Umair Ahmed - Academia.edu (original) (raw)

Papers by Umair Ahmed

Research paper thumbnail of Challenges in Designing Input Method Editors for Indian Languages: The Role of Word-Origin and Context

Abstract Back-transliteration based Input Method Editors are very popular for Indian Languages. I... more Abstract Back-transliteration based Input Method Editors are very popular for Indian Languages. In this paper we evaluate two such Indic language systems to help understand the challenge of designing a back-transliteration based IME. Through a detailed error-...

Research paper thumbnail of Brain abscess in children

Indian Journal of Pediatrics, 2006

Objectives: Brain abscess is a serious life-threatening complication of several diseases. The obj... more Objectives: Brain abscess is a serious life-threatening complication of several diseases. The objective of this study was to look at the clinical profile of patients, predisposing conditions, microbiology and outcome of children suffering from brain abscess.Methods: Thirty children aged less than 15 years were reviewed. There were 15 males and 15 females. The mean age of presentation was 5.6±4.4 years.Results: The duration of illness at the time of admission was 17.6±24.6 days. Typically patients presented with fever, vomiting, headache and seizures. The predisposing conditions found were cyanotic congenital heart disease in 11 (37%) of children, meningitis in 6 (20%), septicemia in 7 (23%), and no underlying cause was found in 5 (17%) children. The most common microbe in children with cyanotic congenital heart disease was of theStreptococcus milleri group (52%). Computerized tomography confirmed the diagnosis and the most common location of the abscess was the parietal lobe of the cerebral hemisphere. All abscesses were large, more than 2 cm in diameter and were aspirated surgically. Excision was performed in 6 children. Five children expired, one due to a intracranial bleeding and the others due to severe cerebral edema and tentorial herniation. Complications were seen in 20 children and 16 had sequelae, hemiparesis in 11 and seizure disorder in 5.Conclusion: Brain abscess is a serious infection with poor outcome if diagnosed late. Delayed surgical drainage has high morbidity and mortality. The threshold for diagnosis should be low, particularly in children with a predisposing condition like cyanotic congenital heart disease.

Research paper thumbnail of Brain abscess in children

Indian Journal of Pediatrics, 2006

Objectives: Brain abscess is a serious life-threatening complication of several diseases. The obj... more Objectives: Brain abscess is a serious life-threatening complication of several diseases. The objective of this study was to look at the clinical profile of patients, predisposing conditions, microbiology and outcome of children suffering from brain abscess.Methods: Thirty children aged less than 15 years were reviewed. There were 15 males and 15 females. The mean age of presentation was 5.6±4.4 years.Results: The duration of illness at the time of admission was 17.6±24.6 days. Typically patients presented with fever, vomiting, headache and seizures. The predisposing conditions found were cyanotic congenital heart disease in 11 (37%) of children, meningitis in 6 (20%), septicemia in 7 (23%), and no underlying cause was found in 5 (17%) children. The most common microbe in children with cyanotic congenital heart disease was of theStreptococcus milleri group (52%). Computerized tomography confirmed the diagnosis and the most common location of the abscess was the parietal lobe of the cerebral hemisphere. All abscesses were large, more than 2 cm in diameter and were aspirated surgically. Excision was performed in 6 children. Five children expired, one due to a intracranial bleeding and the others due to severe cerebral edema and tentorial herniation. Complications were seen in 20 children and 16 had sequelae, hemiparesis in 11 and seizure disorder in 5.Conclusion: Brain abscess is a serious infection with poor outcome if diagnosed late. Delayed surgical drainage has high morbidity and mortality. The threshold for diagnosis should be low, particularly in children with a predisposing condition like cyanotic congenital heart disease.

Research paper thumbnail of Precipitating Factors and The Outcome of Hepatic Encephalopathy in Liver Cirrhosis

