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Your search keyword '"Chakravorty, Subarna"' showing total 6 results
Start Over Author "Chakravorty, Subarna" Topic hematology
6 results on '"Chakravorty, Subarna"'

1. Venous cerebral blood flow quantification and cognition in patients with sickle cell anemia.

Author

Stotesbury, Hanne, Hales, Patrick W, Koelbel, Melanie, Hood, Anna M, Kawadler, Jamie M, Saunders, Dawn E, Sahota, Sati, Rees, David C, Wilkey, Olu, Layton, Mark, Pelidis, Maria, Inusa, Baba PD, Howard, Jo, Chakravorty, Subarna, Clark, Chris A, and Kirkham, Fenella J

Abstract

Prior studies have described high venous signal qualitatively using arterial spin labelling (ASL) in patients with sickle cell anemia (SCA), consistent with arteriovenous shunting. We aimed to quantify the effect and explored cross-sectional associations with arterial oxygen content (CaO2), disease-modifying treatments, silent cerebral infarction (SCI), and cognitive performance. 94 patients with SCA and 42 controls underwent cognitive assessment and MRI with single- and multi- inflow time (TI) ASL sequences. Cerebral blood flow (CBF) and bolus arrival time (BAT) were examined across gray and white matter and high-signal regions of the sagittal sinus. Across gray and white matter, increases in CBF and reductions in BAT were observed in association with reduced CaO2 in patients, irrespective of sequence. Across high-signal sagittal sinus regions, CBF was also increased in association with reduced CaO2 using both sequences. However, BAT was increased rather than reduced in patients across these regions, with no association with CaO2. Using the multiTI sequence in patients, increases in CBF across white matter and high-signal sagittal sinus regions were associated with poorer cognitive performance. These novel findings highlight the utility of multiTI ASL in illuminating, and identifying objectively quantifiable and functionally significant markers of, regional hemodynamic stress in patients with SCA. [ABSTRACT FROM AUTHOR]

Published
2022
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3. The significance of inadequate transcranial Doppler studies in children with sickle cell disease.

Author

Greenwood, Simon, Deane, Colin, Rees, Oliver L., Freedman, Ben, Kumar, Suresh, Ben Ramadan, Naser, Wilkinson, Sarah, Marais, Grant, Lord, Julie, Chakravorty, Subarna, Height, Susan E., Gardner, Kate, and Rees, David C.

Subjects
SICKLE cell anemia in children, TRANSCRANIAL Doppler ultrasonography, CEREBROVASCULAR disease in children, BLOOD transfusion, STROKE prevention, DISEASE prevalence
Abstract

Sickle cell disease (SCD) is a common cause of cerebrovascular disease in childhood. Primary stroke prevention is effective using transcranial Doppler (TCD) scans to measure intracranial blood velocities, and regular blood transfusions or hydroxycarbamide when these are abnormal. Inadequate TCD scans occur when it is not possible to measure velocities in all the main arteries. We have investigated the prevalence and significance of this in a retrospective audit of 3915 TCD scans in 1191 children, performed between 2008 and 2015. 79% scans were normal, 6.4% conditional, 2.8% abnormal and 12% inadequate. 21.6% of 1191 patients had an inadequate scan at least once. The median age of first inadequate scan was 3.3 years (0.7–19.4), with a U-shaped frequency distribution with age: 28% aged 2–3 years, 3.5% age 10 years, 25% age 16 years. In young children reduced compliance was the main reason for inadequate TCDs, whereas in older children it was due to a poor temporal ultrasound window. The prevalence of inadequate TCD was 8% in the main Vascular Laboratory at King’s College Hospital and significantly higher at 16% in the outreach clinics (P<0.0001), probably due to the use of a portable ultrasound machine. Inadequate TCD scans were not associated with underlying cerebrovascular disease. [ABSTRACT FROM AUTHOR]

Published
2017
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4. Prevalence Of Nocurnal Enuresis and Proteinuria In Children With Sickle Cell Disease and Its Relation To Severity Of Painful Crises

Author

Chakravorty Subarna, Ali Mohammed, and Josu de la Fuente

Subjects
medicine.medical_specialty, Pediatrics, Proteinuria, Blood transfusion, business.industry, medicine.medical_treatment, Incidence (epidemiology), Immunology, Renal function, Cell Biology, Hematology, medicine.disease, Biochemistry, Surgery, Enuresis, medicine, Albuminuria, Microalbuminuria, medicine.symptom, business, Kidney disease
Abstract

