Waliul Islam - Academia.edu (original) (raw)

Papers by Waliul Islam

Enhanced permeability and retention (EPR) effect–based nanomedicine is a promising strategy for s... more Enhanced permeability and retention (EPR) effect–based nanomedicine is a promising strategy for successful anticancer therapy. The EPR effect is based on tumor blood flow. Because advanced large tumors, as frequently seen in clinical settings, are heterogeneous, with regions of defective vasculature and blood flow, achieving the desired tumor drug delivery is difficult. Here, we utilized the EPR effect to increase drug delivery. To augment the EPR effect for improved therapeutic effects of nanomedicine, we exploited vascular mediators—the nitric oxide (NO) generators nitroglycerin (NG), hydroxyurea, and l-arginine. These compounds generate NO in tumors with relatively high selectivity. Using different nanosized drugs in our protocol significantly increased (1.5–2 times) delivery of nanomedicines to different solid tumor models, along with markedly improving (2–3-fold) the antitumor effects of these drugs. Also, in 7,12-dimethylbenz[a]anthracene–induced advanced end-stage breast canc...

Supplementary Figure S4 shows the AOM/DSS induced colon tumor nodules after treatment with P-THP ... more Supplementary Figure S4 shows the AOM/DSS induced colon tumor nodules after treatment with P-THP and rhodamine-BSA conjugate (fluorescent image).

Chemistry Letters

Glucosamine-bearing poly(styrene-co-maleic acid) (SMA-G) with the molecular weight of 1.8 × 104 i... more Glucosamine-bearing poly(styrene-co-maleic acid) (SMA-G) with the molecular weight of 1.8 × 104 is water soluble. We found that there is a weak hydrophobic interaction between water soluble serum p...

Bangladesh Journal of Urology, 2020

Advancement in imaging techniques has now made it possible for small renal tumors to be detected ... more Advancement in imaging techniques has now made it possible for small renal tumors to be detected incidentally. This has led to the use of minimally invasive techniques for treatment of these cases. A 40 year-old woman was diagnosed to have a small renal mass after routine abdominal ultrasonography for epigastric discomfort. Computed tomography scan was used to characterize the mass, and an elective partial nephrectomy was successfully carried out. The procedure is safe, less morbid, and has good oncological outcome. Bangladesh Journal of Urology, Vol. 19, No. 1, Jan 2016 p.49-52

Bangladesh Journal of Urology, 2020

Objective: To determine outcome of OMG urethroplasty by different surgical technique comparing AS... more Objective: To determine outcome of OMG urethroplasty by different surgical technique comparing ASOPA, BARBAGLI and KULKARNI TECHNIQUE in the management of anterior urethral stricture. Materials and Methods: A total of 62 patients with an average age of 42 yr(21-55) underwent OMG urethroplasty between 2008 to 2015 for anterior urethral stricture of different etiology. 2 patient lost durig follow up patient with lichen sclerosus and failed hypospadias were not included. OMG was always harvested from cheek using 2 team approach graft were placed using surgical technique of ASOPA, BARBAGLI and KULKARNI technique in 21,27 and 12 patients respectively clinical outcome was considered success or failure at the time any post operative procedure needed mean follow up was 45 month (6-95) Results: Out of 60 cases 51(85%) considered success and 9(15%) were considered failure. success rate were 85.7%,85%,and 83.5% in ASOPA, BARBAGLI and KULKARNI Technique and failure rate were 14.3%,15% and 16.7%...

Bangladesh Journal of Urology, 2020

Not Available Bangladesh Journal of Urology, Vol. 17, No. 2, July 2014 p.59-60

Calcutta medical journal, 1987

Observation chez une fillette de 11 ans. Traitement chirurgical. Bons resultats mis en evidence p... more Observation chez une fillette de 11 ans. Traitement chirurgical. Bons resultats mis en evidence par pyelographie intraveineuse

