Improving the use of venous thromboembolism prophylaxis in an Australian teaching hospital

INTRODUCTION

Hospital-acquired venous thromboembolism (VTE) is a potentially fatal complication of hospitalisation, with meta-analyses and guidelines supporting the use of proven prophylactic measures (graduated compression stockings (GCS) and anticoagulants). Despite this, prophylaxis is underutilised and represents one of the largest gaps between evidence and current clinical practice.

METHODS

All episodes of VTE complicating hospitalisation were ascertained prospectively as part of a quality improvement programme over 3.5 years with a view to designing interventions to improve the use of prophylaxis and reduce the rate of VTE. Interventions initially centred upon highlighting the burden of VTE, the extent of failure to apply guideline evidence into practice, and the development and application of a hospital-wide risk assessment tool. Later interventions sought to build the risk-assessment tool into routine clinical care and enhanced feedback on VTE to clinical teams.

RESULTS

The annual rate of VTE fell in all the years following the intervention (2001), from 2.57 per 1000 cost-weighted separations to a nadir of 1.87 in 2003, with the difference being statistically significant (RR 0.68, 0.47 to 0.99, p = 0.04). The proportion of patients receiving anticoagulant prophylaxis increased (48% to 74%, p = 0.01) but there was no change in the measured use of GCS. There was a marked increase in the use of risk assessment for VTE in the ward setting (7.7% to 100%, p<0.001) during the programme.

CONCLUSION

Affordable and accessible interventions can improve the application of VTE prophylaxis guidelines into daily hospital care and are associated with reductions in this potentially life-threatening complication.

Bridging neurocognitive aging and disease modification: targeting functional mechanisms of memory impairment

Risk for Alzheimer's disease escalates dramatically with increasing age in the later decades of life. It is widely recognized that a preclinical condition in which memory loss is greater than would be expected for a person's age, referred to as amnestic mild cognitive impairment, may offer the best opportunity for intervention to treat symptoms and modify disease progression. Here we discuss a basis for age-related memory impairment, first discovered in animal models and recently isolated in the medial temporal lobe system of man, that offers a novel entry point for restoring memory function with the possible benefit in slowing progression to Alzheimer's disease.

Development and validation of a rapid multi-class method for the confirmation of fourteen prohibited medicinal additives in pig and poultry compound feed by liquid chromatography-tandem mass spectrometry

A confirmatory method has been developed to allow for the analysis of fourteen prohibited medicinal additives in pig and poultry compound feed. These compounds are prohibited for use as feed additives although some are still authorised for use in medicated feed. Feed samples are extracted by acetonitrile with addition of sodium sulfate. The extracts undergo a hexane wash to aid with sample purification. The extracts are then evaporated to dryness and reconstituted in initial mobile phase. The samples undergo an ultracentrifugation step prior to injection onto the LC-MS/MS system and are analysed in a run time of 26 min. The LC-MS/MS system is run in MRM mode with both positive and negative electrospray ionisation. The method was validated over three days and is capable of quantitatively analysing for metronidazole, dimetridazole, ronidazole, ipronidazole, chloramphenicol, sulfamethazine, dinitolimide, ethopabate, carbadox and clopidol. The method is also capable of qualitatively analysing for sulfadiazine, tylosin, virginiamycin and avilamycin. A level of 100 microg kg(-1) was used for validation purposes and the method is capable of analysing to this level for all the compounds. Validation criteria of trueness, precision, repeatability and reproducibility along with measurement uncertainty are calculated for all analytes.

Painful stimuli evoke potentials recorded from the medial temporal lobe in humans

The role of human medial temporal structures in fear conditioning has led to the suggestion that neurons in these structures might respond to painful stimuli. We have now tested the hypothesis that recordings from these structures will demonstrate potentials related to the selective activation of cutaneous nociceptors by a painful laser stimulus (laser evoked potential, LEP) (Kenton B, Coger R, Crue B, Pinsky J, Friedman Y, Carmon A (1980) Neurosci Lett 17:301-306). Recordings were carried out through electrodes implanted bilaterally in these structures for the investigation of intractable epilepsy. Reproducible LEPs were commonly recorded both bilaterally and unilaterally, while LEPs were recorded at contacts on the left (9/14, P=0.257) as commonly as on the right (5/14), independent of the hand stimulated. Along electrodes traversing the amygdala the majority of LEPs were recorded from dorsal contacts near the central nucleus of the amygdala and the nucleus basalis. Stimulus evoked changes in theta activity were observed at contacts on the right at which isolated early negative LEPs (N2*) responses could be recorded. Contacts at which LEPs could be recorded were as commonly located in medial temporal structures with evidence of seizure activity as on those without. These results demonstrate the presence of pain-related inputs to the medial temporal lobe where they may be involved in associative learning to produce anxiety and disability related to painful stimuli.

