Mitral valve disease

In industrially developed countries, moderate or severe mitral valve disease is relatively common and is usually caused by prolapse or is secondary to left ventricular disease. Mitral stenosis (MS), however, is uncommon and usually a sequela of rheumatic fever. This article discusses the natural history of mitral regurgitation and MS and their medical and surgical management.

Prosthetic heart valves

Heart valve replacements improve symptoms and life expectancy but may have potential problems. Biological replacements have limited durability but do not require anticoagulation and are usually used for the relatively elderly. Mechanical valves have a virtually zero primary failure rate but require anticoagulation and are usually used for the relatively younger patient. Transcatheter valves are used for patients in whom conventional surgery is not technically feasible or who have significant comorbidities. This article discusses the management of patients after valve replacement and discusses future developments.

Attractancy toOryzaephilus surinamensis (L.), saw-toothed grain beetle, of extracts of carobs, some triglycerides, and related compounds

A laboratory method has been devised for testing the attractancy of vapors to adultOryzaephilus surinamensis (L.). Of four solvent extracts prepared from pods of the carob tree [Ceratonia siliqua (L.)], all attractedO. surinamensis, but the least polar extract was the most active. Subdivision of extracts yielded a series of fractions, the most attractive of which contained a mixture of triglycerides with three or more double bonds per molecule. Twelve authentic triglycerides, either synthesized or purchased, elicited responses ranging from high to very low attractancy in a way which appeared to be related to the number, position, and geometrical shape of the double bonds in the molecules. By studying the response of the insects to five glyceride acids, three aldehydes, and three volatile fatty acids, it has been shown that it may be possible to explain the attractancy attributed to the triglycerides, which are involatile, in terms of the response to their volatile breakdown products.

Saw-toothed grain beetleOryzaephilus surinamensis (L.) (Coleoptera: Silvanidae) : Antennal and behavioral responses to individual components and blends of aggregation pheromone

The antennal and behavioral responses of the saw-toothed grain beetle,Oryzaephilus surinamensis, to the three components of its male-produced aggregation pheromone were investigated. EAG recordings showed no differences between the responses of the two sexes to the synthetic pheromone components. In contrast, laboratory behavioral assays demonstrated marked differences between the sexes. More females than males were consistently attracted to mixtures of the synthetic components, and this bias appeared to be caused by one component in the blend. Altering the blend ratio resulted in changes in the ratio of the sexes attracted. Thus, if, as suggested by preliminary work, males vary the blend produced, this should alter the relative response of the sexes to the aggregation pheromone.

Identification of the sex pheromone of the guernsey carpet beetle,Anthrenus sarnicus Mroczkowski (Coleoptera: Dermestidae)

It has been confirmed that adult virgin females ofAnthrenus sarnicus Mroczkowski exhibit a characteristic headstand posture that is associated with the release of a sex pheromone. Volatiles trapped on filter papers suspended above calling females were attractive to adult virgin males when tested in a two-choice target bioassay. Separate aeration extracts of males and females were analyzed by gas chromatography-mass spectrometry and showed that decanol and decyln-butyrate were released by females only. These components were present in approximately equal amounts and accounted for about 90% of the total area of the chromatogram. Decyl butyrate produced an electroantennogram response with a larger response from males than females. Behaviorally, a mixture of 10μg of decanol and 10μg of decyl butyrate attracted 88% of males and 10μg of decyl butyrate alone attracted 82% of males in the bioassay. The role of decyl butyrate as a sex pheromone is convincing, but this is not the case for decanol.

Grain weevil,Sitophilus granarius (L.): Antennal and behavioral responses to male-produced volatiles

Coupled GC-EAG techniques have been applied to the study of volatiles from the grain weevil,Sitophilus granarius. for the first time. The size of EAG response was independent of the sex of the responding insect but was consistently larger to extracts of males than those of females. This difference was reflected in a behavioral preference for the male extracts by mated adults of both sexes tested together and virgin adults of both sexes tested separately. The GC-EAG results provide evidence for two materials that are released specifically by the males. Using circular dichroism. one has been found to be identical stereochemically with the (2S,3R)-sitophilate reported by others as the aggregation pheromone in a different strain. This enhances the prospects for the development of a single pheromone lure that would be generally applicable whatever the origin of the strain. The small amount of sitophilate found in the males suggests that it is not stored in large amounts. The other material, present in such a small amount that it has yet to be fully characterized, elicits a higher antennal activity than sitophilate and may have a significant role to play in enhancing the trap catch of this economically important pest.

