Active microrheology using pulsed optical tweezers to probe viscoelasticity of lamin A.

Lamins are nucleoskeletal proteins of mammalian cells that stabilize the structure and maintain the rigidity of the nucleus. These type V intermediate filament proteins which are predominantly of A and B types provide necessary tensile strength to the nucleus. Single amino acid missense mutations occurring all over the lamin A protein form a cluster of human diseases termed as laminopathies, most of which principally affect the muscle and cardiac tissues responsible for load bearing functionalities of the body. One such mutation is A350P which causes dilated cardiomyopathy in patients. It is postulated that a change from alanine to proline in the α-helical coiled-coil forming 2B rod domain of the protein might severely disrupt the propensity of the filaments to polymerise into functional higher order structures required to form a fully functional lamina with its characteristic elasticity. In this study, we have elucidated for the very first time, the application of active microrheology employing oscillating optical tweezers to investigate any alterations in the viscoelastic parameters of the mutant protein meshwork in vitro, which might translate into possible changes in nuclear plasticity. We confirmed our findings from this robust yet fast method by imaging both the wild type and mutant lamin A networks using a super resolution microscope, and observed changes in the mesh size which corroborate our measured changes in the viscoelastic parameters of the lamins. This method could thus be extended to conduct microrheological measurements on any intermediate filament protein thus bearing significant implications in laminopathies and other diseases associated with intermediate filaments.

Dermotropic Leishmania donovani in Sri Lanka: visceralizing potential in clinical and preclinical studies.

The visceralizing potential of apparently dermotropic Leishmania donovani in Sri Lanka (L. donovani-SL) was investigated through long-term follow-up of cutaneous leishmaniasis (CL) patients and in vivo and in vitro experimental infection models. CL patients (n = 250) treated effectively with intra-lesional antimony therapy were followed-up six monthly for 4 years. There was no clinical evidence of visceralization of infection (VL) during this period. Infection of BALB/c mice with L. donovani-SL (test) through intra-dermal route led to the development of cutaneous lesions at the site of inoculation with no signs of systemic dissemination, in contrast to the observations made in animals similarly infected with a visceralizing strain of L. donovani-1S (control). Cytokine (IL-10, IFN-γ) release patterns of splenocytes and lymph node cell cultures derived from mice primed with experimental infections (with either test or control parasites) revealed significantly high IFN-γ response associated with test mice with CL, while prominent IL-10 levels were observed in association with control mice with VL. Furthermore, diminished infection efficiency, intracellular growth and survival of L. donovani-SL parasites compared with L. donovani-1S were evident through in vitro macrophage infection experiments. These studies confirm, for the first time, the essential dermotropic nature of L. donovani-SL suggesting natural attenuation of virulence of local parasite strains.

Gallbladder Volume in Sikkimese Population.

Background Gall bladder volume can have clinical and therapeutic implications and possibly affect certain pathophysiological mechanisms of many diseases affecting the gallbladder including gall stones. Objective The objective of the study was to establish baseline indices of gallbladder volume for the Sikkimese population and determine its correlation with age, sex and Body Mass Index. Method A prospective epidemiologic study on selected 100 patients (equal male to female ratio) over the age of 36 years, undergoing ultrasound scan of abdomen, was undertaken. Age, Sex, Body Mass Index and gall bladder volume for each subject were collected and analysed statistically. Spearman's correlation test was performed to look for significant variables. Result The overall mean gallbladder volume in the present study was 15.47±7.9 ml with 17.2±8.9 ml and 13.74±6.4 ml being average volumes in males and females respectively, which gives the baseline indices for the Sikkimese population. Gall bladder volume was strikingly increased in obese subjects. There was a positive correlation between gall bladder volume and age (r=0.114), gender (r=0.182) and BMI (r= 0.175) but the strength of correlation was weak and not statistically significant (p <0.001). Conclusion Ultrasonography is an easy and effective method for evaluation of gall bladder volume. Sikkimese males have a larger fasting gall bladder volume which is directly correlated with higher body mass index. Fasting gall bladder volume has a weak correlation with advancing age.

Cell-based gene therapy against HIV.