Temporally limited role of substantia nigra-central amygdala connections in surprise-induced enhancement of learning

Prediction error plays an important role in modern associative learning theories. For example, the omission of an expected event (surprise) can enhance attention to cues that accompany those omissions, such that subsequent new learning about those cues is more rapid. Many studies from our laboratories have demonstrated that circuitry that includes the amygdala central nucleus (CeA), the cholinergic neurons in the substantia innominata/nucleus basalis region and their innervation of the posterior parietal cortex is critical for this surprise-induced enhancement of attention in learning. We recently showed that midbrain dopamine neurons, known to code prediction error, are also important for surprise-induced enhancement of learning through their interaction with CeA. The present study examined whether in rats the communication between the substantia nigra pars compacta (SNc) and CeA is critical only at the time of surprise, for example to detect prediction error information, or is also needed to maintain and later express that information as enhanced learning. All animals received unilateral CeA lesions and unilateral cannula implants targeting the SNc located contralateral to the lesioned CeA. As the SNc-CeA connections are mainly ipsilateral, inactivating SNc contralateral to the lesioned CeA provided transient blockage of SNc and CeA communication. The results show that SNc-CeA communication is critical for processing prediction error information at the time of surprise, but neither SNc nor SNc-CeA communication is necessary to express that information as enhanced learning later.

Analyses of volatile organic compounds from human skin

BACKGROUND

Human skin emits a variety of volatile metabolites, many of them odorous. Much previous work has focused upon chemical structure and biogenesis of metabolites produced in the axillae (underarms), which are a primary source of human body odour. Nonaxillary skin also harbours volatile metabolites, possibly with different biological origins than axillary odorants.

OBJECTIVES

To take inventory of the volatile organic compounds (VOCs) from the upper back and forearm skin, and assess their relative quantitative variation across 25 healthy subjects.

METHODS

Two complementary sampling techniques were used to obtain comprehensive VOC profiles, viz., solid-phase microextraction and solvent extraction. Analyses were performed using both gas chromatography/mass spectrometry and gas chromatography with flame photometric detection.

RESULTS

Nearly 100 compounds were identified, some of which varied with age. The VOC profiles of the upper back and forearm within a subject were, for the most part, similar, although there were notable differences.

CONCLUSIONS

The natural variation in nonaxillary skin odorants described in this study provides a baseline of compounds we have identified from both endogenous and exogenous sources. Although complex, the profiles of volatile constituents suggest that the two body locations share a considerable number of compounds, but both quantitative and qualitative differences are present. In addition, quantitative changes due to ageing are also present. These data may provide future investigators of skin VOCs with a baseline against which any abnormalities can be viewed in searching for biomarkers of skin diseases.

Clinical activity and immune modulation in cancer patients treated with CP-870,893, a novel CD40 agonist monoclonal antibody

