Ataxia telangiectasia: a rare case report from Nepal

Introduction and importance

Ataxia telangiectasia (A-T) is a rare autosomal recessive neurodegenerative disorder with early childhood onset. It is characterized by ataxia, oculocutaneous telangiectasia, immunodeficiency, and lymphoid-origin cancer predisposition due to ataxia telangiectasia mutated gene mutations.

Case presentation

The authors present a 19-year-old girl with spastic movements since 18 months, leading to wheelchair dependence. Ocular telangiectasia, dystonic posture, and slurred speech were evident. Diagnosis involved elevated alpha-fetoprotein levels and typical brain imaging.

Clinical discussion

A-T due to ataxia telangiectasia mutated gene mutations located on chromosome 11q22-23. It has varied presentations categorized by age and features. Timely diagnosis relies on characteristic symptoms, lab findings, and imaging. Radiation sensitivity and increased cancer risk underscore cautious radiation use.

Conclusion

A-T is a complex disorder with no cure. Genetic counseling for parents is vital. Its poor prognosis due to infection susceptibility and cancer risk necessitates supportive care. Comprehensive management, including genetic counseling and careful surveillance, is imperative.

Maternal exposure to folate antagonists and susceptibility to congenital heart disease in offspring: A systematic review and meta-analysis

AIMS

The objective of this meta-analysis was to determine whether maternal exposure to folate antagonists is associated with increased rates of congenital heart disease in offspring.

METHODS

A comprehensive search for articles in the MEDLINE (PubMed) and EMBASE databases published up to 21 August 2023 was performed. The search strategy was not limited by study design but only for articles in the English language.

RESULTS

Analysis of 6 cohort studies and 5 cross-sectional studies, published between 1976 and 2020, showed significant increase in rate of congenital heart disease (odds ratio 1.55, 95% confidence interval, 1.28-1.87) when exposed to folate antagonists compared with the control. Further subgroup analysis showed the increased rate for exposure to both dihydrofolate reductase inhibitors and antiepileptic drugs separately. No differences were observed when analyses were stratified by timing of study.

CONCLUSION

Administration of folate antagonists within the 12-week period preceding conception and throughout the second and third months of gestation exhibited a statistically significant elevation in the susceptibility to congenital heart diseases. Notably, the protective effect of folic acid supplementation was reported in cases of congenital heart disease linked to dihydrofolate reductase inhibitors but not that associated with antiepileptic drugs.

Arachnoid cyst presenting as a neurosurgical emergency: a case report

Introduction

Arachnoid cysts are intra-arachnoid lesions filled with cerebrospinal fluid. They account for ~1% of all intracranial mass lesions and are non-neoplastic collections of cerebrospinal fluid within an anomalous arachnoid enclosure.

Case presentation

The authors report a 35-year-old Arabian male who presented to the ER with a history of sudden loss of consciousness, anisocoria, and right hemiparesis. Contrast tomography showed a large frontoparietotemporal cyst (7.7×5.8×5.4) with uncal herniation and a midline shift of 12 mm. An emergency left FTP craniotomy with an excision of the cyst was performed.

Discussion

Arachnoid cysts can be categorized as primary or secondary, arising congenitally or due to factors like trauma, infection, or neoplasia. It can rupture, leading to internal bleeding, causing symptoms such as headaches, seizures, and neurological decline. Rapid diagnosis is vital, with cranial computed tomography scans preferred for emergencies. Treatment options include surgical intervention like craniotomy, fenestration, or cyst peritoneal shunts. For uncal herniation, surgery can be successful and results depends on the amount of herniation.

Conclusion

Although benign, the arachnoid cysts led to uncal herniation when they become 'tension' cysts. A high level of suspicion is crucial for early recognition of the condition. Timely intervention has shown positive recovery outcomes.

Association of vaccination status with the clinicobiochemical profile, hospital stay, and mortality in COVID-19: A case-control study

Background and Aims

The effectiveness of coronavirus disease 2019 (COVID-19) vaccines in reducing symptoms, disease advancement, complications, and mortality in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been well-established. This case-control study aimed to compare different blood parameters, and prognostic and survival outcomes of COVID-19 patients based on vaccination status.

Methods

We performed a case-control study that included hospitalized patients with COVID-19 at Tribhuvan University Teaching Hospital, Kathmandu, Nepal. Individuals who received vaccination were designated as cases and unvaccinated individuals as controls. Demographics, co-morbidity, clinical data, laboratory data, and disease outcomes were recorded for both groups. Multivariate, Cox, and linear regression were used for analysing blood parameters, hospital admission, survival, and hospital stay, respectively, between cases and controls.