To determine precipitants of hepatic encephalopathy (HE) and their impact on hospital stay and mo... more To determine precipitants of hepatic encephalopathy (HE) and their impact on hospital stay and mortality. Study Design: Cross-sectional, analytical study. Place and Duration of Study. The precipitants of HE were correlated with the different grades of HE, and length of hospital stay and mortality. Chi-square test was used to compare the proportion of precipitating factors versus hospital stay and grade with significance at p < 0.05. Results: Of the 404 patients 252 (62%) were males. Hepatitis C virus was the cause of cirrhosis in 283 (70%); Child Turcotte Pugh (CTP) class C was present in 317 (78%) patients. On presentation, 17% patients had grade 1 HE while 44%, 29% and 10% had grades 2, 3 and 4 respectively. The most common precipitant of HE was spontaneous bacterial peritonitis in 83 (20.5%), constipation in 74 (18.3%) and urinary tract infection in 62 (15.3%). One hundred and forty (35%) patients had ≥ 2 precipitating factors while no precipitant was noted in 50 (12%) patients. Mean hospital stay was 4±3 days. The lesser the number of precipitants, shorter was the length of stay (p < 0.01) and lesser was the grade of HE (p=0.025). Complete reversal of HE was noted in 366 patients (91%) while the remaining had grade 1 HE on discharge. Nine (2.2%) patients died during the hospital stay. No mortality was noted in patients without precipitants. Conclusion: Patients presenting with ≥ 2 precipitating factors and advanced grade of HE had a prolonged hospital stay. Moreover, patients without precipitants had better outcomes.

Research paper thumbnail of Outcomes in culture positive and culture negative ascitic fluid infection in patients with viral cirrhosis: cohort study

BMC Gastroenterology, 2008

Background: Ascitic fluid infection (AFI) in cirrhotic patients has a high morbidity and mortalit... more Background: Ascitic fluid infection (AFI) in cirrhotic patients has a high morbidity and mortality. It has two variants namely, spontaneous bacterial peritonitis (SBP) and culture negative neutrocytic ascites (CNNA). The aim of this study was to determine the outcome in cirrhotic patients with culture positive (SBP) and culture negative neutrocytic ascites.

Research paper thumbnail of Frequency and characteristic features of portal hypertensive gastropathy in patients with viral cirrhosis

OBJECTIVE: To determine the frequency and specific characteristic features of portal hypertensive... more OBJECTIVE: To determine the frequency and specific characteristic features of portal hypertensive gastropathy (PHG) in cirrhosis due to viral etiology. STUDY DESIGN: Cross-sectional descriptive study. PLACE AND DURATION OF STUDY: The Aga Khan University ...

Research paper thumbnail of Virological and clinical characteristics of hepatitis delta virus in South Asia

Virology Journal, 2011

Background & Aims There is a paucity of data on the impact of hepatitis D virus (HDV) in patients... more Background & Aims There is a paucity of data on the impact of hepatitis D virus (HDV) in patients with hepatitis B virus (HBV) infection from South Asia. We studied the impact of HDV co-infection on virological and clinical characteristics. Methods We collected data of 480 patients with HBsAg positive and a detectable HBV DNA PCR, who presented to the Aga Khan University, Karachi and Isra University in Hyderabad, Pakistan in the last 5 years. HDV co-infection was diagnosed on the basis of anti-HDV. ALT, HBeAg, HBeAb and HBV DNA PCR quantitative levels were checked in all patients. We divided all patients into two groups based on anti-HDV, and compared their biochemical, serological & virological labs and clinical spectrum. Clinical spectrum of disease included asymptomatic carrier (AC), chronic active hepatitis (CAH), immuno-tolerant phase (IP), and compensated cirrhosis (CC). Results HDV co-infection was found in 169 (35.2%). There were 164 (34.6%) HBeAg positive and 316 (65.4%) HBeAg negative patients. Mean ALT level was 66 ± 73 IU. 233 (48.5%) had raised ALT. HBV DNA level was ≥ 10e5 in 103(21.5%) patients. Overall, among HBV/HDV co-infection, 146/169 (86.4%) had suppressed HBV DNA PCR as compared to 231/311 (74.3%) patients with HBV mono-infection; p-value = 0.002. Among HBeAg negative patients 71/128(55.5%) had raised ALT levels among HBV/HDV co-infection as compared to 71/188 (37.8%) with HBV mono-infection (p-value = 0.002); levels of HBV DNA were equal in two groups; there were 27/128 (21%) patients with CC among HBV/HDV co-infection as compared to 23 (12%) in HBV mono-infection (p-value = 0.009); there were less AC (p-value = 0.009) and more CAH (p-value = 0.009) among HBV/HDV co-infection patients. Among HBeAg positive patients, serum ALT, HBV DNA levels and the spectrum of HBV were similar in the two groups. Conclusions HBV/HDV co-infection results in the suppression of HBV DNA. A fair proportion of HBV/HDV co-infected patients with HBeAg negative have active hepatitis B infection and cirrhosis as compared to those with mono-infection.