The ability to integrate inside the host genome lays a strong foundation for HIV to play hide and seek with the host's immune surveillance mechanisms. Present anti-viral therapies, although successful in suppressing the virus to a certain level, fail to wipe it out completely. However, recent approaches in modifying stem cells and enabling them to give rise to potent/resistant T-cells against HIV holds immense hope for eradication of the virus from the host. In this review, we will briefly discuss previous landmark studies on engineering stem cells or T-cells that have been explored for therapeutic efficacy against HIV. We will also analyze potential benefits and pitfalls of some studies done recently and will share our opinion on emerging trends.

Percutaneous vascular closure using an anchored collagen plug provides effective haemostasis following both antegrade and retrograde femoral arterial punctures.

OBJECTIVES: Small published series suggest a higher failure rate for Angio-Seal vascular closure device (VCD) deployment after antegrade femoral puncture, despite the need for shorter haemostasis times, early discharge, and possibly higher turnover. We seek to compare the deployment efficacy and complications of the Angio-Seal VCD between antegrade and retrograde femoral arterial deployments. METHODS: Radiological data was retrospectively analysed from prospective databases from the hospitals' Computerised Radiology Information System (CRIS) over 2010-2012. Angio-Seal gauge, Rutherford class (as applicable), puncture mode (used to classify deployment as antegrade/retrograde), sheath sizes, and deployment success/failures were recorded. Numerical/statistical analyses were undertaken using Microsoft Excel 10/SISA software. RESULTS: A total of 519 Angio-Seal VIP VCDs were deployed in 470 patients over 2010-2012 (13 other patients could not be analysed due to incomplete data). Sheath sizes for antegrade/retrograde femoral puncture were 5F, n = 22/9; 6F, n = 244/223; 7F, n = 1/5; 9F, n = 4/0. 8F Angio-Seal VIPs were used for 9F punctures only, 6F for the remainder. The overall deployment success rate was 93.7%. In total, 247 (91.1%) successful antegrade deployments were undertaken with 24 (8.9%) failures, compared with 229 (96.6%) successful retrograde deployments with eight (3.4%) failures. Antegrade/retrograde failures were classed as failure to deploy, n = 15/5; bleeding despite successful deployment requiring supplementary compression, n = 6/1; haematoma formation, n = 2/1; groin pain, n = 0/1; vessel stenosis, n = 1/0. Higher deployment failures were noted with antegrade deployment (p < .02, chi-square test). CONCLUSIONS: Angio-Seal deployment is successful for both antegrade/retrograde femoral punctures albeit with a higher antegrade failure rate.

Role of pinch in Argon impurity transport in ohmic discharges of Aditya-U Tokamak.

We present experimental results of the trace argon impurity puffing in the ohmic plasmas of Aditya-U tokamak performed to study the argon transport behaviour. Argon line emissions in visible and Vacuum Ultra Violet (VUV) spectral ranges arising from the plasma edge and core respectively are measured simultaneously. During the experiments, space resolved brightness profile of Ar1+ line emissions at 472.69 nm (3p44s 2P3/2-3p44p 2D3/2), 473.59 nm (3p44s 4P5/2-3p44p 4P3/2), 476.49 nm (3p44s 2P1/2-3p44p 2P3/2), 480.60 nm (3p44s 4P5/2-3p44p 4P5/2) are recorded using a high resolution visible spectrometer. Also, a VUV spectrometer has been used to simultaneously observe Ar13+ line emission at 18.79 nm (2s22p 2P3/2-2s2p2 2P3/2) and Ar14+ line emission at 22.11 nm (2s2 1S0-2s2p 1P1). The diffusivity and convective velocity of Ar are obtained by comparing the measured radial emissivity profile of Ar1+ emission and the line intensity ratio of Ar13+ and Ar14+ ions, with those simulated using the impurity transport code, STRAHL. Argon diffusivities ~ 12 m2/s and ~ 0.3 m2/s have been observed in the edge (ρ > 0.85) and core region of the Aditya-U, respectively. The diffusivity values both in the edge and core region are found to be higher than the neo-classical values suggesting that the argon impurity transport is mainly anomalous in the Aditya-U tokamak. Also, an inward pinch of ~ 10 m/s mainly driven by Ware pinch is required to match the measured and simulated data. The measured peaked profile of Ar density suggests impurity accumulation in these discharges.

Early postnatal exposure of mice to side-steam tobacco smoke increases neuropeptide Y in lung.

