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1.
J Pak Med Assoc ; 74(3 (Supple-3)): S126-S134, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-39262073

RESUMO

Craniopharyngiomas are benign, extra-axial epithelial tumours originating from the pituitary stalk, impacting areas such as the hypothalamus, optic chiasm, and various cranial nerves. These tumours present unique surgical challenges due to their proximity to critical neurovascular structures. Management typically involves maximal safe resection as the primary approach. However, in low- and middle-income countries (LMICs), factors like late presentation, higher risks of endocrine and visual complications, frequent recurrence, and potential for incomplete resection complicate treatment. These challenges are exacerbated by limited access to specialised expertise and surgical equipment, increasing the risk of damage during surgery compared to High- Income Countries. This manuscript outlines management guidelines tailored for LMICs, emphasizing that a combination of surgical resection and chemoradiation therapy, as advised by a neuro-oncology tumour board, often yields the best outcomes.


Assuntos
Craniofaringioma , Países em Desenvolvimento , Neoplasias Hipofisárias , Craniofaringioma/terapia , Craniofaringioma/diagnóstico , Humanos , Neoplasias Hipofisárias/terapia , Neoplasias Hipofisárias/cirurgia , Neoplasias Hipofisárias/diagnóstico , Consenso , Guias de Prática Clínica como Assunto
2.
BMC Complement Med Ther ; 24(1): 93, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38365729

RESUMO

BACKGROUND: Multidrug resistance (MDR) in the family Enterobacteriaceae is a perniciously increasing threat to global health security. The discovery of new antimicrobials having the reversing drug resistance potential may contribute to augment and revive the antibiotic arsenal in hand. This study aimed to explore the anti-Enterobacteriaceae capability of bioactive polyphenols from Punica granatum (P. granatum) and their co-action with antibiotics against clinical isolates of Enterobacteriaceae predominantly prevalent in South Asian countries. METHODS: The Kandhari P. granatum (Pakistani origin) extracts were tested for anti-Enterobacteriaceae activity by agar well diffusion assay against MDR Salmonella enterica serovar Typhi, serovar Typhimurium and Escherichia coli. Predominant compounds of active extract were determined by mass spectrometry and screened for bioactivity by agar well diffusion and minimum inhibitory concentration (MIC) assay. The active punicalagin was further evaluated at sub-inhibitory concentrations (SICs) for coactivity with nine conventional antimicrobials using a disc diffusion assay followed by time-kill experiments that proceeded with SICs of punicalagin and antimicrobials. RESULTS: Among all P. granatum crude extracts, pomegranate peel methanol extract showed the largest inhibition zones of 25, 22 and 19 mm, and the MICs as 3.9, 7.8 and 7.8 mg/mL for S. typhi, S. typhimurium and E. coli, respectively. Punicalagin and ellagic acid were determined as predominant compounds by mass spectrometry. In plate assay, punicalagin (10 mg/mL) was active with hazy inhibition zones of 17, 14, and 13 mm against S. typhi, S. typhimurium and E. coli, respectively. However, in broth dilution assay punicalagin showed no MIC up to 10 mg/mL. The SICs 30 µg, 100 µg, and 500 µg of punicalagin combined with antimicrobials i.e., aminoglycoside, ß-lactam, and fluoroquinolone act in synergy against MDR strains with % increase in inhibition zone values varying from 3.4 ± 2.7% to 73.8 ± 8.4%. In time-kill curves, a significant decrease in cell density was observed with the SICs of antimicrobials/punicalagin (0.03-60 µg/mL/30, 100, 500 µg/mL of punicalagin) combinations. CONCLUSIONS: The P. granatum peel methanol extract exhibited antimicrobial activity against MDR Enterobacteriaceae pathogens. Punicalagin, the bacteriostatic flavonoid act as a concentration-dependent sensitizing agent for antimicrobials against Enterobacteriaceae. Our findings for the therapeutic punicalagin-antimicrobial combination prompt further evaluation of punicalagin as a potent activator for drugs, which otherwise remain less or inactive against MDR strains.