Results

Out of 100 participants enrolled, 46 were vaccinated, and 54 weren't. At admission, ferritin and erythrocyte sedimentation rate (ESR) were significantly lower in cases. At discharge, cases showed a higher monocyte than controls. Ferritin, ESR, and d-imer showed excellent performance in determining the severity of symptoms. Significant correlation and regression of ferritin and ESR with the length of hospital stay was observed. Length of hospital stay was significantly lower in cases than in controls. No significant differences between cases and controls were observed in mortality.

Conclusion

COVID-19 vaccines effectively reduced hospitalization duration. Ferritin and ESR were significantly lower in vaccinated individuals and showed the best utility in monitoring the disease.

A rationale for the rapid extraction of ultra-low-level uranyl ions in simulated bioassays regulated by Mn-dopants over magnetic nanoparticles

Although the sorption of uranyl ions and other heavy metal ions over magnetic nanoparticles is well reported, the parameters governing the sorption process over the magnetic nanoparticles have not been clearly enumerated. However, to increase the efficiency of the sorption over the surface of these magnetic nanoparticles, it is essential to understand the different structural parameters that are involved in the sorption process. The sorption of uranyl ions and other competitive ions in simulated urine samples at different pH was effectively accomplished over magnetic nanoparticles of Fe₃O₄ (MNPs) and Mn-doped Fe₃O₄ (Mn-MNPs). The MNPs and Mn-MNPs were synthesized using an easily modified co-precipitation method and were thoroughly characterised using several techniques, such as XRD, HRTEM, SEM, zeta potential, and XPS. The substitutional doping of Mn (1 to 5 at%) in the Fe₃O₄ lattice (Mn-MNPs) showed better sorption ability as compared to that of MNPs. The sorption properties of these nanoparticles were mainly correlated with the different structural parameters to understand the roles of surface charge and different morphological parameters. The interaction centres over the surface of MNPs with the uranyl ions were designated and the effects of ionic interactions with uranyl ions for these sites were calculated. Extensive XPS, ab initio calculations and zeta potential studies have provided deep insights into the different aspects that play key roles in the sorption process. These materials showed one of the best K_d values (∼3 × 10⁶ cm³) in a neutral medium with very low t_1/2 values (∼0.9 min). The fast sorption kinetics (very low t_1/2) makes them amongst the best sorption materials for uranyl ions and optimal for the quantification of ultra-low-level uranyl ions in simulated bioassays.

Late onset ST-elevation myocardial infarction (STEMI) in patient with COVID-19: A case report from Nepal

Introduction

Although pulmonary consequences are less common in COVID-19 than cardiac issues, it is critical to understand the cause of probable cardiac complications and put the patient on constant watch, especially if they have risk factors such as diabetes mellitus.

Case presentation

Here, we report a case of 82-years old male with ST-segment elevated myocardial infarction (STEMI) that was developed as a complication of COVID-19.

Discussion

COVID-19 is now known to cause cardiovascular issues such as myocardial damage, heart failure, arrhythmia, and venous thromboembolism. With the involvement of COVID-19, the prevalence of cardiovascular manifestation has increased. The precise processes of extrapulmonary and systemic manifestations following COVID-19 are unknown. There is an elevated risk of cardiovascular harm, notably myocardial infraction followed by acute infection.

Conclusion

It is essential to understand the mechanism of potential cardiac complications and to keep the patient on close watch, especially if the patient has risk factors such as diabetes mellitus.

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SARS-CoV-2 causes cardiovascular complication by binding to the angiotensin-converting enzyme-2 receptor.

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ACE-2 receptor are present on the endothelial surface of alveolar and cardiac cells.

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It is important to keep the patient on a close follow-up with risk factors like diabetes mellitus.

Patient with Dravet syndrome: A case report

Dravet syndrome is rare genetic epilepsy syndrome and epileptic encephalopathy. The patient initially has normal developmental profile with plateau or regression that begins after seizure onset. We report a case of two-year-old child diagnosed as dravet syndrome with moderate cerebral atrophy and ventricular dilatation as rare MRI finding.