Research paper thumbnail of Chemistry XI MCQ s

Research paper thumbnail of Challenges in Designing Input Method Editors for Indian Languages: The Role of Word-Origin and Context

Abstract Back-transliteration based Input Method Editors are very popular for Indian Languages. I... more Abstract Back-transliteration based Input Method Editors are very popular for Indian Languages. In this paper we evaluate two such Indic language systems to help understand the challenge of designing a back-transliteration based IME. Through a detailed error-...

Research paper thumbnail of Brain abscess in children

Indian Journal of Pediatrics, 2006

Objectives: Brain abscess is a serious life-threatening complication of several diseases. The obj... more Objectives: Brain abscess is a serious life-threatening complication of several diseases. The objective of this study was to look at the clinical profile of patients, predisposing conditions, microbiology and outcome of children suffering from brain abscess.Methods: Thirty children aged less than 15 years were reviewed. There were 15 males and 15 females. The mean age of presentation was 5.6±4.4 years.Results: The duration of illness at the time of admission was 17.6±24.6 days. Typically patients presented with fever, vomiting, headache and seizures. The predisposing conditions found were cyanotic congenital heart disease in 11 (37%) of children, meningitis in 6 (20%), septicemia in 7 (23%), and no underlying cause was found in 5 (17%) children. The most common microbe in children with cyanotic congenital heart disease was of theStreptococcus milleri group (52%). Computerized tomography confirmed the diagnosis and the most common location of the abscess was the parietal lobe of the cerebral hemisphere. All abscesses were large, more than 2 cm in diameter and were aspirated surgically. Excision was performed in 6 children. Five children expired, one due to a intracranial bleeding and the others due to severe cerebral edema and tentorial herniation. Complications were seen in 20 children and 16 had sequelae, hemiparesis in 11 and seizure disorder in 5.Conclusion: Brain abscess is a serious infection with poor outcome if diagnosed late. Delayed surgical drainage has high morbidity and mortality. The threshold for diagnosis should be low, particularly in children with a predisposing condition like cyanotic congenital heart disease.

Research paper thumbnail of Brain abscess in children

Indian Journal of Pediatrics, 2006

Objectives: Brain abscess is a serious life-threatening complication of several diseases. The obj... more Objectives: Brain abscess is a serious life-threatening complication of several diseases. The objective of this study was to look at the clinical profile of patients, predisposing conditions, microbiology and outcome of children suffering from brain abscess.Methods: Thirty children aged less than 15 years were reviewed. There were 15 males and 15 females. The mean age of presentation was 5.6±4.4 years.Results: The duration of illness at the time of admission was 17.6±24.6 days. Typically patients presented with fever, vomiting, headache and seizures. The predisposing conditions found were cyanotic congenital heart disease in 11 (37%) of children, meningitis in 6 (20%), septicemia in 7 (23%), and no underlying cause was found in 5 (17%) children. The most common microbe in children with cyanotic congenital heart disease was of theStreptococcus milleri group (52%). Computerized tomography confirmed the diagnosis and the most common location of the abscess was the parietal lobe of the cerebral hemisphere. All abscesses were large, more than 2 cm in diameter and were aspirated surgically. Excision was performed in 6 children. Five children expired, one due to a intracranial bleeding and the others due to severe cerebral edema and tentorial herniation. Complications were seen in 20 children and 16 had sequelae, hemiparesis in 11 and seizure disorder in 5.Conclusion: Brain abscess is a serious infection with poor outcome if diagnosed late. Delayed surgical drainage has high morbidity and mortality. The threshold for diagnosis should be low, particularly in children with a predisposing condition like cyanotic congenital heart disease.

Research paper thumbnail of Precipitating Factors and The Outcome of Hepatic Encephalopathy in Liver Cirrhosis

