Bilateral enhancing thalamic lesions in a 10 year old boy: case report

A young boy presented with monoparesis of the left arm. MRI disclosed bilateral enhancing thalamic lesions. Biopsy results and subsequent clinical history were most compatible with postinfectious or acute disseminated encephalomyelitis. This represents one of the first cases of acute disseminated encephalomyelitis affecting the thalami, established by biopsy. This uncommon disease entity is reviewed and how it may affect the deep grey matter is described.     

BDNF blocks caspase-3 activation in neonatal hypoxia-ischemia

Hypoxic-ischemic (H-I) injury to the brain in the perinatal period often leads to significant long-term neurological deficits. In a model of neonatal H-I injury in postnatal day 7 rats, our previous data have shown that cell death with features of apoptosis is prominent between 6 and 24 h after H-I and that neurotrophins, particularly BDNF, can markedly protect against tissue loss. During brain development, caspase-3 is required for normal levels of programmed cell death. Utilizing an antibody specific for the activated form of caspase-3, CM1, we now show that caspase-3 is specifically activated in neuronal cell bodies and their processes beginning at 6 h and peaking 24 h following unilateral carotid ligation and exposure to hypoxia in postnatal day 7 rats. Caspase-3 activation began to occur in cortex at 6 h and in striatum and hippocampus at 12-18 h. Caspase-3 activation was also observed in developing oligodendrocytes. Intracerebroventricular injection of BDNF prior to H-I injury almost completely abolished evidence of H-I-induced caspase-3 activation in vivo. Utilizing a specific molecular marker of an apoptotic pathway, these findings demonstrate that H-I injury to the developing brain is a strong apoptotic stimulus leading to caspase-3 activation, that BDNF can block this process in vivo, and that the ability of BDNF to inhibit caspase activation and subsequent apoptosis likely accounts in large part for its protection against neuronal injury in this model.     

Distal radioulnar joint incongruity after shortening of the ulna

Coronal sections of the distal radioulnar joint (DRUJ) were studied in 13 preserved cadaveric wrists specimens before and after 2 mm of shortening of the ulna. The DRUJs were subclassified on the basis of the DRUJ angle and depth of the sigmoid notch. The changes in extent and location of area of contact and radioulnar separation were noted. Although reduction in area of contact occurred in every specimen and DRUJ type, the maximum radioulnar separation and reduction in area of contact occurred in the DRUJ type IB and IIB. This could be a possible factor producing point loading and subsequent occurrence of DRUJ remodelling in the long-term after shortening of the ulna.     

Autopsy study of maternal deaths.

OBJECTIVES: To obtain an insight into the underlying disorder or pathologies in different organs or systems, and to attempt clinicopathologic correlation in maternal deaths. METHODS: This is a retrospective study of 95 maternal autopsies done from 1993 to 2000 in Sassoon General Hospital, Pune, India. External examination, in situ examination, gross and microscopic examination was done in each case. The cause of death was arrived at after reviewing clinical details, available investigations, morphological findings, and clinicopathologic correlation. RESULTS: Ninety-five (45.02%) out of 211 maternal deaths were autopsied. Out of 95, there were 47 (49.5%) direct obstetric deaths, and 33 (34.7%) indirect obstetric deaths. Fifteen (15.8%) deaths were unrelated to pregnancy, 14 of which were due to infections. CONCLUSIONS: Hypertensive disorders associated with pregnancy (24.2%) and anemia (14.7%) were most common. In the hypertensive group, important findings were disseminated intravascular coagulation, hemorrhages in different organs and thromboemboli. Two cases were HIV seropositive. The autopsy helped to elucidate factors contributing to death and pathology in different organ systems.     