Stereoacuity among Undergraduate Medical and Nursing Students at a Tertiary Care Hospital: A Descriptive Cross-sectional Study

Introduction:

Stereopsis is defined as the ability to perceive object depth. It is measured in seconds of arc. Reduced stereoacuity impinges one's academic as well as a professional performance. Hence in this study, we aim to find out the mean stereoacuity among the undergraduate medical and nursing students using the Titmus fly test.

Methods:

A descriptive cross-sectional study was conducted among undergraduate students at a medical college of Nepal from April 2021 to July 2021. Ethical approval was obtained from the Institutional review committee (Registration number: 487 (6-11) E2 077/078). Simple random sampling method was used. Data were collected from undergraduate medical and nursing students while the post-graduate students were excluded from the study. Overall, 80 students were included in the study. Titmus fly test was used to assess the stereopsis. Statistical Package for Social Sciences version 21 and Microsoft Excel was used for data analysis. Point estimate at 95% confidence interval was calculated along with mean, standard deviation, frequency, and proportion.

Results:

The mean stereoacuity was 62.63±46.56 (range 40-800) sec of arc (52.77-72.49 at 90% Confidence Interval). A total of 80 participants in our study among which 50 (62.5%) were male and 30 (37.5%)were female. About 41 (51.2%) of the study participants had normal, borderline (>40 and ≤ 120) stereopsis was seen in 35 (43.8%) of the study participants while only 4 (5%) had reduced stereopsis (≥120 sec of arc).

Conclusions:

This study showed that the mean stereoacuity among the undergraduate medical and nursing students was in subnormal range which was similar to other studies.

Bronchopleural fistula and bilateral pneumothorax in a patient with COVID-19

COVID-19 pneumonia causes several complications that include pneumothorax, hydropneumothorax, empyema, and rarely leads to bronchopleural fistula (BPF). BPF is a communication between the pleural space and the bronchial tree. We report a case of 24 years man with pneumothorax, hydropneumothorax, and BPF that appeared after COVID-19 infection.

Assessment of Prescribing Pattern and Safety Profile of Drugs Used in Intranasal Route in Paediatric Age Group of Patients in a Tertiary Care Hospital

Background Recently there has been an increased preference for intranasal delivery of drugs due to highly vascular nasal mucosa, bypassing first pass metabolism and the blood brain barrier (BBB) lead in quick drug absorption to the systemic circulation and direct access to brain from olfactory region. For pediatric patients this route offers significant benefits over injections or oral routes, like increased compliance, easy administration, and minimal side effects. Objective Assessment of prescription pattern of drugs and safety profile of drugs used by intranasal route in paediatric age group. Method Our study was a prospective observational study paediatric age group of patients conducted in the departments of Pharmacology, Paediatrics and Otorhinolaryngology of Burdwan Medical College and Hospital, Burdwan. Data were collected in CRF and frequency distribution of collected data done. Microsoft Excel 2010 was used for analysis. Result Common age group was infants. Males were more in number. Most common indication was epistaxis. Intranasal drugs per prescription were 1.05. Most commonly prescribed intranasal drug was nasal saline. Nasal decongestant was the most common prescribed medication. Nasal drops were the most common dose formulation. Conclusion Intranasal drug prescribing in our study was mainly aimed for treating local problems, very few being for systemic action. Some prescribing indicators like prescribing by generic name and prescribing from national essential drug lists were acceptable with scope for improvement. Average number of drugs per prescription and antibiotic use was high. Adverse events after intranasal drug use were primarily local and nose related.

An Open Label Prospective Study on Evaluation of Safety and Efficacy of Cilnidipine Over Amlodipine in Stage 1 Hypertensive Patients