Acta Biomaterialia, 2021

Intralipid, a clinically used lipid emulsion, was reportedly utilized as one strategy to suppress... more Intralipid, a clinically used lipid emulsion, was reportedly utilized as one strategy to suppress off-target delivery of anticancer nanomedicines; Intralipid also effectively improved drug delivery to tumors and produced better therapeutic effects. However, the mechanisms involved-the why and how-in Intralipid's facilitation of delivery of nanomedicines to tumors have not yet been reported in detail. In this study, we investigated Intralipid and discovered the beneficial effects of Intralipid pretreatment when using three anticancer nanomedicines, including the clinically approved drug doxorubicin (Doxil). Intralipid pretreatment induced a 40% reduction in liver uptake of a polymeric nanoprobe used in photodynamic therapy as well as a 1.5-fold-increased nanomedicine accumulation in tumors. This increased accumulation consequently led to significantly better therapeutic effects, and this finding was validated by using Doxil. As an interesting result, Intralipid pretreatment significantly prolonged the plasma half-life of nanomedicines in normal healthy mice but not in tumor-bearing mice, which suggests that tumors become an alternative route of nanomedicine delivery when liver delivery is suppressed. Also, we found markedly increased tumor blood flow, as measured by fluorescence angiography, and significantly lower blood viscosity after Intralipid pretreatment. All our results together indicate that Intralipid treatment not only suppressed off-target nanomedicine delivery by the reticuloendothelial system, but more important, it enhanced nanomedicine delivery to tumors by improving tumor blood flow, which is key to satisfactory drug delivery via the enhanced permeability and retention effect. Significantly better therapeutic outcomes were thus achieved by the strategy of combining utilization of nanomedicines and Intralipid pretreatment. STATEMENT OF SIGNIFICANCE: : Off-target delivery to organs such as the liver and obstructed tumor blood flow as is often seen in advanced cancers are major barriers to the therapeutic efficacy of anticancer nanomedicines. Intralipid has been shown effective for suppressing nanomedicine accumulation in the liver, resulting in improved anticancer effects. Unraveling the mechanisms involved in this process will be greatly helpful for the clinical application of anticancer nanomedicines. We reported here that Intralipid could also significantly increase tumor delivery of nanomedicine, which is beneficial for improving tumor blood flow and lowering blood viscosity. To our knowledge, this is the first study to investigate the role of Intralipid in this regard. This knowledge provides a solid rationale for the use of Intralipid in combination with anticancer nanomedicines.

International Surgery Journal, 2021

Background: The aim of the study was to evaluate the chemical composition of urinary stones and p... more Background: The aim of the study was to evaluate the chemical composition of urinary stones and pattern of changes according to the patient's demographic and geographical distribution.Methods: 150 patients of upper tract urolithiasis were prospectively selected during the study period. Chemical composition was analyzed by FTIR spectroscopy. A subgroup study based on the patient's age, sex and geographical origin was done. For subgroup analysis patients were divided into two age groups; group A (5-18 years, 14 patients) and group B (>18 years, 136 patients). The geographical origin of the patients was recorded according to the administrative division.Results: Male were predominant in all age groups with ratio of 2.49:1. Most of the patients were from Rangpur (28.67%) and Mymensingh (20.67) division. Mixed composition stones were much more common than pure one (75.99% vs 24.01%). Overall, combination of calcium oxalate monohydrate with dehydrate was the most common composit...

Redox Biology, 2021

The NLRP3 inflammasome is a multiprotein complex responsible for the maturation of precursor form... more The NLRP3 inflammasome is a multiprotein complex responsible for the maturation of precursor forms of interleukin (IL)-1β and IL-18 into active proinflammatory cytokines. Increasing evidence suggests that modulation of redox homeostasis contributes to the activation of the NLRP3 inflammasome. However, specific mechanistic details remain unclear. We demonstrate here that ATP exposure evoked a sharp decrease in glutathione (GSH) levels in macrophages, which led to NLRP3 inflammasome activation. We detected an increase in GSH levels in culture supernatants that was comparable to the GSH decrease in macrophages, which suggests that exposure to ATP stimulated GSH efflux. Exogenous addition of P2X7 receptor antagonist, GSH, or the oxidized form GSSG attenuated this efflux. Also, exogenous GSH or GSSG strongly inhibited NLRP3 inflammasome activation in vitro and in vivo. These data suggest that GSH efflux controls NLRP3 inflammasome activation, which may lead to development of novel therapeutic strategies for NLRP3 inflammasome-associated disorders.

Biomacromolecules, 2020

Controlling the particle structure of tumor-targeting nanomedicines in vivo remains challenging b... more Controlling the particle structure of tumor-targeting nanomedicines in vivo remains challenging but must be achieved to control their in vivo fate and functions. Molecular bottlebrushes (MBs), where brush side chains are densely grafted from a main chain, have recently received attention as building blocks of polymer-based prodrugs because their rigid structure would be expected to demonstrate high structural stability in vivo. Here, we synthesized a poly(methacryloyloxyethyl phosphorylcholine) (pMPC)-grafted molecular bottlebrush (PCMB) conjugated with a cancer drug, doxorubicin (DOX), via an acid-cleavable hydrazone bond. A pMPC-based linear polymer (LP) conjugated with DOX was also prepared for comparison. We confirmed the lack of structural transition in the PCMB between before and after conjugation with DOX using small-angle light and X-ray scattering techniques, whereas the structure of LP was significantly influenced by DOX conjugation and transformed from a random-coil structure to a large agglomerate via hydrophobic interactions among DOXs. Although PCMB-DOX and LP-DOX showed comparable tissue permeability, pharmacokinetics, and ability to accumulate in tumor tissues, the antitumor efficacy of PCMB-DOX was better than that of LP-DOX. This was presumably due to the formation of LP-DOX agglomerates. The diffusion of cleaved DOX would be restricted in the hydrophobic core of the agglomerate, resulting in the DOX release at the tumor site being compromised. In contrast to LP-DOX, DOX release from PCMB-DOX was not compromised after accumulation in tumor tissues because it did not form such an agglomerate, resulting in the strong antitumor effect. We have demonstrated the potential of MBs as building blocks of drug carriers and believe that these findings can contribute to the design of polymer-based nanomedicines.

