Search for muon-neutrino to electron-neutrino transitions in MINOS

This Letter reports on a search for nu(mu) --> nu(e) transitions by the MINOS experiment based on a 3.14x10(20) protons-on-target exposure in the Fermilab NuMI beam. We observe 35 events in the Far Detector with a background of 27+/-5(stat)+/-2(syst) events predicted by the measurements in the Near Detector. If interpreted in terms of nu(mu) --> nu(e) oscillations, this 1.5sigma excess of events is consistent with sin2(2theta(13)) comparable to the CHOOZ limit when |Delta m2|=2.43x10(-3) eV2 and sin2(2theta(23))=1.0 are assumed.

Hyperinsulinaemic hypoglycaemia

Hyperinsulinaemic hypoglycaemia (HH) occurs as a consequence of unregulated insulin secretion from pancreatic beta cells. In the newborn period it is the most common cause of severe and persistent hypoglycaemia. As HH is a major risk factor for brain injury and subsequent neurodevelopment handicap, the identification, rapid diagnosis and prompt management of patients with HH is essential if brain damage is to be avoided. Advances in molecular genetics, radiological imaging techniques (such as fluorine-18 L-3, 4-dihydroxyphenylalanine positron emission tomography ((18F)DOPA-PET) scanning) and laparoscopic surgery have completely changed the clinical approach to infants with the severe congenital forms of HH. This review gives an outline of the clinical presentation, the diagnostic cascade, the underlying molecular mechanisms and the management of HH with a particular focus on congenital forms of hyperinsulinism.

The genetic basis of congenital hyperinsulinism

Congenital hyperinsulinism (CHI) is biochemically characterised by the dysregulated secretion of insulin from pancreatic beta-cells. It is a major cause of persistent hyperinsulinaemic hypoglycaemia (HH) in the newborn and infancy period. Genetically CHI is a heterogeneous condition with mutations in seven different genes described. The genetic basis of CHI involves defects in key genes which regulate insulin secretion from beta-cells. Recessive inactivating mutations in ABCC8 and KCNJ11 (which encode the two subunits of the adenosine triphosphate sensitive potassium channels (ATP sensitive K(ATP) channels)) in beta-cells are the most common cause of CHI. The other recessive form of CHI is due to mutations in HADH (encoding for-3-hydroxyacyl-coenzyme A dehydrogenase). Dominant forms of CHI are due to inactivating mutations in ABCC8 and KCNJ11, and activating mutations in GLUD1 (encoding glutamate dehydrogenase) and GCK (encoding glucokinase). Recently dominant mutations in HNF4A (encoding hepatocyte nuclear factor 4alpha) and SLC16A1 (encoding monocarboxylate transporter 1) have been described which lead to HH. Mutations in all these genes account for about 50% of the known causes of CHI. Histologically there are three (possibly others which have not been characterised yet) major subtypes of CHI: diffuse, focal and atypical forms. The diffuse form is inherited in an autosomal recessive (or dominant manner), the focal form being sporadic in inheritance. The diffuse form of the disease may require a near total pancreatectomy whereas the focal form requires a limited pancreatectomy potentially curing the patient. Understanding the genetic basis of CHI has not only provided novel insights into beta-cell physiology but also aided in patient management and genetic counselling.

Search for active neutrino disappearance using neutral-current interactions in the MINOS long-baseline experiment

We report the first detailed comparisons of the rates and spectra of neutral-current neutrino interactions at two widely separated locations. A depletion in the rate at the far site would indicate mixing between nu(mu) and a sterile particle. No anomalous depletion in the reconstructed energy spectrum is observed. Assuming oscillations occur at a single mass-squared splitting, a fit to the neutral- and charged-current energy spectra limits the fraction of nu(mu) oscillating to a sterile neutrino to be below 0.68 at 90% confidence level. A less stringent limit due to a possible contribution to the measured neutral-current event rate at the far site from nu(e) appearance at the current experimental limit is also presented.