Background Calcium channel blockers are considered the first line drug over renin-angiotensinaldosterone system inhibitor in black population and with renin-angiotensinaldosterone system inhibitor in non-black population with Hypertension. Amlodipine has longer biological half life and lower potential to stimulate SNS. But, is associated with reflex tachycardia and pedal oedema. Cilnidipine has potent inhibitory both on voltage gated L-type and N-type calcium channels with better anti-proteinuric effect and good tolerability. Hence, our study compared the efficacy, safety and compliance of cilnidipine over amlodipine in Stage 1 hypertensive subjects. Objective To find out antihypertensive and renoprotective effect of cilnidipine. Method The study was open-label, single centre, prospective, parallel design, randomized controlled was done in Outdoor Patient Department (OPD) of Medicine and Department of Pharmacology in Burdwan Medical College and Hospital (BMCH). Patients with stage 1 HTN received cilnidipine while the other group received amlodipine. There were 4 follow-up visits for each participant consisting of baseline, 1 week, 6 weeks and after 12 weeks. Clinical parameters including pulse rate, blood pressure and ankle oedema noted also laboratory investigations were done. Safety parameters with adverse events and compliance by traditional pill count method. Result Blood pressure was effectively decreased by both amlodipine and cilnidipine. Cilnidipine significantly decreased Pulse Rate while amlodipine increased it and the difference in Pulse Rate comparing both the groups was statistically significant. None of the ADRs were statistically significant except pedal oedema. Pedal oedema was noted only in amlodipine arm and was statistically significant. Compliance to both the drugs was excellent. Total cost of therapy was higher with cilnidipine. Conclusion Though amlodipine is preferred drug, cilnidipine should be a better alternative when we consider subjects with sympathetic over activity, proteinuria or pedal oedema.

Jahn-Teller effect in LiMn2O4: influence on charge ordering, magnetoresistance and battery performance

The phase transition near room temperature in LiMn₂O₄ was studied using thermal expansion measurements, and directly compared with the electrochemical performance of the material. Studies based on thermal expansion indicate the onset of a first-order phase transition at T_c ∼ 220 K for the nearly half-doped material, with [Mn³⁺]/[Mn⁴⁺] ≈ 1. The T_c shifts to a higher temperature, ∼290 K, and signatures for Verwey-type charge ordering at 290 K can be observed when the fraction of Jahn-Teller Mn³⁺ in LiMn₂O₄ is increased, i.e., [Mn³⁺]/[Mn⁴⁺] > 1. These studies show that the first-order phase transition near room temperature in LiMn₂O₄ is associated with charge ordering, which ultimately is a consequence of the Jahn-Teller effect. In addition, the Jahn-Teller effect is proven to be an important cause of magnetoresistance and electrochemical capacity fading in LiMn₂O₄. Electrochemical measurements show that both materials, either with a T_c ∼ 220 K or T_c ∼ 290 K, exhibit capacity fading to almost the same extent. Electrochemical capacity retention is observed only in nanosized LiMn₂O₄, for which the phase transition anomalies are completely absent.

Thermodynamics of interaction of ionic liquids with lipid monolayer

Understanding the interaction of ionic liquids with cellular membrane becomes utterly important to comprehend the activities of these liquids in living organisms. Lipid monolayer formed at the air-water interface is employed as a model system to follow this interaction by investigating important thermodynamic parameters. The penetration kinetics of the imidazolium-based ionic liquid 1-decyl-3-methylimidazolium tetrafluoroborate ([DMIM][BF4]) into the zwitterionic 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) lipid layer is found to follow the Boltzmann-like equation that reveals the characteristic time constant which is observed to be the function of initial surface pressure. The enthalpy and entropy calculated from temperature-dependent pressure-area isotherms of the monolayer show that the added ionic liquids bring about a disordering effect in the lipid film. The change in Gibbs free energy indicates that an ionic liquid with longer chain has a far greater disordering effect compared to an ionic liquid with shorter chain. The differential scanning calorimetric measurement on a multilamellar vesicle system shows the main phase transition temperature to shift to a lower value, which, again, indicates the disordering effect of the ionic liquid on lipid membrane. All these studies fundamentally point out that, when ionic liquids interact with lipid molecules, the self-assembled structure of a cellular membrane gets perturbed, which may be the mechanism of these molecules having adverse effects on living organisms.

Effects of ionic liquids on the nanoscopic dynamics and phase behaviour of a phosphatidylcholine membrane

