The source and hydrochemical makeup of a stream reflects the connectivity between rainfall, groundwater, the stream, and is reflected to water quantity and quality of the catchment. However, in a semi-arid, thick, loess covered catchment, temporal variation of stream source and event associated behaviors are lesser known. Thus, the isotopic and chemical hydrograph in a widely distributed, deep loess, semi-arid catchment of the northern Chinese Loess Plateau were characterized to determine the source and hydrochemical behaviors of the stream during intra-rainfall events. Rainfall and streamflow were sampled during six hydrologic events coupled with measurements of stream baseflow and groundwater. The deuterium isotope (2H), major ions (Cl-, SO42-, NO3-, Ca2+, K+, Mg2+, and Na+) were evaluated in water samples obtained during rainfall events. Temporal variation of 2H and Cl- measured in the groundwater and stream baseflow prior to rainfall was similar; however, the isotope compositions of the streamflow fluctuated significantly and responded quickly to rainfall events, likely due to an infiltration excess, overland dominated surface runoff during torrential rainfall events. Time source separation using 2H demonstrated greater than 72% on average, the stream composition was event water during torrential rainfall events, with the proportion increasing with rainfall intensity. Solute concentrations in the stream had loglinear relationships with stream discharge, with an outling anomaly during an intra-rainfall event on Oct. 24, 2015. Stream Cl- behaved nonconservative during rainfall events, temporal variation of Cl- indicated a flush and washout at the onset of small rainfall events, a dilution but still high concentration pattern in high discharge and old water dominated in regression flow period. This study indicated that streamflow responded to rainfall events quickly and composition was dominated by overland flow. Stream isotope and hydrochemistry controlled by infiltration excess, overland flow indicated that stored water in the thick, loess covered areas were less connected with stream runoff. Solute transport may threaten water quality in the area, requiring further analysis of the performance of the eco-restoration project.

Glucocorticoids are highly effective medicines in the treatment of inflammatory disorders. However they cause severe dose-related adverse reactions, particularly where taken systemically for prolonged periods. Systemic glucocorticoids are therefore given at dosage sufficient to control the disease, then withdrawn as fast as is possible to minimise dose-related adverse effects without losing disease control. End-of-use adverse reactions present a major challenge in the withdrawal of long term (>3 weeks) glucocorticoids. Suppression of the hypothalamic-pituitary-adrenal (HPA) axis causes adrenal insufficiency, which is potentially life threatening and can become symptomatic as treatment is withdrawn. Adrenal insufficiency can be extremely difficult to differentiate from ‘glucocorticoid withdrawal syndrome’, where patients experience symptoms despite adequate adrenal function, and from psychological dependence. Long term systemic glucocorticoids should therefore be withdrawn slowly. The rate at which the dose is tapered should initially be determined by treatment requirements of the underlying disease. Once physiological doses (prednisolone 7.5mg or equivalent) are reached, the rate of reduction is determined by rate of HPA recovery and need for exogenous glucocorticoid cover while endogenous secretion recovers. If symptoms prevent treatment withdrawal, HPA testing should be used to look for adrenal insufficiency. Patients with adrenal insufficiency require physiological doses of glucocorticoids for adrenal replacement, which may be lifelong if the HPA axis fails to recover.

TitleThe Use of Ultrasound Guided Pre-Operative Colloidal Charcoal Injection in the Surgical Management of Recurrent Differentiated Thyroid CancerKeywords: thyroid cancer, neck recurrence, charcoal injection, ultrasound guidance, pre-operative localisation, reoperation