Analysis of vibrational spectra of L-alanylglycine based on density functional theory calculations

FT Raman and IR spectra of the crystallized biologically active molecule, L-alanylglycine (L-Ala-Gly) have been recorded and analyzed. The equilibrium geometry, bonding features and harmonic vibrational frequencies of L-Ala-Gly have been investigated with the help of B3LYP density functional theory (DFT) method. The calculated molecular geometry has been compared with the experimental data. The assignments of the vibrational spectra have been carried out with the help of normal coordinate analysis (NCA) following the scaled quantum mechanical force field methodology (SQMFF). The optimized geometry shows the non-planarity of the peptide group of the molecule. Potential energy surface (PES) scan studies has also been carried out by ab initio calculations with B3LYP/6-311+G** basis set. The red shifting of NH3+ stretching wavenumber indicates the formation of N-H...O hydrogen bonding. The change in electron density (ED) in the sigma* antibonding orbitals and E2 energies have been calculated by natural bond orbital analysis (NBO) using DFT method. The NBO analysis confirms the occurrence of strong intermolecular hydrogen bonding in the molecule.

Testing Lorentz invariance and CPT conservation with NuMI neutrinos in the MINOS near detector

A search for a sidereal modulation in the MINOS near detector neutrino data was performed. If present, this signature could be a consequence of Lorentz and CPT violation as predicted by the effective field theory called the standard-model extension. No evidence for a sidereal signal in the data set was found, implying that there is no significant change in neutrino propagation that depends on the direction of the neutrino beam in a sun-centered inertial frame. Upper limits on the magnitudes of the Lorentz and CPT violating terms in the standard-model extension lie between 10(-4) and 10(-2) of the maximum expected, assuming a suppression of these signatures by a factor of 10(-17).

Vibrational spectra and ab initio molecular orbital calculations of the novel anti-cancer drug combretastatin A-4 prodrug

The NIR-FT Raman and FT-IR spectral studies of the novel antineoplastic and antiangiogenesis substance comprestatin A-4 prodrug (CA4P) were carried out. The equilibrium geometry, various bonding features and harmonic vibrational frequencies of CA4P have been investigated with the help of B3LYP density functional theory (DFT) method. The most preferred cis-configuration for its bioactivity has been demonstrated on the basis of torsional potential energy surface (PES) scan studies. Stability of the molecule arising from hyperconjugative interactions leading to its bioactivity, charge delocalization and mesomeric effects have been analyzed using natural bond orbital (NBO) analysis. Detailed assignments of the vibrational spectra have been made with the aid of theoretically predicted vibrational frequencies. The optimized geometry shows near-planarity of phenyl rings and perpendicular conformation of meta substituted methoxy group. The vibrational analysis confirms the differently acting ring modes, steric repulsion, pi conjugation and back-donation.

Measurement of neutrino oscillations with the MINOS detectors in the NuMI beam

This Letter reports new results from the MINOS experiment based on a two-year exposure to muon neutrinos from the Fermilab NuMI beam. Our data are consistent with quantum-mechanical oscillations of neutrino flavor with mass splitting |Deltam2| = (2.43+/-0.13) x 10(-3) eV2 (68% C.L.) and mixing angle sin2(2theta) > 0.90 (90% C.L.). Our data disfavor two alternative explanations for the disappearance of neutrinos in flight: namely, neutrino decays into lighter particles and quantum decoherence of neutrinos, at the 3.7 and 5.7 standard-deviation levels, respectively.

A novel computer-assisted technique for pedicle screw insertion

BACKGROUND

Commercially available systems for computer-assisted pedicle screw placement are prohibitively expensive, even in advanced countries. The advantage of the great accuracy of computer-assisted systems for pedicle screw insertion makes them highly desirable and essential for current spinal surgeries.

METHODS

We have tried to develop a new software for pedicle screw placement, based on paired point matching.

RESULTS

The newly developed software is much less expensive and is an excellent educational tool. Its accuracy has been established by a cadaveric study, described in this paper.

