Canine-specific tail-in, head-out sperm agglutination.

An interesting pattern of tail-in, head-out sperm agglutination was identified in a Brucella canis seronegative subfertile dog. Centrifuged seminal plasma from this dog could induce a similar pattern of agglutination in six other dogs, but not in ejaculates from a single stallion and two rams. The agglutination pattern was short-lived and appeared to depend on motility of spermatozoa, although intensity of agglutination may have been affected by concentration of agglutinating factor.

Comment on 'Temperature dependent optical properties of PbS nanocrystals'.

We address erroneous statements made by Nordin et al (2012 Nanotechnology 23 275701) claiming the inadequacy of an expression we, Ullrich et al (2011 Appl. Phys. Lett. 99 081901), used to fit the temperature dependence of the photoluminescence and the absorption of PbS quantum dots. We further correct a quote by Nordin et al, who, when referring to our work, mistakenly claimed temperature invariance of the Stokes shift.

Compositional analysis of mixed-cation-anion III-V semiconductor interfaces using phase retrieval high-resolution transmission electron microscopy.

Employing exit-plane wave function (EPWF) reconstruction in high-resolution transmission electron microscopy (HRTEM), we have developed an approach to atomic scale compositional analysis of III-V semiconductor interfaces, especially suitable for analyzing quaternary heterostructures with intermixing in both cation and anion sub-lattices. Specifically, we use the focal-series reconstruction technique, which retrieves the complex-valued EPWF from a thru-focus series of HRTEM images. A study of interfaces in Al(0.4)Ga(0.6)As-GaAs and In(0.25)Ga(0.75)Sb-InAs heterostructures using focal-series reconstruction shows that change in chemical composition along individual atomic columns across an interface is discernible in the phase image of the reconstructed EPWF. To extract the interface composition profiles along the cation and anion sub-lattices, quantitative analysis of the phase image is performed using factorial analysis of correspondence. This enabled independent quantification of changes in the In-Ga and As-Sb contents across ultra-thin interfacial regions (approximately 0.6 nm wide) with true atomic resolution, in the In(0.25)Ga(0.75)Sb-InAs heterostructure. The validity of the method is demonstrated by analyzing simulated HRTEM images of an InAs-GaSb-InAs model structure with abrupt and graded interfaces. Our approach is general, permitting atomic-level compositional analysis of heterostructures with two species per sub-lattice, hitherto unfeasible with existing HRTEM methods.

Intensive training over 5 days improves colonoscopy skills long-term.

BACKGROUND AND AIMS: Poor standards in colonoscopy services and the introduction of a colorectal cancer screening program in the United Kingdom have highlighted the need to establish high-quality training and competency assessments in colonoscopy. The aims of this study were to evaluate the effectiveness of a 1-week hands-on colonoscopy course utilizing novel assessment tools. METHODS: Twenty-one doctors with varying colonoscopy experience who attended an accelerated colonoscopy training week (ACTW) were prospectively studied. They were trained and assessed in key aspects of colonoscopy. Knowledge was assessed with a multiple choice question (MCQ) paper. Practical hand skills were taught and evaluated using a computer simulator and live case teaching. Actual colonoscopy performance was assessed using Direct Observation of Procedural Skills scores (DOPS) and an objective tri-split video score of insertion technique. Two independent trainers taught and assessed the trainees at the start and end of the ACTW and at a median of 9 months' follow-up. RESULTS: Following training there were significant improvements in the MCQ score (P < 0.001), the simulator test case times (P = 0.02, P = 0.003), and the global DOPS score (P < or = 0.02). All improvements following the accelerated training were sustained at a median follow-up of 9 months. CONCLUSIONS: This study is the first in the literature to describe the positive, sustained impact of an intensive hands-on colonoscopy training course. Measurements of performance in key areas of skill acquisition improved following training.

Prevention of the gastrointestinal adverse effects of nonsteroidal anti-inflammatory drugs: the role of proton pump inhibitors.