Backgound: To investigate the right heart function in COVID-19 (coronavirus disease 2019) patients with acute respiratory distress syndrome (ARDS). Methods: A retrospective analysis of 49 COVID-19 patients with ARDS was performed. Patients were divided into severe and critically severe group according to severity of illness. Age-matched healthy volunteers were recruited serving as a control group. The cardiac cavity diameters, tricuspid annular plane systolic excursion (TAPSE), tricuspid valve regurgitation pressure gradient biggest (TRPG), pulmonary arterial systolic pressure (PASP), maximum inferior vena cava diameter (IVCmax) and minimum diameter (IVCmin), and inferior vena cava collapse index (ICV-CI) were measured using echocardiography. Results: We found the TAPSE was significantly decreased in pneumonia patients compared to healthy subjects (P<0.0001), which was significantly lower in critically severe patients (P=0.0068). TAPSE was less than 17mm in 3 (8.6%) severe and 5 (35.7%) critically severe patients. There were no significant differences in PASP and TRPG between severe and critically severe patients. The IVCmax and IVCmin were significantly increased in critically severe patients compared to healthy subjects and severe patients (P < 0.01), whereas ICV-CI was significantly decreased (P < 0.05). COVID-19 patients had significantly larger right atrium and ventricle than healthy controls (P < 0.01). The left ventricular ejection fraction (LVEF) in critically severe patients was significantly lower than that in severe patients and healthy controls (P < 0.05). Conclusion: Right ventricular function is impaired in critically severe COVID-19 patients. The assessment and protection of the right heart function in COVID-19 patients should be strengthened.

Poly (ADP-ribose) polymerase 1 (PARP1) is a post-translational modifying enzyme and is also known to act as transcription factor and co-activator. PARP1 has been shown to be involved with diseases resulting in increased inflammation and several viral diseases have also been associated with PARP1 activation. PARP1 facilitates influenza A virus entry in host cells by degrading interferon receptor type I. PARP1 regulates expression of NFkB and downstream cytokine production and its inhibition is known to attenuate the expression of inflammatory cytokines. Thus, PARP1 plays an important role in host-pathogen interactions and pathogenesis. Moreover, pre-clinical and in vitro studies have shown that PARP1 inhibition may affect viability of several viruses including affecting replication of the SARS-CoV virus, a distant relative of the SARS-CoV-2 virus, the one which caused the SARS epidemic of 2002. Covid-19 has been declared a global pandemic; with symptoms of the disease now not limited to respiratory distress alone. Severe inflammation is observed in the lungs leading to a surge of cytokine release systemically, affecting heart function, ischemia and stroke. Inflammatory cytokines which are associated with severe comorbidities and mortalities due to chronic diseases are being upregulated in an acute fashion. There is no immediate treatment, and only palliative care is being provided. The current review will discuss mechanisms of PARP1 activation during viral infection, inflammatory diseases, cytokine expression and possibility of PARP1 in regulating cytokine storm and hyper-inflammation seen with Covid-19.

Introduction: Though there is currently no approved treatment for COVID-19, potential medications include lopinavir and doxycycline. Lopinavir is a broad-spectrum protease inhibitor successfully used during the SARS outbreak. Doxycycline is an antibiotic with immunomodulatory effects, which successfully treats dengue hemorrhagic fever. Comparing lopinavir combined with doxycycline with other commonly implemented COVID-19 treatment regimens is of medical significance. Methods: We conducted a retrospective study comparing two cohorts. One cohort strictly adhered to a treatment protocol of lopinavir combined with doxycycline (Lop/Dox), while the other cohort (Others) applied protocols based on combinations of favipiravir, hydroxychloroquine, and azithromycin. The outcomes evaluated were death from coronavirus and intubation. Results: During the study period, 161 and 114 patients were followed in the Lop/Dox cohort and the Others cohort, respectively. The Lop/Dox cohort was older and had lower O2 saturation at admission. The proportion of patients needing intubation did not differ between the cohorts (Lop/Dox, 15∙5%; Others, 16∙7%). The overall fatality rate likewise did not differ (12∙4%) in Lop/Dox and 8∙7% in the Others cohort). Older age and elapsed time between the onset of symptoms and hospitalization, O2 saturation at admission, and the lymphocyte to white blood cell ratio were independent risk factors for poor outcomes of the illness. Conclusion: This study showed that lopinavir plus doxycycline therapy is an effective treatment amongst moderate to severe COVID-19 patients.

