 h/day, 5 days/week for 30 weeks. At the end of the study the high-dose level male rats showed a significant reduction on liver weight compared with the control group; this was accompanied by raising SGPT levels. In high-dose female rats there was no significant effect on liver weight but the SGPT levels were raised above control values. No histological abnormalities were observed in the liver or in any other organ.

Finishing of amalgam restorations: a three-year clinical study.

Class I and Class II amalgam restorations were placed in the permanent teeth of 66 patients, each of whom received a minimum of three restorations. At least one of these restorations was carved-only, at least one was immediately finished (using a prophylaxis paste on rubber cups at low speed, 8 or 10 min after trituration), and at least one restoration was polished (using finishing burs and polishing points, more than 24 h after placement). The number of restorations available for assessment of marginal fracture using the 11-unit photographic scale developed by Mahler was 253 at baseline, 249 at 1-year and 2-year recalls and 228 at the 3-year recall. Although polished restorations exhibited greater initial (baseline) marginal fracture, at 1-year, 2-year and 3-year recalls the restorations were found to exhibit a similar amount of marginal fracture regardless of the finishing technique. The amount of perceived marginal fracture increased steadily after 1 year. The immediate finishing of amalgam restorations showed no long-term benefit over the other techniques and has little to commend it. The clinical finishing of amalgam restorations is discussed in the light of this and other research.

The finishing and early marginal fracture of clinical amalgam restorations.

One operator placed 249 Tytin amalgam restorations in Class I and II preparations in the permanent teeth of 60 patients each of whom received a minimum of three restorations. At least one of these restorations was carved-only, at least one was immediately finished (at 8 or 10 min after trituration), and at least one restoration was polished (more than 24 h after placement). Restorations were principally assessed for marginal fracture at baseline and 1 year using the 11-unit scale for the evaluation of photographs developed by Mahler. Five factors were also assessed clinically at 1 year. Amalgam restorations, polished using finishing burs and rubber points at least 24 h after placement, exhibited more initial marginal fracture than carved-only or immediately finished restorations. At 1 year, the three techniques were comparable except for the superior surface texture of the polished restorations. The technique of immediate finishing of amalgam restorations has nothing to commend it in preference to existing techniques.

A clinical evaluation of posterior composite resin restorations: 8-year findings.

OBJECTIVES: From a continuing investigation of the clinical performance of three different types of composite resin, the findings of the clinical evaluation at 8 years are presented. METHODS: One operator placed 330 restorations in Class I and Class II preparations in the posterior teeth of 72 patients. Every patient received at least one restoration of each type of material: a microfilled composite, a small particle hybrid, a relatively coarse particle hybrid, and an amalgam control. Restorations were evaluated using clinical criteria. RESULTS: Forty six patients attended the 8-year recall. Twenty-five of the 213 restorations (13.7% of the composites and 5.8% of the amalgams) originally placed in these 46 patients had previously failed or been lost from the study or were assessed as requiring replacement at the 8-year recall. Bulk fracture and secondary caries at the margin were the most common forms of failure in the composite restorations. Other failures or losses were associated with a non-margin defect in the composite, caries not associated with the restoration, pulpal considerations, extraction for orthodontics and reasons unknown. One-hundred and ninety-three restorations (including five that required replacement) were available for clinical evaluation at 8 years and these included 17 Class II restorations. Significantly fewer restorations placed with the coarse particle hybrid exhibited evidence of marginal deterioration. CONCLUSION: At 8 years, composite restorations in posterior teeth had failed at a rate two to three times that of amalgam restorations. The most common types of failure were bulk fracture and secondary caries at the margin.

Finishing techniques for amalgam restorations: clinical assessment at three years.

Use of the optimum finishing technique for an amalgam restoration may enhance the marginal integrity of the restoration and discourage its unnecessary early replacement. Two hundred and twenty-eight high copper amalgam restorations in 56 patients were evaluated, using clinical assessment criteria, up to three years after placement. Each patient had received at least one carved-only amalgam, at least one immediately finished restoration, and at least one amalgam that was polished at a subsequent appointment. Regardless of the finishing technique, the restorations exhibited similar marginal integrity up to three years after placement. Polished restorations were found to have substantially superior surface texture and less likelihood of surface discoloration. No evidence was found to support the use of immediate finishing techniques. The clinical significance of these findings, with respect to the need to polish amalgam restorations, is discussed.

How to work with FMLA and ADA when granting leave.

AIDS: There is much confusion among employers on how to interpret rights and responsibilities under the Americans with Disabilities Act (ADA) and the Family and Medical Leave Act (FMLA). In many cases, the guidelines seem contradictory. Labor attorney Christopher J. Collins says that the ADA is basically a civil rights act, designed to protect the disabled from discrimination, while FMLA is a labor standards and leave law. Commonly-asked questions are answered, including the amount of leave an employee is entitled to, the amount of information that can be requested from an employee, and the options for dealing with employees who cannot perform assigned tasks.^ieng

Reporting of meticillin-resistant and -susceptible Staphylococcus aureus on death certificates in Irish hospitals.

The documentation of infection with meticillin-resistant Staphylococcus aureus (MRSA) on death certificates has been the subject of considerable public discussion. Using data from five tertiary referral hospitals in Ireland, we compared the documentation of MRSA and meticillin-susceptible S. aureus (MSSA) on death certificates in those patients who died in hospital within 30 days of having MRSA or MSSA isolated from blood cultures. A total of 133 patients had MRSA or MSSA isolated from blood cultures within 30 days of death during the study period. One patient was excluded as the death certificate information was not available; the other 132 patients were eligible for inclusion. MRSA and MSSA were isolated from blood cultures in 59 (44.4%) and 74 (55.6%) cases respectively. One patient was included as a case in both categories as both MRSA and MSSA were isolated from a blood culture. In 15 (25.4%) of the 59 MRSA cases, MRSA was documented on the death certificate. In nine (12.2%) of the 74 patients with MSSA cases, MSSA was documented on the death certificate. MRSA was more likely to be documented on the death certificate than MSSA (odds ratio: 2.46; 95% confidence interval: 1.01-6.01; P < 0.05). These findings indicate that there may be inconsistencies in the way organisms and infections are documented on death certificates in Ireland and that death certification data may underestimate the mortality related to certain organisms. In particular, there appears to be an overemphasis by certifiers on the documentation of MRSA compared with MSSA.