The associations between nonsteroidal anti-inflammatory drugs (NSAIDs) and the presence and complications of gastroduodenal erosions and ulcers are well established. Evidence that acid aggravates NSAID-induced injury provides a rationale for minimising such damage by acid suppression. Other strategies discussed include avoidance of NSAIDs or minimising their dosage, selecting NSAIDs known to cause less damage, and co-prescription of various agents. Cytoprotection with misoprostol, a prostaglandin analogue, has been shown to be effective in reducing NSAID-related peptic ulcers and their complications. Unfortunately, adverse effects may limit compliance in some patients. Histamine H2 antagonists have only limited efficacy in the prevention of NSAID-induced ulcers in humans, particularly in the stomach, except at higher than standard dosages. This may relate to their relatively modest effect in elevating gastric pH, especially in comparison with proton pump inhibitors. Several studies now confirm the efficacy of proton pump inhibitors in the short and longer term prevention of NSAID-induced upper gastrointestinal injury. Placebo-controlled studies suggest reductions of over 70% in gastric and duodenal ulcer rates over 3 to 6 months. The recent ASTRONAUT (Acid Suppression Trial: Ranitidine versus Omeprazole for NSAID-Associated Ulcer Treatment) study documented the greater prophylactic efficacy of omeprazole over ranitidine at standard dosages for 6 months. The OMNIUM (Omeprazole versus Misoprostol for NSAID-Induced Ulcer Management) study showed omeprazole to be slightly more effective overall than misoprostol in preventing the upper gastrointestinal adverse effects of NSAIDs, with both substantially more effective than placebo, although misoprostol was somewhat less well tolerated. Although substantial reductions in NSAID ulceration are now achievable when co-therapy with a proton pump inhibitor is given, a few patients will still develop ulcers and their complications. Hence the judicious use of NSAIDs in the first instance cannot be overemphasised.

Transforming growth factor-beta 2 both stimulates and inhibits neurogenesis of rat cerebellar granule cells in culture.

Transforming growth factor-beta 2 (TGF beta 2) is expressed in the developing cerebellar cortex during the period of granule cell proliferation and maturation. However, the role of TGF beta 2 in granule cell development is confused by conflicting observations regarding TGF beta 2 control of neurogenesis. To resolve these conflicts and determine the effect of TGF beta 2 on neurogenesis, rat cerebellar granule cell cultures were treated with TGF beta 2 (0.1-100 ng/ml, 24 h) in the presence or absence of exogenous serum. Neuroblast proliferation was quantified by bromodeoxyuridine and [3H]thymidine incorporation. TGF beta 2 stimulated proliferation to 220% of controls in the presence of serum (ED50 = 0.4 ng/ml) based on bromodeoxyuridine labeled granule cell counts. In contrast, in serum free medium, TGF beta 2 inhibited proliferation 75% (ED50 = 0.7 ng/ml). DNA synthesis measured by [3H]thymidine incorporation was increased to 122% in the presence of serum factors, but inhibited 70% in serum free medium, as a result of TGF beta 2 activity. Thus, TGF beta 2 differentially regulates neurogenesis of cerebellar granule cells depending on the presence of exogenous, undefined regulatory factors derived from serum. This suggests that TGF beta 2 activity in cerebellar neurogenesis is complex as it may be modulated by the repertoire of other endogenous regulatory factors in the developing cerebellar cortex.

Transforming growth factor-beta2 increases NMDA receptor-mediated excitotoxicity in rat cerebral cortical neurons independently of glia.

The ability of transforming growth factor-beta2 (TGFbeta2) to directly regulate neuronal sensitivity to glutamate and N-methyl-D-aspartate (NMDA) excitotoxicity in rat cerebral cortical neurons was investigated. Mixed neuronal-glial cultures treated with TGFbeta2 (1-10 ng/ml) exhibited a significant 25-50% increase in neuronal death compared to control cultures. TGFbeta2 potentiation of this endogenous glutamate excitotoxicity was blocked by the selective NMDA receptor antagonist, 2-amino-5-phosphonovalerate. In addition, neuronal death induced by brief NMDA exposure in both mixed neuronal-glial and pure neuronal cultures was increased by TGFbeta2 (1-30 ng/ml) with a similar dose-response curve. These findings indicate that TGFbeta2, at physiologically relevant concentrations, potentiates NMDA receptor-mediated excitotoxicity and that this occurs independently of TGFbeta2 effects on glia.

Separation of speech from interfering sounds based on oscillatory correlation.

A multistage neural model is proposed for an auditory scene analysis task--segregating speech from interfering sound sources. The core of the model is a two-layer oscillator network that performs stream segregation on the basis of oscillatory correlation. In the oscillatory correlation framework, a stream is represented by a population of synchronized relaxation oscillators, each of which corresponds to an auditory feature, and different streams are represented by desynchronized oscillator populations. Lateral connections between oscillators encode harmonicity, and proximity in frequency and time. Prior to the oscillator network are a model of the auditory periphery and a stage in which mid-level auditory representations are formed. The model has been systematically evaluated using a corpus of voiced speech mixed with interfering sounds, and produces improvements in terms of signal-to-noise ratio for every mixture. The performance of our model is compared with other studies on computational auditory scene analysis. A number of issues including biological plausibility and real-time implementation are also discussed.

The management of porphyria in dental practice.

From time to time a patient may attend your practice with a systemic condition that you may or may not remember from the small print of your undergraduate text books. This paper describes one such systemic condition, porphyria, and its dental management. This paper also describes the use of relative analgesia as an aid to anxiety management in porphyria.

Root extrusion, a practical solution in complicated crown-root incisor fractures.

