Screening and confirmation of psilocin, mitragynine, phencyclidine, ketamine and ketamine metabolites by liquid chromatography-tandem mass spectrometry

A safe and productive workplace requires a sober workforce, free from substances that impair judgment and concentration. Although drug monitoring programs already exist, the scope and loopholes of standard workplace testing panels are well known, allowing other substances to remain a source of risk. Therefore, a high-throughput urine screening method for psilocin, mitragynine, phencyclidine, ketamine, norketamine and dehydronorketamine was developed and validated in conjunction with a urine and blood confirmation method. There are analytical challenges to overcome with psilocin and mitragynine, particularly when it comes to drug stability and unambiguous identification in authentic specimens. Screening and confirmation methods were validated according to the American National Standards Institute/Academy Standards Board (ANSI/ASB) Standard 036, Standard Practices for Method Validation in Forensic Toxicology. An automated liquid handling system equipped with dispersive pipette extraction tips was utilized for preparing screening samples, whereas an offline solid-phase extraction method was used for confirmation sample preparation. Both methods utilized liquid chromatography-tandem mass spectrometry to achieve limits of detection between 1-5 ng/mL for the screening method and 1 ng/mL for the confirmation method. Automation allows for faster throughput and enhanced quality assurance, which improves turnaround time. Compared to previous in-house methods, specimen volumes were substantially decreased for both blood and urine, which is an advantage when volume is limited. This screening technique is well suited for evaluating large numbers of specimens from those employed in safety-sensitive workforce positions. This method can be utilized by workplace drug testing, human performance and postmortem laboratories seeking robust qualitative screening and confirmation methods for analytes that have traditionally been challenging to routinely analyze.

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.

0573 Screening for Obstructive Sleep Apnea at Home Based on Deep Learning Features Derived from Respiration Sounds

Introduction

Analysis of sleep breathing sounds has been employed to screen obstructive sleep apnea (OSA). However, most current methods rely on specialized equipment (e.g., tracheal microphones), require additional physiological data (e.g., oxygen saturation), are rule-based, or are trained on data collected in-lab, making them less suitable for home use. In this study, deep learning methods were leveraged to explore the hypothesis that sleep audio recordings collected via smartphones can be used alone to screen for OSA by exploiting the temporal pattern of respiration sounds.

Methods

Adult participants with suspected sleep-disordered breathing of varying degrees of severity were recruited from the general population and from GP referrals to sleep clinic. Audio recordings were collected via smartphones during home sleep apnea testing (HSAT). HSAT data were scored by a registered polysomnographic technologist in accordance with current international guidelines (AASM V2.5, 2018) and used as reference. To exploit acoustic respiration temporal pattern, time interval histograms were computed for sequences of audio-words that were automatically learned from spectral features with a deep neural network. Means and standard deviations of the time intervals for each audio-word were employed by a Gaussian mixture model to classify 2-minute audio recording segments as either containing OSA events or not.

Results

Preliminary data from 4 valid nights’ recordings obtained from 2 consented participants was analysed. 550 segments were used for training, with 180 segments used for evaluation. Audio recording demonstrated a sensitivity of 0.71 and specificity of 0.66 when compared with manually-scored HSAT.

Conclusion

Preliminary results suggest that an approach to OSA screening based on deep learning with inter-audio-word intervals to capture information about respiration temporal pattern may be a useful tool in diagnosis of OSA. Further model development is underway using data collected from up to 200 patients and full study data will be presented.

Support

The project is supported by an Innovate UK grant (project number 157358). HR is supported by a joint scholarship from Passion for Life Healthcare Ltd and University of Sheffield. LH acknowledges the financial support of NHS Research Scotland (NRS), through NHS Lothian.

Vibrational Bands of the 2-Butyn-1-yl Radical

The 2-butyn-1-yl radical is an isomer of C₄H₅ and is structurally similar to the propargyl radical, which is the simplest resonance-stabilized hydrocarbon radical. The C₄H₅ radical is likely to be important to astrochemistry and combustion, similar to propargyl, yet little research has been done on its spectroscopic properties. In this work, seven vibrational bands of the 2-butyn-1-yl radical are reported. The radical was formed by pyrolysis of 1-bromo-2-butyne at 800 K and isolated in a low-temperature argon matrix. The experimentally observed frequencies and intensities of the seven vibrational bands were found to be consistent with QCISD predictions from the literature and with new B3LYP calculations in this work.

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.

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.

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.

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.

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.

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.