Ionic liquids (ILs) are potential candidates for new antimicrobials due to their tunable antibacterial and antifungal properties that are required to keep pace with the growing challenge of bacterial resistance. To a great extent their antimicrobial actions are related to the interactions of ILs with cell membranes. Here, we report the effects of ILs on the nanoscopic dynamics and phase behaviour of a dimyristoylphosphatidylcholine (DMPC) membrane, a model cell membrane, as studied using neutron scattering techniques. Two prototypical imidazolium-based ILs 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM[BF4]) and 1-decyl-3-methylimidazolium tetrafluoroborate (DMIM[BF4]), which differ only in terms of the alkyl chain length of cations, have been used for the present study. Fixed Elastic Window Scan (FEWS) shows that the incorporation of ILs affects the phase behaviour of the phospholipid membrane significantly and the transition from a solid gel to a fluid phase shifts to lower temperature. This is found to be consistent with our differential scanning calorimetry measurements. DMIM[BF4], which has a longer alkyl chain cation, affects the phase behaviour more strongly in comparison to BMIM[BF4]. The pressure-area isotherms of the DMPC monolayer measured at the air-water interface show that in the presence of ILs, isotherms shift towards higher area-per lipid molecule. DMIM[BF4] is found to shift the isotherm to a greater extent compared to BMIM[BF4]. Quasielastic neutron scattering (QENS) data show that both ILs act as a plasticizer, which enhances the fluidity of the membrane. DMIM[BF4] is found to be a stronger plasticizing agent in comparison to BMIM[BF4] that has a cation with a shorter alkyl chain. The incorporation of DMIM[BF4] enhances not only the long range lateral motion but also the localised internal motion of the lipids. On the other hand, BMIM[BF4] acts weakly in comparison to DMIM[BF4] and mainly alters the localised internal motion of the lipids. Any subtle change in the dynamical properties of the membrane can profoundly affect the stability of the cell. Hence, the dominant effect of the IL with the longer chain length on the dynamics of the phospholipid membrane might be correlated with its cytotoxic activity. QENS data analysis has provided a quantitative description of the effects of the two imidazolium-based ILs on the dynamical and phase behaviour of the model cell membrane, which is essential for a detailed understanding of their action mechanism.

Effect of pressure on normal and superconducting state properties of iron based superconductor PrFeAsO0.6F y (y = 0.12, 0.14)

The effect of high pressure (up to 8 GPa) on normal and superconducting state properties of PrFeAsO_0.6F_0.12, an 1111-type iron based superconductor close to optimal doped region, has been investigated by measuring the temperature dependence of resistivity. Initially, the superconducting transition temperature (T _c ) is observed to increase slowly by about 1 K as pressure (P) increases from 0 to 1.3 GPa. With further increase in pressure above 1.3 GPa, T _c decreases at the rate of ~1.5 K/GPa. The normal-state resistivity decreases monotonically up to 8 GPa. We have also measured the pressure dependence of magnetization (M) on the same piece of PrFeAsO_0.6F_0.12 sample up to 1.1 GPa and observed T _c as well as the size of the Meissner signal to increase with pressure in this low-pressure region. In contrast, for an over-doped PrFeAsO_0.6F_0.14 sample, magnetization measurements up to 1.06 GPa show that both T _c and the Meissner signal decrease with pressure. The present study clearly reveals two distinct regions in the dome-shaped (T _c -P) phase diagram of PrFeAsO_0.6F_0.12.

Continuously Varying Critical Exponents Beyond Weak Universality

Renormalization group theory does not restrict the form of continuous variation of critical exponents which occurs in presence of a marginal operator. However, the continuous variation of critical exponents, observed in different contexts, usually follows a weak universality scenario where some of the exponents (e.g., β, γ, ν) vary keeping others (e.g., δ, η) fixed. Here we report ferromagnetic phase transition in (Sm_1−yNd_y)_0.52Sr_0.48MnO₃ (0.5 ≤ y ≤ 1) single crystals where all three exponents β, γ, δ vary with Nd concentration y. Such a variation clearly violates both universality and weak universality hypothesis. We propose a new scaling theory that explains the present experimental results, reduces to the weak universality as a special case, and provides a generic route leading to continuous variation of critical exponents and multi-criticality.

Magnetoelectric coupling and exchange bias effects in multiferroic NdCrO3

We report ferroelectricity around  ∼88 K that appears well below T N (∼25 K), unlike other members of RCrO3 series. A synchrotron diffraction study suggests that the occurrence of ferroelectricity in NdCrO3 is coupled to the structural transformation from centrosymmetric Pnma to a non-centrosymmetric Pna21 space group. A strong magnetoelectric coupling is observed in the electric polarization [P(T)]. This coupling is significantly influenced by the magnetic field cooling effect, suggesting an exchange bias effect in P(T). This exchange bias effect is also revealed by the systematic shift of the magnetic hysteresis loops below T(N). The rare occurrence of an exchange bias effect in both the magnetic and electric polarizations associated with a strong magnetoelectric coupling is of fundamental interest, as well as being attractive for technological applications close to liquid nitrogen temperature.