FNAC of salivary gland lesions with histopathological correlation

Hypothesis: Analysis of salivary gland lesions by FNAC and correlation with histopathology. To evaluate utility of FNAC in salivary gland lesions.Back ground: Salivary gland lesions form about 2–6.5% of all head and neck neoplasms in adults. They are easily accessible for FNAC (Fine Needle Aspiration Cytology) and risks of fistula formation or tumour implantation are low compared surgical biopsy. Also, cytology can provide a distinction between asalivary and non salivary lesion, benign and malignant lesions so also specific and non specific inflammation. Methods: Seventy patients were studied prospectively over two years. FNAC was done using 10 cc syringes and 20–22 no. needle. Histomorphology was assessed on routine H & E (haemotxylin and eosin) stained paraffin sections. SPAS (periodic acid Schiff) and mucicarmine satins were also done. Results: 80% of the lesions were neoplastic (61% benign, 31% malignant) and 20% were neoplastic. Pleomorphic adenoma was the most frequent benign neoplasm while mucoepidermoid carcinoma was the most frequent malignant lesion. Among the non neoplastic lesions, the maximum number of cases were of chronic sialadentis. In the present study, FNAC has a sensitivity of 94.54% and specificity of 80.95% for neoplastic lesions. Conclusions: FNAC was found to be a useful diagnostic tool in the evaluation of salivary gland lesions because of its simplicity, excellent patient compliance and rapid diagnosis. This cost effective tool is invaluable in planning the surgical management of the patient.     

Least-cost targets and avoided fossil fuel capacity in India’s pursuit of renewable energy

India has set aggressive targets to install more than 400 GW of wind and solar electricity generation by 2030, with more than two-thirds of that capacity coming from solar. This paper examines the electricity and carbon mitigation costs to reliably operate India’s grid in 2030 for a variety of wind and solar targets (200 GW to 600 GW) and the most promising options for reducing these costs. We find that systems where solar photovoltaic comprises only 25 to 50% of the total renewable target have the lowest carbon mitigation costs in most scenarios. This result invites a reexamination of India’s proposed solar-majority targets. We also find that, compared to other regions and contrary to prevailing assumptions, meeting high renewable targets will avoid building very few new fossil fuel (coal and natural gas) power plants because of India’s specific weather patterns and need to meet peak electricity demand. However, building 600 GW of renewable capacity, with the majority being wind plants, reduces how often fossil fuel power plants run, and this amount of capacity can hold India’s 2030 emissions below 2018 levels for less than the social cost of carbon. With likely wind and solar cost declines and increases in coal energy costs, balanced or wind-majority high renewable energy systems (600 GW or ≈ 45% share by energy) could result in electricity costs similar to a fossil fuel-dominated system. As an alternative strategy for meeting peak electricity demand, battery storage can avert the need for new fossil fuel capacity but is cost effective only at low capital costs (≈ USD 150 per kWh).