Background Clofarabine has been shown to effectively induce remission in children with refractory leukemia. We conducted a prospective study to explore the use of clofarabine-based chemotherapy as a bridge-to-transplant approach. Methods Children with refractory acute leukemia were enrolled to receive two induction courses of clofarabine, etoposide, and cyclophosphamide (CloEC). Responding patients were scheduled for T-cell depleted haploidentical hematopoietic stem cell transplantation (HSCT). The primary objective was to improve survival by achieving sufficient disease control to enable stem cell transplantation. Secondary objectives were to evaluate safety and toxicity. Results Seven children with active disease entered the study. Two children responded to induction courses and underwent transplantation. Five children did not respond to induction: one died in progression after the first course; two received off-protocol chemotherapy and were transplanted; and two succumbed to progressive leukemia. All transplanted children engrafted and no acute skin graft-versus-host disease > grade I was observed. One child is alive and well 7.5 years after the first CloEC course. One child developed fulminant adenovirus hepatitis and died in continuous complete remission 7 months after start of induction. Two children relapsed and died 6.5 and 7.5 months after enrollment. Infection was the most common toxicity. Conclusions CloEC can induce responses in some patients with refractory acute leukemia but is highly immunosuppressive, resulting in substantial risk of life-threatening infections. In our study, haploidentical HSCT was feasible with sustained engraftment. No clinically significant organ toxicity was observed. Also, repeating CloEC probably does not increase the chance of achieving remission.

A reverse phase high performance liquid chromatography (RP-HPLC) method was developed for the quantitative determination of recombinant HIV-1 gp145 produced in CHO-K1 cells, as measured directly in culture supernatants. Samples were diluted in 50% D-PBS and 50% PowerCHO-2 (PC2) spent media, and resolved on a Zorbax 300SB-C8 Rapid Resolution (2.1 x 50 mm, 3.5 µm) column, fitted with a C8 guard column (Zorbax 300SB-C8, 2.1 x 12.5 mm, 5µm), using 0.1% TFA and 2% n-propanol as mobile phase A and 0.1% TFA, 70% isopropanol, and 20% acetonitrile as mobile phase B. The column temperature was 80ºC, the flow rate 1 ml/min and the absorbance monitored at 280 nm. The procedures and capabilities of the method were evaluated against the present criteria for linearity, limit of detection (LOD), accuracy, precision, and robustness of the International Conference on Harmonization (ICH) guidelines. Two different variants of the HIV-1 envelope protein (Env), CO6980v0c22 gp145 and SF162 gp140, were analyzed and their retention times were found to be different. The methods showed good linearity (R2 = 0.9996), a lower LOD of 2.4 µg/ml, and an average recovery of 101%. The analysis includes measurements of accuracy, inter-user precision, and robustness. Overall, we present a RP-HPLC method that could be applied for the quantitation of cell culture titers for this and other variants of HIV Env following ICH guidelines.

The influence of phenolic compounds on the enzymatic hydrolysis of cellulose was studied in depth using spectrophotometric techniques, adsorption analysis and Scanning Electron Microscopy (SEM). In this paper, both possible interactions between phenolic compounds and the enzyme or the substrate were investigated with the use of various phenolic compounds, cellulase from T. reesei, and Avicel. Three classes of phenolic compounds have been identified, based on their effect on the hydrolysis of cellulose: inhibitors (quercetin, kaempferol, cinnamic acid, luteolin, ellagic acid), non-inhibitors, and activators (ferulic acid, syringic acid, sinapic acid, vannilic acid). Secondly, since various structures of phenolic compounds were investigated, it was deduced that an -OCH3 group was necessary for the activating effect. Finally, based on the adsorption spectra and SEM images, a different way of adsorption (either on the enzyme or on the substrate) was noticed, depending if a phenolic compound was an inhibitor or an activator.