Cancer risk in young women at risk of hereditary nonpolyposis colorectal cancer: implications for gynecologic surveillance

OBJECTIVES

The lifetime risk of endometrial and ovarian cancers in hereditary nonpolyposis colorectal cancer (HNPCC) is up to 60 and 12%, respectively, in addition to the high risk of colorectal cancer. International guidelines recommend surveillance of those at risk with colonoscopy every 1--2 years from age 20--25 years and annual gynecologic surveillance from 25--35 years for women. We reviewed our own experience to see whether these recommendations were appropriate.

METHODS

Pedigrees of 120 HNPCC families registered with the Familial Bowel Cancer Service at The Royal Melbourne Hospital were reviewed. Ninety families met our criteria for HNPCC and were included in the study. Pedigrees were analyzed to identify early-age onset colorectal and gynecologic cancers and to calculate cumulative incidence of both cancer types for at-risk women (HNPCC-affected and first-degree female relatives of affected family members) for comparison with the general population.

RESULTS

Colorectal cancer occurred in 434 individuals, endometrial cancer in 43, and ovarian cancer in 24. Gynecologic and colorectal cancers were diagnosed at similar ages (mean 49.3 versus 51.8 years; P = 0.25), with 5 (7.1%) gynecologic cancers diagnosed by 35 years. Cumulative incidences of gynecologic and colorectal cancers to ages 25, 30, 35, and 40 years were substantially higher among at-risk women than in the general population.

CONCLUSIONS

Consideration should be given to offering gynecologic cancer surveillance from the age of 25 years, as for colorectal cancer. However, this approach should be individualized as it has yet to be demonstrated that surveillance reduces the mortality of gynecologic cancer in HNPCC.

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.

Attacking anxiety: a naturalistic study of a multimedia self-help program

The effects of a commercial multimedia self-help program (Attacking Anxiety) were evaluated by examining the outcome of 176 individuals who participated in the treatment. Results suggested that 62 individuals suffering from anxiety achieved clinically significant improvement. An additional 40 achieved reliable change, despite the fact that these individuals had suffered from anxiety-based problems for years prior to their participation. Only one participant experienced negative change. These results are discussed in relation to the growing literature on self-help interventions and the limitations imposed by the naturalistic nature of the investigation.

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.

Knot tying at flexible endoscopy

Four new knotting techniques were developed for use at flexible endoscopy: (1) half hitches tied with knot-pusher, (2) thread-locking device, (3) self-tightening slip-knot, and (4) externally releasable knot. Remoteness from site of action, access through small-diameter orifice, and difficulty in applying lateral traction to tighten knots are problems met in knot tying at endoscopy. All four knotting techniques were studied in experiments on postmortem human stomachs and used for radio-telemetry studies and anti-reflux operations in survival studies in dogs using endoscopic sewing techniques. Half hitches tied at endoscopy with a knot-pusher were also used in human studies to treat esophageal reflux and secure pH radio-telemetry capsules for long-term measurements. Externally releasable knots were used to secure nasogastric tubes to the stomach of five patients for long-term nutrition. Knot tying is feasible at flexible endoscopy by a variety of new techniques. Endoscopically tied knots can be as secure as surgically hand-tied knots and have been used successfully in man.

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.

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.

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.

A community-based study into the possible reasons for the high incidence of cardiovascular disease in the west Highland District of Lochaber

Cardiovascular screening of 726 males in a Fort William group practice was undertaken in an effort to determine possible causes for the high incidence of cardiovascular disease in the area. Sixty-four per cent of those sampled were born outside the area. The mean fasting plasma cholesterol level was surprisingly low at 5.4 mmol/l. Forty-three per cent of the sample were smokers and 22% had diastolic blood pressures above 90 mm Hg, 24% were clinically obese and 29% had a history of ischaemic heart disease amongst first degree relatives. Public awareness of cardiovascular risk factors was found to be low. A local health education programme could prove to be of great benefit.

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.

The development of permanent unidirectional anterograde block in the accessory pathway of a patient with Wolff-Parkinson-White syndrome and observations on the mechanism of the ensuing incessant circus tachycardia

A case is reported, the sixth in the literature, in which permanent anterograde block occurred in the accessory pathway of a patient with Wolff-Parkinson-White syndrome, so that pre-excitation no longer occurred. Retrograde conduction remained intact and the patient developed incessant tachycardia with ventriculo-atrial conduction occurring over the accessory pathway.

Retrogradely conducting pathways are a common cause of supraventricular tachycardia and this case raises the possibility that many of them may previously have had overt pre-excitation.