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Background: The cell-surface molecule CD40 plays a critical role in activating antigen presenting cells (APC) and mediates upregulation of costimulatory and MHC molecules, cytokine release, and enhancement of tumor immunity. CD40 is also expressed by 30%-70% of solid tumors, and engagement of CD40 on tumor cells results in apoptosis. CP-870,893 - a fully human and selective CD40 agonist monoclonal antibody - activates human APC in vitro and inhibits growth of human tumors in immune-deficient and immune-reconstituted SCID-beige mice. Methods: A phase 1, dose-escalation study of CP-870,893 was designed to characterize the safety and maximum tolerated dose (MTD) of single doses of CP-870,893 in patients (pts) with advanced solid tumors. CP-870,893 was administered i.v. on day 1 and pts were followed for 43 days. Results: Twenty-nine pts received CP-870,893 in doses ranging from 0.01 to 0.3 mg/kg. Dose limiting toxicity was observed in 2 of 7 pts at the 0.3 mg/kg dose level (venous thromboembolism and grade 3 headache). The MTD was defined as 0.2 mg/kg. The most common adverse event was dose-related cytokine release syndrome (grade 1 to 2). Abnormal lab findings included dose-related and transient elevations in liver transaminases (grade 1 to 2; one pt with grade 3). Modest elevations in serum D-dimer were observed in pts treated at the highest dose levels. Four pts with melanoma (14% of all pts and 27% of pts with melanoma) had objective partial responses (PR) at day 43 evaluation (one PR sustained at 7+ months and 3 unsustained on follow-up scans). Each pt with a PR received 0.2 or 0.3 mg/kg of antibody. To assess pharmacodynamic actions of CP-870,893, flow cytometry was performed on peripheral blood B cells, which uniformly express CD40. CP-870,893 infusion resulted in depletion of peripheral CD19+ B cells (>80% depletion at the highest dose levels). Among B cells remaining in blood, we found a marked, dose-related upregulation of costimulatory and MHC molecules after treatment. Conclusions: Clinical and laboratory findings demonstrate biological activity of CP-870,893. Antitumor activity was observed in 4 pts with melanoma. Further studies of repeated doses of CP-870,893, and CP-870,893 in combination with other antineoplastic agents, are warranted.

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GABAB receptor antagonist SGS742 improves spatial memory and reduces protein binding to the cAMP response element (CRE) in the hippocampus

Memory storage in the brain requires protein synthesis initiated through signaling pathways that control transcription. Such mechanisms are under active investigation for therapies in disorders involving cognitive dysfunction. Long-term memory can be improved by inhibiting activation or reducing expression of transcription factors such as ATF4/CREB2 and some C/EBP family members which appear to serve as memory suppressors. Here, we provide evidence that GABAB receptor antagonists may enhance cognition, at least in part, by this mechanism. We tested a GABAB receptor antagonist, SGS742 (CGP36742), on hippocampal-dependent memory and hippocampal nuclear CRE-binding activity in rats. As a result, acute in vivo administration of SGS742 both improved memory and reduced total hippocampal CRE-binding activity of which a large proportion in the basal state could be immunoneutralized with CREB2 antibodies. Consistent with its activity on information storage mechanisms, acute SGS742 effectively improved long-term memory in retrograde protocols, in which drug was given at times when memory formation can be interrupted by blocking new protein production. In conclusion, GABAB antagonists may provide a pharmacological therapy for cognitive impairment, sharing mechanistic features with genetic approaches to reduce CREB2 activity and to augment long-term memory.

A comparison of decontamination methods used for dental burs

OBJECTIVES

This study investigated the bacterial and fungal contamination of used dental burs. A novel assay system for comparison of efficacy of pre-sterilisation cleaning techniques for dental burs was used to evaluate manual scrubbing, enzymic agents and washer-disinfectors.

METHODS

Thirty dental burs contaminated during cavity preparation were analysed for micro-biological total viable counts and species of bacteria and fungi present. To simulate clinically contaminated burs, a culture of Streptococcus sanguis NCTC 7863 was used to inoculate unused dental burs, alone and combined with blood, saliva or a mixture of blood and saliva. Contaminated burs were subjected to six pre-sterilisation cleaning techniques and the log reduction in contamination achieved by each method was assessed.

RESULTS

The microbial count from used dental burs ranged from 0 to 6.92 x 10(4) CFU ml(-1). Many potentially pathogenic species were identified. The decontamination assay demonstrated that autoclaving alone was not sufficient to sterilise dental burs. Manual scrubbing in air was less efficacious than manual scrubbing under water (p<0.001). The most effective method of pre-sterilisation cleaning for dental burs was a washer-disinfector.

CONCLUSIONS

Enzymic agents are suitable for soaking contaminated dental burs immediately after use. Washer-disinfectors are recommended as the method of choice for pre-sterilisation cleaning of contaminated dental burs.

Multidetector-row CT duodenography in familial adenomatous polyposis: a pilot study

AIM

To investigate the feasibility of using multidetector-row computed tomography (CT) duodenography to stage duodenal polyposis in patients with familial adenomatous polyposis.