Biomaterials, 2021

We synthesized unique water-soluble synthetic-polymer, styrene-maleic acid copolymer (SMA) conjug... more We synthesized unique water-soluble synthetic-polymer, styrene-maleic acid copolymer (SMA) conjugated glucosamine (SG); which formed a stable complex with boric acid (BA). This complex had a mean particle size of 15 nm by light scattering, and single peak in gel permeation chromatography. The particles were taken up by tumor cells five times faster than free BA in vitro and liberated BA at acidic tumor pH (5-7). Liberated BA inhibited glycolysis and resulted in tumor suppression in vivo. Intravenously injected SGB-complex did bind with albumin, and plasma half-life was about 8 h in mice, and accumulated to tumor tissues about 10 times more than in normal organs. IC50 of SGB-complex for HeLa cells under pO2 of 6-9% was about 20 μg/ml (free BA equivalent), 150 times more potent than free BA. Neutron irradiation of human oral cancer cells with SGB-complex resulted in 16 times greater cell-killing than that without SGB-complex. In vivo antitumor effect was evaluated after neutron irradiation only once in SCC VII tumor bearing mice and significant tumor suppression was confirmed. These results indicate that SGB-complex is a unique multifunctional anticancer agent with much more potent activity under low pO2 conditions as in large advanced cancers.

Pakistan Journal of Biological Sciences, 1999

The use of chemical pesticides against storage pests by farmers in developing countries like Bang... more The use of chemical pesticides against storage pests by farmers in developing countries like Bangladesh is inadequately docummented. The holistic view of pest control technology is required to evaluate its impact on net social welfare, the simultaneous determination of optimal storage operations, consumption and production over time and optimal pest management. To make these variables operational the collaboration of biologists (especially pest management expert), economists, systems analysts, extension workers and social scientists are very much to be solicited. It is apparent that our basic understanding of bruchid pests is still far from being adequate. Therefore, intensive studies of their, biology, ecology and effects on foodstuffs are needed to be vigorously persued. Chemical pesticides are expected to play a major role in pest management programmes. However, the development of alternative pest management strategies involving non-chemical methods should vigorously pursued. There is no single answer to pest problems. The development of an integrated pest management system incorporating the principles, methods and techniques advanced by various disciplines into a coherent and comprehensive programme seems to be the answer.

Bangladesh Journal of Urology, 2020

Objective: To determine the improvement of the quality of life in patient of BPH after transureth... more Objective: To determine the improvement of the quality of life in patient of BPH after transurethral resection of prostate. Methods: A total of 102 of patients complaining lower urinary tract symtoms due to Benign prostatic hyperplasia (BPH). Each of the patient was followed up at 8 weeks (1st visit), 16 weeks (2nd visit) and 24 weeks (3rd visit) after transurethral resection of prostate (TURP). Before TURP for base line study of each patient was evaluated by history, physical examination, digital rectal examination (DRE), International Prostate Symptoms Score (IPSS), Quality of Life Score (QOL), Urinalysis, volume of the prostate and post voidal residual urine (PVR) were determined by ultrasonogram. Improvement of lower urinary tract symptoms and quality of life was determined using IPSS. Improvement was based on the changes from base line in symptoms,urinary flow rate, amount of post voidal residual urine and quality of life.Urine flow rate was measured by uroflowmetry as peak uri...