Evaluation of a bacterial algal control agent in tank-based experiments

A bacterial-based bioremediation product, LakeRelief™ by Novozymes (Waterguru LakeRelief, 2011), was tested in a series of experiments between October 2008 and March 2009 to evaluate its suitability as a short-term intervention technique to reduce algal blooms in the Swan-Canning River system. Results from fibreglass tank experiments (1100 L) suggested that the product did not actively attack and lyse algal cells. The product decreased NH(4) and NO(x) concentrations in treated tanks, both aerated and non-aerated. Product application decreased PO(4) concentrations in non-aerated tanks but not in aerated tanks. The product appeared to suppress algal growth in non-aerated tanks over short periods (several days). Algal growth regularly diminished after product application but reappeared shortly afterwards. Aeration had a negative effect on bacterial proliferation in the tanks, possibly through alteration of environmental conditions (e.g. water mixing). As a consequence of the environmental conditions in the tanks being counterproductive to the development of a representative microbial composition, several aspects regarding the product's effectiveness could not be assessed satisfactorily in the tank experiments. The importance of long-term nutrient immobilisation into a well developed food web and the subsequent nutrient removal through removal of the top order organisms is highlighted.

A placental phenotype for intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy specific liver disease associated with significant risk of fetal complications. It is hypothesised that the risk of adverse fetal outcomes relates to the toxic effects of bile acids, the levels of which are increased in both maternal and fetal serum. Human and rodent studies have shown that transplacental transfer of bile acids is impaired in ICP. Furthermore, the morphology of placentas from the rodent model of ICP is markedly abnormal, and is associated with increased expression of apoptotic markers and oxidative stress. Using placental tissue from ICP cases and normal pregnancies and cultured placental explant fragments we investigated the histological and molecular effects of cholestasis. We also examined the influence of ursodeoxycholic acid (UDCA) administration on these parameters. Here we report that ICP is associated with several morphological abnormalities of the placenta, including an increase in the number of syncytial knots, and that these can be reproduced in an in vitro (explant) model exposed to the bile acids taurocholic acid and taurochenodoexycholic acid. Furthermore, we demonstrate that ursodeoxycholic acid, a drug commonly used in the management of ICP, has a protective effect on placental tissue both in vivo and in vitro.

Cardiovascular screening for men at high risk in Heart of Birmingham Teaching Primary Care Trust: the 'Deadly Trio' programme

BACKGROUND

The Deadly Trio programme offered cardiovascular health checks to men over 40 in inner-city Birmingham. The aim was to increase diagnosis of diabetes, cardiovascular and kidney disease among this deprived and ethnically diverse population. Either patients' own general practitioners (GPs) were paid to provide health checks or patients were invited to an alternative provider.

METHODS

Routine data were sought from 68 participating practices. Logistic regression analysis was undertaken to determine the patient and practice factors associated with being screened and with being added to a disease register.

RESULTS

Data were obtained from 58 practices; 5871 (24.3%) of 24 166 eligible men were screened. Screening uptake was higher in those with a recorded phone number, South Asians and Blacks but lower in smokers. Compared to the alternative provider, uptake was higher among men registered with single-handed (but not multi-partner) GPs paid to provide health checks. South Asian, older and screened men were more often added to disease registers. Men with missing information and GP-screened men were less likely to be added to registers.

CONCLUSIONS

The programme achieved higher screening uptake and diagnosis of disease among minority ethnic men. Single-handed GPs paid to provide screening (and their patients) were more responsive than multi-partner practices.

Aspirin resistance determined from a bed-side test in patients suspected to have acute coronary syndrome portends a worse 6 months outcome

BACKGROUND

Coronary patients resistant to aspirin may have increased risk for ischemic events. Little data were available for patients presenting acutely with chest pain.