To determine precipitants of hepatic encephalopathy (HE) and their impact on hospital stay and mo... more To determine precipitants of hepatic encephalopathy (HE) and their impact on hospital stay and mortality. Study Design: Cross-sectional, analytical study. Place and Duration of Study. The precipitants of HE were correlated with the different grades of HE, and length of hospital stay and mortality. Chi-square test was used to compare the proportion of precipitating factors versus hospital stay and grade with significance at p < 0.05. Results: Of the 404 patients 252 (62%) were males. Hepatitis C virus was the cause of cirrhosis in 283 (70%); Child Turcotte Pugh (CTP) class C was present in 317 (78%) patients. On presentation, 17% patients had grade 1 HE while 44%, 29% and 10% had grades 2, 3 and 4 respectively. The most common precipitant of HE was spontaneous bacterial peritonitis in 83 (20.5%), constipation in 74 (18.3%) and urinary tract infection in 62 (15.3%). One hundred and forty (35%) patients had ≥ 2 precipitating factors while no precipitant was noted in 50 (12%) patients. Mean hospital stay was 4±3 days. The lesser the number of precipitants, shorter was the length of stay (p < 0.01) and lesser was the grade of HE (p=0.025). Complete reversal of HE was noted in 366 patients (91%) while the remaining had grade 1 HE on discharge. Nine (2.2%) patients died during the hospital stay. No mortality was noted in patients without precipitants. Conclusion: Patients presenting with ≥ 2 precipitating factors and advanced grade of HE had a prolonged hospital stay. Moreover, patients without precipitants had better outcomes.

Research paper thumbnail of Outcomes in culture positive and culture negative ascitic fluid infection in patients with viral cirrhosis: cohort study

BMC Gastroenterology, 2008

Background: Ascitic fluid infection (AFI) in cirrhotic patients has a high morbidity and mortalit... more Background: Ascitic fluid infection (AFI) in cirrhotic patients has a high morbidity and mortality. It has two variants namely, spontaneous bacterial peritonitis (SBP) and culture negative neutrocytic ascites (CNNA). The aim of this study was to determine the outcome in cirrhotic patients with culture positive (SBP) and culture negative neutrocytic ascites.

Research paper thumbnail of Frequency and characteristic features of portal hypertensive gastropathy in patients with viral cirrhosis

OBJECTIVE: To determine the frequency and specific characteristic features of portal hypertensive... more OBJECTIVE: To determine the frequency and specific characteristic features of portal hypertensive gastropathy (PHG) in cirrhosis due to viral etiology. STUDY DESIGN: Cross-sectional descriptive study. PLACE AND DURATION OF STUDY: The Aga Khan University ...

Research paper thumbnail of Virological and clinical characteristics of hepatitis delta virus in South Asia

Virology Journal, 2011

Background & Aims There is a paucity of data on the impact of hepatitis D virus (HDV) in patients... more Background & Aims There is a paucity of data on the impact of hepatitis D virus (HDV) in patients with hepatitis B virus (HBV) infection from South Asia. We studied the impact of HDV co-infection on virological and clinical characteristics. Methods We collected data of 480 patients with HBsAg positive and a detectable HBV DNA PCR, who presented to the Aga Khan University, Karachi and Isra University in Hyderabad, Pakistan in the last 5 years. HDV co-infection was diagnosed on the basis of anti-HDV. ALT, HBeAg, HBeAb and HBV DNA PCR quantitative levels were checked in all patients. We divided all patients into two groups based on anti-HDV, and compared their biochemical, serological & virological labs and clinical spectrum. Clinical spectrum of disease included asymptomatic carrier (AC), chronic active hepatitis (CAH), immuno-tolerant phase (IP), and compensated cirrhosis (CC). Results HDV co-infection was found in 169 (35.2%). There were 164 (34.6%) HBeAg positive and 316 (65.4%) HBeAg negative patients. Mean ALT level was 66 ± 73 IU. 233 (48.5%) had raised ALT. HBV DNA level was ≥ 10e5 in 103(21.5%) patients. Overall, among HBV/HDV co-infection, 146/169 (86.4%) had suppressed HBV DNA PCR as compared to 231/311 (74.3%) patients with HBV mono-infection; p-value = 0.002. Among HBeAg negative patients 71/128(55.5%) had raised ALT levels among HBV/HDV co-infection as compared to 71/188 (37.8%) with HBV mono-infection (p-value = 0.002); levels of HBV DNA were equal in two groups; there were 27/128 (21%) patients with CC among HBV/HDV co-infection as compared to 23 (12%) in HBV mono-infection (p-value = 0.009); there were less AC (p-value = 0.009) and more CAH (p-value = 0.009) among HBV/HDV co-infection patients. Among HBeAg positive patients, serum ALT, HBV DNA levels and the spectrum of HBV were similar in the two groups. Conclusions HBV/HDV co-infection results in the suppression of HBV DNA. A fair proportion of HBV/HDV co-infected patients with HBeAg negative have active hepatitis B infection and cirrhosis as compared to those with mono-infection.

Research paper thumbnail of Chemistry XI MCQ s