Pure neuritic leprosy in India: an appraisal

BACKGROUND: Pure neuritic leprosy (PNL) constitutes a significant proportion of all cases in India, however, this form of disease has not been fully recognized and investigated and there is little information in the existing literature. OBJECTIVE: To study the epidemiological characteristics of PNL in India. MATERIALS AND METHODS: A retrospective analysis of leprosy clinic records for the period 1993 to 2003 was undertaken. Detailed demographic profiles and clinical findings were noted from the predesigned clinic proforma. A slit-skin smear for acid-fast baclli (AFB) was done in all cases from the area of sensory loss. A skin biopsy was done from the area of sensory impairment to study histopathological changes. Further investigations such as nerve conduction velocity studies (NCV), fine needle aspiration cytology (FNAC), or nerve biopsy (superficial nerve twigs) were done if indicated in patients whenever there was difficulty in clinical diagnosis. RESULTS: Of the total 1542 leprosy patients seen over this period, 65 (4.2%) had PNL. Males were more commonly affected than females (2.6:1.). The majority of patients 40/65(61.5%) were aged between 15 and 35 yrs. Predominant presenting symptoms were paresthesia, pain, sensory/motor deficit, and trophic changes. A majority of the patients 39/65 (60.0%) presented with involvement of 2 or more nerves in the same extremity. Mononeuritis was seen in 26 (40%) patients. The nerves most often involved were the right ulnar nerve in the upper extremity, and the right common peroneal nerve in the lower limb. In general, the nerves of the upper extremity were more commonly involved than in the lower limbs (67 vs. 55). Motor deformities such as claw hand and foot drop were present in 13/75 (20%) and 7/65 (10.8%) patients, respectively. Slit-skin smears were negative in all patients, and skin histopathology from the area of sensory loss revealed non-specific inflammation in the dermis in a majority of patients, with perineural inflammation in a few. All patients were treated with multi-drug therapy (MDT); patients with >/=2 peripheral nerve trunk involvements were treated with WHO MDT MB regimen, while others were administered WHO MDT PB regimen. Follow-up for up to 2 yrs was available in only 32/65 (49.2%) patients, none of whom developed any skin lesions during this period. CONCLUSION: PNL is a distinct subset of disease frequently seen in India. There is need to pay more attention to this form of leprosy and diagnose and treat patients earlier to prevent deformities and sequelae of nerve damage.     

Maldistribution of pulmonary blood flow in patients after the Fontan operation is associated with worse exercise capacity

Background

Maldistribution of pulmonary artery blood flow (MPBF) is a potential complication in patients who have undergone single ventricle palliation culminating in the Fontan procedure. Cardiovascular magnetic resonance (CMR) is the best modality that can evaluate MPBF in this population. The purpose of this study is to identify the prevalence and associations of MPBF and to determine the impact of MPBF on exercise capacity after the Fontan operation.

Methods

This retrospective single-center study included all patients after Fontan operation who had maximal cardiopulmonary exercise test (CPET) and CMR with flow measurements of the branch pulmonary arteries. MPBF was defined as >?20% difference in branch pulmonary artery flow. Exercise capacity was measured as percent of predicted oxygen consumption at peak exercise (% predicted VO₂). Linear and logistic regression models were used to determine univariate and multivariable predictors of exercise capacity and correlates of MPBF, respectively.

Results

A total of 147 patients who had CMR between 1999 and 2017 were included (median age at CMR 21.8?years [interquartile range (IQR) 16.5–30.6]) and the median time between CMR and CPET was 2.8?months [IQR 0–13.8]. Fifty-three patients (36%) had MPBF (95% CI 29–45%). The mean % predicted VO₂ was 63?±?16%. Patients with MPBF had lower mean % predicted VO₂ compared to patients without MPBF (60?±?14% versus 65?±?16%, p?=?0.04). On multivariable analysis, a lower % predicted VO₂ was independently associated with longer time since Fontan, higher ventricular mass-to-volume ratio, and MPBF. On multivariable analysis, only compression of the branch pulmonary arteries by the ascending aorta or aortic root was associated with MPBF (OR 6.5, 95% CI 5.6–7.4, p?<?0.001).

Conclusion

In patients after the Fontan operation, MPBF is common and is independently associated with lower exercise capacity. MPBF was most likely to be caused by pulmonary artery compression by the aortic root or the ascending aorta. This study identifies MPBF as an important risk factor and as a potential target for therapeutic interventions in this fragile patient population.