METHODS AND RESULTS

We used the VerifyNow Aspirin to determine aspirin responsiveness of 314 patients regularly taking aspirin 75-300 mg daily for >or=4 weeks who presented with suspected acute coronary syndrome in Emergency Department. Aspirin resistance was defined as an aspirin reaction unit (ARU) >or=550, and the clinical team was blinded to the ARU reading. The pre-specified study endpoints were the diagnosis of acute myocardial infarction (AMI) for the index admission and major adverse cardiac events including cardiovascular death or recurrent acute coronary syndrome requiring hospitalization within 6 months. Aspirin resistance was noted in 30 (9.6%) patients. There was no difference in the diagnosis of AMI for the index presentation (3/30, 10% vs. 25/284, 8.8%, P = 0.91). Among the 312 hospital survivors, aspirin resistant patients had increased adverse events over 6 months with an overall hazard ratio of 10.0 [95% confidence interval (CI) 4.6-22.0]. After adjusted for elevated Troponin-T, the only confounder in the model, the hazard ratio was 11.1 (95% CI 4.7-26.0). Results were similar in patients treated only medically without revascularization (adjusted hazard ratio 12.1, 95% CI 4.7-26.4). The increased events were observed both from discharge to 30 days and from 30 days to 6 months.

CONCLUSION

Aspirin resistance occurs in approximately 10% of patients presenting with suspected acute coronary syndrome and is associated with adverse cardiac events.

What factors predict differences in infant and perinatal mortality in primary care trusts in England? A prognostic model

OBJECTIVE

To identify predictors of perinatal and infant mortality variations between primary care trusts (PCTs) and identify outlier trusts where outcomes were worse than expected.

DESIGN

Prognostic multivariable mixed models attempting to explain observed variability between PCTs in perinatal and infant mortality. We used these predictive models to identify PCTs with higher than expected rates of either outcome.

SETTING

All primary care trusts in England. Population For each PCT, data on the number of infant and perinatal deaths, ethnicity, deprivation, maternal age, PCT spending on maternal services, and "Spearhead" status.

MAIN OUTCOME MEASURES

Rates of perinatal and infant mortality across PCTs.

RESULTS

The final models for infant mortality and perinatal mortality included measures of deprivation, ethnicity, and maternal age. The final model for infant mortality explained 70% of the observed heterogeneity in outcome between PCTs. The final model for perinatal mortality explained 80.5% of the between-PCT heterogeneity. PCT spending on maternal services did not explain differences in observed events. Two PCTs had higher than expected rates of perinatal mortality.

CONCLUSIONS

Social deprivation, ethnicity, and maternal age are important predictors of infant and perinatal mortality. Spearhead PCTs are performing in line with expectations given their levels of deprivation, ethnicity, and maternal age. Higher spending on maternity services using the current configuration of services may not reduce rates of infant and perinatal mortality.

Failure to transmit scrapie infection by transferring preimplantation embryos from naturally infected donor sheep

The objective of the study was to examine whether or not the preimplantation embryo can act as a carrier of classic scrapie infection. The study was carried out on quarantined premises with sheep of highly susceptible scrapie genotypes. Uninfected embryos, collected from New Zealand-derived Suffolk ewes, were surgically transferred into recipient ewes that were also of New Zealand origin. Seventeen negative control lambs were born on the study premises from these embryo transfers. Thirty-nine experimental lambs were from embryos collected from naturally infected donor ewes. The experimental lambs were also born on the study premises after their surgical transfer into recipient ewes of New Zealand origin. These embryos had been collected from donor ewes in a scrapie-infected flock where the ewes were clinically sick with scrapie or developed clinical scrapie after embryo collection. All lambs were confirmed as scrapie susceptible of the ARQ/ARQ genotype. Twenty-eight experimental animals survived to the end point of the study at 5 yr of age with a mean survival of 1579 d. In the negative control group, 12 of 17 sheep survived to 5 yr of age with a mean survival of 1508 d. Postmortem examinations were carried out on all animals derived by embryo transfer, and in none was histologic or immunohistochemical evidence of scrapie found. In contrast, in the originating flock the majority of scrapie cases occurred in ARQ/ARQ genotyped animals where a 56% mortality from scrapie had been recorded in animals of this genotype. Thus, the study provides no evidence for transmission of scrapie and reinforces published evidence that vertical transmission of scrapie may be circumvented by embryo transfer procedures.