Our recent study showed that prenatal and early postnatal exposure of mice to side-steam tobacco smoke (SS), a surrogate to environmental tobacco smoke (ETS), leads to increased airway responsiveness and sensory innervation later in life. However, the underlying mechanism initiated in early life that affects airway responses later in life remains undefined. The concomitant increase in nerve growth factor (NGF) after exposures suggests that NGF may be involved the regulation of airway innervation. Since NGF regulates sympathetic nerve responses, as well as sensory nerves, we extended previous studies by examining neuropeptide Y (NPY), a neuropeptide associated with sympathetic nerves. Different age groups of mice, postnatal day (PD) 2 and PD21, were exposed to either SS or filtered air (FA) for 10 consecutive days. The level of NPY protein in lung and the density of NPY nerve fibers in tracheal smooth muscle were significantly increased in the PD2-11SS exposure group compared with PD2-11FA exposure. At the same time, the level of NGF in lung tissue was significantly elevated in the PD2-11SS exposure groups. However, neither NPY (protein or nerves) nor NGF levels were significantly altered in PD21-30SS exposure group compared with the PD21-30FA exposure group. Furthermore, pretreatment with NGF antibody or K252a, which inhibits a key enzyme (tyrosine kinase) in the transduction pathway for NGF receptor binding, significantly diminished SS-enhanced NPY tracheal smooth muscle innervation and the increase in methacholine-induced airway resistance. These findings show that SS exposure in early life increases NPY tracheal innervation and alters pulmonary function and that these changes are mediated through the NGF.

Hydrogeochemical processes controlling the high fluoride concentration in groundwater: a case study at the Boden block area, Orissa, India.

The present investigation reports the assessment of hydrochemical/geochemical processes controlling the concentration of fluoride in groundwater of a village in India (Boden block, Orissa). Boden block is one of the severely affected fluoride-contaminated areas in the state of Orissa (India). The sampling and subsequent analysis of water samples of the study area was carried out following standard prescribed methods. The results of the analysis indicate that 36.60% groundwater F(-) concentration exceeds the limit prescribed by the World Health Organization for drinking water. The rock interaction with groundwater containing high concentration of HCO(3)(-) and Na(+) at a higher pH value of the medium could be one of the important reasons for the release of F(-) from the aquatic matrix into groundwater. Geochemical classification of groundwater based on Chadha rectangular diagram shows that most of the groundwater samples having fluoride concentration more than 1.5 mg L(-1) belongs to the Na-K-HCO(3) type. The saturation index values evaluated for the groundwater of the study area indicated that it is oversaturated with respect to calcite, whereas the same is undersaturated with respect to fluorite content. The deficiency of calcium ion concentration in the groundwater from calcite precipitation favors fluorite dissolution leading to excess of fluoride concentration. The risk index was calculated as a function of fluoride level in drinking water and morbidity of fluorosis categorizes high risk for villages of Amera and Karlakote panchayat of Boden block.

Usability study of a sleeve attachment device for enhancing ease of use of metered dose inhalers in children.

BACKGROUND: Children with asthma often lack the strength to activate their pressurised metered dose inhaler (pMDI). A recently developed sleeve device that attaches to a pMDI reduces the activation force of pMDIs from 36 - 39 Newtons (N) to 12.6 N and monitors the remaining doses with a built-in counter. OBJECTIVES: To examine the usability and patient experience of the Easy Squeezy (ES) sleeve attachment device in the paediatric patient population. METHODS: This cross-over study included 40 participants aged 5 - 10 years, half of whom had previous experience in using a pMDI. The experienced participants had used a pMDI for at least 1 year, and the inexperienced participants had no experience of using a pMDI. Participants and their parents recorded their responses on the ease of use, perceptions and satisfaction with using the pMDI alone and the pMDI with the ES. RESULTS: The participants felt that it was easier for them to activate the pMDI using the ES. They liked the ES device more than the pMDI and felt happier using the ES device. The parents reported that their children would be happier using the ES and would find it easier to activate the pMDI using the ES, that the built-in counter in the ES would make it easier to keep track of the doses, and that their children would be more likely to take the ES to school and use it there compared with the pMDI. They would recommend the ES to other parents and were willing to buy the device with their own money. CONCLUSION: The paediatric participants and their parents reported that the ES made it easier for children to activate the pMDI, that the counter made it easier to keep count of the doses, and that the aesthetics of the ES could potentially remove the stigma attached to use of a pMDI.