Pain relief after ambulatory hand surgery: A comparison between dexmedetomidine and clonidine as adjuvant in axillary brachial plexus block: A prospective, double-blinded, randomized controlled study

BACKGROUND

For ages various adjuvants have been tried to prolong axillary brachial plexus block. We compared the effect of adding dexmedetomidine versus clonidine to ropivacaine for axillary brachial plexus blockade. The primary endpoints were the onset and duration of sensory and motor block and duration of analgesia.

MATERIALS AND METHODS

A total of 90 patients (20-40 years) posted for ambulatory elective hand surgery under axillary brachial plexus block were divided into two equal groups (groups ropivacaine dexmedetomidine [RD] and ropivacaine clonidine [RC]) in a randomized, double-blind fashion. In group RD (n = 45) 30 ml 0.5% ropivacaine + 100 μg of dexmedetomidine and group RC (n = 45) 30 ml 0.5% ropivacaine + 75 μg clonidine were administered in axillary plexus block. Sensory and motor block onset times and block durations, time to first analgesic use, total analgesic need, postoperative visual analog scale (VAS), hemodynamics and side-effects were recorded for each patient.

RESULTS

Though with similar demographic profile in both groups, sensory and motor block in group RD (P < 0.05) was earlier than group RC. Sensory and motor block duration and time to first analgesic use were significantly longer and the total need for rescue analgesics was lower in group RD (P < 0.05) than group RC. Postoperative VAS value at 18 h were significantly lower in group RD (P < 0.05). Intraoperative hemodynamics were insignificantly lower in group RD (P < 0.05) without any appreciable side-effects.

CONCLUSION

It can be concluded that adding dexmedetomidine to axillary plexus block increases the sensory and motor block duration and time to first analgesic use, and decreases total analgesic use with no side-effects.

GA-optimized feedforward-PID tracking control for a rugged electrohydraulic system design

Rugged electrohydraulic systems are preferred for remote and harsh applications. Despite the low bandwidth, large deadband and flow nonlinearities in proportional valves valve and highly nonlinear friction in industry-grade cylinders that comprise rugged systems, their maintenance are much easier than very sophisticated and delicate servocontrol and servocylinder systems. With the target of making the easily maintainable system to perform comparably to a servosystem, a feedforward control has been designed here for compensating the nonlinearities. A PID feedback of the piston displacement has been employed in tandem for absorbing the unmodeled effects. All the controller parameters have been optimized by a real-coded genetic algorithm. The agreement between the achieved real-time responses for step and sinusoidal demands with those achieved by modern servosystems clearly establishes the acceptability of the controller design.

Symptoms of airway reflux predict exacerbations and quality of life in bronchiectasis

AIM

We have explored the association of the upper airway symptoms related to cough with exacerbation frequency, sputum microbiology and inflammatory markers in patients with non cystic fibrosis bronchiectasis.

METHODS

Patients with bronchiectasis completed the Hull Airway Reflux Questionnaire (HARQ). A score of >13 was taken to indicate the presence of reflux. Patients were followed-up with longitudinal spirometry, sputum culture and Leicester cough questionnaire (LCQ). Myeloperoxidase (MPO), free neutrophil elastase (NE) activity, Interleukin (IL)-8 and Tumour Necrosis Factor (TNF)-α was measured from spontaneous sputum samples.

RESULTS

163 completed the study. 59.5% were female. Mean age was 65.7 years. 73.6% reported airway reflux using HARQ. Patients with airway reflux had more severe cough symptoms as assessed by the LCQ [15.2 (3.5) vs. 19.4 (1.9)], p < 0.001. Sputum levels of MPO, NE, IL-8 and TNF-α were all significantly higher in the reflux positive group (p < 0.05 for all comparisons). In a multivariable logistic regression, airway reflux was independently associated with cough severity (-3.27, standard error 0.81, p = 0.0002). Airway reflux, age, FEV1 % predicted and colonization with Pseudomonas aeruginosa were independently associated with an increased risk of ≥3 bronchiectasis exacerbations in one year.

CONCLUSION

The symptoms of airway reflux independently predict severity and exacerbation frequency in non cystic fibrosis bronchiectasis.

