Mian Ahmad - Academia.edu (original) (raw)

Papers by Mian Ahmad

Digestion, 2007

Bangladesh is a developing country with a very high prevalence of Helicobacter pylori infection, ... more Bangladesh is a developing country with a very high prevalence of Helicobacter pylori infection, which has been ascribed to overcrowding and poor sanitary conditions. It has generally been accepted that the re-infection rate is higher in countries with a high prevalence of H. pylori infection. Short-term follow-up studies support this assumption but no long-term studies are available to confirm or refute this assertion. The present study was aimed to define the long-term H. pylori re-infection rate (6 years after successful eradication) in duodenal ulcer patients. In a previous study, 90 patients were successfully eradicated for H. pylori and followed-up for 24 months. 17/90 were found to be re-infected (18% re-infection rate per year in the first 12 months) [Gastroenterology 2001;792-798]. The remaining 73 patients were targeted for long-term follow-up. 26/73 were lost to follow-up; 6 symptomatic patients were tested H. pylori positive in the period between 24 and 60 months post-eradication. The remaining 41 patients were evaluated 72 months after successful eradication. The evaluation included clinical history taking, a (13)C-urea breath test (UBT), and endoscopy. Of the 41 H. pylori-eradicated patients analyzed after 72 months, 16 were H. pylori-positive. If the 6 patients, who were tested positive between 24 and 60 months, are added, the total re-infection cases amount to 22 subjects in the period between 24 and 72 months. Therefore, an overall annual re-infection rate 6 years after eradication of 5.02% can be calculated. Six of the 23 symptomatic patients had duodenal ulcer relapse, 5/6 were H. pylori re-infected and one was H. pylori-negative at 72 months post-treatment. The long-term annual H. pylori re-infection rate in Bangladeshi adults is markedly higher than in Western countries but lower than anticipated. In this study, duodenal ulcer relapse is clearly related to H. pylori re-infection.

The major micronutrients and heavy metals accumulation in soil and leaves irrigated with wastewat... more The major micronutrients and heavy metals accumulation in soil and leaves irrigated with wastewater in Loquat, Peach, Apricot, Plum and pear orchards at Pandu (in district Peshawar) were studied during 2004. The soil samples were collected from two depths 0-30cm and 30-60cm. A total of 10 composite soil samples (mixing of 10-15 sampling) each for both depths from each orchard, along with 5 composite plant leaves and water samples were collected. All the samples were analyzed for macronutrients (N, P, and K) and micronutrients (Cu, Zn, and Mn) and heavy metals (Ni, Cd, and Pb). The average values of N, P, K, Cu, Zn, Mn, Ni, Cd, and Pb were found to be 0.04%, 1.04, 49.25, 2.50, 0.27, 2.09, 0.47, 0.32 and 1.09 mg kg -1 , respectively in 0-30cm soil depth where as 0.03%, 0.66, 78.01, 3.55, 0.35, 2.27, 0.47, 6.26 and 1.52 mg kg -1 , respectively were found in 30-60cm soil depth. The differences in nutrients accumulation were non-significant (using t-test at P< 0.05) between these two soil depths for all micronutrients except P. The macronutrients (N, P and K) in soil, and only N in leaves were deficient; where as P and K accumulation in leaves were adequate. Micro nutrients accumulations in leaves of various orchards were adequate in comparison to P(0.13-0.35), K(2.5-3.0), N(2.0-2.5), Zn(2-150), Cu(5-20), Mn(20-50), Ni(6-10), Cd(0.02), and Pb(2.0) mg kg -1 critical values in plants leaves , while Ni and Cd were high. Cu, Zn, and Mn concentration in wastewater were adequate where as Ni, Cd, and Pb was higher than the standard. Additional N application along with micronutrients and wastewater application may be better to use for improving nutritional status of the study area.

Microbiology and Immunology, 2008

The occurrence of 16S rRNA gene mutations associated with resistance to tetracycline in H. pylori... more The occurrence of 16S rRNA gene mutations associated with resistance to tetracycline in H. pylori isolated in Bangladesh was investigated. Tetracycline susceptibility was determined by the agar dilution method. The 16S rRNA genes of these isolates were sequenced and analyzed. A tetracycline accumulation assay was performed. DNA sequence and transformation tests of nine tetracycline-resistant (MIC = 2 μg/ml) Bangladeshi H. pylori clinical isolates showed that in no case was the resistance due to mutations in the 16S rRNA gene, the only known cause of tetracycline resistance in this pathogen. Tetracycline accumulation assays implicated altered uptake or efflux.

Antimicrobial susceptibility of 120 Helicobacter pylori isolates to metronidazole, tetracycline, ... more Antimicrobial susceptibility of 120 Helicobacter pylori isolates to metronidazole, tetracycline, clarithromycin, and amoxicillin was determined, and 77.5, 15, 10, and 6.6% of the isolates, respectively, were resistant. Only rdxA inactivation and both rdxA and frxA inactivation were responsible for metronidazole resistance in 66% (8 of 12) and 33% (4 of 12) of the isolates, respectively.