Coagulation factor XIII (FXIII) deficiency is a rare recessive bleeding disorder. Severe patients are caused by a complete absence of FXIIIA protein in plasma, but researches on the molecular mechanisms are limited. This study was to analyze the pathogenic mechanisms of three congenital FXIII deficiency patients. Plasma FXIII activities and antigens were significantly decreased in patients compared to healthy controls by fluorescent assay and western blot. One frameshift mutation and four missense mutations (p.Trp188Cys, p.His374Arg, p.Thr559Pro and p.His717Arg) around the catalytic core were identified. The mRNA levels of four mutants were nearly normal in COS7 cells, and the FXIIIA protein could be detected in cell lysis but not be expressed in the supernatant. Confocal microscopy studies showed clear outlines of cells with both wild FXIII and mutants, but some mutants gathered into clusters neither in the endoplasmic reticulum nor in the Golgi apparatus of cytoplasm, compared to the diffusely-distributed wild FXIII. Considering the above, we concluded that the three cases of FXIII deficiency were caused by p.Trp188Cys, p.His374Arg, p.Thr559Pro and p.His717Arg mutations in FXIIIA gene, which led to the gathering of FXIIIA in cytoplasm and then blocking its transportation into medium.

The molecular function of a protein relies on its structure. Understanding how mutations alter structure and function in multi-domain proteins, is key to elucidate how a pathological phenotype is generated. However, one may fall into the logical bias of assessing protein damage only based on the mutations that are viable (survivorship bias), which can lead to partial conclusions. This is the case of PNKP, an important nuclear and mitochondrial DNA repair enzyme with kinase and phosphatase function. Most mutations in PNKP are confined to the kinase domain, leading to a pathological spectrum of three apparently distinct clinical entities. Since proteins and domains may have a different tolerance to disease causing mutations, we evaluated whether mutations in PNKP are under survivorship bias. Even when all mutations in the kinase domain are deleterious, we found a mayor mutation tolerability landscape in terms of survival. Instead, the phosphatase domain is less tolerant due to its low mutation rates, higher degree of sequence conservation, lower dN/dS ratios, and more disease-propensity hotspots. Thus, in multi-domain proteins, we propose the term “Wald’s domain” for those who are not apparently more associated with disease, but that are less resistant to mutations in terms of survival.

Neurodevelopmental disorders, a group of early-onset neurological disorders with significantly clinical and genetic heterogeneity, remain a diagnostic odyssey for clinical genetic evaluation. In a total of 45 parent-child trios/quads with these disorders that was ‘not yet diagnosed’ by the traditional testing methods, we assessed the diagnostic yield by the combined use of standardized phenotypes and whole-exome sequencing data. Using a standardized vocabulary of phenotypic abnormalities from Human Phenotype Ontology (HPO), we performed deep phenotyping for these pedigrees to characterize multiple clinical features that was extracted from Chinese electronic medical records (EMRs). By matching HPO terms with known human diseases or cross-species comparison, together with whole-exome sequencing data, we prioritized candidate mutations/genes that underlies these pedigrees. We obtained a diagnostic yield of 49% (22 out of 45) with probably or possibly genetic diagnosis, of which the compound heterozygosity and de novo mutations accounted for the half of the diagnosis. Of note, the pedigrees with probable or possible diagnosis accompanied with a greater number of phenotypes implicated in non-nervous systems. The combined use of deep phenotyping and whole-exome sequencing provide implications for etiological evaluation for neurodevelopmental disorders in the clinical setting.