Contribution of variant alleles of ABCB11 to susceptibility to intrahepatic cholestasis of pregnancy

BACKGROUND

Intrahepatic cholestasis of pregnancy (ICP) has a complex aetiology with a significant genetic component. ABCB11 encodes the bile salt export pump (BSEP); mutations cause a spectrum of cholestatic disease, and are implicated in the aetiology of ICP.

METHODS

ABCB11 variation in ICP was investigated by screening for five mutant alleles (E297G, D482G, N591S, D676Y and G855R) and the V444A polymorphism (c.1331T>C, rs2287622) in two ICP cohorts (n = 333 UK, n = 158 continental Europe), and controls (n = 261) for V444A. PCR primers were used to amplify and sequence patient and control DNA. The molecular basis for the observed phenotypes was investigated in silico by analysing the equivalent residues in the structure of the homologous bacterial transporter Sav1866.

RESULTS

E297G was observed four times and D482G once. N591S was present in two patients; D676Y and G855R were not observed. The V444A polymorphism was associated with ICP (allelic analysis for C vs T: OR 1.7 (95% CI 1.4 to 2.1, p<0.001)). In addition, CC homozygotes were more likely to have ICP than TT homozygotes: OR 2.8 (95% CI 1.7 to 4.4 p<0.0001). Structural analyses suggest that E297G and D482G destabilize the protein fold of BSEP. The molecular basis of V444A and N591S was not apparent from the Sav1866 structure.

CONCLUSIONS

Heterozygosity for the common ABCB11 mutations accounts for 1% of European ICP cases; these two mutants probably reduce the folding efficiency of BSEP. N591S is a recurrent mutation; however, the mechanism may be independent of protein stability or function. The V444A polymorphism is a significant risk factor for ICP in this population.

150 THE ROLE OF THE PRE-IMPLANTATION EMBRYO IN THE VERTICAL TRANSMISSION OF NATURAL SCRAPIE INFECTION IN SHEEP

The objective of this study was to examine whether or not the pre-implantation embryo can act as a carrier of scrapie. The study was carried out on quarantined premises with sheep of highly susceptible scrapie genotypes. Fifty-seven lambs were produced from embryos collected from donor ewes. These donor ewes were in a scrapie-infected flock and became clinically sick with scrapie or developed clinical scrapie after embryo collection. Fifty of the generated lambs were confirmed as having scrapie-susceptible genotypes with 48 animals identified as ARQ/ARQ and 2 as ARQ/ARH. The respective mean and median ages for the 57 scrapie-susceptible experimental offspring in the study were 1565 and 1826 days. Forty-one of these animals survived to the end point of the study at 5 years of age. In a negative control group the mean and median ages at death for the 17 sheep were 1500 and 1826 days, respectively, and 12 survived to 5 years of age. Post-mortem examinations were carried out on all animals derived by embryo transfer and in none was histological or immunohistochemical evidence of scrapie found. In contrast, in the originating infected flock the majority of scrapie cases occurred in ARQ/ARQ genotyped animals with 56% mortality from scrapie in animals of this genotype. Thus, the study provides no evidence for transmission of scrapie and reinforces published evidence that vertical transmission of scrapie may be circumvented by embryo transfer procedures. This study was commissioned and financially supported by Defra. Amongst the many involved in the study the authors particularly wish to acknowledge Jon Hunton, James Mylne, Tony Wrathall and Chris Lewis. Keith Chalmers Watson is thanked for his interest and for the land rental that made the work feasible.

Rapid method for the detection of storage mites in cereals: feasibility of an ELISA based approach