Advanced Drug Delivery Reviews, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Bangladesh Journal of Urology, 2020

Objective: To evaluate the effectiveness of a lingual mucosal graft (LMG) urethroplasty for long ... more Objective: To evaluate the effectiveness of a lingual mucosal graft (LMG) urethroplasty for long segment (>2cm) anterior urethral strictures. Materials and Methods: A total of 30 patients underwent urethroplasty for anterior urethral strictures using dorsal onlay of a LMG from January 2009 to December 2010. We selected 21 to 56 years old (mean age 36.6). Stricture length was 22 to 59 mm (mean 36); 14 strictures were in the bulbar urethra, 09 were in the proximal penile and 07 were in both bulbar and penile urethra. Postoperatively all patients were followed with urethrography, uroflowmetry, cystourethrography and urethroscopy after 3weeks, 3 months and 06 months. Successful reconstruction criteria were peak flow rate greater than 15 ml per second and no need for postoperative urethral dilation. Results: The mean period of follow-up was 9 months (range 4-12). The overall success rate at 3rd week and 3rd month was 96.7% and at 6th month was 90%. Three patients developed repeat stri...

Fuel, 2020

Biomass gasification derived syngas could be used for different important industrial applications... more Biomass gasification derived syngas could be used for different important industrial applications such as running internal combustion engine, generating electricity, and producing liquid hydrocarbon by Fisher-Tropsch method. The major drawback of syngas production through biomass gasification is the presence of contaminants such as hydrogen sulfide, hydrogen chloride, particulate matter, tar, and other undesired compounds in syngas. Tar is the most difficult to remove from syngas among all of the contaminants and causes severe problems in the downstream syngas applications. Researchers have been investigating different catalysts for removing tars for the last several decades. Dolomite is one of the widely studied catalysts for removing tar from syngas. Numerous research works have been conducted on the effectiveness of dolomite, calcined dolomite and combination of dolomite with other catalysts for removing tar from syngas. In this review, a detailed study on the dolomite catalyst has been conducted. Different aspects of dolomite catalyst such as calcination, mechanism of catalysis, in-situ vs ex-situ use, major problems (attrition, elutriation and coke formation), comparative strength, and the effectiveness of dolomite when used in combination with other catalysts have been studied and presented.

Bangladesh Journal of Urology, 2020

Objective: To determine the correlation of international prostate symptom score with prostate vol... more Objective: To determine the correlation of international prostate symptom score with prostate volume and Intravesical protrusion of prostate. Methods: This cross-sectional study was performed on 60 elderly patients presented with LUTS suggestive of Benign Enlargement of Prostate. Their evaluation included DRE, IPSS, Uroflowmetry (Qmax), serum PSA measurements and transabdominal ultrasound scan. Statistical analysis was performed by SPSS version 13 using Chi square test and scatter plots together with Spearmna’s correlation coefficients were used to assess the relationship between IPP and PV with IPSS. Results: Mean age of the patients was 66.7+9.85 years, IPSS 23.6+6.53, mean prostatic volume was 60.23+38.16 mL, Qmax 7.98+3.87, PVR was 163.18+141.73 mL. Fifty percent of patients had severe degree (>10mm) of intravesical protrusion of the prostate, 30% had moderate and 20% had mild IPP. There was significant positive correlation between IPSS and PV (r=0.585, P < 0.001), IPSS an...

Biological and Pharmaceutical Bulletin, 2019

Metalloporphyrin derivatives have been investigated for their therapeutic potential for oxidative... more Metalloporphyrin derivatives have been investigated for their therapeutic potential for oxidative stressrelated diseases because of their scavenging of reactive oxygen species (ROS). Here, we describe the synthesis, physicochemical properties, and ROS-scavenging activities of one such derivative-polyethylene glycol (PEG)-conjugated manganese protoporphyrin (PEG-MnPP). Carboxyl groups of the protoporphyrin ring at the C6 and C7 positions were first conjugated with ethylenediamine to introduce amino groups into the protoporphyrin structure. The amino groups were then reacted with succinimidyl PEG, with an average molecular weight of 2000, to obtain pegylated protoporphyrin (PEG-PP). Manganese was chelated to the protoporphyrin ring by incubating PEG-PP and manganese acetate in methanol. Dynamic light scattering and fluorescent spectrometry analyses revealed that PEG-MnPP self-assembled into nanoparticles in aqueous media with an apparent diameter of 70 nm. PEG-MnPP effectively eliminated hydrogen peroxide from cell culture media and protected cultured mammalian cells from toxic insults induced by hydrogen peroxide exposure or by 6-hydroxydopamine treatment. Intravenous administration of PEG-MnPP to mice significantly suppressed acute liver failure that had been induced by acetaminophen overdose. These data warrant additional investigation to study the therapeutic potential of PEG-MnPP as a water-soluble metalloporphyrinbased catalase mimic for oxidative stress-associated diseases.

Photochemical & Photobiological Sciences, 2019

Extracorporeal measurements through the skin achieve sufficient SNR to analyze 1O2 kinetics and e... more Extracorporeal measurements through the skin achieve sufficient SNR to analyze 1O2 kinetics and evaluate PDT efficiency.

