Results of ambulatory pH monitoring do not reliably predict response to therapy in patients with eosinophilic oesophagitis

BACKGROUND

The consensus statements for eosinophilic oesophagitis recommend that ambulatory pH monitoring is one means of determining if gastro-oesophageal reflux is the cause of oesophageal eosinophilia and should guide pharmacological therapy.

AIM

To evaluate prospectively the accuracy of pH monitoring as a predictor of endoscopic, histological and symptomatic response in patients with oesophageal eosinophilia.

METHODS

We conducted a prospective trial in which patients with oesophageal eosinophilic infiltration with ≥15 eos/hpf underwent a 24-h pH study and were placed in one of two treatment arms for 6 weeks based on positive or negative results. Patients with abnormal acid exposure were treated with esomeprazole 40 mg twice daily and others were treated with oral viscous budesonide 1 g twice daily. Response to treatment was assessed by oesophageal histology (<5 eos/hpf) and symptoms.

RESULTS

A total of 51 patients were enrolled in the study. The average patient age was 39 years and 31 patients (61%) were male. The average number of eosinophils per hpf, prior to study enrolment was 41.2 (range 15-140, s.d. 27.7). Nineteen (37%) had positive pH studies and 32 (63%) had negative pH studies. Eighteen patients completed treatment with esomeprazole. Only eleven (61%) had histological response and, of these eleven, five (46%) had symptomatic improvement. A total of 28 patients with normal acid exposure completed treatment with budesonide. Only 16 (57%) had histological and 11 (69%) had symptomatic improvement.

CONCLUSION

In this prospective trial of pH-guided treatment, neither positive nor negative results of initial pH monitoring accurately predicted response to therapy.

Ultrasound-guided bilateral dual transversus abdominis plane block: a new four-point approach

BACKGROUND

We describe a new ultrasound-guided bilateral dual transversus abdominis plane block. Our hypothesis was that we could anaesthetize both the upper (Th6-Th9) and the lower (Th10-Th12) abdominal wall bilaterally using a four-point single-shot technique to provide effective post-operative analgesia.

METHODS

A prospective cohort of 25 recovery room patients was included. They had undergone major open or laparoscopic abdominal surgery under general anaesthesia and had severe post-operative pain. The blocks were conducted using a high-frequency linear transducer and a 22 G, 80-mm-long needle. The needle was inserted in-plane from medial to lateral for each injection. Fifteen millilitres of bupivacaine 2.5 mg/ml was injected at each of the four sites.

RESULTS

Block performance took on average 16 min (range 10-20 min). The 25 patients reported a reduction of their maximum pain (visual analogue scale 0-10) from a mean of 8.2 to a mean of 2.2 10 min after block performance (P<0.001). They were discharged from the post-anaesthesia care unit after an average of 34 min. Twenty-one patients (84%) did not require any i.v. opioids in the following 6 h. Sixteen patients (64%) were mobilized within 6 h after the block. Data were similar irrespective of open or laparoscopic surgery (P=0.68).

CONCLUSION

This new four-point single-shot technique was effective in decreasing severe pain after a major abdominal surgery. The block, although short-lived, facilitated discharge from the post-anaesthesia care unit, few patients required opioids on the day of surgery and mobilization was improved.

Patent data mining: a tool for accelerating HIV vaccine innovation

Global access to advanced vaccine technologies is challenged by the interrelated components of intellectual property (IP) management strategies, technology transfer (legal and technical) capabilities and the capacity necessary for accelerating R&D, commercialization and delivery of vaccines. Due to a negative association with the management of IP, patents are often overlooked as a vast resource of freely available, information akin to scientific journals as well as business and technological information and trends fundamental for formulating policies and IP management strategies. Therefore, a fundamental step towards facilitating global vaccine access will be the assembly, organization and analysis of patent landscapes, to identify the amount of patenting, ownership (assignees) and fields of technology covered. This is critical for making informed decisions (e.g., identifying licensees, building research and product development collaborations, and ascertaining freedom to operate). Such information is of particular interest to the HIV vaccine community where the HIV Vaccine Enterprise, have voiced concern that IP rights (particularly patents and trade secrets) may prevent data and materials sharing, delaying progress in research and development of a HIV vaccine. We have compiled and analyzed a representative HIV vaccine patent landscape for a prime-boost, DNA/adenoviral vaccine platform, as an example for identifying obstacles, maximizing opportunities and making informed IP management strategy decisions towards the development and deployment of an efficacious HIV vaccine.