Objective: The main aim was to report the prevalence and severity of serious bacterial infections (SBI) in children with sickle cell disease at King Abdulaziz Hospital, Al Ahsa, Saudi Arabia to aid in determining whether outpatient management of such cases is appropriate. Methods: We conducted a retrospective chart review of febrile children less than 14 years of age admitted with sickle cell disease 2005 through 2015. Results: During 320 admissions, 25 children had SBIs (8%) including pneumonia (n=11), osteomyelitis (n=8), bacteremia (n=3, all with Salmonella species) and UTI (n=3). All recovered uneventfully. Conclusion: It appears that in the current era, less than 10% of febrile children with sickle cell disease in our center are diagnosed with a SBI. Over an 11-year period, there were no sequelae or deaths from SBI. Given these excellent outcomes, outpatient ceftriaxone should be considered for febrile well appearing children with sickle cell disease if they have no apparent source and parents are judged to be reliable.

Ipilimumab has been associated to medication related jaw osteonecrosis (MRONJ) only two times in literature. A woman underwent therapy with ipilimumab for Metastatic Melanoma in 2015 and she developed MRONJ in 2018. She was successfully treated with medical therapy alone. Vigilance in dental management of these patients is needed.

A coupling framework for modeling the non-constant-velocity approach of two fluid particles and the curved film drainage was developed, and an improved model was presented to predict the variable-velocity approach. Using this framework, the effect of the constant-velocity and variable-velocity approach on liquid film drainage was investigated. Two film drainage models based on immobile interface and fully mobile interface were adopted. The simulation results showed that the film thinning rate of the former is much less than that of the latter. In the case of constant-velocity approach, the immobile interface model showed a relatively flat curved film, while in the case of variable-velocity approach, three types of film, wimple, pimple and dimple, can be found. The different combinations of the drainage models and the approach velocity boundary conditions were compared with the experiments. The fully mobile interface model with variable-velocity approach can reasonably predict the coalescence and rebound of bubbles.

A document by Meisi Chen. Click on the document to view its contents.

The reaction of biochar-CO2 (C-CO2) is the speed-control reaction in a real-world gasifier. In this study, a new impulsive H2O(g) approach was introduced and optimized to improve the reactivity and syngas quality from biochar gasification using a TG analyzer and a tube furnace. An interaction of “independent to competitive” effect was observed during D-biochar gasified in CO2/H2O(g) under diffusion reaction regime. Micropores suitable for C-CO2 was produced by H2O(g) within a specific stage, which created the desired synergistic effect between C-CO2 and C-H2O(g). The introduction of pulsating H2O(g) was employed to supply micropores for C–CO2 and avoid the pore expansion effect of C–H2O(g) (which is negative to C–CO2). As a consequence, an improvement on the obtained syngas yield and a remarkable H2O(g)-saving effect were achieved using the new approach on the premise of not significantly reducing the corresponding carbon conversion than using the traditional mixed CO2/H2O(g) method.

Interaction of biochar gasified in the mixed CO2/steam is still unclear. In this study, the interactions between biochar with CO2 (C-CO2) and with steam (C-H2O(g)) were systematically investigated using a TG analyzer and a tube furnace. Results show that the chemical reaction state and intrinsic ash were the essential reasons for the existing together of the three interaction effects between C-CO2 and C-H2O(g). Specially, an inhibitive effect occurred during the demineralized biochar gasified in the CO2/H2O(g) atmosphere, expressing that the C-CO2 was inhibited by the C-H2O(g) under the chemical reaction regime. A competitive effect was dominated the interactions of demineralized biochar-CO2/H2O(g) under either intra- or extra-particle mass transfer regime; while an evolution of “inhibition to competition” appeared under the diffusion reaction regime. The presence of intrinsic ash such as Ca element was conducive to the occurring of the synergistic effect