Assuntos
Anti-Infecciosos , Taninos Hidrolisáveis , Punica granatum , Antibacterianos/farmacologia , Polifenóis , Enterobacteriaceae , Escherichia coli , Ágar , Metanol , Extratos Vegetais/farmacologia , Anti-Infecciosos/farmacologia , Resistência a Múltiplos Medicamentos
3.
J Pak Med Assoc ; 73(10): 2118-2120, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37876087

RESUMO

Schwannomas are benign tumours of the peripheral nerve sheath. When they occur in spine, they are most commonly found in intradural-extramedullary location. Surgery is the mainstay of treatment. Radiation has a limited role in the management of residual or recurrent lesions not suitable for surgery. Here we discuss the existing literature on the outcomes of spinal schwannoma after surgery.


Assuntos
Neurilemoma , Neoplasias da Medula Espinal , Humanos , Neoplasias da Medula Espinal/diagnóstico por imagem , Neoplasias da Medula Espinal/cirurgia , Neurilemoma/diagnóstico , Neurilemoma/cirurgia , Coluna Vertebral
4.
J Pak Med Assoc ; 73(7): 1548-1550, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37469082

RESUMO

Spinal meningiomas are relatively rare, benign, intradural, extramedullary tumours, that are typically slow-growing and well-defined. Surgery is always the first line for treating spinal meningiomas. Here, we have discussed the existing literature on spinal meningiomas and the role of surgery in determining the outcomes.


Assuntos
Neoplasias Meníngeas , Meningioma , Neoplasias da Medula Espinal , Humanos , Meningioma/cirurgia , Meningioma/patologia , Neoplasias da Medula Espinal/cirurgia , Neoplasias Meníngeas/cirurgia , Neoplasias Meníngeas/patologia
5.
Transplant Direct ; 9(4): e1464, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37009166

RESUMO

Enteric hyperoxalosis (EH) is an emerging cause of kidney transplantation (KT) dysfunction. We sought to determine the prevalence of EH and factors that affect plasma oxalate (POx) among at-risk KT candidates. Methods: We prospectively measured POx among KT candidates evaluated at our center from 2017 to 2020 with risk factors for EH namely bariatric surgery, inflammatory bowel disease, or cystic fibrosis. EH was defined by a POx ≥10 µmol/L. Period-prevalence of EH was calculated. We compared mean POx across 5 factors: underlying condition, chronic kidney disease (CKD) stage, dialysis modality, phosphate binder type, and body mass index. Results: Of 40 KT candidates screened, 23 had EH for a 4-y period prevalence of 58%. Mean POx was 21.6 ± 23.5 µmol/L ranging from 0 to 109.6 µmol/L. 40% of screened had POx >20 µmol/L. Sleeve gastrectomy was the most common underlying condition associated with EH. Mean POx did not differ by underlying condition (P = 0.27), CKD stage (P = 0.17), dialysis modality (P = 0.68), phosphate binder (P = 0.58), and body mass index (P = 0.56). Conclusions: Bariatric surgery and inflammatory bowel disease were associated with a high prevalence of EH among KT candidates. Contrary to prior studies, sleeve gastrectomy was also associated with hyperoxalosis in advanced CKD. POx concentrations observed in EH reached levels associated with tissue and potentially allograft deposition. Concentrations can be as high as that seen in primary hyperoxaluria. More studies are needed to assess if POx is indeed a modifiable factor affecting allograft function in patients with EH.

6.
Eur J Rheumatol ; 9(2): 93-99, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35156624

RESUMO

OBJECTIVE: Rituximab (RTX) is approved for remission induction and maintenance of antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV). Observational studies demonstrate decline in immunoglobulin (IgG) in AAV post-RTX. The time course for the onset of hypogammaglobulinemia (Hypo-IgG) post-RTX is unknown. This is a key determinant in deciding whether to continue RTX for reinduction or maintenance of remission for AAV. We evaluated the trends of Hypo-IgG among AAV patients post-RTX therapies. METHODS: An observational single-tertiary-center study of AAV patients treated with RTX for remission induction or maintenance (induction therapy, maintenance therapy, and combined induction and maintenance therapy) between 1998 and 2018. Poisson regression was used to compare the inciden- ces of Hypo-IgG: mild (450-700 mg dL-1), moderate (200-450 mg dL-1), and severe (􏰃200 mg dL-1). Ig levels were measured every 3-6 months after RTX use. RESULTS: Mean (SD) age at last visit was 59 (16) years, 93% were Caucasians, 64% were females, and 71 (63%) had granulomatosis with polyangiitis (GPA). Hypo-IgG occurred in 47 patients: one (2%) severe, 13 (28%) moderate, and 33 (70%) mild. Lower incidences of mild Hypo-IgG post-RTX were seen during induction compared to maintenance (IR 5.04 per 100 000 days vs 5.45 per 100 000 days, incidence rate ratio (IRR) 1.08, 95% CI 0.34, 3.19). Moderate Hypo-IgG occurred at 2.29 per 100 000 days during induc- tion and 1.82 per 100 000 days during maintenance (IRR 0.79, 95% CI 0.08, 4.84). CONCLUSION: Hypo-IgG is common among AAV treated with RTX, occurring in 42% of patients in this single-center cohort. The nadir IgG levels occur during remission induction, and the IgG levels remain relatively stable or increase over time in those receiving RTX for remission maintenance.