Enhanced permeability and retention (EPR) effect–based nanomedicine is a promising strategy for s... more Enhanced permeability and retention (EPR) effect–based nanomedicine is a promising strategy for successful anticancer therapy. The EPR effect is based on tumor blood flow. Because advanced large tumors, as frequently seen in clinical settings, are heterogeneous, with regions of defective vasculature and blood flow, achieving the desired tumor drug delivery is difficult. Here, we utilized the EPR effect to increase drug delivery. To augment the EPR effect for improved therapeutic effects of nanomedicine, we exploited vascular mediators—the nitric oxide (NO) generators nitroglycerin (NG), hydroxyurea, and l-arginine. These compounds generate NO in tumors with relatively high selectivity. Using different nanosized drugs in our protocol significantly increased (1.5–2 times) delivery of nanomedicines to different solid tumor models, along with markedly improving (2–3-fold) the antitumor effects of these drugs. Also, in 7,12-dimethylbenz[a]anthracene–induced advanced end-stage breast canc...

Supplementary Figure S4 shows the AOM/DSS induced colon tumor nodules after treatment with P-THP ... more Supplementary Figure S4 shows the AOM/DSS induced colon tumor nodules after treatment with P-THP and rhodamine-BSA conjugate (fluorescent image).

Chemistry Letters

Glucosamine-bearing poly(styrene-co-maleic acid) (SMA-G) with the molecular weight of 1.8 × 104 i... more Glucosamine-bearing poly(styrene-co-maleic acid) (SMA-G) with the molecular weight of 1.8 × 104 is water soluble. We found that there is a weak hydrophobic interaction between water soluble serum p...

Bangladesh Journal of Urology, 2020

Advancement in imaging techniques has now made it possible for small renal tumors to be detected ... more Advancement in imaging techniques has now made it possible for small renal tumors to be detected incidentally. This has led to the use of minimally invasive techniques for treatment of these cases. A 40 year-old woman was diagnosed to have a small renal mass after routine abdominal ultrasonography for epigastric discomfort. Computed tomography scan was used to characterize the mass, and an elective partial nephrectomy was successfully carried out. The procedure is safe, less morbid, and has good oncological outcome. Bangladesh Journal of Urology, Vol. 19, No. 1, Jan 2016 p.49-52

Bangladesh Journal of Urology, 2020

Objective: To determine outcome of OMG urethroplasty by different surgical technique comparing AS... more Objective: To determine outcome of OMG urethroplasty by different surgical technique comparing ASOPA, BARBAGLI and KULKARNI TECHNIQUE in the management of anterior urethral stricture. Materials and Methods: A total of 62 patients with an average age of 42 yr(21-55) underwent OMG urethroplasty between 2008 to 2015 for anterior urethral stricture of different etiology. 2 patient lost durig follow up patient with lichen sclerosus and failed hypospadias were not included. OMG was always harvested from cheek using 2 team approach graft were placed using surgical technique of ASOPA, BARBAGLI and KULKARNI technique in 21,27 and 12 patients respectively clinical outcome was considered success or failure at the time any post operative procedure needed mean follow up was 45 month (6-95) Results: Out of 60 cases 51(85%) considered success and 9(15%) were considered failure. success rate were 85.7%,85%,and 83.5% in ASOPA, BARBAGLI and KULKARNI Technique and failure rate were 14.3%,15% and 16.7%...

Bangladesh Journal of Urology, 2020

Not Available Bangladesh Journal of Urology, Vol. 17, No. 2, July 2014 p.59-60

Calcutta medical journal, 1987

Observation chez une fillette de 11 ans. Traitement chirurgical. Bons resultats mis en evidence p... more Observation chez une fillette de 11 ans. Traitement chirurgical. Bons resultats mis en evidence par pyelographie intraveineuse