CONCLUSIONS

The cadaveric study supports the view that computer-assisted pedicle screw fixation using the newly developed software is superior to the conventional fluoroscopic method, especially with regard to the thoracic spine, where a higher degree of accuracy is needed. Further clinical studies are planned and the software needs further refinement for complex clinical situations.

On the use of Spectrally Constrained ICA applied to single-channel Ictal EEG recordings within a Dynamical Embedding Framework

Within a dynamical embedding (DE) framework it is possible to extract information on multiple-sources underlying just a single channel recording of electromagnetic brain activity. Independent Component Analysis (ICA) is a technique which, when used in conjunction with DE, can identify and extract statistically independent sources underlying these single channel recordings. However, these powerful techniques still generally require subjective a posteriori analysis in order to visualise neurophysiologically meaningful components in the outputs. For this reason we introduce a variant of ICA known as constrained ICA (cICA) which allows for the extraction of one of many sources underlying the measurement signal, through the provision of a basic reference signal. This constraint can be chosen to reflect neurophysiological prior knowledge of the sources in question given the measured signal. Here we present a technique which allows for the application of spectral constraints on single channel recordings of epileptic EEG data. We show that through a combination of DE and cICA it is possible to extract meaningful information on epileptic seizures and other rhythmic activity from just a single channel of EEG. We further show that accurate extraction of the sources of interest is not critically dependent on the closeness of the measurement channel to the location of the source activity.

Oral rabeprazole vs. intravenous pantoprazole: a comparison of the effect on intragastric pH in healthy subjects

BACKGROUND

Intravenous pantoprazole is often administered inappropriately to hospitalized patients who can take oral medications.

AIM

To compare the antisecretory effects of oral rabeprazole and intravenous pantoprazole in healthy subjects.

METHODS

In a double-blind, double-dummy, two-way crossover study, 38 Helicobacter pylori-negative volunteers were randomized to oral rabeprazole 20 mg or intravenous pantoprazole 40 mg daily for 3 days followed, after a 14-day washout period by the comparator treatment. Intragastric pH was recorded continuously for 24 h at baseline and on days 1 and 3 of each treatment period.

RESULTS

The mean (95% CI) percentage of the 24-h recording with gastric pH >4 was higher with rabeprazole than with pantoprazole on day 1: 37.7% (30.6-44.8%) vs. 23.9% (20.0-27.8). The mean percentage times with pH >3 and >4 for all intervals assessed were greater and the median 24-h intragastric pH values were higher with rabeprazole than with pantoprazole on days 1 and 3. The mean acidity index was lower with rabeprazole on days 1 and 3.

CONCLUSIONS

Oral rabeprazole 20 mg produced greater acid suppression than intravenous pantoprazole 40 mg. Therefore, it may be an appropriate and effective alternative in patients who can take oral medication.

Peripheral exudative and hemorrhagic chorio-retinopathy...the peripheral form of age-related macular degeneration? Report on 2 cases

Report of two patients presenting with peripheral exudative hemorrhagic chorioretinopathy, an underrecognized, possible sight-threatening condition. Thorough examination of the peripheral fundus remains the key factor in recognizing this disease. The greatest immediate risk for the patient is an incorrect diagnosis of suspected choroidal melanoma.

Oncogenic mechanisms in myeloproliferative disorders

Myeloproliferative disorders (MPDs) are clonal haematopoietic malignancies involving the abnormal proliferation of myeloid lineages. The World Health Organisation (WHO) classification of haematopoietic malignancies distinguishes MPDs from myelodysplastic/ myeloproliferative disorders and systemic mastocytosis. These malignancies frequently involve constitutive tyrosine kinase activity, resulting from either oncogenic fusion protein production or from point mutations. Chronic myelogenous leukaemia is the model used for studies of the consequences of such molecular defects. However, the heterogeneity of the clinical course of MPDs should be seen in a more rationale conceptual framework, including the many molecular events associated with these diseases. This review focuses on the various tyrosine kinase-related molecular mechanisms underlying both MPDs and rare diseases with myeloproliferative features. We pay particular attention to the newly identified JAK2 V617F mutation in polycythaemia vera, essential thrombocythaemia and idiopathic myelofibrosis and deal with disease heterogeneity and putative additional molecular mechanisms.