7.
Transplant Proc ; 53(4): 1202-1206, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33413879

RESUMO

Kidney transplant recipients who develop coronavirus disease 2019 (COVID-19) are at increased risk of life-threatening illness, which often requires reducing immunosuppression despite the potential risk of causing an allograft rejection. Herein, we describe the clinical presentation and course of a kidney transplant recipient who acquired COVID-19 and was hospitalized with severe symptoms and hypoxemia. Upon admission, the patient was found to have elevated de novo donor-specific antibodies (DSA) yielding a positive cytotoxicity crossmatch and concurrent elevated plasma donor-derived cell-free DNA (dd-cfDNA) level, indicating a possible ongoing rejection despite improvement in his serum creatinine. Because of persistent positive COVID-19 tests and stable serum creatinine, a kidney allograft biopsy was initially deferred and his dd-cfDNA and DSA were monitored closely postdischarge. Three months later, because of persistent elevated dd-cfDNA and positive DSA, a kidney allograft biopsy was performed, which showed chronic active antibody-mediated rejection. Accordingly, the patient was treated with intravenous immunoglobulin and his maintenance immunosuppressive regimen was increased.


Assuntos
COVID-19/diagnóstico , Rejeição de Enxerto/prevenção & controle , Transplante de Rim , Anticorpos/sangue , Anticorpos/imunologia , COVID-19/complicações , COVID-19/virologia , Ácidos Nucleicos Livres/sangue , Creatinina/sangue , Rejeição de Enxerto/diagnóstico , Antígeno HLA-DR7/imunologia , Humanos , Imunoglobulinas Intravenosas/uso terapêutico , Imunossupressores/sangue , Imunossupressores/uso terapêutico , Masculino , Pessoa de Meia-Idade , Oxigenoterapia , SARS-CoV-2/isolamento & purificação , Tacrolimo/sangue , Tacrolimo/uso terapêutico
8.
Molecules ; 25(20)2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-33066377

RESUMO

Lactic acid bacteria (LAB) can synthesize antimicrobial compounds (AMCs) with nutritional and bioprotective properties in crops and food products. In the current study, AMCs of Lactobacillus coryniformis BCH-4 were evaluated to control fungal spoilage in maize grains. On maize grains treated with 75%-100% (v/v) concentrated AMCs, no fungal growth was observed even after 72 h of Aspergillus flavus inoculation. Proximate analysis of treatments A1 (raw grains), A2 (A. flavus inoculated grains) and A3 (A. flavus + AMCs inoculated grains) revealed that moisture was significantly (p ≤ 0.05) high in A2 than A3 and A1. Meanwhile, protein, fat, fiber and ash contents were significantly decreased in A2 compared to A1 and A3. Moreover, ß-carotene contents were not statistically different between A1 and A3, while in A2 it was significantly decreased. HPLC analysis revealed the presence of 2-oxopropanoic acid, 2-hydroxypropane-1,2,3-tricarboxylic acid, 2-hydroxybutanedioic acid, 2-hydroxypropanoic acid, propanedioic acid and butanedioic acid, which also showed antifungal activity against Aspergillus flavus. FTIR spectroscopy revealed the presence of hydroxyl, carbonyl and ester-groups along with organic and fatty acids, thereby indicating their participation in inhibitory action. Furthermore, the AMCs were found to be a good alternative to chemical preservatives, thereby not only preserving the nutritive qualities but increasing the shelf life as well.