MATERIALS AND METHODS

Six patients underwent multidetector-row CT duodenography before upper gastrointestinal endoscopy. A single-blinded radiologist used a surface shaded three-dimensional endoluminal fly though and two-dimensional axial and multiplanar reformats to assign a score for maximum polyp size and number based on the Spigelman classification. Comparison was made with the corresponding Spigelman scores obtained from subsequent endoscopy.

RESULTS

CT duodenography was technically successful in five of six patients. The CT derived Spigelman score based on maximum polyp size was accurate in all five patients. The CT derived Spigelman score based on polyp number was accurate in only two cases: Polyp number was overestimated in one patient and underestimated in a further two. In retrospect, fine carpeting of tiny duodenal polyps was poorly visualized with CT.

CONCLUSIONS

CT duodenography is technically feasible and accurately predicts maximum polyp size but CT estimates of polyp number are relatively inaccurate. CT duodenography potentially has a useful role for duodenal surveillance in those patients intolerant of conventional endoscopy.

Neurogenesis in a rat model of age-related cognitive decline

Age-related decrements in hippocampal neurogenesis have been suggested as a basis for learning impairment during aging. In the current study, a rodent model of age-related cognitive decline was used to evaluate neurogenesis in relation to hippocampal function. New hippocampal cell survival was assessed approximately 1 month after a series of intraperitoneal injections of 5-bromo-2'-deoxyuridine (BrdU). Correlational analyses between individual measures of BrdU-positive cells and performance on the Morris water maze task provided no indication that this measure of neurogenesis was more preserved in aged rats with intact cognitive abilities. On the contrary, among aged rats, higher numbers of BrdU-positive cells in the granule cell layer were associated with a greater degree of impairment on the learning task. Double-labelling studies confirmed that the majority of the BrdU+ cells were of the neuronal phenotype; the proportion of differentiated neurons was not different across a broad range of cognitive abilities. These data demonstrate that aged rats that maintain cognitive function do so despite pronounced reductions in hippocampal neurogenesis. In addition, these findings suggest the interesting possibility that impaired hippocampal function is associated with greater survival of newly generated hippocampal neurons at advanced ages.

Implementation of the DOTS strategy in prisons at provincial level, Thailand

SETTINGS

Sixteen prisons located in four geographic regions in Thailand.

OBJECTIVES

To assess treatment outcomes of tuberculosis (TB) patients under the DOTS strategy in a prison programme.

METHOD

The programme prospectively included 1412 consecutive TB patients registered during Year 1 (June 1999-May 2000), Year 2 (June 2000-May 2001) and Year 3 (June 2001-May 2002). DOTS implementation consisted of government commitment; passive detection by sputum smear microscopy; standardised short-course chemotherapy, including directly observed treatment by prison nurses; maintenance of drug stocks at provincial health offices; and a recording and reporting system. Data were collected using prison TB registers.

RESULTS

The number of TB patients increased from 348 in Year 1 to 490 in Year 2 and to 574 in Year 3. New smear-positive patients accounted for 82.0% of the total. Of the 1158 new smear-positive cases, 68.7% were cured, 17.6% died, 10.6% were transferred out, 2.6% failed, and 0.5% completed treatment.

CONCLUSIONS

DOTS implementation in these prisons could not achieve the national target to cure 85% of new smear-positive cases. More interventions are needed to help reduce the deaths and transferred cases that mainly affected the treatment outcomes in these settings.

Aging, spatial learning, and total synapse number in the rat CA1 stratum radiatum

The aim of this study was to determine whether spatial learning deficits in aged rats are associated with a loss of hippocampal synapses. The Morris water maze task was used to assess the spatial learning capacity of young and aged rats and to attribute aged animals to learning-impaired and learning-unimpaired groups. The number of axospinous synapses in the entire volume of the CA1 stratum radiatum was estimated with unbiased stereological techniques. The results show that the total number of all axospinous synapses and of their perforated and nonperforated subtypes remains constant in the CA1 stratum radiatum of aged learning-impaired rats as compared to aged learning-unimpaired rats and to young adults. Thus, neither age-related deficits in spatial learning nor advanced chronological age are associated with a loss of axospinous synapses from the rat CA1 stratum radiatum.