This paper describes the development of rapid immunodiagnostic tests for the detection of storage mite infestations in cereals and cereal products. The study's first phase (proof of concept) involved the production of a species-specific enzyme-linked immunoassay (ELISA) for the flour mite, Acarus siro (L.), a major pest of stored commodities. The specificity of this new assay was assessed against key stored product contaminants (13 species of mites of which three were predatory, five species of insects and five species of fungi) in the presence and absence of grain. The assay was species-specific (no cross-reactivity to other storage contaminants) and was unaffected by the presence of cereal antigens in the extract. In the study's second phase, species- and genera-specific ELISAs were developed for a range of key storage mite pests: the cosmopolitan food mite (Lepidoglyphus destructor), the grocers' itch mite (Glycyphagus domesticus), the grainstack mite (Tyrophagus longior), mites of the Tyrophagus and Glycyphagus generas, and all storage mites. All tests were demonstrably specific to target species or genera, with no cross-reactions observed to other storage pest contaminants or cereals. The final, validation phase, involved a comparative assessment of the species-specific A. siro and the genus-specific Tyrophagus ELISAs with the flotation technique using laboratory and field samples. Both ELISAs were quantitative (0-30 mites per 10 g wheat) and produced good comparative data with the flotation technique (A. siro r(2)=0.91, Tyrophagus spp. r(2)=0.99).

Fractional delay estimation for blind source separation and localization of temporomandibular joint sounds

Temporomandibular joint (TMJ) sound sources are generated from the two joints connecting the lower jaw to the temporal bone. Such sounds are important diagnostic signs in patients suffering from temporomandibular disorder (TMD). In this study, we address the problem of source separation of the TMJ sounds. In particular, we examine patients with only one TMJ generating "clicks". Thereafter, we consider the TMJ sounds recorded from the two auditory canals as mixtures of clicks from the TMD joint and the noise produced by the other healthy/normal TMJ. We next exploit the statistical nonstationary nature of the TMJ signals by employing the degenerate unmixing estimation technique (DUET) algorithm, a time-frequency (T-F) approach to separate the sources. As the DUET algorithm requires the sensors to be closely spaced, which is not satisfied by our recording setup, we have to estimate the delay between the recorded TMJ sounds to perform an alignment of the mixtures. Thus, the proposed extension of DUET enables an essentially arbitrary separation of the sensors. It is also shown that DUET outperforms the convolutive Infomax algorithm in this particular TMJ source separation scenario. The spectra of both separated TMJ sources with our method are comparable to those available in existing literature. Examination of both spectra suggests that the click source has a better audible prominence than the healthy TMJ source. Furthermore, we address the problem of source localization. This can be achieved automatically by detecting the sign of our proposed mutual information estimator which exhibits a maximum at the delay between the two mixtures. As a result, the localized separated TMJ sources can be of great clinical value to dental specialists.

Comparison of the relative analgesic efficacies of epidural or intramuscular diamorphine following total knee arthroplasty

BACKGROUND AND OBJECTIVES

Debate has proliferated as to the true site of action of opioids when placed in the epidural space. The aim of this study was to compare the analgesic effects of a bolus of diamorphine given by the epidural or intramuscular route.

METHODS

Sixty patients having elective primary total knee replacements were recruited and randomized to receive epidural or intramuscular diamorphine. A lumbar epidural catheter was sited and 10 mL of bupivacaine 0.5% wt vol-1 was injected. Patients subsequently received diamorphine 5 mg into the epidural space or as an intramuscular injection. Patient-controlled analgesia with intravenous morphine was used for postoperative analgesia. The primary outcome measures included time to first patient-controlled analgesia use and total morphine consumption in 24 h. Secondary end-points considered possible treatment complications.

RESULTS

All primary end-points showed significant differences in favour of epidural diamorphine. Medians for times to first patient-controlled analgesia use and total 24 h morphine requirements were significantly different (P < 0.001) at 418 vs. 198 min and 11 vs. 39 mg, respectively. There were no significant differences in secondary end-points.

CONCLUSIONS

This study has shown the superior analgesic efficacy of epidural diamorphine when compared to intramuscular injection.

2-Aminopyridine—a label for bridging of oligosaccharides HPLC profiling and glycoarray printing

2-Aminopyridine derivatives of oligosaccharides (OS-AP) were printed onto microchips by two different ways. The first method is based on direct covalent insertion of OS-AP in polyacrylamide gel 3D chip. The second method is based on conversion of OS-AP into more reactive OS-aminoalditol followed by covalent printing onto NHS-activated glass slides. This approach extends the range of saccharides suitable for covalent printing due to availability of commercial OS-AP and easy high-performance liquid chromatography separation of glycoprotein N-chains in form of AP derivatives.