India emitted 3.2 billion metric tons of CO₂e in 2016, or 6% of annual global greenhouse gas emissions, placing it third only to China and the United States (1). One-third of these emissions were from coal-based electricity. At the same time, both per capita emissions and energy use remain well below global averages, suggesting a massive potential for growth of electricity generation and emissions (1). India’s primary energy demand is expected to double by 2040 compared to 2017 (2). Whether this energy comes from fossil or low-carbon sources will significantly affect the ability to limit average global temperature rise to below 2 °C.India is already pursuing significant technology-specific renewable energy targets—100 GW of solar and 60 GW of wind by 2022—and, in its Nationally Determined Contributions (NDC), committed to a 40% target for installed generation capacity from nonfossil fuel sources by 2030 (3). In 2019, in part to fulfill its NDC commitment, the Indian government proposed to install 440 GW of renewable energy capacity by 2030, with 300 GW of solar and 140 GW of wind capacity (4). Although costs of solar photovoltaic (PV) and wind technologies have declined significantly in recent years (5–7), the low cost of coal and integration costs associated with variable renewable energy (VRE) technologies like wind and solar may hinder India’s cost-effective transition to a decarbonized electricity system. This paper seeks to answer a number of questions that arise in the Indian context. What targets for wind and solar capacity have the lowest associated integration costs? Will these targets significantly offset the need to build fossil fuel generation capacity? What additional measures can we take to mitigate VRE integration costs?Merely comparing the levelized costs of VRE with the costs of conventional generation ignores additional cost drivers, which depend on the timing of VRE production and other conditions in the power system (8, 9). Quantifying these drivers requires models that choose lowest-cost generation capacity portfolios and simulate optimal system operation with detailed spatiotemporal data. Several prior studies address these system-level integration costs in a capacity expansion planning framework (10–16), often making decisions based on a limited sample of representative hours. Other studies explicitly estimate the relationship between long-run economic value (including integration costs) of VRE penetration levels (17, 18) but do not include VRE investment costs in their analysis. Few prior studies explore the impacts of high VRE penetration on India’s electricity system, and those that do either use the capacity expansion framework and do not evaluate the economic value of multiple VRE targets (4, 19, 20) or do not optimize capacity build around proposed VRE targets (21).Here we address this gap by estimating how different VRE targets affect the cost to reliably operate the Indian electricity system. To do so, we work with three interrelated models. First, using a spatially explicit model for VRE site selection, we identify the lowest levelized cost wind and solar sites to meet different VRE capacity targets, and study how the resource quality—and corresponding levelized cost—of selected sites changes with increasing VRE targets.Second, using a capacity investment model that accounts for VRE production patterns and optimal dispatch of hydropower and battery storage, we determine the capacity requirements and investment costs for coal, combined cycle gas turbines (CCGT), and combustion turbine (CT) peaker plants. Due to uncertainties in their future deployment (22), and because their current targets are relatively low (4), we did not consider new nuclear or hydro capacity in the main scenarios but include those in the sensitivity scenarios presented in SI Appendix, section 2. Third, we use a unit commitment and economic dispatch model to simulate hourly operation of the electricity system and estimate annual system operational costs. This model captures important technical constraints, including minimum operating levels, daily unit commitment for coal and natural gas plants, and energy limits on hydropower and battery storage. Rather than cooptimize VRE capacity, we compute the system-level economic value of a range of VRE targets by comparing the sum of the avoided new conventional capacity and energy generation costs to a no-VRE scenario. The net cost for a scenario is then the difference between the levelized cost of the VRE and the system-level economic value. Materials and Methods provides more detail on this process.Our results show that, despite greater levelized cost reduction forecasts for solar PV compared to wind technologies, VRE targets with greater amounts of wind have the lowest projected net carbon mitigation costs. This finding is robust to a range of scenarios, including low-cost solar and storage, and lower minimum generation levels for coal generators.We find that, although VRE production displaces energy production from conventional generators, it does very little to defer the need for capacity from those generators due to low correlation between VRE production and peak demand. Our findings suggest that VRE in India avoids far less conventional capacity than VRE in other regions in the world. These capacity requirements are slightly mitigated if India’s demand patterns evolve to more closely resemble demand in its major cities. Overall, we conclude that the importance of choosing the right VRE mix is significant when measured in terms of carbon mitigation costs: Whereas most solar-majority scenarios we examined lead to costs greater than or equal to estimates of the social cost of carbon (SCC), wind-majority mixes all cost far less than the SCC.     

The association of comorbid anxiety and depression with asthma-related quality of life and symptom perception in adults

Background and objective:   There are limited data on the association and interaction between anxiety and depression comorbidity and asthma-related quality of life (AQOL) and symptom perception. This study evaluated these associations in patients subsequent to an emergency department (ED) visit for asthma.
Methods:   This was a cross-sectional study of 110 (38 male) adult asthma patients (mean age 42 years), who had visited an ED in the previous 18 months. Participants completed the hospital anxiety and depression scale, measures of AQOL and the asthma symptom checklist.
Results:   Depression symptoms independently showed a significant negative association with AQOL after controlling for depression/anxiety, age, gender, smoking status and ED visits in the previous 12 months (ED-12). Overall, anxiety and depression symptoms accounted for 28.3% of the variance in AQOL. Greater anxiety was associated with increased perception of asthma-specific panic-fear and hyperventilation symptoms during an asthma attack, irrespective of depression status. Categorical analyses of groups of patients, differentiated by psychometric properties on the hospital anxiety and depression scale (anxiety vs normal, anxiety and depression vs normal depression) confirmed most results. However, for the anxiety group there was a significant association with the AQOL domains of emotional functioning and response to environmental stimuli, after controlling for depression symptoms.
Conclusions:   The negative association of depression symptom scores with AQOL and of anxiety with increased panic-fear and hyperventilation symptoms suggests a potential role for interventions addressing this psychological comorbidity, in order to improve AQOL.