With their low lying, flat topography, river deltas and coastal plains are extremely prone to relative sea level rise and other water-related hazards. This calls for accurate elevation data for flood ...risk assessments, especially in the densely populated Southeast Asian deltas. However, in data-poor countries such as Myanmar, where high accuracy elevation data are not accessible, often only global satellite-based digital elevation models (DEMs), suffering from low vertical accuracy and remote sensing artefacts, can be used by the public and scientific community. As the lack of accurate elevation data hampers the assessment of flood risk, studying available information on land elevation and its reliability is essential, particularly in the context of sea level rise impact. Here, we assess the performance of 10 global DEMs in the Ayeyarwady Delta (Myanmar) against the new, local, so-called AD-DEM, which was generated based on topographical map elevation data. To enable comparison, all DEMs were converted to a common vertical datum tied to local sea level. While both CoastalDEM v2.1 (Kulp and Strauss, 2021) and FABDEM (Hawker et al., 2022) perform comparably well, showing the highest correspondence in comparison with AD-DEM and low-elevation spot heights, FABDEM outperforms CoastalDEM v2.1 by the absence of remote sensing artefacts. The AD-DEM provides a high-accuracy, open and freely available, and independent elevation dataset suitable for evaluating land elevation data in the Ayeyarwady Delta and studying topography and flood risk at large scale, while small-scale investigations may benefit from a FABDEM locally improved with data from the AD-DEM.
Background
Posttransfusion hyperhemolysis syndrome is a rare but life‐threatening form of delayed hemolytic transfusion reaction with lysis of both transfused and autologous red cells, seen ...predominantly in patients with sickle cell disease. Macrophage activation is thought to play a major role in its pathophysiology. Standard treatment is with intravenous immunoglobulin and steroids but refractory cases pose a major clinical problem. Tocilizumab is a humanized monoclonal antibody against the IL‐6 receptor that can inhibit IL‐6 induced macrophage activation.
Methods and materials
We describe the case of a 33‐year‐old woman with sickle cell anemia and posttransfusion hyper hemolysis syndrome refractory to standard therapy, treated with Tocilizumab. We also review all cases reported in the literature where Tocilizumab was used for posttransfusion hyperhemolysis.
Results
Treatment with Tocilizumab was well tolerated with no observed adverse events. There was no further drop in Hb after day 2 of treatment with subsequent continuous gradual improvement. Her bilirubin dropped significantly after the first dose and continued to improve, while ferritin and LDH reduced significantly after day 2 of treatment with Tocilizumab and continued to drop thereafter. Like in our case, all other cases in the literature where Tocilizumab was used for posttransfusion hyperhemolysis led to rapid clinical responses and no adverse events.
Discussion
Even though the number of cases of posttransfusion hyper hemolysis syndrome treated with Tocilizumab are few, they have all been associated with rapid clinical responses with no observed adverse events suggesting that the role of Tocilizumab in this context needs to be further explored.
BACKGROUND
The U– phenotype is extremely rare and is found predominantly in black African populations at a frequency of between 0.2 and 1.7%. In European populations, U– units are therefore rare, ...with limited availability in the United Kingdom. Anti‐U is clinically significant and is known to cause hemolytic transfusion reactions (HTRs) and hemolytic disease of the fetus and newborn. It has been suggested that intravenous immunoglobulin (IVIG) may be considered as an option among supportive therapy for urgent transfusion when clinically significant antigen‐matched units are not available. We report three cases with anti‐U transfused with least‐incompatible RBC units, their outcomes, and their clinical management.
STUDY DESIGN AND METHODS
Intravenous immunoglobulin was prescribed when least‐incompatible units must be issued in patients with anti‐U to ameliorate acute HTR and prevent the development of delayed HTR. We report the outcome of these cases.
RESULTS
Of the case reports described, one patient with weak anti‐U developed a delayed HTR after transfusion with incompatible units due to an anamnestic response. Two additional patients are described, with the use of IVIG as a precautionary measure to prevent the development of HTRs when transfused with antigen‐positive incompatible units. No acute HTRs or delayed HTRs were noted upon follow‐up.
CONCLUSION
U– units are not always readily available and transfusion support requires close collaborative working among a multidisciplinary team. Transfusion with antigen‐positive incompatible units with IVIG cover both ameliorates acute HTRs and prevents the development of delayed HTRs.
BACKGROUND
The therapeutic value of the use of intravenous immunoglobulin (IVIG) to correct anemia and thrombocytopenia as a result of immunologic causes (hemolytic disease of the fetus and newborn ...and fetal or neonatal alloimmune thrombocytopenia) have been well established. Few published papers exist regarding the use of IVIG in adult settings. We report two patients with clinically significant antibodies against high‐incidence antigens, who were successfully transfused with incompatible red blood cells (RBCs), in conjunction with IVIG plus steroids and IVIG.