Ultrasound-guided continuous suprascapular nerve block for adhesive capsulitis: one case and a short topical review

We present a case with an ultrasound-guided (USG) placement of a perineural catheter beneath the transverse scapular ligament in the scapular notch to provide a continuous block of the suprascapular nerve (SSN). The patient suffered from a severe and very painful adhesive capsulitis of the left shoulder secondary to an operation in the same shoulder conducted 20 weeks previously for impingement syndrome and a superior labral anterior-posterior tear. Following a new operation with capsular release, the placement of a continuous nerve block catheter subsequently allowed for nearly pain-free low impact passive and guided active mobilization by the performing physiotherapist for three consecutive weeks. This case and a short topical review on the use of SSN block in painful shoulder conditions highlight the possibility of a USG continuous nerve block of the SSN as sufficient pain management in the immediate post-operative period following capsular release of the shoulder. Findings in other painful shoulder conditions and suggestions for future studies are discussed in the text.

Ergometer rowing with and without slides

A rowing ergometer can be placed on a slide to imitate 'on-water' rowing. The present study examines I) possible differences in biomechanical and physiological variables of ergometer rowing with and without slides and II) potential consequences on training load during exercise. 7 elite oars-women rowed in a randomized order in a slide or stationary ergometer at 3 predefined submaximal and at maximal intensity. Oxygen uptake was measured and biomechanical variables of the rowing were calculated based upon handle force (force transducer) and velocity/length (potentiometer) of the stroke. Stroke frequency was higher (%-difference between conditions) at each intensity level (1-11.4%, p<0.05) during slide compared to stationary rowing. Furthermore, at the 2 highest intensities a lower mean force (4.7-9.0%, p<0.05) and max force (3.2-10.6%, p<0.05) were observed on the slide ergometer. During maximal rowing no difference was seen in heart rate, mean oxygen uptake and R-value while maximal oxygen deficit was higher (30.8%, p<0.05) during slide rowing. In conclusion the biomechanical load is lower on a slide than on a stationary ergometer. However, as a training tool the slide ergometer seems just as demanding with regard to aerobic energy sources, and for anaerobic sources possibly even higher, compared with the stationary ergometer.

Quantum noise limited and entanglement-assisted magnetometry

We study experimentally the fundamental limits of sensitivity of an atomic radio-frequency magnetometer. First, we apply an optimal sequence of state preparation, evolution, and the backaction evading measurement to achieve a nearly projection noise limited sensitivity. We furthermore experimentally demonstrate that Einstein-Podolsky-Rosen entanglement of atoms generated by a measurement enhances the sensitivity to pulsed magnetic fields. We demonstrate this quantum limited sensing in a magnetometer utilizing a truly macroscopic ensemble of 1.5x10(12) atoms which allows us to achieve subfemtotesla/square root(Hz) sensitivity.

High quality anti-relaxation coating material for alkali atom vapor cells

We present an experimental investigation of alkali atom vapor cells coated with a high quality anti-relaxation coating material based on alkenes. The prepared cells with single compound alkene based coating showed the longest spin relaxation times which have been measured up to now with room temperature vapor cells. Suggestions are made that chemical binding of a cesium atom and an alkene molecule by attack to the C = C bond plays a crucial role in such improvement of anti-relaxation coating quality.

Non-linear analysis of the structure of variability in midfoot kinematics

INTRODUCTION

Evaluation of structural variability in biological time series through measures such as sample entropy (SaEn) has provided important information in neurology and cardiology. This has contributed to the development of the "loss of complexity hypothesis" where high variability has been described as healthy flexibility and low variability associated with pathology. The purpose of this study was to calculate sample entropy (SaEn) to establish normal values of non-linear variability and to examine which factors are associated with SaEn in midfoot kinematics.

METHOD

Static foot posture was measured using Foot Posture Index. A video sequence analysis system was used to quantify midfoot kinematics during walking in the sagittal plane. SaEn was calculated for navicular drop during stand phase as an expression of the dynamic complexity.