Evaluation of a diabetes referral pathway for the management of hypoglycaemia following emergency contact with the ambulance service to a diabetes specialist nurse team

OBJECTIVES

To evaluate the effectiveness of ambulance crew referral of patients treated for acute hypoglycaemia, to a diabetes specialist nurse (DSN) team. Patients were assessed by the ambulance service and did not attend an emergency department.

METHODS

For a 3 month period patients were referred from two areas of West Yorkshire by the ambulance service to specialist diabetes teams. The DSNs contacted the patients within 7 days by telephone and arranged further review if necessary. Satisfaction questionnaires were sent to patients.

RESULTS

Thirty eight patients were referred and all were reviewed by telephone; 30 (79%) also required a clinic review appointment. Warning signs of hypoglycaemia were identified by 21 (55%) patients, but 14 (37%) had none (three had incomplete data). Twelve patients had had a self-treated episode in the previous 6 months; nine patients had had three or more. Fifteen (39%) patients had called an emergency ambulance for similar reasons in the previous 6 months (27 "999" calls). Twenty patients (53%) had their drug treatment altered at a clinic appointment and 14 (37%) required ongoing review. Twenty six patients returned the satisfaction questionnaire; of these 88% agreed or strongly agreed that they had improved their understanding of hypoglycaemia and 73% felt more able to treat a hypoglycaemic episode in the future. Patient satisfaction with this care pathway was high.

CONCLUSIONS

The ambulance service can coordinate successful referral of patients with episodes of acute hypoglycaemia to a DSN-led service. Patients often required treatment review. They valued this service and felt more confident managing their diabetes.

Observation of muon neutrino disappearance with the MINOS detectors in the NuMI neutrino beam

This Letter reports results from the MINOS experiment based on its initial exposure to neutrinos from the Fermilab NuMI beam. The rates and energy spectra of charged current nu(mu) interactions are compared in two detectors located along the beam axis at distances of 1 and 735 km. With 1.27 x 10(20) 120 GeV protons incident on the NuMI target, 215 events with energies below 30 GeV are observed at the Far Detector, compared to an expectation of 336+/-14 events. The data are consistent with nu(mu) disappearance via oscillations with |Delta(m)2/32|=2.74 +0.44/-0.26 x10(-3)eV(2) and sin(2)(2theta(23))>0.87 (68% C.L.).

Predicting outcome of acute non-variceal upper gastrointestinal haemorrhage without endoscopy using the clinical Rockall Score

BACKGROUND

The Rockall risk scoring system uses clinical criteria and endoscopy to identify patients at risk of adverse outcomes after acute upper gastrointestinal haemorrhage. A clinical Rockall score obtained using only the clinical criteria may be able to predict outcome without endoscopy.

AIM

To validate the clinical Rockall Score in predicting outcome after acute non-variceal upper gastrointestinal haemorrhage.

METHODS

A retrospective observational study of consecutive patients who were admitted with non-variceal acute upper gastrointestinal haemorrhage was undertaken. Medical records were abstracted using a standardised form.

RESULTS

102 cases were identified (51 men and 51 women; mean age 59 years). 38 (37%) patients considered to be at low risk of adverse outcomes (clinical Rockall Score 0) had no adverse outcomes and did not require transfusion. Patients with a clinical Rockall Score of 1-3 had no adverse outcomes, although 13 of 45 (29%) patients required blood transfusions. Clinical Rockall Scores >3 (n = 19) were associated with adverse outcomes (rebleeding in 4 (21%), surgery in 1 (5%) and death in 2 (10%)).

CONCLUSIONS

The clinical Rockall Score without endoscopy may be a useful prognostic indicator in this cohort of patients with acute non-variceal upper gastrointestinal haemorrhage. This score may reduce the need for urgent endoscopy in low-risk patients, which can instead be carried out on a more elective outpatient basis.