Implants and fixed and removable prostheses are very successful in replacing missing units but their cost can be inhibitory to a number of patients. In addition fixed and removable prostheses can be destructive to sound abutment teeth and can result in damage to dental and soft tissue. This report describes the restoration of a tooth with a complicated incisor crown-root fracture that extended below both the gingival cuff and the alveolar crest, by using remaining tooth tissue. The restoration was completed after root extrusion with a cast post, diaphragm and core, and porcelain crown.

Comparison of terbinafine and clotrimazole in treating tinea pedis.

OBJECTIVE: To compare the efficacy and safety of terbinafine 1% cream and clotrimazole 1% cream in the treatment of tinea pedis. DESIGN: Multicentre, double blind parallel group study. SETTING: 32 general practices and one hospital. PATIENTS: 256 patients with mycologically confirmed tinea pedis. Of the 211 patients evaluable, 107 were randomised to terbinafine (75 male, 32 female; mean (range) age 40 (12-81) years) and 104 to clotrimazole (79 male, 25 female; mean (range) age 36 (12-71) years). INTERVENTIONS: Terbinafine 1% cream applied twice daily for one week and inert cream applied twice daily for the next three weeks. Clotrimazole 1% cream applied twice daily for four weeks. MAIN OUTCOME MEASURES: Mycological cure (negative results on microscopy and culture) and effective treatment (mycological cure plus no or minimal signs and symptoms) measured at weeks 1, 2, 3, 4, and 6. RESULTS: At week four rates of mycological cure were 93.5% for terbinafine and 73.1% for clotrimazole (p = 0.0001); and at week six 97.2% for terbinafine and 83.7% for clotrimazole (p = 0.001). Rates of effective treatment at week 4 were 89.7% for terbinafine and 58.7% for clotrimazole (p = 0.0001); and 89.7% for terbinafine and 73.1% for clotrimazole (p = 0.002) at week 6. CONCLUSION: These results indicate that a one week course of terbinafine 1% cream is more effective in the treatment of tinea pedis than a four week course of clotrimazole 1% cream, both in terms of mycological cure and effective treatment.

Computational auditory scene analysis: listening to several things at once.

The problem of distinguishing particular sounds, such as conversation, against a background of irrelevant noise is a matter of common experience. Psychologists have studied it for some 40 years, but it is only comparatively recently that computer modelling of the phenomenon has been attempted. This article reviews progress made, possible practical applications, and prospects for the future.

Capsule endoscopy versus magnetic resonance enterography for the detection of small bowel polyps in Peutz-Jeghers syndrome.

Our study aimed to assess the diagnostic utility of magnetic resonance enterography (MRE) compared to capsule endoscopy (CE) for the detection of small bowel polyps in patients with Peutz-Jeghers syndrome (PJS); with findings verified by balloon enteroscopy (BE). Adult patients were prospectively recruited across two tertiary centres and underwent MRE followed by CE, with a subsequent BE performed in patients with significant (≥10 mm) polyps. The primary endpoint was the total number of significant (≥10 mm) small bowel polyps detected. The number of patients with at least one significant polyp, correlation with BE findings, and patients' preferences were secondary endpoints. A total of 20 patients (7 male; mean age 34.9 years) underwent both investigations. The number of polyps ≥10 mm detected by CE was greater than by MRE (47 vs 14 polyps, P = 0.02). The number of patients with at least one significant polyp identified by CE was 11 (55 %) compared with 7 (35 %) identified by MRE (P = 0.25). Subsequent BE in 12 patients identified a total of 26 significant polyps in 8 patients. The positive predictive value of finding a polyp at BE was higher for MRE (100 %) compared to CE (60 %). Overall patient preferences identified CE as the preferred modality. This prospective study demonstrated that CE identifies significantly more small bowel polyps compared with MRE in patients with PJS. Correlation between the two techniques and subsequent BE however was relatively poor.

Note: Phase sensitive detection of photoluminescence with Fourier transform spectroscopy.

Although known for more than twenty years, there is limited information in the literature regarding the experimental parameters of lock-in based phase sensitive emission detection in conjunction with Fourier spectrometers. For this technique - also known as double modulation spectroscopy - we present a guideline for parameter optimization by measuring the photoluminescence of InSb:Te at cryogenic temperatures.

Light scattering by inclusions in crystals.

Optical transmission data can aid in the analysis of nonabsorbing inclusions in crystals. For illustration, the inclusions in a AgGaSe(2) sample are analyzed.

Mesenteric panniculitis.

We have reviewed the case of a young man with an omental mass diagnosed as mesenteric panniculitis. The clinical history, physical findings, and laboratory and radiologic studies were typical of this disorder. The diagnosis was suggested by CT scan, and confirmed on surgical biopsy. Our patient has had the typically benign course seen with mesenteric panniculitis.