Acta Biomaterialia, 2021

Intralipid, a clinically used lipid emulsion, was reportedly utilized as one strategy to suppress... more Intralipid, a clinically used lipid emulsion, was reportedly utilized as one strategy to suppress off-target delivery of anticancer nanomedicines; Intralipid also effectively improved drug delivery to tumors and produced better therapeutic effects. However, the mechanisms involved-the why and how-in Intralipid's facilitation of delivery of nanomedicines to tumors have not yet been reported in detail. In this study, we investigated Intralipid and discovered the beneficial effects of Intralipid pretreatment when using three anticancer nanomedicines, including the clinically approved drug doxorubicin (Doxil). Intralipid pretreatment induced a 40% reduction in liver uptake of a polymeric nanoprobe used in photodynamic therapy as well as a 1.5-fold-increased nanomedicine accumulation in tumors. This increased accumulation consequently led to significantly better therapeutic effects, and this finding was validated by using Doxil. As an interesting result, Intralipid pretreatment significantly prolonged the plasma half-life of nanomedicines in normal healthy mice but not in tumor-bearing mice, which suggests that tumors become an alternative route of nanomedicine delivery when liver delivery is suppressed. Also, we found markedly increased tumor blood flow, as measured by fluorescence angiography, and significantly lower blood viscosity after Intralipid pretreatment. All our results together indicate that Intralipid treatment not only suppressed off-target nanomedicine delivery by the reticuloendothelial system, but more important, it enhanced nanomedicine delivery to tumors by improving tumor blood flow, which is key to satisfactory drug delivery via the enhanced permeability and retention effect. Significantly better therapeutic outcomes were thus achieved by the strategy of combining utilization of nanomedicines and Intralipid pretreatment. STATEMENT OF SIGNIFICANCE: : Off-target delivery to organs such as the liver and obstructed tumor blood flow as is often seen in advanced cancers are major barriers to the therapeutic efficacy of anticancer nanomedicines. Intralipid has been shown effective for suppressing nanomedicine accumulation in the liver, resulting in improved anticancer effects. Unraveling the mechanisms involved in this process will be greatly helpful for the clinical application of anticancer nanomedicines. We reported here that Intralipid could also significantly increase tumor delivery of nanomedicine, which is beneficial for improving tumor blood flow and lowering blood viscosity. To our knowledge, this is the first study to investigate the role of Intralipid in this regard. This knowledge provides a solid rationale for the use of Intralipid in combination with anticancer nanomedicines.

International Surgery Journal, 2021

Background: The aim of the study was to evaluate the chemical composition of urinary stones and p... more Background: The aim of the study was to evaluate the chemical composition of urinary stones and pattern of changes according to the patient's demographic and geographical distribution.Methods: 150 patients of upper tract urolithiasis were prospectively selected during the study period. Chemical composition was analyzed by FTIR spectroscopy. A subgroup study based on the patient's age, sex and geographical origin was done. For subgroup analysis patients were divided into two age groups; group A (5-18 years, 14 patients) and group B (>18 years, 136 patients). The geographical origin of the patients was recorded according to the administrative division.Results: Male were predominant in all age groups with ratio of 2.49:1. Most of the patients were from Rangpur (28.67%) and Mymensingh (20.67) division. Mixed composition stones were much more common than pure one (75.99% vs 24.01%). Overall, combination of calcium oxalate monohydrate with dehydrate was the most common composit...

Redox Biology, 2021

The NLRP3 inflammasome is a multiprotein complex responsible for the maturation of precursor form... more The NLRP3 inflammasome is a multiprotein complex responsible for the maturation of precursor forms of interleukin (IL)-1β and IL-18 into active proinflammatory cytokines. Increasing evidence suggests that modulation of redox homeostasis contributes to the activation of the NLRP3 inflammasome. However, specific mechanistic details remain unclear. We demonstrate here that ATP exposure evoked a sharp decrease in glutathione (GSH) levels in macrophages, which led to NLRP3 inflammasome activation. We detected an increase in GSH levels in culture supernatants that was comparable to the GSH decrease in macrophages, which suggests that exposure to ATP stimulated GSH efflux. Exogenous addition of P2X7 receptor antagonist, GSH, or the oxidized form GSSG attenuated this efflux. Also, exogenous GSH or GSSG strongly inhibited NLRP3 inflammasome activation in vitro and in vivo. These data suggest that GSH efflux controls NLRP3 inflammasome activation, which may lead to development of novel therapeutic strategies for NLRP3 inflammasome-associated disorders.

Biomacromolecules, 2020

Controlling the particle structure of tumor-targeting nanomedicines in vivo remains challenging b... more Controlling the particle structure of tumor-targeting nanomedicines in vivo remains challenging but must be achieved to control their in vivo fate and functions. Molecular bottlebrushes (MBs), where brush side chains are densely grafted from a main chain, have recently received attention as building blocks of polymer-based prodrugs because their rigid structure would be expected to demonstrate high structural stability in vivo. Here, we synthesized a poly(methacryloyloxyethyl phosphorylcholine) (pMPC)-grafted molecular bottlebrush (PCMB) conjugated with a cancer drug, doxorubicin (DOX), via an acid-cleavable hydrazone bond. A pMPC-based linear polymer (LP) conjugated with DOX was also prepared for comparison. We confirmed the lack of structural transition in the PCMB between before and after conjugation with DOX using small-angle light and X-ray scattering techniques, whereas the structure of LP was significantly influenced by DOX conjugation and transformed from a random-coil structure to a large agglomerate via hydrophobic interactions among DOXs. Although PCMB-DOX and LP-DOX showed comparable tissue permeability, pharmacokinetics, and ability to accumulate in tumor tissues, the antitumor efficacy of PCMB-DOX was better than that of LP-DOX. This was presumably due to the formation of LP-DOX agglomerates. The diffusion of cleaved DOX would be restricted in the hydrophobic core of the agglomerate, resulting in the DOX release at the tumor site being compromised. In contrast to LP-DOX, DOX release from PCMB-DOX was not compromised after accumulation in tumor tissues because it did not form such an agglomerate, resulting in the strong antitumor effect. We have demonstrated the potential of MBs as building blocks of drug carriers and believe that these findings can contribute to the design of polymer-based nanomedicines.