RESULTS

A significant difference was observed between the three major foot types and between genders (p<0.001). Mean SaEn in women were 1.10+/-0.19 (supinated foot posture), 0.96+/-0.17 (neutral foot posture) and 0.77+/-0.16 (pronated foot posture) and 1.25+/-0.24 (supinated foot posture), 1.06+/-0.23 (neutral foot posture) and 0.86+/-0.19 (pronated foot posture) in males. The regression model showed that foot posture and dynamic navicular drop (dND) were both associated with SaEn.

CONCLUSION

This study confirmed that non-linear analysis is of relevance in the interpretation of kinematic data. Pronated foot posture, large navicular drop and women were characterized by low values of non-linear variability. Future studies should investigate if measurements of SaEn are capable of identifying subjects with an increased risk of injury.

Kinetic analysis of evoked IPSCs discloses mechanism of antagonism of synaptic GABAA receptors by picrotoxin

BACKGROUND AND PURPOSE

Although picrotoxin is a well-established antagonist of GABA(A) receptors, detailed studies of its action on inhibitory synaptic transmission have not previously been made.

EXPERIMENTAL APPROACH

Electrophysiological techniques were used to study the action of picrotoxin on inhibitory postsynaptic currents (IPSCs) evoked in hippocampal neurones, in culture and slice preparations prepared from Wistar rat embryos and juveniles, respectively.

KEY RESULTS

Picrotoxin gradually reduced the amplitude of GABA(A) receptor-mediated eIPSCs in a concentration-dependent manner. This was accompanied by a marked acceleration of the eIPSC decay kinetics, which, in contrast to the effect on amplitude, developed immediately and was completely reversed on washing. The decaying phase of the IPSC could be resolved into two components; 30 microM picrotoxin reduced tau(fast) by 34% and increased its relative amplitude, while tau(slow) was reduced by 38%, and its relative amplitude decreased. The area under the decaying phase of the normalized eIPSC showed an immediate reduction by 36% in 30 microM picrotoxin. With increasing concentrations of picrotoxin, this normalized area converged towards 55% of the control, indicating that the rate of relaxation and block has a finite maximum. This implies that picrotoxin does not act by a pore-occluding mechanism (open-channel blocking), and suggests allosteric stabilization of desensitized receptor states as a more likely alternative. This was corroborated by modelling, based on two established microscopic GABA(A) receptor transition schemes.

CONCLUSIONS AND IMPLICATIONS

Although the identity of the stabilized state has not been determined unequivocally, picrotoxin effectively traps synaptic GABA(A) receptors in a desensitized state.

Tuning nanoelectromechanical resonators with mass migration

We demonstrate tuning of nanoelectromechanical resonators via mass migration. Indium nanoparticles can be reversibly migrated to different locations along cantilevered multiwalled carbon nanotube resonators using electrical currents as the control parameter. Nonvolatile mass redistributions result in stable resonant frequency shifts as large as 20%. The tuning method is robust and can be utilized for nanoelectromechanical resonators operating at frequencies from audio to microwave.

Generation of two-mode squeezed and entangled light in a single temporal and spatial mode

We analyse a novel squeezing and entangling mechanism which is due to correlated Stokes and anti-Stokes photon forward scattering in a multi-level atom vapour. We develop a full quantum model for an alkali atomic vapour including quantized collective atomic states which predicts high degree of squeezing for attainable experimental conditions. Following the proposal we present an experimental demonstration of 3.5 dB pulsed frequency nondegenerate squeezed (quadrature entangled) state of light using room temperature caesium vapour. The source is very robust and requires only a few milliwatts of laser power. The squeezed state is generated in the same spatial mode as the local oscillator and in a single temporal mode. The two entangled modes are separated by twice the Zeeman frequency of the vapour which can be widely tuned. The narrow-band squeezed light generated near an atomic resonance can be directly used for atom-based quantum information protocols. Its single temporal mode characteristics make it a promising resource for quantum information processing.

The successful use of peripheral nerve blocks for femoral amputation

We present a case report of four patients with severe cardiac insufficiency where peripheral nerve blocks guided by either nerve stimulation or ultrasonography were the sole anaesthetic for above-knee amputation. The patients were breathing spontaneously and remained haemodynamically stable during surgery. Thus, use of peripheral nerve blocks for femoral amputation in high-risk patients seems to be the technique of choice that can lower perioperative risk.