Nocturnal enuresis and albuminuria or proteinuria are markers of renal damage in sickle cell disease (SCD) and commonly develop early on in life. Proteinuria progresses with age, leading to chronic kidney disease in adulthood. The aims of this study were to identify the prevalence of enuresis and albuminuria/proteinuria in paediatric patients with SCD in London and to determine the relationship between these and various demographic and clinical variables. Methods A cross sectional, single centre study was conducted. Questionnaire-based interviews themed on nocturnal enuresis were undertaken for patients between the ages of 6 and 17. Urinalysis was performed for the presence of albuminuria or proteinuria. Hospital patient records were accessed for clinical data. Results A total of 56 patients were recruited to the study, of which 27 (51.8%) were female. Twenty patients (35.7%) had a history of enuresis and met the DSM IV (Diagnostic and Statistical Manual of Mental Disorders, fourth edition) criteria for nocturnal enuresis compared to 5% prevalence in children in the general population1. There was a statistically significant association between enuresis and age, overactive bladder (OAB) symptoms, sleep-disordered breathing (SDB), painful crises and regular transfusions (Table 1). Fourteen out of 29 patients (48.3%) with OAB symptoms reported nocturnal enuresis compared to six out of 27 patients (22.2%) who did not (p Seven patients (13.4%) had albuminuria/proteinuria. (Table 2) There was no difference in albuminuria/proteinuria prevalence between the hydroxycarbamide or blood transfusion group compared to the non-treatment group. There was no difference in HbF percentage, systolic BP, frequency of emergency admissions, painful crises per month, haemoglobin levels and estimated glomerular filtration rates (eGFR) in patients with albuminuria/proteinuria and those without. The prevalence of haematuria increased with age; 6.7% in the 6-9 age category compared to 36.4% in the 16 to 17 age category (p= Conclusions Nocturnal enuresis and albuminuria or proteinuria is prevalent at an early age in many children with SCD. Early identification and initiation of treatment such as Angiotensin Converting Enzyme inhibitors2 may delay onset of complications especially alongside beneficial sickle cell treatments such as hydroxycarbamide and regular blood transfusions. Questioning parents on enuresis, OAB and SDB sumptoms and undertaking regular urinalysis on younger age groups is a practical and cost-effective surveillance method. References 1. American Psychiatric Association. Diagnostic and statistical manual of mental disorders: DSM-IV-TR. American Psychiatric Publishing, Inc.; 2000. Angiotensin-converting enzyme (ACE) inhibitors for proteinuria and microalbuminuria in people with sickle cell disease Cochrane Database of Systematic Reviews, 2013. Disclosures: No relevant conflicts of interest to declare.

Published
2013

5. How I manage neonatal thrombocytopenia.

Author

Chakravorty, Subarna and Roberts, Irene

Subjects
*HEMATOLOGY, *INTERNAL medicine, *THROMBOCYTOPENIA, *NEWBORN infants, *BLOOD platelet disorders
Abstract

Summary Although neonatal thrombocytopenia (platelet count < 150 × 109/l) is a common finding in hospital practice, a careful clinical history and examination of the blood film is often sufficient to establish the diagnosis and guide management without the need for further investigations. In preterm neonates, early-onset thrombocytopenia (<72 h) is usually secondary to antenatal causes, has a characteristic pattern and resolves without complications or the need for treatment. By contrast, late-onset thrombocytopenia in preterm neonates (>72 h) is nearly always due to post-natally acquired bacterial infection and/or necrotizing enterocolitis, which rapidly leads to severe thrombocytopenia (platelet count < 50 × 109/l). Thrombocytopenia is much less common in term neonates and the most important cause is neonatal alloimmune thrombocytopenia (NAIT), which confers a high risk of perinatal intracranial haemorrhage and long-term neurological disability. Prompt diagnosis and transfusion of human platelet antigen-compatible platelets is key to the successful management of NAIT. Recent studies suggest that more than half of neonates with severe thrombocytopenia receive platelet transfusion(s) based on consensus national or local guidelines despite little evidence of benefit. The most pressing problem in management of neonatal thrombocytopenia is identification of safe, effective platelet transfusion therapy and controlled trials are urgently needed. [ABSTRACT FROM AUTHOR]

Published
2012
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6. Higher oxygen saturation with hydroxyurea in paediatric sickle cell disease

Author

Lisa Van Geyzel, Baba Inusa, Atul Gupta, David C. Rees, Gary Ruiz, Wanda Kozlowska, Bethany Singh, Cara Bossley, Subarna Chakravorty, Michele Arigliani, Arigliani, Michele [0000-0002-5366-4594], Chakravorty, Subarna [0000-0003-3862-3230], and Apollo - University of Cambridge Repository

Subjects
Male, medicine.medical_specialty, Pediatrics, congenital, hereditary, and neonatal diseases and abnormalities, Adolescent, Longitudinal data, Disease, Anemia, Sickle Cell, hypoxaemia, 03 medical and health sciences, 0302 clinical medicine, Antisickling Agents, 030225 pediatrics, Internal medicine, hemic and lymphatic diseases, medicine, Humans, Hydroxyurea, Longitudinal Studies, Oximetry, Respiratory system, Child, Oxygen saturation, Retrospective Studies, Retrospective review, Hematology, business.industry, Infant, Clinical trial, Oxygen, haematology, hydroxyurea, sickle cell disease, 030220 oncology & carcinogenesis, Child, Preschool, Pediatrics, Perinatology and Child Health, Female, business
Abstract

IntroductionSickle cell disease (SCD) is one of the most common inherited diseases worldwide. It is associated with lifelong morbidity and reduced life expectancy. Hydroxyurea (HU) has been shown to reduce the frequency and severity of vaso-occlusive episodes in SCD. Hypoxaemia and intermittent nocturnal oxygen desaturations occur frequently in children with SCD and contribute to the associated morbidity, including risk of cerebrovascular disease.ObjectiveTo evaluate the effect of HU on oxygen saturation (SpO2) overnight and on daytime SpO2 spot checks in children with SCD.MethodsA retrospective review of children with SCD and respiratory problems who attended two UK tertiary sickle respiratory clinics and were treated with HU. Longitudinal data were collected from 2 years prior and up to 3 years after the commencement of HU.ResultsForty-three children, 23 males (53%) with a median age of 9 (range 1.8–18) years were included. In the 21 children who had comparable sleep studies before and after starting HU, mean SpO2 was higher (95.2% from 93.5%, p=0.01) and nadir SpO2 was higher (87.2% from 84.3%, p=0.009) when taking HU. In 32 of the children, spot daytime oxygen saturations were also higher (96.3% from 93.5%, p=0.001).ConclusionChildren with SCD had higher oxygen saturation overnight and on daytime spot checks after starting HU. These data suggest HU may be helpful for treating persistent hypoxaemia in children with SCD pending more evidence from a randomised clinical trial.

Published
2019

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