Biomaterials, 2021

We synthesized unique water-soluble synthetic-polymer, styrene-maleic acid copolymer (SMA) conjug... more We synthesized unique water-soluble synthetic-polymer, styrene-maleic acid copolymer (SMA) conjugated glucosamine (SG); which formed a stable complex with boric acid (BA). This complex had a mean particle size of 15 nm by light scattering, and single peak in gel permeation chromatography. The particles were taken up by tumor cells five times faster than free BA in vitro and liberated BA at acidic tumor pH (5-7). Liberated BA inhibited glycolysis and resulted in tumor suppression in vivo. Intravenously injected SGB-complex did bind with albumin, and plasma half-life was about 8 h in mice, and accumulated to tumor tissues about 10 times more than in normal organs. IC50 of SGB-complex for HeLa cells under pO2 of 6-9% was about 20 μg/ml (free BA equivalent), 150 times more potent than free BA. Neutron irradiation of human oral cancer cells with SGB-complex resulted in 16 times greater cell-killing than that without SGB-complex. In vivo antitumor effect was evaluated after neutron irradiation only once in SCC VII tumor bearing mice and significant tumor suppression was confirmed. These results indicate that SGB-complex is a unique multifunctional anticancer agent with much more potent activity under low pO2 conditions as in large advanced cancers.

Pakistan Journal of Biological Sciences, 1999

The use of chemical pesticides against storage pests by farmers in developing countries like Bang... more The use of chemical pesticides against storage pests by farmers in developing countries like Bangladesh is inadequately docummented. The holistic view of pest control technology is required to evaluate its impact on net social welfare, the simultaneous determination of optimal storage operations, consumption and production over time and optimal pest management. To make these variables operational the collaboration of biologists (especially pest management expert), economists, systems analysts, extension workers and social scientists are very much to be solicited. It is apparent that our basic understanding of bruchid pests is still far from being adequate. Therefore, intensive studies of their, biology, ecology and effects on foodstuffs are needed to be vigorously persued. Chemical pesticides are expected to play a major role in pest management programmes. However, the development of alternative pest management strategies involving non-chemical methods should vigorously pursued. There is no single answer to pest problems. The development of an integrated pest management system incorporating the principles, methods and techniques advanced by various disciplines into a coherent and comprehensive programme seems to be the answer.

Bangladesh Journal of Urology, 2020

Objective: To determine the improvement of the quality of life in patient of BPH after transureth... more Objective: To determine the improvement of the quality of life in patient of BPH after transurethral resection of prostate. Methods: A total of 102 of patients complaining lower urinary tract symtoms due to Benign prostatic hyperplasia (BPH). Each of the patient was followed up at 8 weeks (1st visit), 16 weeks (2nd visit) and 24 weeks (3rd visit) after transurethral resection of prostate (TURP). Before TURP for base line study of each patient was evaluated by history, physical examination, digital rectal examination (DRE), International Prostate Symptoms Score (IPSS), Quality of Life Score (QOL), Urinalysis, volume of the prostate and post voidal residual urine (PVR) were determined by ultrasonogram. Improvement of lower urinary tract symptoms and quality of life was determined using IPSS. Improvement was based on the changes from base line in symptoms,urinary flow rate, amount of post voidal residual urine and quality of life.Urine flow rate was measured by uroflowmetry as peak uri...