     

ADARRI: a novel method to detect spurious R-peaks in the electrocardiogram for heart rate variability analysis in the intensive care unit

We developed a simple and fully automated method for detecting artifacts in the R-R interval (RRI) time series of the ECG that is tailored to the intensive care unit (ICU) setting. From ECG recordings of 50 adult ICU-subjects we selected 60 epochs with valid R-peak detections and 60 epochs containing artifacts leading to missed or false positive R-peak detections. Next, we calculated the absolute value of the difference between two adjacent RRIs (adRRI), and obtained the empirical probability distributions of adRRI values for valid R-peaks and artifacts. From these, we calculated an optimal threshold for separating adRRI values arising from artifact versus non-artefactual data. We compared the performance of our method with the methods of Berntson and Clifford on the same data. We identified 257,458 R-peak detections, of which 235,644 (91.5%) were true detections and 21,814 (8.5%) arose from artifacts. Our method showed superior performance for detecting artifacts with sensitivity 100%, specificity 99%, precision 99%, positive likelihood ratio of 100 and negative likelihood ratio <0.001 compared to Berntson’s and Clifford’s method with a sensitivity, specificity, precision and positive and negative likelihood ratio of 99%, 78%, 82%, 4.5, 0.013 for Berntson’s method and 55%, 98%, 96%, 27.5, 0.460 for Clifford’s method, respectively. A novel algorithm using a patient-independent threshold derived from the distribution of adRRI values in ICU ECG data identifies artifacts accurately, and outperforms two other methods in common use. Furthermore, the threshold was calculated based on real data from critically ill patients and the algorithm is easy to implement.     

Hierarchical CdMoO4 nanowire–graphene composite for photocatalytic hydrogen generation under natural sunlight

Herein, a facile in situ solvothermal technique for the synthesis of a CdMoO₄/graphene composite photocatalyst is reported. Graphene oxide (GO) was synthesised by an improved Hummers'' method and was further used for the in situ synthesis of graphene via GO reduction and the formation of a CdMoO₄ nanowire/graphene composite. The structural phase formation of tetragonal CdMoO₄ was confirmed from X-ray diffraction measurements. The small nanoparticle assembled nanowires, prismatic microsphere morphology and crystalline nature of the synthesized material were investigated using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Due to its unique morphology and stability, the CdMoO₄/graphene composite was used as a photocatalyst for H₂O splitting. In comparison to pristine CdMoO₄, the CdMoO₄/graphene composite showed the best hydrogen evolution rate, i.e. 3624 μmole h⁻¹ g⁻¹, with an apparent quantum yield of 30.5%. The CdMoO₄/graphene composite has a higher photocatalytic activity due to the inhibition of charge carrier recombination. H₂ production measurements showed that the ternary semiconductor/graphene composite has enhanced photocatalytic activity for H₂ generation.

Herein, a facile in situ solvothermal technique for the synthesis of a CdMoO₄/graphene composite photocatalyst for hydrogen generation under natural solar light.     

Crystal chemistry and single-phase synthesis of Gd3+ substituted Co–Zn ferrite nanoparticles for enhanced magnetic properties

Rare earth (RE) ions are known to improve the magnetic interactions in spinel ferrites if they are accommodated in the lattice, whereas the formation of a secondary phase leads to the degradation of the magnetic properties of materials. Therefore, it is necessary to solubilize the RE ions in a spinel lattice to get the most benefit. In this context, this work describes the synthesis of Co–Zn ferrite nanoparticles and the Gd³⁺ doping effect on the tuning of their magnetic properties. The modified sol–gel synthesis approach offered a facile way to synthesize ferrite nanoparticles using water as the solvent. X-ray diffraction with Rietveld refinement confirmed that both pure Co–Zn ferrite and Gd³⁺ substituted Co–Zn ferrite maintained single-phase cubic spinel structures. Energy dispersive spectroscopy was used to determine the elemental compositions of the nanoparticles. Field and temperature dependent magnetic characteristics were measured by employing a vibration sample magnetometer in field cooled (FC)/zero field cooled (ZFC) modes. Magnetic interactions were also determined by Mössbauer spectroscopy. The saturation magnetization and coercivity of Co–Zn ferrite were improved with the Gd³⁺ substitution due to the Gd³⁺ (4f⁷)–Fe³⁺ (3d⁵) interactions. The increase in magnetization and coercivity makes these Gd³⁺ substituted materials applicable for use in magnetic recording media and permanent magnets.

Rare earth (RE) ions are known to improve the magnetic interactions in spinel ferrites if they are accommodated in the lattice, whereas the formation of a secondary phase leads to the degradation of the magnetic properties of materials.     

Electrocardiographic criteria for the diagnosis of right ventricular involvement in the setting of acute inferior infarction.

Surface electrocardiograph of twelve cases of isolated left ventricular inferior infarction and 24 cases of biventricular inferior infarction confirmed by two-dimensional echocardiography were analysed. ST segment elevation in lead III more than in lead II and ST segment depression in leads I and aVL were highly sensitive in diagnosing right ventricular involvement. ST segment depression in lead V3 equal to or greater than ST segment elevation in lead III was highly specific but had low sensitivity. These findings can be helpful in cases where right sided chest leads have not been recorded or are inconclusive.