Electric field driven destabilization of the insulating state in nominally pure LaMnO3

We report an electric field driven destabilization of the insulating state in nominally pure LaMnO3 single crystal with a moderate field which leads to a resistive state transition below 300 K. The transition is between the insulating state in LaMnO3 and a high resistance bad metallic state that has a temperature independent resistivity. The transition occurs at a threshold field (Eth) that shows a steep enhancement on cooling. While at lower temperatures the transition is sharp and involves a large change in resistance, it softens on heating and is eventually absent above 280 K. When the Mn(4+) content is increased by Sr substitution up to x = 0.1, the observed transition, although observable in a certain temperature range, softens considerably. This observation has been explained as a bias driven percolation type transition between two co-existing phases, where the majority phase is a charge and orbitally ordered polaronic insulating phase and the minority phase is a bad metallic phase. The mobile fraction f of the bad metallic phase deduced from the experimental data follows an activated kinetics as f = fo(E)exp(-Δ/kBT) with the activation energy Δ ≈ 200 meV, and the pre-factor fo(E) is a strong function of the field that leads to a rapid enhancement of f on application of field, leading to the resistive state transition. We suggest likely scenarios for such co-existing phases in nominally pure LaMnO3 that can lead to the bias driven percolation type transition.

Eight-weekly intravenous antibiotics is beneficial in severe bronchiectasis

AIM

The aim of our study was to assess the impact of 8-weekly intravenous (IV) antibiotics on exacerbation frequency and health-related quality of life in bronchiectasis.

METHODS

Patients were recruited prospectively from June 2008 to December 2010. Patients with recurrent exacerbations (five or more exacerbations per year) and subjectively reporting ill health between antibiotic courses were recruited. Eight-weekly IV antibiotics (for 14 days) were initiated. Patients were followed up for 1 year. Main outcome was reduction in exacerbation frequency and improvement in health-related quality of life (HRQoL) at 1 year after starting intravenous antibiotic therapy. Other outcomes recorded were forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC), incremental shuttle walk test (ISWT), 24-h sputum volume, sputum microbiology, body mass index (BMI), markers of inflammation--white cell count (WCC), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR).

RESULTS

In total, 19 patients were recruited. Mean age was 64.1 years and 52.6% were female. With 8-weekly antibiotics, there was a significant reduction in the number of exacerbations [mean (SE): 9.3 (0.5) in the year before vs. 8.0 (0.4) in the year after; P = 0.02]. In 63.2%, Leicester Cough Questionnaire (LCQ) improved by ≥1.3 U (P = 0.006)] and in 42.1% St. George's Respiratory Questionnaire (SGRQ) improved by ≥4 U (P = 0.03). Exercise capacity increased by 58.7 m (P = 0.004). There was no improvement in the other end points.

CONCLUSION

Treatment with 8-weekly intravenous antibiotics in severe bronchiectasis reduced exacerbation frequency and improved exercise tolerance and health-related quality of life.

Contact tracing in pulmonary and non-pulmonary tuberculosis

AIM

The aim of our study was to determine the effectiveness of contact tracing for both pulmonary and non-pulmonary tuberculosis (TB).

METHODS

The authors studied contact tracing in South East of Scotland, Edinburgh TB Clinic, UK, for 3 years. New index cases of both pulmonary and non-pulmonary TB were identified from reviewing TB nurses records. Pulmonary involvement was excluded from all non-pulmonary cases. Active TB was diagnosed as per the national TB guidelines. Latent TB was diagnosed based on history, tuberculin skin test and interferon γ release assay. TB contacts were identified from reviewing TB nurses notes on index TB patients. A positive screening episode was defined as identification of either active or latent TB in a contact following relevant investigations.

RESULTS

Total number of positive screening episodes for pulmonary TB was 43.1% and non-pulmonary TB was 26.1%. Of these, 78.8% were household contacts and 21.2% were casual contacts.

CONCLUSION

Contact tracing in low-prevalence TB countries, for both pulmonary and non-pulmonary TB, is an essential intervention to identify and reduce the number of infected patients that will progress to active disease. This is the key for effective TB control.

Near-room-temperature colossal magnetodielectricity and multiglass properties in partially disordered La2NiMnO6

We report magnetic, dielectric, and magnetodielectric responses of the pure monoclinic bulk phase of partially disordered La2NiMnO6, exhibiting a spectrum of unusual properties and establish that this compound is an intrinsically multiglass system with a large magnetodielectric coupling (8%-20%) over a wide range of temperatures (150-300 K). Specifically, our results establish a unique way to obtain colossal magnetodielectricity, independent of any striction effects, by engineering the asymmetric hopping contribution to the dielectric constant via the tuning of the relative-spin orientations between neighboring magnetic ions in a transition-metal oxide system. We discuss the role of antisite (Ni-Mn) disorder in emergence of these unusual properties.