Assuntos
Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Conservantes de Alimentos/farmacologia , Lactobacillus/química , Zea mays/efeitos dos fármacos , Anti-Infecciosos/química , Antifúngicos/farmacologia , Antioxidantes/química , Cromatografia Líquida de Alta Pressão , Testes de Sensibilidade Microbiana , Peso Molecular , Sementes/efeitos dos fármacos , Sementes/metabolismo , Sementes/microbiologia , Espectroscopia de Infravermelho com Transformada de Fourier , Zea mays/metabolismo , Zea mays/microbiologia , beta Caroteno/metabolismo
9.
Appl Microbiol Biotechnol ; 104(8): 3391-3402, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32088761

RESUMO

Birnaviridae is a family of viruses (birnaviruses) which consists of four genera, members of which cause diseases in fish, birds, mollusks, and insects. The genome of birnaviruses encodes the highly immunogenic VP2 capsid protein. In order to demonstrate that the VP2 protein can be exploited as a diagnostic antigen for birnaviruses, we developed a lateral flow assay based on the surface-exposed VP2 protrusion domain of a representative birnavirus, infectious bursal disease virus (IBDV) of serotype 1 which causes the highly devastating infectious bursal disease in chickens. The biophysical characterization of the purified domain reveals that the domain predominantly consists of ß-sheets, exists in a trimeric form, and remains folded at high temperatures, making it suitable for diagnostic purposes. Owing to its highly immunogenic nature and excellent biophysical properties, we employed the VP2 protrusion domain in a gold nanoparticle-based lateral flow assay for rapid detection of anti-IBDV antibodies in serum samples of infected chickens. Our results indicate that the domain binds anti-IBDV antibodies with high specificity during laboratory testing and on-site testing. The lateral flow assay reported here yields comparable results in a qualitative manner as obtained through a commercial enzyme-linked immunosorbent assay (ELISA). As VP2 is a common capsid protein of birnaviruses, the lateral flow assay can be generalized for other birnaviruses, and members of Tetraviridae and Nodaviridae families which contain homologous VP2 capsid proteins.


Assuntos
Antígenos Virais/imunologia , Infecções por Birnaviridae/diagnóstico , Infecções por Birnaviridae/veterinária , Birnaviridae/imunologia , Proteínas Estruturais Virais/imunologia , Animais , Anticorpos Antivirais/sangue , Antígenos Virais/genética , Sítios de Ligação de Anticorpos , Birnaviridae/genética , Infecções por Birnaviridae/sangue , Galinhas/imunologia , Dicroísmo Circular , Ouro , Imunoensaio , Nanopartículas Metálicas/química , Doenças das Aves Domésticas/diagnóstico , Doenças das Aves Domésticas/virologia , Domínios Proteicos , Espectroscopia de Infravermelho com Transformada de Fourier , Proteínas Estruturais Virais/genética
10.
BMC Nephrol ; 21(1): 14, 2020 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-31931743

RESUMO

BACKGROUND: Eosinophils in kidney disease are poorly understood and are often incidental findings on kidney biopsy. Eosinophilia in blood and renal biopsy tissue is associated with a host of immune and non-immune kidney diseases. The significance of eosinophilia in renal diseases has not been well addressed. We evaluated the presence of peripheral eosinophilia (> 4% of blood leukocytes) with biopsy tissue eosinophilia and their association with end-stage-kidney-disease (ESKD). METHODS: A nested case-control (2:1) of patients who underwent kidney biopsies at Johns Hopkins Hospital and Medical University of South Carolina from 2004 to 2018 were included in the study. From the 616 eligible patients, 178 patients were identified through the registry of kidney biopsies as 18 years or older without missing biopsy reports or hematology results. Controls (n = 154) had no ESKD at the time of case (n = 24) designation and were assembled using incident density sampling and matched on age and sex. The association of peripheral eosinophilia (> 4% of peripheral blood leukocytes) with the risk of progression to ESKD was evaluated using conditional logistic model after adjusting for clinical demographics. RESULTS: Among 178 patients, 65 (37%) had peripheral eosinophilia and 113 (63%) had no eosinophilia. Compared to patients without eosinophilia, patients with peripheral eosinophilia were notably male and had a higher serum creatinine at the time of their biopsy. Peripheral eosinophilia was associated with higher risk of ESKD (OR 15.9 [1.9, 134.7]) adjusted for patient demographics including hypertension, proteinuria and eGFR at the time of kidney biopsy. Peripheral eosinophilia had a significant linear association with kidney tissue eosinophils, 22 (standard deviation [SD] 20) per high power field (hpf) in 4-10% peripheral eosinophilia, 19 (SD 18) per hpf in ≥10% eosinophilia and 3 (SD 7) per hpf in no eosinophilia (P <  0.001). CONCLUSIONS: Peripheral eosinophilia is an independent predictor of tissue eosinophilia and subsequent progression to ESKD. Peripheral eosinophilia may be an early biomarker for underlying inflammation and disease, but further studies to investigate this clinical association are warranted.