Initial results from near-infrared spectroscopy on ADITYA-U tokamak.

Spectroscopy in vacuum ultraviolet (VUV) and visible ranges plays an important role in the investigation and diagnosis of tokamak plasmas. However, under harsh environmental conditions of fusion grade devices, such as ITER, VUV-visible systems encounter many issues due to the degradation of optical components used in such systems. Here, near-infrared (NIR) spectroscopy has become an effective tool in understanding the edge plasma dynamics. Considering its importance, a NIR spectroscopic diagnostic has been developed and installed on the ADITYA-U tokamak. The system consists of a 0.5 m spectrometer having three gratings with different groove densities, and it is coupled with a linear InGaAs photodiode array. Radiation from the ADITYA-U edge plasma has been collected using a collimating lens and optical fiber combination and transported to the spectrometer. The spectrum in the NIR range from the ADITYA-U plasma has been recorded using this system, in which Paß and Paγ along with many spectral lines from neutral and singly ionized impurities have been observed. The influxes of H and C have been estimated from measurements. The H influx value is found to be 2.8 × 1016 and 1.9 × 1016 particles cm-2 s-1 from neutral hydrogen lines Hα and Paß, respectively, and the C influx value is found to be 3.5 × 1015 and 2.9 × 1015 particles cm-2 s-1 from the neutral carbon and singly ionized carbon, respectively. A good agreement is seen between these results and the results obtained by using a routine photomultiplier tube based diagnostic.

The impact of COVID-19 national lockdown on orthopaedic trauma admissions in the northern part of South Africa: A multicentre review of tertiary- and secondary-level hospital admissions.

BACKGROUND: COVID-19 national lockdown measures in South Africa (SA) have been under scrutiny since they were implemented in March 2020. Currently there are no studies showing the effect of the first lockdown on hospital admissions in the northern provinces of SA. OBJECTIVES: To evaluate the impact of national lockdown restrictions on musculoskeletal injury admissions in three hospitals across three provinces (Gauteng, Limpopo and North West). METHODS: In a retrospective review, we compared orthopaedic trauma admissions from 1 April 2020 to 30 June 2020 (during alert level 5 of the national lockdown) with cases admitted during the same period in 2019 (non-lockdown). We reviewed the number of admissions, demographic data and mechanisms of injury in the adult and paediatric population groups. RESULTS: A total of 449 patients were admitted with musculoskeletal injuries during the lockdown period compared with 664 patients in 2019, equating to a 32% reduction in total admissions. While there was an 8% increase in paediatric admissions during lockdown at Dr George Mukhari Academic Hospital, adult admissions decreased in all centres. More young males were admitted during both lockdown (mean age 39.8 years) and non-lockdown (mean age 41.2 years) periods than females (p=0.004). There were significant reductions in the number of injuries due to motor vehicle accidents (59%) and in the number of gunshot wounds (36%) during lockdown. However, we observed an 11% rise in injuries related to suicide attempts among adult admissions during the lockdown period. CONCLUSIONS: Lockdown restrictions resulted in a significant reduction in orthopaedic trauma admissions, and were effective in terms of allowing institutions to direct resources to the management of COVID-19 patients. In the light of the increased suicide attempts observed during lockdown, future lockdown regulations should include comprehensive measures to relieve socioeconomic stress.

Low 30-day mortality in South African orthopaedic patients undergoing surgery at an academic hospital during the first wave of the COVID-19 pandemic: It was safe to perform orthopaedic procedures at our hospital during the first COVID-19 peak.