Mössbauer spectroscopic study of spin reorientation in Mn-substituted yttrium orthoferrite

The first-order spin-reorientation transition in the Mn-substituted yttrium orthoferrites, YFe(1-x)Mn(x)O(3) (x = 0.1, 0.15 and 0.2), has been investigated using (57)Fe Mössbauer spectroscopy. Owing to its large anisotropy, substitution of Mn(3+) ions in YFeO(3) induces a spin-reorientation transition from the low-temperature antiferromagnetic state to a high-temperature weak ferromagnetic state. With increasing x, the spin-reorientation transition temperature (T(SR)) increases whereas the Néel temperature (T(N)) decreases. Analysis of the Mössbauer spectra unambiguously confirms the occurrence of spin reorientation relative to crystal axes. At a given temperature, the mean hyperfine field decreases with the increasing Mn concentration. The variation of canting angle with temperature for YFe(0.85)Mn(0.15)O(3) has been estimated.

Spin-reorientation, ferroelectricity, and magnetodielectric effect in YFe(1-x)Mn(x)O3(0.1 ≤ x ≤ 0.40)

We report the observation of magnetoelectric and magnetodielectric effects at different temperatures in Mn-substituted yttrium orthoferrite, YFe(1-x)Mn(x)O(3)(0.1 ≤ x ≤ 0.40). Substitution of Mn in antiferromagnetic YFeO(3)(T(N) = 640 K) induces a first-order spin-reorientation transition at a temperature, T(SR), which increases with x whereas the Néel temperature (T(N)) decreases. While the magnetodielectric effect occurs at T(SR) and T(N), the ferroelectricity appears rather at low temperatures. The origin of magnetodielectric effect is attributed to spin-phonon coupling as evidenced from the temperature dependence of Raman phonon modes. The large magnetocapacitance (18% at 50 kOe) near T(SR) = 320 K and high ferroelectric transition temperature (∼115 K) observed for x = 0.4 suggest routes to enhance magnetoelectric effect near room temperature for practical applications.

Seven-day antibiotic courses have similar efficacy to prolonged courses in severe community-acquired pneumonia--a propensity-adjusted analysis

There are no studies to guide the optimal duration of therapy in severe community-acquired pneumonia (CAP). The aim of this study was to determine whether 7 days of antibiotic treatment is equivalent to longer-course therapy in severe CAP. In this prospective observational study, we included patients with severe CAP (CURB65 score 3-5) admitted to the hospital with signs and symptoms consistent with pneumonia. A propensity score, derived through multiple logistic regression, was used to match patients into two groups: treated for 7 days vs. treated for >7 days. Patients who died, were admitted to the intensive-care unit, developed complicated pneumonia, failed to reach clinical stability or had positive cultures for microorganisms requiring prolonged treatment within the first 7 days were excluded. Patients outside the mutual range of the propensity score were also excluded. The primary outcome of this study was 30-day mortality. Secondary outcomes were subsequent requirement for mechanical ventilation and/or inotropic support and the development of complicated pneumonia or re-admission within 30 days. Four hundred and twelve patients were suitable for derivation of the propensity score. After matching on propensity score, 164 patients treated for 7 days were compared with 164 treated for >7 days; they were well matched in terms of age, gender, comorbidities, and physiological parameters. The results showed no significant differences in the primary and the secondary outcomes between the two groups. This study therefore suggests that, in the majority of severe CAP patients who have clinically responded, antibiotics can be safely discontinued at 7 days.

Dependence of surface enhanced Raman scattering on the plasmonic template periodicity

Surface enhanced Raman scattering has been investigated from rhodamine 6G molecules embedded in polymethyl methacrylate (R6G+PMMA) and coated on one-dimensional and two-dimensional gold-dielectric gratings fabricated by laser interference lithographically. The Raman signals from these plasmonic templates are 200 to 400 times larger than the signal from R6G+PMMA coated on plain gold films. The enhancement of the Raman signal varies almost periodically with the period of the grating. Finite-difference time-domain simulations show that large electromagnetic near fields occur at the metallic edges due to the resonant excitation of localized surface plasmon of the gold patches by the pump laser. These give rise to large enhancements of the Raman signal. The dependence on period is due to the combined effects of the localized surface plasmon and the periodic grating that couples the pump laser to the surface plasmon polariton.