Assuntos
Eosinofilia/complicações , Falência Renal Crônica/etiologia , Nefrite Intersticial/complicações , Adulto , Análise de Variância , Biópsia , Estudos de Casos e Controles , Creatinina/sangue , Progressão da Doença , Eosinófilos , Feminino , Humanos , Achados Incidentais , Rim/imunologia , Rim/patologia , Masculino , Pessoa de Meia-Idade , Nefrite Intersticial/imunologia , Fatores de Risco , Distribuição por Sexo
11.
Saudi Med J ; 40(9): 887-892, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31522215

RESUMO

OBJECTIVES: To evaluate any association between the frequency of hereditary hemochromatosis (HFE) gene mutation (H63D and C282Y) and iron overload in beta-thalassemia major (BTM) patients. METHODS: The case-control study was conducted from June 2016 to February 2018. Blood samples from 204 BTM patients and 204 normal controls were taken from the Sundas Foundation Blood Bank. These samples were analyzed for serum ferritin assay and HFE mutation. Ferritin level was measured on the ARCHITECT 1000SR. Both patient and control samples were analyzed for mutations using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: Serum ferritin levels for all patients were greater than 1000ng/mL. The p.H63D mutation was observed in 23 (11.3%) cases, out of which 19 cases were heterozygous for p.H63D and 4 cases were homozygous. In control samples, 4 cases (2%) were found heterozygous for the p.H63D, and no homozygous mutation was found. Significantly high serum ferritin levels were found in BTM patients with the H63D mutation (p=0.00). In the case of p.C282Y, neither homozygous nor heterozygous mutation was found in patients or in controls. CONCLUSION: H63D polymorphism is associated with iron overload in BTM patients. Larger-scale research is required to give an elaborated view of the association of the HFE mutation with iron overload in these patients and to confirm our conclusion.


Assuntos
Ferritinas/sangue , Proteína da Hemocromatose/genética , Hemocromatose/sangue , Talassemia beta/sangue , Adulto , Transfusão de Sangue , Estudos de Casos e Controles , Criança , Pré-Escolar , Comorbidade , Feminino , Hemocromatose/epidemiologia , Hemocromatose/genética , Humanos , Sobrecarga de Ferro/sangue , Sobrecarga de Ferro/epidemiologia , Sobrecarga de Ferro/etiologia , Sobrecarga de Ferro/genética , Masculino , Mutação , Paquistão/epidemiologia , Prevalência , Reação Transfusional , Talassemia beta/epidemiologia , Talassemia beta/genética
12.
Am J Case Rep ; 18: 617-621, 2017 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-28572561

RESUMO

BACKGROUND Follicular B cell lymphomas account for a significant portion of all newly diagnosed non-Hodgkin's lymphomas. While involvement can be varied, the most common extranodal presentation is within the gastrointestinal tract beyond the stomach. In addition, the stomach has a diffuse multivessel vascular supply, which decreases the likelihood of developing ischemic gastritis. CASE REPORT An 89-year-old woman with history of diabetes, deep venous thromboembolism, and hypertension was referred due to a newly diagnosed retroperitoneal mass. Biopsy of a left para-aortic node was consistent with low-grade follicular B cell lymphoma. Following mainstream treatment guidelines, rituximab was administered. Approximately 12 hours later, the patient presented to the Emergency Department with intractable vomiting and nausea. After admission, an esophagogastroduodenoscopy (EGD) revealed extensive ischemic gastritis. Due to recurrent ascites requiring frequent paracenteses, and the clinical aggressiveness of the patient's underlying lymphoma, a second dose of rituximab was administered with concurrent initiation of total parenteral nutrition. Approximately 1 week later, the patient underwent a repeat EGD for quality of life planning while in hospice. The repeat EGD revealed resolved ischemic gastritis. Her diet was advanced and she was subsequently discharged home. CONCLUSIONS Rituximab alone shows promise in treating extensive follicular B cell lymphoma complicated by ischemic gastritis, which has not been previously reported in the literature.


Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Gastrite/tratamento farmacológico , Isquemia/tratamento farmacológico , Linfoma de Células B/tratamento farmacológico , Linfoma Folicular/tratamento farmacológico , Rituximab/uso terapêutico , Idoso de 80 Anos ou mais , Feminino , Humanos
13.
Int Med Case Rep J ; 9: 385-387, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27994488

RESUMO

BACKGROUND: While blood transfusions are commonly used for prophylaxis and treatment for acute chest syndromes and strokes in sickle cell patients, accumulation of excess iron resulting in secondary hemochromatosis remains a rare disease. Chelation is the mainstay for preventing and treating iron overload to deter potential end-organ damages; it is rare when therapy fails. CASE REPORT: A 52-year-old African American woman with chronic anemia secondary to sickle cell anemia and history of multiple blood transfusions presented with elevated serum ferritin (8000 ng/mL) and bilirubin (16.8 mg/dL). She had no previous personal or family history of liver disease. A magnetic resonance cholangiopancreatography (MRCP) and a liver biopsy confirmed the secondary hemochromatosis with marked fibrosis and 4+ iron deposits, but since she was therapeutically on deferasirox, her treatment regimen involved only closer monitoring. Her hemochromatosis led to readmission within a year for rapid progression of cardiac and hepatic failure. CONCLUSION: Since chronically transfused sickle cell patients are at a significantly higher risk of mortality due to the secondary hemochromatosis and end-stage organ damage, knowledge of prophylactic iron chelation is important. Minimizing unnecessary transfusions should be strongly emphasized to reduce the sequelae as iron burden remains a threat. The effectiveness of iron-chelating therapy is best monitored via periodic magnetic resonance imaging, liver transaminases, bilirubin, creatinine, ferritin, and cardiac function tests. Despite the prophylactic treatment and quarterly blood work, in this case the initial presentation did not correlate with the severity of end-stage liver failure. The damage was not discovered until proven by liver biopsy and MRCP, too late to deter the sequelae and the mortality exactly 1 year after diagnosis of the secondary hemochromatosis.

14.
Comput Methods Programs Biomed ; 114(2): 141-52, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24548898

RESUMO

Medical systems based on state of the art image processing and pattern recognition techniques are very common now a day. These systems are of prime interest to provide basic health care facilities to patients and support to doctors. Diabetic macular edema is one of the retinal abnormalities in which diabetic patient suffers from severe vision loss due to affected macula. It affects the central vision of the person and causes total blindness in severe cases. In this article, we propose an intelligent system for detection and grading of macular edema to assist the ophthalmologists in early and automated detection of the disease. The proposed system consists of a novel method for accurate detection of macula using a detailed feature set and Gaussian mixtures model based classifier. We also present a new hybrid classifier as an ensemble of Gaussian mixture model and support vector machine for improved exudate detection even in the presence of other bright lesions which eventually leads to reliable classification of input retinal image in different stages of macular edema. The statistical analysis and comparative evaluation of proposed system with existing methods are performed on publicly available standard retinal image databases. The proposed system has achieved average value of 97.3%, 95.9% and 96.8% for sensitivity, specificity and accuracy respectively on both databases.


Assuntos
Retinopatia Diabética/diagnóstico , Diagnóstico por Computador/métodos , Técnicas de Diagnóstico Oftalmológico , Edema Macular/complicações , Edema Macular/diagnóstico , Algoritmos , Bases de Dados Factuais , Retinopatia Diabética/classificação , Exsudatos e Transudatos/fisiologia , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Macula Lutea/patologia , Edema Macular/classificação , Distribuição Normal , Reconhecimento Automatizado de Padrão/métodos , Máquina de Vetores de Suporte
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