Antimicrobial Agents and Chemotherapy, 2004

Twelve clarithromycin-resistant (MIC, >1 g/ml) Helicobacter pylori isolates were analyzed for poi... more Twelve clarithromycin-resistant (MIC, >1 g/ml) Helicobacter pylori isolates were analyzed for point mutations in the 23S rRNA gene. Sequence analysis of all of the resistant isolates revealed a T-to-C transition mutation at position 2182. Transformation experiments confirmed that a single T-to-C transition mutation at position 2182 is associated with clarithromycin resistance.

A research study was conducted to estimate net revenue from tobacco crop in district Swabi, NWFP.... more A research study was conducted to estimate net revenue from tobacco crop in district Swabi, NWFP. Four villages were selected through purposive sampling. The sample includes hundred farmers selected through random sampling process, who were interviewed through a well-designated questioner. The area of the sampled respondents was 1327.5 acres total in kharif and rabi seasons with an average of 13.275 acres. Tobacco was grown on 656 acres with an average of 6.56 acres. The average total cost of tobacco production was Rs. 24080.99 per acre. On average, rent of land for tobacco crop was Rs. 5000 per acre, nursery raising cost for one acre was Rs. 1005, tillage cost was Rs. 973.66 per acre, fertilizer and pesticide cost was Rs. 3771.95 per acre, cultural practices, topping and irrigation cost was Rs. 1302.73 per acre, and loading barn, curing and marketing cost were Rs. 16743.44 per acre. The average gross revenue from tobacco was Rs. 53145.77 per acre. While net revenue was Rs. 29064.78 per acre.

Pakistan Journal of Biological Sciences, 2007

The production of Brassica germplasm with a wider genetic base is essential for using them proper... more The production of Brassica germplasm with a wider genetic base is essential for using them properly in the genetic improvement of rapeseed/mustard. During the present study, different RAPD (Random Amplified Polymorphic DNA) primers were used to estimate the genetic distances among thirty different genotypes in all possible combinations. Level of genetic polymorphism at DNA level observed during present study varied, but in general it was in the range of 21.54 to 59.36%. The dissimilarity coefficient matrix of these lines based on the data of four RAPD markers using UPGMA method was also used to construct a dendrogram. The dendrogram analysis indicated that the lines UCD-319/2, UCD-310/2 and P34/R3 were genetically apart from other lines that can be exploited in a synergistic way to create wider genetic base in local Brassica germplasm thus augmenting the Brassica breeding program.

Digestion, 2007

Bangladesh is a developing country with a very high prevalence of Helicobacter pylori infection, ... more Bangladesh is a developing country with a very high prevalence of Helicobacter pylori infection, which has been ascribed to overcrowding and poor sanitary conditions. It has generally been accepted that the re-infection rate is higher in countries with a high prevalence of H. pylori infection. Short-term follow-up studies support this assumption but no long-term studies are available to confirm or refute this assertion. The present study was aimed to define the long-term H. pylori re-infection rate (6 years after successful eradication) in duodenal ulcer patients. In a previous study, 90 patients were successfully eradicated for H. pylori and followed-up for 24 months. 17/90 were found to be re-infected (18% re-infection rate per year in the first 12 months) [Gastroenterology 2001;792-798]. The remaining 73 patients were targeted for long-term follow-up. 26/73 were lost to follow-up; 6 symptomatic patients were tested H. pylori positive in the period between 24 and 60 months post-eradication. The remaining 41 patients were evaluated 72 months after successful eradication. The evaluation included clinical history taking, a (13)C-urea breath test (UBT), and endoscopy. Of the 41 H. pylori-eradicated patients analyzed after 72 months, 16 were H. pylori-positive. If the 6 patients, who were tested positive between 24 and 60 months, are added, the total re-infection cases amount to 22 subjects in the period between 24 and 72 months. Therefore, an overall annual re-infection rate 6 years after eradication of 5.02% can be calculated. Six of the 23 symptomatic patients had duodenal ulcer relapse, 5/6 were H. pylori re-infected and one was H. pylori-negative at 72 months post-treatment. The long-term annual H. pylori re-infection rate in Bangladeshi adults is markedly higher than in Western countries but lower than anticipated. In this study, duodenal ulcer relapse is clearly related to H. pylori re-infection.