CASE REPORTS
Case 1 was a 25‐year‐old patient (Hb SC) who was admitted with low hemoglobin (Hb) and low reticulocyte count. A diagnosis of parvovirus‐induced RBC hypoplasia was made. The patient's sample contained anti‐E, anti‐N, and anti‐U. The Hb decreased to 37 g/dL and urgent transfusion was provided with E–, N–, “least‐incompatible” RBC units covered by IVIG and hydrocortisone. Case 2 was a 54‐year‐old patient who was admitted after a road traffic accident. Nonspecific weak antibody was detected. She received 6 units of least‐incompatible RBCs. She was transferred to another hospital and received 2 least‐incompatible units. Hb level decreased further and an additional unit was transfused. Samples were referred to the reference laboratory and strong anti‐Jra detected. As there was clinical and laboratory evidence of hemolysis and Jr(a–) units were not available, IVIG was prescribed and least‐incompatible units were transfused.
RESULTS
There were no hemolytic transfusion reactions, hemolysis ceased, and anemia improved in both cases.
CONCLUSION
Prophylaxis with IVIG plus steroids and IVIG should be considered as a therapeutic option when transfusion of incompatible units is necessary.
BACKGROUND
Antenatal cases of Bombay‐phenotype (Oh) individuals and hemolytic disease of the fetus and newborn (HDFN) are not well described in the literature. We present two case reports of ...high‐titer anti‐H in pregnant Oh individuals and their serologic investigation, clinical management, and subsequent outcomes. We describe current published cases detailing pregnancy in Oh individuals, to add to the evidence base for clinical decision making and management of pregnancy.
STUDY DESIGN AND METHODS
We describe two case reports of high‐titer anti‐H in pregnancy in Oh individuals. We summarize published cases to date, to inform clinical decision making and antenatal management in individuals with the Bombay phenotype.
RESULTS
Of the case reports described, neither were affected by HDFN due to anti‐H. Antibody titers were high in both cases (immunoglobulin G titer scores, 512 and 4000, respectively) and would be expected to cause some degree of HDFN, a surprising finding. Regular mean cerebral artery Doppler ultrasound was normal. Patient blood management (PBM) techniques ensured that the patient's hemoglobin (Hb) levels were monitored and maintained. Transfusion intervention was not required, with minimal blood loss recorded at birth in both cases.
CONCLUSION
High‐titer anti‐H in Oh pregnancies may, in rare cases, cause HDFN, but evidence suggests that this may not be the case in all pregnancies. We recommend a multidisciplinary approach, with prompt referral to a fetomaternal medicine unit, combined with PBM strategies, and a planned delivery with the provision of rare‐phenotype units (if available and if indicated) on standby.
Summary
Post‐transfusion hyperhaemolysis syndrome (PTHS) is a rare life‐threatening transfusion complication reported mainly in sickle cell patients. Its pathogenesis is poorly understood. ...Antibody‐mediated haemolysis and bystander effect have been proposed as putative mechanisms, but in half of cases, red cell antibodies are undetectable, and PTHS develops despite transfusion of cross‐matched compatible RBC. An alternate hypothesis proposes activated macrophages as the main drivers of red cell destruction through direct phagocytosis. We report the histopathological findings of two patients with PTHS showing extensive macrophage expansion and erythrophagocytosis, supportive of macrophage activation driving PTHS. This supports a possible role for novel therapies that target macrophage activation.
Wind is a great sustainable energy source for harvesting due to its abundant characteristic. Typically, large space, loud noise, and heavy equipment are essential for a general wind power plant and ...it is solely operated by big-scale wind. However, wind energy can be efficiently harvested by utilizing the triboelectric nanogenerator due to its abundance, ubiquity, and environmentally friendliness. Furthermore, a few previously reported wind-driven triboelectric nanogenerators, which have the bulk fluttering layer by wind, still show difficulty in generating electricity under the conditions of weak wind because of the static friction arisen from the inherent structure. In this case, the output performance is deteriorated as well as the generator cannot operate completely. In this work, a wind-driven triboelectric nanogenerator (wind-TENG) based on the fluttering of the PTFE strips is proposed to solve the aforementioned problems. At the minimum operating wind pressure of 0.05 MPa, this wind-driven TENG delivers the open-circuit voltage of 3.5 V, short-circuit current of 300 nA, and the associated output power density of 0.64 mW/m
at the external load resistance of 5 MΩ. Such conditions can be used to light up seven LEDs. Moreover, this wind-TENG has been utilized as a direction sensor which can sense the direction at which the wind is applied. This work thus provides the potential application of the wind-TENG as both self-driven electronics and a self-powered sensor system for detecting the direction under environmental wind.
We investigated the role of nano-silver (NAg) and the bacterial strain
in increasing the vase life of cut carnation flowers 'Omea.' NAg treatment extended vase life of the flowers by increasing ...relative fresh weight, antioxidant activities, and expression level of the cysteine proteinase inhibitor gene (
), and by suppressing bacterial blockage in stem segments, ethylene production and expression of ethylene biosynthesis genes and
gene, compared with the control. Out of all the treatments, administration of 25 mg L
NAg gave the best results for all the analyzed parameters. Interestingly, application of
also extended the vase life of cut flowers by 3 days in comparison with control flowers, and overall, showed better results than the control for all the analyzed parameters. Taken together, these results demonstrate the positive role of NAg and
in increasing the longevity of cut carnation flowers, and indicate that this effect is brought about through multiple modes of action.
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