Advanced Drug Delivery Reviews, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Bangladesh Journal of Urology, 2020

Objective: To evaluate the effectiveness of a lingual mucosal graft (LMG) urethroplasty for long ... more Objective: To evaluate the effectiveness of a lingual mucosal graft (LMG) urethroplasty for long segment (>2cm) anterior urethral strictures. Materials and Methods: A total of 30 patients underwent urethroplasty for anterior urethral strictures using dorsal onlay of a LMG from January 2009 to December 2010. We selected 21 to 56 years old (mean age 36.6). Stricture length was 22 to 59 mm (mean 36); 14 strictures were in the bulbar urethra, 09 were in the proximal penile and 07 were in both bulbar and penile urethra. Postoperatively all patients were followed with urethrography, uroflowmetry, cystourethrography and urethroscopy after 3weeks, 3 months and 06 months. Successful reconstruction criteria were peak flow rate greater than 15 ml per second and no need for postoperative urethral dilation. Results: The mean period of follow-up was 9 months (range 4-12). The overall success rate at 3rd week and 3rd month was 96.7% and at 6th month was 90%. Three patients developed repeat stri...

Fuel, 2020

Biomass gasification derived syngas could be used for different important industrial applications... more Biomass gasification derived syngas could be used for different important industrial applications such as running internal combustion engine, generating electricity, and producing liquid hydrocarbon by Fisher-Tropsch method. The major drawback of syngas production through biomass gasification is the presence of contaminants such as hydrogen sulfide, hydrogen chloride, particulate matter, tar, and other undesired compounds in syngas. Tar is the most difficult to remove from syngas among all of the contaminants and causes severe problems in the downstream syngas applications. Researchers have been investigating different catalysts for removing tars for the last several decades. Dolomite is one of the widely studied catalysts for removing tar from syngas. Numerous research works have been conducted on the effectiveness of dolomite, calcined dolomite and combination of dolomite with other catalysts for removing tar from syngas. In this review, a detailed study on the dolomite catalyst has been conducted. Different aspects of dolomite catalyst such as calcination, mechanism of catalysis, in-situ vs ex-situ use, major problems (attrition, elutriation and coke formation), comparative strength, and the effectiveness of dolomite when used in combination with other catalysts have been studied and presented.

Bangladesh Journal of Urology, 2020

Objective: To determine the correlation of international prostate symptom score with prostate vol... more Objective: To determine the correlation of international prostate symptom score with prostate volume and Intravesical protrusion of prostate. Methods: This cross-sectional study was performed on 60 elderly patients presented with LUTS suggestive of Benign Enlargement of Prostate. Their evaluation included DRE, IPSS, Uroflowmetry (Qmax), serum PSA measurements and transabdominal ultrasound scan. Statistical analysis was performed by SPSS version 13 using Chi square test and scatter plots together with Spearmna’s correlation coefficients were used to assess the relationship between IPP and PV with IPSS. Results: Mean age of the patients was 66.7+9.85 years, IPSS 23.6+6.53, mean prostatic volume was 60.23+38.16 mL, Qmax 7.98+3.87, PVR was 163.18+141.73 mL. Fifty percent of patients had severe degree (>10mm) of intravesical protrusion of the prostate, 30% had moderate and 20% had mild IPP. There was significant positive correlation between IPSS and PV (r=0.585, P < 0.001), IPSS an...

Biological and Pharmaceutical Bulletin, 2019

Metalloporphyrin derivatives have been investigated for their therapeutic potential for oxidative... more Metalloporphyrin derivatives have been investigated for their therapeutic potential for oxidative stressrelated diseases because of their scavenging of reactive oxygen species (ROS). Here, we describe the synthesis, physicochemical properties, and ROS-scavenging activities of one such derivative-polyethylene glycol (PEG)-conjugated manganese protoporphyrin (PEG-MnPP). Carboxyl groups of the protoporphyrin ring at the C6 and C7 positions were first conjugated with ethylenediamine to introduce amino groups into the protoporphyrin structure. The amino groups were then reacted with succinimidyl PEG, with an average molecular weight of 2000, to obtain pegylated protoporphyrin (PEG-PP). Manganese was chelated to the protoporphyrin ring by incubating PEG-PP and manganese acetate in methanol. Dynamic light scattering and fluorescent spectrometry analyses revealed that PEG-MnPP self-assembled into nanoparticles in aqueous media with an apparent diameter of 70 nm. PEG-MnPP effectively eliminated hydrogen peroxide from cell culture media and protected cultured mammalian cells from toxic insults induced by hydrogen peroxide exposure or by 6-hydroxydopamine treatment. Intravenous administration of PEG-MnPP to mice significantly suppressed acute liver failure that had been induced by acetaminophen overdose. These data warrant additional investigation to study the therapeutic potential of PEG-MnPP as a water-soluble metalloporphyrinbased catalase mimic for oxidative stress-associated diseases.

Photochemical & Photobiological Sciences, 2019

Extracorporeal measurements through the skin achieve sufficient SNR to analyze 1O2 kinetics and e... more Extracorporeal measurements through the skin achieve sufficient SNR to analyze 1O2 kinetics and evaluate PDT efficiency.