Biometric signal processing has many of its applications in health care, rehabilitation research, and security systems. Nonetheless, over the last couple of decades, the biometric signal has encountered a new niche in educational research. In this work, the development of an eye-tracking device intended to be used for educational monitoring tasks is presented and learning studies. The device is based on the Electrooculography technique in contrast to the most common approaches that are based on image processing and computer vision devices and techniques. The proposed eye tracking device makes use of machine learning algorithms to detect the movements of the user's eye and in this way serve as a way of monitoring the cognitive activities of subjects or students. Moreover, a brief analysis of the cognitive skills related to the learning process of students that can be measure with the proposed system is presented. Also, a general comparison of other systems available in the current literature is made to compare the capabilities and areas of opportunity of the presented system. It is concluded that the device can recognize basic eye movements that can monitor basic cognitive behaviors like reading, writing, copying, or watching multimedia content through electronic devices.  With further development and the generation of study cases, the eye-tracking system can be enhanced for further research related to the educational field. 

Point 1: Deep learning algorithms are revolutionizing how hypothesis generation, pattern recognition, and prediction occurs in the sciences. In the life sciences, particularly biology and its subfields,  the use of deep learning is slowly but steadily increasing. However, prototyping or development of tools for practical applications remains in the domain of experienced coders. Furthermore, many tools can be quite costly and difficult to put together without expertise in Artificial intelligence (AI) computing.Point 2: We built a biological species classifier that leverages existing open-source tools and libraries. We designed the corresponding tutorial for users with basic skills in python and a small, but well-curated image dataset. We included annotated code in form of a Jupyter Notebook that can be adapted to any image dataset, ranging from satellite images, animals to bacteria. The prototype developer is publicly available and can be adapted for citizen science as well as other applications not envisioned in this paper.Point 3: We illustrate our approach with a case study of 219 images of 3 three seastar species. We show that with minimal parameter tuning of the AI pipeline we can create a classifier with superior accuracy. We include additional approaches to understand the misclassified images and to curate the dataset to increase accuracy.Point 4: The power of AI approaches is becoming increasingly accessible. We can now readily build and prototype species classifiers that can have a great impact on research that requires species identification and other types of image analysis. Such tools have implications for citizen science, biodiversity monitoring, and a wide range of ecological applications.

Objective Surgery is the standard treatment for most tumors in the prestyloid parapharyngeal space (PPS) but it can be a challenging procedure because of the anatomical complexity of the area. Prestyloid surgery can be performed with various lateral approaches or with a medial approach using transoral robotic surgery (TORS) – either alone or in combination with a transcervical incision. Here we report our experience in the surgical management of prestyloid PPS tumors. Design We have retrospectively compared results with lateral or medial approaches to surgical resection of prestyloid tumors. Participants Between 2015 and 2020, 28 patients with prestyloid PPS tumors underwent surgery at our center: 14 with lateral approaches, including transcervical, transcervical-parotid, and transcervical-mandibular, 12 with TORS, and two with TORS plus a transcervical incision. Main outcome measures Surgical time, post-surgical complications, length of hospital stay, need for feeding tube, and relapse-free survival in the two patient groups. Results Pleomorphic adenoma was the most frequent tumor and 60.7% of the tumors were benign. Tumor volume and maximum length were similar in patients undergoing surgery with a lateral approach and in those undergoing TORS. Intraoperative image guidance and ultrasound were used in 33% of TORS. TORS was associated with less surgical time, fewer complications, and shorter hospital stays. Survival rates were similar in the two groups. Conclusion The medial approach by TORS offers better surgical results in prestyloid tumors than the open lateral approach and can be refined by intraoperative guidance.