BACKGROUND:  Initial local and global evidence suggests that SARS-CoV-2-infected patients who undergo surgery, and those who become infected perioperatively, have an increased mortality risk post surgery. OBJECTIVES: To analyse and describe the 30-day mortality, presurgical COVID-19 status and hospital-acquired SARS-CoV-2 infection rates of patients, both SARS-CoV-2-positive and negative, undergoing orthopaedic surgery at a tertiary academic hospital in South Africa (SA) during the first COVID-19 peak. METHODS: This single-centre, observational, prospective study included patients who underwent orthopaedic procedures from 1 April 2020 (beginning of the COVID-19 case increase in SA) to 31 July 2020 (first COVID-19 peak in SA). All patients were screened for COVID-19 and were confirmed positive if they had a positive laboratory quantitative polymerase chain reaction test for SARS-CoV-2 RNA on a nasopharyngeal or oral swab. Thirty-day mortality, presurgical COVID-19 status and hospital-acquired SARS-CoV-2 infection were assessed. RESULTS:  Overall, a total of 433 operations were performed on 346 patients during the timeframe. Of these patients, 65.9% (n=228) were male and 34.1% (n=118) were female. The mean (standard deviation) age was 42.5 (16.8) years (range 9 - 89). Of the patients, 5 (1.4%) were identified as COVID-19 patients under investigation (PUI) on admission and tested positive for SARS-CoV-2 before surgery, and 1 (0.3%) contracted SARS-CoV-2 perioperatively; all survived 30 days post surgery. Twenty-nine patients were lost to follow-up, and data were missing for 6 patients. The final analysis was performed excluding these 35 patients. Of the 311 patients included in the final 30-day mortality analysis, 303 (97%) had a follow-up observation ≥30 days after the operation. The overall 30-day mortality for these patients was 2.5% (n=8 deaths). None of the recorded deaths were of screened COVID-19 PUI. CONCLUSIONS: We report a low 30-day mortality rate of 2.5% (n=8) for patients undergoing orthopaedic surgery at our hospital during the first COVID-19 peak. None of the deaths were COVID-19 related, and all patients who tested SARS-CoV-2-positive, before or after surgery, survived. Our overall 30-day mortality rate correlates with several other reports of orthopaedic centres analysing over similar timeframes during the first peak of the COVID-19 pandemic. Regarding mortality and SARS-CoV-2 infection risk, we can conclude that with the appropriate measures taken, it was safe to undergo orthopaedic procedures at our hospital during the first peak of the COVID-19 pandemic in SA.

Drastic reduction of orthopaedic services at an urban tertiary hospital in South Africa during COVID-19: Lessons for the future response to the pandemic.

BACKGROUND: The COVID-19 pandemic has impacted on the global surgery landscape. OBJECTIVES: To analyse and describe the initial impact of the COVID-19 pandemic on orthopaedic surgery at Groote Schuur Hospital, a tertiary academic hospital in South Africa. METHODS: The number of orthopaedic surgical cases, emergency theatre patient waiting times, and numbers of outpatient clinic visits, ward admissions, bed occupancies and total inpatient days for January - April 2019 (pre-COVID-19) were compared with the same time frame in 2020 (COVID-19). The COVID-19 timeframe included initiation of a national 'hard lockdown' from 26 March 2020, in preparation for an increasing volume of COVID-19 cases. RESULTS: April 2020, the time of the imposed hard lockdown, was the most affected month, although the number of surgical cases had started to decrease slowly during the 3 preceding months. The total number of surgeries, outpatient visits and ward admissions decreased significantly during April 2020 (55.2%, 69.1% and 60.6%, respectively) compared with April 2019 (p<0.05). Trauma cases were reduced by 40% in April 2020. Overall emergency theatre patient waiting time was 30% lower for April 2020 compared with 2019. CONCLUSIONS: COVID-19 and the associated lockdown has heavily impacted on both orthopaedic inpatient and outpatient services. Lockdown led to a larger reduction in the orthopaedic trauma burden than in international centres, but the overall reduction in surgeries, outpatient visits and hospital admissions was less. This lesser reduction was probably due to local factors, but also to a conscious decision to avoid total collapse of our surgical services.

Climate change and respiratory disease: European Respiratory Society position statement.

Climate change will affect individuals with pre-existing respiratory disease, but the extent of the effect remains unclear. The present position statement was developed on behalf of the European Respiratory Society in order to identify areas of concern arising from climate change for individuals with respiratory disease, healthcare workers in the respiratory sector and policy makers. The statement was developed following a 2-day workshop held in Leuven (Belgium) in March 2008. Key areas of concern for the respiratory community arising from climate change are discussed and recommendations made to address gaps in knowledge. The most important recommendation was the development of more accurate predictive models for predicting the impact of climate change on respiratory health. Respiratory healthcare workers also have an advocatory role in persuading governments and the European Union to maintain awareness and appropriate actions with respect to climate change, and these areas are also discussed in the position statement.