Reduced fear and aggression and altered serotonin metabolism in Gtf2ird1-targeted mice

The GTF2IRD1 general transcription factor is a candidate for involvement in the varied cognitive and neurobehavioral symptoms of the microdeletion disorder, Williams-Beuren syndrome (WBS). We show that mice with heterozygous or homozygous disruption of Gtf2ird1 exhibit decreased fear and aggression and increased social behaviors. These findings are reminiscent of the hypersociability and diminished fear of strangers that are hallmarks of WBS. Other core features of WBS, such as increased anxiety and problems with spatial learning were not present in the targeted mice. Investigation of a possible neurochemical basis for the altered behaviors in these mice using high-performance liquid chromatography analysis showed increased levels of serotonin metabolites in several brain regions, including the amygdala, frontal cortex and parietal cortex. Serotonin levels have previously been implicated in fear and aggression, through modulation of the neural pathway connecting the prefrontal cortex and amygdala. These results suggest that hemizygosity for GTF2IRD1 may play a role in the complex behavioral phenotype seen in patients with WBS, either individually, or in combination with other genes, and that the GTF2I transcription factors may influence fear and social behavior through the alteration of neurochemical pathways.

Fluorine-18 fluorodeoxyglucose positron emission tomography in the preoperative staging of thoracic oesophageal and gastro-oesophageal junction cancer: a prospective study

BACKGROUND

The pre-operative staging in oesophageal cancer is often challenging and underestimation of the extent of the disease may lead to unnecessary surgery.

AIM

To audit the use and assess the value of fluorine-18 fluorodeoxyglucose positron emission tomography ((18)F FDG-PET) as a staging tool for thoracic oesophageal and gastro-oesophageal junction (GOJ) cancers in our oncological surgical practice.

PATIENTS AND METHODS

Over a 3 year period, between 2002 and 2004, 134 patients with thoracic oesophageal or GOJ cancer were referred to our unit for treatment. The standard preoperative staging investigation in all cases was CT (thorax, abdomen and pelvis). A preoperative FDG-PET scan was further requested in 22 patients. The case notes of all the patients that underwent a FDG-PET scan were reviewed and compared with the preoperative imaging, the operative findings and the histopathology of the resected tumours.

RESULTS

Eighteen men and 4 women with a median age of 65 (range 43-79) years were studied. After FDG-PET, 13 out of 22 patients (59%) were deemed suitable for tumour resection. Twelve of the 13 patients were fit to undergo surgery. At laparotomy, 2 of those (17%) were found inoperable due to widespread disease. The sensitivity of CT versus FDG-PET to detect infiltrated lymph nodes was 29% (95% CI: 3-70) versus 71% (95% CI: 29-96) (P=0.0412), whereas both tests had 67% specificity (95% CI: 9-99) in detecting lymph nodes. The sensitivity and the specificity of CT versus FDG-PET to detect distant organ metastases (M1b) were 33% (95% CI: 4-77) and 88% (95% CI: 47-99) versus 50% (95% CI: 6-93) and 100% (95% CI: 69-100), respectively (P>0.05). The FDG-PET regarding the N and M status differed from the CT in 11 patients and led to modification of the planned management in 5 of them.

CONCLUSIONS

FDG-PET is more accurate than CT in defining N and M status. It can result in a reduction of unnecessary surgery in a significant number of patients. The combined PET-CT scan as a single imaging modality is expected to further improve diagnostic accuracy of FDG-PET.

Role of non-invasive imaging in the management of coronary artery disease: an assessment of likely change over the next 10 years. A report from the British Cardiovascular Society Working Group

Coronary angiography has been the gold standard for determining the severity, extent and prognosis of coronary atheromatous disease for the past 15-20 years. However, established non-invasive testing (such as myocardial perfusion scintigraphy and stress echocardiography) and newer imaging modalities (multi-detector x ray computed tomography and cardiovascular magnetic resonance) now need to be considered increasingly as a challenge to coronary angiography in contemporary practice. An important consideration is the degree to which appropriate use of such techniques impacts on the need for coronary angiography over the next 10-15 years. This review aims to determine the role of the various investigation techniques in the management of coronary artery disease and their resource implications, and should help determine future service provision, accepting that we are in a period of significant technological change.