Abstract Background: The relation between health investment and research has been portrayed previously in several medical fields, showing a positive relation between economic resources and academic yield. Purpose: To assess the relations between various economic and bibliometric parameters in otolaryngology - head and neck surgery (ORL-HNS) of the OECD countries. Methods: Data regarding bibliometric parameters in ORL-HNS; number of publications, citations, citations per document and H index, between the years 1996 and 2019, were gathered from the Scimago Journal and Country Rank source. These data were then analysed in several breakdowns – seldom county, regional and language comparisons, in order to assess variations in ORL-HNS scholar activity. Economic data regarding each OECD country; GDP per capita, total health expenditure as percent of the GDP and GERD as percent of the GDP were gathered from the OECD and World Bank websites. The correlation between economic and bibliometric indicators was analysed. Results: Among 209,949 documents analysed, a strong correlation was found between H index and health expenditure (r=0.734, p=0.000), and a moderate connection was found between H index and both GDP per capita (r=0.459, p=0.005) and GERD as percent of GDP (r=0.579, p=0.000). Health expenditure showed the strongest correlations to bibliometric parameters. Nonetheless, most data showed some degree of positive correlations between economics and scholar productivity. Conclusion: This study emphasizes the positive relation between scholar productivity and economic indicators, mostly health expenditure, in the OECD countries in the field of ORL-HNS, implying the importance of health investment to ORL-HNS research.

Objective: To find out the prevalence, etiology, risk factor, presentation and treatment option of the dysphonic people, facilitate the prevention of the risk factor of it. Study Design: Cohort retrospective study. Setting: Academic tertiary care medical center. Subjects and Methods: A total 1739 dysphonic patient’s demographic data collected and analysed who attended in the department of Otolaryngology and Head-Neck Surgery, Comilla Medical College, and Comilla Medical Centre, Bangladesh. Results: Incidence of dysphonic patient was 1.16%, and yearly prevalence 33.33%. Out of 1739, the male was 1006 (57.85%), and the female was 733 (42.15%), 50-59 years were highest presentation 488 (28.06%). Among 1739, non-specific chronic laryngitis was 1015 (58.37%), dysphonia without structural change (MTD) 417 (23.98%), and malignancy 90 (5.17%). Off them, smoker was 911 (52.39%), voice abuser 469 (26.97%), industrial worker was 477 (27.43%), teacher 359 (20.64%), singer 151 (8.68%), and slum dweller was 528 (30.36%). Presenting feature revealed hoarse voice, reduced loudness, and tiring to talk above 90%. All patients assessed by rigid Hopkin’s telescope. Non-neoplastic benign and suspected malignant lesion was 1503 (86.43), neoplastic benign and malignancy was 236 (13.57%), conservatively treated 1512 (86.43%), and surgically 227 (13.6%) treated by micro-laryngeal surgery. Conclusion: Dysphonia effect more than 33% of people at some point of life. It definitely influences the quality of life and losing the patient health and wealth. Early and effective treatment decreases the further loss.

Background: There is paucity of literature on long term follow-up of patients with Hereditary angioedema (HAE) from developing countries. Objective: This study was carried out to analyse the clinical manifestations, laboratory features and genetic profile of 32 patients (21 male and 11 female) from 23 families diagnosed with HAE between January 1996 and December 2019. Methods: Data were retrieved from medical records of the Paediatric Immunodeficiency Clinic, Post Graduate Institute of Medical Education and Research, Chandigarh, India. Results: Median age at onset of symptoms was 6.25 years (range 1–25 years) and median age at diagnosis was 12 years (range 2-43 years). Serum complement C4 level was decreased in all patients. All patients had low C1- esterase inhibitor (C1-INH) quantitative level (type 1 HAE). SERPING1 gene sequencing could be carried out in 20 families. Of these, 11 were identified to have a pathogenic disease-causing variant in the SERPING1 gene. While 2 of these families had a previously reported mutation, remaining 9 families had novel pathogenic variants in SERPING1 gene. Because of non-availability of C1-INH therapy in India, all patients were given long term prophylaxis (attenuated androgens or tranexamic acid or a combination of the 2). Life-threatening episodes of laryngeal oedema were managed with fresh frozen plasma infusions. Only one disease related mortality was reported in the entire cohort. Conclusions: We report largest single centre cohort of patients with HAE from India. Attenuated androgens, fibrinolytic agents and fresh frozen plasma may be effectively used for management of HAE in resource limited settings.