The major micronutrients and heavy metals accumulation in soil and leaves irrigated with wastewat... more The major micronutrients and heavy metals accumulation in soil and leaves irrigated with wastewater in Loquat, Peach, Apricot, Plum and pear orchards at Pandu (in district Peshawar) were studied during 2004. The soil samples were collected from two depths 0-30cm and 30-60cm. A total of 10 composite soil samples (mixing of 10-15 sampling) each for both depths from each orchard, along with 5 composite plant leaves and water samples were collected. All the samples were analyzed for macronutrients (N, P, and K) and micronutrients (Cu, Zn, and Mn) and heavy metals (Ni, Cd, and Pb). The average values of N, P, K, Cu, Zn, Mn, Ni, Cd, and Pb were found to be 0.04%, 1.04, 49.25, 2.50, 0.27, 2.09, 0.47, 0.32 and 1.09 mg kg -1 , respectively in 0-30cm soil depth where as 0.03%, 0.66, 78.01, 3.55, 0.35, 2.27, 0.47, 6.26 and 1.52 mg kg -1 , respectively were found in 30-60cm soil depth. The differences in nutrients accumulation were non-significant (using t-test at P< 0.05) between these two soil depths for all micronutrients except P. The macronutrients (N, P and K) in soil, and only N in leaves were deficient; where as P and K accumulation in leaves were adequate. Micro nutrients accumulations in leaves of various orchards were adequate in comparison to P(0.13-0.35), K(2.5-3.0), N(2.0-2.5), Zn(2-150), Cu(5-20), Mn(20-50), Ni(6-10), Cd(0.02), and Pb(2.0) mg kg -1 critical values in plants leaves , while Ni and Cd were high. Cu, Zn, and Mn concentration in wastewater were adequate where as Ni, Cd, and Pb was higher than the standard. Additional N application along with micronutrients and wastewater application may be better to use for improving nutritional status of the study area.

Microbiology and Immunology, 2008

The occurrence of 16S rRNA gene mutations associated with resistance to tetracycline in H. pylori... more The occurrence of 16S rRNA gene mutations associated with resistance to tetracycline in H. pylori isolated in Bangladesh was investigated. Tetracycline susceptibility was determined by the agar dilution method. The 16S rRNA genes of these isolates were sequenced and analyzed. A tetracycline accumulation assay was performed. DNA sequence and transformation tests of nine tetracycline-resistant (MIC = 2 μg/ml) Bangladeshi H. pylori clinical isolates showed that in no case was the resistance due to mutations in the 16S rRNA gene, the only known cause of tetracycline resistance in this pathogen. Tetracycline accumulation assays implicated altered uptake or efflux.

Antimicrobial susceptibility of 120 Helicobacter pylori isolates to metronidazole, tetracycline, ... more Antimicrobial susceptibility of 120 Helicobacter pylori isolates to metronidazole, tetracycline, clarithromycin, and amoxicillin was determined, and 77.5, 15, 10, and 6.6% of the isolates, respectively, were resistant. Only rdxA inactivation and both rdxA and frxA inactivation were responsible for metronidazole resistance in 66% (8 of 12) and 33% (4 of 12) of the isolates, respectively.

Antimicrobial Agents and Chemotherapy, 2004

Twelve clarithromycin-resistant (MIC, >1 g/ml) Helicobacter pylori isolates were analyzed for poi... more Twelve clarithromycin-resistant (MIC, >1 g/ml) Helicobacter pylori isolates were analyzed for point mutations in the 23S rRNA gene. Sequence analysis of all of the resistant isolates revealed a T-to-C transition mutation at position 2182. Transformation experiments confirmed that a single T-to-C transition mutation at position 2182 is associated with clarithromycin resistance.

A research study was conducted to estimate net revenue from tobacco crop in district Swabi, NWFP.... more A research study was conducted to estimate net revenue from tobacco crop in district Swabi, NWFP. Four villages were selected through purposive sampling. The sample includes hundred farmers selected through random sampling process, who were interviewed through a well-designated questioner. The area of the sampled respondents was 1327.5 acres total in kharif and rabi seasons with an average of 13.275 acres. Tobacco was grown on 656 acres with an average of 6.56 acres. The average total cost of tobacco production was Rs. 24080.99 per acre. On average, rent of land for tobacco crop was Rs. 5000 per acre, nursery raising cost for one acre was Rs. 1005, tillage cost was Rs. 973.66 per acre, fertilizer and pesticide cost was Rs. 3771.95 per acre, cultural practices, topping and irrigation cost was Rs. 1302.73 per acre, and loading barn, curing and marketing cost were Rs. 16743.44 per acre. The average gross revenue from tobacco was Rs. 53145.77 per acre. While net revenue was Rs. 29064.78 per acre.

Pakistan Journal of Biological Sciences, 2007

The production of Brassica germplasm with a wider genetic base is essential for using them proper... more The production of Brassica germplasm with a wider genetic base is essential for using them properly in the genetic improvement of rapeseed/mustard. During the present study, different RAPD (Random Amplified Polymorphic DNA) primers were used to estimate the genetic distances among thirty different genotypes in all possible combinations. Level of genetic polymorphism at DNA level observed during present study varied, but in general it was in the range of 21.54 to 59.36%. The dissimilarity coefficient matrix of these lines based on the data of four RAPD markers using UPGMA method was also used to construct a dendrogram. The dendrogram analysis indicated that the lines UCD-319/2, UCD-310/2 and P34/R3 were genetically apart from other lines that can be exploited in a synergistic way to create wider genetic base in local Brassica germplasm thus augmenting the Brassica breeding program.